Characterization of low density lipoprotein receptor (LDLR) gene mutations in Albania

Introduction

Familial hypercholesterolaemia (FH) is a clinical syndrome characterised by elevated serum total cholesterol (TCHOL) levels due to an increase in low-density lipoprotein (LDL) cholesterol, by tendon xanthomata and clinical manifestations of ischaemic heart disease in early life. Typically, it results from mutations in the low-density lipoprotein receptor (LDLR) gene. So far, more than 800 mutations have been reported for the LDLR gene and account for FH. The nature of LDLR gene mutations varies among different ethnicities. Until now no mutations of LDLR have been reported in the Albanian population.

Material and methods

We assessed the contribution of the LDLR gene mutations as causes of FH in an Albanian population. Fifty probands with a clinical diagnosis of FH were included. We analysed all the exons and the promoter of the LDLR gene by using restriction isotyping or direct sequencing.

Results

Twenty-one patients were heterozygous for the 1646G>A mutation (FH Genoa) in exon 11 and 9 patients were heterozygous for the 81T>C mutation in exon 2 of the LDLR gene.

Conclusions

This report describes two LDLR gene mutations accounting for FH in Albania (1646G>A, 81T>C).     

Analysis of intron 22 inversions of the factor VIII gene in severe hemophilia A: implications for genetic counseling

Intrachromosomal recombinations involving F8A, in intron 22 of the factor VIII gene, and one of two homologous regions 500 kb 5' of the factor VIII gene result in large inversions of DNA at the tip of the X chromosome. The gene is disrupted, causing severe hemophilia A. Two inversions are possible, distal and proximal, depending on which homologous region is involved in the recombination event. A simple Southern blotting technique was used to identify patients and carriers of these inversions. In a group of 85 severe hemophilia A patients, 47% had an inversion, of which 80% were of the distal type. There was no association with restriction fragment length polymorphism (RFLP) haplotypes. The technique has identified a definitive genetic marker in families previously uninformative on RFLP analysis and provided valuable information for genetic counselling information may now be provided for carriers without the need to study intervening family members and the diagnosis of severe hemophilia A made in families with only a nonspecific history of bleeding. Analysis of intron 22 inversion should now be the first-line test for carrier diagnosis and genetic counselling for severe hemophilia A and may be particularly useful when there is no affected male family member or when intervening family members are unavailable for testing.     

Natural history of hepatic fibrosis progression in chronic hepatitis C virus infection in India

Background and Aim:  The rate of fibrosis progression per year can predict the time for the development of cirrhosis in chronic hepatitis C (CHC). We assessed the rate of fibrosis progression and the predictors of disease severity in Indian CHC patients.
Methods:  Of the 355 treatment-naïve, histologically-proven CHC patients, the precise duration of infection (from the time of exposure to HCV until liver biopsy) could be determined in 213 patients (age = 41.6 ± 14.7 years, male : female = 139 : 74, genotype 3 = 75%). The rate of fibrosis progression per year was calculated. The correlation of the advanced degree of fibrosis and age, duration of infection, age at the onset of infection, sex, mode of infection, hepatitis C virus (HCV) genotype, histological activity index (HAI), and the presence of diabetes mellitus were studied.
Results:  The median rate of fibrosis progression per year was 0.25 (0.0–1.5) fibrosis units. The fibrosis progression rate was higher in patients who acquired infection at > 30 years of age, those < 30 years (0.33 vs 0.15; P  < 0.001), and those who acquired HCV infection with a history of blood transfusion than with other modes of transmission (0.25 vs 0.19; P  = 0.04). The median time to progress to cirrhosis was 16 years. The multivariate analysis found that the HAI score (odds ratio [OR]= 14.03; P  < 0.001) and the duration of infection > 10 years (OR = 4.83; P  < 0.001) correlated with severe liver disease (fibrosis ≥ 3).
Conclusion:  The median rate of fibrosis progression per year in Indian CHC patients is 0.25 fibrosis units. A higher HAI and longer duration of infection are associated with a significant risk of advanced liver disease, and merit early therapeutic interventions.     

Glycosidic residues involved in human sperm-zona pellucida binding in vitro

Glycosidic residues of the mammalian zona pellucida (ZP) are known to be involved in sperm binding, suggesting the presence of complementary carbohydrate binding sites on spermatozoa. However, in previous studies, in which sperm suspensions were incubated with monosaccharides, no inhibitory effect was observed. Results of studies in which sperm were treated shortly after swim-up suggest that the use of non-capacitated cells may explain the apparently conflicting results. In the present report, we studied the effect of preincubation of capacitated spermatozoa with different monosaccharides on their ability to bind to ZP. After 5 h under capacitating conditions, spermatozoa were incubated in medium with or without a monosaccharide, resuspended in fresh medium and used for hemizona (HZ) binding assay. When ZH were incubated with spermatozoa treated with N-acetyl-D- glucosamine, D-mannose, D-fucose, L-fucose or D-galactose, a significant decrease in the number of spermatozoa bound was observed (level of inhibition: 62, 58, 82, 68 and 48% respectively) while treatment of spermatozoa with D-glucose produced no inhibition. Sugar treatment neither altered sperm motility nor the rate of acrosome reaction. These results suggest that N-acetylglucosamine, mannose, fucose and galactose residues are involved in human sperm-zona pellucida binding in vitro.      

Relationships of gp70 of MuLV envelopes to gp70 components of mouse lymphocyte plasma membranes

The family of glycoproteins called gp70 includes molecules that are the main constituent of murine C-type viral envelopes, and some that are expressed as mendelian constituents of thymocyte plasma membranes in the absence of virions. To investigate further the relation of viral gp70s to plasma- membrane gp70s we compared peptide maps of gp70s derived by immunoprecipitation from cells infected with chosen viruses and from various thymocytes and leukemiacells known to express one or more of three immunogenetically defined gp70 types: Glx-gp70, X-gp70, and O-gp70. Maps of gp70 from cultured cells infected with ecotropic and xenotropic viruses were distinguishable from one another, and in general resembled gp70 maps prepared directly from ecotropic and xenotropic virions respectively. Maps of gp70s immunoprecipitated from thymocytes of five mouse strains and from two A strain T-cell leukemias also fell into two distinguishable and generally corresponding patterns. Thus peptide-mapping substantiates earlier conclusions that viral gp70s and plasma-membrane gp70s inherited independently of virus-production are highly related or identical molecules. The gp70 maps of thymocytes from B6, B6-G(+IX), 129, and A mice formed a group resembling the map from cultured cells infected with xenotropic virus. Thymocytes from AKR mice, and the two A strain leukemias, gave gp70 maps conforming more to the second pattern, that of cultured cells infected with ecotropic virus. This second pattern probably comprises at least two gp70 types, one of which is X-gp70. Our data indicate that the G(IX)-gp70 and O-gp70 sub-species of gp70 expressed in the cell populations we have studied are coded by xenotropic viral genomes, and X-gp70 by ecotropic viral genomes.     

Herpesvirus infections in solid organ transplant patients at high risk of primary cytomegalovirus disease

The epidemiology of infections with 5 human herpesviruses (HHVs) (HHV-6, HHV-7, HHV-8, varicella zoster virus [VZV], and Epstein-Barr virus [EBV]) was investigated during the first year after solid organ transplantation in 263 patients who received oral ganciclovir or valganciclovir prophylaxis. HHV-6B DNAemia was uncommon, HHV-6A DNAemia was not observed, and HHV-7 DNAemia was prevalent. HHV-6 and HHV-7 DNAemia were not significantly associated with cytomegalovirus (CMV) disease, although a trend toward higher incidence of CMV disease was observed in HHV-6 DNAemic patients. VZV and HHV-8 DNAemia were not detected. EBV infection was common, although incidence of high-level EBV DNAemia was low, especially in patients who received valganciclovir prophylaxis. EBV-related posttransplant lymphoproliferative disease was not observed up to 12 months after transplantation. Compared with historic data, data from the present study suggest that antiviral prophylaxis may lower the incidence, prevalence, or level of DNAemia for infection with HHV-6, HHV-8, VZV, and EBV but not for infection with HHV-7.     

Radiation shielding in dentistry: an update

The purpose of this article was to review the literature and provide guidelines on the use of radiation protection for patients in the dental setting. There are limited published data on the effects of low radiation doses such as those used in dental radiology. Most of the evidence is subject to bias, with risk models extrapolated from higher dose models such as studies of the Hiroshima bomb survivors. However, the lack of evidence does not denote the absence of risk, as there is no established ‘safe’ level of radiation exposure. All imaging utilizing ionizing radiation carries a risk for the patient. Hence the patient benefits of imaging must outweigh the potential risk. All diagnostic imaging should adhere to three basic principles, these being justification, optimization and application of dose limits. This article discusses dose reduction techniques and shielding of sensitive organs, particularly the thyroid, during procedures such as intraoral imaging, orthopantomograms and imaging of the pregnant patient.