Hepatitis B virus DNA in the serum of Sardinian blood donors negative for the hepatitis B surface antigen

The high endemicity of hepatitis B virus (HBV) infection and liver disease in Sardinia led us to assess the occurrence of HBV DNA in 1,411 sera of two selected groups of hepatitis B surface antigen (HBsAg)- negative blood donors: 793 with abnormal serum alanine aminotransferase (ALT) and 618 with normal serum ALT values (determined during routine testing of their blood donation). HBV DNA sequences were detected by dot-blot hybridization in 68 of 793 subjects (9%) with abnormal ALT but only in three of 618 subjects (0.5%) with normal ALT. HBV-core antibody (anti-HBc) was detected in 338 of 793 subjects (43%) with abnormal ALT as well as in 125 of 618 subjects (20.2%) with normal ALT. Among the 71 subjects positive for serum HBV DNA, 22 (31%) were positive for anti- HBc, while 49 (69%) were negative for all serologic markers of HBV infection. Thus, a high frequency of anti-HBc in apparently healthy HBsAg-negative individuals and a high prevalence of serum HBV DNA in the absence of immunologic markers of HBV infection suggest the existence of genetic variants of HBV that may be responsible for some of the presumed NANB hepatitis encountered in Sardinia and possibly other areas of high endemicity for HBV.     

Early detection of antibodies against rDNA-produced HIV proteins with a flow cytometric assay

There is evidence that some human immunodeficiency virus (HIV)-infected individuals have prolonged periods of seronegativity. A flow cytometric immunoreactive bead (IRB) assay is described for quantitative, simultaneous, and early detection of antibodies to HIV. Polystyrene beads of four diameters, each size coated with a different HIV recombinant DNA-produced protein (p24, p31, gp41, or gp120), bound anti- HIV antibodies detected with fluorescent antiglobulin. The IRB assay was performed on a panel of blood donor samples, many giving consistently false-positive enzyme immunoassay (EIA) and indeterminant Western blot (WB) results. The IRB assay proved as sensitive and more specific than currently licensed EIA and WB tests. Results on serial samples from eight HIV-infected individuals indicated that quantitation of anti-p24 by IRB assay may be useful in monitoring disease progression. Sequential pre- and post-EIA seroconversion sera from 35 HIV-infected homosexual men were tested by the IRB assay using IgM- and IgG-specific fluorescent probes. All 35 cases were IRB assay positive for at least one rDNA-p either before (17 of 35, 49%) or at the time of EIA positivity. Eleven cases (31%) initially had only IgM anti-HIV, primarily to gp41 (17%). In two individuals, the IgM response was detected at least 18 months before EIA seroconversion. The IRB assay is a widely applicable analytic procedure, potentially useful in pretransfusion anti-HIV screening of blood.     

Chloride transport in primary cultures of rabbit colonocytes at different stages of development

BACKGROUND & AIMS: Ontogeny of colonic Cl- transport and its regulation has been characterized inadequately. The aim of this report was to study developmental changes in Cl- transport in primary cultures of rabbit distal colonocytes. METHODS: Colonocytes from newborn (7-9 days old), weanling (25-28 days old), and adult (6 months old) rabbits were cultured for 24 hours on a collagen IV matrix, and Cl- transport was measured using the fluoroprobe 6-methoxyquinolyl acetoethyl ester. RESULTS: Cl- permeabilities were dependent on [Cl-]o with maximal rates (in millimoles per liter per second) at [Cl-]o = 75 mmol/L (newborns; 0.15 +/- 0.04; weanlings; 0.2 +/- 0.02; and adults, 0.32 +/- 0.06). Influx was inhibited significantly by the Cl- channel (50 mumol/L diphenylamine-2-carboxylate) and the Na(+)-K(+)- 2Cl- cotransport (10 mumol/L furosemide) inhibitors. The adenosine 3',5'-cyclic monophosphate (cAMP)-dependent secretagogues, prostaglandin E1 (1 mumol/L), forskolin (1 mumol/L), and 8-bromo-cAMP (100 mumol/L), and the protein kinase C activator, phorbol 12-13 dibutyrate (1 mumol/L), increased Cl- influx significantly in all groups with adults showing greatest stimulation. However, taurodeoxycholate (0.025-1 mmol/L) had an effect only in the adult and the guanosine 3',5'-cyclic monophosphate (cGMP) activators STa and 8-bromo-cGMP had no effect. CONCLUSIONS: Rabbit distal colonocytes possess inhibitor-sensitive Cl- permeabilities even in neonates. However, the ontogeny of their regulation depends on the secretagogue-signaling pathway. (Gastroenterology 1996 Dec;111(6):1541-50)     

Imaging modalities for renal artery stenosis in suspected renovascular hypertension: prospective intraindividual comparison of color Doppler US, CT angiography, GD-enhanced MR angiography, and digital substraction angiography

The aim of the study was to evaluate the diagnostic accuracy of Color Doppler US, CT Angiography (CTA), and GD-enhanced MR Angiography (MRA) compared with digital subtraction angiography (DSA) for the detection of renal artery stenosis in patients with clinically suspected renovascular hypertension. Fifty-eight patients with suspected renovascular hypertension were enrolled in the study. All patients underwent Color Doppler US, CTA and GD-enhanced MRA. DSA was the gold standard method for the number of renal arteries, existence and degree of stenosis, or evidence of fibromuscular dysplasia. DSA depicted 132 renal arteries, 16 stenoses, and 4 arteries with fibromuscular dysplasia. Color Doppler US failed to detect 1 main and 14 polar arteries. CTA depicted all main renal arteries and 7/16 polar arteries, but failed to detect stenosis in two accessory vessels. Likewise, MRA did not detect stenotic accessory renal arteries, depicted 9/16 polar renal arteries, but missed two main renal arteries. All methods depicted the four main renal arteries with fibromuscular dysplasia. The overall sensitivity, specificity, and positive and negative predictive accuracy were 75%, 89.6%, 60% and 94.6%, respectively, for color Doppler US; 94%, 93%, 71%, and 99%, respectively, for CTA; and 90%, 94.1%, 75%, and 98%, respectively, for GD-enhanced MRA. CTA and GD-enhanced MRA have comparable and satisfactory results with respect to the negative predictive accuracy of the suspected renal artery stenosis. The concept of an imaging algorithm including US as screening test when appropriate and CTA or MRA as the second step-procedure is suggested. Therefore, DSA may be reserved for cases with major discrepancies or therapeutic interventions.     

Retinoid receptor alpha and Beta expression in serous ovarian tumors

The expression of retinoid acid receptors alpha (RARalpha) and beta (RARbeta) and estrogen receptor alpha (ERalpha) was assessed by immunohistochemistry and Western blotting in normal ovaries, serous cystadenoma (n = 20), serous borderline (n = 14), and serous ovarian cancer (n = 47) and was correlated in cancer cases with stage, grade, progress-free survival (PFS), and survival. RARalpha was increasingly expressed in benign cystadenomas, borderline, and low-stage and advanced-stage neoplasms (p < 0.001). In stage III, G3 serous carcinoma, increased RARalpha expression was an independent prognostic factor associated with lower chemoresponse to first-line chemotherapy (taxol and carboplatin) and shorter PFS (p < 0.002).RARbeta and ERalpha expression did not correlate with RARalpha tumor characteristics or PFS and survival.     

Echocardiographic evaluation of mitral tethering for 'chordal cutting' procedure.

'Chordal cutting' is a recently proposed surgical option for the treatment of functional mitral regurgitation due to leaflet tethering. With this technique the surgeon sections second order chordae, restores leaflet's convexity towards the left atrium and eliminates mitral incompetence. Preoperative assessment of tethering mechanism, degree of leaflet distortion, surface of coaptation, annular dilation, origin and quantification of valve incompetence by echocardiographic means is essential in indicating this surgical option. Intraoperative transesophageal evaluation is crucial to assess the morphology and the absence or degree of residual incompetence after procedure.     

Triangular resection and folding of posterior leaflet for mitral valve repair

The conventional treatment of mitral insufficiency, due to posterior leaflet prolapse, is quadrangular resection. This technique sacrifices a great amount of valve tissue resulting in leaflet stiffness and altered annular geometry. To avoid such problems we performed a small triangular leaflet resection sparing the second-order chordae, a folding plasty, implantation of artificial chordae, and annuloplasty. Fourteen patients underwent this procedure. No hospital death and no repair failure were observed. Echocardiography at 12 months on 12 patients showed trivial incompetence in three and mild in one and an overall improvement of end-diastolic and end-systolic diameters. Our technique has the main objectives of sparing second-order chordae and subvalvular apparatus in order to preserve mobility of the posterior mitral leaflet, left ventricular geometry, and function. Preliminary results are encouraging.     

Normalization of thyroid hormone levels in patients with either hyper- or hypothyroidism results in a profound change of atrial natriuretic peptide (ANP) levels

Atrial Natriuretic Peptide (ANP) is a hormone produced by cardiac atrial myocytes. Thyroid hormones may affect its release. The aim of this study was to analyze the effect of hyper and hypothyroidism on the secretion of ANP and its relationship with the changes of the renin-angiotensin-aldosterone system. Plasma ANP concentration as well as plasma renin activity (PRA) and aldosterone (ALDO) were measured in 21 patients with hyperthyroidism, 12 patients with hypothyroidism and 29 normal controls. Moreover, in 5 hyperthyroid and 8 hypothyroid patients hormones measurements were performed at diagnosis and 15, 30, 45 and 60 days after starting the appropriate therapy. Statistical analysis was performed employing the Wilcoxon two sample test to compare the ANP levels in normal and hyper or hypothyroid patients while the pairwise comparisons were evaluated using the Spermans rank correlation. Partial correlation and regression models were used to examine the joint effects of multiple predictors on ANP. ANP levels were significantly higher in hyperthyroid (mean+/-SEM, 17+/-1.7 pmol/L, +/-<0.001) and lower in hypothyroid patients (6.18+/-1.14 pmol/L, p<0.01) compared to normals (10.35+/-0.59 pmol/L). In the hyperthyroid patients following treatment with antithyroid drugs plasma ANP levels reached normal values after 15 days and remained stable thereafter. In the hypothyroid patients, ANP levels increased gradually following initiation of treatment with thyroxine, reaching values comparable to controls at day 45. PRA was significantly higher only in hyperthyroid patients compared to controls. ALDO concentrations were not different in all groups studied. No correlation was found between plasma ANP levels and T3, T4, TSH, PRA and ALDO levels in the individual groups, while a positive correlation for T3 (r=0.610, p<0.01), T4 (r=0.653, p<0.01) and pulse rate (r=0.704, p<0.01) and negative correlation with TSH (r=-0.519, p<0.01) was found when all groups were pooled together. In conclusion, our data indicate that thyroid hormones affect positively ANP secretion from cardiac myocytes. This effect may be, at least in part, indirect via hemodynamic alterations.     

Assessment of sperm motion characteristics from fertile and infertile men using a fully automated computer-assisted semen analyzer

Sperm curvilinear velocity (Vc) and linearity (L) were analyzed in semen from 20 fertile men and from 53 patients with unexplained infertility by a computer-assisted semen analyzer (CASA). Because the frequency distribution of Vc from patient's spermatozoa showed a nongaussian distribution, comparison of mean values of Vc and L between men with unexplained infertility and fertile men is inappropriate. As an alternative, the authors compared the cumulative distribution of the percent of cells measured at increasing intervals of Vc and L, and observed a significant difference between patients and fertile men from the level of Vc30 through Vc70 micron/sec for curvilinear velocity and L2 through L6 for linearity (P less than 0.001). Furthermore, the authors coanalyzed these two parameters at the greatest point of difference (Vc40 and L3) and observed that their patient population can be differentiated into four subpopulations of subjects accordingly to their Vc40 and L3 values. In this study, 43 of the 53 patients had a motility disorder characterized by having a higher percent of cells being substantially slower and less directional than cells from normal men. However, in some patients, motion characteristics were indistinguishable from those in normal men.