Progression from Nonalcoholic Fatty Liver to Nonalcoholic Steatohepatitis Cirrhosis Confirmed by Liver Histology after 14 Years

A 44-year-old patient progressed from nonalcoholic fatty liver (NAFL) to nonalcoholic steatohepatitis (NASH) cirrhosis. She was diagnosed with NAFL via a liver biopsy. At 56 years old, she was diagnosed with NASH stage 3 via a second liver biopsy. One year later, she was diagnosed with NASH cirrhosis via a third liver biopsy. This is the first study to report the gradual deterioration of liver histology shown via three liver biopsies and fibrosis markers in a patient who progressed from NAFL to NASH cirrhosis. Following menopause, it is necessary to be aware of the rapid development of liver fibrosis.     

Clinical impact of amyloid PET using 18F-florbetapir in patients with cognitive impairment and suspected Alzheimer’s disease: a multicenter study

Annals of Nuclear Medicine - Amyloid positron emission tomography (PET) can reliably detect senile plaques and fluorinated ligands are approved for clinical use. However, the clinical impact of...     

Direct demonstration of the cross-bridge recovery stroke in muscle thick filaments in aqueous solution by using the hydration chamber

Despite >50 years of research work since the discovery of sliding filament mechanism in muscle contraction, structural details of the coupling of cyclic cross-bridge movement to ATP hydrolysis are not yet fully understood. An example would be whether lever arm tilting on the myosin filament backbone will occur in the absence of actin. The most direct way to elucidate such movement is to record ATP-induced cross-bridge movement in hydrated thick filaments. Using the hydration chamber, with which biological specimens can be kept in an aqueous environment in an electron microscope, we have succeeded in recording ATP-induced cross-bridge movement in hydrated thick filaments consisting of rabbit skeletal muscle myosin, with gold position markers attached to the cross-bridges. The position of individual cross-bridges did not change appreciably with time in the absence of ATP, indicating stability of time-averaged cross-bridge mean position. On application of ATP, individual cross-bridges moved nearly parallel to the filament long axis. The amplitude of the ATP-induced cross-bridge movement showed a peak at 5–7.5 nm. At both sides of the filament bare region, across which the cross-bridge polarity was reversed, the cross-bridges were found to move away from, but not toward, the bare region. Application of ADP produced no appreciable cross-bridge movement. Because ATP reacts rapidly with the cross-bridges (M) to form complex (M·ADP·Pi) with an average lifetime >10 s, the observed cross-bridge movement is associated with reaction, M + ATP → M·ADP·Pi. The cross-bridges were observed to return to their initial position after exhaustion of ATP. These results constitute direct demonstration of the cross-bridge recovery stroke.     

Polymorphism of CCR5 affecting HIV disease progression in the Japanese population

Among several factors associated with HIV-1 disease progression, genetic polymorphism of CCR2, CCR5, and CXCR4 in HIV-1 infection has been found. Single-nucleotide polymorphisms (SNPs) in the CCR2, CCR5, and CXCR4 genes as well as a 32-base pair deletion in the open reading frame of the CCR5 gene are associated with HIV disease progression among Caucasians and African-Americans in North America and Europe. However, in populations other than Caucasians and African-Americans, SNPs have not been fully examined. In our study SNPs in CCR2 coding and CCR5 regulatory regions have been examined in 98 Japanese HIV-positive individuals. The alleles of CCR5 regulatory regions at -2135T and -2086G are associated with late onset of AIDS (p < 0.05; odds ratio for the early onset of AIDS, 0.502 and 0.404, respectively). In contrast to this, the allele of CCR5 at -2086A is associated with the early onset of AIDS (p < 0.05; odds ratio for the early onset of AIDS, 2.133). A haplotype including two alleles at -2135G and -2086G is associated with the late onset of AIDS (p < 0.05; odds ratio for the early onset of AIDS, 0.372). Thus we found that a CCR5 SNP and haplotype polymorphism affect HIV disease progression even in the Japanese population. This indicates that the CCR5 genetic polymorphism affecting disease progression should be studied in a wider range of population.     

Asp361Val Mutant of alkaline phosphatase found in patients with dominantly inherited hypophosphatasia inhibits the activity of the wild-type enzyme

Hypophosphatasia is characterized by the hypomineralization of bone associated with the mutation of the tissue-nonspecific alkaline phosphatase (TNSALP) gene. Although the disease is usually autosomal recessive, an autosomal dominant form is also recognized. Approximately 50 mutations have been found in the TNSALP gene in patients with hypophosphatasia. However, the mutations identified to date do not seem to account for the dominantly inherited form of the disease. We have examined a German family in which the father and all 4 children were affected with hypophosphatasia, whereas the mother was healthy. The affected members of this family showed premature loss of deciduous teeth at or shortly before 2 yr of age and low levels of serum ALP with elevated levels of urinary phosphoethanolamine. DNA analysis by direct sequencing revealed a heterozygous missense mutation that caused the conversion of amino acid Asp to Val at position 361 (D361V) in the patients. Another substitution was detected in exon 12 (Val to Ala conversion at codon 505: V505A) in 1 allele of the mother and 3 children, indicating no association of the substitution with the disease. Reconstruction experiments demonstrated that the D361V mutant protein lost its enzymatic activity and that it inhibited the function of wild-type enzyme when coexpressed in COS-7 cells. On the other hand, the V505A mutant exhibited enzymatic activities equal to those of the wild-type ALP. It is likely that the mutant D361V protein forms dimers with the wild-type protein, and the protein-protein interaction contributes to the dominant effect of the mutant D361V. The mutation that causes D361V is the first one proven to be associated with the dominant form of hypophosphatasia.     

Calcitonin gene-related peptide modulates adrenal hormones in conscious dogs.

The effects of a small dose (2 pmol/kg) of human calcitonin gene-related peptide I on plasma renin activity and hormones, including, aldosterone, ACTH, cortisol, AVP and ANH, were investigated in 14 conscious dogs. In addition, we studied the effects of calcitonin gene-related peptide on aldosterone secretion when it is stimulated by angiotensin II and ACTH. An intravenous bolus injection of 2 pmol/kg of calcitonin gene-related peptide raised plasma renin activity (by 216%, p less than 0.05), ACTH (by 85%, p less than 0.05), AVP (by 89%, p less than 0.05), and ANH (by 36%, p less than 0.05). Despite the elevation of plasma renin activity, aldosterone was decreased (by 52%, p less than 0.05). Cortisol did not change significantly. Infusion of 1 pmol.kg-1.min-1 of angiotensin II produced an elevation of aldosterone (by 186%, p less than 0.01), which was completely inhibited by pretreatment with an injection of 2 pmol/kg of calcitonin gene-related peptide. On the other hand, aldosterone secretion stimulated by ACTH was not altered significantly by pretreatment with an injection of 2 pmol/kg of calcitonin gene-related peptide. These results suggest that calcitonin gene-related peptide inhibits aldosterone secretion, especially when aldosterone is stimulated by angiotensin II. In addition, calcitonin gene-related peptide may be involved as an endocrine modulator in the physiological control of other several hormones closely related to the hemodynamics.     

Genetic Analysis of Non-Hydrogen Sulfide-Producing Salmonella enterica Serovar Typhimurium and S. enterica Serovar Infantis Isolates in Japan

Whole-genome sequencing of non-H₂S-producing Salmonella enterica serovar Typhimurium and S. enterica serovar Infantis isolates from poultry meat revealed a nonsense mutation in the phsA thiosulfate reductase gene and carriage of a CMY-2 β-lactamase. The lack of production of H₂S might lead to the incorrect identification of S. enterica isolates carrying antimicrobial resistance genes.