Biomedical subjects
Publications and source records attributed to I Schneider.
There is a significant increase in the percentage and absolute number of activated lymphocytes (OKT10+, IL2R1+) after ECT treatment of major depressive disorder. There is an acute decrease in the absolute number of total lymphocytes, T8+ and Leu11+ cells one hour after a single ECT.
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Reversible conductive hearing loss created during the first 4 weeks post partum caused marked alterations in the maturation of binaural interaction components in the auditory brainstem responses of guinea pigs. In untreated control animals all three components investigated demonstrated postnatal development in terms of latency shortening that was completed during the first 3 weeks of life. Plugging of both external ear canals caused a significant delay in the maturation of the late component DN2, where latency values of the controls were reached only 2 weeks after the end of the treatment, i.e. after 6 weeks of life. Monaural deprivation likewise led to a retarded development of peak latencies during the phase of imbalanced sensory input. After the end of the one-sided conductive hearing loss the maturation process was markedly enhanced, even resulting in latency values for DN2 and DP1 that were significantly shorter than those of the controls. This phenomenon persisted until the end of the study period and was the case for both plugged and untreated ears in this group of animals. The time course of latencies in two other groups of experimental animals which were deprived in the same way as adults suggests that the effects observed are due to a sensitive period in the maturation process of the auditory pathway.
Sporozoites and free circumsporozoite (CS) protein were stained immunoenzymatically in 1-min saliva samples collected from Anopheles stephensi mosquitoes infected with either Plasmodium berghei or P. falciparum. The number of sporozoites in 1-min saliva-streak samples significantly increased as the salivary gland index rose from 3+ to 4+. For P. berghei-infected mosquitoes from which saliva had been collected before 30 days postfeed, the median sporozoite counts for 3+ and 4+ gland indexes were 4.5 and 116, respectively. For P. falciparum-infected mosquitoes, the median counts obtained in two experiments were 4.5 and 14.5 (3+) and 97 and 107 (4+), respectively. The frequency of sporozoite detection in the saliva of mosquitoes containing < 100 salivary-gland sporozoites was low (0.1), whereas that in the saliva of mosquitoes with > 100 sporozoites was high (0.96). In highly infected 4+ P. berghei-infected mosquitoes from which saliva had been collected after 30 days postinfection, both the volume of saliva collected and the median number of sporozoites recovered decreased significantly.
Twenty-one malaria-naive volunteers were immunized with a vaccine consisting of a 22-kDa recombinant peptide (R32LR), derived from the repeat region of Plasmodium falciparum circumsporozoite (CS) protein, covalently coupled to detoxified Pseudomonas aeruginosa toxin A. Nineteen volunteers received a second dose of vaccine at 8 weeks, and eighteen received a third dose at 8 to 12 months. The vaccine was well tolerated, with only one volunteer developing local discomfort and induration at the site of injection which limited function for 48 h. The geometric mean anti-CS immunoglobulin G antibody concentration 2 weeks after the second dose of vaccine was 10.6 micrograms/ml (standard deviation = 3.0 micrograms/ml). Eleven volunteers (52%) developed anti-CS antibody levels of greater than 9.8 micrograms/ml, the level measured in the one volunteer protected against P. falciparum challenge after immunization with the alum-adjuvanted recombinant protein R32tet32 in a prior study. Three separate experimental challenges were conducted with 10 volunteers 2 to 4 weeks after the third dose of vaccine. The four best responders, on the basis of antibody levels (6 to 26 micrograms/ml), were challenged with two infected-mosquito bites, but only one of four immunized volunteers and one of three malaria-naive controls became parasitemic. In a second challenge study using five infected-mosquito bites as the challenge dose, three of three malaria-naive control volunteers and two of three immunized volunteers developed malaria. The third vaccine was apparently completely protected. In the third and last challenge, three of three controls and five of five vaccinees became infected. Sera obtained on the days of challenge inhibited sporozoite invasion of hepatocytes variably in vitro (range, 45 to 90% inhibition), but the degree of inhibition did not correlate with protection. Although antibody against the CS repeat region may protect some individuals against experimental challenge, this protection cannot be predicted from antibody levels by current in vitro assays. The functionality and fine specificity of anti-CS antibody are probably critical determinants.
A direct, double- and triple-staining immunoenzymatic method detected and differentiated sporozoites by color in Anopheles stephensi salivary glands and in mixed sporozoite slide preparations. A double-staining method used beta-galactosidase- and alkaline phosphatase-labeled monoclonal antibodies to the circumsporozoite (CS) proteins of Plasmodium berghei and P. falciparum in mosquito salivary glands. The CS proteins were distinguished clearly by the blue-green and red substrate products of beta-galactosidase and alkaline phosphatase, respectively. A triple-staining method differentiated by color among a mixture of P. falciparum and two strains of P. vivax sporozoites. Monoclonal antibodies to the CS proteins conjugated to beta-galactosidase (P. falciparum), alkaline phosphatase (P. vivax variant), and horseradish peroxidase (P. vivax predominant) readily color differentiated sporozoites by the blue-green, purple-blue, and orange-brown substrate products, respectively. This assay may have potential use in malaria transmission studies, genetic crosses of variant strains of plasmodia to determine assortment of CS antigen alleles, and as a technique to determine the fate of the CS antigen in infected mosquitoes.
The authors examined sera from 92 patients (78 adults, 14 children) with atopic dermatitis (AD), for the presence of circulating immune complexes (CIC). Using the PEG precipitation technique they found an increase in CIC total protein. In the quantity of precipitated proteins, elevated IgA and IgG levels and decreased C3 in CIC were measured. Neither the acute nor the subacute stage of the disease, nor skin involvement, correlated with CIC. In increased content of CIC was found in patients who had AD with associated disease recurrent infections, recurrent conjunctivitis, asthma, allergic rhinitis) and especially with pustulosis varicelliformis Kaposi, i.e. eczema herpeticatum. The T lymphocytes, together with other surface complement receptor-positive cells, are able to induce CIC production and keep them in solution.
The authors describe the case of a 40-year-old female patient. Since childhood her urine had caused black discoloration on her underwear. For about a year the skin of the axillae and pinnae had been bluish-black without subjective complaints. One year before admission, pain in the thoracic and lumbar spine began, with limitation of motion. Examination of the urine, histological and electron microscopical findings, and X-ray examination of the spinal column confirmed the diagnosis of alkaptonuria and congenital ochronosis.
Between 1976 and 1987 at the Surgical Department of the University of Erlangen-Nürnberg, 671 fractures of the trochanteric region of the femur were treated by Ender nailing. In 54 cases (8.0%) there were intraoperative complications, in 82 cases (12.2%) postoperative complications occurred. Reoperation became necessary at 57 (8.5%) patients. Because of this complication rate we only see indications for Ender nailing in patients with skin lesions over the fracture site, valgus angulation of the proximal fragment and in the palliative treatment of pathological fractures.
Development of a consistent pattern in responses to frequency changes is revealed with individual differences scaling. Newborn chicks respond to changes in a background tone to which they have become habituated with momentary delays in their otherwise regular peeping. Durations of these delays are used as measures of perceived difference between all possible pairs of five frequencies between 500 and 608 Hz. Coordinates of five points are calculated to create a map of these frequencies such that distances between points are maximally correlated with delays. A steeply sloped s-shaped curve describes the rapid emergence, from the beginning to the middle of the first postnatal day, of maps that explain significantly more of the input data than expected by chance. This implies that over a few hours birds come to reliably rank different frequencies along a consistent scale. Controlled rearing conditions of decreased external stimulation or early exposure to frequency changes have no effect on this development. In conclusion, scaling is a replicable way to evaluate the development of consistent responses to frequency changes. Similar processes are likely important in other aspects of perceptual development, learning, and memory.
An 11-year-old boy had lentil-sized lichenoid papules, localized to the limbs and trunk, together with acute, nonicteric, hepatitis B surface antigen-positive hepatitis. The clinical picture and course were typical of Gianotti-Crosti disease. Monoclonal antibodies were used to study the lymphocyte subpopulations and surface antigens in the inflammatory infiltrate in frozen sections of a skin biopsy specimen. The results provide data on the pathogenic mechanism of the papular exanthem.
The portrayal of mentally ill persons in movies and television programs has an important and underestimated influence on public perceptions of their condition and care. Movie stereotypes that contribute to the stigmatization of mentally ill persons include the mental patient as rebellious free spirit, homicidal maniac, seductress, enlightened member of society, narcissistic parasite, and zoo specimen. The authors suggest that mental health professionals can fight this source of stigma by increasing their collaboration with patient advocacy groups in monitoring negative portrayals of mentally ill people, using public information campaigns such as Mental Illness Awareness Week to call attention to the process of stigmatization, and supporting accurate dramatic and documentary depictions of mental illness.
Deet and permethrin were evaluated as protectants against Plasmodium falciparum-infected, P. berghei-infected and uninfected Anopheles stephensi mosquitoes. Deet 50% effective dose (ED50) values were 3.2 micrograms/cm2 for P. falciparum-infected and 1.9 micrograms/cm2 for uninfected mosquitoes; permethrin values were 0.5 micrograms/cm2 and 0.6 micrograms/cm2, respectively. Deet ED50 values were 2.3 micrograms/cm2 for P. berghei-infected and 1.3 micrograms/cm2 for uninfected mosquitoes; the permethrin values were both 0.5 micrograms/cm2. There were no significant differences in the protective efficacy of deet or permethrin between malaria-infected and uninfected An. stephensi mosquitoes.
Chlorpromazine (10 mumol/L) causes a marked increase in portal pressure in perfused rat liver. Simultaneously, oxygen consumption, hepatic clearance of taurocholate and bile flow are diminished. These effects are prevented by the cyclooxygenase inhibitors indomethacin (15 mumol/L), acetylsalicylate (3 mmol/L) or ibuprofen (200 mumol/L). On addition of chlorpromazine the liver releases increased amounts of prostaglandin D2; this increase does not occur in the presence of indomethacin. At higher concentrations of chlorpromazine (100 mumol/L) the inhibition of taurocholate clearance and bile flow is accompanied by only a moderate increase of portal pressure, and indomethacin is without effect. At this high concentration, substantial cell damage, as indicated by the release of lactate dehydrogenase, is present. We conclude that arachidonic acid-derived metabolites, notably prostanoids, are involved in the inhibition of bile flow and of taurocholate clearance observed at low concentrations of chlorpromazine. The data suggest that changes in the microcirculation are responsible for the impairment of the liver functions. At higher concentrations of chlorpromazine the cell toxicity of the drug becomes prominent.
The authors describe a typical case of a rare disease, disseminated cicatricial pemphigoid. At the site of the subepidermal bulla excessive scarring in seen. Electron microscopic examination reveals elastic fibrin deposition and incipient vacuolation under the basement membrane. The indirect immunoperoxidase study shows increased numbers of positive Langerhans cells, which support their antigen-presenting role.
Midazolam is useful as an intravenous supplement to local anaesthesia techniques in producing sedation, amnesia and anxiolysis, and has about five times the sedative potency of diazepam. Considerable interpatient variability exists in dose requirements, especially in elderly patients. The combined effects of local anaesthetics and midazolam may contribute to enhanced haemodynamic effects and changes in the respiratory pattern, impairing ventilation and oxygenation. Flumazenil can be titrated in incremental doses to reverse the residual sedative effects of midazolam, without intrinsic haemodynamic or respiratory effects, but may not fully antagonise the decrease in chemoreceptor sensitivity nor the changes in breathing pattern induced by midazolam. Patients treated with epidural or spinal anaesthesia supplemented with midazolam should be monitored to avoid hypoxaemia risks even after the administration of flumazenil.
A recombinant DNA Plasmodium vivax sporozoite vaccine containing the repeating region of the Salvador I strain circumsporozoite (CS) protein was produced in Escherichia coli. This vaccine was tested in 13 naive volunteers at doses of 10-1,000 micrograms. No serious adverse reactions were noted. None of 4 volunteers receiving the 10 micrograms dose developed antibodies measurable by ELISA. Six of 9 volunteers in the other dose groups developed measurable antibodies: 5 of 5 volunteers receiving 100 micrograms and 1 of 4 receiving 1,000 micrograms. Antibody responses measured by immunofluorescence assays paralleled those seen by ELISA. None of the volunteers developed antisera that inhibited sporozoite invasion of human hepatoma cells in vitro. Lack of a classical anamnestic response and lack of a typical dose response to increasing amounts of antigen suggests the possible presence of an immunosuppressive epitope in the repetitive region of the CS protein.
Malaria was transmitted to only 5 of 10 volunteers bitten by 1-2 Anopheles stephensi carrying sporozoites of the 3D7 clone of the NF54 strain of Plasmodium falciparum in their salivary glands. Parasites were detectable by culture in blood taken 7-10 days following exposure and by thick blood film 14-16.5 days after exposure. Infectivity did not correlate with the numbers of sporozoites in the salivary glands.