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Biomedical subjects

S Katz

Publications and source records attributed to S Katz.

At least 91 records · Page 5Linked to original sources
PubMed1998

Fibrous fusion between the liver and the lung: an unusual complication of right congenital diaphragmatic hernia.

A congenital right diaphragmatic hernia was diagnosed in a full-term newborn who presented with respiratory distress at the age of 10 hours. The patient required respiratory support, and was operated on at age 6 days. During surgery, a central defect of the diaphragm was found. The herniated liver was only partially reducible because of intrathoracic adhesions. The patient died at 10 days of age as a result of persistent fetal circulation. Postmortem pathological examination demonstrated a central diaphragmatic defect and a nonseparable fibrous fusion between the liver and the lung.

Fatal Outcome↗
PubMed1998

Can cardiovascular risk be predicted by newborn, childhood, and adolescent body size? An examination of longitudinal data in urban African Americans.

OBJECTIVE: Recent retrospective studies of older adults have demonstrated a correlation between lower birth weight and hypertension and insulin resistance. We tested this finding in our sample of urban African Americans with prospective data on growth and blood pressure and also tested other variables (in addition to birth weight) for their relationship to adult cardiovascular risk. STUDY DESIGN: A prospective study of birth weight, growth, and blood pressure (Philadelphia Perinatal Collaborative Project) followed a sample of 137 African Americans, with nine examinations from birth through 28.0 +/- 2.7 years. Metabolic measurements (oral glucose tolerance testing, euglycemic hyperinsulinemic clamp, and plasma lipid concentration) were performed on the subjects as adults. Bivariate correlations among parameters were computed using the Pearson r. The chi-squared statistic was used to determine associations of outcomes with birth weight. Stepwise multiple linear regressions were computed using newborn, early childhood, adolescent, and young adult parameters to predict adult outcomes. RESULTS: Birth weight and blood pressure at age 28 years are not correlated (Pearson r = 0.06). Birth weight is also unrelated to adult obesity. However, weight at 0.3 years and after and body mass index at 7 years and after are correlated with adult weight. Furthermore, weight at age 14 years is significantly negatively correlated with measures of insulin-stimulated glucose use, indicating that obese adolescents may be at greater risk than nonobese adolescents for development of non-insulin dependent diabetes in adulthood. CONCLUSIONS: We found no relationship between birth weight and adult outcomes pertaining to cardiovascular risk in this sample of adult African Americans. However, we did find evidence that somatic growth (body weight and body mass index) is significantly related to obesity and attenuated insulin-stimulated glucose utilization in adulthood. These findings indicate that the origins of adult cardiovascular disease are related to somatic growth, but not intrauterine growth, and are evident during childhood.

Adolescent↗
PubMed1998

The digital cardiac network: today and the future.

Cine replacement or cineless angiography is now a serious consideration for any new cardiac catheterization laboratory installation. Standards have been set by the Dicom committee, and CD's are rapidly appearing instead of angiogram film. Core labs. are geared to perform CD interpretation as well as film during this transition phase. Attempts are made to network multiple labs. and maintain the same kind of flow encountered in an analog lab. Labour and material costs seem to be cheaper for cineless labs. The future will see faster and deeper storage and commercially available means to network hospitals. This technology may be the forerunner of the digital patient record.

Cineangiography↗
PubMed1998

Dehydroepiandrosterone (DHEA) and DHEA-sulfate (DS) as therapeutic options in menopause.

In recent years, there has been increasing interest in the potential of androgen replacement in menopausal women and specifically adrenal androgen replacement. There is unfortunately increasing unmonitored use of dehydroepiandrosterone (DHEA) among adults in the United States with only limited and preliminary human data. An extensive body of literature in laboratory animals exists to suggest DHEA used in extremely large doses has multifaceted effects; though the inapplicability of this data to humans is not appreciated, as the physiology of adrenal androgens in humans and a few primates is unique. Currently, there is much international and multidisciplinary interest in the physiology and use of DHEA "replacement" in men and menopausal women. The scientific community anxiously await the results of these investigations, but in the interim DHEA and/or DHEA-Sulfate (DHEAS) supplementation is not recommended as a therapeutic option in menopause outside of clinical trials.

Adult↗
PubMed1998

Pseudogastroparesis as a presentation of adenocarcinoma of the proximal jejunum.

Establishing the presence of adenocarcinoma of the small bowel is exceedingly difficult. Survival is contingent on prompt diagnosis. We describe a patient with an atypical presentation of jejunal adenocarcinoma visualized via small bowel enteroclysis. She was referred with "gastroparesis," based on both a radionucleotide scan that revealed markedly delayed gastric emptying and a "normal" small bowel series. A markedly abnormal scintigraphic study and a negative small bowel series does not exclude disease of the small intestine and should provide the impetus to further pursue the possibility of an obstructing lesion. The enteroclysis is a relatively safe and effective study in the preoperative diagnosis of small bowel tumors.

Adenocarcinoma↗
PubMed1998

Jejunal diverticulitis with localized perforation and intramesenteric abscess.

We report a rare case of a 69-yr-old white man with jejunal diverticulitis with localized perforation and intramesenteric abscess formation. This entity is often overlooked as a cause of acute abdominal pain in the elderly. Although the clinical diagnosis is difficult, a high index of suspicion should warrant a computed tomography scan or enteroclysis.

Abdominal Pain↗
PubMed1998

Anticipation in Crohn's disease may be influenced by gender and ethnicity of the transmitting parent.

OBJECTIVE: We sought to examine whether anticipation (an earlier age of onset in succeeding generations) is observed in Crohn's disease (CD) patients within the New York metropolitan area, and whether there are differences in the degree of anticipation with respect to gender and ethnicity of the affected parent. METHODS: Sixty-one parent-child pairs both affected by CD were identified; about half of the pairs were of Ashkenazi Jewish descent. An additional 17 pairs of second-degree relatives with CD were also identified. The intergenerational difference in age at diagnosis (AAD) was used to perform regression analysis and the degree of anticipation among subsets of patients separated on the basis of gender and ethnicity of the transmitting parent was determined. RESULTS: The AAD was consistently (90% of the time) lower in the younger member of the 61 parent-child pairs (35.3+/-1.6 yr vs 20.8+/-1.1 yr, p = 0.0001). Furthermore, the degree of anticipation was significantly greater for father-child pairs (20.6+/-3.2 yr) than for mother-child pairs (11.7+/-2.1 yr). However, when the patient population where the parent had an AAD of < 28 was analyzed separately, there was a lack of clear-cut evidence of anticipation in the population as a whole. Only when the population was subdivided by ethnicity was there convincing evidence of anticipation in the Jewish population. CONCLUSION: Ascertainment bias may be responsible for the apparent anticipation observed in the CD population as a whole or in the nonJewish CD subgroup. However, the Jewish CD population displays strong evidence of anticipation even after correction for ascertainment bias.

Adult↗
PubMed1998

Topical tretinoin replenishes CD1a-positive epidermal Langerhans cells in chronically photodamaged human skin.

Excessive exposure to sunlight results in drastic degradative changes in the constitutive cells of the epidermis. Among these is a profound abrogation of Langerhans cell number and function, leading to compromised immunologic competency. Retinoids have recently been shown to restore immunologic function in the setting of iatrogenic immunosuppresion. We asked whether topical tretinoin would reverse Langerhans cell depletion in chronically photodamaged skin. We examined the skin of 8 volunteers immunohistochemically before and after 6 months of daily applications of tretinoin. At baseline, there was a profound depletion of CD1a-positive Langerhans cells in the interfollicular epidermis, but not in the adjoining follicular epithelium. After tretinoin, all patients demonstrated replenishment of interfollicular epidermis by CD1a-positive Langerhans cells. This was associated with induction of HLA-DR expression on infundibular keratinocytes, as well as the appearance of CD1a dendritic cells in the papillary dermis. Thus, the enhancement of epidermal immunity in photodamaged skin may reflect restoration of antigen-presenting Langerhans cells. The source of this renewed dendritic cell population is likely to be follicular infundibulum and the papillary dermis.

Administration, Topical↗
PubMed1998

Comparison of PRA-STAT, sHLA-EIA, and anti-human globulin-panel reactive antibody to identify alloreactivity in pretransplantation sera of heart transplant recipients: correlation to rejection and posttransplantation coronary artery disease.

BACKGROUND: Screening pretransplantation recipient sera for percent panel reactive antibodies (%PRA) by an anti-human globulin (AHG) assay may identify recipients who are at risk for graft rejection or development of posttransplantation coronary artery disease. However, the pretransplantation AHG-%PRA does not always correlate with the occurrence of graft rejection or coronary artery disease. METHODS: We compared the predictive capacity of the AHG-%PRA with that of an enzyme-linked immunoassay (EIA)-based PRA assay that identifies immunoglobulin G bound to soluble human leukocyte antigen (sHLA) class I molecules from pooled platelets of 240 random donors (sHLA-EIA), and that of an EIA-based assay that detects immunoglobulin G anti-HLA class I antibodies bound to sHLA derived from individual HLA-typed cell cultures (PRA-STAT). The pretransplantation sera from 130 cardiac allograft recipients were comparatively tested and results evaluated. RESULTS: Although AHG-%PRA- and sHLA-EIA-determined PRA results were comparable, neither assay discriminated potential recipients at risk for rejection or coronary artery disease. However, cardiac allograft recipients with pretransplantation PRA-STAT sera > 10% were at risk for (1) graft rejection (77% vs 56%, p < .05); (2) more rejections/recipient (1.9 vs 1.0, p < .02); (3) graft rejection within 30 days (92% vs 38%, p < .001); or (4) development of coronary artery disease (48% vs 23%, p < .05) than recipients with pretransplantation PRA-STAT sera < 10%. CONCLUSIONS: PRA-STAT analysis of pretransplantation sera from potential cardiac allograft recipients may be more clinically informative about HLA alloimmunity and a better predictor of adverse clinical events than either AHG-%PRA- or sHLA-EIA-determined PRA.

Antibody Specificity↗
PubMed1997

Prevalence of asymptomatic cholelithiasis and risk of acute cholecystitis after kidney transplantation.

Prophylactic cholecystectomy for asymptomatic cholelithiasis is sometimes required before transplantation. However, there is little indication in the literature that transplant recipients are at any greater risk than individuals in the general population. Between January 1990 and December 1993, 211 renal transplant recipients underwent duplex sonography. All were asymptomatic. Twenty-one had positive findings: gallstones were found in 15 patients (7.11%) and sludge was found in 6 (2.84%). Of gallstone patients, seven (3%) were men and eight (4%) were women. One gallstone patient also had diabetes mellitus. The mean age by gender of the patients with calculi was 54 years for men and 38 years for women. Thirteen of the 15 patients with calculi (87%) have remained asymptomatic. Two patients (one diabetic) developed acute cholecystitis and underwent uncomplicated laparoscopic cholecystectomy. Patients with sludge were similar in gender and age to patients with gallstones; one patient had diabetes. No sludge patients became symptomatic. The incidence and morbidity of gallstones after kidney transplantation are low. Prophylactic cholecystectomy in asymptomatic patients before transplantation is not justified.

Acute Disease↗
PubMed1997

Activation of Pak by membrane localization mediated by an SH3 domain from the adaptor protein Nck.

BACKGROUND: The adaptor protein Nck consists of three Src homology 3 (SH3) domains followed by one SH2 domain. Like the Grb2 adaptor protein, which is known to couple receptor tyrosine kinases to the small GTPase Ras, Nck is presumed to bind to tyrosine-phosphorylated proteins using its SH2 domain and to downstream effector proteins using its SH3 domain. Little is known, however, about the specific biological function of Nck. The Pak family of serine/threonine kinases are known to be activated by binding to the GTP-bound form of Cdc42 or Rac1, which are small GTPases of the Rho family that are involved in regulating the organization of the actin cytoskeleton. RESULTS: We present evidence that Nck can mediate the relocalization and subsequent activation of the Pak1 kinases. We show that Nck associates in vivo with Pak using the second of its three SH3 domains, and that localization of this individual Nck SH3 domain, or of Pak kinase itself, to the membrane results in activation of Pak and stimulation of downstream mitogen activated protein kinase cascades. Activation of downstream signaling by the membrane-localized Nck SH3 domain is blocked by a kinase-inactive mutant form of Pak1. CONCLUSION: These results demonstrate that localization of Pak1 to the membrane in the absence of other signals is sufficient for its activation, and imply that the Nck adaptor protein could function to link changes in tyrosine phosphorylation of cellular proteins to the Cdc42/Pak signaling pathway.

Adaptor Proteins, Signal Transducing↗
PubMed1997

Chemotherapy is a safe and effective initial therapy for infected malignant breast and chest wall ulcers.

BACKGROUND AND OBJECTIVES: Locally advanced breast cancers may form large, infected skin ulcers, which were traditionally treated with radiation therapy. Neoadjuvant chemotherapy is now standard treatment for locally advanced breast cancer. METHODS: The response of 33 patients with ulcerated breast cancer to primary chemotherapy was retrospectively analyzed. Antibiotics were not used in primary treatment. Tumor and ulcer responses were evaluated independently. RESULTS: Chemotherapy alone healed 18 of these ulcers. Neither responding nor refractory patients developed sepsis during this treatment. CONCLUSIONS: Chemotherapy is safe and effective treatment for patients with infected malignant breast ulcers and does not cause systemic sepsis.

Adult↗
PubMed1997

Brain concussion produces transient hypokalemia in children.

Hyperglycemia and hypokalemia caused by catecholamine discharge have been reported to occur in patients after severe head trauma. The aim of this prospective study was to evaluate whether a similar neuroendocrine and metabolic response is found in children after minor head trauma such as brain concussion (Glasgow Coma Scale (GCS) > or = 13). One hundred fifty patients aged 2 to 14 years (average, 6 years) were divided into three groups (n = 50 in each group). Group 1 included patients admitted to the emergency department for brain concussion (Glasgow Coma Scale (GCS) > or = 13); group 2 included patients admitted for fractures of long bones without head injury; and group 3 were control patients electively admitted for hernia repair. All patients had complete physical and neurological examinations. Complete blood count and blood chemistry were obtained on admission. All blood tests were repeated at 6, 12, and 24 hours in patients belonging to group 1. An electrocardiogram was obtained in selected patients and catecholamine levels were measured in some patients. Statistical analysis was performed using analysis of variance (ANOVA). Serum potassium and sodium levels in patients with brain concussion (group 1) were 3.6 +/- 0.6 and 136 +/- 3 mEq/L, respectively and were significantly lower (P < 0.01) than those in patients belonging to group 2, 4 +/- 0.4 and 138 +/- 3, respectively, and the controls (group 3), 4.2 +/- 0.5 and 140 +/- 2, respectively. Serum glucose level was 124 +/- 34 and 118 +/- 32 mg% in groups 1 and 2 and was significantly higher than that of the controls (group 3), 90 +/- 23 mg%. There was no correlation between serum electrolytes and GCS. No electrocardiogram changes or elevation of serum catecholamines were found. Hypokalemia resolved spontaneously within 24 hours. All patients recovered without neurological sequalae. Transient hypokalemia frequently occurs in children even with minor head trauma. This hypokalemia resolves spontaneously, without treatment and within 24 hours.

Adolescent↗
PubMed1997

The ankle-brachial index in normal neonates and infants is significantly lower than in older children and adults.

UNLABELLED: Vascular trauma from accidental or iatrogenic causes is becoming more common in children. In early infancy, the most common arterial injuries are caused by diagnostic or interventional cardiac catheterizations. Doppler arterial pressure measurements and the computed ankle-brachial pressure index (ABI) are the most helpful diagnostic modalities in the assessment and follow-up of the ischemic extremity. Because normative ABI data in small children are not available, an ABI of 0.9 or less (based on data obtained from an adult population), is used to indicate limb ischemia in young infants. The purpose of this study was to define the normal values of ABI in newborns and infants. MATERIALS AND METHODS: Three hundred and fifty patients were divided into two groups: group 1 (n = 200; male-to-female ratio, 1:1) were full-term (gestational age 40 +/- 1.3 weeks, surface area 0.22 +/- 0.02 m2) healthy newborns following uneventful pregnancy and delivery. Group 2 (n = 150) were healthy patients aged 2 weeks to 2.5 years admitted for elective hernia repair. All the patients underwent a complete physical examination, which excluded any cardiovascular pathology. The systolic blood pressure (BP) was measured bilaterally over the brachial, tibialis posterior, and dorsalis pedis arteries. All BP data were obtained in the supine position, using an ultrasonic Doppler flow detector, an appropriately-sized pneumatic cuff and a sphygmomanometer. The chosen cuff size was long enough to completely encircle the circumference and wide enough to cover 75% of the length of the upper arm. The same cuff was applied around the ankle above the malleoli. BP values were expressed as mean +/- SD in mm Hg. If there was a difference between the BP in the two arms, the higher pressure was used for calculation of the ABI. RESULTS: The BP measurements in newborns (group 1) were left brachial, 98 +/- 11; right brachial, 90 +/- 10 (P < .001), left and right tibialis posterior and left and right dorsalis pedis were 83, 81, 84, and 82 mm Hg, respectively. The mean computed ABI was 0.88 +/- 0.11. Fifty eight percent of the newborns had an ABI less than 0.9 (lower limit of normal in adults). The ABI values in patients belonging to group 2 increased with age and surface area. The mean ABI was 1.0, 1.1, and more than 1.1 in patients aged, 1, 1.5, and 2 years with surface areas of 0.4, 0.5 and 0.6 m2, respectively (P < .001 compared with group 1). CONCLUSION: The normative ABI in newborns and infants is significantly lower than in older children and reaches normal (adult) values during the second year of life. These data may be used as a reference when assessing lower extremity ischemia caused by trauma in young patients.

Adult↗