Koebner phenomenon on skin graft donor site in cutaneous angiosarcoma

An 81-year-old woman developed a necrotic plaque and a surrounding purple-red, irregularly shaped macule on her scalp. The diagnosis of angiosarcoma was confirmed histologically. A wide surgical excision was made followed by a split-thickness skin graft from her right buttock. Nine months later, she noticed a dark purple-red lesion on the donor site which grew rapidly into a large mass. Histological examination revealed irregular clefts and vascular channels lined by atypical endothelial cells. Lung metastasis and pneumothorax were also noted. The secondary tumor appeared to represent Koebner phenomenon in a patient with angiosarcoma of the scalp.

Thyroid gland tumour, pemphigus foliaceus and myasthenia gravis in the daughter of a woman with myasthenia gravis

We describe a rare case of pemphigus foliaceus associated with familial myasthenia gravis (MG). A 35-year-old woman developed MG during oral corticosteroid treatment for pemphigus foliaceus. She had been operated on for a thyroid gland tumour that was confirmed histopathologically to be papillary carcinoma without metastasis. At the time of treatment, her mother had had MG for 30 years and undergone thymectomy 22 years ago. A specific ELISA technique showed that antidesmoglein 1 antibody was present in the daughter. There are many reports of multiple diseases such as pemphigus, thymoma, malignancy, and other autoimmune diseases associated with MG. However, familial MG following pemphigus foliaceus has not been reported previously.

ATP analogue binding to the A subunit induces conformational changes in the E subunit that involves a disulfide bond formation in plant V-ATPase

Vacuolar H+-ATPase (V-ATPase) consists of a catalytic head, a stalk part and a membrane domain. We indirectly investigated the interaction between the A subunit (catalytic head) and the E subunit (stalk part) using an ATP analogue, adenosine 5'-[beta,gamma-imino]triphosphate (AMP-PNP), which holds the enzyme in the substrate-binding state. AMP-PNP treatment caused a mobility shift of the E subunit with a faster migration in SDS/polyacrylamide gel electrophoresis without a reductant, while ATP treatment did not. A mobility shift of the E subunit has been detected in several plants. As polypeptides with intramolecular disulfide bonds migrate faster than those without disulfide bonds, the mobility shift may be due to the formation of an intramolecular disulfide bond by two cysteine residues conserved among several plant species. The mobility shift may be involved in the binding of AMP-PNP to the ATP-binding site, which exists in the A and B subunits, as it was inhibited by the addition of ATP. Pretreatment with 2'-3'-O-(4-benzoylbenzoyl)-ATP (Bz-ATP), which modifies the ATP-binding site of the B subunit under UV illumination, did not inhibit the mobility shift of the E subunit caused by AMP-PNP treatment. The response of V-ATPase following the AMP-PNP binding may cause a conformational change in the E subunit into a form that is susceptible to oxidation of cysteine residues. This is the first demonstration of interaction between the A and E subunits in the substrate-binding state of a plant V-ATPase.

[An autopsy case of dementia with motor neuron disease accompanying Alzheimer's disease lesion]

We report the case of a 60-year-old man with autopsy-proven dementia with motor neuron disease (D-MND) and Alzheimer's disease lesion. The patient presented with clumsiness of his right hand at the age of 55 years old and subsequently developed dysarthria, weakness and atrophy of his upper limbs. He was unaffectionate towards his family, repeated the same phrase, and showed severe disorientation of time and place. Neurological examination on admission showed not only diffuse lower motor neuron signs, such as weakness, atrophy, fasciculation and areflexia in both upper limbs, but also dementia (HDS-R 9/30). He died of respiratory insufficiency. Neuropathological examination showed mild atrophy of the frontal and temporal lobes and anterior spinal roots. Microscopic examination of cortical sections revealed degenerative changes with simple atrophy and gliosis, and these changes were predominant in layers 1 and 2 of the frontal and temporal cortices. Using immunohistochemical staining, ubiquitin-positive but tau-negative inclusions were frequently found in neurons of the hippocampal granular cell layers and temporal lobes. Many senile plaques and neurofibrillary tangles were present in all sections of the brain. Our final diagnosis was dementia with motor neuron disease accompanying Alzheimer's disease lesion, because of hypoperfusion in the parietal lobe as well as the frontal lobe demonstrated by SPECT, and the presence of many senile plaques and neurofibrillary tangles in the cerebral cortex. Overlapping of pathologically-proven D-MND and Alzheimer's disease lesion is extremely rare, and this case may improve our understanding of the process of neurodegeneration.

Cold acclimation-induced WAP27 localized in endoplasmic reticulum in cortical parenchyma cells of mulberry tree was homologous to group 3 late-embryogenesis abundant proteins

We have shown that two 27-kD proteins, designated as WAP27A and WAP27B, were abundantly accumulated in endoplasmic reticulum-enriched fractions isolated from cortical parenchyma cells of mulberry tree (Morus bombycis Koidz.) during winter (N. Ukaji, C. Kuwabara, D. Takezawa, K. Arakawa, S. Yoshida, S. Fujikawa [1999] Plant Physiol 120: 480--489). In the present study, cDNA clones encoding WAP27A and WAP27B were isolated and characterized. The deduced amino acid sequences of WAP27A and WAP27B cDNAs had 12 repeats of an 11-mer amino acid motif that was the common feature of group 3 late-embryogenesis-abundant proteins. Under field conditions, transcripts of WAP27 genes were initially detected in mid-October, reached maximum level from mid-November to mid-December, and then gradually decreased. The transcript levels of WAP27 genes in cortical parenchyma cells harvested in October was drastically induced by cold treatment within a few days, whereas those in cortical parenchyma cells harvested in August were low even by cold treatment for 3 weeks. Immunocytochemical analysis by electron microscopy confirmed that WAP27 was localized specifically in vesicular-form ER and also localized in dehydration-induced multiplex lamellae-form ER. The role of WAP27 in the ER is discussed in relation to acquisition of freezing tolerance of cortical parenchyma cells in mulberry tree during winter.

A novel autosomal dominant spinocerebellar ataxia (SCA16) linked to chromosome 8q22.1-24.1

OBJECTIVE

To characterize a distinct form of autosomal dominant cerebellar ataxia (ADCA) clinically and genetically.

BACKGROUND

ADCAs are a clinically, pathologically, and genetically heterogeneous group of neurodegenerative disorders. Nine responsible genes have been identified for SCA-1, -2, -3, -6, -7, -8, -10, and -12 and dentatorubral-pallidoluysian atrophy (DRPLA). Loci for SCA-4, -5, -11, -13, and -14 have been mapped.

METHODS

The authors studied a four-generation Japanese family with ADCA. The 19 members were enrolled in this study. The authors performed the mutation analysis by PCR and a genome-wide linkage analysis.

RESULTS

Nine members (five men and four women) were affected. The ages at onset ranged from 20 to 66 years. All affected members showed pure cerebellar ataxia, and three patients also had head tremor. Head MRI demonstrated cerebellar atrophy without brain stem involvement. The mutation analysis by PCR excluded diagnoses of SCA-1, -2, -3, -6, -7, -8, and -12 and DRPLA. The linkage analysis suggested linkage to a locus on chromosome 8q22.1-24.1, with the highest two-point lod score at D8S1804 (Z = 3.06 at theta = 0.0). The flanking markers D8S270 and D8S1720 defined a candidate region of an approximately 37.6-cM interval. This candidate region was different from the loci for SCA-4, -5, -10, -11, -13, and -14.

CONCLUSION

The family studied had a genetically novel type of SCA (SCA-16).

High cardiac angiotensin-II-forming activity in infarcted and non-infarcted human myocardium

The aims of this study were to compare human cardiac angiotensin-II-forming activity (AIIFA) between the intact area of control autopsy hearts without cardiac disease (n = 10) and the infarcted or non-infarcted area of autopsy hearts with myocardial infarction (MI, n = 7) and to determine responsible angiotensin-II-forming enzymes. Cardiac total and chymase-dependent AIIFAs were significantly higher in the infarcted and non-infarcted myocardium than those in non-MI heart, while angiotensin-converting enzyme-dependent AIIFA increased only in the infarcted myocardium. The density of chymase antibody-positive mast cells in the non-infarcted area of MI heart correlated positively with total or chymase-dependent AIIFA. Augmented AIIFA was also detected in the left atrium of post-MI hearts. Our results indicated that cardiac angiotensin II formation could be activated in the infarcted as well as in non-infarcted myocardium of the post-MI human heart.

Effect of coronary risk factors on arterial compensatory enlargement in japanese middle-aged patients with de novo single-vessel disease--an intravascular ultrasound study

BACKGROUND

Compensatory enlargement (CE) of atherosclerotic human arteries has been reported; however, the pattern of arterial remodeling in response to plaque formation is not unique.

HYPOTHESIS

The study was undertaken to determine the extent of coronary artery compensatory enlargement at stenotic lesions and to correlate the arterial compensatory enlargement with risk factors.

METHODS

We studied 62 patients with stable angina and de novo single-vessel disease using intravascular ultrasound and obtained good images in 42 patients (68%). The vessel cross-sectional area (VA), lumen cross-sectional area (LA), and plaque cross-sectional area (PA) were measured at the lesion site and at proximal and distal reference sites. Positive CE was defined as increase in VA of lesion site > 10% compared with that of proximal reference site (CE group, n = 15); shrinkage was defined as reduction in VA of lesion site > 10% compared with that of proximal reference site (S group, n = 14); inadequate CE was defined as intermediate between CE and S (IE group, n = 13). All subjects had coronary risk factors measured before this study.

RESULTS

There was no difference in VA, LA, or PA among the three groups at the proximal and distal reference sites, nor in LA at the lesion site; however, VA and PA were significantly smaller in the S group than in the other groups (p < 0.01). Of coronary risk factors, increased systolic blood pressure (SBP), increased diastolic blood pressure (DBP), and decreased high-density lipoprotein cholesterol (HDL-c) levels had the strongest association with shrinkage (p < 0.05).

CONCLUSION

Hypertension and decreased HDL level may contribute to the shrinkage response in middle-aged patients with stable angina.

Evaluation of central nervous system involvement in nasal lymphomas

OBJECTIVES

To clarify the usefulness of evaluating central nervous system (CNS) involvement in patients with nasal lymphomas at the initial staging procedure, and of CNS prophylaxis for patients with clinical stage I/II.

PATIENTS AND METHODS

We retrospectively reviewed 43 patients with nasal lymphomas who had been treated from 1973 through 1999. The staging procedure included mainly computed tomography (CT), ultrasonography, gallium scintigraphy, upper gastrointestinal study, magnetic resonance (MR) imaging, and bone marrow biopsy. Forty-two patients received radiotherapy, and 25 patients received chemotherapy. All 38 patients with stage I/II were not subjected to CNS prophylaxis.

RESULTS

Four patients demonstrated CNS involvement at the staging procedure. MR imaging demonstrated the tumor had directly infiltrated the skull base in 3 patients, but CT demonstrated CNS infiltration in only one patient. In another patient, cerebrospinal fluid (CSF) cytologic analyses demonstrated CNS involvement, but MR imaging and CT did not. These 4 patients complained of frontonasal pain and/or cerebral nerve dysfunction. No patient with stage I/II developed CNS relapse.

CONCLUSIONS

MR imaging and CSF cytologic analyses should be performed at the initial staging of nasal lymphomas, especially in patients with frontonasal pain and/or cerebral nerve dysfunction. Patients with stage I/II might not need CNS prophylaxis.

Inhibitory effect of hyperglycemia on insulin-induced Akt/protein kinase B activation in skeletal muscle

To determine the molecular mechanism underlying hyperglycemia-induced insulin resistance in skeletal muscles, postreceptor insulin-signaling events were assessed in skeletal muscles of neonatally streptozotocin-treated diabetic rats. In isolated soleus muscle of the diabetic rats, insulin-stimulated 2-deoxyglucose uptake, glucose oxidation, and lactate release were all significantly decreased compared with normal rats. Similarly, insulin-induced phosphorylation and activation of Akt/protein kinase B (PKB) and GLUT-4 translocation were severely impaired. However, the upstream signal, including phosphorylation of the insulin receptor (IR) and insulin receptor substrate (IRS)-1 and -2 and activity of phosphatidylinositol (PI) 3-kinase associated with IRS-1/2, was enhanced. The amelioration of hyperglycemia by T-1095, a Na(+)-glucose transporter inhibitor, normalized the reduced insulin sensitivity in the soleus muscle and the impaired insulin-stimulated Akt/PKB phosphorylation and activity. In addition, the enhanced PI 3-kinase activation and phosphorylation of IR and IRS-1 and -2 were reduced to normal levels. These results suggest that sustained hyperglycemia impairs the insulin-signaling steps between PI 3-kinase and Akt/PKB, and that impaired Akt/PKB activity underlies hyperglycemia-induced insulin resistance in skeletal muscle.

Alcohol consumption and severity of angiographically determined coronary artery disease in Japanese men and women

The relation of alcohol consumption to the severity of coronary atherosclerosis was examined among 323 men and 220 women who underwent coronary arteriography. Severity of coronary atherosclerosis was assessed by the number of vessels obstructed > or =75% in diameter and Gensini's severity score. Alcohol consumption was divided into 5 categories in men (never, past, 1-24, 25-49, and > or =50 ml per day) and 3 categories in women (never, past, and current). Among men, odds ratios of severe stenosis (multiple-vessel disease or Gensini's score >15) decreased substantially and significantly in all current drinking categories but without dose-response effect. There was a weak, inverse association of current alcohol consumption with one-vessel disease, but not with moderate stenosis in terms of Gensini's score (< or =15). Past drinkers showed a fairly large, but statistically nonsignificant, decrease in the odds ratios of not only severe stenosis but also of moderate stenosis. Among women, current drinkers showed a small, statistically nonsignificant decrease in the risk of severe stenosis in terms of Gensini's score. These associations with alcohol use did not change after adjustment for known coronary risk factors. The present findings add to evidence that alcohol drinking confers protection against coronary atherosclerosis.

Mechanism of the cardioprotective effect of inhibition of the renin-angiotensin system on ischemia/reperfusion-induced myocardial injury

Inhibition of the renin-angiotensin system (RAS) has been shown to be beneficial in providing cardioprotective effects in humans, but the mechanism of these effects is not well understood. In this study, we examined the effects and mechanism of RAS inhibitors on ischemia/reperfusion (IR)-induced myocardial injury in rats. Rats were randomly divided into five groups and treated with vehicle (C), angiotensin converting enzyme inhibitor (ACE-I), angiotensin II type 1 receptor antagonist (AT1-A), angiotensin II type 2 receptor antagonist (AT2-A) or ACE-I plus bradykinin B2 antagonist. Ten minutes after administration, the left main coronary artery was ligated for 45 min, and then reperfused for 120 min. IR-induced cardiomyocyte apoptosis was assessed by terminal deoxyribonucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) assay and confirmed by typical DNA laddering. Mitogen-activated protein kinase, extracellular signal-regulated protein kinase (ERK) and c-Jun NH2-terminal protein kinase (JNK) activity in the ischemic zone were measured by an in vitro kinase assay. The duration of ventricular tachycardia (VT) during ischemia was reduced by AT2-A and ACE-I, and increased by AT1-A and ACE-I+icatibant. ACE-I and AT2-A reduced apoptosis (by 54% and 53%) and infarct size (by 42% and 41%), while AT1-A increased apoptosis (by 86%) and infarct size (by 45%). These changes were negatively correlated with the change in ERK activity. The effects of ACE-I on apoptosis and infarct size were abolished by the coadministration of icatibant. Apoptosis was correlated with the occurrence of VT (r=0.837, p<0.001). These results suggest that both the accumulation of bradykinin and inhibition of AT2 receptor are cardioprotective against IR injury through the activation of ERK, but not JNK.

Substituted 3-phenylsulfonylquinazoline-2,4-dione derivatives as novel nonpeptide inhibitors of human heart chymase

A series of 3-phenylsulfonylquinazoline-2,4-dione derivatives have been synthesized and evaluated for their ability to inhibit human heart chymase. The structure-activity relationship studies on these compounds gave the following results. The phenyl moiety of quinazoline participates in a hydrophobic interaction where an optimum size is required. In this moiety, 7-chloroquinazoline is the best moiety for inhibiting chymase, chymotrypsin and cathepsin G. A 3-phenylsulfonyl moiety substituted with hydrophobic electron-withdrawing groups at the 4-position potentiated the activity. Anthranil moiety also enhanced the activity. Pyridylmethyl and N-pyridylacetamide at the 1-position gave an IC50 in the order of 10(-8)M. Molecular modeling studies on the interaction of 7-chloro-3-(4-chlorophenylsulfonyl) quinazoline-2,4(1H, 3H)-dione (4) with the active site of human heart chymase suggested that the phenyl moiety of quinazoline interacts with the hydrophobic P1 pocket, the 3-phenylsulfonyl moiety resides in the S1'-S2' subsites, the moiety at the 1-position locates in the S2-S3 subsites and the 4-carbonyl and 3-sulfonyl group interact with the oxyanion hole and the His57 side-chain of chymase, respectively.

Effects of a slow-release nifedipine on 24-hour ambulatory blood pressure and ischemic changes on 24-hour ambulatory electrocardiogram in patients with severe coronary artery disease

Calcium antagonists have long been used as first-line drugs for hypertension and angina. However, deleterious effects have also been reported in patients treated with calcium antagonists. Thus, we evaluated the effect of a slow-release twice-daily formulation of nifedipine in 10 patients with severe coronary artery disease. Twenty-four-hour ambulatory electrocardiography (AECG) and blood pressure monitoring (ABPM) were performed simultaneously to detect any association between ischemic episodes on the ECG and changes in blood pressure (BP) and heart rate with and without nifedipine. Increased oxygen demand due to an increased systolic BP and heart rate was associated with ischemic episodes without nifedipine, while those with nifedipine were accompanied by a fall in diastolic BP and a rapid increase in heart rate. This slow-release twice-daily formulation of nifedipine may induce myocardial ischemia through a heart-rate increase and a decrease in coronary blood flow due to lower diastolic BP in patients with severe coronary artery disease. A once-daily formulation of nifedipine might be of great value for such patients.

Genetic, dietary, and other lifestyle determinants of plasma homocysteine concentrations in middle-aged and older Chinese men and women in Singapore

BACKGROUND

Epidemiologic studies have identified the plasma homocysteine concentration as a risk factor for atherothrombotic vascular disease. There is little information on the distributions and determinants of homocysteine concentrations in Asian populations.

OBJECTIVE

The present study was designed to examine the relations between genetic and lifestyle factors and plasma homocysteine concentrations among Chinese in Singapore.

DESIGN

Plasma total homocysteine, folate, vitamin B-12, and vitamin B-6 concentrations and genetic variation at the methylenetetrahydrofolate reductase (MTHFR) locus were measured in 486 Chinese men and women aged 45-74 y in Singapore. Data on dietary and other lifestyle factors were collected in face-to-face interviews.

RESULTS

Men had higher plasma concentrations of total homocysteine than women (P = 0.0001). Age was positively associated with plasma homocysteine in both sexes (P for trend = 0.0001). Plasma concentrations of folate, vitamin B-12, and vitamin B-6 were inversely associated with homocysteine concentrations. Among individuals with low plasma folate, those possessing 2 copies of MTHFR mutant alleles had significantly higher homocysteine concentrations than did those with > or = 1 copy of the wild-type allele. Cigarette smoking, daily coffee consumption, and physical inactivity were positively related to plasma homocysteine concentrations in both sexes (P < 0.05). However, these associations disappeared after adjustment for plasma folate concentrations.

CONCLUSIONS

Age, sex, plasma folate, vitamin B-12 and B-6 concentrations, and MTHFR genotype are independent determinants of plasma homocysteine in middle-aged and older Chinese in Singapore. These factors combined could account for up to 40% of the total variation in homocysteine concentrations in this Asian population.

Obesity, body fat distribution and coronary atherosclerosis among Japanese men and women

OBJECTIVE

To investigate the relation of the obesity and body-fat distribution with angiographically defined coronary atherosclerosis.

DESIGN

Cross-sectional study in a clinical setting.

SUBJECTS

Three hundred and twenty men (median age, 59 y) and 212 women (median age, 67 y) who underwent coronary angiography for suspected or known coronary heart disease at 5 cardiology departments between September 1996 and August 1997. Patients with disease duration >1 y were excluded.

MEASUREMENTS

The body mass index (BMI) and the waist to hip circumference ratio (WHR) were used as main exposure variables, and either the presence of significant coronary stenosis or the Gensini's score (> or =10 vs<10) as an outcome variable, in a sex-specific multiple logistic regression analysis controlling for age, hospital, and other coronary risk factors.

RESULTS

Among male patients, BMI was progressively higher with an increasing number of vessels involved (P trend=0.05); the adjusted odds ratios for the presence of significant stenosis across quartiles of BMI were 1.0 (reference), 1.1, 1.9 and 2.5 (P trend=0.02), and the positive association was more pronounced for younger patients. Among females, however, such associations were not evident. Employing the Gensini's score as an outcome gave similar results. WHR was not significantly associated with either outcome regardless of sex.

CONCLUSION

These results suggested that BMI was predictive of coronary stenosis among male patients, but not among female patients. Unlike most previous studies, this study failed to detect a positive association with WHR.

Effect of AVT antisense oligodeoxynucleotides on AVT release induced by hypertonic stimulation in chicks

In birds, arginine vasotocin (AVT) and mesotocin (MT) are the neurohypophyseal hormones. AVT is known to be an avian antidiuretic hormone and is released from the neurohypophysis by dehydration or hyperosmotic stimulation. The purpose of this study was to determine whether the mechanism of AVT synthesis is related to the mechanism of hormone release from the neurohypophysis. Four-day-old chicks received an AVT antisense oligodeoxynucleotide (ODN) injection into the cerebral ventricle (icv). Following antisense administration, the chicks received hypertonic saline stimulation. Plasma levels of AVT and MT were measured by radioimmunoassays. In control birds, a hypertonic saline injection resulted in the increase of plasma AVT level. The administration of a high dose (50 microg) of antisense ODN inhibited the increase of plasma AVT level induced by the hypertonic saline stimulation. Plasma levels of MT did not change with the administration of hypertonic saline or antisense ODN. These results suggest that the mechanisms that regulate the secretion of AVT from the neurohypophysis may be coupled to the mechanisms that regulate the synthesis of AVT.

[A case of paraneoplastic cerebellar degeneration with resting tremor]

A 65-year-old woman was operated for gastric adenocarcinoma in 1989. Six years later, peritonitis carcinomatosa, swelling of periaortic lymphnodes and high serum CA-125 were discovered. She received chemotherapy with 5-FU and cisplatin resulting in reduction of ascites. In September, 1998, the swelling of left supraclavicular lymphnodes and the elevation of serum CA-125 reappeared. Pathological diagnosis of supraclavicular lymphnodes was adenocarcinoma. Serum CA-125 was normalized by chemotherapy using cisplatin, farumorubicin and endoxan. However, unsteadiness appeared since December 10, 1998 followed by dysarthria and involuntary movement of neck and upper limbs. These symptoms progressed subacutely. The physical examination on admission revealed swelling of left suraclavicular lymphnodes, nystagmus on lateral gaze, saccadic eye movement on smooth pursuit and severe cerebellar ataxia. In addition, resting tremor of 3-4 Hz was observed at right hand, left wrist and neck which tended to increase amplitude by calculation. Similar movements were seen in the left first toe, though the frequency was lower. Brain MRI revealed mild cerebellar atrophy. She was diagnosed as paraneoplastic cerebellar degeneration (PCD) by serum anti Yo antibody and clinical course. The study of HLA showed positive link to A4 without A24. The primary focus of adenocarcinoma in cervical lymphnodes was suggested to be ovary rather than stomach due to the pattern of immunostaining for cytokeratin, CEA and CA125, although no carcinoma was found in ovarium clinically. The feature of this case is a PCD with resting tremor of frequency of 3-4 Hz and negative link to HLA-A24 in Japanese.

The orientation bias of Chi sequences is a general tendency of G-rich oligomers

The Chi sequences are specific oligomers that stimulate DNA repair by homologous recombination, and are different sequences in each organism. Approximately 75% of the copies of the Chi sequence (5'-GCTGGTGG-3') of Escherichia coli reside on the leading strand, and this orientation bias is often believed to be a consequence of the biological role of Chi sequences as the signal sequence of RecBCD pathway in DNA replication. However, our computer analysis found that many G-rich oligomers also show this asymmetric orientation pattern. The shift in the Chi orientation bias appears around the replication origin and terminus, but these locations are also coincident with the shift points in GC content or GC skew. We conducted the same analysis with the genome of Bacillus subtilis, and found that in addition to Chi, other G-rich oligomers show similar asymmetric orientation patterns, whose shift points were coincident with those of the GC skew. However, the genome of Haemophilus influenzae Rd, whose GC skew is not so pronounced, does not clearly show asymmetric orientation patterns of Chi or other G-rich oligomers. These results lead us to suggest that the uneven distribution of the Chi orientation between the two strands of the double helix is mostly due to the uneven distribution of G content (GC skew) and that the replication-related function of Chi sequences is not the primary factor responsible for the evolutionary pressure causing the orientation bias.

Antihyperglycemic effect of T-1095 via inhibition of renal Na+-glucose cotransporters in streptozotocin-induced diabetic rats

T-1095, a derivative of phlorizin, is an orally active inhibitor of Na+-glucose cotransporter (SGLT). We investigated the acute antihyperglycemic effect of T-1095 in streptozotocin-induced diabetic rats (STZ rats). T-1095 and its metabolite T-1095A inhibited the SGLT activity in brush border membranes prepared from kidneys of both normal and STZ rats, but the latter agent was approximately 10 times more potent than the former. Single oral administration of T-1095 (30-100 mg/kg) dose-dependently induced glycosuria in normal rats. The fed glucose levels in STZ rats were dose-dependently suppressed by single oral administration of T-1095 (3-100 mg/kg), whereas there was only marginal hypoglycemic effect in normal rats. Since there was no effect on blood glucose in nephrectomized STZ rats, inhibition of renal glucose reabsorption rather than intestinal glucose absorption mainly contributes to the antihyperglycemic effect of T-1095. In conclusion, T-1095 is the first orally active agent which has an acute antihyperglycemic action in the absence of endogenous insulin secretion with a low risk of hypoglycemia and has therapeutic potential for treatment of diabetes mellitus.

A case of hyperreninemic hypertension after extracorporeal shock-wave lithotripsy

A 53-year-old male was found to have hypertension caused by the significant secretion of renin from an atrophic left kidney. He had undergone extracorporeal shock-wave lithotripsy (ESWL) for left renal lithiasis 11 years previously. A renal dynamic study with 99mTc-diethylenetriaminepentaacetic acid (DTPA) indicated that the rate of renal excretion and uptake was decreased in the left kidney and normal in the right kidney. Renal angiography demonstrated a normal right renal artery and a small but nonstenotic left renal artery. The ratio of PRA in the left renal vein to that in the right renal vein was 1.7. Blood pressure could be lowered to the range of 140-150/80-90 mmHg with imidapril, an ACE inhibitor. ESWL may cause hypertension via the well-known Page kidney effect. In this case, the kidney, atrophic probably due to ESWL, released a significant amount of renin.