Search PubMed⌕ Search

Biomedical subjects

J Waldman

Publications and source records attributed to J Waldman.

At least 19 recordsLinked to original sources
PubMed2001

Association of surgical specialty and processes of care with patient outcomes for carotid endarterectomy.

BACKGROUND AND PURPOSE: Because there is considerable variation in practice patterns and outcomes for carotid endarterectomy (CE), there is a need to study the processes of care that are associated with adverse outcomes. The purpose of this study was to examine the impact of processes of care and surgical specialty on adverse outcomes for CE. METHODS: A retrospective cohort study based on a voluntary CE registry containing 3644 patients undergoing CE between April 1, 1997, and March 31, 1999, in New York hospitals was used in the study. A multivariable statistical model was used to identify significant independent patient risk factors and to examine the association of processes of care and surgical specialty with outcomes after adjustment for differences in patient risk factors. RESULTS: The overall adverse outcome (in-hospital death or stroke) rate was 1.84%. After adjustment for differences in 7 patient risk factors that were significantly related to adverse outcomes, the use of >/=1 specific processes of care (eversion endarterectomy, protamine, or shunts) was found to be associated with lower odds of an adverse outcome relative to patients undergoing CE without the processes (OR=0.42, P=0.006). Similarly, patients undergoing surgery performed by vascular surgeons had lower odds of experiencing an adverse outcome (OR=0.36, P=0.009). Processes of care and surgical specialty were highly correlated with one another. CONCLUSIONS: Processes of care and surgical specialty are significant interrelated determinants of adverse outcome for CE.

Aged↗
PubMed1999

Modification of human cytomegalovirus tropism through propagation in vitro is associated with changes in the viral genome.

Following extensive propagation in fibroblasts, human cytomegalovirus (HCMV) loses tropism for a number of otherwise natural host cells, in particular, endothelial cells. In this study, the hypothesis was tested that loss of endothelial tropism is associated with the appearance of genomic variants. Initial quantitative focus expansion assays on endothelial monolayers demonstrated that, while the laboratory strains AD169 and Towne failed to form detectable foci, 29 out of 30 recent clinical HCMV isolates had the potential to expand in endothelial cell culture. By long-term adaptation in fibroblast cultures, nonendotheliotropic strains could be selected from clinical HCMV isolates, while long-term endothelial-adapted strains of the same isolates retained both fibroblast tropism and endothelial tropism. Such differentially adapted isolate pairs always displayed genomic differences in restriction fragment length analyses. Coinfection of endothelial cells by two nonendotheliotropic HCMV strains yielded an endotheliotropic recombinant HCMV variant combining portions of the genomes of both parental viruses. When DNA purified from various isolates was transfected into fibroblasts, progeny virus retained the specific tropism of parental virus from which the DNA was isolated. These findings demonstrate that endothelial tropism is an inherent property of most clinical HCMV isolates and is determined by the viral genome. Although the specific determinants of HCMV cell tropism are still unknown, this study provides the first evidence for a genetic contribution.

Cells, Cultured↗
PubMed1998

Cloning, characterization, and gene organization of K-Cl cotransporter from pig and human kidney and C. elegans.

We isolated and characterized the cDNAs for the human, pig, and Caenorhabditis elegans K-Cl cotransporters. The pig and human homologs are 94% identical and contain 1,085 and 1,086 amino acids, respectively. The deduced protein of the C. elegans K-Cl cotransporter clone (CE-KCC1) contains 1,003 amino acids. The mammalian K-Cl cotransporters share approximately 45% similarity with CE-KCC1. Hydropathy analyses of the three clones indicate typical KCC topology patterns with 12 transmembrane segments, large extracellular loops between transmembrane domains 5 and 6 (unique to KCC), and large COOH-terminal domains. Human KCC1 is widely expressed among various tissues. This KCC1 gene spans 23 kb and is organized in 24 exons, whereas the CE-KCC1 gene spans 3.5 kb and contains 10 exons. Transiently and stably transfected human embryonic kidney cells (HEK-293) expressing the human, pig, and C. elegans K-Cl cotransporter fulfilled two (pig) or five (human and C. elegans) criteria for increased expression of the K-Cl cotransporter. The criteria employed were basal K-Cl cotransport; stimulation of cotransport by swelling, N-ethylmaleimide, staurosporine, and reduced cell Mg concentration; and secondary stimulation of Na-K-Cl cotransport.

Amino Acid Sequence↗
PubMed1998

Relationship between provider volume and mortality for carotid endarterectomies in New York state.

BACKGROUND AND PURPOSE: The objective of this study was to assess the relationship between each of 2 provider volume measures for carotid endarterectomies (CEs) (annual hospital volume and annual surgeon volume) and in-hospital mortality. New York's Statewide Planning and Research (SPARCS) administrative database was used to identify all 28 207 patients for whom carotid endarterectomy was the principal procedure performed in New York State hospitals between January 1, 1990, and December 31, 1995. METHODS: A statistical model was developed to predict in-hospital mortality using age, admission status, and several conditions found to be associated with higher-than-average mortality. This model was then used to calculate risk-adjusted mortality rates for various intersections of hospital and surgeon volume ranges. RESULTS: Risk-adjusted in-hospital mortality ranged from 1.96% (95% confidence interval, 1.47 to 2.57) for patients having surgeons with annual CE volumes of <5 in hospitals with annual CE volumes of </=100 to 0.94% (95% confidence interval, 0.73 to 1.19) for patients having surgeons with annual volumes of >/=5 in hospitals with annual CE volumes of >100. These 2 rates were statistically different. CONCLUSIONS: We conclude that the in-hospital mortality rates for carotid endarterectomies performed by surgeons with extremely low annual volumes (<5) and for hospitals with low volumes (</=100) are significantly higher than the in-hospital rates of higher-volume surgeons and hospitals, even after taking preprocedural patient severity of illness into account.

Adult↗
PubMed1994

The nature and origins of acid summer haze air pollution in metropolitan Toronto, Ontario.

During July and August of 1986, 1987, and 1988, a field study was conducted of ambient acidic aerosol levels in Toronto, Ontario. Fine particle mass (da < 2.5 microns) samples were collected twice daily at a central-city site for the determination of particulate-phase strong acidity (H+) and sulfate (SO4 =). Two additional H(+)-monitoring sites were concurrently operated during the summers of 1986 and 1987 to examine the spatial variability of H+ within the metropolitan area. During the summer of 1986, a quasi-continuous total sulfate/sulfuric acid analyzer was also deployed to allow a determination of the chemical form of H+. Results indicate that acid aerosol episodes (H+ > or = 100 nmole/m3) did occur in this city during the summer months, and that H+ peaks were well correlated with sulfate peaks. Virtually all of the H+ was found to be present as ammonium bisulfate (NH4HSO4). While H+ concentrations were highly correlated among the three monitoring sites (r = 0.9), the highest H+/SO4 = ratios prevailed during SO4 = episode periods and at the least urbanized site. This latter trend was apparently due to greater neutralization of H+ by local ammonia at the more urbanized sites. Comparisons of day vs night H+/SO4 = ratios, an examination of air mass back-trajectories, and contemporaneous H+ measurements at surrounding sites collectively indicated that transported regional haze air pollution from the United States is a major contributor to the H+ events recorded within Toronto.

Acids↗
PubMed1994

Epidemiology and partial nucleotide sequence of four novel genital human papillomaviruses.

Polymerase chain reaction (PCR)-based genital human papillomavirus (HPV) detection methods that use consensus primers have enabled the broad-spectrum detection of most characterized HPV types. In addition, these techniques have allowed the identification of potentially novel viral sequences in clinical specimens. These methods were used to determine the partial L1 nucleotide sequence (the region generated by L1 consensus primers MY09 and MY11) of four novel viruses. The prevalence of these viruses in cytologically normal and dysplastic cervical specimens and in invasive cervical cancer was also determined. The partial DNA sequences of W13B (MM4), PAP291 (MM7), PAP155 (MM8), and PAP238a (MM9) are most similar to HPV-51, -61, -61, and -34, respectively. Prevalence studies suggest that W13B and PAP238a are cancer-associated, while PAP155 and PAP291 appear to be lower-risk viruses.

Base Sequence↗
PubMed1992

Comparison of nomogram- and ultrasound-determined renal depths for calculation of glomerular filtration rates in spinal cord injury patients.

In an informal survey, poor correlation was found between 24-hour creatinine levels and glomerular filtration rates calculated from nuclear medicine studies in spinal cord injury patients. It was speculated that the discrepancies were because the nomograms used in the calculations did not take into account differences in body fat distribution for this patient group. Twenty-five chronic spinal cord injury patients were prospectively studied to compare glomerular filtration rates (GFR) using the nomograms based on height and weight and those using renal depth determined by ultrasound. It was found that the renal depth determined by nuclear medicine was significantly less than that determined sonographically. The mean difference between the total nuclear medicine-based GFR and total ultrasound-based GFR was 17.576 ml +/- 15.449 ml (P < or = 0.001). It was found that there was a significant difference between calculated GFRs based on renal depths as determined by the different methods. In addition, calculated GFRs based on ultrasound-determined depths corresponded more closely to 24-hour creatine clearance levels and with a smaller degree of error than those using renal depths determined by the nuclear medicine nomograms.

Adipose Tissue↗
PubMed1990

Cortical function assessment in the elderly.

The Cortical Function Assessment (CFA) is a 10-point test developed to overcome the limitations of current bedside mental status exams which emphasize orientation and memory. Items measure higher cortical function, such as naming, writing, drawing, and stereognosis. The test was given to young and old normal subjects, young and old depressive patients, and patients with dementia. Interrater reliability was high (alpha = .95) as was the correlation between it and the Short Portable Mental Status Questionnaire (r = .87) and the Mini-Mental State (r = .92). The study demonstrates the utility of the CFA as a screening tool in dementia and depression in the elderly and suggests its use in routine geriatric evaluations.

Adolescent↗
PubMed1989

Hydrostatic reduction of ileocolic intussusception: a second attempt in the operating room with general anesthesia.

Over a 3-year-period, standard treatment with hydrostatic pressure from a contrast enema failed to reduce ileocolic intussusception in 31 of 62 children. With the child anesthetized in the operating room, a second contrast enema was given before laparotomy. Of the 31 intussusceptions, 21 (68%) were reduced without complication, thereby avoiding the discomfort, longer hospitalization, complications, and expense of surgery. Nine of the remaining 10 intussusceptions were difficult to reduce manually during surgery or required resection. The overall nonoperative reduction rate for the 3-year period was 84%; for the last 2 years it was 90%. Success with the second enema may be related to the effects of general anesthesia. In addition, partial reduction with the first enema may improve blood flow from the intussusceptum so that it becomes smaller and easier to reduce with the second enema. Because it can easily be added to standard management protocols without increased risk, routine use of this second enema with anesthesia is recommended.

Anesthesia, General↗
PubMed1989

Neurofibromatosis and other disorders among children with CNS tumors and their families.

We conducted a population-based case-control study with 338 patients, less than 15 years of age, diagnosed with a primary tumor of the central nervous system from January 1968 through December 1977 in 53 New York State counties. The study also included 676 controls selected from the birth certificate files of the New York State Department of Health. We collected information on neurofibromatosis and congenital anomalies in study subjects, their siblings and parents by telephone interview with the mother of each case and control. We obtained supplemental information on neurofibromatosis in the patients and their families from hospital medical records. This study confirmed the strong association of neurofibromatosis with risk of CNS tumors. Thirteen cases and no controls had neurofibromatosis. Two fathers and 3 mothers of cases had neurofibromatosis. Five cases had siblings with neurofibromatosis. None of the first-degree relatives of controls had neurofibromatosis. We observed a relative risk of 4.49 for history of seizures. Seizures are often among the presenting symptoms for CNS tumors. We observed no difference between cases and controls in the occurrence of congenital anomalies. There was a nonsignificant excess of congenital anomalies among siblings of cases compared with controls. This decreased to 1.13 when adjusted for number of siblings.

Brain Neoplasms↗
PubMed1989

Cytomegalovirus infection of gastrointestinal endothelium demonstrated by simultaneous nucleic acid hybridization and immunohistochemistry.

To demonstrate the degree of involvement of endothelial cells in cytomegalovirus (CMV) infection of the gastrointestinal tract we have stained sections from gastrointestinal specimens that showed inclusion bodies on hematoxylin-eosin staining. Factor VIII was first detected using a rabbit anti-factor VIII primary antibody and an alkaline phosphatase-labeled sheep anti-rabbit secondary antibody. The CMV was then visualized with a biotin-labeled CMV probe detected by a streptavidin peroxidase technique with aminoethyl carbazole as the chromogen. Factor VIII staining was a bright blue and CMV a brick red. The specimens included one small-bowel resection and four colonic resections, as well as an esophageal biopsy. The patients' diagnoses included bone marrow transplant recipient, acquired immunodeficiency syndrome, ulcerative colitis, and renal transplant recipient. Cells positive for both CMV and factor VIII ranged from 35% to 60% of positive cells in a representative section, and the relative percentages (mean +/- SE) for cell type for infected cells were: endothelial, 48.9 +/- 4.5; vascular luminal (factor VIII negative), 6.1 +/- 1.7; perivascular (factor VIII negative in vascular wall), 16.2 +/- 3.2; and other cell (non-vascular factor VIII negative), 28.9 +/- 5.1. These findings and clustering of infected cells around the vessels provide evidence that CMV infection of the gastrointestinal tract is primarily vasculitic and related to infection of endothelial cells.

Adult↗