PATHOLOGICAL STUDY ON AMYLOIDOSIS —RELATIONSHIP OF AMYLOID DEPOSITS IN THE AORTA TO AGING—

Senile aortic amyloidosis in 224 autopsy cases over 40 years was investigated comparing cardiac and pancreatic amyloidosis in them. A total of 176 cases of aortic amyloidosis was found for an average incidence of 79%. Under the 5th decade the incidence was 51% and it rose sharply with age and reached 95% in over the 8th decade. The incidence of cardiac amyloidosis also increased with age, but it was always higher in the aorta. Aortic and cardiac amyloid were both positive in the DMAB method for tryptophan. The major part exposed to amyloidosis in the aorta was the media. The medial amyloid consisted of numerous minute deposits and had no relation to atherosclerosis. Some comments about the pathogenesis of senile amyloidosis were also mentioned.     

High incidence of cytomegalovirus, human herpesvirus-6, and Epstein-Barr virus reactivation in patients receiving cytotoxic chemotherapy for adult T cell leukemia

The etiology of cytomegalovirus (CMV), human herpesvirus-6 (HHV-6), and Epstein-Barr virus (EBV) reactivation and the potential for complications following cytotoxic chemotherapy in the absence of allogeneic transplantation are not clearly understood. Patients with adult T cell leukemia (ATL) are susceptible to opportunistic infections. In this study, the incidence, kinetics and clinical significance of reactivation of CMV, HHV-6, and EBV in ATL patients were investigated. Viral DNA in a total of 468 plasma samples from 34 patients was quantified using real-time PCR. The probability of CMV, HHV-6, and EBV reactivation by 100 days after the start of chemotherapy was 50.6%, 52.3%, and 21.6%, respectively. Although most CMV reactivations were self-limited, plasma CMV DNA tended to persist or increase if the CMV DNA levels in plasma reached ≥ 10(4) copies/ml. CMV reactivation was negatively associated with survival, but the P-value for this association was near the borderline of statistical significance (P=0.052). One patient developed fatal interstitial pneumonia concomitant with peak CMV DNA accumulation (1.6 × 10(6) copies/ml plasma). Most HHV-6 and EBV reactivations were self-limited, and no disease resulting from HHV-6 or EBV was confirmed. HHV-6 and EBV reactivation were not associated with reduced survival (P=0.35 and 0.11, respectively). These findings demonstrated that subclinical reactivation of CMV, HHV-6, and EBV were common in ATL patients receiving chemotherapy. There were differences in the viral reactivation patterns among the three viruses. A CMV load ≥ 10(4) copies/ml plasma was indicative of subsequent exacerbation of CMV reactivation and developing serious clinical course.     

Characteristics of occult hepatitis B virus infection in the Solomon Islands

Hepatitis?B virus (HBV) infection is highly endemic in the Solomon Islands. However, little is known about the status of occult HBV infection in the Solomon Islands. This study aimed to investigate the prevalence of occult HBV infection and its clinical and virological features in the community of Solomon Islands. Blood samples were collected from a total of 564 asymptomatic individuals aged over 18 years in the Western province. The samples used in the present study consisted of 200 samples from 108 males and 92 females (mean age, 37.4 years; range, 18-71 years) that were randomly selected among the hepatitis?B surface antigen (HBsAg)-negative samples from all the participants enrolled in this study. HBV-DNA was detected by real-time?PCR in 25 (12.5%) of the 200 HBsAg-negative samples. Most of the HBV-DNA-positive individuals were infected with wild-type HBV, and only 3 strains demonstrated specific amino acid substitutions (P121X, T123N, C138S, P142S and D144E) in the α?determinant region. In conclusion, occult HBV infection was documented in 12.5% of individuals that demonstrated serologic evidence of resolved HBV infection in this study. The prevalence of occult infection was also influenced by ethnicity; it was more prevalent in Melanesians than Micronesians. In addition, occult HBV infection demonstrated a weak association with the S-variants.     

Does increased nuchal translucency indicate a fetal abnormality? A retrospective study to clarify the clinical significance of nuchal translucency in Japan

The results of a chromosomal test by genetic amniocentesis in 58 cases with an increased nuchal translucency (NT; > or =3 mm thickness) revealed 47 cases showing a normal karyotype (81%) and 11 cases (19%) showing an abnormal karyotype. However, the cases of a normal karyotype with increased NT also included those with fetal abnormalities. Among the 49 cases in which NT was observed during the first trimester and then subsequently disappeared, chromosomal abnormalities were observed in five, and fetal abnormalities other than chromosomal abnormalities were observed in two. Meanwhile, all nine cases in which an increased NT remained or in which NT continued to increase in size during the second trimester were diagnosed as having cystic hygroma, and chromosomal abnormalities were found in six cases (67%). It should be noted that the shape of increased NT includes NT with a notch (notched NT) and NT without a notch (smooth NT). Among the 20 cases of notched NT, chromosomal abnormalities were observed in eight (40%), and cystic hygroma was observed in nine (45%). On the other hand, among the 38 cases of smooth NT, chromosomal abnormalities were observed in three (7.9%), but no cystic hygroma was observed. Our results confirm that increased NT does not always indicate a fetal abnormality. Whether NT thickness should be measured as a screening tool for fetal abnormalities remains controversial. However, increased NT may be detected by chance, because a maternal-fetal medical examination using ultrasonography is usually performed in Japan. It is therefore considered to be extremely important to establish a system in which cases are referred to obstetricians who are licensed clinical genetic specialists to obtain appropriate genetic counseling whenever increased NT is clinically observed.     

The relationship between serum uric acid and spirometric values in participants in a health check: the Takahata study

Background: Tissue hypoxia induces the degradation of adenosine triphosphate, resulting in the production of uric acid (UA). Patients with chronic obstructive pulmonary disease (COPD) have been reported to have high serum levels of UA (sUA), compared with control subjects. However, the relationship between sUA levels and spirometric measures has not been investigated in detail in a general population.Methods: Subjects aged 40 years or older (n = 2,917), who had participated in a community-based annual health check in Takahata, Japan, in 2004 and 2005, were enrolled in the study. These subjects performed spirometry, their blood pressure was measured, and a blood sample was taken.Results: sUA levels were significantly higher in males than in females. Percent predicted forced vital capacity [FVC %predicted] (r = -0.13) and forced expiratory volume in 1 s [FEV₁ %predicted] (r = -0.118) were inversely correlated with sUA levels in females but not in males. Univariate regression analysis indicated that age, body mass index (BMI), ethanol intake, mean blood pressure (BP), and serum creatinine (sCr) were significantly associated with sUA levels in males. In females, age, BMI, mean BP, hemoglobin A1c, sCr, FVC %predicted, and FEV₁ %predicted were significantly associated with sUA levels. Multiple linear regression analysis showed that for both genders, FVC %predicted and FEV₁ %predicted were predictive for sUA levels, independently of the other clinical parameters. Subjects with lung restriction had higher sUA levels than subjects without lung restriction. In addition, subjects with moderate and severe airflow limitation had higher sUA levels than subjects without airflow limitation or those with mild airflow limitation.Conclusion: FVC %predicted and FEV₁ %predicted were significantly associated with sUA levels in a general population.     

Simple method for the identification of oxidative fibers in skeletal muscle

Skeletal muscle is composed of several different types of myofiber: slow oxidative (SO), fast glycolytic oxidative and fast glycolytic. However, the classification is usually determined by myosin heavy chain typing rather than by metabolic index. In this study, the oxidative metabolic index was investigated as a possible method of myofiber typing. Myoglobin, which is involved in oxygen transport and storage in myofibers, and mitochondria, which are the central organelles for oxidative metabolism, were studied. High levels of myoglobin and mitochondria are believed to exist in SO fibers, but the current study showed that they are considerably richer in some fast type fibers. As myofiber typing using the oxidative metabolic index is important physiologically, an attempt was made to find a simple method for this purpose. Some mitochondrial proteins have been observed to auto-fluoresce but until now this effect was too faint to detect easily. Owing to the recent advances in cooling charge-coupled device technology, such auto-fluorescence can now be used for myofiber typing, and the simple and rapid method for doing so is reported here.     

Pioglitazone,a peroxisome proliferator–activated receptor γ agonist,reduces the progression of experimental osteoarthritis in guinea pigs

Objective

To evaluate the in vivo therapeutic effect of pioglitazone, a peroxisome proliferator–activated receptor γ (PPARγ) agonist, on the development of lesions in a guinea pig model of osteoarthritis (OA), and to determine the influence of pioglitazone on the synthesis of matrix metalloproteinase 13 (MMP‐13) and interleukin‐1β (IL‐1β) in articular cartilage.

Methods

The OA model was created by partial medial meniscectomy of the right knee joint. The guinea pigs were divided into 4 treatment groups: unoperated animals that received no treatment (normal), operated animals (OA guinea pigs) that received placebo, OA guinea pigs that received oral pioglitazone at 2 mg/kg/day, and OA guinea pigs that received oral pioglitazone at 20 mg/kg/day. The animals began receiving medication 1 day after surgery and were killed 4 weeks later. Macroscopic and histologic analyses were performed on the cartilage. The levels of MMP‐13 and IL‐1β in OA cartilage chondrocytes were evaluated by immunohistochemistry.

Results

OA guinea pigs treated with the highest dosages of pioglitazone showed a significant decrease, compared with the OA placebo group, in the surface area (size) and grade (depth) of cartilage macroscopic lesions on the tibial plateaus. The histologic severity of cartilage lesions was also reduced. A significantly higher percentage of chondrocytes in the middle and deep layers stained positive for MMP‐13 and IL‐1β in cartilage from placebo‐treated OA guinea pigs compared with normal controls. Guinea pigs treated with the highest dosage of pioglitazone demonstrated a significant reduction in the levels of both MMP‐13 and IL‐1β in OA cartilage.

Conclusion

This is the first in vivo study demonstrating that a PPARγ agonist, pioglitazone, could reduce the severity of experimental OA. This effect was associated with a reduction in the levels of MMP‐13 and IL‐1β, which are known to play an important role in the pathophysiology of OA lesions.

     

Laninamivir octanoate for post-exposure prophylaxis of influenza in household contacts: a randomized double blind placebo controlled trial

Laninamivir octanoate, a long-acting neuraminidase inhibitor, is an effective treatment for influenza. However, its effectiveness for the prevention of influenza has not yet been demonstrated. We conducted a double-blind, multicenter, randomized, placebo-controlled trial to determine whether laninamivir octanoate was superior to a placebo for post-exposure prophylaxis of influenza in household contacts. Eligible participants, who were household members who did not have influenza and were in contact with an influenza-infected index patient, were randomly assigned (1:1:1) to one of three groups: 20 mg of laninamivir octanoate once daily for 2 days (LO-2), 20 mg of laninamivir octanoate once daily for 3 days (LO-3), or a placebo. The primary endpoint was the proportion of participants who developed clinical influenza during a 10-day period. A total of 1711 participants were enrolled, and 1451 participants were included in the primary analysis. The proportion of participants with clinical influenza was 3.9 % (19/487) in the LO-2 group, 3.7 % (18/486) in the LO-3 group, and 16.9 % (81/478) in the placebo group (P < 0.001 for each of the laninamivir octanoate group). The relative risk reductions, compared with the placebo group, were 77.0 % [95 % confidence interval (CI) 62.7–85.8] and 78.1 % (95 % CI 64.1–86.7 %) for the LO-2 and LO-3 groups, respectively. The incidences of adverse events in the laninamivir octanoate groups were similar to that in the placebo group. The inhalation of 20 mg of laninamivir octanoate once daily for 2 or 3 days was well tolerated and effectively prevented the development of influenza in household contacts.