Biochemical and molecular mechanisms in the development of diabetic vascular complications

Hyperglycemia is the major causal factor in the development of diabetic vascular complications. The mechanism by which hyperglycemia causes the complications is not clear; however, it is very likely that hyperglycemia is mediating its adverse effects through multiple mechanisms. We have summarized some of these mechanisms in this review, with particular attention to the effect of hyperglycemia on the activation of diacylglycerol (DAG)-protein kinase C (PKC) pathway. We have reviewed existing information regarding various vascular tissues that show increased DAG and PKC levels. In addition, the mechanism by which hyperglycemia increases DAG as well as the cellular physiological consequences on the activation of PKC have been reviewed.

[A proposal of a composite patch for early repair of ventricular septal perforation after acute myocardial infarction]

A 68-year-old female presented ventricular septal perforation (VAP) 3 days after acute myocardial infarction. The patient, supported with intraaortic balloon pumping, underwent surgical repair with success on day 15. At operation, the VAP, measuring 2.5 x 1.5 cm, was repaired using a composite patch consisting of Dacron felt and xenopericardium attached each other with fibrin glue. The composite patch was found really useful for repair of VSP in such early phase as when VSP-sorrounding myocardium was very fragile, particularly in respect to the prevention of residual and/or recurrent shunt. This was because the composite patch was considered to have such excellent characteristics as: 1) toughness with sufficient compressibility and extensibility, 2) high antithrombogenesity and good tissue compatibility, 3) zero porosity, and 4) easy handling because of unification of two materials.

Standardization of HbA1c value and its comparison to immunoassay--two years of experience

In spite of the routine use of hemoglobin Alc (HbAlc) value to guide diabetes therapy, substantial differences have been noted between results obtained by different instruments and laboratories. It was suggested that confusion between the terms used for HbA1c, i.e. between "total HbA1c' which includes labile content, and "stable HbA1c', which does not, may account for some of these inter-instrument and inter-laboratory differences. However, an undesirable difference was found even in measurements of only the stable component of HbAlc using the two most commonly used HPLC analyzers in our country. We found that a two-point calibration using lyophilized hemoglobin at lower and higher ranges was effective in matching up results of HbA1c measurement. This finding was concordant with a report by the Committee of the Japan Diabetes Society and other reports. Two methods of HbA1c immunoassay, one performed with the DCA 2000 automated analyzer and another performed using the Liquitech kit or a general automated analyzer, were evaluated and found to perform as well as HPLC analyzers in all respects except precision. The results derived from immunoassay were in good agreement with the calibrated results by HPLC, with (Liquitech) and without (DCA 2000) conversions.

Congenital coronary artery fistulae arising from bilateral coronary arteries and emptying into both pulmonary artery and left ventricle: a rare presentation

Congenital coronary artery fistulae rarely empty into both the pulmonary artery and the left ventricle. To our knowledge, there have been only two such cases reported in the literature. This paper presents a third case. The pattern of drainage into the left ventricle in the present case was, however, quite different from that observed in the previous reports.

[Clinical evaluation of ultrasound hyperthermia system]

We studied clinically ultrasound (US) hyperthermia system developed in Japan. The prototype system consists of a power delivery unit (0.5MHz frequency) and a coolded water bolus. The modified type has three frequency applicators (0.5, 1.0, 1.5MHz) with a secondary bolus. Thirty-four patients with recurrent or metastatic tumors located in the shallow tissues were treated. Fourteen patients (Group I) were treated with the prototype system and 20 patients (Group II) with the modified type. In 13 of the Group II patients, aluminum-urethane shields were used to protect nearby bone from overheating. The heating goal was 42.0 degrees C for at least 30 minutes in the tumor's center. The temperature was raised to 42.0 degrees C in 7 of 14 cases (50%) and in 17 of 41 sessions (41.5%) in Group I. In Group II the temperature was raised in 19 of 20 cases (95.0%) and in 67 of 80 sessions (83.7%). Response rates were 50.0% and 75.0% respectively in Groups I and II. The incidence of side effects including burn and ostalgia were 100% and 20% respectively in Groups I and II. These results suggest that the modified US hyperthermia system was valuable in clinical use.

[Evaluation of ultrasound hyperthermia system with a phantom model]

Ultrasound (US) hyperthermia is a local heating method that has recently been introduced into clinical practice. A prototype and modified version of this system using a phantom model (agar with bone inserted) were evaluated. The prototype system consists of a power delivery unit (0.5 MHz frequency) with a circulating cooled water bolus. This system heats a shallow area irrespective of power output, but has a tendency to overheat the phantom surface. We incorporated three modifications into the prototype. The modified type has three frequency applicators (0.5, 1.0, 1.5MHz) and a secondary bolus. Aluminum-urethane shields were used to cover the phantom surface located over bone preventing overheating of bone. By changing the applicator's US frequency, we could change the depth of the heating area. Overheating of the phantom surface and bone thus was avoided. These results suggest that our modified US hyperthermia system with multiple frequency applicators, a secondary bolus and aluminum-urethane shields provided a good heating pattern.

[Renal cell carcinoma accompanied with ossification: a case report]

Renal cell carcinoma accompanied with ossification reported in Japan is very rare. We report a case of renal cell carcinoma with ossification pathologically in a 61-year-old woman. She suddenly presented with hypercalcemia that caused acute renal failure, 6 months after the operation and died shortly thereafter. We discuss the relationship between the tumor and the hypercalcemia.

Scintigraphic evaluation of testicular torsion and acute epididymitis

PURPOSE OF THE STUDY

To evaluate the effectiveness of testicular scintigraphy in differentiating testicular torsion from acute epididymitis.

METHOD

14 out of 17 patients previously screened by urologist were referred for testicular scintigraphy. Preoperative diagnosis was made based on dynamic and static image findings. Close follow-up was done and final diagnosis was confirmed on the basis of operative findings or relief of symptoms after conservative management.

RESULTS

Eight of the nine patients with a photopenic area in the hemiscrotum were confirmed surgically as having testicular torsion. One patient was diagnosed as having an inflammatory process. Relief from symptoms after conservative management was noted in three patients with increased activity on the affected side and in two others whose uptake patterns were not different from the unaffected side.

CONCLUSION

Testicular scintigraphy is effective in differentiating testicular torsion from acute inflammation when all other scrotal anomalies have been eliminated.

Clinical and angiographic analysis of congenital coronary artery fistulae in adulthood. Is there any new trend?

Fifteen (2.1%) patients were diagnosed as having congenital coronary artery fistula (CAF) in a consecutive series of 704 adult patients undergoing selective coronary arteriography; the incidence was astonishingly higher than previous observations. The presentation of clinical symptoms and the electrocardiographic changes at rest and/or after exercise testing probably attributable to the CAF were observed unexpectedly often in spite of the fact that the magnitude of the shunt seemed not to be significant. With respect to the anatomy of the CAF, the incidence of origination from plural coronary arteries and that of fistulation into the left ventricle were also unexpectedly high. These observations presented a striking contrast to those of previous reports, but we were unable to determine the reason. In four cases, the CAF was ligated either electively or concurrently with mitral valve surgery, and the results were satisfactory. Taking these circumstances into consideration, we should not minimize the impact of a CAF with a seemingly small shunt.

Molecular cloning of the defense factor in the albumen gland of the sea hare Aplysia kurodai

Aplysianin-A, an antibacterial glycoprotein in the albumen gland of the sea hare Aplysia kurodai, inhibited the growth of both Gram-positive and Gram-negative bacteria. Aplysianin-A cDNA clones were isolated from an albumen gland cDNA library. Sequence analysis reveals that aplysianin-A is produced as a precursor protein of 556 amino acid residues with a signal peptide of 19 amino acid residues and contains 6 potential N-glycosylation sites. Aplysianin-A mRNA was expressed tissue-specifically in the albumen gland. Homology search reveals that aplysianin-A has a 50% overall amino acid sequence homology to achacin, an antibacterial glycoprotein of the giant African snail Achatina fulica.

A rainbow trout SRY-type gene expressed in pituitary glands

A Sox (SRY-type HMG box) gene, designated SoxP1, was isolated from a cDNA library made from pituitaries of immature rainbow trout. Sequence analysis indicated that the cDNA had an open reading frame encoding 467 amino acid residues containing a DNA binding motif, known as the high mobility group (HMG) box. Northern blot analysis showed trout SoxP1 mRNA was detected in pituitaries and gonadal tissues, but not in liver, spleen, and heart. In pituitaries, trout SoxP1 mRNA was more abundant in immature fish than in mature fish. Gel shift retardation analysis indicated that the recombinant HMG box protein of SoxP1 produced in E. coli had a DNA binding property for an AACAAT or AACAAAG sequence. These findings suggest that the trout SoxP1 protein may play certain roles in growth or maturation in pituitaries as a transcription factor.

Onset of diabetes with high titer anti-GAD antibody after IFN therapy for chronic hepatitis

A case of hyperglycemia induced by the injection of interferon-alpha was experienced in our hospital. This patient showed a sustained high titer of anti-GAD antibody after the onset of diabetes, suggesting that the involvement of immunological disturbance by IFN induces the onset of the disease. However, the susceptibility and the response of the immune system differs from patient to patient, and only limited destruction of beta-cells in the islet of Langerhans and normalization of glucose tolerance by CSII was induced in this patient.

Purification and characterization of the Pseudomonas aeruginosa NfxB protein, the negative regulator of the nfxB gene

The protein NfxB, involved in conferring resistance to quinolones in Pseudomonas aeruginosa, has a helix-turn-helix motif which is similar to that of other DNA-binding proteins. It appears to affect the membrane-associated energy-driven efflux of some antibiotics (H. Nikaido, Science 264:382-388, 1994). We constructed a plasmid that overproduced NfxB in Escherichia coli and purified the protein. Two species of NfxB (23 and 21 kDa), which are probably translated from different initiation codons, were isolated. Both proteins are also expressed in vivo in P. aeruginosa, with the 23-kDa NfxB being the major species. NfxB specifically binds upstream of the nfxB coding region as demonstrated by gel retardation and DNase I footprinting. Expression of the phi (nfxB'-lacZ+) (Hyb) gene was repressed in the presence of the nfxB gene product provided by a second compatible plasmid in E. coli. In the P. aeruginosa wild-type strain (PAO2142), NfxB was undetectable by immunoblotting; however, it was detected in the nfxB missense mutant (PK1013E). These results suggested that NfxB negatively autoregulates the expression of nfxB itself. Since the 54-kDa outer membrane protein (OprJ) (N. Masuda, E. Sakagawa, and S. Ohya, Antimicrob. Agents Chemother. 39:645-649, 1995) was overproduced in nfxB mutants, NfxB may also regulate the expression of membrane proteins that are involved in the drug efflux machinery of P. aeruginosa.

Decrease in culturability of Vibrio cholerae caused by glucose

The culturability of Vibrio cholerae O1 serotype Inaba strain 569B was decreased by the addition of glucose to cell suspensions in starvation media. A similar effect was observed with sucrose, maltose, and fructose. We term this inhibitory effect glucose shock. It was not observed with arabinose or xylose or with carboxylates, such as acetate and pyruvate. No acidification of the medium occurred in the presence of these carbohydrates. Glucose shock was prevented by the addition of nitrogen or phosphorus sources. In the presence of phosphate, the bacterium produced formic acid from glucose. The phenomenon of glucose shock was also observed in V. cholerae O1 serotype Inaba strain RIMD 2203082 but not in strain RIMD 2203088 (O1 Inaba), IID 936 (O1 Ogawa), or RIMD 2214034 (non-O1). The culturability of Escherichia coli, Enterobacter aerogenes, and Listonella anguillarum did not decrease in starvation media with added glucose. Hence, the phenomenon should have ecological significance in determining the distribution of bacteria in marine ecosystems in situations where carbohydrates are abundant, but nitrogen and phosphorus are limiting.

A gene that is related to SRY and is expressed in the testes encodes a leucine zipper-containing protein

SRY-related cDNA encoding a protein with a high-mobility-group (HMG) box and a leucine zipper motif, which was designated SOX-LZ, was isolated from a rainbow trout testis cDNA library. Comparison of this cDNA with the mouse homologous cDNA isolated from a testis cDNA library exhibits an overall amino acid sequence identity of 77%, which is in striking contrast to the abrupt loss of amino acid sequence homology outside the HMG box found among mammalian SRY genes. In both rainbow trout and mice, Northern (RNA) blot analyses have revealed the presence of a testis-specific 3-kb-long SOX-LZ mRNA, and this transcript appeared coincidentally with the protamine mRNA, suggesting its expression in the germ line. A recombinant HMG box region protein encoded by SOX-LZ could bind strongly with an oligonucleotide containing an AACAAT sequence, which is also recognized by mouse Sry and Sox-5. Upon cotransfection into CHO cells, SOX-LZ transactivated transcription through its binding motif when the region including the leucine zipper motif was deleted [SOX-LZ (D105-356)]; however, the intact SOX-LZ failed to transactivate. The intact SOX-LZ could form homodimers through the leucine zipper, which resulted in inhibition of DNA binding by the HMG box, while SOX-LZ (D105-356), which was incapable of dimerization, showed specific binding with the AACAAT sequence. Thus, the repressed transactivation of the intact SOX-LZ in CHO cells was primarily attributable to the low level of DNA binding of SOX-LZ homodimers.

Purification and characterization of [3H]mepyramine (histamine H1 antagonist)-binding protein from rat liver: a highly homologous protein with cytochrome P450 2D

A protein having a high-affinity binding site for [3H]mepyramine (MBP) was purified to homogeneity from rat liver membranes. The purified MBP has a single type of binding site for [3H]mepyramine with Kd value of 18.5 nM, and its molecular weight was determined to be 56,000 by SDS polyacrylamide gel electrophoresis. Amino acid sequences of twelve tryptic peptides derived from MBP are highly homologous with those of rat debrisoquine 4-hydroxylase (cytochrome P450 2D1) and other rat P450 2D subfamily members. In immunoblotting analysis, an antibody against rat P450 2D1 stained a band corresponding to MBP with Mr of 56,000; its migration position was clearly different from that of rat P450 2D1. Substrates and inhibitors of debrisoquine 4-hydroxylase potently displace [3H]-mepyramine binding to MBP. Quinine and quinidine showed 400 and 80 times, respectively, higher affinity for MBP than for debrisoquine 4-hydroxylase. These results suggest that MBP is a novel P450 2D family member.

The gene for a major exopolyphosphatase of Saccharomyces cerevisiae

The gene encoding a major exopolyphosphatase (scPPX1) in Saccharomyces cerevisiae (H. Wurst and A. Kornberg, J. Biol. Chem. 269:10996-11001, 1994) has been isolated from a genomic library. The gene, located at 57 kbp from the end of the right arm of chromosome VIII, encodes a protein of 396 amino acids. Overexpression in Escherichia coli allowed the ready purification of a recombinant form of the enzyme. Disruption of the gene did not affect the growth rate of S. cerevisiae. Lysates from the mutants displayed considerably lower exopolyphosphatase activity than the wild type. The enzyme is located in the cytosol, whereas the vast accumulation of polyphosphate (polyP) of the yeast is in the vacuole. Disruption of PPX1 in strains with and without deficiencies in vacuolar proteases allowed the identification of exopolyphosphatase activity in the vacuole. This residual activity was strongly reduced in the absence of vacuolar proteases, indicating a dependence on proteolytic activation. A 50-fold-lower protease-independent activity could be distinguished from this protease-dependent activity by different patterns of expression during growth and activation by arginine. With regard to the levels of polyP in various mutants, those deficient in vacuolar ATPase retain less than 1% of the cellular polyP, a loss that is not offset by additional mutations that eliminate the cytosolic exopolyphosphatase and the vacuolar polyphosphatases dependent on vacuolar protease processing.

Cloning and analysis of the gene encoding lectin from the acorn barnacle Megabalanus rosa

In the acorn barnacle Megabalanus rosa, two types of galactose-binding C-type lectins (BRA-2 and BRA-3) have been identified. Here, we report the isolation and characterization of BRA-2 cDNA and genomic clones. In contrast to the BRA-3 gene, which consists of four exons, BRA-2 is encoded by a single exon, implying differences in the physiological roles of the two lectins.

Characterization of phorbol ester-stimulated serine phosphorylation of the human insulin receptor

Phorbol 12-myristate 13-acetate (PMA)-stimulated phosphorylation of the human insulin receptor (IR) was characterized and compared in two cell types of different lineage: normal rat kidney epithelial (NRK) cells and Chinese hamster ovary (CHO) fibroblasts. PMA stimulation increased IR beta-subunit phosphorylation to 252 +/- 43 and 25- +/- 47% (+/- S.D.) of the unstimulated control in NRK and CHO cells respectively. Tryptic phosphopeptide analysis by Tricine/SDS/PAGE revealed significant differences in the PMA-stimulated phosphorylation of the IR in these two cell types. This phosphorylation of the IR was predominantly located in two tryptic phosphopeptides, and these phosphopeptides were absent in an IR mutant truncated by 43 C-terminal amino acids. The major PMA-stimulated tryptic phosphopeptide from in vivo-labelled CHO/IR was immunoprecipitated with an antibody against residues Ser1315 to Lys1329, and this precipitation was blocked with excess unlabelled peptide containing this sequence. Radiosequencing by manual Edman degradation revealed that this tryptic phosphopeptide was phosphorylated at Ser1315. This PMA-stimulated phosphorylation did not inhibit autophosphorylation of the IR in vivo. These results demonstrate that PMA-stimulated phosphorylation of the IR can exhibit significant differences when expressed in different cell types, and that Ser1315 is a major PMA-stimulated phosphorylation site on the human IR.

[Late recurrence of renal cell carcinoma: report of three cases]

A 70-year-old woman underwent a left radical nephrectomy. The pathological examination revealed renal cell carcinoma (RCC), grade 1 and no lymph node metastasis. She suffered a recurrence in the renal fossa 11 years after the operation. The doubling time of the recurrent lesion was calculated to be very long for the cancer; about 1.3 years. Another case was in a 61-year-old woman, who underwent a right radical nephrectomy. The pathological examination revealed RCC, grade 1 with vascular invasion and no lymph node metastasis. Eleven years postoperatively she developed metastases in both lungs. The other case was in a 39-year-old woman, who underwent right radical nephrectomy. The pathological examination revealed RCC, grade 1 with vascular invasion and no lymph node metastasis. Eight years postoperatively she developed a recurrence in the left kidney. The doubling time of the recurrent lesion was about 0.9 year. All three patients responded to conservative therapy including interferon. Taking those doubling times into account, the recurrent lesions in the first and third cases seemed to have been growing very slowly and not rapidly immediately before clinically evident recurrence. Patients with a low grade RCC must have life-long followup.

Normalization of retinal blood flow in diabetic rats with primary intervention using insulin pumps

PURPOSE

Prior results have demonstrated a significant reduction in retinal blood flow in streptozotocin (STZ)-induced diabetic rats. These studies were extended to investigate whether retinal blood flow changes, in the diabetic rat model, could be prevented with strict glycemic control using insulin pumps. Retinal blood flow changes also were measured during hyperoxia and after intravitreal histamine infusion to validate the methodology.

METHODS

Retinal blood flow changes were measured using video-based fluorescein angiography and computer-assisted image analysis. A total of 48 male Sprague-Dawley and 9 Brown Norway rats were used in these experiments. Retinal blood flow after primary insulin intervention was evaluated in diabetic rats implanted with mini-osmotic insulin pumps within 24 hours of STZ-induced diabetes. Diabetic rats, not treated with insulin, were used for comparison.

RESULTS

Hyperoxia caused a significant (P = 0.001) reduction (54%) in retinal blood flow, whereas intravitreal infusion of 10(-3) M histamine caused a significant (P = 0.009) increase (108%) in retinal blood flow. Retinal blood flow in the primary insulin intervention group, after 1 week of diabetes, was not statistically different from retinal blood flow of nondiabetic controls as measured at baseline from the animals used in the hyperoxia and histamine infusion experiments. In contrast there was a significant (P = 0.0001) retinal blood flow reduction in the untreated diabetic group.

CONCLUSIONS

The results showed that the local effect of histamine and hyperoxia on the retina produced the expected responses in retinal blood flow, further confirming the validity of the methodology. Primary insulin intervention demonstrated that strict glycemic control initiated immediately after induction of diabetes was sufficient to maintain normal retinal blood flow in STZ-induced diabetic rats.

Cellular and molecular abnormalities in the vascular endothelium of diabetes mellitus

Diabetic vascular complications affect both micro- and macrovasculature, primarily in the retina, renal glomeruli, and multiple sites in the macrovessels. This review presents a summary of the abnormal function found in vivo and in cultured vascular cells exposed to elevated levels of glucose. We also discuss the various biochemical hypotheses that have been proposed to explain the adverse effects of hyperglycemia on vascular cells.

Correlation of diacylglycerol level and protein kinase C activity in rat retina to retinal circulation

The increases in diacylglycerol (DAG) level and protein kinase C (PKC) activity have been characterized biochemically and functionally in the retina and the brain of diabetic rats as well as in cultured vascular cells. PKC specific activities were increased in the membraneous fraction of retina from streptozotocin (STZ)-induced diabetic rats and the genetically determined diabetic BB rats, respectively, after 1 or 2 wk of diabetes, compared with control. The ratio of total PKC activities from membraneous and cytosol fractions was also increased in the retina of diabetic rats. With diabetes, all the isoenzymes and the total DAG level were increased in the rat retina, whereas no changes were found in the rat brain. Insulin treatment normalized plasma glucose levels and partially prevented the increases in the membraneous PKC activity and all the isoenzymes in the retina. In the retinal endothelial cells, the total DAG level and PKC specific activities are increased by 36 and 22%, respectively, in the membraneous pool when the glucose levels are changed from 5.5 to 22 mM. Activation of PKC activity and isoform beta II by the vitreal injection of phorbol dibutyrate mimicked the abnormal retinal blood circulation observed in diabetic rats (2.22 +/- 0.24 vs. 1.83 +/- 0.40 s). Thus diabetes and elevated glucose levels will increase DAG level and PKC activities and its isoenzyme specifically in vascular cells and may affect retinal hemodynamics.

X-Neu5Ac: a novel substrate for chromogenic assay of neuraminidase activity in bacterial expression systems

A chromogenic substrate 1, 5-bromo-4-chloroindol-3-yl 5-acetamido-3,5-dideoxy-alpha-D-glycero-D-galacto-2-nonulopyranosidon ic acid (X-Neu5Ac), has been synthesized to facilitate the screening of bacterial colonies or plaques for the detection of either natural or mutant neuraminidase activity. Substrate 1 was hydrolyzed by neuraminidase isolated from Clostridium perfringens to release a halogenated indol-3-ol 2 that undergoes rapid aerobic oxidation to form the dark blue pigment, 5,5'-dibromo-4,-4'-dichloroindigo 3. Preliminary kinetic studies indicate that this compound is a good substrate (Km 0.89 x 10(-3) M) for neuraminidase and is quite stable under identical conditions in the absence of enzyme. These results suggest that X-Neu5Ac 1 can be useful to screen for bacterially-encoded enzyme production directly on agar plates.

cDNA cloning of the beta subunit of teleost thyrotropin

cDNA clones encoding the beta subunit of thyrotropin (thyroid-stimulating hormone; TSH) were isolated from a cDNA library made from the pituitaries of immature rainbow trout and sequenced. The precursor of rainbow trout TSH beta consists of 147 aa, which can be cleaved into a signal peptide (20 aa) and a mature protein (127 aa) containing one potential N-glycosylation site and 12 cysteine residues. The protein showed highest homology with human TSH beta (51%) and lesser homology with human follitropin (42%), human lutropin (32%), and salmon gonadotropin (31-33%) beta subunits. The identification of TSH in addition to two gonadotropins (gonadotropins I and II) in the teleost fish suggests that the divergence of three kinds of glycoprotein hormones from an ancestral molecule took place earlier than the time of divergence of teleosts from the main line of evolution leading to tetrapods. Northern blot analysis showed that the expression of the rainbow trout TSH beta gene is specific to the pituitary gland and is significantly higher in immature fish than in mature fish, suggesting that TSH plays some role in the biological processes of immature fish.

[Clinical study of allylestrenol (Perselin) on patients with prostatic hypertrophy]

The efficacy and safety of allylestrenol were studied in 22 patients with benign prostatic hypertrophy. A 25 mg allylestrenol tablet (Perselin tablet) was administered twice a day. A significant decrease in frequency of nocturnal urination was observed and improvement rates of subjective symptoms, such as sensation of residual urine, delay in start of urination, straining during urination and strength of urinary stream, were 59.1-68.2%. The rate of decrease of maximum area of transverse plane of prostate estimated by transrectal sonography was 13.2% and presumed circle area ratio (PCAR) improved significantly. The incidence of total side effects was 22.7%, whereas a decrease in sexual potency was observed in only 4.5% of the cases. The final global improvement rating of allylestrenol was 72.2% and the rate of usefulness was estimated in 63.6% of the patients. The present findings confirmed that allylestrenol is a useful and safe drug for the treatment of benign prostatic hypertrophy.

Acorn barnacle Megabalanus rosa lectin (BRA-3): cDNA cloning, gene structure and seasonal changes of mRNA and protein levels

We have isolated cDNA clones coding for a lectin (BRA-3) from the acorn barnacle, Megabalanus rosa. Sequence comparison of the cDNA clones has revealed polymorphism in the BRA-3 mRNA, which results from single-nucleotide (nt) differences at three positions. All three differences are within the coding region and cause conservative amino acid (aa) changes. The BRA-3 gene is composed of four exons, and the three single-nt differences are located on different exons. In addition, the BRA-3 mRNA and BRA-3 protein levels increased during early summer in a similar fashion, indicating that BRA-3 production is regulated mainly at the level of transcription.

Identity of a major 3-deoxyglucosone-reducing enzyme with aldehyde reductase in rat liver established by amino acid sequencing and cDNA expression

We have purified a rat liver enzyme that catalyzes the NADPH-dependent reduction of 3-deoxyglucosone (3-DG), a major intermediate in the Maillard reaction and a potent cross-linker responsible for the polymerization of proteins. Comparison of the amino acid (aa) sequences of nine peptides obtained from the rat 3-DG-reducing enzyme by lysylendopeptidase digestion with the aa sequence of human aldehyde reductase (ALR) [Bohren et al., J. Biol. Chem. 266 (1991) 24031-24037] strongly suggested that the purified enzyme was rat ALR. We cloned the cDNA encoding ALR from a rat kidney cDNA library using a human ALR cDNA fragment, amplified by polymerase chain reaction, as a probe. All nine peptides identified in the purified rat 3-DG-reducing enzyme were found in the aa sequence deduced from the rat ALR cDNA. Moreover, cell extract from COS-1 cells transfected with the rat ALR cDNA exhibited NADPH-dependent 3-DG-reducing activity and cross-reacted with antiserum raised against the purified rat 3-DG-reducing enzyme. All the above data indicate clearly that the 3-DG-reducing enzyme is identical with ALR. Northern blot analysis of total mRNA from a variety of rat tissues showed fairly high levels of expression of ALR mRNA. This suggests that sufficient ALR is present to detoxify 3-DG when it is formed through the Maillard reaction in vivo.

Hibernation-associated gene regulation of plasma proteins with a collagen-like domain in mammalian hibernators

In mammals, hibernation is expressed by only a limited number of species, and the molecular mechanisms underlying hibernation are not well understood. Recently, we have found plasma proteins which disappear from blood specifically during hibernation in a mammalian hibernator, the chipmunk. Here, we report the cDNA cloning of these chipmunk hibernation-related proteins, HP-20, -25, and -27, and analyses of their expression. All three proteins contain a collagen-like domain near the N terminus and are highly homologous to each other. Their mRNAs were detected only in liver in nonhibernating chipmunks, and in hibernating chipmunks, the amounts were reduced to less than 1/10 of those in nonhibernating chipmunks, indicating that HP-20, -25, and -27 mRNA expression is regulated similarly in association with hibernation. Southern blot analyses of the squirrel family with each of chipmunk HP-20, -25, and -27 cDNA revealed that a nonhibernating species (tree squirrel) as well as another hibernating species (ground squirrel) retained the corresponding genes. However, their transcripts were detected only with the hibernating species, and in hibernating ground squirrels, their levels were greatly reduced compared with those in nonhibernating animals, as were the cases with the chipmunk. These observations are the first line of evidence for occurrence of hibernation-associated gene regulation. The results would indicate the commitment of HP-20, -25, and -27 to hibernation and support the idea that genetic controls are involved in mammalian hibernation.

Escherichia coli RuvA and RuvB proteins involved in recombination repair: physical properties and interactions with DNA

Escherichia coli RuvA and RuvB proteins are encoded by an SOS-regulated operon, which is involved in DNA repair and recombination. RuvB has weak ATPase activity, which is enhanced by the addition of RuvA and DNA, and RuvA and RuvB in the presence of ATP promote branch migration at Holliday junctions. In this work, the physical states of RuvA and RuvB and their interactions with DNA were studied by sedimentation analysis and gel filtration chromatography. RuvA formed a stable tetramer in solution, which resisted dissociation by SDS at room temperature. RuvB formed a dimer in solution. When RuvA and RuvB were mixed, an oligomer complex was formed consisting of a tetrameric form of RuvA and a dimeric form of RuvB, and this complex bound to DNA. The maximal enhancement of the RuvB ATPase activity by RuvA was achieved at this stoichiometry in the presence of excess DNA.

Lipoma of the falciform ligament: US, CT, and MRI appearances

A case of lipoma of the falciform ligament was demonstrated using computed tomography (CT), ultrasonography (US), and magnetic resonance imaging (MRI). US demonstrated a heterogeneous solid mass anteriorly in the upper portion of the abdomen. CT and MRI revealed a solitary, fatty mass with a small amount of soft tissue in it.

Efficient amplification of Drosophila simulans copia directed by high-level reverse transcriptase activity associated with copia virus-like particles

The number of retrotransposon copia per genome in Drosophila melanogaster cultured cells is two to three times higher than that in D. melanogaster embryo cells. Here, we have found that the genome of the related species, Drosophila simulans, contains in cultured cells more efficiently amplified copia DNA (approximately ten fold). Furthermore, we analyzed copia virus-like particles (VLPs) prepared from D. melanogaster and D. simulans cultured cells, which contain copia RNA and reverse transcriptase (RT) activity, and thus, play a major role in copia replication. The RT activity associated with the D. simulans VLPs was 25 times higher than that associated with the D. melanogaster VLPs. Taken together with the fact that copia is believed to transpose through an RNA intermediate, these results suggest that the amplification of copia DNA should relate to copia RNA-mediated transposition, and the higher RT activity associated with the D. simulans VLPs would lead to the efficient amplification of copia DNA. In a comparison between D. melanogaster and D. simulans copia nucleotide (nt) sequences, five nt substitutions, which cause the respective amino acid changes, were found in the copia RT-coding region. Polymerase chain reaction direct sequencing showed that these five substitutions are the vast majority in each Drosophila species. The substitutions, therefore, may be responsible for the high level of the RT activity associated with the D. simulans VLPs.

[Anti-bacterial zeolite balloon catheter and its potential for urinary tract infection control]

We present here a production of anti-bacterial zeolite balloon catheter and investigated its potential for controlling urinary tract infection. This anti-bacterial balloon catheter showed a bactericidal effect against Pseudomonas aeruginosa, Staphylococcus aureus and Escherichia coli in vitro studies. The antibacterial effects were correlated with the concentration of anti-bacterial zeolite and size of catheter. We tried this catheter for 11 various urological patients who needed a long-term indwelling of a balloon catheter for lower urinary tract obstruction and neurogenic bladder. All patients were already indwelled silicon balloon catheter for 3 to 6 months and suffered with complicated urinary tract infection. Nine patients who had this anti-bacterial zeolite balloon catheter indwelled for 3 to 7 months and exchanged every 2 to 4 weeks, and no patient was taking antibiotics during this trial. Two patients (22.2%) showed good results by the urinary tract infection (UTI) criteria and 5 patients (55.4%) showed good effects by doctor's judgment. This anti-bacterial zeolite balloon catheter might be useful for patients who need long-term balloon catheter indwelling.

[Prostatic cancer after transurethral resection for benign prostatic hypertrophy]

Five cases of prostatic cancer developed after transurethral resection of prostate for benign hypertrophy are reported. Duration of transurethral resection of prostate (TUR-P) to diagnosis of prostatic cancer ranged from one year and seven months to seven years and two months, on average four years and seven months and frequency of prostatic cancer after TUR-P was estimated at 1.2%. Four of five patients complained of macroscopic hematuria. The cystourethrogram showed the mass protruded in the dilated prostatic urethra or bladder-neck in four patients (80%), a remarkable finding, and four cases were at stage D. Risk of development of prostatic cancer is not decreased even after prostatectomy and prostatic carcinoma diagnosed after TUR-P often advances in stage. Therefore, periodical examinations of the patients who had a prior prostatectomy are very important.

Metal-inducible activities of metallothionein promoters in fish cells and fry

Activities of trout metallothionein-A promoter and mouse metallothionein-I promoter in fish cells and fry were examined using the chloramphenicol acetyltransferase (CAT) gene as a reporter. Transfection and transient CAT assays on a trout liver cell line indicated that both promoters were inducible by metals, including zinc. In vivo activities of both promoters were examined using microinjection system into medaka eggs. Some of the hatched fry were exposed to zinc and their CAT activities were assayed. Both promoters revealed considerable activities after exposure to zinc while only weak activities were detected in unexposed fry.

Structure of Drosophila virilis glycerol-3-phosphate dehydrogenase gene and a comparison with the Drosophila melanogaster gene

The complete glycerol-3-phosphate dehydrogenase gene of Drosophila virilis isolated by screening with alpha GPDHM cDNA of the adult fly was sequenced. The gene contains eight exons spread over a total of approximate 8 kb DNA. Its exon/intron organization is identical to that of D. melanogaster. A single transcription initiation site was determined by primer extension. The stop codons are located at the 3' end of each of the exons 6 to 8. TATA and CAAT boxes are present upstream of the transcriptional start site. Adult alpha GPDH protein is encoded by exons 1 to 6 and exon 8. Comparison of the sequence with that of D. melanogaster showed that the homology of the nucleotide sequence of the coding region is 85% and that the homology of the amino acid sequence is 98%. On the contrary, the non-coding region is quite different in length and nucleotide sequence.

Production of a unique multi-lamella structure in the nuclei of yeast expressing Drosophila copia gag precursor

Drosophila retrotransposon copia produces virus-like particles (VLPs) in the nuclei of cultured Drosophila cells. The VLPs contain copia RNA and reverse transcriptase activity, and thus, play a major role in copia replication. Here we have expressed the copia gag polyprotein precursor in yeast. The precursor, which includes copia protease itself, showed correct autoprocessing to produce a unique multi-lamella structure in the nuclei of the yeast cells. This expression system should be useful for the analysis of nuclear localization of the major copia VLP protein, and furthermore, would provide important information concerning the mechanism of copia VLPs formation.

Evaluating retinal circulation using video fluorescein angiography in control and diabetic rats

Video fluorescein angiography has been used to evaluate retinal circulatory parameters in diabetic and non-diabetic Sprague-Dawley rats. Video fluorescein angiograms were recorded from the retina using a modified retinal fundus camera following a 5 ul bolus injection of sodium fluorescein dye into the jugular vein. Retinal circulatory parameters were measured using computer assisted image analysis. These analyses were performed on 25 diabetic rats with 1 week duration of diabetes and 26 matched, non-diabetic, rats. There was a significant (p = .0001) increase in retinal Mean Circulation Time (MCT) in the diabetic group (1.83 +/- 0.40 s) compared to the control group (1.09 +/- 0.27 s). There were no significant differences in arterial or venous diameters comparing diabetic and control groups. In a separate paired experiment, measurements were made from the same animals both before and after one week duration of diabetes. A paired t-test analysis demonstrated significantly increased MCT times in the 6 diabetic animals (p = .001) while there was no significant differences detected in the 4 corresponding control animals. These results indicate that significant increases in retinal circulation times can be measured as early as 1 week after streptozotocin induced diabetes in this animal model.

Stimulation of endothelin-1 gene expression by insulin in endothelial cells

The present study characterized the regulation of the genetic expression of the vasoactive peptide endothelin-1 (ET-1) by insulin in bovine aortic endothelial cells. By RNA blot analysis, insulin (1.67 x 10(-8) M) increased ET-1 mRNA levels by 2.3-fold over the basal within 10 min and attained a maximum (5.3-fold increase) in 2 h. Dose-response studies showed that a maximum effect of insulin was reached at 1.67 x 10(-8) M although a significant increase can be observed at 1.66 x 10(-9) M. Radioligand receptor studies indicated that the affinity constant for insulin receptors on endothelial cells correlated closely with the dose response observed for ET-1 mRNA. The ET-1 mRNA half-life was estimated with actinomycin D studies to be 20 min in control cells and was not affected by insulin treatment. Moreover, the effects of phorbol 12-myristate 13-acetate (PMA) and insulin were additive in the induction of ET-1 gene expression. When protein kinase C in the bovine aortic endothelial cells was down-regulated by preincubation with 8 x 10(-7) M PMA for 24 or 48 h, insulin was still able to increase ET-1 mRNA levels whereas PMA was ineffective. Using a chloramphenicol acetyltransferase (CAT) fusion plasmid containing the CAT gene and the 5'-flanking region of the ET-1 gene (Lee, M. E., Bloch, K. D., Clifford, J. A., and Quertermous, T. (1990) J. Biol. Chem. 265, 10446-10450), we observed that 1.67 x 10(-8) M insulin increased CAT enzyme activity and mRNA levels. The insulin dose-response curve observed for CAT activity correlated with that observed for ET-1 mRNA levels. These results suggest that insulin stimulates expression of the ET-1 gene at the transcriptional level via its own receptors. This effect is mediated mostly through a protein kinase C-independent pathway, suggesting the existence of an insulin-responsive element in the ET-1 gene 5'-flanking sequence.

Escherichia coli RuvC protein is an endonuclease that resolves the Holliday structure

Genetic evidence suggests that the Escherichia coli ruvC gene is involved in DNA repair and in the late step of RecE and RecF pathway recombination. To study the biochemical properties of RuvC protein, we overproduced and highly purified the protein. By employing model substrates, we examined the possibility that RuvC protein is an endonuclease that resolves the Holliday structure, an intermediate in genetic recombination in which two double-stranded DNA molecules are linked by single-stranded crossover. RuvC protein cleaves cruciform junctions, which are formed by the extrusion of inverted repeat sequences from a supercoiled plasmid and which are structurally analogous to Holliday junctions, by introducing nicks into strands with the same polarity. The nicked ends are ligated by E.coli or T4 DNA ligases. Analysis of the cleavage sites suggests that DNA topology rather than a particular sequence determines the cleavage site. RuvC protein also cleaves Holliday junctions which are formed between gapped circular and linear duplex DNA by the function of RecA protein. However, it does not cleave a synthetic four-way junction that does not possess homology between arms. The active form of RuvC protein, as studied by gel filtration, is a dimer. This is mechanistically suited for an endonuclease involved in swapping DNA strands at the crossover junctions. From these properties of RuvC protein and the phenotypes of the ruvC mutants, we infer that RuvC protein is an endonuclease that resolves Holliday structures in vivo.

Attenuation of ischemia-induced regional myocardial acidosis by LP-805, a newly developed vasodilator, in dogs

The effect of 8-tert-butyl-6,7-dihydropyrrolo[3,2-e]-5-methyl- pyrazolo[1,5-a]pyrimidine-3-carbonitrile (LP-805), a newly developed vasodilator, on myocardial acidosis induced by ischemia was studied in anesthetized open-chest dogs. Ischemia was induced by partially occluding the left anterior descending coronary artery. The coronary flow was artificially reduced to about 1/3 of the original flow. Myocardial pH was measured with a glass micro pH electrode inserted into the left ventricular wall perfused by the occluded artery. Myocardial pH decreased from about 7.5 to about 6.9 after the onset of ischemia and remained at this low level until the occluded coronary artery was released. After 30 min of ischemia, either saline containing 0.1 N HCl or 10, 30 or 100 micrograms/kg of LP-805 was injected intravenously. LP-805 attenuated the decrease in myocardial pH induced by ischemia in a dose-dependent manner. In conclusion, LP-805 may reduce the influence of ischemia on the myocardium.

SOS-inducible DNA repair proteins, RuvA and RuvB, of Escherichia coli: functional interactions between RuvA and RuvB for ATP hydrolysis and renaturation of the cruciform structure in supercoiled DNA

The ruv operon is induced by treatments that damage DNA and is regulated by the LexA repressor. It encodes two proteins, RuvA and RuvB, that are involved in DNA repair, recombination in RecE and RecF pathways, and mutagenesis. RuvB protein was previously purified and has ATP-binding activity and weak ATPase activity. To study the biochemical properties of RuvA and its interaction with RuvB, we purified RuvA protein to near homogeneity from an over-producing strain. RuvA bound more efficiently to single-stranded DNA than to double-stranded DNA. RuvA bound to DNA greatly enhanced the ATPase activity of RuvB; the enhancing effect of various forms of DNA was in the order of supercoiled DNA greater than single-stranded DNA greater than linear double-stranded DNA. UV irradiation further enhanced the ATPase stimulatory effect of supercoiled DNA dose dependently. The RuvA-RuvB complex has an activity that renatures the cruciform structure in supercoiled DNA. From these experiments and previous work, we infer that the RuvA-RuvB complex may promote branch migration in recombination and may correct irregular structures in DNA, such as cruciforms and hairpins, to facilitate DNA repair using ATP as the energy source.

Synthesis and biological activities of analogs of a lipid A biosynthetic precursor: 1-O-phosphonooxyethyl-4'-O-phosphono-disaccharides with (R)-3-hydroxytetradecanoyl or tetradecanoyl groups at positions 2, 3, 2' and 3'

Two novel analogs of a biosynthetic precursor of lipid A (2) were synthesized. The one analog (3) has acyl groups identical to those of 2, and the other (4) has tetradecanoyl groups in place of the (R)-3-hydroxytetradecanoyl groups of 2. Both 3 and 4 possess an alpha-glycosidically-bound phosphonooxyethyl group in place of the alpha-glycosyl phosphate group of 2. Compounds 3 and 4 exhibited definite antitumor activity against Meth A fibrosarcoma and low toxicity in rabbits, as the original compound 2 does. The replacement of the hydroxytetradecanoyl groups with tetradecanoyl groups barely affected the antitumor activity, but slightly enhanced the toxicity in rabbits.

Identification of an unusual structure in the Drosophila melanogaster transposable element copia: evidence for copia transposition through an RNA intermediate

The Drosophila melanogaster transposable element copia is usually 5 kb long with long terminal repeats (LTRs), and its major transcripts are a full-length 5-kb RNA and a 2-kb RNA. We have previously shown that the 2-kb RNA is generated through splicing. Here, we have cloned a genomic intronless copia using an oligodeoxyribonucleotide probe which is specific for the junction of the two exons. The unusual copia is bounded by two LTRs and lacks precisely the intron of the 2-kb copia RNA. Identification of genomic intronless copia strongly suggests that copia transposes through an RNA intermediate. Moreover, we have found that copia virus-like particles (VLPs), in which reverse transcription of copia RNA seems likely to occur, packages the spliced copia RNA much less efficiently than the full-length copia RNA. This result leads to the suggestion that much lower copy number of genomic intronless copia, as compared with that of 'normal' copia, may be responsible for the inefficient packaging of the spliced copia RNA into the VLP.

Autoprocessing of Drosophila copia gag precursor to generate a unique laminate structure in Escherichia coli

Drosophila copia protease is likely to be encoded in the gag gene. We have expressed copia gag polyprotein precursor in E. coli. The gag precursor was correctly processed to generate a unique laminate structure in E. coli. The processing was almost completely blocked by a mutation at the putative active site of copia protease, and resulted in accumulation of the precursor. Furthermore, the laminate structure was not found in E. coli expressing the mutant precursor. These results indicate that the protease is involved in cleaving the gag precursor itself. Also, the assembly of copia gag protein should correlate to the autoprocessing of copia gag polyprotein precursor.

Thoracoabdominal aortic aneurysm associated with Marfan's syndrome--report of a case

A case of Marfan's syndrome associated with thoracoabdominal aortic aneurysm and mitral regurgitation in a 29 year old male is reported herein. The aneurysm was replaced with a Y-shaped graft using Crawford's technique, while the major branches of the abdominal aorta were separately cannulated from inside the aneurysm and perfused via partial extracorporeal circulation using a left femoro-femoral bypass. We found this technique useful in the prevention of tissue ischemia during the operation. The patient's postoperative course was uneventful and he has encountered no problems in the year and half since his operation.

Partial degradation and biological activities of an antitumor polysaccharide from rice bran

A rice bran polysaccharide designated RON was subjected either to partial hydrolysis with formic acid or to partial degradation by ultrasonic irradiation. A significant change in the molecular size was also observed during simple chromatography of RON on a strongly acidic ion exchange resin, although the apparent molecular weight of RON had been assumed to be more than 1 x 10(6) daltons (Da). This fact indicates that RON exists as molecular aggregates, presumably mediated by metal cations. Degradation products with average molecular weights above ca. 1 x 10(4) Da which were obtained by any of the three methods still retained the following activities of RON: in vivo antitumor activity against Meth-A fibrosarcoma in mice by oral administration, and in vitro macrophage stimulatory effects to induce tumoricidal activity and interleukin 1 production. This molecular size was proven to be the minimum requisite for these activities because smaller fragments were scarcely active. The aggregation was characteristic of RON but not essential for its antitumor activity because definite, though slightly reduced, activity was exhibited even by the smaller fragments obtained after the ion exchange resin treatment.

Structure-activity relationships of sarafotoxins: chemical syntheses of chimera peptides of sarafotoxins S6b and S6c

The three chimera peptides of sarafotoxins S6b (SRTb) and S6c (SRTc), [Thr2]SRTb, [Asn4]SRTb and [Glu9]SRTb, were synthesized chemically. From the comparisons of lethality, vasoconstrictor activity and receptor binding activity of SRTb, SRTa [( Asn13]SRTb), SRTc [( Thr2,Asn4,Glu9,Asn13]SRTb), [Thr2]SRTb, [Asn4]SRTb and [Glu9]SRTb, it appears that the Lys9 to Glu9 substitution greatly diminishes these activities while the Lys4 to Asn4 substitution does not affect them, and the Ser2 to Thr2 substitution or the Tyr13 to Asn13 substitution slightly diminishes these activities. These results suggest that the very low activities of SRTc are caused mainly by the Lys9 to Glu9 substitution, but not by the Ser2 to Thr2 substitution, which was suggested to be responsible for the weak bioactivities of SRTd [( Thr2,Ile19]SRTb).

Synthetic low-toxicity muramyl dipeptide and monophosphoryl lipid A replace Freund complete adjuvant in inducing growth-inhibitory antibodies to the Plasmodium falciparum major merozoite surface protein, gp195

The Plasmodium falciparum major merozoite surface protein (gp195) is a protective antigen against lethal malaria. However, increasing evidence indicates that the efficacy of a malaria vaccine will require a strong adjuvant that is safe for human use. We compared the efficacies of two low-toxicity synthetic immunomodulators, B30-MDP (a lipophilic muramyl dipeptide derivative) and LA-15-PH (a synthetic equivalent of monophosphoryl lipid A), with that of Freund complete adjuvant (FCA) in eliciting an antibody response to gp195. Rabbits were immunized with native gp195 and B30-MDP, LA-15-PH, or the two in combination, with liposomes as the vehicle. Aluminum hydroxide and FCA were used as reference adjuvants. Results showed that adjuvant formulations based on B30-MDP alone or in combination with LA-15-PH induced high antibody titers to gp195, as compared with FCA. LA-15-PH alone was less effective. Aluminum hydroxide induced significantly lower antibody titers. The functional activity of the rabbit anti-gp195 antibodies induced by different adjuvants was evaluated in an in vitro parasite growth inhibition assay previously shown to correlate with anti-gp195 immunity in the Aotus monkey model. All rabbits immunized with B30-MDP-LA-15-PH and two of three rabbits immunized with B30-MDP alone produced sera that strongly inhibited parasite growth. The degree of growth inhibition was similar to that with FCA. The antibody titers of the rabbits receiving B30-MDP-LA-15-PH strongly correlated with the degree of in vitro growth inhibition. Our findings provided strong evidence that adjuvant formulations based on synthetic B30-MDP and LA-15-PH can replace FCA as adjuvants in stimulating protective immunity specific for gp195.

Properties of the Escherichia coli RuvA and RuvB proteins involved in DNA repair, recombination and mutagenesis

The ruvA and ruvB genes constitute an operon, which is regulated by the SOS system and involved in DNA repair, recombination and mutagenesis. RuvA protein binds to both single-stranded and double-stranded DNA. RuvB protein has weak ATPase activity. RuvA bound to DNA greatly enhances ATPase activity of RuvB. UV-irradiation to supercoiled DNA further enhances the stimulatory effect of RuvA on the RuvB ATPase activity. In the presence of ATP the RuvA-RuvB complex has an activity that renatures cruciform structures formed by heating and gradually cooling supercoiled DNA with an inverted repeat. These findings suggest that the RuvA-RuvB complex interacts with an irregular conformation in damaged DNA and induces conformational changes in DNA using energy provided by ATP hydrolysis, so that it facilitates DNA repair, recombination and error prone replication.