PubMed Health⌕ Search

Biomedical subjects

M Moriarty

Publications and source records attributed to M Moriarty.

At least 37 records · Page 2Linked to original sources

Comparison of the inhibitory roles of neuropeptide Y and galanin on cardiac vagal action in the dog.

Prolonged attenuation of cardiac vagal action occurs following cardiac sympathetic nerve stimulation or intravenous neuropeptide Y (NPY) injections in anaesthetised dogs. Equimolar intravenous injections of galanin (GAL) had no effect on cardiac vagal action in this species. Immunohistochemical analysis of dog stellate ganglia and cardiac muscle showed that most nerve cell bodies showing tyrosine hydroxylase immunoreactivity (TH-IR) also showed immunoreactivity to both NPY and GAL. The results are consistent with the proposal that NPY released from cardiac sympathetic nerves is responsible for the prolonged inhibition of cardiac vagal action known to be caused by such stimulation. A role for GAL, shown here to exist in cardiac sympathetic nerves in the dog, has yet to be determined.

Anesthesia↗

Inhibition of arterial baroreceptor and chemoreceptor reflex responses by neuropeptide Y in anaesthetised dogs.

The effects of bolus intravenous injections of neuropeptide Y (NPY) on increases in pulse interval (PI) evoked reflexly by arterial chemoreceptor and baroreceptor stimulation were investigated in anaesthetised dogs. The arterial chemoreceptors were stimulated by rapid injections of small volumes of CO2 into the carotid sinus or brief episodes of tracheal occlusion. Intravenous injections of NPY produced a prolonged attenuation of the reflex prolongation of PI induced by both methods. Two methods of testing the arterial baroreceptor reflex were used: steady-state increases in PI evoked in response to maintained step increases in systolic arterial blood pressure (SABP) from inflation of an aortic balloon-tipped catheter, and beat-by-beat increases in PI evoked reflexly by 'ramp' increases in blood pressure caused by intravenous injections of phenylephrine. In both methods the relationship between SABP and PI is linear over the range tested (up to SABP 200 mmHg), the slope of the line indicating the sensitivity of the reflex response. Intravenous injections of NPY produced a prolonged attenuation of the baroreceptor-cardiodepressor reflex measured by both methods. No significant differences were observed between the NPY-mediated inhibition of the direct effects on PI of electrical stimulation of a vagus nerve, and its inhibition of the reflex responses of PI to chemoreceptor or baroreceptor stimulation. The results indicate that the attenuation of reflex PI responses to arterial chemoreceptor and baroreceptor stimulation following an intravenous injection of NPY can be accounted for in terms of the action of NPY on vagal nerve endings at the heart, although additional sites of action cannot be ruled out.

Anesthesia↗

Cytological differences between normal and malignant human cell populations in culture.

Cells from early-passage cultures of normal and malignant human tissues were analyzed for the presence of multiple nucleoli and tri- or multipolar mitoses; these properties are characteristic of malignant cell populations in tissue sections. For the cell types examined the presence of tri- or multipolar mitoses was characteristic of cells of malignant origin. Within epithelial cell populations, cells containing more than 4 nucleoli were found in populations of malignant but not of normal origin; this distinction did not apply to fibroblast populations. Large numbers of cells must be analyzed quantitatively to establish the distinctions described here, since they are properties characteristic of populations, not of individual cells. This approach may facilitate identification of normal and malignant cell populations in primary and early-passage culture.

Cell Nucleus↗

Lymphoid irradiation in intractable rheumatoid arthritis. Long-term followup of patients treated with 750 rads or 2,000 rads.

Twenty patients with intractable rheumatoid arthritis were randomized to receive 750 or 2,000 rads of lymphoid irradiation (LI) in a double-blind comparative study, and were followed for a maximum of 48 months (mean 40 months) after treatment. During followup, sustained immunomodulation (including lymphopenia, particularly of the T helper cell subset; reduced ratio of helper cells to suppressor cells; and impaired in vitro lymphocyte proliferation in response to phytohemagglutinin and pokeweed mitogen) was observed. Significant improvements in early morning stiffness, Ritchie articular index, pain score, grip strength, and 15-meter walk time were observed in both treatment groups, but these were not sustained through the followup period. Progressive joint damage was observed radiologically in both groups during followup. Thus, LI induced sustained immunosuppression, but resulted in only short-lived clinical improvement and was associated with progressive joint erosion in these patients.

Arthritis, Rheumatoid↗

Surgical treatment of skin cancer.

Eight hundred and twenty cases of skin cancer treated surgically at Saint Luke's Hospital over a ten-year period were reviewed retrospectively. Those undergoing excision, ie simple excision and primary closure, had significantly shorter hospitalization than those requiring grafts or amputation. The only prognostic factor in this particular series identified for local recurrence was a past history of skin carcinoma. Surgery was effective both as primary treatment and after failed irradiation. Local recurrence rates for skin carcinoma and melanoma were 8% and 10% respectively.

Basal Cell Carcinoma↗

Lymphoid irradiation in intractable rheumatoid arthritis. A double-blind, randomized study comparing 750-rad treatment with 2,000-rad treatment.

Twenty patients with intractable rheumatoid arthritis were treated with 750-rad or 2,000-rad lymphoid irradiation in a randomized double-blind comparative study. Over a 12-month followup period, there was a significant improvement in 4 of 7 and 6 of 7 standard parameters of disease activity following treatment with 750 rads and 2,000 rads, respectively. Transient, short-term toxicity was less frequent with the lower dose. In both groups, there was a sustained peripheral blood lymphopenia, a selective depletion of T helper (Leu-3a+) lymphocytes, and reduced in vitro mitogen responses. These changes did not occur, however, in synovial fluid. These results suggest that 750-rad lymphoid irradiation is as effective as, but less toxic than, that with 2,000 rads in the management of patients with intractable rheumatoid arthritis.

Adult↗

Lymphoid irradiation in intractable rheumatoid arthritis: effects on the production of immunoglobulins and rheumatoid factors.

Changes in the production of immunoglobulins and rheumatoid factors (RF's) were studied in 20 patients with intractable rheumatoid arthritis (RA) following total doses of 750 rad or 2,000 rad lymphoid irradiation. Over a 12 month follow up period there was no consistent change in absolute serum or synovial fluid levels, or in synovial membrane production of either total IgG, IgA or IgM, or the corresponding RF fractions. The invitro production of immunoglobulins and IgM RF by peripheral blood mononuclear cells was also unaltered, except for one patient who had a dramatic rise in IgM RF production. Over the same period there was a significant overall reduction in disease activity following both doses of radiotherapy. It is concluded that the clinical response which occurs following lymphoid irradiation is not due to a reduction in RF production. Furthermore, the production of RF's appears to be unaffected by the changes in T cell immunity which occur following lymphoid irradiation.

Arthritis, Rheumatoid↗

Lymphocyte lactate dehydrogenase isoenzymes in association with depressed mitogen responsiveness.

Purified lymphocyte preparations from cancer patients were less responsive to the mitogen phytohaemagglutinin (PHA) than were lymphocytes from healthy donors as measured by [3H]-thymidine uptake over periods in culture up to 96 hours. The uptake of radiolabel was paralleled by total cellular lactate production. The isoenzymic composition of lactate dehydrogenase (LD) in lymphocytes from healthy individuals was altered following PHA stimulation with increasing proportions of LD-1 and LD-2 throughout the culture period. This phenomenon was markedly reduced in lymphocytes from cancer patients. This defect in lymphocytes from cancer patients is thought to reflect an impaired capacity to accomplish an early mitogen-induced enhancement of glucose metabolism, which is a prerequisite for lymphocyte proliferation.

Aged↗

Lactate-mediated changes in growth morphology and transformation frequency of irradiated C3H 10T1/2 cells.

Treatment of mammalian cells with lactate or inhibitors of glycolysis alters their radiation response, particularly in the low dose region of the dose response curve. The occurrence of both high lactate levels and high glycolytic metabolism in tumours is well known and therefore the effect of lactate on a cell line sensitive to radiation induced transformation was examined using a single exposure to Cobalt 60 gamma rays as the carcinogen challenge. The results indicate that cells treated with 5mM lactate before irradiation exhibit changes in morphology and growth rate and that the transformation frequency is increased by three to ten fold following 24 hours lactate treatment just prior to irradiation. Examination of radiation survival curves showed a positive correlation between transformation frequency and size of the shoulder, but increasing transformation frequency was associated with a decrease in Do. A mechanism involving altered Redox potential in lactate treated cells is suggested. The results are discussed in terms of their possible significance for radiotherapy.

Animals↗

Controlled studies of nutritional intake in patients with malignant disease undergoing treatment.

Ninety-seven patients with cancer, undergoing radiation treatment, were studied. Forty-two were given special dietary counseling and supplements of Sustagen or Isocal; 42 controls received no special advice or supplements. Thirteen patients were excluded because of poor prognoses and the ethical need for food supplements. Nutrient intake of all groups was assessed by 3-d diet records in household measures in the first and the last week of treatment. Intake was significantly higher in the adjunctive than the control group. The excluded group, despite supplementation, had intakes similar to the control group. No difference was observed between the control and adjunctive groups in clinical status at the end of treatment or in long-term outcome.

Abdominal Neoplasms↗

Etretinate in treatment of actinic keratosis. A double-blind crossover study.

50 patients with actinic keratosis were studied over four months of treatment with either etretinate ('Tigason') or placebo. Each treatment was given for two months and the order of administration was randomised. The clinical response to treatment was assessed by direct measurement and photographs of the lesions at monthly intervals. Of the 44 patients who completed treatment with etretinate 37 had a complete or partial response. Of the 42 patients who completed treatment on placebo only 2 showed a complete or partial response. The response to treatment occurred within the first month of therapy and was maintained even when the dose was reduced because of toxicity.

Aged↗