Evaluation of saliva as an alternative matrix for monitoring plasma Zidovudine, Lamivudine and nevirapine concentrations in Rwanda

Saliva may provide interesting advantages as matrix for compliance measurements, pharmacokinetic studies and therapeutic drug monitoring in resource limited countries. We investigated the feasibility of using saliva for compliance monitoring of zidovudine (ZDV), lamivudine (3TC) and nevirapine (NVP) in 29 HIV-1 infected patients from Rwanda. ZDV, 3TC and NVP drug levels were quantified by an LC/MS-MS method in plasma and stimulated saliva samples and compared using Bland-Altman analysis. Seven patients demonstrated undetectable saliva ZDV levels while five out of these seven also showed no 3TC salivary concentrations. For the other samples, we observed a good agreement between salivary and plasma concentrations of each antiretroviral drug. A significant relation between the difference in saliva and plasma ZDV concentrations and the average ZDV concentration in the two matrices was deduced as follow: y = -380.15 + 1.79 x. The log saliva and plasma concentration difference of both 3TC and NVP was consistent across the range of average log concentration. Overall, we showed large agreement limits suggesting a wide inter patient variability that may result to non-reliable plasma level predictions from saliva drug measurements. Therefore, our results indicate that saliva may serve as a valuable tool only for NVP compliance testing because of its high salivary concentration.     

The influence of treatment of hypercholesterolemic patients with simvastatin on plasma chemotactic activity and adherence of neutrophils

BACKGROUND: there is some evidence to indicate that statins may affect the function of immune and inflammatory cells. This study investigates the influence of short term treatment with simvastatin on plasma chemotactic activity and adherence of polymorphonuclear neutrophils in hypercholesterolemic patients. METHODS AND RESULTS: 20 hypercholesterolemic patients (250-400 mg/dl) were given simvastatin (20 mg daily for 12 weeks). Peripheral blood samples were taken before and after 4 and 12 weeks of the therapy. The percentage of neutrophils adhering to plastic surface coated with albumin was significantly higher when cells were incubated with plasma obtained after 12 weeks of treatment with simvastatin in comparison with plasma collected before the therapy (unstimulated neutrophils: 5.945+/-0.475% vs. 8.155+/-0.96%, P=0.0477, stimulated neutrophils: 39.09+/-4.540% vs. 29.18+/-3.702%, P=0.032). There was a significant negative correlation between adherence of stimulated neutrophils and total cholesterol levels ((r)=-0.2796, 95% CI -0. 4999 to -0.02526, r(2)=0.07817, P=0.032). Migration of neutrophils towards plasma obtained after 12 weeks of treatment with simvastatin was significantly higher than towards plasma collected before the therapy (7.038+/-1.127 vs. 4.505+/-0 618 P=0.0475). CONCLUSION: treatment of hypercholesterolemic patients with simvastatin increases the chemotactic activity of plasma and augments the adherence of human neutrophils.     

The pharmacokinetics of total and unbound concentrations of tenoxicam in synovial fluid and plasma

Tenoxicam is a nonsteroidal antiinflammatory drug with an elimination half-life of 60-80 hours; it is administered once daily. Tenoxicam concentrations were measured in plasma (10 samples) and synovial fluid (6 samples) over a 24-hour dosage interval at steady state in 10 subjects with arthritis who had been taking the drug at a dosage of 20 mg/day for at least 2 weeks. Total tenoxicam concentrations in synovial fluid were always less than those in plasma, and there was little fluctuation in plasma or synovial concentrations over the dosage interval, although there was substantial inter-subject variation in both concentrations. There was a significant relationship between the tenoxicam dosage when expressed as mg/kg of body weight and the average steady-state total concentration of tenoxicam in plasma (r = 0.80, P = 0.006); this accounted for a substantial proportion of the intersubject variation. The mean +/- SD steady-state concentrations in synovial fluid and plasma were 3.9 +/- 1.8 micrograms/ml and 9.2 +/- 3.7 micrograms/ml, respectively, yielding a mean +/- SD synovial fluid: plasma ratio of 0.43 +/- 0.12. Synovial fluid:plasma ratios of total tenoxicam correlated with synovial fluid:plasma ratios of albumin (r = 0.71, P = 0.02). The synovial fluid:plasma ratio of unbound tenoxicam was 0.90 +/- 0.3 (95% confidence interval 0.68-1.11), which was not significantly different from a value of 1 (t = -1.09, P = 0.31).     

Detection of corticosteroid binding globulin in parotid fluids: evidence for the presence of both protein-bound and non-protein-bound (free) steroids in uncontaminated saliva

Corticosteroid binding globulin (CBG) was detected by a specific radioimmunoassay in mixed saliva (25.4 +/- 4.0 micrograms/l, mean +/- SEM) and in pure, uncontaminated parotid fluids (17.4 +/- 2.7 micrograms/l) at resting flow-rates of approximately 500 microliters/min and 50 microliters/gland per min, respectively. In parotid fluids collected at stimulated flow-rates of between 300-1000 microliters/gland per min, CBG could not be detected. This observation suggests the direct flow-rate-dependent transfer/secretion of CBG in saliva. When cortisol was measured (RIA) in dilution experiments in both mixed saliva and parotid fluids using phosphate buffer at pH 7.4 as diluent, a protein-binding effect analogous to that found in plasma samples was observed. However, this effect was abolished if a known CBG inhibitor, phosphate:citrate buffer at pH 4, was used as the diluent in the assay. A bound fraction of cortisol was found in both mixed saliva (14.0 +/- 4.0%) and parotid fluid samples (12.3 +/- 1.3%) by equilibrium dialysis. These findings appear to contradict the currently accepted notion that specific plasma steroid binding proteins, and hence the protein-bound steroids, are absent in uncontaminated saliva; and that their presence in mixed saliva is the consequence solely of contamination by gingival fluid and/or plasma from mouth or gum abrasions. We conclude that both protein-bound and free steroids are present in uncontaminated saliva and that salivary total and plasma free steroid concentrations are not identical.     

Saliva cotinine levels as a function of collection method

Saliva cotinine is commonly used to estimate nicotine intake but laboratories use different methods of collection. In three small trials, comparisons were made between (1) sugar vs. unstimulated saliva production (n=29), (2) wax chewing vs. unstimulated production (n=15) and (3) between two consecutive unstimulated saliva samples (n=10). Sugar-stimulated saliva cotinine scores were 26% below unstimulated levels (p<0.001); correlation between measures was high (r=0.90; p<0.001). Wax stimulated saliva yielded levels 6% below unstimulated (p<0.05; correlation: r="0.98;" p<0.001). No differences were observed between two unstimulated samples taken within a 20-minute period (correlation: r="0.99;" p<0.001). It is postulated that changes in salivary flow can account for the findings.     

Studies of the androgen binding protein in the rete testis fluid of the ram and its relation to sexual season.

An androgen binding protein (ABP) with an electrophoretic mobility (Rf) of 0.56 is present in the rete testis fluid of adult rams. Its steroid specificity was found to be in the following order: 5alpha-DHT, testosterone, oestradiol-17 beta, dehydroepiandrosterone 5beta-DHT, androstenedione, cyproterone, cyproterone acetate, cortisol and progesterone. The characteristics of the ABP are similar to those found for the ABP of the testis and the epididymis of the rat and the rabbit. The concentration of ABP, determined by the dextran-coated charcoal method and sometimes confirmed by the steady-state polyacrylamide gel electrophoresis method, was significantly higher in the breeding season than in the non-breeding season (4.40 +/- 0.98 X 10(-9) M vs. 2.60 +/- 0.62 X 10(-9) M; P less than 0.037). The affinity constant of the ABP was independent of the season (2.45 +/- 0.21 X 10(9) M-1 vs. 2.66 +/- 0.1 X 10(9) M-1; NS). In addition, ABP was positively correlated with 5alpha-DHT (r = 0.506; P less than 0.0009), testosterone (r = 0.445; P less than 0.0003), total protein (r = 0.329; P less than 0.02) and spermatozoa (r = 0.406; P less than 0.006) in the RTF and with blood plasma testosterone (r = 0.584; P less than 0.0001). Furthermore, testosterone and 5alpha-DHT in RTF were positively correlated (r = 0.582; P less than 0.0001). These androgens were also correlated with plasma testosterone (r = 0.262, P less than 0.052 for testosterone in RTF; r = 0.341, P less than 0.018 for 5 alpha-DHT). Total proteins and spermatozoa were found to be positively correlated in the RTF (r = 0.789; P less than 0.0001).     

Acetaminophen does not impair clearance of zidovudine

OBJECTIVE: To determine whether concurrent treatment with acetaminophen and zidovudine impairs clearance of zidovudine, thereby increasing the risk for zidovudine-induced hematologic toxicity. DESIGN: Dose escalation, drug interaction study. SETTING: University clinical research center. PATIENTS: Patients with the acquired immunodeficiency syndrome (AIDS) or advanced AIDS-related complex. INTERVENTIONS: Acetaminophen and 200 mg of zidovudine simultaneously every 4 hours. For 13 patients, the unit dosage of acetaminophen was 325 mg for 3 days; for 8 patients, the dosage was 650 mg for 3 days; and, for 6 patients, the dosage was 650 mg for 7 days. MEASUREMENTS: Zidovudine clearance and production of the glucuronide conjugate of zidovudine were assessed after acetaminophen treatment. MAIN RESULTS: Neither zidovudine clearance nor production of the glucuronide conjugate of zidovudine was impaired after treatment with acetaminophen. Clearance of zidovudine was actually accelerated by 5%, 11%, and 33% with the three acetaminophen regimens, respectively (P = 0.002 by analysis of variance; P = 0.04 for linear trend when changes in the area-under-the-curve for zidovudine were compared). CONCLUSION: Because serum concentrations of zidovudine decrease after the coadministration of acetaminophen, a pharmacokinetic interaction between zidovudine and acetaminophen is unlikely to increase the risk for hematologic toxicity associated with zidovudine.     

Free estradiol, free testosterone, and sex hormone-binding globulin in perimenopausal women

To determine whether menstrual status had an effect on plasma sex hormone-binding globulin (SHBG) capacity and nonprotein-bound estradiol (% free E2) and testosterone (% free T), we measured these as well as plasma FSH, total E2, and T and the MCRs of E2 and T in a group of 78 perimenopausal women. The women were allocated to 4 groups: women with cycles whose plasma FSH level was less than 40 mIU/mL (A; n = 16), women with cycles whose plasma FSH level was greater than 40 mIU/mL (B; n = 19), women who were amenorrheic for less than 1 yr (C; n = 13), and women who were amenorrheic for more than 1 yr (D; n = 30). The mean plasma SHBG values were 51.4 +/- 5.7 (+/- SE), 48.3 +/- 4.3, 45.9 +/- 5.4, and 51.1 +/- 3.7 nM in groups 1-4 respectively, and were not significantly different from one another. The mean % free E2 and % free T values also were not different between the groups. However, the mean total E2 and free E2 (% free E2 X E2/100) concentrations were significantly (P less than 0.05) higher in both groups A and B than in groups C and D. The E2 concentration was also higher in group A than in group B. There were strong correlations between the E2 and free E2 concentrations between the T and free T (% free T X T/100); (P less than 0.0001) concentrations, between SHBG capacity and weight, and between the MCRs of both E2 and T and % free E2 and % free T. In normal women, the menopause is not associated with changes in SHBG or % free steroids. Hence, the measurement of E2 could be used to predict the mass of free E2 in these women.     

A preliminary study on the role of interleukin-1 in chronic lung disease

Pulmonary alveolar macrophages (PAM) obtained by bronchoalveolar lavage in 13 normal individuals, 17 lung cancer patients and 10 patients with chronic obstructive pulmonary disease (COPD) were incubated in vitro for 24 hours. Every specimen was divided into two portions and lipopolysaccharides were used to stimulate PAMs to produce interleukin-1 (1L-1) in one. The levels of 1L-1 in normal subjects were 5547.65 +/- 2420.42 cpm/10(6) cells (stimulated) and 718.46 +/- 472.25 (unstimulated), which were higher than the 2733.20 +/- 1611.17 (stimulated, P less than 0.01) and 327.57 +/- 226.86 (unstimulated, P less than 0.05) in lung cancer patients, but lower than that of 8716.26 +/- 2977.66 (stimulated, P less than 0.05) in COPD patients. The enhanced 1L-1 activity in COPD patients might contributed to the active inflammatory process and tissue destruction of COPD. Our findings that 1L-1 activity in patients with bronchogenic carcinoma was decreased may reflect the local immune deficiency in malignant disease. The release of 1L-1 by PAMs stimulated by smoking was suggested to be associated with the development of COPD, but its role in immune response has to be determined.     

Effect of a hypertonic saline load on plasma concentrations of atrial natriuretic peptide in fetal calves and their dams

Plasma concentrations of atrial natriuretic peptide (ANP) were studied in eight adult non-pregnant cows and in two groups of six chronically catheterized bovine fetuses and their mothers in the eighth month of pregnancy. The first group of fetuses was used for studying the effect of an acute i.v. sodium load (240 mmol NaCl/fetus) on fetal ANP; the second group acted as controls. The mean basal ANP levels in the third-trimester bovine fetus were three to four times higher than maternal values (39.5 +/- 5.5 and 9.4 +/- 0.6 pmol/l respectively; P less than 0.01). Basal maternal plasma ANP levels were twice as high in pregnant cows in the third trimester of pregnancy than in non-pregnant cows (9.4 +/- 0.6 and 4.3 +/- 0.7 pmol/l respectively; P less than 0.05). In response to an i.v. hypertonic saline injection, fetal plasma ANP levels increased significantly (P less than 0.01) to a maximum of 86.7 +/- 17.6 pmol/l 10 min after the injection, and returned to baseline within 60 min after the treatment; during the 20 min following the i.v. sodium load, fetal plasma ANP correlated significantly with fetal plasma sodium concentrations (r = 0.96; n = 12) and with fetal plasma osmolality (r = 0.94; n = 12). No significant changes in maternal ANP values were observed in the two groups of animals. These results suggest that ANP secretion is stimulated during pregnancy in cows, and that, in the bovine fetus, a hypertonic sodium load appears to be a potent stimulus for ANP release.     

A normal population study of human salivary insulin-like growth factor 1 (IGF 1) concentrations from birth through puberty.

Insulin-like growth factor 1 (IGF 1) concentrations in mixed saliva samples, collected from a normal population (n = 327, ranging in age from birth to adolescence), were determined by RIA. Salivary IGF 1 concentrations remained steady over a 24-h period when collected at basal rates, but were diminished in saliva samples collected at a maximally stimulated flow rate. A similar pattern was observed for males and females, when IGF 1 levels in saliva were plotted as a function of age. The pattern was that of low levels in early childhood, rising with age, peaking in puberty and falling again in late adolescence. Salivary IGF 1 measurement differed from plasma measurement in three ways: 1) salivary IGF 1 concentrations (70 +/- 50 pM) were 100- to 200-fold less than plasma IGF 1 levels; 2) salivary IGF 1 levels in age-matched male and female samples were not different outside of pubertal influences; 3) salivary IGF 1 levels in neonates were highly variable with concentrations ranging up to pubertal concentrations. The study provides salivary IGF 1 reference data for a pediatric population.     

PLASMA AND SALIVARY ANDROSTENEDIONE AND DIHYDROTESTOSTERONE IN WOMEN WITH HYPERANDROGENISM

Sensitive radioimmunoassays (RIA) have been developed to measure salivary and plasma androstenedione and dihydrotestosterone levels in normal women, women with polycystic ovaries (PCO) and idiopathic hirsutism, and patients on antiandrogen therapy. There was a highly significant correlation (r = 0.92, P less than 0.001) between the concentration of androstenedione in saliva and the unbound concentration in plasma. The unbound plasma androstenedione was measured in the dialysate by RIA and ranged from 6.0-10.4% of the total concentration. Salivary and plasma androstenedione levels in patients with PCO (185 +/- 72 pg/ml (n = 11) and 3262 +/- 814 pg/ml (n = 12) respectively) and in those with hirsutism (151 +/- 110 pg/ml (n = 25) and 2177 +/- 1096 pg/ml (n = 25) were significantly higher than levels in normal women (78 +/- 30 pg/ml (n = 18) and 787 +/- 355 pg/ml (n = 18). A good correlation (r = 0.82, P less than 0.001) was also found between salivary and unbound plasma dihydrotestosterone concentrations. Salivary and plasma dihydrotestosterone levels in patients with PCO (8.2 +/- 3.3 pg/ml (n = 9) and 167 +/- 45 pg/ml (n = 11) respectively and hirsutism (6.0 +/- 2.1 pg/ml (n = 14) and 176 +/- 69 pg/ml (n = 17) were significantly higher than levels in normal women (4.5 +/- 1.3 pg/ml (n = 17) and 90 +/- 44 pg/ml (n = 16), although there was a large overlap between groups. A similar decrease was observed in salivary and plasma androstenedione levels after treatment with cyproterone acetate (CA) and ethinyl oestradiol (EE) for 3 months. Plasma dihydrotestosterone levels remained elevated in 47% of treated women whereas only 21% of cases had raised salivary dihydrotestosterone levels. It is concluded that, as with testosterone salivary androstenedione and dihydrotestosterone measurements give a good reflection of their biologically active levels in normal, hyperandrogenic and CA + EE treated women.     

Pituitary-adrenal axis activity in treated congenital adrenal hyperplasia: static and dynamic studies.

The pituitary-adrenal axis activity was evaluated in 43 patients, treated for congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency, by measuring plasma ACTH, 17-hydroxyprogesterone (17-OHP), testosterone, and aldosterone. Dynamic studies were performed by injecting 250 micrograms synthetic ACTH im and collecting blood samples 1 h later for steroid analysis. Twelve to fourteen hours after the last hydrocortisone dose given the evening before, plasma ACTH fluctuated widely from less than 10-475 pg/ml, 17-OHP exceeded normal values and varied from 1-275 ng/ml, while testosterone ranged from 3-151 ng/100 ml. The correlations between ACTH and 17-OHP (n equal 61, r equal 0.665, P less than 0.001) and between 17-OHP and testosterone (n = 43, r = 0.761, P less than 0.001) were good, while that between 17-OHP and aldosterone (n = 64, r = 0.512, P less than 0.001) was rather poor. One hour after ACTH injection, the mean level of 17-OHP was significantly increased as compared to the mean basal level [96.8 ng/ml +/- 10.6 (SE) as compared to 67.0 ng/ml +/- 8.1 (SE)]. However, only 12 out of the 48 tests showed a positive response equal to or greater than 100%, and the majority of these responses (10 out of 12) occurred when basal levels of 17-OHP were between 10-70 ng/ml. This suggests that when basal levels fall outside these values, the pituitary-adrenal axis is either too inhibited or too stimulated to react to exogenous ACTH. Of the 48 tests where 17-OHP was measured, 23 had basal level values within these limits, the mean being 40.3 ng/ml. The corresponding mean ACTH level was 99 pg/ml with a wide range (1-230 pg/ml). On the other hand, in prepubertal children who exhibited 17-OHP concentrations between 10-70 ng/ml, testosterone varied from 3-30 ng/100 ml, with a mean of 16.0 ng/100 ml +/- 1.9 (SE) which is not different from the mean level found in normal children [14.0 ng/100 ml +/- 1.3 (SE)]. Thus, under the influence of endogenous ACTH which is moderately increased, 17-OHP concentrations far exceed normal values, whereas plasma testosterone seems to be unaffected.     

Soluble interleukin-2 receptor decrease in the sera of HIV-infected patients treated with zidovudine.

Laboratory parameters which are modified following administration of zidovudine are becoming increasingly useful in monitoring the efficacy of treatment of early stages of HIV-1 infection. The serum levels of soluble interleukin (sILR)-2 receptor, which have been reported to increase early in HIV-1 infection, were found to be significantly lower in 24 patients being treated with zidovudine than in 69 patients who were not treated, 28 of whom had CD4+ counts greater than 400 x 10(6)/l, and 41 less than 400 x 10(6)/l, respectively (P less than 0.0001). A prospective study group of 33 subjects treated with zidovudine demonstrated a decrease in sIL-2R during therapy (base values 2113 +/- 1131 versus 1444 +/- 728 after 90 days of therapy; P less than 0.0007). The reduction of sIL-2R was greater in those subjects were p24 antigen became negative during treatment. sIL-2R therefore seems to be a useful tool in the monitoring of therapy with zidovudine.     

The impact of sex and contraceptive therapy on the plasma and intracellular pharmacokinetics of zidovudine

OBJECTIVES: Zidovudine remains part of combination antiretroviral therapy. Pharmacological studies rely on quantitation of active triphosphates in peripheral blood mononuclear cells. This study evaluated the impact of female sex and contraceptive therapy on zidovudine plasma and intracellular pharmacokinetics and the impact of contraceptive therapy on HIV viral load. METHODS: Serial plasma and intracellular zidovudine pharmacokinetics following oral and intravenous dosing were determined in 18 men and 20 women treated with zidovudine. Women could repeat pharmacokinetics assessment following 2 months oral or injectable contraceptive therapy. Zidovudine plasma and intracellular mono-, di- and triphosphate concentrations were determined by liquid chromatography tandem mass spectrometry. Plasma and cervical viral loads were determined preceding and following 2 months of contraceptive therapy in women. RESULTS: Men exhibited higher area under the concentration versus time curve for intracellular zidovudine and zidovudine-monophosphate following oral and intravenous dosing and higher zidovudine triphosphate following oral dosing. There was no difference between men and women in plasma zidovudine parameters. Furthermore, contraceptive therapy had no effect on zidovudine plasma or intracellular pharmacokinetics or on plasma or cervical HIV-1 RNA levels. CONCLUSIONS: Using an optimized pharmacokinetic design, this study indicated men exhibit significantly higher zidovudine-monophosphate and zidovudine-triphosphate exposure following zidovudine oral administration, having implications for drug toxicity and overall tolerance of zidovudine therapy. The lack of an effect of contraceptive therapy on zidovudine pharmacokinetics is surprising in light of previous pharmacokinetic studies for drugs eliminated primarily through glucuronidation. Contraceptive therapy had no effect on plasma or cervical viral load, results consistent with previous findings.     

Reduction of plasma lipid and homocysteine levels by pyridoxine, folate, cobalamin, choline, riboflavin, and troxerutin in atherosclerosis

Elevated plasma homocysteine and lipid levels are risk factors for atherosclerosis. The plasma levels of homocysteine, determined in acid hydrolyzates of plasma, were found to be correlated with total cholesterol (r = 0.47, P less than 0.001), triglycerides (r = 0.40, P less than 0.01), and body mass index (r = 0.42, P less than 0.01) in 52 males, aged 30-60. A group of 12 male survivors of acute myocardial infarction was given pyridoxine, folate, cobalamin, choline, riboflavin, and troxerutin for 21 days. The plasma concentrations of homocysteine and alpha-amino adipic acid declined to 68% (P less than 0.001) and 57% (P less than 0.001) of the pretreatment values, and the cholesterol, triglycerides, and LDL apo B declined to 79% (P less than 0.001), 68% (P less than 0.01), and 63% (P less than 0.001) of the pretreatment values, respectively. The results suggest a new strategy for control of the metabolic abnormalities in atherosclerosis through the use of naturally occurring, non-toxic nutrients which minimize homocysteine accumulation.     

Effects of disodium EDTA and calcium infusion on prolactin and thyrotropin responses to thyrotropin-releasing hormone in healthy man

To determine the impact of induced hypo- and hypercalcemia on TRH (400 micrograms)-stimulated TSH and PRL release, healthy subjects (n = 11) were infused with 5% glucose in water (n = 11), disodium EDTA (n = 11), or calcium gluconate (n = 7). TRH was given as an iv bolus 60 min (5% glucose and EDTA) and 120 min (calcium) after initiation of the respective infusion. Basal plasma concentrations of TSH remained unchanged during induced hypo- and hypercalcemia, whereas those of PRL fell during the latter (P less than 0.05). The mean sum of increments (0-90 min) in PRL and TSH was considerably greater during hypocalcemia than during hypercalcemia (PRL, P less than 0.002; TSH, P less than 0.005). The increments in the plasma hormone concentration above basal after iv TRH were increased compared to those in normocalcemia (PRL, 98.4 +/- 37.9 ng/ml; TSH, 38.9 +/- 11.8 microU/ml) during hypocalcemia [PRL, 128 +/- 47.8 ng/ml (P less than 0.002); TSH, 46.7 +/- 12.8 microU/ml; (P less than 0.005)], but were impaired during hypercalcemia [PRL, 70.1 +/- 27 ng/ml (P less than 0.002); TSH, 28.9 +/- 8.5 microU/ml (P less than 0.025)]. The mean sum of increments in PRL was related to concentrations of both serum calcium (r = -0.59; P less than 0.01) and PTH (r = 0.51; P less than 0.05). A relation was also seen between the incremental responses of TSH and serum calcium (r = -0.52; P less than 0.05), PTH (r = 0.55; P less than 0.01), and phosphorus (r = -0.55; P less than 0.01). We conclude that in healthy man, TRH-mediated release of both PRL and TSH are inversely related to serum calcium concentrations in such a manner that hormone secretion is enhanced by acute hypocalcemia, but blunted by hypercalcemia.     

Plasma adiponectin and serum advanced glycated end-products increase and plasma lipid concentrations decrease with increasing duration of type 2 diabetes

OBJECTIVE: To prospectively follow the concentrations of plasma adiponectin (p-adiponectin) and serum advanced glycation end-products (s-AGE) in relation to plasma lipids and retinopathy over 3 years in type 2 diabetic patients. DESIGN AND METHODS: P-adiponectin, s-AGE, plasma lipids and diabetic retinopathy were prospectively evaluated in 61 type 2 diabetic patients at baseline and at follow up 3 years later. RESULTS: Mean p-adiponectin (from 8.84+/-5.14 to 11.05+/-6.16 microg/ml; P=0.006) and s-AGE (from 637+/-242 to 781+/-173 ng/ml; P<0.0001) concentrations had increased at follow up. In addition, HbA1c (7.7+/-1.7 to 7.4+/-1.4%; P=0.0045) and fasting C-peptide (1.00+/-0.38 to 0.81+/-0.35 nM; P=0.019) had decreased and all lipid variables had significantly improved at follow up. P-adiponectin correlated inversely with fasting C-peptide (r(s)=-0.273; P=0.045) and low-density lipoprotein (LDL)/high-density lipoprotein (HDL) ratio (r(s)=-0.362; P=0.011), and directly with plasma HDL cholesterol (r(s)=0.381; P=0.005) at follow up. Analysis of variance with adiponectin and s-AGE as dependent variables and fasting C-peptide, plasma HDL and plasma LDL cholesterol as covariates demonstrated that the increase in s-AGE was independent (P=0.001) and the increase in p-adiponectin dependent on covariate changes (P=0.862). There was a slight correlation between s-AGE at baseline versus the degree of retinopathy at follow up (r(s)=0.281; P=0.0499). CONCLUSION: Both p-adiponectin and s-AGE increased during the 3 years. The increase in p-adiponectin was explained by improvements in insulin sensitivity and dyslipidaemia, whereas the increase in s-AGE was independent of changes in metabolic covariates. s-AGE increase when the duration of type 2 diabetes increases.     

Chemical analysis of whole saliva in Sj?gren's syndrome.

In some studies, but not in all, abnormally high concentrations of salivary Na+, K+, and IgA have been found in patients with Sjögren's syndrome (SS). The lack of agreement between various reports might be due to the different ways in which saliva was collected. Some analysed stimulated parotid or whole saliva, whereas others used unstimulated saliva. In this study, therefore, the rate of flow and Na+, K+, and IgA levels in unstimulated and stimulated whole saliva in normals and in rheumatoids with and without SS have been determined. The results confirmed significantly raised levels of Na+, K+, and IgA in unstimulated whole saliva in SS. In response to stimulation there was marked decrease in Na+, K+, and IgA levels, whereas normally, as shown by the other two groups, there is an increase in Na+, no change in K+, and a mild decrease in IgA. As a result, the differences between SS and normals became much less significant (K+, IgA) or were even completely obliterated (Na+). The abnormal response of SS to stimulation may be partially explained by the initially low rate of flow and by the extremely high IgA levels. Thus chemical analysis of unstimulated whole saliva is much more sensitive than analysis of stimulated whole saliva in the detection of salivary gland involvement in SS.