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Biomedical subjects

J Braun

Publications and source records attributed to J Braun.

At least 451 records · Page 25Linked to original sources
PubMed1991

[Electromyographic and manometric studies of stomach motility after vagotomy].

Vagotomy coincides not only with a reduction of the cephalic phase of secretion but also with a significant reduction of the motor activity of the stomach. Electrical and mechanical activity of the gastric wall after truncal vagotomy were verified in animal experiments (dog n = 5) by means of implanted electrodes and pressure transducers. Longlasting motility disturbances expressed as a disorganisation of the basic electrical rhythm occurred in the gastric wall. According to the pattern periods of tachygastria and tachyarrhythmia were identified. Those periods interrupted the regular fasted motility and persisted in the postprandial period. Simultaneous registration of the mechanical activity of the gastric wall during disorders of the electrical rhythm revealed a complete absence of contractility which probably is the pathophysiological correlate for the frequently described delayed gastric emptying after vagotomy.

Animals↗
PubMed1991

A study of the hematologic effects of chronic low-level exposure to benzene.

A study of 200 persons working with benzene showed no differences in commonly measured hematologic outcomes when compared with 268 nonbenzene workers in the same plant. Exposures ranged from 0.01 ppm to a high of 1.40 ppm 8-hour time weighted average over a 10-year period. Several other factors (age, sex, race, and smoking), however, were associated with these outcomes, indicating the importance of considering confounding factors when comparing hematology results. Exposure to low levels of benzene does not appear to produce an increased level of abnormal hematology measures detectable in routine medical surveillance.

Adult↗
PubMed1991

[Rectum resection with colo-anal anastomosis. Results of continence with radical surgery].

The long-term clinical and functional results of coloanal anastomosis (CAA) in the management of low and midrectal cancer were analyzed and compared with an age matched group of patients with abdomino-perineal resection (APR). Between 1977 and 1990 85 patients underwent CAA following resection for carcinomas of the mid and low rectum (67 male and 18 female, mean age 57.3 years). In 62 patients the tumor was in the lower and in 23 patients in the middle third of the rectum. A hand-sewn anastomosis was performed in 20 patients, in the 65 most recent patients the anastomosis was performed using a circular stapling instrument. No patient died as a result of pelvic sepsis. Anastomotic leakage occurred in 7% (handsewn 20%, stapled 3%), anastomotic strictures in 2.4%. 9 months after CAA complete or near complete continence was achieved by 85% of the patients. One patient was totally incontinent. More than 3 years postoperatively (1977-1987) 57 patients with curative resection could be analyzed. 39% of the patients had Dukes' A, 31% Dukes' B and 30% Dukes' C lesions. After a mean (+/- SD) length of follow-up of 6.7 years (3-13.6 years) local recurrence cumulative rates were 11% after CAA and 17% after APR, distant recurrence rates were 33% and 34% respectively. According to Dukes' stage the cancer-related 5-years survival of patients after CAA was in Dukes' A stage 88%, in Dukes' B 56%, in Dukes' C 29% and after APR 100, 53, and 22% respectively (p greater than 0.05). From these results we conclude that intersphincteric resection with CAA is a safe and efficient alternative to APR in many distal rectal carcinomas.

Adult↗
PubMed1991

[Results of Parks postanal repair in idiopathic anal insufficiency].

To assess the functional results of postanal repair of faecal incontinence we carried out clinical, physiological and radiological studies in 31 patients. Continence was improved in 26 (84%) patients, 19 (62%) of whom regained normal continence at a minimum of 12 months follow-up. A successful clinical outcome after postanal repair does appear to be related more to an improvement in sphincter pressures than to any reduction of the anorectal angle.

Anal Canal↗
PubMed1991

[Surgical therapy of chronic constipation].

Results of the surgical treatment for conservative intractable constipation in 70 adult patients are reviewed. 49 patients with severe symptoms have been treated by partial colectomy as sigmoid colectomy (n = 23) or left hemicolectomy (n = 26). 33 patients underwent colectomy with cecorectal anastomosis (n = 25) or ileorectal anastomosis (n = 8). Out of these patients with colectomy seven had undergone previous segmental colonic resection or internal sphincterotomy. Of those patients with cecorectal anastomosis who were dissatisfied, three underwent ileorectal anastomosis. Overall, a mortality rate of 3.3% and morbidity rate of 22.5 resp. 54.5% for partial and total colectomy were observed. The most frequent occurring complication after colectomy was small bowel obstruction in 30% requiring laparotomy in 40%. Of 45 patients who underwent partial colectomy, 34 (75%) had normal bowel function or were markedly improved. In 28 of 32 patients (87.5%) treated by colectomy a successful result has been achieved. The operation of sigmoid colectomy or left hemicolectomy may be recommended as a treatment for constipation only in patients with less severe symptoms or patients with recurrent sigmoid volvulus. For those patients with severe constipation, at present, colectomy with ileorectal anastomosis seems to be the surgical procedure that offers the greatest probability of improvement. However, the significant morbidity claimed the need for a careful patient selection.

Adolescent↗
PubMed1990

Proteinase-antiproteinase imbalance in meningitis: determination of alpha 1 proteinase inhibitor (alpha 1PI), elastase-alpha 1PI complex, and elastase inhibition capacity in cerebrospinal fluid.

Mortality and long-term neurologic sequelae are still frequent complications of meningitis despite effective antibiotic treatment. This suggests that pathogen-independent inflammatory mechanisms may play an important role in the course of this illness. Neutrophil granulocytes form the primary immune defense in meningitis. Once activated, these cells release elastase into the cerebrospinal fluid (CSF). Elastase may induce tissue damage if local antiproteinase capacity is low as under normal conditions. To define the relevance of this mechanism we studied 22 patients with meningitis. Concentrations of elastase in complex with the main antiproteinase alpha 1-proteinase inhibitor (elastase-alpha 1 PI), alpha 1-proteinase inhibitor (alpha 1PI), and elastase inhibition capacity (EIC) were measured in CSF of 9 patients with bacterial meningitis (BM), aged 1 month-14 years; 13 patients with non-bacterial meningitis (NBM), aged 1 month-15 years; and 20 patients in whom meningitis was excluded after spinal tap (control group), aged 6 months-15 years. The concentration of elastase-alpha 1PI in the BM group (median 552 micrograms/l) was significantly higher than in either the NBM group (median 30 micrograms/l, p less than 0.01) or the control group (median 30 micrograms/l, p less than 0.01). Similarly, the alpha 1PI-concentration in the BM group was significantly higher (median 113 mg/l) than either the NBM group (median 13.7 mg/l, p less than 0.025) or the control group (median 6.3 mg/l, p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1990

A murine model for B-cell lymphomagenesis in immunocompromised hosts: c-myc-rearranged B-cell lines with a premalignant phenotype.

Activation of c-myc or bcl-2 protooncogene is a common event in B-cell lymphomagenesis. Alone, each is insufficient to produce lymphoma, prompting the search for the additional steps required to complete the malignant phenotype. Among the existing systems of murine or human B-cell neoplasia, no commonly occurring complementary oncogenic activation has been found. This study introduces a new series of murine B-cell lines with a phenotype suggesting that such additional events might not involve intrinsic growth control, but instead host immune mechanisms which normally suppress tumorigenicity of premalignant B-cells. Four murine B-cell lines were isolated from the long-term culture of normal lymphoid tissue bearing a premalignant phenotype. (a) Their phenotype resembled naturally occurring lymphoid tumors of immunocompromised hosts with regard to c-myc activation, aberrant or absent immunoglobulin expression, preferential rearrangement of the lambda light chain locus, and a distinctive pattern of tissue invasion and tumor histology. (b) Their tumorigenicity was strictly dependent on host permissiveness correlated with immunodeficient status: C.B-17-scid greater than BALB/c-nu/nu greater than normal BALB/c much greater than other H-2d strains (NZB x NZW F1, NZB, DBA/2). (c) Host passage selected for malignant variants distinguished by a 10(4)-fold increase in tumorigenicity (as judged by limiting cell dose) and by novel tumorigenicity in nonpermissive syngeneic hosts. These features are analogous to properties of human lymphomas arising in immunocompromised states and, to our knowledge, unique among previously reported murine B-cell lines.

Animals↗
PubMed1990

A murine model for B-cell lymphomagenesis in immunocompromised hosts: natural killer cells are an important component of host resistance to premalignant B-cell lines.

The accompanying paper (D. W. Felsher et al., Cancer Res., 50:7042-7049, 1990) describes a new panel of cloned murine B-cell lines with a premalignant phenotype and in vivo-derived malignant variants. This paper assesses the contribution of immune mediated antitumor mechanisms which might account for host resistance to the tumorigenicity of these cell lines. Conventional T-cell-dependent responses did not appear to be critical to host resistance. In vivo elimination of T-helper cells with anti-L3T4 monoclonal antibody did not reduce host resistance to the tumorigenicity of these cell lines, nor did these cell lines elicit cytotoxic T-cell activity. However, a strong correlation was found between tumorigenicity and host natural killer (NK) activity. In vitro studies demonstrated that the cell lines were as NK sensitive as the prototypical NK target, YAC-1, whereas the malignant variants fully tumorigenic in normal hosts were greater than 20-fold less NK sensitive than were the parent cell lines. In vivo depletion of NK cells with anti-asialo-GM1 in BALB/c strongly diminished host resistance to cell line tumorigenicity, whereas polydeoxyinosinic-deoxycytidilic acid induction of NK cells enhanced host resistance. These findings indicate that NK function is a critical component to host resistance in this system and suggest that endogenous cellular mechanisms which overcome NK sensitivity could be a target for secondary transforming events in B-cell lymphomagenesis. They also raise the unexpected possibility that a non-antigen-dependent (versus immune cytotoxic T-lymphocytes) effector mechanism may be the key deficit promoting B-cell neoplasia in the setting of immunocompromised states.

Animals↗
PubMed1990

[Bronchoscopic diagnosis of pneumonia with quantitative microbial count determination].

Micro-organism counts of bronchoalveolar lavage (BAL) and microbrush swabs were obtained from 40 immunocompetent (group A) and 23 immunosuppressed (group B) patients with nosocomial pneumonia, and a control group consisting of 40 patients with noninfectious pulmonary infiltrates. The sensitivity of BAL was high: 77.5% for group A and 85% for group B, while microbrush swabs gave many false-negative results. Microorganism counts were at or above 10(5) cfu/ml in 32 of 44 examinations (bacterial or mycotic pneumonia), but in only one case of the control group. Lower counts were obtained with localized infection and microorganisms difficult to culture (Aspergilla and Legionella). Granulocytosis in the lavage fluid was demonstrated in 38 of 41 patients with bacterial pneumonia and thus proved useful in the differential diagnosis. In 16 of 40 immunocompetent and 13 of 23 immunosuppressed patients with pneumonia the results were therapeutically of importance. Thus, invasive diagnosis is indicated especially in complicated or treatment-resistant nosocomial infections.

Adult↗
PubMed1990

Fine-mapping of DNA damage and repair in specific genomic segments.

The susceptibility of various genomic regions to DNA damage and repair is heterogeneous. While this can be related to factors such as primary sequence, physical conformation, and functional status, the exact mechanisms involved remain unclear. To more precisely define the key features of a genomic region targeted for these processes, a useful tool would be a method for fine-mapping gene-specific DNA damage and repair in vivo. Here, a polymerase chain reaction-based assay is described for measuring DNA damage and repair in small (less than 500 bp) genomic segments of three transcriptionally active but functionally distinct loci (rearranged immunoglobulin heavy chain variable region [Ig VDJ], low-density lipoprotein receptor gene, and N-ras proto-oncogene) in human tonsillar B lymphocytes. Analysis of ultraviolet (254 nm)-induced DNA damage revealed single-hit kinetics and a similar level of sensitivity (D50% approximately 6000 joule/m2) in all three regions, indicating that a single photoproduct was sufficient to fully block PCR amplification. A similar time period per unit length was required for repair of this DNA damage (average t1/2 per fragment length = 23.5 seconds per bp). DNA damage and repair was also detectable with the base adducting agent, 4-nitroquinoline-1-oxide. However, in this case IgVDJ differed from segments within the other two loci by its relative inaccessibility to alkylation. This assay thus permits high-resolution mapping of DNA damage and repair activity.

B-Lymphocytes↗
PubMed1990

Evolving abundance and clonal pattern of human germinal center B cells during childhood.

Childhood is a critical period for the development of the memory B-lymphocyte repertoire necessary in protective humoral immunity. This study addressed the natural history of memory B cells based on the previous identification of germinal center and mantle zone cells as the probable precursor and mature memory cell populations, respectively. Using flow cytometric quantitation of these B-cell subpopulations in human tonsil, we found that germinal center cells were abundant (70% of tonsil B cells) during early childhood (2 to 3 years), but decline by early adolescence (8 to 14 years) to a low level (33%, P = .0003). To study the clonal evolution of these B-cell subpopulations, germinal center and mantle zone B cells were isolated using a preparative magnetic immunobead method, and analyzed using a novel polymerase chain reaction-based quantitative assay to measure the abundance of B-cell clones bearing certain rearranged VH subfamilies. Two VH subfamilies were informative: VH1N clones were uniquely deficient in germinal center B cells at the early age period, but became abundant in later childhood; and VH3L clones were absent among germinal center cells regardless of age. In contrast, B-cell clones bearing each VH subfamily were abundant in the mantle zone subpopulation throughout childhood. These findings suggest that the abundance and clonal pattern of germinal center B cells evolves during childhood, presumably due to changing antigenic or ontogenic processes. Moreover, the distinct clonal pattern of germinal center versus mantle zone B cells suggests that a major phase of clonal selection occurs after germinal center emigration.

Adolescent↗
PubMed1990

[Long-term substitution in homozygous alpha 1-antitrypsin deficiency. Effect of the proteinase-antiproteinase equilibrium in plasma and sputum].

Long-term replacement with human alpha 1-antitrypsin (60 mg/kg once a week intravenously) was carried out in seven patients with homozygous alpha 1-antitrypsin deficiency (7 males, mean age 50.8 [40-59] years) and progressive pulmonary emphysema for an average of 16 (13-20) weeks. After at least 12 weeks' therapy the concentrations of alpha 1-antitrypsin, elastase-alpha 1-antitrypsin complex, alpha 2-macroglobulin, lactoferrin and elastase inhibition capacity in plasma and sputum were assayed, these assays being performed before starting the alpha 1-antitrypsin infusion and at various times during the following week. After the infusion the plasma concentration of alpha 1-antitrypsin rose from a depressed initial level (median 1.22 g/l) to a level approximately five times higher (median after 1 hour: 5.96 g/l, P less than 0.001), and then declined exponentially, though it never fell below the threshold of 35% of normal which is regarded as the protective level. Elastase inhibition capacity displayed similar changes (r = 0.85). The sputum concentration of alpha 1-antitrypsin rose more slowly than the plasma concentration; from the initial level (median 8 mg/l) it reached a maximum about four times higher after 24 hours (median 36 mg/l; P less than 0.02). Elastase inhibition capacity rose from 151 mIU/ml (median) before the alpha 1-antitrypsin infusion to 450 mIU/ml at 24 hours. These findings suggest that alpha 1-antitrypsin replacement will have beneficial effects on proteinase-antiproteinase equilibrium. Determination of elastase inhibition capacity in the sputum is suitable for monitoring dosage during replacement therapy.

Adult↗
PubMed1990

[Successful use in horses of deep-frozen semen specimens stored for 18 years].

In 1970 semen from a Haflinger-stallion was frozen by the pellet method. 18 years later semen samples were used to inseminate 4 mares. Inseminations were performed shortly after ovulation with a total number of motile spermatozoa between 150 and 636 x 10(6), the percentage of motile spermatozoa being 20% to 40%. Three mares conceived after a single insemination, one mare got pregnant after 4 inseminations during 3 oestrous periods. Meanwhile, 3 foals were born and one of the mares is still pregnant. The results demonstrate that long-term storage of frozen semen in liquid nitrogen does not impair its fertilizing capacity.

Animals↗
PubMed1990

[The reproductive function in experimentally-produced monozygotic twin bulls].

Reproductive functions were evaluated in 12 experimentally derived monozygotic cattle twins (6 pairs). In 4 twin pairs GnRH (20 micrograms Receptal i.m.) was administered in monthly intervals from 6 through 12 months of age. LH-secretion was determined by radioimmunoassay up to 6 hours after the GnRH-challenge in hourly collected peripheral blood samples. In 5 twin pairs (age 14 to 20 months) semen was collected 5 times and processed for cryoconservation. In fresh and in frozen-thawed semen samples sperm motility was determined by means of a computerized system. Twins showed a remarkable uniform response to the GnRH-challenge. One set of twins (HF-breed) had a significantly reduced response compared to the other pairs (DFV-breed). Both individuals of this particular pair had a low percentage of progressively motile spermatozoa. In pairs with physiological sperm motility, variance of this parameter within pairs and between pairs was not different. In contrast, twin uniformity concerning the average velocity of motile spermatozoa was high; differences between set of twins explained most of the total variance. According to this study, reproductive parameters in monozygotic cattle twins are strongly influenced by twin uniformity.

Animals↗
PubMed1990

Walker-Warburg syndrome with microtia and absent auditory canals.

Walker-Warburg syndrome is a lethal, autosomal recessive disorder characterized by anomalies of the central nervous system and eye. Typical findings include hydrocephalus, agyria, retinal dysplasia, cerebellar dysgenesis, anterior chamber dysgenesis, and encephalocele. Recently, the phenotypic spectrum has been expanded to include congenital muscular dystrophy. Two sibs with Walker-Warburg syndrome are reported. One sib had congenital glaucoma and hydrocephalus. The other sib had hydrocephalus, microtia, absent auditory canals, and pale retinas, barely within the phenotypic spectrum of the disorder. Elevation of muscle enzymes was consistent with the diagnosis of Walker-Warburg syndrome.

Abnormalities, Multiple↗
PubMed1990

Brain tumor as a second malignant neoplasm following neuroblastoma stage IV S.

A rare brain tumor (spongioblastoma polare) occurring 7 years after treatment of neuroblastoma stage IV S is reported. The literature concerning the occurrence of a second cancer in children exposed to mutagenic therapy for their initial tumor is reviewed, and genetic and environmental factors are discussed. Diminishing aggressiveness of the treatment in childhood cancer with good prognosis should be considered. Continuous follow-up of children cured of cancer is warranted.

Abdominal Neoplasms↗
PubMed1990

[Early postoperative intestinal motility following abdominal surgery in an animal experiment].

Gastrointestinal myoelectrical activity was registered in 6 dogs after different surgical procedures such as laparotomy, segmental resection of the jejunum and right hemicolectomy. Animals were studied in the fasted- and fed state and after pharmacological stimulation with Ceruletide. The electrical activity was recorded by means of 6 bipolar electrodes implanted along the intestinal wall. Abdominal surgery abolished normal motility in the stomach and small intestine only for a short period of time. The time for the reappearance of regularly recurring activity fronts varied with the type of the surgical procedure from 3 h after segmental resection of the jejunum to 49 h after colon resection. Severe disturbances of the BER (basic electrical rhythm) in the stomach as tachygastria and tachyarrhythmia persist even after restoration of the MMC (migrating motor complex) in the small intestine. Feeding induced a typical fedpattern but never before restoration of the MMC. Stimulation of the intestine during postoperative ileus with Ceruletide increases segmental myoelectrical activity. The period of postoperative ileus was not reduced.

Animals↗