Homologs of genes and anonymous loci on human chromosome 13 map to mouse chromosomes 8 and 14

To enhance the comparative map for human Chromosome (Chr) 13, we identified clones for human genes and anonymous loci that cross-hybridized with their mouse homologs and then used linkage crosses for mapping. Of the clones for four genes and twelve anonymous loci tested, cross-hybridization was found for six, COL4A1, COL4A2, D13S26, D13S35, F10, and PCCA. Strong evidence for homology was found for COL4A1, COL4A2, D13S26, D13S35, and F10, but only circumstantial homology evidence was obtained for PCCA. To genetically map these mouse homologs (Cf10, Col4a1, Col4a2, D14H13S26, D8H13S35, and Pcca-rs), we used interspecific and intersubspecific mapping panels. D14H13S26 and Pcca-rs were located on the distal portion of mouse Chr 14 extending by approximately 30 cM the conserved linkage between human Chr 13 and mouse Chr 14, assuming that Pcca-rs is the mouse homolog of PCCA. By contrast, Cf10, Col4a1, Col4a2, and D8H13S35 mapped near the centromere of mouse Chr 8, defining a new conserved linkage. Finally, we identified either a closely linked sequence related to Col4a2, or a recombination hot-spot between Col4a1 and Col4a2 that has been conserved in humans and mice.

Deoxyribonuclease II (DNase II) activity in mouse tissues and body fluids

The distribution of deoxyribonuclease II (DNase II) in tissues and body fluids was examined in 12-week-old C3H/He mice. Activity was observed in most tissues and body fluids except erythrocytes and serum, but their levels were quite different among tissues. Activity was high in the spleen, salivary gland, and preputial gland, moderate in the liver, kidney, thymus, lung, heart, pancreas, seminal vesicle, coagulating gland and prostate and low in the brain, testis and muscles. Sex difference, males having a significantly higher DNase II activity level than females, was observed in salivary gland, kidney and urine.

Purification and properties of extracellular carboxyl proteinase secreted by Candida pulcherrima

An extracellular proteinase secreted by Candida pulcherrima KSY 188-5 was purified about 60-fold to electrophoretical homogeneity from its culture supernatant, by ammonium sulfate fractionation, anion-exchange chromatography, and gel filtration. The proteinase had a molecular weight of approximately 36,500 and an isoelectric point of pH 4.7. The enzyme had an optimum pH of around 2.5-3.5 for activity and 3.0-5.0 for stability. The optimum temperature was around 45 degrees C at pH 3.0. The enzyme showed a broad substrate specificity for a variety of proteins to hydrolyze casein, BSA, hemoglobin keratin, and collagen. Among several proteinase inhibitors, pepstatin A completely abolished the enzyme activity; indicating that the extracellular proteinase from C. pulcherrima KSY 188-5 was classified in the group of carboxyl proteinases.

Suppressive effect of molybdenum on hepatotoxicity of N-nitrosodiethylamine in rats

In order to elucidate the mechanism by which molybdenum prevents the carcinogenesis of N-nitroso compounds, the effects of Na2MoO4-pretreatment on N-nitrosodiethylamine (NDEA)-induced DNA strand breaks, fluctuation in cation contents and lipid peroxidation levels in rat liver were examined. Male Wistar rats weighing 170-190 g were pretreated with Na2MoO4 (1.24 mmol/kg body weight, i.p., once a day) for 3 d and on day 4, they were exposed to NDEA (50 mg/kg body weight, once, i.p.). Three days after exposure to NDEA, the nitroso compound caused DNA strand breaks and disrupted potassium (K) and calcium (Ca) metabolism in the liver but did not affect lipid peroxidation levels. Na2MoO4-pretreatment prevented both NDEA-induced DNA damage and disruption of the metabolism of those cations but rather enhanced lipid peroxidation. These results suggest that Mo prevented NDEA-induced DNA damage by preventing disruption of intracellular Ca metabolism while stimulating the metabolism of the nitroso compound via a nontoxic pathway.

Chemotherapy administered using two-route infusion of cisplatin and sodium thiosulfate and intravenous infusion of vinblastine and peplomycin in patients with oral cancer

The therapeutic effects of neo-adjuvant chemotherapy administered by two-route infusion of cisplatin and its antidote, sodium thiosulfate, and intravenous infusion of vinblastine and peplomycin were studied in 22 patients with previously untreated squamous cell carcinoma of the oral cavity or maxillary sinus. The overall response rate to chemotherapy was 90.9%, with a complete response in 12 patients (54.5%), a partial response in 8 patients (36.4%), and no change in 2 patients (9.1%). Histologic assessment showed a grade V response in 7 patients (31.8%), grade IV in 3 patients (13.6%), grade III in 5 patients (22.7%), grade II in 4 patients (18.2%), and grade I in 3 patients (13.6%). The cumulative 5-year survival rate, including 3 patients who died of another disease, was 72.2%. Leukocytopenia, an important side effect apparently induced by vinblastine, was seen, but no life-threatening complications occurred. Renal toxicity by cisplatin was minimal because of the use of sodium thiosulfate and fosfomycin. These data indicate that this mode of chemotherapy may be more effective for treating head and neck cancer than ordinary chemotherapy, from clinical and histologic standpoints. The high complete-response rate is especially noteworthy. No serious side effects or reductions in treatment period occurred. The results are preliminary and additional studies using a larger patient population are needed.

Surgical experience with massive lobar haemorrhage caused by cerebral amyloid angiopathy

Nineteen patients with massive lobar haemorrhage without angiographic lesions received direct or stereotactic surgery, and biopsy specimens were examined histologically. Ten patients (53%) were found to have vessels positive for Congo-red staining, and demonstrating amyloid angiopathy. In the patients with amyloid angiopathy, CT scan and surgical findings were investigated. Subarachnoid haemorrhage (9/10), irregularly shaped haematoma (9/10) and fluid-blood density level in the haematoma cavity (7/10) were frequently found on CT scan. The characteristic surgical findings in patients treated by direct surgery were subarachnoid haemorrhage adjacent to intracerebral haematoma (8/8) and the existence of a tangle of vessels in the haematoma cavity (4/8). Evacuation of haematomas was relatively easy, and difficulty of haemostasis was not encountered during surgery.

Potent thyrotropic activity of human chorionic gonadotropin variants in terms of 125I incorporation and de novo synthesized thyroid hormone release in human thyroid follicles

Using a highly sensitive bioassay for TSH, in which human thyroid follicles incorporate 125I and release de novo synthesized thyroid hormone into the culture medium, the thyrotropic activities of various hCG preparations were studied. Under the culture conditions employed, bovine TSH (bTSH) was approximately 6- to 9-fold more active than human TSH (hTSH). Highly purified hCG prepared from urine of normal pregnant women (CR 127) had only a trivial thyrotropic activity equipotent to 0.00022 microU bTSH/U hCG or 0.0013 microU hTSH/U hCG (19.7 microU hTSH/mg hCG). Hybrid hCG (AB1ER) also elicited low thyrotropic activity (14.0 microU hTSH/mg), whereas crude hCG had moderate thyrotropic activity (0.041 hTSH microU/U hCG or 127 microU/mg protein). Deglycosylated hCG, a very weak LH/hCG receptor agonist, was the most potent agonist in thyroid follicles (588 microU hTSH/mg protein). hCGs purified from urine of patients with trophoblastic tumors had greater TSH-like activity (37-84 microU hTSH/mg protein) than purified hCG. Asialo-hCG purified from a patient with choriocarcinoma had very potent TSH-like activity (468 microU hTSH/mg). Submaximal doses of bTSH and hCG variants produced additive stimulation of thyroid function. Furthermore, the thyrotropic effect of hCG was inhibited by anti-TSH receptor antibody obtained from patients with myxedema. These in vitro findings suggest that although hCG is reported to exert potent cAMP-stimulating activity on rat thyroid-like cells (FRTL-5) and Chinese hamster ovary cells transfected with hTSH receptor complementary DNA (0.092-0.72 microU hTSH/U hCG), the thyrotropic activity induced by authentic hCG in human thyroid follicles is too weak to cause hyperthyroidism in normal pregnancy. However, hCG produced by some trophoblastic tumors, particularly asialo-hCG, has potent thyrotropic activity sufficient to cause clinically overt hyperthyroidism when produced excessively.

Fibrinolytic therapy for acute embolic stroke: intravenous, intracarotid, and intra-arterial local approaches

To clarify the efficacy and limitations of the intra-arterial local infusion of a high-dose fibrinolytic agent for acute embolic stroke, we analyzed the results of 44 patients and compared them with those of 51 patients treated with intracarotid (18 patients) or intravenous (33 patients) infusion therapy. Ten megaunits of recombinant tissue plasminogen activator or 24 x 10(4) IU of urokinase were administered through a microcatheter placed into or proximal to an embolus for 20 minutes. When arterial recanalization was not achieved, a second or third infusion was performed. The rates of complete and partial recanalization just after the local infusion were 52 and 32%, respectively. They were high in middle cerebral and basilar artery occlusion and low in internal carotid artery occlusion (69, 78, and 20%, respectively). In our use, there was no difference between tissue plasminogen activator and urokinase in restoring blood flow. The mean time interval from onset to recanalization in patients with middle cerebral artery occlusion showing marked improvement was 4.8 hours, and it was 5.8 hours with basilar artery occlusion. The size of infarction was reduced, and the outcome was good in patients with complete recanalization achieved. The incidence of hemorrhagic infarction within 24 hours was 22%, and only one patient clinically deteriorated. In the intracarotid infusion group (20 x 10(4) IU of urokinase for 30 min), only two patients showed partial recanalization without clinical improvement. The incidence of hemorrhagic infarction was 28%. The outcome in this group and the intravenous infusion group (18 x 10(4) IU of urokinase a day for 1 wk) was poor compared with that in the local infusion group showing complete recanalization. This preliminary study appears to suggest that intra-arterial local fibrinolytic therapy could be a new strategy for acute embolic stroke.

In vitro insulinotropic action of a new non-sulfonylurea hypoglycemic agent, calcium (2s)-2-benzyl-3-(cis-hexahydro-2-isoindolinyl-carbonyl) propionate dihydrate (KAD-1229), in rat pancreatic B-cells

We examined the in vitro insulinotropic action of a novel non-sulfonylurea compound, calcium (2S)-2-benzyl-3-(cis-hexahydro-2-isoindolinyl-carbonyl) propionate dihydrate (KAD-1229), which is a succinate derivative, using rat pancreatic islets and perfused pancreas. The sodium salt of KAD-1229 free acid (KAD-1229-Na) stimulated insulin secretion from isolated rat islets and perfused rat pancreas in a concentration-dependent manner at 0.1 to 10 microM. It produced a predominant first phase and a less prominent second phase response in the presence of 5.55 mM glucose. An ATP-sensitive K+ (K+ATP) channel activator, diazoxide, eliminated the insulinotropic effect of KAD-1229-Na. Glucose primed the B-cell in the perfused pancreas, but KAD-1229-Na did not. When the insulinotropic effects of 16.7 mM glucose on isolated rat islets were inhibited submaximally by 1 microM norepinephrine, the addition of 1 microM KAD-1229-Na reversed this inhibition. All of these insulinotropic effects of KAD-1229-Na were qualitatively indistinguishable from those of sulfonylurea compounds. We conclude that KAD-1229-Na acts on K+ATP channels of pancreatic B-cells despite its non-sulfonylurea structure.

Protective effect of metallothionein on intracellular pH changes induced by cadmium

In order to gain further insight into the protective mechanism of metallothionein (MT) against Cd cytotoxicity, the effects of in vivo Zn- or Cd-pretreatment on the cytotoxicity and alteration in cellular pH induced by Cd were examined in isolated rat hepatocytes and testicular Leydig cells. These pretreatments both induced the synthesis of MT in the hepatocytes, but not in the Leydig cells. Both pretreatments alleviated Cd cytotoxicity in the hepatocytes. Cd- or Zn-pretreatment was also effective in preventing Cd-induced cellular acidification in hepatocytes but neither pretreatment was effective in Leydig cells. In fact, Cd-pretreatment stimulated acidification in Leydig cells. Exposure in vitro of hepatocytes from untreated rats to probenecid, an inhibitor of HCO3-/Cl- exchange, also ameliorated Cd-induced cellular acidification, suggesting an involvement of HCO3-/Cl- exchange in the preventive action of MT against Cd-induced acidification. These results suggest that Cd cytotoxicity in various cells may be initiated by alterations in plasma membrane ion transport systems such as the HCO3-/Cl- exchange and consequential cellular acidification. Induction of MT, therefore, may prevent Cd cytotoxicity, at least in rat hepatocytes, by preventing an alteration in ion transport at the plasma membrane as well as by intracytoplasmic binding of the metal molecules.

Normalization of impaired glucose tolerance by the short-acting hypoglycemic agent calcium (2S)-2-benzyl-3-(cis-hexahydro-2-isoindolinylcarbonyl)propionate dihydrate (KAD-1229) in non-insulin-dependent diabetes mellitus rats

We have investigated the hypoglycemic effects of the newly synthesized short-acting nonsulphonylurea hypoglycemic agent calcium (2S)-2-benzyl-3-(cis-hexahydro-2-isoindolinylcarbonyl)-propionate dihydrate (KAD-1229) in non-insulin-dependent diabetes mellitus (NIDDM) rats. NIDDM rats that were given a neonatal injection of 60 mg/kg streptozotocin showed a dose-dependent but attenuated response to oral administration of KAD-1229 and gliclazide, and their impaired glucose tolerance was improved but not normalized. We next produced, using a neonatal injection of 30 mg/kg streptozotocin, a mild type of NIDDM rat with less impaired glucose tolerance. These rats responded well to these insulinotropic hypoglycemic agents. Their impaired glucose and meal tolerance were completely normalized by oral administration of 3 mg/kg KAD-1229. The efficacy of KAD-1229 in this NIDDM rat model 1-3 h after oral glucose administration was comparable with similar doses of gliclazide, despite its shorter hypoglycemic action (compared with gliclazide), in fasting normal rats. In meal tolerance tests (20 kcal/kg; 1 cal = 4.2 J), KAD-1229 reduced abnormally enhanced plasma glucose levels 1-3 h after administration. This effect disappeared by 5 h. In contrast, gliclazide showed sustained hypoglycemic effects until 5 h after oral administration, with a lower postprandial (0.5-1 h) effect. These data indicated that the rapid- and short-acting efficacy of KAD-1229 would be beneficial and sufficient to control postprandial plasma glucose in NIDDM rats.

Effects of probenecid and cimetidine on the renal excretion of 3'-azido-3'-deoxythymidine in rats

The mechanisms underlying the inhibitory effects exerted by probenecid and cimetidine on the renal excretion of 3'-azido-3'-deoxythymidine (AZT) were investigated in rats in vivo. On i.v. administration, the findings indicated that both probenecid and cimetidine increased the plasma concentration of AZT and inhibited its renal excretion. To clarify the mechanisms underlying the interaction of these drugs with AZT and to elucidate the process of renal secretion of AZT, further investigation was performed, in which [3H]AZT (0.5 microM) was injected rapidly into the right renal artery, and its outflow profile from the right ureter was compared with that from the left ureter. In control experiments, 56.6% of the administered AZT was secreted from the right kidney, and it was calculated that the transcellular transit time of AZT in this process was 0.30 min. In the presence of 10 mM probenecid and of 10 mM cimetidine, the secretion of AZT was reduced to 15.3 and 32.3%, respectively, the inhibition induced by probenecid being more effective than that induced by cimetidine. However, the transcellular transit time of AZT increased to 0.53 and 1.21 min in the probenecid and cimetidine studies, respectively. Thus, cimetidine was more potent than probenecid in its effects on the transit time. These findings indicate that probenecid and cimetidine affect different steps in the renal secretion of AZT. It was therefore concluded that, on the renal plasma membrane, AZT is transported by anion transport systems, whereas on the brush border membrane, AZT is secreted by cation transport systems.

Changes in pulmonary vascular tone during exercise. Effects of nitric oxide (NO) synthase inhibition, L-arginine infusion, and NO inhalation

Nitric oxide (NO) is a potent endogenous vasodilator. Its role in the normal and stressed pulmonary circulation is unclear. To better understand the importance of endogenous NO in normal physiological responses, we studied the effects of altered NO availability on the change in pulmonary vascular tone that accompanies exercise. In paired studies we measured blood flow and pressures in the pulmonary circulation at rest and during treadmill exercise at a speed of 4 mph with and without (a) N omega-nitro-L-arginine, 20 mg/kg intravenously, a selective inhibitor of NO synthase; (b) L-arginine, 200 mg/kg intravenously, substrate for NO synthase; (c) combination of the inhibitor and substrate; and (d) inhalation of NO > 30 ppm, to determine if endogenous release of NO elicits maximal vasodilation. In addition, we sought to determine the site of NO effect in the pulmonary circulation by preconstriction with either U-44619 or hypoxia (fraction of inspired O2 = 0.12) using a distal wedged pulmonary catheter technique. NO synthase inhibition raised pulmonary vascular tone equally at rest and exercise. L-Arginine reversed the effects of NO synthase inhibition but had no independent effect. NO inhalation did not reduce pulmonary vascular tone at rest or enhance the usual reduction in pulmonary vascular resistance with exercise. The effect of NO synthase inhibition was in pulmonary vessels upstream from small veins, suggesting that endogenous NO dilates primarily small arteries and veins at rest. We conclude that, in sheep, endogenous NO has a basal vasodilator function that persists during, but is not enhanced by, exercise.

Pharmacological evidence of distinct alpha 1-adrenoceptor subtypes mediating the contraction of human prostatic urethra and peripheral artery

1. The alpha 1-adrenoceptor subtypes mediating contractions of the smooth muscle in human prostatic urethra and branches of internal iliac artery were characterized in isometric contraction experiments. 2. Phenylephrine produced concentration-dependent contractions in both the urethra and artery. These responses were competitively inhibited by prazosin, WB4101 and 5-methyl-urapidil, and the slopes of Schild plots for all these antagonists were close to unity. 3. The pA2 values for prazosin were not significantly different between the urethra (9.42 +/- 0.11; mean +/- s.d.) and artery (9.50 +/- 0.27), while the pA2 values for WB4101 and 5-methyl-urapidil in the human prostatic urethra (8.94 +/- 0.19 and 8.42 +/- 0.14, respectively) were significantly greater than in the branches of human internal iliac artery (7.94 +/- 0.21 and 7.43 +/- 0.22, respectively; P < 0.01). 4. Pretreatment with chlorethylclonidine (CEC) at concentrations ranging from 0.1 microM to 100 microM attenuated the maximum contraction to phenylephrine in a concentration-dependent manner in both the urethra and artery. However, the urethra was significantly less affected by CEC than the artery. The pD'2 values (negative logarithm of the molar concentration of antagonist which reduced the maximum contraction to one half) in the urethra and artery were 4.35 +/- 0.27 and 5.20 +/- 0.37, respectively (P < 0.01). 5. The present results indicate that there are distinct populations of alpha 1-adrenoceptor subtypes in the human prostatic urethra and branches of the internal iliac artery. The alpha 1-adrenoceptors responsible for the contraction of the human internal iliac artery branches are predominantly alpha 1 B-subtype, whereas those in the human prostatic urethra are considered to be not alpha 1 B, but alpha 1 c or possibly alpha 1 A or alpha 1A/D-subtype.

Analysis of IL-2 gene regulation in c-fos transgenic mice. Evidence for an enhancement of IL-2 expression in splenic T cells stimulated via TCR/CD3 complex

Effects of the deregulated c-fos gene product on IL-2 expression were studied in splenic T cells from c-fos transgenic (H2-c-fos) mice. IL-2 gene expression and IL-2 production by H2-c-fos T cells stimulated with immobilized anti-CD3 Abs were enhanced and prolonged as compared with those by control T cells. Activator protein-1 activity in nuclear extract from the H2-c-fos T cells was also higher than that from the control cells. There was no significant difference in the activity of other transcription factors including IL-2 kappa B, NFAT, and Oct-1, between the H2-c-fos and the control T cells. However, activity of a negative regulatory element binding factor (NRE-A) in the H2-c-fos T cells was much lower than that in the control cells. These results suggest that c-Fos/activator protein-1 is a major regulatory factor for IL-2 gene expression in splenic T cells activated through the TCR/CD3 complex.

Analysis of IL-2 gene regulation in c-fos transgenic mice. Evidence for an enhancement of IL-2 expression in splenic T cells stimulated via TCR/CD3 complex

Effects of the deregulated c-fos gene product on IL-2 expression were studied in splenic T cells from c-fos transgenic (H2-c-fos) mice. IL-2 gene expression and IL-2 production by H2-c-fos T cells stimulated with immobilized anti-CD3 Abs were enhanced and prolonged as compared with those by control T cells. Activator protein-1 activity in nuclear extract from the H2-c-fos T cells was also higher than that from the control cells. There was no significant difference in the activity of other transcription factors including IL-2 kappa B, NFAT, and Oct-1, between the H2-c-fos and the control T cells. However, activity of a negative regulatory element binding factor (NRE-A) in the H2-c-fos T cells was much lower than that in the control cells. These results suggest that c-Fos/activator protein-1 is a major regulatory factor for IL-2 gene expression in splenic T cells activated through the TCR/CD3 complex.

Transgenic mouse model of hemifacial microsomia: cloning and characterization of insertional mutation region on chromosome 10

The 643 transgenic mouse line carries an autosomal dominant insertional mutation that results in hemifacial microsomia (HFM), including microtia and/or abnormal biting. In this paper, we characterize the transgene integration site in transgenic mice and preintegration site of wildtype mice. The locus, designated Hfm (hemifacial microsomia-associated locus), was mapped to chromosome 10, B1-3, by chromosome in situ hybridization. We cloned the transgene insertion site from the transgenic DNA library. By using the 5' and 3' flanking sequences, the preintegration region was isolated. The analysis of these regions showed that a deletion of at least 23 kb DNA occurred in association with the transgene integration. Evolutionarily conserved regions were detected within and beside the deleted region. The result of mating between hemizygotes suggests that the phenotype of the homozygote is lethality in the prenatal period. These results suggest that the Hfm locus is necessary for prenatal development and that this strain is a useful animal model for investigating the genetic predisposition to HFM in humans.

Potential mechanism of cadmium-induced cytotoxicity in rat hepatocytes: inhibitory action of cadmium on mitochondrial respiratory activity

The present study was designed to clarify the mechanism of cadmium (Cd)-induced toxicity in rat hepatocytes. Cd and Mg-ATP induced cellular acidification at concentrations lower than 25 microM. In Mg-ATP-treated cells, maximal acidification occurred within 2.5 min, with a subsequent return to control levels. In Cd-treated cells, maximal acidification (pH 6.76) occurred 10 min after exposure to the metal, then the cytoplasmic pH began to rise but did not return to normal. Cd eliminated the membrane potential of isolated mitochondria in media at both pH 6.5 and 7.4. This effect of Cd on membrane potential was approximately equivalent in both media when the metal concentration was 5 microM, but was more intense in the medium at pH 6.5 than in the medium at pH 7.4 at the metal concentration > 5 microM. Acidic medium alone had no effect on membrane potential. Mitochondrial uptake of Cd increased in a dose-dependent manner in media at both pH 7.4 and 6.5. The uptake of 5 microM Cd was significantly increased by acidic medium, however at Cd concentrations > 5 microM, there were no pH-dependent differences in Cd uptake. The incubation of hepatocytes in the medium at pH 6.0 and 6.5 resulted in 5 and 7.5% inhibition of mitochondrial respiration in intact cells, respectively. The presence of 10 microM Cd in the medium at pH 6.0 enhanced this inhibition. Mitochondrial respiration was inhibited to 60% of the control mitochondria at pH 7.4 when exposed to the medium at pH 6.5 without Cd and this inhibition was extended to 70% by the presence of 5 microM Cd. Cd in the medium at pH 7.4 had no deleterious effect on mitochondrial respiration at all concentrations examined. The results indicate that the respiratory activity of mitochondria is sensitive to the low pH rather than to Cd although the metal strongly inhibits the activity when in the medium at low pH. Therefore, it appears Cd-induced acidification plays an important role in the initiation of deteriorative processes in mitochondria.

Effects of ONO-5046, a specific neutrophil elastase inhibitor, on endotoxin-induced lung injury in sheep

The purpose of the present study was to assess the role of polymorphonuclear leukocyte (neutrophil) elastase in endotoxin-induced acute lung injury in sheep with lung lymph fistula. We studied the effects of ONO-5046, a specific inhibitor of neutrophil elastase, on the lung dysfunction induced by the intravenous infusion of 1 microgram/kg of Escherichia coli endotoxin. Endotoxin alone produced a biphasic response as previously reported. Early (0.5-1 h) after endotoxin, pulmonary arterial pressure increased from 19.5 +/- 0.9 cmH2O at baseline to a peak of 46.8 +/- 2.4 cmH2O (P < 0.05). Pulmonary vascular resistance increased from 3.03 +/- 0.17 cmH2O.l-1.min at baseline to a peak of 9.77 +/- 0.70 cmH2O.l-1.min (P < 0.05). Circulating neutrophils decreased from 7,355 +/- 434/mm3 at baseline to a nadir of 1,762 +/- 32/mm3 (P < 0.05). Thromboxane B2 and 6-ketoprostaglandin F1 alpha concentrations in plasma and lung lymph were significantly increased. Late (3-5 h) after endotoxin, pulmonary arterial pressure and pulmonary vascular resistance returned to baseline levels, but lung lymph flow remained increased from 4.2 +/- 0.3 ml/0.5 h at baseline to 7.3 +/- 0.7 ml/0.5 h (P < 0.05), with a slight increase in lung lymph-to-plasma protein concentration ratio, suggesting increased pulmonary vascular permeability. The histopathological features of the lungs during the early period in sheep treated with endotoxin alone revealed a large increase in neutrophils per 100 alveoli and changes of pulmonary edema such as thickening of the interstitium of the lung and alveolar flooding.(ABSTRACT TRUNCATED AT 250 WORDS)

The structure-activity relationship between phenylene-polymethylene bis-ammonium derivatives and their neuromuscular blocking action on mouse phrenic nerve-diaphragm muscle

The structure-activity relationship of phenylene-polymethylene bis-ammonium (PMBA) derivatives, C6H4[X(CH2)nR]2, on isolated mouse phrenic nerve-diaphragm muscle was investigated to obtain more potent and stable compounds for use as pharmacological tools to clarify the mechanism of succinylcholine (SuCh)-induced neuromuscular blockade. The neuromuscular blocking effect of all the PMBA derivatives was not reversed by neostigmine, a cholinesterase inhibitor. The potency of the neuromuscular blockade was in the order p- > o- > m- with respect to the side-chain substituents. A PMBA composed of X = CH2, n = 5 and R = N+Et3 was 5.9- and 23-fold more potent than SuCh and decamethonium, respectively. The derivatives of R = N+Et3 were observed to be more potent than those of R = N+Me3, N-Me-piperidinio and pyridinio derivatives. Replacement of X = CH2 with O, CHOH and CHOAc decreased the neuromuscular activity while replacement with S, SO and SO2 increased it. Introduction of NO2 into the phenylene ring increased the activity, while the introduction of an alcohol, aldehyde and ketone group decreased it. Removal of a carbonyl or ether group from SuCh decreased its activity, whereas the introduction of these into PMBA failed to increase it. We managed to synthesize unhydrolyzable neuromuscular blocking agents which are more potent than SuCh.

Radiographic and hemodynamic changes during recovery from high-altitude pulmonary edema

It has been suggested that accentuated pulmonary hypertension is a contributing factor in the development of high-altitude pulmonary edema (HAPE). The purpose of this study was to evaluate the chest radiographic features associated with pulmonary hemodynamic changes in HAPE. We studied 16 patients with HAPE using posteroanterior chest roentgenograms taken in the standing position both on admission and following recovery. The cardiothoracic ratio (CTR) as well as the area and volume of the main pulmonary artery were measured. During HAPE, we found slight enlargement of the CTR, especially the right ventricle, and prominence of the main pulmonary artery. These abnormalities significantly improved in the recovery state. The changes in area and volume of the main pulmonary artery were closely correlated with a decrease in CTR during recovery from HAPE, and correlated with the pulmonary hemodynamic changes observed by right heart catheterization (n = 4). Radiographic changes reflect the alterations in pulmonary hemodynamics in patients with HAPE.

Immediate arousal response and adaptation to low-dose x-rays in mouse and its disappearance by olfactory bulbectomy and nitric oxide inhibitor

The effects of low-dose x-rays (4 cGy) on mouse brain were examined. EEG recording were made on sleeping mice before, during and after exposure. Exposure to x-rays induced the immediate change in EEG pattern from a low-frequency and high-amplitude (sleep) to a high-frequency and low-amplitude (arousal). Repeated exposure caused a decrease in number of mice showing arousal, suggesting that adaptation to x-ray stimuli was acquired by mice. In the olfactory bulbectomized mice, no arousal response could be noticed. When mice were injected with N-nitro-L-arginine or N-monomethyl-L-arginine, nitric oxide inhibitor, no decrease in the arousal mouse number occurred, even after the repeated exposure. These results indicate clearly that olfactory bulbs play an important role in immediate detection of x-rays and a possible involvement of NO in the adaptation to x-ray stimuli by mouse.

Kinetic analysis of neuromuscular blockade. I. Relationship between twitch depression and stimulation frequency after d-tubocurarine administration

The degree of twitch depression induced by nondepolarizing neuromuscular blocking drugs is known to be dependent on the stimulation frequency employed. Train-of-four (TOF) stimulations with different frequencies (0.67, 1.33 and 2.0 Hz) were delivered to a sciatic nerve of a rat and series of four twitch heights of a tibialis anterior muscle were measured after d-tubocurarine (d-TC) administration. With a decrease of stimulus interval, twitch heights were intensely depressed. We hypothesized that the oservations are due to the changes of released amount of neuromuscular transmitter, acetylcholine, dependent on stimulus interval, and a pharmacokinetic/pharmacodynamic model based on the hypothesis was proposed. The model allowed simultaneous fitting of the twitch height depression after d-TC administration. It also could give a rationale to the fact that TOF stimulation at 2.0 Hz is a more sensitive monitoring method of neuromuscular function than single twitch stimulation (0.1-0.2 Hz).

Kinetic analysis of neuromuscular blockade. II. Train-of-four fade induced by d-tubocurarine and alpha-bungarotoxin

The degree of train-of-four (TOF) fade, i.e., the reduction of the fourth to the first twitch height in a train, induced by d-tubocurarine (d-TC) and alpha-bungarotoxin (alpha-BX) was investigated. The fade induced by d-TC was pronounced in comparison with that by alpha-BX, and the difference was analyzed using a kinetic model. Based on the assumptions: (1) Acetylcholine (ACh) binds to the nicotinic receptor and evokes twitch response. (2) The amount of released ACh is dependent on stimulus interval. (3) d-TC interacts competitively with the receptor. (4) alpha-BX interacts irreversibly with the receptor. It was suggested that the fade by d-TC and alpha-BX can be explained by the difference of the receptor occupancy by ACh which was caused by different interaction mechanisms of the two muscle relaxants with receptors.

The murine homologues of the Huntington disease gene (Hdh) and the alpha-adducin gene (Add1) map to mouse chromosome 5 within a region of conserved synteny with human chromosome 4p16.3

Huntington disease (HD) is a severe autosomal dominant neurodegenerative disorder associated with a novel gene (IT15). Recently, we reported the cloning of Hdh, the murine homologue of IT15. Here, using an interspecific backcross, we have mapped both Hdh and the mouse homologue of human alpha-adducin (Add1), a membrane-associated cytoskeletal protein gene. Both of these genes map in the same position on mouse chromosome 5 in a region associated with ancestral chromosomal rearrangements and show no recombination with D5H4S43, D5H4S115, and D5H4S62, the murine homologues of D4S43, D4S115, and D4S62, respectively. Further mapping studies of humans, mice, and other mammalian species should reveal the nature of the rearrangements affecting this chromosomal segment during mammalian evolution.