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D Soni

Publications and source records attributed to D Soni.

13 recordsLinked to original sources
PubMed1999

Inosine stimulates extensive axon collateral growth in the rat corticospinal tract after injury.

The purine nucleoside inosine has been shown to induce axon outgrowth from primary neurons in culture through a direct intracellular mechanism. For this study, we investigated the effects of inosine in vivo by examining whether it would stimulate axon growth after a unilateral transection of the corticospinal tract. Inosine applied with a minipump to the rat sensorimotor cortex stimulated intact pyramidal cells to undergo extensive sprouting of their axons into the denervated spinal cord white matter and adjacent neuropil. Axon growth was visualized by anterograde tracing with biotinylated dextran amine and by immunohistochemistry with antibodies to GAP-43. Thus, inosine, a naturally occurring metabolite without known side effects, might help to restore essential circuitry after injury to the central nervous system.

Animals↗
PubMed1999

Analgesic responses to intrathecal morphine in relation to CSF concentrations of morphine-3,beta-glucuronide and morphine-6,beta-glucuronide.

This study was performed to determine whether variations in analgesic responses to intrathecal morphine could be explained by cerebrospinal fluid (CSF) concentrations of morphine metabolites. Twenty-four CSF samples were collected at the beginning, middle and end of treatment periods in seven cancer patients with pain of malignant origin. CSF concentrations of morphine-3,beta-glucuronide (M3G) and morphine-6,beta-glucuronide (M6G) metabolites were measured by gas chromatography/mass spectrometry. Analgesic responses to morphine were estimated concurrent with CSF collection using a visual analog scale representing percentages of pain relief. Effective analgesia was defined as > or = 75% pain relief. CSF concentration of M3G and M6G in the 24 samples were 722 +/- 116 ng/ml and 699 +/- 158 ng/ml, respectively. CSF samples were categorized into two groups: (1) those collected during effective analgesia (N=14), and (2) those collected during ineffective analgesia (N=10). M6G levels detected in group 1 samples (effective analgesia) were significantly greater than those found in group 2 samples (ineffective analgesia) (978 +/- 243 ng/ml vs 309 +/- 68 ng/ml, P<0.05). Intergroup differences in CSF M3G concentrations and M3G/M6G ratios were not significant. It is concluded that CSF M6G may be indicative of effectiveness of analgesia in cancer patients subjected to intrathecal morphine.

Adult↗
PubMed1994

Necrosis in pontine gliomas: radiation induced or natural history?

PURPOSE: To determine whether the central necrotic lesions that develop in a large number of patients with pontine gliomas are secondary to radiation therapy, specifically high-dose (7,200-7,800 cGy) hyperfractionation radiation therapy, or are part of the biologic progression of this tumor. MATERIALS AND METHODS: The authors analyzed neuroimaging studies of 31 consecutive patients with pontine-centered gliomas and assessed the time of onset of necrosis, the type and dose of radiation therapy administered, and the length of survival. RESULTS: Necrosis was present at diagnosis in eight of the 31 patients (26%). Time to appearance and total prevalence of central necrosis did not differ in the standard versus hyperfractionated therapy groups. The time between diagnosis and the appearance of necrosis correlated with length of survival (P = .005, Kendall correlation). CONCLUSION: In a substantial number of patients, central necrosis in pontine gliomas is not caused by radiation therapy but is an indication of an advanced tumor stage. Children with central necrosis at diagnosis have a significantly shorter median survival than do those without, regardless of the type of therapy administered.

Brain Neoplasms↗
PubMed1992

Factors influencing platelet serotonin uptake in essential hypertension.

In a study of the mechanism(s) of platelet serotonin uptake alteration in essential hypertension, a total of 90 blood samples were analysed for platelet count and platelet serotonin uptake. These included 20 blood samples each of hypertensives, controls before and after cross-incubation experiments and 10 samples of hypertensives after control of blood pressure. It was observed that serotonin uptake was markedly reduced in hypertensive platelets. Diminished serotonin uptake in essential hypertension correlated directly with diastolic and mean arterial blood pressure and inversely with plasma total cholesterol values. In cross-incubation experiments using control platelets and hypertensive plasma, there was a significant reduction in platelet serotonin uptake (303.06 +/- 86.28 cpm/10(8) vs. 204.26 +/- 66.45 cpm/10(8); P less than 0.001), whereas hypertensive platelets when incubated with control plasma, showed increased serotonin uptake (233.50 +/- 75.19 cpm/10(8) vs. 312.64 +/- 79.54 cpm/10(8); P less than 0.01). Upon control of blood pressure, the platelet serotonin uptake improved significantly (205.45 +/- 70.0 cpm/10(8) vs. 266.77 +/- 61.68 cpm/10(8); P less than 0.05-0.01). From these results, it appears that reduced platelet serotonin uptake in essential hypertension is a reversible phenomenon probably governed by the presence of plasma factor(s) and/or altered platelet-membrane function.

Adult↗
PubMed1991

Stroke as a late sequela of cranial irradiation for childhood brain tumors.

Cerebrovascular disease involving large and medium-size vessels is thought to be an uncommon sequela of treatment of childhood brain tumors. We reviewed 11 children who developed cerebrovascular disease manifested by strokes or transient ischemic attacks 6 months to 4 years after treatment of brain tumors, while their tumors were in remission. All had received radiation therapy, and seven had received chemotherapy. One child died of acute bilateral cerebral infarctions due to carotid occlusion on one side and marked stenosis on the other 2 years after receiving radiation therapy for an incompletely resected craniopharyngioma. Pathologically, there was marked subendothelial fibrosis of the vessels of the circle of Willis, with inflammatory changes surrounding some of the vessels. In addition to the widely recognized small-vessel damage caused by radiation and chemotherapy in children (mineralizing microangiopathy), damage to medium and large intracranial vessels may result in late sequelae, manifested by stroke or transient ischemic attacks.

Adolescent↗
PubMed1985

Combination chemotherapy with cyclophosphamide, vincristine, procarbazine, and prednisone (COPP) in children with brain tumors.

The chemotherapeutic combination of cyclophosphamide, vincristine, procarbazine, and prednisone (COPP) was used to treat 15 children with recurrent central nervous system tumors and seven children with newly diagnosed brainstem tumors. In patients with recurrent tumors, marginal activity was seen in various histologic types. COPP chemotherapy was clearly ineffective in patients with brainstem tumors. Toxicity consisted of mild to moderate myelosuppression and neurotoxicity.

Adolescent↗
PubMedDate not supplied

Modified cephalic vein guide wire technique for permanent pacemaker implantation.

This report describes a modified cephalic vein guide wire technique used for implantation of 18 consecutive pacemakers using bipolar leads. The modified technique appears to be a safe and simple procedure for single chamber permanent pacing. Its use may also be extended in implanting dual chamber pacemakers.

Adult↗
PubMedDate not supplied

Use of captopril as an isolated agent for the management of stable angina pectoris--a double blind randomised trial.

In this double blind randomised placebo controlled study, we investigated the antianginal efficacy of oral captopril in 33 patients of angiographically documented coronary artery disease (chronic stable angina). Apart from sublingual nitrates, all other antianginal drugs were withdrawn. Patients were then evaluated both subjectively by questionnaire and objectively by treadmill stress test. No patient had more than mild hypertension and all patients had good left ventricular function. One group of patients received oral captopril while the other group was given placebo. A repeat assessment was done after six weeks and the results compared with baseline. Anginal attacks decreased from 20.11 +/- 1.86 per week on placebo to 9.92 +/- 1.38 (p < 0.01) on captopril as also the number of sublingual nitrates (18.84 +/- 3.01 to 11.14 +/- 2.94, p < 0.01). Assessment by the treadmill stress test showed that in comparison to the pretreatment test, captopril therapy resulted in a significantly increased exercise duration (6.26 +/- 0.21 to 6.98 +/- 0.31 minutes, p < 0.05), total work done (6.76 +/- 0.26 METS to 7.48 +/- 0.29 METS, p < 0.05). In addition there was a significant increase in time to angina (6.16 +/- 0.18 to 6.85 +/- 0.24 min, p < 0.05) and time to 1mm ST depression (5.18 +/- 0.26 to 6.46 +/- 0.30 min, p < 0.01). We conclude that captopril is an effective monotherapy for patients with chronic stable angina and has both antianginal as well as anti-ischemic effects, possibly secondary to direct coronary vasodilation.

Aged↗
PubMedDate not supplied

The efflux of nor-epinephrine from platelets in genetic hypertension.

Platelets have been used as a model of sympathetic neurons to study the storage of nor-adrenaline in normotensive individuals belonging to families with essential hypertension for at least two generations. The efflux and initial efflux rate (K) of noradrenaline was determined in 36 young relatives (mean age 29.2 years) and in 20 young controls with no family history of hypertension (mean age 26.5 years). From the groups of relatives all those with definite hypertension had been excluded. Efflux and efflux rate K was significantly higher in young relatives (50.82 +/- 3.84 and 28.2 +/- 6.3) than in the controls (39.2 +/- 0.71 and 15.2 +/- 4.8). Of the relatives 25.2% had higher K values than any of the controls.

Adolescent↗
PubMedDate not supplied

Clinical relevance of vegetations in infective endocarditis.

Two-dimensional echocardiograms of 58 patients with infective endocarditis were examined to determine if presence and/or size of vegetations on echocardiogram were predictive of morbidity and mortality. Group 1 (38 patients) with one or more vegetations, had a significantly higher rate of complications (emboli, congestive heart failure, need for surgery and death) than group 2 (20 patients) without vegetations (p less than 0.001). Analysis of morphologic characteristics of the vegetations in group 1 was of no predictive value for complications in individual patients. In contrast, patients whose echocardiograms demonstrated vegetations on aortic valve had a significantly higher incidence of heart failure, embolisation, surgery and death than those with vegetations on mitral valve. Thus, the detection of vegetations on initial echocardiogram clearly identifies a subgroup at risk for complications, more so if vegetations are present on the aortic valve, but the vegetations size does not predict an adverse clinical outcome.

Adult↗
PubMedDate not supplied

Sites of right ventricular outflow tract obstruction in tetralogy of Fallot--a retrospective study.

Fifty one angiographically proved cases of tetralogy of Fallot (TOF) in the age group of 5-50 years were analysed retrospectively for the level(s) of right ventricular outflow tract (RVOT) obstruction. Mean age was 18.1 +/- 11 yrs. Subvalvular stenosis was found to be the commonest site of RVOT obstruction in 49 (96.1%) patients. Evidence of valvular pulmonary stenosis was seen quite commonly (42/51, 83.9% cases), mostly in association with obstruction at other sites. Supravalvular stenosis was also seen in 17 (33.3%) cases. Higher incidence of pulmonary valvular involvement in patients with TOF, in higher average age of patient population may represent valvular involvement to be an acquired phenomenon.

Adolescent↗
PubMedDate not supplied

The efflux of nor-epinephrine from platelets in essential hypertension.

The precise role of sympathetic nervous system in initiation and/or maintenance of essential hypertension is unclear even today. Platelets have been used as a suitable model for studying neuronal turnover of biogenic amines. The present study comprised of hypertensive subjects (23) and normotensive controls (10). Hypertensive subjects exhibited significantly enhanced norepinephrine efflux from platelets at both 30 minutes and 60 minutes (p less than 0.001). The percent norepinephrine efflux from platelets correlated with diastolic (r = 0.66 and 0.76) and mean arterial blood pressure (r = 0.54 and 0.65) but not with systolic blood pressure. The norepinephrine efflux rate (K) similarly correlated with diastolic and mean arterial blood pressure in hypertensive subjects studied. From the above findings it appears that operative sympathetic nervous system activity is enhanced in essential hypertension. The enhanced efflux of norepinephrine from platelets may also indicate activated state of platelets in hypertension. Both could be important in genesis and complications of essential hypertension.

Adult↗