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Biomedical subjects

W Karp

Publications and source records attributed to W Karp.

At least 19 recordsLinked to original sources
PubMed1999

Effects of exercise training and its cessation on components of the insulin resistance syndrome in obese children.

OBJECTIVE: To determine the effect of exercise training (ET) on components of the insulin resistance syndrome (IRS) in obese children. DESIGN: Randomized, modified cross-over study, with subjects assigned to one of two conditions: (1) 4 months of ET followed by 4 months of no-ET; or (2) 4 months of no-ET followed by 4 months of ET. Measurements were made at three time points: 0, 4 and 8 months. SUBJECTS: 79 obese, but otherwise healthy children (age: 7-11 y, percent fat (%fat) 27-61%). MEASUREMENTS: Plasma lipid and lipoprotein concentrations, plasma insulin and glucose concentrations; %fat; submaximal heart rate (HR) as an index of fitness. EXERCISE TRAINING: ET was offered 5 d/week 40 min/d. For the 73 children who completed 4 months of ET, the mean attendance was 80% (that is, 4 d/week) and the average HR during ET was 157 bpm. RESULTS: Significant (P < 0.05) group x time interactions were found for plasma triglyceride (TG) and insulin concentrations and %fat. The average change for both groups, from just before ET to just after the 4 month ET was -0.24 mmol.l-1 for TG, -25.4 pmol.l-1 for insulin and -1.6 units for %fat. When Group 1 ceased ET, over the following 4 month period the average change for insulin was +26.6 pmol.l-1 and for %fat +1.3 units. CONCLUSION: Some components (plasma TG, insulin, %fat) of the IRS are improved as a result of 4 months of ET in obese children. However, the benefits of ET are lost when obese children become less active.

Analysis of Variance↗
PubMed1998

Visceral adipose tissue and cardiovascular risk factors in obese children.

OBJECTIVE: In adults visceral adipose tissue (VAT) has been shown to be more highly correlated with cardiovascular (CV) risk factors than are other measures of adiposity such as subcutaneous abdominal adipose tissue (SAAT), percent body fat (%BF), or total body fat mass (TFM). We examined the relations between these measures of fatness and CV risk factors in obese children. STUDY DESIGN: Subjects were 64 obese (27% to 61% BF) children (24 black girls, 19 white girls, 11 black boys, 10 white boys) aged 7 to 11 years. VAT and SAAT were measured with magnetic resonance imaging. TFM and %BF were determined with dual x-ray absorptiometry. Hierarchical stepwise multiple regression analyses were used to determine the proportions of variance in CV risk factors explained by the demographic and adiposity measures. RESULTS: VAT but not SAAT, %BF, or TFM explained a significant proportion of the variance (r2 range = 0.10 to 0.21) in several lipid/lipoprotein risk factors including triacylglycerols, high-density lipoprotein cholesterol, the ratio of total cholesterol to high-density lipoprotein cholesterol, and low-density lipoprotein particle size. CONCLUSION: Many of the deleterious relations between VAT and lipid/lipoprotein risk factors seen in adults were already present in this sample of obese children.

Abdomen↗
PubMed1997

Weight-independent cardiovascular fitness and coronary risk factors.

BACKGROUND: It is unclear whether cardiovascular fitness influences risk factors for coronary artery disease and non-insulin-dependent diabetes mellitus independently of level of body fat because fitness is often measured in tasks that involve moving body weight (eg, running) and because body weight and level of body fat are correlated. OBJECTIVE: To measure fitness during a task in which body weight was controlled experimentally (ie, supine cycling). DESIGN: Cross-sectional. PARTICIPANTS: Seventy-four children, 7 to 13 years of age, recruited through school flyers and newspaper advertisements, varying in level of body fat from 7% to 61%. There were 31 boys and 43 girls; 35 were white and 39 were black. MAIN INDEPENDENT VARIABLES: Cardiovascular fitness was expressed as submaximal heart rate while cycling at a power output of 49 W, and level of body fat was measured with dual x-ray absorptiometry. MAIN OUTCOME MEASURES: Blood pressure and levels of triglycerides, total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, insulin, glucose, and glycohemoglobin. RESULTS: Controlling for age and sex, level of body fat was significantly (P < .01) related to unfavorable levels of systolic blood pressure (r = 0.32), triglycerides (r = 0.42), high-density lipoprotein cholesterol (r = -0.31), insulin (r = 0.50), and total cholesterol to high-density lipoprotein cholesterol ratio (r = 0.37); submaximal heart rate was not significantly correlated with any of the other variables. CONCLUSIONS: When cardiovascular fitness was measured in a weight-independent task, it was not significantly related to level of body fat or the major coronary artery disease and non-insulin-dependent diabetes mellitus risk factors. In addition, we confirmed previous findings that higher levels of body fat are associated with a very unfavorable risk profile.

Adipose Tissue↗
PubMed1990

Comparison of the binding characteristics of serum albumins from various animal species.

In order to develop an animal model to study the bilirubin displacing effect of various drugs, we compared the bilirubin binding ability of human, pig, dog, rabbit, hamster, rat, guinea pig, and cat albumin. These albumins were used also to study the binding of monoacetyldiaminodiphenyl sulfone (MADDS). Using human, rat, guinea pig, and rabbit albumin, we studied the effect of sulfisoxazole, ceftriaxone, and tin protoporphyrin on bilirubin binding. Our results demonstrate that each animal albumin has different binding characteristics for the various chemicals tested. This variable must be considered before using an animal as a model for studying factors influencing bilirubin deposition in the brain.

Animals↗
PubMed1988

Effect of cephalosporins on bilirubin-albumin binding.

The effect of parenterally administered cephalosporins on bilirubin-albumin binding was measured in vitro by means of the peroxidase method with human serum albumin and by means of a dialysis rate method with newborn infants' serum. Ceftriaxone and cefoperazone have been shown to affect bilirubin-albumin binding. In this study, 13 additional cephalosporins were tested. Cefonicid, cefotetan, and cefmetazole competed with bilirubin for albumin binding and, at reported mean peak serum levels, decreased the reserve albumin concentration by 75%, 56%, and 40%, respectively. We suggest that these five cephalosporins may increase the risk of bilirubin encephalopathy in jaundiced neonates.

Bilirubin↗
PubMed1988

The relationship of gestational age to reserve albumin concentration for binding of bilirubin.

The authors studied bilirubin binding ability in the umbilical cord serum of 68 newborn infants ranging in gestational age from 18 to 42 weeks. There was no correlation between gestational age and the binding fraction (i.e., the ratio of the potential bilirubin binding concentration to the albumin concentration). Previous reports of the relationship between gestational age and bilirubin binding ability used bilirubin data derived from samples drawn at variable times after birth and probably reflect the unexplained effect of illness on bilirubin binding.

Bilirubin↗
PubMed1987

Ceftriaxone effect on bilirubin-albumin binding.

The effect of ceftriaxone on bilirubin-albumin binding was measured in vitro using the peroxidase method with human serum albumin and a dialysis rate method with adult and newborn serum. Ceftriaxone competes with bilirubin for binding to human serum albumin; the displacement constant is 1.5 X 10(4) L/mol. Therapeutic levels of ceftriaxone decrease the reserve albumin concentration in newborn serum by 39%. These results indicate that ceftriaxone may increase the risk of bilirubin encephalopathy in jaundiced premature infants.

Adult↗
PubMed1986

Albumin binding of bumetanide.

Bumetanide binding to human serum albumin was studied using ultrafiltration. The first stoichiometric binding constant for bumetanide is 6.4 X 10(4) M-1. Bumetanide competes with bilirubin for human serum albumin binding, having a KDispl (displacement constant) of 6.2 X 10(3) M-1 measured by the peroxidase method. This displacement effect is also observed using pooled umbilical cord serum and pooled adult serum employing a dialysis rate method. Bumetanide competes to a lesser degree with diazepam binding to human serum albumin. No competition with diazepam occurs using umbilical cord or adult serum. Pharmacologic concentrations of bumetanide would not significantly affect bilirubin-albumin binding and should not increase the risk of bilirubin encephalopathy in newborn infants.

Adult↗
PubMed1984

Contrast tomography of the gallbladder wall and ultrasonography in the diagnosis of acute cholecystitis.

Rapid and reliable diagnostic methods are necessary for regular early surgical intervention in patients with acute cholecystitis. Eighty-three patients with clinical suspicion of acute cholecystitis were investigated with ultrasonography (US) and contrast tomography of the gallbladder wall (CTGW). The diagnosis in each case included in the study was verified either at operation or follow-up cholecystography. The sensitivity and specificity of US were 69 and 100 per cent, respectively. With CTGW the corresponding figures were 73 and 100 per cent. The combined use of these methods resulted in a sensitivity of 89 per cent and a specificity of 100 per cent.

Acute Disease↗
PubMed1983

Radiologic evaluation of subdiaphragmatic spread of Hodgkin's disease.

A prospective investigation is presented on the usefulness of lymphography, computed tomography, ultrasound, radionuclide examinations and fine-needle aspiration biopsy of the spleen and the liver in assessing subdiaphragmatic spread of Hodgkin's disease. Initial staging laparotomy is superior to all other diagnostic procedures. If laparotomy cannot be performed, CT and scintigraphy of the spleen are recommended. At restaging CT and lymphography provide equal diagnostic yield; CT is suggested, however, to be used in the first place.

Adolescent↗
PubMed1981

Palliative embolization of renal tumors: follow-up of 19 cases.

Palliative renal artery embolization (without subsequent nephrectomy) was performed in 19 patients with renal carcinoma, and the follow-up is presented. Seventeen of the patients had metastatic disease at the time of embolization. Three patients were alive 11, 52, and 56 months after embolization. Gross hematuria was eliminated in 5 patients. Temporary remission of suspected pulmonary metastases was seen in 2 patients. It is concluded that transcatheter embolization alone is not curable and in this series did not affect the overall survival rate; however, local tumor symptoms may be palliated by this method.

Adenocarcinoma↗
PubMed1981

A case of papillary-cystic epithelial neoplasm of the pancreas.

A 16-year-old girl presented with a left-sided abdominal mass. X-ray examination and computed tomography disclosed a well-defined tumor close to the tail of the pancreas, stretching the pancreatic branches from the splenic artery as demonstrated by arteriography. Ultrasonography suggested a partly cystic character. Cytologic fine-needle biopsy, histopathological and electron microscopical examination disclosed a cysto-papillary tumor, probably benign, and of an exocrine, ductular origin, and with pseudo-cystic areas similar to those found in adenoid cystic carcinoma of salivary glands. Immunohistochemistry did not demonstrate the presence of polypeptide hormones. The patient is without signs of tumor recurrence 18 months after operation.

Adolescent↗
PubMed1981

Computed tomography, angiography and ultrasound in staging of renal carcinoma.

Preoperative evaluation of the extent of the renal tumor is of value in determining the prognosis of the patient and the most suitable therapy. CT and angiography were reviewed in 27 cases of renal carcinoma to evaluate tumor involvement of lymph nodes, renal vein, vena cava, and the perinephric space. In 26 of these cases the ultrasound examination was similarly reviewed. Comparison of ultrasound, CT, and angiography demonstrated that staging of renal tumors with ultrasound is mainly limited by its inability to demonstrate extrarenal infiltration. Both CT and ultrasound proved reliable in the demonstration of tumor spread to the renal vein and inferior vena cava. CT and angiography were equally effective in the evaluation of tumor extension; since CT is easier to perform, less invasive and less time consuming than angiography it should be the primary method for staging of renal neoplasms. Angiography offers detailed information on the vascular supply of the tumor important for the choice of surgical approach and should be performed only on special indications.

Adolescent↗