Development of an outside flow membrane oxygenator using a silicone hollow fiber

A new membrane oxygenator was devised and assessed for performance in animal experiments. A silicone fiber membrane oxygenator, heat exchanger, and arterial blood reservoir are the components. The oxygenator is an outside flow type with minimum intrapulmonary resistance and, consequently, gas transfer is by gravity venous drainage. This device was used to conduct normothermic cardiopulmonary bypass (CPB) in 10 sheep over a period of 8 hrs (high flow group: 6 sheep, mean flow, 4.7 + 0.5 L/min; low flow group: 4 sheep, mean flow, 1 L/min). Performance was evaluated with gas transfer capacity, hematologic examination during CPB, and scanning electromicroscopic (SEM) appearance of the membrane after CPB. Blood gas was maintained with high PO2 and acceptable PCO2 levels throughout CPB. Plasma free hemoglobin was significantly low and fibrinogen was also maintained within physiologic levels. Scanning electron microscopy showed no thrombus formation on the membranes of either group. These results indicate this oxygenator to be quite adequate for gas exchange and prevention of blood cell trauma; it is also applicable to pulsatile or separating CPB because of the arterial blood reservoir.

[The intracuff pressure changes in N2O gas-barrier cuff made of a special material]

During inhalation anesthesia using N2O, the intracuff pressure has been reported to increase due to diffusion of N2O into the cuff. The excessive intracuff pressure may produce ischemia of the tracheal mucosa. In this study, the changes in the intracuff pressure of endotracheal tube with a cuff made of a material with high N2O gas-barrier properties were compared with those of the normal endotracheal tubes. Forty adult patients (16 males and 24 females) were anesthetized with oxygen 2 l.min-1, N2O 4 l.min-1 and isoflurane under controlled ventilation and they were divided into the following three groups according to the type of the endotracheal tube used: the tube with a standard cuff made by PORTEX Co. Ltd; the tube with a profile cuff (high volume cuff) made by PORTEX Co. Ltd; the tube with gas-barrier cuff made by TERUMO Co. Ltd. The changes of each intracuff pressure were recorded continuously for 180 minutes after cuff inflation. A marked increase of the pressure was observed after inhalation of N2O in standard and profile cuff groups. In gas-barrier cuff group, there was a tendency of increasing cuff pressure without a statistically significant difference. The present study suggests that the use of a cuff with a material of high N2O gas-barrier properties would be effective to prevent increased intracuff pressure by N2O diffusion, and this would be especially useful during long anesthesia and hypotensive anesthesia.

Effect of leukotrienes on sheep airway smooth muscle

The effects of leukotrienes (LT) C4, LTD4, LTE4 and LTB4 on the development of isometric tension by sheep airway smooth muscle were determined in a tissue bath. LTE4 (1.5 x 10(-7) M) had no contractile effect. LTB4 contracted only lung parenchymal strips. LTC4 (8 x 10(-8) M) and LTD4 (1.1 x 10(-7) M) caused contractions in trachea, bronchi and lung parenchyma that developed slowly and persisted. The tracheal contractions caused by LTD4 and ACh were potentiated approx. 30% by the cyclooxygenase inhibitor meclofenamate (10(-6) M). Meclofenamate had no effect on leukotriene induced contractions in bronchi or lung parenchymal strips. The bronchodilator prostaglandins PGI2 and PGE2 were released from sheep trachea at rest and after contraction by LTD4. Inhibition of their release by meclofenamate may explain the potentiation of LTD4 contractions by meclofenamate. In vitro, LTD4 and LTC4 have potent contractile effects on sheep airway smooth muscle that are not mediated by the secondary release of constrictor cyclooxygenase products. These leukotrienes may play a substantial role in the pathogenesis of allergen and endotoxin induced lung mechanics changes in sheep.

Improved oral absorption of a poorly water-soluble drug, HO-221, by wet-bead milling producing particles in submicron region

N-[[[4-(5-Bromo-2-pyrimidinyloxy)-3-chlorophenyl]amino]carbonyl]-2 -nitrobenzamide (HO-221) is being developed as an anticancer agent with a novel mode of action. HO-221 shows poor oral absorption and is only slightly soluble in water (0.055 micrograms/ml at 37 degrees C). In this study, it was shown that the reduction in particle size of HO-221 to the submicron region (0.453 microm, mean by volume) could be achieved by a wet milling in a decaglycerin monolaurate aqueous solution with small glass beads. The wet milling suspension obtained showed improved dissolution rate and oral absorption in rats. A solid dosage form could also be made from that suspension with addition of sucrose palmitate which prevented aggregation caused by the hydrophobic interaction. The solid dosage form thus obtained showed twice as much oral absorption in dogs as the preparation made by dry milling.

Administration of bromodeoxyuridine in early postnatal rats results in lung changes at maturity

The purpose of this study was to examine how lungs in early postnatal animals that are administered bromodeoxyuridine (BrdU), a thymidine analog known to be a cytogenetically toxic agent, change in adult life. BrdU was injected (1 mg/g body weight) intraperitoneally in suckling rats on day 6 after birth. Immunohistochemical studies revealed that BrdU was incorporated in alveolar cells, and infrequently in the mesothelium, endothelium, and bronchiolar epithelium. The number (per high-power field) of alveolar cells incorporating BrdU was 8.76 +/- 0.50 in the interstitium and 1.66 +/- 0.25 in the epithelium. The animals were sacrificed at 2 and 8 weeks and 12 months of age. Control animals were treated the same as the BrdU-treated animals except for the injection of BrdU. Body weight, body size (nose-tail length), and lung weight were identical between BrdU-treated animals and control animals at all experimental periods. The histopathology and physiology of these lungs were studied. At 2 weeks of age, the BrdU-treated animals appeared morphologically and functionally similar to control animals. At 8 weeks and 12 months of age, the lungs in the BrdU-treated animals showed abnormal enlargement of the airspace, few alveoli, and less complexity in pulmonary architecture with or without increased lung compliance. These findings suggest that lung injured cytogenetically in early postnatal life may develop functional and structural abnormalities in later life.

The pharmacokinetics of primaquine in calves after subcutaneous and intravenous administration

The pharmacokinetics of primaquine was studied in calves of 180-300 kg live weight. Primaquine was injected at 0.29 mg/kg (0.51 mg/kg as primaquine diphosphate) intravenously (IV) or subcutaneously (SC) and the plasma concentrations of primaquine and its metabolite carboxyprimaquine were determined by high-performance liquid chromatography. The extrapolated concentration of primaquine at zero time after IV administration was 0.50 +/- 0.48 microgram/ml (mean +/- SD) which decreased with an elimination half-life of 0.16 +/- 0.07 h. Primaquine was rapidly converted to carboxyprimaquine after either route of administration. The peak concentration of carboxyprimaquine was 0.50 +/- 0.08 microgram/ml at 1.67 +/- 0.15 h after IV administration. The corresponding value was 0.47 +/- 0.07 micrograms/ml at 5.05 +/- 1.20 h after SC administration. The elimination half-lives of carboxyprimaquine after IV and SC administration were 15.06 +/- 0.99 and 12.26 +/- 3.06 h, respectively. The areas under the concentration-time curve for carboxyprimaquine were similar following either IV or SC administration of primaquine; the values were 11.85 +/- 2.62 micrograms.h/ml after the former and 10.95 +/- 2.65 micrograms.h/ml after the latter. The mean area under the concentration-time curve for primaquine was less than 0.1 micrograms.h/ml after either route of administration.

Central cholinergic agents. IV. Synthesis and acetylcholinesterase inhibitory activities of omega-[N-ethyl-N-(phenylmethyl)amino]-1-phenyl-1-alkanones and their analogues with partial conformational restriction

Inhibitors of acetylcholinesterase (AChE) have been designed based on a working hypothesis of the enzyme's active site. These compounds were tested for their inhibitory activities on AChE and omega-[N-ethyl-N-(phenylmethyl)amino]-1-phenyl-1-alkanones (3) were found to be potent inhibitors. Various analogues of 3 were prepared to study the effect on AChE inhibition of partial restriction of conformation. Compounds with potent AChE inhibition were further evaluated in terms of central selectivity: the ratio of central action (ameliorating effect on scopolamine-induced memory impairment using a T-maze alternation task) to peripheral action.

Enhanced proliferation of fetal rat hepatocytes in primary culture induced by ritodrine

OBJECTIVE

Although ritodrine crosses the placenta, its direct effect on fetal cell proliferation has not been reported. We hypothesized that beta 2-adrenergic receptor stimulation could promote fetal liver growth.

STUDY DESIGN

Ritodrine was added to serum- and hormone-free primary cultures of fetal, neonatal, or adult rat hepatocytes. We measured both tritiated thymidine incorporation into deoxyribonucleic acid and nucleus number. The effect of ritodrine on cell cycle was also analyzed with flow cytometry.

RESULTS

Ritodrine enhanced the proliferation of fetal rat hepatocytes. Ritodrine remarkably stimulated deoxyribonucleic acid synthesis of fetal and neonatal but not adult hepatocytes. The effect was dose dependent and was antagonized by propranolol. Analysis of the nuclear deoxyribonucleic acid content derived from flow cytometry revealed that cells stimulated by ritodrine entered S phase.

CONCLUSION

These results indicate that ritodrine may promote the proliferation of fetal hepatocytes through the stimulation of beta 2-adrenergic receptors, followed by induction of deoxyribonucleic acid synthesis.

Elevation of amniotic fluid interleukin 6 (IL-6), IL-8 and granulocyte colony stimulating factor (G-CSF) in term and preterm parturition

We determined the levels of inflammatory cytokines such as interleukin 6 (IL-6) granulocyte-colony stimulating factor (G-CSF) and IL-8 in the amniotic fluids from women with premature or term delivery. Cytokines were detectable even in the absence of apparent infection (group 1), but much higher cytokine levels were found in cases of intrauterine infection, particularly in cases of premature delivery (group 2). In cases of term delivery (groups 3-5), all of the cytokine levels showed c. 3- to 4-fold increase during labor pain (group 4) and an 8- to 13-fold increase in the presence of endotoxin (group 5), in comparison with the levels in cases where neither factor was present (group 3). Regarding infection, the cytokine levels were 20- to 30-fold higher in chorioamnionitis-positive premature delivery group (group 2), than in the infection-negative group (group 1). All the cytokines were simultaneously induced in amniotic fluid by labor pain and infection, and a significant positive correlation was observed among these three cytokine levels. In-vitro culture system and immunohistochemical study indicated that the cytokines in the amniotic fluid appeared to originate from trophoblasts and decidual cells. Thus, infection and labor pain may trigger the production of inflammatory cytokines at term as well as premature delivery and the determination of these cytokine levels will be a good indication for the prediction of the presence of intrauterine infection.

Detection of early lesions of "ungual" malignant melanoma

BACKGROUND

The nail area is commonly affected by malignant melanoma. The prognosis of malignant melanoma of the nail is poor, because at the time of diagnosis most lesions are in the advanced stage. Correct diagnosis of early lesions could improve the prognosis.

METHODS

For 3 years, all patients with nail pigmentation at the dermatology clinic were screened for five specific criteria for the diagnosis of early lesions of malignant melanoma. Histologic examination was performed on 10 of 29 lesions.

RESULTS

Five of the 29 lesions were advanced malignant melanoma, easily diagnosed clinically. Two of the remaining 24 lesions fulfilled most of our clinical criteria of early malignant melanoma of the nail apparatus; that is, they appeared as melanonychia striata during adulthood, were wide in breadth measuring 9 and 11 mm, and showed variegated shades of brown. Periungual pigmented macule (Hutchinson's sign) was observed in one of the two cases. Total resection of the lesions was performed, followed by skin grafting.

CONCLUSIONS

Histologically, an increased number of atypical melanocytes, mainly arranged as solitary units, were observed only in the epithelia of the nail matrix and of the nail-bed, confirming that these lesions were "ungual" malignant melanoma in situ. Such an early lesion of malignant melanoma of the nail apparatus can be completely cured with conservative excision, and the phalanx of the affected digit can be preserved.

The 11q- syndrome with mosaic partial deletion of 11q

A female child with mosaic partial deletion of 11q is reported. At 1 month of age she was presented with cogenital glaucoma, trigonocephaly and multiple minor anomalies. She exhibited growth retardation and the typical phenotype of 11q- syndrome. G-banding analysis failed to show any abnormality, although subsequent high resolution banding revealed the abnormal karyotype 46,XX,del(11)(q23.3 q24.2)/46,XX,del(11)(q23.3 q25). This case is a second case of mosaic 11q- syndrome and her karyotype suggests that the region of 11q23.3-11q24.2 is critical in 11q-syndrome. Congenital glaucoma has never been reported as a complication of 11q- syndrome.

Downregulation of blood and bone marrow neutrophils decreases expression of acute lung injury in sheep

We have shown that infusion of zymosan-activated plasma (ZAP) in sheep causes acute lung injury and downregulates peripheral blood neutrophils in that elicited superoxide release is reduced for at least 24 h after the infusion. The present study was designed to test the following hypotheses: 1) peripheral blood neutrophils are representative of neutrophils marginated in the pulmonary circulation, 2) blood neutrophils are downregulated because neutrophils developing in bone marrow are similarly affected, and 3) downregulated neutrophils have a reduced capacity to produce tissue injury. In a series of experiments in 21 sheep, we showed that elicited superoxide release was similar in peripheral blood neutrophils and in marginated neutrophils washed out of the pulmonary vascular bed. Measurements of superoxide release from blood and bone marrow neutrophils collected 2-24 h after ZAP infusion revealed progressive downregulation with time and greater downregulation of superoxide release in bone marrow neutrophils compared with peripheral blood neutrophils. Finally, after downregulating peripheral blood neutrophils, subsequent infusion of ZAP in conscious sheep produced sequestration of neutrophils in the pulmonary circulation but failed to produce a sustained increase in lung lymph protein clearance. The results suggest that neutrophil downregulation, as measured in vitro, is expressed in vivo as reduced ability of neutrophils to produce tissue injury when challenged by an activating agent.

High-performance liquid chromatographic determination of pamaquine, primaquine and carboxy primaquine in calf plasma using electrochemical detection

A high-performance liquid chromatographic method with electrochemical detection is described for quantification of pamaquine, primaquine and carboxy primaquine in calf plasma. After the proteins had been precipitated with acetonitrile, the drugs were separated on a 5-microns C18-modified polymer gel column with an isocratic mobile phase. The detection limit was 0.01 microgram/ml in plasma for all three compounds. The applicability of the method in pharmacokinetic studies was demonstrated by determining the plasma concentrations of the three substances in calves administered a single dose of pamaquine or primaquine.

[Rapid diagnosis of influenza infection by PCR method--detection of influenza virus HA gene in throat swab]

We studied the detection of the HA gene of human influenza viruses in throat swabs obtained from the outbreaks of influenza in school children utilizing the polymerase chain reaction (PCR) method. Sensitivity and specificity of the PCR method was compared to conventional virus isolation using MDCK cells. Three pairs of primers for PCR in detecting the HA genes of AH1, AH3, and B influenza viruses showed both subtype and type specificity. The dilution experiments showed that influenza viruses, as few as 1.1-3.5 plaque-forming units per 50 microliters, were sufficient for the detection of HA genes by PCR method and the detection rate by PCR method was 2-3 fold higher than that by conventional method. Our results showed that the PCR method was a fast, sensitive and reliable method for the diagnosis of influenza infections.

[The mechanism of neutrophil-induced lung injury--autoregulation of superoxide generation in cells]

Neutrophils which are isolated in the lung adhere to endothelial cells due to chemotactic factors, and release various proteases, superoxide anions and prostanoids in inflammatory processes. However, this host defense mechanism can cause tissue damage. Excessive adherent neutrophils are not always derived from lung injury. We have previously reported that an increase in cell density in human neutrophils attenuates superoxide anion generation by cell to cell communication (autoregulation). Autoregulation of the protein kinase c stimulator, phorbol myristate acetate, and also of the cell membrane receptor stimulator, N-formyl-methionyl-leucyl-phenyl-alanine was observed. The autoregulation was not related to the presence of extracellular Ca2+ not to a change of [Ca2+]i induced by stimulants. These results suggest that neutrophils accumulated in the lung tissue have a built-in defense mechanism induced by membrane to membrane contact of neutrophils, which protects tissues from an excessive inflammatory response.

[Family-acquired hepatitis A--prevalence of hepatitis A among the family in Aichi Prefecture, 1990]

We studied the transmission of hepatitis A virus (HAV) in 45 families, which members were diagnosed as hepatitis A in 8 hospitals in 1990. Feces and sera from 50 patients and their 126 family members were tested for HAV-specific antigen and IgM antibody by ELISA or polymerase chain reaction (PCR) technology. From the interval of the onset of hepatitis or detection of HAV antigen in feces, HAV transmission was recognized in 11 (24.4%) of 45 families. The transmission was found to be concerned with contacts of the children and that from children to parents was found in 4 families and the reverse in 2. HAV antigen was detected from feces of 4 family members before onset of icterus by ELISA and furthermore, 3 by PCR. It was indicated that these methods would be used to prevent the transmission in a family, day-care centers, or institutions for the mentally retarded.

Adenovirus infection and specific secretory IgA responses in the intestine of infants

We investigated adenovirus (Ad) infection of the intestine and Ad group-specific fecal IgA antibody responses in seven infants who were followed up from birth to 16 months to seven years of age. We isolated in tissue culture from fecal samples not only enteric Ad type 41 but also other Ads (types 2, 3, 5, 6, and 12). We also detected Ad antigens in the feces by ELISA at the times of infection with even non-enteric Ads, suggesting that a large amount of antigens were produced in the intestine. We found that repeated Ad infections with different serotypes were occurring and there were good fecal IgA antibody responses at each time. The infection seemed usually mild or asymptomatic: only one out of 23 occasions of the detected infections required hospitalization.

Central cholinergic agents. III. Synthesis of 2-alkoxy-2,8- diazaspiro[4.5]decane-1,3-diones as muscarinic agonists

A series of 2-alkoxy-2,8-diazaspiro[4.5]decane-1,3-diones and related compounds were synthesized and tested for muscarinic receptor binding affinity using [3H]pirenzepine and [3H]oxotremorine M as ligands. They were also evaluated for agonistic activities in the guinea pig ileum assay. 2-Methoxy- 2,8-diazaspiro[4.5]decane-1,3-dione (1i) was found to be a relatively M1 selective agonist. It reversed CO2-induced impairment of passive avoidance response with long duration of action, but also displayed peripheral effects at low doses. To minimize these side effects, we proposed the idea of conjugation of 1i with a muscarinic antagonist. The carbamate linked conjugate (1u) of 1i with methylatropine was therefore examined.

Administration of α1-Proteinase Inhibitor Ameliorates Bleomycin-induced Pulmonary Fibrosis in Hamsters

The effect of alpha 1-proteinase inhibitor (alpha 1Pi) administration on the acute lung injury and subsequent fibrosis induced by bleomycin (BLM) was examined in hamsters. Pulmonary lesions were quantitatively reduced in alpha 1Pi-administered BLM-treated (BLM-alpha 1Pi) animals compared with animals treated by BLM alone (BLM-control) at both 7 days (acute stage) and 30 days (fibrotic stage) after BLM treatment. Analysis of intraalveolar cells from bronchoalveolar lavage (BAL) fluid revealed that neutrophils and lymphocytes were significantly decreased in the BLM-alpha 1Pi animals at 7 days after BLM treatment and that 30 days after BLM treatment macrophages as well as neutrophils and lymphocytes were remarkably decreased in the BLM-alpha 1Pi animals. The elastase activity in supernatants of BAL fluid during 7 days following BLM treatment was detected, but there was no difference between the two groups. In vitro studies on neutrophil responsiveness to stimulation of BAL fluid at 3 days after BLM treatment revealed noticeable chemotaxis and generation of superoxide anion of isolated neutrophils, but alpha 1Pi did not show any inhibitory effects on neutrophil responsiveness. We suggest that alpha 1Pi administration ameliorates pulmonary fibrosis preceded by acute lung injury induced by BLM treatment in hamsters and that the inhibitory effects of alpha 1Pi on lung injury may not be brought about by altered elastase activity, chemotaxis, or superoxide generation in neutrophils. Alternative mechanisms are discussed.

[Effects of surgical stress on peripheral venous functions]

Postoperative changes in peripheral venous functions were determined by Ga-In strain gauge plethysmography in 28 surgical patients, and central venous functions and urine catecholamine levels were also measured. The results were as follows: 1. The maximum venous outflow (MVO) and arterial blood inflow volume (AF) of the healthy arms tended to increase with age, but showed no sex or right-to-left difference. 2. MVO, AF and venous distensibility were decreased postoperatively, and the decreases were greater in the patients with major surgery than in those with minor surgery. 3. MVO in the patients with high urine levels of adrenaline and noradrenaline showed a greater decrease than those in normal subjects, and the majority of these patients were found to have had major surgery. There was a negative correlation between the urine noradrenaline level and MVO. 4. The decrease in peripheral venous functions preceded the decrease in central venous functions. 5. The postoperative decrease in peripheral venous functions was considered to be the result of active vasoconstriction due to hypersecretion of catecholamines caused by surgical stress and increase in the extravascular pressure. 6. Measurement of venous functions of the arm may be a good parameter for detecting circulatory disturbances due to surgical stress.

[Descriptive epidemiology of mushroom poisoning in Japan]

The Incidence of mushroom poisoning was surveyed statistically from 1959 to 1988 in Japan. The results are summarized as follows: 1. During the past three decades, the total number of incidents of mushroom poisoning was 2,096, which involved 10,924 patients and 72 deaths. The average number of incidents was 70 cases per year, involving 364 patients and 2.4 deaths, and the number of incidents decreased gradually every year. Mushroom poisoning usually happened most frequently in September and October. 2. Considering regional differences, the incidence of mushroom poisoning was more frequent in the northeastern part of Japan than in the southwestern part. The incidences of mushroom poisoning in the prefectures of Nagano, Hokkaido, Niigata, Iwate and Fukushima were relatively high. 3. Three species of mushrooms, L. japonicus, R. rhodopolius (R. sinuatus) and T. ustale caused the majority of all poisonings. 4. The rates of total patients and fatalities for each type of poisoning, which were classified according to the symptoms caused, were 90.3% and 10.7% in the type with cholera-like symptoms, 90.2% and 0.2% in that with gastro-intestinal irritation, and 74.1% and 0% in that with neurological symptoms, respectively.

A 2-year survey of the prevalence of enteric viral infections in children compared with contamination in locally-harvested oysters

We studied, for two years, the prevalence of indigenous human enteric viruses in wild oysters gathered each month from the bottom of Mikawa Bay, Aichi Prefecture, Japan. Viruses were detected periodically in 9 out of 54 oyster pools prepared by the acid or polyethylene glycol precipitation method although all these 9 pools met current national bacteriological safety standards. Since most of the serotypes of the enteric viruses detected in the oysters were identical with those of viruses isolated from sick children living in the area, it is suggested that contamination of enteric viruses in the oysters would depend on the prevalence of enteric viral infections in the local inhabitants.