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Biomedical subjects

G Weber

Publications and source records attributed to G Weber.

At least 163 records · Page 9Linked to original sources
PubMed1997

Pleural empyema caused by Leuconostoc spp.

A rare case of pleural empyema caused by Leuconostoc spp. is reported. The patient was treated successfully with clindamycin. To our knowledge this is the first reported case of pleural empyema caused by Leuconostoc spp. In a patient with characteristic predisposing factors, such as a serious underlying disease, previous vancomycin therapy and thoracic access device. Our case illustrates that Leuconostoc spp. can cause pleural infection as further evidence of its human pathogenicity.

Anti-Bacterial Agents↗
PubMed1997

Sleep apnea and cognitive dysfunction in myasthenia gravis.

19 middle-aged patients with myasthenia gravis (MG) and 10 age, sex and education-matched controls underwent overnight polysomnography and neuropsychological testing, in order to test the hypothesis of whether cognitive dysfunction and REM-sleep disturbance in MG are related to nocturnal respiratory problems or caused by CNS-involvement. We observed in 60% of the myasthenics central type of sleep apneas and hypopneas with resulting oxygen desaturations occurring during REM-sleep, but no decrease of REM sleep. In neuropsychological testing, we found normal vigilance performance but decreased memory function in the myasthenics. In comparison with patients without sleep apnea, myasthenics with sleep apneas had an impaired memory function.

Adult↗
PubMed1997

[Theories of nursing professionals about the elderly].

Our study emphasizes the implicit theories of nursing professionals about the elderly and their influence on nursing behavior styles. According to our central hypothesis we expected a correlation between the differentiation of attitudes towards the elderly and the quality of nursing interventions. By means of a new methodological approach based on Forgas' theory of "social episodes" we investigated attitudes towards the elderly and behavior intentions in specific nursing situations. The sample consists of 133 professionals working in nursing homes for the elderly or in home care services. In a first step the structure of attitudes towards the elderly was examined by employing multivariate techniques, e.g. factor analysis and multidimensional scaling. Three aspects of older patients' competence constitute the images which influence nursing personnel's interactions with the elderly. In the next step a significant correlation between the complexity of attitudes towards the elderly and the quality of nursing behavior could be demonstrated. In general, the findings in our sample support personalized rather than stereotyped perceptions of the elderly. In particular such qualities will be stressed by nursing professionals which facilitate or disturb the nursing process.

Aged↗
PubMed1997

A randomized comparison between minilaparotomy and conventional approach for aortoiliac reconstructive surgery.

To decrease the surgical stress on patients undergoing aortic surgery the authors developed a less extensive procedure utilizing minilaparotomy and videoendoscopy. From June 1993 through July 1996, patients undergoing surgery for aortoiliac occlusive disease were randomized comparing the minilaparotomy (ML) with conventional approach (CA). Sixty-two patients participated in this trial, with 37 in the ML group and 25 in CA group. There were no significant differences between the groups in terms of age, sex or comorbid conditions. The incidence of intraoperative complications was similar for both groups. After surgery, nasogastric drainage was significantly (p = 0.01) shorter, bowel movement and initiation of alimentation began earlier in ML group. Both groups of patients showed a significant decrease in vital capacity and forced exspiration volume postoperatively, but this depression was significantly higher (p = 0.05) in CA group. The ML group also had significantly shorter stay in the intensive care unit (p = 0.001) and the mean duration of the postoperative hospital stay was also significantly less (p = 0.05). Generally, the patients operated by ML method during the postoperative recovery period required less analgesia, and expressed better "overall satisfaction". In long-term follow-up (mean 21 months), there was no significant difference in survival rates between two groups.

Analgesia↗
PubMed1997

Synergistic action of quercetin and genistein in human ovarian carcinoma cells.

Ovarian carcinoma is the fourth most common cause of cancer death in women and there has been a steady increase in the age-adjusted cancer death rates in the past 25 years in the US. However, patients who become cisplatin resistant respond poorly to available cytotoxic agents; therefore, discovering novel targets for ovarian carcinoma is vital. Quercetin, an anticancer agent, arrests the cell cycle at G1 and S phase boundary. Genistein, a plant flavonoid, attacks the cell cycle at G2 and/or early M phases in most carcinoma cells. Quercetin and genistein block the phosphatidylinositol conversion to IP3 signal transduction pathway mainly by inhibiting 1-phosphatidylinositol 4-kinase (PI kinase, EC 2.7.1.67) and 1-phosphatidylinositol 4-phosphate 5-kinase (PIP kinase, EC 2.7.1.68), respectively. Because each drug attacks a different phase of the cell cycle and reduces IP3 concentration by attacking different signal transduction enzymes, we tested the hypothesis that the two drugs might be synergistic in human carcinoma cells. In human ovarian carcinoma OVCAR-5 cells in growth inhibition assay, the IC50S for quercetin and genistein were (mean +/- SE) 66 +/- 3.0 and 32 +/- 2.5 microM; in clonogenic assays they were 15 +/- 1.2 and 5 +/- 0.5 microM, respectively. When quercetin was added to the cultures of OVCAR-5 cells followed 8 h later by genistein, synergism was observed in growth inhibition and clonogenic assays. The synergistic action of quercetin and genistein may be of interest in clinical treatment of human ovarian carcinoma.

Antineoplastic Agents↗
PubMed1996

Persistent confusion of total entropy and chemical system entropy in chemical thermodynamics.

The change in free energy with temperature at constant pressure of a chemical reaction is determined by the sum (dS) of changes in entropy of the system of reagents, dS(i), and the additional entropy change of the surroundings, dS(H), that results from the enthalpy change, W. A faulty identification of the total entropy change on reaction with dS(i) has been responsible for the attribution of general validity to the expressions (d deltaG/dT)p = -deltaS(i) and d(deltaG/T)/d(1/T)= deltaH, which are found in most textbooks and in innumerable papers.

Kinetics↗
PubMed1996

Sequence and expression of the mouse homologue to human phospholipase C beta3 neighboring gene.

We describe the isolation and expression of a murine homologue of the Phospholipase C beta3 Neighboring Gene (PNG), located in the MEN1 region on chromosome 11q13. The PNG cDNA was isolated using a human PNG cDNA clone (SOM172). Human and mouse PNG do not have any marked similarity to other known genes on the DNA level, but the predicted protein display similarity to the C-terminal part of Phospholipase C beta2. Northern blots with mouse PNG probes revealed expression of a 1 kb message in multiple tissues, and an additional 2.3 kb band in testis. The predicted murine protein contains 203 amino acids. In situ hybridization histochemistry displayed png mRNA expression in several tissues of the midstage mouse embryo, including the central nervous system. In late stage embryos, png was highly expressed in skeletal muscle, retina and neocortex. In the adult animal, expression was restricted to testis and thymus.

Aging↗
PubMed1996

Characterization of the murine VEGF-related factor gene.

We describe here the molecular cloning and characterization of the murine homolog of the human vascular endothelial growth factor-related factor (VRF) gene. cDNAs for two alternatively spliced forms of the murine vrf gene have been isolated, the putative translation products of which differ at their carboxyl termini due to a shift in reading frame caused by insertion, or lack thereof, of exon 6, in a similar fashion to human VRF (hVRF). The message lacking exon 6 encodes a protein (mvrf167) with 86% identity and 92% conservation of amino acid residues with hVRF. The protein coding region of the gene spans approximately 5kb of genomic DNA and is composed of 8 exons ranging in size from 36 to 398bp. The genomic structure of murine vrf is highly conserved with the human homolog in relation to position of splice junctions and the presence of contiguous exons 6 and 7. A short polymorphic AC repeat is present in the 3' untranslated region of murine vrf. A major band of approximately 1.3kb was expressed in all adult mouse tissues examined.

Amino Acid Sequence↗
PubMed1996

Expression of the VEGF-related factor gene in pre- and postnatal mouse.

We have previously identified a novel gene closely related to the vasoactive endothelial growth factor (VEGF) gene. The human VEGF related factor (VRF) gene was initially isolated using an 11q13 specific cosmid probe (D11S750). Subsequently human VRF was used to isolate the corresponding mouse gene (vrf). Here, we report the spatiotemporal expression pattern of vrf during pre- and postnatal development. Mouse vrf gene expression starts early in fetal development. At day 14 post coitum it is expressed in most cells of the embryo although the heart, spinal cord and the cerebral cortex show significantly higher levels of expression than other tissues. At 17 days post coitum expression is almost exclusively seen in heart, brown fat and spinal cord. This pattern of expression could be consistent with a role of vrf as a growth factor in these tissues.

Animals↗
PubMed1996

Molecular recognition by calmodulin: pressure-induced reorganization of a novel calmodulin-peptide complex.

The interaction of apocalmodulin (apoCaM) with a peptide (Neurop) based on the primary sequence of the calmodulin-binding domain of neuromodulin has been studied by fluorescence spectroscopy. The 1:1 complex (12 microM) formed between apoCaM and the Neurop peptide is extremely sensitive to salt and is half dissociated in less than 0.1 M KCl, suggesting that electrostatic interactions contribute strongly to complex formation. Ion pair interactions are frequently sensitive to high hydrostatic pressure due to electrostriction effects in the solvated ion state. Application of high pressure to the apoCaM.Neurop complex causes a red shift of the Neurop tryptophan emission center of mass and a reduced residual anisotropy but with insignificant reduction in quantum yield. The transition is smooth, reversible, and apparently two-state with a midpoint pressure of approximately 0.8 kbar. The residual anisotropy, quantum yield, and center of mass of the emission spectrum are consistent with the movement of the tryptophan side chain to a more solvated, slightly less restricted environment upon the pressure-induced transition. The pressure effect is independent of the concentration of the complex. These and other data are consistent with the pressure-induced reorganization being a unimolecular event not requiring dissociation of the complex. A volume change of approximately 66 mL mol-1 and a free energy change of approximately 1.7 kcal mol-1 are associated with the reorganization. The residual interactions maintaining the complex under high pressure are characterized by low standard molar volume and/or high standard free energy changes upon disruption but are destroyed by 200 mM KCl. It is postulated that the main effect of salt on the complex at high pressure is to drive the collapse of the hydrophobic pocket to which the peptide is binding.

Amino Acid Sequence↗
PubMed1996

Human growth hormone treatment in prepubertal children with achondroplasia.

We studied the effects of recombinant human growth hormone (GH) treatment in 6 prepubertal children with achondroplasia. The patients' age ranged from 2 11/12 to 8 5/12 years and the GH dose was of 0.1 IU/kg/day subcutaneously. Auxological assessments and bone age determinations were performed 6 months before, at the beginning, and after 6 and 12 months of therapy. The growth velocity increase during the whole year of treatment ranged from 1.1 to 2.6 cm/year in 3 patients while in the others no variation was detected. No side effects were observed during the trial apart from a slight advancement of bone age in two patients. MRI at the cervicomedullary junction and CT scan of the base of the skull did not show any variation of the dimensions of the foramen magnum at the end of the trial compared to baseline. Our study shows that r-hGH can safely increase short-term growth velocity in some but not all prepubertal children with achondroplasia. Our data confirm the individual variability in the response to the GH treatment.

Achondroplasia↗
PubMed1996

Isolation and characterization of a novel gene close to the human phosphoinositide-specific phospholipase C beta 3 gene on chromosomal region 11q13.

We describe the isolation, characterization, and genomic structure of a gene, Phospholipase C beta 3 Neighboring gene (PNG), located on chromosome 11q13. The cDNA was isolated using a cosmid that also contains the phospholipase C beta 3 gene (PLCB3). PNG does not have any marked similarity to other known genes on the DNA level. However, analysis of hybridization to a panel of somatic cell hybrids indicates the existence of related sequences on chromosomes 2, 4, 7, and 22. PNG showed expression of a 1-kb message in multiple tissues. The predicted protein is 199 amino acids. The gene spans approximately 2.5 kb, divided into four exons and three introns. It is located 4.4 kb upstream of PLCB3, with the 5' ends facing each other. The intergenic region has been completely sequenced, revealing separate CpG islands at both ends of this region. The islands are separated by a stretch of 2 kb, characterized by periodic alteration of the GC content. The 5'-flanking region of PNG does not contain TATA or CCAAT, suggesting a housekeeping promoter structure.

Amino Acid Sequence↗
PubMed1996

Sodium chloride in preparative free-flow cell electrophoresis: recent developments.

Three buffer systems for free-flow electrophoresis have been designed, which proved useful for performing cell electrophoresis in the presence of 50 mM NaCl. Each system consists of one central cell suspension buffer with 50 mM NaCl, two margin buffers, and two electrode buffers. With the aid of a bromophenol blue/maxilon blue accumulation test the various buffers were adjusted to ensure a laminar flow and remain unchanged on their way through an electrophoresis chamber.

Buffers↗
PubMed1996

Optimized continuous flow electrophoresis.

Continuous flow electrophoresis (CFE) was optimized by employing (i) electrophoretic regimes with stacking properties, to eliminate electrohydrodynamic dispersion, (ii) quasi-mixed zones to prevent precipitation of the stacked analytes, (iii) sheath liquid streams at the electrode compartment membranes to prevent penetration of the electrode reaction products into the separation chamber, (iv) proper engineering of the separation chamber to provide efficient dissipation of Joule heat, and (v) counterflow at the collection outlets to eliminate the problems of dead volumes and uneven collection of separated species. Data on direct temperature measurements in the separation chamber at various levels of the dissipated electric power are presented. Preparative runs of amyloglucosidase in the isoelectric focusing (IEF) mode and rat liver organelles in the isotochophoresis (ITP) mode demonstrate the high performance of the optimized CFE system.

Animals↗
PubMed1996

Videotunneler for minimal and direct access aortoiliac reconstructive surgery.

UNLABELLED: Despite improvements in surgical practice and postoperative care, the large vertical midline or transverse transperitoneal approaches used in abdominal aortic surgery are still associated with a relatively high perioperative morbidity and mortality rate even in patients who are considered good risks for undergoing aortic surgery. This significant perioperative morbidity is partly caused by the major surgical trauma. To decrease the surgical stress on these patients we have developed a less-extensive procedure for this type of vascular reconstruction. TECHNIQUE: The abdominal aorta is explored using a special retractor through a short upper median minilaparotomy utilizing modified conventional surgical hand instruments. For an aortobifemoral graft implantation, a retroperitoneal tunnel is necessary. During the creation of this tunnel special care should be exercised to avoid troublesome hemorrhage with iliac and other vein lacerations. To overcome these difficulties, we have developed a new tunneling device, which allows us to have visual control of the tunneling procedure. This prototype device contains a semiflexible tube with an inflatable balloon and a flexible videoendoscope. It is introduced along the external iliac artery into the retroperitoneal space and creates a tunnel through step-by-step inflation of the balloon. After this, the graft is implanted in the usual manner. To date, 19 abdominal vascular reconstructions have been performed with this method.

Aorta, Abdominal↗
PubMed1996

A phase II study of weekly oral methotrexate and zidovudine (AZT) in advanced adenocarcinoma of the pancreas and hepatocellular carcinoma.

From January 1992 through May 1993, 31 patients with adenocarcinoma of the pancreas or hepatocellular carcinoma were treated with weekly oral methotrexate (7.5 mg/M2 every 6 hours for 6 doses) and continuous oral AZT (200 mg four times daily). Patients were treated for a total of 6 months or until disease progression. The median age was 66 (range 44-79) and the median KPS was 80. No patient had received prior chemotherapy. Hematologic toxicity was severe with 50% of patients developing hemoglobins less than 8 gm/dl and 70% with granulocyte counts less than 1000 per mm3. One patient achieved a radiographic complete remission and 2 had stable disease. Two-thirds of patients progressed within 2 months of beginning therapy. The combination of methotrexate and AZT is an inactive regimen in pancreatic and hepatocellular carcinoma and is associated with considerable toxicity.

Adenocarcinoma↗
PubMed1996

Congenital hypothyroidism: auxological retrospective study during the first six years of age.

We examined length, height and weight from birth to six years of age and head circumference during the first two years in 89 children with congenital hypothyroidism (CH). The patients were divided in two groups: children diagnosed by clinical criteria during the first year of life (group A) and children detected by neonatal screening (group B). Group A showed a complete catch up growth for height and weight 10 months after the beginning of the replacement therapy; to the contrary, group B did not show any difference for height and weight compared to normal standards. Head circumference, evaluated only in group B, was significantly higher in comparison with normal standards. When etiology of CH was taken into consideration, children with athyreosis showed a significantly lower length at birth and at three months of age and their growths curves normalized after institution of replacement therapy. In conclusion our data suggest a direct relationship between severity and duration of hormone deficiency and growth retardation and confirm that replacement therapy started within the first year of live in CH patients clinically diagnosed allows a catch up growth.

Body Height↗