The fate and function of oligodendrocyte progenitor cells after traumatic spinal cord injury

Oligodendrocyte progenitor cells (OPCs) are the most proliferative and dispersed population of progenitor cells in the adult central nervous system, which allows these cells to rapidly respond to damage. Oligodendrocytes and myelin are lost after traumatic spinal cord injury (SCI), compromising efficient conduction and, potentially, the long-term health of axons. In response, OPCs proliferate and then differentiate into new oligodendrocytes and Schwann cells to remyelinate axons. This culminates in highly efficient remyelination following experimental SCI in which nearly all intact demyelinated axons are remyelinated in rodent models. However, myelin regeneration comprises only one role of OPCs following SCI. OPCs contribute to scar formation after SCI and restrict the regeneration of injured axons. Moreover, OPCs alter their gene expression following demyelination, express cytokines and perpetuate the immune response. Here, we review the functional contribution of myelin regeneration and other recently uncovered roles of OPCs and their progeny to repair following SCI.     

Employee absenteeism measures reflecting current work practices may be instrumental in a re‐evaluation of the relationship between psychological distress/mental health and absenteeism

Absenteeism rates are the cornerstone metrics guiding corporate policy for health care investment in employees. However, traditional absenteeism measures do not reflect the contemporary workplace milieu. It is accepted practice that employees work evenings or weekends to makeup time. Using a hours‐based absenteeism measure, that accounts for time made‐up as well as time lost, this paper evaluates the impact of psychological distress on employee absenteeism. Psychological distress and absenteeism data were collected from 54,264 full‐time employees. Consistent with traditional approaches, employees indicated how many days they were absent. Hours based absenteeism was formulated from the ratio of how many hours the employees worked and how many hours were they expected to work in the past seven‐days. Concordant with previous concinnous evidence, traditional absenteeism computation indicated that elevated psychological distress is associated with increasing absenteeism. Using the hours‐based method psychological distress did not significantly influence absenteeism. Traditional calculations of absenteeism do not reflect the current work practices of the majority of employees. Employees with psychological distress may take time off work but it appears that they make up for lost time possibly to stay up to speed with task driven occupations and avoid performance review. Copyright © 2009 John Wiley & Sons, Ltd.     

Short-duration (three cycles) cisplatin combination chemotherapy with alkylating agent consolidation in advanced epithelial ovarian cancer

Forty-eight patients with advanced epithelial ovarian cancer were treated with a two-part cytotoxic regimen consisting of three cycles of cisplatin-based induction therapy followed by five cycles of escalating doses of cyclophosphamide, all given at 3-weekly intervals. The total cisplatin dose was 225 mg/m2. Seventeen patients with optimal primary surgery received chemotherapy only, while 17 of the 31 patients with suboptimal primary surgery underwent optimal interval cytoreductive surgery at the end of induction (cisplatin) therapy. Median survival for all patients was 15.4 months. Median survival was 15 months for patients with optimal primary surgery and 22 months for patients who had optimal secondary cytoreduction. Only 10 patients suffered WHO grade 3 or greater toxicity during therapy. This study suggests that the total dose of cisplatin can be reduced for patients with advanced ovarian carcinoma, resulting in reduced overall toxicity, without compromising response or response duration. A randomized trial to test this concept is now underway.     

The neuropeptide histidyl proline diketopiperazine throughout human pregnancy: an inverse correlation with amniotic fluid prolactin

Histidyl proline diketopiperazine values have been established in human amniotic fluid (n = 81) and maternal serum (n = 36) throughout gestation (10 to 42 weeks). Newborn cord serum (n = 10) and first-voided fetal urine (n = 10) levels were also documented. These measurements reveal increasing amniotic fluid levels with term gestation values (15,551 pg/ml) nearly thirteen-fold higher than maternal serum concentrations (1150 pg/ml). Corresponding fetal urine and cord serum concentrations were 16,781 and 2160 pg/ml, respectively. The amniotic fluid values are not influenced by fetal sex or maternal labor, nor do they correlate with amniotic fluid alpha-fetoprotein levels. However, there is a significant inverse correlation (r = -0.628; p less than 0.0001) between amniotic fluid prolactin and histidyl proline diketopiperazine after midgestation. The hypothesis that histidyl proline diketopiperazine may be a regulatory peptide for decidual prolactin production was tested by culturing term decidua in the presence of varying concentrations of histidyl proline diketopiperazine, but no inhibitory effect was observed. Decidual cultures did not produce measurable amounts of histidyl proline diketopiperazine. It is suggested that amniotic fluid histidyl proline diketopiperazine is derived from fetal urine.     

The use of intravaginal oestrogen cream in genuine stress incontinence

Ten women presenting with symptoms of post-menopausal urogenital oestrogen deficiency, including atrophic vaginal changes and a variety of urinary symptoms, were studied urodynamically and shown to have genuine stress incontinence. Their urethral function was assessed by resting and stress pressure profiles before and after treatment with an intravaginal oestrogen cream. A reduction in the severity of symptoms of stress incontinence, urgency and voiding difficulties was found. No significant changes were induced in the resting urethral pressure profile although the maximum urethral closure pressure on stress was significantly increased as a consequence of improved pressure transmission in mid-urethra. The distribution of pressure transmission suggests that the effect of oestrogen therapy may be due to improved efficiency of urethral closure by the pelvic floor in response to stress.     

A late complication of spousal kidney donation

An 83-year-old female who had previously (32 years ago) donated a kidney to her husband presented with loin pain, confusion and oliguria. Acute renal failure and pulmonary edema necessitated emergency hemodialysis. The history and findings were thought to be consistent with acute renal artery occlusion on a background of atherosclerosis and severe renal artery stenosis. We present this case, not to imply that renal donation is a hazardous procedure, but rather as an illustration of a complication of donor nephrectomy that in a very large series has proved to be extremely rare. This case illustrates the point that even very rare events become more likely as the period of follow-up increases.     

Generating mouse models of retinal disease using ENU mutagenesis

We used the chemical mutagen, N-ethyl-N-nitrosourea, to induce random point mutations in the germline of the mouse strain C57BL/6 in order to generate models of retinal diseases. 1163 mutagenised first generation mice produced using this approach were examined for eye abnormalities. Approximately one-third (412) presented with some form of ocular abnormality. Most changes were unilateral and confined to the anterior segment of the eye. Less than 10% (44) of identified changes affected the posterior segment of the eye. 21 mice with varying ocular abnormalities, including 17 with retinal changes, were bred to produce second generation mice to confirm genetic inheritance. Genetic inheritance was confirmed in several of these lines including three with retinal changes.     

Clinical and personality correlates of a new measure of depression: a general practice study

OBJECTIVE: There is a need for a brief, efficient depression screening measure for general practice settings, particularly for identifying those who are at high risk of depression. We therefore test the usefulness of a measure developed in a sample of medically ill hospitalized patients. METHOD: More than 600 patients attending six Sydney general practices completed the Depression in the Medically Ill (DMI-10) measure, in conjunction with sociodemographic, depression history and personality profile measures. The impacts of sociodemographic, personality and lifetime depression variables on DMI-10 scores (and identified 'cases') were examined as a measure of its usefulness. RESULTS: Gender did not influence depression scores, while there were slight associations between DMI-10 scores and age, marital and occupational status. Higher scores were returned by those with more severe, lengthier and perceived stressful medical illnesses. Using a predetermined cut-off score, 36% rated as putative 'cases', a prevalence almost identical to our general hospital study. 'Cases' were distinctly more likely to have had previous depressive episodes, to have sought help for such episodes and to have received antidepressant medication. They also scored higher on measures of anxious (anxious worrying and irritability) and self-critical ('depressive personality') personality styles. CONCLUSIONS: The DMI-10 appears useful as a brief and acceptable screen for depression in a general practice setting, both identifying those who are likely to be currently depressed and those with a background of previous depression.