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Biomedical subjects

D Katz

Publications and source records attributed to D Katz.

At least 127 records · Page 7Linked to original sources
PubMed1989

Orf: a case report.

Ecthyma contagiosum (orf), a viral disease endemic to sheep and goats, can be zoonotically transmitted to humans through contact with infected animals. While the disease is common among sheep and goat herders worldwide, it comes to medical attention infrequently since it is generally a mild self-limited illness. We recently treated a healthy 36-year-old female who presented with bullous lesions on her fingers and a diffuse macular rash which had developed after antibiotic therapy for her bullae. She had been caring for her neighbor's goats which had recently been ill with "sore mouth." We discuss this case of orf and review the medical literature on this self-limited illness uncommon to the midwestern United States.

Adult↗
PubMed1988

Outcome of untreated infection with Entamoeba histolytica in homosexual men with and without HIV antibody.

Among homosexual men the prevalence of infection with Entamoeba histolytica is high. To determine the clinical importance of this infection 55 homosexual men carrying the parasite were investigated in detail. No clinical, serological, or histological evidence of invasive amoebiasis was found in any of them. The patients were not treated and were followed up for 12 to 29 months (mean 21.6 months), during which period none developed symptoms that could be attributed to E histolytica. Spontaneous loss of the parasite occurred in 17 patients, some of whom later became reinfected. Sixteen patients had antibody to human immunodeficiency virus, and infection with E histolytica showed the same benign course in them as in the patients who did not have antibody. Throughout the study classification of the isolates of E histolytica consistently showed that they belonged only to non-pathogenic zymodemes. The findings provide further evidence that E histolytica in homosexual men is a commensal organism.

Animals↗
PubMed1988

Indomethacin sensitive suppressor-cell activity in head and neck cancer patients. The role of the adherent mononuclear cell.

Head and neck cancer (H&N CA) patients have known depression of cell-mediated immunity. There is suggestive evidence that prostaglandin (PGE2)-secreting cells may be a major factor. The authors have sought to determine the role of PGE2-releasing monocytes-macrophages in this immune depression by determining the effects of adherent cell depletion and by measuring the effects of indomethacin, a PGE2 synthetase inhibitor, on selected tests of lymphocyte function. Lymphocyte stimulation with phytohemagglutinin (PHA) (T-cell stimulant) and Staph phage lysate (SPL) (B-cell stimulant) was done in the presence of varying concentrations of indomethacin; the effect of adherent cell depletion also was determined. The study population included 45 patients with localized or locoregional squamous CA of the H&N and 40 controls. Results included the following: (1) lymphocyte stimulation responses to PHA and SPL were generally depressed in the CA patients versus controls; (2) incubation with indomethacin produced bivalent effects in both controls and CA patients, depending on the concentration of indomethacin and lymphocyte stimulant; incubation with optimum concentrations of indomethacin generally produced augmented responses in both study groups whereas high concentrations of indomethacin were suppressive; (3) the immune potentiating effects were not observed in older patients with advanced disease; and (4) removal of adherent leukocytes (mainly monocytes) also restored depressed lymphocyte responses. Although other factors also are operative, our data suggest that PGE2-secreting monocytes-macrophages may have a major role in the immune depression of H&N CA patients. Age and host effects of the cancer and the malnutrition common to these patients probably are involved also, although their singular contribution has not been measured. This depression is largely reversible by a PGE2 synthesis inhibitor, indomethacin, which suggests the potential value of in vivo administration of indomethacin to H&N CA patients as an adjunct.

Adult↗
PubMed1988

Conformational and receptor binding properties of human EGF and TGF-alpha second loop fragments.

The solution conformation of the second loop fragment of human EGF, [Ala20] EGF (14-31), was determined using two-dimensional NMR homonuclear Hartmann-Hahn and rotating frame nuclear Overhauser enhancement spectroscopy. The results are compared with the conformation of the second loop fragment of human TGF-alpha, [Ala21] TGF-alpha(16-32), and with that of the second loop of intact EGF. Comparison of the two experimentally determined structures of the second loop fragments shows significant differences in the turn regions of each peptide. For the EGF fragment, hydrophobic side chain groups protrude away from the ring, whereas for the TGF-alpha fragment hydrophilic groups are directed away from the ring. Although these turn regions represent the putative receptor binding sites, neither second loop fragment binds to the EGF receptor. The biological activity is discussed in terms of the conformational differences found for the two second loop fragments.

Amino Acid Sequence↗
PubMed1988

Muscle and bone in paraplegic patients, and the effect of functional electrical stimulation.

1. Four paraplegic men volunteered for an exercise programme in which their paralysed quadriceps muscles were stimulated by means of computer-regulated electrical impulses applied through external electrodes. The first exercise regimen consisted of leg raising against a graded load, and during the second regimen exercise took the form of cycling on a modified bicycle ergometer. Each subject exercised five times weekly for 10 weeks during the first regimen and 32 weeks during the second regimen. 2. Whole-body protein turnover determined by L-[1-13C]leucine during feeding remained constant during both exercise regimens, when expressed either in terms of body weight or fat-free mass derived from measurements of total body potassium. 3. Quadriceps muscle protein synthetic rate increased during the study, from 0.0712 to 0.0985%/h (P less than 0.05), as did quadriceps muscle area assessed by computed tomography. 4. Bone mineral content for lumbar vertebrae was normal in all four patients, but for the femoral mid-shaft bone mineral content averaged only 66% of normal for three of the patients. Trabecular bone density in the distal tibia ranged from normal to 2% of normal for the men with the shortest and longest periods of disability, respectively. No changes in bone mineral content or bone density occurred during the exercise period.

Adult↗
PubMed1988

Pharmacology and phase I/II study of continuous intravenous infusions of iododeoxyuridine and hyperfractionated radiotherapy in patients with glioblastoma multiforme.

Forty-seven adult patients with glioblastoma multiforme (GBM) were treated in a phase I/II study combining continuous intravenous (IV) infusions of iododeoxyuridine (IdUrd) and hyperfractionated radiation therapy. IdUrd was administered as a continuous infusion (24 h/d) for two separate 14-day infusion periods. The dose of IdUrd was escalated from 500 to 1,200 mg/m2/d. The initial wide-field tumor volume was treated to 45 Gy at 1.5 Gy fractions twice daily over 3 weeks. Following a planned 2-week break, a reduced-field boost of 25 Gy was delivered using 1.25 Gy fractions twice daily over 2 weeks (total dose, 70 Gy over 9 weeks). The IdUrd infusion preceded both the wide-field and reduced-field irradiation by 1 week. All treatment was performed on an outpatient basis. Dose-limiting systemic toxicity to the bone marrow (primarily thrombocytopenia) and gastrointestinal (GI) tract (both stomatitis and diarrhea) established the maximum tolerable dose (MTD) at 1,000 mg/m2/d for a 14-day infusion. Significant local toxicity (within the radiation field) was not seen. The kinetics of IdUrd were linear with dose escalation and reached steady-state plasma concentrations of 1.3 to 3.4 mumol/L. The total body clearance of IdUrd was .82 L/min/m2. The primary metabolite, 5-iodouracil (IUra) approached steady state by day 6 of the infusion when plasma levels were 60 times higher than IdUrd. Plasma levels of uracil and thymine, but not thymidine, were elevated throughout the infusion. With a minimum follow-up of 1 year, ten patients remain alive, while 33 patients died of progressive disease, and four patients died of other causes (including one treatment-related death). The median survival for all 47 patient and for the 40 patients receiving the MTD was 45 and 47 weeks, respectively, with 12% and 14% survivals at 24 months. Using a Cox regression analysis, age (less than or equal to 50 years v greater than 50 years) and pretreatment performance status (PS) (Eastern Cooperative Oncology Group [ECOG]-PS 0 to 1 v PS 2 to 3) were independent, statistically significant (P2 less than .05) predictors of survival, with the ECOG status being a better predictor. Patients with a PS 0 to 1 (28 patients) had a median survival of 64 weeks with 21% survival at 24 months, compared with a median survival of 29 weeks and 0% survival at 12 months in the 19 patients with PS 2 to 3. The overall and subgroup survival data are at least comparable to other combined modality treatment approaches in patients with GBM.

Adult↗
PubMed1988

Population density estimation.

In many modeling situations, a set of values for the model parameters is regarded as characterizing an individual. The modeler may, however, be interested in estimating the distribution of parameter values in the population from which the individuals are sampled. Some applications of population estimation, a survey of approaches to the estimation problem and some current work will be discussed. The approaches discussed include the "naive pooled data approach," two stage methods, the first order method proposed by Sheiner and Beal and a nonparametric maximum likelihood procedure. General approaches employing Bayes' Theorem are also considered.

Humans↗
PubMed1987

Aging-associated increase in intestinal permeability to polyethylene glycol 900.

Effect of aging on the intestinal permeability to medium size [3H]polyethylene glycol (PEG 900) was examined in vivo by gavage and in vitro in intestinal everted sacs of rats ranging in age from 5 to 102 weeks. Rats were gavaged with PEG 900 solution and urinary recovery of PEG 900 was measured for 6 hr in order to assess its absorption. Young rats, 5-15 weeks of age, absorbed 1-1.3% of administered PEG 900. In contrast, rats 35-102 weeks of age absorbed 1.8-2.4% of administered PEG 900 (P less than 0.05 vs younger animals). The increased absorption of PEG 900 with aging is due to changes in intestinal permeability since the total uptake (serosal appearance + tissue uptake) of PEG 900 by jejunum, ileum, and colonic everted sacs was significantly higher (P less than 0.05) in older rats (100 weeks) than young rats (9 1/2 weeks), while urinary excretion of PEG 900 following intravenous injection was the same in the two age groups. These studies indicate that aging rats have diminished capacity to exclude larger size molecules from penetrating the intestinal mucosa. The diminished barrier functions of the small intestine with aging may allow antigenic or mutagenic compounds to reach the systemic circulation.

Aging↗
PubMed1987

Halogenated pyrimidines as radiosensitizers in the treatment of glioblastoma multiforme.

Sixty patients with high-grade gliomas (including 50 patients with glioblastoma multiforme) were entered on four sequential Phase I trials combining continuous intravenous infusions of halogenated pyrimidines and high-dose brain irradiation. Patients received two 14-day infusions of bromodeoxyuridine (BUdR) or iododeoxyuridine (IUdR) during the initial wide field and later reduced field radiation treatment (total radiation dose 65-70 Gy). All patients were followed a minimum of 6 months or until death. The actuarial median survival was 13 months for the entire group, with an 18-month survival of 24%. No significant survival differences were observed based on BUdR versus IUdR, 12-h versus 24-h infusion schedule, degree of surgical resection, or sex. Good performance status and age under 50 years were significant favorable prognostic factors. Of interest, the 48 patients who completed planned treatment had a 14-month median survival, with a 30% 18-month survival. These survival observations are at least comparable to other combined modality trials in patients with glioblastoma multiforme. Ongoing and planned clinical trials using the halogenated pyrimidine analogs as radiosensitizers in patients with glioblastoma multiforme are discussed.

Astrocytoma↗
PubMed1987

Dementia of the Alzheimer type: clinical and family study of 22 twin pairs.

We studied 22 twin pairs in which one or both twins had dementia of the Alzheimer type (DAT). In four twins, diagnosis was confirmed by autopsy. Seven monozygotic (MZ) pairs were concordant for DAT; 10 MZ pairs were discordant. Two dizygotic (DZ) pairs were concordant for DAT, and 3 DZ pairs were discordant. The current concordance rate was 41% for MZ twins and 40% for DZ twins. The study supports the belief that, etiologically, DAT cannot be entirely accounted for by a single autosomal dominant gene. The data also suggest that in certain genetic circumstances, disease expression may be delayed in females.

Aged↗
PubMed1987

Recurrent cavitary nodules secondary to Hodgkin's disease.

A patient with nodular sclerosing Hodgkin's disease had at least three episodes of lung involvement consisting of an infiltrate on one occasion and multiple cavitating nodules on the other two. The cytologic and histologic studies of the lung specimens disclosed the presence of Reed-Sternberg cells on each occasion without any evidence for infection. This represents the first time in which recurrent cavitating nodules have been reported with Hodgkin's disease.

Adult↗
PubMed1987

Toxoplasma encephalitis in patients with acquired immune deficiency syndrome: diagnosis and response to therapy.

Although Toxoplasma gondii is the most commonly recognized cause of central nervous system mass lesions in patients with acquired immune deficiency syndrome, published investigations have provided little information about criteria for diagnosis of toxoplasmosis or the response to therapy. In this series the method of diagnosis and response to therapy were assessed in 14 patients who had evidence for toxoplasmosis based on routine histopathology, immunoperoxidase staining, or mouse inoculation. These patients presented with clinical and radiologic findings that did not clearly distinguish them from patients with other infectious or neoplastic processes. Excisional biopsies usually showed tachyzoites on routine histology, but needle biopsies were usually negative unless mouse inoculation or immunoperoxidase staining was employed. Response to pyrimethamine and sulfadiazine therapy was often prompt, but therapy had to be continued for long periods of time to maintain a clinical response, and no alternative regimen of one or more drugs appeared to be effective in patients unable to tolerate both pyrimethamine and sulfadiazine.

Acquired Immunodeficiency Syndrome↗
PubMed1986

Production of and response to interleukin-2 in peripheral blood lymphocytes of cancer patients.

Interleukin-2 (IL2) is essential for the expansion of antigen-triggered lymphocytes and cytotoxic T-cells, processes necessary for tumor control that are frequently depressed in malignancy. The authors measured certain aspects of IL2 function in cancer patients and controls and correlated the findings with the general immune response as indicated by the proliferative response to phytohemagglutinin (PHA) in peripheral blood lymphocytes (PBL). The major questions focused on the capacity of PBL to produce IL2, the correlation of this with the proliferative response to PHA, and whether exogenous IL2 could restore T-cell responses and natural killer cell activity in immunodepressed cancer patients. IL2 production was measured by the 3H-thymidine-labeled CT6 assay on the supernatants of the PBL of cancer patients and normal controls after 24 hours of stimulation with PHA. There were 115 cancer patients (70 head and neck, 13 melanoma, 12 breast, 10 colorectal, and 6 other) and 52 controls. IL2 production was essentially normal in the head and neck cancer patients as a group, although their PHA response was depressed. The mean IL2 generated per 3 X 10(6) PBL over 24 hours were 129 mu/ml in the head and neck patients and 132 mu/ml in the breast patients, similar to the 129 mu/ml generated in the controls. There was modest but not significant depression in the melanoma (78 mu/ml) and colorectal cancer patients (81 mu/ml). Although subsets of patients showed depressed IL2 production, there was no significant correlation of IL2 production with the PHA response. Depressed IL2 production showed only limited correlation with depressed lymphocyte responses (r = -0.25), which suggested a dissociation of these functions. Of interest was the finding that indomethacin did augment IL2 production in both cancer patients and controls, suggesting that prostaglandin-mediated regulation is involved. Addition of exogenous IL2 of recombinant origin (Biogen) produced significant augmentation in more than three fourths of the cancer patients and controls. Adding indomethacin further increased this response. Addition of IL2 also significantly increased natural killer activity in both groups. It was concluded that PBL in cancer patients generally have a normal capacity to generate IL2, and this capacity is not related to the proliferative response, which is frequently depressed in these patients. Exogenous IL2 can significantly augment lymphoproliferative and natural killer responses in cancer patients, suggesting that there is merit in exploring the potential therapeutic role of IL2 in these patients.

Adult↗
PubMed1986

Age determination of the male os pubis.

An extensive (n = 739) sample of well-documented male pubic bones was examined for age-related features. Using the traditional aging methods, Todd's system was found to over-age and both the Todd and the McKern-Stewart systems did not account for age variability seen in advanced pubic bone patterns. Based on a 5-year interobserver error study, certain categories in each system were collapsed because observers could not consistently differentiate between them by morphological pattern. The traditional and the modified versions were than analyzed using linear regression analysis. All approaches perform poorly when the entire sample is used. Truncation strategies to eliminate older individuals result in substantial improvement. The traditional Todd system and its modified form are found to be the best systems. When implementation is considered, a modified Todd six-phase system is recommended.

Adolescent↗