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Biomedical subjects

S Fleming

Publications and source records attributed to S Fleming.

At least 145 records · Page 8Linked to original sources
PubMed1988

Hysteresis of the ventricular paced QT interval in response to abrupt changes in pacing rate.

The rate of QT adaptation to abrupt changes in pacing rate was studied in seven patients with newly diagnosed complete heart block with a ventricular escape rate of less than 40 beats.min-1. Their median age was 70 (range 36-84) years, and none was taking any cardioactive medication known to affect the QT interval. From a baseline pacing rate of 50 or 110 beats.min-1 the ventricular rate was increased or decreased to a new level. The time taken for the ventricular paced QT interval to complete 90% of the change secondary to the change in rate was found to be 136(16) s (mean(SEM] when the rate was increasing and 189(25) s when the rate was decreasing (p less than 0.01). This time interval was independent of the magnitude of the rate change and the baseline heart rate from which the change occurred. Furthermore, the time course of QT adaptation was found to be exponential and was characterised by a time constant of 49.1(2.2) s when the rate was increasing and 60.4(2.0) s when the rate was decreasing (p less than 0.01). It is concluded that QT measurements in response to a change in pacing rate should take into account the time dependent nature of QT changes.

Adult↗
PubMed1988

Reimbursement for intensive care services under diagnosis-related groups.

Current governmental policy, in an effort to reduce the federal deficit, has switched to a prospective payment system for hospital care of Medicare patients based on Diagnosis-Related Groups (DRGs). In New Jersey, all hospital care is reimbursed using a DRG system. This study examines the relationship between charges and reimbursement in a university hospital ICU under a DRG system for the care of patients who consume a large amount of the ICU resources. For patients who were classified Class IV under the Therapeutic Intervention Scoring System, with the possible exception of open heart patients, the charges for care delivered exceeded income received, with a net revenue of -$24,098 and an adjusted net revenue of -$5,057 for ICU Class IV patients (excluding open hearts). Thus, it appears that the care given to these patients may have resulted in a financial loss to the institution. If this were to continue, the financial impact might have a negative effect upon attempts to regionalize intensive care services.

Critical Care↗
PubMed1988

The structure of fucosylated blood group substances in fetal rat skin. The combined use of monoclonal antibodies and glycosyl hydrolases.

Cell surface carbohydrates are thought to be important during embryonic development. We have studied a group of defined cell surface carbohydrates during the differentiation of fetal rat skin by the use of immunocytochemical techniques. We used monoclonal antibodies to the LeX and human blood group H type II haptens. The structure of the molecules carrying these haptens has been inferred by the sensitivity of the immune reactions to digestion by glycosyl hydrolases. The primitive ectoderm expressed the LeX hapten. The differentiating epidermis carries the H type II antigen, but this was only detected following cleavage of a terminally modified portion of the carbohydrate containing linear poly-N-acetyl lactosamine chains. These carbohydrates on epidermal cells are carried N linked to glycoproteins.

Animals↗
PubMed1988

Trends and regional variations in hospital utilization and quality during the first two years of the prospective payment system.

The Commission on Professional and Hospital Activities monitored both Medicare and non-Medicare hospital discharges for a cohort of 646 U.S. nonfederal, short-term general hospitals from nonwaivered states over the period 1980-1985. Using this data base and a linear forecasting model, we studied utilization and quality-of-care trends for the years preceding implementation of the prospective payment system (PPS) and the two years following its implementation. We found that Medicare discharges declined significantly in both 1984 and 1985, length of stay was unchanged from 1984 to 1985 (except in the West, where further declines occurred), and skilled nursing facility and home health care use for postdischarge care increased both years. Our unadjusted measures of quality showed no adverse effects in either 1984 or 1985 for Medicare patients.

Commission on Professional and Hospital Activities↗
PubMed1988

Hashimoto's disease in Turner's syndrome.

Sera from 52 patients with Turner's syndrome were analyzed for thyroxine and TSH concentrations, resin T3 uptake, and thyroid antibodies. Thyroid antibody titers were compared to those previously obtained in 53 women with long-standing infertility. Thyroid microsomal and/or thyroglobulin antibody titers were elevated to a level diagnostic of Hashimoto's disease (greater than 1:400) in 25 (48%) patients with Turner's syndrome. Microsomal antibody levels only were elevated in five (9%) patients with infertility. The mean microsomal antibody titers in the patients with Turner's syndrome (1:25, 167 +/- 31,531) were significantly higher than in the infertile patients (1:2560 +/- 2149). The incidence of Hashimoto's disease did not differ significantly among the various karyotypes. The entire clinical spectrum of Hashimoto's thyroiditis was present in Turner's syndrome. Three patients had overt hypothyroidism necessitating L-thyroxine, four had compensated hypothyroidism (serum TSH concentration greater than 10 microU/L and normal serum thyroxine concentrations), while the remaining 18 had normal thyroid function. No relationship was demonstrated between Hashimoto's disease or family history of thyroid disease and karyotype.

Adolescent↗
PubMed1987

The radiology of sarcomas and sarcomatoid carcinomas of the kidney.

Tumours of the kidney with sarcomatoid elements are uncommon. The radiological findings in 11 patients with such lesions are presented. It is important to separate pure sarcomas from lesions with sarcomatous and carcinomatous elements since they have different radiological appearances and prognosis. These tumours often show calcification on radiographs and on angiography appear predominantly avascular with a blood supply from capsular vessels. Because of their rarity and the overlap of radiographic findings with more common tumours the diagnosis cannot be made by current imaging methods alone.

Adenocarcinoma↗
PubMed1987

Carcinosarcoma (mixed mesodermal tumor) of the ureter.

An unusual tumor of the ureter in an elderly man is reported. The tumor showed evidence of epithelial and mesenchymal differentiation based on histological and immunocytochemical criteria, and it behaved aggressively, comparable to that seen in other mixed tumors of this type arising from elsewhere within the genitourinary tract. It is proposed that this tumor be designated carcinosarcoma of the ureter.

Aged↗
PubMed1987

The distribution of cytokeratin antigens in the kidney and in renal tumours.

The distribution of cytokeratin antigens during embryogenesis of the kidney and in 57 renal tumours has been studied using immunocytochemical techniques. A polyclonal antiserum to epidermal prekeratins and the monoclonal antibodies CAM 5.2 and PKK1 have been used to identify cytokeratins of different molecular weights. The ureteric bud-derived structures expressed large molecular weight cytokeratins. The tubular component of the kidney expressed cytokeratins detected by CAM 5.2 and PKK1. During glomerular development there was transient expression of low molecular weight cytokeratins by the visceral glomerular epithelium but in the adult kidney only the parietal epithelium expressed cytokeratins. Tubules in nephroblastomas contained low molecular weight cytokeratins but the blastema did not. Some ureteric bud-derived structures were identified in six nephroblastomas. Renal carcinomas expressed low molecular weight cytokeratins. Four collecting duct carcinomas were studied; these all expressed the large molecular weight cytokeratins found in collecting duct epithelium. These results indicate that the cytokeratin phenotype of renal tumours is unchanged from that of the normal epithelial cells.

Antibodies, Monoclonal↗
PubMed1987

The expression of 3-fucosylated-N-acetyl lactosamine carbohydrate determinants in renal tumours.

The distribution in renal tumours of 3-fucosyl-N-acetyl lactosamine has been studied by using the monoclonal antibodies AGF 4.36 and AGF 4.48 and immunoperoxidase methods on tissue sections. Seven of 19 nephroblastomas and 12 of 30 renal cell carcinomas contained the epitope. In nephroblastomas the epitope was found on the terminals of type B tubules in six cases and in one case on the type A or neoplastic tubules. In renal carcinoma the antigen was found on the surface of tumour cells. The results suggest that in kidneys bearing nephroblastomas ureteric bud elements may grow into the tumour from the adjacent kidney.

Antibodies, Monoclonal↗
PubMed1987

Renal tubular antigens in regenerative epithelium and renal carcinoma.

Antibodies to brush border antigen (BB) and epithelial membrane antigen (HMFG2) have been used in immunocytochemical preparations to define specific portions of the nephron. In both fetal and adult kidney BB was confined to the proximal tubule and HMFG2 to the distal tubule and collecting duct. The distribution of the antigens was studied in regenerative epithelium (15 cases) and renal carcinoma (35 cases). Regenerative epithelium in six cases expressed both antigens, and 29/35 renal carcinomas expressed both antigens. These results demonstrated some antigenic similarities between regenerative hyperplastic tubular epithelium and renal carcinoma.

Antigens↗
PubMed1987

Immunocytochemical localization of ferritin in the kidney and renal tumours.

The distribution of ferritin in the kidney and renal tumors was studied using a polyclonal anti-ferritin antiserum and immunocytochemical techniques. Ten fetal kidneys, 5 adult kidneys and 56 renal tumours were studied. Ferritin first appears in the maturing fetal nephron where it is confined to the proximal tubule. In the adult kidney ferritin is also restricted to the proximal tubule. Ferritin was not seen in 18 nephroblastomas nor in 4 renal sarcomas, but 14 of 26 renal cell carcinomas and 5 of 8 renal oncocytomas contained ferritin. The relationship between the expression of ferritin and tumour differentiation is discussed.

Carcinoma, Renal Cell↗
PubMed1987

The early effects of the prospective payment system on inpatient utilization and the quality of care.

Concern is often expressed that hospitals may be making cost/quality trade-offs under Medicare's prospective payment system. To evaluate the early effects of PPS on inpatient utilization and quality of care, we studied a cohort of 729 U.S. short-term general hospitals from nonwaivered states. We used a linear forecasting model to project 1984 figures based on trends from 1980 to 1983. We found no evidence that the quality of care deteriorated in 1984 for Medicare patients. Consultation rates remained constant, and in-hospital deaths and readmission rates were consistent with previous trends for the Medicare population. Overall, it appears that PPS has reduced hospital utilization without producing deterioration in the quality of care.

Coronary Care Units↗
PubMed1987

Immunocytochemical evidence for transferrin-dependent proliferation during renal tubulogenesis.

The role of the transferrin receptor and of cell proliferation during human renal embryogenesis has been studied by using immunocytochemical techniques. Tissue sections of human fetal kidneys have been stained using monoclonal antibodies to the cell surface transferrin receptor (HB21) and the nuclear proliferation antigen (Ki67). Both antigens appear during nephron induction, are strongly expressed during the early stages of renal tubulogenesis, but are lost with progressive maturation. Simultaneous changes in the intermediate filament phenotype at this developmental stage have also been demonstrated by the use of monoclonal antibodies to vimentin and low molecular weight cytokeratin. This study provides immunocytochemical evidence that in the human kidney, as in in vitro development of the mouse kidney, one of the early events in tubule induction involves transferrin-dependent proliferation.

Cell Division↗
PubMed1986

Comparison of radionuclear scintigraphy and liver biopsy in the evaluation of neonatal cholestasis.

Twenty-eight patients with neonatal cholestasis were given appropriate tests to arrive at a definitive diagnosis. Comparison of the results showing total obstruction on scintigraphy but not on liver biopsy is presented. It is suggested that liver biopsy be performed to confirm the diagnosis prior to undertaking exploratory laparotomy when radionuclear scan suggests extrahepatic biliary atresia.

Bile Ducts↗
PubMed1986

Collecting duct carcinoma of the kidney.

Six cases of renal epithelial neoplasms, which show atypical histological features previously described in cases of collecting duct carcinomas, are presented. The tumours were of a tubulo-papillary architecture, arose in the renal medulla and showed prominent infiltrating tubules with an associated desmoplastic reaction. Atypical hyperplastic changes were present in the medullary collecting ducts in five cases.

Adenocarcinoma, Papillary↗
PubMed1986

Proteinase inhibitors in the kidney and its tumours.

The proteinase inhibitors alpha-1-antitrypsin and alpha-1-antichymotrypsin are found in a variety of tissues including the kidney. We have used the immunoperoxidase technique to study the distribution of these glycoproteins in 10 fetal and five adult kidneys and in 44 renal tumours. Proteinase inhibitors were found in fetal kidneys in the cells of the metanephric blastema, primitive mesenchyme and in proximal tubules. They were found in proximal tubules of adult kidneys. These substances were also found in the mesenchyme of nephroblastomas and in the tumour cells of clear cell, oncocytic and sarcomatoid variants of renal cell carcinoma. These observations are significant in the understanding of the patterns of differentiation of which renal cell carcinoma is capable.

Adult↗