Sarcoglycan complex is selectively lost in dystrophic hamster muscle

We recently reported that the dystrophin-associated glycoprotein (DAG) complex is biochemically divided into two subcomplexes: one is the dystroglycan complex comprised of 156DAG and 43DAG and the other is the sarcoglycan complex comprised of 50DAG, A3b, and 35DAG. A3b is a novel dystrophin-associated glycoprotein with an approximate molecular mass of 43 kd but is distinct from 43DAG. In the present study, we examined the striated muscles of the dystrophic hamster with anti-A3b antibody in addition to anti-50DAG, anti-43DAG, anti-35DAG, anti-dystrophin, and anti-laminin antibodies by both immunohistochemistry and immunoblot analysis and found that 50DAG, A3b, and 35DAG are selectively lost. This selective defect of the sarcoglycan complex in dystrophic hamster muscles may give rise to dystrophic changes in striated muscles. Thus, the differentiation of the dystrophin-associated glycoprotein complex into the dystroglycan and sarcoglycan complexes is important not only from a biochemical standpoint but also in understanding the cause of muscular dystrophy in the hamster. Our findings further show that the dystrophic hamster may serve as an animal model for a human disease, severe childhood autosomal recessive muscular dystrophy, which has recently been shown to result from a selective defect in the sarcoglycan complex.

Mammalian alpha 1- and beta 1-syntrophin bind to the alternative splice-prone region of the dystrophin COOH terminus

The carboxy-terminal region of dystrophin has been suggested to be crucially important for its function to prevent muscle degeneration. We have previously shown that this region is the locus that interacts with the sarcolemmal glycoprotein complex, which mediates membrane anchoring of dystrophin, as well as with the cytoplasmic peripheral membrane protein, A0 and beta 1-syntrophin (Suzuki, A., M. Yoshida, K. Hayashi, Y. Mizuno, Y. Hagiwara, and E. Ozawa. 1994. Eur. J. Biochem. 220:283-292). In this work, by using the overlay assay technique developed previously, we further analyzed the dystrophin-syntrophin/A0 interaction. Two forms of mammalian syntrophin, alpha 1- and beta 1-syntrophin, were found to bind to very close but discrete regions on the dystrophin molecule. Their binding sites are located at the vicinity of the glycoprotein-binding site, and correspond to the amino acid residues encoded by exons 73-74 which are alternatively spliced out in some isoforms. This suggests that the function of syntrophin is tightly linked to the functional diversity among dystrophin isoforms. Pathologically, it is important that the binding site for alpha 1-syntrophin, which is predominantly expressed in skeletal muscle, coincides with the region whose deletion was suggested to result in a severe phenotype. In addition, A0, a minor component of dystrophin-associated proteins with a molecular mass of 94 kD which is immunochemically related to syntrophin, binds to the same site as beta 1-syntrophin. Finally, based on our accumulated evidence, we propose a revised model of the domain organization of dystrophin from the view point of protein-protein interactions.

Significance of altered fluidity of plasma membranes of the liver and kidney in rats with sepsis

The present study was conducted to investigate changes in plasma membrane fluidity of the liver and kidney in sepsis, which is the main cause of multiple organ failure. Male Wistar rats weighing 200-250 g were used in all experiments. Sepsis was induced by cecal ligation and puncture. As a control, a sham operation was performed. The time course of plasma membrane fluidity of the liver and the renal cortex in septicemic rats or in controls was studied. To evaluate the fluidity, fluorescence polarization was measured using 1,6-diphenyl-1,3,5-hexatriene. The fluorescence polarization values of liver plasma membranes increased after cecal ligation and puncture: 0.183 +/- 0.004 (mean +/- SEM), 0.194 +/- 0.008, 0.206 +/- 0.003, and 0.210 +/- 0.002 at 0, 24, 48, and 72 hr, respectively. Corresponding values for membranes of the renal cortex increased in a similar fashion. To determine whether factors involved in cell membrane damage exist in blood, the direct effects of lipopolysaccharide (LPS), platelet-activating factor (PAF), and serum from normal rats or from septicemic rats on membrane fluidity were studied. The fluorescence polarization of plasma membranes of the liver or renal cortex to which septicemic rat serum was added was higher than that of plasma membranes to which normal rat serum was added. The fluorescence polarization of liver plasma membranes was increased by LPS, but that of plasma membranes of the renal cortex was slightly decreased. In addition, the fluorescence polarization of liver plasma membranes was increased by PAF, but that of plasma membranes of the renal cortex was decreased.(ABSTRACT TRUNCATED AT 250 WORDS)

A large-scale, hospital-based case-control study of risk factors of breast cancer according to menopausal status

We conducted a large-scale, hospital-based case-control study to evaluate differences and similarities in the risk factors of female breast cancer according to menopausal status. This study is based on a questionnaire survey on life style routinely obtained from outpatients who first visited the Aichi Cancer Center Hospital between January 1, 1988 and December 31, 1992. Among 36,944 outpatients, 1,186 women with breast cancer detected by histological examination were taken as the case group (607 premenopausal women and 445 postmenopausal women) and 23,163 women confirmed to be free of cancer were selected as the control group. New findings and reconfirmed factors of breast cancer were as follows. 1) The risk of at least one breast cancer history among subjects' first-degree relatives was relatively high among pre- as well as post-menopausal women. 2) A protective effect of physical activity against breast cancer was observed among both pre- and post-menopausal women. 3) Dietary control decreased the risk of premenopausal breast cancer. 4) Current smoking and drinking elevated the risk of breast cancer in premenopausal women. 5) Decreasing trends of breast cancer risk were associated with intake of bean curd, green-yellow vegetables, potato or sweet potato, chicken and ham or sausage in premenopausal women, while in postmenopausal women a risk reduction was associated with a more frequent intake of boiled, broiled and/or raw fish (sashimi). Further study will be needed to clarify the age group- and/or birth cohort-specific risk factors for breast cancer among the young generation in Japan.

[Complete remission achieved by low-dose Ara-C, aclarubicin and rhG-CSF (CAG) therapy in acute non-lymphocytic leukemia with monosomy 7 occurring after severe aplastic anemia]

We report a case of acute myelogenous leukemia (AML), which developed from severe aplastic anemia (SAA) and was successfully treated by low-dose Ara-C and aclarubicin with concomitant use of G-CSF (CAG therapy). A 37-year-old male was admitted for scrutiny of pancytopenia and diagnosed as SAA because of hypocellular bone marrow without abnormal or dysplastic cells. Although hematopoiesis recovered with steroid pulse therapy followed by administration of anabolic steroids, 29 months after initial onset of SAA, he presented as AML (FAB-M6), as his bone marrow Contained 21.6% leukemic myeloblasts and 56% of erythroblasts. Chromosome study revealed 45, XY, -7 in 14 of 20 cells analyzed. Complete remission was achieved by administration of low-dose Ara-C (20 mg/m2 for 7 days) and aclarubicin (14 mg/m2 for 4 days) along with G-CSF (200 micrograms/m2 for 7 days), without any severe complications. In the previous reports in Japan since 1982, 7 out of 8 cases with AML developing from SAA died within a year. Our results indicate that CAG therapy is useful for treatment for this subset of AML with poor prognosis.

[Bilateral ankle ulcers associated with hydroxyurea therapy for chronic myelogenous leukemia]

Bilateral ankle skin ulcers developed in a 61-year-old man in the chronic phase of chronic myelogenous leukemia receiving hydroxyurea therapy. The circulating immune complex (anti-C3d antibody) was high in this case, but vasculitis was not observed in the pathological findings of biopsied skin materials. This association has been reported in patients who had chronic myelogenous leukemia or other myeloproliferative disorders and were treated with hydroxyurea. It is likely that skin ulcers are caused by hydroxyurea.

Plasma (1-->3)-beta-D-glucan measurement in diagnosis of invasive deep mycosis and fungal febrile episodes

(1-->3)-beta-D-glucan is a characteristic fungal cell-wall constituent. To assess the clinical usefulness of this glucan in screening for invasive fungal infection or fungal febrile episodes, we measured the plasma concentration at the time of routine blood culture in 202 febrile episodes by means of factor G, a horseshoe-crab coagulation enzyme that is extremely sensitive to this polysaccharide. With a plasma cut-off value of 20 pg/mL, 37 of 41 episodes of definite fungal infections (confirmed at necropsy or by microbiology) had positive results (sensitivity 90%). All of 59 episodes of non-fungal infections, tumour fever, or collagen diseases had concentrations below the cut-off value (specificity 100%). Of 102 episodes of fever of unknown origin, 26 had plasma glucan concentrations of more than 20 pg/mL. With those 102 cases taken as non-fungal infections, the positive predictive value of the test was estimated as 59% (37/63), the negative predictive value as 97% (135/139), and the efficiency as 85% (172/202). The positive predictive value should improve if there were a sensitive gold standard that could discriminate fungal from non-fungal infections. Causative fungi included candida, aspergillus, cryptococcus, and trichosporon. Determination of plasma (1-->3)-beta-D-glucan with factor G is a highly sensitive and specific test for invasive deep mycosis and fungal febrile episodes, and will substantially benefit immunocompromised patients.

Prenatally diagnosed female prune belly syndrome associated with tetralogy of Fallot

Female prune belly syndrome and tetralogy of Fallot were diagnosed in obstetric ultrasound screening at 13 and 28 weeks of gestation, respectively. The baby was born at 38 weeks showing abdominal distension, hypoplasia of abdominal muscles, vaginal atresia, imperforate anus and clubfeet. Radiologic and ultrasound examinations confirmed our prenatal diagnosis and revealed other abnormalities of patent ductus arteriosus, major aortopulmonary collateral arteries, bilateral vesicoureteral reflux, rectourethral fistula and hypoplasia of the right kidney. Urination has been smooth, but cystitis was observed repeatedly once a month. The infant was discharged in good condition and has been followed in the outpatient clinic.

Effects of acoustic overstimulation on 2f1-f2 distortion product in the cochlear microphonics

The cochlear microphonics (CM) in response to two-tone stimuli as well as the threshold of compound action potential (CAP) were measured before and after exposure to 4 kHz pure tone at 100 dB SPL for 10 min. Although the loss of CM output at the primary frequencies was limited to around 2 dB, the 2f1-f2 distortion products in the CM (CM-DPs) were markedly reduced immediately after the exposure, especially at low primary levels (i.e. less than 65 dB). The low level CM-DPs recovered gradually near the initial level within 7 days from the exposure. The elevation of CAP threshold closely paralleled with the reduction of CM-DPs in not only the acute phase but also in the recovery phase from the exposure. These results show that the active transduction process in the cochlea was affected by acoustic overstimulation. This impairment of the active transduction was postulated to play an important role in developing the noise induced temporary threshold shift.

[MR imaging of the anterior spinal artery in a case of bilateral vertebral arterial occlusion]

A 66-year-old woman, who had been suffering from frequent episodes of vertebro-basilar insufficiency for 10 years, was admitted because of brainstem ischemic symptoms. Magnetic resonance (MR) images were almost normal, but small flow voids were observed in front of the medulla oblongata and the upper cervical spinal cord. Cerebral angiography revealed that both of the vertebral arteries were completely occluded after branching off the respective posterior inferior cerebellar arteries. The basilar artery was fed only by a retrograde collateral flow via the anterior spinal artery which, arising from the left vertebral artery at the level of the fifth to sixth cervical vertebra, ascended the ventral aspect of the cord. These findings clarified that the flow voids on the MRI were from the anterior spinal artery, and were unusually prominent, as a collateral flow to the basilar artery. To the best of our knowledge, an anterior spinal flow void found on routine brain MR imaging has not been documented in the literature. Our case suggested that the flow void, a very small finding on the MRI, could be a useful sign in the diagnosis of serious vertebral arterial diseases.

Detection of green algae (Chlorophyceae) for the diagnosis of drowning

The plankton test (generally, diatom test) is one of the methods available to diagnose the cause of death of submerged bodies. The solubilization method using tissue solubilizer Soluene-350 was used in this study to detect not only diatoms but also green algae, based on the fact that the solubilizer does not digest the cell walls of green algae which are made from cellulose. Detection of green algae from organs of submerged cadavers is very informative to determine drowning in fresh water, and also in cases where only few diatoms are detected in the organs.

Portal and peripheral endotoxins in patients with esophageal varices undergoing surgery

Under the hypothesis that portal endotoxemia, which has been considered evidence of endogenous endotoxemia, is actually a false-positive reaction of the Limulus test, the conventional method of determination, Toxicolor (TOX) and a new endotoxin-specific method, Endospecy (ES) were investigated, whereby portal endotoxemia was reexamined. Peripheral and portal blood samples were collected from 12 patients at various intervals during surgery for esophageal varices, and then evaluated by TOX and ES, the normal values of which are under 60.0 pg/ml and under 9.8 pg/ml, respectively. The mean peripheral and portal endotoxin (Et) levels by TOX were 23.1 pg/ml and 38.9 pg/ml, 1.5 h after the start of surgery, which continued to increase thereafter, the corresponding levels being 48.1 pg/ml and 58.7 pg/ml 8 h after the start of surgery, respectively. The portal Et levels were significantly higher by ES, indicating portal endotoxemia, the mean peripheral and portal Et levels being 6.9 pg/ml, and 6.5 pg/ml, 1.5 h after the start of surgery, these levels showing changes within a similar range. The levels determined by the conventional TOX method increased with time, to a portal Et level of 5.0 pg/ml 8 h after the start of surgery, whereas those determined by ES changed within the same range suggesting that the onset of portal endotoxemia primarily involves the G-factors and that endogenous endotoxemia does not occur.

Utilization behavior after right thalamic infarction

We report a patient who showed exaggerated responses to external cues (utilization behavior), motor impersistence, and a right-hand-predominant instinctive grasp reaction after right thalamic infarction. High-resolution computed tomography with stereotaxic lesion localization revealed almost complete destruction of the ventroanterior nucleus and intralaminar nuclei of the right thalamus; the dorsomedial nucleus was only partially involved. Single photon emission computed tomography revealed hypoperfusion in the right thalamus and over the entire right cerebral cortex with some prominence in the frontal area. From these observations, we believe that the utilization behavior in our case was caused by the disturbance in maintaining cortical tone of the right hemisphere as well as by the dysfunction of the right frontal lobe, both secondary to the damage to the right ventroanterior nucleus and intralaminar nuclei.

Lesser sac herniation through the greater omentum and gastro-pancreatic ligament: report of a case

We report herein the case of a woman who developed a lesser sac hernia which was especially unusual in that the small bowel prolapsed through a defect in the greater omentum and was thereafter strangulated by a hole in the gastro-pancreatic ligament. The gastro-pancreatic ligament has never before been documented as causing an internal hernia. In our patient, a plain abdominal X-ray demonstrated as soft-tissue mass displacing the stomach to the left while abdominal computed tomography and ultrasonography showed a sac-like encapsulation of the small bowel loops between the liver and stomach. Careful evaluation of these radiographic findings allowed for the preoperative diagnosis of a lesser sac hernia to be made.

Nucleotide sequence of a highly repetitive element isolated from Opsariichthys uncirostris (Osteichthyes). O. uncirostris repetitive sequence

A highly repetitive DNA element has been isolated from Opsariichthys uncirostris. It contains several oligo-dA tracts and potential regions for the secondary structures.

Detection of gamma-aminobutyric acid in a living rat brain using in vivo microdialysis-capillary electrophoresis/mass spectrometry

Coupling of in vivo microdialysis with capillary electrophoresis/mass spectrometry (MD-CE/MS) was demonstrated. A microdialysis probe was inserted in the striatum of a rat brain and gamma-aminobutyric acid (GABA) in the brain was detected by CE/MS without any chemical treatment of the sample. MD-CE/MS is expected to be a useful technique for analyzing brain substances, because of the relatively small damage it causes to a living structure and the high selectivity of the analytical technique.

Comparative pharmacodynamic analysis of TAT-59 and tamoxifen in rats bearing DMBA-induced mammary carcinoma

TAT-59 suppressed the growth of DMBA-induced mammary tumors in rats earlier and more strongly than tamoxifen (TAM). After oral administration of the drugs, DP-TAT-59, one of the main metabolites of TAT-59, was found in 10- to 15-fold higher concentrations in both the tumor and blood compared to 4-OH-TAM, an active metabolite of TAM. In a 3-day antiuterotrophic test, every detected metabolite of TAT-59 showed stronger antiestrogenic activity than did TAM. In a competition assay, the affinity of the metabolites for estrogen receptors ranged from that of estradiol to that of TAM. These results suggest that the superior antiestrogenic activity of TAT-59 compared to TAM was either due to its higher penetration into tumor tissue or to the stronger antiestrogenic activity of its metabolites.