Relationship between visual field loss and contrast threshold elevation in glaucoma

Background  

There is a considerable body of literature which indicates that contrast thresholds for the detection of sinusoidal grating patterns are abnormally high in glaucoma, though just how these elevations are related to the location of visual field loss remains unknown. Our aim, therefore, has been to determine the relationship between contrast threshold elevation and visual field loss in corresponding regions of the peripheral visual field in glaucoma patients.     

hCMV and Tet promoters for inducible gene expression in rat neurons in vitro and in vivo

To advance our understanding of the central nervous system, there is a need for refined approaches to control gene expression in neuronal culture as well as in the brain in vivo. In this study, we have applied a doxycycline-responsive Tet system to obtain a tightly controlled gene expression in neurons. In the absence of doxycycline, the Tet promoter-driven transgene expression was blocked by Tet transrepressor (tTR). Expression was doxycycline activated with the aid of a reverse Tet transactivator (rtTA). Application of both tTR and rtTA resulted in a much greater inducibility, as compared to rtTA alone, mainly due to a decreased basal level of expression. Such effects were observed when tTR and rtTA were driven in cultured neurons by the alpha CaMKII promoter. However, introduction of the human CMV major immediate-early promoter resulted only in a mediocre neuronal gene expression, unless the cells were treated, either in culture or in vivo, with depolarizing concentrations of KCl. Thus, in the present report, we have examined hCMV and Tet promoter inducibility in neurons to produce an important improvement in the functioning of the Tet system.     

Health Status in Patients with Alzheimer’s Disease: An Investigation of Inter-rater Agreement

Objective: The purpose of the present study was to examine the level of agreement between health status ratings provided by patients with Alzheimer’s disease and by their proxies. Background: Because proxy-completed responses are often necessary in assessing health outcomes for the elderly, it is necessary to determine the feasibility and potential limitations of using proxies as a patient substitutes. Methods: To assess the potential utility of proxy responses on health status when subjects present a cognitive impairment, this study compared the responses of 70 subjects with Alzheimer‘s disease and those of their family and/or care provider proxy using the SF-36. Agreement between proxies and patients was measured by intraclass correlation coefficients (ICCs). Results: The proportion of exact agreement between patients and proxies on the 36 items ranged from 3.3 to 41.7%. Results reveal poor to moderate agreement between patient and proxy reports. Proxy reliability varied according to the relationship of the proxy to the index subject. Agreement decreased significantly with increasing severity of dementia and with increasing severity of Physical status (Katz ADL). Agreement was better for measures of functions that are directly observable and relatively poor for more subjective measures. Conclusions: Our results confirm the importance of the information source used for patient health status.     

Exercise heart rate response to facial cooling

Summary The heart rate responses of physically untrained men to exercise with and without facial cooling were determined. Cold wind (10‡ C, 6.5 m·s⁻¹, or 2‡ C, 6.5 m·s⁻¹) was directed at the faces of the subjects during a 16 min bout of progressively intense exercise. The 10‡ C wind resulted in a significant (p<0.05) lowering of heart rate that appeared to be associated with a decline in forehead temperature at 4, 6, and 8 min of exercise. No differences were observed for blood pressure or rectal temperature. The significant (p<0.05) reduction in heart rate with the 2‡ C cold wind did not appear to be associated with changes in facial temperature. The 2‡ C wind also resulted in a persistent peripheral vasoconstriction (p<0.05). The results suggest that the heart rate response to facial cooling during exercise is mediated not through a reflex associated with increased stroke volume but rather via a central thermoregulatory response.     

Patient satisfaction with the management of infertility

The objective of this study was to assess patient satisfaction with the investigation and initial management of infertility. A postal questionnaire survey was carried out of 1366 women attending outpatient clinics for the investigation and initial management of infertility at 12 hospitals throughout Scotland. The response rate to the questionnaire was 59% (806/1366). Overall, 87% of responders were satisfied or very satisfied with their care but a number of deficiencies were identified. Thirty-nine per cent had never been asked to bring their partner to the clinic and 86% felt they had not been given enough help with the emotional aspects of infertility. Forty- seven per cent felt they were not given a clear plan for the future and 23% of those who had been given drug treatments reported receiving little or no information about the treatment or possible side-effects. Overall, only a third had been given any written information and 78% expressed a wish for more written information. Women ranked 'the information and explanation given' and the 'attitude of the doctor at the clinic' highly in comparison to other aspects of their care, including 'help with the emotional aspects of infertility'. In general women were satisfied with their care but improvements may be made by giving more explanation and written information and by adopting a more couple-centred approach. Where resources allow, clinics should take steps to address the emotional aspects of infertility.      

Cytogenetic abnormalities of unfertilized oocytes generated from in- vitro fertilization and intracytoplasmic sperm injection: a double- blind study

In the present study we have assessed the cytogenetic abnormalities of unfertilized oocytes from in-vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) programmes during a one year period (July 1995 to July 1996) with the cytogenetic analysis being carried out in a double-blind manner. A total of 88 unfertilized ICSI and 85 unfertilized IVF oocytes were used for the study and of these 51 and 62 oocytes, in each respective group, were suitable for analysis. The haploidy, diploidy and aneuploidy rates between ICSI (62.7, 7.8 and 5.9%) and IVF (61.3, 9.7 and 14.5%) groups were similar. A significant inter-patient variation in the incidence of hypohaploidy was observed within the IVF group. Chromosomal fragmentation or breakage was observed at a similar rate in both groups of unfertilized oocytes (23.5 and 14.5% for ICSI and IVF respectively). A significantly higher proportion of ICSI oocytes contained sperm nuclei (27/51, 52.9%) than did IVF oocytes (20/62, 32.3%, P < 0.01). The distribution and state of sperm head chromatin in relation to oocyte chromosomal complement was studied in both groups. ICSI oocytes contained decondensed or swollen sperm nuclei in association with haploid oocyte chromosomes (12/27, 44.4%) or condensed sperm heads in oocytes showing no chromosomal complements (7/27, 25.9%). In IVF oocytes sperm heads were either arrested in the condensed state (5/20, 25%), metaphase stage (3/20, 15%) or had undergone premature chromosome condensation (PCC; 6/20, 30%) in association with haploid oocyte chromosomes. The incidence of PCC was similar in the two groups. A marked variation in the incidence of total chromosomal abnormality was observed between patients within both ICSI (0-75%) and IVF (0-71%) groups indicating a possible similarity in oocyte quality between the majority of male factor and tubal infertility patients. The type of sperm used in the two fertilization procedures showed an increased incidence of chromosomal breakage with ICSI-MESA (microepididymal sperm aspiration) spermatozoa (4/6, 67%) compared to the ICSI-ejaculated (6/35, 17.1%; P < 0.05), ICSI-testicular biopsy (2/10, 20%) and IVF-normospermic (9/62, 14.5%; P < 0.01) spermatozoa. Chromosomal fragmentation may be associated with the degree of difficulty experienced at sperm injection, especially with sperm retrieved from the reproductive tract. Thus chromosomal fragmentation in ICSI may need further investigation using a larger sample size in order to assess the possible causative factors.      

CD79 alpha/CD79 beta heterodimers are expressed on pro-B cell surfaces without associated mu heavy chain

During B cell development, the surface expression of CD79 alpha/CD79 beta heterodimers had been thought to begin in the pre-B cell stage where the heterodimers constitute pre-B cell receptors together with mu heavy and surrogate light chains. Thereafter, in mature B cells, CD79 alpha/CD79 beta associates with surface Ig to form B cell antigen receptors. In this study, we revealed by using newly established mAb that CD79 beta was expressed on the surface of pro-B cells which had not undergone the productive Ig gene rearrangement. Biochemical analysis showed that CD79 beta on pro-B cells existed either as monomers or as disulfide-linked heterodimers with CD79 alpha, non- covalently associated with four unidentified membrane molecules. Our finding that CD79 beta is expressed on earlier B-lineage cells than previously expected coincides with the recent study in which CD79 beta- deficient mice exhibit a blockade of B cell differentiation at the pro- B cell stage. Thus, it is speculated that the CD79 beta-containing complexes on pro-B cell surfaces may function to induce early B cell differentiation.