Parvovirus B19 infection and Diamond-Blackfan anaemia

It is the purpose of the study to report the frequency of parvovirus in children with a diagnosis of Diamond-Blackfan anaemia and to discuss the possible aetiological role of parvovirus in Diamond-Blackfan anaemia. We found parvovirus DNA in 3 of 11 bone marrow smears. Giant pronormoblasts showed low sensitivity (33%) and poor specificity (75%). The presence of giant pronormoblasts was associated with a very high myeloid: erythroid ratio, and may not be specific for parvovirus infection, but a feature of severely suppressed erythropoiesis. The three parvovirus-positive patients were the only children who experienced a remission, and who are free of medication. The seven surviving parvovirus-negative patients are all currently on steroid treatment.     

IMPOTLENCE: I

Mr. X is a 49-year-old black male with end-stage renal disease (ESRD) secondary to long-standing insulin-dependent diabetes and hypertension. He currently is on hemodialysis three times per week via a left forearm prosthetic A-V graft, and is on the renal transplant waiting list. He is on insulin as well as the standard regimen of vitamins, antacids, erythrogenic agents and antihypertensives. Mr. X has noted a slow progressive loss in his ability to attain an erection over the past four to five years and, even after attaining an erection, he notes that he can only maintain it for a few moments. On occasion his erection is firm enough for vaginal intercourse, but he loses it soon after penetration. In most instances, his erection is not firm enough for vaginal penetration, and he achieves vaginal penetration by “stuffing” the penis into the vagina. At peak, he was having intercourse three times per week, but now it is only once a month. He masturbates only on occasion. He is able to ejaculate, and reaches orgasm with seminal expulsion, but the ejaculate volume is markedly diminished compared to that seen in his youth. Occasionally, he gets a morning erection, which is “five” on a scale of one to 10, with 10 the maximal erection he achieved during his peak years. With masturbation or with sexual stimulation he describes his erection as a “four of 10.” He denies trauma to the erect or flaccid penis. He claims to have had a gradual change in his penile sensitivity over the past three years. He denies radiation to his pelvic area, recreational drug use, and does not use alcohol. He has no drug allergies. His surgical history is noncontributory. He denies neurologic disease, hypercholesterolemia, heart disehse, and claudication, and had smoked 2 packs of cigarettes per day for 20 years, quitting seven years ago. Mr. X is currently separated from his wife; however, the same erectile dysfunction occurs, even with his new sexual partner. Physical examination was unremarkable. The penis was circumcised with no lesions or plaques. The testes were descended and normal. There were no hernias. The bulbocavernosus reflex was absent. The penile-brachial index was 0.40 on the left and 0.52 on the right. Penile biothesiometry was abnormal on the penile shaft as well as the glans. The hormonal profile, including prolactin and testosterone were normal. The patient underwent a nocturnal penile tumescence (NPT) evaluation which confirmed the organicity of his disease. It demonstrated three short-lived REM-associated erections of poor quality. He opted for penile seif-injection therapy, which he uses only on nondialysis days, combined with prophylactic oral antibiotics. This therapy, along with psychologic counseling has worked well, with return of a full rigid erection of 1/2 hr in duration. He is now quite satisfied, and has vaginal intercourse with his new partner two times per week.     

Protein restriction in chronic renal failure

The aim of the study was to investigate the effect of a protein restricted diet on renal function and growth of children with chronic renal failure. In a multicentre prospective study 56 children (aged 2-18 years) with chronic renal failure were randomly assigned to the protein restricted (0.8-1.1 g/kg/day) or the control group. All children were followed up by the same paediatrician and dietitian. After a follow up period of three years there was no significant difference in glomerular filtration rate between children on a protein restricted diet and children of the control group. There was no significant difference in weight with respect to height and height SD score between the protein restricted and the control group. Compliance with the protein restricted diet, as indicated by the prospective diet diaries and the serum urea:creatinine ratio, was good. This study shows that children with chronic renal failure do not benefit from a protein restricted diet.     

The Emerging Buprenorphine Epidemic in the United States

The authors sampled for expanded drug testing of 1,061 urine specimens collected by Maryland Division of Parole and Probation staff. They found an increase in the percentage of individuals testing positive for buprenorphine and found that these specimens often contained other drugs, suggesting misuse. Subsequent interviews with 15 probationers and parolees in Baltimore, Maryland, showed wide-scale availability of buprenorphine on the street and in prisons. Medical examiners and drug testing programs should immediately initiate routine testing for buprenorphine to track a possible outbreak of buprenorphine diversion and misuse. Physician education programs should redouble their efforts to teach strategies to deter diversion and misuse of the drug.     

Diurnal changes in retinal nerve fiber layer thickness with obstructive sleep apnea/hypopnea syndrome

AIM: To compare the retinal nerve fiber layer (RNFL) thickness in the morning and evening in Thai patients with varying degrees of obstructive sleep apnea/hypopnea syndrome (OSAHS). METHODS: In this cross-sectional study, potential OSAHS patients at Siriraj Hospital underwent polysomnography to determine the severity of OSAHS and an eye examination (including best corrected visual acuity, slit-lamp examination, and Goldmann applanation tonometry). RNFL thickness was recorded once in the morning and once in the evening, using spectral domain optical coherence tomography. Thickness was expressed as an average and given for each quadrant. Patients with ocular or systemic diseases that might affect RNFL thickness were excluded. RESULTS: Forty-one eyes of 41 patients were classified into 4 OSAHS groups. The average and mean RNFL thickness in most of the four quadrants of the severe OSAHS group trended toward being less than those in the comparable quadrants of the other groups in both the morning and evening. In the moderate OSAHS group, the average RNFL thickness and temporal and superior quadrant thickness in the morning were significantly higher than in the evening (P=0.01, P=0.01, and P=0.03, respectively). In the severe OSAHS group, the inferior quadrant thickness in the morning was significantly higher than in the evening (P=0.03). CONCLUSION: The RNFL thickness in the morning was higher than in the evening in moderate OSAHS.     

An explanation of the coping strategies used by Community Psychiatric Nurses in Wales

Abstract Six hundred and fourteen Community Psychiatric Nurses (CPNs) were surveyed to estimate the extent to which they used various coping strategies in order to reduce occupation-related stress. A questionnaire booklet, which included a number of validated measures and the Psychnurse methods of coping questionnaire, were used. 'Having a stable home life that was separate from work' and 'knowing that my life outside of work is healthy, enjoyable and worthwhile' were methods used most in order to cope with work-based stress. 'Through having team supervision' and 'by having confidential one to one supervision' were the methods used the least. The mean overall coping scores were significantly higher for females and those who felt that they had job security. Those people who scored higher on the coping test instrument were significantly more likely to be older and have worked within the field of community mental health for longer. The current drive towards clinical supervision promoted through policy initiatives, appears not to be supported by these findings. The implications for CPN services and for further study are highlighted.     

Pharmacological preconditioning by diazoxide downregulates cardiac L-type Ca2+ channels

BACKGROUND AND PURPOSE

Pharmacological preconditioning (PPC) with mitochondrial ATP-sensitive K⁺ (mitoK_ATP) channel openers such as diazoxide, leads to cardioprotection against ischaemia. However, effects on Ca²⁺ homeostasis during PPC, particularly changes in Ca²⁺ channel activity, are poorly understood. We investigated the effects of PPC on cardiac L-type Ca²⁺ channels.

EXPERIMENTAL APPROACH

PPC was induced in isolated hearts and enzymatically dissociated cardiomyocytes from adult rats by preincubation with diazoxide. We measured reactive oxygen species (ROS) production and Ca²⁺ signals associated with action potentials using fluorescent probes, and L-type currents using a whole-cell patch-clamp technique. Levels of the α_1c subunit of L-type channels in the cellular membrane were measured by Western blot.

KEY RESULTS

PPC was accompanied by a 50% reduction in α_1c subunit levels, and by a reversible fall in L-type current amplitude and Ca²⁺ transients. These effects were prevented by the ROS scavenger N-acetyl-L-cysteine (NAC), or by the mitoK_ATP channel blocker 5-hydroxydecanoate (5-HD). PPC signficantly reduced infarct size, an effect blocked by NAC and 5-HD. Nifedipine also conferred protection against infarction when applied during the reperfusion period. Downregulation of the α_1c subunit and Ca²⁺ channel function were prevented in part by the protease inhibitor leupeptin.

CONCLUSIONS AND IMPLICATIONS

PPC downregulated the α_1c subunit, possibly through ROS. Downregulation involved increased degradation of the Ca²⁺ channel, which in turn reduced Ca²⁺ influx, which may attenuate Ca²⁺ overload during reperfusion.     

Collection of pluripotential hematopoietic stem cells by cytapheresis

Successful complete hematopoietic reconstitution (CHR) using nonleukemic peripheral stem cells (PSC) after marrow ablation has been reported in animals but not man. Previous studies of cytapheresis products from humans, as a prelude to use for CHR, have documented the presence of committed myeloid (CFU-GM) and erythroid (BFU-E) precursors. We have examined mononuclear cell (MNC) products collected on the Fenwal CS3000 Blood Cell Separator for these plus the more primitive mixed (granulo-, erythro-, mono-, and megakaryocytic) cell colony-forming units (CFU-GEMM) and for various lymphocytic subpopulations (LSP). One to two-hour products contained 36 +/- 7 CFU- GEMM/10(6) MNC (mean +/- SE, n = 8) or 490 +/- 131/ml product. This compared favorably with blood (23 +/- .4/10(6) MNC or 46 +/- 8/ml, n = 14) and bone marrow (146 +/- 58/10(6) MNC, n = 12). Collection efficiency for E-rosette-positive cells approximated that for total lymphocytes and was variable for other LSP. Recovery of CFU-GEMM after freezing in 10% dimethylsulfoxide at a controlled rate and storage in liquid N2 was 54% +/- 8% (n = 8). Cytapheresis collection of large numbers of pluripotent hematopoietic precursors and demonstration of adequate recovery of these after cryopreservation, both previously unreported, are significant steps toward eventual CHR using nonleukemic PSC.