Synganglial morphology and neurosecretory centers of adult Amblyomma americanum (L.) (Acari: Ixodidae). Lone star ticks, Amblyomma americanum (L.), were processed by standard histological means for paraffin embedding, sectioning, and staining by the paraldehyde-fuchsin technique. The synganglion is highly condensed around the esophagus and possesses paired optic, cheliceral, palpal, pedal I-IV nerves, and opisthosomal nerves and a single unpaired esophageal nerve. Although optic nerves were observed leading from the eyes to the protocerebrum, distinct optic ganglia were not seen in any of the preparations examined. The paraldehyde-fuchsin technique revealed 14 neurosecretory centers (11 paired, 3 unpaired) within the synganglion, which are described in relation to the underlying neuropilar structure. A previously undescribed internal subesophageal center that consists of a single cell was observed within a cluster of perikarya lying posteriorly adjacent to the esophagus. A three-dimensional reconstruction of the internal neuropilar structure of the synganglion was made, and the included neurosecretory centers were mapped. Comparisons are made to previous work on other ticks, and physiological relationships are considered.


Female Aedes aegypti (Diptera: Culicidae) in Thailand rarely feed on sugar. Female Aedes aegypti (L.) of two different body sizes and provided with different diets (20% sucrose, water only, or 20% sucrose + human blood) were marked and released together in a rural Thai village. Recaptured marked and unmarked (wild) adults were tested for fructose by the cold-anthrone reaction. Both released and wild females showed a low frequency of sugar feeding in nature; both small-bodied and large-bodied individuals failed to sugar feed significantly. Marked females released with sugar in their crop utilized this energy source over the following 2-3 d but failed to replenish it. In contrast, about one-third of wild, resting males showed evidence of recent sugar feeding. This indicated that the absence of plant sugar in females was not caused by a shortage of nectar sources in this rural domestic environment. Presumably, the nonutilization of plant sugar as an energy source increases the frequency of blood feeding and, therefore, the vectorial capacity of Ae. aegypti.


Differentiation of vector species of phlebotominae (Diptera: Psychodidae) in Kenya by chorionic sculpturing of their eggs. Chorionic sculpturing on eggs of Phlebotomus pedifer Lewis, Mutinga, and Ashford; the closely related Phlebotomus aculeatus Lewis, Minter, and Ashford (= P. elegonensis Ngoka, Madel, and Mutinga); and Phlebotomus martini Parrot was examined and compared by scanning electron microscopy. The eggs of P. pedifer had a general pattern of longitudinal ridges; those of P. aculeatus and P. martini exhibited intraspecific differences. Chorionic patterns of eggs were not reliable to differentiate these species. It is suggested that other methods of differentiation should be used on these species.


Detection and identification of mammalian DNA from the gut of museum specimens of ticks. A method for detection and identification of mammalian DNA in the gut of alcohol-preserved ticks has been developed. Successful amplification and sequencing of host cytochrome b is reported from ticks preserved in 70% alcohol for more than 40 yr. The method described shows promise for determination of unknown tick hosts.


Distribution of Ixodes dammini (Acari: Ixodidae) in residential lawns on Prudence Island, Rhode Island. The distribution of nymphal Ixodes dammini Spielman, Clifford, Piesman & Corwin in residential lawns was assessed by flagging on Prudence Island, RI. The number of ticks per sample was five times greater in lawns adjacent to woods than in lawns adjacent to other lawns. Relative tick abundance was negatively correlated with distance from the woods, but the decline was gradual. Spirochete prevalence in ticks did not differ among lawn types or at different distances from the woods. Therefore, barriers that keep people away from the wood edge probably lower the risk of acquiring Lyme disease, but there is still a risk. Even with physical barriers at lawn-wood edges, personal precautions to prevent tick bites should be followed.


Similar reproductive status and body size of horse flies (Diptera: Tabanidae) attracted to carbon dioxide-baited canopy traps and a Jersey bullock. The reproductive status and body size of four Tabanus species collected from canopy traps baited with carbon dioxide and from a Jersey bullock were compared. Parity rates, sperm prevalence, stage of follicular development in terminal follicles of parous females, prevalence of females retaining eggs, average number of eggs retained in parous flies, and the body size of parous females did not differ significantly between sampling methods. Based on the presence of nulliparous host-seeking flies, Tabanus pallidescens Philip and T. wilsoni Pechuman can be added to the list of tabanids found to be anautogenous.


Occurrence of Ixodes pacificus (Parasitiformes: Ixodidae) in Arizona. Adults and immatures of Ixodes pacificus Cooley & Kohls were collected by flagging vegetation and from lizards during a 3-mo period in the Hualapai Mountain Park, Mohave County, AZ, in 1991. Collections were made at altitudes > or = 2,134 m. Two of 48 gut-salivary gland extracts of adult ticks were positive by IFA using a monoclonal antibody (H5332) specific to Borrelia burgdorferi. These are the first records of I. pacificus and of spirochetes tentatively identified as B. burgdorferi in Arizona.


Isolation of the Lyme disease spirochete, Borrelia burgdorferi, from Ixodes dammini (Acari: Ixodidae) collected on Prince Edward Island, Canada. Studies were undertaken to monitor for the presence of Borrelia burgdorferi, the etiologic agent of Lyme disease, on Prince Edward Island, Canada. Gut contents were removed for culturing from seven engorged ticks collected in 1991-1992 including five Ixodes dammini (Spielman, Clifford, Piesman & Corwin) and two I. scapularis (Say) removed from a dog that had recently traveled to the southern United States. B. burgdorferi was recovered from one I. dammini that had been removed from a cat in Charlottetown in October 1991. The cat had not traveled off the island. Immunofluorescent antibody (IFA) studies on sera from 75 dogs, 7 cats, and 8 white-tailed deer (Odocoileus virginianus) collected on Prince Edward Island between 1989 and 1992 revealed one reactor with an IFA titer > or = 1:256. The reactor was a dog with a history of travel to the United States. This report documents the first isolate of B. burgdorferi in Atlantic Canada, possibly because of the introduction of I. dammini on migratory birds. Serological studies do not indicate widespread occurrence of B. burgdorferi on Prince Edward Island.


Clothing impregnations of dibutylphthalate and permethrin as protectants against a chigger mite, Eutrombicula hirsti (Acari: Trombiculidae). A field study to compare the effects of wearing military uniforms treated with permethrin or dibutylphthalate as protection against the chigger Eutrombicula hirsti (Sambon) was conducted in northern Queensland, Australia, during November 1990. Volunteers who wore treated uniforms received significantly fewer chigger attachments than individuals who wore untreated uniforms. Australian military uniforms treated with dibutylphthalate provided a 97.6% increase in protection, whereas uniforms treated with 0.058-0.101 mg/cm2 permethrin provided 96.4% protection. U.S. Army uniforms treated with 0.125 mg/cm2 permethrin provided 83.2% protection. The differences between the clothing treatments were not significant. The results show that wearing clothing impregnated with either compound is an effective method for personal protection against E. hirsti.


Failure of dengue viruses to replicate in Culex quinquefasciatus (Diptera: Culicidae). Culex quinquefasciatus (Say) and Aedes aegypti (L.) were parenterally infected with dengue viruses and virus replication was monitored at intervals after infection in each species. Dengue viruses replicated rapidly in Ae. aegypti, reaching a peak titer of 10(6)-10(7) mosquito infectious dose 50 (MID50) per mosquito. In Cx. quinquefasciatus, however, dengue virus replication did not occur. We conclude that this mosquito species is refractory to infection with dengue viruses and, therefore, does not serve as a vector in nature.


Studies on the ecology of Lyme disease in a deer forest in County Galway, Ireland. The abundance of the tick Ixodes ricinus (L.) and the infection rate of ticks with Borrelia burgdorferi (Johnson et al.) were compared on either side of a deer fence in a forest park in County Galway, Ireland, in an attempt to elucidate the role of fallow deer, Dama dama, and woodmice, Apodemus sylvaticus, in determining the population density of I. ricinus and the transmission of B. burgdorferi. The results showed that tick numbers were much higher on the deer side of the fence, although the density of mice was similar on both sides. This suggests that, in the absence of other obvious factors, deer rather than mice are responsible for tick abundance in this habitat. Tick infection rates, determined by immunofluorescence, were consistently higher outside the deer fence than inside it. It is suggested, therefore, that mice rather than deer may be the important reservoir hosts of B. burgdorferi in this habitat and that deer, by feeding many larvae, probably contribute large numbers of uninfected ticks to the population. If this is the case, there will not be a direct relationship between deer abundance and tick infection rates. This has important implications for risk assessment.


Relationship between female Anopheles dirus (Diptera: Culicidae) body size and parity in a biting population. Wing length of host-seeking Anopheles dirus Peyton & Harrison was measured in Tha-Mai District, Chanthaburi Province, Thailand. Overall, wing length of nulliparous females (mean = 3.035 mm) was not significantly smaller than that of parous females (mean = 3.039 mm). Wing length was correlated with rainfall and minimum air temperature; females tended to be smaller in the rainy season and larger in the cool and early dry seasons, often in association with a high parity rate. Malaria transmission potential based on daily survivorship was estimated to be highest during the cool and early dry seasons, and during the first half of the rainy season.


Xenopsylla bantorum is an east African subspecies of X. cheopis (Siphonaptera: Pulicidae). The geographic distribution, host association, and male genital morphology of Xenopsylla bantorum Jordan were examined and compared with the Nilotic and Oriental "strains" of Xenopsylla cheopis (Rothschild). The more acute shape of the ninth sternite separates X. bantorum from all types of X. cheopis; however, the length of the first process of the male's clasper and the number of setae on this process are significantly different among all three groups; the Nilotic strain of X. cheopis is intermediate to the others. Specimens collected from both wild and commensal rodents in Nakuru, Kenya, were all X. bantorum, suggesting that X. cheopis present early in the century that resulted from introductions on Rattus rattus had been absorbed by the native X. bantorum population. These factors and a review of opinions by others concerning the status of X. bantorum demonstrate that this flea is not specifically distinct from X. cheopis. The trinomial X. cheopis bantorum is erected. Furthermore, the Nilotic and Oriental "strains" of X. cheopis are distinguishable morphologically solely by the length of the male's first process.


Host immunity to mosquitoes: effect of antimosquito antibodies on Anopheles tessellatus and Culex quinquefasciatus (Diptera: Culicidae). Rabbit antibodies to antigens derived from the tissues of sugar-fed Anopheles tessellatus Theobald were fed to An. tessellatus and Culex quinquefasciatus Say in blood meals. These antibodies tended to reduce the number of eggs produced by An. tessellatus, but had no effect on the fecundity of Cx. quinquefasciatus. Ingestion of the rabbit antibodies did not detectably affect the mortality of An. tessellatus but increased the mortality of Cx. quinquefasciatus. The results provide preliminary evidence for the potential of antimosquito antibodies to disrupt the physiology of mosquito vectors and indicate the need for further studies with high-titer, monospecific antibodies against the relevant target antigens.


Random amplified polymorphic DNA of mosquito species and populations (Diptera: Culicidae): techniques, statistical analysis, and applications. A polymerase chain reaction (PCR)-based method is described for the identification and differentiation of mosquito species and populations. The method, described first by Williams et al. (1990), employs single 10 base-long primers of arbitrary DNA sequence and results in the amplification of random segments of DNA known as random amplified polymorphic DNA (RAPD). We wished to determine if RAPD of mosquito DNA could be used for the differentiation of species and populations, identification of unknown specimens, and the reconstruction of phylogeny. RAPD of mosquito DNA results in the amplification of a series of DNA fragments of varying length. Most amplified fragments are unique to an individual; however, our data indicated that in each of the five species of Aedes examined, some fragments are species-specific and are present in all individuals of that species. This enabled us to derive a diagnostic profile for each of the five species. A nearest-neighbor analysis of all the amplified DNA fragments discriminated among species on a multivariate basis. Several individuals of Aedes albopictus (Skuse), included in the analysis as "unknowns," were correctly identified as belonging to Ae. albopictus. UPGMA clustering of presence-absence data enabled the separation of different Aedes species as well as different populations of Ae. albopictus. The entomological applications of RAPD include the construction of diagnostic profiles for species identification and differentiation among conspecific populations.


Reproductive activity of Synosternus cleopatrae (Siphonaptera: Pulicidae) in relation to host factors. Reproductive activity of Synosternus cleopatrae (Rothschild) infesting Gerbillus andersoni allenbyi Thomas was studied in a natural setting in Israel. Rodents were trapped and measured (weight and length), their sex was identified, and their reproductive status estimated. Their ectoparasites were removed, and fleas were dissected and their oocytes measured. Two indices of flea reproductive activity were analyzed: "reproductive status," which distinguished between gravid and nongravid females, and "reproductive intensity," which was estimated as the sum over the two largest oocytes of the products of oocyte length multiplied by oocyte width. Both indices showed that no reproduction took place between November and January, but reproduction was relatively stable during the rest of the year. Although flea reproductive activity differed significantly among individual hosts, only a small fraction of gerbils (10-15%) carried a significantly different proportion of reproductive fleas than their monthly sample proportion (based on all fleas regardless of hosts). All these hosts carried a lower proportion of reproductive fleas than their monthly sample proportion. The host's sex, but not reproductive status or age, had a significant effect on flea reproduction, expressed as a higher reproductive activity on male gerbils. Infestation burden expressed as ectoparasite counts was included in the statistical analysis. Only lice, Polyplax gerbilli Ferris, but not S. cleopatrae, Stenoponia tripectinata (Tiraboschi), and a total of five mesostigmatid Acari had a significantly negative association with S. cleopatrae reproductive activity. These relationships between S. cleopatrae reproductive activity and the host infestation burden do not support the hypothesis of modulation of S. cleopatrae reproduction by the infestation burden. However, differences in the reproductive activity of ectoparasites between their hosts may play a major role to generate the parasite clumped distribution. Thus, gerbil males probably carry more fleas than gerbil females because of the higher reproductive activity of S. cleopatrae on gerbil males.


Preparation and examination of flea larvae (Siphonaptera) by light and electron microscopy. Techniques are described for making permanent slide-mounted specimens. Larvae were thoroughly macerated in KOH to remove soft internal tissue, yielding specimens with enhanced transparency and allowing examination of most of the exoskeleton in a single larva. Fatty material was removed in acetone to eliminate confusion of fat globules with sensilla in the cuticle. The more sclerotized exoskeletal elements, such as integumentary scales and the body sclerites together with their setae and sensilla, were highlighted by staining with carbol fuchsin. Resolution of numbers and arrangement of setae, especially those on the dorsum of the head capsule, in the anal comb, and on the anal mounds, was greatly facilitated by mounting larvae in dorsal orientation. Clearer views of the antennae and mouthparts were obtained, in orientations seldom achieved in whole mounts, by dissecting the head capsule. Discrimination of many taxonomically valuable features was enhanced by the use of phase-contrast microscopy. Interpretation of structures noted in light microscopy was complemented using scanning electron microscopy. The latter allowed differentiation between surface and internal cuticular structures.


Food ingestion and digestive enzymes in larval Aedes aegypti and Ae. albopictus (Diptera: Culicidae). Frequency of the labral brush movements of first, second, and fourth instars of Aedes aegypti (L.) and Aedes albopictus (Skuse) was studied comparatively in the laboratory. A frequency of 197 strokes per min for the first and second instars was observed in the former species compared to 118 strokes per min in the latter species. A faster ingestion rate of algal cells also was observed in first and second instars of Ae. aegypti (mean 57.5 cells per s) compared with first and second instars of Ae. albopictus (mean 22.4 cells per s). The digestive enzymes chymotrypsin (EC 3.4.21.1) and trypsin (EC 3.4.21.4) were more active in the peritrophic membrane (including food contents) than in the midgut epithelium of both species. Chymotrypsin activity in 11-d-old third and fourth instars of Ae. albopictus was 28 times higher than in the corresponding stadia of Ae. aegypti, indicating that the former species may have a superior enzymatic process for digesting food proteins.


The genus Parasecia (Acari: Trombiculidae), with the description of a new species from Mexico. The genus Parasecia Loomis, 1966, is redefined, and Parasecia bulbocalcar Goff is described as new from specimens collected off a Yellow-shouldered Bat, Sturnia ludovici Anthony, taken in Morelos, Mexico. A key to the 15 species of Parasecia is provided.


Effects of Ascogregarina barretti (Eugregarinida: Lecudinidae) infection on Aedes triseriatus (Diptera: Culicidae) in Illinois. Ascogregarina barretti (Vavra), a gregarine protozoan parasite, infected 23.6 and 5.0% of Aedes triseriatus (Say) adults that emerged from pupae collected from an east-central Illinois tire dump in 1990 and 1991, respectively. Infection significantly reduced the wing length of males and females in both years, but its effect was greatest in 1991. Females were approximately 1.7 times as likely to be infected as males. Infected pupae were 3.53 and 2.76 times more likely to die than uninfected pupae in 1990 and 1991, respectively. Wing length also was affected by location within the tire dump and by tire water volume. We conclude that the A. barretti infection was deleterious to Ae. triseriatus and that the effects of this pathogen may be moderated by environmental factors.


Laboratory evaluation of Acanthocyclops vernalis and Diacyclops bicuspidatus thomasi (Copepoda: Cyclopidae) as predators of Aedes canadensis and Ae. stimulans (Diptera: Culicidae). Predatory effectiveness of two vernal-pool copepods, Acanthocyclops vernalis (Fischer) and Diacyclops bicuspidatus thomasi (Forbes), was assessed against cohabiting larvae of Aedes canadensis (Theobold) and Aedes stimulans (Walker) in laboratory bioassays. D. b. thomasi did not exhibit predatory behavior toward first instars, even when both organisms were confined in 35-mm wells for 7 d and alternative food sources were not available. A. vernalis did feed on early instars, but its effectiveness was significantly influenced by the presence of alternate food, the size of the container, and the size and age of the larval prey. Results strongly suggest that in a comparatively unrestricted natural vernal-pool habitat where an abundance of other food sources are available, neither copepod species plays a major role in reducing larval mosquito populations.


Detection of Borrelia burgdorferi in laboratory-reared Ixodes dammini (Acari: Ixodidae) fed on experimentally inoculated white-tailed deer. Larvae and nymphs of Ixodes dammini Spielman, Piesman, Clifford & Corwin from a laboratory colony were fed on two white-tailed deer, Odocoileus virginianus (Zimmerman) inoculated with either the SH2-82 or JD-1 strains of Borrelia burgdorferi Johnson, Schmid, Hyde, Steigerwalt & Brenner. Ticks were exposed to one deer 43 and 69 d after inoculation of the spirochete and to a second deer 35 and 61 d after inoculation. Polymerase chain reaction assays amplified the 158 bp OspA DNA target sequence in 11.1% (n = 9) of fed larvae and 3.3% (n = 30) of nymphs from the deer inoculated with the SH2-82 strain, and 22.7% (n = 22) of larvae and 0% (n = 21) of nymphs from a second deer inoculated with the JD-1 strain of B. burgdorferi. One of three females derived from nymphs fed on one of the inoculated deer showed presence of B. burgdorferi DNA, but none of four males was positive. Experimentally inoculated deer can serve as a source of at least two geographic strains of B. burgdorferi to I. dammini larvae and nymphs for at least several weeks.


Variation in the efficiency of vertical transmission of dengue-1 virus by strains of Aedes albopictus (Diptera: Culicidae). Five geographical strains of Aedes albopictus (Skuse) were compared for their ability to transmit vertically a dengue-1 isolate from Jamaica. The OAHU strain of Ae. albopictus and a strain of Aedes aegypti (L.) from the United States were included as controls. The offspring of orally infected females were assayed individually for vertical infection. Vertical transmission rates among strains ranged from 11 to 41%, and filial infection rates of strains ranged from 0.5 to 2.9%. Filial infection rates of individual positive families within strains ranged from 1.4 to 17.4%. These rates were higher than those previously recorded for Ae. albopictus. The observed differences in rates of vertical transmission among the strains were not statistically significant, because 95% of the measured variation was attributed to families within strains. The most significant source of variation in vertical transmission of dengue-1 by Ae. albopictus was at the individual level.


African swine fever virus infection in the soft tick, Ornithodoros (Alectorobius) puertoricensis (Acari: Argasidae). In total, 1,186 second instar Ornithodoros (Alectorobius) puertoricensis Fox second instars were fed on a pig when it had a viremia of 10(5.2) hemadsorption units (HAd50/ml) and 420 second-instar O. puertoricensis were fed on an uninfected pig. Subsequent blood meals for ticks in both groups were from uninfected pigs. The effects of African swine fever virus (ASFV) infection on O. puertoricensis populations were evaluated for the following parameters: mortality; mean time to death; percentage molted per instar; percentage molted to male, female, or subsequent instar; effects on duration of premolt period; and the number of blood meals per instar. The cumulative virus-induced mortality rate for all immature stages (second to fifth instar) of O. puertoricensis that had been fed as second instars on a pig infected with ASFV was 43.2%. In contrast, 23.1% mortality was observed among ticks fed on uninfected pigs. The mortality rate among third instars that fed on the viremic pig was 55.3% versus 4.8% among nymphs fed on normal pigs. One-third to more than one-half of all third, fourth, and fifth instars required at least two blood meals to molt. Mean premolt periods for second, third, fourth, fifth, and sixth instars fed on uninfected pigs were approximately 12, 15, 32, 22, and 14 d, respectively. Mean weights for unfed second to fifth instars, males, and females were: 0.6, 1.0, 1.5, 1.7, 1.5, and 3.1 mg per tick, respectively.


Could Aedes albopictus (Diptera: Culicidae) become established in California tree holes? The ability of temperate zone-adapted Aedes albopictus (Skuse) to survive and complete development in California tree holes was evaluated in laboratory experiments that assessed development under simulated wet-season conditions, larval competition with Aedes sierrensis at different food levels, temporal survivorship of eggs stored under different humidities and temperatures, and suitability of larvae as hosts for the indigenous parasite Lambornella clarki. At all resource levels, Ae. albopictus completed development at temperatures similar to those in natural tree hole water in spring and early summer (> or = 16 degrees C), but not those during the rainy winter months (4-11 degrees C). In competition studies at 21 degrees C, the population performance (i.e., survivorship, pupation time, and adult size) of Ae. albopictus at all resource levels was as good or better when larvae developed with Ae. sierrensis compared with when reared with only conspecifics. Egg survivorship declined with increased storage time, increased temperature, and decreased humidity; > 55% of eggs hatched following 24-wk storage at 11 degrees C with relative humidities > 78%. In host suitability tests, parasitic theronts of L. clarki consistently attacked Ae. albopictus larvae at rates significantly lower than Ae. sierrensis. L. clarki that successfully invaded Ae. albopictus larvae failed to multiply and kill their hosts; thus, Ae. albopictus is not a suitable host for L. clarki. The protracted drying of most tree holes and low water temperatures during the rainy season will hinder but not preclude establishment of Ae. albopictus in California.


HIV infection and AIDS: the ethics of medical confidentiality. An Institute of Medical Ethics working party argues that an ethically desirable relationship of mutual empowerment between patient and clinician is more likely to be achieved if patients understand the ground rules of medical confidentiality. It identifies and illustrates ambiguities in the General Medical Council's guidance on AIDS and confidentiality, and relates this to the practice of different doctors and specialties. Matters might be clarified, it suggests, by identifying moral factors which tend to recur in medical decisions about maintaining or breaching confidentiality. The working party argues that two such factors are particularly important: the patient's need to exercise informed choice and the doctor's primary responsibility to his or her own patients.


On visibility: AIDS, deception by patients, and the responsibility of the doctor. Contrary to the usual discussion of lying or deceiving in medical ethics literature where the lying or deceiving is done by the doctor or surgeon, this paper deals with lying or deceiving on the part of the patient. Three cases involving HIV-infected male homosexual or bisexual persons are presented. In each case the patient deceives or wants the doctor to deceive a third party on his behalf. Are such deceptions or lies expressions of compassion? Are they in the patient's best interests? Do they compromise the doctor's integrity? It is submitted that societal attitudes towards male homosexual acts were internalised by the men described in these cases. Thus, a dichotomy was created between the private life and the public image. Fear of condemnation by the doctor or others restricted communication towards the goal of the maintenance of the patient's health. The lack of trust which inhibits truth-telling results in mutual and progressive isolation and impedes the provision of optimal care.


Ethical dilemmas in malaria drug and vaccine trials: a bioethical perspective. Malaria is a disease of developing countries whose local health services do not have the time, resources or personnel to mount studies of drugs or vaccines without the collaboration and technology of western investigators. This investigative collaboration requires a unique bridging of cultural differences with respect to human investigation. The following debate, sponsored by The Institute of Medicine and The American Society of Tropical Medicine and Hygiene, raises questions concerning the conduct of trans-cultural clinical malaria research. Specific questions are raised about the difficulties of informed consent in different cultural settings and whether there is any role for community involvement. Discussants debate whether drug and vaccine trials not approved in an industrialised country are ever defensible if performed in a third-world setting. Potential conflicting priorities between investigators are discussed and ideas regarding conflict resolution are offered.


Epidemiology and moral philosophy.

Epidemiology and moral philosophy. To an increasing extent ethical controversies affect and sometimes obstruct public health work and epidemiological research. In order to improve communication between the concerned parties a model for identification and analysis of ethical conflicts in individual-based research has been worked out in co-operation between epidemiologists and moral philosophers. The model has two dimensions. One dimension specifies relevant ethical principles (as beneficence, non-maleficence, autonomy and justice). The other dimension specifies the groups of persons involved in the conflict under consideration (for example: the study-population, individuals who may benefit from the results, the researchers and their personnel, the community at large). The model has been applied to the problem of legitimacy of case-register research and to problems in psychiatric health services research as well as epidemiological research.


Should public health respect autonomy?

Should public health respect autonomy? This paper suggests that public health, due to its community orientation, may be ignoring certain ethical principles--namely the rights of individuals and communities to self-determination. The expectation of individual rights as a member of a community is reviewed and the additional right of a community for self-determination is proposed. The influences on ethical evaluations by the legal and economic environments are suggested, using US examples. The conclusion argues that as the focus of health-care delivery changes, it will become more important to consider these questions of group ethics.


Gilligan: a voice for nursing?

Gilligan: a voice for nursing? The current reform of nursing education is resulting in major changes in the curricula of colleges of nursing. For the first time, ethical and moral issues are being seen as an important theme underpinning the entire course. The moral theorist with whose work most nurse teachers are acquainted is Kohlberg. In this paper, it is suggested that his work, and the conventions of morality which he exemplifies, may not be the most appropriate from which to address the moral issues facing the nurse. The author suggests that the work of Carol Gilligan of Harvard university is of great significance, not only for nurses involved in the teaching of ethics, but for all nurses. Gilligan's emphasis on caring and relationships accords with the common experience of the nurse, and echoes the current revival of interest within nursing in examining, and valuing, the phenomenon of caring.


Let's keep metaphysics out of medical ethics: a critique of Poplawski and Gillett. I argue that the concept of 'longitudinal form', which Poplawski and Gillett have introduced into ethical discussions about embryos and gametes, involves too many metaphysical subtleties to be a useful aid to making moral decisions. I conclude by suggesting a criterion for relevance in medical ethics.


Serum antibodies to verotoxin-producing Escherichia coli (VTEC) strains in patients with haemolytic uraemic syndrome. Serological evidence of infection with verotoxin-producing Escherichia coli (VTEC) was sought in 28 patients suffering from haemolytic uraemic syndrome (HUS) and 25 age- and sex-matched controls. ELISA was used to detect anti-lipopolysaccharide (LPS) antibodies to E. coli strains O157, O111, O26 and NCTC 10418, a non-VTEC strain, and Shigella dysenteriae O1. Sera from 19 of the HUS patients but from none of the 25 controls had significant antibody levels to the verotoxin-producing bacteria. Sera from 13 patients reacted with only one LPS of the four verotoxin-producing bacteria; sera from six reacted with more than one LPS antigen but not with LPS of E. coli NCTC 10418. Paired sera taken 2-3 weeks apart were obtained from 20 HUS patients; 14 of these had high levels of antibody in the acute phase sample. Analysis of antibody levels in the convalescent sera showed that one patient had an increase, one was unchanged and 12 patients had a decrease in antibody to the verotoxin-producing bacteria.


Comparison of cell-wall teichoic acid with high-molecular-weight extracellular slime material from Staphylococcus epidermidis. Extracellular high-mol.-wt material was separated from liquid cultures of Staphylococcus epidermidis. This material contained protein c. 20% w/w and polysaccharide c. 80% w/w. The polysaccharide was isolated by gel and ion-exchange chromatography and contained glycerol phosphate, glucose, N-acetylglucosamine, and D-alanine. Cell-wall teichoic acid was isolated from strain RP-62A and had a similar composition.


Immunological response to a Staphylococcus aureus fibronectin-binding protein. A protein (gal-FnBP), constructed by fusion of the genes encoding beta-galactosidase of Escherichia coli and the binding domains of fibronectin-binding protein (FnBP) of Staphylococcus aureus was used. FnBP is a surface protein responsible for attachment of bacteria to extracellular matrix of various host tissues. Gal-FnBP is more stable and can be produced in larger quantities than native FnBP. The binding specificity of this fusion protein was established in a Western blot analysis. Treatment of gal-FnBP with formalin inactivated the binding capacity of the protein but immunogenicity was retained. Immunisation of mice with formalin-treated gal-FnBP resulted in high antibody titres against the fibronectin-binding part of this fusion protein. These antibodies were measured by their ability to block the specific binding of fibronectin to gal-FnBP in a blocking assay. Sera raised against formalin-treated gal-FnBP and non-treated gal-FnBP blocked this binding to 40 and 25% respectively, thereby indicating the usefulness of gal-FnBP as a vaccine component.


Protection from Shigella sonnei infection by immunisation of rabbits with Plesiomonas shigelloides (SVC 01). Plesiomonas shigelloides, an organism commonly found in water, is only rarely associated with diarrhoea in man. P. shigelloides serotype O:17 (SVC O1), which is antigenically similar to Shigella sonnei, was found to be neither virulent nor toxic for rabbits. Rabbits immunised by feeding with P. shigelloides (SVC O1) were completely protected against an oral challenge with 10(10) cells of S. sonnei but non-immunised rabbits were not. P. shigelloides (SVC O1) may be a useful vaccine strain for shigellosis.


Character and origin of vacuoles induced in mammalian cells by the cytotoxin of Helicobacter pylori. Cytotoxic activity of culture supernates of Helicobacter pylori is manifested by vacuolation of mammalian cells in vitro. The formation and maturation of toxin-induced vacuoles in HeLa cells has been studied to examine the possibility that they are autophagosomal in nature. Observation by light microscopy revealed that vacuoles originate in a perinuclear position, increasing in number and size until cell degeneration and lysis occur after 48 h. Ultrastructural study of mature vacuoles indicated the presence of a bounding membrane with contents consisting of degenerate cytoplasmic components and acid phosphatase activity. Confocal fluorescence imaging demonstrated acridine orange accumulation in the vacuoles of toxin-treated cells, indicating an acidic intravacuolar pH. These features are characteristic of autophagosomes. In addition, the size of vacuoles in living, acridine orange-stained cells tended to be inversely proportional to fluorescence intensity. Fluid phase endocytic markers were observed only rarely within nascent vacuoles. Over the succeeding 24 h, labelling of most vacuoles with these dyes was observed. This, along with the observation of intravacuolar acid phosphatase activity, provides evidence that vacuoles communicate at some point during their development with endocytically derived compartments. These observations provide direct evidence for an autophagic origin of these structures.


The significance of free and immune-complexed hydatid-specific antigen(s) as an immunodiagnostic tool for human hydatidosis. Micro-enzyme-linked immunosorbent assay (Micro-ELISA) systems were developed and evaluated for the detection of circulating (free or immune-complexed) hydatid antigens in the sera of patients with hydatidosis, by employing monospecific antibodies to hydatid-specific antigens of 8-kDa and 116-kDa. Fifteen (75%) of 20 sera from patients with hydatidosis had both 8-kDa and 116-kDa antigens freely circulating in their sera while three and two samples, respectively, had only 8-kDa or 116-kDa antigen. All the surgically confirmed cases of hydatidosis had detectable levels of both 8-kDa and 116-kDa circulating immune complexes in glycine HCl-treated sera. However, none of the sera from control subjects (patients with cysticercosis, ascariasis, ancylostomiasis, hymenolepiasis, amoebic liver abscess or viral hepatitis) had any detectable level of either type of circulating specific antigen. These results suggest that the demonstration of either 8- or 116-kDa antigen(s) in free or immune-complex form could confirm the diagnosis of hydatidosis.


Evaluation of a recombinant antigen ELISA for the diagnosis of acute toxoplasmosis and comparison with traditional antigen ELISAs. An evaluation of five ELISA methods for the diagnosis of acute toxoplasmosis was undertaken by comparing a laboratory-produced ELISA employing two recombinant Toxoplasma gondii polypeptides as antigen with a laboratory-produced ELISA and three commercially available ELISAs employing traditional parasite antigen preparations derived from whole tachyzoites. With a panel of 75 sera from patients who showed either serological and clinical evidence of acute toxoplasmosis, or of diseases caused by other infectious agents, or from patients who showed no evidence of infectious disease, the ELISAs gave overall positive predictive values of 81.6-100%, negative predictive values of 87.8-100%, sensitivities of 81.3-100%, and specificities of 83.7-100%. No two ELISAs gave identical results with all sera tested. In total, the ELISA based on the two recombinant T. gondii polypeptides appeared to be the most specific ELISA in this comparison, showing positive predictive values and specificities of 100% for all groups of patients tested. The overall negative predictive value for this ELISA was 87.8% and the sensitivity was 81.3%. Therefore, the ELISA based on recombinant antigen appears to be a promising advance in the serological diagnosis of acute toxoplasmosis.


The clinical comparison of Oxoid Signal with Bactec blood culture systems for the detection of streptococcal and anaerobic bacteraemias. Blood cultures were taken from 47 patients 1-2 min after dental extraction. These samples were tested by the radiometric Bactec 460 and Oxoid Signal systems for the detection of streptococcal and anaerobic bacteraemias. Streptococci were isolated from 19 (40%) patients and anaerobes from 15 (32%). In this study the Oxoid Signal system was significantly better for isolating oral anaerobes than the Bactec system; five isolates were obtained with the Bactec system and 14 with the Signal system. There was no significant difference in the isolation of streptococci between these two systems (Bactec 14, Oxoid Signal 10). The contamination rate was 4.1% for Bactec and 7.5% for the Oxoid Signal system.


Identification of surface-exposed Yersinia pestis proteins by radio-iodination and biotinylation. When whole cells (stationary phase) of Yersinia pestis strain EV76 were radiolabelled with Iodogen and 131I, 16 major and 10 minor surface-exposed outer membrane proteins (OMPs) were identified. Labelling with N-hydroxysuccinimidyl 6-biotinylamino-hexanoate (biotin X-NHS) resulted in a complex protein profile detectable after blotting and developing with peroxidase-conjugated avidin. Y. pestis cell fractionation revealed that biotin X-NHS labelled not only OMPs but also proteins of inner cell compartments. Therefore, radiolabelling was the more reliable technique for identifying the OMPs of Y. pestis.


Acute urinary retention due to a free-standing broad ligament leiomyoma. A 38-year-old woman who had used oral contraceptives continuously since age 22 presented with acute urinary retention. Physical examination revealed a bladder outlet obstruction due to a large paravaginal/broad ligament mass. Magnetic resonance imaging (MRI) demonstrated that the mass was separate from the uterus which was confirmed at surgery when an isolated free-standing leiomyoma was removed.


Evaluation of mammographic stellate lesions. Breast masses can be classified into circumscribed masses and stellate masses. Stellate masses are more difficult to detect but are easier to analyze. Good technique, proper processing, proper viewing conditions, and critical comparison of right vs. left and current vs. old can aid in the detection of stellate masses. Once detected, analysis is straightforward. Most will be scirrhous carcinomas. A few will be radial scars, traumatic fat necrosis, or rare benign lesions. Additional signs such as architectural distortion and microcalcifications can be very important. Additional views, including spot compression films, may be decisive. Not all stellate lesions are malignant, but most will require biopsy. Traumatic fat necrosis may be differentiated on the basis of history or radiographic appearance and does not need intervention. Lesions suspicious for carcinoma and radial scars should be excised and examined histologically.


Herbicides and cancer.

Herbicides and cancer. Herbicides are a heterogeneous class of chemicals used in agriculture, forestry, and urban settings to kill weeds, shrubs, and broad-leaved trees. The role of herbicides in the etiology of cancer is controversial. Potential studies for review were identified through a MEDLINE search and from a check of references in related review articles. This review of the literature shows reasonable evidence suggesting that occupational exposure to phenoxy herbicides results in increased risk of developing non-Hodgkin's lymphoma. Several studies have noted large increases in risk of soft-tissue sarcomas with phenoxy herbicide exposure. In contrast, others have failed to observe increased risks, and evidence of an exposure-risk relationship is lacking. Although there have been too few appropriate studies for adequate assessment of risk of cancer at other sites, some findings have linked herbicide exposure with cancers of the colon, lung, nose, prostate, and ovary as well as to leukemia and multiple myeloma. Future studies must better identify and quantify the nature of herbicide exposures. In the interim, it seems only prudent to monitor and promote safety practices among persons occupationally exposed to phenoxy herbicides, particularly farmers and professional sprayers.


Natural killer (NK) cell lytic dysfunction and putative NK cell receptor expression abnormality in members of a family with chromosome 3p-linked von Hippel-Lindau disease. BACKGROUND. Using antibodies to a putative natural killer (NK) cell receptor (pNKR), we recently cloned a novel cDNA and localized this gene to the short arm of human chromosome 3, region 3p21-3p24. Individuals susceptible to or clinically manifesting von Hippel-Lindau disease (VHL) have a genetic defect telomeric to this region on chromosome 3. This defect, resulting in VHL, is manifested by a high incidence of certain tumors. Based on the location of this gene, we sought to determine if VHL patients have a defect in gene expression of pNKR. Because of the proximity of the VHL and pNKR genetic regions, the variable expression of VHL tumors, and the ability of NK cells to target tumor cells, we investigated NK cell activity and other aspects of the immunologic status in 40 members (four branches) of a family with a high incidence of VHL tumors. Individuals affected with VHL and lacking in normal surface expression of pNKR had virtually no NK cell lytic activity. Analysis of genotypes and phenotypes of all subjects revealed that the greatest difference in NK cell lytic activity (P = .0002) was seen when family members exhibited both VHL and pNKR surface expression defects, compared with normal relatives who had neither defect. Furthermore, the lack of NK cell activity strongly correlated (P = .0005) with abnormal pNKR protein surface expression. Of particular interest, individuals who lacked NK cell activity had normal numbers of NK cells. In addition, analysis of leukocyte subsets indicated normal numbers of T and B cells, monocytes, and NK cells in both affected and normal individuals. These data indicate that although all affected individuals have the cell population responsible for NK cell activity, many have cells low in expression of pNKR and lack functional NK cell activity. Overall, these results indicate that, in addition to a predisposition to the development of neoplasms, VHL patients have a defect in a specific mechanism of natural immunosurveillance that correlates with a defect in expression of a novel large granular lymphocyte pNKR protein.


Cancer incidence and mortality in workers exposed to fluoride. Although a recent bioassay showed increased frequency of bone cancer in rats with high oral intake of fluoride, the data are reported as equivocal evidence of carcinogenicity. In humans, occupational fluoride exposure may cause skeletal fluorosis, and our earlier follow-up of fluoride-exposed workers showed increased incidence of respiratory cancers. To further evaluate occupational fluoride exposure as a carcinogenic risk factor, we extended by approximately one decade the follow-up of a cohort of 425 men and 97 women employed for at least 6 months in the period 1924-1961 at the Copenhagen cryolite processing plant. Cryolite ore contains about 50% fluoride. Cancer mortality was determined for the period 1941-1989, and incidence for 1943-1987. For comparison, we used national mortality rates and cancer incidence rates for the Copenhagen area. Among the men, 300 deaths occurred; 223 were expected. Respiratory (lung and laryngeal) cancers and violent death were responsible for most of this excess; rates for mortality from cardiovascular disease were close to the rates expected. Of the 423 male workers, 119 developed cancers; 103.6 were expected. There was excess incidence of cancers of the lungs (35 men; standard incidence ratio [SIR] = 1.35), larynx (5 men; SIR = 2.29), and urinary bladder (17 men; SIR = 1.84). Maximum incidence occurred after 10-19 years of employment, but otherwise, no stable relationship between cancer incidence and duration of employment was observed. The incidence of respiratory and urinary cancers was particularly high in men less than 35 years old at first employment. Cancers in female workers were too few to allow detailed evaluation. The increased incidence of respiratory cancers suggests that cigarette smoking was frequent in this cohort, despite the unremarkable cardiovascular mortality, but the disproportionate increase in the incidence of bladder cancer is difficult to explain by smoking habits alone. Because this industrial cohort was exposed to high concentrations of fluoride dust, heavy respiratory exposure to fluoride may have contributed to the increased cancer risk. If these workers inhaled a carcinogenic substance partly excreted in the urine, an increased incidence of respiratory and bladder cancers would not be inconceivable. The potential role of fluoride as a cause of bladder cancer needs to be explored.


Growth inhibition of estrogen-dependent and estrogen-independent MXT mammary cancers in mice by the bombesin and gastrin-releasing peptide antagonist RC-3095. Many breast cancers are estrogen independent, and even in patients who initially respond to estrogen suppression therapy, the regression is often temporary. We have recently shown that antagonists of bombesin and gastrin-releasing peptide, including RC-3095, inhibit the growth of pancreatic, colonic, and prostatic cancers in experimental animals. This effect was associated with a substantial decrease in epidermal growth factor (EGF) receptor levels in pancreatic and colon cancers. In view of these findings, we investigated the effects of our synthetic bombesin and gastrin-releasing peptide receptor antagonist D-Tpi6,Leu13 psi (CH2NH)-Leu14 bombesin(6-14) (RC-3095) on the growth of hormone-dependent and hormone-independent MXT mouse mammary cancers in vivo. Female (C57BL x DBA/2)F1 mice bearing estrogen-dependent or estrogen-independent MXT mammary carcinomas were treated with small doses (20 micrograms/d) of RC-3095 administered from osmotic minipumps. Separate groups of mice with estrogen-independent tumors received RC-3095, bombesin, or gastrin-releasing peptide(14-27) at 20 micrograms/d. We determined tumor volume and weight, mitotic index, apoptosis (programmed cell death), and argyrophilic nucleolar organizer regions, an indicator of tumor cell proliferation. Levels of receptors for EGF and bombesin were measured in tumor membrane fractions. Growth of both estrogen-dependent and estrogen-independent MXT breast cancers was significantly inhibited by RC-3095. Bombesin or gastrin-releasing peptide had no effect on the growth of estrogen-independent tumors. Inhibition of tumor cell proliferation was indicated by a 45%-65% reduction in tumor volume, a 35%-58% reduction in tumor weight, and statistically significant decreases in argyrophilic nucleolar organizer region counts after treatment with RC-3095. In estrogen-independent cancers, tumor inhibition was associated with a decrease in the capacity of EGF receptors from 0.21 +/- 0.016 pmol/mg membrane protein in controls to 0.03 +/- 0.003 pmol/mg membrane protein in the RC-3095-treated group. This is the first demonstration of inhibitory effects of bombesin and gastrin-releasing peptide antagonists on the growth of breast cancers in vivo. These findings suggest that bombesin antagonists should be considered for breast cancer therapy.


Karyotypic derivation of H9 cell line expressing human immunodeficiency virus susceptibility. The T-cell lymphoma HUT78 cell line and the H9 clone of the CD4-positive HT cell line, derived from HUT78, are known to be genetically identical on the basis of allozyme (allelic isozyme) patterns and DNA fingerprinting, but the chromosome compositions of these cell lines have not been determined. The HT cell line and its H9 clone carry susceptibility to the human immunodeficiency virus (HIV). The purpose of this study was to examine specific chromosome changes linking the expression of the HIV susceptibility that is unique to H9 cells by characterizing the karyotypes of the HUT78 and the H9 cell lines, by comparing chromosome differences between these lines, and by evaluating the relationships between them. Air-dried chromosome slides were prepared, and the fast Giemsa-trypsin method was used to delineate G-bands. The numerical distribution of chromosomes from the two cell lines was determined, and complete chromosome analysis in 47 HUT78 metaphases and 21 H9 metaphases with discernible G-banding was used to specify the modal karyotypes of each cell line. Both cell lines had complex karyotypes that contained 47%-65% structurally modified marker chromosomes. The distribution of numbers of chromosomes in HUT78 cultures was broad. There were two distinct modal numbers of chromosomes at 42 and 43 and at 73, resulting from the presence of three actively growing sublines: two hypodiploid (1s) sublines (HUT78/1sA and HUT78/1sB) and a hypertriploid (2s) subline (HUT78/2s), respectively. HUT78/1sA and HUT78/1sB differed by five reciprocal chromosome replacements, and HUT78/2s had double copies of most of the chromosomes in 1s cells. H9 and HUT78/2s had had 21 matching markers, 10 of which were paired; contained 21 chromosomes with the same number of copies; consistently lacked eight homologous normal chromosomes; and showed close modal numbers of chromosomes at 69 and 73, respectively. Derivation of the 2s subline from the 1s subline by polyploidization is apparent. All lines apparently had the same progenitor cell population, and HUT78/2s represents an intermediate linking HUT78/1s to H9. These data should be useful for studying specific chromosome changes linking the expression of the HIV susceptibility unique to H9 cells. Karyologic studies such as those presented here can provide data (a) to clearly identify the clonal cell population of a subline, (b) to examine relationships among sublines of the same progenitor, and (c) to provide a clue that may link a subtle chromosome change to a phenotypic expression.


Analysis of prehospital delay among inner-city patients with symptoms of myocardial infarction: implications for therapeutic intervention. In this study, we analyzed the duration and determinants of prehospital delay in a group of inner-city patients hospitalized with suspected myocardial infarction. The average prehospital delay was 11.9 +/- 25.1 hours. Mean and median delays were similar for males (mean: 10.9 +/- 24.2 hours; median: 2.8 hours) and females (mean: 12.7 +/- 25.7 hours; median: 3.5 hours), but were longer for blacks (mean: 13.1 +/- 27.5 hours, P < .001; median: 3 hours, P = .06) and Hispanics (mean: 12.4 +/- 19.3 hours, P < .01; median: 4 hours, P = .07) than for whites (mean: 3.3 +/- 2.9 hours; median: 2 hours). Most of the observed delay was due to the time it took for patients to decide to seek medical care following onset of symptoms. Patients were more likely to arrive at the hospital within 4 hours if they thought their symptoms might be a heart attack (79% versus 41%, P < .01), if they believed that coronary heart disease was preventable (68% versus 42%, P < .01), and if they took an ambulance to the hospital (68% versus 47%, P < .01). The factor most strongly associated with early hospital arrival was the patient's belief that the symptoms might represent a heart attack; these patients were five times more likely to get to the hospital within 4 hours than others, independent of other factors. Interventions designed to decrease prehospital delay must focus not only on improving knowledge of symptoms, but also on identifying high-risk patients and increasing patient awareness of the benefits of early response and treatment.


Leukoedema: a review of the literature.

Leukoedema: a review of the literature. Leukoedema, a grayish-white lesion of the oral mucosa in humans, was once thought to be a probable precursor to leukoplakia. Clinical examination differentiates leukoedema from leukoplakia, lichen planus, white sponge nevus, and pathomimia morsicatio buccarum. Prevalence rates vary greatly in different countries and in different ethnic groups. For many years, leukoedema was alleged to occur only in adult populations until Martin and Crump found this lesion in children and youth. There is a definite predilection for this lesion in black Americans. Although the etiology is unknown, it has been suggested that leukoedema develops in areas of local irritation. This article reviews the literature related to the prevalence of leukoedema and correlates the independent findings, which might pertain to its etiology.


Pitfalls in communication with Hispanic and African-American patients: do translators help or harm? The Martin Luther King County General Hospital, Los Angeles, California, provides services for an equal number of Hispanics (most are recent immigrants from Mexico) and African Americans who have lived in the community since before the Watts riot in 1965. The hospital is staffed by a large percentage of foreign-trained doctors and other personnel who speak some English, but suffer from a lack of understanding of the Hispanic as well as the African-American patients. Very few trained interpreters are provided for the Spanish-speaking population, and no interpreters are provided for African Americans. A 100-question survey on common African-American expressions was conducted in the Department of Family Medicine, as well as an opinion poll to determine if adequate understanding existed between patients and providers. The data revealed that native African-American providers understood significantly more African-American expressions than foreign, white, and Hispanic providers. The opinion poll also revealed inadequate translation of medical complaints from patients through interpreters. In addition, the poll found that diagnoses and instructions were not adequately related to the patients. Furthermore, it was felt that trained interpreters should be provided for all patients who presented communication problems.


Paratesticular liposarcoma: a report of two cases and review of the literature. Paratesticular liposarcoma is extremely rare. Only 41 cases have been reported in the literature. This article reports two cases, reviews the literature, discusses the pathology, and proposes the use of combined surgery and radiation therapy in selected cases.


Musculoskeletal trauma: the baseball bat. Between July 1987 and December 1990 in Washington, DC, 116 patients sustained 146 fractures and seven dislocations due to an assault with a baseball bat. The ulna was the most common site of trauma (61 fractures), followed by the hand (27 injuries) and the radius (14 injuries). Forty-two of the 146 fractures were significantly displaced and required open reduction and internal fixation to restore satisfactory alignment. Twenty-nine of the 146 fractures were open fractures. Treatment protocol for open fractures consisted of irrigation and debridement, antibiotic therapy, and bone stabilization with either internal or external fixation, or casting. Recognition of the severity of the soft tissue and bone damage is important in the management of musculoskeletal trauma secondary to the baseball bat.


Time-related effects of heparin sulfate on regional and systemic anticoagulation. Optimal timing of vascular clamping to anticoagulation during cardiovascular surgical procedures is poorly defined. This study uses a canine model to determine the effectiveness of three different methods of heparin administration. Heparin sulfate (150 IU/kg) was administered by: injection into the jugular vein 5 minutes before infrarenal aortic clamping (Group 1), injection into the terminal aorta immediately after infrarenal aortic clamping (Group 2), and injection into the jugular vein immediately after infrarenal aortic clamping (Group 3). Thrombin clotting times and partial thromboplastin times were measured in venous blood from the upper and lower extremities before (baseline) heparin administration, and 1, 3, and 5 minutes following heparin administration. Activated clotting times were assessed in lower extremity blood at baseline, and at 1 and 5 minutes after heparin injection. Significant differences existed between groups in both upper and lower extremities. Systemic anticoagulation occurred within 1 minute after intravenous heparin administration in Groups 1 and 2 in the lower extremity, and Groups 1 and 3 in the upper extremity. Delayed anticoagulation in the lower extremity was noted with systemic injection after aortic clamping in Group 3, and after regional intra-aortic administration in the upper extremity of Group 2 subjects. Complete anticoagulation was noted by 5 minutes in all groups in both the upper and lower extremities. These results suggest that the safe time period between heparin administration and vascular clamping varies with the route and the timing of its administration. Intravenous administration prior to aortic cross-clamping provided adequate anticoagulation in this canine model in both the upper and lower extremity blood after 1 minute of heparin circulation.(ABSTRACT TRUNCATED AT 250 WORDS)


Neuroleptic malignant syndrome.

Neuroleptic malignant syndrome. Neuroleptic malignant syndrome is a life-threatening reaction of neuroleptic medication. The estimated incidence rate of neuroleptic malignant syndrome is between 1% and 1.5% of patients treated with neuroleptics. The reported mortality rate varies from 11% to 38%. Risk factors include younger males (80% less than 40 years) and physical disability. Although 80% of neuroleptic malignant syndrome cases develop within the first 2 weeks of treatment, the syndrome can develop anytime during the therapy period. The clinical picture and laboratory findings are not always unique. Less than 50% of cases manifest with classical symptoms. Deaths usually result from cardiovascular collapse. Renal failure, pulmonary emboli, aspiration pneumonia, and respiratory failure are also reported. Familiarity with the syndrome, baseline laboratory values including creatine phosphokinase, lactate dehydrogenase, serum glutamicoxaloacetic transaminase, and complete blood cell count with a differential count, and a high index of suspicion are of the utmost importance in making the diagnosis of neuroleptic malignant syndrome. A judicial choice of neuroleptic medication and careful observation of patients may reduce the incidence, morbidity, and mortality of neuroleptic malignant syndrome.


Injuries to the bowel and bladder.

Injuries to the bowel and bladder. The initial challenge facing the traumatologist in the management of bowel and bladder injuries is prompt diagnosis. Intestinal perforations following penetrating trauma are caused by direct penetration or by blast effect, and are most commonly diagnosed by physical examination (signs of peritoneal irritation) or peritoneal lavage. Bowel rupture from blunt trauma is more difficult to diagnose and results from different mechanisms of injury including crushing between the spinal column and the offending blunt object, shearing of the bowel and mesentery at fixed points from sudden deceleration, and rupture secondary to sudden increase in intra-abdominal pressure. Bladder rupture is most commonly seen in association with pelvic fractures, and the diagnosis is made by a well-performed cystogram. This article presents essentials for diagnosis and therapeutic strategies.


Fused pelvic kidneys: case report.

Fused pelvic kidneys: case report. A case of fused pelvic kidneys is presented. We believe this to be the first report using ultrasound, computed tomography, and magnetic resonance imaging for presentation of a rare anatomic renal anomaly.


Decision tree for the management of substance-abusing psychiatric patients. This paper describes a short-term approach developed at a time of numerous drug-related incidents occurring at a large VA Hospital to help staff manage psychiatric patients abusing alcohol or drugs during hospitalization. This was accomplished through the development of a decision tree designed to improve the clinical problem-solving process by identifying key decision points. Prior to this, staff responded emotionally either by prematurely discharging patients or by not recognizing the problem at all. Decision Trees have widespread applicability for resolving complex clinical problems.


Therapist techniques used during the cognitive therapy of opiate-dependent patients. A review of current substance abuse literature indicates that although clinicians espouse cognitive and behavioral methods in the treatment of drug-dependent patients, little is known about the process of cognitive-behavioral therapy with these individuals. Our objective is to examine the specific techniques used by manual-guided cognitive-behavioral therapists during the treatment of opiate-dependent patients. Ratings of audiotaped sessions using the Collaborative Study Psychotherapy Rating Scale indicate that the cognitive-behavioral therapists did not rely on behavioral methods early in treatment as predicted by both theory and the clinical literature. Cognitive techniques and techniques oriented toward establishing a collaborative structure predominated and increased from early- to late-in-treatment sessions. We discuss the implications of the results in terms of treatment manual revisions and directions for future research.


Psychological treatment of anabolic-androgenic steroid-dependent individuals. Anabolic-androgenic steroids (AAS) are synthetic derivatives of the sex hormone testosterone. Anabolic refers to the "growth-promoting" effect while androgenic refers to the "masculinizing" effect. It is becoming more evident that nonathletes as well as athletes are abusing AAS. Although the abuse of alcohol and other drugs contribute significantly to current chemical use problems in American society, AAS abuse is one of the fastest growing "new drug" problems facing secondary and higher education institutes of learning. The purpose of this discussion is to present working hypotheses regarding the psychological treatment of AAS dependent individuals. The treatment approach presented incorporates the approaches used with eating disorders, substance abuse/dependence, and narcissistic personality disorders. This paper considers some of the preliminary considerations for the first phase of treatment, some pitfalls to avoid, and therapist characteristics, as well as treatment modalities that might be helpful in the treatment of AAS-dependent individuals.


Safe sex behavior in drug-addicted males as a function of object relations. An inventory of sexual behavior was administered in a hospital detoxification program to 127 drug-addicted males, who also completed a modified form of the Defense Mechanisms Inventory (DMI) which yields a measure of object relations. Condom use was shown to be related to an object relations mode that typifies the individual who can structure reality and needs without requiring an integral aspect of "the other" in his approach. Standardization and factor analytic data are also presented for the DMI and the object relations measure for this population. The resulting pattern and the small effect size are discussed within the reality constraints of the addicted patient, as well as within the psychometric parameters inherent in psychoanalytic research.


Assessing drug abusers with the Millon Clinical Multiaxial Inventory: a review. This paper reviews studies that used the Millon Clinical Multiaxial Inventory with drug abusers. Although the test has been used with over 2000 such patients in the published literature, there is still a dearth of basic research with the MCMI with this population. Preliminary evidence suggests that the Personality Disorder Scales are quite useful to assess personality styles of drug abusers, but the Clinical Syndrome Scales present some problems. Specifically, the Drug Dependence Scale has had difficulty in reliably "detecting" drug addicted individuals who were in treatment for drug abuse. However, a reliable modal MCMI profile among this population seems to exist, although cluster research suggests several subtypes, each with different personality styles. MCMI computer-narrative reports may overdiagnose paranoid disorder and under diagnose antisocial disorders among this population.


Pathogenesis and ecology: the case of cholera. The way in which the results of various studies of cholera have influenced the understanding of the disease are discussed. Attention is given to the outcomes of medical research, targeted on problems of cholera and biological research focused on understanding Vibrio cholerae. The contrast between these approaches has produced a new understanding of the ecological nature of disease. The importance of the environmental reservoir of V. cholerae as the engine for the generation of diversity is highlighted.


The EPI in Borno State, Nigeria: impact on routine disease notifications and hospital admissions. An earlier report on the Nigerian expanded programme on immunization (EPI), covering 1974-1988, failed to demonstrate a clear-cut impact of the programme. This report attempts to determine the effectiveness of EPI in Borno State, Nigeria. We analysed trends in routine notifications for diphtheria, pertussis, tetanus, tuberculosis, measles, and pneumonia, from 1985 to 1991; data on poliomyelitis were excluded because of poor documentation, while we included data on pneumonia for comparison. We also performed a before (1983-1987) after (1988-1991) comparison in terms of the intensifications of EPI by age-specific strata amongst paediatric hospitalization for all EPI diseases at the University of Maiduguri Teaching Hospital, the sole referral hospital for childhood infectious diseases. Our results show an apparent reduction in morbidity from diphtheria, pertussis, tetanus, measles and pneumonia, and this was particularly prominent following intense vaccinations between 1988 and 1991. The reduction in these EPI diseases and pneumonia occurred despite the prevailing adverse socioeconomic conditions, and the absence of a specific control strategy for pneumonia in Nigeria. On the other hand, in spite of national BCG coverage of about 90% there has been a recent (1989-1991) increase in the registered cases of tuberculosis in infants and older children in Borno State. There is a need to intensify other intervention measures alongside EPI activities.


The effect of malaria on work time: analysis of data from two Nepali districts. Malaria patients' loss of effective work time can account for an important proportion of the disease's economic cost. Here the extent, incidence and determinants of this loss are investigated. Data from 695 matched patient-control pairs from Nawal Parasi and Dhanusa districts in Nepal are analysed. Pairwise differences in work time are attributed to malaria, and the individual influences of the differences' determinants identified by regression. The mean pairwise differences in the number of days wholly and partially disabled by illness in the month preceding interview were respectively 5.31 (95% confidence interval 4.82-5.79) and 1.21 days (95% CI 0.95-1.47). The interval between fever onset and presumptive treatment, parasite species, the density of peripheral parasitaemia and district of residence each exerted significant influences over the difference in complete disability. The mean pairwise difference in the number of minutes worked on the day before the interview was 108 (95% CI 97-120). Socioeconomic variables, the interval between interview and perceived complete recovery, the pairwise difference in the number of days' complete disability in the month preceding interview and district of residence were significant to this difference. Poorer patients lose more time. The results corroborate past assumptions of debility, demonstrate that malaria's effect on effective work time may vary between socioeconomic groups, and underline the economic importance of speedy case detection and presumptive treatment.


Schistosoma mansoni: cercaricidal effects of cedarwood oil and various of its components. Cercariae of Schistosoma mansoni exposed to cedarwood oil show early phases of the penetration response before they succumb to the toxic effects of the oil. The toxic effect is also seen when cercariae are exposed to certain components of the oil followed by exposure to a known penetration stimulant, linolenic acid, which accelerates the inactivation of the organism. It is postulated that the process of penetration which results in the disruption of the cercarial glycocalyx alters physiological processes related to osmoregulation. This may increase the absorption of the toxic substances in cedarwood oil by the organisms.


Antibacterial agents for wounds and burns in the developing world. Report on a workshop. Publications on the use of antibacterial agents for wounds and burns in the developing world continue to emphasize the value of antiseptics such as Eusol and gentian violet. In the developed world these agents have been mostly discredited. A workshop organized by the European Society for Tissue Repair concluded that clearer instructions about the role of antibacterial agents in the management of wounds and burns could clarify appropriate usage. The report considers the factors contributing to infection and rationalizes the use of disinfectants, antiseptics and antibiotics, especially in the developing world.


The impact of Schistosoma haematobium infection and of praziquantel treatment on the growth of primary school children in Bertoua, Cameroon. Our objective was to determine in a Cameroonian school population the effect of mild to moderate S. haematobium infection intensity on growth and development of children before and 6 months after praziquantel treatment. Previous studies have yielded contradictory results. Children from Bertoua schools were divided into four study groups: heavily infected (> 500 eggs 10 ml-1), moderately infected (1-499 eggs 10 ml-1) treated with praziquantel, a similar group treated with placebo, and an uninfected control group. Anthropometric measures--height for age per cent median (HAPM), and weight for age per cent median (WAPM)--were significantly higher among the uninfected children. Stepwise regression analysis showed that S. haematobium and Ascaris infections were the strongest predictors of the HAPM with hookworm and malaria infections playing a lesser role. Post treatment comparison of the praziquantel treatment group and the placebo group showed no significant differences for the anthropometric indicators except for mid-arm circumference. Longer observations of growth after treatment as well as monitoring of the rate of reinfection would be necessary to understand better the effect of S. haematobium on growth.


Cervical lymphadenopathy in Khartoum.

Cervical lymphadenopathy in Khartoum. In this prospective study, 92 patients with cervical lymphadenopathy presenting at Khartoum Teaching Hospital were studied. The commonest cause was found to be tuberculous cervical lymphadenitis (TCA) comprising 49%, followed by malignancy (35%) including both primary neoplasm (15 cases) and metastatic lesions (17 cases). The tuberculous group were young patients mainly from low socioeconomic classes. The most affected nodes were in the posterior triangle, followed by upper jugular and supraclavicular nodes. In the malignant group, half the patients had primary reticulo-endothelial neoplasm and the other half had metastatic tumours, most often from the nasopharynx. The triad of symptoms of fever, fatigue and loss of weight was found equally in tuberculous and lymphoma patients. Hence empirical use of antituberculous therapy without histological diagnosis resulted in delay in diagnosis of malignancy. Antituberculous therapy should be preceded by histological proof wherever possible.


The effect of plastering in a house persistently infested with Triatoma infestans (Klug) 1934. The replastering of a house in Mambai-Goias, Brazil, as a measure to wall-in Triatoma infestans, is briefly described. Unfortunately, because the houseowner would not cooperate the roof tiles were not improved and eventually T. infestans reappeared at this site. A brief discussion follows of some aspects of house improvement in the vigilance phase of a Chagas Disease Control Programme. T. infestans appeared in the house described 51 and 258 days after the replastering.


Detection of rifampicin-induced nephrotoxicity by N-acetyl-3-D-glucosaminidase activity. The objective of the present study was to assess renal damage, if any, by non-invasive technique, viz NAG activity in urine and GFR in patients on continuous and intermittent rifampicin therapy. Eighty-four tuberculosis patients for cross-sectional study and six subjects for longitudinal study on antitubercular therapy and ten patients on withdrawal of rifampicin participated in the investigation; 13 leprosy patients intermittently treated with rifampicin were also included. Twenty-seven normal subjects served as controls. Rifampicin on continuous use resulted in a progressive increase in enzymuria with no change in GFR. An additive toxic effect was obvious in patients receiving streptomycin; when the treatment was withdrawn the urinary NAG activity stabilized within 15-21 days. However, patients receiving rifampicin intermittently did not show any evidence of renal damage. The results suggest that there is a need for monitoring renal damage, particularly on antitubercular therapy, when nephrotoxic agents are administered together.


Locally acquired cutaneous leishmaniasis in Sri Lanka. Cutaneous leishmaniasis in a Sri Lankan, who had not left the country, is reported. The diagnosis was confirmed by detecting the parasite in smears under microscopic examination. This is the first case report of locally acquired leishmaniasis in Sri Lanka.


Magnetic resonance angiography of peripheral runoff vessels. Recent improvements in magnetic resonance imaging techniques have made magnetic resonance angiography (MRA) a very useful adjunct to invasive angiography. Fifty-five limbs in 51 patients with occlusive peripheral vascular disease were studied with both MRA and contrast arteriography. The magnetic resonance and contrast arteriograms were read by radiologists and surgeons and separate interventional plans were based on each study. The MRA findings differed significantly from those of conventional arteriography in 26 limbs (48%). In every case MRA visualized all of the same vessels and hemodynamic stenoses seen on the contrast arteriogram. In 48% of the cases, however, MRA revealed additional findings. Thus the discrepancies in the two studies were always the result of the failure of the arteriogram to reveal all of the patent vessels seen on MRA. The additional information provided by MRA resulted in alteration of the interventional plan in 11 cases (22%). In nine cases (18%) target vessels suitable for use in a limb-salvage procedure were identified by MRA, although they had been missed by conventional arteriography. In all of these cases, intraoperative arteriograms confirmed the suitability of these vessels for use in technically successful bypass procedures. In two cases (4%) additional information provided by MRA identified a target runoff vessel for bypass grafting that proved to be a better alternative than the one that would have been chosen on the basis of contrast arteriography.(ABSTRACT TRUNCATED AT 250 WORDS)


Polytetrafluoroethylene versus human umbilical vein in above-knee femoropopliteal bypass: six-year results of a randomized clinical trial. In a prospective, randomized trial 6 mm polytetrafluoroethylene (PTFE) and 6 mm human umbilical vein (HUV) were compared in above-knee femoropopliteal bypass grafting. In claudicants a prosthetic graft was used intentionally, in limb-salvage cases only when autologous vein was insufficient. Ninety-six extremities were randomized (49 PTFE and 47 HUV). Operative indication was disabling claudication in 77 and limb salvage in 19 extremities. The two groups were comparable as to preoperative risk factors and operative and postoperative treatment. Median follow-up was 76 months (range 47 to 91 months), during which 23 patients died of nonrelated causes with functioning grafts. Thirty-eight grafts failed (33 because of occlusion and five for other reasons). At 6 years the primary patency rate was 38.7% in the PTFE group and 71.4% in the HUV group (p < 0.001). Corresponding rates for secondary patency at 6 years were 51.4% and 76.4% (p < 0.005).


Transfusion guidelines for cardiovascular surgery: lessons learned from operations in Jehovah's Witnesses. Patients undergoing cardiovascular surgery are among the top users of homologous blood transfusion (HBT). Awareness of the risks of disease transmission and immune system modulation from HBT has prompted us to find alternatives such as autologous predonation (APD) and intraoperative autotransfusion (IAT). However, these latter options are not appropriate for all patients. We reviewed our experience with 59 Jehovah's Witness patients who underwent 63 elective cardiovascular procedures without either HBT or APD to determine the safety of operation without these modalities and to develop revised maximum surgical blood-ordering schedule guidelines for cardiovascular surgery. Estimated blood loss averaged 870 ml, but one third to one half of losses were replaced by IAT. IAT was not needed in lower extremity bypass operations in which the estimated blood loss was less than 150 ml. Three of 59 patients died (5.1%), but only one died of operative bleeding complications. We conclude that (1) elective cardiovascular operations can be done safely without the use of either HBT or APD, (2) HBT is not necessary in leg bypass procedures, and (3) maximum surgical blood-ordering schedule guidelines for HBT in major cardiovascular operations can be reduced to near zero by the use of intraoperative autotransfusion and acceptance of a postoperative hemoglobin nadir of 7.0 gm/dl.


Treatment of iatrogenic femoral artery injuries with ultrasound-guided compression. Iatrogenic injuries of the groin are becoming more common after increasingly sophisticated vascular intervention. These injuries are accurately detected by duplex and color Doppler ultrasonography. Recent treatment of these lesions by ultrasound-guided compression repair (UGCR) has been described. During a 1-year period we identified 18 femoral artery injuries, including 17 pseudoaneurysms and one arteriovenous fistula. Three of the pseudoaneurysms thrombosed spontaneously before attempted treatment. The remaining 15 lesions underwent a trial of UGCR. Successful closure was accomplished in 10 patients (56%). Seven of these lesions were successfully treated during the initial session, and thrombosis was accomplished after repeat compression in three additional lesions. Three patients who were given anticoagulants had a failed UGCR, but their pseudoaneurysms thrombosed after administration of anticoagulants was discontinued. Two patients had failed UGCR and required operation. Seven (88%) of eight patients who were not given anticoagulants were successfully treated. In contrast only two (29%) of seven patients given therapeutic doses of anticoagulant medication were successfully treated by the technique. There was no statistical difference between mean pseudoaneurysm diameter, mean width and length of pseudoaneurysm neck, or depth of pseudoaneurysm neck from skin surface in patients in whom successful initial closure was achieved when compared with those patients in whom the initial attempt failed. UGCR is a safe, simple, noninvasive technique that can be used to treat many femoral artery injuries that traditionally were treated with surgery. The technique can be applied by any laboratory that has the necessary ultrasonography equipment and is currently the method of choice for treating uncomplicated iatrogenic femoral artery injuries at our institution.


Iliofemoral versus femorofemoral bypass: the case for an individualized approach. The treatment of unilateral iliac occlusion remains controversial. We report our experience with femorofemoral bypass (FF) and iliofemoral bypass (IF). One hundred sixty-two FFs and 82 IFs were performed during a 25-year period. Demographic characteristics of the two groups were similar. Operative indications included claudication in 32.1% of FFs and 19.5% of IFs, rest pain in 26.5% of FFs and 36.6% of IFs, ulcer in 8.0% of FFs and 3.7% of IFs, gangrene 13.6% of FFs and 23.2% of IFs, and acute thrombosis in 13.0% of FFs and 3.7% of IFs. Five-year primary and secondary patency rates for all FFs were 56.9% and 65.4% respectively. Those for all IFs were 74.9% and 79.2%. The primary patency rate of FF performed for chronic arterial occlusive disease was 73.3% at 3 years and 60.4% at 5 years and for IF it was 73.4% at 3 years. In the absence of prior arterial surgery in the groin, the primary patency rates of bypasses for chronic arterial occlusive disease were 78.3% for FF and 86.8% for IF at 4 years. Distal endarterectomy and acute ischemia adversely affected patency. The operative mortality rate was 6.2% for FF and 3.7% for IF. Eleven wound complications occurred in the FF group. Seven patients underwent graft removal without limb loss. One minor wound problem occurred in the IF group. Iliofemoral bypass avoids operation on an asymptomatic limb; FF avoids entry in the abdomen or retroperitoneum and can be performed under local anesthesia. In patients in whom either IF or FF is applicable, the choice between these two procedures should be individualized with these factors in mind.


Aneurysmal change at or above the proximal anastomosis after infrarenal aortic grafting. We conducted a retrospective review of all patients undergoing repair of abdominal aortic aneurysm at or above the proximal anastomosis of a previous infrarenal aortic graft between 1986 and 1991. Infected grafts and patients with suprarenal aneurysms present at the time of the original graft were excluded. Twenty-one patients, 19 men and two women, were included. The original indication for surgery was aneurysm in 14 patients and occlusive disease in seven; the mean interval from initial surgery to presentation was 10 years (range, 3 to 23 years). Twelve lesions were anastomotic false aneurysms, and nine were true aneurysms beginning in the proximal juxta-anastomotic aorta. Fourteen patients had an asymptomatic abdominal mass. Seven patients had symptoms of acute expansion (three), rupture (three), or thrombosis (one). True aneurysm and symptomatic presentation were correlated with aneurysm as the original indication for surgery. Repair was accomplished by an interpositional graft in 13 and graft replacement in eight. Seven patients required suprarenal anastomosis or renal and visceral reconstruction. Five operative deaths (24%) occurred, including two of three patients with rupture (67%) and two of seven patients (28%) in the suprarenal group. The mortality rate for elective repair with an infrarenal anastomosis was 11%. Two additional late deaths occurred during the follow-up period.


Treatment of angioaccess-induced ischemia by revascularization. Upper extremity ischemia related to the construction of a chronic angioaccess is a serious and occasionally devastating complication. Fourteen patients with end-stage renal disease (mean age 58 +/- 18 years, 13 with diabetes, 10 female) had ischemia after construction of an angioaccess. Twelve patients had a polytetrafluoroethylene brachioaxillary bridge arteriovenous fistula (BAVF), one patient had a radiocephalic arteriovenous fistula (AVF) and one patient had a brachiocephalic AVF. All patients had severe ischemia and five of them had established gangrenous changes. Symptoms appeared immediately after construction of the access in 10 patients. The remaining four patients had late onset of ischemia. The technique used for revascularization in all of these patients consisted of ligating the artery just distal to the takeoff of the AVF or BAVF and establishing an arterial bypass from a point proximal to the AVF or BAVF inflow to a point distal to the ligature. Bypass grafts consisted of saphenous vein in 13 cases and polytetrafluoroethylene in one case. Thirteen patients had a complete recovery, including healing of gangrenous lesions. One patient with severe gangrene of the hand at the time of revascularization required forearm amputation 13 months later because of progressive occlusive arterial disease. All AVFs were patent at 1 year. The 1-year patency rate for the BAVFs was 81.7%. All arterial bypasses were patent at 1 year. It is concluded that this technique offers consistent and durable hemodynamic and clinical improvement in arms affected by access-induced ischemia, with minimal morbidity, and does not affect the longevity of the angioaccess.


Natural history, duplex characteristics, and histopathologic correlation of arterial injuries in a canine model. The treatment of patients with penetrating extremity trauma in proximity to major arteries as well as the nonoperative treatment of clinically occult arterial injuries remain controversial. Duplex ultrasonography (DUS) has recently been advocated in this setting. We therefore studied experimentally induced arterial injuries in dogs to correlate the natural history, duplex findings, and histopathologic condition of different injuries and to help define criteria for operation. Fifty-two canine femoral and carotid arteries were randomized to have surgically created intimal flaps (n = 15), crush injuries (n = 15), or lacerations (n = 15) or to be controls (n = 7). An experienced sonographer, blinded to the presence or type of injury, evaluated the vessels every 10 days for 1 month. Histopathologic study was performed 1 month after injury when the arteries were retrieved. The sensitivity (96.5%), specificity (86.4%), and accuracy (95.1%) of DUS in evaluating arterial injuries at 1 month correlated well with histopathologic evaluation. All arteries subjected to crush injuries showed abnormal duplex findings. These findings correlated well with the histologic picture of severe injury (arterial wall thickness = 2.72 x +/- 0.23 x control; intramural hemorrhage, 93%; mural thrombus, 60%). DUS and histologic study revealed healing of intimal flaps in 27% of the arteries. Other intimal flaps deteriorated (stenoses, 47%; dilation, 13%; occlusion, 13%). Most lacerations (86%) revealed duplex evidence of healing within 10 days of injury. This was confirmed by histologic study at 1 month in 73% of lacerated arteries. This study confirms the accuracy of DUS in diagnosing various arterial injuries and shows that the natural history of these injuries varies with the mechanism of injury.(ABSTRACT TRUNCATED AT 250 WORDS)


Infrapopliteal arterial injury: prompt revascularization affords optimal limb salvage. Sixty-nine limbs with infrapopliteal arterial injuries were evaluated in 68 patients. Thirty-five (50%) cases were complicated by acute limb-threatening ischemia. Management consisted of revascularization (26 limbs), ligation (15 limbs), fasciotomy only (2 limbs), observation (18 limbs), and primary amputation (8 limbs). Penetrating injuries (n = 35) had a 33% incidence of ischemia and a reduced frequency of associated injury. One delayed amputation (3%) was required. In contrast, blunt injuries (n = 34) had a 68% incidence of ischemia and a greater frequency of associated injury. There were 20 amputations in the blunt group, including eight primary amputations performed in limbs with profound ischemia, complex open fractures, severe soft-tissue damage, and neural injury. Observation or ligation of single arterial injuries resulted in no early amputations. Associated local injuries in both groups included fracture or ligamentous disruption (64%), severe soft-tissue damage (32%), and nerve dysfunction (36%). In both groups, 15 of 35 ischemic limbs were salvaged by prompt revascularization (11 penetrating and four blunt injuries). Aggressive revascularization with autogenous repair or bypass is recommended for management of penetrating trauma. Though a good outcome will be achieved in some patients with combined blunt trauma and infrapopliteal arterial injury, the probability of delayed amputation and prolonged disability must be consciously integrated into the decision to pursue limb salvage. The prognosis for blunt injury complicated by arterial ischemia is poor; thus the severity of associated local and remote injuries will affect the results of revascularization program.


Central and regional hemodynamics determine optimal management of major venous injuries. Controversy continues in the selection of optimal management of major venous injuries. We analyzed our experience with 191 major venous injuries in 163 patients (1986 to 1991). The mechanism of injury was gunshot (112), stab (44), blunt (six), and iatrogenic (one). Eighteen cervicothoracic, 51 caval, 30 iliac, 36 visceral, and 56 extremity veins were involved. Of the 191 injuries, 105 (54.9%) were repaired (lateral repair 76, end-to-end anastomosis 15, vein patch four, vein graft five, Gore-Tex graft four, and compilation one). Of the remaining venous injuries, 64 were ligated as a result of hemodynamic instability. Twenty-two injuries in 18 patients did not receive treatment because 16 of 18 patients died before vascular control or repair. The overall amputation rate was 1.2%, and the mortality rate was 28.2% (46/163). The highest mortality rate occurred in those patients who required resuscitative thoracotomy (100%, p < 0.00001), retrohepatic caval injuries (90%, p < 0.0004), and multiple venous injuries (81.8%, p < 0.00001). Seventeen patients underwent fasciotomies (15 prophylactic and two therapeutic). Clinical or measured venous hypertension by stump pressure assisted in deciding for venous repair in 20 patients. A significant decrease in venous stump pressure (p < 0.000001) was noted after venous reconstruction. Thus the decision to ligate or repair venous injuries correlated primarily with (1) hemodynamic stability, and in stable patients, with (2) extent and location of injury and (3) clinical and measured venous hypertension. Venous ligation in clinically stable patients did not increase the need for fasciotomy or amputation.(ABSTRACT TRUNCATED AT 250 WORDS)


Management of peripheral vascular problems in recipients of cardiac allografts. Five hundred and twenty consecutive heart transplant cases (458 adult, 62 pediatric) were reviewed to assess the impact of peripheral vascular problems. Peritransplant interventions requiring vascular cannulation (e.g., intraaortic balloon pump procedures, catheterization of the right and left sides of the heart, femoral bypass) resulted in 10 complications that necessitated nine surgical procedures. Five aortic aneurysms (three infrarenal and two suprarenal) were resected. There was one death unrelated to the aneurysm resection. Sixteen patients had evidence of peripheral vascular disease (PVD). There were three deaths in this group, none directly related to the PVD. Three patients required vascular reconstruction (axillobifemoral, bilateral femoral distal and popliteal endarterectomy) in the posttransplant period, all for advanced ischemic symptoms. Except for one patient in whom ischemia-related ulcers developed on the heels, all patients had improved or stable symptoms that did not require intervention. There were no limb losses or vascular infections. We conclude that despite the rigors of posttransplant immunosuppression, patients with stable manifestations of PVD may successfully undergo heart transplantation and subsequent vascular reconstruction, when indicated, without prohibitive risk.


The influence of human immunodeficiency virus infection and intravenous drug abuse on complications of hemodialysis access surgery. To examine the influence of human immunodeficiency virus (HIV) infection on complications in dialysis access surgery, a review was performed on patients undergoing hemodialysis at two major metropolitan medical centers over a 30-month period. One hundred eight patients underwent a total of 169 graft procedures; mean follow-up was 14 1/2 months. There were 18 (17%) patients who were HIV-positive who had no symptoms, 11 (10%) patients with acquired immunodeficiency syndrome (AIDS), and 79 (73%) patients who were HIV-negative. Twenty-three percent (25/108) of patients had a history of intravenous drug abuse (IVDA), most of whom also had either AIDS or asymptomatic HIV infection. Dialysis procedures included 44 autogenous reconstructions (26%), 117 polytetrafluoroethylene (PTFE) grafts (69%), and 8 (5%) procedures of unknown type. Arteriovenous fistula or graft thrombosis was a frequent complication. The overall 12-month graft patency rate was 41%, and patients with HIV infection or a history of IVDA did not have a significantly increased risk of thrombosis. Multivariate analysis showed that the use of PTFE as opposed to autogenous reconstruction was the only significant risk factor found for occlusion within the first 12 months after operation (p < 0.01). Twenty-five graft infections occurred, all in PTFE grafts. The PTFE graft infection rate was 43% in patients with AIDS, 36% in patients who were HIV-positive and who had no symptoms, and 15% in patients who were HIV-negative (p < 0.05). Patients with a history of IVDA had a 41% PTFE graft infection rate versus a 13% infection rate in patients who did not have a history of IVDA (p < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)