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Biomedical subjects

M Tellez

Publications and source records attributed to M Tellez.

16 recordsLinked to original sources
PubMed1992

Graves' ophthalmopathy in relation to cigarette smoking and ethnic origin.

OBJECTIVE: We aimed to study the effect of cigarette smoking on the prevalence and severity of Graves' ophthalmopathy (GO). PATIENTS: One hundred and fifty-five newly diagnosed patients with Graves' disease (GD) were diagnosed clinically and by routine biochemical methods. Twenty-five per cent (39) were of Asian origin. METHODS: Eye signs were classified according to the American Thyroid Association Classification. A detailed smoking questionnaire and data from hospital notes were used to calculate an index of cigarette consumption. RESULTS: Thirty-four per cent of all patients had Graves' ophthalmopathy, and the prevalence in males (26%) and females (36%) did not differ significantly. There was a prevalence of 42% among Europeans compared to 7.7% in Asians (P = 0.0002). The overall risk for Europeans for developing Graves' ophthalmopathy was 6.4 (1.78-22.7 confidence interval) times higher than for Asians. Corrected for the ethnic factor the increased risk from smoking for Europeans was 2.4 (1.12-5.18, 95% confidence interval) times higher. There was a significant dose effect (P = 0.008). CONCLUSIONS: The present findings confirm an effect of cigarette smoking on Graves' ophthalmopathy and in addition show that Europeans have a substantially greater risk of developing Graves' ophthalmopathy than have Asians.

Adolescent↗
PubMed1991

A five year audit of the role of parathyroid hormone assays and thallium-technetium isotope subtraction scanning in the preoperative investigation of primary hyperparathyroidism.

An audit has been performed of the value of parathyroid hormone assays and thallium-technetium isotope scanning in the pre-operative investigation of 67 hypercalcaemic patients referred for surgery over a 5 year period. Parathyroid hormone assay by region-specific technique was found to have a diagnostic sensitivity of 75% (n = 52) whilst the more recent assay for the intact molecule was 97% sensitive (n = 34). Thallium-technetium isotope scanning was only 64% sensitive overall (n = 59), due in part to the small size of adenomata now being referred for surgery. This study confirms the role of the intact parathyroid hormone assay but questions that of thallium-technetium isotope scanning in standard protocols of investigation for hypercalcaemia.

Adult↗
PubMed1990

Comparison of fine needle aspiration cytology, radioisotopic and ultrasound scanning in the management of thyroid nodules.

In 175 patients presenting with thyroid nodules, the diagnostic value in management of fine needle aspiration and cytology (FNAC), pertechnetate (99mTc) scanning and ultrasound imaging was examined. In 82 patients, the diagnosis was confirmed at operation; in the remaining 93, there was a follow-up period of at least 2 years. Thyroid cancer was found in 13 patients. For FNAC the sensitivity, specificity and positive predictive value for thyroid cancer were 92%, 85% and 41% respectively compared with 82%, 34% and 11% for 99mTc pertechnetate scanning, 75%, 61%, 19% for ultrasound and 73%, 58% and 19% for combined pertechnetate and ultrasound scanning. In 14% of patients, the aspirates were inadequate for cytology at the first examination. FNAC is therefore the preferable initial investigation and usually gives results adequate for a decision on surgical or medical management. With medical management and follow-up, ultrasound is of value in defining the nodule and the appearance of the rest of the gland.

Biopsy, Needle↗
PubMed1988

Hyperthyroidism and thyroid cancer.

Ten of 502 patients presenting with thyroid cancer were hyperthyroid due to Graves' disease (4 patients), multinodular goitre (3), an autonomous functioning nodule (1) and a large functioning tumour (2). In addition eight patients had a past history of Graves' disease and four of hyperthyroidism associated with multinodular goitre. Mortality in patients with Graves' disease and with multinodular goitre appeared similar to that of other patients of comparable age. Both patients with large functioning tumours died from progressive disease. Concentration 131I by tumour metastases was present in one patient with active Graves' disease who had a high serum concentration of TSH-receptor binding antibodies, indicating that these antibodies may chronically stimulate tumour function. The potential for 131I concentration by tumour when TSH secretion is suppressed should therefore be determined in patients with Graves' disease and if demonstrable tumour function is present, reflecting stimulation by Graves' immunoglobulins, then elimination of tumour remnants is particularly important.

Adult↗
PubMed1988

Skeletal blood flow, iliac histomorphometry, and strontium kinetics in osteoporosis: a relationship between blood flow and corrected apposition rate.

In 20 untreated patients with idiopathic or postmenopausal osteoporosis, kinetic studies of skeletal blood flow (using 18F) and bone turnover (using 85Sr) were combined with dynamic histomorphometry performed on transiliac biopsies taken within 6 weeks of each other. In 8 patients the combined studies were repeated after treatment. A further 5 patients were studied only while receiving treatment. As expected, skeletal blood flow measured by 18F correlated with an index of 85Sr uptake into the exchangeable pools of bone. Additionally and independently, skeletal blood flow correlated with an index of the work rate of the osteoblasts in each multicellular unit of bone (the corrected apposition rate of Parfitt). These correlations were statistically significant in both the untreated patients (P less than 0.05) and the whole group (P less than 0.001). Further indices related to bone turnover at the level of the skeleton as a whole were significantly associated with skeletal blood flow only in the combined group.

Aged↗
PubMed1987

Estimation of whole body bone resorption rate: a comparison of urinary total hydroxyproline excretion with two radioisotopic tracer methods in osteoporosis.

In 37 female patients with primary osteoporosis, urinary hydroxyproline excretion, determined in 18 24-h consecutive complete urine collections was compared with two radioisotopic measurements of bone resorption rate measured simultaneously using 85Sr. A somewhat better fit was obtained when the kinetically determined bone resorption rate was corrected for long-term exchange processes within bone. Regression analysis showed that the intercept of the regression of hydroxyproline excretion on resorption rate, corrected or uncorrected for exchange, was significantly higher than zero at about 100 mumol/day. This is consistent with a substantial fraction of urinary hydroxyproline arising from non-bony sources. Fifteen paired studies were analysed and the results suggested that intra-individual variability in these relationships (when studies were separated by a year or more) were similar to inter-individual variability. We calculated the precision with which an estimate of bone resorption could be determined based on the calculated regressions. As a means of non-invasive quantitation of whole body bone resorption rate, the excretion rate of hydroxyproline, measured over 5 days, for example, appeared competitive with isotopic methods making no correction for exchange and relatively little worse than our exchange corrected method.

Aged↗
PubMed1987

The assessment of bone formation and bone resorption in osteoporosis: a comparison between tetracycline-based iliac histomorphometry and whole body 85Sr kinetics.

Bone formation and resorption have been measured in patients with idiopathic osteoporosis by histomorphometry of 7.5-mm trephine biopsies and in the whole body by 85Sr radiotracer methodology and calcium balances. The studies were synchronized and most were preceded by double in vivo tetracycline labeling. Correlations between histological and kinetic bone formation indices were better when better when based on the extent of double tetracycline labels than on measurements of osteoid by visible light microscopy. Correction of the kinetic data for long-term exchange, using 5 months' serial whole body counting of retained 85Sr, improved the fit of the kinetic to the histological data. A statistical analysis of the measurement uncertainties showed that the residual scatter in the best correlations (between exchange-corrected bone formation rates and double-labeled osteoid surface indices) could be attributed to measurement imprecision alone. The exchange-corrected resorption rate correlated fairly well with iliac trabecular resorption surfaces, and using a volume referent rather than a surface referent for the histological index improved the statistical fit when patients with therapeutically accelerated bone turnover were included. A much better correlation was obtained by including osteoid volume acting as an independent predictor of bone resorption in a bivariate regression with a resorption surface index. The residual errors could then be accounted for by known measurement uncertainties. Whereas osteoid taking a double label closely predicted the kinetic rate of bone formation, further analysis suggested that osteoid that took no label or a single label was more closely related to bone resorption, presumably as a secondary result of the coupling of bone formation to bone resorption. The idea that continued bone loss in some patients is associated with defective osteoblastic bone formation is supported by the low rates found in some patients by both techniques. Heuristically these studies validate both in vivo tetracycline labeling for dynamic histomorphometry and corrections for long-term exchange in kinetic studies of bone formation, providing a quantitative framework for the design and analysis of future studies of bone remodeling in the osteoporoses.

Adult↗
PubMed1987

Skeletal blood flow in metabolic disorders of the skeleton.

Results are presented of measurements of skeletal blood flow made in 80 patients with painful benign or malignant diseases of the skeleton, excluding patients with Paget's disease. In crush fracture osteoporosis, total bone blood flow was slightly lower than normal although skeletal perfusion was normal. High values of bone blood flow were seen in 14/20 patients with osteomalacia and 3/12 patients with primary hyperparathyroidism. Very high values, comparable to those seen in the most severely affected patients with Paget's disease, were seen in polyostotic fibrous dysplasia, 2 out of 4 cases of Engelmann's disease and 1 out of 3 cases of renal osteodystrophy. Results were less elevated in myositis ossificans, secondary skeletal involvement with breast and prostatic carcinomata, myelomatosis and sympathetic osteodystrophy.

Adolescent↗
PubMed1987

Periodic courses of human 1-34 parathyroid peptide alternating with calcitriol paradoxically reduce bone remodelling in spinal osteoporosis.

In an attempt to achieve an anabolic response in both axial and peripheral bone, we treated twelve patients with osteoporosis using human 1-34 parathyroid peptide given discontinuously. The peptide was given as seven daily subcutaneous injections followed by 21 days' treatment with 0.25 mg calcitriol orally. This regime was repeated cyclically for at least sixteen cycles, of which the first four were at a lower dose of hPTH 1-34 than used subsequently. The results of treatment were monitored by kinetic, densitometric, histomorphometric and biochemical studies performed before and during treatment. Two patients developed hPTH 1-34 binding in their plasma during treatment: this was presumed to be due to the development of antibodies. The remainder, instead of increasing their indices of bone turnover as judged by iliac bone histomorphometry, were found to have consistent reductions in trabecular resorption surfaces. The other indices of bone formation and resorption measured showed no change or comparable reductions. The small increases seen in total body calcium were consistent with 'in-filling' of deleted basic multicellular units (BMUs). Because there is no evidence that calcitriol alone causes comparable reductions in activation of bone remodelling in osteoporosis, interruption of treatment with hPTH 1-34 after 7 days may have led to a failure of the activation mechanism to proceed to the resorption stage, with a consequent overall reduction in remodelling activity. This type of treatment regime, with its calcitonin-like effect, might be effective in reducing net bone loss due to imbalance between bone formation and resorption at the BMU level, particularly in patients with increased numbers of BMUs ('high turnover' osteoporosis).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1987

Trabecular and cortical bone in the radii of women with parathyroid adenomata: a greater trabecular deficit, with a preliminary assessment of recovery after parathyroidectomy.

Radial bone mineral content (BMC) has been reported to be lower than normal in patients with hyperparathyroidism, but those measurements have been made with techniques which do not discriminate between trabecular and cortical bone. We have used a low radiation dose computed tomography technique to make differential measurements of trabecular and cortical bone in the radii of 18 out of 27 eligible female patients with surgically proven adenomata. Prior to parathyroidectomy there was a mean deficit of 40% (P less than 0.001) in trabecular bone density in the distal radius, and a deficit of 16% in cortical bone in the radius mid-shaft compared to normal values. Seventeen months after parathyroidectomy there was a small but significant increase in trabecular bone density in the distal radius in 13 of these patients, and no significant change in cortical bone. If these results represented the situation throughout the skeleton, it is possible that parathyroidectomy may provide some reduction in future risk of fracture in women with primary hyperparathyroidism.

Adult↗
PubMed1986

In-vivo studies of a human-thyrotrophin preparation.

The effects on thyroid function of a new preparation of human thyrotrophin (hTSH) were studied in four subjects whose endogenous production of TSH had been suppressed by administration of thyroxine (T4). The hTSH, prepared from human cadaveric pituitary glands and highly purified using a monoclonal antibody technique, was given as an intravenous bolus of 2 i.u. hTSH. Serum TSH levels rose rapidly to a maximum of about 150 mu./l and then declined exponentially with a half-life of 100 min. After injection, the hTSH distributed rapidly in a volume averaging about 13 litres which corresponded approximately to the expected extracellular fluid volume of the subjects. Serum free tri-iodothyronine and free T4 rose significantly, reaching a maximum between 4 and 8 h after injection of hTSH; serum thyroglobulin was not altered significantly. The rise of thyroid pertechnetate uptake, a measure of the thyroid iodide uptake, occurred later, being only slightly increased at 8 h after administration of hTSH and reaching a maximum at 24 h.

Adult↗
PubMed1985

Radiation-induced osteochondroma-like lesion in young rat radius.

To investigate the effects of radiation on the perichondrial groove of Ranvier in osteochondroma development, the external surface of the distal growth plate of the radius in both forelimbs of 30 ten-day-old rats was exposed to a single low dose of radiation (150 r), which was focused on the perichondrial groove. This induced the formation of a chondrocyte nest at the proximal external edge of the growth plate (five to nine days after irradiation). With advancing longitudinal growth of the bone, the chondrocyte nest occupied a diaphyseal position. At nine to 11 days the chondrocyte nest underwent endochondral ossification. At 13-15 days, this osteochondroma-like lesion began to regress with the disappearance of the chondrocyte nest. After 19-21 days, only an irregularly thickened cortical bone remains at the osteochondroma site. Although the possible role of the growth plate subjacent to the irradiated perichondrial groove must be taken into account, the continuity between the perichondrial groove and the osteochondroma, which is separated from the growth plate by the periosteal ring (bone bark), suggests that the perichondrial groove was involved in osteochondroma-like lesion development.

Animals↗
PubMedDate not supplied

[Infiltrating transitional carcinoma of the bladder (I). Comparison of 2 groups treated with preoperative radiotherapy (long-term protocol and short-term protocol) + radical cystectomy versus radical cystectomy only. Analysis of local recurrence and metastasis].

We analyze our experience in 175 patients with transitional bladder cancer for whom radical cystectomy was indicated. Patients were divided into three groups: one group was managed with radical cystectomy only and the other two with pre-operative radiotherapy: long-term approach and short-term approach. No significant differences have been observed when comparing current survival rate and disease-free intervals of all three groups. It can be deduced from our series that, by the scarce number of local recurrences observed, there is no other measure to be added to surgery directed to improve the tumour's local management. Most metastasis were diagnosed within 18 months after cystectomy. 58.4% patients presented bone dissemination. The risk of distant dissemination increases with the extent of vesical wall invasion, degree of anaplasia and presence of positive glands. The gland stage is not necessary for the metastasis to be present. Death's ratio with distant dissemination is significantly lower in the group managed Without pre-operative radiotherapy than in the others. Of the 11 patients where no tumour was observed in the cystectomy piece, 2 developed metastasis, indicating that this was already present before bladder extraction. Management of patients with infiltrating++ bladder cancer is complex, but no efforts should be spared to advise the most appropriate approach for each particular case. Chemotherapy plays an unquestionable role among the procedures we have to control, since most patients' deaths happen within two years after local-regional treatment of the primitive tumour and nearly all of them as a consequence of metastasis. Cytostatic agents are the only effective therapy for distant dissemination. We believe that every patient with a cancer extended to the perivesical fat or with dissemination to regional glands, whichever the stage, should be treated with chemotherapy after extirpation of the bladder, and starting as early as the patient's general status would allow it.

Actuarial Analysis↗
PubMedDate not supplied

[Primary necrotizing cellulitis of the scrotum in a diabetic patient].

Necrosing infections of subcutaneous cell tissue are uncommon processes which constitute a diagnostic and therapeutic vital emergency. Generally secondary to anorectal or genitourinary processes, a small percentage of these infections have no apparent cause. This paper presents one case of primary necrosing cellulitis in a diabetic patient. Etiological and diagnostic aspects are discussed, outlining the need of an aggressive surgical attitude as the only valid therapeutic offer.

Aged↗