Apolipoprotein A-IV: a circulating satiety signal produced by the small intestine

How fat feeding, especially lipoproteins and apolipoproteins, may affect food intake is unclear. Apolipoprotein A-IV (apo A-IV) is a protein associated with chylomicrons, and its synthesis by the small intestine is markedly stimulated following ingestion of fat. We explored the anorectic effect of chylous lymph on feeding behavior. Intestinal lymph samples collected during lipid infusion intraduodenally when administered intravenously markedly suppressed food intake in fasting rats. To determine if the suppressor was lipid or apo A-IV, fasting rats were infused intravenously with a 2% Intralipid emulsion, but it did not suppress food intake. These data suggest that the factor in chylous lymph that suppresses food intake is probably apo A-IV. To test this, apo A-IV in chylous lymph was removed by immunoprecipitation, and the chylous lymph with apo A-IV removed lost its anorectic effect. Next, we infused purified apo A-IV intravenously in fasted rat, and it inhibited food intake in a dose-dependent manner. We therefore conclude that increased apo A-IV in chylous lymph is a factor involved in anorexia after fat feeding. Infusion of 0.5 microgram of apo A-IV into the third ventricle failed to suppress food intake. Higher doses (1 microgram or higher) of apo A-IV infused into the third ventricle inhibited food intake in a dose-dependent manner. To further test the hypothesis that apo A-IV is an important factor controlling food intake, we administered goat anti-rat apo A-IV serum into the third ventricle of rats that were allowed food and water ad libitum. In all rats tested, this treatment resulted in enhanced food intake. In conclusion, we propose that apo A-IV may act centrally to control food intake.

Histaminergic control of mucosal repair in the small intestine

The aim of the present paper was to summarize histamine-mediated repair of rat intestinal mucosa. To evaluate intestinal repair, we examined lipid transport (an index of intestinal mucosal function) after 15 minutes occlusion of the superior mesenteric artery. Rats were pretreated with alpha-fluoromethylhistidine (a suicide inhibitor of histidine decarboxylase, a synthesizing enzyme of histamine), H1-receptor antagonist (chlorpheniramine maleate), H2-antagonist (cimetidine), or H3-antagonist (thioperamide) before ischemia-reperfusion (I/R). Lipid transport to rat mesenteric lymph decreased significantly 24 hours after I/R in all groups tested compared to sham-treated rats. Lipid transport was restored 48 hours after I/R in the vehicle-pretreated control group. Lipid transport was not restored to the control level 48 hours after I/R in rats pretreated with H1-antagonist and a suicide inhibitor of histidine decarboxylase. In contrast, intestinal function was restored to the control level 48 hours after I/R in rats pretreated with H2- and H3-antagonists. These results support our previous findings that newly formed histamine after I/R plays an important role in mucosal recovery through H1-receptors.

Three novel mutations of thyroid hormone receptor beta gene in unrelated patients with resistance to thyroid hormone: two mutations of the same codon (H435L and H435Q) produce separate subtypes of resistance

We report three novel mutations of the thyroid hormone receptor beta (TR beta) gene in three unrelated Japanese patients with resistance to thyroid hormone (RTH). Patients A and B exhibited generalized resistance phenotype, while patient C displayed more pituitary-selective unresponsiveness. Direct sequencing of TR beta gene exon 10 disclosed novel point mutations in all three patients. A Phe to Ile (TTC-->ATC) substitution at codon 451, a His to Leu (CAT-->CTT) substitution at codon 435, and a His to Gln (CAT-->CAA) substitution at codon 435 were identified in patients A, B, and C, respectively. Sequencing of TR beta gene exons 5-9 as well as TR alpha gene exons 4-9 failed to detect any additional mutations. All three patients were heterozygous for respective mutations. The unaffected parents of patients A and B, having normal thyroid function, possessed no mutations of TR beta gene exon 10, indicating that the F451I and H435L mutations occurred de novo. The F451I mutation is located near the most frequent mutation site in the ligand 2 subdomain. The identical codon mutations H435L and H435Q, which lie at the extreme carboxyl-terminus of the dimerization subdomain near the 9th heptad, were found in clinically different subtypes of RTH: patient B with generalized resistance and patient C with pituitary-selective resistance, respectively. The mutations broaden the growing catalogue of the TR beta gene mutations that could cause different phenotypes, despite the defects at the same codon.

Effect of levofloxacin-albumin Dacron graft on graft infection

The susceptibility of Dacron grafts to infection is compared with Dacron grafts applied with levofloxacin-bonded albumin (LVFX-ALB) following the inoculation of 10(7) cells Staphylococcus aureus in rats. Staphylococcus epidermidis was inoculated in the same manner. While the control grafts were infected at the time of removal, the LVFX-ALB Dacron grafts resisted infection, thus demonstrating their effectiveness.

Role of nitric oxide in the control of blood pressure in young and adult spontaneously hypertensive rats

1. The depressor response to sodium nitroprusside (SNP) and the pressor response to Nomega-nitro-L-arginine methyl ester (L-NAME) were investigated in anaesthetized and ganglion-blocked 6 week old (young) and 20 week old (adult) spontaneously hypertensive rats (SHR), and the results were compared with those in age-matched normotensive Wistar-Kyoto (WKY) rats. 2. SNP produced a dose-dependent decrease of the mean blood pressure (BP) in both strains, and no differences in vascular sensitivity to SNP were observed between the strains. 3. L-NAME caused dose-dependent pressor responses in both strains. The sensitivity and the maximal response to L-NAME in SHR were significantly greater than those in age-matched WKY (P< 0.05 or 0.01; t-test, 13 d.f. in both ages). However, there were no significant differences in the responses between ages in each strain. 4. Acute reduction of BP induced by 7-O-ethylfangchinoline did not affect the responses to SNP and L-NAME in the adult SHR. 5. These results indicate that a greater amount of NO is tonically released in SHR and that its contribution to BP control is greater in SHR than in WKY, whereas vascular sensitivity to NO does not differ between the strains. In addition, acute changes in BP do not affect the degree of dependency on NO for BP control.

Effect of prone position on apnea severity in obstructive sleep apnea

We describe a patient with obstructive sleep apnea (OSA) whose apnea-hypopnea index (AHI) improved remarkably in the prone position accompanied by an improved sleep quality, despite a higher AHI in the supine position and even in the lateral position. Magnetic resonance imaging revealed the most dilated upper airway in the prone position, which suggests the role of anatomical narrowing of the upper airway as an important component in the pathophysiology of positional apnea patients. Further studies are needed to determine the therapeutic efficacy of a prone sleeping position in patients with OSA.

A role for phosphorylation in the proteolytic processing of the human NF-kappa B1 precursor

A precursor, p105, for one of the subunits (p50) of the NF-kappa B transcription factor, plays an important role in inducible expression of diverse cellular genes. p105 also functions as a cytoplasmic inhibitor for NF-kappa B, and the proteolytic processing of its inhibitory C-terminal region is required for generation of active NF-kappa B. Here, it is reported that the human p105 C-terminal region is phosphorylated in vivo on Ser894 and Ser908, which are potential phosphorylation sites in vitro for proline-directed serine/threonine kinases such as cyclin-dependent kinase. Furthermore, the mutation of these in vivo phosphorylation sites retards p105 processing in vivo, suggesting that p105 processing is regulated in a phosphorylation-dependent manner.

Freeze-fracture replica electron microscopy combined with SDS digestion for cytochemical labeling of integral membrane proteins. Application to the immunogold labeling of intercellular junctional complexes

We propose a new electron microscopic method, the sodium dodecylsulphate (SDS)-digested freeze-fracture replica labeling technique, to study the two-dimensional distribution of integral membrane proteins in cellular membranes. Unfixed tissue slices were frozen with liquid helium, freeze-fractured, and replicated in a platinum/carbon evaporator. They were digested with 2.5% SDS to solubilize unfractured membranes and cytoplasm. While the detergent dissolved unfractured membranes and cytoplasm, it did not extract fractured membrane halves. After SDS-digestion, the platinum/carbon replicas, along with attached cytoplasmic and exoplasmic membrane halves, were processed for cytochemical labeling, followed by electron microscopic observation. As an initial screening, we applied this technique to the immunogold labeling of intercellular junction proteins: connexins (gap junction proteins), occludin (tight junction protein), desmoglein (desmosome protein), and E-cadherin (adherens junction protein). The immunogold labeling was seen superimposed on the image of a fracture face visualized by platinum/carbon shadowing. The immunoreaction was specific, and only the structures where the proteins were expected were labeled. For instance, anti-occludin immunogold complexes were observed immediately adjacent to the tight junction strands on the protoplasmic and exoplasmic fracture faces. No significant levels of gold label were associated with non-tight-junctional regions of plasma membranes. The procedures of the SDS-digested freeze-fracture replica labeling and its potential significance are discussed.

Chemiluminescence detection of mono-, bis-, and tris-hydroperoxy triacylglycerols present in vegetable oils

A reliable method was needed to analyze molecular species of oxidized vegetable oils. In order to accomplish this goal, mono-, bis-, and tris-hydroperoxides (Mono-OOH, Bis-OOH, and Tris-OOH, respectively) of triacylglycerols formed during autoxidation and photosensitized oxidation of oils were determined by reversed-phase high-performance liquid chromatography in combination with chemiluminescence detection (CL-HPLC). Mono-OOH was the major species (96% of total hydroperoxides) in trioleoylglycerol [peroxide value (PV) 0.16 meg/kg], and Bis-OOH and Tris-OOH showed prolonged accumulation with photooxidation. This profile was confirmed in photooxidation of trilinoleoylglycerol and trilinoleoylglycerol. Soybean oil (PV 6 meq/kg) contained Mono-OOH oleoyl-linoleoylglycerol as the main peroxidic molecular species (50% of total hydroperoxides). Mono-OOH trilinoleoylglycerol was the principal species (61% of total hydroperoxides) in safflower oil (PV 5 meq/kg), and Mono-OOH oleoyl-oleoyl-linoleoylglycerol was the representative species (66% of total hydroperoxides) in olive oil (PV 3 meq/kg). The CL-HPLC method, which is specific for the detection of hydroperoxides, should prove useful in studies of triacylglycerol oxidation in foods and vegetable oils.

Antihypertensive effect of chronic KT3-671, a structurally new nonpeptide angiotensin AT1-receptor antagonist, in stroke-prone spontaneously hypertensive rats

KT3-671 (2-propyl-8-oxo-1-[(2'-(1H-tetrazole-5-yl)biphenyl-4-yl)methyl]-4,5,6, 7-tetrahydrocycloheptimidazole), a structurally new nonpeptide angiotensin AT1-receptor antagonist, was administered orally and repeatedly to 15-week-old stroke-prone spontaneously hypertensive rats for 7 weeks; and its effects on blood pressure, heart rate, renal function, plasma renin concentration (PRC), plasma aldosterone concentration (PAC) and hypertension-related tissue damage in the brain, heart, kidney and mesenteric artery were investigated. KT3-671 at a dose of 3 or 10 mg/kg, p.o. per day prevented development of hypertension and produced a significant and consistent reduction of blood pressure in a dose-dependent manner. Enalapril at a dose of 10 mg/kg per day produced cardiovascular effects similar to those of KT3-671 at 10 mg/kg. Despite marked reduction in blood pressure, neither KT3-671 nor enalapril affected the heart rate. KT3-671 at 10 mg/kg produced a transient and significant reduction of urinary sodium excretion in the second week, but did not affect renal function at any other time during the experimental period. Both KT3-671 at 10 mg/kg and enalapril at 10 mg/kg produced a significant increase in PRC and showed a tendency to decrease PAC. Repeated administration of KT3-671 reduced the severity of the pathological changes in the kidney. These results suggest that KT3-671 is a potentially useful antihypertensive drug.

Effect of the initial bolus volume of recombinant tissue-type plasminogen activator on coronary recanalization and infarct size in Japanese acute myocardial infarction patients. Kumamoto University Myocardial Infarction Study (KUMIS) Group

Coronary recanalization rate and infarct size were compared between 2 different methods of intravenously administering recombinant tissue-type plasminogen activator (rt-PA) 41.4 mg; 1) an initial bolus dose of 30% followed by infusion of the remainder over 60 min (30% group), and an initial bolus dose of 10% followed by infusion of the remainder over 60 min (10% group). Thirty min after beginning rt-PA infusion, the coronary recanalization rate was higher in the 30% group than in the 10% group (82.9% (34/41) vs 53.7% (22/41), p < 0.01). The peak creatine kinase and peak creatine kinase-MB levels were lower in the 30% group than in the 10% group. We conclude that a higher initial bolus dose of rt-PA gives a higher rate of recanalization of the infarct-related artery at the very early phase, and probably leads to a smaller infarct size.

Effects of fatty acids and fatty acyl CoA esters on Cu(2+)-induced conversion of xanthine dehydrogenase to oxidase in rabbit liver

Effects of various fatty acids and fatty acyl CoA esters on Cu(2+)-induced conversion of xanthine dehydrogenase to oxidase in rabbit liver were examined. Cu2+ (2-10 microM) brought about the conversion of xanthine dehydrogenase to oxidase in a dose-dependent manner. Oleic, arachidonic, eicosapentaenoic, and docosahexaenoic acids (50-200 microM) prevented the conversion of xanthine dehydrogenase to oxidase catalyzed by 6 microM-Cu2+. The effect of these four fatty acids was concentration-dependent, whereas palmitic, stearic, and linoleic acids had no effect on the conversion of xanthine dehydrogenase to oxidase at the same concentration range. On the other hand, palmitoyl, linoleoyl, and arachidonoyl CoAs elicited the inhibition of 6 microM-Cu(2+)-induced conversion of xanthine dehydrogenase to oxidase at concentrations of 50, 100, and 200 microM. These results suggest that oleic, arachidonic, eicosapentaenoic and docosahexaenoic acids, and fatty acyl CoAs have the potential to inhibit the conversion of xanthine dehydrogenase to oxidase in rabbit liver.

Snake-strike--induced ischemic colitis with colonic stricture complicated by disseminated intravascular coagulation

A 57-year-old farmer was struck on the right thumb by a pit viper (Agkistrodon blomhoffü). Subsequently, he had acute renal failure and disseminated intravascular coagulation (DIC), associated with melanotic stools and abdominal pain. Renal failure caused by renal cortical necrosis was successfully treated with hemodialysis. A double-contrast barium enema examination revealed multiple stenoses of the colon, regional edema, and longitudinal ulcer. Histologic examination of the stenotic lesions after laparotomy revealed fibrosis of both submucosa and proper muscle layer, with fibrotic thickness in the small arteries of the colonic wall, indicating that ischemic colitis was associated with DIC. In this case, DIC from viper toxins played an etiologic role in the development of ischemic colitis with stricture, as well as acute renal failure.

[Septic lung caused by methicillin-resistant Staphylococcus epidermidis]

A 55-year-old man was admitted to our department one month after resection of rectal carcinoma, with complaints of fever and general malaise. Shock developed rapidly after admission. The chest X-ray film and computed tomography showed diffuse small nodular shadows and bilateral pleural effusion. Septic lung caused by Methicillin-resistant Staphylococcus epidermidis (MRSE) was diagnosed from the results of a bacteriological study. This bacteria is a Coagulase Negative Staphylococcus (CNS). Chemotherapy with Minocycline and Cefotiam was effective. Characteristic radiologic features of this case may be related to the early stage of adult respiratory distress syndrome (ARDS) and septic pulmonary microembolism.

[Analgesic efficacy of E2078 (dynorphin analog) in patients following abdominal surgery]

Studies were carried out to elucidate the efficacy and safety of E2078, a metabolically stable dynorphin analog, in patients with severe pain following lower abdominal surgery. E2078 was administered intramuscularly in a single dose of 1 to 15 mg. The efficacy was determined by evaluating the pain intensity score (PI) and global improvement rating (GIR) by the investigator. E2078 exhibited analgesic effect at doses of 10 mg or more. At the dose of 10 mg (n = 24). PI decreased from 3.0 to 1.3, and GIR was 83%. When the dose was increased to 12.5 mg (n = 15), PI improved from 3.0 to 1.3, and GIR was 100%. The improvement in PI, GIR and the duration of efficacy were 3.0 to 0.8, 100% and 6 hours 40 minutes with E2078 15 mg (n = 10), respectively. E2078 did not produce any adverse effects at doses of up to 15 mg. The results of the present study indicate that E2078 begins to exhibit analgesic effect at a dose of 10 mg, and at 15 mg its effect is comparable to that of pentazocine 15 mg.

Linkage and haplotype analysis of familial early-onset Alzheimer disease in Japanese population

Linkage and haplotype analysis of eleven early-onset Alzheimer disease (AD) families was performed in relation to D21S210 and microsatellite DNA polymorphisms localized on chromosome 14q24.3. Linkage analysis of eight informative families out of eleven early-onset AD families disclosed the highest LOD score of 3.45 (theta = 0.00) at D14S77, while the locus of beta/A4 amyloid protein precursor gene was formally excluded within 10 cM from D21S210, given the evidence of recombinations in five families. Transmission disequilibrium study between the patients and controls without dementia indicated significant differences at D14S43 (p = 0.0001) and D14S71 (p = 0.02). Association study between genotypes linked or related to onset of AD and those of control also revealed a significant difference at D14S43 (p < 0.05), suggesting the existence of linkage disequilibrium. Moreover, the haplotypes at D14S43 linked with the onset of AD indicated a significant relationship with the mean age at onset. These results support that the major locus of early-onset familial AD is located on 14q24.3, and its close linkage to D14S43 and the existence of allelic heterogeneity were suggested.

Nucleotide sequence of the cDNA encoding the proenzyme of phenol oxidase A1 of Drosophila melanogaster

Clones encoding pro-phenol oxidase [pro-PO; zymogen of phenol oxidase (monophenol, L-dopa:oxygen oxidoreductase, EC 1.14.18.1)] A1 were isolated from a lambda gt10 library that originated from Drosophila melanogaster strain Oregon-R male adults. The 2294 bp of the cDNA included a 13-bp 5'-noncoding region, a 2070-bp encoding open reading frame of 690 amino acids, and a 211-bp 3'-noncoding region. A hydrophobic NH2-terminal sequence for a signal peptide is absent in the protein. Furthermore, there are six potential N-glycosylation sites in the sequence, but no amino sugar was detected in the purified protein by amino acid analysis, indicating the lack of an N-linked sugar chain. The potential copper-binding sites, amino acids 200-248 and 359-414, are highly homologous to the corresponding sites of hemocyanin of the tarantula Eurypelma californicum, the horseshoe crab Limulus polyphemus, and the spiny lobster Panulirus interruptus. On the basis of the phylogenetic tree constructed by the neighbor-joining method, vertebrate tyrosinases and molluscan hemocyanins constitute one family, whereas pro-POs and arthropod hemocyanins group with another family. It seems, therefore, likely that pro-PO originates from a common ancestor with arthropod hemocyanins, independently to the vertebrate and microbial tyrosinases.

Prevention of recurrent bleeding from gastric ulcer with a nonbleeding visible vessel by endoscopic injection of absolute ethanol: a prospective, controlled trial

We performed a prospective, randomized trial to assess the efficacy of endoscopic injection therapy with absolute ethanol in preventing recurrent bleeding in patients with nonbleeding visible vessels in gastric ulcers. During the period of 1990 to 1993, 62 patients who bled were found to have gastric ulcers with nonbleeding visible vessels; all of them were enrolled for this trial. The 62 patients were randomly divided into two groups, which were comparable at entry. In group I (33 patients), we performed endoscopic injection therapy with absolute ethanol. In group II (29 patients), we sprayed the ulcers with 0.1% epinephrine and thrombin. Endoscopic injection therapy with ethanol was performed at the second endoscopy in the patients in both groups who had recurrent bleeding. Among the 33 patients in group I, 4 patients (12.1%) rebled after the initial ethanol injection therapy, whereas 10 of 29 patients (34.5%) rebled in the control group (p < .05). No patients in group I required surgical intervention, and ultimate hemostasis was achieved in all 33 group I patients (100%), indicating that endoscopic ethanol injection therapy achieves ultimate hemostasis and prevents recurrent bleeding in patients with gastric ulcers and nonbleeding visible vessels.

Pericyte-endothelial gap junctions in developing rat cerebral capillaries: a fine structural study

BACKGROUND

Fine structural study revealed the intercellular coupling between the pericyte and the endothelial cells via the gap junctions, in the capillaries of the basal forebrain of rat embryos.

RESULTS

Gap junctions were constructed by the adluminal plasmalemma of pericyte and the abluminal plasmalemma of endothelial cells.

CONCLUSIONS

Gap junctions are membranous channels that directly join the cytoplasms of the pericyte and endothelial cell and imply some substantial role for the pericyte on the endothelial proliferation. It is postulated that the function of the pericyte in the prenatal mammals are assigned to the regulation of the development of cerebral microcirculation.

[Prognostic predictors in colorectal cancer]

The prognostic significance of clinicopathologic factors in colorectal cancer was evaluated in a multivariate analysis. The most important independent factor affecting survival was stage (depth of penetration through the bowel wall and the presence of positive lymph nodes). All other clinicopathologic factors were of less importance than stage in determining prognosis. Although the prognostic relevance of biologic and molecular variables has been investigated extensively, the importance of these factors as prognostic predictors remains uncertain and further studies are needed.

[Trial of combined cytosine arabinoside with granulocyte colony-stimulating factor therapy or refractory acute myeloid leukemia]

Thirteen cases, including 10 relapse cases, of refractory acute myeloid leukemia (AML) (aged 17-70, median 46) by cytosine arabinoside (Ara-C) combined with granulocyte colony-stimulating factor (G-CSF) simultaneously to enhance the sensitivity to Ara-C. Low dose Ara-C (10-40 mg/day) combined with G-CSF was administered in most of them. Complete (CR) and partial remission (PR) were achieved in 5 and 4 patients, respectively, and response (CR + PR) rate was 69.2%. We obtained 5 CRs and 3 PRs in 10 patients with relapsed AML. However, CR and PR duration was short in all cases. None of the 3 patients with MO, AML transformed from myelodysplastic syndrome (MDS), and de novo AML with trilineage myelodysplasia (TMDS) had any response. There was no leukemic colony formation in the culture medium containing G-CSF in the nonresponding patients. The combination therapy caused severe myelosuppression, and most patients experienced prolonged neutropenia, and suffered from infections. In some patients enhanced chemosensitivity of leukemic cells induced by G-CSF was indicated but, the effect of this approach must be determined by large scale controlled studies.