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Biomedical subjects

N Kaufman

Publications and source records attributed to N Kaufman.

At least 55 records · Page 3Linked to original sources
PubMed1990

Thyroid function tests in patients undergoing bone marrow transplantation.

Thyroid function was studied prospectively in 27 patients receiving bone marrow transplants to determine the effect of this procedure and its sequelae on serum thyroid hormone levels and thyrotropin secretion. Serum triiodothyronine and free triiodothyronine concentrations declined to subnormal levels in nearly all of the patients; free thyroxine concentration became subnormal in 15 patients. At the time of the nadir of the serum T3 concentration, serum thyrotropin concentration, measured by a sensitive immunoradiometric assay, declined significantly and became subnormal in nine patients. The data suggest that the reduction of serum thyroxine levels after transplantation is attributable, at least in part, to inhibition of thyrotropin secretion.

Adult↗
PubMed1989

[Tuberculous meningitis].

2 cases of tuberculous meningitis are presented, 1 in a 54-year-old woman who had immigrated to Israel from Turkey 36 years before, and the other in a 10-year-old girl who recently immigrated from Ethiopia. Since diagnosis is difficult and prompt antituberculous treatment is life-saving, treatment may be instituted before the bacteriological diagnosis is established. A short term treatment of 9 months and a combination of rifampicin and isoniazid were successful in our patients.

Child↗
PubMed1989

Remote afterloading intraluminal brachytherapy in the treatment of rectal, rectosigmoid, and anal cancer: a feasibility study.

From 1981 to 1986, 28 patients (27 evaluable) were treated with intraluminal brachytherapy (ILBT) using a remote afterloading technique for persistent or recurrent anal, rectal and rectosigmoid cancers. Eighty-nine percent underwent previous surgery for colorectal cancer. Seventy-seven percent of the patients received external beam irradiation (ERT) as a part of the present treatment. Intraluminal brachytherapy was given with a 2 cm diameter cylinder and the dose per fraction ranged from 440 cGy to 840 cGy at 0.5 cm from the surface of the cylinder. Follow-up ranged from 1 to 74 months with a median of 12 months. Patients were divided into two groups. Group I consisted of 15 patients receiving elective ILBT; Group II: 13 patients with recurrent disease. Seventy-one percent of the patients in Group I and 39% of the patients in Group II achieved local control. The majority of patients tolerated treatment well with only transient reactions. However, three patients (11%) developed grade 3 (G3) complications requiring surgical intervention. Eight patients developed moderate complications--grade 2 (G2)--requiring only conservative treatment. This study has identified several factors which appear to influence the risk of developing complications with this combined treatment, using remote afterloading apparatus, among which are technique of previous external beam irradiation, treatment length, anatomical location, intraluminal brachytherapy fractionation, and total cumulative dose (ERT + ILBT). This experience suggests that intraluminal brachytherapy appears to be an acceptable form of treatment, as a boost to external beam radiation therapy, in the management of rectal and colorectal cancers.

Adult↗
PubMed1989

Human neutrophils contain and bind high molecular weight kininogen.

Because plasma kallikrein activates human neutrophils, and in plasma prekallikrein (PK) circulates complexed with high molecular weight kininogen (HMWK), we determined whether HMWK could mediate kallikrein's association with neutrophils. HMWK antigen (237 +/- 61 ng HMWK/10(8) neutrophils) was present in lysates of washed human neutrophils. Little if any plasma HMWK was tightly bound and nonexchangeable with the neutrophil surface. Human neutrophils were found to possess surface membrane-binding sites for HMWK but no internalization was detected at 37 degrees C. 125I-HMWK binding to neutrophils was dependent upon Zn2+. Binding of 125I-HMWK to neutrophils was specific and 90% reversible. 125I-HMWK binding to neutrophils was saturable with an apparent Kd of 9-18 nM and 40,000-70,000 sites per cell. Upon binding to neutrophils, 125I-HMWK was proteolyzed by human neutrophil elastase (HNE) into lower relative molecular mass derivatives. Furthermore, HMWK found in neutrophils also served as a cofactor for HNE secretion because neutrophils deficient in HMWK have reduced HNE secretion when stimulated in plasma deficient in HMWK or with purified kallikrein. These studies indicate that human neutrophils contain a binding site for HMWK that could serve to localize plasma or neutrophil HMWK on their surface to possibly serve as a receptor for kallikrein and to participate in HNE secretion by this enzyme.

Antigens↗
PubMed1985

A system of classifying leisure activities in terms of the psychological benefits of participation reported by older persons.

The psychological benefits of 18 commonly chosen leisure activities were investigated using the Paragraphs About Leisure-Form E (PAL-E), which measures the psychological benefits of participation in leisure activities. The data were cluster analyzed using Ward's heirarchical grouping procedure, and a conceptual framework was developed for understanding the psychological benefits derived from participation in leisure activities by persons in the 55 to 75 age range. The data support the conclusions that leisure activities may be grouped into meaningful families or clusters on the basis of their psychological benefits.

Aged↗
PubMed1984

Isolated right ventricular infarction: a diagnostic challenge.

Right ventricular involvement during myocardial infarction of the diaphragmatic and posterior wall of the left ventricle is not an infrequent complication, but isolated right ventricular infarction is rare. We report a case of rupture of the anterior wall of right ventricle and tamponade due to infarction at this site. The lack of characteristic clinical and electrocardiographic findings made the isolated right ventricular infarction a diagnostic challenge.

Cardiac Tamponade↗
PubMed1983

Chemotherapeutic drugs as indirect oxygen radiosensitizer.

We have characterized the oxygen distribution in V-79 spheroids which were grown by the spinner flask method. Using ultramicroelectrodes with tip diameters of 1-5 microns and a perfusion system whereby the spheroids' milieu could be maintained and controlled, we found plateau pO2 values of less than 10 mm Hg in spheroids of greater than 500 microns in diameter. Data from experiments using respiration inhibitory drugs indicate that the characteristics of the outer layers of cells is the major determinant of the oxygen profile in the interior. Parallel control radiobiological experiments confirmed the control pO2 measurements, and formed the basis for the experiments using the potential indirect radiation sensitizers: Chlorambucil and Mustargen.

Animals↗
PubMed1982

An electron microscopic study of heme uptake by rat duodenum.

The uptake of heme by mucosal absorptive cells of rat duodenum was studied by electron microscopy; normal and iron-deficient animals were used. Heme was administered as hemoglobin or hemin chloride by means of an intragastric tube and also by injection into a closed duodenal loop. The peroxidatic activity of heme was utilized to locate it on the cell surface and within the cell; aldehyde-fixed mucosal tissue was incubated in a solution of 3,3'-diaminobenzidine. Heme was observed first on the surfaces of the microvilli of the absorptive cell and in apical pits between individual microvilli. Shortly thereafter, heme appeared within membrane-bound tubules which apparently communicated with the apical pits. At later intervals, secondary lysosomes, located in apical cytoplasm and in the supranuclear region of the cell, contained heme; the manner of heme transfer from the apical pit-tubular system to the lysosomal compartment was not defined. Gradual loss, with time, of 3,3'-diaminobenzidine reaction product from secondary lysosomes indicated cleavage of heme therein. Normal and iron-deficient rats handled heme in a similar manner.

3,3'-Diaminobenzidine↗
PubMed1981

Diagnosis of iron deficiency anemia in a rural population of children. Relative usefulness of serum ferritin, red cell protoporphyrin, red cell indices, and transferrin saturation determinations.

The diagnostic usefulness in iron deficiency anemia of serum ferritin, red cell protoporphyrin (Epp), mean corpuscular volume, mean corpuscular hemoglobin (MCH), and transferrin saturation measurements has been studied in a population of 294 children aged 1 to 6 yr. Of the children studied 19% had hemoglobin below 11 g/dl. Iron deficiency, diagnosed by at least two abnormal independent laboratory parameters, was the cause of anemia in all except two cases. The Pearson correlation coefficient for hemoglobin was highest with MCH, followed in decreasing order of magnitude by MCV, Epp, transferrin saturation, and finally by ferritin. Sensitivity and specificity were highest for MCH and lowest for ferritin. Of anemic, iron deficient individuals 97 to 100% could be identified by low MCH, 88 to 100% by transferrin saturation, 66 to 83% by ferritin, and 61 to 74% by Epp. In contrast, only 0 to 6% of normal, nonanemic individuals had low MCH, 0 to 4% had high Epp, but 21 to 39% had low transferrin saturation and 25 to 39% had low ferritin. Although reduced serum ferritin in anemic individuals is good evidence of iron deficiency, a significant proportion of anemic iron-deficient patients is missed by this procedure rendering it less useful than other, less expensive laboratory methods.

Age Factors↗
PubMed1981

Radiation sensitivity modification by chemotherapeutic agents.

Three chemotherapeutic agents, chlorambucil, mustargen, and BCNU-409962, being investigated for their possible clinical use in conjunction with radiation therapy have been shown in vitro to dramatically affect the characteristics of standard radiation survival curves (in V79 cells and spheroids). The agent mustargen, at a concentration of 0.25 microgram/ml administered 1 hour prior to 9-MeV-electron exposure, had a significant effect in reducing D0. The 165-rad D0 observed in control curves was reduced to 105 rads in the presence of drug. One hour preincubation with BCNU (prior to radiation exposure) at a concentration of 3.0 microgram/ml was found to dramatically reduce the initial shoulder region with n number values for drug curves approximately one-half those seen for controls. No effect is seen when chlorambucil is combined with radiation in exponential or confluent cultures but an enhancement ratio of 1.8 is found when intact spheroids are pretreated with this drug.

Animals↗
PubMed1981

A system for determining the pharmacology of indirect radiation sensitizer drugs on multicellular spheroids.

We have characterized some of the physiology of multicellular spheroids of different sizes grown from Chinese hamster lung fibroblast (V79) cells. Among the parameters studied were oxygen tension distributions within the spheroid. This was achieved using ultramicroelectrodes with tip diameters of 1-5 mu and a perfusion system whereby environmental conditions such as flow, temperature, and chemical makeup of the milieu could be measured and controlled. Plateau pO2 values of less than 10 mm Hg were consistently obtained from spheroids under various conditions. We were able to modify these distributions by use of indirect radiation sensitizer drugs such as mechlorethamine HCl (mustargen) at nontoxic doses. We have also made determinations of the inhibitory capacities of several other drugs on the respiration rate of constituent cells of multicellular spheroids in single-cell suspensions. We have concluded that there are indeed hypoxic cells in spheroids whose radioresistance may be modified by essentially nontoxic levels of indirect radiosensitizer drugs and that the system described shows great promise for screening agents which may modify radiation response.

Animals↗
PubMed1980

Anemia among Druze children in the Golan Heights.

The prevalence and causes of anemia were studied in 294 Druze children aged 10 months to six years. The hemoglobin level was less than 11.0 g/dl in 19%; none of these anemic children had folate deficiency. Iron deficiency, diagnosed on the basis of abnormal values for at least two independent laboratory parameters, was the cause of anemia in all but two cases. The Pearson correlation coefficient for hemoglobin was highest with mean corpuscular volume, erythrocyte protoporphyrin, serum iron, transferrin saturation, total-iron-binding capacity, and serum ferritin. Mean corpuscular hemoglobin and transferrin saturation were abnormal in greater than 90% of anemic children, whereas serum ferritin and total-iron-binding capacity were abnormal in only 70%. In view of its limited sensitivity, serum ferritin appears to be a less useful diagnostic aid in iron-deficiency anemia than other, less expensive laboratory methods.

Anemia, Hypochromic↗