Expression of protein kinase C isoforms in euxanthone-induced differentiation of neuroblastoma cells.

Euxanthone, a potent neuritogenic compound isolated from the roots of the medicinal herb Polygala caudata, has recently been shown to induce the differentiation of murine neuroblastoma Neuro 2A (BU-1) cells. In this study, the role of protein kinase C (PKC) and the expression of various PKC isoforms in euxanthone-treated BU-1 cells were examined. mRNA phenotyping using the reverse-transcription polymerase chain reaction (RT-PCR) showed that BU-1 cells express six different PKC isoforms, namely PKC-alpha, -beta, -delta, -epsilon, -lambda, and -zeta. Differential regulation and expression of PKC isoforms was observed in BU-1 cells treated with 100 microM euxanthone. PKC-apha, -beta, -delta, -lambda and -zeta were all up-regulated, with 1.7- to 9.5-fold increase, at around 30 to 60 minutes after euxanthone treatment. The expression level of PKC-epsilon remained relatively constant during the treatment. PKC-gamma, -eta, and -theta were not detected in both untreated and euxanthone-treated BU-1 cells. Staurosporine, a broad spectrum PKC inhibitor, was found to inhibit both spontaneous and euxanthone-induced neuritogenesis in BU-1 cells. A significant reduction of the euxanthone-induced neuritogenic effect was also observed when the PKC isoform-specific inhibitor Go6976 was included in the culture. These results suggest that the euxanthone-induced differentiation of the neuroblastoma BU-1 cells may be mediated through the differential expression of PKC-alpha, -beta, -delta, -lambda and -zeta isoforms.

Applying social skills training in the context of vocational rehabilitation for people with schizophrenia.

This paper describes a model for the conceptualization of social skills necessary for the vocational success of people with schizophrenia. Based on this model, a two-part measure was developed and validated to assess social skills necessary for job search and tenure. The measure consists of a 10-item self-administered checklist and a role-play exercise. The self-administered checklist measures clients' perceived competence in handling work-related social situations. The role-play exercise assesses the social skills necessary for job acquisition and maintenance in two simulated situations (participating in a simulated job interview and requesting urgent leave from work). Furthermore, a social skills training module has been designed, which enhances vocational outcome and fills a gap in the existing, commonly used modules. A pilot study shows that the training module together with appropriate professional support afterward is effective in enhancing the social competence and vocational outcomes of persons with schizophrenia. Implications for cross-cultural applications are discussed.

Reliability and validity of a simple measure for assessing the social skills of people with schizophrenia necessary for seeking and securing a job.

The literature shows that social and vocational impairments are common problems among people with schizophrenia. However, assessment instruments available for measuring social competence of people with schizophrenia in the workplace are limited. This article describes a two-part measure developed and validated based on a model (Tsang & Pearson, 1996) for assessing social skills necessary for seeking and maintaining a job for people with schizophrenia. The measure consists of a 10 item self-administered checklist and a role-play exercise. The self-administered checklist measures clients' perceived competence in handling work-related social situations. The role-play exercise assesses the social skills necessary for job acquisition and maintenance in two simulated situations (participating in a simulated job interview and requesting urgent leave from work). Cronbach alpha coefficients (self-administered checklist: .80 (n = 140); role-play test: .96 (n = 60)) show that both parts had good internal consistency. In addition, correlation coefficients show that the self-administered checklist has acceptable test-retest reliability (.35 to .78), and the role-play exercise has good interrater reliability (.77 to .90). The concurrent validity is also shown to be good for both parts of the measure using the method of contrasted groups. It is suggested that this measure is suitable for use by clinicians, rehabilitation administrators and researchers. Application of the instrument in other countries is discussed. Finally, further research is suggested.

A randomized double-blind controlled calcium supplementation trial, and bone and height acquisition in children.

There is limited information relating Ca intake to bone and height acquisition among Oriental children who consume little or even no milk. The present controlled study investigated the acquisition of bone mass and height of Chinese children with an initial Ca intake of approximately 567 mg/d who were supplemented to about 800 mg/d. Eighty-four 7-year-old Hong Kong Chinese children underwent an 18-month randomized, double-blind, controlled Ca-supplementation trial. The children were randomized to receive either 300 mg elemental Ca or a placebo tablet daily. Bone mass of the distal one-third radius was measured by single-photon absorptiometry, lumbar spine and femoral neck were determined using dual-energy X-ray absorptiometry. Measurements were repeated 6-monthly. Baseline serum 25-hydroxycholecalciferol concentration and physical activity were also assessed. Baseline Ca intakes of the study group and controls were respectively 571 (SD 326) and 563 (SD 337) mg/d. There were no significant differences in baseline serum 25-hydroxycholecalciferol concentration (P = 0.71) and physical activity (P = 0.36) between the study and control groups. After 18 months the study group had significantly greater increases in lumbar-spinal bone mineral content (20.9 v. 16.34%; P = 0.035), lumbar-spinal area (11.16 v. 8.71%; P = 0.049), and a moderately greater increment in areal bone mineral density of the radius (7.74 v. 6.00%; P = 0.081) when compared with the controls. The results confirm a positive effect of Ca on bone mass of the spine and radius but no effects on femoral-neck and height increase. A longer trial is warranted to confirm a positive Ca effect during childhood that may modify future peak bone mass.

Inhibition of the human flexion reflex by low intensity, high frequency transcutaneous electrical nerve stimulation (TENS) has a gradual onset and offset.

The present study examines the inhibitory effect of segmentally applied TENS on the nociceptive component of the flexion reflex elicited in various lower limb muscles, in an attempt to gain some insight into the underlying mechanism. The flexion reflex from 11 normal subjects was recorded electromyographically from the biceps femoris (BF), the tibialis anterior (TA), and in 2 subjects, the hip flexor (HF), in the manner described in a previous paper [9]. Amplitude and area values of the flexion reflex of each muscle were computerized prior to, during, and 50 min after the application of placebo or low intensity TENS at 100 Hz, for 30 min to the low back, at levels of segmental innervation (L4-S1) similar to those of the muscles under study. In the majority of subjects, we found that: Low intensity TENS caused a significant inhibition of the flexion reflex in proximal limb flexors. Thus, the BF measured 64% and 52%, and the HF 45% and 51%, of their respective mean control amplitude and area values at the time of maximum inhibition during TENS. Moreover, less reduction of the mean values of the flexion reflex was observed in the TA, a distal limb (ankle) flexor. It is noteworthy that in both the BF and HF, the time to peak maximum inhibitory effect took 30 and 20 min respectively after the onset of TENS, and the flexion reflex often did not return to control values even at 40-50 min after TENS. In contrast, placebo TENS application resulted in no significant change of the flexion reflex in all the muscles examined. These findings showed that prolonged stimulation of large diameter fibers by conventional TENS application to the lumbosacral level, exerts a progressive and long latency inhibitory influence on a number of lower limb flexor motoneurons. In keeping with functional demand, this effect was found to be more prominent on the proximal than distal limb muscles. Furthermore, a gradual onset and offset of this inhibitory action is consistent with the results of some investigators demonstrating the possible involvement of endogenous opioids.