Angiotensin I-converting enzyme inhibitory peptides derived from bonito bowels autolysate

Six angiotensin I-converting enzyme inhibitory peptides were isolated from a bonito bowels autolysate. Their amino acids were sequenced as Tyr-Arg-Pro-Tyr, Gly-His-Phe, Val-Arg-Pro, Ile-Lys-Pro, Leu-Arg-Pro, and Ile-Arg-Pro. Peptides having corresponding amino acid sequences were synthesized by a solid-phase method and their inhibition of the activity measured. IC50 of these peptides were estimated to be 320, 1100, 2.2, 2.5, 1.0, and 1.8 microM, respectively. The role of carboxyl terminal proline residues on the inhibition is discussed.

Albumin-binding superoxide dismutase with a prolonged half-life reduces reperfusion brain injury

To test the possible involvement of superoxide radicals in the pathogenesis of reperfusion injury, we synthesized a superoxide dismutase (SOD) derivative [poly(styrene-co-maleic acid) butyl ester (SM) covalently linked to SOD] that circulates bound to albumin, has a prolonged in vivo half-life, and accumulates in pH-decreased tissues. The protective effects of SM-SOD on regional cerebral blood flow, intracranial pressure, cardiac index, vascular permeability, and neurological outcome were investigated using a model of global brain ischemia in dogs. Intra-arterial injection of SM-SOD (10 mg/kg) just before reperfusion increased reactive hyperemia (SM-SOD, 160 +/- 36 ml.100 g-1.min-1, means +/- SD, n = 6; control, 100 +/- 34 ml.100 g-1.min-1, n = 6, P = 0.015), ameliorated delayed hypoperfusion (7 h after ischemia: SM-SOD, 40 +/- 14 ml.100 g-1.min-1; control 17 +/- 6 ml.100 g-1.min-1, P = 0.003), vascular permeability, and neurological outcome without affecting the cardiac index. These results indicate that superoxide radicals and/or their metabolite(s) might play a critical role in the pathogenesis of reperfusion injury in the brain.

Increased concentration of endothelin messenger RNA in the mesenteric arteries of cyclosporine-induced hypertensive rats

The aim of this study was to investigate the expression of endothelin-1 (ET-1) in the mesenteric arteries of cyclosporine-induced hypertensive rats. The concentration of plasma ET-1 and of mesenteric artery ET-1 messenger RNA was measured in cyclosporine-induced hypertensive and control rats. The concentration of ET-1 messenger RNA in the mesenteric arteries of cyclosporine-treated rats (25 mg/kg/day for 6 weeks) was significantly greater than in control rats (P < .05). We propose that cyclosporine-induced hypertension may be due to an increased synthesis of ET-1 in the resistant vessels.

Identification and characterization of heat-stable enterotoxin II-producing Escherichia coli from patients with diarrhea

Stock strains of Escherichia coli isolated from patients with traveller's diarrhea were examined for production of heat-stable enterotoxin II (STII). Of 400 strains examined, 3 were found to produce STII. The nucleotide sequence of the STII gene of these human strains was shown to be identical to that of porcine strains. Cultured cells of these strains induced fluid accumulation in ligated mouse intestinal loops and the activity was neutralized by anti-STII antiserum. These results suggest that STII-producing enterotoxigenic E. coli can cause human diarrhea.

Effects of MS-551, a new class III antiarrhythmic drug, on action potential and membrane currents in rabbit ventricular myocytes

1. Electrophysiological effects of MS-551, a new class III antiarrhythmic drug, were examined and compared with those of (+)-sotalol in rabbit ventricular cells. 2. In rabbit ventricular muscles stimulated at 1.0 Hz, MS-551 (0.1-10 microM) and (+)-sotalol (3-100 microM) prolonged action potential duration (APD) and effective refractory period without affecting the maximum upstroke velocity of phase 0 depolarization (Vmax). The class III effect of MS-551 was approximately 30 times more potent than that of (+)-sotalol. 3. Class III effects of MS-551 and (+)-sotalol showed reverse use-dependence, i.e., a greater prolongation of APD at a longer cycle length. 4. In rabbit isolated ventricular cells, 3 microM MS-551 and 100 microM sotalol inhibited the delayed rectifier potassium current (IK) which was activated at more positive potentials than -50 mV and saturated around +20 mV. 5. MS-551 at a higher concentration of 10 microM decreased the transient outward current (Ito) and the inward rectifier potassium current (IK1) although 100 microM sotalol failed to inhibit these currents. 6. MS-551 is a non-specific class III drug which can inhibit three voltage-gated K+ channels in rabbit ventricular cells.

Apoptosis of lung cancer cells caused by some anti-cancer agents (MMC, CPT-11, ADM) is inhibited by bcl-2

To determine whether the apoptotic cell death induced by anti-cancer agents could be inhibited by bcl-2, we established a bcl-2-transfected human small cell lung cancer cell line, SBC-3/Bcl2. SBC-3/Bcl2 showed higher resistance to ADM, CPT-11 and MMC compared with the parental line SBC-3, with relative resistance values of 3.4, 7.6 and 5.7, respectively. However, there was no difference in sensitivity to CDDP, VP-16, ACNU, MTX and taxol between SBC-3 and SBC-3/Bcl2. Agarose gel electrophoresis showed typical DNA fragmentation of SBC-3 following treatment with CPT-11 or MMC, in a concentration-dependent manner. In contrast, the same concentration of the drugs did not induce DNA fragmentation in SBC-3/Bcl2. Treatment with CDDP resulted in the same degree of DNA fragmentation in SBC-3 and SBC-3/Bcl2. These studies indicate that bcl-2 can modulate the cytotoxicity of some anti-cancer agents by inhibiting the process of apoptosis.

Endoscopic evaluation of the depth of invasion of the depressed type early gastric cancer and apparently early advanced cancer in cases of a peptic ulcer within the cancer lesion

Depressed-type early and apparently early advanced cancers were divided into two groups according to whether or not an associated peptic ulcer was present within the cancer lesion, and the accuracy of preoperative endoscopic diagnosis was reviewed. As a result it was found that evaluation of depth of invasion was more difficult in the ulcer [UL(+)] group than in the group without an ulcer [UL(-)]. In the UL(+) group it was difficult to identify endoscopic findings which indicate depth of invasion at the tip of the folds, the volume of cancer invasion of the deeper layers was small, and there many cases of invasion of deeper layers in a portion of the margins of the peptic ulcers.

Multivariate analysis of magnetic resonance imaging of focal hepatic lesions

A total of 124 lesions from 1 to 6cm in diameter, including 31 cavernous hemangiomas, 32 metastases and 61 hepatocellular carcinomas (HCC) were analyzed to study the usefulness of magnetic resonance imaging (MRI) at 0.5 Tesla to differentiate focal hepatic lesions on the basis of qualitative criteria. Each focal hepatic lesion was assessed for shape, internal architecture and signal intensity relative to normal liver parenchyma. While all cavernous hemangiomas and metastases except one lesion could be detected, detection rate of HCC was significantly inferior to that of the other two diseases. A tumor capsule and a hyperintense focus on T1-weighted images were demonstrated in only HCC lesions in strong contrast with the other two diseases; however, metastases with slow-growing characteristics or subacute hematoma may appear as similar images. Cavernous hemangiomas appeared markedly hyperintense on T2-weighted images in 23 of 31 lesions, but one metastasis and one HCC had similar images. A multivariate analysis of several MRI resulted in the following mean discriminant scores: cavernous hemangioma, -1.2652; metastasis, 0.1830; and HCC, 0.7138. It appeared to be possible to differentiate the three diseases with 84.4 percent accuracy.

Effects of growth hormone on follicle growth, oocyte maturation, and ovarian steroidogenesis

OBJECTIVES

To assess the effects of GH on follicle growth, oocyte maturation, ovulation, and ovarian steroidogenesis.

DESIGN

In vitro perfused rabbit ovary.

INTERVENTIONS

The rabbit ovaries were perfused with medium alone, with GH at 1, 10, 100, or 200 ng/mL, or with 50 IU hCG for 12 hours.

MAIN OUTCOME MEASURES

The follicle diameter, the percent change in follicle diameter, the percentage of oocytes achieving germinal vesicle breakdown, and the production of P and E2 by the perfused rabbit ovaries.

RESULTS

The addition of GH to the perfusate increased the follicle diameter at 12 hours after perfusion in a dose-dependent manner. The percent change in follicle diameter in GH-treated ovaries did not differ significantly from that in hCG-treated ovaries at each time point of perfusion. However, ovulation did not occur in either the control ovaries or the experimental ovaries treated with GH. Exposure to GH at a concentration of > 10 ng/mL significantly stimulated the resumption of meiosis, as compared with the contralateral control ovaries. Although the concentration of P in the perfusate did not differ significantly between GH-treated and control ovaries, GH stimulated E2 production by the perfused rabbit ovaries in a dose-dependent manner.

CONCLUSIONS

Growth hormone acts on the rabbit ovary to stimulate follicle growth, oocyte maturation, and ovarian E2 production.

[Incidence and prevalence of serotypes of enteroaggregative Escherichia coli from diarrheal patients in Brazil, Myanmar and Japan]

By using HeLa cells, we tried to detect enteroaggregative Escherichia coli from stock strains derived from infants with or without diarrhea in Brazil and Myanmer, and from diarrheal patients in Osaka, Japan. Enteroaggregative E. coli was detected from 7.9% in diarrheal cases, 5.6% in control cases in Brazil and from 5.4% in diarrheal cases, 3.4% in control cases in Myanmar. A total of 38 strains that showed aggregative adherence to HeLa cells was examined for colony hybridization with the 32P-labeled EAggEC probe. Thirty-four strains hybridized with the EAggEC probe, while 4 strains did not hybridize with the probe, suggesting an existence of another aggregative factor. Seventeen of the 38 strains were O-antigen serotypeable. Eight strains belonged to serogroups O44, O86, O111, O125 and O126, which have been considered to be enteropathogenic E. coli serogroups. Most of the 38 strains were H-antigen serotypeable.

Cyclosporine A induces endothelin-1 release from cultured rat vascular smooth muscle cells

Since vascular smooth muscle cells in culture are capable of secreting endothelin-1 (ET-1), we investigated the effect of cyclosporine A on ET-1 release from rat vascular smooth muscle cells. Cyclosporine A 10 microM significantly (P < 0.05) enhanced the secretion of ET-1 at 2, 8, 24 and 48 h (6.5 +/- 0.5, 11 +/- 0.7, 19 +/- 0.5, 37 +/- 1.6 fmol/10(6) cells, respectively) compared with vehicle (4.7 +/- 0.3, 8.1 +/- 0.6, 15 +/- 0.4, 27 +/- 2.0 fmol/10(6) cells, respectively). The cyclosporine-induced synthesis of ET-1 by vascular smooth muscle cell may participate in the pathogenesis of cyclosporine-induced vasoconstriction and vasculopathy via an autocrine regulatory mechanism.

Inhibitory effects of insulin-like growth factor (IGF)-binding proteins-1 and -3 on IGF-activated glucose consumption in mouse BALB/c 3T3 fibroblasts

We have examined the biological effects of insulin-like growth factor-binding proteins (IGFBPs) on insulin-like growth factor (IGF)-activated glucose consumption in a BALB/c 3T3 subline. The method employed was a colorimetric measurement of glucose consumption, allowing the detection of changes from the initial glucose concentration in conditioned medium, following the addition of IGFs and IGFBPs. Human IGFBP-1, purified from amniotic fluid, inhibited IGF-activated glucose consumption, although it had no effect on insulin-activated glucose consumption. The median effective dose (ED50) of IGFBP-1 to cause inhibitory effects on IGF-activated glucose consumption was 100-200 micrograms/l and was similar for both IGF-I and IGF-II at a concentration of 1.0 microgram IGF/l. Therefore, at IGF concentrations of comparable activity, the inhibitory effects of IGFBP-1 were greater for IGF-I than for IGF-II, because of the higher activity of IGF-I in this assay. Recombinant human IGFBP-3 also inhibited IGF-activated glucose consumption, without affecting insulin-stimulated glucose consumption. The inhibitory effects of IGFBP-3 were greater for IGF-II than for IGF-I when IGFBP-3 was coincubated with either of the IGFs, at both IGF concentrations of comparable activity and equivalent molar concentrations. Thus, it became clear that the inhibitory effects of these IGFBPs on IGF biological action depended primarily upon their affinity for the specific IGF ligand and molar ratio of IGFBP/IGF peptide. Interestingly, when cells were pretreated with IGFBP-3, prior to the simultaneous addition of IGFs and IGFBP-3, the inhibitory effect was higher for IGF-I than for IGF-II. Either no effect or a minor inhibitory effect on IGF-activated glucose consumption was detected with IGFBP pretreatment alone. When the ED50 for inhibition of IGF action by IGFBPs in this in-vitro assay was compared with the physiological concentrations of IGFs and IGFBPs in normal human serum and in amniotic fluid, it was estimated that the IGFBP-1 concentration present in serum was not sufficient to modulate IGF action effectively while the concentration in amniotic fluid was enough for effective suppression. IGFBP-3 exhibited an ED50 low enough to suppress IGF-II and possibly IGF-I action when cells were pretreated with IGFBP-3. Thus, our data suggested that IGFBP-1 in amniotic fluid and IGFBP-3 in serum could be a potent inhibitor for IGF action. IGFBP-1 in serum, however, may not be able to function as a direct inhibitor under physiological conditions but, rather, may modulate IGF action together with other IGFBPs.

Aminoalkylbisphosphonates, potent inhibitors of bone resorption, induce a prolonged stimulation of histamine synthesis and increase macrophages, granulocytes, and osteoclasts in vivo

Aminoalkyl derivatives of bisphosphonates are potent inhibitors of bone resorption. A single I.P. injection of 4-amino-1-hydroxybutylidene-1,1-bis-phosphonate (AHBuBP) induced a prolonged enhancement of histidine decarboxylase (HDC) activity in the bone marrow, spleen, lung, and liver of mice and resulted in an increase in histamine. The induction of HDC by the agent was dose dependent (16-80 mumol/kg) and peaked 3-4 days after its injection (40 mumol/kg). Repeated S.C. injections of smaller doses of AHBuBP (0.32 or 1.6 mumol/kg/day) for 4 days also enhanced HDC activity. However, the minimum dose capable of inhibiting bone resorption (0.064 mumol/kg/day) was lower than that inducing HDC. Unexpectedly, AHBuBP, at the doses inducing HDC, increased macrophages, granulocytes, and even osteoclasts. The size of osteoclasts was also enlarged by the agent. Another aminobisphosphonate, 3-amino-1-hydroxypropylidene-1,1-bisphosphonate, but none of non-amino derivatives, also exhibited essentially the same effects as those of AHBuBP. These results indicate that in spite of increase in osteoclasts and their enlargement, bone resorption is still inhibited by amino bisphosphonates. As granulocyte and granulocyte-macrophage colony-stimulating factors and interleukin-3 induce HDC in hematopoietic organs, and histamine has a hematopoietic activity, the HDC induction by aminobisphosphonates may be relevant to the proliferation of progenitor cells of macrophages, granulocytes, and osteoclasts.

[Clinical assessment of meningeal carcinomatosis; from the viewpoint of the analysis of intracranial pressure]

Meningeal carcinomatoses (MC) have been mainly studied from the viewpoint of the analysis of intracranial pressure (ICP). From the CT findings, ten patients were divided into two groups: group I, six patients showed characteristics of MC; group II, four showed normal characteristics. Ventricular fluid pressure (VFP) was continuously measured by a controlled ventricular drainage tube using a Spectramed P-10EZ at 3.1 +/- 2.1 months after the onset of the neurological symptoms. At the same time as VFP monitoring, the CBF by 133Xe method was measured in 5 cases and RI cisternography was performed in 9 cases. "A" wave was observed in 5 cases of group I and in 3 cases of group II. "B" wave was observed in all cases of both groups. In all 10 cases, the occurrence rate of both A and B waves (ORA, ORB) were high, averaging 2.34 +/- 0.54 times/hour, 74.0 +/- 16.6% time, respectively. Mean resting pressure(R) and mean peak pressure(P) tended to be high, averaging 28.8 +/- 12.2mmHg, 58.9 +/- 13.7mmHg, respectively. Mean cerebral perfusion pressure corresponding with R and P (CPPR, CPPP) was markedly reduced, averaging 79.1 +/- 15.9mmHg, 50.9 +/- 12.7mmHg, respectively. Both ORA and ORB in group I were higher, and both CPPR and CPPP in group 1 were lower, than in group II. Statistically, this is significant. Both R and P in Group I tended to be higher than in group II. This has no statistical significance. CBF in all 5 cases averaged 34.8 +/- 8.4ml/100g/min. No significant difference in the impairment of CBF was found between both groups. RI cisternography showed delayed clearance in all 9 cases.(ABSTRACT TRUNCATED AT 250 WORDS)

Role of growth factors on fetal growth and maturation

Several growth factors have been demonstrated to be involved in fetal growth. In this study, physiological significance of two growth factors, epidermal growth factor (EGF) and insulin-like growth factor-I (IGF-I) on fetal growth was evaluated. IGF-I stimulated 3H-glycine uptake by cultured trophoblast cells from term pregnancy while EGF did not stimulate it. A large part of IGF-I was associated with its binding proteins (IGFBPs) in the circulation and one of IGFBPs, IGFBP-1 inhibited 3H-glycine uptake by IGF-I in a dose dependent manner. IGF-I also stimulated 3H-aminoisobutyric acid (3H-AIB) release by trophoblast cells when cells were saturated with 3H-AIB first, then stimulated with IGF-I. In animal experiments, placental weight but not fetal weight was suppressed when EGF antiserum was administrated to maternal mice, however, fetal lung maturity in terms of lamella body produced in type II alveolar cells was suppressed in antiserum given group. When anti IGF-I antiserum was administrated to pregnant mice, both fetal and placental weight were significantly suppressed and transfer of 3H-AIB to fetus was also suppressed. In contrast, antiserum to IGFBP-1 stimulated fetal growth and transfer of 3H-AIB to fetus. Furthermore, fetal lung on Day 17 in anti IGFBP-1 antiserum administrated mice showed morphologically advanced changes that were equivalent to Day 18 or 19 of control. These results indicate that EGF and IGF-I regulate fetal growth and maturation independently and that IGF-I and IGFBP-1 influence fetal development in a counter regulatory system.

[A case of cortical deafness with bilateral putaminal hemorrhage]

A 56 years old right-handed female, a housewife, had suffered from right putaminal hemorrhage which had been treated surgically in July, 1985. Since it was difficult to approach the trans-sylvian fissure, evacuation of the hematoma was performed transcortically through the superior temporal gyrus. She was neurologically free and lived normally until she suddenly became completely deaf in April, 1991. On admission, she was alert, well oriented and spontaneously stated that she was deaf. She showed no response to verbal commands or loud noises but followed complex written commands. No other neurological deficit was observed. In addition to an irregular low-density area in the right temporal lobe, CT scan revealed a left putaminal hemorrhage. Audiological testing disclosed pure tone thresholds to be below 90db on both sides. Auditory brain stem response (ABR) showed waves I to VI in normal latency ranges, but wave VII was not observed. She was treated conservatively. Although her hearing loss had been gradually improving for 1 month, she suffered from word deafness, an inability to comprehend speech, for the following 2 months. Clinical features, CT findings as well as results of ABR suggest that hearing loss observed in this case, cortical deafness, was presumably due to bilateral damage of acoustic radiation of the temporal lobe. It was also suggested that, although she was asymptomatic, cortical and subcortical damage to the right temporal lobe following evacuation of the putaminal hematoma may have been extensive. During surgical procedures for evacuation of the putaminal hematoma, it has to be always kept in mind not to damage the auditory cortex and its radiations.

Oncocytic hyperplasia in the human minor salivary glands: a post-mortem study

Oncocytic hyperplasia in the human labial salivary glands was sought in a series of 217 post-mortem subjects. Oncocytic change occurred in 183 subjects and hyperplasia was found in 19 of those (the overall incidence being 8.8%), ranging in age from the third decade to the ninth. The sex distribution showed a significantly greater rate in males (16 of 139 males, 11.5%; 3 of 78 females, 3.8%). Oncocytic hyperplasia occurred in the duct system, and not in the acinar regions; it was frequently seen in the interlobular and intralobular ducts. Oncocytic hyperplasia was classified into four types; focal hyperplasia of the duct wall resulting in partial thickening of the duct wall; marked hyperplasia resulting in thickening of the duct wall, extending over half of the circumference; marked hyperplasia extending to the whole duct wall and intralobular adeno-tubular hyperplasia with or without cystic dilatation. About half of the subjects with oncocytic hyperplasia showed a few hyperplastic foci in one gland. The changes increased in severity in older subjects.

Serum antibody production by oral immunization with dextran B512

Serum antibodies to dextran were detected when dextran B512 was orally administered to C3H/He mice. The amounts of serum antibodies were increased along with the dose of orally administered dextran B512. For serum antibody production, differences were observed among the strains of mice. C3H/He, C57BL/6 and CBA mice produced high levels of serum antibodies to dextran, while BALB/c and DBA/2 mice produced low levels of serum antibodies. The serum antibodies had groove-type combining sites, as determined by ELISA inhibitory assay.

Distribution of the zot (zonula occludens toxin) gene among strains of Vibrio cholerae 01 and non-01

The distribution of the zot gene that encodes the zonula occludens toxin, a newly described toxin of Vibrio cholerae, among clinical, environmental and food isolates of V. cholerae 01 and non-01 was investigated. Both the zot gene and the ctx gene that encode cholera toxin were found in 247 of 257 clinical strains and 62 of 415 environmental or food isolates of V. cholerae 01. The zot gene, but not the ctx gene was found in 37 strains (one clinical strain and 36 environmental or food isolates). In addition, two of 31 clinical strains and six of 98 environmental or food isolates of V. cholerae' non-01 possessed both the zot gene and the ctx gene. These results demonstrated the predominantly concurrent occurrence of the zot gene and ctx genes among strains of V. cholerae 01 which suggests a possible synergistic role of ZOT in the causation of acute dehydrating diarrhea produced by V. cholerae 01.

Characterization of mammary plaques in DDD mice congenic for Mtv-2 gene, DDD/1-Mtv-2/Mtv-2

DDD/1 mice free from exogenous mouse mammary tumor virus (MMTV) do not develop any neoplastic mammary lesions. In GR mice, the expression of Mtv-2, an endogenous proviral MMTV, leads to 100% incidence of mammary ductal hyperplasias and tumors. An Mtv-2 congenic line, DDD/1-Mtv-2/Mtv-2, was established by introducing Mtv-2 from GR into DDD/1 to elucidate its function. Development of mammary plaques (MPQ) characterized by ductal hyperplasias was investigated in 152 congenic females on day 17 to 19 of the first pregnancy. The incidence of MPQ was 48.0% and most MPQ-positive mice (75.3%) had only one MPQ. Generally, MPQ were small in size: the diameter was as small as < or = 3 mm in 77.6% of them. Of 84 MPQ implanted into intact fat pads, 43 (51.2%), 38 (45.2%) and 3 (3.6%) showed undetectable, pregnancy-dependent and autonomous growths; respectively when the hosts underwent pregnancy. Almost all MPQ produced normal-appearing ductal-alveolar outgrowths in mammary epithelium-divested or cleared fat pads of virgins. MPQ implanted into cleared fat pads were very similar to normal mammary glands in the responses to progesterone (P) and estradiol (E) alone or in combination except for association of ductal hyperplasias in 4 of 12 MPQ under E+P treatment. These findings revealed the preneoplastic nature of MPQ. Exogenous MMTV proviruses were demonstrated in all MPQ. The int-2 DNA rearrangement was found in 2 of 10 MPQ but in none of 9 mammary carcinomas and the int-1 DNA rearrangement in none of 10 MPQ but in 5 of 10 carcinomas. It is thus likely that the Mtv-2 gene participates in a very early stage of mammary tumorigenesis not directly but indirectly through insertion mutation of host genes, while the cellular oncogenes, int-2 and int-1, may contribute to preneoplastic transformation of mammary epithelium and progression from preneoplastic to more malignant states, respectively.