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Biomedical subjects

S Love

Publications and source records attributed to S Love.

At least 235 records · Page 13Linked to original sources
PubMed1985

The use of pathologic features in selecting the extent of surgical resection necessary for breast cancer patients treated by primary radiation therapy.

The extent of the surgical resection necessary for breast cancer patients treated by primary radiation therapy is unknown. A simple gross excision of the tumor provides the best cosmetic result, but a wide local resection may be important to prevent local recurrence in some patients. In order to identify patients who are not adequately treated by gross excision of the tumor and radiation therapy, we performed a retrospective clinical-pathologic review of 221 treated women with infiltrating duct carcinoma. There were 53 cases in which the excision specimen showed a constellation of three pathologic features: prominent intraductal carcinoma in the tumor, intraductal carcinoma in the grossly-normal adjacent tissue, and poorly-differentiated nuclei. These cases had a 37% risk of a local recurrence at 6 years compared to eight per cent for all other cases (p less than 0.0001). In cases with all three features, the use of a supplemental dose of radiation to the primary site did not significantly reduce the risk of a local recurrence. Local recurrence at 6 years was 34% in cases with all three features, who received supplemental local radiation, compared to 49% in cases not receiving a supplemental dose (p = 0.28). Survival was also worse for patients with all three features compared to other cases (69% vs. 90% at 6 years, p = 0.002). These results indicate that patients with all three pathologic features have a high risk of local recurrence following gross excision of the tumor and radiation therapy. If primary radiation therapy is selected for these patients, they should first undergo a re-excision of the tumor site in order to be certain that areas of extensive intraductal carcinoma have been adequately resected. Patients whose tumors do not show all three features are adequately treated by gross excision of the tumor prior to radiation therapy.

Breast↗
PubMed1985

Effects of Phoneutria nigriventer spider venom on mouse peripheral nerve.

A physiological and morphological study has been made of the effects of the venom of the spider Phoneutria nigriventer on peripheral nerve and skeletal muscle of the mouse. Venom was injected either into the sciatic nerve, via a glass micropipette, or into the calf muscles. Repetitive firing of nerve fibres commenced within seconds of injection and caused fasciculation of muscles and irregular trains of end-plate potentials. These physiological disturbances were associated with swelling of the nodal and paranodal axoplasm and the development of vacuoles in the periaxonal space. The segments of internode between the vacuoles became attenuated, with an increase in the density of axoplasmic organelles and a reduction in axonal calibre. The repetitive firing ceased after 1-3 h with development of conduction block. Both the physiological and the morphological abnormalities gradually resolved and by 24 h nerve conduction and morphology had largely returned to normal. It seems likely that these short-lived abnormalities are a consequence of the influx of sodium ions at the nodes of Ranvier, caused by the action of the venom on sodium channels.

Animals↗
PubMed1985

Granulomatous angiitis of the central nervous system: a case with recurrent intracerebral haemorrhage.

A 43-year-old man with a history of radiculomyelopathy developed recurrent intracerebral haemorrhage confirmed by CT brain scan. Cerebral angiography and systemic investigations showed no underlying cause for the haemorrhage. Cerebral biopsy at the time of evacuation of a haematoma revealed granulomatous angiitis. This condition may be responsive to steroids and should be considered in cases of intracerebral haemorrhage of obscure origin.

Adult↗
PubMed1984

Radiological features of subependymoma with emphasis on computed tomography.

The features of 17 symptomatic subependymomas on X-ray computed tomography are described. Thirteen were reviewed from isolated case reports and 4 were original material. Over half were entirely intraventricular, 6 extended into brain substance and 2 into subarachnoidal cisterns. Twelve were isodense, 15 showed diffuse but irregular enhancement, and 5 contained nodular calcification. Large low density cysts, intratumoural haemorrhage and brain oedema were found almost exclusively in lesions extending into brain substance. It is concluded that subependymomas resemble ependymomas too closely on CT to be distinguished radiographically from them as a separate group. However subependymomas contain calcification slightly less frequently, and usually appear as mainly intraventricular lesions even when they occur above the tentorium.

Adolescent↗
PubMed1984

Effects of experimental radiation-induced hypomyelinating neuropathy on motor end-plates and neuromuscular transmission.

Morphological and physiological techniques were used to study the effects of radiation-induced hypomyelinating neuropathy on the innervation of skeletal muscle in the mouse. The right sciatic nerve was crushed focally and 3 days later the hind limb exposed to 20Gy X-rays. After reinnervation of original end-plate sites there was extensive formation of ultraterminal sprouts and of new end-plates characterized by small nerve terminals and rudimentary postsynaptic folds. In vitro examination of soleus nerve-muscle preparations showed reduced frequency of spontaneous miniature end-plate potentials and low quantal content of evoked potentials. The findings indicate that hypomyelinating neuropathy may cause reduction in quantal release of neurotransmitter.

Acetylcholine↗
PubMed1984

Reinnervation of muscle in the mouse following nerve crush and X-irradiation.

The effects of X-irradiation on nerve regeneration were examined in adult mice. The right sciatic nerve was crushed focally and 3 d later the hind limb was exposed to 20 Gy X-rays. Compound muscle action potentials (m.a.p.s) were recorded in vivo from the posterior crural muscles. Stimulation of the sciatic nerve proximal to the crush injury evoked m.a.p.s of low amplitude with marked temporal dispersion. Stimulation at 20 or 50 Hz resulted in almost immediate intermittent failure of the longer latency m.a.p.s. In vitro physiological examination showed X-irradiation to have no effect on the timing of reinnervation. However, the latency of evoked end-plate potentials was prolonged and, on repetitive nerve stimulation, increased markedly until failure occurred. Nerves which regenerated after X-irradiation showed impaired conduction, particularly of trains of impulses.

Action Potentials↗
PubMed1983

Regression of thyroid hormone induced cardiac hypertrophy: effect on cardiac beta receptors and adenyl cyclase activity.

Adrenergic mechanisms may be important in the symptomatic manifestations of hyperthyroidism. The chronic administration of thyroid hormone also results in cardiac hypertrophy and increased numbers of beta-adrenergic receptors in cardiac membranes. The roles of adrenergic mechanisms in the initiation and perpetuation of this hypertrophy has been open to speculation. Rats treated chronically with L-thyroxin were sacrificed after 7 days of treatment and 1-4 days after cessation of treatment. Hearts were removed and weighed and norepinephrine measured. In other groups of identically treated rats, membranes were prepared from the left ventricle for in vitro measurements of beta-adrenergic receptor characteristics and adenyl cyclase activity. Regression of cardiac hypertrophy with a decrease in receptor number to control values was seen as early as 2 days after stopping thyroxine. Cardiac norepinephrine concentrations had also returned to control values at this time. Displacement of bound [H3] dihydroalprenolol by isoproterenol was not changed from control. Basal and isoproterenol stimulated adenyl cyclase activity was not changed by thyroxine administration or its cessation. The rapid reversal of the increased beta-adrenergic receptor number and cardiac hypertrophy raises the possibility that thyroid hormone may play a regulatory role in cardiac function. Although the enhancement of myocardial contractility by thyroid hormone may be mediated through cardiac hypertrophy this effect of thyroid hormone is independent of the catecholamine sensitive adenyl cyclase system.

Adenylyl Cyclases↗
PubMed1983

An experimental study of peripheral nerve regeneration after x-irradiation.

The effects of x-irradiation on peripheral nerve regeneration in the mouse were examined using quantitative and ultrastructural techniques. One hind limb was exposed to 15 or 20 Gy one day before, or 20 Gy three days after the right sciatic nerve was crushed. The distal sciatic and posterior tibial nerves were examined up to 120 days after injury. Irradiation before injury initially reduced the proliferation of endoneurial cells although cell numbers reached control levels after a few weeks. Myelination was delayed but not prevented, and after exposure to 20 Gy the myelin sheaths remained abnormally thin. In nerves irradiated after injury endoneurial cellular proliferation was severely and persistently reduced, and many fibres showed segmental absence of myelin. Internodes abutting the nonmyelinated segments were abnormally long, suggesting that contact with adjacent internodes may limit elongation of internodes during normal regeneration.

Animals↗
PubMed1982

Familial cerebellar ataxia with cerebrovascular amyloid.

We report a rare association of familial cerebellar ataxia (without dementia) and cerebrovascular amyloid. Postmortem neuropathological examination of one member of the family showed amyloid angiopathy of the central nervous system with heavy infiltration of capillaries in the hippocampus and cerebellum.

Amyloidosis↗
PubMed1981

Stimulation of hexose uptake by human eosinophils with chemotactic factors.

The ability of several stimuli, all of which have been reported to stimulate eosinophil motility, to augment uptake or extracellular deoxyglucose (DOG), a glucose analogue, was studied. DOG uptake was stimulated in a concentration-dependent manner by the more potent chemotaxins--zymosan-activated serum, partially purified C5a. N-formyl-methionyl-leucyl-phenylalanine, and 5- and 11-hydroxyeicosatetraenoic acids. Less potent stimuli--the eosinophil chemotactic factor of anaphylaxis, histamine, and prostaglandin E2--did not stimulate DOG uptake. However, the correlation between the abilities of the agents to stimulate motility and DOG uptake was not completely uniform. Prostaglandin F2 alpha was a potent stimulant of DOG uptake yet is known to enhance only weakly chemokinesis and to be not chemotactic for eosinophils. The combined data from this and other studies indicate that these stimuli elicit specific and different sets of functional responses from eosinophils.

Arachidonic Acids↗
PubMedDate not supplied

The management of chronic lymphocytic leukemia at a single centre over a 24-year period: prognostic factors for survival.

Over a 24-year period, 137 patients were referred for management of newly diagnosed chronic lymphocytic leukemia. One hundred and nineteen patients have been reviewed in terms of response to therapy and prognostic factors for survival; 18 patients were excluded either because lymph node biopsy was not compatible with the diagnosis of CLL (11 patients), or because the lymphocyte count at presentation was < 5 x 10(9)/l (seven patients). Patients were staged retrospectively according to both the Rai and Binet Classifications. Forty-eight per cent (57/119) were deemed not to be in need of any treatment at presentation, 36 per cent (43/119) have never received any specific therapy. The majority of patients received chlorambucil alone, at a dose of 10 mg daily given for 6 weeks, followed by a 2-week interval, followed by three, 2-week cycles. The overall response rate (complete+partial remission) was 38 per cent. In terms of survival, there was a trend in favour of patients who responded to treatment in comparison with those who did not but this did not reach statistical significance (P = 0.07). Correlations with stage were highly significant, the median survivals for patients with stage A, B and C disease (Binet) were 12.5, 8 and 3.5 years respectively. On univariate analysis, the absolute lymphocyte count at presentation was the most significant prognostic factor for survival, patients presenting with an absolute lymphocyte count above 50 x 10(9)/l having a less favourable prognosis (P = 0.002). However, on multivariate analysis, older age, a low hemoglobin, low platelet count, and the presence of lymphadenopathy and fever at presentation correlated adversely with survival. Overall, 40 patients died as a consequence of CLL or from disease-related causes, 34/40 dying of infection. Twenty-one patients developed second cancers. With a median follow-up of 13 years, these results confirm that the two staging systems can separate patients into prognostic groups, however in practice, there is heterogeneity of outcome within stage. New approaches are urgently needed.

Adult↗
PubMedDate not supplied

Equine Cushing's disease.

In the horse, adenomata of the pairs intermedia of the pituitary gland have been associated with the distinct clinical entity of Cushing's disease which arises largely as a result of excessive secretion of adrenocorticotropin (ACTH) or other proopiomelanocortin (POMC) peptides. Pars intermedia peptide secretion is under dopaminergic control and compounds such as pergolide or bromocriptine, which are dopamine agonists, can palliate the clinical signs. A variety of endocrinological abnormalities, relevant to both pathogenesis and diagnosis, may be demonstrated in equine Cushing's disease, including hyperadrenocorticism, peripheral insulin resistance and excessive POMC-peptide secretion from the pituitary gland. Preliminary studies on carbohydrate metabolism suggest that quantification of insulin activity may be a useful prognostic index in cases of equine Cushing's disease, and that insulin therapy of secondary diabetes mellitus may be indicated in some cases.

Animals↗
PubMedDate not supplied

Patient-administered nitrous oxide/oxygen inhalation provides effective sedation and analgesia for colonoscopy.

In a double-blind, randomized, placebo-controlled study of patients undergoing colonoscopy, sedation with an inhaled mixture of nitrous oxide/oxygen was compared with conventional intravenous sedation (pethidine 50 mg, midazolam 2.5 mg). In the patients studied, no significant differences were noted in number of pain episodes, need for additional intravenous sedation, or patient pain scores between the group receiving the nitrous oxide/oxygen mixture (n = 30) and those managed with conventional benzodiazepine/opiate injection (n = 29). Both methods were significantly more effective than placebo (n = 30). Six patients in the benzodiazepine/opiate group had oxygen desaturation, whereas none did in the nitrous oxide/oxygen group. Duration of stay after the procedure was significantly shorter in the gas inhalation group than in those receiving conventional intravenous sedation. Except for patients with severe chronic obstructive pulmonary disease, nitrous oxide/oxygen inhalation is a safe and acceptable alternative method of sedation and analgesia during colonoscopy.

Adolescent↗