Wolfring dacryops.

Wolfring dacryops. A unique series of 13 cases of ductal cysts of the accessory lacrimal glands of Wolfring is presented. Once appreciated, they are an easily recognized clinical entity. The 13 cases were verified histologically as arising from ductal epithelium. Biochemical analyses for serum and cyst fluid concentrations of IgA, IgG, and IgM were performed on three of the cases. Histologic staining of the cyst wall using monoclonal antibodies to immunoglobulins was performed on one case. All patients had evidence of extensive trachomatous scarring. High levels of IgA were found in the cyst fluid, consistent with an active secretory mechanism. Monoclonal antibody staining suggested a significant role for paraductal IgA-secreting plasma cells. The formation of a ductal cyst appears to require two successive, inter-related events. The first is an ongoing active secretory process, and the second is an occlusion of the duct. The sequential occurrence of these two events is forwarded as the explanation of dacryops formation. Excision using a conjunctival approach is recommended. A small strip of tarsal border should be removed with the cyst to prevent cyst rupture. The excretory ducts of the Wolfring glands exit through this area.


Malignant lymphoma of the ocular adnexa associated with the benign lymphoepithelial lesion of the parotid glands. Report of two cases. The benign lymphoepithelial lesion of the salivary/lacrimal glands is generally regarded as a lymphoproliferative disorder that may be associated with Sjögren syndrome. Although lymphomatous transformation in patients with Sjögren syndrome is well documented, few reports have appeared describing similar findings in patients with a benign lymphoepithelial lesion. The authors report the unusual occurrence of malignant lymphoma involving the ocular adnexa in two patients with a histopathologically documented benign lymphoepithelial lesion of the parotid glands. Both patients developed B-cell lymphomas. The eyelid tumor in case 1 expressed IgM/kappa cell surface markers by flow cytometry, and the orbital/conjunctival masses in case 2 showed neoplastic nodules of B cells that were only immunoreactive to lambda light chains (avidin-biotin complex method). To the authors' knowledge, this is the first report of ocular adnexal lymphoma arising in patients with a benign lymphoepithelial lesion of the parotid glands. This report establishes that ocular adnexal lymphoma may arise in a patient with a preexisting benign lymphoepithelial lesion.


Orbital lymphangioma. Correlation of magnetic resonance images and intraoperative findings. Orbital lymphangiomas generally are invasive, slow-growing lesions that can produce proptosis, motility impairment, and compressive optic neuropathy. Successful surgical management requires detailed preoperative radiologic imaging with the capacity to determine the location and size of the tumors, the presence of cystic or solid components, and extent of infiltration of the tumor into normal orbital structures. The records of 12 patients with orbital lymphangioma were reviewed with attention to the clinical, radiologic, operative, and histologic findings. Preoperative magnetic resonance imaging (MRI) produced highly detailed renderings of the orbital mass that were both diagnostic and predictive of the intraoperative findings. Magnetic resonance imaging was particularly sensitive to the presence of cysts within the tumor and was able to predict the contents of the cysts. Using preoperative MRI, a more detailed and accurate surgical plan can be formulated than with any other noninvasive technique.


Malignant peripheral nerve sheath tumor of the orbit in a 15-month-old child. Nine-year survival after local excision. Malignant peripheral nerve sheath tumors are extremely rare orbital tumors that carry a poor prognosis despite wide excision with disfiguring surgery, chemotherapy, or radiotherapy. The authors present the youngest reported case, a 15-month-old boy who underwent an orbitotomy to excise a bilobed tumor from the right orbit. Histologic examination revealed a malignant peripheral nerve sheath tumor; standard treatment options, including orbital exenteration, chemotherapy, and radiotherapy, were denied and instead the patient was followed with serial computed tomography scans and magnetic resonance imaging. Nine years later, the patient remains without evidence of recurrent tumor and visual acuity is 20/20. This patient's course suggests that orbital malignant peripheral nerve sheath tumors, if believed to be completely excised at the time of surgery, might be followed with careful neuroimaging studies for signs of recurrence.


Complications associated with alloplastic implants used in orbital fracture repair. The treatment of orbital wall fractures involves observation and/or surgical reduction with repositioning of herniated orbital tissues. To prevent reherniation of tissue and development of enophthalmos, the orbital floor or wall defect is commonly covered with an alloplastic implant. Complications associated with these implants are infrequent and generally appear as isolated case reports. The authors reviewed the files of four consultative oculoplastic surgeons and searched for individuals with complications secondary to their alloplastic implants used during orbital fracture repair. Seventeen patients were identified with a variety of complications related to their alloplastic implant. Although these implants are relatively inert and develop a fibrous capsule walling them off from the surrounding orbit, they remain foreign bodies and are thus subject to possible complications at any time. The authors review the spectrum of complications occurring with various alloplastic implants.


A new classification of superior oblique palsy based on congenital variations in the tendon. Superior oblique palsy is the most frequent isolated cranial nerve palsy seen in strabismus practice. It is traditionally diagnosed according to etiology as acquired, congenital, or idiopathic, but surgical treatment is based on deviation not etiology. Observations at surgery led to speculation that the superior oblique tendon is different in congenital compared with acquired superior oblique palsy and that this difference should be considered in surgical treatment. The authors reviewed the charts of 82 patients (89 eyes) undergoing surgery on the superior oblique tendon for superior oblique palsy. In each case, the palsy had been diagnosed preoperatively as acquired, congenital, or idiopathic, and, at surgery, characteristics of the tendon anatomy were described. Thirty-eight superior oblique tendons (36 patients), diagnosed as congenital superior oblique palsy, included 33 abnormal tendons and 5 normal tendons. Twenty-four tendons (21 patients), diagnosed as traumatic superior oblique palsy, included 22 normal and 2 abnormal tendons. Twenty-seven tendons (25 patients), diagnosed as idiopathic, included 19 normal and 8 abnormal tendons. Abnormal tendons were divided into 4 categories: (1) redundant, (2) misdirected, (3) inserted in posterior Tenon's capsule, and (4) absent. The authors conclude that congenital superior oblique palsy is usually associated with a structural abnormality of the superior oblique tendon (87%). Whereas acquired superior oblique palsy usually has a normal tendon (92%). Superior oblique underaction in acquired superior oblique palsy results from a neural deficit. Potential variance in anatomy of the superior oblique tendon should be considered when undertaking surgery for superior oblique palsy.


Results of amblyopia therapy in eyes with unilateral structural abnormalities. The purpose of this study is to analyze the visual results of full-time occlusion therapy in pediatric patients with monocular structural abnormalities and amblyopia. The authors reviewed the charts of visually immature patients with unilateral structural abnormalities and decreased visual acuity, who presented to the University of Iowa Hospitals and Clinics over a 20-year period, and underwent amblyopia therapy. The results were categorized according to the type of structural abnormality (i.e., partial media opacity, macula lesion, or optic nerve abnormality). Associated factors, including anisometropia, strabismus, age of presentation, and pupillary responses, were analyzed. Fifty-one percent of the 51 patients in the study achieved a visual acuity of at least 20/80, including 72% of the patients with media opacities, 42% with macular lesions, and 21% with optic nerve anomalies. Strabismus and anisometropia occurred frequently and were not prognostically significant. Relative afferent pupillary defects did not contraindicate good results. Amblyopia recurred in 31% of patients and was successfully treated with resumption of full-time occlusion. Occlusion amblyopia occurred in only one patient and was easily reversed. The authors recommend a trial of full-time occlusion for patients with all three types of unilateral structural abnormalities. The patients with partial media opacities have a high success rate. Despite lower success rates for the other two groups, good results are possible; no better treatment option exists.


Visual rehabilitation. The challenge, responsibility, and reward. A multispecialty ophthalmology clinic created a not-for-profit foundation to establish a center for visual rehabilitation. The Center's objective of equipping and enabling visually impaired people to lead more productive, independent, and satisfying lives by improving their remaining functional sight is performed through a four-phase program comprised of an intake interview, low vision examination, rehabilitation training, and counseling. Since its inception in 1986, the Center has cared for 947 females and 511 males. Although the majority of the patients examined are 61 to 90 years of age, all age groups have received care, including 41 patients younger than 10 years of age and 42 patients 91 years of age or older. The role of the ophthalmologist in the visual rehabilitation process is pivotal. The author acknowledges that most practices are unable to develop such a center. A number of suggestions are made, however, that may enable many practices to participate in the rehabilitation of their patients.


Serious complications of topical mitomycin-C after pterygium surgery. The use of topical mitomycin (mitomycin-C) as a medical adjunct to pterygium and glaucoma surgery is increasing. The authors report on a series of 10 patients who experienced serious, vision-threatening complications associated with the use of this drug after pterygium surgery. Complications included severe secondary glaucoma (4 patients), corneal edema (3 patients), corneal perforation (1 patient), corectopia (2 patients), iritis (8 patients), sudden onset mature cataract (2 patients), scleral calcification (1 patient) and incapacitating photophobia and pain (8 patients). Two patients required penetrating keratoplasties and a third required three lamellar keratoplasties. Another patient underwent four additional surgeries including a conjunctival Z-plasty, scleral patch grafting, and conjunctival autografting before his intractable pain and photophobia resolved 15 months after the original surgery. Because of these complications, 6 patients required a total of 20 return visits to the operating room after their original pterygium surgery. In 5 eyes, visual acuity remained at 20/200 or less. Three of the six patients with the most severe complications had concomitant chronic external diseases (rosacea [3 patients], ichthyosis [1 patient], keratitis sicca [1 patient]). The authors urge extreme caution in the use of mitomycin. If mitomycin is used, the lowest possible concentration should be applied for the shortest time period in an effort to avoid these complications. A prospective multicenter study of the ophthalmic use of this medication is needed.


Sterile endophthalmitis after sutureless cataract surgery. Sutureless cataract surgery has recently increased in popularity because of the rapid visual rehabilitation and the inherent reduction of surgically induced astigmatism. This procedure is dependent on a lamellar, multiplaned incision. As with new surgical techniques, associated complications become evident with time. Recently, there have been several cases of infectious endophthalmitis after this procedure. The authors report on nine cases of sterile endophthalmitis. In all nine cases, surgery was performed with refrigerated balanced salt solution (BSS) and 100 mg of cefazolin and/or 20 mg of methylprednisolone sodium succinate, given subconjunctivally, at its completion. All nine cases occurred in a period of time during which 68 cases were performed using refrigerated BSS for irrigation. These nine cases came from two different surgeons using basically the same surgical technique. After the investigation of these complications, the refrigerated BSS was discontinued, and there have been no episodes of sterile endophthalmitis in the last 650 cases. It appears that refrigerated BSS should be avoided if periocular injections are going to be used. It may be that the cold BSS fails to allow sufficient tissue swelling to seal the surgical incision, allowing for subconjunctival injections to seep into the wound, and leading to a sterile endophthalmitis.


Comparison of depth of focus and low-contrast acuities for monofocal versus multifocal intraocular lens patients at 1 year. Multifocal lenses have been shown to produce enhanced near and intermediate vision. The division of incoming light into more than one focal point must physically produce retinal images of reduced contrast. The purpose of this report is to provide quantitative data on the increased depth of focus and decreased contrast sensitivity demonstrated in patients receiving the 3M diffractive multifocal lens versus the parent monofocal control lens. Uncorrected and best-corrected distance and near acuities, Regan and Pelli-Robson contrast sensitivity measurements, and defocus curves were obtained on 22 eyes with monofocal and 16 eyes with multifocal age-matched, pathology-free implants at 1 year after surgery. Visual acuity data demonstrated significantly improved (P < 0.001) near acuities in multifocal patients with manifest refraction in place. No difference was noted between implants for other acuity measures. A statistically significant reduction (P < 0.05) in contrast sensitivity was measured for multifocal implants at the limits of contrast and resolution (Regan 4%); however, careful patient questioning revealed no clinical impact. Defocus curves demonstrated significantly increased (P < 0.0001) depth of focus at the 20/40 acuity level of 3.8 diopters (D) in multifocal patients versus 1.8 D in monofocal patients. The quantifiable and expected loss of contrast sensitivity in the examining lane, not manifest in patient awareness, appears to be an acceptable tradeoff for enhanced near/intermediate vision and depth of focus.


Macular pseudoholes. Clinical features and accuracy of diagnosis. Epimacular membrane with pseudohole is an important vitreomacular disorder that belongs in the differential diagnosis of impending and established macular hole. To better characterize this lesion, the authors attempted to identify various features of eyes with epimacular membrane and pseudohole. Demographic, clinical, photographic, and fluorescein angiographic data for 14 eyes with epimacular membrane and pseudohole were reviewed. Horizontal and vertical diameters of the pseudoholes were measured, and the original diagnosis was recorded for each eye. Fluorescein angiography was performed in 11 eyes. The mean age of patients with macular pseudoholes was 61.6 years, and median visual acuity for pseudohole eyes was 20/30. Mean horizontal and vertical diameters of the pseudoholes were 384 and 410 microns, respectively. None of the eyes with pseudoholes had the characteristic ophthalmoscopic features associated with full-thickness macular holes or impending macular holes. Results of fluorescein angiography showed three eyes with increased tortuosity or abnormal straightening of the perifoveal vessels; three eyes with a foveal window defect; and three eyes with late leakage from the perifoveal vessels. The original diagnosis of the initial examining physician was correct in only 43% of eyes with epimacular membrane and pseudohole. Epimacular membrane with pseudohole may be an underdiagnosed lesion and commonly mistaken for impending macular hole, full-thickness hole, or lamellar hole. These data may be of use as more patients are being considered for recently advocated surgical treatments for impending and established macular hole.


Retinal pigment epitheliopathy after macular hole surgery. Full-thickness idiopathic macular holes were previously considered untreatable, but surgical intervention has been proposed to collapse the hole and improve vision. This study evaluates the fluorescein angiographic changes that occur after macular hole surgery. Sixteen patients with stage III idiopathic macular holes underwent pars plana vitrectomy, removal of the posterior hyaloid, peeling of fine epiretinal sheets along the edges of the holes, and fluid-gas exchange. Preoperative fluorescein angiograms were performed, and best-corrected preoperative visual acuity was 20/200 or less in all eyes. Postoperatively, the macular hole disappeared in 12 eyes (75%). In all 12 eyes, retinal pigment epithelial swelling was present, with a unique fluorescein angiographic appearance. This pattern slowly resolved over months, with gradual visual improvement but residual retinal pigment epithelial mottling. Systemic and periocular steroids had no significant impact on the process. The combination of prolonged intraocular gas contact and light exposure exceeding threshold for an already compromised macula appears to be responsible for this pigmentary pattern. Depending on the severity of the pigment epithelial alteration, this unique pattern may portend a guarded visual prognosis in affected patients undergoing successful macular hole repair.


Detection of drusen and early signs of age-related maculopathy using a nonmydriatic camera and a standard fundus camera. The study was designed to compare the severity of age-related maculopathy as graded from photographs taken using three different techniques. Two methods of nonstereoscopic 45 degrees retinal photography of the macula (through a nonpharmacologically dilated pupil and through a pharmacologically dilated pupil) were compared with results from standard 30 degrees stereoscopic photographs in 112 subjects. Corresponding photographic fields were graded by a masked grader for the presence of any drusen, soft drusen, retinal pigment epithelial degeneration, increased retinal pigmentation, and early and late age-related maculopathy. Exact agreement between gradings of the 45 degrees photographs taken through nonpharmacologically dilated pupils and 30 degrees photographs taken through dilated pupils was 75% for any drusen, 72% for soft drusen, 72% for retinal pigment epithelial degeneration, 74% for increased retinal pigment, 85% for pure geographic atrophy, and 89% for exudative macular degeneration. The kappa scores varied from 0.33 for geographic atrophy to 0.60 for exudative macular degeneration. Slightly higher rates of agreement between gradings were found after dilation. These data suggest that 45 degrees nonstereoscopic fundus photographs, when graded according to a standard classification scheme, should be considered for detection of age-related maculopathy in situations where the pupils cannot be pharmacologically dilated and retinal specialists are not available to examine the fundus.


Scleritis as an initial manifestation of choroidal malignant melanoma. The purpose of this article is to present the unusual circumstances in which malignant melanoma of the choroid can masquerade as scleritis, thus confounding its diagnosis. Three cases of plaque-like malignant melanomas of the choroid are reported that, on initial examination, had features of scleritis. The events leading to their eventual correct diagnosis also are presented. In each case, there was ocular pain, blurred vision, anterior chamber and/or vitreous cavity cellular reaction, and an exudative retinal detachment associated with an ill-defined, relatively flat variably pigmented choroidal mass. In all three cases, the inflammatory component responded promptly to corticosteroid treatment and was accompanied by visual improvement. In two eyes, shrinkage of the choroidal mass accompanied the corticosteroid treatment, lending support to a working diagnosis of scleritis. By demonstrating expansion of the choroidal masses, examination of sequential fundus photographs influenced the decision to enucleate the eyes for presumed malignant choroidal melanoma. Clinicians should be alert to the circumstances in which malignant melanomas of the choroid can masquerade as scleritis. Careful evaluation by ophthalmoscopy, ultrasonography, fundus photography, and subsequent sequential examination is necessary to arrive at the correct diagnosis.


Natural history of diffuse uveal melanocytic proliferation. Case report. Diffuse uveal melanocytic proliferation is a rare paraneoplastic syndrome resulting in rapid bilateral visual loss due to proliferation of benign melanocytes within the choroid and ciliary body. Most of the previously reported cases have been seen with bilateral involvement and typical ocular features. The authors report the case of a 61-year-old man who presented with uniocular posterior pole lesions at the level of the retinal pigment epithelium and subsequently developed the typical bilateral lesions of diffuse uveal melanocytic proliferation. His clinical course was typical, with visual disturbance preceding signs and symptoms of malignancy by 5 months. Rapid decline ensued, and he eventually died 10 months after the onset of visual symptoms. Results of ocular pathologic examination showed the typical choroidal thickening due to the proliferation of melanocytes and the primary tumor was found to be an undifferentiated adenocarcinoma originating in either the pancreas or the esophagus. The very early funduscopic and fluorescein angiographic findings of diffuse uveal melanocytic proliferation are presented as well as the evolution, ocular pathology, and possible mechanisms for its development.


Pigmented adenoma of the optic nerve head simulating a melanocytoma. The purpose of this report is to describe a clinicopathologic correlation of an unusual pigmented tumor of the optic nerve head, to point out that such a lesion can simulate clinically a melanocytoma of the optic disc, and to discuss the differential diagnosis of pigmented epipapillary lesions. Histopathologic studies of the affected eye showed a peculiar pigmented tumor of the optic disc that was compatible with an adenoma arising from the juxtapapillary retinal pigment epithelium. Adenoma of the retinal pigment epithelium can closely simulate a melanocytoma of the optic disc. There are some clinical features that may serve to differentiate the two lesions.


Cellular blue nevus of the conjunctiva.

Cellular blue nevus of the conjunctiva. Cellular blue nevi of the conjunctiva are extremely rare, and their natural history and malignant potential have not been fully ascertained. A report of an unusually well-documented case of growth of a cellular blue nevus is presented, along with a review of current knowledge of this lesion. A 71-year-old woman presented with a darkly pigmented raised lesion of the conjunctiva, which had slowly enlarged over 47 years. There were nonconfluent areas of involvement of the upper and lower lids. Results of biopsy showed the lesion to be a cellular blue nevus, with no evidence of malignancy. This well-documented case of slow growth and spread without malignant transformation adds to the knowledge of this rare lesion.


Retinal findings after head trauma in infants and young children. Many authorities believe that the finding of retinal hemorrhages in a child younger than 3 years of age with a history of head trauma, in the absence of an obvious cause for the injury, is pathognomonic of child abuse. To date, no studies have examined the prospective retinal examination of children who have had head trauma. The authors undertook such a study because the presence of retinal hemorrhage from any head trauma in children may have medicolegal diagnostic significance in differentiating accidental from nonaccidental trauma. Seventy-nine children younger than 3 years of age, each of whom experienced head injury, underwent an ophthalmologic assessment, which included a dilated funduscopic examination. Seventy-five children sustained accidental head injuries and had normal funduscopic examinations. Three children had nonaccidental head injuries and all were found to have varying degrees of retinal hemorrhages. One child, with a normal fundus examination, had injuries that were of indeterminate cause. The finding of retinal hemorrhages in a child with a head injury suggests a nonaccidental cause.


Effect of mydriasis on visual field area in retinitis pigmentosa. The effect of mydriasis on Goldmann visual field area in patients with retinitis pigmentosa has not been suitably defined. The aim of this study is to determine whether visual field area in these patients varies with pharmacologic mydriasis. Fifteen adult patients with retinitis pigmentosa were studied prospectively. Goldmann visual fields with II4e and V4e isopters were obtained in both eyes before and after full pharmacologic mydriasis of the right eye. The isopter areas were quantified and analyzed to determine the effect of mydriasis on visual field area. The difference in the right eye isopter areas was compared with the difference in the left eye isopter areas using paired t tests, where the differences were computed from areas obtained before and after dilation of the right eye. Mydriasis had no significant effect on the visual field in terms of isopter area difference (II4e, P = 0.87; V4e, P = 0.45) and percent change in isopter area (II4e, P = 0.81; V4e, P = 0.24). Pharmacologic mydriasis had no appreciable effect on the Goldmann visual field area in a selected group of patients with retinitis pigmentosa. These findings suggest that visual fields of such patients obtained in the dilated or undilated state can be meaningfully compared.


Augmentation laser for proliferative diabetic retinopathy that fails to respond to initial panretinal photocoagulation. A study was performed to determine if diabetic subjects who fail to respond to initial panretinal photocoagulation with regression of retinopathy risk factors do better with supplemental panretinal photocoagulation. Thirty-five patients with 3 or more retinopathy risk factors who failed to respond to panretinal photocoagulation with regression to less than 3 retinopathy risk factors by 3 weeks after initial panretinal photocoagulation were prospectively randomized to augmentation laser panretinal photocoagulation (MORE) or to no additional treatment (NOMORE). Six months after initial treatment, the MORE group (n = 16) had regressed a mean of -0.94 retinopathy risk factors (with 95% confidence interval [CI] -1.60 to -0.26), compared with -0.21 retinopathy risk factors (95% CI -0.69 to 0.27) in the NOMORE (n = 19) group (P = 0.055). However, by 1 year, there was no statistically significant difference in the amount of regression of retinopathy risk factors with a mean decrease of -1.12 (95% CI -2.0 to -0.24) versus -1.05 retinopathy risk factors (95% CI -1.80 to -0.28) in the 2 groups, respectively. Similarly, for visual acuity, there was no difference in outcome. For all study patients, the persistence of three or more retinopathy risk factors was associated with a poorer visual result than if there was regression to less than three retinopathy risk factors. This study shows that although augmentation panretinal photocoagulation achieved faster regression of retinopathy risk factors, by 1 year, there was no difference in either mean regression of retinopathy risk factors or visual acuity between eyes treated or not treated with augmentation panretinal photocoagulation. In addition, the study shows that the persistence of 3 or more retinopathy risk factors 1 year after treatment was associated with a poorer visual result. Because sample size limited the power of the study to find small differences between groups, and because in proliferative diabetic retinopathy small differences could be important clinically, the authors do not recommend changes in current clinical practice.


Gonioscopic ab interno laser sclerostomy. A pilot study in glaucoma patients. The purpose of this study is to evaluate the safety and efficacy of gonioscopic ab interno laser sclerostomy (GLS) in patients with glaucoma. The technique of GLS involves iontophoresis of methylene blue dye (1%) at the limbus to focally dye the sclera and to provide subsequent delivery of 10-microsecond pulsed laser energy to the dyed area through a goniolens. The laser emits at 660 nm, a wavelength that is maximally absorbed by the methylene blue dye. Patients were evaluated for fistula formation, intraocular pressure (IOP) reduction, and adverse sequelae. Thirty-eight treatments were performed in 35 eyes. Successful complete sclerostomies were achieved in 21 eyes (55%), which was associated with an acute mean reduction in IOP of 23 mmHg. Mean preoperative IOP for all patients was 35 mmHg, and 1 hour after treatment it was reduced to 18.5 mmHg. In 4 of the 38 treatments, there was no acute IOP reduction, and these eyes were judged as failures. The mean follow-up time was 8.2 months with a maximum follow-up of 15 months. By 9 months, 50% of patients had an IOP of 22 mmHg or lower. The number of antiglaucoma medications decreased from 3.1 to 1.7 for all eyes over the 15-month follow-up period. Hyphemas (13%) were the only major complication, and these resolved spontaneously. In only one case did the IOP increase after the procedure. The results of this trial indicate that GLS is technically feasible, and preliminary results of IOP control are promising.


Molluscum contagiosum of the eyelids in patients with acquired immune deficiency syndrome. Infection with molluscum contagiosum has been reported in patients with acquired immune deficiency syndrome (AIDS). Involvement of the eyelids by molluscum in patients with AIDS has rarely been mentioned. Two patients with AIDS presented with eyelid molluscum contagiosum. Detailed examination and follow-up was performed. One patient had noted ocular irritation with epiphora for several weeks and showed a typical viral keratoconjunctivitis in both eyes. The other patient progressed to confluent masses involving the entire lower eyelid on one side. Removal of the lesions by surgery and cryotherapy was followed by recurrences in both patients within 6 to 7 weeks, the incubation period for this viral infection. Molluscum contagiosum can form confluent lesions on the eyelids in patients with AIDS, which may cause a keratoconjunctivitis. Local removal of molluscum eyelid nodules appears to be of limited long-term value in patients with T-cell immunodeficiency.


The evolution of aminoacyl-tRNA synthetases, the biosynthetic pathways of amino acids and the genetic code. In this paper the partition metric is used to compare binary trees deriving from (i) the study of the evolutionary relationships between aminoacyl-tRNA synthetases, (ii) the physicochemical properties of amino acids and (iii) the biosynthetic relationships between amino acids. If the tree defining the evolutionary relationships between aminoacyl-tRNA synthetases is assumed to be a manifestation of the mechanism that originated the organization of the genetic code, then the results appear to indicate the following: the hypothesis that regards the genetic code as a map of the biosynthetic relationships between amino acids seems to explain the organization of the genetic code, at least as plausibly as the hypotheses that consider the physicochemical properties of amino acids as the main adaptive theme that lead to the structuring of the code.


[Three decades of roentgen-diagnosis of the upper digestive tract in the light of modern endoscopy]. The author commemorating professor Géza Hetényi, discusses the relation of endoscopy and x-ray diagnostic. He observes that the spreading of recent fibre optical endoscopes did not solve the problem of the early gastric cancer diagnosis. The experiences of the author based on his practice for several decades, data from the literature and, especially, the Japanese results show that x-ray did not lose its position but rather strengthened it in the diagnostics of the upper gastrointestinal tract. For examinations at identical levels, both diagnostic methods have equal opportunities to reveal gastric cancer at an early stage. In accordance with the type variety of early gastric cancer, the author discusses the relationship between early gastric cancer and gastric ulcer, and he proposes a rational algorithm for its diagnosis and follow-up. He shows that the most effective method for the diagnosis of the upper gastrointestinal tract is a reasonable combination of all available methods, and "primus inter pares" of them is x-ray examination, in addition to endoscopy.


Experimental studies on the origin of the genetic code and the process of protein synthesis: a review update. This article is an update of our earlier review (Lacey and Mullins, 1983) in this journal on the origin of the genetic code and the process of protein synthesis. It is our intent to discuss only experimental evidence published since then although there is the necessity to mention the old enough to place the new in context. We do not include theoretical nor hypothetical treatments of the code or protein synthesis. Relevant data regarding the evolution of tRNAs and the recognition of tRNAs by aminoacyl-tRNA-synthetases are discussed. Our present belief is that the code arose based on a core of early assignments which were made on a physico-chemical and anticodonic basis and this was expanded with new assignments later. These late assignments do not necessarily show an amino acid-anticodon relatedness. In spite of the fact that most data suggest a code origin based on amino acid-anticodon relationships, some new data suggesting preferential binding of Arg to its codons are discussed. While information regarding coding is not increasing very rapidly, information regarding the basic chemistry of the process of protein synthesis has increased significantly, principally relating to aminoacylation of mono- and polyribonucleotides. Included in those studies are several which show stereoselective reactions of L-amino acids with nucleotides having D-sugars. Hydrophobic interactions definitely play a role in the preferences which have been observed.


[Varicella pneumonia in adults].

[Varicella pneumonia in adults]. The authors treated 93 adult patients (83 male, 10 female) with varicella from 1st June 1987 to 30th April 1991. 13 patients had varicella pneumonia, two patients died. Special attention has been focused upon the diagnostic and prognostic problems, including bacterial superinfection. Authors stress the importance of the early diagnosis and treatment and discuss in detail the recent therapeutical and prophylactic opportunities.


[Spontaneous and cytostatic therapy induced chromosome aberrations in testicular cancer patients]. Chromosomal aberrations were studied in peripheral blood lymphocytes from only surgery treated testicular cancer patients and treated with chemo- and/or radiotherapy. A distinct increase in spontaneous aberration frequency over the level of 27 healthy controls in 27 patients treated with surgery alone was found. Our data suggest the existence of a certain degree of chromosome instability, which may be a factor to the development of testicular tumour. The frequency of aberrant cells was much higher in 102 treated patients than in the controls. The decrease in aberrant cells was only time-dependently gradual in VPB and X-ray treated patients, while the second line combined treatment modalities caused the highest frequency of aberrant cells in the first two years after the end of courses. The possible relationship between the persistence of chromosomal aberrations and the development of malignancies are discussed in this paper.


[Initial experience with ESWL therapy of pancreatic duct calculi]. Extracorporeal shock wave lithotripsy of pancreatic stones was performed in four patients with chronic pancreatitis and a dilated duct system harbouring stones 5-12 mm in diameter. The stones were disintegrated by shock waves using a Dornier lithotripter in one or more sessions. Disintegration of stones was achieved in 4/4 patients, initial (6-11 months) relief of pain in 3/4 patients, and total clearance of pancreatic duct in 3/4 patients. No complications were observed. In the first patient in whom ESWL was not completely successful, underwent an operation: a longitudinal pancreato-gastrostomy and the stones were found completely disintegrated. From these early data they conclude that ESWL of pancreatic duct stones is a provisional new alternative for surgery in the treatment of chronic pancreatitis.


[A successfully treated case of congenital hydrops by Kell-alloimmunization]. The authors report a successfully treated case of congenital hydrops caused by Kell alloimmunization. It is very important the early proper therapy and to make difference between the non immune hydrops fetus and the hydrops caused by alloimmunization. It seems to be indicated--also in Hungary, as the other European countries--the introduction of the screening of irregular antibodies during the pregnancy.


Clinical contrast sensitivity chart evaluation. Three different types of contrast sensitivity chart were used on normal patients by six optometrists in clinical practice. The charts were the Vistech, the Pelli-Robson and the Cambridge low-contrast gratings test. We examine the data in terms of the differences between optometrists and the variation of contrast sensitivity with the age of the patient. There was a highly significant difference between the scores from different optometrists for all three charts. We attribute this to variability in measurement technique. There was also a highly significant effect of age for all three charts, with older observers tending to exhibit lower contrast sensitivity. On the Vistech chart, this sensitivity deficit was most pronounced at higher spatial frequencies. The level of redundant information in the tests is discussed.


Use of scrolled text in a scanning laser ophthalmoscope to assess reading performance at different retinal locations. A new technique is described for assessing reading performance using a scanning laser ophthalmoscope. Letters of different sizes and contrasts were projected onto specific retinal locations of normal and low vision observers. Successive letters were scrolled in a horizontal direction at different speeds through a 'window'. Throughout the experiments the subjects' fundus and the retinal location of the stimuli could be visualized. With this scanning laser ophthalmoscope text-scrolling computer program the subject does not search for adjacent letters, and because the eye is held relatively stationary the tedious eye movement analysis incurred in other studies is reduced. Five retinal areas were investigated in two normal observers. The percentage of letters correctly identified decreased with eccentricity, increased velocity of the text and reduced text contrast. The reading performance of two patients, one with age-related macular degeneration and the other with juvenile macular disease, was investigated. Decrements in performance were related to morphology of the lesions.


Intraocular pressure measurement in children using the Keeler Pulsair tonometer. A study to determine whether Keeler Pulsair tonometry is a feasible alternative to tonometry under general anaesthesia in children was undertaken. We recruited 53 children aged from 6 months to 9 years old. Readings were obtainable from 78% and a complete set of four readings from each eye was obtained from 45% of the group in an out-patient setting. Averaged Pulsair measurements agreed well with Perkins applanation tonometry values under general anaesthesia. Techniques to improve compliance are discussed. In conclusion, the Pulsair tonometer is a viable method for obtaining estimates of intraocular pressure in children in this age-group.


Effect of restriction of the binocular visual field on driving performance. The importance of the visual field on driving performance was investigated. This was undertaken by simulating binocular visual field defects for a group of young normal subjects and assessing the impact of these defects on performance on a driving course. Constriction of the binocular visual field to 40 or less, significantly increased time taken to complete the course, reduced the ability to detect and correctly identify road signs, avoid obstacles and to manoeuvre through limited spaces. Accuracy of road positioning and reversing were also impaired. Constriction of the binocular visual field did not significantly affect speed estimation, stopping distance, or the time taken for the reversing and manoeuvring tasks. The monocular condition did not significantly affect performance for any of the driving tasks assessed.


Effect of induced fixation disparity on binocular visual acuity. Fixation disparities were artificially created for distance vision by prisms, and the monocular and binocular visual acuities were measured. The normal approximate 10% improvement in binocular visual acuity compared to monocular visual acuity, deteriorated in proportion to the amount of fixation disparity created by the prisms. This was true in both eso- and exo-disparity, although not to the same extent.


Spatial adaptation to text on a video display terminal. We employed vertical sinusoidal test gratings to search for spatial adaptation to lower-case text presented on a standard video display terminal. The parameters of the contrast sensitivity test were selected on the basis of waveform analysis of horizontal spatial luminance profiles of the text. We found that subjects exhibited a small (4-5 dB), but significant, frequency-specific spatial adaptation consistent with the frequency spectrum of the stimulus. The theoretical and practical significance of this finding is discussed.


Negative feedback control model of proximal convergence and accommodation. A comprehensive model has been developed to illustrate the interactions between the observer and the surrounding environment in the control of oculomotor responses to distance or 3-D space. Accommodation and vergence respond to both spatiotopic (body reference) proximal percepts and retinotopic (eye referenced) physical stimuli of blur and disparity. Both spatiotopic and retinotopic stimuli are derived respectively from perceptual and physical correlates of negative feedback for eye position. The spatiotopic and retinotopic stimulus errors are combined in the feedforward path and drive a common oculomotor controller which has a phasic-tonic organization. Spatiotopic and retinotopic stimuli are shown to be effective over complementary operating ranges. Perceptual spatiotopic errors of gaze provide optimal stimuli for near responses to large depth intervals whereas physical-retinotopic cues of blur and disparity provide quantitative information about small binocular fixation errors. Small dynamic variations of target distance are sensed both spatiotopically and retinotopically. Coarse and fine spatiotopic errors of gaze are processed differently. Large spatiotopic errors are sampled intermittently at the beginning of the near response, whereas small retinotopic position errors and spatiotopic velocity errors are sampled continuously throughout the near response. Former reports of empirically observed higher velocity of vergence responses to very large depth intervals is explained in terms of stimulus sampling modes rather than in terms of separate oculomotor control mechanisms. The model demonstrates a complementary function of top-down spatiotopic cues, which are used to initiate the near response, and bottom-up retinotopic cues, which are used to refine and complete the near response. Cross-couplings by vergence-accommodation and accommodative-vergence serve to coordinate the components of the near response when feedback from sensed response of one motor system (i.e. vergence) is more accurate than that of the other motor system (i.e. accommodation). The model presented here is concerned primarily with the near response mediated by accommodation and disjunctive eye movements and not by the independent vergence mediated by non-conjugate or yoked saccades of unequal amplitude.


Adaptation model of accommodation and vergence. Both accommodation and vergence have been shown to exhibit adaptation after extended near viewing. Normally, when the stimulus to accommodation is removed, the accommodation system returns rapidly towards its tonic position. However, if the stimulus is removed after an extended focusing effort, the decay is much slower. A similar effect can be observed in the vergence system. After prolonged wearing of horizontal prisms, blockage of one eye results in a much slower decay of the vergence output towards its tonic value. No previous models have been shown to simulate quantitatively these effects. An interactive dual-feedback model of accommodation and vergence was developed to simulate the adaptive behaviour found experimentally. The unique feature of the model is that the output of each controller drives a dynamic adaptive component whose output governs the time constant of the controller. The model was able to simulate the rapid and slow decays following short and long viewing intervals in each of the accommodative and vergence systems. It also simulated adaptation during alternate binocular and monocular viewing under the accommodation closed-loop condition. Thus, this model can serve as the basis for detailed quantitative evaluation of adaptive behaviour in the accommodation and vergence systems.


Time-averaged accommodation response to flickering stimuli. Experiments are described in which the steady-state accommodation response versus stimulus curve was measured with an infrared autorefractor for high-contrast stimuli having a 100% square-wave temporal modulation of luminance in the frequency band 1-200 Hz. Slightly more accurate responses were found at frequencies approximately 50-100 Hz, i.e. above flicker fusion. The relevance of the results to practical situations in which flicker may be experienced is discussed.


Compensatory eye movements during near fixation after fast adaptation to lenses. When the eyes are converged on a near target, the gain of the vestibulo-ocular reflex (VOR) during a subsequent head rotation is dependent upon both the amount of vergence and the degree to which it is asymmetrical. In conditions without visual feedback, we measured the gain of the VOR in the right eye of observers as they rotated their heads to the right or left while viewing a target placed 22, 32.5 or 200 cm from the centre of head rotation. We then adapted the VOR to the magnifying effects of +5 D lenses, and retested the VOR under the former convergence conditions. We found an inverse relationship such that the greater the VOR gain due to convergence, the less the effect of the rapid adaptation to lenses.


Effects of monochromatic and chromatic oblique aberrations on visual performance during spectacle lens wear. An optical system is described which allows overall visual performance to be studied when the wearer of a spectacle lens views objects through the lens periphery. Performance with lenses of any refractive power can be explored without any need for subjects to have the appropriate complementary refractive errors. In comparison with the effects of dioptric defocus, transverse chromatic aberration (TCA) is found to cause a relatively greater degradation in contrast sensitivity at high spatial frequencies when tangentially-oriented gratings are observed. The relative importance of TCA appears to have been underestimated in some previous studies. As vision is found to be affected by both TCA and defocus, a careful compromise between chromatic and monochromatic aberrations is required.


QROC curves and kappa functions: new methods for evaluating the quality of clinical decisions. The application of statistical methods for measuring the ability of clinical judgements and tests to discriminate between normal and diseased patients is increasing in optometry and ophthalmology. This paper presents two new methods for assessing the quality of such diagnostic decisions. Both are based on measurement of the kappa coefficient of association and offer theoretical and practical advantages over traditional methods. The paper first introduces the family of kappa coefficients with examples of their calculation and application. The use of weighted kappa values for measuring test sensitivity and specificity is explained, and it is shown how the results may be plotted in the form of the QROC curve which enables different aspects of test discriminability to be represented graphically. Kappa functions are then proposed as an alternative method for representing and predicting test performance, having the advantage of identifying optimal test criteria in addition to providing measures of discriminability. The clinical application of the new methods is illustrated using data for the detection of glaucoma from measurements of intraocular pressure.


Accommodative responses to eccentric and laterally-oscillating targets. There is little information on the accommodative response to stimuli having naturalistic motion on the retina. In the present experiment, the steady-state accommodative response at various dioptric levels was assessed with a Hartinger coincidence optometer as sinusoidal frequency of a small target was systematically altered across the horizontal foveal region (+/- 2 degrees). The steady-state accommodative response became less accurate as target oscillation frequency increased, approaching the tonic accommodation level when the frequency was between 0.5 and 1 Hz (corresponding to peak velocities of 6.3 and 12.6 deg s-1, respectively). These results suggest that the accommodation system is reasonably robust to naturally-occurring retinal-image motion.


Variation in ocular modulation and phase transfer functions with grating orientation. For circular pupils of diameters < or = 2 mm the optical performance of the eye in monochromatic light is effectively diffraction-limited, so that its modulation transfer function (MTF) is essentially independent of grating orientation and its phase transfer function (PTF) is close to zero. For larger pupils, however, the wave aberration of the eye usually exceeds the Rayleigh quarter-wavelength limit. It is shown that the monochromatic MTF may then display marked variation with orientation and the associated PTFs can be non-zero. The exact effects vary markedly with the individual subject. In white light additional asymmetries may occur due to transverse chromatic aberration.


Scheme for the calculation of ocular components in a four-surfaced eye without need for measurement of the anterior crystalline lens surface Purkinje images. The computing scheme described in this paper allows calculation of the internal radii of the human eye on the assumption that it possesses four (two corneal and two lenticular) axially aligned spherical surfaces separated by homogeneous optical media. It involves measurement of Purkinje images I, II and IV. This approach is novel in that it accounts for the contribution of the posterior corneal surface and does not require measurement of the Purkinje images arising from the anterior crystalline lens surface which are notoriously poor in quality.


Keratoreformation by contact lenses after radial keratotomy: a re-analysis. A recent paper analysed change in refraction and corneal curvature associated with contact lens wear in patients who had had radial keratotomy at least a year beforehand. Conventional methods of analysis were used. This paper applies methods that have only recently become available. The results are clearer and less ambiguous. Formally, the analysis shows that there are significant mean changes in refraction (estimated to be +1.69/-0.50 x 105) and corneal power (-0.66/-0.25 x 155). In spite of the difference between these two mean changes, the analysis shows that the change in refraction may be associated with change in the corneal power alone. There is no reason to believe that any other change is occurring in the eye. Care needs to be executed in assigning a causative role to contact lenses in changing refraction and corneal curvature. Almost certainly the lenses do have such a role but the analysis does not formally allow an unequivocal conclusion concerning that role.


Colorimeter for the intuitive manipulation of hue and saturation and its role in the study of perceptual distortion. A simple optical method for mixing coloured light is described. The observer has intuitive and approximately independent control over hue and saturation at constant brightness. The method facilitates colour matching by unpracticed observers. It allows children with reading difficulties to select a colour that reduces perceptual distortion of text. The chromaticity coordinates of this colour vary from one observer to another but can be very specific. Complementary colours can exacerbate the distortions and induce pain. For the majority of children reporting beneficial perceptual effects, the u' coordinate is less than 0.25.


Postoperative analgesia: pain by choice? The influence of patient attitudes and patient education. Postoperative pain control can be unsatisfactory for a variety of reasons, including patients' attitudes towards pain treatment itself. To assess patients' expectations and their influence on postoperative analgesia, as well as the prevalence of pain following common gynaecological surgery, a prospective study was performed in 166 patients with either abdominal hysterectomy, mastectomy, laparoscopy or uterine curettage. After a first postoperative period with routine on-demand analgesia, a nurse specialised in pain treatment discussed the purposes and risks of pain treatment with the patients and cared for these patients in the second, subsequent study period. Following this discussion, 30 of 40 patients refusing analgesics in the first study period agreed to be given pain medication. In the groups with hysterectomy or mastectomy, pain control improved in the second postoperative period, even though the doses of analgesics administered were generally lower. Education of patients regarding the aims and risks of pain therapy is an essential part of pain control and can lead to an improvement of postoperative analgesia.


Chronic pain, relationships and illness self-construct. A standardised illness self-construct repertory grid was used to evaluate relationships between people with chronic pain and the person to whom they felt closest. The 'Closest Other' was used to evaluate a wider range of relationships than generally included in research on 'spouse' reactions to chronic pain. The illness self-construct repertory grid indicated that closest others tended to place illness more centrally in the life of the individual with pain than did the person who had pain. The repertory grid provided information about the relationship which was not available from responses to open-ended questions. The statistical and theoretical assumptions of repertory grid technique make it ideal for intensive study of small groups or individuals best suited to clinical settings and not for screening large numbers of subjects.


The Toddler-Preschooler Postoperative Pain Scale: an observational scale for measuring postoperative pain in children aged 1-5. Preliminary report. This study evaluates the reliability and validity of the Toddler-Preschooler Postoperative Pain Scale (TPPPS), an observational scale developed to be a clinically useful measure of postoperative pain in children aged 1-5 years. The TPPPS consists of 7 items divided among 3 pain behavior categories: (1) Vocal pain expression; (2) Facial pain expression; and (3) Bodily pain expression. These items were derived from preliminary studies by the authors and from other observational studies of children's pain behavior. Seventy-four children between the ages of 12 and 64 months seen for inguinal hernia or hydrocele repair were the subjects of the study. Subjects were observed postoperatively for six 5-min intervals, commencing with their awakening from anesthesia, using the TPPPS. Two raters independently observed 28 of the children to assess inter-rater reliability. Validity was assessed by relating TPPPS scores to the timing and type of analgesics used, visual analog and numerical scale pain ratings made by parents and nurses, and perioperative vital signs. The TPPPS was found to possess satisfactory internal reliability (Cronbach's alpha = 0.88). Inter-rater reliability was good, with kappas for the pain behavior items ranging from 0.53 to 0.78. Preliminary evidence of the scale's validity is provided by the sensitivity of the scale to analgesic regimen, the convergence between TPPPS scores and nurse and parent ratings of postoperative pain, and the associations found between TPPPS scores and perioperative vital signs.


Evaluation of constricted affect in chronic pain: an attempt using the Toronto Alexythymia Scale. The Toronto Alexythymia Scale (TAS) was applied as a potential measure of constricted affect among a sample of patients with chronic, non-malignant pain (n = 195). As previously demonstrated with non-clinical samples, the scale was found to possess moderate reliability with two principal internal factors. These factors seemed to reflect social introversion and a lack of proneness to fantasy. There was a moderate, negative association between them. The domain sampled by the TAS was apparently heterogeneous, with total scores showing no relationship to reported disability or pain intensity and a low relationship to reported distress. These results suggest potential limitations of the TAS and the alexythymia construct as means for evaluating constricted affect that accompanies chronic pain.


Transdermal fentanyl and initial dose-finding with patient-controlled analgesia in cancer pain. A pilot study with 20 terminally ill cancer patients. This pilot study evaluated the efficacy and side effects of a combination of initial patient-controlled analgesia (PCA) for dose-finding with transdermal fentanyl administration. Twenty inpatients, requiring strong opioids for severe cancer pain, received intravenous fentanyl on an on-demand basis over a 24-h period. The amount of fentanyl administered was then used as a guideline for selecting a suitable transdermal therapeutic system (TTS) on the 2nd day, which remained in place for 3 days. The size of a 2nd TTS, being used from day 5 to 7, was adjusted according to the amount of supplementary intravenous fentanyl doses on day 3. From day 4 to 7 intravenous fentanyl was stopped, and subcutaneous morphine was made available as a rescue medication. A standardized adjuvant medication was allowed. Pain intensity, pain relief, quality of sleep, mood, general state of health, activity, mobility, rescue morphine consumption and side effects were assessed using a diary after baseline pain and symptoms were recorded. Vital functions were monitored and fentanyl plasma levels were measured daily in 15 patients. The use of TTS fentanyl in combination with initial dose titration using PCA gave rapid and statistically significant pain relief. Patient compliance and acceptance were excellent. In the absence of severe side effects the main complaints were dryness of the mouth and constipation. Increasing pain intensity and increasing supplementary morphine requirements as well as decreasing plasma fentanyl levels on day 7 may indicate that conversion ratios from intravenous to transdermal administration should be increased or that TTS should be changed earlier.(ABSTRACT TRUNCATED AT 250 WORDS)


Influence of alprazolam on opioid analgesia and side effects during steady-state morphine infusions. The primary purpose of this study was to examine whether alprazolam pretreatment can increase the analgesic potency of morphine without increasing opioid side-effect intensities. We employed computer-controlled, variable-rate morphine infusions based on each subject's pharmacokinetic profile for morphine derived from a tailoring bolus dose of the drug administered 1 or 2 weeks before the infusion test sessions. On each of 2 test days, we used dental electrical stimulation to determine stimulus intensity that produced consistent reports of strong (but tolerable) pain; this intensity was used for the rest of that session. Then, we measured baseline (no drug) pain intensity reports, pain-related evoked potentials recorded from vertex, and other parameters typically affected by opioids (subjective side effects). We administered alprazolam (1 mg) or placebo (lactose) orally to the subject and then repeated the test battery 30 min later. One hour after the alprazolam or placebo dose, we initiated the tailored morphine infusion to reach target plasma morphine concentration plateaus of 16, 32 and 64 ng/ml (45-min duration each) on both test days. The test battery used during baseline was then repeated at each target concentration plateau. The order of alprazolam versus placebo pretreatments was counterbalanced across subjects and known only to the investigator operating the infusion system. Results suggest that alprazolam at the dose studied did not alter analgesic potency of morphine. However, alprazolam did clearly decrease the intensity of nausea reported by subjects during and after termination of the morphine infusions. Of special interest, alprazolam alone (30 min after oral dosing) decreased evoked potential amplitude consistently without affecting pain intensity reports.(ABSTRACT TRUNCATED AT 250 WORDS)


Intracerebroventricular micro-injections of non-steroidal anti-inflammatory drugs abolish reperfusion hyperalgesia in the rat's tail. Prostaglandins are mediators of reperfusion hyperalgesia; their site of action may be in the periphery, in the central nervous system, or both. We have investigated whether prostaglandins play a role in the central nervous system during reperfusion hyperalgesia, by intracerebroventricular (i.c.v.) micro-injection of non-steroidal anti-inflammatory drugs (NSAID), to inhibit local prostanoid synthesis. We induced tail ischaemia in conscious rats by applying an inflatable cuff at the base of the tail. The cuff was released at the first signs of co-ordinated escape behaviour. Responses to a noxious thermal stimulus were assessed, by measuring tail flick latency following immersion of the tail in water at 49 degrees C, prior to and immediately after release of the tourniquet. Tail flick latency decreased significantly following ischaemia, that is there was post-ischaemic reperfusion hyperalgesia. Intracerebroventricular micro-injection of NSAID prior to applying the tourniquet had no effect on the co-ordinated escape behaviour during ischaemia or on the tail flick latency after application of a sham tourniquet (uninflated cuff). However all the drugs abolished the hyperalgesia evident during reperfusion. Doses required to abolish hyperalgesia were 0.001 mg/kg indomethacin, 0.08 mg/kg dipyrone, 0.09 mg/kg ibuprofen, 0.2 mg/kg diclofenac sodium and 0.2 mg/kg paracetamol. These doses are 2-3 orders of magnitude less than those necessary to abolish reperfusion hyperalgesia when the same drugs are administered systemically. Our results indicate that the development of reperfusion hyperalgesia of the rat's tail depends on the synthesis of prostanoids within the central nervous system.


The effects of a non-competitive NMDA receptor antagonist, MK-801, on behavioral hyperalgesia and dorsal horn neuronal activity in rats with unilateral inflammation. The involvement of NMDA receptors in rats with peripheral inflammation and hyperalgesia was evaluated by administration of the non-competitive NMDA receptor antagonist, MK-801. Inflammation and hyperalgesia was induced by intradermal injection of complete Freund's adjuvant (CFA) or carrageenan into the left hind paw. The latency of paw withdrawal from a thermal stimulus was used as a measure of hyperalgesia in awake rats. MK-801 (1.6 mg/kg, i.p., or 31.5 micrograms, intrathecal) significantly attenuated thermal hyperalgesia and reduced its duration in comparison to saline-injected rats (P less than 0.05). The receptive field size of nociceptive-specific and wide-dynamic-range neurons in the superficial and deep spinal dorsal horn recorded 24 h after injection of CFA was significantly reduced to 73 +/- 6% (P less than 0.05, n = 8) and 74 +/- 4% (P less than 0.05, n = 8) of control values, respectively, by a cumulative dose of 3 mg/kg of MK-801 (i.v.). MK-801 (2 mg/kg) prevented the expansion of the receptive fields of dorsal horn neurons recorded 5 +/- 0.4 h (n = 5) after intradermal injection of CFA as compared to saline-injected rats (P less than 0.05). MK-801 had no significant effect on receptive field size of dorsal horn neurons in rats without CFA-induced inflammation but blocked a transient expansion of the receptive fields induced by 1 Hz, C-fiber intensity electrical stimulation of the sciatic nerve. The background activity and noxious heat-evoked response of dorsal horn neurons in rats with CFA-induced inflammation were primarily inhibited and noxious pinch-evoked activity was both facilitated and inhibited by the administration of MK-801. These results support the hypothesis that NMDA receptors are involved in the dorsal horn neuronal plasticity and behavioral hyperalgesia that follows peripheral tissue inflammation.


Putative mechanisms of buspirone-induced antinociception in the rat. Intraperitoneal administration of the serotonin 5-HT1A agonist, buspirone (1-5 mg/kg), produced dose- and time-related core hypothermia that was coincident with analgesia against a thermally noxious stimulus. Surface body temperature was not altered by buspirone. The 5-HT1A antagonist, NAN-190 (2 mg/kg, s.c.), blocked both hypothermic and analgesic effects, while systemic administration of the opioid antagonist, naloxone (1 mg/kg, s.c.), did not change the pattern of buspirone-induced hypothermia or analgesia. The apparent lack of opioid involvement and the documented role of the 5-HT1A receptor system in neuroendocrine substrates of thermoregulation and pain modulation prompted study of adrenal function in these buspirone-induced effects. Buspirone (5 mg/kg, i.p.) produced significant elevations in plasma epinephrine (EPI) and corticosterone (CST). Bilateral adrenalectomy reduced both control and buspirone-elevated EPI and CST levels and attenuated the antinociceptive, but not hypothermic, effects of buspirone (1-5 mg/kg, i.p.). Administration of the phenylethanolamine-N-methyltransferase (PNMT) inhibitor, dichloromethylbenzylamine (DCMB: 25 mg/kg, i.p.) reduced basal and buspirone-elevated plasma EPI, but not CST levels. This treatment did not affect buspirone-induced hypothermia, while significantly reducing buspirone antinociception. Pretreatment with the CST synthesis inhibitor, aminoglutethemide (AG: 2 x 25 mg/kg, i.p.), reduced plasma CST levels while not significantly affecting EPI. AG pretreatment did not alter the hypothermic effects of buspirone, but attenuated antinociception produced by the highest buspirone dose. The AG-induced reductions of buspirone antinociception were less than those effects produced by DCMB treatment. These data suggest that buspirone-induced antinociception may be a non-opioid, adrenally mediated co- and/or epi-phenomenon to core hypothermia evoked by 5-HT1A receptor agonism.


Effects of selective neurotoxic lesion of lumbosacral serotonergic and noradrenergic systems on autotomy behaviour in rats. Male rats underwent unilateral ligation and transection of the sciatic and saphenous nerves 2, 7 or 14 days after being injected intrathecally (at the thoracolumbar junction) with 6-hydroxydopamine (6-OHDA), 5,6-dihydroxytryptamine (5,6-DHT) or vehicle, and the development of autotomy was monitored. The effects of both neurotoxins on cervicothoracic (C5-T1) and lumbosacral (L1-S1) norepinephrine (NE), dopamine (DA) and 5-hydroxytryptamine (5-HT) spinal cord levels were analysed by HPLC in separate groups of rats. 6-OHDA treatment (20 micrograms/10 microliters) produced a rapid (from day 2) and significant (90-95%) fall in NE content only at L1-S1. 5,6-DHT administration (20 micrograms/10 microliters) produced a gradual (68%, 90% and 94%, at 2, 7 and 14 days, respectively) and selective depletion of 5-HT only at L1-S1. DA levels remained essentially unchanged after both neurotoxins. No differences in monoamine levels were detected among groups injected with vehicle. The main effects of neurotoxins on autotomy were: (1) a significant delay in the onset of autotomy in the rats injected with 6-OHDA 2 days before neurectomy; (2) a trend to autotomize earlier and more severely in the rats injected with 5,6-DHT 7 days before neurectomy and (3) an almost complete suppression of autotomy in the rats injected with 5,6-DHT 14 days before neurectomy. These results revealed that the expression of autotomy in rats can be modulated by interfering with spinal cord serotonergic activity and suggest new possible avenues for the treatment of certain specific pain diseases, such a phantom limb pain, by using selective agents capable of activating or blocking spinal cord serotonergic receptor subtypes.


T-lymphocyte subsets in otherwise healthy patients with herpes zoster and relationships to the duration of acute herpetic pain. T-lymphocyte subsets (CD3, CD4, and CD8 lymphocytes) in peripheral blood, parameters of cell-mediated immunity, were serially measured in 62 otherwise healthy Japanese patients with herpes zoster (HZ), and the findings were compared with those of 20 age-matched healthy controls who had had varicella but not HZ. Our objective was to elucidate whether there were changes in cell-mediated immunity, even in immunocompetent patients with HZ, and to investigate relationships between these variables and the duration of acute herpetic pain (AHP). All the patients underwent repeated sympathetic nerve blocks until pain was relieved. As compared with controls, there were slight increases in the percentages of CD4 lymphocytes (helper/inducer) and highly significant increases in the percentages of CD8 lymphocytes (suppressor/cytotoxic), resulting in marked decreases in CD4/CD8 ratios in the acute phase of HZ. The percentages of CD3 lymphocytes (pan-T lymphocytes) did not differ significantly. The duration of AHP was analyzed in 49 patients in whom T-lymphocyte subsets were measured more than twice. There was a weak but statistically significant positive linear correlation between age and the duration of AHP (r = 0.43, P < 0.01). There were statistically highly significant positive linear correlations between the number of days on which percentages of CD3 (r = 0.72, P < 10(-8)) and CD4 lymphocytes (r = 0.60, P < 10(-5)), and CD4/CD8 ratios (r = 0.62, P < 10(-5)) reached the maximum values after the onset of HZ and the duration of AHP. These correlation coefficients were higher than that between age and the duration of AHP.(ABSTRACT TRUNCATED AT 250 WORDS)


The antinociceptive effects of intrathecally administered cannabinoids are influenced by lipophilicity. Previous research has demonstrated that intravenously administered cannabinoids produce potent antinociception in rodents. The present study examined the ability of 16 cannabinoid analogs to produce antinociception and hypothermia after intrathecal administration. Fifteen of the compounds tested produced significant increases in the tail-flick response to radiant heat. This effect was stereoselective because N-methyl-dextronantradol, the inactive stereo-isomer of the potent cannabinoid analog N-methyl-levonantradol, failed to elevate tail-flick latencies above baseline values. In general, the drugs tended to be more effective in producing hypothermia than antinociception. A positive correlation found between the ED50 values in producing antinociception and lipophilicity indicated that the most lipid-soluble drugs were the least active. In contrast, no apparent relationship between cannabinoid-induced hypothermia and lipophilicity was found. The finding that the antinociceptive effects of spinally administered cannabinoids is inversely related to lipophilicity is similar to that reported for the opiates.


Quantitative sensory examination in human epidural anaesthesia and analgesia: effects of lidocaine. To characterize the sensory effects of epidural lidocaine, 2 groups each of 10 human subjects received 25 ml of 2% lidocaine at the L1-L2/L2-L3 interspace (high lumbar group) or at the L3-L4/L4-L5 interspace (low lumbar group). Twelve quantitative sensory tests in the L5 and S1 dermatomes and leg extension strength were determined every 30 min for 3 h. Sensory and motor blockade were more pronounced in the low than in the high lumbar group. Sensory functions were blocked in the following order by epidural lidocaine: warm > cold > electrical stimuli. Perception of brief localized noxious stimuli was attenuated more than perception of noxious stimuli of longer duration and involving larger stimulus areas. It is suggested that both peripheral mechanisms (differential conduction blockade of afferent fibres) and central mechanisms (temporal and spatial summation) play a role in the sensory effects of epidural lidocaine.


The role of stressful life events in the persistence of primary headache: major events vs. daily hassles. This study investigated the role of major stressful life events vs. minor life events (i.e., daily hassles) in the persistence of primary headache. It was hypothesized that chronic headache patients (n = 83) would be characterized not so much by exposure to a continued surfeit of inherently major life events as by a tendency to appraise cognitively and emotionally any ongoing microstressor or daily hassle as being more arousing or impactful than headache-free controls (n = 51). As predicted, chronic headache patients reported a significantly higher frequency (P < 0.01) and density (P < 0.01) of daily hassles, but not of major life events, than controls. Furthermore, minor life events were significantly correlated with headache frequency (P < 0.001) and density (P < 0.001) but not with gender, age and headache history. In terms of item content, health-related hassles (e.g., trouble relaxing) were perceived as being the most stressful. Significant differences between headache subgroups (chronic tension-type headache, migraine, mixed headache) were found, with tension-type and mixed headache sufferers reporting a higher incidence and density of daily hassles than migrainous patients. It was concluded that daily hassles were significantly associated with the persistence of headache and might be a better life event approach to chronic headache than major stressful events.


Cervicogenic headache, migraine without aura and tension-type headache. Diagnostic blockade of greater occipital and supra-orbital nerves. The diagnostic value of greater occipital and supra-orbital nerve blockades in patients with cervicogenic headache, migraine without aura, and tension-type headache was investigated. The pain reduction after greater occipital nerve blockade was significantly more marked in the cervicogenic headache group than in the other categories. Moreover, pain reduction in the forehead was generally only found in the cervicogenic headache patients (77%). Pain reduction (in %) was significantly more marked following the greater occipital than the supra-orbital nerve blockade. The volume effect per se was evaluated by saline injection. This procedure did not result in distinct pain reduction. The effect obtained in cervicogenic headache is, accordingly, probably due to the local anaesthesia. The present results support the postulate that different pathogenetic factors probably are responsible for cervicogenic headache, tension-type headache, and migraine without aura.


Long-term efficacy of combined relaxation: biofeedback treatments for chronic headache. Thirty-four patients having chronic idiopathic headaches participated in a long-term study comparing autogenic relaxation training alone (REL) with combinations of relaxation and electromyographic biofeedback (REL + EMG) or relaxation and temperature biofeedback (REL + TEMP). Assignment to treatment conditions was balanced on demographics and clinical characteristics, as well as headache classification according to muscle contraction or vascular headache symptomatology. The results indicate that REL + TEMP produced no additional improvements over REL following the 8-week treatment program, or at 6-month, or 12-month follow-up. However, REL + EMG produced significantly greater reductions in headache activity measures than the REL and REL + TEMP conditions at all post-treatment time points. Headache activity continued to improve over the follow-up period independent of treatment condition. These data indicate that EMG biofeedback augments long-term clinical improvements in headache patients who undergo autogenic relaxation training.


The formalin test: an evaluation of the method. The formalin test for nociception, which is predominantly used with rats and mice, involves moderate, continuous pain generated by injured tissue. In this way it differs from most traditional tests of nociception which rely upon brief stimuli of threshold intensity. In this article we describe the main features of the formalin test, including the characteristics of the stimulus and how changes in nociceptive behaviour may be measured and interpreted. The response to formalin shows an early and a late phase. The early phase seems to be caused predominantly by C-fibre activation due to the peripheral stimulus, while the late phase appears to be dependent on the combination of an inflammatory reaction in the peripheral tissue and functional changes in the dorsal horn of the spinal cord. These functional changes seem to be initiated by the C-fibre barrage during the early phase. In mice, the behavioural response in the late phase depends on the ambient temperature. We argue that the peripheral tissue temperature as well as other factors influencing the peripheral inflammation may affect the response, possibly confounding the results obtained with the test. Furthermore, we discuss the methods of recording the response and the value of observing more than one aspect of behaviour. Scoring of several behavioural variables provides a means of assessing motor or sensorimotor function as possible causes for changes in behaviour. In conclusion, the formalin test is a valuable addition to the battery of methods available to study nociception.


Dissociating spontaneous and deliberate expressions of pain: signal detection analyses. Neuro-anatomical and behavioral findings suggest that spontaneous and deliberate facial expressions are regulated by separate systems. The present study examined whether spontaneous and deliberate expressions of pain could be distinguished and, if so, the dimensions on which they differ. Forty subjects were exposed to electric shocks that varied from painless to strong pain. They also simulated facial reactions to the same levels. Observers rated the apparent pain in subjects' expressions and whether they were feigned or genuine. Signal detection analyses indicated that the intensity of deliberate expressions was greater than spontaneous expressions at levels below strong pain. Observers were able to distinguish between deliberate and spontaneous expressions to a modest degree. The intensity of deliberate expressions was related to role-playing ability. The results suggest that deliberate and spontaneous expressions of pain probably differ in intensity, topography and temporal features. They suggest that facial expressions of pain have different determinants than other forms of pain behavior.


A canonical correlation analysis of the influence of neuroticism and extraversion on chronic pain, suffering, and pain behavior. The relationship between neuroticism and extraversion on the 4 major stages of pain processing, that of pain sensation intensity, pain unpleasantness, suffering, and pain behavior, were studied in 205 chronic pain patients (88 male and 117 female). Patients underwent psychological evaluation which included the Pain Experience visual analogue scales (VAS) (Price et al. 1983), NEO Personality Inventory (NEO-PI) (Costa and McCrae 1985), and the Psychosocial Pain Inventory (PPI) (Getto and Heaton 1980). Canonical correlation was used to control for pain sensation intensity in evaluating affective dimensions of pain and to control for neuroticism in assessing effects of extraversion on different stages and dimensions of pain. Neither neuroticism nor extraversion were related to pain sensation intensity. Only neuroticism was associated with pain unpleasantness. Personality factors had their greatest impact on stages 3 (suffering) and 4 (illness behavior) of pain processing. The results of multiple regression analyses indicated that life-long vulnerability to anxiety and depression is paramount in understanding the relationship between personality and suffering in chronic pain. These findings provide support for the idea that personality traits influence the ways in which people cognitively process the meanings that chronic pain holds for their life, and hence the extent to which they suffer.


The relationship between spouse solicitousness and pain behavior: searching for more experimental evidence. In this study 42 chronic back pain patients participated twice in a treadmill test. During 1 of these 2 sessions, the partner was present. Walking time, pain intensity ratings, and heart rate were measured before and after the tests. From the results of previous studies it was expected that, in the presence of a relatively solicitous spouse, patients would report more pain, would have a shorter walking time, and would exert themselves less physically. Spouse solicitousness was measured in 2 ways: from the patient's perspective as well as from that of the spouse. Results based on the patient's interpretation of his/her partner's responses are not in accordance with previous findings. Results based on the spouse's view demonstrate, however, that patients with solicitous spouses do, in fact, report more pain and walk for a shorter duration in the presence of the spouse than patients with relatively non-solicitous spouses. Theoretical and practical implications are discussed.


The behavioral response to formalin in preweanling rats. The behavioural response of rat pups, 1-20 days of age, to subcutaneous injection of formalin in a rear paw is described. Formalin-injected pups were compared to handled controls and to pups that received an injection of normal saline. Ongoing behaviour was recorded every 2 min for 60 min after injection. Injection of normal saline produced little disorganization of behaviour, although day-1, -3 and -6 pups did frequently flex the limb on the injected side early in the session. Injection of 10 microliters of 1% formalin depressed active and quiet sleep in pups 10 days old and younger. Much less disruption of sleep was observed in day-15 pups, and in day-20 pups it was necessary to increase the concentration of formalin to 2.5% to produce a consistent behavioural response. The specific responses of pups to formalin injection were flexion of the limb, shaking the limb, and licking the injected paw. Pups of all ages displayed all of these responses, but in pups younger than 10 days, only limb flexion was consistent. Shaking became a consistent response in day-10 pups and licking in day-15 and -20 pups. Non-specific behaviours (squirming, vigorous rear kicks with both hind limbs and convulsive whole body jerks) were markedly increased by formalin in younger pups with a developmental pattern: squirming and kicking in day-1 pups, kicking and jerking in day-3 to -15 pups. Non-specific behaviours decreased and specific behaviours increased with age. In addition, the overall intensity and duration of the response decreased with age. The biphasic time course of the response of adult rats to formalin injection did not appear until 15 days of age.


Vagal afferent fibers excite upper cervical neurons and inhibit activity of lumbar spinal cord neurons in the rat. Effects of electrical stimulation of the cervical vagus nerve were determined in cervical or lumbar spinal neurons in 27 rats anesthetized with pentobarbital. Ipsilateral cervical vagus stimulation (ICVS) increased activity of 44 neurons in the C1 segment. At the same stimulation parameters, contralateral cervical vagus stimulation (CCVS) either increased, decreased or did not affect activity of C1 neurons that were excited by ICVS. For C1 cells excited by both ICVS and CCVS, the mean latency for activation was significantly longer for CCVS than for ICVS, and ICVS produced a greater degree of excitation than CCVS. In segments C2-C6, 16 of 18 neurons were excited by ICVS and 2 were inhibited. However, CCVS did not excite the C2-C6 neurons but either inhibited or did not affect activity. In 6 cervical cells, a CCVS conditioning stimulus reduced the level of excitation by ICVS (test stimulus). Transection of the C2 or C3 dorsal roots did not significantly affect the excitatory vagal input to C1 cells. Excitatory somatic receptive fields were classified for 60 cervical spinal cells that responded to vagal stimulation. Most (87%) cells were excited by noxious pinch; 29 were wide dynamic range (WDR) cells and 21 were high threshold cells. In contrast to upper cervical neurons, spinothalamic tract (STT) and spinal cells in lumbar segments were not excited by ICVS or CCVS at the stimulation parameters used in this study, but were primarily inhibited by vagal stimulation. Results of this study showed that a group of cells in upper cervical segments were excited by vagal afferents. This excitatory vagal input reaches the C1 segment primarily via an ipsilateral, supraspinal route.


Opposite influences of host anaemia on blood feeding rate and fecundity of mosquitoes. We tested a theoretical model based on the physics of capillary flow and confirmed that anaemia accelerates blood intake in the yellow-fever mosquito, Aedes aegypti (L.). We also investigated the influence of anaemic blood on egg production of mosquitoes and found that it has a negative influence on fecundity. Based strictly on egg production and the physics of fluid intake, we propose that although anaemia associated with blood-borne parasites may be detrimental to mosquitoes that can engorge to repletion in one session, it may be beneficial to those interrupted before repletion because the greater quantity of the bloodmeal may compensate for its lower quality. Epidemiological consequences are discussed but require further inquiry.


[The parasitism of the itch mite Sarcoptes scabiei (Acariformes: Sarcoptidae)]. The life cycle of the itch mite Sarcoptes scabiei (L.), an intracutaneous parasite of man and animals, has been studied. The paper concerns morphological adaptations, embryonal and postembryonal development, life cycle pattern, scabious passage as a reproductive formation, invasive stages, feeding, reproduction and topical relationships with the host, distribution and survival in the environment.


[The organization of purine and pyrimidine nucleotide biosynthesis in Sporozoa (Protozoa)]. Analysis of peculiarities in organization and functioning of metabolic ways of biosynthesis of purine and pyrimidine nucleotides in representatives of Sporozoa type has shown that molecular aftereffects of adaptation to intracellular parasitism in unicellular eukaryotes consists in the increase in the level of molecular organization, loss of some metabolic path ways and some enzymes, origin of a new metabolic system, a host-parasite one. Functioning of this system is achieved due to developing by the parasite mechanisms that are similar to the host's ones.


Endogenous superoxide dismutase activity in two Babesia species. Babesia hylomysci and B. divergens were studied for superoxide dismutase (SOD) activity by enzyme assay and isoelectric focusing (IEF). In the two Babesia species, parasite-associated SOD is cyanide-insensitive and inhibited by H2O2, indicating that iron is the cofactor metal. Measurements of SOD activity from purified parasites show that the SOD activity detected in Babesia is, for the main part, due to an endogenous enzyme.


[Nematodirus nemorhaedi sp. n. (Nematoda: Trichostrongylidae) from the Amur goral Nemorhaedus caudatus raddeanus]. Nematodirus nemorhaedi sp. n. is described. The new species was found in the small intestine in three long-tailed gorals from the Maritime Territory. The species differs from other species of the genus, parasites of ungulates, by very large (over 1.5 mm) spicules and characteristic structure of their distal end in males; by long (about 1 mm) ovijector in females and by a specific combination of characters of synloph, genital bursa in males, sizes of body, structure of vulva, sizes and shape of eggs and tail in females.


Axenic cultivation and characterization of Leishmania mexicana amastigote-like forms. A new method is described which has made possible the long-term axenic cultivation of Leishmania mexicana amastigote-like forms in Schneider's Drosophila medium supplemented with 20% (v/v) foetal calf serum. Unlike previous methods, it utilizes direct culture of parasites obtained from the lesions of infected animals rather than adaptation of promastigotes in vitro. Ultrastructural (possession of megasomes), biochemical (cysteine proteinase activity and gelatin SDS-PAGE banding pattern) and infectivity (in vivo) data are presented which show the close similarity of the cultured forms to lesion amastigotes. The axenically cultured forms grew optimally at a temperature of 32-33 degrees C, providing further evidence for their amastigote nature. It was found that adjustment of the pH of the growth medium to 5.4 was required in order to retain the amastigote morphology of the cultured parasites. This supports the notion that leishmanial amastigotes are acidophiles.


[The dependence of the quantitative indices of the infection of Yamal rodents with ectoparasites on the method of trapping]. Comparative data on the effect of the method of catching rodents in tundra on the composition and quantitative indices of parasite fauna are analyzed. The catching of rodents by means of traps in the isolated areas results in 30 to 60% decrease in the indices of abundance of gamasid mites as compared to the catching of animals with dogs. The infection of dead animals with fleas is 4 times lower than that of living ones.


The ENZYMEBA test: detection of intestinal Entamoeba histolytica infection by immuno-enzymatic detection of histolysain. We describe a new, improved test for the detection of intestinal infection by Entamoeba histolytica. The test depends upon immunoadsorption of the E. histolytica cysteine proteinase, histolysain, from faecal samples, and subsequent visual detection of the enzyme by a colour reaction. With samples from 200 volunteers, results agreed closely with those obtained by the conventional microscopic technique, and there were no false positive reactions with samples containing other parasites. The test is suitable for use either in the laboratory or in the field.


Circulating antibodies to histolysain, the major cysteine proteinase of Entamoeba histolytica, in amoebic liver abscess patients. A solid-phase enzyme immunoassay (EIA) was used to detect circulating antibodies to histolysain, the major cysteine proteinase of Entamoeba histolytica. Serum samples from 40 healthy controls, 33 asymptomatic E. histolytica cyst passers and 22 patients with amoebic liver abscess were tested. Antibodies to histolysain were found in 72.7% of cases of amoebic liver abscess, 18.1% of the cyst passers and 2.5% of healthy controls, which suggests that a humoral immune response is induced by histolysain during amoebic liver abscess.


Purification and characterization of a 47 kDa protease from Schistosoma mansoni cercarial secretion. Fractionation of Schistosoma mansoni cercariae gland secretion on a Sephadex G-150 column followed by a Superose-12 column in an FPLC system, isolated a 47 kDa protease which migrated as a single band on SDS-PAGE gels. A monoclonal antibody (MAb) was produced which recognizes only the 47 kDa protease, and an immuno-affinity column with the MAb was used to isolate the protease. The 47 kDa protease showed activity on several macromolecules such as elastin and collagen type VI besides gelatin and casein. This suggests that this enzyme can be one of the enzymes that might facilitate invasion of the cercariae through host skin. The optimal pH of the protease against the synthetic substrate, Ac-Phe-Arg-Nan, in Tris-HCl buffer was 10. Experiments with protease inhibitors indicate that the purified enzyme is a serine protease.


On the use of age-intensity data to detect immunity to parasitic infections, with special reference to Schistosoma mansoni in Kenya. We consider two phenomena, related to the host age-intensity profiles of parasitic infections, which have been suggested to be indicative of acquired immunity: (i) a lower age of peak intensity among more intensely infected hosts; and (ii) a decline with age in the dispersion of the distribution of parasites between hosts. We demonstrate that these phenomena occur among Kenyan schoolchildren infected with Schistosoma mansoni, although the magnitude of both is small. We also examine the mathematical models underlying these predictions and conclude that both phenomena are possible in the absence of acquired immunity or, indeed, in the absence of any density-dependent effect. In our opinion, insufficient attention has been focused upon mathematical models, describing the null hypothesis, i.e. density-independent models. In particular, we regard the usual assumptions made for the two stochastic components of these models, describing the heterogeneity between hosts and the probabilistic nature of infection and death of parasites, as too rigid and unrealistic. We demonstrate that deviation from these assumptions undermines the qualitative distinctions between models which describe acquired immunity or density dependence and those which are density-independent.


The effects of computer-controlled shadow stimuli on the success of cercarial transmission by Cryptocotyle lingua (Digenea: Heterophyidae). Pectoral fins from juvenile rainbow trout (Oncorhynchus mykiss) were used in a bioassay, the object of which was to quantify the effect of simulated shadow stimuli on the transmission success of the cercariae. For a period of 60 min, parasites and fins were exposed to a sequence of computer-controlled shadow stimuli, continuous light or total darkness, and subsequently the number of infections was counted. Trials were conducted with cercariae 1, 12 and 24 h old. Within the constraints of the experimental procedure, shadows were found to increase significantly the number of infections achieved by the 12-h-old parasites. As the cercariae aged, their ability to infect host tissue declined. The relevance of these results to transmission in the natural environment is discussed.


The dynamics of trickle infections with Ancylostoma ceylanicum in inbred hamsters. Trickle infections with a hamster-adapted strain of the hookworm Ancylostoma ceylanicum were studied by administering doses of 5-30 larvae twice weekly to inbred DSN hamsters. The worm burdens were regulated at very low levels, and this was found to be independent of the size of the infective dose. It is likely that there is some turnover of adult worms during trickle infection, as larvae of all stages were recovered from most time-points. This regulation is immunologically mediated and both the worm burdens and fecundity were increased in hamsters that were immunosuppressed by cortisone treatment. A trickle infection regime also induced a 67% protective immunity to a single subsequent challenge. The resistance that occurred during trickle infections was, however, incomplete, and some worms were found to survive in hamsters that had been repeatedly infected for over 10 weeks. Thus, although hamsters are capable of regulating the infection, some worms are capable of surviving the host immune effectors.


The use of suckling mice to isolate and grow Giardia from mammalian faecal specimens for genetic analysis. A simple technique is described for preparation of Giardia cysts from faecal samples, the growth of trophozoites in suckling mice and the isolation of trophozoites for genetic analysis by allozyme electrophoresis. In total, 125 new isolates of Giardia have been collected from human and animal sources over a wide geographical area of South Australia and the Northern Territory of Australia. A number of long-established axenized isolates of G. intestinalis belonging to Groups I and II also adapted to grow in suckling mice. These findings indicate that suckling mice are permissive hosts for a variety of genetically dissimilar but morphologically similar organisms of the G. duodenalis type and that this in vivo technique may be less selective than isolation by in vitro culture. The use of suckling mice has revealed that infections can be composed of mixed genotypes and that isolation and purification techniques can be selective. Allozymic interpretation is essential to reveal the genetic complexity of such mixtures.