Role of paraoxonase-1 as a diagnostic marker for feline infectious peritonitis

Feline infectious peritonitis (FIP) is characterised by the presence of systemic inflammation accompanied by oxidative stress. Paraoxonase-1 (PON-1) is a negative acute phase reactant produced by the liver. A paraoxon-based method has been validated to measure PON-1 activity in feline serum. The aim of this study was to investigate the usefulness of PON-1 activity as a biomarker to discriminate FIP from other diseases with similar clinical signs. Of 159 cats enrolled, 71 were healthy, 34 had FIP and 54 had another disease but presented with clinical signs that could be consistent with FIP. PON-1 activity was lower (P <0.0001) in cats with FIP (median, 26.55 U/L; range, 5.40-78.20 U/L) compared to healthy (median, 87.5 U/L; range, 46.60-215.50 U/L) and Non-FIP Sick group cats (median, 57.90 U/L; range, 3.80-122.60 U/L). Two receiver operating characteristic curves were used to determine the thresholds that maximised the performance of PON-1 activity in predicting FIP both from a screening and diagnostic point of view. A threshold of 78.30 U/L yielded a sensitivity of 100%, a specificity of 50.4%, and a negative likelihood ratio of 0.00 (screening curve). While a threshold of 24.90 U/L maximised specificity (94.4%), had a sensitivity of 44.1%, and increased the likelihood ratio to 7.94, making PON-1 activity a good confirmatory test for FIP (diagnostic curve). Using these thresholds, serum PON-1 activity showed good diagnostic performance in discriminating FIP affected cats from cats with other inflammatory conditions.

Preliminary comparative serological evaluation of Histamine H2 receptors in dogs with an acute onset of vomiting treated with Ranitidine and healthy dogs

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Ranitidine (RT) is an antagonist against H2 histamine receptors (H2R) that weakly suppress acid secretion in patients. Despite that a clinical effect is often achieved.

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H2 antagonists (H2RA) also called H2 blockers, are a group of medications that block the action of histamine at the H2R of parietal cells in the stomach.

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Preliminary analysis indicates that the levels of H2 receptors in the serum and gastric walls are the same.

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Evidence suggests that the level of H2 receptors in dogs with acute vomiting is greater than in healthy dogs, thus probably contributing to a greater efficiency of ranitidine treatment.

Despite the lack of evidence of the ability to suppress gastric acid secretion in dogs, ranitidine (RT) is often used to control clinical signs in dogs with acute vomiting even if the way it happens it is still largely unknown. The aim of this study was thus to evaluate the therapeutic effect of ranitidine on H2 receptors in dogs with acute vomiting. To investigate the RT activity a preliminary study was performed in dogs which underwent gastroscopy analyses, demonstrating that the level of H2R observed in the serum and gastric wall tissue was the same [1.473(1.30; 1.79) ng/ml and 1.498 (1.33; 1.85) ng/ml, respectively]. After that H2R levels in the serum of 22 healthy dogs (Group 1) and in a group of 22 dogs with acute vomiting (Group 2) were compared both before (T0), after 7–10 days (T1) of 2 mg/kg twice a day ranitidine administration and after 11 days since the drug was discontinued (T2). Significant differences (p<0.001) were detected between the level of circulating H2R among Group 1: 0.41 ng/ml (0.28;0.54) and Group 2: 2.27 ng/ml (2.11;2.49) at T0. In Group 2, no difference in the level of H2R was detected in samples collected at T0 compared to those at T1 [T1: 2.32 ng/ml (2.14; 2.49)] and T2 [T2: 2.30 ng/ml (1.99;2.69)]. In Group 2 all patients but one displayed remission of symptoms attributable to inflammatory gastropathy at the first withdrawal (T1: 7–10 days), while at the second withdrawal (T2: after 21 days), remission was detected in all dogs. Our preliminary hypothesis is that the clinical efficacy of ranitidine is related to the greater expression of H2 receptors in patients with acute vomiting. This increased expression may be due to continuous pathological stimulus at the gastric level. Further studies with a wider population are needed to better investigate the activity of RT in dogs with acute onset of vomiting.

Vaginal progesterone in menopause: Crinone 4% in cyclical and constant combined regimens

Compliance with hormone replacement therapy (HRT) is notoriously low despite ample documentation of clinical efficacy. The two major reasons given by women who discontinue HRT are uterine bleeding and side-effects. The recent development of a controlled and sustained vaginal progesterone gel allowed single daily application and made prolonged use such as for menopause possible. Here we report our clinical experience with two therapeutic options for HRT using natural progesterone administered vaginally. A first group of 69 menopausal women received the sustained release vaginal progesterone gel, Crinone 4% (45 mg daily) from days 1-10 of each calendar month with oestrogens taken continuously. A second group of 67 women received Crinone 4% twice weekly in conjunction with continuous oestrogen therapy. Endometrial thickness was evaluated before and after 6 months of treatment. Histological verification was obtained in all cases of abnormal bleeding. At 6 months, 63 out of 69 (91.9%) women receiving progesterone cyclically experienced predictable withdrawal bleeding. The vast majority, 54 (80.6%) of 67 women receiving Crinone in constant combined association with oestrogen therapy, remained amenorrhoeic throughout 6 months of therapy. All cases of abnormal bleeding were biopsied and no hyperplasia was seen. Our results indicate that both regimens using the sustained release vaginal progesterone gel controlled bleeding in HRT. Combined with the lower incidence of side-effects characteristic of vaginal progesterone, both vaginal progesterone regimens have the potential of improving HRT compliance.

Purified recombinant CD4 inhibits HIV-1 infection of peripheral blood macrophages

Purified recombinant soluble CD4 (rCD 4) is a new antiviral agent which has been shown to block HIV infection of lymphocytic and monocytic cell lines as well as peripheral blood mononuclear cells. The authors investigated here the ability of rCD4 to inhibit HIV-1 infection of peripheral blood macrophages. In this system, purified preparations of rCD4 provided, at concentrations above 10 micrograms/ml, a complete protection against a challenge with the monocytotropic strain HIV-1 Ba-L. Also, anti-CD 4 monoclonal antibodies directed at the V1 domain of the CD 4 molecule blocked infection of macrophages by HIV. Recombinant CD 4 is therefore a potent antiviral agent able to prevent HIV-1 infection of peripheral blood macrophages, and the CD 4 molecule is likely to be the main HIV receptor on these cells.