Friedreich's ataxia: a clinical and genetic analysis

We report a patient with genetically confirmed Friedreich's ataxia (FRDA) who developed a previously unreported feature of a mixed sleep apnea. Initial mutation analysis, by PCR, of the parental frataxin alleles showed an apparent de novo mutation in the maternal germline. Further investigation using Southern blot analysis showed that the mother did carry an expanded mutant frataxin allele. Based upon published data, FRDA resulting from at least one allelic spontaneous expansion mutation is rare with a frequency of less than 1/1,000,000. The presence of such a mutation should be confirmed by Southern blot analysis. Our patient expands the neurological features of FRDA to include sleep apnea. The genetic analysis of the family demonstrates the importance of Southern blot analysis for accurate genotyping which, in turn, has implications for genetic counseling.     

Direct Detection of Mycobacterial Species in Pulmonary Specimens by Two Rapid Amplification Tests,the Gen-Probe Amplified Mycobacterium tuberculosis Direct Test and the GenoType Mycobacteria Direct Test

Nucleic acid amplification tests have improved tuberculosis diagnostics considerably. This study evaluates a new amplification test, the GenoType Mycobacteria Direct (GTMD) test, for detection of the Mycobacterium tuberculosis complex, Mycobacterium avium, Mycobacterium intracellulare, Mycobacterium kansasii, and Mycobacterium malmoense directly in 61 sputum samples. Thirty (49.2%) samples were auramine smear positive, and 31 (50.8%) were smear negative. The GTMD results were compared to the Gen-Probe Amplified M. tuberculosis Direct (MTD) test results, using culturing and sequencing of the 16S rRNA gene as reference methods. The GTMD test could identify 28 of 29 samples containing the M. tuberculosis complex and was negative in a sputum sample containing M. intracellulare. The overall sensitivity and specificity results were 93.3% and 90.0% for the GTMD test, respectively, and 93.1% and 93.5% for the MTD test, respectively. The GTMD test is rapid and can be easily included in routine clinical laboratories for the direct detection of the M. tuberculosis complex in smear-positive sputum samples as an adjunct to microscopy and culture. Further studies are needed to evaluate the performance of the GTMD test for the detection of atypical mycobacteria.Worldwide, tuberculosis (TB) is a major cause of illness and death. WHO estimates that in 2006, 9.2 million new cases and 1.7 million deaths occurred from TB globally (25), and the incidence is increasing. The emergence of multidrug-resistant TB, and recently also extensively drug-resistant TB, and the human immunodeficiency virus-TB coinfection are further worsening the situation, and effort to accelerate progress in global TB control is needed. Important factors for TB control are increased case detection and treatment success rates (25). The slow growth of most pathogenic mycobacteria results in diagnosis and treatment delay and has stimulated the development of nucleic acid amplification (NAA) tests for identification of mycobacteria directly in clinical specimens. NAA tests provide test results within 1 day. In general, the specificity result for NAA tests ranges from 95% to 100% (1, 12, 16, 23), but the sensitivity result, especially for acid-fast bacillus (AFB) smear-negative samples, varies greatly, from 33 to 96% (1, 12, 16, 23). For AFB smear-positive respiratory specimens, the sensitivity level is approximately 95%.Two direct systems approved by the United States Food and Drug Administration (FDA) for detection of pulmonary TB are commercially available, as follows: the Amplicor Mycobacterium tuberculosis test (Roche Diagnostic Systems, Indianapolis, IN) and the Gen-Probe Amplified M. tuberculosis Direct test (MTD test; Gen-Probe, San Diego, CA). Both tests use the 16S rRNA gene as the target amplification gene. The 16S rRNA gene represents a stable property of microorganisms and is widely used as the target for identifying mycobacterium species. Several studies have confirmed an excellent test proficiency (sensitivity and specificity levels of more than 95%) in AFB smear-positive sputum samples but a reduced sensitivity level (82 to 85%) when applied on AFB smear-negative samples (1, 16, 23, 24). Thus, their use was limited to respiratory smear-positive samples from untreated patients. An enhanced version of the MTD test was later approved for use in both smear-positive and smear-negative specimens (5). A novel, commercially available NAA test for diagnosis of TB directly in patient specimens which has not yet been FDA approved is the BD ProbeTec ET test (Becton Dickinson Diagnostic Systems, Sparks, MD). The test is based on strand-displacement amplification of target sequences in IS6110 and the 16S rRNA gene and has a sensitivity level of 90 to 100% and a specificity level of 92% in smear-positive sputum samples (16). To make the NAA tests more rapid, robust, and applicable in laboratories without substantial technical infrastructure, the following novel NAA tests have been developed: the loop-mediated isothermal amplification (LAMP) test (Eiken Chemical Co., Ltd., Tokyo, Japan) (2, 3), the GeneXpert system (Cepheid, Sunnyvale, CA) (9), and the gold nanoparticle probes assay (21). Simple sample processing, amplification, and detection steps make these NAA tests more applicable in low-income countries with high incidence of TB. However, data on test proficiencies are limited so far. Ongoing studies will show if these rapid molecular tests can be alternatives to the conventional TB diagnostic tests.Recently, a new DNA strip test for detection of mycobacteria directly in smear-positive and smear-negative respiratory samples has been developed. The GenoType Mycobacteria Direct (GTMD) test (Hain Lifescience GmbH, Nehren, Germany) is based on nucleic acid sequence-based amplification and amplifies single-stranded nucleic acids from the 23S rRNA gene in an isothermal reaction. The biotinylated amplified DNA product is hybridized to specific oligonucleotide probes immobilized on the strip. The GTMD test detects members of the M. tuberculosis complex (MTC), Mycobacterium avium, Mycobacterium intracellulare, Mycobacterium kansasii, and Mycobacterium malmoense directly from decontaminated respiratory specimens, and the result is available within 1 day. Few studies have previously evaluated the GTMD test (7, 15, 20).The aim of this study was to evaluate the performance of the GTMD test and compare that test to the MTD test. Thus, the GTMD and MTD tests were evaluated for sensitivity and specificity using 61 respiratory specimens from patients suspected to suffer from pulmonary TB. Amplification and sequencing of the 16S rRNA gene of strains isolated from specimen culture (solid and automated liquid media) were used as reference methods.     

Effect of menstrual cycle phase on dopamine D2 receptor availability in female cynomolgus monkeys

Sex differences have been reported in a variety of affective and neurodegenerative disorders that involve dysfunctional dopamine (DA) neurotransmission. In addition, there is evidence for differences in sensitivity to the abuse-related effects of psychostimulants across the menstrual cycle which may result from effects of ovarian hormones on DA function. The goal of the present study was to extend previous work examining menstrual cycle-related changes in DA D2 receptor availability in humans to drug-naive female cynomolgus monkeys (n=7) using the selective D2-like receptor ligand [(18)F]fluoroclebopride (FCP) and a high-resolution microPET P4 scanner. Menstrual cycle phase was characterized by daily vaginal swabs and measurements of serum progesterone levels. PET studies were conducted once during the luteal phase and once during the follicular phase. Regions of interest in the caudate nucleus, putamen, and cerebellum were defined on coregistered MRIs. Distribution volumes were calculated for FCP in each structure and the distribution volume ratio (DVR) for both brain regions relative to the cerebellum was used as a measure of D2 receptor availability. FCP DVRs were significantly higher in the luteal phase compared to the follicular phase in both the caudate nucleus (11.7% difference, p=0.02) and putamen (11.6% difference, p=0.03). These findings extend earlier work in humans and suggest that changes in DA receptor availability may be involved in the variation in symptoms of various neuropsychiatric disorders across the menstrual cycle, including differences in sensitivity to the abuse-related effects of stimulants.     

Factors Associated With Successful Completion in an Adolescent-Only Day Hospital Program for Eating Disorders

The purpose of this study was to examine factors associated with completion of an adolescent-only eating disorder day hospital program. A total of 65 adolescents were included. Completers were compared to non-completers on multiple variables including diagnosis, weight, and medication use. Adolescents who completed the program were more likely to have been prescribed antidepressants and less likely to purge. The two groups did not differ significantly on other variables. Few factors differentiated completers from non-completers of the eating disorder day hospital program. Further research is needed to determine the role medications or purging may play in completing treatment.     

Surgical considerations for ‘intrinsic＇ brainstem gliomas： proposal of a modification in classification

BACKGROUND： Brainstem gliomas are highly heterogeneous tumors both in their clinical manifestation and in their pathology. Despite significant advances in the surgery for brainstem gliomas many aspects of this pathology are still unelear. OBJECTIVE： To evaluate the clinical, radiological and surgical outcome of 40 focal ＂intrinsic＂ brainstem gliomas and propose a surgical strategyoriented classification. MATERIALS AND METHODS： A total of 40 focal ‘intrinsie’ （＂expanding variety＂） tumors have been operated over a period of 8.5-years （January 1998-June 2007）. Our criteria included patients with （1） well-defined gadolinium enhancing tumor, （2） relatively long duration of symptoms （〉 six months） and （3） good neurological functional status and independent for all activities of davy living. The cutoff size of 2 cm was not rigidly adhered to. RESULTS： The ＂intrinsic＂ brainstem tumors were classified into three types： Expanding, diffuse infiltrative and pure ventral varieties.     

Management of saddle nose deformity in atrophic rhinitis

Correction of a saddle nose deformity due to atrophic rhinitis is a formidable task. The thick and puckered skin secondary to long standing disease makes the creation of a dorsal subdermal pocket difficult. On the one hand, these patients tolerate synthetic implants poorly and on the other they show an unusually high rate of absorption of autologous bone graft. Our experience of treating 15 patients with saddle nose deformity secondary to atrophic rhinitis is presented.