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Biomedical subjects

J Weber

Publications and source records attributed to J Weber.

At least 145 records · Page 8Linked to original sources

[Craniocerebral trauma in sports. With recommendations for prevention].

Traumatic brain injury (TBI) is found in many sports. A mild head injury (concussion of brain) is found in more than 80%, mainly in sports with contact to others. Especially affected by death are air sports, horse riding and cycling, whereby brain damage often is the leading injury. With the example of a cycling accident the possible processing dynamics of a mild head injury with secondary brain damage through an intracranial hematoma is demonstrated in the following. For the assessment of sports ability, there is often made the division with symptoms as confusion, amnesia and unconsciousness after a mild head injury (scale 1-3). According to the gravitational scale of cerebral concussion, an adequate sports break should be kept. Postcommotional symptoms prove sports inability. A chronic brain damage is not rarely found in some combative sports. In this case the injury may result in a traumatic encephalopathia with the evaluation of dementia and in some cases also Parkinson's disease is observed. To prevent a TBI there should be worn an adequate protective headgear especially by children in training and in sports contests concerning risk sports. Further recommendations for prevention are presented and with them there will also be responded to sports ability in neurosurgical diseases.

Accidents, Traffic↗

Immunization with human immunodeficiency virus type 1 rgp120W61D in QS21/MPL adjuvant primes T cell proliferation and C-C chemokine production to multiple epitopes within variable and conserved domains of gp120W61D.

Human immunodeficiency virus type 1 (HIV-1) gp120W61D-specific T cell lines (TCL) were generated from an HIV-1-seronegative volunteer who received rgp120W61D in QS21/MPL adjuvant with emulsion. TCL were challenged with pools of consecutive, overlapping peptides spanning the gp120W61D sequence and then with the individual peptides of the immunostimulatory pool. T cell epitopes were found within both variable and conserved domains, and there was no evidence of a single immunodominant epitope. The two most frequently recognized peptides were located in the C1 domain and in the C-terminal region of the V3 loop. Several TCL were shown to recognize multiple peptides from nonoverlapping regions. Peptides from both conserved and variable domains were capable of inducing MIP-1alpha, MIP-1beta, and RANTES production. When tested against the equivalent peptide from the HIV-1IIIB sequence, however, TCL were able to tolerate only minor conserved changes in the amino acid sequence.

AIDS Vaccines↗

Relationship between the response to influenza vaccination and the nutritional status in institutionalized elderly subjects.

BACKGROUND: Influenza is a major health problem among elderly people in industrialized countries. Nursing homes may be a particularly good setting for outbreaks of influenza. Thus, the aim of the present study was to evaluate some aspects of the nutritional status of institutionalized elderly subjects in relation to their response to influenza vaccination. Certain aspects of the cellular immune response were also investigated. METHODS: Twenty-three patients participated in this cross-sectional study. All patients were vaccinated on day 0 with FluviralR, 1994-95 preparation: A/Shangdong/09/93, A/Texas/36/91, B/Panama/45/90. At the same time the prevaccination antibody titer, the nutritional status by the Mini Nutritional Assessment, biochemical parameters, and lymphocyte proliferation were assessed. On day 28, the postvaccination antibody titer was determined. The determination of pre- and postvaccination antibody titers against the various influenza antigens was carried out by the hemagglutination inhibition test. An increase of 4x for any of the virus antigens was considered as a seroconversion. A titer higher than 40 at the prevaccination period was considered as protective. RESULTS: Eleven elderly subjects were responsive and 12 were not. We have shown that the nutritional parameters such as hemoglobin, hematocrit, total protein, iron and vitamin E levels, as well as the DHEA level and the cellular immune response were significantly lower in the nonresponsive group as compared to the responsive group. Thus, they might be associated with the influenza vaccine responsiveness of institutionalized elderly subjects. CONCLUSIONS: These results will help design intervention studies for improving the immune response by achieving an optimal nutritional status, mainly in the frail elderly population, that could have a great public health impact.

Aged↗

Comparison of the diagnostic information in relative cerebral blood volume, maximum concentration, and subtraction signal intensity maps based on magnetic resonance imaging of gliomas.

RATIONALE AND OBJECTIVES: The authors investigate the validity of regional relative cerebral blood volume (rCBV) versus maximum concentration and subtraction signal intensity (SI) maps using simple reconstruction modes in patients with gliomas. METHODS: Twenty-five patients were studied using a 1.5 T magnetic resonance imaging scanner. To calculate the rCBV map, the magnetic resonance susceptibility effect SI/time curves were first transformed into concentration/time curves; then a gamma-variate function was fitted and the area under the curve was integrated. From the concentration/time data, the maximum concentration (MAX) maps were calculated pixel per pixel as the maximum peak amplitude of the concentration/time curve. Subtraction (SUB) maps are a result of simple image subtraction of pixelwise baseline SI minus the highest peak of susceptibility change pixel per pixel. Region of interest means SI measurement of the different maps was compared using statistical t test correlation. RESULTS: Normal gray to white matter contrast did not show a significant difference among the rCBV, MAX, and SUB maps. Based on statistical evaluation, the low-grade lesions did not differ significantly in the rCBV, MAX, and SUB maps. The group with high-grade lesions (12 patients) showed no significant difference in standardized rCBV, MAX, and SUB maps. CONCLUSION: Compared to rCBV maps, the simple MAX and SUB maps demonstrated good correlation in both high-grade and low-grade gliomas. This simpler approach could establish first-pass reconstruction in clinical settings because it reduces the need for time-consuming postprocessing.

Adult↗

Intratype sequence variation among clinical isolates of the human papillomavirus type 6 L1 ORF: clustering of mutations and identification of a frequent amino acid sequence variant.

Human papillomavirus type 6 (HPV-6) is the causative agent of condyloma acuminata, a common sexually transmitted disease. Virus-like particles (VLPs) assembled from the L1 major capsid protein represent promising candidates for prophylactic vaccines. However, any intratype sequence variation among HPV-6 L1 ORFs will influence which sequence is used for a vaccine according to its prevalence in the population and its propensity for VLP production. Therefore, we have analysed the entire L1 nucleotide sequence of 17 clinical isolates of HPV-6 from the London area. We found 28 positions where changes from the prototype HPV-6b L1 occurred, showing that HPV-6 L1 intratype variation is greater than previously reported. The most frequently observed substitutions are clustered into three discrete regions: R1 (nt 5920-6075), R2 (nt 6590-6670) and R3 (nt 7070-7230). Indeed, most of the nucleotide substitutions within the HPV-6 L1 reported worldwide also map to these regions. The R3 region contains predominantly non-silent substitutions, the most common of which is a G-to-C substitution at position 7079. This results in a Glu-to-Gln change at aa 431, although this change had no effect on VLP yield or stability. This substitution defines a new HPV-6 L1 amino acid sequence that is more abundant in the isolates examined than any other reported sequence.

Amino Acid Sequence↗

Comparison of the antibody repertoire generated in healthy volunteers following immunization with a monomeric recombinant gp120 construct derived from a CCR5/CXCR4-using human immunodeficiency virus type 1 isolate with sera from naturally infected individuals.

We have characterized sera from healthy volunteers immunized with a monomeric recombinant gp120 (rgp120) derived from a CCR5/CXCR4 (R5X4)-using subtype B isolate of human immunodeficiency virus type (HIV-1), HIV-1W61D, in comparison to sera from long-term HIV-1-infected individuals, using homologous reagents. Sera from vaccinees and HIV-1 positive subjects had similar binding titers to native monomeric rgp120W61D and showed a similar titer of antibodies inhibiting the binding of soluble CD4 (sCD4) to rgp120W61D. However, extensive peptide binding studies showed that the overall pattern of recognition of vaccinee and HIV-1-positive sera is different, with vaccinee sera displaying a wider and more potent recognition of linear V1/V2 and V3 domain epitopes. Neutralization of homologous HIV-1W61D or heterologous HIV-1M2424/4 peripheral blood mononuclear cell (PBMC)-derived virus lines by vaccinee sera could be achieved, but only after adaptation of the viruses to T-cell lines and was quickly lost on readaptation to growth in PBMC. Sera from HIV-positive individuals were able to neutralize both PBMC-grown and T-cell line-adapted viruses. Interestingly, rgp120W61D was recognized by monoclonal antibodies previously shown to neutralize primary HIV-1 isolates. The use of very potent adjuvants and R5X4 rgp120 led to an antibody response equivalent in binding activity and inhibition of binding of sCD4 to gp120 to that of HIV-positive individuals but did not lead to the induction of antibodies capable of neutralizing PBMC-grown virus.

AIDS Vaccines↗

Sequence variations in human immunodeficiency virus type 1 Nef are associated with different stages of disease.

nef alleles derived from a large number of individuals infected with human immunodeficiency virus type 1 (HIV-1) were analyzed to investigate the frequency of disrupted nef genes and to elucidate whether specific amino acid substitutions in Nef are associated with different stages of disease. We confirm that deletions or gross abnormalities in nef are rarely present. However, a comparison of Nef consensus sequences derived from 41 long-term nonprogressors and from 50 individuals with progressive HIV-1 infection revealed that specific variations are associated with different stages of infection. Five amino acid variations in Nef (T15, N51, H102, L170, and E182) were more frequently observed among nonprogressors, while nine features (an additional N-terminal PxxP motif, A15, R39, T51, T157, C163, N169, Q170, and M182) were more frequently found in progressors. Strong correlations between the frequency of these variations in Nef and both the CD4(+)-cell count and the viral load were observed. Moreover, analysis of sequential samples obtained from two progressors revealed that several variations in Nef, which were more commonly observed in patients with low CD4(+)-T-cell counts, were detected only during or after progression to immunodeficiency. Our results indicate that sequence variations in Nef are associated with different stages of HIV-1 infection and suggest a link between nef gene function and the immune status of the infected individual.

Acquired Immunodeficiency Syndrome↗

Risky business: health and safety in the sex industry over a 9 year period.

OBJECTIVES: To assess whether a previously established low sexually transmitted infection/HIV risk in prostitutes in London has been sustained, and to measure other occupational risks, including mortality. DESIGN: 9 year prospective study in west London. SUBJECTS: 402 prostitutes recruited from 1985 to 1991, 320 were followed up for 675 person years to 1994. MAIN OUTCOME MEASURES: Condom use in commercial and non-commercial sex; viral and bacterial sexually transmitted infection at initial and follow up visits; death. RESULTS: Condom use increased significantly from 1986 to 1993 and protected the majority of commercial sexual contacts. Baseline prevalence: HIV 1.3%, hepatitis C 6.7%, hepatitis B 6.6%, syphilis 2.3%, HTLV-I/II 0.4%, gonorrhoea 3.0%, chlamydia 8.2%, genital herpes 16.8%. Incidence (per 100 person years): HIV 0.2, hepatitis C 0.3, gonorrhoea 5.6, chlamydia 12.6, genital herpes 6.5. Viral infections were associated with injecting drug use and non-British nationality; bacterial infections were associated with numbers of non-commercial partners but not with sexual contacts at work. Four women died during the course of the study; two had AIDS, two were murdered. This mortality of 5.93 per 1000 person years was 12 times the expected rate for women of a similar age. CONCLUSIONS: This study shows that it is possible to have a larger number of sexual partners and remain free from sexually transmitted infections provided that condoms are used consistently: there has been a sustained increase in condom use in the sex industry. None the less, prostitutes are at increased risk of sexually transmitted infections, primarily through non-commercial sexual partnerships. Infectious diseases are only one of the risks facing prostitutes, as illustrated by the mortality from violence as well as from HIV infection.

Adolescent↗

Glycerol and fatty acid kinetics in rainbow trout: effects of endurance swimming

Continuous infusions of 2-[3H]glycerol and 1-[14C]palmitate were performed in vivo in rainbow trout to measure the effects of prolonged swimming on (1) the rate of appearance of glycerol (Ra glycerol or lipolytic rate), (2) the rate of appearance of non-esterified fatty acids (Ra NEFA) and (3) the rate of triacylglycerol:fatty acid cycling (TAG:FA cycling or re-esterification). Our goals were to test the hypothesis that sustained exercise for up to 4 days causes the progressive mobilization of triacylglycerol reserves to supply fuel to contracting muscles, and to assess whether TAG:FA cycling plays a role in the regulation of NEFA availability in teleosts. Contrary to expectation, the rates of lipolysis and fatty acid release in resting trout are not affected by endurance exercise. Unlike mammals, which increase the rate of lipolysis by two- to fourfold during submaximal exercise, these active teleosts do not mobilize triacylglycerol reserves beyond resting levels to supply more NEFAs to working muscles. Furthermore, they maintain Ra glycerol and Ra NEFA well in excess of oxidative fuel requirements even at rest. More than two-thirds of the NEFAs produced are re-esterified, but the results show that TAG:FA cycling is not involved in the regulation of NEFA availability during or after swimming. We propose that the observed high rates of re-esterification represent an important feature of ectothermic metabolism that allows the restructuring of membrane phospholipids to be synchronized with frequent changes in body temperature.

Journal Article↗

The value of transbronchial needle aspiration in the diagnosis of peripheral pulmonary lesions.

BACKGROUND: Transbronchial needle aspiration (TBNA) is a bronchoscopic sampling technique used for the diagnostic workup of mediastinal lymph nodes, but the value of its routine use in evaluating peripheral pulmonary lesions is not yet firmly established. DESIGN: Retrospective analysis of routine diagnostic bronchoscopies. SETTING: University teaching hospital. PATIENTS AND METHODS: One hundred seventy-two consecutive patients (126 with malignant and 46 with nonmalignant disease) who underwent bronchoscopy for a peripheral pulmonary lesion. RESULTS: In 87 patients (51%), a final diagnosis was established by bronchoscopy; diagnoses included 81 malignant lesions (69 lung cancer and 12 pulmonary metastases) and 6 benign lesions (all tuberculosis). TBNA was used in 152 of the 172 patients (89%). Other endoscopic techniques included bronchial washing (100%), bronchial brushing (45%), and transbronchial biopsy (TBB) (27%). Concerning the different bronchoscopic sampling techniques, TBNA showed a positive result in 35% of cases, in comparison to 17% for TBB, 22% for bronchial washing, and 30% for bronchial brushing. While TBNA was diagnostic in 27.5% of the malignant lesions < 3 cm in diameter, the success rate in lesions > 3 cm was 65.5% (p = 0.03). Endoscopy-related complications included pneumothorax (n = 1), self-limiting bleeding (n = 12), prolonged coughing (n = 2), and vasovagal reactions (n = 2). None of these complications required further treatment. CONCLUSION: TBNA is an effective bronchoscopic sampling technique in the diagnosis of peripheral pulmonary lesions. In our study, the use of TBNA increased the diagnostic yield of bronchoscopy from 35 to 51% without additional risk. The use of TBNA in the clinical routine should be encouraged.

Aged↗

[Stapler hemorrhoidectomy. A new alternative to conventional methods].

Conventional, generally accepted methods of hemorrhoidectomy as the methods of choice in the therapy of IIIrd and IVth degree hemorrhoids often involve problems of attaining sufficient mucosa preservation or are technically highly complex. A new surgical procedure, stapler hemorrhoidectomy, is less risky, permits the preservation of more mucosa, and takes significantly less time (only 5 to 15 minutes) than conventional procedures. Especially important is the high degree of acceptance on the part of patients and operators. The operation is based on the principle of a mucosectomy at least 2 cm above the dentate line. A purse-string suture placed 3-4 cm above the dentate line is tied around the stapler shaft (Ethicon Endosurgery SDH 33). Then the resection and stapling of the mucosa are carried out. This procedure effectively reduces mucosa and blocks the end branches of the upper rectal artery, thus stopping venous and arterial blood flow of the hemorrhoidal plexus. During the period April-September 1998 we treated 42 patients with an average age of 55.5 years using stapler hemorrhoidectomy. We treated IIIrd-IVth degree hemorrhoids (in 29% of cases), partial (in 22% of cases) and circular mucosa prolapse (in 49% of cases). The complication rate was 14%; we observed one case of bleeding, two submucosal hematomas, one partially interrupted suture, one short incontinence (I degree after Parks), and one partial recurrence. All complications occurred at the start of application of the new method and could be brought under control with no difficulties; after a short time the patients were without any discomforts whatsoever. In particular, post-operative pain was generally slight, measuring by means of the visual analog scale (VAS) ranging from 0-100. From the day of the operation until the 21st postoperative day the pain score ranged from 0 to 35. The use of analgetics was significantly less, with 50% of the patients not using analgetics on and following the 1st postoperative day. First experiences with stapler hemorrhoidectomy have shown that patients with distinct hemorrhoids and/or mucosa prolapse benefit greatly by this procedure, when indications and operative techniques are correctly used.

Adult↗

Effects of distance, age and sex upon attitudes toward nuclear power plants: an empirical study.

Several aspects regarding nuclear power plants and works of the chemical industry were assessed by self-report inventories. The inventories included items related to attitudes and mood. Subjects (N = 228) were divided according to living distance to a nuclear power plant (up to 5 km, 5-10 km, 10-15 km), age (18-39 versus 40-59 years) and sex. Results demonstrate different risk perception referring to nuclear power plants and works of the chemical industry. Women and older persons reported more negative attitudes. In addition, the results confirm the assumption of an inverted U-shaped relationship between strength of negative attitudes toward nuclear power plants and distance of dwelling to the plant. The results are best explained by psychobiological models of stress.

Adolescent↗

Phase I trial of a MART-1 peptide vaccine with incomplete Freund's adjuvant for resected high-risk melanoma.

Twenty-five patients with high-risk resected stages IIB, III, and IV melanoma were immunized with a vaccine consisting of the minimal epitope, immunodominant 9-amino acid peptide derived from the MART-1 tumor antigen (AAGIGILTV) complexed with incomplete Freund's adjuvant. The last three patients received the MART-1(27-35) peptide with incomplete Freund's adjuvant mixed with CRL 1005, a block copolymer adjuvant. Patients were immunized with increasing doses of the MART-1(27-35) peptide in a Phase I trial to evaluate the toxicity, tolerability, and immune responses to the vaccine. Immunizations were administered every 3 weeks for a total of four injections, preceded by leukapheresis to obtain peripheral blood mononuclear cells for immune analyses, followed by a post-vaccine leukapheresis 3 weeks after the fourth vaccination. Skin testing with peptide and standard delayed-type hypersensitivity skin test reagents was also performed before and after vaccinations. Local pain and granuloma formation were observed in the majority of patients, as were fevers or lethargy of grade 1 or 2. No vaccine-related grade III/IV toxicity was observed. The vaccine was felt to be well tolerated. Twelve of 25 patients were anergic to skin testing at the initiation of the trial, and 13 of 25 developed a positive skin test response to the MART-1(27-35) peptide. Immune responses were measured by release of IFN-gamma in an ELISA assay by effector cells after multiple restimulations of peripheral blood mononuclear cells in the presence of MART-1(27-35) peptide-pulsed antigen-presenting cells. An ELISPOT assay was also developed to measure more quantitatively the change in numbers of peptide-specific effector cells after vaccination. Ten of 22 patients demonstrated an immune response to peptide-pulsed targets or tumor cells by ELISA assay after vaccination, as did 12 of 20 patients by ELISPOT. Nine of 25 patients have relapsed with a median of 16 months of follow-up, and 3 patients in this high-risk group have died. Immune response by ELISA correlated with prolonged relapse-free survival. These data suggest a significant proportion of patients with resected melanoma mount an antigen-specific immune response against a peptide vaccine and support further development of peptide vaccines for melanoma.

Antigens, Neoplasm↗