Cytomegalovirus infections in seropositive patients after transfusion. The effect of red cell storage and volume

Antibody responses to cytomegalovirus (CMV) after red cell (RBC) transfusion were studied in 84 seropositive surgery patients and 82 seropositive oncology patients. The surgery patients were randomized to receive RBCs stored either 3 to 8 or 20 to 42 days after donation. Of 38 patients receiving RBCs stored 8 days or less, 3 developed a rise in titer (4-fold increase) of IgG antibody to CMV 8 to 12 weeks after transfusion. This rate of response (8%) did not differ significantly (p = 0.23) from that (16%) in the 46 patients receiving RBCs stored 20 to 42 days. Seropositive oncology patients were randomized to receive RBCs from seronegative or random donors. Five (19%) of 27 oncology patients receiving seronegative RBCs and 13 (23%) of 55 patients receiving random RBCs (mean, 2 seropositive RBC units/patient) developed a rise in titer of antibody to CMV. No CMV morbidity occurred in either patient group. For both patient groups, a rise in titer of antibody to CMV was associated with the number of transfused RBC units. These results confirm that CMV-seronegative RBCs are unnecessary for infrequently transfused seropositive patients. They also suggest that multiple transfusions of stored RBCs are as immunosuppressive as multiple transfusions of RBCs used within a few days after donation.     

Work-Home Interference,Perceived Total Workload,and the Risk of Future Sickness Absence Due to Stress-Related Mental Diagnoses Among Women and Men: a Prospective Twin Study

Purpose

Work-home interference has been proposed as an important explanation for sickness absence (SA). Previous studies show mixed results, have not accounted for familial factors (genetics and shared everyday environment), or investigated diagnosis specific SA. The aim was to study whether work-home interference and perceived total workload predict SA due to stress-related mental diagnoses, or SA due to other mental diagnoses, among women and men, when adjusting for various confounders and familial factors.

Methods

This study included 11,916 twins, 19–47 years (49% women). Data on work-to-home and home-to-work conflicts, perceived total workload, and relevant confounders were derived from a 2005 survey, and national register data on SA spells until 2013 were obtained. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated. Discordant twin pair design was applied to adjust for familial factors.

Results

Each one unit increase in work-to-home and home-to-work conflicts, and perceived total workload was associated with higher odds for SA due to stress-related mental diagnoses and to SA due to other mental diagnoses among women, when adjusting for sociodemographic factors (ORs 1.15–1.31). Including health or familial factors, no associations remained. For men, each one unit increase in work-to-home conflicts was associated with higher odds for SA due to stress-related diagnoses (ORs 1.23–1.35), independently of confounders.

Conclusion

Work-to-home conflict was independently associated with future SA due to stress-related diagnoses among men only. Health- and work-related factors seem to be important confounders when researching work-home interference, perceived total workload, and SA. Not including such confounders involves risking drawing incorrect conclusions. Further studies are needed to confirm sex differences and whether genetic factors are important for the associations studied.

     

Purinergic receptors on insulin-secreting cells

Summary— The insulin secreting B cell is fitted with the two types of purinergic receptors: P₂ (for ATP and/or ADP) and P₁ (for adenosine). The activation of P₂ purinoceptors by ATP or ADP evokes a biphasic stimulation of insulin secretion from isolated perfused rat pancreas; this stimulation is dose-dependent between 10^?6 and 10^?4 M. Non hydrolysable structural analogues are also effective, and the relative potency of various agonists (2-methylthio ATP ? ATP = ADP = α, β-methylene ATP ? AMP) gave evidence for a P_2y purinoceptor subtype. Proposed mechanisms include both an increased Ca²⁺ uptake and an increased intracellular Ca²⁺ mobilization via the hydrolysis of polyphosphoinositides. ATP (or ADP) potentiates physiological insulin-secreting agents (glucose and acetylcholine) and P₂ purinoceptors could play a physiological role in the stimulation of insulin secretion. The activation of P₁ purinoceptors (adenosine receptors) decreases insulin secretion. Using structural analogues of adenosine, the receptor was characterized as an A₁ subtype; it is coupled to a pertussis toxin sensitive G protein and it inhibits adenylate cyclase. It is of physiological relevance that the B cell has the two types of purinoceptors with opposite effects. Recently, a metabolically stable structural analogue of ADP, adenosine-5′-0-(2-thiodiphosphate) or ADPßS, has been described as a potent secretory agent, effective at nanomolar concentrations on isolated perfused rat pancreas. In vivo, this substance is able to increase insulin secretion and to improve glucose tolerance after IV administration in rats and oral administration in dogs. Furthermore in streptozotocin-induced diabetes, ADPßS retains its insulin secreting effects. These results suggest that P_2y purinoceptors could be a new target for antidiabetic drugs.     

INTRACEREBRAL HAEMORRHAGE IN A YOUNG ADULT: CONSIDER AMPHETAMINE ABUSE

SUMMARY We present the case of a young female who suffered a massive intracerebral bleed following the ingestion of a small quantity of amphetamine (speed). Physicians should be aware that amphetamine abuse can lead to cerebrovascular events in young adults.