Visual discrimination and short-term memory for random patterns in patients with a focal cortical lesion

Visual discrimination and short-term recognition memory for computer- generated random patterns were explored in 23 patients with a postsurgical lesion in one of the cortical hemispheres. Their results are compared with those of 23 age-matched volunteers. In a same- different forced-choice discrimination task, d' and log beta (measures of sensitivity and bias), as well as reaction time (RT) were determined. All participants viewed patterns defined either by luminance contrast or isoluminant red-green color contrast, the amplitude of which was adjusted to be 10 times the respective detection threshold level. Block patterns consisting of a 6 x 6 matrix of light and dark (red and green) checks were randomly configured on each presentation. They were presented in pairs, randomly in two visual quadrants for a duration of 200 msec. Three presentation conditions were used: simultaneous presentation of reference and test stimulus, sequential presentation with a short delay (interstimulus interval, ISI = 3 s), and sequential presentation with a long delay (ISI = 6 s). The results indicate that patients with a lesion in the occipitotemporal cortex, the superior temporal cortex and the frontal cortex were significantly impaired on both luminance-contrast and color-contrast pattern discrimination. Patients with damage in the anterior inferotemporal cortex showed no overall impairment. The results suggest that performance in visual discrimination and recognition memory tasks rely on distributed neural processes with more than one neocortical location.      

HIV/AIDS infection control enforcement: a comparison between Nigeria and the United States

We examined differences in approaches to HIV-related infection control practices in two university teaching hospitals in the United States and Nigeria. Health care workers (n = 202 in Nigeria and 186 in the USA) responded to a previously validated measure of infection control practices. There were significant differences in the estimated probability of treating a person with HIV disease (higher in USA), and a greater probability of peer ridicule as a way of enforcing group norms on infection control in Nigeria. Peer enforcement of norms was significantly lower in the USA. In both countries, more precautions would be taken if it was known that the patient was HIV infected. Infection control practices were more likely to be followed in the USA compared with Nigeria if they were praised for this activity, if appropriate facilities (sharps containers, gloves, etc.) were nearby, and if they felt that infection control procedures were effective. These data point to the importance of normative social pressures in Nigeria and of knowing the patient is HIV infected in the USA and feeling that infection control procedures are effective ways of avoiding occupational HIV infection. The role of normative pressures and assumptions about HIV infection status as well as cues and availability of facilities for infection control appear to differ between these health care workers in Nigeria and the USA.     

阿片受体拮抗剂在TNF－α所致体温升高中的作用

为探索细胞介素ＴＮＦ－α升体温效应与下丘脑前部、视前区（ＰＯＡＨ）中的阿片受体的关系。应用脑神经核团微量注射方法给自由状态下的雄性ＳＤ大鼠ＰＯＡＨ区微量注射ＴＮＦ－α致热源。给药前３０ｍｉｎ分别用通常阿片受体拮抗剂Ｎａｌ（１０～２０μｇ）和特异性阿片受体μ、δ和κ的拮抗剂ＣＴＡＰ（１．０～２．５μｇ）、ＮＴＩ（０．２５～０．５μｇ）和ｎｏｒ－ＢＮＩ（０．１～３μｇ）对ＰＯＡＨ做预处理。结果：单独给ＴＮＦ－α可致剂量相关的体温升高△Ｔ（１℃～１．４℃）；经Ｎａｌ１０μｇ，ＣＴＡＰ１．０μｇ和ＮＴＩ０．５μｇ处理后使ＴＮＦ－α的升体温效应减弱；用Ｎａｌ２０μｇ，ＣＴＡＰ２．５μｇ和ＮＴＩ０．２５μｇ处理后可完全阻断ＴＮＦ－α所致的体温升高；ｎｏｒ－ＢＮＩ（０．１～３μｇ）对ＴＮＦ－α的升体温效应无影响。     

Long-term follow-up of autoantibody profiles in black female lupus patients and clinical comparison with Caucasian and Asian patients

The aim was to determine whether the autoantibody profile in Black female lupus patients is associated with clinical subsets, fluctuates over time and/or reflects disease activity. A clinical comparison with Caucasian and Asian patients matched for age of onset and disease duration was also undertaken. Up to seven serial bleeds from Black female lupus patients who had been followed up for periods of 3.15 yr were tested for antibodies to Ro/SSA, La SSB. Sm, RNP and ribosomal P using ELISA research assays. Significant differences in both clinical and serological profiles between the ethnic groups were found. Varying aspects of disease activity were linked to anti-DNA (renal, cardiovascular, global score), anti-ribosomal P (musculoskeletal, haematology) and anti-Sm (general) antibodies. There are differences in clinical and serological profiles amongst systemic lupus erythematosus patients of different ethnic origin. However, using the BILAG system, relatively few antibodies were found to reflect disease activity accurately in serial measurements.