Involvement of alkylating agents in schistosome-associated bladder cancer: the possible basic mechanisms of induction.

Carcinoma of the urinary bladder is a common malignancy in many tropical and subtropical countries. There is a well documented sequela of chronic urinary schistosomal infection and bladder cancer associated with schistosomiasis is a major cause of morbidity and mortality in the endemic areas. Experimental bladder cancer can be induced in schistosome-infected animals. Multiple factors have been suggested as causative agents in schistosome-associated bladder carcinogenesis and the N-nitroso compounds appear to be of particular importance. These agents have long been suspected to play a major role in the aetiology of a variety of human cancers. A model for the induction of bladder cancer associated with schistosomiasis is proposed which takes into account the interrelationships between different factors resulting from the infection, especially the role of alkylating agents that can contribute to the induction of this neoplasm.     

Comparative value of prostaglandin E1 and papaverine in treatment of erectile failure: double-blind crossover study among Egyptian patients.

In a double-blind, crossover designation penile intracavernous prostaglandin E1 and papaverine hydrochloride were compared in regard to effectiveness and safety in 52 patients investigated and treated for sexual erectile dysfunction. In evidence of the reliable effectiveness, prostaglandin E1 (20 micrograms/ml.) induced significant positive erectile response in 42 of 52 patients (81%). This rate reached 100% with neurogenic, hyperprolactinemic and/or psychogenic impotence. However, with papaverine hydrochloride (30 mg./ml.) and exclusively in cases of vasculogenic (most probably arteriogenic) impotence, negative erectile response was revealed as absent erection in 6 of 52 patients (11.5%) and nonrigid tumescence in 13 (25%) versus 2 (3.8%) and 8 (15.4%), respectively, with prostaglandin E1. Moreover, with prostaglandin E1 the regional pain was tolerable and transient, and the positive erectile response was not attended by priapism even in patients who formerly had priapism with papaverine hydrochloride. However, presently with prostaglandin E1 the relatively higher cost and shorter expiration period would probably limit its diagnostic and therapeutic use in Egypt, and probably in other developing countries.     

Determination of hepatitis C virus genotype by Pyrosequencing

A simple sequencing-based assay is described for genotyping of hepatitis C virus (HCV). RT-PCR was employed to amplify a 237-nucleotide-long fragment from the 5' untranslated region (UTR) of the genome using one biotinylated and one normal primer. Subsequent to capture of the PCR products on streptavidin-coated beads, single-stranded DNA separation, and hybridization of sequencing primer, Pyrosequencing was performed. The genotype of 98 samples out of which 77 samples were from American veterans and 21 samples were from Iran was determined. The samples from the American veterans contained six different subtypes, while five subtypes were found in Iranian samples. For rapid population-specific HCV subtyping, a multiplex assay was developed. This study demonstrates the suitability of this technology for low-cost, high throughput and accurate microbial genotyping.     

REM sleep deprivation inhibits LTP in vivo in area CA1 of rat hippocampus

Rapid eye movement (REM) sleep deprivation has previously been shown to interfere with normal learning and memory and to inhibit long-term potentiation (LTP) in vitro. Previous studies on REM sleep deprivation and LTP have relied on in vitro analysis in isolated brain slices taken from animals following several days of sleep deprivation. LTP in the hippocampus in situ may differ from LTP in vitro due to modulatory inputs from other brain regions, which are altered after REM sleep deprivation. Here, we examined LTP in unanesthetized, behaving animals on the first and second recovery days following REM sleep deprivation to determine if similar effects are seen in vivo as previously reported in vitro. We found that LTP was significantly impaired in REM sleep-deprived animals on the second recovery day but not the first recovery day. Our results extend previous findings by showing that REM sleep deprivation continues to affect hippocampal function for more than 24h following the end of deprivation. Our results also suggest the presence of a modulatory process not present in vitro. Our findings are not explained by stress during REM sleep deprivation because equivalent circulating corticosterone levels (an index of stress) were found during both REM sleep deprivation and control treatment.     

Direct toxic effect of iodide in excess on iodine-deficient thyroid glands: epithelial necrosis and inflammation associated with lipofuscin accumulation

Involution of thyroid hyperplasia (induced by a low iodine diet and a goitrogen, propylthiouracil, PTU) was obtained in mice by administering a high or a moderate dose of iodide (HID or MID, respectively). In HID involuting glands, vasoconstriction was observed after 12 hr whereas necrosis and inflammation were very abundant as early as after 6 hr and maximal after 48 hr. They were not prevented by papaverine by which vasoconstriction was inhibited, but were inhibited by the continuation of PTU by which iodide oxidation and organification were inhibited. Lipofuscin inclusions in thyroid and inflammatory cells were always associated with necrosis. On the contrary, when involution was induced by MID or by HID + triiodothyronine (T3), or by T3 alone, neither necrosis nor inflammation occurred and apoptosis was the only mode of cell deletion. No lipofuscin inclusion occurred. Our results demonstrate that iodide in excess, after being oxidized or organified, is directly toxic for iodine-deficient thyroid cells. The presence of lipofuscin suggests that its toxicity is mediated by lipid peroxidation, a consequence of production of free radicals in excess.     

New and sensitive standard cell culture technique for the detection of cytomegalovirus in clinical specimens

Conventional tube cell culture has been recognised as the most sensitive technique available for human cytomegalovirus (HCMV) detection. Low-speed centrifugation of specimen inocula onto cell culture monolayers has been shown to increase the efficiency of infection with the AD 169 strain of HCMV. Therefore a centrifugal force of 900g for 1 hour at 37 degrees C was used to enhance the detection of HCMV cytopathic effect (CPE) in shell vials that contained circular coverslips with a monolayer of human embryonic lung (HEL) fibroblasts. Of 195 specimens, HCMV CPE was detected in 18 specimens (9.02%) on shell vial culture assay, whereas conventional tube cell culture was positive in only 13 specimens (6.6%). The shell vial culture assay was significantly more sensitive (P less than 0.05). Furthermore the development of the cytopathic effect on shell vial culture assay was significantly earlier (P less than 0.01) and more extensive. Urine samples were sonicated and the results obtained with immunofluorescence using human immune serum demonstrated that sonication increased both the intensity of fluorescence and number of fluorescent foci of HCMV-infected cells and also decreased the non-specific fluorescence of the background.