Molecular and hereditary mechanisms of sensorineural hearing loss with focus on selected endocrinopathies

Hearing loss is one of the most widespread sensory disorders. The incidence of deafness in general population is 1:1000 newborns. About one half of the cases of the congenital sensorineural hearing loss (SNHL) is inherited. Recessive mutations in the gap junction beta 2 (GJB2) gene are the most common genetic causes of the nonsyndromic SNHL. The GJB2 encodes a protein connexin 26 which forms a subunit of gap junction essential for the correct function of the inner ear. The syndromic SNHL is associated with a wide range of other symptoms, which encompass also dysfunctions of endocrine organs. The Pendred syndrome associated with the hearing impairment is characterized by a prelingual, bilateral sever to profound SNHL, goiter, and iodine organification defect. It is an autosomal recessive disorder, which develops due to mutations in pendrin, an anion channel encoded by SLC26A4 gene. Another important type of syndromic hearing loss is the Maternally Inherited Diabetes and Deafness syndrome, which is caused by several mitochondrial DNA mutations. These mutations are clinically manifested by a hearing impairment with development of the diabetes in the adult age. Hearing impairment occurs during puberty when sensation of high frequency tones is affected following with further progress to profound bilateral sensorineural hearing impairment in the whole frequency range. This review deals with the molecular mechanisms of common genetic causes of the hereditary SNHL along with the selected endocrinopathies emphasizing that the DNA analyses along with the functional studies significantly contribute to the early SNHL diagnosis followed by personalized therapy and genetic counseling.

Short-term prophylaxis in hereditary angioedema due to deficiency of the C1-inhibitor--a long-term survey

BACKGROUND

Hereditary angioedema is a potentially life-threatening disorder, because edema occurring in the mucosa of the upper airways can lead to suffocation. The management of HAE consists of avoiding the triggering factors, prophylaxis, and the acute treatment of edematous episodes. Medical procedures can also provoke edematous attacks, and therefore, short-term prophylaxis (STP) is recommended before such interventions. Our aim was to evaluate the efficacy and safety of STP administered before medical procedures.

METHODS

We conducted a retrospective analysis before and a prospective survey after establishing the diagnosis in a group of 137 (60 males, 77 females; 20 pediatric and 117 adult) patients with HAE. Both were implemented using questionnaires, patient diaries and hospital charts focusing on medical interventions provoking edematous attack, and the medicinal products (C1-INH concentrate, tranexamic acid, and danazol) administered for STP.

RESULTS

Comparing surgical interventions performed without pre-event STP (in 39/89 patients before HAE was diagnosed), or after STP (in 3/55 cases after diagnosis), we found a significant (P < 0.0001, Fisher's exact test) reduction in the number of edematous episodes. Evaluating the efficacy of the drugs administered for STP revealed that C1-INH concentrate (Berinert(®) , CSL Behring, Marburg, Germany) was significantly (P = 0.0096, Fisher's exact test) superior to orally administered drugs in reducing the instances of postprocedural edema. None of the medicinal products caused adverse events potentially related to STP.

CONCLUSIONS

STP reduces the number of postprocedural edematous episodes. C1-INH concentrate is safe and effective for prophylaxis. When this agent is not available, danazol is a potential alternative for prophylaxis before elective medical interventions.

Isolation of 11 new polymorphic microsatellites from CA enriched turkey genomic libraries (Short communication)

Abstract. Microsatellite loci from the ancient Hungarian variety of the Broad Breasted Bronze Turkey (Meleagris gallopavo) were isolated. CA-repeat enriched libraries were constructed from DNA of randomly collected samples. Libraries were screened for repeat-containing clones by PIMA (PCR Isolation of Microsatellite Arrays) and the DNA-sequence of 167 positive clones was determined. A total of 136 microsatellite repeat-containing sequences were found, 59 sequences were unique. Comparing these with the genomic databases, we found 7 previously annotated microsatellite sequences. The newly isolated 52 microsatellites were tested on the mapping population of the University of Minnesota, and the map position of 11 microsatellites was determined.

Changes in the levels of some acute-phase proteins in human immunodeficiency virus-1 infected patients, following interleukin-2 treatment

Intermittent interleukin (IL)-2 administration to human immunodeficiency virus (HIV)-1 infected patients is well documented and generally used, but there is limited information about the changes of acute-phase protein (APP) levels in response to this treatment. Fifteen patients undergoing highly active anti-retroviral therapy (HAART) treatment, with undetectable viral load, but low CD4+ cell count (<300/microl), have been treated with 3.6 M IU Proleukine administered twice daily by subcutaneous injection over 5 days. C-reactive protein (CRP), D-dimer, C3, C9, C1-inh and alpha-2HS glycoprotein levels were measured immediately before IL-2 administration, as well as on day 5 and 2-3 weeks thereafter. After IL-2 administration, both mean D-dimer and CRP levels increased significantly (P<0.001), but returned (P<0.001) to baseline within the subsequent 2-3 weeks. Alpha-2HS glycoprotein decreased immediately after IL-2 administration. No significant differences were detected in the levels of C3, C9 and C1-inh. A significant, positive correlation (r=0.5178, P=0.0008) was ascertained between the changes of CRP level, measured immediately before as well as 5 days after IL-2 administration, and changes in CD4 T cell counts measured 2-3 weeks before and after treatment, respectively. IL-2 administration induces rapid elevation of two major APPs (CRP, D-dimer). The positive correlation observed between the changes of CRP levels and CD4+ cell counts after IL-2 administration may indicate that the abrupt, but transitory overproduction of CRP might contribute to the CD4+ cell count-increasing effect of the drug and/ or may be associated with serious side effects.

C1-inhibitor autoantibodies in SLE

The presence of anti-C1-inhibitor (anti-C1-INH) autoantibodies is a hallmark of acquired C1-inhibitor deficiency. However, only scarce data are available on their prevalence, diagnostic value, and/or significance in systemic lupus erythematosus (SLE). In a multicentre study, we determined the levels of autoantibodies to C1-inhibitor in sera from 202 patients with SLE and 134 healthy controls. Additional clinical and laboratory parameters, such as organ involvement, as well as anti-C1q, anti-double-stranded DNA antibody, erythrocyte sedimentation rate, C-reactive protein, C3 and C4 serum complement levels have been studied in patients. The level of anti-C1-INH IgG was significantly higher (p = 0.034) in SLE patients, than in the controls. A high anti-C1-INH level of ≥0.4 U/ml (mean of controls + 2 SD) was found in 17% of the patients, but in only 4% of the controls (p = 0.0003). The SLEDAI score was significantly higher (p = 0.048) and the duration of SLE was significantly longer (p = 0.0004) among patients with elevated anti-C1-INH levels compared with patients without this autoantibody (median disease duration 8 vs. 17 years, respectively). Anti-C1-INH level was not correlated with any other laboratory parameter or organ manifestation of the disease. These findings indicate that the anti-C1-INH level is higher in SLE patients than in healthy controls and furthermore, the anti-C1-INH level correlates with the duration and activity of the disease. Lupus (2010) 19, 634—638.

Sequence and expression analysis of the androgen receptor gene from Compact mouse (Brief Report)

Abstract. The phenotype of hypermuscled Compact mouse is determined by the MstnCmpt-dl1Abc myostatin mutation and also by additional modifier genes, mapped to different chromosome regions (VARGA et al. 1997, SZABÓ et al. 1998, VARGA et al. 2003, VARGA et al. 2005). The androgen receptor gene (Ar) was considered to be a potential candidate gene on the basis of our mapping results and its function, as it is located in that region of the X chromosome, where the strongest modifier effect was detected in the males and because Ar was described earlier as a regulator of TGF-ß (CHIPUK et al. 2002). A similar regulation could thus also be assumed through the androgen response element of myostatin, a member of the TGF-ß superfamily (MA et al. 2001). The sex-influenced nature of the Compact phenotype (VARGA et al. 1997, BÜNGER et al. 2005) appeared to strengthen this hypothesis. In this study we analysed the coding sequence of the Ar locus in Compact mice and the expression of Ar mRNA by quantitative Real-Time PCR.

Mycoplasma infection of geese. 1. Incidence of mycoplasmas and acholeplasmas in geese

This paper presents data about the isolation of members of the order Mycoplasmatales from material of goose origin. Acholeplasma laidlawii strains were isolated from 2 to 8 day old goslings with heavy fibrinous airsacculitis, peritonitis and perihepatitis. Losses reached 30% of the flock by the end of the 8th week of age. Acholeplasma axanthum strains were detected in goose-embryos that died on the 13th day of incubation. A significant loss (up to 60%) of embryos was observed in the flock and some layers died showing fibrinous peritonitis, salpingitis and abdominal airsacculitis. Mycoplasma gallinarum also was isolated from goose-embryo fibroblast tissue cultures. All strains except A. laidlawii caused cytoplasmic vacuolization and intracytoplasmic inclusion bodies in goose-embryo fibroblast tissue cultures. The alteration observed in chicken-embryo fibroblast cell cultures were similar; in addition, the A. laidlawii caused a marked pycnosis of the cells.

Depressed activation of the lectin pathway of complement in hereditary angioedema

The possibility of simultaneous measurement of the classical pathway (CP), mannan-binding lectin (MBL)--lectin pathway (LP) and alternative pathway (AP) of complement activation by the recently developed Wielisa method allowed us to investigate the in vivo significance of the C1-inhibitor (C1INH) in three complement activation pathways. Functional activity of the CP, LP and AP were measured in the sera of 68 adult patients with hereditary angioedema (HAE) and 64 healthy controls. In addition, the level of C1q, MBL, MBL-associated serine protease-2 (MASP-2), C4-, C3- and C1INH was measured by standard laboratory methods. MBL-2 genotypes were determined by polymerase chain reaction. Besides the complement alterations (low CP and C1INH activity, low C4-, C1INH concentrations), which characterize HAE, the level of MASP-2 was also lower (P = 0.0001) in patients compared with controls. Depressed LP activity was found in patients compared with controls (P = 0.0008) in homozygous carriers of the normal MBL genotype (A/A), but not in carriers of variant genotypes (A/O, O/O). Activity of CP correlated with LP in patients (Spearman's r = 0.64; P < 0.0001), but no significant correlation was found in the control group and no correlation with AP was observed. In contrast, the activity of CP and AP correlated (Spearman's r = 0.47; P < 0.0001) in healthy controls, but there was no significant correlation in the HAE patients. We conclude that the activation of LP might also occur in subjects with C1INH deficiency, which is reflected by the low MASP-2 and C4 levels.

Characterization of Staphylococcus aureus strains isolated from bovine milk in Hungary

Staphylococcus aureus is a major foodborne pathogen due to its capability to produce a wide range of heat-stable enterotoxins. The primary purpose of this research was to characterize S. aureus isolates recovered from mammary quarter milk of mastitic cows and from bulk tank milk produced on Hungarian dairy farms of different sizes. Macrorestriction analysis of chromosomal DNA from S. aureus isolates was performed using the restriction enzyme SmaI followed by pulsed-field gel electrophoresis (PFGE). The prevalence rates of nine S. aureus enterotoxin genes (sea, seb, sec, sed, see, seg, seh, sei, and sej) and of the toxic shock syndrome toxin 1 gene (tst) were determined by multiplex polymerase chain reaction (PCR). The bulk tank milks of 14 out of 20 farms were contaminated with S. aureus at levels of up to 6.0x10(3 )CFU/ml. Farm size had no significant effect (P>0.05) on the S. aureus counts in bulk milk. The prevalence rates of penicillin resistance were 88.9% and 20.0% among the S. aureus recovered from mastitic quarter milk and bulk tank milk, respectively. After phenotypic characterization, a total of 59 S. aureus isolates were selected for genotyping. PFGE analysis revealed 22 distinct pulsotypes, including 14 main types and 8 subtypes, at a similarity level of 86%. Only one or two main types were observed on each of the farms tested, indicating a lack of genetic diversity among S. aureus isolates within farms, and there were only two pulsotypes which occurred on more than one farm. The PFGE patterns showed genetic relatedness between the S. aureus strains recovered from quarter milk and bulk milk on two large farms, implying that on farms having a high number of mastitic cows, S. aureus from infected udders may contaminate bulk milk and, subsequently, raw milk products. Sixteen (27.1%) of the S. aureus isolates tested by multiplex PCR were found to be positive for enterotoxin genes, with 15 of them carrying just one gene and one strain carrying two genes (seg and sei). The most commonly detected toxin genes were seb, sea, and sec, whereas none of our isolates possessed the see, seh, sej, or tst genes. On 75% of the dairy farms surveyed, no enterotoxigenic staphylococci were recovered from either mastitic quarter milk or bulk tank milk.

Survey of rotavirus infection in a Hungarian paediatric hospital. A short communication

In anticipation of a future vaccination program against rotavirus disease, a longitudinal survey has been set up to evaluate the epidemiologic features of rotavirus infections. In this report hospitalisation data and serotyping results are compiled from an epidemiologic survey conducted in Baranya County, Hungary. It was found that rotavirus-associated hospitalisation constituted a major part of infectious gastroenteritis cases (range, 14.9% to 28.5%). A higher proportion of rotavirus-positive cases was recorded when the serotype of predominant strains changed from G1 (1996-1999) to G4 (1999-2000), however, due to the short time period it was not possible to demonstrate a firm association between serotype prevalence and rotavirus-associated hospitalisation rate. In the future, such studies might help to understand if serotype-specific immunity against rotavirus infection plays an important role at the population level and if (re-)emerging rotavirus strains make an impact on the annual disease burden.