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Biomedical subjects

A Wunderlich

Publications and source records attributed to A Wunderlich.

13 recordsLinked to original sources
PubMed1998

[Temperature stress for patients in routine magnetic resonance examinations].

PURPOSE: To determine energy exposure and temperature changes in routine magnetic resonance imaging practice. MATERIALS AND METHODS: Body core and skin temperatures were compared in 155 persons (143 patients, 12 volunteers) undergoing routine magnetic resonance examinations with a 1.5 T field-strength magnetic resonance tomography unit using a fluoroptic temperature measurement system. RESULTS: Average applied energy was 0.3 W/kg for whole body and 1.92 W/kg for spatially localized SAR. The maximum whole-body SAR was 1.43 W/kg spatially localized. Body core temperatures differed from those of the control group by a median 0.1 degree C and only a few patients (16.8%) exceeded the limit (+/- 0.5%) at which regulatory mechanisms set in. All patients remained within the normal physiological circadian temperature range (+/- 1 degree C). Skin temperature rose a median 0.49 degree C, with a maximal increase of 5.31 degrees C, which may be considered to be within the limits of physiological temperature change. CONCLUSIONS: Clinically relevant warming of the body is unlikely in routine magnetic resonance imaging practice.

Adolescent↗
PubMed1998

Virtual cystoscopy based on helical CT scan datasets: perspectives and limitations.

The purpose of the study was to simulate cystoscopy based on three-dimensional helical CT scan datasets in real-time in patients with tumours of the urinary bladder. A helical CT scan with double detector technology was carried out pre-operatively in 11 patients with histologically confirmed carcinoma of the urinary bladder and one patient with chronic cystitis. A non-enhanced scan was first performed, followed by an examination in the early phase of contrast medium enhancement. Further images were acquired after adequate filling of the bladder with contrast medium, approximately 30 min after injection. These data were transferred to a separate graphic computer workstation and reconstructed. The results were then compared with the cystoscopic and histopathological findings. All tumours of the urinary bladder identified at fibreoptic cystoscopy were shown on virtual cystoscopy. The best reconstruction results were obtained from data acquired 30 min after injection of contrast medium. The ureteric orifices were not visualized at virtual cystoscopy. These data lead us to conclude that, at present, virtual cystoscopy has not reached the quality of fibreoptic examination and remains restricted to use in specific cases, for example patients with urethral strictures.

Aged↗
PubMed1997

Alopecia areata but not androgenetic alopecia is characterized by a restricted and oligoclonal T-cell receptor-repertoire among infiltrating lymphocytes.

Although the etiology of alopecia areata is still unknown, evidence has accumulated to support an autoimmune pathogenesis for this disease. To evaluate the role of T cells in alopecia areata the T-cell receptor VB-repertoire was investigated in lesional skin and blood of 5 patients by means of a semiquantitative technique based on the reverse transcriptase polymerase chain reaction. Three patients with androgenetic alopecia served as controls. Amplification products were screened for clonality by temperature gradient gel electrophoresis. Four of 5 patients with alopecia areata exhibited a lesional T-cell receptor-repertoire characterized by an almost exclusive utilization of variable regions beta 2, 4, and 13. Temperature gradient gel electrophoresis revealed the oligoclonal constitution of the infiltrate. The restricted nature of the lesional T-lymphocytic infiltrate in alopecia areata strongly suggests that an antigen-specific T-cell response plays an important role in the pathogenesis of this disease.

Adult↗
PubMed1996

[Virtual cystoscopy based on spiral CT data].

Simulation of three-dimensional cystoscopy based on helical CT scan data in real-time in patients with tumours of the urinary bladder. In three patients with histologically confirmed carcinoma of the urinary bladder, a helical CT scan with double detector technology was carried out preoperatively. A native scan was first performed, followed by an examination in the early contrast medium enhanced phase. After adequate contrasting of the urinary bladder (30 minutes latency), further images were acquired. These data were transferred to a separate graphic computer workstation and reconstructed. The results were then compared with the cystoscopic and pathohistological findings. All tumours of the urinary bladder identified at fiberoptic cystoscopy were also visualised by virtual cystoscopy. The best reconstruction results were obtained from data acquired after the 30-minute latency period. Virtual cystoscopy represents an interesting option in helical CT scanning, which is able to visualise polypoid tumours of the urinary bladder. Its clinical relevance, however, must be demonstrated in studies with a larger number of patients examined.

Aged↗
PubMed1995

HIV gp120-specific cell-mediated immune responses in mice after oral immunization with recombinant Salmonella.

Salmonella is of great interest as a potential human immunodeficiency virus vaccine vector because of its ability to elicit potent mucosal and systemic immune responses when administered orally. To determine whether such a vaccine could elicit an immune response in mice, plasmids expressing HIV gp120-LAI were introduced into attenuated S. typhimurium. Three serial doses of 10(10) recombinant organisms were administered orally to BALB/c mice at 2-week intervals. Immunized mice but not control mice demonstrated proliferative T cell responses to gp120-LAI, comparable in magnitude to the proliferative responses to Salmonella antigens. Immunized mice had detectable serum and intestinal Salmonella-specific IgA and serum Salmonella-specific IgG. However, no gp120-specific antibody was detected in either serum or intestinal washes. These results indicate that live recombinant Salmonella-based vaccine constructs can induce HIV-specific cellular immune responses in vivo.

AIDS Vaccines↗
PubMed1987

Encystation and expression of cyst antigens by Giardia lamblia in vitro.

The cyst form of Giardia lamblia is responsible for transmission of giardiasis, a common waterborne intestinal disease. In these studies, encystation of Giardia lamblia in vitro was demonstrated by morphologic, immunologic, and biochemical criteria. In the suckling mouse model, the jejunum was shown to be a major site of encystation of the parasite. Small intestinal factors were therefore tested as stimuli of encystation. An antiserum that reacted with cysts, but not with cultured trophozoites was raised in rabbits and used as a sensitive probe for differentiation in vitro. Cultured trophozoites that were exposed to bile salts showed a more than 20-fold increase in the number of oval, refractile cells that reacted strongly with anticyst antibodies, and in the expression of major cyst antigens. Exposure to primary bile salts resulted in higher levels of encystation than exposure to secondary bile salts. These studies will aid in understanding the differentiation of an important protozoan pathogen.

Animals↗
PubMed1985

Protection against gram-negative bacteremia and endotoxemia with human monoclonal IgM antibodies.

Hybridomas producing human monoclonal IgM antibodies (mAbs) against bacterial lipopolysaccharide (LPS) were generated by fusion of B lymphocytes from sensitized human spleen with heteromyeloma cells. The splenocytes were from patients undergoing splenectomy during staging for Hodgkin disease after vaccination with the J5 mutant of Escherichia coli, which is deficient in O antigenic side chains. This deficiency exposes the core oligosaccharide, common to LPS of all Gram-negative bacteria. The mAbs cross-reacted strongly with endotoxins from a wide range of unrelated species of Gram-negative bacteria. The mAbs also gave strong protection against LPS in the dermal Shwartzman reaction and against lethal Gram-negative bacteremia in mice. These findings indicate that monoclonal IgM against LPS endotoxin can neutralize its toxicity in vivo and might be valuable for treatment of patients with Gram-negative bacteremia. Analysis of one of the hybridoma clones, A6(H4C5), showed that the IgM mAb is directed against the covalently bound lipid A, which represents the most conservative and least variable structural element of LPS.

Animals↗
PubMed1983

Immunity to pasteurellosis in compromised rabbits.

Pasteurellosis in the rabbit inoculated with a malignant variant of Shope fibroma virus (SFV-MV) is presented as a model for the study of immunosuppression and immunoprophylaxis in pasteurellosis. The rabbits, before the inoculation, were healthy carriers of Pasteurella multocida. They were intradermally inoculated with SFV-MV, and 3 to 6 days later, a primary tumor appeared at the site of inoculation. By postinoculation day (PID) 7 or 8, the rabbits had snuffles, conjunctivitis, and tumor metastases; death occurred on PID 10 to 14. Rabbits given the nonmalignant Patuxent strain of SFV developed local primary tumors, but not pasteurellosis nor metastases. In SFV-MV-inoculated rabbits, there was decreased responsiveness of spleen lymphocytes to B and T cell mitogens by day 6, and of spleen and peripheral blood lymphocytes by day 10. In addition, SFV-MV antigen was detected (by immunofluorescence) in mononuclear phagocytes in all major organs and in epithelial cells of the conjunctiva and nasal mucosa. Both nasal and conjunctival epithelia showed squamous metaplasia as well. These changes did not appear in SFV-infected rabbits. With SFV-MV-inoculated rabbits, we obtained partial protection against pasteurellosis by immunization with heat-killed P multocida or a cross-protective core lipopolysaccharide mutant of Escherichia coli (J5). Rabbits were immunized before the inoculation with SFV-MV which precipitated "spontaneous" pasteurellosis due to impaired defenses. Rabbits immunized with J5 or P multocida had less severe conjunctivitis and snuffles than nonimmunized controls, indicating that immunization with the J5 mutant may be useful as prophylaxis against pasteurellosis in compromised hosts.

Animals↗
PubMed1977

Role of urinary solutes in natural immunity to gonorrhea.

Natural resistance of the male urethra to gonococci has not been explained by classical immune mechanisms but could result from antibacterial properties of urine. Accordingly, we measured survival in midmorning urine of 10(7) F-62 T2 gonococci per ml by serial dilutions and plate counts. Fifteen killer urines from eight people all killed greater than 3 logs (average, 5.3), and 13 of 15 were sterilized. Fourteen nonkiller (inhibitor) urines from seven subjects allowed no growth. Killer urines were more acidic (pH 5.4 versus 6.4) and more concentrated (861 versus 717 mosmol/kg) than nonkillers. Upon addition of hydrogen ion, urea, and sodium chloride to urines and broth, pH proved to be the major killing factor, but urea and NaCl were also bactericidal. Susceptibility to urine bactericidal power did not vary with colony type (T2 versus T4) or strain (F-62 versus two fresh isolates). Killing was rapid (0.5 to 3 h) and not bacteriolytic. Escherichia coli multiplied 10-fold in urines that inhibited growth of gonococci. Thus, the bacteriostatic effect of urine may explain why gonococci do not infect the bladder and kidney during gonorrhea. The bactericidal properties of urine may contribute to resistance against gonococcal urethritis.

Bacteriolysis↗