Pilot evaluation of venlafaxine hydrochloride for the therapy of hot flashes in cancer survivors

PURPOSE: Hot flashes can be a prominent clinical problem for breast cancer survivors and men who undergo androgen-deprivation therapy. Anecdotal information suggested a low dose of a relatively new antidepressant, venlafaxine, could abrogate this clinical problem. MATERIALS AND METHODS: This study included 28 consecutive assessable patients entered onto a phase II clinical trial. Hot flash data were collected by daily diary questionnaires during a 1-week baseline period and then for 4 weeks, during which time patients received venlafaxine 12.5 mg orally twice daily. RESULTS: Fifty-eight percent of patients who completed the study had a greater than 50% reduction in hot flash scores (frequency times severity) during the fourth treatment week as compared with the baseline week. Median weekly hot flash scores were reduced by 55% from baseline during the fourth week of venlafaxine therapy. Therapy was generally well tolerated and appeared to alleviate fatigue, sweating, and trouble sleeping. CONCLUSION: Venlafoxine appears to represent an efficacious new method to alleviate hot flashes. Further evaluation of this compound for alleviating hot flashes is indicated.     

Gln368STOP myocilin mutation in families with late-onset primary open-angle glaucoma

PURPOSE: To examine families ascertained for late-onset primary open-angle glaucoma (POAG) to determine mutations in the gene coding for myocilin. METHODS: The diagnosis of late-onset POAG was defined as age at diagnosis more than 35 years, intraocular pressure (IOP) 22 mm Hg or more in both eyes or 19 mm Hg or more while the patient was taking two glaucoma medications, glaucomatous optic neuropathy in both eyes, and visual field loss consistent with optic nerve damage in at least one eye of the proband. Two of three criteria were required in other family members. DNA from all families was screened for polymorphisms in myocilin using single-strand conformation polymorphism analysis. All polymorphisms were sequenced for mutations. RESULTS: Eighty-three affected people in 29 families with late-onset POAG were screened for mutations. Three mutations, two novel missense (Thr377Met and Glu352Lys) and one nonsense (Gln368STOP), were identified. The missense mutations did not segregate with the disease phenotype in these families. The nonsense mutation was found in 3 of 29 unrelated families with POAG. All affected family members and 8 of 12 in whom glaucoma was suspected had the Gln368STOP mutation. All people with this mutation had elevated IOP, and 78% had POAG by age 70. CONCLUSIONS: Three mutations were identified in the gene coding for myocilin in families with late-onset POAG. Of these, the Gln368STOP mutation was highly associated with the development of glaucoma. All people with this mutation had glaucoma or elevated IOP by age 70. In the United States, the Gln368STOP mutation in myocilin is strongly associated with the development of late-onset POAG. However, factors in addition to the presence of this mutation seem to play a role in the development of ocular hypertension and glaucoma in these families.     

Registration of MR and SPECT without using external fiducial markers

The aim of our work is to present, test and validate an automated registration method used for matching brain SPECT scans with corresponding MR scans. The method was applied on a data set consisting of ten brain IDEX SPECT scans and ten T1- and T2-weighted MR scans of the same subjects. Of two subjects a CT scan was also made. (Semi-) automated algorithms were used to extract the brain from the MR, CT and SPECT images. Next, a surface registration technique called chamfer matching was used to match the segmented brains. A perturbation study was performed to determine the sensitivity of the matching results to the choice of the starting values. Furthermore, the SPECT segmentation threshold was varied to study its effect on the resulting parameters and a comparison between the use of MR T1- and T2-weighted images was made. Finally, the two sets of CT scans were used to estimate the accuracy by matching MR to CT and comparing the MR-SPECT match to the SPECT-CT match. The perturbation study showed that for initial perturbations up to 6 cm the algorithm fails in less than 4% of the cases. A variation of the SPECT segmentation threshold over a realistic range (25%) caused an average variation in the optimal match of 0.28 cm vector length. When T2 is used instead of T1 the stability of the algorithm is comparable but the results are less realistic due the large deformations. Finally, a comparison of the direct SPECT-MR match and the indirect match with CT as intermediate yields a discrepancy of 0.4 cm vector length. We conclude that the accuracy of our automatic matching algorithm for SPECT and MR, in which no external markers were used, is comparable to the accuracies reported in the literature for non-automatic methods or methods based on external markers. The proposed method is efficient and insensitive to small variations in SPECT segmentation.     

Testolactone-associated high androgen levels, a pharmacologic effect or a laboratory artifact?

Testolactone, an aromatase inhibitor, blocks conversion of androgens to estrogens. In familial male precocious puberty, slowing of pubertal progression and growth velocity occurs with testolactone and spironolactone. Girls with McCune-Albright syndrome, given testolactone, respond similarly. A 2-yr-old female (case 1) on testolactone for non-McCune-Albright gonadotropin independent precocious puberty had marked elevations of androstenedione (18 ng/mL, normal: 0.2-3.1) and testosterone (3.6 ng/mL, normal < 0.2) but no virilization. Investigations were undertaken to determine whether elevations in testosterone and androstenedione were caused by interference in these RIAs. After a single oral dose of testolactone (5 mg/kg in case 1; 4 mg/kg in case 2, a 3-yr-old boy with familial male precocious puberty; 10 mg/kg in a healthy postmenopausal control), serum testosterone and androstenedione were measured serially by RIA for 24 h. Androstenedione went from normal to a mean peak of 45.4 ng/mL at 1-2 h and returned to baseline by 24 h. Testosterone, undetectable at baseline (case 1 and control) or 1.8 ng/mL (case 2) rose to a mean peak of 6.9 ng/mL and returned to baseline by 24 h. Testolactone, in serial dilutions, cross-reacted in the testosterone assay. Testolactone significantly interferes in these serum RIAs, making their use unreliable in follow-up of patients treated with testolactone.     

Use of transesophageal left atrial cardiac pacing for assessment of cordarone effectiveness in patients with atrioventricular tachycardia

AIM: To assess by means of transesophageal left atrial pacing the effectiveness of cordarone treatment for arrhythmias caused by re-entry mechanism. MATERIALS AND METHODS: Effectiveness of cordarone treatment was estimated in 25 patients with atrioventricular nodal tachycardia (AVNT) and in 33 patients with WPW syndrome and reciprocal atrioventricular tachycardia (RAVT) with frequent paroxysms of tachycardia 1-5 times per week. Transesophageal left atrial pacing (TELAP) was performed before antiarrhythmic treatment and on cordarone treatment day 14-18. Cordarone was given for two months in common regimen (the first 10 days--600 mg/day, the next 10 days--400 mg/day and then 200 mg/day). RESULTS: The first TELAP induced paroxysmal AVNT or RAVT in all the patients. According to the results of the second TELAP, all the patients were divided into three groups. Group 1 included 28 patients in whom the second TELAP was unable to induce tachycardia. All these patients had increased effective refractory period (ERP) of AV node and/or of accessory pathway (AP) values and a decreased Wenkebach point (WP) < 150/min during the second TELAP in comparison with the first TELAP. All these patients had no spontaneous paroxysms of T during the 3-month follow-up. Group 2 included 18 patients in whom the second TELAP induced AVT lasting < 30 seconds. 16 of these patients had tachycardia with less heart rate during the second TELAP in comparison with the first TELAP, 153 + (-) 8 bpm vs 188 + (-) 10 bpm, p < 0.001, respectively. Also, in these 16 patients we found an increase of values of ERP of AV node and/or AP > 360 ms and a decrease of WP < 150 bmp. 14 of these 16 patients had no spontaneous paroxysms of AVT and 2 patients had short episodes of AVT during the 3-month follow-up with effects of vagal manoeuvers. From 2 other patients of group 2 one had short episodes of spontaneous T and one had long episodes of tachycardia with effect of verapamil i.v. Group 3 included 12 patients in whom the second TELAP induced the same AVT as the first TELAP. Values of ERP of AV node and/or AP and WP during the first and second TELAP were not different. All of these patients had long spontaneous paroxysms of AVT during cordarone treatment day 14-18. The treatment was discontinued in all patients of group 3. CONCLUSION: Cordarone is effective in prevention of AVT. Negative results in provocation of AVT during TELAP after 14-18 days of cordarone treatment is a very specific predictor of cordarone treatment effectiveness. Provocation by TELAP of short episodes of AVT with reduced heart rate and higher values of ERP of AV node and AP and lowering of WP < 150 bpm may not predict ineffectiveness of cordarone in patients with AVT. Moreover, the majority of these patients had no spontaneous episodes of AVT. Provocation by TELAP during cordarone treatment of the same AVT episodes as before cordarone treatment is a very specific predictor of cordarone effectiveness.     

Synthesis and comparative evaluation of two antiviral agents: beta-L-Fd4C and beta-D-Fd4C

The synthesis of beta-D-Fd4C was achieved in a stereoselective fashion from D-xylose. The antiviral activity and cytotoxicity of beta-D-Fd4C was compared with that of beta-L-Fd4C and 3TC (Lamivudine). Of the three agents compared, beta-L-Fd4C was found to be the most potent antiviral agent.     

Protein kinase C and casein kinase 2 phosphorylate in vitro proteins of the annexin family from eggs of loach Misgurnus fossilis

A mixture of proteins of the annexin family was obtained from the cytoplasm of mature eggs of loach Misgurnus fossilis (by reprecipitation with acid phospholipids in the presence of Ca2+). This mixture comprised five proteins with molecular weights of 58, 38, 36, 35, and 31 kD. Polyclonal rabbit antibodies against the major 31-kD protein were obtained. Western blot analysis showed that the obtained antibodies exhibit a high specificity towards the 31-kD protein from eggs and other tissues of loach and zebrafish (Brachydanio rerio). The analysis of cDNA corresponding to the 31-kD protein by screening the zebrafish cDNA library confirmed that this protein belongs to the annexin family. Phosphorylation of the obtained annexins in vitro was studied. It is shown that the 58-kD protein is phosphorylated by casein kinase 2 (CK2), whereas the 38-, 36-, 35-, and 31-kD proteins are phosphorylated by protein kinase C (PKC).     

Glu-320 and Asp-323 are determinants of the CYP4A1 hydroxylation regiospecificity and resistance to inactivation by 1-aminobenzotriazole

Little information is available on the active site structure of the CYP4A family of enzymes or the mechanism by which their omega-hydroxylation regiospecificity is enforced. We report here that the E320A, D323E, and E320/D323E mutations decrease the catalytic rate of CYP4A1 approximately 5-fold and cause up to a 10-fold shift from omega- to (omega-1)-hydroxylation. The decreased catalytic rate is due to an increase in the uncoupled reduction of molecular oxygen. Tighter binding of 1- and 4-substituted imidazoles to the double mutant than to the other proteins suggests that its active site is less constrained. The reaction of these proteins with phenyldiazene causes heme degradation without the detectable formation of a phenyl-iron complex. CYP4A1 and its E320A mutant are not inactivated by 1-aminobenzotriazole (1-ABT), but the D323E and E320A/D323E mutants are inactivated. The resistance of purified CYP4A1 to inactivation by 1-ABT is surprising in view of the fact that 1-ABT causes the loss of the omega-hydroxylase activity both in microsomal preparations and in vivo. Collectively, the results establish that Glu-320, and particularly Asp-323, help to define the active site dimensions, the degree of coupled versus uncoupled versus uncoupled turnover, the omega-versus (omega-1)-hydroxylation regiospecificity, and the susceptibility to inactivation by mechanism-based inhibitors. Furthermore, they provide experimental evidence for a structural analogy between the CYP4A1 and P450BM-3 active sites.     

Coreceptor-independent T cell activation in mice expressing MHC class II molecules mutated in the CD4 binding domain

We have previously reported that efficient selection of the mature CD4+ T cell repertoire requires a functional interaction between the CD4 coreceptor on the developing thymocyte and the MHC class II molecule on the thymic epithelium. Mice expressing a class II protein carrying the EA137/VA142 double mutation in the CD4 binding domain develop fewer than one-third the number of CD4+ T cells found in wild-type mice. In this report we describe the functional characteristics of this population of CD4+ T cells. CD4+ T cells that develop under these conditions are predicted to be a CD4-independent subset of T cells, bearing TCRs of sufficient affinity for the class II ligand to undergo selection despite the absence of accessory class II-CD4 interactions. We show that CD4+ T cells from the class II mutant mice are indeed CD4 independent in their peripheral activation requirements. Surprisingly, we find that CD4+ T cells from the class II mutant mice, having been selected in the absence of a productive class II-CD4 interaction, fail to functionally engage CD4 even when subsequently provided with a wild-type class II ligand. Nevertheless, CD4+ T cells from EA137/VA142 class II mutant mice can respond to T-dependent Ags and support Ig isotype switching.     

The polo-like kinase Plx1 is required for M phase exit and destruction of mitotic regulators in Xenopus egg extracts

Polo-like kinases (Plks), named after the Drosophila gene product polo, have been implicated in the regulation of multiple aspects of mitotic progression, including the activation of the Cdc25 phosphatase, bipolar spindle formation and cytokinesis. Genetic analyses performed in yeast and Drosophila suggest a function for Plks at late stages of mitosis, but biochemical data to support such a function in vertebrate organisms are lacking. Here we have taken advantage of Xenopus egg extracts for exploring the function of Plx1, a Xenopus Plk, during the cell cycle transition from M phase to interphase (I phase). We found that the addition of a catalytically inactive Plx1 mutant to M phase-arrested egg extracts blocked their Ca2+-induced release into interphase. Concomitantly, the proteolytic destruction of several targets of the anaphase-promoting complex and the inactivation of the Cdc2 protein kinase (Cdk1) were prevented. Moreover, the M to I phase transition could be abolished by immunodepletion of Plx1, but was restored upon the addition of recombinant Plx1. These results demonstrate that the exit of egg extracts from M phase arrest requires active Plx1, and they strongly suggest an important role for Plx1 in the activation of the proteolytic machinery that controls the exit from mitosis.