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Biomedical subjects

S Becker

Publications and source records attributed to S Becker.

At least 451 records · Page 25Linked to original sources

Characterization of periplasmic Escherichia coli protein expression at high cell densities.

We have used two-dimensional electrophoresis (2-DE) to analyze changes in protein expression profiles during a microbial cultivation process on an industrial scale. An Escherichia coli strain W31 10 containing the gene for recombinant human growth hormone production was used. Samples were taken at time intervals ranging from fast to slow growth rate (late growth phase at high cell density/starvation) and 2-DE analysis combined with image analysis using the PDQuest software showed significant alterations in expression levels of a number of proteins. Twenty-four protein spots were identified using a combination of matching with SWISS-2DPAGE E. coli map, N-terminal sequence analysis and mass spectrometry matrix-assisted laser desorption/ionization (MALDI). Two of the most abundant proteins expressed at late growth phase (pI 5.4/28 kDa and pI 5.5/28 kDa) were subjected to N-terminal sequence analysis after electrotransfer of the proteins from a preparative 2-DE gel to polyvinylidene difluoride (PVDF) membrane. Sequence tags of five amino acids in combination with approximate pI and Mr identified both proteins as deoxyribose phosphate aldolase (gene name deoC). In addition, both spots were subjected to tryptic in-gel digestion and analyzed using MALDI. Peptide mass fingerprints from both spots showed similar MALDI spectra and 10 of 10 tryptic fragments confirmed the identity as deoC. The identification of the acidic variant of deoC on 2-DE gels and the observation of this variant as induced during late growth phase is novel.

Acrylic Resins↗

Necrotizing fasciitis caused by Vibrio vulnificus: first published infection acquired in Turkey is the second time a strain is isolated in Germany.

Vibrio vulnificus, a marine vibrio, has recently been recognized as a potential human pathogen. It causes human infections with mortality rates up to 60%. Until 1991, most human isolations were reported from the USA, Japan and Taiwan. The second strain isolated in Germany is documented and a significant case of V. vulnificus infection acquired in Turkey is published for the first time.

Aged↗

CT findings of laryngeal involvement in von Recklinghausen disease.

In two patients with laryngeal von Recklinghausen disease, CT demonstrated hypodense, well-defined, septated masses sparing the epiglottis, and with little enhancement after contrast medium injection. Additional cervical lesions, benign or occasionally malignant, may also be seen.

Adolescent↗

Identification of significant variation in the composition of lipophosphoglycan-like molecules of E. histolytica and E. dispar.

The lipophosphoglycan-like (LPG-like) molecules of E. histolytica virulent strains are clearly distinct from those of the avirulent E. histolytica and E. dispar strains. Abundant 'LPG' levels are apparently limited to virulent strains, while lipophosphopeptidoglycans ('LPPG's) are common to both virulent and avirulent strains of E. histolytica and E. dispar. It is therefore conceivable that 'LPPG' performs a function that is essential to survival within the host, while the 'LPG' performs a more specific function related to virulence.

Animals↗

Haemate P in children with von Willebrand's disease.

In our center, 289 children with von Willebrand's disease (vWD) have been diagnosed since 1982. The majority of cases (n = 198) were congenital vWD whereas 91 patients suffered from vWD induced by valproate (VPA). We overview bleeding episodes in 45 children and 64 operative procedures requiring therapeutic intervention. The aim of therapeutic and prophylactic procedures in vWD is correcting the hemostatic disorder and normalization of bleeding time. This can be achieved by application of Haemate P leading to an elevation of plasma levels of von Willebrand parameters together with normalization of bleeding time. In patients with vWD type I, DDAVP will be preferred if contraindications can be excluded and efficacy has been shown. Severe bleeding complications could be prevented in a total of 50 surgical procedures in children with vWD type I by prophylactic treatment with DDAVP or Haemate P. Two children initially treated with DDAVP had to be substituted with Haemate P in the follow-up because of continuous bleeding. In type IIa and type III vWD as well as in VPA-induced vWD, the use of Haemate P was essential for sufficient hemostasis in all bleeding and operations. We conclude that Haemate P provides effective bleeding prophylaxis and treatment in all types of vWD except platelet-type.

Child↗

Children who care: a case for nursing intervention?

A large number of children are providing primary care for family members. This article aims to alert nurses to the issues involved and highlight the plight of these hidden and neglected carers.

Caregivers↗

Effect of pentamidine on cytokine (IL-1 beta, TNF alpha, IL-6) production by human alveolar macrophages in vitro.

Pentamidine (Pe) is an aromatic diamidine drug used clinically to treat Pneumocystis carinii pneumonia by aerosol inhalation. Nothing has been reported about the effects of this drug on human alveolar macrophage (AM) properties. In this study AM were exposed in vitro to various concentrations of Pe (10(-4)-10(-6) M) alone or in combination with bacterial endotoxin (LPS). Supernatants were collected at 3, 6, and 24 h and assayed for secreted IL-1 beta, IL-6, and TNF alpha. While the drug did not induce release of these cytokines, LPS-induced secretion of all three cytokines was inhibited by Pe in a dose-dependent manner. At the most effective Pe dose, 10(-5) M, AM viability (as determined by trypan blue dye exclusion) was reduced by 14% at 24 h, while no effect on viability was seen at lower concentrations. mRNA expression of all three cytokines was examined by PCR and Northern analysis to establish if the decrease in cytokine secretion was determined on a pre- or post-translational level. Reduced steady-state mRNA levels were found as early as 3 h after LPS stimulation, with Pe concentrations corresponding to those that decreased cytokine secretion. At the later time points, Pe also inhibited beta-actin, ornithine decarboxylase, and GAPDH mRNA expression, indicating that pentamidine had a general toxic effect on mRNA transcription in the macrophages. It is concluded that Pe, at pharmaceutically relevant concentrations and with apparent low cytotoxicity as determined by dye uptake, nonspecifically inhibits cytokine production by a toxic effect on transcriptional events.

Base Sequence↗

Clinical laboratory radioimmunoassay usage.

OBJECTIVES: To determine the extent of radioimmunoassay utilization in clinical laboratories in the state of Texas; to ascertain what methods have replaced it as an analytical tool; to identify trends and elicit comments regarding attitudes toward radioimmunoassay; and to ascertain the extent of instruction of radioimmunoassay principles required in clinical laboratory science curricula. DESIGN: Mailed, written survey designed by the authors. PARTICIPANTS: Laboratory managers or directors of 203 clinical pathology laboratories in Texas. MAIN OUTCOME MEASURE: Responses to seven forced-choice items, prompting information regarding laboratory type and size, extent of radioimmunoassay use, benefits or radioimmunoassay, and replacement technologies; a single item that elicited responses and opinions regarding general attitudes about radioimmunoassay and its place in clinical laboratory science curriculum. DATA SOURCE: Clinical laboratory managers or directors in the state of Texas. RESULTS: A total of 203 surveys were mailed within 127 respondents, yielding a response rate of 63%. The majority (77%) of clinical laboratories surveyed no longer use radioimmunoassay as a diagnostic tool with the predominant reason being the availability and affordability of automated enzyme immunoassays. Time-consuming recordkeeping was another common reason for abandoning the technique. Enzyme immunoassays were by far the most common method replacing radioimmunoassay. Comments reflected the general attitude that radioimmunoassay is a technique of the past in the clinical laboratory. A variety of views were elicited regarding the education of the principles of RIA to clinical laboratory science students. CONCLUSION: Radioimmunoassay, although a viable assay in some situations, has been abandoned as an analytical tool in most clinical laboratories in Texas. Current users are unhappy with the amount of paperwork that accompanies use of the technology, while non-users consider non-isotopic assays equivalent in sensitivity to RIA. In regard to information presented to clinical laboratory science students, the advent of molecular diagnostic techniques requires continued instruction in the principles of radioactivity, although not radioimmunoassay.

Clinical Laboratory Techniques↗

[Jejunal volvulus secondary to torsion of a pedunculated subserosal lipoma: CT diagnosis of a rare cause of bowel obstruction].

The authors report a case of a bowel obstruction secondary to jejunal volvulus in relation with the torsion of a large pedunculated subserosal lipoma. To our knowledge, no such case has ever been reported. The differential diagnosis of intra-abdominal fatty tumors and differential diagnosis of such tumors in association with small bowel obstruction will be discussed. Small bowel volvulus secondary to torsion of a subserosal lipoma should be considered when CT shows a large encapsulated fatty tumor in a patient with suggestion of mechanical small bowel obstruction.

Abdominal Pain↗

An experiment using a month-by-month calendar in a family planning survey in Costa Rica.

Recent demographic surveys have incorporated a month-by-month calendar for the five-year reference period before the survey for the recording of fertility-related events (sexual unions, contraceptive use, pregnancies, and breastfeeding). In the 1986 survey of Maternal and Child Health and Family Planning in Costa Rica, approximately one-half of the 3,527 women interviewed were administered a questionnaire with traditional fertility and family planning questions; the other half were asked virtually the same questions, but the women's responses were entered in a month-by-month calendar. The assignment of questionnaire type was randomly alternated by cluster. Comparisons of the number of events (live births, pregnancy losses, and contraceptive use) showed that more events were recorded among the women in the calendar group. Significantly less erroneous superposition of events (contraceptive use in the last trimester of pregnancy and hormonal contraceptive use in the first month postpartum) was noted when the calendar was used.

Adolescent↗