Dysgenesis of thyroid is the common type of childhood hypothyroidism in environmentally iodine deficient areas of north India

Forty-five children (28 girls and 17 boys; mean age 4.5 years) with hypothyroidism referred to us from January 1989 to November 1990 were evaluated prospectively for the pattern of hypothyroidism by hormone assays, scintiscan and urinary iodine estimation. Among the 6 children from non-endemic areas, athyreosis and/or hypoplasia were seen in 3, ectopia in 2 and dyshormonogenesis in 1. Of 39 children from moderate to severe environmentally iodine deficient regions, 18 (46%) had athyreosis and/or hypoplasia and 10 (26%) ectopic thyroid. Iodine deficiency was seen in 4, dyshormonogenesis in 4, secondary/tertiary hypothyroidism in 2 and thyroiditis in 1. The mean age of these children at the onset of symptoms was 1.4 years and at clinical presentation 4.5 years. There was significant growth retardation with 54% of children being below the 5th centile of Indian standards. There was no significant difference in the age at onset of symptoms and presentation, clinical features and bone age for the different types. The levels of serum total T4 were significantly low in dysgenesis (athyreosis, hypoplasia and ectopia, p < 0.001). Dysgenesis of the thyroid is the most common type of childhood hypothyroidism in iodine deficiency endemias. We postulate that severe iodine deficiency in the intrauterine and early neonatal period may lead to dysgenesis of the thyroid.

Thoracic stomach: comparative evaluation of endoscopy, gastric aspirate analysis and hepatobiliary scintigraphy in the diagnosis of duodeno-gastric reflux

Twenty patients with thoracic stomach were subjected to hepatobiliary scintigraphy for the diagnosis of duodenogastric reflux. The results of the radionuclide studies were correlated with those of endoscopy and biochemical estimation of total intragastric bile acid. Hepatobiliary scintigraphy was found to be more sensitive (91.6%) and accurate (95%) than endoscopy (25% and 55% respectively) and biochemical estimation of total intragastric bile acid content (66.6% and 80% respectively). Being noninvasive and physiological, radionuclide study appears suitable for routine clinical use in the diagnosis of duodeno-gastric reflux.

Radionuclide detection of gastroesophageal reflux in children suffering from recurrent lower respiratory tract infection

Radionuclide gastro-esophageal scintigraphy was performed on 25 control and 183 children suffering from recurrent lower respiratory tract infection. Gastro-esophageal reflux (GER) of varying grades was observed in 135 patients. The severity of clinical symptoms in the patients was found to be directly related to the severity of reflux observed in the radionuclide study. In some patients an attempt was also made to quantitate GER by calculating the Gastro-esophageal reflux index. The results of the scintigraphic study were correlated with the results of the other commonly used and more conventional Barium swallow and fluoroscopy study. Gastro-esophageal scintigraphy was found to be much superior in terms of sensitivity, specificity and accuracy in detecting GER. It was also possible to objectively evaluate and monitor response to treatment following conservative or corrective surgical therapy using the radionuclide technique. The results of the study demonstrated a remarkably high incidence of GER in the patients. Whether GER is the cause of recurrent lower respiratory tract infection or not is difficult to establish firmly. But within the preview of the study the association seems to be very strong and cannot be easily ignored.

Effect of Lugol's iodine on the vascularity of thyroid gland in hyperthyroidism

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.

Emptying of the intrathoracic stomach with and without pyloroplasty

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.

Significance of transplant perfusion index in the diagnosis of acute rejection in live related renal allograft recipients

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.

Profile of thyroid disorders in a referral centre in north India

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.

Effects of acute administration of nifedipine on glomerular filtration rate and urinary excretion of sodium and uric acid in patients with mild-moderate essential hypertension

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.

Evaluation of thyroid function in children with undiagnosed short stature in north India

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.

Effect of internal irradiation on the maturing Purkinje cells in the rat. A Golgi study

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.

Serendipity in technetium-99m DTPA renal dynamic study

A nine-year-old child was referred for a routine renal dynamic study to detect a renal and/or renovascular cause for hypertension. Tc-99m DTPA renography accidentally discovered and correctly localized a pheochromocytoma.

Marrow uptake index (MUI): a quantitative scintigraphic study of bone marrow in aplastic anaemia

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.

Prognostic implications of complex ventricular ectopy in patients with and without structural heart disease. A study based on programmed electrical stimulation

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.

Hepatobiliary scintigraphy in congenital cystic dilatation of biliary tract

Six preoperative and five postoperative hepatobiliary scans in children having cystic dilatation of the biliary tract were analyzed. The preoperative hepatobiliary scans revealed three distinct patterns. The type 1 pattern showed, in early scans, good hepatic uptake of radioactivity, and photon deficient area(s) around the porta hepatis or in the subhepatic region. These area(s) showed progressive accumulation of radio activity in the delayed scans. The type 2 pattern revealed poor hepatic uptake, nonvisualization of major biliary channels, and photon deficient area(s) in the porta hepatis or subhepatic region which persisted throughout the study. Preoperatively, it was possible to diagnose cystic dilatation of biliary tract in cases that showed type 1 and type 2 patterns. No preoperative diagnosis was possible when the scans showed a type 3 pattern. Analysis of results revealed a correct pre-operative diagnostic rate of 83.3% for the cystic dilatation of biliary tract. It was also possible to provide correct functional information regarding the patency of the bile outflow tract in all 11 cases, both pre- and postoperatively, with a diagnostic rate of 100%. On the basis of the overall accuracy of results obtained in this series, hepatobiliary scintigraphy is strongly advocated in suspected cases of cystic dilatation of the biliary tract for the initial diagnosis and for the assessment of the status of the bilioenteric bypass postoperatively.

Evaluation of quantitative sacroiliac scintigraphy for the early detection of sacroiliitis

Quantitative sacroiliac scintigraphy (QSS) was evaluated for the detection of sacroiliac (SI) joint disease before the appearance of radiographic/changes. QSS with fractional quantitation was done in 13 age- and sex-matched controls and 28 patients with different grades of radiographic sacroiliitis. The SI index of each joint was considered separately. The mean SI index values in patients with grade I radiographic sacroiliitis (1.54) and HLA-B27 positive patients with low back pain (1.50) were significantly (P less than 0.01) higher than the mean SI index of controls (1.22); but more than 50% of their SI index values were within the 97.5% confidence limits of the control range. The mean SI index values of patients with grade II (1.38) and grade III (1.34) radiographic sacroiliitis did not differ significantly from the mean SI index of controls (P greater than 0.05). Thus a large overlap between the normal and abnormal ranges of sacroiliac ratios limits the utility of quantitative sacroiliac scintigraphy for the early diagnosis of sacroiliac joint disease.

Role of radio-aerosol and perfusion lung imaging in early detection of chronic obstructive lung disease

The efficacy of radio-aerosol and perfusion lung imaging in the early detection of chronic obstructive lung disease was evaluated in 38 subjects. The subjects included 5 non-smokers, 21 smokers with minimal or no respiratory symptoms and 12 patients with chronic obstructive lung disease. Each subject consented to a respiratory questionnaire, detailed physical examination, chest X-ray examinations, detailed pulmonary function tests and 99mTc-radio aerosol-inhalation lung imaging. Perfusion lung imaging with 99mTc-labelled macroaggregated albumin was performed in 22 subjects. A significant correlation (P less than 0.001) was observed between the degree of abnormalities on radio-aerosol imaging and pulmonary function tests (PFTs) including forced expiratory volume in 1 s, maximum mid-expiratory flow rate and mean transit time analysis. Abnormal radio-aerosol patterns and deranged PFTs were observed in 21 subjects each. Of 21 subjects with abnormal radioaerosol pattern 8 had normal PFTs. Of 21 subjects with abnormal PFTs 8 had normal aerosol images. Aerosol lung images and PFTs were abnormal more frequently than perfusion lung images. The results suggest that radio-aerosol lung imaging is as sensitive an indicator as PFTs for early detection of chronic obstructive lung disease and can be usefully combined with PFTs for early detection of alteration in pulmonary physiology in smokers.

Ultrastructural observations in experimental hydrocephalus in the rabbit

Changes in the ependyma and periventricular brain tissues of the lateral, 3rd and 4th ventricles and the cervical spinal canal were studied electron-microscopically in young rabbits on the 9th day after injecting kaolin into the cisterna magna. The ependyma of the lateral ventricle overlying the white matter was notably stretched causing increased egress of CSF and disorganisation of the normal architecture of the white matter and capillaries. The neurons and glial cells close to the white matter showed edematous changes. The changes in the ependymal lining and the underlying grey matter were less severe in the dorsal part of the 3rd and the 4th ventricle. The ventral part of the 3rd ventricle was the least affected. The height and the arrangement of the ependymal cells, the surrounding grey matter with narrow interstitial spaces and the absorbing tanycytes seemed to be factors which were responsible for the minimal changes in these regions. The changes appeared to be reversible if the CSF pressure was relieved at this stage. The spinal canal remained unaffected in the majority of our hydrocephalic animals, which could probably be attributed to the type of animal and the degree of hydrocephalus.