Clinical Spectrum of Capillary Malformation–Arteriovenous Malformation Syndrome Presenting to a Pediatric Dermatology Practice: A Retrospective Study

Capillary malformation–arteriovenous malformation syndrome (CM‐AVM) is an autosomal dominant disorder caused by RASA1 mutations. The prevalence and phenotypic spectrum are unknown. Evaluation of patients with multiple CMs is challenging because associated AVMs can be life threatening. The objective of this study was to describe the clinical characteristics of children presenting with features of CM‐AVM to an academic pediatric dermatology practice. After institutional review board approval was received, a retrospective chart review was performed of patients presenting between 2009 and 2012 with features of CM‐AVM. We report nine cases. Presenting symptoms ranged from extensive vascular stains and cardiac failure to CMs noted incidentally during routine skin examination. All demonstrated multiple CMs, two had Parkes Weber syndrome, and two had multiple infantile hemangiomas. Seven patients had family histories of multiple CMs; three had family histories of large, atypical CMs. Six had personal or family histories of AVMs. Genetic evaluation was recommended for all and was pursued by six families; four RASA1 mutations were identified, including one de novo. Consultations with neurology, cardiology, and orthopedics were recommended. Most patients (89%) have not required treatment to date. CM‐AVM is an underrecognized condition with a wide clinical spectrum that often presents in childhood. Further evaluation may be indicated in patients with multiple CMs. This study is limited by its small and retrospective nature.     

Do children with primary nocturnal enuresis have a retarded bone age? A cross‐sectional study

OBJECTIVE: Nocturnal enuresis is a common pediatric problem, the etiology of which is unclear. In recent years, various studies have been published stating that children with nocturnal enuresis exhibit growth and skeletal maturation retardation. METHODS: In this cross-sectional study, we included 27 patients (16 boys, 11 girls) between the ages of 6 and 14 years who had presented with primary nocturnal enuresis (PNE) complaints. We included in the evaluation 19 healthy subjects (12 boys, 7 girls), who were the siblings of the children with PNE, as the control group. RESULTS: The patients in both groups were similar in chronological age, bone age, height and weight, with no significant difference between groups (P>0.05). CONCLUSION: The two groups in our study consisted of the same genetic background. Thus, our results were found to be different from the previous studies. We have concluded that there is no direct relationship between enuresis nocturnal and skeletal maturation.     

Biochemical studies of stimulus convergence during classical conditioning in Aplysia: dual regulation of adenylate cyclase by Ca2+/calmodulin and transmitter.

Activity-dependent facilitation is a mechanism of associative synaptic plasticity that contributes to classical conditioning in Aplysia. Previous studies of activity-dependent facilitation in the mechanosensory neurons of Aplysia suggested that the Ca2+ influx during paired spike activity enhances the transmitter-stimulated, cAMP-dependent, presynaptic facilitation in these cells. Moreover, paired activity was found to potentiate the activation of the adenylate cyclase by transmitter. It was therefore proposed that the Ca2+/calmodulin-sensitive cyclase may serve as a site of interaction between the inputs from the conditioned and unconditioned stimuli. These studies were carried out to test whether a Ca2+/calmodulin-sensitive adenylate cyclase in the Aplysia CNS has the properties necessary to mediate such an associative interaction. Three lines of evidence indicate that the same cyclase molecules that are sensitive to Ca2+/calmodulin are also stimulated by receptor to facilitatory transmitter via the stimulatory G-protein, Gs: First, calmodulin inhibitors reduced stimulation of the cyclase by facilitatory transmitter. When membranes had been preexposed to one of these inhibitors, trifluoperazine, the addition of exogenous calmodulin partially reversed the inhibition. Second, when Gs had been activated by GTP gamma S, so that it persistently activated the catalytic unit of the cyclase, stimulation of the cyclase by Ca2+ was greatly amplified, suggesting that the two inputs interact in activating a common population of the enzyme. Third, solubilized cyclase activity that bound to calmodulin-Sepharose in a Ca(2+)-dependent manner was stimulated by Gs, which had been partially purified from Aplysia CNS, as well as by Ca2+/calmodulin. Having demonstrated dual activation of the cyclase, we have explored the dependence of cyclase activation on the temporal pattern of Ca2+ and transmitter addition. Optimal activation required that a pulse of Ca2+ temporally overlap the addition of facilitatory transmitter. These several results suggested that the dually regulated adenylate cyclase might underlie the temporal requirements for effective classical conditioning in this system.     

Serum ionic fluoride levels in haemodialysis and continuous ambulatory peritoneal dialysis patients

High serum fluoride (F-) in patients with chronic renal failure (CRF) and end-stage renal disease (ESRD) is associated with risk of renal osteodystrophy and other bone changes. This study was done to determine F- in normal healthy controls and patients with ESRD on haemodialysis (HD) or peritoneal dialysis (PD). Seventeen healthy controls (12 males, 5 females) and 39 ESRD patients on dialysis (17 males, 22 females) were recruited in the study in a community with 47.4 +/- 3.28 microM/l (range 44-51 microM/l) of F- content in drinking water. Control subjects showed a mean serum F- concentration of 1.08 +/- 0.350 microM/l. Males in control group showed slightly higher F- levels (1.15 +/- 0.334, range 0.55-1.9 microM/l) than females (0.92 +/- 0.370, range 0.6-1.5 microM/l). Mean serum F- concentration did not correlate significantly with age and sex among control subjects, whereas such correlation was observed in patients with ESRD on dialysis. Mean serum F- concentration was significantly higher in patients on dialysis (2.67 +/- 1.09, range 0.8-5.2 microM/l) than normal controls. When grouped according to sex, the mean serum F- concentration in males (3.05 +/- 1.04, range 1.8-5.2 microM/l) was significantly higher than females (2.38 +/- 1.08, range 0.8-5.2 microM/l). When patients were grouped according to age, it was observed that F- concentration was significantly higher in patients with age groups 21-70 (2.86 +/- 1.05) than those with age group 13-20 years (1.42 +/- 0.531). Thus F- concentration correlated with age and sex, being higher in males and above 20 years. Despite appreciable clearance of F- (39-90%) across the peritoneum, patients on CAPD showed higher serum F- concentration than those on HD (3.1 +/- 1.97 vs 2.5 +/- 1.137 microM/l). Of the total 39 patients on dialysis 39% had their serum F- concentration above 3.0 microM/l, posing the risk of renal osteodystrophy.      

THE IMPACT OF PRE-CLERKING CLINICS ON SURGICAL OPERATION CANCELLATIONS: A PROSPECTIVE AUDIT

Pre-clerking of all patients undergoing elective general surgical operations was introduced at our hospital in an attempt to reduce an unacceptably high operation cancellation rate. A prospective audit has been performed on the effect of this policy on the cancellation rate. Before the introduction of pre-clerking there was a marked seasonal variation in the number of patients who failed to attend for surgery, which could be explained by absence on holiday. This seasonal variation disappeared after the start of pre-clerking clinics, but there has been no reduction in the number of cancellations for medical reasons.     

Selective elimination of mRNAs in vivo: complementary oligodeoxynucleotides promote RNA degradation by an RNase H-like activity.

Oligodeoxynucleotides lead to translation arrest of complementary mRNAs in the wheat germ translation system by a degradation of the mRNA. In an attempt to develop an effective reverse genetic approach in vivo, we demonstrate that injection of short (15- to 30-nucleotide) oligonucleotides into Xenopus oocytes leads to complete degradation of both injected and endogenous mRNAs by means of an RNase H-like activity.     

Cyclin alterations in giant cell tumor of bone.

Cyclins play an important role in regulating the passage of dividing cells through critical checkpoints in the cell cycle. Because alterations of several cyclins, especially cyclin D1, have been implicated in the development of many human neoplasms, we examined 32 cases of giant cell tumor of long bones for cyclin D1 gene amplification and protein overexpression using differential polymerase chain reaction and immunohistochemistry, respectively. In addition, the expression of cyclin D3, cyclin B1, and the proliferation-associated antigen Ki-67 (MIB-1) was assessed immunohistochemically. Low-level cyclin D1 gene amplification was detected in 61% of giant cell tumor cases. All tumors showed cyclin D1, cyclin D3, cyclin B1, and Ki-67 (MIB-1) staining; however, the distribution was very characteristic. Cyclin D1 protein expression was seen predominantly in the nuclei of the giant cells, with occasional mononuclear cells staining. There was no correlation between cyclin D1 gene amplification and protein overexpression. Cyclin D3 staining showed a similar distribution, with 88% of cases showing protein overexpression. Cyclin D1 and/or D3 staining in the giant cells was never associated with staining for either cyclin B1 or Ki-67 (MIB-1), as the expression of the latter two proteins was restricted to the mononuclear cells. Cyclin B1 overexpression was seen in 44% of cases. Ki-67 (MIB-1) staining was present in all cases, and between 10 to 50% of the mononuclear cells were positive. These results suggest that alterations in cyclin D1 and/or D3 might play a role in the pathogenesis of giant cell tumor of bone.