Chronotherapeutics: are there meaningful differences among antihypertensive drugs?

In the past decade, many publications have dealt with the possible relationship between biological rhythms and the incidence of cardiovascular events. A high proportion of treated hypertensive patients have cardiovascular complications, and chronotherapy, which permits the use of drugs that are maximally effective at different points in the circadian cycle, may be an interesting and valuable approach to decreasing morbidity and mortality in these patients. This article summarizes current knowledge on the new science of chronopharmacology, as demonstrated in several clinical studies that have used conventional agents administered at various points in the circadian cycle as well as new chronotherapeutic agents, such as controlled onset extended release (COER)-verapamil. In addition, emphasis is given to a rigorous evaluation of antihypertensive agents in terms of efficacy and duration of effect to obtain adequate and sustained lowering of blood pressure over the 24-hour period.

Human pancreatic islet quality control: easy assessment of metabolic functions

We describe simplified and rapid methods to assess islet function with the aim to develop better protocols for islet isolation and to determine islet characteristics before transplantation. These methods are also useful in the assessment of the potentially beneficial or deleterious effects of compounds added to the culture media in stimulation experiments. To this end, we took advantage of the multiscreen assay system produced by Millipore SA. This 96-well unit allowed the free-floating culture of islets on filter membranes, the rapid vacuuming and collection of conditioned media or reaction buffer and thus successive testing of the same number of islets, possibly at different culture times. We estimated islet viability by determination of the metabolic activity of cells, normal function of islets by their ability to metabolize glucose and to synthesize and secrete insulin and of nitrite release, a reflection of nitric oxide (NO) status of cells, which may be involved in a signaling pathway during glucose-stimulated insulin secretion or in cytokine inducible pathway. Assays may be performed either on selected islets or on aliquots of semi-purified preparations designated for grafting, allowing thus the rapid estimation of graft function of the entire preparation. This herein described system may be also extended to many other functional tests.

[Relationship between corticotropin and arginine vasopressin in endocrine diseases]

VASOPRESSIN: The action of vasopressin (AVP) is not limited to regulating water excretion but also plays an essential role in regulating the corticotropic axis during stress. PHYSIOLOGY: Vasopressin is synthesized in the hypothalamus and stored in the posterior pituitary. It acts on 3 types of receptors (RV). RV1a are vascular receptors mediating the vasoconstrictor and glycogenolytic effects of the hormone. Anterior pituitary RV1b or V3 mediate stimulating effects on the corticotropic axis. Renal RV2 regulate water and urea excretion. Hypothetical extrarenal RV2 would be responsible for the vasodilator and procoagulant effects of the hormone. MODIFICATIONS IN ENDOCRINE DISEASES: Pituitary or adrenal hypocorticism syndromes include hyponatremia with secondary plasma hypoosmolality and reduced glomerular filtration due to the direct effect of glucocorticoids and also the effect of vasopressinism. Certain endogenous hypercorticisms appear to be related to an overexpression of RV: in ACTH-independent Cushingís syndrome, adrenal overexpression of eutopic RV1a, and in ACTH-dependent Cushingís syndrome, pituitary overexpression of eutopic RV1b or ectopic RV2. In addition, inappropriate secretion of antidiuretic hormone is frequent after transphenoidal surgery, particularly for corticotropic adenomas. DYNAMIC TESTS: The physiological response of ACTH and also AVP to corticotropin releasing hormone (CRH) in the petrous sinus, the unusual responses of certain corticotropic tumors to dDAVP, or certain forms of ACTH-independent hypercortisolism to lysine vasopressin (LVP) suggest excessive or ectopic expression of RV in corticotropic or adrenal cells: tumorgenesis of these cells could also depend, at least partially, on AVP.

Changes in serum amylase, lipase and leukocyte elastase during diabetic ketoacidosis and poorly controlled diabetes

Diabetic ketoacidosis (DKA) is frequently associated with pancreatic enzyme abnormalities. In order to determine the main factors that lead to this increase, serum total amylase (TA), pancreatic amylase (PA), lipase (L) and leukocyte elastase (LE), an early predictor of acute pancreatitis, were measured in four groups of patients on admission. Group 1 consisted of 52 patients with DKA (age: 41.9 +/- 19.2 years; blood glucose (Glc): 27.4 +/- 11.5 mmol/L; pH: 7.20 +/- 0.16; plasma bicarbonate: 10.5 +/- 6.2 mmol/L; blood urea nitrogen (BUN): 0.60 +/- 0.44 g/L; HbA(1C): 12.5% +/- 2.8%). Group 2 consisted of 90 patients with poorly controlled non-ketotic diabetes (age: 53.4 +/- 16.0; Glc: 14.3 +/- 0.6; HCO(3)(-): 26.6 +/- 3.2; BUN: 0.38 +/- 0.20; HbA(1C): 11.3 +/- 2.1). Group 3 consisted of 22 patients with well-controlled diabetes (age: 53.7 +/- 12.8; Glc: 10. 1 +/- 5.2; HCO(3)(-): 27.4 +/- 3.8; BUN: 0.36 +/- 0.19; HbA(1C): 6.8 +/- 0.8). Group 4 (controls) comprised 27 non-diabetic patients (age: 46.0 +/- 15.0; Glc: 4.9 +/- 0.5; HCO(3)(-): 28.4 +/- 2.5; BUN: 0.30 +/- 0.16; HbA(1C): 5.2 +/- 0.7) (means +/- SD). Increased enzyme activities were more frequent in group 1 (TA: 30.7; PA: 27.0; L: 36.5; LE: 73%) than in groups 2 (TA: 8.9; PA: 7.1; L: 8.9; LE: 45. 5%), 3 (TA: 13.6; PA: 9.0; L: 18.1; LE: 31.8%) and 4 (TA: 7.0; PA: 3. 0; L: 0.0; LE: 29.6%). Mean serum enzyme activities were significantly different in the 4 groups (ANOVA, P < 0.01) and were higher in group 1 than in groups 2, 3 and 4 (Student's t-test; group 1 vs 2 or 3 or 4: P < 0.001). In groups 1 + 2 + 3 + 4 (all patients), the four enzymes correlated with one another and also with Glc, BUN and HCO(3)(-) (P < 0.001). In group 1, TA correlated negatively with HCO(3)(-) (P < 0.001) and pH (P < 0.05); PA and L correlated positively with Glc and BUN (P < 0.01) and negatively with HCO(3)(-) (respectively, p < 0.01 and 0.05). PA correlated positively with pH (P < 0.01); LE correlated with Glc (P < 0.05) and BUN (P < 0.01). In conclusion, this study suggests that the serum levels of pancreatic enzymes increase with the degree of diabetic disequilibrium, and mainly correlate with metabolic factors such as hyperglycaemia, dehydration and acidosis. Increased pancreatic enzyme activities in patients with DKA, even in combination with abdominal pain, should not be diagnosed as acute pancreatitis; this could be important, particularly for younger clinicians.

Second generation of the automated Cobas Amplicor HCV assay improves sensitivity of hepatitis C virus RNA detection and yields results that are more clinically relevant

The first and second generations of the Cobas Amplicor HCV assay were compared among patients at risk of hepatitis C virus (HCV) infection. The second-generation test was found to be of greater sensitivity and of good specificity among clinical specimens containing HCV RNA of different genotypes. Finally, this new test is shown to predict the outcome of interferon therapy better.

[Atrial natriuretic hormone and endocrine functions]

The atrial natriuretic hormone (ANP) is a cardiac hormone which gene and receptors are widely present in the body. Its main function is to lower blood pressure and to control electrolyte homeostasis. Its main targets are the kidney and the cardiovascular system but ANP interacts with many other hormones in order to regulate their secretion. The adrenal glands are the first endocrine target. Steroidogenesis, especially mineralocorticoid synthesis, is inhibited by ANP, but glucocorticoid production seems to be depressed too. As ANP synthesis is enhanced by the latter, it suggests a regulatory loop. Moreover ANP inhibits the thyroid synthesis whereas its production is enhanced by thyroid hormone. The hypothalamo-hypophyseal axis is another important target. ANP inhibits ACTH release and arginine vasopressin secretion. Vasopressin enhances ANP synthesis while GH decreases it. Finally the endocrine effects of ANP strengthen the cardiovascular and renal effects of the hormone, antagonizing the salt and water retention due to aldosterone and AVP. Because of a local production, ANP may also act as a paracrine hormone that influences the function of many endocrine systems (ovarian function for instance). In the central nervous system, ANP acts as a neurotransmitter in order to regulate pituitary and vegetative functions. Plasma ANP levels are impaired in several endocrine diseases : the plasma hormone levels increase in hypercortisolism, hyperaldosteronism, thyrotoxicosis and inappropriate antidiuretic hormone secretion; it decreases in hypothyroidism. In case of Addison's disease, ANP may be used to assess the quality of mineralocorticoid treatment, in association with the other biological criteria.

Transient pseudo-hypoaldosteronism following resection of the ileum: normal level of lymphocytic aldosterone receptors outside the acute phase

Pseudo-hypoaldosteronism (PHA) is due to mineralocorticoid resistance and manifests as hyponatremia and hyperkalemia with increased plasma aldosterone levels. It may be familial or secondary to abnormal renal sodium handling. We report the case of a 54-year-old woman with multifocal cancer of the colon, who developed PHA after subtotal colectomy, ileal resection and jejunostomy. She was treated with 6 g of salt daily to prevent dehydration, which she stopped herself because of reduced fecal losses. One month later she was admitted with signs of acute adrenal failure, i.e. fatigue, severe nausea, blood pressure of 80/60 mmHg, extracellular dehydration, hyponatremia (118 mmol/l); hyperkalemia (7.6 mmol/l), increased blood urea nitrogen (BUN) (200 mg/dl) and creatininemia (2.5 mg/dl), and decreased plasma bicarbonates level (HCO3-: 16 mmol/l; N: 27-30). However, the plasma cortisol was high (66 microg/100 ml at 10:00 h; N: 8-15) and the ACTH was normal (13 pg/ml, N: 10-60); there was a marked increase in plasma renin activity (>37 ng/ml/h; N supine <3), active renin (869 pg/ml; N supine: 1.120), aldosterone (>2000 pg/ml; N supine <150) and plasma AVP (20 pmol/l; N: 0.5-2.5). The plasma ANH level was 38 pmol/l (N supine: 5-25). A urinary steroidogram resulted in highly elevated tetrahydrocortisol (THF: 13.3 mg/24h; N: 1.4+/-0.8) with no increase in tetrahydrocortisone (THE: 3.16 mg/24h; N: 2.7+/-2.0) excretion, and with low THE/THF (0.24; N: 1.87+/-0.36) and alpha THF/THF (0.35; N: 0.92+/-0.42) ratios. The number of mineralocorticoid receptors in mononuclear leukocytes was in the lower normal range for age, while the number of glucocorticoid receptors was reduced. Small-bowel resection in ileostomized patients causes excessive fecal sodium losses and results in chronic sodium depletion with contraction of the plasma volume and severe secondary hyperaldosteronism. Nevertheless, this hyperaldosteronism may be associated with hyponatremia and hyperkalemia suggesting PHA related to the major importance of the colon for the absorption of sodium. In conclusion, this case report emphasizes 1) the possibility of a syndrome of acquired PHA with severe hyperkalemia after resection of the ileum and colon responding to oral salt supplementation; 2) the major increase in AVP and the small increase in ANH; 3) the strong increase in urinary THF with low THE/THF and alpha THF/THF ratios; 4) the normal number of lymphocytic mineralocorticoid receptors outside the acute episode.

Noninvasive imaging of insulinomas and gastrinomas with endoscopic ultrasonography and somatostatin receptor scintigraphy

BACKGROUND

Classic morphological techniques are of limited value for imaging endocrine duodenopancreatic tumors, and invasive procedures such as intraarterial stimulation are often used. Two noninvasive procedures, endoscopic ultrasonography (EUS) and somatostatin receptor scintigraphy (SRS), were recently described with promising results.

METHODS

In this study we correlated the results of preoperative EUS (n = 34) and SRS (n = 30) with operative findings in patients with histologically proven insulinoma (n = 20) or gastrinoma (n = 21).

RESULTS

The sensitivity and positive predictive value (PPV) of EUS were respectively 77% and 94% for pancreatic tumors (insulinomas and gastrinomas), 40% and 100% for duodenal gastrinomas, and 58% and 78% for metastatic lymph nodes. The sensitivity and PPV of SRS for insulinoma were 60% and 100%, respectively. In patients with gastrinoma, the sensitivity and PPV of SRS were respectively 25% and 100% for pancreatic gastrinomas, 72% and 100% for duodenal gastrinomas or periduodenal metastatic lymph nodes, and 67% and 80% for liver metastasis. In patients with multiple endocrine neoplasia, neither one of the two techniques detected all tumors. Overall sensitivity of combined EUS and SRS was 89% for insulinoma (n = 9) and 93% for gastrinoma (n = 14).

CONCLUSIONS

EUS and SRS for gastrinomas and insulinomas should be considered as the initial preoperative imaging procedures and may render invasive procedures unnecessary for most patients.

Intraoperative insulin measurement during surgical management of insulinomas

Intraoperative hormonal measurements have been used successfully to guide the surgical treatment of various endocrine diseases. In this study, we report the results of intraoperative insulin measurement (IIM) in patients with organic hypoglycemia. IIMs were performed during 52 operations in 51 patients. Hyperinsulinism was secondary to a sporadic insulinoma (M = 40), a type I multiple endocrine neoplasia (MEN-I) (M = 8), an insulin-secreting carcinoma (M = 1), or pancreatic nesidioblastosis (M = 2). The insulin was measured with a radioimmunologic assay in blood samples simultaneously drawn from a peripheral vein and the portal vein at the beginning of the operation (T1) and 20 minutes after tumor removal (T2). Normoglycemia was achieved after surgery in 50 cases (96%). Systemic and portal insulin levels were normal at T1 in eight patients, precluding any further interpretation of the test. Completeness of surgery was confirmed by normalization of both systemic and portal insulin levels at T2 in 36 patients. In seven cases the systemic or portal insulin levels (or both) remained elevated at T2 despite a favorable outcome after surgery. Failure of the surgical procedure was predicted in two patients by the persistence of high levels of insulin at T2. In patients with initially elevated serum insulin levels, the positive predictive value and the specificity of intraoperative insulin measurement for completeness of surgery were both 100%. The sensitivity was 84%, the negative predictive value 22%, and the accuracy of the test 84%. We concluded that IIM is a simple, highly reliable tool for predicting the completeness of surgery in patients with organic hypoglycemia. IIM appears to be a valuable addendum to the surgical armamentarium against insulinoma especially for patients with atypical causes, such as MEN, insulin-secreting carcinoma, or pancreatic nesidioblastosis.

Essential hypertension: first reason for persistent hypertension after unilateral adrenalectomy for primary aldosteronism?

BACKGROUND

Despite cure of primary aldosteronism by surgical resection, hypertension persists postoperatively in 30% to 50% of patients. The aim of this study was to determine factors influencing long-term outcome of blood pressure after unilateral adrenalectomy for primary aldosteronism.

METHODS

Records of 100 patients who underwent unilateral adrenalectomy for primary aldosteronism from 1970 through 1997 were reviewed. Patients were distributed in 2 groups according to whether blood pressure was normal (criteria of World Health Organization). Clinical, biochemical, and pathologic data were compared.

RESULTS

All patients were biochemically cured. Blood pressure was normal in 56 patients and improved in 44 (mean follow-up, 69 and 59 months). Persistent hypertension correlated with age, known duration and seriousness of preoperative hypertension, family history of hypertension, no preoperative response to spironolactone, and contralateral adrenal hypertrophy. Gender, surgical approach, and pathologic findings were not predictive factors of blood pressure outcome. The prevalence of hypertension was almost the same in these postoperative patients as the prevalence of essential hypertension in a random population of the same age.

CONCLUSIONS

Early unilateral adrenalectomy allows cure or improvement of hypertension in all patients with primary aldosteronism induced by unilateral excessive source of aldosterone secretion regardless of the pathologic findings. Persistent hypertension suggests that coexisting essential hypertension is present.

Immunohistochemical detection of glycoprotein hormone alpha subunit in somatoprolactinic and pure somatotroph adenomas

Glycoprotein hormone alpha subunit (alpha SU) is expressed in nearly all thyreotroph adenomas and most gonadotrophinomas, but is less well documented in plurisecreting adenomas. We therefore examined the immunohistochemical (IHC) expression of alpha SU in a generally accepted model of plurisecreting adenomas (somatoprolactinic type) by comparison to a series of pure monosecreting somatotroph tumors. Fifty patients (32 females, 18 males) aged 15 to 68 years with clinical and/or biological acromegaly requiring adenomectomy were studied. Forty-five had clinical acromegaly and 5 had isolated amenorrhea and/or galactorrhea syndromes. Forty-eight of the 49 patients who had baseline assessments of plasma GH had a mean concentration of 5 ng/ml or more (normal value < 5). Fifteen of the 46 patients who had baseline measurements of plasma PRL had a prolactinemia value greater than 20 ng/ml (normal value < 20) but below 100 ng/ml, except for one patient. All the adenomas studied were positive by GH immunohistochemistry; 21 were immunostained by an antiPRL antibody and formed the "somatoprolactinic" (GH-PRL) group. Five of these 21 patients were male. The 12 female patients younger than 50 years had amenorrhea or galactorrhea, and one male patient complained of impotence. Eleven patients (9 females, 2 males) in this GH-PRL group had hyperprolactinemia. Sixteen of these GH-PRL adenomas were immunolabeled by alpha SU antiserum. The remaining 29 adenomas, which were immunonegative with the PRL antibody and formed the "somatotroph adenoma" (GH) group, were more frequent in male patients (13/29; 45%) compared to GH-PRL group. Eight amenorrhea or galactorrhea syndromes occurred among the 14 women younger than 50 years, 3 of whom had hyperprolactinemia. Thirteen of these 29 adenomas (45%) were immunopositive with alpha SU antibody. Compared to the GH group, the GH-PRL group had a significant higher frequency of amenorrhea and/or galactorrhea syndromes among women under 50 years (100% vs 57%; p < 0.01), as well as hyperprolactinemia (55% vs 15%; p < 0.01) and positive alpha SU immunoreactivity (76% vs 45%; p < 0.05). The frequency of extrasellar macroadenomas was not different according to PRL or alpha SU immunoreactivity. Thus, in this series of somatoprolactinic adenomas, alpha SU immunopositivity was slightly more frequent than in a control group of pure somatotroph adenomas. Moreover, hyperprolactinemia was more frequent in patients with GH-PRL adenomas, although the size of the pure and mixed adenomas was not different. These results suggest that hyperprolactinemia and/or alpha SU immunopositivity are more often associated with mixed GH-PRL adenomas.

Factors related to utilization of services for mental health reasons in Montreal, Canada

This study examines factors related to the utilization of services for mental health reasons by Montreal residents. Data were drawn from telephone interviews. A random sample of 893 respondents completed a questionnaire on service utilization and the Diagnostic Interview Schedule Self Administered to assess DSM-III-R psychiatric disorders. Results indicate that 12.8% of the population had used such services in the past year. Medical doctors and psychiatrists, whose services are free of charge under universal health coverage, were consulted, respectively, by 4.1% and 2.0% of respondents. Psychologists, whose services are not free, were seen by 3.4% of respondents. In all, 42.0% of respondents who presented a current diagnosis used services in the past year. The highest proportion of users (48.0%) was found among respondents who presented both current and lifetime diagnoses and among respondents with comorbidity. The choice of caregiver was related also to pattern of disorders: respondents with current and comorbid disorders tended to consult general practitioners, while respondents with lifetime disorders or with lifetime and current disorders favoured specialized care. In line with other studies, self-perception of mental health, gender and marital status were related to utilization; unlike other studies, attitudes and age were not. It is argued that particularities found in this study stem not only from methodological considerations, but also from the configuration of the mental health system in Quebec, where the greater availability of psychologists may facilitate service utilization.

Comparative effects of felodipine ER, amlodipine and nifedipine GITS on 24 h blood pressure control and trough to peak ratios in mild to moderate ambulatory hypertension: a forced titration study

OBJECTIVE

To evaluate the 24 h antihypertensive efficacy and duration of action of felodipine extended release (ER) in comparison with two other long acting dihydropyridine calcium antagonists, amlodipine and nifedipine gastrointestinal therapeutic system (GITS), in patients with mild to moderate essential hypertension substantiated by ambulatory blood pressure (BP) monitoring.

DESIGN

Randomized, forced titration, parallel group study. Clinic BP was measured at every patient's visit, and 24 h ambulatory BP was monitored at baseline and at the end of each dose-titration period.

SETTING

Single centre: hypertension research unit in Quebec City, Quebec.

PATIENTS

There were 89 patients enrolled into the study. Eighty-four eligible patients were randomized, and 83 completed the study and were included in the final efficacy analysis.

INTERVENTIONS

Following a two-to four-week washout period (baseline), patients were randomly allocated to receive felodipine ER 5 mg, amlodipine 5 mg or nifedipine GITS 30 mg for four weeks (low dose). All study patients had their daily dose doubled to felodipine ER 10 mg, amlodipine 10 mg or nifedipine GITS 60 mg for a further four weeks (high dose).

MAIN RESULTS

Significant (P < 0.001) and similar changes from baseline in clinic BP were observed in all treatment groups for low and high doses. Ambulatory BP profiles showed comparable blood pressure reductions with felodipine ER and amlodipine, and a trend towards a lesser reduction with nifedipine GITS during 24 h, daytime and night-time periods. BP loads were similarly reduced with the three treatments. Trough to peak ratios (T:Ps) were calculated from 24 h ambulatory BP curves according to two different approaches: for diastolic and systolic BP, respectively, the global approach produced T:Ps of 0.49 and 0.50 with felodipine ER 5 mg; 0.50 and 0.34 with felodipine ER 10 mg; 0.70 and 0.60 with amlodipine 5 mg; 0.88 and 0.82 with amlodipine 10 mg; 0.65 and 0.55 with nifedipine GITS 30 mg; 0.68 and 0.53 with nifedipine GITS 60 mg. T:Ps in the individual approach were 0.07 and 0.10 with felodipine ER 5 mg; 0.23 and 0.31 with felodipine ER 10 mg; 0.22 and 0.31 with amlodipine 5 mg; 0.45 and 0.58 with amlodipine 10 mg; 0.27 and 0.31 with nifedipine GITS 30 mg; and 0.24 and 0.40 with nifedipine GITS 60 mg.

CONCLUSION

There was no evidence in this study of a difference among felodipine ER, amlodipine and nifedipine GITS in lowering ambulatory or clinic BP. Treatment based on ambulatory BP may be preferable to treatment guided by T:Ps because ambulatory BP is firmly established as a predictor of cardiovascular risk. Furthermore, there is no consensus on how to calculate T:Ps, and different methods of calculation may give divergent results.

Coxsackie B virus infection and beta cell autoantibodies in newly diagnosed IDDM adult patients

BACKGROUND

Environmental agents such as viruses have been identified as potentially important determinants of insulin-dependent diabetes mellitus (IDDM). Enterovirus infections, Coxsackievirus B especially, could be linked to the beta cell damaging process and to the onset of clinical IDDM.

OBJECTIVES

Enteroviral (EV) infection and beta cell autoimmunity were studied in adult patients at the onset of IDDM.

STUDY DESIGN

A total of 14 newly diagnosed-IDDM patients with ketosis or ketoacidosis were compared to, anteriorly diagnosed IDDM patients with metabolic decompensation, non-IDDM patients with metabolic decompensation and healthy adults. EV infection was studied by genomic RNA detection in whole blood using a RT-PCR assay. In order to assess the level of beta cell autoantibodies at the time of the initial metabolic decompensation, serum specimens from IDDM patients were tested for GAD65 antibodies and islet cell antibodies (ICAs).

RESULTS

Coxsackie B3 or B4 virus genome was detected and genotyped in five of 14 (35.7) newly diagnosed IDDM patients and in one of 12 (8%) patients in the course of IDDM. By contrast, none of the 12 non-IDDM patients and none of the 15 healthy adults was positive for enterovirus RNA detection in whole blood. Positive GAD65 antibodies and ICAs assays were not significantly correlated to a positive EV-RNA detection.

CONCLUSION

The present study demonstrates that Coxsackie B virus RNA sequences can be detected in the peripheral blood from adult patients at the onset or in the course of IDDM and suggests that a Coxsackie B virus infection could initiate or accelerate beta cell autoimmune damaging process.

Urinary cortisol metabolites in the assessment of peripheral thyroid hormone action: overt and subclinical hypothyroidism

Biological assessment of peripheral thyroid hormone action may be important in subclinical hypothyroidism, where decision-making is often difficult. The impairment of urinary cortisol metabolites in overt hypothyroidism reflects an acquired 11 beta hydroxysteroid dehydrogenase (11 beta OHSD) deficiency, and is assessed in terms of a reduction in the tetrahydrocortisone (THE)/tetrahydrocortisol (THF) ratio or THE/THE + alpha THF ratio; the alpha THF/THF ratio reflects 5 beta reductase activity. The aim of this study was to determine if urinary cortisol metabolite ratios are a good index of peripheral thyroid hormone action in subclinical hypothyroidism.

MATERIALS AND METHODS

the THE/THF, THE/THF + alpha THF and alpha THF/THF ratios were measured in 24 h urine samples from 3 groups of subjects: 1) 18 euthyroid subjects; 2) 25 patients with elevated serum TSH and low FT4 levels (overt hypothyroidism); and 3) 25 patients with increased serum TSH and normal FT4 levels (subclinical hypothyroidism.

RESULTS

7/25 overtly and 5/25 subclinically hypothyroid patients had a THE/THF + alpha THF ratio below the mean control value -2 SD, while respectively 20/25 and 11/25 patients had a THE/THF ratio below the mean control value -2 SD. The mean THE/THF + alpha THF, THE/THF and alpha THF/THF ratios were significantly different among the 3 groups (ANOVA) and were lower in the overtly hypothyroid group than in the other two groups (Fisher's test); daily urine sodium output was also significantly different between the three groups and lower in the overtly and subclinically hypothyroid groups than in the control group (Fisher's test). FT3 and FT4 both correlated with THE/THF + alpha THF in the overtly hypothyroid patients (r = 0.43; p < 0.05 and r = 0.40; p < 0.05, respectively). In the subclinically hypothyroid patients, TSH correlated with THE/THF + alpha THF (r = 0.44; p < 0.05) and THE/THF (r = 0.43; p < 0.05). FT3, FT4 and TSH levels correlated with THE/THF + alpha THF (p < 0.001), THE/THF (p < 0.001), alpha THF/THF (p < 0.001) and daily natriuresis (p < 0.05) in the whole population (patients + controls). In conclusion, urinary cortisol metabolites, although impaired in overt hypothyroidism, are not an accurate index of peripheral thyroid hormone deficiency in subclinical hypothyroidism. We also identified an increase in the alpha THF/THF ratio in overt hypothyroidism, which may be related to 5 beta reductase disturbances.

Effects of pH and salt environment on the association of beta-lactoglobulin revealed by intrinsic fluorescence studies

The effects of pH, ionic strength and heat on the structure of beta-lactoglobulin (beta-lg) have been investigated by studying the intrinsic tryptophan fluorescence of the protein. Between pH 2 and 9, for sodium chloride concentrations varying from 0.0 to 0.2 M, the position of the fluorescence emission maximum at 20 degrees C remained constant at 328 nm, suggesting that the hydrophobic environment of the fluorophores remained unchanged. The fluorescence intensity increased significantly at pH 2, 7 and 9 on reducing the NaCl concentration of the solutions. The most likely explanation for this, supported by recent light scattering data, is that the presence of NaCl is necessary for beta-lg to dimerize. At the higher NaCl concentrations it was found that dimerization accompanied a reduction in fluorescence intensity. Thus, dissociation appears to reduce the self-quenching of tryptophan residues that occurs within the dimer. The fluorescence of solutions heated below the denaturation temperature reflected the state of association of the protein molecules. Above the denaturation temperature and associated with protein aggregation, an irreversible increase in intrinsic tryptophan fluorescence was observed. We also report what we believe to be the first front-face fluorescence measurements on globular protein gels, showing effects of pH and NaCl concentration.

Prevalence of chlamydial infection and frequency of risk behaviours for STDs and HIV infection among adolescents in public juvenile facilities in the province of Quebec

This study aimed to determine the prevalence of chlamydial infection in adolescents entering public juvenile facilities in the province of Quebec and the frequency of their risk behaviours for STDs and HIV infection. Adolescents were asked to complete an anonymous self-administered questionnaire and to be screened for Chlamydia trachomatis. Of 731 sexually active adolescents, 62% agreed to be tested. The overall prevalence rate was 7.7% (95% confidence interval: 5.1%-10.3%). The prevalence was significantly higher in female than in male teenagers: 12% vs 3% (p < 0.001, Fisher's exact test). These results suggest that screening for chlamydial infection should be offered to all sexually active female teenagers admitted into juvenile facilities. For males, selective screening taking into account sexual history would be a more realistic approach. The frequency of high risk activities for STDs and HIV infection points to the importance of specific prevention programs for this population.

[The protein of fibrocystic breast disease--methods of measurement and clinical implications]

The gross cystic disease of the breast has been reported to be associated with a two to fourfold increased breast cancer risk. The cyst fluid contains several hormones and proteins among whom we have isolated and characterized one of these proteins with an estimated molecular weight at 17.4 kilodaltons (Gross Cystic Disease Fluid Protein-17 kDa or GCDFP-17). A specific antiserum against GCDFP-17 was produced and an enzyme-linked immunosorbent assay (ELISA) was perfected to obtain a simple and sensitive method for the study of the GCDFP-17. This protein is also stimulated by androgens in vitro like in vivo and is a potential marker of an androgens' excess. Subsequently, we were able to study 33 ovarian micropolycystic syndromes (OPCS) with a biological hyperandrogenism (Hyperandrogenic Group or GH) compared with 32 control women (GT). The body mass index (BMI) of GH was significantly greater than that of G.T. (29.8 +/- 9.3 vs 21.3 +/- 2.7 kgs/m2--p. < 0.01). The mean plasma value of testosterone (T), delta 4-androstenedione (delta 4-A), dehydroepiandrosterone sulfate (SHDA) and the ratio of T. on sex binding protein (SBP) or free testosterone index (ITL) were significantly greater in GH than in GT (p < 0.01). Despite the circulating excess of androgens in GH, there were no significant differences for GCDFP-17 between the 2 groups (G.H. = 222 +/- 74 vs G.T. = 230 +/- 84 ng/ml) and any correlation between plasma androgens and GCDFP-17 (p < 0.05). Nevertheless, the androgens' excess in G.H. was clearly smaller than that which was seen with the doses of potent androgens used in the treatment of metastatic breast cancer.

Detection of coxsackie B virus RNA sequences in whole blood samples from adult patients at the onset of type I diabetes mellitus

Enteroviruses may be linked to insulin-dependent diabetes mellitus (IDDM). The prevalence of enteroviral (EV) infection at onset of adult IDDM was investigated by detection of specific EV sequences in peripheral blood using a reverse transcription and a seminested polymerase chain reaction (seminested RT-PCR). EDTA-treated whole blood samples taken from 12 newly diagnosed IDDM patients with ketosis or ketoacidosis were examined. The comparison groups were 12 adult patients suffering from metabolic decompensation in the course of IDDM, 12 adult patients with decompensated non-IDDM, and 15 healthy adults without any presumed EV infection or metabolic disease. EV genome was detected in five of 12 (42%) newly diagnosed IDDM patients and in one of 12 (8%) patients in the course of IDDM. By contrast, none of the 12 non-IDDM patients and none of the 15 healthy adults had EV sequences in whole blood. Subsequent sequencing of the EV PCR products from the six positive patients showed a significant homology with Coxsackie B3 or B4 viruses, and some common patterns were observed among the sequences. The present study demonstrates that Coxsackie B virus RNA sequences can be detected in peripheral blood from patients at the onset or in the course of IDDM and provides evidence for a role for enteroviruses in adult type I diabetes.

Detection of coxsackie B virus RNA sequences in whole blood samples from adult patients at the onset of type I diabetes mellitus

Enteroviruses may be linked to insulin-dependent diabetes mellitus (IDDM). The prevalence of enteroviral (EV) infection at onset of adult IDDM was investigated by detection of specific EV sequences in peripheral blood using a reverse transcription and a seminested polymerase chain reaction (seminested RT-PCR). EDTA-treated whole blood samples taken from 12 newly diagnosed IDDM patients with ketosis or ketoacidosis were examined. The comparison groups were 12 adult patients suffering from metabolic decompensation in the course of IDDM, 12 adult patients with decompensated non-IDDM, and 15 healthy adults without any presumed EV infection or metabolic disease. EV genome was detected in five of 12 (42%) newly diagnosed IDDM patients and in one of 12 (8%) patients in the course of IDDM. By contrast, none of the 12 non-IDDM patients and none of the 15 healthy adults had EV sequences in whole blood. Subsequent sequencing of the EV PCR products from the six positive patients showed a significant homology with Coxsackie B3 or B4 viruses, and some common patterns were observed among the sequences. The present study demonstrates that Coxsackie B virus RNA sequences can be detected in peripheral blood from patients at the onset or in the course of IDDM and provides evidence for a role for enteroviruses in adult type I diabetes.