Search

Myocardial perfusion scintigraphy with adenosine is an effective and safe method for diagnosing coronary artery disease (CAD). Various reports suggest that a 3 min stress regime is as efficacious as a 6 min regime. The aim of the study was to study the tolerance and efficacy of these two regimes. Two hundred and eighty-one patients (100, 6 min; 181, 3 min) had adenosine stressed myocardial scintigraphy. Blood pressures, heart rate and ECG were recorded at baseline and during the test. Any symptoms (flushing, headache, chest pain, dyspnoea and neck pain) were also recorded throughout and for 5 min after the adenosine infusion. 117/281 patients (41.6%) reported side effects including flushing (33% in 3 min vs 45% 6 min, P more...

The conventional method of inducing status epilepticus by injecting pilocarpine 24 h after lithium chloride (LiCl) administration lacks kinetic correlate. Therefore, the present study was conducted to see the effect of altering the time schedule of lithium administration (from 2 to 72 h) on the convulsive behavior in response to pilocarpine challenge in rats. It was observed that reducing the pretreatment time of lithium from 24 to 2 h produced convulsions in 100% of the rats. However, incidence of convulsions decreased when lithium pretreatment time was increased to 48 h and no convulsions were recorded with 72-h lithium time schedule. The neuronal damage assessed histologically and the effectiveness of diazepam was similar irrespective of time schedule. This study provides evidence that LiCl pretreatment schedule can be adopted at any time between 2 to 24 h to suit the convenience and objectives of the experiment. more...

Fifty-five children with short stature were investigated for the aetiology of short stature with special reference to hypothyroidism. Clinical and laboratory parameters including anthropometry were determined to exclude any chronic systemic disorders. Thyroid function tests such as thyroxine (T4) and thyroid stimulating hormone (TSH) estimation by radioimmunoassay, radioactive iodine uptake and thyroid scan, using 131I and perchlorate discharge test, were performed. In addition, growth hormone was estimated under basal conditions and after insulin-induced hypoglycaemia. Thirty-five were boys and 20 were girls. The age at presentation in the boys was 3-12 years whereas in the girls it was 8-13 years. Forty-three of the 55 children had delayed bone age. Abnormal thyroid function was present in 25 children (45.45%). Of these, 11 (20%) had primary hypothyroidism with low or normal uptake, whereas 14 (25.45%) had glands with high uptake of 131I and elevated TSH. Three children with primary hypothyroidism had reduced growth hormone reserve. On follow-up with thyroxine, there was an increase in growth velocity in all. This study indicates that thyroid function tests should be performed routinely in children with undiagnosed short stature. more...

The hepatotoxic effect of oral halothane in the horse is increased by pretreatment with phenobarbitone or DDT but not by chlorpromazine. Phenobarbitone and DDT increase the activity of hepatic amidopyrine N-demethylase but chlorpromazine does not. Carbon disulphide protects the liver of the horse against halothane. more...

Continuous irradiation in utero is reported to produce mental retardation and gross abnormalities of the brain in the human. A few experimental studies conducted so far also report gross brain defects in animals exposed to continuous irradiation in utero. Despite the increasing use of nuclear energy for power and radioisotopes in medicine, there is hardly any literature available on the effect of continuous irradiation on the structural details of the developing brain. After intraperitoneal injections of different doses of 131I (8, 18 and 32 microCi) and 32P (10 microCi) in new-born rats on the 6th postnatal day, cerebella stained by Golgi techniques were cut sagittally and the sections were examined on the 10th, 15th and 21st postnatal days. In the animals injected with 18 and 32 microCi of 131I and 10 microCi of 32P a large number of Purkinje cells showed morphological alterations not seen in the control groups or in the groups injected with 8 microCi of 131I. The changes observed included persistence of the perisomatic processes beyond the 10th postnatal day, multiple primary dendrites, angulation of the primary dendrites, long segments of primary dendrites without branches and significantly reduced dendritic volume. The number of affected cells was less on the 21st postnatal day. The effective radiation dose estimated in these groups ranged from 15 to 26 rad. Since the rats irradiated with 6 rad had not shown such changes it is believed that there is a threshold dose of radiation beyond which only changes are perceptible at neuronal level. more...

By radioisotope technique, we studied the emptying function of the vagotomized intrathoracic stomach after esophagectomy for carcinoma of the esophagus in 24 patients, and compared it with the preoperative emptying function. The patients were randomized into a control group (no pyloroplasty) and a study group (pyloroplasty). Gastric emptying was delayed in both groups, postoperatively; however, the delay was greater in the control group than in the study group. Therefore, vagotomy delays the emptying of the thoracic stomach, and this delay is not completely corrected by pyloroplasty. more...

Vascularity of the thyroid gland was measured in twenty thyrotoxic patients (including Graves and multinodular goitres) and eight normal subjects by a new objective parameter--'Thyroid Vascularity Index' (TVI). The TVI was calculated by comparing the areas under the normalized thyroid and carotid artery curves up to the time of peak of the arterial curve caused by the first passage of a radioactive bolus. Compared to normal thyroid, all the toxic goitres had increased TVI (p less than 0.001); it being maximum in Graves disease (p less than 0.05). TVI in Graves disease was not affected by carbimazole therapy but decreased dramatically in eight out of ten patients (p less than 0.01) two weeks after Lugol's iodine was added. There was a sustained fall in TVI in all the ten patients (p less than 0.001) with chronic iodine therapy up to six weeks without any hormonal escape. TVI in multinodular goitres showed no significance change with carbimazole or iodine therapy. more...

Aplastic anaemia affects the entire bone marrow. Current methods of assessment of bone marrow function, like bone marrow biopsy or peripheral blood examination are either invasive or inadequate and cannot be expected to represent fully the changes in the entire bone marrow tissue. This prospective study was undertaken to develop and standardise a new Nuclear Medicine technique called 'Dynamic Bone marrow Imaging'. Eleven patients and ten controls were studied. Serial images of the pelvis were obtained in frame mode following intravenous injection of 185-370 mBq of 99mTc S. Colloid, and an index, called the Bone Marrow Uptake Index (P) was calculated by taking into consideration the time activity curve obtained over the iliac crest. This was followed by static imaging of the entire bone marrow in all cases. It was possible to obtain excellent information regarding topographic distribution of bone marrow as well as detect early changes in bone marrow function following treatment. An attempt was also made to correlate bone marrow cellularity as obtained by bone marrow biopsy with the results of dynamic bone marrow scintigraphy. On the basis of the encouraging results obtained in the present study, the authors feel that dynamic bone marrow imaging is an excellent technique for the objective evaluation of bone marrow in aplastic anaemia. Aplastic anaemia affects the entire bone marrow tissue. Although much progress has been made in the management of this disease, many aspects of it await better understanding. There is almost total lack of knowledge regarding the distribution of functioning marrow in various phases of aplastic anaemia, such as in relapse and remission. Current methods of assessment of marrow function rely mainly on bone marrow biopsy and peripheral blood examination. Bone marrow biopsy is invasive and cannot be expected to represent fully the changes in the entire tissue. Changes in peripheral blood picture lag behind the changes in the bone marrow. Thus, there is a need for an investigation which is safe, simple, sensitive, non invasive and capable of assessing the global function of bone marrow. Radio-nuclide imaging of bone marrow requires labelling of one or more components of this widely dispersed tissue. The reticuloendothelial and erythropoietic components can be labelled with radio-colloids and radio-iron respectively. Experimental studies have shown that the reticuloendothelial and erythropoietic elements are invariably found together in the marrow and have similar distribution. This report is based on a prospective study of bone marrow function in patients with aplastic anaemia, using 99mTc. Sulphur colloid. more...

From 1983-88, 157 patients were investigated in our clinic for thyroid disorders: 117 (75%) were hypothyroid, 10 (6%)-hyperthyroid, and 30 had euthyroid goiters. Average age of presentation of congenital hypothyroids was 4.07 years. Children with goitrous hypothyroidism (n = 19) were divided into: (i) thyroiditis: RAIU low and patchy, TMA positive: 2 children; (ii) dyshormonogenesis: RAIU high, family history positive, perchlorate discharge test positive: 2 children; (iii) iodine deficiency: RAIU high, urinary iodine low: 2 children, and (iv) cause unknown: RAIU normal or high, other investigations normal: 13 children. Ninety eight hypothyroid children without goiter were divided into 6 groups: (i) athyreosis: RAIU low, no thyroid tissue identifiable (n = 39); (ii) hypoplasia: RAIU low, gland small, in normal position (n = 7); (iii) ectopia: RAIU low, gland in ectopic position (n = 24); (iv) thyroiditis: TMA positive (n = 2); (v) iodine deficiency: low urinary iodine (n = 1); and (vi) cause unknown: RAIU and scan normal, other investigations normal and not done (n = 8). Proportionate short stature was present in 44.4% children. Twenty two children presented only with growth failure; 72% of them had dysgenetic glands. Early onset marked the group with hyperthyroidism (n = 10). Euthyroid goiter was present in 30 (19%). Hypothyroidism is still being diagnosed very late. All children with growth failure, even if proportionate, must have thyroid status evaluated. more...

Fifty-six patients with complex ventricular premature beats (Lown grade IVa, IVb), but no evidence of ventricular tachycardia on 48 hours of continuous monitoring were evaluated by programmed electrical stimulation. Thirty patients had coronary atherosclerotic heart disease, 3 had valvular heart disease, 2 had cardiomyopathy and 21 had no structural heart disease. Programmed stimulation identified two groups of subjects: Group I comprised 11 patients in whom ventricular tachycardia was induced and Group II comprised 45 patients (which included 21 patients without heart disease) in whom no ventricular tachycardia was induced. The incidence of left ventricular dysfunction (ejection fraction less than 40%) was significantly higher in Group I as compared to Group II (P less than 0.001). There was, however, no difference between the grade of ventricular ectopy, HV interval or the incidence of bundle branch block between the 2 groups. Patients with inducible ventricular tachycardia (Group I) were put on laboratory directed anti-arrhythmic drug therapy. Patients without inducible tachycardia (Group II) were not given anti-arrhythmic therapy. The patients were followed up for 34 +/- 10 months. The incidence of sudden death (36.3% vs 6.6%, P less than 0.001) was significantly higher in Group I as compared to Group II. No patients without structural heart disease died during the follow-up. Programmed electrical stimulation fails to induce ventricular tachycardia in patients with complex ventricular ectopy but no structural heart disease. It is, however, possible to define a high risk subset in patients with structural heart disease and complex ectopy. The high risk patients with inducible ventricular tachycardia do not seem to benefit by anti-arrhythmic drugs, which may independently increase the risk of sudden death in treated patients. Patients in whom ventricular tachycardia is not inducible have better left ventricular function, a good long-term prognosis and do not require anti-arrhythmic agents. more...

A prospective study was conducted in 25 patients with essential hypertension to study the effects of sublingual administration of nifedipine on some renal functions. Glomerular filtration rate was estimated by radioisotope clearance techniques using Tc-99m diethylene triamine pentaacetic acid (DTPA). The change in urinary excretion of sodium and uric acid were also monitored. A basal estimation of these parameters was followed by repeat studies after lowering the blood pressure to normotensive levels by sublingual administration of nifedipine. It was observed that acute administration of nifedipine does not produce a significant change in the glomerular filtration rate, but causes marked and significant natriuresis and uricosuria. more...

Summary. Mice given daily i.p. injections of immunoglobulins against ovine LH on Days 3\p=n-\7of pregnancy were devoid of implantation sites on Day 8 whereas mice treated with antibodies to hCG had embryos of normal number and appearance on Day 8. These antibody treatments reduced the mean \m=+-\s.d. serum progesterone concentrations from 65\m=.\4\m=+-\15\m=.\3ng/ml (control globulins) to 8\m=.\6\m=+-\4\m=.\9ng/ml (anti-LH) and 9\m=.\2\m=+-\3\m=.\1ng/ml (anti-hCG) on Day 8 and had no differential effect on serum oestrogen levels on Day 4. However, the mice treated with anti-hCG did not litter; resorption of the embryos took place between Days 10 and 14 of pregnancy. Indirect immunofluorescence and quantitative immunoenzymic assays showed the presence of anti-ovine LH and anti-hCG reacting antigens in the mouse feto-placental unit. On Day 6, the values of reacting antigens (mean \m=+-\s.d. absorbance units/10 \g=m\m section of embryo) were 0\m=.\050\m=+-\0\m=.\002with control globulins, 0\m=.\059\m=+-\0\m=.\002with anti\x=req-\ hCG-Ig and 0\m=.\196 \m=+-\ 0\m=.\018with anti-LH-Ig; the corresponding values on Day 12 were 0\m=.\075\m=+-\0\m=.\009,0\m=.\402 \m=+-\0\m=.\02and 0\m=.\416\m=+-\0\m=.\015.The quantitative disposition of the reacting antigens to the two types of anti-gonadotrophins seems to bear a temporal relationship to their respective antifertility action. The pregnancy terminating action of immunoglobulins to ovine LH (Days 6, 7 & 8) and hCG (Days 8, 9 & 10) was counteracted by administration of 2 mg medroxyprogesterone acetate on Days 6, 9 and 12, indicating the importance of progesterone in the maintenance of pregnancy in the mouse. more...

The study was undertaken to assess the usefulness of transplant perfusion index (TPI) in the differential diagnosis of renal allograft dysfunction with special reference to acute rejection. It was observed that the TPI has a sensitivity of 100 per cent and specificity of 98.1 per cent in the diagnosis of acute rejection. It was also observed that the serial values of TPI provided valuable clues and guide in the management of transplant dysfunction and helped in the immediate and long term follow-up of patients with renal allografts. more...

Undernutrition of the newborn rats, produced during the first 3 weeks by increasing the litter size and restricting the mother's diet, resulted in reduction of the body and brain weights of the experimental animals. One group of undernourished animals showed especially severe reduction of body and cerebellar weights. These animals, on the 10th postnatal day, had an immature cerebellar cortex corresponding to that of the 7th day postnatal control animals. The external granular layer persisted in the cerebellar cortex of the underweight animals until the 23rd day, while it disappeared by 20th day in the control animals. Mitotic activity was evident until the 21st postnatal day in these animals while it stopped in the normal animal by 16th postnatal day. There was no marked difference in the fine structure of the various cell types in the control and undernourished animals. Midsagittal tracings of the cerebellar cortex showed a reduced surface area in the undernourished animals, while the thickness of the external granular layer and molecular layer did not show any significant difference when compared to that of the control animals, thus showing a reduction in total cell number, but not per unit area. The normal morphological appearance of the cerebellar cortex in the un-derfed animals of higher weight probably indicates that these animals are adequately nourished in spite of the reduction in weight when compared to the control animals, which probably are overfed. more...