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Biomedical subjects

R Weiss

Publications and source records attributed to R Weiss.

At least 19 recordsLinked to original sources
PubMed1992

Digital chemiluminescence imaging of DNA sequencing blots using a charge-coupled device camera.

Digital chemiluminescence imaging with a cryogenically cooled charge-coupled device (CCD) camera is used to visualize DNA sequencing fragments covalently bound to a blotting membrane. The detection is based on DNA hybridization with an alkaline phosphatase(AP) labeled oligodeoxyribonucleotide probe and AP triggered chemiluminescence of the substrate 3-(2'-spiro-adamantane)-4-methoxy-4-(3"-phosphoryloxy)phenyl- 1,2-dioxetane (AMPPD). The detection using a direct AP-oligonucleotide conjugate is compared to the secondary detection of biotinylated oligonucleotides with respect to their sensitivity and nonspecific binding to the nylon membrane by quantitative imaging. Using the direct oligonucleotide-AP conjugate as a hybridization probe, sub-attomol (0.5 pg of 2.7 kb pUC plasmid DNA) quantities of membrane bound DNA are detectable with 30 min CCD exposures. Detection using the biotinylated probe in combination with streptavidin-AP was found to be background limited by nonspecific binding of streptavidin-AP and the oligo(biotin-11-dUTP) label in equal proportions. In contrast, the nonspecific background of AP-labeled oligonucleotide is indistinguishable from that seen with 5'-32P-label, in that respect making AP an ideal enzymatic label. The effect of hybridization time, probe concentration, and presence of luminescence enhancers on the detection of plasmid DNA were investigated.

Adamantane↗
PubMed1992

[Comparative plasmid profile analysis of Salmonella typhimurium var. Copenhagen strains from a Salmonella outbreak in hospitalized horses].

From April 1990 through June 1991 clinical salmonellosis and asymptomatic faecal excretion of Salmonella spp. were seen in hospitalized horses at two veterinary hospitals. 76 Salmonella strains from hospitalized horses and 18 strains from horses without any clinical contact were characterized by serotyping and plasmid profile analysis. From April 1990 through January 1991 97.8% of the hospitalized horses were infected with strains of S. typhimurium var. Copenhagen, which were closely related according to their similar plasmid patterns. Other strains of S. typhimurium var. Copenhagen and serotype S. enteritidis were isolated not before February 1991. In the same period various plasmid profile types of S. typhimurium var. Copenhagen and strains of S. typhimurium, S. enteritidis and S. lexington were isolated from horses of the control group. Our results suggest that the high incidence of salmonellosis and latent salmonella infection in hospitalized horses was mainly due to the spread of one particular strain of S. typhimurium var. Copenhagen and that this strain was obviously acquired during hospitalisation.

Animals↗
PubMed1992

Spontaneous chromomycosis in the marine toad (Bufo marinus).

Post-mortem examinations were performed on two marine toads, one animal showing neurological disorders and the other multifocal dermatitis. In one case, lesions consisted of a severe granulomatous encephalomyelitis and in the other of multiple granulomas in the nasal cavity, lungs, heart, bone marrow, ovaries and skin. Histologically, the lesions revealed varying amounts of dark brown fungal elements, predominantly sclerotic bodies indicative of a mycotic infection due to a pigmented fungus.

Animals↗
PubMed1992

Familial occurrence of pruritic urticarial papules and plaques of pregnancy.

BACKGROUND: The occurrence of pruritic urticarial papules and plaques of pregnancy (PUPPP) was noted in four women with unusual family relationships. OBJECTIVE: The purpose of the study was to document the occurrence of PUPPP in these families and to make observations on their possible relevance. METHODS: Case reports of the four patients are detailed. Histologic and HLA studies are recorded. RESULTS: In both families, sisters were married to brothers. A common paternal influence is suggested. CONCLUSION: We postulate that PUPPP may be a maternal response to a circulating paternal factor for which tolerance develops in subsequent pregnancies.

Adolescent↗
PubMed1992

Characteristics at entry of children with severe primary vesicoureteral reflux recruited for a multicenter, international therapeutic trial comparing medical and surgical management. The International Reflux Study in Children.

A total of 532 children, 401 from Europe and 131 from the United States, was recruited into an international multicenter study comparing the results of medical and surgical treatment of children with international grade III or IV vesicoureteral reflux and urinary tract infection. Patient age was less than 11 years, glomerular filtration rate was greater than 70 ml. per minute per 1.73 m.2 and there was no obstruction, renal malformation, previous urinary tract surgery or neuropathic bladder. A total of 80 children had less than grade III vesicoureteral reflux on a second pre-entry cystourethrogram required by the European protocol, and they were followed separately as a sideline group. At entry the age distribution, history of urinary tract infection and proportion of children with grade IV vesicoureteral reflux were similar in Europe and the United States. Of the European and United States children 48% and 54% had renal scarring, and 17% and 14% had parenchymal thinning, respectively. In each group renal length and planimetric area were normal in two-thirds and 5% had small kidneys (<2 standard deviations from normal). Differences included sex distribution (24% boys in Europe and 11% in the United States group), the proportion of children in whom vesicoureteral reflux was previously known (18% Europe and 69% United States) and the proportion of children with bilateral reflux (77% Europe and 57% United States). Randomization and stratification for treatment were successful.

Child↗
PubMed1992

Results of a randomized clinical trial of medical versus surgical management of infants and children with grades III and IV primary vesicoureteral reflux (United States). The International Reflux Study in Children.

A total of 132 infants and children with grades III and IV primary vesicoureteral reflux was entered into a prospective trial comparing medical to surgical management. Inclusion criteria were an age not exceeding 10 years and a glomerular filtration rate of at least 70 ml. per minute per 1.73 m.2. Children with significant urinary tract malformations and clinical signs/symptoms of dysfunctional voiding were not accepted into the trial. Medical therapy consisted of continuous low dose antibiotic prophylaxis until vesicoureteral reflux resolved. The type of surgical procedure used for the correction of reflux was left to the discretion of the surgeon. Outcome variables included the appearance or progression of renal lesions, rate of renal growth, recurrence rate of urinary tract infection or pyelonephritis, changes in total kidney glomerular filtration rate, development of hypertension and resolution rate of vesicoureteral reflux. Followup at 6, 18, 36 and 54 months after entry included, in addition to history and physical examination, voiding cystourethrography, excretory urography and a urine culture. Of the patients 68 were allocated to the medical group and 64 to the surgical group. They were stratified for age, sex and preexisting renal scarring. Of the patients 10% were boys, 47% were between 2 and 6 years old at entry, 93% had a history of pyelonephritis, 67% had either scarring or thinning of the parenchyma at entry, 87% had grade IV vesicoureteral reflux in at least 1 unit and 56% had bilateral reflux. There were no significant differences in the frequency distribution of entry characteristics between the patients allocated to either group. New renal scarring developed in 22% of medical and 31% of surgical patients (p < 0.4). Growth of kidneys with grade IV vesicoureteral reflux was slightly less than normal in the medical (-0.67 +/- 0.15 standard deviation) and surgical (-0.42 +/- 0.11 standard deviation) groups (p < 0.7). Pyelonephritis occurred in 15 medical patients versus 5 surgical patients (p < 0.05). There was no significant change in glomerular filtration rate within each treatment group and no difference in glomerular filtration rate between groups. No patient had hypertension during the followup period. The disappearance rate of vesicoureteral reflux in patients with grade IV reflux was approximately 8% per year. Of the medical patients 75% still had vesicoureteral reflux after 3 years of observation.(ABSTRACT TRUNCATED AT 400 WORDS)

Child↗
PubMed1992

Surgical results: International Reflux Study in Children--United States branch.

A total of 87 patients in the United States underwent surgical correction of vesicoureteral reflux as part of the International Reflux Study in Children. Of the 66 patients randomized to surgical treatment 2 were transferred to the medical group before surgery was performed, while 23 patients originally assigned to receive medical management ultimately underwent surgery. Of the patients 17 (20%) were less than 1 year old, while the remaining children were evenly distributed by age in 2-year intervals up to age 9 years. Reimplantation was performed by the Cohen technique in 52% and by the Politano-Leadbetter technique in 28% of the patients. Bilateral reimplantation was done in 70 patients (80%). The results were satisfactory, with no obstructions. In 81% of the patients average followup was 3.9 years, although followup of less than 1 year in 19% was satisfactory to determine obstruction. Only 3% of the children were lost to followup. Postoperative reflux, which was noted in 5 patients, resolved in all but 1 ureter. These results reflect the experience of senior surgeons in pediatric urology.

Child↗
PubMed1992

The California Family Health Project: I. Introduction and a description of adult health.

Little research has addressed patterns of family and health relationships that reflect both the scope and complexity of family life and the breadth and diversity of health. In the first of a series of articles, we describe the California Family Health Project, a study in which four large "domains" of family life (Structure/Organization, World View, Problem Solving, and Emotional Management) were mapped, described, and compared with a large battery of adult health measures. We first present a brief critical overview of the literature on family and health research, then explain our rationale, define our approach to the multivariate analysis of family and health data, and describe our sample of 225 community-based families. To prepare for analyses with the family variables, we next present descriptive data based on separate principal components analysis (PCA) and multidimensional scaling analysis (MDS) of 14 self-reported health scores for husbands and for wives. No grouping or clustering of health variables emerged for either husbands or wives in the PCAs. A two-dimensional MDS analysis for husbands and for wives displayed the health variables in a circular pattern in which no predominant descriptive dimension or group of discrete dimensions emerged. Consequently, we decided that all 14 health scores will be used in the analyses, with the family variables to follow.

Adult↗
PubMed1992

[Riding arenas and different riding track surfaces in relation to the airway contamination in horses. Laboratory studies on riding surfaces].

29 samples of commonly used surfaces were tested for their water characteristics (litre weight, water capacity, water binding, water evaporation) and their contribution to airborne fungal spores (dust formation, dust setting). The results are discussed in comparison to the literature with regard to the environment. The results are: 1. Any surface--no matter of what material--eventually causes air pollution with fungal spores and dust. 2. Correct watering prevents air pollution by any surface. 3. Artificial products have no advantage over natural materials in the parameters tested. 4. The question of proper disposal of old surface material has to be clarified before purchase. The results show that a mixture of sand and wood shavings should be recommended as a surface for indoor arenas, especially in regard to environmental protection and proper disposal.

Air Pollution, Indoor↗
PubMed1991

Extramedullary blast crisis in chronic myelogenous leukemia. Demonstration of T-cell lineage and Philadelphia chromosome in a paraspinal tumor.

A case of chronic myelogenous leukemia (CML) with penetrance of the Ph1 molecular alteration into the T-cell lineage of a paraspinal tumor is reported. The T-cell nature of the paraspinal tumor was documented by immunochemical study and genotyping. The Philadelphia chromosome was also detected by genotyping in the same tumor cell population. To the authors' knowledge, this is the first case of extramedullary T-cell blast crisis in CML demonstrated in an extranodal tumor. The clinical significance of detecting extramedullary blast crisis, and the theories for the scarcity of T-cell transformation in CML are discussed.

Blast Crisis↗
PubMed1991

Caesium fluoride-induced changes in the c.d. spectra of synthetic DNA fragments.

Ten DNA fragments containing self-complementary alternating sequences of adenine and thymine differing in length and the starting nucleotide were studied by c.d. spectroscopy. It was found that d(TATATATA) but not d(ATATATAT), d(TATATA), d(CTATATAG) or (dT-dA)20 isomerized into the unusual X-DNA double helix at molar concentrations of CsF in solution. But in contrast to poly(dA-dT), the octamer (dT-dA)4, isomerized very slowly, at relatively low CsF concentrations and the isomerization was strongly dependent on the octamer concentration. A model is proposed to account for the observed properties of the B-to-X isomerization on the oligomer level.

Adenine Nucleotides↗