Functional and morphological examinations of P1A1 purinoceptors in the normal and inflamed urinary bladder of the rat

The aim of the present study was to investigate the relaxatory function of adenosine receptor subtypes in rat urinary bladder, and if it is altered in the state of inflammation. The in vitro responses to the P1 receptor agonist adenosine were investigated in the presence of the general P2 receptor antagonist pyridoxal-phosphate-6-azophenyl-2′,4′-disulfonic acid (PPADS; 1 ? 10^? 4 M). Experiments were performed on preparations from normal (healthy) rats and rats with cyclophosphamide (CYP; 100 mg kg^? 1 i. p.)-induced cystitis. The specific P1A₁ antagonist 1,3-dipropyl-8-cyclopentylxanthine (DPCPX; 1 ? 10^? 5 M) decreased the adenosine relaxatory response in normal bladders (? 60%), but not in preparations from CYP pre-treated rats. Immunohistochemical findings support the hypothesis that the expression of P1A₁ receptors in the rat urinary bladder is decreased during cystitis. The adenosine-evoked relaxation was not affected by the specific P1A_2A antagonist SCH 58261 (3 ? 10^? 7 M), neither in normal nor in CYP pre-treated rats. The relaxation to adenosine was, however, significantly increased by the specific P1A₃ antagonist MRS 1523 (1 ? 10^? 5 M) in preparations from both normal and CYP pre-treated rats, suggesting P1A₃ to be mediating bladder contraction. Thus, in the rat urinary bladder the relaxation to adenosine is mainly due to the P1A₁ receptor, while the P1A₃ receptor seems to be responsible for contractile responses. The DPCPX-resistant part of the relaxation is possibly due to the P1A_2B receptor, the fourth subtype of the adenosine receptor family.     

Retinal function after scleral buckling for recent onset rhegmatogenous retinal detachment: assessment with electroretinography and optical coherence tomography

PURPOSE: To investigate central and peripheral retinal function after scleral buckling surgery for recent onset rhegmatogenous retinal detachment (RD). METHODS: Fifteen phakic patients with rhegmatogenous RD for <1 week underwent scleral buckling surgery. Clinical investigation, optical coherence tomography (OCT), full-field electroretinography (ERG), and multifocal ERG (mfERG) with fundus illumination were performed preoperatively and 6 months postoperatively. RESULTS: Anatomical success was achieved in 14 patients. mfERG amplitudes were reduced preoperatively in detached retina, with significant improvement at follow-up (P = 0.002). Foveal amplitudes improved significantly (P = 0.027). There was no significant difference in postoperative mfERG amplitudes between areas that had been preoperatively detached or attached (P = 0.739). In the subgroup of eight patients in whom the detachment engaged the fovea preoperatively, rod function improved significantly as assessed with full-field ERG (P = 0.008). In these patients, the extent of detachment ranged between 4 clock hours and 6 clock hours, as compared with 2 clock hours and 5 clock hours in the remaining patients. OCT showed subretinal foveal fluid in four patients at follow-up. CONCLUSIONS: In recent onset rhegmatogenous RD, total rod and localized central retinal dysfunction in detached retina can improve significantly after reattachment. mfERG and OCT are suitable tools for further studies of functional outcomes in RD.     

Effects of emotional prosody on auditory extinction for voices in patients with spatial neglect

The response of attention systems to emotional stimuli has been intensively investigated in the visual modality. Several findings suggest that neural mechanisms influencing selective attention towards emotional stimuli involve brain systems that are partly independent of cortical networks associated with the control of voluntary attention. To test this hypothesis in the auditory modality, we used a dichotic-listening paradigm in six right-hemisphere patients with left spatial neglect syndrome and left ear extinction during bilateral auditory stimulation. Three different meaningless emotional prosodic utterances (anger, fear, and happiness) were presented to the right or left ear, either alone or paired with another neutral utterance on the other side. Results showed fewer misses for emotional relative to neutral stimuli presented to the left ear, for all emotion categories, including happiness. In addition, we also examined the correlation between the site of brain lesions and the performance of patients for reporting left-ear stimuli. This exploratory anatomical analysis suggested that the relative advantage for emotional over neutral voices may be modulated by the site and extent of brain damage. This modulation consists of reduced influences of emotional prosody in patients with lesions in right ventral prefrontal lobe or right superior temporal cortex. Taken together, our results have provided new evidence that emotional attention mechanisms may be triggered in the auditory modality by negative and positive vocal stimuli.     

A simple method for long-term storage of Acanthamoeba species

We present a novel and simple technique for storing live Acanthamoeba for long periods of time. The amoebae are maintained at refrigerator temperatures in a peptone–yeast extract–glucose (PYG) medium normally used for cultivation. Using this method, we obtained survival rates of at least 4 years for Acanthamoeba polyphaga and 3 years for Acanthamoeba castellanii and Acanthamoeba rhysodes. Advantages of this storage method are: (1) it is quick and simple, (2) inexpensive, (3) does not require encystment before storage, (4) resuscitation of cysts can be achieved within a week of culture in PYG medium at 27°C, and does not require co-culture with bacteria or any special equipment.     

A case of asymptomatic pontine myelinolysis

Central pontine myelinolysis is an acquired, non-inflammatory demyelinating lesion usually localized in the brainstem pons basis; it usually affects patients with a history of chronic alcoholism, malnutrition or dysionemia. The exact pathogenesis of myelinolysis is still unclear. A 69-year-old Caucasian male presented intensive headache and underwent cranial MRI that showed the typical feature of central pontine myelinolysis. Neurological valuation was negative. Other examinations included extensive blood tests, electroencephalogram and multimodal evoked potentials which all gave normal results. Alcohol abuse and malabsorption syndrome were excluded. The medical history revealed a continuative use of anti-depressive drugs and exposure to glue for years. Our patient may represent one of the rare cases of asymptomatic CPM. The actual reason why he presented this lesion is not clear, but we discuss the possible role in the etiopathogenesis of his chronic use of anti-depressive drugs and the exposure to glue and chemical agents.     

Hydroxyapatite growth on anodic TiO2 nanotubes

In the present work, we study the growth of hydroxyapatite formation on different TiO(2) nanotube layers. The nanotube layers were fabricated by electrochemical anodization of titanium in fluoride-containing electrolytes. To study various nanotube lengths, layers with an individual tube diameter of 100 nm were grown to a thickness of approximately 2 mum or 500 nm. The ability to form apatite on the nanotube layers was examined by immersion tests combined with SEM, XRD and FT-IR investigations. For reference, experiments were also carried out on compact anodic TiO(2) layers. The results clearly show that the presence of the nanotubes on a titanium surface enhances the apatite formation and that the 2-mum thick nanotube layer triggers deposition faster than the thinner layers. Tubes annealed to anatase, or a mixture of anatase and rutile are clearly more efficient in promoting apatite formation than the tubes in their "as-formed" amorphous state.     

Isolation of human immunodeficiency virus-type 1 (HIV-1) clones with biological and molecular properties of the primary isolate

We developed a new biological cloning system for HIV-1 isolates using the U87.CD4 cell lines that express different chemokine receptors. We demonstrate that our method is sensitive and specific because the clones isolated had the same coreceptor usage and genotype as viruses of the primary isolate. We evaluated our cloning system by isolating 27 biological clones from two primary HIV-1 R3R5X4 isolates. Three HIV-1 phenotypes (R3R5X4, R3R5 and R5) were identified in isolate 29 and two (R3R5X4 or R5X4) in isolate 31. Each phenotype was distinguished by a unique genotype. Sequencing of 20 molecular clones from each isolate did not reveal additional genotypes. One of the three genotypes identified from isolate 29 was not found by molecular cloning of the original isolate, suggesting high specificity and sensitivity of the biological cloning system in isolating minor virus populations. Our results suggest that the new cloning approach can be used as an alternative to the existing method for isolating biological clones in PBMC.     

Identification of susceptibility loci for cervical carcinoma by genome scan of affected sib-pairs

Cervical cancer is caused by a combination of environmental and genetic risk factors. Infection by oncogenic types of human papillomavirus is recognized as the major environmental risk factor and epidemiological studies indicate that host genetic factors predispose to disease development. A number of genetic susceptibility factors have been proposed, but with exception of the human leukocyte antigen CHLA, class II, have not shown consistent results among studies. We have performed the first genomewide linkage scan using 278 affected sib-pairs to identify loci involved in susceptibility to cervical cancer. A two-step qualitative non-parametric linkage analysis using 387 microsatellites with an average spacing of 10.5 cM revealed excess allelic sharing at nine regions on eight chromosomes. These regions were further analysed with 125 markers to increase the map density to 1.28 cM. Nominal significant linkage was found for three of the nine loci [9q32 (maximum lod-score, MLS) =1.95, P<0.002), 12q24 (MLS=1.25, P<0.015) and 16q24 (MLS=1.35, P<0.012)]. These three regions have previously been connected to human cancers that share characteristics with cervical carcinoma, such as esophageal cancer and Hodgkin's lymphoma. A number of candidate genes involved in defence against viral infections, immune response and tumour suppression are found in these regions. One such gene is the thymic stromal co-transporter (TSCOT). Analyses of TSCOT single nucleotide polymorphisms further strengthen the linkage to this region (MLS=2.40, P<0.001). We propose that the 9q32 region contains susceptibility locus for cervical cancer and that TSCOT is a candidate gene potentially involved in the genetic predisposition to this disease.