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Biomedical subjects

E Weiss

Publications and source records attributed to E Weiss.

At least 19 recordsLinked to original sources
PubMed1992

[Light and electron microscopic studies of calf kidneys after exposure to subtoxic lead levels].

Eight calves were fed from the fourth to the twentieth week of age a milk powder diet containing 40 mg lead acetate per kg dry substance. This is twice the lead concentration legally permitted. In average, each animal has daily taken up 0.834 mg lead per kg body weight. Eight calves were used as controls. The animals gained the usual fattening weights and did not show clinical symptoms. Beginning with week 14, increased levels of blood urea were encountered in the animals which received lead in their diet. Morphologically, severe renal lesions were found in these calves. The kidneys were increased in weight, pale and of firm consistency. Histologically, fibrosis and periglomerular interstitial non-purulent nephritis were found. Light- and electronmicroscopically, numerous intranuclear inclusion-bodies typical for lead poisoning were demonstrated in epithelial cells of proximal tubules. The results show, that daily uptake of less than 1 mg lead per kg body weight must be considered as a toxic dose for calves, and not 5-7 mg as stated in literature.

Animal Feed↗
PubMed1992

Determination of kinetic constants for the interaction between a monoclonal antibody and peptides using surface plasmon resonance.

Differences in the affinity of a monoclonal antibody raised against the protein of tobacco mosaic virus for 15 related peptides (residues 134-146) carrying single-residue modifications were investigated using a novel biosensor technology (Pharmacia BIAcore). Analysis of the peptide-antibody interaction in real time allowed fast and reproducible measurements of both association and dissociation rate constants. Out of 15 mutant peptides analyzed, five were not recognized by the antibody at all, and seven were recognized as well as the wild-type peptide. For three of the peptides, the rate constants were different for the mutant and wild-type peptides. The pattern of residue recognition suggests that the epitope is formed by three residues (140, 143, and 144) in a helical conformation that mimics the structure in the protein. Even a minor modification of these residues totally abolishes recognition by the antibody. Modifications of adjacent residues result in small but significant differences in association and/or dissociation rate constants. One of the recognized residues is totally buried in the three-dimensional structure of TMV protein, suggesting that a structural rearrangement next to the helix occurs during protein-antibody interaction.

Amino Acid Sequence↗
PubMed1992

Blood flow velocity waveforms of the middle cerebral artery and abnormal neurological evaluations in live-born fetuses with absent or reverse end-diastolic flow velocities of the umbilical arteries.

We studied 37 fetuses with absent or reverse end-diastolic flow velocities (AREDFV) of the umbilical arteries with respect to the mode of delivery, fetal acidosis, resistance index of the middle cerebral arteries, and abnormal neurological evaluation at the time of discharge from the department of pediatrics. A control group with normal umbilical artery flow velocity waveforms was matched for gestational age. Fetuses with AREDFV were delivered almost exclusively by cesarean section, in most cases due to fetal distress. Metabolic changes with decreased base excess values were found more often in fetuses with AREDFV, but no difference could be detected with respect to severe fetal acidosis. The number of fetuses with abnormal neurological evaluations during the first 6 months of life was significantly higher in cases with AREDFV than in the control group. More than two thirds of the fetuses with AREDFV showed an abnormal blood flow velocity waveform of the middle cerebral arteries with elevated end-diastolic flow velocities. The combination of extreme premature delivery before 28 weeks of gestation, severe idiopathic respiratory distress syndrome, and a resistance index of the middle cerebral arteries under the 5th percentile seems to be a risk factor for early neurological morbidity in fetuses with AREDFV. Premature delivery of fetuses with AREDFV--as we did during our study in order to prevent intra-uterine death or fetal asphyxia--should therefore be critically regarded in cases under 28 weeks of gestational age and abnormal flow velocity waveforms of the middle cerebral arteries.

Acid-Base Imbalance↗
PubMed1992

[The polymerase chain reaction (PCR) for the detection of DNA of equine herpesviruses 1 and 4].

Formalin-fixed and Paraplast-embedded tissue samples of 42 aborted equine fetuses were examined by polymerase chain reaction for the presence of equine herpesvirus DNA. The used set of primers was located in the glycoprotein 13 open reading frame and allowed the amplification of both EHV 1 und EHV 4. By cleaving pattern analysis after Hinf I digestion EHV 1 could be distinguished from EHV 4. In 9 of the cases investigated EHV 1-DNA was detected. This finding is in absolute context with the results of the virological investigations.

Abortion, Veterinary↗
PubMed1992

Condition at birth of infants with previously absent or reverse umbilical artery end-diastolic flow velocities.

In a case control study we assessed 47 fetuses with absent or reverse end-diastolic flow velocities (AREDFV) of the umbilical artery with respect to the mode of delivery, fetal acidosis, and abnormal neurological evaluations at the time of discharge from the department of pediatrics. We also studied a control group which was matched for gestational age and had normal umbilical artery flow velocity waveforms. Fetuses with AREDFV were delivered almost exclusively by cesarean section which was usually done for fetal distress. The number of fetuses with abnormal neurological signs was significantly increased compared to the control group. Fetuses with AREDFV showed an increased incidence of fetal acidosis. Forty per cent of these fetuses were delivered within one day of the first abnormal flow measurement; Sixty per cent were observed clinically for up to four weeks before delivery.

Blood Flow Velocity↗
PubMed1992

Measurement of affinity of viral monoclonal antibodies using Fab'-peroxidase conjugate. Influence of antibody concentration on apparent affinity.

The binding affinity of a monoclonal antibody to tobacco mosaic virus (TMV) was studied using a Fab'-peroxidase conjugate. Measurement of the enzymatic activity allowed the determination of the amount of free antibody present after ultracentrifugation of virus-antibody complexes at equilibrium. The method was very sensitive and allowed measurements over a 1000-fold range of antibody concns. The calculated affinity constant decreased about 25 fold when the antibody concn used in the binding assay was increased from 30 ng/ml to 35 micrograms/ml.

Antibodies, Monoclonal↗
PubMed1991

Chimerization of antibodies by isolation of rearranged genomic variable regions by the polymerase chain reaction.

We describe a new method for amplification, by polymerase chain reaction (PCR), of rearranged segments encoding the variable part of light and heavy chains of an antibody (Ab) from the chromosomal DNA of hybridoma cells for the chimerization of Abs. A fundamental prerequisite for this is the knowledge of the exact sequences in the 5'-untranslated region of light and heavy chain mRNA, and of the joining segment used for rearrangement. This allows the design of nondegenerated oligodeoxyribonucleotides for PCR. The primer design permits directional cloning of the amplified, promoterless fragments into cassette vectors, in which they will be linked to the appropriate human constant domains and immunoglobulin (Ig) promoter/enhancer elements. The method is illustrated for chimerization of an Ab directed against the human T-lymphocyte antigen, CD4. The chimerized Ab is secreted in abundant quantities after transfection of the engineered plasmids into non-Ig-producing myeloma cells.

Animals↗
PubMed1991

[Detection of bovine papillomavirus DNA in equine sarcoids using the polymerase chain reaction (PCR)].

Unfixed and formalin-fixed frozen sections and paraffin-sections of histopathologically confirmed sarcoids of 20 horses were studied in the PCR. The used set of primers was located in the E5 open reading frame fitting both to bovine papillomavirus 1 (BPV-1) and BPV-2. Independent of the quality of the used tissues BPV-DNA was detected in all 20 sarcoids. By cleaving with restriction endonuclease Bst XI it was shown that the DNA-sequences amplified by PCR were identical with that of BPV-1. The results support the general view that BPV play an important role in equine sarcoids.

Animals↗
PubMed1991

Biology of ehrlichiae.

The isolation and cultivation of the agent of Potomac horse fever, Ehrlichia risticii, by Holland, Ristic, et al., afforded Weisburg et al. an opportunity to examine its phylogeny. E. risticii is clearly related to the genus Rickettsia and not to chlamydiae. A reevaluation of the significance of phenotypic characteristics is thus required, since ehrlichiae, in some respects, resemble chlamydiae. For example, unlike rickettsiae, ehrlichiae and chlamydiae multiply in the phagosome of their host cells, but may not have the same mechanism of inhibition of phagosome-lyososome fusion. Rickettsiae, which multiply in the cytoplasm, may have a mechanism of survival in the phagosome similar to that of the ehrlichiae, but, in addition, utilize a phospholipase, which permits prompt escape from the phagosome. Rickettsiae, as most Gram negatives, multiply by binary fisson. Chlamydiae, on the other hand, undergo a cycle of development. Elementary bodies (EB) infect, but do not divide, while the reverse is true of reticulate bodies (RB). Ehrlichiae superficially resemble chlamydiae rather than rickettsiae, but ehrlichiae have not yet been submitted to the rigorous criteria of separation of EB and RB. Investigations in our laboratory of the metabolic activities of E. risticii and E. sennetsu link them to the rickettsiae and not to the chlamydiae. Ehrlichiae and rickettsiae, but not chlamydiae, derive some ATP from their catabolic activities. In conclusion, in further investigations of the monocytic ehrlichiae, it is safer to be guided by what we know of rickettsiae, than chlamydiae.

Animals↗
PubMed1991

Primary peritoneal papillary serous adenocarcinoma: clinical and management aspects.

From January 1, 1984 to April 30, 1990, 38 patients were surgically found to have an intraabdominal disease resembling epithelial ovarian cancer. This diagnosis was confirmed in 31 patients; the remaining 7 met the criteria of primary peritoneal papillary serous carcinoma. Five of these were diagnosed retrospectively and two during surgery. The mean age at diagnosis was 61.2 years. Tumor histology revealed papillary serous carcinoma in six and mixed (papillary serous and papillary clear cell carcinoma) in one patient. Optimal debulking was achieved in three of seven cases (42.8%). Cisplatin-based combination chemotherapy was administered to all in the study group. Complete response was obtained in four patients, with one surviving for 76 months. The median survival in these patients was 34.5 months (range 6-76 months). Currently, three patients with complete response are alive with clinically undetectable disease. CA-125 assays were available in three cases and blood levels corroborated the clinically determined status of the disease. Tumor steroid hormone receptor status was determined in one case and revealed low levels of estrogen and progesterone receptors. To the best of our knowledge, the usefulness of CA-125 in the diagnosis, management, follow-up, and determination of tumor steroid hormone receptor status, mixed papillary serous and clear cell subtype histological patterns for primary peritoneal papillary serous carcinoma are first described in this report. It seems that this neoplasm may be treated and followed up as in epithelial ovarian cancer, obtaining long-term survival; however, the biologic behavior and management problems of this relatively new entity deserve further clinical experience.

Adult↗
PubMed1991

Umbilical artery blood flow velocity waveforms during variable deceleration of the fetal heart rate.

Blood flow velocities of the umbilical arteries were measured by Doppler ultrasonography during variable decelerations of the fetal heart rate. The flow velocity waveforms, being normal between uterine contractions, showed either an unchanged flow velocity waveform with an exclusive fetal heart rate effect on end-diastolic velocities or a rapid change to absent and reverse diastolic flow during the decelerations, indicating an abrupt increase in placental resistance with a halt in placental perfusion. Computer-aided reconstruction of the fetal heart rate curve revealed the exact temporal relationship between the reduction of umbilical artery perfusion and deceleration of fetal heart rate. We showed that variable decelerations of fetal heart rate can be observed during only slightly changed umbilical perfusion or can be caused by a halt in placental perfusion, which does not necessarily mean an absence of any movement of the fetal blood column, but is a result of a systolic forward and diastolic reverse flow to the same extent.

Blood Flow Velocity↗
PubMed1991

[Maternal morbidity after abdominal cesarean section in relation to bacterial amniotic fluid colonization and premature rupture of fetal membranes].

At the time of Caesarean section, amniotic fluid was collected transabdominally from 1025 patients. In 990 patients cultures were performed on the amniotic fluid. The incidence of Caesarean section of all patients was 16.1%, the perinatal mortality in all patients 0.61%, in cases of Caesarean section 1.93%. The influence of bacterial colonisation in the amniotic cavity was analyzed with respect to premature ruptured membranes and frequency of vaginal examinations on the maternal post-operative morbidity (wound-seroma and abscess 2.4%, febrile morbidity 17%, urinary tract infection 19%). Bacterial contamination was present in 33.3% of the amniotic fluid or uterine cavity, after ruptured membranes in 44.3%, without ruptured membranes in 23.35%. There is a significant influence of the positive cultured amniotic fluid on the wound healing and on the febrile morbidity, while the urinary tract infection has been not influenced. The bacterial contamination of the amniotic fluid is correlated to the frequency of vaginal examination and the presence of ruptured membranes. The following microbiologic isolates were found in the amniotic fluids: Staphylococcus epidermidis 36.38%, Streptococcus B 12.23%, Streptococcus D 10.3%, Escherichia coli 8.42%, Staphylococcus aureus 7.88%, Peptococci 3.26%, Streptococcus salivarius 2.99%, Bacteroides 2.4%. According to these data, patients with ruptured membranes of an interval of more than 12 hrs and with more than 7 vaginal examinations could be selected for antibiotic prophylaxis to achieve a reduction in febrile morbidity and in wound infection.

Amniotic Fluid↗
PubMed1991

[Local administration of metronidazole before hysterectomy--effect on infectious morbidity. A prospective study].

A prospective clinical trial was designed to examine the influence of a local application of metronidazole on postoperative infectious morbidity in 134 women undergoing vaginal and in 108 women undergoing abdominal hysterectomy. 116 patients received on the evening before hysterectomy a vaginal suppository of metronidazole (500 mg). The control group (126 patients) had no metronidazole prophylaxis. All patients, who underwent vaginal hysterectomy, were given additionally a single-shot prophylaxis with 1500 mg cefuroxim. With regard to febrile morbidity, urinary tract infection and abdominal wound or pelvic infection, there was a significant decrease in infectious morbidity. In women undergoing vaginal hysterectomy the infectious morbidity was reduced from 35.7% to 20.3% (p less than 0.05) in spite of systemic prophylaxis. In cases with abdominal hysterectomy, we saw a decrease from 64.3% to 26.9% (p less than 0.001). There was no effect on the incidence of urinary tract infections. Local prophylaxis with metronidazole in abdominal hysterectomy and additional to a systemic prophylaxis in vaginal hysterectomy reduces the infectious morbidity in our patients.

Administration, Intravaginal↗
PubMed1991

Wedges in restorative dentistry: principles and applications.

Overhanging margins of proximal restorations are a well-known, iatrogenic cause of periodontal pathology. The high incidence of such findings in Western societies should arose the concern of the dental community. However, overhanging margins represent only part of the iatrogenic problem created by the misuse of wedges in restorative procedures. Other causes include incorrect proximal contouring, inadequate contact points and under- or overfilling the restorative material. The understanding of the variables associated with wedge selection and positioning has a major role to play in the prevention of iatrogenic periodontal pathology associated with restorative procedures. It is concluded that: (i) the occlusion of the matrix band to the remaining healthy tooth structure of the gingival cavosurface line angle should be achieved solely by the correct application of the wedges; (ii) the effect of the wedges on the proximal contour and contact area should be carefully re-evaluated prior to insertion of the restorative material; (iii) various sizes and shapes of wedges and a sharp knife for carving must be readily available.

Dental Caries↗
PubMed1990

[Serum fructosamine assay in the evaluation and follow-up of diabetics].

Fructosamine (FRA) levels were determined in diabetic and nondiabetic patients. A normal mean of 2.38 mmol/L +/- 0.21 (SD), and range of 2.0-2.8, was found in 156 nondiabetic subjects. A highly significant correlation was found between FRA and glycosylated hemoglobin, and between FRA and fasting glucose and 2-hour postprandial glucose in the 163 diabetics. The mean FRA in 60 diabetics receiving oral hypoglycemic agents was 3.05 +/- 0.34. It ranged from 3.28 +/- 0.65 in patients with NIDDM receiving insulin to 3.50 +/- 1.03 in those with IDDM. Over 60% of the latter were inadequately controlled, as assessed by FRA levels. FRA repeated during 4-12 months in 68 patients showed no improvement in 45%, despite determined attempts to control blood glucose. However, fasting blood glucose in diabetics with normal FRA was 134 +/- 51 mg/dl. Therefore, a consistently normal level of FRA does not indicate normoglycemia. The FRA assay is rapid, simple, economical and of significant aid in the control of diabetes.

Blood Glucose↗