Neurofibromatosis of the vulva

Neurofibromatosis can be very variable in its expression. A case of neurofibromatosis presenting with vulval lesions is described.     

Additional chromosome abnormalities confer worse prognosis in acute promyelocytic leukaemia

Acute promyelocytic leukaemia (APL) has been associated with a favourable prognosis in many studies of acute myeloid leukaemia. A series of 54 patients treated at the Royal Marsden Hospital between 1979 and 1996, with APL and the t(15;17) chromosome translocation at pres-entation, was examined for the effect of additional chromosome abnormalities in their presentation karyotype on survival.
The patients were aged between 2 and 62 years with a median age of 31 years. There were approximately equal numbers of males and females. Presentation white cell count ranged from 0.7 to 156 × 10⁹/l with a median of 1.0 × 10⁹/l. 39% of patients (21/54) had additional chromosome abnormalities at presentation. Statistical analyses were performed for factors thought to influence survival such as age, sex, white cell count, and number of courses of chemotherapy required to enter remission. These showed that the presence of additional chromosome abnormalities has an adverse effect on prognosis, independent of other prognostic indicators, reducing it to the level of patients with AML from less-favourable cytogenetic subgroups. These data indicate that additional therapeutic strategies may be required in patients with APL who demonstrate cytogenetic aberrations over and above the t(15;17) at presentation. The biological basis for the more aggressive nature of these cases remains to be determined.     

Atovaquone has no effect on the pharmacokinetics of phenytoin in healthy male volunteers

The potential pharmacokinetic interaction between atovaquone and phenytoin was investigated in 12 healthy male volunteers. Each volunteer received a single 600  mg oral dose of phenytoin in the two treatment periods. On one occasion phenytoin was taken alone and on the other after pre-treatment with 2000  mg atovaquone taken as two doses of 1000  mg as a microfluidized suspension. The mean (±s.d.) peak plasma concentrations ( C _max), apparent total clearance (CL/ F ) and terminal half-life ( t _½) for phenytoin when administered alone were 10.6(1.8)  mg l⁻¹, 24.3 (7.7)  ml min⁻¹ and 25(8)  h, respectively. When administered together with atovaquone, phenytoin C _max, CL/ F and t _½,z were 10.9 (2.0)  mg l⁻¹, 23.8  ml min⁻¹ and 24(6)  h, respectively. There were no statistically significant differences in any of these plasma pharmacokinetic parameters. There were also no statistically significant differences in the fraction of circulating drug not bound to plasma protein or urinary excretion of 5-hydroxyphenyl-phenyl-hydantoin. In conclusion, there was no effect of atovaquone on the pharmacokinetics of phenytoin or its major metabolite after a single dose.     

Percutaneous Microwave Ablation with a Long Side-Firing Antenna Array Can Successfully Treat a Nonsurgical Chronic Ovine Atrial Flutter Model

Introduction: Long side-firing microwave (MW) arrays can deliver energy uniformly over its length without the need for intimate endocardial contact. We hypothesize that a novel 6 Fr 20 mm long percutaneous high-efficiency MW antenna array ablation catheter can rapidly create long, continuous, and transmural linear ablation lesions.
Methods and Results: Cavotricuspid isthmus (CTI)-dependent atrial flutter (AFL) was created in 11 sheep by a line of radiofrequency ablation lesions in the posterior right atrium (RA) linking the venae cavae. After 4–6 weeks recovery, CTI-dependent AFL was still inducible in all 11 sheep (cycle length 178 ± 13 ms). MW ablation of the CTI at 100 W for 30 seconds was then performed with an endpoint of AFL noninducibility. AFL was not inducible in all 11 sheep after 4.3 ± 3.3 MW applications (129 ± 99 seconds). The last 6 animals needed fewer ablations (2.2 ± 1.5) and 3 of these sheep required only a single ablation. Although conduction times from proximal coronary sinus to lateral RA and vice versa increased postablation (51 ± 14 ms to 118 ± 31 ms [P = 0.0002] and 60 ± 13 ms to 119 ± 28 ms [P = 0.0001], respectively), AFL was still inducible in 2 sheep and further ablation was needed to reach the endpoint.
Conclusions: High-efficiency side-firing MW array ablation can rapidly create long linear and electrically intact lesions in an ovine AFL model. AFL noninducibility may be a more reliable indicator than CTI conduction times of an intact line of ablation in this animal model.     

A hard day's night: a longitudinal study on the relationships among job demands and job control, sleep quality and fatigue

This prospective four-wave study examined (i) the causal direction of the longitudinal relations among job demands, job control, sleep quality and fatigue; and (ii) the effects of stability and change in demand–control history on the development of sleep quality and fatigue. Based on results of a four-wave complete panel study among 1163 Dutch employees, we found significant effects of job demands and job control on sleep quality and fatigue across a 1-year time lag, supporting the strain hypothesis (Demand–Control model; Karasek and Theorell, Basic Books, New York, 1990). No reversed or reciprocal causal patterns were detected. Furthermore, our results revealed that cumulative exposure to a high-strain work environment (characterized by high job demands and low job control) was associated with elevated levels of sleep-related complaints. Cumulative exposure to a low-strain work environment (i.e. low job demands and high job control) was associated with the highest sleep quality and lowest level of fatigue. Our results revealed further that changes in exposure history were related to changes in reported sleep quality and fatigue across time. As expected, a transition from a non-high-strain towards a high-strain job was associated with a significant increase in sleep-related complaints; conversely, a transition towards a non-high-strain job was not related to an improvement in sleep-related problems.