Associations between Drug Use and Sexual Risk Behaviours among Men Who Have Sex with Men in Japan: Results from the Cross-Sectional LASH Study

This study assessed drug use patterns among men who have sex with men (MSM) in Japan, and evaluated their potential associations with sexual risk behaviours. Between September and October 2016, study subjects were recruited through a cross-sectional survey (LASH: Love Life and Sexual Health) using a geosocial networking application for MSM. Of the participants, 25.4% (1756/6921) reported ever having used drugs, and 11.3% (780/6921) reported having done so in the past six months. Those who used drugs were more likely to have greater knowledge of HIV/sexually transmitted infections (STIs). Drug use in the past six months was independently associated with each of the following sexual risk behaviours in the same period: (i) six or more sexual partners (adjusted odds ratio [aOR] = 2.70, 95% confidence interval [CI]: 2.30-3.17); (ii) condomless anal intercourse (aOR = 2.88, 95% CI: 2.43-3.42); (iii) group sex (aOR = 2.60, 95% CI: 2.22-3.05); and (iv) sex work (aOR = 2.30, 95% CI: 1.67-3.16). These results suggest that MSM in Japan who use drugs are more likely to report sexual risk behaviours, while also having greater knowledge of HIV/STIs. Supporting MSM to minimise the harm from drug use may be helpful in reducing HIV transmission among this priority population.

Characterizing changes in drug use behaviour following supply shortages of 5-MeO-DIPT, alkyl nitrites and new psychoactive substances among men living with HIV in Japan

BACKGROUND

Since 2005, Japan has incrementally banned a range of new psychoactive substances (NPS), including 5-MeO-DIPT (5MO; foxy) and alkyl nitrites (AN; rush, poppers) that have commonly been used among men who have sex with men (MSM). After the largest ban in 2014, these drugs were reported to have disappeared from the domestic market. Given that 5MO/AN/NPS use has been prevalent among men living with HIV in Japan, a population largely comprised of MSM, we sought to characterize changes in their drug use behavior following the supply shortages.

METHODS

Using data from two waves of a nationwide survey of people living with HIV in Japan in 2013 and 2019-20 (n = 1042), we employed multivariable modified Poisson regression to identify correlates of self-reported reactions to the 5MO/AN/NPS shortages and changes in drug use behavior in 2019-20 vs. 2013.

RESULTS

Among 391 men (96.7% MSM) surveyed in 2019-20, following the supply shortages, 234 (59.8%) stopped using 5MO/AN/NPS, 52 (13.3%) retained access to the supply, and 117 (29.9%) used substitute drugs: most commonly, methamphetamine (60.7%). Individuals who used substitutes were more likely to report unprotected sex (adjusted relative risk [ARR]=1.67; 95% confidence interval [CI]: 1.13-2.47) as well as low (ARR=2.35; 95% CI: 1.46-3.79) and lower middle (vs. upper middle to high) socioeconomic status (ARR=1.55; 95% CI: 1.00-2.41). The prevalence of past-year methamphetamine use (ARR=1.93; 95% CI: 1.11-3.35) and self-reported uncontrollable drug use (ARR=1.62; 95% CI: 1.07-2.53) were significantly higher in 2019-20 compared to 2013.

CONCLUSION

Following the supply shortages, approximately one-fifth of our participants used methamphetamine as a substitute for 5MO/AN/NPS. Methamphetamine use and perceived uncontrollable drug use also appeared to have increased at the population level after the supply shortages. These findings suggest a potentially harmful substance displacement effect of the aggressive ban. Harm reduction interventions are needed in this population.

The prevalence and risk factor control associated with noncommunicable diseases in China, Japan, and Korea

BACKGROUND

Noncommunicable disease (NCD) has become the leading cause of mortality and disease burden worldwide.

METHODS

A cross-sectional survey was carried out to investigate the prevalence of NCDs and risk factor control on dietary behaviors and dietary intake in China, Japan, and Korea.

RESULTS

There were significant differences among the three countries on the prevalence of hypertension (24.5% in China, 17.6% in Korea, and 15.2% in Japan), diabetes (8.9% in China, 5.7% in Korea, and 4.8% in Japan), hyperlipidemia (13.1% in China, 9.2% in Korea, and 6.9% in Japan), and angina pectoris (3.6% in China, 1.7% in Korea, and 1.5% in Japan). The prevalence rate of hypertension, diabetes, hyperlipidemia, and angina pectoris was highest in China and lowest in Japan. However, 82.2%, 48.4%, and 64.4% of Chinese, Koreans, and Japanese presented good dietary behavior, respectively. Multivariable logistic regression analysis found that sex, age, and marital status were predictors of good dietary behavior. In addition, in comparison with subjects without hypertension, diabetes, or hyperlipidemia, subjects with hypertension, diabetes, or hyperlipidemia significantly improved their dietary behaviors and controlled their intake of salt, sugar, and oil.

CONCLUSIONS

The prevalence of NCDs and trends in major modifiable risk factor control in China, Korea, and Japan remain troubling. Public efforts to introduce healthy lifestyle changes and systematic NCDs prevention programs are necessary to reduce the epidemic of NCDs in these three Asian countries.

High prevalence of quasi-legal psychoactive substance use among male patients in HIV care in Japan: a cross-sectional study

Background

Syndemics of illicit drug use and HIV remain as significant public health issues around the world. There has been increasing concern regarding the rapidly growing market of new psychoactive substances, particularly in Asia. In response, the Japanese government has increasingly banned such substances in recent years. We sought to identify the prevalence and correlates of use of quasi-legal psychoactive substances among people living with HIV/AIDS (PLHIV) in Japan.

Methods

Data were derived from a nationwide survey of PLHIV conducted at nine leading HIV/AIDS care hospitals between July and December 2013. The prevalence and correlates of the use of quasi-legal psychoactive substances (e.g., synthetic cannabinoids, cathinone derivatives, etc. that had not been prohibited from using at the time of survey) among male participants were examined using multivariate survey logistic regression.

Results

Among 963 study participants, the majority (95.3%) were male. The most commonly used drug among men was quasi-legal psychoactive substances (55.3% ever and 12.8% in the previous year). In multivariate analysis, the lifetime use of tryptamine-type derivatives (i.e., 5-MeO-DIPT or N,N-diisopropyl-5-methoxytryptamine) (adjusted odds ratio [AOR]: 2.42; 95% confidence interval [CI]: 1.36–4.28) and methamphetamine/amphetamine (AOR: 3.59; 95% CI: 2.13–6.04) were independently associated with recent quasi-legal psychoactive substance use.

Conclusions

In our sample of male PLHIV in Japan, quasi-legal psychoactive substances were the most commonly used drugs. Individuals who had ever used tryptamine-type derivatives or methamphetamine/amphetamine were more likely to report recent quasi-legal psychoactive substance use, suggesting a potential shift in drug use patterns from regulated to unregulated substances among this population. These findings indicate a need for further research to examine implications for HIV care.

Recreational drug use and related social factors among HIV-positive men in Japan

This study aims to determine the relationship between recreational drug use in HIV-positive males in the past year and socio-economic factors and/or social support networks in Japan. A national online survey in a cross-sectional study was conducted by HIV Futures Japan project from July 2013 to February 2014. Of the 1095 HIV-positive individuals who responded, 913 responses were determined to be valid; responses from the 875 males were analysed. A total of 282 participants used addictive drugs (32.2%) in past year. New psychoactive substances were used by 121 participants (13.8%), methamphetamine or amphetamine by 47 (5.4%), air dusters/sprays/gas by 31 (3.5%), 5-methoxy-N,N-diisopropyltryptamine (5MeO-DIPT) by 16 (1.8%) and cannabis (1.0%) by 9. Multiple logistic regression analysis was performed with the use of alkyl nitrites, addictive drugs, air dusters and thinners, which are low illegality, as dependent variables. We found that the odds ratio (95% confidence interval) for use among participants with full-time and temp/contracted/part-time employees compared to management/administration professions were 2.59 (0.99-6.77) and 2.61 (0.91-7.51). Also, a correlation was observed between alkyl nitrites and new psychoactive substances and usage rates in people engaged in few HIV-positive networks. It is necessary to develop targeted policies for drug use prevention and user support among HIV-positive men and to support and provide care for drug users who are isolated or have a narrow HIV/AIDS support network.

Sexual activities and social relationships of people with HIV in Japan

Sixty-one Japanese with sexually transmitted HIV were investigated to clarify the state of, and difficulties in, their sexual activities and social relationships. The study revealed the following difficulties in social relationships due to HIV infection. Thirty-one per cent had experienced discrimination or breach of confidentiality. Self-restriction due to anxiety over discrimination was observed in approximately 90%, and the self-restriction score tended to be higher in those who were not employed, those with economic problems, those who were in a relatively poor state of health, those who had developed AIDS and those who had previously experienced discrimination or breach of confidentiality. The experience of discrimination or breach of confidentiality, and the experience of receiving negative support tended to increase as the respondents had a wider emotional support network. About 60% were dissatisfied with their sex lives, and the degree of satisfaction was significantly lower in those who had fewer sexual contacts and those who had a suppressive attitude toward sexual contacts. A low degree of satisfaction with sex life was found to be an important factor that escalates the level of depression or anxiety.

[A nationwide survey for implementation of Health Japan 21 anti-smoking countermeasures in municipalities throughout Japan]

PURPOSE

Smoking cessation is one of the most important items for improvement of health in Japan. The Japanese government started a new campaign called the "Health Japan 21" to promote better health of Japanese citizens in the 21st century. The purpose of the present study was to observe the situation of the municipalities throughout Japan regarding implementation of anti-smoking countermeasures and setting of the level of target values to be achieved over the next ten years.

METHODS

Mail questionnaire forms were sent to 953 municipalities which had formulated specific local plans for the promotion of health. Of this total, 793 (83.2%) responded to the inquiry.

RESULTS

The most commonly implemented countermeasure against smoking was restricting smoking only to limited areas in municipality offices (75%), followed by providing support for stopping smoking (35%), and providing a complete smoke free environment in municipality offices (32.4%). Proportions of local governments putting a ban on smoking on public roads (7.5%), giving publicity to restaurants with smoking restrictions (< 5%) and setting no smoking times in the municipality offices (< 5%) were low. Some 70% of municipalities provided anti-smoking education for school children. Very few local governments took measures such as identifying age at purchasing tobacco, removing vending machines and restricting tobacco advertisement.

CONCLUSION

Most municipalities have made much of anti-smoking activities. However, measures for school children were not satisfactorily implemented. The execution rates for anti-smoking activities are low in small-scale municipalities and therefore it is necessary to provide particular support in these cases.

[Family influences on future smoking habits among junior high school students in Japan]

OBJECTIVE

To examine the effects of health-related behavior and family smoking habits on the future smoking habits of junior high school students in two Japanese cities with different life expectancies.

METHODS

A cross-sectional study was conducted in January 2005 of all second-grade students in a junior high school in city A located in Aomori prefecture (399 students) and city B located in Nagano prefecture (447 students). Life expectancies in city B were 4.2 years longer in men and 2.9 years longer in women than in city A. Data on feelings about future smoking habits, dislike of tobacco smoke, family smoking habits and health-related behavior were collected.

RESULTS

The proportion of boys who went on to become smokers was higher in city A (18.7%) than in city B (10.3%). The proportions of smoking mothers and other smoking family members were also higher in city A, while the proportion of students who disliked tobacco smoke was lower. For girls in both cities, there was a significant positive association between future smoking and maternal smoking.

CONCLUSION

The findings suggest that maternal smoking habits are especially strongly correlated with future smoking in girls. The family smoking environment and health-related behavior should therefore be considered in measures to prevent smoking by students.

The intent and practice of condom use among HIV-positive men who have sex with men in Japan

To evaluate the intent and practice of condom use among Japanese HIV-positive men who have sex with men (MSM), a survey using anonymous questionnaires was carried out and 117 respondents were investigated. For anal sex and oral sex, respectively, 58.1% and 15.2% intended to use condoms and 47.2% and 12.4% used condoms all of the time. The intent of condom use decisively affected the practice of condom use and was closely related to the perceived risk level of HIV/sexually transmitted (STI) transmission. In anal sex, willingness to protect sexual partners from HIV infection was strongly related not only to the intent but also to the practice. Enhancement of willingness to protect oneself from STI was suggested to enhance willingness to protect his/her sexual partners from HIV infection with secondary enhancement of the intent or the practice of condom use. Specific support of MSM with HIV for improving the intent and practice of condom use is urgently needed.

Implementation of a smoke-free policy on school premises and tobacco control as a priority among municipal health promotion activities: nationwide survey in Japan

We conducted a nationwide survey to evaluate the effect of implementing a smoke-free policy in municipalities that forbid teachers to smoke on school premises. Questionnaires were mailed to 3207 municipalities throughout Japan. After we adjusted for population size and the standardized mortality ratio for male lung cancer, we found that assigning a high priority to tobacco control in municipal health promotion activities was significantly associated with implementation of school tobacco-control policies (odds ratio = 1.50, 95% confidence interval=1.24, 1.81).

[A nationwide survey of municipalities' policy for smoking control and its implementation in relation to its priority grading by public health officers]

PURPOSE

The purpose of this study was to investigate the present situation regarding implementation of smoking control programs and to clarify relations with public health officers' attitudes toward smoking control measures.

METHODS

A questionnaire form was mailed to the 3,207 local municipalities throughout Japan. The items included in the form were the contents of the smoking control programs, educational activities for passive smoking prevention, interaction with the media to spread education and awareness, and public health officers' attitudes toward smoking control measures.

RESULTS

Of 3,207 municipalities, 2,570 (80.1%) responded. Over 95% of local municipalities were undertaking smoking control programs. Among the programs carried out in practice, dividing areas into smoking and non-smoking sections in local government office buildings had the highest proportion of support (80%). On the other hand, complete prohibition of smoking in local government office buildings and non-smoking support programs were conducted by less than 20%. The dissemination of education activities were executed in 60 percent of government office buildings, and 36% of schools, but only 20% of athletic gyms, hospitals, and other facilities. Sixty percent of public health officers recognized the importance of smoking control programs. A non-smoking support program and complete prohibition of smoking in government office buildings were more likely to be executed in for local municipalities with a higher priority for smoking control programs. No significant association was found between attitudes regarding program importance and the division of areas into smoking and non-smoking sections in government office buildings.

CONCLUSIONS

Our results suggest that promotion of smoking control measures in local municipalities may be dependent on the public health officers' attitude toward the issues. High priority should be given to assisting public health officials and other key personnel in recognizing the importance of implementing smoking control measures for attaining better health.

How HIV infected haemophiliacs in Japan were informed of their HIV-positive status

The purpose of this study is to find out how HIV-infected haemophiliacs were informed and notified of their HIV infection. Self-reporting questionnaires were mailed to approximately 500 patients, about one half of the haemophiliac patients with HIV in Japan. The response rate was about 57% (n=283); and 270 (male=269) patients, apart from secondary and tertiary infected patients, were eligible as subjects for the study. The mean age was 31.2 +/- 9.9 years. Of these subjects, approximately 60% did not receive explanation regarding the risk of HIV infection via unheated blood products. More than 60% did not receive notification until 1990, or five years after the test became available in Japan. Contents of the explanations being given at the time of notifications were poor. In this paper, some problems of notifications of medically induced HIV are discussed, and the lack or delay of explanation/notification is concluded to be a consequence of the paternalistic attitudes of Japanese physicians and the iatrogenic nature of HIV infection.

SHP-1 Requires Inhibitory Co-receptors to Down-modulate B Cell Antigen Receptor-mediated Phosphorylation of Cellular Substrates

Signaling through the B cell antigen receptor (BCR) is negatively regulated by the SH2 domain-containing protein-tyrosine phosphatase SHP-1, which requires association with tyrosine-phosphorylated proteins for activation. Upon BCR ligation, SHP-1 has been shown to associate with the BCR, the cytoplasmic protein-tyrosine kinases Lyn and Syk, and the inhibitory co-receptors CD22 and CD72. How SHP-1 is activated by BCR ligation and regulates BCR signaling is, however, not fully understood. Here we demonstrate that, in the BCR-expressing myeloma line J558L mu 3, CD72 expression reduces the BCR ligation-induced phosphorylation of the BCR component Ig alpha/Ig beta and its cytoplasmic effectors Syk and SLP-65. Substrate phosphorylation was restored by expression of dominant negative mutants of SHP-1, whereas the SHP-1 mutants failed to enhance phosphorylation of the cellular substrates in the absence of CD72. This indicates that SHP-1 is efficiently activated by CD72 but not by other pathways in J558L mu m3 cells and that inhibition of SHP-1 specifically activated by CD72 reverses CD72-induced dephosphorylation of cellular substrates in these cells. Taken together, BCR-induced SHP-1 activation is likely to require inhibitory co-receptors such as CD72, and SHP-1 appears to mediate the negative regulatory effect of CD72 on BCR signaling by dephosphorylating Ig alpha/Ig beta and its downstream signaling molecules Syk and SLP-65.

CD72 negatively regulates signaling through the antigen receptor of B cells

The immunoreceptor tyrosine-based inhibition motif (ITIM) is found in various membrane molecules such as CD22 and the low-affinity Fc receptor for IgG in B cells and the killer cell-inhibitory receptor and Ly-49 in NK cells. Upon tyrosine phosphorylation at the ITIMs, these molecules recruit SH2 domain-containing phosphatases such as SH2-containing tyrosine phosphatase-1 and negatively regulate cell activity. The B cell surface molecule CD72 carries an ITIM and an ITIM-like sequence. We have previously shown that CD72 is phosphorylated and recruits SH2-containing tyrosine phosphatase-1 upon cross-linking of the Ag receptor of B cells (BCR). However, whether CD72 modulates BCR signaling has not yet been elucidated. In this paper we demonstrate that expression of CD72 down-modulates both extracellular signal-related kinase (ERK) activation and Ca2+ mobilization induced by BCR ligation in the mouse B lymphoma line K46micromlambda, whereas BCR-mediated ERK activation was not reduced by the ITIM-mutated form of CD72. Moreover, coligation with CD72 with BCR reduces BCR-mediated ERK activation in spleen B cells of normal mice. These results indicate that CD72 negatively regulates BCR signaling. CD72 may play a regulatory role in B cell activation, probably by setting a threshold for BCR signaling.

Functional magnetic resonance imaging of auditory cortex: with special reference to the side of aural stimulation

PURPOSE

To determine whether left- or right-side uniaural stimulation produces different fMRI activation patterns.

METHODS

Subjects were 12 volunteers (8 right-handed, 4 left-handed) with normal hearing. Functional imaging using FE-type multishot echo planar imaging was obtained in the axial plane during pure-tone and pseudoword tasks. Auditory stimuli were presented to each ear individually. In pure-tone tasks, subjects heard clustered sequences at 2000 Hz. In pseudoword tasks, subjects heard spoken Japanese syllables. The numbers of activated pixels in the auditory cortex were counted and compared for pure-tone and pseudoword tasks, as was activation according to the side of aural stimulation.

RESULTS

In right-handed subjects, prominent activation in pure-tone tasks was noted in the dominant hemisphere in 100% of cases and was unrelated to the side of the stimulation. In pseudoword tasks, prominent activation was noted on the side contralateral to the stimulus in 62.5-100% of cases. In left-handed subjects, prominent activation was noted on the side contralateral to the stimulus in both pure-tone and pseudoword tasks.

CONCLUSION

Left- and right-side stimulation produced differences in fMRI responses, especially between pure-tone and pseudoword tasks. Moreover, right-handedness and left-handedness affected results. This type of auditory fMRI may be a noninvasive indicator of language lateralization.

An intestinal bacterial metabolite of ginseng protopanaxadiol saponins has the ability to induce apoptosis in tumor cells

Our previous study demonstrated that the in vivo anti-metastatic effect induced by oral administration of ginseng protopanaxadiol saponins was mediated by their metabolic component M1, and that the growth, invasion and migration of tumor cells were inhibited by M1 but not by ginsenosides. Here we investigated the inhibitory mechanism of M1 on the growth of tumor cells. M1 inhibited the proliferation of B16-BL6 mouse melanoma cells in a time- and dose-dependent manner, with accompanying morphological changes at the concentration of 20 microM. In addition, at 40 microM M1 induced apoptotic cell death within 24 h. Fluorescence microscopy revealed that dansyl M1 entered the cytosol and quickly reached the nuclei (approximately 15 min). Western blot analysis revealed that M1 rapidly up-regulated the expression of p27Kip1, but down-regulated the expression of c-Myc and cyclin D1 in a time-dependent manner. Thus, the regulation of apoptosis-related proteins by M1 is responsible for the induction of apoptotic cell death, and this probably leads to the anti-metastatic activity in vivo.

Synthesis of a biologically active fluorescent derivative of GM1, a main Ginseng saponin metabolite formed by intestinal bacteria

A fluorescent derivative of GM1 [20-O-beta-D-glucopyranosyl-20(S)-protopanaxadiol], a main Ginseng saponin metabolite formed by intestinal bacteria, was obtained from the condensation of its trisnor-aldehyde derivative with dansyl hydrazine. The dansylated GM1 fluoresced strongly and showed almost the same properties as its parent compound in lipophilicity and biological activities, so this fluorescent compound might provide an insight into the mechanism of pharmacological activities of GM1.

In vivo antimetastatic action of ginseng protopanaxadiol saponins is based on their intestinal bacterial metabolites after oral administration

The present study demonstrated in vivo and in vitro antimetastatic activities of a major intestinal bacterial metabolite M1 formed from protopanaxadiol saponins of ginseng (the root of Panax ginseng C. A. Meyer) in comparison with its whole standardized extract and ginsenosides Rb1, Rb2, and Rc. Although Ginseng extract (1 mg/mouse) and ginsenosides (0.5 mg/mouse) significantly inhibited lung metastasis produced by i.v. injection of B16-BL6 melanoma cells in syngeneic mice (27-61% of untreated control), they hardly inhibited the invasion and migration of B16-BL6 melanoma and HT1080 fibrosarcoma cells in vitro. However, the intestinal bacterial metabolite M1 inhibited lung metastasis of melanoma cells and in vitro tumor cell invasion and migration at nontoxic or marginally toxic concentrations. Additionally, pharmacokinetic studies of ginsenoside Rb1 and M1 after oral administration (2 mg/mouse) revealed that intact Rb1 was not detectable in serum for 24 h by HPLC analysis, whereas the level of M1 in the serum reached maximum at 8 h (8.5 +/- 0.4 micrograms/ml) after Rb1 administration and at 2 h (10.3 +/- 1.0 micrograms/ml) after M1 administration. These findings suggest that the in vivo antimetastatic effect by oral administration of ginsenosides is mediated by their metabolic component M1.

[Magnetic resonance imaging of brainstem lesions in a case of neuro-Behçet disease]

We reported a 28-year-old man with multiple lesions in the brainstem which were clearly identified and followed up with MRI. He had been treated for Behçet uveitis using cyclosporine and colchicine during the past 5 years, and he acutely presented with fever and headache, followed left hemiparesis, dysarthria and dysphagia. MRI on admission revealed multiple lesions in the ventral pontine region which showed mixed-intensity on T1WI, high-intensity on T2WI and enhancement with Gd-DTPA. His clinical symptoms spontaneously and gradually improved, but more rapidly improved due to additional administration of corticosteroid. The lesions in the brainstem became smaller and finally rudimentary during two months after the onset of neurological symptoms.

Unilateral megalencephaly in linear nevus sebaceous syndrome: a neuroradiological case report

We report a case of linear nevus sebaceous syndrome with seizure, mental retardation, and hemiparesis. Magnetic resonance imaging (MRI) clearly demonstrated associated brain malformations of unilateral megalencephaly with cortical dysplasia and white matter change ipsilateral to the sebaceous nevi of the face and neck. Although magnetic resonance angiography (MRA) demonstrated only distortion of the main cerebral arteries without any occlusive or dysplastic findings, single photon emission computed tomography (SPECT) using [123I]N-Isopropyl-p-iodoamphetamine (IMP) revealed hypoperfusion in the affected cerebral hemisphere.

[Unilateral dissection of the cervical portion of the internal carotid artery and ipsilateral multiple cerebral infarctions caused by suicidal hanging: a case report]

This paper presents a case of traumatic dissection of the unilateral internal carotid artery of the cervical portion caused by hanging. A 63-year-old man attempted suicide by hanging and was rescued immediately after. No neurological deficits were detected for the first 4 hours. But then, right hemiplegia, aphasia and disturbed consciousness suddenly developed. On the 2nd day, MRI revealed multiple infarctions in the left cerebral hemisphere. MR angiography demonstrated severe stenosis at the cervical portion of the left internal carotid artery due to dissection. The left middle cerebral artery was not demonstrated. The patient was conservatively treated with fibrinolytic agents and regained consciousness gradually. But aphasia and right hemiplegia remained. During the next few weeks, the stenosis at the ICA slightly improved and the MCA was completely recanalized. Extracranial Doppler sonography revealed chronological hemodynamic changes of mean flow velocity and pulsatility index at the proximal and distal portion of the ICA stenosis.

Effect of diltiazem on hypoxic pulmonary vasoconstriction in dogs

We have examined the effect of diltiazem upon the pulmonary vascular response to the left lower lobe (LLL) hypoxia in dogs. Without diltiazem, the fraction of cardiac output perfusing the LLL (QLLL/QT) measured by the ultrasonic doppler rheometer in the hypoxic phase was 21.0 +/- 11.7(%) of the ratio in the first normoxic phase. When diltiazem was given as a 0.48 mg/kg intravenous bolus followed by an intravenous infusion of 0.48 mg/kg/hr and 0.96 mg/kg intravenous bolus followed by an intravenous infusion of 0.96 mg/kg/hr, QLLL/QT in the hypoxic phase were 34.0 +/- 14.0, 48.6 +/- 16.1(%) of the ratio in the first normoxic phase respectively. Significant difference was observed at all diltiazem concentrations. With respect to PaO2, significant difference was not observed at all diltiazem concentrations in the ratio of the hypoxic phase to the first control phase. So we concluded that diltiazem obviously attenuated hypoxic pulmonary vasoconstriction (HPV) response but did not decrease PaO2 because of keeping myocardial oxygen balance and better ventilation/perfusing relationship.

Studies on experimental coronary insufficiency. II. Effects of beta-adrenergic blocking agent (propranolol) on metabolic response to adrenaline and noradrenaline in dogs with coronary constriction

To obtain further information on the mechanism by which catecholamines produce myocardial ischemia, the effects of propranolol on metabolic and mechanical responses to adrenaline or noradrenaline were investigated in coronary-constricted dogs. Propranolol suppressed the myocardial ischemia produced by noradrenaline and adrenaline in dogs with moderate coronary constriction.

Studies on experimental coronary insufficiency. I. Effects of a physiological dose of adrenaline and noradrenaline on myocardial metabolism in dogs with graded coronary constriction

To investigate the mechanism by which catecholamines produce myocardial ischemia, the effect of intracoronary-administered adrenaline and noradrenaline was studied in dogs with graded coronary constriction. A physiological dose of catecholamines was favorable for augmentation or improvement of myocardial metabolism and cardiac function in dogs without or with slight coronary constriction. However, in dogs with moderate or severe coronary constriction, similar doses of catecholamines produced myocardial ischemia and cardiac dysfunction.