Refinement of lymphoma cytogenetics by the chromosome 18q21 major breakpoint region

A small (2.8-kilobase, kb) major breakpoint region localized to segment 18q21 rearranges in greater than 70% of t(14;18)(q32;q21) lymphomas. This rearrangement interrupts the Bcl-2 gene and introduces it into the Ig locus at 14q32. The rearrangement between the joining region (JH) of Ig on chromosome 14 and the 18q21 region creates a translocation- specific DNA rearrangement. We generated probes that distinguish the 14;18 juncture on the derivative (der) 14 and der (18) chromosomes, providing a molecular approach to t(14;18) identification. Approximately 60% of unselected follicular lymphomas, 20% of diffuse large cell lymphomas, and 50% of adult undifferentiated non-Burkitt lymphomas demonstrated 14;18 rearrangements within the major breakpoint region. Examination of DNA for 14;18 rearrangements resolved the identity of 14q+ chromosomes in two patient's cells that lacked an obvious reciprocal partner. Identification of the exact restriction fragments that mediate translocations complements routine cytogenetics. The detection of DNA rearrangements does not require dividing cells or the presence of an identifiable reciprocal partner and can detect clonal translocation rearrangements when the neoplastic cells are only a minority of all cells present.     

Delta glycophorin (glycophorin B) gene deletion in two individuals homozygous for the S--s--U-- blood group phenotype

Blood cells from two unrelated individuals whose erythrocytes exhibit respectively N S-s-U- and MN S-s-U- blood group phenotypes were examined by immunoblotting, periodic acid-Schiff (PAS) staining, and Southern blotting. Protein bands characteristic of delta glycophorin (glycophorin B) were absent from the immunoblots of whole erythrocyte lysates when probed with polyclonal glycophorin antisera and from isolated erythrocyte membranes stained with PAS reagents. Genomic DNA from the two individuals' leukocytes was digested with a panel of restriction enzymes and probed with alpha M glycophorin cDNA obtained from human K562 leukemic cell line. The EcoRI, PstI, and KpnI restriction site patterns were identical to those of S+s+U+ controls in fragment numbers and relative size but differed from controls in band intensities. Restriction mapping with HindIII, PvuII, SacI, MspI, and BamHI revealed that S-s-U- individuals lack fragments that are reproducibly observed in S+s+U+ controls, and most likely encode delta glycophorin. Using truncated 5' and 3' cDNA segments as probes and comparing, in control individuals, hybridization intensities of fragments with amino acid sequence homologies, we have inferred the assignment of restriction fragments to the alpha and delta glycophorin genes. Our results suggest that the absence of delta glycophorin in the two S-s-U- individuals is a result of deletion of the entire delta glycophorin gene. This is the first report of a glycophorin gene deletion.     

Liver transplantation for hepatitis C-associated cirrhosis in a single Australian centre: Referral patterns and transplant outcomes

During the study period, 63 patients with hepatitis C virus (HCV) cirrhosis were referred to our unit for liver transplantation. All cases referred and transplanted were retrospectively examined. Eighty-six per cent of referred patients were male, 35% consumed alcohol in the harmful hazardous range, 13% were infected with hepatitis B and 7% had hepatocellular carcinoma. Patients with sporadic infection were more likely to be born outside Australia and were an average of 10 years older than those with HCV acquired via intravenous drug use (P< 0.001). However, patients were an average of 12 years younger at referral if they consumed harmful amounts of alcohol than if they abstained (P = 0.002). We examined the impact of HCV on the outcome of 28 patients who underwent liver transplantation (mean follow up 25 months; range 3–76 months). The use of OKT3, HCV genotype and hepatitis B status were examined for their effect on HCV-related graft dysfunction. Three year survival was 84%, equivalent to a control group. Chronic HCV-related graft dysfunction occurred in 15 (56%) patients, of whom 10 had an asymptomatic elevation in serum amino transferase, two had cholestatic hepatitis and three had severe hepatitis C that progressed onto chronic rejection. Hepatitis C virus genotype 1b tended to be associated with HCV graft dysfunction (5/6 type 1b vs 10/16 in non-type 1b). In conclusion, HCV is an increasingly common-indication for liver transplantation. Alcohol and hepatitis B were frequently occurring cofactors in the referral cohort. Most patients referred were male, although the reason why is not clear. Transplantation offers a good medium-term outcome, despite the high incidence of HCV-associated graft dysfunction.     

Outcome from a rapid-assessment chest pain clinic

Chest pain accounts for much of the rising numbers of emergency admissions, but in-patient assessment is not necessarily the best way of dealing with these patients. We ran a 'rapid-assessment chest pain clinic' to provide an alternative route of assessment, and audited its outcome. General practitioners referred patients with recent-onset chest pain, increasing chest pain, chest pain at rest, or other chest pain of concern, on the understanding that they would be seen within 24 h. During 8 1/2 months, 334 patients were referred and 317 patients were seen, most of whom had exercise electrocardiography. A median of 6 months later, 278 patients were personally contacted to determine outcome. Of these, 18% had been admitted immediately with acute coronary syndromes, and 49% had been diagnosed as non-coronary chest pain (none of whom subsequently infarcted or died). Continuing symptoms were infrequent, and satisfaction was high, although 13% of patients had been revascularized. A significant number of patients required immediate admission and/or ultimate revascularization, but many more did not. The majority of these patients had non-coronary chest pain, and this diagnosis was substantiated by their excellent outcome and (in some cases) by further investigation.      

Intramyocellular lipid accumulation is associated with permanent relocation ex vivo and in vitro of fatty acid translocase (FAT)/CD36 in obese patients

Aims/hypothesis

Intramyocellular lipids (IMCL) accumulation is a classical feature of metabolic diseases. We hypothesised that IMCL accumulate mainly as a consequence of increased adiposity and independently of type 2 diabetes. To test this, we examined IMCL accumulation in two different models and four different populations of participants: muscle biopsies and primary human muscle cells derived from non-obese and obese participants with or without type 2 diabetes. The mechanism regulating IMCL accumulation was also studied.

Methods

Muscle biopsies were obtained from ten non-obese and seven obese participants without type 2 diabetes, and from eight non-obese and eight obese type 2 diabetic patients. Mitochondrial respiration, citrate synthase activity and both AMP-activated protein kinase and acetyl-CoA carboxylase phosphorylation were measured in muscle tissue. Lipid accumulation in muscle and primary myotubes was estimated by Oil Red O staining and fatty acid translocase (FAT)/CD36 localisation by immunofluorescence.

Results

Obesity and type 2 diabetes are independently characterised by skeletal muscle IMCL accumulation and permanent FAT/CD36 relocation. Mitochondrial function is not reduced in type 2 diabetes. IMCL accumulation was independent of type 2 diabetes in cultured myotubes and was correlated with obesity markers of the donor. In obese participants, membrane relocation of FAT/CD36 is a determinant of IMCL accumulation.

Conclusions/interpretation

In skeletal muscle, mitochondrial function is normal in type 2 diabetes, while IMCL accumulation is dependent upon obesity or type 2 diabetes and is related to sarcolemmal FAT/CD36 relocation. In cultured myotubes, IMCL content and FAT/CD36 relocation are independent of type 2 diabetes, suggesting that distinct factors in obesity and type 2 diabetes contribute to permanent FAT/CD36 relocation ex vivo.     

Hepatitis C virus (HCV) genotype analysis in apparently healthy anti- HCV-positive Parisian blood donors

BACKGROUND: As only a few studies have examined the prevalence of various hepatitis C virus (HCV) subtypes in blood donors, information about the variability and route of infection in apparently healthy persons is limited. STUDY DESIGN AND METHODS: Blood donations collected at a large Parisian hospital (52,441) were investigated for antibodies to HCV. Serum samples were screened with an enzyme immunoassay. All HCV- positive donations were retested with a second enzyme immunoassay and confirmed by immunoblot. The HCV genotype was determined for all polymerase chain reaction-positive subjects. Untypable genotypes were sequenced in the NS5B region. RESULTS: In total, 83 (0.26%) blood donors were anti-HCV positive. Men (0.34%) were significantly more likely to be infected (p < 0.001) than women (0.19%). Prevalence rates in men between 20 and 39 years of age were higher than those in similar women (p = 0.01), but greater in women aged from 50 to 65 years (p = 0.05). Fifty-five sera were viremic, of which 49 could be genotyped by a line probe assay. One new HCV type 1 subtype and three new HCV type 2 subtypes were discovered. In total, 28, 10, 11, 5, and 1 serum samples were grouped into HCV types 1 through 5, respectively, involving a total of 13 subtypes. The mean age of HCV type 2-infected donors was 42 +/− 11 years, but that for type 3-infected subjects was only 30 +/− 4 years (p = 0.0048). Forty-nine subjects showed elevated alanine aminotransferase levels; 39 (80%) of these subjects were viremic (p < 0.05). CONCLUSION: Among the sampled population, an HCV prevalence rate of 0.26 percent was found, with the five most common European genotypes causing the infections. Four new subtypes were discovered. Correlation between genotype and risk factors was not apparent, but links with age, sex, and ethnic origin emerged.     

Virus inactivation by pepsin treatment at pH 4 of IgG solutions: factors affecting the rate of virus inactivation

BACKGROUND: IgG preparations have rarely transmitted infectious diseases; however, because such transmission has occurred a few times, manufacturers are required to present experimental proof that their specific production process removes and/or inactivates viruses that may be present in the starting material. STUDY DESIGN AND METHODS: The kinetics of virus inactivation mediated by pepsin treatment at pH 4 during the production of intravenous immunoglobulin was assessed with spiking experiments using human immunodeficiency virus, bovine viral diarrhea virus, Semliki Forest virus, and pseudorabies virus. The influence of various factors on the rate of virus inactivation also was studied by modifying the composition of the IgG solutions with respect to IgG, sucrose, and NaCl content. RESULTS: Virus inactivation at 37 degrees C was extremely rapid and resulted in a complete loss of infectivity within 5 minutes to 1 hour. Inactivation was much slower at lower temperatures. Furthermore, inactivation was dependent on the solute composition. Increasing the sucrose content from 0 to 15 percent reduced the rate of inactivation of pseudorabies virus but did not affect the rate of inactivation of Semliki Forest virus. In contrast, increasing the NaCl content from 0 to 150 mM resulted in a reduction in the rate of inactivation of Semliki Forest virus, whereas the rate of inactivation of pseudorabies virus remained unaffected. Moreover, increasing the IgG concentration from 0 to 10 percent resulted in an increased rate of inactivation of pseudorabies virus but a decreased rate of inactivation of Semliki Forest virus. CONCLUSION: Inactivation of viruses by pepsin treatment at pH 4 essentially is temperature- dependent, and the reaction rate is selectively influenced by the solute composition of the IgG solution. This has to be taken into account when safety data for different products are compared.