Postoperative complications of repeat hepatectomy for liver metastasis from colorectal carcinoma

BACKGROUND/AIMS

When a repeat hepatectomy is possible, it is the most effective treatment modality for recurrent colorectal liver metastasis. The aim of this study was to evaluate the surgical risks of repeat hepatectomy for liver metastasis from colorectal carcinoma.

METHODOLOGY

Between 1986 and 1996, 60 patients with hepatic metastasis from colorectal carcinoma underwent surgery in the Department of Surgery I, Oita Medical University. Ten of them underwent a repeat hepatectomy. The cases of these 10 patients were studied retrospectively; in particular, postoperative complications and intraoperative blood loss were compared between the initial and second operation.

RESULTS

During the second surgery, recurrence was detected adjacent to the hepatic stump in 9 of the 10 patients. During the initial surgery, 6 underwent non-anatomic resections, and 4 had anatomic resection, including 1 extended lobectomy, 1 lobectomy, and 2 segmentectomies. For the second surgery, 3 had anatomic resections, including 2 lobectomies, and 1 segmentectomy, and 7 underwent non-anatomic resections. There were no mortalities during the initial or second operation. There was no morbidity following the initial surgeries and 7 postoperative complications (intraabdominal abscess, 4 cases; biloma, 3 cases) following the second surgeries. Mean blood loss during the second operation (1044 mL) was significantly greater than during the initial operation (561 mL).

CONCLUSIONS

The present results show that repeat hepatectomy for recurrent liver metastasis from colorectal carcinoma resulted in significantly greater intraoperative blood loss and postoperative complications than those of the initial surgeries. The blood loss and complications in the second operation, the one for the recurrence, were directly associated with the fact that the recurrence was so close to the hepatic stump. Since the resection line in the second surgery was adjacent to the hepatic hilus, resection of the lesion caused much more injury to the main bile duct and main portal vein than that caused by the.

[Clinical study of an outbreak of aseptic meningitis due to echovirus type 30 in Munakata City in 1997-1998]

From October, 1997 through July, 1998, an outbreak of aseptic meningitis due to echovirus type 30 occurred in the northern part of Kyushu area in Japan. In this outbreak, clinical and virologic observations were carried out on 157 in-patients with aseptic meningitis at our hospital. The age of the patients ranged from 1 year and 9 months to 57-year old. One hundred and twenty out of 157 cases were the children under 15 years of age, and in this age group, male/female ratio was 2:1. The largest proportion of cases occurred in the 5- to 9-year age group. The number of cases reached a peak in December, 1997, but the epidemic extended to the next summer. In 12 families, more than one person became ill (total 22 cases). Virus isolation from cerebrospinal fluid (CSF) was tried on 130 out of 157 cases. Echovirus 30 was isolated in 74 cases (58 children, 16 adults), and echovirus 18 in 9 cases from June, 1998 until the end of the study. Paired acute and convalescent sera were available from the 25 patients with negative virus isolation, and 7 out of 25 patients had a fourfold or greater rise in neutralizing antibodies. Headache, fever, vomiting, nuchal rigidity were detectable in most cases, but in this outbreak, continued severe headache was characteristic. Eye pain was experienced by 2% of the total cases. In children, gastrointestinal symptoms were noted in 12% of the cases, but were not in adult patients. The CSF cell counts ranged from 2 to 3,478 cells per cubic millimeter. Fifty-eight percent were predominantly lymphocytic, while 42% were polymorphonuclear predominant. Virus was highly isolated from the CSF when the specimens were obtained within three days after the onset of the acute illness, but in one case, virus was isolated on day 7. In a few cases, virus was isolated without pleocytosis in CSF.

Novel practical synthesis of Kdn2en and its C-4 nitrogen-modified derivatives

A practical synthesis of Kdn2en and 4-amino-4-deoxy-Kdn2en has been achieved via a key intermediate, methyl 4,5,7,8,9-penta-O-acetyl-2,6-anhydro-3-deoxy-D-glycero-D-galacto-non-2- enonate, which has been prepared from Kdn in three steps in 91% overall yield.

Preparation of fine emulsified fat particles without glycerol for intravenous nutrition

A method of preparing fine emulsified fat particles without glycerol for intravenous nutrition was investigated. The factors assessed were the oil phase ratio, the glucose level of the aqueous phase and the temperature of high-pressure homogenization. The particle size decreased with an increase in the oil phase ratio and it went below 250 nm only in the emulsion with a 50% oil phase ratio. The weight-weighted particle size (dw)/number-weighted particle size (dn) value reflected the particle size distribution. The emulsion with a 50% oil phase ratio had a very narrow distribution of particle sizes and the dw/dn value was below 1.1. With the use of glucose solutions for the aqueous phase, smaller particle sizes and narrower distributions were obtained with increasing glucose concentrations. The controlled temperature of 50 degrees C was appropriate for high-pressure homogenization, producing particles below 160 nm. The rate of the layer separation was a function of particle size. The particle sizes below 180 nm can be expected to suppress the separation of the formulation which consisted of 10.0% soybean oil, 1.2% phospholipids and 5.0% glucose. The stability studies were conducted at 40 degrees C for 3 months and the fat emulsion was stable during storage. These investigations contribute to the preparation of a new caloric source for peripheral parenteral nutrition.

Degradation kinetics of L-glutamine in aqueous solution

The degradation kinetics of L-glutamine (Gln) in aqueous solution was studied as a function of buffer concentration, pH and temperature. Stability tests were performed using a stability-indicating high-performance liquid chromatographic assay. The degradation product of Gln was 5-pyrrolidone-2-carboxylic acid. The reaction order for Gln in aqueous solution followed pseudo-first-order kinetics under all experimental conditions. The maximum stability of Gln was observed in the pH range from 5.0 to 7. 5. The pH-rate profile described by specific acid-base catalysis and hydrolysis by water molecules agreed with the experimental results. Arrhenius plots showed the temperature dependence of Gln degradation, and the apparent activation energy at pH 6.41 was determined to be 9.87 x 10(4) J mol(-1).

Treatment for extrahepatic metastasis of hepatocellular carcinoma following successful hepatic resection

BACKGROUND/AIMS

Recent advances in both the diagnosis and treatment of hepatocellular carcinoma (HCC) have improved its prognosis. Intrahepatic recurrence after hepatectomy can be treated with repeated hepatectomy, transhepatic arterial embolization (TAE), percutaneous ethanol injection therapy (PEIT), or microwave coagulo-necrotic therapy. However, treatment for extrahepatic recurrence is also important in prolonging survival in some patients.

METHODOLOGY

After radical hepatectomy in 155 patients, extrahepatic recurrences were found in 15 patients that underwent subsequent treatment. The interval between completing treatment for the primary tumor and the discovery of metastasis, the location and mode of treatment of the metastasis, and the outcomes were analyzed.

RESULTS

Distant metastasis was detected at a mean of 7 months after radical resection of the primary tumor. Location of the metastasis included lung, bone, and adrenal gland. Four patients had no intrahepatic recurrence and 11 patients had simultaneous intrahepatic recurrence. Six patients with intrahepatic and extrahepatic recurrence that underwent systemic chemotherapy had poor prognoses, and all died within 12 months as a result of progression of the intrahepatic tumor. Five patients with intra- and extrahepatic recurrence that underwent systemic chemotherapy combined with hepatic arterial infusion chemotherapy had relatively good outcomes; all survived for more than 12 months.

CONCLUSIONS

These results suggest that to obtain a good prognosis for extrahepatic metastasis coexisting with intrahepatic recurrence, intrahepatic recurrence should be controlled by locoregional therapy, and extrahepatic metastasis should be controlled by systemic chemotherapy and/or irradiation therapy.

Gene 61.3 of bacteriophage T4 is the spackle gene

The bacteriophage T4 e gene encodes lysozyme (e-lysozyme), which releases progeny phage after normal infection of Escherichia coli cells. A mutation in the spackle gene suppresses the defect in e-lysozyme (Emrich, 1968). The spackle gene was mapped between genes 41 and 61, but its precise location has not previously been determined. In the current study, we constructed an amber mutant of gene 61.3, amST14, by site-directed mutagenesis. The gene 61.3 mutant shares phenotypes with spackle mutants: The amST14 mutant forms large plaques with sharp edges and exhibits truncated lysis inhibition, and furthermore, the mutation can suppress the defect in e-lysozyme activity. In addition, cloned gene 61.3 can rescue (by homologous recombination) as well as complement the S12 mutation in the spackle gene. These results strongly suggest that gene 61.3 is the spackle gene. Indeed, the S12 mutant has one base deletion of five in a consecutive A tract in the gene 61.3 coding region, substituting an unrelated 6-amino acid sequence for the 9 C-terminal amino acids in the gene 61.3 protein. The gene 61.3 protein is predicted to localize in the periplasmic space after cleavage of a signal sequence.

[Effects of topical alpha 1- and beta 2-adrenoceptor stimulants on nasal nitric oxide level]

The effects of locally administered alpha 1- and beta 2-stimulants (naphazoline and salbutamol) on the nasal nitric oxide (NO) level were investigated. Twenty-four healthy volunteers (except nasal allergy) were subjected to the examination. First, nasal cavity air was sampled continuously from the right nostril for 20 seconds at the rate of 3.5 l/m, and NO-free air was supplied passively to the left nostril. During the sampling time, subjects were made to hold their breath at deep inspiration, which obviated the effect of lower airways by closing their glottises. The sampled air was analyzed using a chemiluminescence technique for NO detection. In addition, nasal airway resistances (NAR) were estimated by a rhinomanometer, and minimum cross-section area (MCA) and nasal cavity volume (NCV) were estimated by an acoustic rhinometer. After these estimations, 12 subjects received naphazoline nitrate 15 micrograms per nostril, and the other 12 subjects received salbutamol sulfate 100 micrograms per nostril. Finally, after 15 minutes rest, these four parameters were reviewed. The results demonstrated that naphazoline significantly decreased NO concentration and NAR, and increased NCV. Furthermore, salbutamol significantly increased NO concentration and NAR, and decreased MCA and NCV. The changes in NAR, MCA and NCV indicated that nasal mucosa became contracted and swollen by topical naphazoline and salbutamol application. Naphazoline, a nasal decongestant, contract nasal vessels by stimulating alpha 1-adrenoceptors, whereas salbutamol dilates then by stimulating beta 2-adrenoceptors, and this vasodilation does not intervene NO and cyclic GMP. Thus, nasal NO concentration is significantly affected by the change of blood supply caused simply by vasocontraction and vasodilation. In conclusion, it appeared that nasal NO concentration was possibly altered by the change of nasal blood supply, moreover, by the change in the supply of NO substrate.

Hematopoietic progenitor cells from allogeneic bone marrow transplant donors circulate in the very early post-transplant period

Despite the therapeutic efficacy of allogeneic bone marrow transplantation (allo-BMT), circulating hematopoietic progenitor cells after bone marrow transplantation have not been well characterized. In the present study, we focused on these 'post-transplant circulating progenitor cells (PTCPC)' which may be on their way to bone marrow. We analyzed the number of myeloid progenitor cells (CFU-GM) per 10 ml of peripheral blood (PB) on days 0 (just before transplantation), 1 (8-15 h after the completion of transplantation), 2, 3, 5, 7, 10, 14, 17, 21, 28 and 35 after allo-BMT in five transplant patients using a standard methylcellulose assay. In addition, high proliferative potential colony-forming cells (HPP-CFC) of the harvested donor bone marrow (BM) and day 1 PB of recipients were assayed in five patients. The origin of HPP-CFC from day 1 PB was analyzed by polymerase chain reaction of a DNA region containing a variable number of tandem repeats. The replating potential of these HPP-CFC was evaluated by a secondary colony assay. The proportion of CD38negative cells among CD34+ cells in the harvested BM and day 1 PB was evaluated by two-color flow cytometric analysis. The number of CFU-GM on day 1 ranged from 6 to 73/10 ml PB, and became undetectable on day 5. The reappearance of PTCPC was observed on day 14, along with hematopoietic recovery. The proportion of HPP-CFC among myeloid colonies from day 1 PB was significantly higher than that from harvested BM (44.3+/-10.4% vs 11.3+/-2.1%, respectively, n=5, P=0.0030). These HPP-CFC from day 1 PB were confirmed to be of donor origin. More than 90% of these HPP-CFC had replating potential. Two-color flow cytometric analysis revealed that the proportion of CD34+CD38negative cells was significantly higher in day 1 PB than in the harvested BM (61.0+/-16.5% vs 9.3+/-3.5%, respectively, n=7, P=0.0002). These observations suggest that both primitive and committed transplanted myeloid progenitor cells may circulate in the very early period following allo-BMT.

[Effective treatment combining antithymocyte globulin, cyclosporin A, and granulocyte colony-stimulating factor for atypical paroxysmal nocturnal hemoglobinuria accompanied by bone marrow hypoplasia]

A 25-year-old man was admitted for evaluation of pancytopenia on May 2, 1997. On admission, he had pancytopenia with a normal reticulocyte count. Bone marrow aspirate specimens displayed a normal karyotype and hypocellularity without myelodysplasia. Although total bilirubin and lactate dehydrogenase levels were within their normal ranges, the haptoglobin level was low; additionally, two-color flow cytometric analysis determined that 3.3% of erythrocytes were double-negative for CD55 and CD59 expression. Atypical paroxysmal nocturnal hemoglobinuria with bone marrow hypoplasia was diagnosed. Because initial treatment with cyclosporin A was not effective, the patient was subsequently given a combination of antithymocyte globulin, cyclosporin A, and granulocyte colony-stimulating factor. Although the pancytopenia subsided, the percentage of double-negative erythrocytes in the patient's blood remained almost unchanged compared to findings obtained on admission.

Renin-angiotensin system stimulates cardiac and renal disorders in Tsukuba hypertensive mice

1. The role of the renin-angiotensin system (RAS) in cardiac hypertrophy and nephropathy was examined in Tsukuba hypertensive mice (THM) carrying both human renin and angiotensinogen genes. 2. Tsukuba hypertensive mice were treated with 20 mg/kg per day lisinopril, 30 mg/kg per day hydralazine or nothing. Administration of drugs was performed for 6 months from 12 weeks of age; water intake and urine volume were measured and urine albumin excretion, heart to bodyweight ratio and the glomerulosclerosis index were examined. 3. Systolic blood pressure was significantly lowered by treatment with lisinopril and hydralazine. Urine volume, water intake and urinary albumin excretion were significantly decreased by lisinopril. When hydralazine was administered to THM, these parameters were transiently decreased, but eventually reached almost the same levels as those in the untreated group. The heart to bodyweight ratio was significantly decreased by lisinopril, but not by hydralazine. The glomerulosclerosis index was significantly lowered by lisinopril, but the index in the hydralazine group was not significantly different from that in the untreated group. 4. These results suggest that the RAS plays an important role in the progression of cardiac hypertrophy in THM. In addition, the RAS may also play an important role in the progression of nephropathy; however, this may also be partially regulated by elevated blood pressure in the short term.

Complement sensitivity of erythrocytes in a patient with inherited complete deficiency of CD59 or with the Inab phenotype

We investigated the complement sensitivity of erythrocytes from three patients, one with inherited complete deficiency of CD59, one with the Inab phenotype, and one with paroxysmal nocturnal haemoglobinuria (PNH). The complement lysis sensitivity units on the erythrocytes were 11.7, 4.6, and 47.6 for inherited CD59 deficiency, Inab phenotype, and PNH, respectively. Two-colour flow cytometric analysis showed that the erythrocytes from the three patients consisted of a single population negative for CD59, negative for decay accelerating factor (DAF), and negative for both proteins, respectively. In addition, only the Inab phenotype patient had no haemolysis in vivo. These facts suggest that CD59 deficiency plays a more important role than DAF deficiency in complement-mediated haemolysis in vitro and in vivo, and that deficiency of both proteins, but not CD59 or DAF alone, causes complement sensitivity corresponding to that of PNH III erythrocytes in vitro.

Degradation kinetics of L-alanyl-L-glutamine and its derivatives in aqueous solution

The degradation kinetics of five glutamine dipeptides in aqueous solution, i.e. glycyl-L-glutamine (Gly-Gln), L-alanyl-L-glutamine (Ala-Gln), L-valyl-L-glutamine (Val-Gln), L-leucyl-L-glutamine (Leu-Gln) and L-isoleucyl-L-glutamine (Ile-Gln), were studied. Stability tests were performed using a stability-indicating high-performance liquid chromatographic assay. Two different Ala-Gln degradation routes, i.e. the cleavage of a peptide bond and the deamination of an amide group, were observed. The degradation was adequately described by pseudo-first-order kinetics. The maximum stability of Ala-Gln was obtained at an approximate pH of 6.0. The pH-rate profile described by specific acid-base catalysis and hydrolysis by water molecules agreed with the experimental results. The activation energy of Ala-Gln at pH 6.0 was determined to be 27. 1kcal mol-1, and the shelf-life (90% remaining) at 25 and 40 degrees C was predicted to be 5.3 years and 7.1 months, respectively. The rate constants of the glutamine dipeptides were influenced by the N-terminal amino acid residue and decreased in the order: Gly-Gln, Ala-Gln, Leu-Gln, Val-Gln and Ile-Gln.

Halothane attenuates calcium sensitization in airway smooth muscle by inhibiting G-proteins

BACKGROUND

Halothane directly relaxes airway smooth muscle partly by decreasing the Ca2+ sensitivity. In smooth muscle, receptor stimulation is thought to increase Ca2+ sensitivity via a cascade of heterotrimeric and small monomeric guanine nucleotide-binding proteins (G-proteins). Whether this model is applicable in the airway and where halothane acts in this pathway were investigated.

METHODS

A beta-escin-permeabilized canine tracheal smooth muscle preparation was used. Exoenzyme C3 of Clostridium botulinum, which inactivates Rho monomeric G-proteins, was used to evaluate the involvement of this protein in the Ca2+ sensitization pathway. The effects of halothane on different stimulants acting at different levels of signal transduction were compared: acetylcholine on the muscarinic receptor, aluminum fluoride (AIF4-) on heterotrimeric G-proteins, and guanosine 5'-O-(3-thiotriphosphate) (GTPgammaS) on all G-proteins.

RESULTS

Exoenzyme C3 equally attenuated acetylcholine- and AIF4--induced Ca2+ sensitization, suggesting that these pathways are both mediated by Rho. Halothane applied before stimulation equally attenuated acetylcholine- and AIF4--induced Ca2+ sensitization. However, when added after Ca2+ sensitization was established, the effect of halothane was greater during Ca2+ sensitization induced by acetylcholine compared with AIF4-, which, along with the previous result, suggests that halothane may interfere with dissociation of heterotrimeric G-proteins. Halothane applied during GTPgammaS-induced Ca2+ sensitization had no significant effect on force, suggesting that halothane has no effect downstream from monomeric G-proteins.

CONCLUSION

Halothane inhibits increases in Ca2+ sensitivity of canine tracheal smooth muscle primarily by interfering with the activation of heterotrimeric G-proteins, probably by inhibiting their dissociation.

Tissue-localized angiotensin II enhances cardiac and renal disorders in Tsukuba hypertensive mice

OBJECTIVE

To evaluate the relation of tissue-localized angiotensin II (Ang II) concentration with cardiac hypertrophy and glomerulosclerosis in Tsukuba hypertensive mice (THM) carrying both human renin and angiotensinogen genes.

DESIGN

Thirty THM aged 12 weeks were distributed equally to a lisinopril dosage group, a hydralazine dosage group, and an untreated group. Ten age-matched C57BL/6 mice were used as normal controls. Administration was performed for 8 weeks from 12 weeks of age. All mice were euthanized at 20 week of age, and the heart-to-body weight ratio, the renal glomerulosclerosis score, tissue Ang II concentration and tissue catecholamine concentration were measured.

RESULTS

In the untreated group, a significant increase in every examination item was found as compared with that in C57BL/6 mice. In the lisinopril group, the observed value of every item was significantly lower than that in the untreated group. In the hydralazine group, tissue Ang II and catecholamine concentrations and the heart-to-body weight ratio were not different from those in the untreated group. Although the glomerulosclerosis score in the hydralazine group was significantly less than that in the untreated group, this was significantly higher than that in the lisinopril group.

CONCLUSION

Tissue Ang II concentration is more important than hypertension in causing cardiac hypertrophy, and both tissue Ang II level and hypertension are important in causing glomerulosclerosis in THM.

Involvement of other bacteriophage T4 genes in the blockade of protein synthesis and mRNA destabilization by a mutation of gene 61. 5

Gene 61.5 of bacteriophage T4 is required for gene expression at late stages of infection; a mutant of gene 61.5 shows a reduced rate of synthesis of late proteins and accumulates short transcripts upon infection of nonpermissive host cells at 30 degreesC (T. Kai, H. E. Sellick, and T. Yonesaki, Genetics 144, 7-14, 1996). Here we describe that, although the defects are only apparent at late stages, gene 61.5 is expressed early after infection and that the requirement of a functional gene 61.5 is partially compensated by the passage of early and middle stages of infection at high temperatures, suggesting that T4 genes expressed at early and middle stages bypass the requirement for the gene 61.5 at high temperatures. Furthermore, we isolated five pseudorevertants of a gene 61.5 mutant, designated as ssf1 through ssf5, which partially restored the growth ability at low temperatures, stabilized mRNAs, and stimulated protein synthesis at late stages. These results strongly suggest that the products of other T4 genes interact with the product of gene 61.5 in stabilizing mRNAs late in T4 infection.

Inhibitory effects of a subdepressor dose of L-158,809, an angiotensin II type 1 receptor antagonist, on cardiac hypertrophy and nephropathy via the activated human renin-angiotensin system in double transgenic mice with hypertension

The effects of L-158,809, an angiotensin II type 1 receptor antagonist, on cardiac hypertrophy and nephropathy were examined using Tsukuba hypertensive mice (THM) carrying both human renin and angiotensinogen genes. Nine male THM aged 20 weeks were assigned to each of a no-dosage group and an L-158,809 dosage group, and L-158,809 was administered for 8 weeks. Nine age-matched male C57BL/6 mice were used as normal control animals. At 28 weeks of age, all of the mice were euthanized. Systolic blood pressure, urinary volume, water intake volume, urinary albumin excretion, heart weight and kidney weight to body weight ratios and a glomerulosclerosis index were measured. In the no-dosage group, the values of all of these parameters were larger than those in the control mice. In the L-158,809 group, all of the parameters showed significant improvement, except for blood pressure, which was not significantly different from that in the no-dosage group. These results suggest that the renin-angiotensin system played a crucial role in the cardiac hypertrophy and nephropathy in THM, and that L-158,809 exhibited strong curative effects on cardiac hypertrophy and nephropathy by blocking the angiotensin II type 1 receptor.

Drug-specific effects of volatile anesthetics on Ca2+ sensitization in airway smooth muscle

Halothane directly relaxes airway smooth muscle, partly by decreasing the Ca2+ sensitivity during membrane receptor stimulation. The effects of other volatile anesthetics on Ca2+ sensitivity are unclear. In the current study, we compared the ability of halothane, sevoflurane, and isoflurane to inhibit increases in Ca2+ sensitivity during muscarinic receptor stimulation. Beta-escin-permeabilized canine tracheal smooth muscle strips were used. Anesthetics were applied during contractions induced by 3 microM acetylcholine and 10 microM guanosine 5'-triphosphate at a constant cytosolic Ca2+ concentration of 0.3 microM. Effects were evaluated as a percent relaxation from initial force corrected for time. Halothane significantly decreased force at both low (0.76 minimum alveolar anesthetic concentration [MAC]) and high (1.8 MAC) concentrations in a concentration-dependent manner. Sevoflurane also decreased force, significantly so at a high concentration (1.7 MAC). Isoflurane did not significantly affect force even at a high concentration (1.7 MAC). Halothane's relaxing effect was significantly greater than that of the other two anesthetics at each corresponding MAC concentration. Among these three volatile anesthetics compared at equipotent anesthetic concentrations, halothane was the most potent in reducing Ca2+ sensitivity during muscarinic receptor stimulation in canine tracheal smooth muscle. This may contribute to halothane's greater relaxing effect compared with isoflurane at the same MAC concentrations in intact airway smooth muscle.

IMPLICATIONS

In this study, we showed that three volatile anesthetics (halothane, sevoflurane, and isoflurane) compared at equipotent anesthetic concentrations differed in their ability to inhibit Ca2+ sensitivity during muscarinic receptor stimulation in airway smooth muscle. The potency order was halothane > sevoflurane > or = isoflurane.

Enhanced angiotensin II stimulates renal disorders in transgenic Tsukuba hypertensive mice

Tsukuba hypertensive mice (THMs) are transgenic mice carrying human renin-angiotensin system (RAS) genes. The aim of this study is to evaluate whether renal disorders are present in THMs. Twenty-week-old THMs and C57BL/6 mice (C57s) were used for this study. Each group consisted of 8 mice. Systolic blood pressure, urinary volume, water intake and urinary albumin excretion were measured in each mouse. Each mouse was then euthanized, and the renal glomerulosclerosis index and glomerular size were measured. Systolic blood pressure of THMs was about 40 mmHg higher than that of C57s. Urinary volume, water intake and urinary albumin excretion were significantly higher in THMs than in C57s. The renal glomerulosclerosis index and glomerular size were also significantly higher in THMs than in C57s. These results suggested that an enhanced renin-angiotensin system, including its hypertensive effects, stimulates albuminuria, renal glomerulosclerosis and glomerular hypertrophy in THMs.

Significant role of the increase in renin-angiotensin system in cardiac hypertrophy and renal glomerular sclerosis in double transgenic tsukuba hypertensive mice carrying both human renin and angiotensinogen genes

Tsukuba hypertensive mice (THM) are a hypertensive model prepared by mating a transgenic mice with human renin gene and a transgenic mice with human angiotensinogen gene. In the present study, we examined effects of renin-angiotensin system (RAS) on cardiac hypertrophy and renal disorders using Tsukuba hypertensive mice. While THM showed an increase of about 30 mmHg in systolic pressure compared to C57BL/6 mice employed as normal control animals, the increase in blood pressure was not observed in the mice to which either gene was transferred. Urinary volume, water intake volume, urinary albumin excretion, heart to body weight ratio and renal glomerular sclerosis index increased significantly in THM, but none of these parameters showed a significant difference from the C57 mice when they were examined in mice to which either of the genes was transferred. In contrast, when lisinopril was administered to THM, all the parameters decreased significantly without lowering the systolic pressure. From these findings, it was demonstrated that RAS was playing a significant role in cardiac hypertrophy and renal disorders of THM and that lisinopril had inhibitory effects on cardiac hypertrophy and renal glomerular sclerosis by inhibiting RAS.

Effect of phorbol esters on Ca2+ sensitivity and myosin light-chain phosphorylation in airway smooth muscle

We studied in beta-escin-permeabilized canine tracheal smooth muscle (CTSM) the effect of the protein kinase C (PKC) agonist phorbol 12,13-dibutyrate (PDBu) on isometric force at a constant submaximal Ca2+ concentration (i.e., the effect on Ca2+ sensitivity) and regulatory myosin light-chain (rMLC) phosphorylation. PDBu increased Ca2+ sensitivity, an increase associated with a concentration-dependent, sustained increase in rMLC phosphorylation. PDBu altered the relationship between rMLC phosphorylation and isometric force such that the increase in isometric force was less than that expected for the increase in rMLC phosphorylation observed. The effect of four PKC inhibitors [calphostin C, chelerythrine chloride, a pseudosubstrate inhibitor for PKC, PKC peptide-(19-31) (PSSI), and staurosporine] on PDBu-induced Ca2+ sensitization as well as the effect of calphostin C and PSSI on rMLC phosphorylation were determined. Whereas none of these compounds prevented or reversed the PDBu-induced increase in Ca2+ sensitivity, the PDBu-induced increase in rMLC phosphorylation was inhibited. We conclude that PDBu increases rMLC phosphorylation by activation of PKC but that the associated PDBu-induced increases in Ca2+ sensitivity are mediated by mechanisms other than activation of PKC in permeabilized airway smooth muscle.

Role of the renin-angiotensin system in cardiac hypertrophy and renal glomerular sclerosis in transgenic hypertensive mice carrying both human renin and angiotensinogen genes

Tsukuba hypertensive mice (THMs) are transgenic mice carrying human renin and angiotensinogen genes. The aim of this study was to evaluate the role of the renin-angiotensin system (RAS) in cardiac hypertrophy and renal disorders in THMs. After a 2-wk control period, 10-wk-old THMs were treated with lisinopril (ACEI group) or hydralazine (hydralazine group) or left untreated (control group) for 8 wk. C57BL/6 mice of similar age (wild group) were used as normal controls. Systolic blood pressure and urinary albumin excretion were measured once a week. All mice were sacrificed at 20 wk of age, and heart to body weight ratio, cardiac myocyte diameter, renal glomerular sclerosis index, and glomerular size were measured. Fibronectin expression was also evaluated. At 20 wk of age, systolic blood pressure and urinary albumin excretion in the control group were significantly higher than those in the wild group and significantly lower than those in the ACEI and hydralazine groups. Heart to body weight ratio and cardiac myocyte diameter were significantly higher in the hydralazine and control groups than in the other groups. Renal glomerular sclerosis index and glomerular size were also significantly higher in the control group than in the other groups, and there were significant differences between the ACEI and hydralazine groups in these variables. Fibronectin expression was marked in the control and hydralazine groups. These findings suggest that the RAS plays an important role in cardiac hypertrophy in THMs, but that both the RAS and elevation of blood pressure contribute to the pathogenesis of renal glomerular sclerosis.