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Biomedical subjects

R Hurwitz

Publications and source records attributed to R Hurwitz.

At least 55 records · Page 3Linked to original sources
PubMed1985

Radionuclide angiocardiography in children.

Clinical use of radiotracer techniques in pediatric cardiology is increasing. Three basic methods being employed are first pass radionuclide angiocardiography, gated blood pool scanning and myocardial perfusion scintigraphy. These methods are rapid, safe and accurate. They are minimally invasive and result in a low radiation dose to the patient. The development of ultrashort-lived radionuclides (such as iridium-191m with a half-life of only 5 seconds), improvements in nuclear imaging instrumentation and numerical analysis should contribute to a further utilization of these methods.

Angiocardiography↗
PubMed1982

Femoral artery spasm in children: catheter size is the principal cause.

The incidence of femoral artery spasm and subsequent thrombosis complicating angiography is greater in children than adults. This study was designed to assess femoral artery spasm and to determine its causes in children. In 100 unselected, consecutive infants and children undergoing left heart angiocardiography by the Seldinger technique, angiography of the femoral artery was performed to include the puncture site after completion of angiocardiography. Arterial spasm was quantified and, with mathematical analysis, related to various clinical and angiographic factors. Some degree of arterial spasm was noted in 62% of all cases; it was more frequent and severe in neonates. Although it was more intense in the infant with a small femoral artery, analysis of the data indicates that patient age, weight, length of catheterization, size of femoral artery, and catheter size have only minimal relative importance in the occurrence and severity of arterial spasm. The most important factor in spasm is the relative size of catheter to artery.

Adolescent↗
PubMed1981

Effects of asphyxia and oral gentamicin on intestinal lactase in the suckling rat.

The effect of oral gentamicin on lactase, the major disaccharidase of the neonatal intestine, was studied using the suckling Wistar rat as a model. The jejunal lactase-specific activity of asphyxiated animals given oral gentamicin at a dose of 20 mg/kg/day for two days was significantly decreased compared to that of nonasphyxiated animals given oral saline (P less than 0.01). Although the intestinal lactase-specific activity of nonasphyxiated animals given oral gentamicin at a dose of 20 mg/kg/day for two days was not significantly different from that of animals given oral saline, a high dose of oral gentamicin (160 mg/kg/day) was associated with decreased lactase-specific activity in both the jejunum and ileum. Intramuscular administration of gentamicin was not associated with decreased intestinal lactase-specific activity. More information is needed regarding the mechanism of the biochemical injury associated with the oral use of aminoglycosides and its clinical significance, if any, in the human infant. Until this is known, the potential for such injury should be of special concern where prophylaxis against necrotizing enterocolitis is being considered, particularly in view of the increased tendency for treated infants to become colonized with gram negative organisms resistant to the antibiotic being used.

Animals↗
PubMed1980

Evolution of cultured leukemic cell lines monitored by chromosomal and immunologic analysis.

We have investigated the karyotypes and markers of B lymphocyte differentiation in two leukemic cell lines, NALM-6-B and NALM-6-MI, both derived from a patient with non-T, non-B acute lymphoblastic leukemia. Both possess characteristics of thymus-independent, bursal-equivalent (B) lymphocytes. By means of immuno-fluorescence techniques, NALM-6-B was shown to possess 47% surface membrane immunoglobulin-positive (Slg+) cells, while NALM-6-MI is surface membrane immunoglobulin-negative (Slg-), but does possess cytoplasmic immunoglobulin M (ClgM+) in more than 90% of the cells. The Slg- ClgM+ phenotype, coupled with morphologic features, is consistent with NALM-6-MI being arrested at a stage early in B-lymphocyte differentiation (a "pre-B" cell). The predominant banded chromosome karyotype of NALM-6-B is pseudodiploid with a translocation of chromosomal material from the long arm of a chromosome 5 to the short arm of a chromosome 12 (5q-/12p+) and a marker Y chromosome. NALM-6-MI possesses the same marker Y chromosome and a deletion of the long arm of chromosome 5(5q-) since in most cells material missing from chromosome 5 does not appear on the short arm of chromosome 12. Within the limits of resolution available with the banding technique, no other karyotypic differences are observed in the two cell lines. The history of the two cell lines, the karyotypic analysis, and the pattern of immunoglobulin markers indicate the possible clonal evolution of NALM-6-MI from NALM-6-B and implicate a portion of the long arm of chromosome 5 in lymphoid differentiation of these leukemic cell lines.

Adult↗
PubMed1980

Improved results in newborns undergoing coarctation repair.

Among 172 children who underwent repair of coarctation of the thoracic aorta from June 1, 1967, to June 1, 1979, there were 50 who were less than 6 weeks old. A review was undertaken to assess mortality and postoperative residual hypertension in this newborn age group. Forty-five (90%) had one or more associated congenital cardiac lesions, which were repaired or paliated at the time of coarctation repair. The three most common associated lesions were patent ductus arteriosus (74%), atrial septal defect (74%), and ventricular septal defect (62%). Thirty-one newborns underwent resection with parimary end-to-end repair with 8 deaths (26%), and 18 underwent Dacron patch angioplasty and 1 underwent subclavian angioplasty with 4 deaths (21%). Of the 38 survivors, 36 (95%) had good pedal pulses on postoperative clinical examination 3 months to eleven years postoperatively. Seventeen (45%) had upper and lower extremity blood pressure measured; 2 (5%) showed residual upper extremity hypertension (greater than 2 standard deviations above the mean and a gradient less than 20 mm Hg). One of these 2 patients has undergone repeat repair. Based on this low mortality and infrequent need for repeat repair, we advocate aggressive early operation and judicious use of palliative procedures in newborns, when indicated, for associated defects.

Aorta, Thoracic↗
PubMed1979

Childhood leukemia-lymphoma. Heterogeneity of phenotypes and prognoses.

Results are reported on 724 children and adolescents with acute leukemia-lymphoma. One hundred patients had immunologic marker analysis that defined the major phenotypic groups, i.e., T-cell, B-cell (Burkitt), myeloid, and the most frequent form, non-T, non-T "common" or "undifferentiated" acute leukemia. Pre-T, pre-B, and "null" leukemias are included in the latter group. Response to therapy and survival was best in non-T, non-B acute lymphocytic leukemia, intermediate in T-cell disease, and worst in B-cell (Burkitt) disease. Additional factors resulting in decreased survival include elevated peripheral leukocyte count, presence of enlarged nodes, less depression of hemoglobin and platelets, and age greater than 7 years (all associated with 'lymphomatous" disease). Other factors resulting in decreased survival include age under 3 years and depression of serum immunoglobulins. Definition of the heterogeneity of childhood leukemia-lymphoma dictates differing forms of therapy for the various types of these diseases.

Adolescent↗
PubMed1978

Lactose malabsorption among adult Indians of the Great Basin and American Southwest.

The prevalence of primary adult lactose malabsorption and the pattern of milk use were studied among 109 Indians from various tribes of the American Great Basin and Southwest. Included were 100 persons who reported being full-blooded Indians as well as three with Mexican admixture and 6 with some European ancestry. Lactose malabsorption was found in 92% of the full-blooded Indians but in only 50% Indians who acknowledged European admixture. These results agree with those of studies of native Americans done elsewhere which show very high prevalences of such lactose malabsorption among adults reported as fullblooded and lower prevalences among individuals with admitted European ancestors. The suggestion made is that in pre-Colombian times, before interbreeding with Europeans began on any scale, such lactose malabsorption may have been nearly universal among native American adults. Most of the Indians studied consumed abundant milk since childhood but were nevertheless predominantly malabsorbers as adults. This argues against the induction hypothesis advanced by some to explain the striking ethnic differences that occur around the world in primary adult lactose malabsorption.

Adult↗
PubMed1977

Adaptation of rat pancreatic amylase and chymotrypsinogen to changes in diet.

This study represents an attempt to determine the effect of dietary protein quality and hypophysectomy on the enzymic adaptability of the pancreas in the rat. The specific enzymes studied were amylase, which was purified by immunologic techniques and chymotrypsinogen (activated), which was isolated by affinity column chromatography. Content and synthesis of each enzyme were accurately determined in relation to total pancreatic protein. When rats were fed a 64% sucrose diet (19% casein), there was a two- to three-fold increase in synthesis of amylase. However, if a poor-quality protein (gelatin, gluten, or zein) was substituted for casein, there was no increase in the synthesis of amylase in response to increased carbohydrate. When rats were fed a 19% sucrose diet (64% casein), there was a significant increase in chymotrypsinogen synthesis. Of the poor-quality proteins, gluten was the only one effective in stimulating synthesis of chymotrypsinogen. Peptides, either free or as part of a protein, were necessary for the stimulation of chymotrypsinogen synthesis. Amylase synthesis in hypophysectomized rats was considerably depressed and unresponsibe to increased carbohydrate. This effect could be partially relieved with hydrocortisone, corticosterone, or thyroxin, but not with growth hormone. Hypophysectomy had little effect on synthesis or content of chymotropsinogen.

Amylases↗
PubMed1977

Lactose malabsorption among the Pima indians of Arizona.

Lactose loading tests and other means were used to determine the pattern of primary "adult" lactose malabsorption (LM) and milk use among 171 subjects, including 122 children and 49 adults, almost all of them Pima Indians of Arizona. LM develops at quite young ages in full-blooded Pima children: already in the 3- to 4-year age group, 40% had LM. Of 62 full-blooded Indians (greater than or equal to 4 years of age), 59 (95%) had LM. Of 41 Indians (greater than or equal to 4 years) who were of mixed Indian-northern European ancestry, however, only 25 (61%) had LM, and, among them, prevalence of LM correlated with degree of northern European admixture. Whereas only 21% of Pima lactose absorbers reported symptoms after the loading test, 72% of malabsorbers did so, with older malabsorbers more likely to experience symptoms. In their everyday lives, only 23% of malabsorbers recognized symptoms brought on by milk consumption, but the percentage of malabsorbers making such an association increased with age. Nevertheless the Pima, adults as well as children, continue to drink reasonable quantities of milk. Family pedigrees are consistent with the hypothesis that adult lactose absorption is inherited as an autosomal dominant trait. Over-all results of this study, moreover, support the geographic hypothesis advanced to explain ethnic or racial differences in prevalence of LM, rather than the induction hypothesis.

Adolescent↗
PubMed1975

Asymmetric septal hypertrophy in a large amish kindred.

We report a large Amish kindred in which asymmetric septal hypertrophy (ASH) appeared to segregate as an autosomal dominant gene. This kindred was ascertained through a 3-month-old infant and her father. The striking differences between father and daughter regarding clinical presentation and course exemplify the variable expressivity of this condition. The importance of genetic factors in diagnosis and counseling are discussed. Previous reports of ASH in infants and children are reviewed.

Adult↗