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Biomedical subjects

M Horowitz

Publications and source records attributed to M Horowitz.

At least 451 records · Page 25Linked to original sources
PubMed1987

Growth of an interleukin 2/interleukin 4-dependent T cell line induced by granulocyte-macrophage colony-stimulating factor (GM-CSF).

Lymphokine activities in conditioned medium from activated helper T cell lines are most commonly defined by the proliferation of "specific" lymphokine-dependent cell lines. Various sublines of IL 2-dependent (and ostensibly specific) HT-2 and CTLL cells have now been shown to proliferate in response to BSF-1/IL 4 as well. After activation with antigen or mitogen, D10.G4.1, an antigen-specific cloned T helper cell that has recently been shown to produce IL 4 but not IL 2, secretes two distinct cytokines that induce the growth of HT-2 cells. These "T cell growth factors" (TCGF) can be separated by reversed phase high-performance liquid chromatography (RP-HPLC). The TCGF activity of one of these factors can be blocked by 11B11, an antibody specific for IL 4. The second TCGF activity is not affected by 11B11 or by antibodies specific for IL 2. This TCGF activity can be neutralized by a goat polyclonal antibody to granulocyte-macrophage colony-stimulating factor (GM-CSF), and has a RP-HPLC elution profile identical to that of recombinant GM-CSF. Recombinant GM-CSF induces both proliferation and long-term growth of HT-2 but not CTLL cells, and this activity can be neutralized by the same antibody to GM-CSF. GM-CSF is best known as a factor that induces the maturation and growth of granulocytes and macrophages from bone marrow-derived hematopoietic precursor cells. The ability of GM-CSF to induce the growth of certain T cell lines indicates that this molecule may play a role in T cell-mediated immune responses, either as an autocrine growth factor or a paracrine stimulus from both lymphoid and nonlymphoid tissues that produce this cytokine.

Animals↗
PubMed1987

Role of the transferrin receptor in lymphocyte growth: a rat IgG monoclonal antibody against the murine transferrin receptor produces highly selective inhibition of T and B cell activation protocols.

We have produced a new rat IgG monoclonal antibody against the murine transferrin receptor (TR). This antibody (C2F2) exhibits a surprisingly selective pattern of inhibition of murine lymphocyte activation protocols. C2F2 inhibits the mixed lymphocyte reaction (MLR) and the generation of cytotoxic T cells. Interestingly, although interleukin 1 (IL 1)-dependent thymocyte co-stimulatory activity is strongly inhibited by C2F2, interleukin 2 (IL 2)-dependent thymocyte co-stimulation is only marginally reduced. IL 2-dependent growth of CTLL cells is also not inhibited by C2F2. These data suggest that IL 1-dependent helper T cell activation is very sensitive to C2F2-mediated inhibition. Studies with phytohemagglutinin, Concanavalin A, and lipopolysaccharide induced activation also indicate that the inhibitory effects of C2F2 are selective, and T cell activation may be more sensitive to inhibition than B cell activation. Although there is little published information about the functional effects of other rat anti-mouse TR antibodies, the available data suggest that the patterns of inhibition produced by anti-TR antibodies may be individually distinct. Anti-TR antibodies may constitute a new set of highly selective probes for the study of lymphocyte activation.

Animals↗
PubMed1987

Anti-tumor activity of class II MHC antigen-restricted cloned autoreactive T cells. I. Destruction of B16 melanoma cells mediated by bystander cytolysis in vitro.

Two Lyt-1+, L3T4a+ autoreactive T cell clones specific for self-class II major histocompatibility complex (MHC) gene products were established from lymph node cells and spleen cells of C57BL/6J mice, respectively, by different methods. They were stimulated to proliferate in culture in response to I-Ab antigen-bearing syngeneic spleen cells in a class II MHC-restricted manner. This stimulation was inhibited completely by the addition of anti-L3T4a (GK1.5) or anti-I-Ab (3JP) monoclonal antibodies. The autoreactive T cell clones lysed syngeneic I-Ab+ target cells such as lipopolysaccharide (LPS) blasts. They also lysed I-A- bystander cells such as Cloudman and B16 melanoma and lymphoid tumor cells in the presence of I-Ab+ stimulator cells but not I-Ad+ cells. This bystander killing was most likely mediated by soluble factors released from the autoreactive T cells in response to I-Ab antigens, because culture supernatants from activated autoreactive T cells inhibited the proliferation of B16 melanoma cells in vitro and also had significant cytolytic activity. Both lymphotoxin and interferon-gamma were released from activated autoreactive T cells, suggesting that these cytotoxic lymphokines were responsible for autoreactive T cell-mediated cytolysis. The finding that the two clones, established independently and by different methods, show self-class II MHC antigen-restricted cytolysis, and bystander cytolysis suggests that these properties are not restricted to a unique population of autoreactive T cells. These results favor the concept that in vivo, autoreactive T cells may express not only regulatory activity in regard to antibody responses, but also anti-tumor activity via bystander cytolysis.

Animals↗
PubMed1987

Promoter and enhancer elements in the rearranged alpha chain gene of the human T cell receptor.

We cloned and compared the sequence of a rearranged human T cell receptor (TCR) V alpha J alpha gene and its germline counterparts. The only difference in the coding region sequence was confined to the joining region where three nucleotides, TTG, unaccountable by either V alpha or J alpha sequence, were present. By nuclease S1 mapping we identified the mRNA start of the alpha chain 70 nucleotides upstream from the initiator ATG. A 600 bp fragment containing the sequences upstream to the ATG drives the expression of the bacterial chloramphenicol acetyltransferase (CAT) gene. This promoter activity is T cell specific since it can be demonstrated in human T cells but not in B cells or HeLa cells. A 1.1 kb BamHI- HindIII fragment located 5' to the first exon of the C alpha gene was found to enhance transcription from either the heterologous SV40 promoter or the homologous TCR alpha chain promoter. This enhancement activity was independent of the location of the fragment with respect to CAT and was specific to lymphoid cells (either T or B cells) but cannot be demonstrated in HeLa cells.

Amino Acid Sequence↗
PubMed1987

Effects of nandrolone decanoate on forearm mineral density and calcium metabolism in osteoporotic postmenopausal women.

Although anabolic steroids have been used for many years to treat osteoporosis there is little available evidence about their efficacy or mode of action. These agents have recently been shown to produce an increase in total body calcium and bone density and it has been suggested that they stimulate bone formation. In this study 27 osteoporotic postmenopausal women were given 50 mg of nandrolone decanoate intramuscularly, every 2 or 3 weeks for 3 months, and the changes in forearm mineral density, fasting plasma, and urinary calcium, urinary hydroxyproline, and radiocalcium absorption were measured. Associated with a rise in forearm mineral density was a significant fall in fasting urinary calcium, but no significant change in fasting urinary hydroxyproline. The plasma calcium and phosphate fell significantly and there was a significant rise in the renal tubular reabsorption of calcium and a fall in the renal tubular reabsorption of phosphate. In a subset of 22 patients there was a significant rise in radiocalcium absorption. The results are consistent with the concept that nandrolone exerts a significant positive effect on bone formation and that this results in a fall in the fasting plasma calcium level, and consequently calcium excretion.

Absorption↗
PubMed1987

The effect of an oral calcium load on plasma ionized calcium and parathyroid hormone concentrations in osteoporotic postmenopausal women.

Plasma ionized calcium (IC) and parathyroid hormone (PTH) concentrations were measured in 31 osteoporotic postmenopausal women at hourly intervals for 5 hours after a 1 g oral calcium load. Fifteen subjects had normal radiocalcium absorption and 16 subjects were malabsorbers of calcium. IC rose and PTH fell after the calcium load in both groups with a plateau at 3-4 hours, and the rise in IC was greater (P less than 0.01) in the normal absorbers. There was a nonsignificant trend for the fall in PTH to be greater in the normal absorbers. In the group as a whole the mean increase in IC (above baseline) at 4 hours was directly related to calcium absorption (P less than 0.025) and the mean change in PTH was inversely related to calcium absorption (P less than 0.05). These results demonstrate that in subjects with postmenopausal osteoporosis the responses of IC and PTH to an oral calcium load are a function of calcium absorptive status.

Administration, Oral↗
PubMed1987

Gastric and esophageal emptying in dystrophia myotonica. Effect of metoclopramide.

Gastric and esophageal emptying were measured using scintigraphic techniques in 16 patients with dystrophia myotonica and in 22 normal volunteers. Gastric emptying of a solid meal was slower than the normal range (defined as the mean +/- two standard deviations obtained in the normal volunteers) in 15 of the 16 patients, and gastric emptying of the liquid meal was slower than the normal range in 10 of the patients. Esophageal emptying was also markedly delayed in patients, with 15 of 16 patients having an emptying time longer than the normal range. There was no relationship between gastrointestinal symptoms, or the severity of the peripheral (skeletal) muscle weakness, and either gastric or esophageal emptying. Oral administration of metoclopramide resulted in a significant improvement in gastric emptying of the solid meal and a nonsignificant trend toward more rapid liquid emptying, but no change in esophageal emptying. These results indicate that there is a very high prevalence of gastric and esophageal smooth muscle dysfunction in dystrophia myotonica and that gastroparesis is likely to be a treatable cause of morbidity in this disease.

Adult↗
PubMed1987

Effect of cisapride on gastric and esophageal emptying in insulin-dependent diabetes mellitus.

The effects of cisapride on gastric emptying, esophageal emptying, gastrointestinal symptoms, and glycemic control were evaluated in 20 insulin-dependent diabetics who had delayed gastric emptying of the solid or liquid component of a meal, or both. A double-isotope technique was used to measure gastric emptying, and esophageal emptying was measured as the time for a bolus of the solid meal to enter the stomach. On 2 days each patient received cisapride (20 mg) or placebo orally, 60 min before an esophageal and gastric emptying test. A third gastric and esophageal emptying test was performed after each patient had orally taken 10 mg of cisapride or placebo q.i.d. for 4 wk. Single-dose cisapride increased esophageal emptying (p less than 0.01) and both solid and liquid gastric emptying (p less than 0.001). The response to cisapride was most marked in patients with the greatest delay in esophageal and gastric emptying (p less than 0.05). After administration of cisapride for 4 wk, gastric emptying of solid and liquid were faster (p less than 0.001), but esophageal emptying was not significantly different from the placebo test. Upper gastrointestinal symptoms were less after cisapride (p less than 0.05), whereas there was no change on placebo (p greater than 0.2). Plasma glucose and glycosylated hemoglobin concentrations were not different after cisapride compared with placebo. These results indicate that single-dose cisapride increases esophageal emptying in insulin-dependent diabetics and that chronic administration of cisapride is effective in the treatment of diabetic gastroparesis.

Adult↗
PubMed1987

Effects of cisapride on gastric and esophageal emptying in progressive systemic sclerosis.

The effects of cisapride on gastric emptying, esophageal emptying, and gastrointestinal symptoms were evaluated in 8 patients with progressive systemic sclerosis who had delayed gastric emptying of the solid or liquid component of a meal, or both. A double-isotope technique was used to measure gastric emptying, and esophageal emptying was measured as the time for a bolus of the solid meal to enter the stomach. Gastrointestinal symptoms were assessed by a questionnaire. On 2 days each patient received cisapride (10 mg) or placebo intravenously, 5 min before an esophageal and gastric emptying test. After these 2 days each subject took cisapride (10 mg q.i.d., p.o.) for 1 mo. Cisapride improved solid and liquid gastric emptying (p less than 0.001), but had no significant effect on esophageal emptying (p less than 0.1). Upper gastrointestinal symptoms were reduced after cisapride (p less than 0.001), and no side effects were reported. These results indicate that gastroparesis is a treatable cause of morbidity in progressive systemic sclerosis.

Adult↗
PubMed1987

Efficient in vitro and in vivo expression of human glucocerebrosidase cDNA.

A human glucocerebrosidase cDNA clone was isolated from a human chronic myelogenous leukemia (line K562) cDNA library using a 36-nucleotide-long synthetic probe (GC-36). The 2.4-kb cDNA contains 184 bp of 5' nontranslated sequences, the complete coding region, and 546 bp of 3' nontranslated sequences followed by 100 bp of poly(A). A primer extension experiment indicated that the cDNA is at least 51 bp shorter than the mRNA at the 5' end. In normal human placenta as well as in fibroblasts from Gaucher's disease patients, a major mRNA species of 2.6 kb hybridizes with the cDNA probe. The amounts of the glucocerebrosidase mRNA in normal placenta and Gaucher's cells are comparable. The cDNA was linked to the SP6 promoter and transcribed in vitro. The resultant RNA, when translated in a cell-free system, yielded a polypeptide of 55 kD, which is the size expected from the coding sequence. The cDNA was inserted into an SV40 shuttle vector, under the transcription control of the SV40 early promoter. COS-M6 cells were transfected with this construct and the biological activity of the cDNA was assayed by monitoring the increase in glucocerebrosidase activity, using 4-methyl umbiliferyl glucopyranoside as a substrate. There was a two- to three-fold increase in enzymatic activity in the transfected cells, compared to nontransfected cells. These results prove the authenticity of the glucocerebrosidase cDNA and provide the basis for experiments to understand the nature of the genetic alterations responsible for Gaucher's disease.

Cloning, Molecular↗
PubMed1987

Closed interlocking nailing of the femur complicated by an intramedullary calcified lesion.

The interlocking intramedullary nail has greatly expanded the indications for closed intramedullary nailing of the femur. We describe a complication caused by the presence of a calcified lesion located at the proximal metaphyseal-diaphyseal junction of the femur. This lesion could not be penetrated by hand reamers. We used a long 3.5-mm drill bit to place a hole in the infarct, which then allowed passage of the hand reamer. The operation then proceeded in the standard fashion without complications.

Adult↗
PubMed1987

Indium-111 T101 monoclonal antibody is superior to iodine-131 T101 in imaging of cutaneous T-cell lymphoma.

We have reported that [111In]T101 is highly effective in the detection of cutaneous T-cell lymphoma (CTCL) in nodal and cutaneous (erythroderma and tumor) sites. This study compares the biodistribution of [131I]T101 (1 to 7.1 mg, 2 mCi) in four patients with CTCL; two of these patients also received [111In]T101 (1 mg, 5 mCi). There was rapid clearance of [131I]T101 from whole-body, spleen, liver, and bone marrow, with evidence of loss of 131I tracer from the T101. Lymph node uptake was minimal in three of four patients, and there was no localization in skin lesions. This contrasted with [111In]T101 where there was prolonged retention of activity in these organs and excellent uptake in skin tumors, erythroderma, and lymph nodes. The study showed that [131I]T101 was suboptimal for imaging CTCL patients and demonstrates that the isotope or labeling method can dramatically alter the apparent biodistribution and tumor targeting of a given monoclonal antibody.

Animals↗
PubMed1987

Radiation enteritis.

Acute radiation enteritis is almost inevitable in the curative treatment of malignant tumors of the abdomen and pelvic area. It is frequently a self-limiting disorder of intestinal function associated with reversible mucosal changes of the intestine. The prevalence of chronic radiation enteritis has been underestimated in most surgical series and the majority of patients with symptoms probably do not seek medical advice until a serious complication occurs. Although associated with specific histologic features, the mechanism of chronic radiation injury is poorly understood. The prevalence, pathogenesis, diagnosis and approaches to the treatment and prevention of acute and chronic radiation enteritis are discussed herein. Recent investigative techniques should lead to a better understanding of the physiopathologic characteristics of radiation enteritis and, thereby, provide a more rational basis for treatment which, at the present time, is unsatisfactory. Attempts to reduce the prevalence of radiation enteritis should be directed toward careful patient selection for radiation treatment of the pelvis and to minimize injury to the small intestine, by reducing the volume of small intestine in the radiation area and providing more individualized dosimetry.

Abdominal Neoplasms↗
PubMed1987

External fixation of open comminuted fractures of the proximal phalanx.

External fixation is an accepted method of treatment for many injuries, however, only a limited number of reports concern its use in open, comminuted fractures of the hand. Ten patients with eleven fractures of the proximal phalanx were treated using the AO/ASIF small external fixator. Five fractures involved the interphalangeal joint (IPJ), two the metacarpophalangeal joint (MPJ), and four the shaft. Nine fractures were caused by small caliber gunshot wounds, one was due to a power saw injury, and one occurred during a three wheeler accident. The patients with interphalangeal joint involvement all had extensive involvement of one or both of the joint surfaces. The fixator was placed across the joint and a stable ankylosis allowed to occur with the IPJ in 30 degrees to 40 degrees of flexion. MPJ motion averaged 75 degrees in these patients while distal interphalangeal joint (DIPJ) motion averaged 20 degrees. The four patients with shaft fractures all healed, but three required bone grafting. These patients averaged 85 degrees of MPJ motion, 25 degrees of proximal interphalangeal joint (PIPJ) motion, and 30 degrees of DIPJ motion. One patient with metacarpophalangeal joint involvement regained 85 degrees of MPJ motion but had limited motion at the PIPJ and DIPJ. The other patient with MPJ involvement suffered massive bone loss; a ray amputation was eventually performed. Complications included pin tract drainage in three of the eleven fractures and slight loss of reduction in two fractures. The best clinical results occurred when the fixator was used as a digit salvage procedure in interphalangeal joint fractures.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1987

Effects of nandrolone therapy on forearm bone mineral content in osteoporosis.

Forearm bone mineral content (BMC) was measured sequentially on and off anabolic steroid therapy in 52 postmenopausal women with osteoporosis. The steroid used was nandrolone decanoate in a dose of 50 mg every two weeks by intramuscular injection. In 16 of the patients nandrolone was given first (for 6.2 +/- 0.6 months) followed by a control period (6.1 +/- 1.0 months) and in 36 there was an initial control period (9.5 +/- 1.1 months) followed by nandrolone (for 5.8 +/- 0.4 months). Any other therapy was continued unchanged during both treatment and control periods. There was a significant rise in BMC on nandrolone (p less than 0.001) and a nonsignificant fall in BMC off nandrolone. The difference between the rates of change on and off nandrolone was highly significant (+53 vs. -7 mg/cm/year; p less than 0.001).

Aged↗