Case report: Enteroviruses and sudden deafness

A YOUNG, HEALTHY MAN PRESENTED with sudden severe sensorineural hearing loss and tinnitus. The results of the workup and neuroimaging were normal, as were the auditory brain stem responses. Methylprednisolone pulse therapy was associated with significant hearing improvement within 10 days. A history of a short self-limited febrile illness preceding admission (with headache, photophobia, myalgia and fatigue), a raised serum C-reactive protein level and transient leukopenia suggested an infectious cause. Lumbar puncture revealed a mononuclear pleocytosis of the cerebrospinal fluid, with negative cultures but positive polymerase chain reaction test results for enterovirus, which was later cultured from the patient's stool. The patient's wife and baby had had a similar febrile illness without hearing loss 10 days earlier, and an outbreak of enterovirus meningitis was identified in the area, which was associated with familial clustering and echovirus serotype 4 infection. The varied causes of sudden sensorineural hearing loss, which should include enterovirus, are reviewed here.     

Multiple Subclinical Syringomatous Proliferations Encountered during Mohs Surgery for Basal Cell Carcinoma

BACKGROUND: Examination of Mohs surgery frozen sections may lead to discovery of incidental benign neoplasms such as syringomas. OBJECTIVE: An unusual occurrence of numerous subclinical syringomatous proliferations discovered during Mohs surgery for a basal cell carcinoma that posed a diagnostic and management dilemma is reported. METHODS: Clinical records and histologic sections are examined. RESULT: Multiple syringomatous proliferations were noted around a basal cell carcinoma during Mohs surgery. A few foci were atypical appearing and focally extending into the deep dermis causing a diagnostic dilemma. All atypical syringomatous proliferations were excised. Evaluation of final Mohs margins by permanent sections and biopsies of normal-appearing facial skin showed multiple benign syringomas. CONCLUSION: Although solitary subclinical syringomas have been described in association with basal cell carcinomas, the occurrence of multiple syringomas and syringomatous proliferations has not been previously reported. Dermatologists should be aware of the existence of this phenomenon and consider permanent section evaluation to better determine nature of unusual incidental tumors identified in frozen sections during Mohs surgery.     

Obsessive compulsive disorder--prevalence in Xhosa-speaking schizophrenia patients.

Obsessive compulsive disorder (OCD) has been reported in up to 31% of schizophrenia sufferers. This study evaluated the presence of OCD in a Xhosa-speaking schizophrenia group. Xhosa patients (N = 509, including 100 sibships) with schizophrenia were recruited from hospital and community settings. The patients underwent a structured clinical interview for the presence of lifetime co-morbid schizophrenia and OCD. Only 3 patients (0.5%) fulfilled criteria for OCD. No concordance for OCD was noted in the sibship group. Our findings differ from those in other parts of the world, and if replicated, might suggest unique protective environmental or genetic factors for OCD in certain ethnic groups.     

Editorial

The square-wave voltammetry of isolated isomers of C₈₄ is reported. Based on their relative abundance, the isomers are assumed to have D₂ and D_2d symmetry. The D₂ isomer has four reversible reductions at ?0.65, ?0.98, ?1.34, and ?1.75 V versus Fc/Fc⁺ prior to electrolyte decomposition. This behavior is consistent with previous reports, and is similar to the voltammetry of C₆₀ and C₇₀ (e.g. sequential reductions spaced at slightly increasing intervals). The D_2d isomer has five reversible reductions at ?0.46, ?0.77, ?1.58, ?1.98, and ?2.27 V versus Fc/Fc⁺ prior to the onset of electrolyte decomposition. The large potential difference separating the second and third reductions of the D_2d isomer is an aspect of the voltammetry not reported when the D_2d isomer was analyzed as part of a mixture of C₈₄ isomers (P.L. Boulas, M.T. Jones, R.S. Ruoff et al., J. Phys. Chem. 100 (1996) 7573–7579). The large potential difference between the second and third reductions of the D_2d isomer of C₈₄ is similar to the voltammetric behavior of C₈₂.     

Inversion recovery radial MRI with interleaved projection sets.

The radial trajectory has found applications in cardiac imaging because of its resilience to undersampling and motion artifacts. Recent work has shown that interleaved and weighted radial imaging can produce images with multiple contrasts from a single data set. This feature was investigated for inversion recovery imaging of scar using a radial technique. The 2D radial imaging method was modified to acquire quadruply interleaved projection sets within each acquisition window of the cardiac cycle. These data were reconstructed using k-space weightings that used a smaller segment of the acquisition window for the central k-space data, the determinant of image contrast. This method generates four images with different T1 weightings. The novel approach was compared with noninterleaved radial imaging, interleaved radial without weightings, and Cartesian imaging in simulations, phantoms, and seven subjects with clinical myocardial infarction. The results show that during a typical acquisition window after an inversion pulse, magnetization changes rapidly. The interleaved acquisition provided better image quality than the noninterleaved radial acquisition. Interleaving with weighting provided better quality when the inversion time (TI) was shorter than optimal; otherwise, interleaving without weighting was superior. These methods enable a radial trajectory to be employed in conjunction with preparation pulses for viability imaging.     

Myocyte-specific enhancer binding factor 2C expression in fetal mouse brain development

We have previously found that myocyte-specific enhancer binding factor 2C (MEF2C) is expressed in the brain, where it is found at high levels in the developing cerebral cortex. We have now examined MEF2C expression in fetal mouse brain byin situ hybridization and by immunohistochemistry from E11 to E17, the period when most cortical neurons are born. The distribution of MEF2C mRNA detected byin situ hybridization closely resembles that of MEF2C immunoreactivity. MEF2C is not present in proliferative zones in the brain. It is present at high levels in cells that have migrated to the subplate and cortical plate. MEF2C is also found in the olfactory bulb at high levels and at lower levels in hippocampus, basal forebrain, striatum, cerebellum, and inferior colliculus, and in some nuclei of the hypothalamus, thalamus and brainstem. The pattern of expression suggests that MEF2C is expressed in a subset of postmitotic neurons in the brain and that it may therefore function to promote terminal differentiation of the cells that express it.     

Mutation R120G in αB-crystallin, which is linked to a desmin-related myopathy, results in an irregular structure and defective chaperone-like function

alphaB-crystallin, a member of the small heat shock protein family, possesses chaperone-like function. Recently, it has been shown that a missense mutation in alphaB-crystallin, R120G, is genetically linked to a desmin-related myopathy as well as to cataracts [Vicart, P., Caron, A., Guicheney, P., Li, A., Prevost, M.-C., Faure, A., Chateau, D., Chapon, F., Tome, F., Dupret, J.-M., et al. (1998) Nat. Genet. 20, 92-95]. By using alpha-lactalbumin, alcohol dehydrogenase, and insulin as target proteins, in vitro assays indicated that R120G alphaB-crystallin had reduced or completely lost chaperone-like function. The addition of R120G alphaB-crystallin to unfolding alpha-lactalbumin enhanced the kinetics and extent of its aggregation. R120G alphaB-crystallin became entangled with unfolding alpha-lactalbumin and was a major portion of the resulting insoluble pellet. Similarly, incubation of R120G alphaB-crystallin with alcohol dehydrogenase and insulin also resulted in the presence of R120G alphaB-crystallin in the insoluble pellets. Far and near UV CD indicate that R120G alphaB-crystallin has decreased beta-sheet secondary structure and an altered aromatic residue environment compared with wild-type alphaB-crystallin. The apparent molecular mass of R120G alphaB-crystallin, as determined by gel filtration chromatography, is 1.4 MDa, which is more than twice the molecular mass of wild-type alphaB-crystallin (650 kDa). Images obtained from cryoelectron microscopy indicate that R120G alphaB-crystallin possesses an irregular quaternary structure with an absence of a clear central cavity. The results of this study show, through biochemical analysis, that an altered structure and defective chaperone-like function of alphaB-crystallin are associated with a point mutation that leads to a desmin-related myopathy and cataracts.