Multiple optical stimulation to neuron using Si opto-neural probe with multiple optical waveguides and metal-cover for optogenetics

We have developed a Si opt-neural probe with multiple waveguides and metal cover for highly accurate optical stimulation. This neural probe had 16 recording sites, three optical waveguides, and metal cover for suppressing light leakage. We evaluated electrochemical properties of the recording sites, and confirmed that the neural probe had suitable characteristics for neural recording. We also demonstrated the optical stimulation to the neurons expressing ChR2 using our probe. As a result, we succeeded multisite optical stimulation, and observed that no light leakage from the optical waveguides because of the metal cover. From in vivo experiments, we successfully recorded optically modulated local field potential using the fabricated Si neural probe with optical waveguides. Moreover, we applied current source density analysis to the recorded LFPs. As a result, we confirmed that light induced membrane current sink in locally stimulated area. Our Si opto-neural probe with multiple optical waveguides and metal-cover is one of the most versatile tools for optogenetics.

Seroprevalence of toxoplasmosis among migrant workers from different Asian countries working in Malaysia

A serologic study of Toxoplasma antibodies among 501 foreign migrant workers in Malaysia was conducted in a plantation and detention camp. The highest prevalence rate of 46.2% was among Nepalese workers. Statistical analysis indicated the IgG positivity rate among local residents was significantly higher than the migrants studied (p < 0.05). The IgM positivity rate showed no significant difference between the two groups (p > 0.05). No significant difference in the prevalence rate was noted between the migrants and the local workers when grouped by agricultural and non-agricultural occupations (p > 0.05). The continuous introduction of these infections may influence the epidemiology and further compromise efforts in control and prevention. It is therefore important to monitor of non-notifiable diseases.

Variationally optimized basis orbitals for biological molecules

Numerical atomic basis orbitals are variationally optimized for biological molecules such as proteins, polysaccharides, and deoxyribonucleic acid within a density functional theory. Based on a statistical treatment of results of a fully variational optimization of basis orbitals (full optimized basis orbitals) for 43 biological model molecules, simple sets of preoptimized basis orbitals classified under the local chemical environment (simple preoptimized basis orbitals) are constructed for hydrogen, carbon, nitrogen, oxygen, phosphorous, and sulfur atoms, each of which contains double valence plus polarization basis function. For a wide variety of molecules we show that the simple preoptimized orbitals provide well convergent energy and physical quantities comparable to those calculated by the full optimized orbitals, which demonstrates that the simple preoptimized orbitals possess substantial transferability for biological molecules.

A brief survey of free-living amebae in Thailand and Hamamatsu District, Japan

The aim of this study was to determine the presence of free-living amebae in aquatic habitats of human environments in Thailand and Hamamatsu district, Japan. Genus identification was based on the morphology of cyst and trophozoite forms and a flagellation test for genus Naegleria. The pathogenic potential was tested in mice by nasal instillation for genus Naegleria and Acanthameba. In 14 provinces of Thailand, amebae were isolated in 43 from 95 water samples and 67 from 120 soil swabs. Amebae of 49 isolates from waters were identified as Acanthameba (36.7%), Naegleria (28.6%), Hartmannella (20.4%), Vahlkampfia (12.2%) and Vannella (2%). Soil samples have significantly higher levels of Acanthameba and Hartmannella (p<0.05) but lower for Naegleria (p<0.05) and 7 unidentified amebae were found. In Hamamatsu district, Japan, 62 amebae of the same genera were isolated from 47 of 95 water samples. There were significantly higher levels of Acanthameba (22.6%) (p<0.05) but lower for Naegleria (4.8%) (p<0.05) than those of Thailand which each of them caused death in mice. Three unidentified amebae were isolated. This finding serves as additional evidence for the presence of free-living amebae under natural and the difference in distribution between tropic and subtropic areas.

Role of a highly conserved YPITP motif in 2-oxoacid:ferredoxin oxidoreductase: heterologous expression of the gene from Sulfolobus sp.strain 7, and characterization of the recombinant and variant enzymes

2-Oxoacid:ferredoxin oxidoreductase from Sulfolobus sp. strain 7, an aerobic and thermoacidophilic crenoarchaeon, catalyses the coenzyme A-dependent oxidative decarboxylation of pyruvate and 2-oxoglutarate, a cognate Zn-7Fe-ferredoxin serving as an electron acceptor. It comprises two subunits, a (632 amino acids) and b (305 amino acids). To further elucidate its structure and function, we constructed a gene expression system. The wild-type recombinant enzyme was indistinguishable from the natural one in every criterion investigated. A series of variants was constructed to elucidate the role of the YPITP-motif (residues 253-257) in subunit a, which is conserved universally in the 2-oxoacid:ferredoxin oxidoreductase (OFOR) family. Single amino-acid replacements at Y253 and P257 by other amino acids caused a drastic loss of enzyme activity. T256, the hydroxyl group of which has been proposed to be essential for binding of the 2-oxo group of the substrate in the Desulfovibrio africanus enzyme, was unexpectedly replaceable with Ala, the kcat and Km for 2-oxoglutarate being approximately 33% and approximately 51%, respectively, as compared with that of the wild-type enzyme. Replacement at other positions resulted in a significant decrease in the kcat of the reaction while the Km for 2-oxoacid was only slightly affected. Thus, the YPITP-motif is essential for the turnover of the reaction rather than the affinity toward 2-oxoacid.

Epidemiology, symptoms and treatment of paragonimiasis in Sin Ho district, Lai Chau province, Vietnam

Sin Ho is a district of the northern mountainous province of Lai Chau, Vietnam, where the people have the habit of eating undercooked crabs. A study on paragoniamiasis carried out from 1994 to 1995 with 1,642 persons in this endemic area, showed that the rate of eating raw-crab was 72.5%. Crab examination (Ranguna kimboiensis) showed an infection rate of Paragonimus metacercaria of 98.1%. With 624 stool samples examined by Kato technique, the infection rate of Paragonimus in humans was 6.4%. With 338 sputum samples examined by direct and centrifuge methods, the infection rate of Paragonimus was 7.4%. Most of the patients were children (63.2%). The infection rate of Paragonimus in dogs was 18.2 - 33.3%. Adult worms, collected from the dogs in the field and from the cats in laboratory, were identified as Paragonimus heterotremus. The main symptoms of Paragonimus patients were cough and hemoptysis (92%), discontinuously developed (96%), without fever (94%), chest pain (70%), pleural effusion (26%), neurogical symptoms (8%), eosinophilia (88.9%), nodular ring shadows in the lungs, as shown by chest X-ray examination and more in lower lobe, (76.2%). Paragonimiasis patients were treated by (a) Praziquantel 25 mg/kg/day x 3 days; the cure rate was 68.8%. (b) Praziquantel 50 mg/kg/day x 3 days; the cure rate was 75%.

Epidemiology of clonorchiasis in Ninh Binh Province, Vietnam

Clinical and stool examinations for clonorchiasis were carried out in an endemic area, Kim Son District, Ninh Binh Province, Vietnam. Stool examination with the Kato-Katz technic revealed that in 306 residents selected randomly, 42 people (13.7%) were infected with Clonorchis sinensis. The rate was biased towards men (23.4%) as opposed to women (1.5%) and increased with age. No children younger than 10 years old were infected, reflecting difference in a chance for acquisition of infection through a habit of eating raw fish. Few clinical abnormalities were found by blood and urine examinations of the patients. Treatment with praziquantel decreased the infection rate to 5.3% at 6 weeks later. Snails, Melanoides tuberculatus, collected from ponds around the settlements were infected with cercariae at a rate of 13.3%. Farmed fish (Hypophthalmichtys molitrix) in the ponds were infected with metacercariae at rates of 56.4% in small individuals and 100% in large ones. The life cycle of C. sinensis is exclusively completed in the ponds and the traditional habit of eating raw fish in summer was thought to be a major route of infection.

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

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

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

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

[Medical practice-supporting system in pulmonary function testing]

A pulmonary function testing system which automates measurement, storage and reporting as much possible has been functioning in Mitsui Memorial Hospital since 1992. Data obtained from four measurement apparatus are transferred to the central microcomputer by a local area network (LAN). To facilitate automatic interpretation, we developed a knowledge-based system using 87 production rules called 'PADRES', because the knowledge-based system had the following advantages over other systems; (1) The expression of knowledge is understandable and new pieces of knowledge can be easily added, (2) the process of reasoning can be clearly shown, and (3) the accumulation of many instances of data is not required. Using 'PADRES', it takes 2.6 seconds to interpret one set of data on average. Our system performs about 5,000 routine pulmonary function tests per year without faults. Because the program for interpretation is a separate module written in C language, it is readily portable to other operating systems (OS), although its original target was OS-9, a multitask operating system for microcomputers. In conclusion, the application of a knowledge-based system for microcomputers in the pulmonary function test laboratory was considered successful.

Effect of an angiotensin II receptor antagonist, TCV-116, on neointimal formation following balloon injury in the SHR carotid artery

1. In the present study, we examined the effect of a novel angiotensin II type I receptor antagonist, TCV-116, on carotid neointimal formation after balloon injury in SHR and WKY rats. 2. Oral administration of TCV-116 at a dose of 10 mg/kg per day reduced not only systolic blood pressure but also neointimal formation after carotid balloon injury. TCV-116 also suppressed cardiac hypertrophy. An angiotensin-converting enzyme inhibitor, lisinopril (20 mg/kg per day), had a similar effect to that of TCV-116. 3. In the WKY experiment, both TCV-116 and lisinopril suppressed neointimal formation as well as systolic blood pressure, but did not suppress cardiac hypertrophy. 4. Although SHR showed markedly enhanced neointimal formation after balloon injury compared with age-matched WKY rat, both TCV-116 and lisinopril showed similar suppressive effects on neointimal formation in both SHR and WKY rats. 5. These results confirm the important role of angiotensin II in neointimal formation following balloon injury. Further studies are needed to clarify the mechanism of the difference between SHR and WKY rats in the response of vascular smooth muscle cells.

Atrial natriuretic peptide and antihypertensive action due to beta-blockade in essential hypertensive patients

The effects of beta-blocker treatment on hemodynamics were studied in relation to plasma atrial natriuretic peptide (ANP) levels in 17 outpatients with essential hypertension. Administration of propranolol for twelve weeks to untreated subjects resulted in a significant (P < 0.001) rise in plasma ANP levels (from 37.9 +/- 21.2 to 66.7 +/- 46.2 pg/mL, mean +/- SD). Systolic and diastolic blood pressures were significantly decreased (P < 0.05 and P < 0.01, respectively). Heart rate was also significantly decreased (P < 0.001). On the other hand, a significant reduction of cardiac index was detected (from 4.12 +/- 1.34 to 2.96 +/- 0.75 L/min/m2, P < 0.01) with chronic administration of propranolol, suggesting a reflection of decreased cardiac function. A significant negative correlation was observed between %changes in systolic blood pressure and %changes in plasma ANP (r = -0.594, P < 0.05). These results suggest that the increased plasma ANP levels may contribute to the antihypertensive effect with propranolol.

Pathologic changes related to subcutaneous implantation of chlormadinone acetate for preventing estrus in bitches

Pathologic changes related to chlormadinone acetate (CAP) implantation were examined using 14 bitches given doses 2.5 to 25 mg/kg for 2 years. Absence of corpus luteum in bitches given 5 mg/kg or more supported long-term preventive effect of CAP on estrus. The uteri were dose-dependently enlarged and mucometra was occasionally found. Endometrial epithelium hyperplasia was observed but less in smaller doses. Changes in the mammary gland were only growth and lactation at normal degree. No remarkable changes were observed in ACTH and LH cells in the pituitary gland. Low, stable levels of CAP maintained in plasma by subcutaneous implantation seemed to be the main reason for absence or slight CAP-related pathologic changes.

Characterization of renal aldosterone receptors in genetically hypertensive rats

To investigate the aldosterone responsiveness of genetically hypertensive rats, we compared characteristics of renal cytosolic aldosterone receptors from the M strain of stroke-prone, spontaneously hypertensive rats (M-SHRSP) with normotensive Wistar-Kyoto rats (WKY). In M-SHRSP, blood pressure was elevated significantly at 6 wk of age, when their plasma aldosterone concentrations were similar to those in WKY. Decreases in urine volume and sodium excretion were also observed in M-SHRSP. At 10 wk of age, M-SHRSP plasma aldosterone concentrations became significantly higher than those in WKY. On the other hand, the concentration of renal cytosolic aldosterone receptors (type I, aldosterone specific) had already increased at 6 wk of age in M-SHRSP, with no difference in affinity, and levels remained increased thereafter. There were no significant differences in molecular weights or ionic charges of either "activated" or "non-activated" aldosterone-receptor complexes between M-SHRSP and WKY, indicating that the molecular properties were similar in both groups. These results suggest that the increased concentration of aldosterone receptors in the kidneys of M-SHRSP might increase their aldosterone responsiveness and contribute to the development of high blood pressure in these animals.

Effects of mebendazole on Angiostrongylus costaricensis in mice, with special reference to the timing of treatment

Mebendazole was given to mice infected with Angiostrongylus costaricensis at a single dose of 5 mg/kg at 6, 11, 16 or 21 days post-infection (p.i.) and in five successive doses at 5 mg/kg daily at 6, 11 or 16 days p.i. The effects were comparatively assessed by examining various parameters in host mice and worms. As a whole, the effects of mebendazole were caused more conspicuously by five successive treatments than by a single treatment. In both treatment modalities, the effects were more remarkable in earlier treatments, and nearly complete effects were caused by five successive treatments before 15 days p.i. These results suggest that the inhibition of egg formation and/or oviposition will inhibit the pathological changes caused in the disease by A. costaricensis, especially before the onset of the changes.

Sphingolipids of a cestode Metroliasthes coturnix

Sphingolipids of Metroliasthes coturnix were studied. The cestode contained no detectable amounts of sphingomyelin. The major glycosphingolipids found were monogalactosylceramide, galactosyl-alpha-1-4-galactosylceramide, galactosyl-beta-1-6-galactosyl-beta-1-6-galactosylceramide and galactosyl-beta-1-6-galactosyl-beta-1-6-galactosyl-beta-1-6-galactosylce ramide. Their ceramides were mostly composed of C18-20 sphinganine or 4-D-hydroxysphinganine, which is N-acylated by extraordinarily long normal and 2-hydroxy acids such as C26 acid (range C16 to C30) except tetragalactosylceramide. The structure of glycosphingolipids was confirmed after their chromatographic separation into each molecular species using a novel analytical device, fast atom bombardment-mass spectrometry linked with reversed-phase high-performance liquid chromatography.

[Diaphragmatic fatigue under inspiratory resistive load in healthy subjects and the effect of several selections of frequency bands on the H/L (high/low) ratio]

In seven normal adult males the authors studied diaphragmatic fatigue by analysis of the power spectrum of the diaphragmatic electromyogram obtained with an esophageal electrode, and of the change of transdiaphragmatic pressure. Diaphragmatic fatigue was produced by inspiring through a resistive load, and mean value of the index of the tension time of the diaphragm (TTdi) maintained until fatigue was 0.33 +/- 0.09, which has been known to produce fatigue. The mean value of ratios of power at high frequencies to power at low frequencies (H/L) decreased to 61.2 +/- 16.8% of the initial value at just before breaking time. Breaking time was 4.88 +/- 1.37 minutes in average. The selection of low and high band widths for analysis of H/L ratio has differed slightly in the literature, but such differences do not have any substantial influence on the estimation of the changes of H/L ratio.

[A case of fatal asthma induced by timolol eye-drop]

A 74 year-old man, a known asthmatic since 1972, was treated by timolol eye-drop for acute glaucoma. Several hours later the patient developed a severe attack of asthma, and died subsequently. The autopsy findings were consistent with those of typical status asthmaticus. Our patient is, to our knowledge, the first case of fatal asthma induced by timolol eye-drop in Japan.

[Acute myeloblastic leukemia development in a patient with small cell lung cancer in complete remission]

A 67 year-old man was admitted to our hospital because of cough and sputum. He smoke one pack of cigarettes a day for more than twenty years and the chest X-ray film revealed a mass in the left hilum and left sided pleural effusion. The diagnosis of small carcinoma of the lung (limited disease, T4N1MO, stage 3B) was made by trans-bronchial lung biopsy and radiographic studies. Both chemotherapy (nimustine (ACNU), cyclophosphamide, vincristine, and methotrexate) and radiation therapy was started, however, the chemotherapy was discontinued in July 1987 because of severe anemia. The diagnosis of refractory anemia with excess of blasts in transformation (RAEB in T) was made by bone marrow aspiration and the patient was treated by transfusion (400-800 ml/week). In December 1987 transition to acute myeloblastic leukemia was confirmed by another bone marrow aspiration biopsy and the patient was given low dose cytosine arabinoside (Ara-C). The response was favorable in the beginning but in about two months pancytopenia became refractory and the patient died in June 1988. Clinically there was no sign of local or distal recurrences of lung cancer, and the complete remission of small cell lung cancer (SCLC) was confirmed by autopsy. Survival in SCLC remains poor, so that the choice of treatment is still the primary concern, however, development of other malignancies which include acute leukemia is another problem which should be taken into account when the treatment is extensive.

Learning from lesions: patterns of tissue inflammation in leprosy

The clinical forms of leprosy constitute a spectrum that correlates closely with the degree of cell-mediated immunity. Patients with tuberculoid leprosy develop strong cell-mediated responses and have only a few, localized lesions, whereas patients with multibacillary lepromatous leprosy are specifically unresponsive to antigens of Myobacterium leprae. T cells of the CD4+ subset predominate in tuberculoid lesions, whereas CD8+ cells predominate in lepromatous lesions. Monoclonal antibodies that distinguish subpopulations of CD4+ and CD8+ cells were used to analyze the distribution of T cells infiltrating lesions across the disease spectrum. In lepromatous lesions, T cells of T-suppressor phenotype (9.3-) were the predominant CD8+ cells and suppressor/inducer cells (2H4+, Leu-8+) represented half of the CD4+ subset. In tuberculoid lesions, helper T cells (CD4+4B4+) outnumbered suppressor/inducer T cells by 14:1, compared with a ratio of 1.2:1 in peripheral blood. Analysis of the precursor frequency of antigen-reactive T cells permitted us to estimate that there was a 100-fold enrichment of T cells able to proliferate in response to M. leprae antigens in tuberculoid lesions (2/100), when compared with blood from the same patients. The methods used here to characterize the T-lymphocyte subsets and frequency of antigen-reactive T cells in leprosy may be useful in analyzing immunological reactions occurring in lesions of other inflammatory and autoimmune diseases.

Relationship between forced expiratory flow and tracheal sounds. Possible effect of vortices on flow

We measured both tracheal sounds and forced expiratory flows simultaneously in 20 normal subjects and 4 patients with stenosis of the main bronchus. Spectral analysis of the tracheal sounds revealed development of discrete line spectra, the frequencies of which ranged between 488 and 942 Hz. There was a positive correlation between these frequencies and the peak flows (r = 0.601). We speculate that the origin of these line spectra are vortices rather than the vibrations of the wall. It is postulated that the pressure drops caused by vortices make the airways more susceptible to collapse and may lead to flow limitation.

Differences in biological characteristics of two strains of the cestode Hymenolepis diminuta

Biological characteristics of infectivity, growth rate and fecundity of Hymenolepis diminuta isolated from wild Rattus rattus in Japan were compared with parasites of Texas origin maintained for several generations in this and many other laboratories in laboratory bred Rattus norvegicus. The timing of development and maturation was similar in parasites from both sources, but the mean parasite dry weight was less and the mean egg production lower in Japanese parasites in both single and multiple infections. The differences persisted over 10 weeks in single infections, and were unaffected by rat strain. In all experiments there was much greater variation and heterogeneity in the biological characteristics of the Japanese parasites. It was concluded that the Texas parasites were better adapted to R. norvegicus and in the course of adaptation had become more homogeneous, and that the difference between the parasite strains had a complex genetic basis. Some Japanese parasites of the early isolated generations failed to produce normal eggs, but the proportion of these decreased in later generations. However, selected individual Japanese parasites whose egg production was equal to that of parasites of Texas origin did not produce offspring of larger mean size or higher mean fecundity, and heterogeneity of these characteristics was maintained. In the intermediate host, the mean number of cysticercoids of the Japanese isolate per beetle was higher than that of the Texas strain in Tribolium confusum but lower in Tenebrio molitor. The greater heterogeneity exhibited by Japanese parasites and the genetic basis of the strain difference are discussed with particular reference to geographical isolation, differences in definitive hosts and co-evolution of wild and laboratory host and parasite populations.

Paradoxical functions of alveolar macrophages from Calmette-Guérin bacillus-immunized rats

The effect of autologous alveolar macrophages on the lymphoproliferative response to mitogens was investigated using Calmette-Guérin bacillus (BCG)-immunized rats. The proliferation of lymphocytes obtained from normal rats was suppressed when the lymphocytes were cultured with alveolar macrophages at any proportion, but there was an enhancement in the lymphoproliferative response when the lymphocytes from BCG-immunized rats were incubated with alveolar macrophages at the ratio of 100:1. The supernatant of alveolar macrophage cultures from both normal and BCG-immunized rats showed a suppressive effect on lymphocytes while the supernatant of lymphocyte-alveolar macrophage cultures from BCG-immunized rats enhanced the lymphoproliferation. The results indicate that there are soluble factors elaborated by alveolar macrophages which have opposite effects on lymphoproliferation, and that these factors may be involved in the development of the hyperimmune state of the lung in tuberculosis.

Parasite density and the fecundity of Angiostrongylus cantonensis in rats

The larval output of Angiostrongylus cantonensis at different initial densities in rats was examined throughout the reproductive life-span of the worms using a modified dilution technique. With an initial density of 2 worms the mean duration of larval output was 414.2 days. The output was at a level above 50000 larvae/female/day from 15 to 45 weeks after infection. The mean total output was 18.9 X 10(6) larvae/female. The larval output/female decreased with an increase in the worm burden and also with the passage of time after infection. The longevity of host rats also decreased with increasing worm density and many of the heavily infected rats died early during infection. These results suggest that worm density has an effect on the fecundity of this parasite, and that the effects may be due to fibrous changes in host lung tissue but not changes in the physiology of the worms. It is also suggested that density-dependent effects on fecundity play a role in the population dynamics of both the parasite and host as regulatory mechanisms in the field.

Angiostrongylus cantonensis: paralysis due to avermectin B1a and ivermectin

Paralysis due to avermectin B1a and ivermectin of Angiostrongylus cantonensis was compared to that of phenylephrine (an alpha-adrenergic agonist) and strychnine (a cholinergic inhibitor). The paralyzing action of ivermectin (2.5 X 10(-9) g/ml) was inhibited by the single, simultaneous addition of picrotoxin (3 X 10(-5) M), whereas the effect of the drug (2.5 X 10(-7) g/ml) was reversed only when picrotoxin was given with cholinergic spasmogens such as pyrantel and eserine. Bicuculline (3 X 10(-5) M) had a similar antagonistic effect for picrotoxin, but bicuculline was less effective. The paralyzing action of avermectin B1a (3.6 X 10(-14) M, 3.0 X 10(-14) g/ml) was antagonized only when picrotoxin was given with cholinergic spasmogens such as pyrantel, eserine, and N-methylcytisine (N-MC), or alpha-adrenergic antagonists such as phentolamine and dibenamine. On the other hand, the paralyzing action of strychnine (3 X 10(-6) M) or phenylephrine (3 X 10(-5) M) was relatively uninfluenced by picrotoxin, but was antagonized by pyrantel and N-MC or dibenamine. These results suggest that a gabergic mechanism is involved in the paralyzing action of ivermectin, as well as avermectin B1a, in A. cantonensis.

[Plethysmogram of the human uterine cervix in late pregnancy--with special reference to maturation of the cervix]

Plethysmograms of the human pregnant uterine cervix have been recorded to elucidate same facets of the local hemodynamics in terms of the characteristic plethysmographic patterns referable to cervical maturation in late pregnancy. The author has developed a transparent type of transducer by which the plethysmograms have been able to be recorded serially from the entire tissue layer of the cervical wall. With this method, it has also been possible to calibrate quantitatively and to analyze the wave patterns in the same way as with finger tip plethysmography. A monophasic plethysmogram pattern is peculiar to the cervix of non-pregnant women. With the progress of pregnancy, it has been observed frequently that the wave height has become low with fine oscillations in the descending phase of waves. These changes found in late pregnancy have disappeared immediately in the early stage of puerperium. The characteristic patterns of plethysmogram in late pregnancy were classified into four types, A, B, C and D. In late pregnancy, when the cervix reached mature status, types C and D, lower height of waves showing a plateau pattern, with fine oscillations in the descending phase of waves, have been observed frequently. From these observations, it would appear that this characteristic plethysmographic pattern indicates the matured cervix prepared for labor. The plethysmographic changes of pregnant cervix with special reference to the histological characteristics of pregnant cervix have been discussed.

Studies on chemotherapy of parasitic helminths (XVIII). Mechanism of spastically paralyzing action of pyrantel in Angiostrongylus cantonensis

Pyrantel tartrate caused spastic paralysis through stimulating nicotinic cholinoceptors in Angiostrongylus cantonensis.

Studies on chemotherapy of parasitic helminths (VIII). Effects of some possible neurotransmitters on the motility of Angiostrongylus cantonensis

Effects of some possible neurotransmitters such as GABA, adrenergic drugs, and 5-HT and their antagonists on the motility of Angiostrongylus cantonensis were studied. Paralysis was caused by GABA, avermectin BIa (Av-BIa), piperazine and alpha-adrenergic agonists such as adrenaline, noradrenaline, phenylephrine, clonidine and methoxamine, but not by beta-adrenergic agonists such as isoproterenol. The paralysis by GABA or Av-BIa was antagonized by GABA antagonists such as picrotoxin and/or bicuculline with cholinergic agents such as N-methylcytisine (N-MC) or eserine. The paralysis elicited by alpha-adrenergic agonists was antagonized by alpha-adrenergic antagonists such as phentolamine and dibenamine, but not by beta-adrenergic antagonists such as propranolol. 5-HT affected the motility of A. cantonensis paralytically or spastically. The paralysis induced by 5-HT was antagonized by alpha-adrenergic antagonists such as phentolamine and dibenamine, while the contraction induced by this compound was further stimulated by N-MC, but antagonized by strychnine. Other agents such as glutamine, glycine, aspartic acid, taurine, and substance P showed little effect on the motility of A. Cantonensis. From these findings on the neuropharmacological properties of A. cantonensis, it is suggested that this worm is useful as an excellent nematodal model for the investigation of anthelminthics. In addition, this worm may also useful as one of screening models of drugs affecting the central nervous system in mammals.

Studies on chemotherapy of parasitic helminths (VII). Effects of various cholinergic agents on the motility of Angiostrongylus cantonensis

Effects of various cholinergic agents on the motility of Angiostrongylus cantonensis were studied to define the neuropharmacological properties of this worm. Stimulation of the motility and/or contraction were shown by eserine, ACh, carbachol, nicotine, DMPP, pyrantel, and Ba2+, but not by pilocarpine and McN-A-343. Contraction was similarly observed by these agents in the preparations paralyzed with praziquantel. Paralysis was caused remarkably by d-tubocurarine and slightly by succinylcholine, while the contraction induced by eserine and DMPP was little influenced by these drugs. Both the motility and the eserine-induced contraction were little influenced by hexamethonium, but stimulated remarkably by atropine. Though hemicholinium-3, morphine, and picrate showed little effect, guanidine stimulated remarkably the motility and also the eserine-induced contraction. The stimulatory action of guanidine was antagonized by strychnine. Strychnine paralyzed the motility, and the eserine-induced contraction was antagonized by the pre- and post-treatment with strychnine. From these results, it is suggested that the excitatory cholinergic mechanism in A. cantonensis is nicotinic, and it is basically similar to that reported in Ascaris suum.

Studies on chemotherapy of parasitic helminths (VI) effects of various neuropharmacological agents on the motility of Dipylidium caninum

Effects of various neuropharmacological agents on the motility of Dipylidium caninum was studied. 5-HT stimulated the motility of D. caninum, while other drugs such as GABA, adrenaline, phenylephrine, isoproterenol, dibenamine, and propranolol showed little effect. The stimulatory action of 5-HT was antagonized by tryptophol. Stibnal caused paralysis which was blocked by the pretreatment with 5-HT. Paralytic effects were caused by eserine, dichlorovos, ACh, carbachol and DMPP, but not by pilocarpine and McN-A-343. d-Tubocurarine, hexamethonium, and atropine all showed little effect on the motility and on the paralytic action of eserine. Though guanidine showed little effect, strychnine remarkably stimulated the motility. The action of strychnine was stimulated by 5-HT but partially inhibited by tryptophol. Morphine and picrate slightly stimulated the motility, but showed little influence on the paralytic action of eserine. These two agents stimulated the paralyzed preparation by tryptophol transiently and sustainedly, respectively. These results on the cholinergic and serotonergic drugs basically showed good agreement with those reported in trematodes such as Schistosoma mansoni and Fasciola hepatica.

Experimental light infection of Angiostrongylus cantonensis in rats

An experimental infection with a smaller number of Angiostrongylus cantonensis, using rats as hosts, was carried out. When the rats were infected with one and two larvae of A. cantonensis, the infection rates were 45.5% and 73.3% and recovery rates of the adult worms were 45.5% and 66.7%, respectively. In cases when more than three larvae were given to rats, all rats were found to be infected and recovery rates were around 70%, which is the same as in the case of infection with many larvae. The recovered worms were all mature and showed no important difference in their morphological measurements. It was concluded that the larvae of A. cantonensis were able to infect rats in small numbers, and completely develop into adult worms. It is suggested that human infection could occur in the same way.

[Studies on chemotherapy of parasitic helminths (IV). Effects of alkaloids from Sophora flavescens on the motility of parasitic helminths and isolated host tissues (author's transl)]

Effects of N-methylcytisine (N-MC) and matrine (Mat), alkaloids from Sophora flavescens on the motility of parasitic helminths and isolated frog rectus and mouse ileum were studied. 1) The motility of Angiostrongylus cantonensis was affected spastically by N-MC (1.2 X 10(-6) approximately 1.2 X 10(-4) M), but paralytically by Mat (10(-5) approximately 10(-4) M). 2) The motility of Dipylidium caninum and Fasciola hepatica was affected paralytically by N-MC (1.2 X 10(-4) approximately 1.2 X 10(-3) M), but spastically by Mat (10(-4) approximately 10(-3) M). 3) Treatment with N-MC (10(-3) M) and Mat (8 X 10(-4) M) had little effect on the motility of Schistosoma japonicum. 4) Both N-MC (1.2 X 10(-5) approximately 2.4 X 10(-5) M) and Mat (10(-4) M) stimulated the twitch response induced by guanidine (2.5 X 10(-5) M) in the frog isolated rectus preparation. 5) The motility of the mouse isolated ileum preparation was affected paralytically by N-MC (1.2 X 10(-5) approximately 1.2 X 10(-4) M), but spastically by Mat (10(-4) approximately 10(-3) M). Thus, N-MC and Mat acted antagonistically on all the preparations with the exception of the frog rectus preparation. From the results on interactions between these alkaloids and known neuropharmacological agents, it is suggested that the effects of both alkaloids are elicited through a neuropharmacological mechanism in parasitic helminths and host tissues.

[Studies on chemotherapy of parasitic helminths (III). Effects of tuberostemonine from Stemona japonica on the motility of parasitic helminths and isolated host tissues (author's transl)]

Effects of tuberostemonine (TS), an alkaloid from Stemona japonica, on the motility of parasitic helminths and isolated frog rectus and mouse ileum were studied. 1) TS (6.7 X 10(-6) approximately 2 X 10(-5) M) paralyzed the motility of Angiostrongylus cantonensis. 2) TS (6.7 X 10(-5) M) showed contractive effects on the motility of Dipylidium caninum and Fasciola hepatica. 3) Treatment with TS (6.7 X 10(-5) approximately 4.8 X 10(-4) M) had little effect on the motility of Schistosoma japonicum. 4) TS (6.7 X 10(-5) M) paralyzed the motility of the mouse isolated ileum preparation. 5) TS (6.7 X 10(-7) 6.7 X 10(-6) M) stimulated the twitch response induced by guanidine (2.5 X 10(-3) M) in the frog isolated rectus preparation. 6) Eserine and TS acted antagonistically on all preparations with the the exception of S. japonicum. 7) TS and strychnine were antagonistic in isolated host tissues, whereas these compounds acted similarly on parasitic helminths. Thus, it is suggested that some of the experiential effects of the crude extracts of Stemona such as the anthelmintic effects are caused through the action of TS on parasitic helminths and host tissues.

[Pressures on the human fetus during labor - intrauterine and on the fetal head (author's transl)]

During labor, the body surface of the fetus is subjected to strong pressure exerted by uterine contractions. In 40 cases, intrauterine pressure (IUP) which acts on the fetal body in the uterine cavity and pressure between the presenting part of the fetus and birth canal (PFB) which acts on the part of the fetus engaged in the birth canal were measured to determine the difference in pressure depending on the parts of the fetal body and their changes during the progress of labor. 1) Both peak IUP and PFB values increased gradually in the first stage of labor, and they became double in the period of labor with bearing-down efforts. 2) Since the peak value of PFB was 2.2 to 3.5 times higher than that of IUP, the part of the fetus engaged in the birth canal should always be subjected to 2.2 to 3.5 times more pressure than the intrauterine part of the fetal body. 3) Manual procedures such a vacuum extraction and Krysteller's compression on the uterine fundus increased the peak value of PFB markedly. The objective measurement of the pressure which acts on the fetal head during labor can be considered to contribute to the prevention of cerebral damage and fetal hypoxia.

Experimental light infection of Angiostrongylus cantonensis in hamsters

An experimental infection with a small number of larvae of A. cantonensis in hamster was carried out. When hamsters were infected with one larva, infection rate and recovery rate were 66.7%. In the case of infection with more than two larvae, all hamsters were infected had recovery rates were around 65%. The recovered worms were all matured and showed no important morphological differences. It was concluded that the hamster would be able to serve as a final host for A. cantonensis only in the case of a small number of larvae infection.

Biodynamics of the cervical dilatation in human labor

We recorded the pressure between the fetus and birth canal (PFB) with small strain-gauge type pressure transducers in 37 cases of human labor and estimated expulsive activity for evaluation of the expulsive forces. Expulsive activity increased progressively in conjunction with cervical dilatation and markedly increased after rupture of the membranes. At less than 200 Hashimoto units of expulsive activity, the cervical canal could not be dilated and labor was prolonged in all periods of the first stage of labor. There were three types of modes of changes in the expulsive activities at three points on the cervical canal. These three types had different clinical characteristics of cervical dilatation during labor. New parameters such as the expulsive effort, efficiency index and resistance index of the uterine cervix, estimated together with the expulsive activity, were proposed in an attempt to evaluate the effect of expulsive forces on cervical dilatation.

Studies on the examination of imported laboratory monkey, Macaca fascicularis for E. histolytica and other intestinal parasites

Infection rate of imported monkeys, under this study, with intestinal protozoa is higher than the infection rate with intestinal nematodes. Mostly encountered protozoa were E. coli, E. nana, E. histolytica and I. butschlii. Formalin-Ether concentration method yielded higher % positive for E. histolytica than the culture method using Tanabe-Chiba medium, but the results obtained from these 2 methods correlate perfectly well with each other. Efficacy of thiabendazole against intestinal nematodes such as Strongyloides, Trichuris, Physaloptera, Oesophagostomum and Capillaria was very satisfactory.