Comparative studies of lipase and phospholipase A2 acting on substrate monolayers. The kinetic aspects of lipolysis by pancreatic lipase and phospholipase A2 from different sources have been compared using monomolecular films of short chain lipids as the substrates. Phosphatidylcholine monolayers, in contrast to phosphatidylethanolamine and phosphatidylglycerol monolayers, were resistant to hydrolysis by pancreatic lipase. The induction time, measured during pre-steady state conditions, increased abruptly for a given value of the surface pressure. This appears to be due to a degree of lipid packing above which the enzyme no longer can penetrate the lipid film. The existence of an optimum in the velocity versus surface pressure profile is the result of at least two counterbalancing factors. As the surface pressure increases, the amount of enzyme present in the interface decreases, whereas the minimal specific activity of the enzyme increases. From this study with monolayers we can conclude that activity of lipolytic enzymes used as tools for probing biological membranes will be greatly influenced by the physiochemical nature of the membrane-water interface. Thus, studies such as this one which can measure the penetrating ability of various lipolytic enzymes can be useful in deriving a better understanding of biological membrane structure.


The folding pathway of reduced lysozyme. Studies on the mechanism of the glutathione regeneration (Saxena, V.P., and Wetlaufer, D.B. (1970) Biochemistry 9, 5015-5023) of hen egg lysozyme have been carried out. The first two stoichiometric disulfides in lysozyme are formed about 8 times more rapidly than the second two. Almost no enzymic activity is regained until the first two disulfides are formed, thus ruling out an all-or-none mechanism. The disulfide peptides formed early in the regeneration have been isolated and identified. The results show a limited search of folding intermediates, and outline a folding pathway. The early disulfides involve cysteinyl residues III, IV, V, and VI. At the same time cysteinyl residues I, II, VII, and VIII are still reduced, as demonstrated by their isolation as S-alkylated derivatives. At slightly later times a peptide is found which contains the (native) disulfide between cysteinyl residues II and VII. It is likely, but as yet unproven, that formation of disulfide I-VIII completes the cross-linking of lysozyme.


Formation of three-dimensional structure in protein fragments. Reactivation of reduced hen egg lysozyme fragment 1-127. Regeneration of enzymic activity from reduced hen egg lysozyme peptide 1-127 was effected with a glutathione oxidation-reduction buffer. The rate of regeneration was nearly as great for peptide 1-127 as for reduced lysozyme itself, and the yields were the same (greater than 80%). The regenerated fragment 1-127 was shown to be indistinguishable from fragment 1-127 before reduction by ion exchange chromatography, amino acid analysis, polyacrylamide gel electrophoresis, and disulfide analysis. These results show that the COOH-terminal dipeptide Arg-Leu is not essential for the acquisition of the native three-dimensional structure of lysozyme.


Stimulation of 25-hydroxyvitamin D3-1alpha-hydroxylase by phosphate depletion. The ability of low phosphorus diets to stimulate the activity of the 25-hydroxyvitamin D3-1alpha-hydroxylase was tested in the chick. Feeding low phosphorus diets for 2 weeks resulted in a marked increase in enzyme activity relative to chicks fed a normal phosphorus diet. Stimulation of the 25-hydroxyvitamin D3-1alpha-hydroxylase activity by low phosphorus diets, however, was not as great as that observed with a low calcium diet. The low phosphorus and low calcium diets probably results from increased 1,25-dihydroxyvitamin D3 synthesis, whereas the stimulation by phosphate deprivation is only partly the result of increased 1,25-dihydroxyvitamin D3 production.


Preliminary x-ray investigation of an orthorhombic crystal form of human plasma albumin. An orthorhombic form of single crystals of human plasma albumin, suitable for x-ray diffraction studies, has been grown with ammonium sulfate from protein solutions purified from fresh frozen single donor plasma as well as from a commercial sample of plasma albumin. The space group is P2(1)2(1)2 with 12 molecules in the unit cell. The cell dimensions are: a = 133.3 +/- 1.2 A, b = 274.8 +/- 3.3 A,, and c = 58.02 +/- 0.02 A.


On the 4'-phosphopantetheine content of chicken and rat liver fatty acid synthetases. The finding that animal synthetases are complexes consisting of two polypeptide chains (Stoops, J.K., Arslanian, M.J., Oh, Y.H., Vanaman, T.C., and Wakil, S.J. (1975) Proc. Natl. Acad. Sci. U. S. A. 72, 1940-1944) led us to investigate their 4'-phosphopantetheine content. We have found that the chicken and rat synthetases contain 1.6 to 2.2 mol of 4'-phosphopantetheine per mol of the complex. The implications of this finding concerning the structure of the complex and the biosynthetic pathway of fatty acid synthesis are discussed.


Preliminary observations of bone ingrowth into porous materials. A preliminary investigation has been performed (a) to determine the kinetics of bone ingrowth into porous materials and to determine if this ingrowth could be catalyzed by the presence of a foreign substrate; and (b) to measure the bonding capability of bone with a porous-surfaced metallic implant. Tests on porous-surfaced implants corroborate the work of other investigators in showing that bony tissue will grow into a porous substance that has pores large enough to support tissue nourishment. The shear strength of the bone-implant interface appears to increase with pore size and time of healing. Furthermore, it may be possible to catalyze this tissue ingrowth by the introduction into the fracture site of a foreign substance; in this experiment, glass beads 200-290mu in diameter were used.


The effects of pylon shape on bone-pylon interface performance in direct skeletal attachment. The attachment of a prosthesis directly to the part of the skeleton remaining after an amputation offers many improvements over coupling schemes used in conventional prostheses. However, the stresses induced in the bone by the macrostructure of the attached prosthetic device must first be understood because they are a significant consideration in the design of a successful direct skeletal attachment (DSA) system. This investigation utilizes the finite element method of analysis to structurally model some possible DSA systems. Static stress-response models for an above-the-knee human femoral amputation are formulated to investigate the effect of variations in pylon macrostructure on system performance. The models approximate the initial stages of support following the insertion of a pylon into the medullary cavity of the bone and are also used to assess the bond strengths that must be developed between the bone and pylon for a "no-slip" condition to hold at their interface. The analyses indicate that either a shaped, marrow cavity-fit pylon or four 135 degree wedges with a complementary pylon are favorable geometries for a DSA system. The stress levels caused by these two geometries are on the order of 20% of the axial compressive strength of cortical bone. For each, local stress levels at the bone-biomaterial interface remain the critical parameters for investigation.


Tissue response to implanted polymers: the significance of sample shape. Studies were designed to demonstrate the need for standardization of shape of samples used as implants to evaluate histotoxicity of polymer materials. Six medical-grade polymers (polypropylene, polyethylene, polyurethane, silicone rubber, poly(vinyl chloride), and Teflon) were extruded as rods with circular-, triangular-, and pentagonal-shaped cross sections, and were implanted in rat gluteal muscles for 14 days. Evaluation of the tissue response was assessed by quantitating cellular lysosomal acid phosphatase enzyme activity by using microspectrophotometry. All triangular-shaped implants showed the highest enzyme activity and cellular response; pentagon shapes showed less, and circular rods showed the lowest activity. The results demonstrate the need for standard sample shape for valid comparative studies of tissue response to implanted polymers.


A statistical treatment of fatigue of the cast Co-Cr-Mo prosthesis alloy. Fatigue tests have been conducted on commercially produced cast Co-Cr-Mo alloy in tension-tension while surrounded by a physiological solution at 37 degrees C. The data have been analyzed by statistical techniques to yield an allowable stress such that there is 95% confidence of less than one failure in 1,000 after 5 X 10(7) cycles of stress fluctuation. These results are valid for a substantially sounder material than may be common in commercial use and therefore a more conservative allowable stress probably ought to be used for design purposes.


Mechanism of failure of biocompatible-treated surfaces. In recent years, significant advances have been made in treating surfaces to enhance their biocompatibility. This has generally involved the chemical attachmet of very thin molecular coatings to a substrate. Because failure of coated surfaces occurs often, an investigation of the stability of one such molecular coating was undertaken. The specific system studied is a polytetrafluoroethylene polymer (Teflon) with organic macromolecules of heparin ionically bonded to the polymer through use of an intermediate bonding agent. Polymers properly treated in this fashion have been shown to have excellent antithrombogenic properties. To investigate the molecular stability of the heparin coating, the surface heparin concentration of a properly    coated sample was reduced by using three different methods: exposure of bonding agent to a suitable solvent; mechanical flexing; and ultrasonic vibration in saline solution...


Adhesion of platelets to artificial surfaces: effect of red cells. Adhesion of platelets to several polymer- and protein-coated glass surfaces has been studied in vitro. The apparatus consists of a cylindrical probe rotating in a test tube containing the platelet medium and allows close control of fluid shear and mass transport. Suspensions of washed pig platelets constitute the basic platelet medium, and can be modified by adding back red cells and plasma proteins. Adhesion is measured via 51Cr-labeling of platelets. In the absence of red cells, identical low levels of adhesion were seen on all surfaces and saturation was reached within 2 min. In the presence of red cells, adhesion was greater. Saturation on all surfaces except fibrinogen and collagen again occurred within 2 min. The adhesion levels on polymer surfaces and glass were indistinguishable, while those on albumin were lower and those on fibrinogen were higher. Collagen was the most reactive surface. It did not equilibrate within 15 min., and kinetic data indicated a platelet diffusivity strongly dependent on hematocrit. These effects were attributed to rotational and translational motion of the red cells causing increased diffusion and surface-platelet collision energy.


Flame-sprayed alumina on stainless steel for possible prosthetic application. Various methods of roughening type 316 stainless steel substrate surfaces for flame-spraying alumina (Al2O3) were investigated and tested for the best alumina-to-metal bond strength. Best strength values were obtained by means of roughening via anodic polarization pitting of the stainless steel. Subsequent in vitro testing indicated a severe loss in bond strength following exposure to aerated Ringer's solution. It is suggested that the utilization of flame-sprayed devices has potential in orthopedic prostheses, but precautions must be observed.


In vivo degradation of silicone rubber poppets in prosthetic heart valves. Dynamic shear modulus G' was measured throughout the volume of three nonvariant silicone rubber poppets which were recovered from aortic prosthetic heart valves that had been implanted for 4 days, 52 days, and 8 years. Similar measurements were obtained for two unused silicone rubber poppets. Although the recovered poppets exhibited no obvious physical evidence of damage, the silicone rubber had undergone in vivo degradation throughout the poppet volume as indicated by decreases in modulus. The measurements also indicate that the poppet surface degrades at a rate faster than the core. Further, comparison with data reported in the literature suggests that the surfaces of variant poppets degrade at a rate faster than the surfaces of nonvariant poppets.


Total hip replacement without deep infection in a standard operating room. In a consecutive series of 298 total hip-joint replacements performed by a single surgeon using a standard operating room, early deep infection was eliminated by simple inexpensive methods of controlling contamination in the operating room. Settling-plate monitoring revealed an average of 4.8 colonies of bacterial growth per hour of exposure. All patients received prophylactic antibiotics. One patient had a superficial wound infection which was controlled with antibiotic therapy. No deep infections were encountered in the 252 hips followed for two to five years after operation. We conclude that total hip arthroplasty can be performed in the standard operating room without undue risk of infection by consistently employing strict measures of operating-room discipline to limit contamination.


Secondarily infected total joint replacements by hematogenous spread. Three fatal cases of infections that followed total joint replacement are repoarted, in each of which a hematogenous source of infection was identified. There also were five non-fatal cases presumable arising hematogenously which were reported in the literature. It is emphasized that concomitant disease, including active rheumatoid arthritis, may predispose to this complication.


Total hip arthroplasty in Paget's disease of the hip. For thirty-two patients with Paget's disease of the pelvis, mechanical disruption of the hip joint caused sufficient pain and disability to require total hip-replacement arthroplasty. Three of the patients had had fractures of the femoral neck. No unusual complications were encountered and the results were excellent.


The postoperative management of scoliosis patients treated with Harrington instrumentation and fusion. A retrospective study of maintenance of correction as affected by modifications in the management of patients surgically treated for scoliosis showed better results in Group B than in Group A. No supplementary bone was used in the 187 patients in Group A, who were maintained recumbent for three months postoperatively and who wore an underarm body cast for six months. The 177 patients in Group B received autogenous iliac-bone grafts, were allowed to walk seven to ten days postoperatively, and wore an underarm body cast for nine months. By two years postoperatively the patients in Group A had lost an average of 8.3 degrees of correction, and the patients in Group B had lost 4.3 degrees. A pseudarthrosis developed in eight patients in Group A and in one patient in Group B.


Screw fixation for certain fractures of the phalanges and metacarpals. Twenty-one patients with fractures of the bones of the hand were treated by open reduction and internal fixation with compression screws. The firm fixation allowed range-of-motion exercises in most patients to be begun on the third postoperative day. On follow-up mild restriction in digital motion was seen in only one patient, and significant disturbance in joint function was not encountered. In spite of these advantages, the method is indicated in only a small percentage of such fractures. Usually traditional methods of open reduction and internal fixation are preferred when an open procedure is needed. However, oblique and spiral fractures of the proximal phalanx, some fractures with large single articular fragments particularly involving the proximal interphalangeal joint, and appropriate Bennett's fractures are suitable for screw fixation.


Review and analysis of silicone-rubber metacarpophalangeal implants. A series of 530 consecutive arthroplasties using silicone-rubber implants in 119 patients was reviewed. Clinical and roentgenographic evaluations were completed on sixty patients and 254 implants, with an average follow-up of two and a half years; the remaining fifty-nine patients were evaluated by questionnaire. All but three patients had rheumatoid disease, usually with severe deformity, and many of the patients underwent other procedures on the upper extremity; these procedures often precluded early motion after the arthroplasties. Three prostheses (0.6 per cent) were removed because of infection, and reoperation was required in 2.4 per cent of the joints. Detailed clinical follow-up of 254 prostheses revealed the following: for Swanson prosthesis-average motion 38 degrees, fracture rate 26.2 per cent, and recurrence of clinical deformity 11.3 per cent; for Neibauer prostheses-average motion 35 degrees, fracture rate 38.2 per cent, and recurrence of clinical deformity 44.1 per cent. It should be noted that use of early implant types and some variations from the designer's recommended rehabilitation protocols were features of this series.


Congenital longitudinal deficiency of the fibula: follow-up of treatment by Syme amputation. Congenital longitudinal deficiency of the fibula presented two major problems in management: severe shortening of the limb and equinovalgus deformity of the ankle and foot. When the deformity was severe, our attempts at reducing the deformities of the foot and ankle with soft-tissue procedures and our attempts at achieving limb-length equality with various lengthening procedures were unsuccessful. Our best results in these patients were achieved with an early Syme amputation. The pattern of the deformity and the determination of the growth inhibition factor in the involved limb now enable us to make an early estimate of the deformity and plan appropriately. Syme amputation is definitive and allows the patient to have nearly normal function of the limb and a prosthesis of excellent appearance.


Transfer of tibialis posterior tendon in cerebral palsy. Posterior tendon transfer to the dorsum of the foot through the interosseous membrans is an effective procedure for spastic equinovarus deformity. The complications of excessive calcaneal or excessive valgus deformity can be avoided if the transfer is not inserted too tightly with the foot in dorsiflexion and if it is not transferred to a cuboid insertion. Electromyographic activity was demonstrated in some of the transferred muscles during the swing phase of gait. Tendo achillis lengthening in association with posterior tibial transfer must be done judiciously to avoid deformity of the calcaneus.


Passive motion of the elbow joint.

Passive motion of the elbow joint. A previously unreported method of measuring three-dimensional motion of joints, applied to two elbows obtained post mortem, showed that during flexion there is a continuous and linear change in the carrying angle, the forearm going into varus angulation as elbow flexion progresses. In addition, internal axial rotation of the forearm occurs near the beginning and external axial rotation, toward the end of flexion. With the elbow extended, the ulna shows little tendency to deviate laterally or to rotate axially during pronation and supination. The axis of rotation during elbow flexion lies approximately at the center of the trochlea.


The permeability of articular cartilage under compressive strain and at high pressures. The permeability of bovine articular cartilage was measured in an apparatus designed to permit this measurement while the fluid pressure gradient across the cartilage and the axial compressive strain applied to the cartilage were varied independently. For all of the pressure gradients tested the permeability of the cartilage decreased as the compressive strain increased. From previous work, it was postulated that joint lubrication is accomplished first by fluid exudation into the joint space. both at the leading edge of the moving contact area and between portions of the opposing cartilaginous surfaces, and second by imbibition of the expelled fluid back into the cartilage toward the trailing edge of the contact area caused by the "elastic" recovery of the tissue. The present work extends this model to include the condition that the permeability of cartilage is dependent on the extent to which it is deformed.


The effect of patellectomy on knee function. Thirty-three patients were evaluated after patellectomy for subjective complaints, objective physical findings, quadriceps strength, and knee motion during activities of daily living. Partial and complete patellectomy caused an equal loss of active and passive range of motion. Complete patellectomy resulted in greater ligament instability, quadriceps atrophy, and loss of quadriceps strength compared with partial patellectomy. Complete patellectomy casued a reduction in the degree of stance-phase flexion during level walking and negotiating stairs.


Hip fusion utilizing the cobra head plate. Sixteen consecutive patients underwent hip fusion with fixation by a cobra head compression plate. In six patients on osteotomy of the innominate bone also was done. Four patients had no osteotomy whatsoever, while in six patients medial displacement of the femur was accomplished by centrally dislocating the femoral head through the acetabulum. This modification made the surgical procedure and postoperative care simpler, and rehabilitation was easily accomplished. All of the hips treated in this series had successful bone fusion. All of the patients were out of bed within the first postoperative week, and ambulation with crutches was begun after the second week.


Anterior tibial-compartment syndrome complicating fractures of the shaft of the tibia. Twenty-five cases of anterior tibial-compartment syndrome in twenty-four patients were seen as complications of fractures of the shaft of the tibia. Six patients had fasciotomy within the first six hours of the onset of their symptoms and signs and all made an uneventful recovery. Eighteen patients, in whom treatment was withheld for an average of eighteen hours, were left with a variety of complications including persistent weakness of dorsiflexion in fourteen, a complete footdrop in three, and the necessity for a below-the-knee amputation in one.


The use of tomography in the assessment of fractures of the tibial plateau. Tomography was useful in the preoperative assessment of twenty-one tibial-plateau fractures. It helped in classifying these fractures more precisely, information which is very important if the results of different methods of treatment are to be compared. It demonstrated clearly the extent of fracture depression or displacement, or both, as well as the site of the fracture and the extent of fracture comminution. The findings were confirmed at operation in the thirteen patients who had surgery.


Metaphysial dysostosis (Jansen type). Report of a case with long follow-up. A case of the Jansen type of metaphysial dysostosis, followed for fifteen years from childhood to the age of nineteen, is reported. Radiographs taken at five years revealed the characteristic metaphysial changes in all the tubular bones, especially those of the hands and feet. The acetabular and glenoid areas, the costochondral junctions and the sternal ends of the clavicles were also involved. Radiographs taken at nineteen years, however, showed only marked deformities, which shows that the involvement of the metaphyses can regress by the end of growth. Biopsy of the lower end of radius at the age of twelve revealed changes in the growth plate or physis, especially in the zone of resting cartilage. This finding suggests that cellular function in this zone is disturbed by some unknown mechanism. Hence, the term physial dysostosis may be more accurate than metaphysial dysostosis.


Protection from stress in bone and its effects. Experiments with stainless steel and plastic plates in dogs. In a preliminary experiment the paired radii and femora of dogs were tested for bone mineral mass and mechanical properties including the load at break, the ultimate bending strength and the modulus of elasticity; symmetry was observed for most of the parameters determined. The influence of the elasticity of materials used for the internal splintage of bone and its relationship to bone remodeling were then investigated for stainless steel and plastic plates applied to the femora of dogs. A significant decrease in bone mineral mass per centimetre length of bone and in mechanical properties was demonstrated for the femora plated with steel, and microradiography showed that this was due to massive endosteal resorption. A model for determining the influence of protection from stress in bone is presented.


Infection of intervertebral discs after operation. Infection of the intervertebral space is a rare complication of operation on the disc (Ford and Key 1955). It occurred in five cases in a series of 650 operations for lumbar disc protrusion done by two of the authors of this paper--an incidence of 0-8%. Symptoms began between seven and twelve days after operation. After initial relief of the original sciatic pain, the patients developed severe back pain and muscle cramps in the legs. Straight-leg raising became much more limited than before operation. The erythrocyte sedimentation rate was raised in all cases. The diagnosis was confirmed by rescreening the Myodil, when an indentation was seen opposite the intervertebral space from which the disc had been excised. Early removal of infected material from the disc space resulted in complete relief of pain and cure of the infection.


Periosteal pedicle grafting in dogs.

Periosteal pedicle grafting in dogs. An experimental model was designed to find a theoretical solution to the clinical problem of congenital tibial pseudarthrosis in children. The osteogenic properties of periosteum having been accepted, paired pedicled flaps of periosteum were raised from the subcutaneous surface of the tibia, tubed and anastomosed in a series of young dogs. In the last twenty-four consecutive cases the rate of complete ossification in these tubes rose to one in three. In the later stages of the work, in addition to the construction of periosteal tube grafts, pseudarthroses were induced in the middle third of each canine tibia in order to see if hypertrophy would occur under the stress of weight-bearing. It was found that in each of twenty-four specimens some hypertrophy occurred in the ossified periosteal tube grafts, and in three of the specimens this hypertrophy was associated with complete ossification of the graft that by-passed the pseudarthrosis.


Remodelling by asymmetrical epiphysial growth. An experimental study in dogs. Spontaneous correction of deformity is produced by bone remodelling during the period of growth. The purpose of this experimental study was to find out in which phase and to what extent asymmetrical epiphysial growth participated in the correction of an experimentally produced deformity. Transverse wedge osteotomy was performed in the legs of twenty growing mongrel dogs, the fragments being fixed with bent AO-plates. From radiographs taken at intervals of two weeks the epiphysial and axial angles were measured. Nine dogs were given tetracycline ten to twenty days before death and the cut surfaces were photographed in reflected ultra-violet light. It was found that epiphysial growth played an important role in the remodelling process. This factor accounted for roughly half of the total correction and averaged 12-5 degrees during the observation time of 160 days. The greatest correction occurred during the first weeks. Correction of the epiphysial angle took place with acceleration of growth.


Subcapital fractures of the femur. A prospective review. This abridged account of a report to the British Medical Research Council describes a long-term investigation of 1,503 subcapital fractures of the femur, almost all of which were treated by reduction and internal fixation. With three exceptions, union occurred in all Garden Stage I and Stage II fractures and in 67% of Stage III and Stage IV fractures, of which only 14-5% were united at six months. In women, late segmental collapse was seen after union had occurred in 16% of Stage I and in 27-6% of Stage III and Stage IV fractures. Delay of up to one week before operation had no significant effect on the incidence of non-union or of late segmental collapse. The incidence of union followed by late segmental collapse was higher in women with normal bone density than in those with osteoporosis. Smith-Petersen nailing was found to be the least effective form of fixation in displaced fractures. The age and physical state of the patient, the accuracy of reduction, and the security of fixation had the greatest influence on union.


Coxa plana: a radiological comparison of the rate of healing with conservative measures and after osteotomy. Subtrochanteric osteotomy has been reported to interrupt the destructive phase of coxa plana and speed up the rate of healing. The aim of this investigation was to test the validity of these statements. The material comprised twenty-five patients treated by osteotomy and thirty-three patients treated by support in a Thomas's splint. For every patient the extent of the radiological changes was estimated and plotted against time as a percentage of the normal epiphysial volume. The graph so obtained represents the rate of destruction and re-ossification, as well as the maximum involvement of the epiphysis. The curves for each group of patients were superimposed in a graph with all the minima coincident in time. The two patterns of curves are closely similar. It was confirmed statistically that the rates of destruction and re-ossification did not differ between the two groups. The results afford no evidence that osteotomy interrupts the disease or speeds up healing.


A controlled study of the indications for and the results of femoral osteotomy in Perthes' disease. We have considered the reasons for securing containment of the femoral head in Perthes' disease and have reviewed briefly the methods used. The present investigation describes the outcome in a controlled series of forty-eight hips treated by containment by femoral varus-rotation osteotomy in selected patients. In assessing the results we have emphasised that controls are essential, and for this purpose we have used two comparable groups, one untreated and the other treated by methods other than containment. The same factors were considered in assessment--namely age, duration, group, and the presence or absence of "at risk" signs. The results were graded similarly as good, fair and poor in all groups. We have concluded that containment by femoral osteotomy is the treatment of choice in patients with "at risk" signs provided that severe deformity has not already occurred. There is no evidence that treatment of any kind favourably influences the course of the disorder in the remainder. Although this is predominantly a radiological study some clinical features are discussed.


Late open reduction of traumatic dislocation of the hip. Report of three cases. Three patients were reviewed seven, eight and fourteen years after delayed open reduction of traumatic posterior dislocation of the hip. The delay between injury and operation varied from twenty-eight to ninety-three days. At the time of review symptoms were minimal or absent, and in all cases the injured hip was clinically normal. Radiological examination showed loss of articular cartilage in one hip and trabecular changes in the bone of all three. On the basis of these three results the traditional pessimism about prognosis in such cases may not be justified.


Excision arthroplasty of the hip.

Excision arthroplasty of the hip. The results of excision arthroplasty on forty hips in thirty-two patients have been studied by personal review. The mean follow-up was ten years and the results were graded in the Lazansky system. The outcome was fairly predictable, most patients achieving a fair to good result. The patients were satisfied with the operation in unilateral cases as a secondary operation, but it was generally unsatisfactory as a primary procedure or when performed bilaterally. Pain relief was satisfactory, and previously infected hips achieved sound wound and bone healing. Half could walk with no aid or one stick. No correlation could be found between the radiological appearances and the quality of the result.


Treatment of scoliosis by posterior fusion, Harrington instrumentation and early walking. One hundred and three patients with scoliosis treated by posterior fusion and Harrington instrumentation are reviewed. The fusion technique described does not require added bone. Walking in a localiser plaster is encouraged as soon as the wound is healed, usually two weeks after operation. The results compare satisfactorily with others published. It is concluded that added bone is not necessary unless neural arch defects are present, and that early walking is advantageous and without risk to the correction.


The rib hump in idiopathic scoliosis. Measurement, analysis and response to treatment. This paper describes a simple method for the recording of rib deformity in idiopathic scoliosis. The relationships have been recorded between the measured rib hump and rib depression deformities and 1) the rotation of the vertebral bodies (as measured by the method of Nash and Moe on the standing radiograph); 2) the degree of lateral curvature (as measured by the method of Cobb on the standing radiograph); and 3) the rib-vertebra angles and their differences (as described by Mehta). No clear linear relationships were found. Many examples of irregular relationship were recorded, for example, marked spinal rotation with minimal rib hump. The response of the rib deformities to treatment by Milwaukee brace in fifty-two patients is described; the hump is little changed but the depression on the opposite side may be considerably reduced. Harrington instrumentation may have a similar effect.


The management of thoracic and thoraco-lumbar injuries of the spine with neurological involvement. The results of treatment of injuries of the thoracic and thoraco-lumbar spine with neurological involvement have been reviewed in a retrospective study of 115 patients, of whom eighty-nine received conservative and twenty-six surgical treatment. Operation was reserved, in general, for patients with irreducible dislocations and incomplete neurological lesions, open reduction and internal fixation being the commonest procedure. Only three patients required a delayed spinal fusion for suspected instability after a period of conservative treatment. On the other hand, ten patients, eight of whom had been treated surgically, were left with severe chronic spinal pain. Of the patients treated conservatively, 35% showed significant neurological improvement compared to 38% of those treated surgically, but the latter group contained a much higher proportion of incomplete lesions with a far better prognosis. It is concluded that the place for early operation might be still further restricted.


Strontium 87mSr bone scanning for the evaluation of total hip replacement. In a series of seventeen patients with unilateral osteoarthritis of the hip a scintiscanning follow-up study was made before and after total hip replacement for the assessment of the normal course of the 87mSr-scintiscan. In another series of twenty-eight patients with total hip replacement a photoscan was made as a supplement for the diagnosis of loosening of one or both components of a total hip implant. In most of these cases it proved to be a useful method, especially when clinical and raidological examination was inconclusive. It is concluded that up to six months after operation increased osteoblastic activity exists; the scintiscan became normal after that time. 87mSr scintiscanning offers a safe and simple technique for the assessment of the success and stability of total hip arthroplasty. It is also a useful aid for the early detection of loosening and infection. The procedure can help in the differential diagnosis of complaints after total hip replacement.


The importance of gastrocnemius recession in the correction of equinus deformity in cerebral palsy. Spasm or contracture of the gastrocnemius muscle is predominantly responsible for the equinus deformity of the foot in cerebral palsy. Its release is therefore logical in the treatment of all cases which do not respond to conservative measures. The authors have demonstrated, by the use of metal markers and radiographic control at operation, that adequate release cannot be achieved by severance of the calcaneal tendon alone, and that in order to ensure relaxation of the gastrocnemius muscle, the operation of choice is gastrocnemius recession by the method of Strayer, coupled with lengthening of the calcaneal tendon to deal with such degree of the deformity as may be attributable to shortening of the soleus. A survey of 100 limbs treated by this method revealed a recurrence rate of equinus of 9% and a degree of calcaneus deformity resulting in inadequate push-off in 3% of cases after an average follow-up period of six years.


Local excision of cyst of lateral meniscus of knee without recurrence. Twenty-two patients with cysts of the lateral meniscus have been treated by operation. A modified operative procedure is described whereby the meniscus is inspected for a concomitant tear. A tear of the meniscus was found in ten patients and these were treated by meniscectomy. The remaining twelve cases were treated by excision of the cyst only. The rehabilitation period was considerably less in these patients. Recurrence of the cyst did not occur. The rationale for local excision is based on the similarity between the cyst of a meniscus and a simple ganglion, and also on the desirability of preserving the meniscus.


Disability of the hindfoot after fracture of the tibial shaft. Hindfoot (subtalar) movement and disability after fracture of the tibial shaft have been studied. One hundred patients with soundly healed fractures of the tibial shaft treated by immobilisation in a long leg plaster cast were examined at least one year after the fracture had healed. Subtalar movement was accurately measured by a special technique and the patients were questioned specifically about any disability associated with their hindfoot. Subtalar movement was limited to some degree in 72% of patients. Forty-three per cent of patients complained of symptoms related to their subtalar joint and 12% found these symptoms troublesome.


Long-term follow-up results of the iliofemoral venous thrombosis. During the past 7 years 116 patients with acute and chronic iliofemoral venous thrombosis were treated surgically and medically. Exploration was undertaken mainly by clinical assessment and routine venography for follow-up was not considered as a requisite. Thrombectomy was performed 18 times in 17 patients with excellent or good results in 66.6%. Palma's operation was carried out 17 times in 17 patients with satisfactory results in 82.3%. These were contrasted with 34.2% satisfactory results among the medical patients. These lead to the following conclusion: 1. Venous thrombectomy within 14 days after the onset is effective. 2. The usefulness of delayed thrombectomy is uncertain. 3. Palma's operation offers satisfactory results for chronic iliofemoral venous thrombosis. 4. In Japan, in contrast with America and Europe, pulmonary thromboembolism is exceedingly rare and ligation or interruption of the inferior vena cava or the femoral vein is not performed routinely.


Peripheral arterial embolectomy in the aged. A series of 65 geriatric patients, operated upon for 76 peripheral arterial embolic events, is presented. The underlying condition was rheumatic heart disease in 8 and arteriosclerotic in 57. No patient was denied surgery unless widespread irreversible ischemia of the limb was present. Limb salvage was accomplished in 35 patients (54%). It was influenced by age, the underlying disease and time elapsed until resumption of circulation to the limb. The mortality rate experienced in this series was very high. 31 patients (48%) died postoperatively, mainly from cardiorespiratory failure. Death was related to the severity of the patients condition before surgery. 29 out of the 34 surviving patients were discharged with a viable limb. The high death rate observed is discussed.


Subendocardial myocardial necrosis: a preventable lesion. Left ventricular subendocardial hemorrhagic necrosis, a lesion entirely different from conventional myocardial infarction, has been an important cause of serious morbidity and mortality in open heart surgery, particularly aortic valve replacement. An established experimental model in which this lesion could be consistently produced in calves, was utilized to examine the protective role of hypothermia and/or Solumedrol infusion. Solumedrol infusion and systemic hypothermia were not sufficiently effective in protecting the myocardium against 40 minutes of left coronary artery occlusion during total cardiopulmonary bypass. Profound continuous irrigation of the pericardial cavity with 4 degrees centigrade Ringers lactate solution, with or without Solumedrol infusion, under similar circumstances yielded excellent results, both in terms of myocardial performance and preservation. This experiment has encouraged the clinical use of this technique in our institution.


Detection and treatment of pre-operative coagulation abnormalities in cardiac surgical patients. A pre-operative coagulation profile was performed on 10 consecutive patients undergoing open-heart surgery. 16.3% of patients had at least one abnormal result. The most common abnormality was found in the partial thromboplastin time system. All patients were treated with replacement of appropriate specific blood products during surgery. These measures prevented significant excess blood loss in the study group as compared to a control group of patients, both at surgery and over a twenty-four hour post-operative period.


Conservation of ribosomal RNA during compensatory renal hypertrophy. A major mechanism in RNA accretion. After removal of one mouse kidney, compensatory hypertrophy in the remaining kidney is marked in 2 days by a 20% average increase in ribosomal RNA (rRNA) per cell. Both 28S and 18S RNA are conserved during the initial stages of compensatory renal hypertrophy to an extent sufficient to account for the rest of the observed accumulation of rRNA. Like some cultured cells, the kidney conserves rRNA during physiological growth.


Support of cardiac performance following heart valve surgery by raising heart rate to the optimal pacing rate. Effects of hemodynamic parameters of heart rate were studied in 19 patients with low cardiac output syndrome following open heart surgery for mitral and/or aortic valve replacement in the first five postoperative days. The central venous pressure (CVP), left atrial mean pressure (LAMP), and arterial blood pressures were determined at spontaneous heart rate (SHR), and during graded atrial (12 pts.) or ventricular (7 pts.) pacing each day. An "optimal pacing rate" (OPR), characterized by the most advantageous arterial pressures at the possible lowest levels of CVP and LAMP, and by the suppression of preexisting arrhythmias, if any, was established daily for maintaining each patient on that rate. The SHR was 69 +/- 9 and the OPR was 102 +/- 9 on the first postoperative day. For the fifth postoperative day the SHR was 68 +/- 10 and the OPR decreased to 90 +/- 9. Pacing with the OPR significantly increased cardiac performance. E.g. the hemodynamic improvement on the first postoperative day induced by pacing was comparable to the spontaneous improvement seen during the first five postoperative days. The hemodynamic effect of atrial pacing on circulation was more definitive than that of ventricular pacing. Since OPR may be significantly higher than SHR and varies from day to day, we suggest that, in cases where pacing is applied to improve cardiac performance, it be determined for each patient individually each postoperative day.


Collagenous bone matrix-induced endochondral ossification hemopoiesis. Transplantation of collagenous matrix from the rat diaphyseal bone to subcutaneous sites resulted in new bone formation by an endochondral sequence. Functional bone marrow develops within the newly formed ossicle. On day 1, the implanted matrix was a discrete conglomerate with fibrin clot and polymorphonuclear leukocytes. By day 3, the leukocytes disappeared, and this event was followed by migration and close apposition of fibroblast cell surface to the collagenous matrix. This initial matrix-membrane interaction culminated in differentiation of fibroblasts to chondroblasts and osteoblasts. The calcification of the hypertrophied chondrocytes and new bone formation were correlated with increased alkaline phosphatase activity and 45Ca incorporation. The ingrowth of capillaries on day 9 resulted in chondrolysis and osteogenesis. Further remodelling of bony trabeculae by osteoclasts resulted in an ossicle of cancellous bone. This was followed by emergence of extravascular islands of hemocytoblasts and their differentiation into functional bone marrow with erythropoietic and granulopoietic elements and megakaryocytes in the ossicle. The onset and maintenance of erythropoiesis in the induced bone marrow were monitored by 59Fe incorporation into protein-bound heme. These findings imply a role for extracellular collagenous matrix in cell differentiation.


Developmental changes in mitochondria during the transition into lactation in the mouse mammary gland. Mitochondrial biogenesis in the parenchymal cell of the mouse mammary gland appears to occur in two distinct phases: replication during cell proliferation, and maturation during cell differentiation. This study of the mitochondrial maturation phase in the mouse gland demonstrates a significant increase in organelle density on isopycnic sucrose gradient centrifugation during the transition from late pregnancy to day 8 of lactation. Differential fragility to high sucrose concentrations or changes in mitochondrial lipid composition do not satisfactorily explain the density increases. When organelle densities were assessed by centrifugation under iso-osmotic conditions with Ficoll gradients in 0.25 M sucrose, the mitochondria from pregnant glands were observed to be more dense than those from lactating glands. The two mitochondrial populations were also found to differ in their response to changes in sucrose concentration in the Ficoll gradients. When sucrose concentration was increased, the density of both pregnant and lactating gland mitochondria increased nonlinearly, the increase being greater with the lactating gland organelles. By use of mathematical models, the differing response was interpreted as a change in the density and osmotic activity of the mitochondrial internal compartment (inner membrane plus matrix space). We have proposed that the changes reflect a large expansion of the inner mitochondrial membrane and perhaps the matrix material during the transition into lactation in the differentiating parenchymal cell.


Properties of growth-related acetylcholinesterase in a cell line of fibroblastic origin. We have previously reported the presence and regulation of an acetylcholine-hydrolyzing enzyme in high density suspension cultures of WRL-10A fibroblasts where its activity increases 100-fold when growth is arrested. Substrate specificity, substrate inhibition, and product identification studies indicate that this enzyme is acetylcholinesterase (AChE, EC 3.1.1.7). Treatment of whole cells with 5 mM diazotized sulfanilic acid revealed that most of the AChE is located on the external surface of the cell membrane. It was also found that the enzyme is released in the medium at a rate of 0.5 U/h/mg cell protein and that within a 24-h period the de novo synthesized and liberated AChE is equivalent to 90% of the activity associated with the cells. No similar synthesis of AChE was found in six order fibroblastic cell lines examined. These and related findings indicating that acetylcholine is also present in high density populations of WRL-10A cells suggest that this unique phenotype may be used profitably in exploring further the relationship between components of the cholinergic system and non-neuronal cell growth.


Changes in number, mobility, and topographical distribution of lectin receptors during maturation of chick erythroid cells. Plant lectins have been used to probe changes in cell surface characteristics that accompny differentiation in a complete series of chick erythroid cells. Dramatic differences in lectin receptor mobility were observed between the most immature cells of the series, the proerythroblasts, and cells at the next stage of maturation, the erythroblasts. Both concanavalin A and Ricinus communis agglutinin form caps on proerythroblasts, whereas they develop a patchy distribution on erythroblasts. Erythroid cells at later developmental stages show a homogeneous distribution of surface-bound R. communis agglutinin. Concanavalin A also shows a uniform distribution on the cell periphery, but appears to be concentrated in a ring above the perinuclear region of the cell. In addition to changes in mobility of lectin receptors, a large reduction (50-70%) in the number of lectin receptors per cell accompanies maturation of proerythroblasts to erythroblasts. Pretreatment of the cells with neuraminidase results in enhanced binding of R. communis agglutinin to proerythroblasts. The number of additional R. communis agglutinin receptors exposed by enzyme treatment remains relatively constant during subsequent cell maturation.


Orderly arrangement of ribosomes in the embryogenic callus tissue of Corylus avellana L. Cultured callus tissue of hazel (Corylus avellana L.), which has the potency of somatic embryogenesis, was used for the study of cell ultrastructure in the course of callus growth and embryoid formation. The meristematic cells of this tissue exhibit a specific organization of rough endoplasmic reticulum (RER), stacked into extensive parallel sheets. The membranes of the aggregated RER are associated with orderly arrays of bound ribosomes. The high regularity of the alignment of the attached ribosomes seems to be influenced by the distance between the two neighbouring membranes in the RER aggregate. The RER aggregates with orderly attached ribosomes are more frequently found in callus cells and in early embryogenesis than in the advanced stages of embryo development.


Ultrastructural and molecular characteristics of crayfish photoreceptor membranes. The ultrastructure of photoreceptor cells of the crayfish (P. clarkii) has been examined by means of thin sections and freeze-fracturing. The study reveals that in the photoreceptor membranes there are particles associated primarily with the A faces of freeze-fracture preparations which have a mean diameter of 80-84 A and a density of 6,600 per per micrometer2. Treatment of the retina with digitonin (a substance capable of extracting visual photopigments) in Ringer's causes marked disruption of the hexagonal arrangement of the microvilli, breakdown of the microvilli into smaller segments, and gradual removal of the particles. The estimated photopigment concentration in the microvillus is 4,000 per micrometer. It is suggested that the observed particles represent  the photopigment in situ.


DNA replication in Chinese hamster ovary cells made permeable to nucleotides by tween-80 treatment. We have developed a method for permeabilizing CHO cells to nucleotides under conditions which allow most cells to remain viable. Permeabilized cells can carry out ATP-dependent, semiconservative synthesis of DNA. The data are consistent with the continuation of DNA synthesis in those cells in S phase at the time of treatment, possibly limited to completion of replicon synthesis without new initiations.


Steroids and hematopoiesis. I. The effect of steroids on in vitro erythroid colony growth: structure/activity relationships. When substituted steroids of several classes are added to cultures of rat bone marrow cells in the presence of erythropoietin a consistent enhancement of the number of colonies of hemoglobin synthesizing cells is obtained. Maximum steroid effectiveness was found to be between 10(-6) and 10(-7) M. Representative compounds of several classes of steroids were examined for their ability to enhance colony growth, including delta 4-estrenes, delta 4-androstenes, 5alpha-H androstanes and estranes, 5beta-H estranes, pregnanes and androstanes. While testosterone and its 5alpha-H derivatives had little or no activity, many synthetic derivatives of testosterone were highly active in increasing erythroid colony growth. All 5beta-H androstanes, estranes, and all but one 5beta-H pregnane were active. Cortisol consistently inhibited colony growth and estradiol and progesterone had no significant effect.


Electrical properties of developing oocytes of the migratory locust, Locusta migratoria. The electrical properties of developing nonfertilized oocytes of Locusta migratoria were studied, using intracellular microelectrodes. The inseries potential of the combined oomembrane and of the follicular cells was about 20 mV in the youngest oocytes. It increased as the oocytes developed and it reached a plateau of about 50 mV before full maturation, generally four to seven oocytes away from the fully-developed terminal oocyte. Current-voltage relations were always linear for hyperpolarizing currents. Most oocytes exhibited, however, rectification to outward current. Input resistance values varied with oocyte size from about 5 X 10(6) ohm for young oocytes to about 0.2 X 10(6) ohm for the more developed ones. Some oocytes displayed a transient depolarization on turning off a hyperpolarizing step of current. This depolarization was not correlated with the size of the oocyte or with any observed morphological feature. Any two adjacent oocytes were electrotonically coupled. A single ovariole thus represented a longitudinal chain of developing oocytes which were connected electrically. This was supported by electron microscope observations which revealed junctions partially impermeable to lanthanum and gap junctions between the follicular cells themselves and between follicular cells and oocytes. The coupling coefficient was dependent on the direction of current flow. The attenuation of voltage along an ovariole was always greater at the distal than at the proximal side.


Interrelationships between water and cellular metabolism in Artemia cysts. IV. Adenosine 5'-triphosphate and cyst hydration. The concentration of ATP in cysts of the brine shrimp, Artemia salina, has been studied as a function of cyst hydration. Cysts dried over CaSO4 contain 0.02 gH2O/g cysts and 0.54 +/- 0.05 (S.D.) mumoles of ATP/g dried cysts. Addition of water up to 0.05 g/g cysts produced no net change in the level of ATP during incubation. Hydration levels between 0.05 and 0.62 g/g cysts resulted in a net loss of ATP, whereas above 0.65 g/g cysts a net increase was observed with incubation time. No net change in the amount of ATP, compared with dried cysts, was detected between the latter two hydrations. These results, when integrated with those from previous work, indicate that conventional aerobic energy metabolism does not begin until cyst hydrations of about 0.65 g/g are achieved. The fate of ATP in cysts hydrated to levels lower than 0.65 g/g was discussed.


The transport of chloride in Ehrlich ascites tumor cells. The steady state transport and distribution of chloride between the intracellular and extracellular phases was investigated when the extracellular chloride concentration was varied by isosmotic replacement with nitrate, bromide and acetate. The results of these experiments show that chloride transport, measured by uptake of 36Cl, is sensitive to the replacement anion. In the presence of nitrate, chloride transport is a linear function of the extracellular chloride concentration. The relationship between chloride transport and extracellular chloride in the presence of bromide is concave upward which suggests that this anion inhibits chloride movement. However, when acetate replaces chloride, the relationship between chloride transport and extracellular chloride is concave downward. The chloride distribution ratio of cells incubated in 145-155mM chloride medium is 0.386 and is not effected by the replacement of chloride with nitrate, bromide or acetate. These findings are consistent with the assertion that chloride transport is composed of two parallel pathways, a diffusional plus a saturating, mediated component. Of the total chloride flux (9.1 mmoles Cl-/kg dry weight per minute) measured in chloride medium (145-155 mM Cl-), the mediated component represents 40% and the diffusional component 60%.


Wasting of 18 S ribosomal RNA by human myeloma cells cultured in adenosine. When human myeloma cells are pulsed for one hour with 3H-uridine and chased for six hours in fresh medium containing unlabeled uridine, the processing of 45 S rRNA precursor into the stable 28 S and 18 S rRNA components can be followed. However, when the cells are chased in exogenous adenosine instead of uridine, the accumulation of 18 S rRNA is selectively inhibited. Cells pulsed with 3H-adenosine and chased in the absence of exogenous nucleosides exhibit normal rRNA precursor processing, while cells pulsed simultaneously with 3H-uridine and 3H-adenosine and chased with uridine and adenosine are deficient in labeled 18 S rRNA. Consequently, the inhibition of 18 S rRNA accumulation by adenosine is not an artifact of labeling nor is it relieved by an equal molar concentration of uridine. The wasting of 18 S rRNA in human myeloma cells is similar to that reported to occur in normal lymphocytes during the quiescent state.


Surface interactions between mammalian sperm and egg: variation of spermatozoa concentration as a probe for the study of binding in vitro. The pre-penetration binding interactions between gametes of the golden hamster were investigated in vitro. Binding between capacitated spermatozoa and the surface of eggs, that is the zonae pellucidae with intact vitelli, as a function of the concentration of spermatozoa, followed a sigmoidal curve. This was in sharp contrast to the linear binding obtained with mechanically isolated zonae pellucidae (zonae lacking vitelli). Penetration of eggs as a function of the concentration of spermatozoa paralleled the binding curve that occurred between gametes. The binding curve obtained with uncapacitated spermatozoa and eggs was not sigmoidal but was linear after a slight lag and parallel to the curve obtained with uncapacitated spermatozoa and isolated zonae pellucidae. Taken together these results support previous work which implicated a vitelline factor in the binding reaction between the surfaces of eggs and capacitated spermatozoa. By scoring binding at one minute intervals it was possible to relate the rapid uninterrupted binding that occurs between capacitated spermatozoa and isolated zonae pellucidae with the equally rapid but transient and vitellus-influenced binding that occurs between gametes. It was concluded that the vitelline factor acts by preventing most of the early type of binding that occurs between spermatozoa and isolated zonae pellucidae and not by terminating the early, rapid, initial binding as previously postulated. Thus, this early binding never occurs between most of the gametes that finally bind 30 to 40 minutes later and, therefore, does not play a role in the establishment of the late binding step which leads to penetration.


Effect of serum on the growth of Balb oT3 A31 mouse fibroblasts and an SV40-transformed derivative. The effect of serum on the growth properties of non-transformed Balb 3T3 A31 and SV40-transformed Balb 3T3 A31 was studied. The concentration of serum in the growth medium of non-transformed cells had little effect on the initial population doubling time, but did regulate the cell density at which the population became quiescent in G1. The doubling time of transformed cells, however, was increased significantly as the concentration of serum was decreased below 4%. This effect on the growth of transformed cells was seen at serum concentrations so low that non-transformed cells did not complete one population doubling. Flow microfluorometric analysis of these populations indicated that the primary effect of different serum concentrations on the non-transformed cells was to modulate the average residence time in G1, whereas, all the cell cycle phases of the transformed cells were affected by serum. At saturation densities, the non-transformed cells became quiescent in G1, but the transformed cells still traversed the cell cycle and their saturation density appeared to be a balance between cell production and cell death occurring primarily in the G1 phase of the cell cycle.


Carbohydrate preferences of mammalian cells. Carbohydrate preferences of mammalian cells can be utilized to biochemically distinguish between different cell lines. Ninety-three carbohydrates were examined of which (a) 15 supported cell proliferation and (b) 42 were toxic or growth inhibitory. The present investigation has employed an enzymatic system to eliminate trace glucose levels from reagents and glucose generated by serum enzymes.


Degradation of abnormal proteins in HeLa cells. Canavanine, an arginine analog, is incorporated into HeLa cell protein when cells are incubated in the absence of arginine, and this incorporation can result in the production of nonfunctional enzymes or abnormal proteins. The cells degrade these abnormal proteins up to three times more rapidly than normal cell proteins. The capacity for selective degradation of abnormal proteins is not limited to HeLa cells since human fibroblasts also showed increased degradative rates following exposure to canavanine. In addition, enhanced degradation is not a peculiar property of canavanine incorporation since other amino acid analogs also promoted protein degradation. Thus, mammalian cells have the capacity to recognize and selectively degrade abnormal proteins.


Inhibition of cell division in amoebae: the incorporation of tritiated precursors into Amoeba proteus after the injection of non-homologous cytoplasm. The injection of non-homologous cytoplasm into any strain of large free-living amoebae leads to a 60% inhibition of division amongst recipient cells. When the post-microsomal supernatant fraction of Amoeba discoides was injected into A. proteus, this inhibition of division was as high as 95%. The incorporation of tritiated precursors, either [3H]uridine or 3H-amino acids, into these inhibited amoebae was studied at various times after the injection of the inhibitory material using autoradiography. When cells were grown in [3H]uridine, autoradiographs indicated that RNA synthesis had ceased 2 days after the injection of non-homologous material. However, if [3H]uridine was injected into the inhibited cells, some synthesis of RNA could be detected up to 4 days after the injection of inhibitor. These results suggested that uptake of [3H]uridine was impaired and that one site of action of the inhibitory molecules was RNA synthesis for membrane components. Experiments with a variety of 3H-amino acids suggested that protein synthesis continued for at least 9 days after the injection of non-homologous cytoplasm, and that in these cells some informational RNA molecules were long-lived. There seemed to be accumulation of material containing [3H]lysine in the nuclei of control cells taken at random from cultures, and this was seen in the nuclei of inhibited cells 1 day after injection. However, 2 days after the injection of inhibitor, no accumulation of [3H]lysine-containing material was found in the nuclei.


The cell cycle during amphibian limb regeneration. The duration of the cell cycle in the blastema of regenerating limbs of axolotls has been measured by means of [3H]thymidine pulse labelling and autoradiography. A chase was required to define the pulse period. An average cell cycle at 20 degrees C takes 53 h, S-phase takes 38 h; including parts of mitosis, G1 is 10 h and G2 is 5 h long. The protracted cycle and S-phase are consonant with the large genome in axolotis and other urodeles. The rapidly growing blastema probably contains a steady population of about 5000 proliferating cells, as there is a regular withdrawal of differentiating cells from the population. The kinds of determination which exist in this population of cells, or are exerted on it, are briefly considered.


Meiotic maturation of mouse oocytes in vitro: association of newly synthesized proteins with condensing chromosomes. The nature, intracellular distribution, and role of proteins synthesized during meiotic maturation of mouse oocytes in vitro have been examined. Proteins synthesized during the initial stages of maturation are concentrated within the nucleus (germinal vesicle) and become intimately associated with the condensing chromosomes. Inhibition of protein synthesis during this period does not prevent germinal vesicle dissolution or chromosome condensation, but meiotic progression is blocked reversibly at the circular bivalent stage. A protein is synthesized during meiotic maturation of the mouse oocyte which exhibits several of the characteristics of the very lysine-rich histone, FI; this and other histones are phosphorylated during the initial stages of maturation. These results are discussed in relation to studies of meiotic maturation of oocytes from non-mammalian species and chromosome condensation in both oocytes and mitotic cells.


Similarities between platelet contraction and cellular motility during mitosis: role of platelet microtubules in clot retraction. The effects of inhibitors of mitosis, energy metabolism and protein synthesis on clot retraction were investigated. The results show that (1) Incubation of colchicine (0-01-0-1 mM) with platelet-rich plasma (PRP) inhibits the subsequent retraction of clots derived from diluted PRP. (2) Inhibition of clot retraction by high concentrations of colchicine (up to 40 mM) can be overcome by increasing the platelet concentration in the system. (3) Incubation of clots in colchicine or 80% D2O solutions inhibits their retraction. Exposure of partially retracted clots to these agents is without effect. (4) Hydrostatic pressure retards clot retraction. (5) Incubation of PRP with either 2-deoxy-D-glucose or antimycin alone does not affect clot retraction, but a combination of these agents is inhibitory. (6) Clot retraction is not inhibited by puromycin or cycloheximide. (7) Platelets in retracting clots have constricted regions containing microfilaments and pseudopods containing microtubules. Fibrin strands are progressively condensed around the constricted regions as retraction advances. (8) The development of platelet constriction, platelet pseudopods and the intracellular microfilaments are delayed in colchicinized clots, corresponding to the retardation of retraction. Following the initial delay of retraction colchicinized clots, like controls, show condensation of fibrin strands adjacent to these constricted areas of platelets containing microfilaments. The formation of pseudopods is impaired and no microtubules are found in platelets in the presence of colchicine. The above results suggest that the thrombin-induced platelet contraction during clot retraction is a coordinated movement, which, under optimal conditions involves both microtubules and microfilaments. The contraction of microfilaments produces the constriction of platelets and brings about clot retraction by reducing the angle between fibrin strands. Platelet microtubules are related to the development of pseudopods and play a supplementary role in facilitating microfilament-mediated cellular constriction. The similarities between platelet contraction and cellular motility in mitosis is discussed.


Rotary movements and fluid membranes in termite flagellates. We previously described a remarkable type of cell motility that provided direct, visual evidence for the fluid nature of cell membranes. The movement involved continual, unidirectional rotation of one part of a protozoan, including the plasma membrane and cytoplasmic organelles, in relation to a neighbouring part. The cell membrane in the 'shear zone' appeared continuous with that of the rest of the cell. The rotary motor consisted, at least in part, of a non-contractile, microtubular axostyle which extended centrally through the cell. The protozoan was a devescovinid flagellate found in the hindgut of a Florida termite. In this paper, we have confirmed earlier reports of this type of motility in other kinds of devescovinids from Australian termites. By demonstrating continuity of the plasma membrane in the shear zone of the Australian devescovinids as well, we have obtained additional examples that provide direct, visual evidence for fluid membranes. A comparative analysis of rotational motility in various devescovinids revealed 2 different kinds of rotary mechanisms. Hyperdevescovina probably have an internal motor, in which one part of the cell exerts forces against another part, as in the Florida termite devescovinid. Devescovina species, on the other hand, have an external motor, in which flagellar and/or papillar movements exert forces against the surrounding medium. The structure of the axostyle in different devescovinids was compared, and its role in rotational motility discussed with respect to the behavioural data.


Flagellar regeneration in Chlamydomonas reinhardtii: evidence that cycloheximide pulses induce a delay in morphogenesis. The behaviour of a pool of flagellar precursors, assayed by the ability of cells to regenerate flagella in the absence of de novo protein synthesis, has been examined during organelle morphogenesis in the biflagellate alga Chlamydomonas. The results demonstrate that flagellar elongation can continue even when this pool is apparently empty and suggest that 2 sources of precursors are available to the regenerating flagella: those pre-existing in the cellular pool and those synthesized de novo. Further evidence for this was obtained by subjecting regenerating cells to pulses of cycloheximide. Cells exposed to this drug during the first 60 min post deflagellation formed only half-length (5-mum) flagella, whereas a pulse administered after this point allowed the formation of longer flagella and suggested that some de novo protein synthesis was required for the formation of full-length flagella, although it was not a prerequisite for the initiation of regeneration. In addition, it was found that, subsequent to the removal of the cycloheximide, flagellar regeneration did not recommence immediately, but was delayed for a period of approximately 45 min, irrespective of length of flagella formed prior to drug inhibition. The nature of this cycloheximide-induced delay is unclear and certain alternatives, based on the exhaustion of structural/regulatory components are considered. Although it is not possible to distinguish between these alternatives, tubulin is not the limiting component, since a pool of this protein is present when flagellar elongation is prevented by cycloheximide.


Developmental mechanisms in heterospory. III. The plastid cycle during megasporogenesis in Isoetes. The megasporocyte of Isoetes englemanni at the leptotene-zygotene interval of meiosis contains 4 disk-shaped proplastids about 12 mum in diameter. The disposition of these organelles in the cell is such that each of the four megaspores delimited during cytokinesis contains a single proplastid. During prophase and following their incorporation into the spores, the proplastids are undergoing fission by budding. The buds are first discernible as low surface evaginations which contain a complement of granular somal material, some wefts of tubular membrane and osmiophilic globuli, in addition to a number of vesicles derived by invagination from the inner membrane of the proplastid envelope. As the evaginations emerge they enlarge and the link with the parent body is reduced to a narrow channel. At this stage one or more of the vesicles derived from the proplastid envelope comes into register with the lumen of the channel. One vesicle is transported into the lumen, elongating as it passes through. The passage of the vesicle into the channel destroys the connexion between the matrix of the evagination and the stroma of the proplastid. The occurrence in the cytoplasm around the proplastid of bodies not connected to the proplastid, but identical in structure to the evaginations and carrying a membranous tail suggests that the evaginations are released by abscission of the channel close to the surface of the parent body. After release the bodies undergo division by constriction. Regression of the tail follows division in those bodies which are regular in outline and in which the matrix is ultrastructurally similar to the stroma of the parent organelle. The process does not seem to occur in co-existing forms which have assumed an irregular outline and have a less-opque matrix. The more mature megaspore of Isoetes contains proplastids up to 4 mum in greatest dimension. The stroma in these is dense and granular and contains membrane-bound vesicles, osmiophilic globuli, starch granules and wefts of tubular membrane. There is no evidence that the large budding organelle persists to this later stage in development. The resemblance of the plastids in the more mature megaspore to the bodies produced by evagination earlier in development suggests a common identity. The observations and interpretations lead to the proposition that the plastids in Isoetes englemanni are autonomous. This situation contrasts with the one described for another heterosporous haploid dioecious pteridophyte, Marsilea vestita, where nucleocytoplasmic interaction has been interpreted as the de novo creation of plastids and mitochondria following the elimination by autophagy of the organelles inherited at meiosis. It is suggested that an explanation to account for the 2 different mechanisms might be sought in regard to the degree of developmental success enjoyed by the individual megaspores in the 2 plants. In Isoetes all 4 megaspores of every tetrad survive and develop, while in Marsilea the mature megasporangium contains a single functional megaspore.


Brittle fracture of epidermal cells by liquid shear. A suspension of epidermal cells obtained from pig tail skin by trypsinization was subjected to high liquid-shear forces in a French press. The material issuing from the press was examined by phase-contrast microscopy, transmission electron microscopy and scanning electron microscopy. The cytoskeleton of tonofibrils retained the shape of cell fragments, and subcellular organelles remained enmeshed in the network of tonofibrils. Examination of some cell fragments by scanning electron microscopy revealed the internal organization of the tonofibrils. The relevance of these findings to the problem of isolating subcellular fractions from epidermis is discussed.


On-line information systems in perspective. The rationale supporting the desirability of on-line information systems and the arguments underlying their development are discussed. A major argument in favor of on-line retrieval has been the assumption that the opportunity to negotiate search problems through on-line access to the data base has the inherent effect of improved system performance. The extent to which on-line retrieval has fulfilled this and other expectations is considered along with trends relating to the operational characteristics of existing systems.


Selection of descriptors according to discrimination and redundancy. Application to chemical structure searching. Descriptors, for our purposes, will be fragment screens in a chemical search system. Given a file of compounds, the discrimination of a set of descriptors can be defined in terms of their incidence and mutual incidence in the file. A theory is developed which provides both a heuristic for selecting descriptors and a method for evaluating their marginal discrimination. These ideas have been used to generate an efficient screen code for a large file of chemical structures.


Gas-liquid chromatographic analysis of protein amino acids as N-isobutyloxycarbonylamino acid methyl esters. A practical method for the quantitative determination of protein amino acids by gas-liquid chromatography (GLC) is described. All of the common protein amino acids except arginine can be readily converted into their N-isobutyloxycarbonyl (N-isoBOC) methyl ester derivatives by a simple procedure involving isobutyloxycarbonylation with isobutyl chloroformate in aqueous medium, followed by methylation with diazomethane. Arginine was converted into N-isoBOC ornithine methyl ester by treatment with arginase, followed by the above derivatization procedure. The resulting N-isoBOC methyl esters of the amino acids have good GLC properties. Complete resolution of the derivatives of 20 protein amino acids was achieved by using a dual-column system consisting of a 0.65% Poly-A-101A column and a 0.70% FFAP-Poly-A-101A (1:1, w/w) column. The reproducibility of response was found to be good for derivatives carried through the entire chemical and chromatographic procedure. The calibration graphs were linear and showed no statistical bias. The results of recovery experiments with synthetic mixtures containing known amounts of the amino acids were satisfactory, the recoveries ranging from 94.3 to 106.2%.


Chromatography of cephalosporins on DEAE-sephadex. A method is described for separating and quantifying new cephalosporin derivatives by means of column chromatography on DEAE-Sephadex A-25. The procedure has been used to determine some breakdown products of cefacetril.


Gas chromatography of bile acids as their hexafluoroisopropyl ester-trifluoroacetyl derivatives. Bile acids, such as cholic, chenodeoxycholic, deoxycholic, lithocholic and ursodeoxycholic acids, were allowed to react with hexafluoroisopropanol and tri-fluoracetic anhydride at 37 for 30 min. The resulting derivatives were gas chromatographed on QF-1, with flame ionization detection, and were identified by gas chromatography-mass spectrometry. Separation was good. By using this method, these acids were detected in samples of human duodenal fluid; the ratios of each were 24.4, 41.5, 24.9, 2.3 and 6.9%, respectively.


High-performance liquid chromatographic determination of kanamycin. A fast, selective, and precise liquid chromatographic method for simultaneous, independent determination of kanamycins A and B is described. Sample components are separated on a pellicular cation exchanger and monitored by fluorescence using post-column on-line derivatization. Less than 0.35 mug of kanamycin B can be detected in as much as 7 mug kanamycin A injected. The detection limit for kanamycin A is less than 20 ng injected. Reproducibility of the entire chromatographic system is about 1% (2 theta) based upon repeated injections of standards. Precision of repeated process sample preparation is about 6% (2 theta). Chromatographic analysis time is less than 15 min per sample.


Chromatographic separation of cannabinoids and their monooxygenated derivatives. delta1-Tetrahydrocannabinol, delta6-tetrahydrocannabinol, cannabinol, cannabidiol and several of their monooxygenated derivatives have been separated from each other by a combination of liquid, thin-layer and gas chromatography. Retention volumes (on Sephadex LH-20), Rf values and retention times can be recorded, and may provide guidance in the separation and identification of these known cannabinoids.


Quantitative gas chromatography and gas chromatography-mass spectrometry of Cephalotaxus alkaloids. Plants of the genus Cephalotaxus contaim many alkaloids, some of which have demonstrated antitumor activity. Analysis of crude alkaloid mixtures by gas chromatography provides quantitation of the active principles and other, non-active, alkaloids. Mass spectrometry is used to identify known alkaloids in extracts and to confirm the presence of previously unknown ones. Such data provide a means for predicting the biological activity of new plant accessions.


A quantitative gas-liquid chromatographic method for the determination of neostigmine and pyridostigmine in human plasma. A sensitive and selective analytical method was used to measure the concentration of neostigmine and pyridostigmine in human plasma. The procedure involved preliminary ion-pair extraction of the drugs into dichloromethane, followed by concentration and anlysis of the ion-pair complex using a gas-liquid chromatographic system fitted with a nitrogen detector. Using the peak area ratio technique, pyridostigmine bromide was used as the internal standard for the quantitation of neostigmine in plasma; neostigmine bromide was the internal marker for the determination of pyridostigmine. The method depends on the thermal dequaternisation of the quaternary amines, and can be used to detect 5 ng/ml in a 3-ml plasma sample. Accurate measurement can be made at levels of 50-1000 ng/ml. This assay procedure has been applied to the separate determination of the plasma concentration of neostigmine and pyridostigmine after single administration of intravenous doses in aneasthetised patients.


Comparison of chromatographic methods for the analysis of glycerol esters. Column, thin-layer and gel chromatography have been compared as methods for the analysis of glycerol esters. It was found that gel chromatography gave much easier and faster analyses of monoglyceride emulsifiers, while at the same time providing a satisfactory distribution of fractions and giving an accuracy of determination corresponding to that of the standard method for their analysis.


[Separation of pharmaceutical compounds using high-performance liquid chromatography. Influence of water II. (author's transl)]. The use of ternary solvent systems as mobile phases in combination with highly efficient chromatographic columns is of particular interest for the analysis of pharmaceutical and biological compounds. The solute-silanol group interactions decrease when the eluent is blended with water. Good selectivities are found with such systems.


Liquid ion exchangers in reversed-phase systems for chromatography of steroidal glucosiduronic acids. Steroidal glucosiduronic acids were chromatographed on paper by the reversed-phase technique using five different liquid ion exchangers as stationary phase and aqueous KCl as mobile phase. The relationship of mobility of the acids (Rm) to both the amount of exchanger on the paper and the concentration of KCl in the mobile phase is discussed: the relationships may be expressed as Rm=n.log [exchanger] + const. and RM=-N.LOG [KCl] + const., respectively. Migration of the acids in the presence of different exchangers is correlated by use of the equation Rm (exchanger Y)=a.Rm (exchanger X) + b. The lack of appreciable correlation between migration of the acids in a reversed-phase system and a corresponding straight-phase system is discussed and expressed by means of regression equations. The correlation coefficients and standard errors of estimate from these equations provide useful indices for selecting two solvent systems that are to be used sequentially to obtain maximal resolution of a group of compounds. deltaRm values obtained for various functional groups with reversed-phase and straight-phase techniques are compared.


Determination of benomyl and 2-(4-thiazolyl) benzimidazole in plant tissues by high-performance liquid chromatography using fluorimetric detection. Methods for determining benomyl [methyl 1-(butylcarbamoyl)-2-benzimidazole carbamate] residues in plant tissues involve isolation of the residue by extraction with ethyl acetate, hydrolysis of the extracted residue to 2-aminobenzimidazole and final determination by high-performance liquid chromatography using a fluorimeter. 2-(4-Thiazolyl) benzimidazole is also determined by a similar procedure without hydrolysis. The sensitivities of these methods are 0.02 ppm for benomyl and 0.001 ppm for 2-(4-thiazolyl) benzimidazole. Recoveries of these compounds from various plant tissues were 90.5-102.9%. No interference with these methods from the plant tissues tested was found.


Determination of the carotenoid phytoene in blood by high-pressure liquid chromatography. A sensitive and specific high-pressure liquid chromatographic assay was developed for the determination of phytoene in blood with an overall recovery of 86 +/- 6.0% and a limit of detection of 50-100 ng per ml of blood. This method provides for rapid and simple quantitation of phytoene using 1 ml or less of blood. The assay was used in the determination of phytoene blood levels in the dog following intravenous and oral administration of 10-mg/kg doses.


Rapid screening and confirmation of amphetamine, methamphetamine, methadone, and methadone metabolite in urine by gas/thin layer chromatography. A method suitable for large scale screening and confirmation of urine speciments for amphetamine, methamphetamine, methadone, and its primary metabolite (2-ethylidene-1,5-dimethyl-3,3-diphenlypyrrolidine) is described. The drugs are extracted from alkaline urine into an organic solvent. The amphetamine drugs are then back-extracted into a small volume of acid and identified by gas chromatography both as free bases on a 10% Apiezon L-10% KOH column and as their trifluoracetamide derivatives on a 3% OV-17 column. The organic layer, which still contains methadone and its primary metabolite, is analyzed by split-sample thin-layer chromatography using two solvent systems: ethyl acetate: methylene cloride: concentrated ammonium hydroxide (90:10:0.7) and methanol: chloroform: concentrated ammonium hydroxide (74:25:0.8). These solvent systems separate methadone from its primary metabolite without interference from other drugs or urinary substances.


Constituents of peppers: IV. The hydrocarbons of pepper essential oil. Twenty-six hydrocarbons were identified in the essential oil of black pepper. Three of these are sesquiterpenes which have not been reported previously as occurring in this oil (beta-cubebene, alpha-guaiene and gamma-cadinene). Some other hydrocarbon constituents mentioned in the literature were absent in our pepper oil.


Quantitative gas-liquid chromatography of iproniazid and iproclozide. Analytically packed columns prepared with Versamid-930, Versamid-900, XE-60, and OV-225 as stationary phases were examined for quantitative gas-liquid chromatography of the potent monamine oxydase inhibitor (MAOI) drugs iproniazid and iproclozide. With the aid of chemically related substances as internal standards, response ratios were determined and linearities calculated by regression analysis. Using the 2-butyl analogs of compounds all four column systems permit quantitation of iproniazid and iproclozide with a percent standard deviation sigmaK of about 1% or less.


Gastric inhibitory polypeptide (GIP) in chronic pancreatitis. The plasma gastric inhibitory polypeptide (GIP), pancreatic glucagon-like immunoreactivity (PGLI), and gut glucagon-like immunoreactivity (GGLI) responses to oral glucose have been measured in five patients with chronic pancreatitis (with diabetic glucose tolerance tests) and in matched nondiabetic controls. Plasma GIP levels rise rapidly after glucose ingestion before changes in circulating glucose and insulin concentration. Patients with pancreatitis have a greater than normal GIP response to oral glucose, which may account for the relatively unimparied insulin response to oral glucose in these patients compared with that to iv glucose, as has been previously found. Patients with pancreatitis also have a paradoxical rise in PGLI and an exaggerated rise in GGLI concentration following oral glucose.


Volume of sella turcica in normal subjects and in patients with primary hypothyroidism and hyperthyroidism. In an attempt to assess a possible relationship between pituitary size and TSH secretion, the volume of sella turcica was measured in 570 subjects, 26 primary hypothyroid patients, and 34 thyrotoxic patients. The volume of sella turcica, measured by a 3-dimensional approach, increased progressively with age until 20 years of age and was rather constant thereafter in normal subjects. In thyrotoxic patients, the volume of sella turcica was normal in spite of decreased plasma TSH concentration. In contrast, 81% of primary hypothyroid patients had an abnormal enlargement of the sella turcica. The magnitude of an increase of sella turcica inversely related with a decrease in serum T4 and T3 concentrations. On the other hand, the magnitude of an increase of sella turcica correlated well with an increase of circulating TSH. We suggest that an increase of sella turcica indirectly reflects an increase in pituitary size and TSH-secreting capacity, possibly due to hypertrophy and hyperplasia of TSH cells in primary hypothyroid patients.


Radioimmunoassay for 3,3',5'-triiodo-L-thyronine in unextracted serum: method and clinical results. Serum 3,3',5'-triiodothyronine (rT3) was measured with a radioimmunoassay in unextracted serum. The assay was specific and reproducible. The coefficients of variation for 3 different sera known for high, normal, and low rT3 concentrations between assays were 4, 6, and 9% within assays 4, 9, and 7%, respectively. In euthyroid subjects 20 to 60 years old, rT3 was 450 +/- 200 pg/ml (mean +/- 2 SD.n = 83). Serum rT3 was found to be increased in hyperthyroidism (range: 762-2581 pg-ml; n = 11) but also in acute and chronic illness (up to 2400 pg/ml; n = 24) and in anorexia nervosa (536-1058 pg/ml; n = 7). In the latter two situations there was mostly an inverse change in serum 3,5,3'-triiodothyronine (T3) which was in the low normal range or decreased. These findings suggest a metabolic control of thyroxine deiodination. A low serum rT3 was found in 9 of 12 hypothyroid patients and in the serum of 1 chronically ill patient. Long-term treatment (1-7 years) with lithium carbonate slightly reduced serum rT3, although the changes were inside the normal range. Kidney function was not found to be necessary for its production as anephric patients had normal rT3 values. In addition, hemodialysis increased serum rT3, which is probably due to the heparin therapy.


Body composition in Cushing's disease.

Body composition in Cushing's disease. Lean body mass and body fat mass were estimated in 12 patients with Cushing's disease before treatment, in 5 of these after correction of the adrenal hyperfunction, and in 23 patients with simple obesity. The methods used, whole-body counting of 40K and tritiated water dilution, may in Cushing's disease over- and underestimate, respectively, the body fat mass and may therefore be considered to give upper and lower limits of that entity. By a comparison with the results in simple obesity, we conclude that the total body fat mass generally is increased in patients with Cushing's disease.


Comparison of the effectiveness of various routes of insulin injection: insulin levels and glucose response in normal subjects. The difference in absorption of insulin and its glucose lowering-effect after the administration of crystalline insulin by the intravenous, intramuscular, and subcutaneous routes was compared in 14 lean normal subjects. Insulin in a dose of 0.1 U/kg body weight was given by the three different routes. Blood was drawn from the opposite arm at regular intervals for the determination of insulin, glucose, glucagon, cortisol, and potassium. Intravenous insulin produced the highest pharmacological level of insulin in 2 minutes (2099 +/- 414 muU/ml) with marked hypoglycemia at 30 minutes (a 68% drop). Intravenous insulin injection produced an increase in plasma glucagon and cortisol reaching a 2-fold increase above the fasting level 30 minutes after the glucose nadir. An equivalent amount of intramuscular insulin produced a maximal increase in plasma insulin at 50 minutes (45 +/- 4 muU/ml) and caused a 35% drop in plasma glucose at 60 minutes, which effects were greater than those caused by subcutaneous injection (highest IRI = 36 +/- 3.5 muU/ml and 23% glucose drop at 180 minutes). No significant increase in glucagon or cortisol was noted with equivalent amounts of subcutaneous or intramuscular insulin injection. Our studies suggest that, in normal lean subjects, insulin injection by the intramuscular route provides a faster absorption of insulin with a concomitant greater drop in plasma glucose than does injection by the subcutaneous route.


Early skeletal effect of alkali therapy upon the osteomalacia of renal tubular acidosis. The administration of alkaline agents to a 16-year-old girl with severe renal tubular acidosis and osteomalacia caused an almost immediate rise of the urinary excretion of total hydroxyproline. The increment of the dyalizable fraction predominated over the nondyalizable component. Gradually serum phosphate and serum alkaline phosphatase increased whereas urinary calcium and magnesium and phosphate clearance declined. Serum PTH remained elevated throughout. We suggest that the correction of the metabolic acidosis might increase the transport of phosphate and calcium across the functional bone membrane leading to a rapid deposition of lime salts in the uncalcified matrix with a concomitant increase in bone collagen turnover.


A testosterone-producing adrenal cortical adenoma in an elderly woman. A 76-year-old woman with virilization had menopausal levels of circulating LH and FSH, and a markedly elevated concentration of plasma testosterone (9130 pg/ml) into the range for adult men. Plasma cortisol and androstenedione levels andurinary 17-ketosteroid secretion were normal. Ethinyl estradiol suppressed plasma testosterone, LH, and FSH levels into the normal range for premenopausal women, but the testosterone concentration was unaffected by the administration of dexamethasone or ACTH. Retrograde venous sampling and angiography localized a right adrenal adenoma preoperatively. Following adrenalectomy, there was a prompt fall in testosterone, but there was no change in the LH concentration. Thus, this patient had an adrenal adenoma which secreted only testosterone and appeared to be gonadotropin-responsive. Testosterone levels in the adult male range failed to suppress gonadotropins. The significance of these findings is discussed.


Testicular chromosomal mosaicism and infertility. A healthy young man with azoospermia and no other endocrinological abnormalties was shown to have chromosomal mosaicism with the cytogenetic errors found only in testicular tissue. Three clones of cells were identified in both meiosis I and meiosis II by cytogenetic analysis of direct testicular smears. Peripheral blood karyotypes and buccal smear preparations revealed no abnormalities. It is postulated that the gonadal cytogenetic defects account for this patient's azoospermia. In addition, it is hypothesized that this type of incomplete spermatogenesis nonetheless produces sufficiet feedback material ("inhibin") so that FSH levels are not affected.


Urine aldosterone radioimmunoassay: validation of a method without chromatography. A simplified radioimmunoassay of urinary aldosterone is reported. Acid-hydrolyzed urine was extracted with dichloromethane and the extract assayed without further purification, Urinary aldosterone values in patients with Cushing's syndrome, low and normal-renin essential hypertension, congenital adrenal hyperplasia, and primary aldosteronism determined by this method agreed closely (r = 0.95, P less than 0.01) with values obtained using a standardized chromatographic method. This simplified assay represents a significant advance in out capabilitites for evaluating patients for abnormalities in aldosterone physiology.


Depression of growth hormone and cortisol response to insulin-induced hypoglycemia after prolonged oral delta-9-tetrahydrocannabinol administration in man. Six hospitalized volunteer male subjects were given insulin, 0.15 U/kg, before and after 14 days of administration of delta-9-tetrahydrocannabinol (THC) at a dose of 210 mg/day. A diminished maximal serum human growth hormone (GH) increase followed the prolonged THC ingestion. The mean maximal GH response was: 52.6 ng/ml +/- 8.7 (+/-SE) before THC and 18.8 ng/ml +/- 6.7 (+/-SE) during THC, P less than 0.01; corresponding cortisol responses were 20.1 mug/dl +/- 3.0 before THC and 10.0 mug/dl +/- 1.1 during THC, P less than 0.05. The data suggest suppression of the hypothalamic-pituitary axis after prolonged high dose THC use. This is consistent with other reported endocrine effects of marijuana in man.


Cortisol-dihydrotachysterol antagonism in a patient with hypoparathyroidism and adrenal insufficiency: apparent inhibition of bone resorption. This report describes a case of chronic mucocutaneous candidiasis with associated hypoparathyroidism and acutely developed adrenocortical insufficiency. The latter was heralded by hypercalcemia. Upon the institution of cortisol therapy, while still under the effects of a vitamin D analog dihydrotachysterol (DHT), the patient exhibited severe hypocalcemia and tetany. Since calcium intake was minimal during this period of presumed corticosteroid-DHT antagonism, it is suggested that the cortisol disturbed calcium homeostasis by in inhibiting bone calcium resorption.