Magnetic resonance imaging of avascular necrosis of the femoral head

This study investigates the role of magnetic resonance imaging (MR) in identifying avascular necrosis (AVN) of the femoral head and in monitoring its therapy. The detection of AVN, particularly in its early stages, is imperative to give therapeutic intervention the best opportunity for successful management. The results of magnetic resonance imaging are compared with those of the standard diagnostic modalities in evaluation of patients with the lesion. Examinations were performed at 0.12T with a repetition time (TR) of 143 ms and times to echo (TE's) of 10 or 20 ms. This study represents a retrospective review of 90 hips which were examined in 45 consecutive patients. Of these, 52 hips were biopsied as part of treatment. MR was shown to be sensitive in the detection of AVN. Comparison of MR with radionuclide imaging showed comparable sensitivity and specificity. MR was also noted to be sensitive in the detection of early AVN. Preliminary results suggest that MR can monitor treatment of the affected hip, and may even be able to predict patient response to therapy. Although further work is necessary to determine the role of MR in the evaluation of the patient presenting with hip pain, MR is a sensitive method in detecting AVN and in monitoring its course in patients suspected of having the disease.

Stress hormonal response to exercise after sleep loss

While prolonged loss of sleep is unpleasant and demanding, it remains unclear if it blunts or enhances the physiological stress imposed by subsequent exercise. To investigate this, we deprived eight subjects of sleep prior to exercise to see if this altered the stress hormonal response to that exercise. In a first series of experiments, two fragmented nights of sleep preceded 30 min of heavy treadmill walking exercise. While sleep loss disturbed mood before and during exercise (p less than 0.05), it left stress hormonal levels (cortisol and beta-endorphin) in blood identical to control. In a second series, subjects performed light treadmill walking exercise for 3 h after 36 sleepless hours. As before, sleep deprivation disturbed mood before and throughout exercise (p less than 0.05), but failed to change blood levels of stress hormones. In both series, sleeplessness left heart rate, oxygen uptake, minute ventilation, and body core temperature unchanged in exercise. We conclude that sleep loss provokes psychological changes during subsequent exercise without measurably altering the stress hormonal response to that exercise.

Comparison of a videotape instructional program with a traditional lecture series for medical student emergency medicine teaching

An emergency medicine faculty has reported that the use of the videotape medium for presenting curricular material to medical students is both cost effective and well suited to the educational milieu of the emergency department. In order to compare the effectiveness of videotape instruction with that of a traditional lecture, groups of students received instruction in one topic by videotape and in another topic by lecture. The students' retention of material was tested by a multiple-choice examination administered ten days later. The students scored 76.1% (683 of 898 questions) on material taught by lecture and 76.2% (673 of 883 questions) on material taught by videotape (P greater than 0.7). We conclude that videotape instruction is as effective an educational tool as the traditional lecture for an emergency medicine course.

Distribution of ATPase-positive Langerhans cells in normal adult human skin

The distribution of ATPase-positive Langerhans cells (LC) was investigated in 117 specimens of normal adult human skin and mucosa taken from different areas of the body. Although there were significant variations in the numbers of LC in each area examined, skin from the face and neck contained the highest density of cells (976 +/- 30.93/mm2). The densities of LC in trunk skin (740 +/- 28.97/mm2), scalp (693 +/- 69.56/mm2) and arm or leg skin (640 +/- 40.95/mm2) were similar. Buccal mucosa had significantly fewer LC (567 +/- 42.94/mm2) than trunk skin, and sacrococcyx skin and palm and sole skin displayed the smallest number of these cells (267 +/- 56.14/mm2 and, 189 +/- 19.15/mm2 respectively). No ATPase-positive LC were detected in the centre of two corneal specimens.

Radiographic and histologic analyses of stress fracture in rabbit tibias

Sequential changes in remodeling of the internal structure of the tibia caused by controlled, excessive jumping and running were studied in 20 rabbits. Vascular changes and circulatory disturbances within the cortical bone occurred before osteoclastic resorption. Degeneration and necrosis of osteocytes due to circulatory disturbances also occurred. Periosteal new bone formation, found at and after 12 days of the experiment, was a compensatory reaction to support the tibia weakened by accelerated osteoclastic resorption. Small cracks appeared at the cement line and developed through the neighboring cement line of the haversian systems. At 21 days, incomplete fracture of the tibial cortex was found in two rabbits. Complete fracture through one side of the cortex was seen in one animal at the 50th day of the experiment. In this study, however, most of the tibias did not have visible fracture lines after a period of stressful exercise. This result suggests that most tibias adapt to changes in stress requirements through proper internal remodeling so that a complete fracture does not occur.

Goldenhar syndrome, anterior encephalocele, and aqueductal stenosis following fetal primidone exposure

Fetal exposure to primidone was associated with Goldenhar syndrome, hemifacial microsomia, tetralogy of Fallot, aqueductal stenosis, and anterior encephalocele in this male infant. No similar cases in anticonvulsant-exposed pregnancies were found on literature review, despite the increased incidence of other anomalies following such exposure. Goldenhar syndrome, especially related to rare central nervous system anomalies, is reviewed. Experimental production of hemifacial microsomia by a folic acid antagonist, triaxene, is mediated via hemorrhage in the fetus. Intraventricular hemorrhage was noted in this infant as were dilated lateral and third ventricles. The hemorrhagic diathesis and/or the folic acid depletion of newborns following fetal anticonvulsant exposure may have been the underlying mechanism.

Inspiratory muscle training in patients with chronic obstructive pulmonary disease

To investigate the effects of inspiratory muscle resistive loading training (IMT) on exercise performance in chronic obstructive pulmonary disease (COPD), 13 patients undergoing standard pulmonary rehabilitation were divided into control (n = 6) and experimental (n = 7) groups. Prior to training, we measured inspiratory muscle strength and endurance, resting pulmonary function, and exercise performance on a bicycle ergometer (a progressive test and an endurance test at two thirds of maximal work load). We then determined their resistive loads for training by measuring their 10-min maximal sustainable resistance. Training by patients in the experimental group involved inspiring against a predetermined resistive load. The control subjects breathed through a sham training tube, so that studies were performed in double-blind fashion. The training consisted of 15-min sessions twice daily for 4 wk. The IMT dramatically improved inspiratory muscle endurance--represented as either sustainable inspiratory pressure (SIP) or endurance time at 60% of maximal inspiratory mouth pressure (Pimmax) at functional residual capacity. The SIP of the trained group increased from 29 +/- 11 to 46 +/- 11% of Pimmax (p less than 0.005). Training slightly increased inspiratory muscle strength (p less than 0.05), as determined by Pimmax. In contrast, resting pulmonary function and performance of both progressive and constant-load exercise remained unchanged. We conclude that 4-wk IMT in a pulmonary rehabilitation setting improves inspiratory muscle endurance in patients with COPD without changing pulmonary function or exercise performance.

Detection of a thermostable brain antigen in the circulation of patients after cerebrovascular accident

Enzyme immunoassay was developed with a thermostable antigen of human brain and its corresponding antiserum of rabbit origin. Inhibition of this assay proved to be a sensitive technique for detection of this antigen in the circulation. Using the inhibition test, we tested 170 serum samples originating from 42 patients with cerebrovascular accident (CVA), 166 sera from 166 patients with other neurological disorders, and 56 sera from 56 normal subjects. Fourteen patients with CVA were found to be "positive' and 28 "negative'. Positive results in inhibition tests were first noted within 1-2 days after CVA and they appeared to decline to negative values within 3-5 weeks after CVA. None of the sera from subjects without CVA were positive.

A student emergency medicine clerkship that uses new information technologies

The effective teaching of clinical emergency medicine to medical students requires efficiency in the management of both student and faculty time. Presented is a course outline that makes use of the following elements to structure and augment clinical time in the emergency department (ED): Videotape to present a 19.7-hour series of faculty-produced lectures covering a "core" emergency medicine curriculum. A microcomputer to facilitate staggered scheduling of clinical time. A microcomputer test generation program that permits a secretary to formulate, administer, and grade a different final exam with each rotation. Computer-assisted recordkeeping for faculty evaluation of a student's clinical performance. Once established, this program can be administered with fewer than five faculty hours per month assisted by a part-time (25% full-time equivalent) clerical coordinator. The total cost for the instructional program is $86.37 per student using the new technologies, and $144.15 per student when presenting the same program using traditional teaching techniques. The use of new technologies in student teaching will therefore result in significant savings.

A "new" lethal multiple congenital anomaly syndrome: joint contractures, cerebellar hypoplasia, renal hypoplasia, urogenital anomalies, tongue cysts, shortness of limbs, eye abnormalities, defects of the heart, gallbladder agenesis, and ear malformations

Three cases of a lethal malformation syndrome with severe visceral anomalies were seen in two families and include one pair of sibs. The predominating external manifestations are mesomelic dwarfism, micrognathia, V-shaped upper lip, microglossia, thick alveolar ridges, ambiguous genitalia, webbed neck, highly arched palate, clubfeet, fused fontanelles, inclusion cysts of the tongue, four-finger creases, digital anomalies, apparently low-set ears, widely spaced nipples, and dislocated thighs and forearms. The internal findings include oligopapillary renal hypoplasia, severe congenital heart defect, cerebellar hypoplasia, pulmonary hypoplasia, hypoplastic larynx, and hypoplastic gallbladder. Other findings from the two autopsies and one clinical investigation not documented in all three patients include unilobar lungs, hydrocephalus, cataracts, microphthalmia, polydactyly, islet cell hyperplasia, suprapubic skin crease, urethral anomalies, and a decreased number of turns of the cochlea. The hypoplasia seen in the several affected organs is similar to the disordered development seen in experimental models of branching epithelial morphogenesis in which mesenchymal-epithelial interaction has been disrupted.

Syndrome of multiple pterygia, camptodactyly, facial anomalies, hypoplastic lungs and heart, cystic hygroma, and skeletal anomalies: delineation of a new entity and review of lethal forms of multiple pterygium syndrome

Three unrelated stillborn infants (cases 1-3) are presented here with a distinct constellation of multiple anomalies: namely, multiple pterygia involving chin-to-sternum, cervical, axillary, antecubital, crural and/or popliteal areas, flexion contractures of multiple joints, small chest, hydrops, characteristic abnormal facial appearance with hypertelorism, markedly flattened nasal bridge with hypoplastic nasal alae, cleft palate, micrognathia, apparently low-set malformed ears, short neck with a cystic hygroma at the back of the neck and head, and pulmonary and cardiac hypoplasia. Radiographic studies, in addition, showed scalp edema, microbrachycephaly, flattened mandibular angle, lack of normal curvature at the cervico-thoracic junction, marked bony fusion of posterior spinous processes of older fetuses (cases 1, 2), thin crowded ribs, markedly hypoplastic scapulae, hypoplastic iliac wings, ischia and pubic bones, undermodeling of tubular bones, and radio-ulnar synostosis. Histologic studies of the skeletal system showed cartilaginous and bony fusion of the spinous processes (cases 1, 2), fusion of epiphyseal cartilages of distal humerus and proximal ulna, a poorly developed joint space, an abnormal growth plate, and weak safranin staining of the resting cartilages (cases 1, 2). To the best of our knowledge, this pattern of anomalies constitutes a previously undescribed syndrome. Prenatal diagnosis of this entity is possible by ultrasonographic studies on the basis of nonimmune fetal hydrops, a cystic hygroma at the back of the head and neck, diminished fetal activity, short and fixed limbs, and/or maternal hydramnios. Three additional cases (cases 4-6) are also presented to show a possible heterogeneity of this syndrome.

Cardiotoxicity of Forssman antibodies in in vitro perfusion experiments

Guinea pig heart was perfused in vitro by xenogeneic sera. Sera from both Forssman-positive and Forssman-negative animals exerted strong cardiotoxicity. The toxic effect of rabbit sera could be very significantly decreased by absorption or neutralization of the naturally occurring Forssman antibodies, pointing to the significant role played by these antibodies in the "rejection" of a Forssman-positive organ.

Total lipid and cholesterol content in the blue crab, Callinectes sapidus Rathbun

Total lipid and cholesterol concentrations in hepatopancreas, gonad and muscle were analyzed for 70 blue crabs. The concentrations were highest in hepatopancreas, then gonad, and muscle was the lowest. In male crabs, the concentrations decreased from the immature stage (feeding and growth stage) to the mature stage (breeding stage), and from August to September (breeding period) in mature males. In female crabs, the concentrations were comparatively high for peelers (pre-molting stage) and mature females in October (pre-spawning migration period). The total lipid and cholesterol concentrations were significantly, positively correlated in both sexes. The total lipid and cholesterol concentrations were independent of both body weight and tissue weight. Exceptions were the immature females whose concentrations in hepatopancreas were negatively correlated with both body weight and hepatopancreas weight, and the mature females whose concentrations in gonads were positively correlated with gonad weight.

Immunological studies of autoimmune thyroid disorders: abnormalities in the inducer T cell subset and proliferative responses to autologous and allogeneic stimulation

Various immunological parameters were investigated in patients with Hashimoto's thyroiditis (HT) and Graves' disease (GD). The total T cell numbers were significantly decreased in both diseases whether they were enumerated by E rosetting or by pan-T cell monoclonal antibodies (OKT3 and anti-Leu 1). This diminution was due to a loss in the inducer T cell subset (OKT4+/Leu 3a+) whereas the cytotoxic/suppressor T cells (OKT8+/Leu 2a+) were present at normal levels in both diseases. The B cells were significantly higher in GD patients than in controls but were not modified in HT patients. Monocyte percentages remained unchanged and DR+ cells were slightly increased in the two diseases. On the other hand, T lymphocyte responses to stimulation by autologous or allogeneic cells were significantly impaired in GD but not in HT whether cultures were performed in autologous plasma or AB serum. In addition, lymphocytes from normal subjects were unable to proliferate in auto- or allo-MLR in the presence of plasma from GD patients but they were reactive in the presence of HT plasma or AB serum. Taken together, these results suggest that the patients with autoimmune thyroid disorders exhibit a T cell imbalance within the OKT4+/Leu 3a+ subset. Moreover, this abnormality is correlated with the observation that autoreactive and alloreactive cells are defective in GD.

The Pena-Shokeir syndrome: report of five cases and further delineation of the syndrome

We report on five cases of lethal Pena-Shokeir syndrome from three families with affected sibs. In addition to multiple anklyoses, camptodactyly, facial anomalies, and pulmonary hypoplasia, one fetus had pterygia of the neck and axillae and cardiac hypoplasia. Radiographic changes are nonspecific and probably are related to a lack of intrauterine movement. Our data and review of the literature suggest that pterygium formation is one of the manifestations of the Pena-Shokeir syndrome. A recently described lethal form of the recessively inherited multiple pterygium syndrome may represent a severe form of the Pena-Shokeir syndrome.

Fabrication of a 360 degrees astigmatic rainbow hologram

A 360 degrees astigmatic rainbow holographic recording scheme is proposed. The experimental result is also included.