Exploring the experiences and learning of young primary care physicians in disaster-affected areas: A qualitative study on the Great East Japan Earthquake

Background

Primary care physicians (PCPs) play a critical role in disaster medicine. However, it is unclear how PCPs who provide chronic support to disaster-affected areas learn from their experiences.

Methods

This qualitative study investigates the learnings of young PCPs who provided medical care during the chronic phase of the Great East Japan Earthquake disaster.

Results

Thematic analysis of interviews with five physicians revealed the challenges faced by them and their learnings in providing medical support to disaster-affected areas.

Conclusions

They not only learned medical skills but also humanistic aspects such as empathizing with the survivors' loss.

Mental health training in family medicine residencies: International curriculum overview

Integration of mental health into primary care has become a global trend, and many countries have developed mental health training in primary care. However, systematic mental health training for family physicians is insufficient in Japan. The newly established Japan Primary Care Association Mental Health Committee surveyed the current status of mental health training curricula in family medicine residency internationally. Participants were individuals involved in family medicine residency programs who were from Australia, Brazil, Hong Kong, the Philippines, Taiwan, the United Kingdom, and the United States. The results revealed that many academic societies have created competency lists and curriculum guidelines for mental health training; however, the implementation varied. This study is novel as it examined and compared different countries' curriculum; the findings of which can be used as a reference to develop future mental health training curriculum in Japan.

Management of unspecified anxiety disorder: Expert consensus

AIMS

Treatment guidelines with respect to unspecified anxiety disorder have not been published. The aim of this study was to develop a consensus among field experts on the management of unspecified anxiety disorder.

METHODS

Experts were asked to evaluate treatment choices based on eight clinical questions concerning unspecified anxiety disorder using a nine-point Likert scale (1 = "disagree" to 9 = "agree"). According to the responses from 119 experts, the choices were categorized into first-, second-, and third-line recommendations.

RESULTS

Benzodiazepine anxiolytic use was not categorized as a first-line recommendation for the primary treatment of unspecified anxiety disorder, whereas multiple nonpharmacological treatment strategies, including coping strategies (7.9 ± 1.4), psychoeducation for anxiety (7.9 ± 1.4), lifestyle changes (7.8 ± 1.5), and relaxation techniques (7.4 ± 1.8), were categorized as first-line recommendations. Various treatment strategies were categorized as first-line recommendations when a benzodiazepine anxiolytic drug did not improve anxiety symptoms, that is, differential diagnosis (8.2 ± 1.4), psychoeducation for anxiety (8.0 ± 1.5), coping strategies (7.8 ± 1.5), lifestyle changes (7.8 ± 1.5), relaxation techniques (7.2 ± 1.9), and switching to selective serotonin reuptake inhibitors (SSRIs) (7.0 ± 1.8). These strategies were also highly endorsed when tapering the dosage of or discontinuing benzodiazepine anxiolytic drugs. There was no first-line recommendation regarding excusable reasons for continuing benzodiazepine anxiolytics.

CONCLUSIONS

The field experts recommend that benzodiazepine anxiolytics should not be used as a first-line option for patients with unspecified anxiety disorder. Instead, several nonpharmacological interventions and switching to SSRIs were endorsed for the primary treatment of unspecified anxiety disorder and as alternatives to benzodiazepine anxiolytics.

Physicians' attitudes toward hypnotics for insomnia: A questionnaire-based study

INTRODUCTION

Benzodiazepines and non-benzodiazepines are still widely prescribed despite safety concerns and the introduction of novel hypnotics (orexin receptor antagonists [ORA] and melatonin receptor agonists [MRA]), which may be influenced by physicians' attitudes toward hypnotics.

METHODS

A questionnaire survey was administered to 962 physicians between October 2021 and February 2022, investigating frequently prescribed hypnotics and the reasons for their selection.

RESULTS

ORA were the most frequently prescribed at 84.3%, followed by non-benzodiazepines (75.4%), MRA (57.1%), and benzodiazepines (54.3%). Compared to non-frequent prescribers of hypnotics, a logistic regression analysis showed that frequent ORA prescribers were more concerned with efficacy (odds ratio [OR]: 1.60, 95% confidence interval [CI]: 1.01-2.54, p = 0.044) and safety (OR: 4.52, 95% CI: 2.99-6.84, p < 0.001), frequent MRA prescribers were more concerned with safety (OR: 2.48, 95% CI: 1.77-3.46, p < 0.001), frequent non-benzodiazepine prescribers were more concerned with efficacy (OR: 4.19, 95% CI: 2.91-6.04, p < 0.001), and frequent benzodiazepine prescribers were more concerned with efficacy (OR: 4.19, 95% CI: 2.91-6.04, p < 0.001) but less concerned with safety (OR: 0.25, 95% CI: 0.16-0.39, p < 0.001).

DISCUSSION

This study suggested that physicians believed ORA to be an effective and safe hypnotic and were compelled to prescribe benzodiazepine and non-benzodiazepine frequently, choosing efficacy over safety.

Attitudes and Difficulties Associated with Benzodiazepine Discontinuation

Long-term use of benzodiazepine receptor agonists (BZDs) may depend on clinicians' BZD discontinuation strategies. We aimed to explore differences in strategies and difficulties with BZD discontinuation between psychiatrists and non-psychiatrists and to identify factors related to difficulties with BZD discontinuation. Japanese physicians affiliated with the Japan Primary Care Association, All Japan Hospital Association, and Japanese Association of Neuro-Psychiatric Clinics were surveyed on the following items: age group, specialty (psychiatric or otherwise), preferred time to start BZD reduction after improvement in symptoms, methods used to discontinue, difficulties regarding BZD discontinuation, and reasons for the difficulties. We obtained 962 responses from physicians (390 from non-psychiatrists and 572 from psychiatrists), of which 94.0% reported difficulty discontinuing BZDs. Non-psychiatrists had more difficulty with BZD discontinuation strategies, while psychiatrists had more difficulty with symptom recurrence/relapse and withdrawal symptoms. Psychiatrists used more candidate strategies in BZD reduction than non-psychiatrists but initiated BZD discontinuation after symptom improvement. Logistic regression analysis showed that psychosocial therapy was associated with less difficulty in BZD discontinuation (odds ratio, 0.438; 95% confidence interval, 0.204-0.942; p = 0.035). Educating physicians about psychosocial therapy may alleviate physicians' difficulty in discontinuing BZDs and reduce long-term BZD prescriptions.

Social Isolation and Patient Experience in Older Adults

PURPOSE

Social isolation has been identified as a major health problem, particularly in the elderly. In the present study, we examine the association between social isolation and patient experience in elderly primary care patients.

METHODS

This cross-sectional study was conducted in a primary care practice-based research network (28 clinics) in Japan. We assessed social isolation using an abbreviated Lubben Social Network Scale and patient experience of primary care using a Japanese version of the Primary Care Assessment Tool (JPCAT), which comprises 6 domains: first contact, longitudinality, coordination, comprehensiveness (services available), comprehensiveness (services provided), and community orientation. We used a linear mixed effects model to adjust clustering within clinics and individual covariates.

RESULTS

Data were analyzed for 465 elderly primary care patients aged ≥65 years. After adjustment for possible confounders and clustering within clinics, social isolation was negatively associated with the JPCAT total score, (mean difference = -3.67; 95% CI, -7.00 to -0.38). Among the JPCAT domain scores, social isolation was significantly associated with longitudinality, comprehensiveness (service provided), and community orientation scores.

CONCLUSIONS

Social isolation was associated with negative patient experience in elderly primary care patients. Raising awareness regarding patient social networks among primary care providers and targeted interventions for socially isolated elderly patients aimed at improving the experience of primary care, especially regarding longitudinality, comprehensiveness, and community orientation, may be warranted.

Attributes of primary care in relation to polypharmacy: a multicenter cross-sectional study in Japan

Objective

To investigate the association between attributes of primary care and polypharmacy.

Design

Cross-sectional study.

Setting

A primary care practice-based research network in Japan (28 primary care clinics).

Participants

Adult outpatients filled out a standardized questionnaire.

Main outcome measure

Polypharmacy defined as the use of five or more concurrent prescription or over-the-counter medications.

Methods

Attributes of primary care were assessed via patient experience using the Japanese version of Primary Care Assessment Tool (JPCAT). Poisson mixed effects model was used to adjust for clustering within clinics and covariates.

Results

Data were analyzed for 544 primary care outpatients. After adjusting for patients' sociodemographic and health characteristics, the JPCAT community orientation score was found to be inversely associated with polypharmacy at the clinic level [risk ratio per 1 standard deviation increase = 0.83; 95% confidence interval (CI), 0.73-0.96; P = 0.008]. Sensitivity analyses using a different definition of polypharmacy showed results similar to those of the primary analyses.

Conclusions

We found that a higher level of community-oriented primary care is associated with a lower prevalence of polypharmacy in outpatients at the clinic level. These findings may be useful in developing community-based interventions to minimize polypharmacy.

Influence of overstated abstract conclusions on clinicians: a web-based randomised controlled trial

OBJECTIVES

To investigate whether overstatements in abstract conclusions influence primary care physicians' evaluations when they read reports of randomised controlled trials (RCTs) DESIGN: RCT setting: This study was a parallel-group randomised controlled survey, conducted online while masking the study hypothesis.

PARTICIPANTS

Volunteers were recruited from members of the Japan Primary Care Association in January 2017. We sent email invitations to 7040 primary care physicians. Among the 787 individuals who accessed the website, 622 were eligible and automatically randomised into 'without overstatement' (n=307) and 'with overstatement' (n=315) groups.

INTERVENTIONS

We selected five abstracts from published RCTs with at least one non-significant primary outcome and overstatement in the abstract conclusion. To construct a version without overstatement, we rewrote the conclusion sections. The methods and results sections were standardised to provide the necessary information of primary outcome information when it was missing in the original abstract. Participants were randomly assigned to read an abstract either with or without overstatements and asked to evaluate the benefit of the intervention.

OUTCOME MEASURES

The primary outcome was the participants' evaluation of the benefit of the intervention discussed in the abstract, on a scale from 0 to 10. A secondary outcome was the validity of the conclusion.

RESULTS

There was no significant difference between the groups with respect to their evaluation of the benefit of the intervention (mean difference: 0.07, 95% CI -0.28 to 0.42, p=0.69). Participants in the 'without' group considered the study conclusion to be more valid than those in the 'with' group (mean difference: 0.97, 95% CI 0.59 to 1.36, P<0.001).

CONCLUSION

The overstatements in abstract conclusions did not significantly influence the primary care physicians' evaluations of the intervention effect when necessary information about the primary outcomes was distinctly reported.

TRIAL REGISTRATION NUMBER

UMIN000025317; Pre-results.

Patient experience of primary care and advance care planning: a multicentre cross-sectional study in Japan

BACKGROUND

Advance care planning (ACP) is becoming increasingly important in the primary care setting because of its positive impact on the end-of-life care.

OBJECTIVE

We aimed to investigate the relationship between patient experience of primary care and ACP.

METHODS

This cross-sectional study was conducted in 28 primary care clinics in Japan. We assessed patient experience of primary care using a Japanese version of Primary Care Assessment Tool (JPCAT), which comprises six domains: first contact, longitudinality, coordination, comprehensiveness (services available), comprehensiveness (services provided) and community orientation. The primary outcome measures were ACP discussion between patients and primary care providers and completion of advance directives (AD). We used a generalized linear mixed model to adjust clustering within clinics and individual covariates.

RESULTS

Data were analysed for 535 primary care patients. After adjustment for patients' sociodemographic and health characteristics, the JPCAT total score was found to be significantly associated with ACP discussion [odds ratio (OR) per 1 SD increase = 4.33; 95% confidence interval (CI), 2.53-7.47] but not with completion of AD (OR per 1 SD increase = 1.42; 95% CI, 0.94-2.12). All domains of JPCAT, which represent attributes of primary care, had positive associations with ACP discussion. First contact and comprehensiveness (services provided) domain scores were significantly associated with completion of AD.

CONCLUSIONS

We found that better patient experience of primary care was strongly associated with ACP discussion. Our findings reinforce the significance of patient experience in primary care as part of quality end-of-life care.

Synthesis and antibacterial activity of novel 7-substituted-6-fluoro-1- fluoromethyl-4-oxo-4H-[1,3thiazeto[3,2-a]quinoline-3-carboxylic acid derivatives

A series of 7-substituted-6-fluoro-1-fluoromethyl-4-oxo-4H- [1,3]thiazeto[3,2-a]quinoline-3-carboxylic acid derivatives (2a-1) was prepared and evaluated for antibacterial activity. These compounds were obtained by deacylation of 4-benzoyloxy-2-(1-chloro-2-fluoroethyl)thio-6,7- difluoroquinoline-3-carboxylate (10) and subsequent intramolecular cyclization followed by substitution with cyclic amines and then hydrolysis. The intramolecular cyclization reaction of 18, one of the diastereomers (17, 18) revealed that the cyclization reaction proceeded through an inversion to afford (-)-11a in good chemical and optical yield. The enantiomers of 2a were prepared from the enantiomers of 11a, which were obtained by the optical resolution of the racemate using high-performance liquid chromatography (HPLC). Compounds 2a,b showed excellent in vitro and in vivo antibacterial activity against both gram-negative and gram-positive bacteria including quinolone and Methicillin-resistant Staphylococcus aureus.

Involvement of cholinergic and GABAergic systems in the reversal of memory disruption by NS-105, a cognition enhancer

The effects of (+)-5-oxo-D-prolinepiperidinamide monohydrate (NS-105) on the scopolamine-, electrolytic lesion of the nucleus basalis magnocellularis (NBM)-, AF64A-, baclofen-, cerebral ischemia- and electroconvulsive shock (ECS)-induced memory disruption in the passive avoidance response or radial arm maze tasks were investigated in rats. The effects of NS-105 were compared with those of aniracetam, bifemelane, idebenone, and indeloxazine in two tasks of the passive avoidance response. Furthermore, effects of NS-105 on in vivo release of acetylcholine (ACh) in the cerebral cortex, high-affinity choline uptake (HACU) of the cerebral cortex in rats with lesion of NBM, HACU of the hippocampus in rats treated with pentobarbital and activity of choline acetyltransferase (ChAT) of the cerebral cortex in rats with lesion of NBM were examined. NS-105 showed antiamnestic actions in a variety of animal models of cholinergic dysfunction employed in this study. Aniracetam improved memory disruption caused by scopolamine, but bifemelane, idebenone, and indeloxazine did not. NS-105 (10 mg/kg) showed the increase of ACh release from the cerebral cortex and the enhancement of HACU both in the cerebral cortex and hippocampus, but showed no change in activity of ChAT. NS-105 also reversed memory disruption induced by baclofen, a potent GABA(B) receptor agonist, but all of reference drugs did not. These results suggest that antiamnestic action of NS-105 is due to the facilitation of cholinergic neuronal activity and the suppression of GABA(B) receptor-mediated responses.

Inhibition of stress-stimulated colonic propulsion by alpha 2-adrenoceptor antagonists in rats

Alpha2-adrenoceptor antagonists have been reported to stimulate colonic motor activity, but the effect on colonic motor dysfunction is unclear. We have investigated the effect of alpha 2-adrenoceptor antagonists on wrap-restraint stress-stimulated and normal colonic propulsion in rats. Colonic propulsion was evaluated by the transit of a charcoal marker along the colon. Faecal pellets output was also measured. A 30-min exposure to wrap-restraint stress starting 120 min after infusion of the charcoal marker significantly stimulated colonic transit with a concomitant increase in faecal pellets. Yohimbine and idazoxan, alpha 2-adrenoceptor antagonists, clonidine, an alpha 2-adrenoceptor agonist, and atropine suppressed wrap-restraint stress-stimulated colonic transit and faecal excretion in a dose-dependent manner. Ondansetron and YM060, 5-hydroxytryptamine3 (5-HT3) receptor antagonists, potently inhibited wrap-restraint stress-stimulated colonic transit, but only weakly inhibited faecal excretion. Neither alpha 2-adrenoceptor antagonists nor atropine had any significant effect on normal colonic transit, whereas clonidine and the 5-HT3 receptor antagonists inhibited it. alpha 2-Adrenoceptor antagonists as well as clonidine, atropine and 5-HT3 receptor antagonists inhibit the stress-induced colonic motor dysfunction in rats.

Effect of YNS-15P, a new alpha-2 adrenoceptor antagonist, on stress-stimulated colonic propulsion in rats

We studied effects of a novel alpha-2 adrenoceptor antagonist, YNS-15P (N-[(2R,11bS)-9-methoxy-1,3,4,6,7, 11b-hexahydro-2H-benzoquinolizin-2-yl]-N-methylmethanesulfonami de hydrochloride), on colonic propulsion stimulated by wrap-restraint stress (WRS) or bethanechol, on normal colonic propulsion and on diarrhea induced by castor oil in rats. Alpha-2 adrenoceptor antagonists, rauwolscine and RX821002, decreased the increase in the number and weight of fecal pellets induced by WRS. YNS-15P also inhibited WRS-stimulated fecal excretion in a dose-dependent manner. A 5-hydroxytryptamine3 receptor antagonist, granisetron, trimebutine and diazepam, but not a 5-hydroxytryptamine4 receptor antagonist, GR113808, significantly inhibited WRS-stimulated fecal excretion. YNS-15P inhibited WRS-stimulated colonic transit in a dose-dependent manner. However, YNS-15P had no significant effect on normal fecal excretion and colonic transit or on bethanechol-stimulated fecal excretion. YNS-15P also failed to inhibit castor-oil-induced diarrhea. These results indicate that YNS-15P selectively inhibits WRS-stimulated colonic propulsion, and that alpha-2 adrenoceptors may be involved in stress-induced colonic motor dysfunction in fed rats.

In vivo antibacterial activity of a prodrug of NM394, a thiazetoquinoline carboxylic acid derivative

NM394 (6-fluoro-1-methyl-4-oxo-7-(1-piperazinyl)-4H-[1,3]-thiazeto [3,2-a]quinoline-3-carboxylic acid) has potent, broad-spectrum antibacterial activity in vitro, but not in vivo. To increase the bioavailability of NM394, various prodrugs were synthesized and tested. One of them, NM441, an N-(5-methyl-2-oxo-1,3-dioxol-4-yl) derivative, showed potent in vivo antibacterial activity. Using thin-layer chromatography-bioautography, we confirmed that after oral administration, NM441 was readily absorbed and hydrolyzed to NM394. Other prodrugs of NM394 were only partially metabolized to NM394. In pharmacokinetic studies in mice and monkeys, we found that the blood levels of NM394 were 7.8 and 5.9 times greater, respectively, when NM441 rather than NM394 was administered. These findings suggest that NM441 is an effective prodrug of NM394.

Structure-antibacterial activity and cytotoxicity relationships of thiazolo and thiazetoquinolone derivatives

In the course of our search for derivatives with potent antibacterial activity and low cytotoxicity, we have studied the relationships among the structure, antibacterial activity and cytotoxicity of thiazoloquinolone and thiazetoquinolone derivatives (the term quinolone as used in this paper includes the quinolone, 1,8-naphthyridine and pyridopyrimidine nuclei). The antibacterial activities and cytotoxicity of these derivatives were compared with those of norfloxacin, ofloxacin, enoxacin and ciprofloxacin. The antibacterial activities of the thiazoloquinolone derivatives were more potent than those of the dihyrothiazoloquinolone derivatives, and comparable to that of ciprofloxacin. All of the thiazoloquinolone derivatives were highly cytotoxic against mammalian cells, but some of the dihyrothiazoloquinolone derivatives were less cytotoxic, being comparable in cytotoxicity to the reference drugs. The thiazetoquinolone derivatives were less cytotoxic than the thiazoloquinolone derivatives, and one of them, 6-fluoro-1-methyl-4-oxo-7-(1-piperazinyl)-4H-[1,3]thiazeto[3,2-a] quinoline-3-carboxylic acid, showed the most potent antibacterial activity of all compounds tested in this study, as well as a very low cytotoxicity. The antibacterial activity and cytotoxicity of this compound were similar to that of ciprofloxacin.

Studies on pyridonecarboxylic acids. IV. Synthesis and antibacterial activity evaluation of S-(-)- and R-(+)-6-fluoro-1-methyl-4-oxo-7- (1-piperazinyl)-4H-[1,3] thiazeto[3,2-a]quinoline-3-carboxylic acids

Optically active isomers of 6-fluoro-1-methyl-4-oxo-7-(1-piperazinyl)-4H- [1,3] thiazeto [3,2-alpha] quinoline-3- carboxylic acid (NM394, 3) were prepared through optical resolution of their racemic intermediate ( +/- )-1 by high-performance liquid chromatography (HPLC). The absolute configuration at the C-1 position in the thiazeto-quinolone ring of ( - )-3 was confirmed by X-ray analysis ( - )-4 to be S. The in vitro antibacterial activity of ( - )-3 was 2--8 times that of (+)-3.

Nucleoside-nucleotide mixture increases peripheral neutrophils in cyclophosphamide-induced neutropenic mice

The importance of nucleotides and nucleosides in human nutrition has now become an area of intensive research and clinical interest. To determine any potential benefits of administering a nucleoside-nucleotide mixture (NNM) to cyclophosphamide (CPA)-induced neutropenic mice, we randomly assigned 20 BALB/c mice to two groups and fed them a nucleic-acid-free 20%-casein diet for 20 days. The mice were intraperitoneally administered NNM or saline daily from the onset of the experiment. On the 10th day of this treatment, the mice were intraperitoneally injected with CPA. Blood was collected retro-orbitally and differential counts of leucocytes were done on blood smears by counting microscopically on day 0 (before) and 1, 3, 5, 7, and 10 days after CPA injection. By the 7th and 10th days after CPA injection, respectively, the peripheral neutrophil number in the saline group was significantly lower compared with the neutrophil number in the NNM group (p < 0.05). Also in the NNM group, more clusters of matured neutrophils were observed compared with the saline group. These results suggest that NNM may stimulate the proliferation, differentiation, and maturation of neutrophils, and that NNM alone or in combination with other pharmacologic agents may be an important therapeutic agent in patients after chemotherapy, immunosuppressive therapy, and organ transplant.

A mixture of nucleosides and nucleotides increases bone marrow cell and peripheral neutrophil number in mice infected with methicillin-resistant Staphylococcus aureus

We studied the effects of a mixture of nucleosides and nucleotides on the peripheral neutrophil number and the proliferation of bone marrow cells in mice challenged with methicillin-resistant Staphylococcus aureus. BALB/c mice were fed a nucleotide-free 20% casein diet (control) or this diet supplemented with nucleosides and nucleotides orally (Expt. 1) or intraperitoneally (Expt. 2 and 3). On d 10, the mice were challenged intravenously with methicillin-resistant S. aureus (6.7 x 10(12) colony forming units/L). In Expt. 1 and 2, numbers of total and differential counts of blood leucocytes were counted on d 0 (before), 1, 3 and 5 after the infection. In Expt. 3, 30 min before killing, bromodeoxyuridine (20 mg/kg), an analogue of thymidine, was administered intraperitoneally and its incorporation in the DNA synthetic phase of bone marrow cells was determined at 0 h (before), 3, 6 and 24 h after the infection. Mice fed the supplemented diet had higher (P < 0.05) leucocyte and neutrophil numbers on d 0 compared with the control group. The neutrophil numbers tended to be greater in the supplemented group at 1, 3 and 5 d after the infection. Intraperitoneal administration of nucleosides and nucleotides increased (P < 0.05) neutrophil numbers before and after the infection. Twenty-four h after the infection, incorporation of bromodeoxyuridine into the DNA synthetic phase of bone marrow cells in the group administered nucleosides and nucleotides was higher (P < 0.05) than in the control group. We conclude that, following methicillin-resistant S. aureus injection, intraperitoneal administration of a nucleoside-nucleotide mixture may stimulate bone marrow cell proliferation and increase the peripheral blood neutrophil numbers. Oral administration may elicit weaker effects.

Studies on pyridonecarboxylic acids. III. Synthesis and antibacterial activity evaluation of 1,8-disubstituted 6-fluoro-4-oxo-7-piperazinyl-4H-[1,3]thiazeto[3,2- a]quinoline-3-carboxylic acid derivatives

A series of 1,8-disubstituted 6-fluoro-4-oxo-7-piperazinyl-4H-[1,3]thiazeto[3,2-a]quinoline-3- carboxylic acid derivatives was prepared and evaluated for antibacterial activity. In the 7-piperazinyl series, addition of a fluorine at C-8, which increased the in vitro activity for the 1-hydrogen and 1-methyl analogues and decreased it for the 1-phenyl analogue, improved the in vivo activity of all the analogues. Introduction of a methoxy group at C-8 of the 1-methyl-7-piperazinyl analogue also improved its in vivo antibacterial activity. The effect of 8-substituents on the in vitro and in vivo antibacterial activity of the 1-methyl-7-(4-methyl-1-piperazinyl) series is also discussed.

Intraperitoneal administration of leukotriene B4 (LTB4) and omega-guanidino caproic acid methane sulfonate (GCA) increased the survival of mice challenged with methicillin-resistant Staphylococcus aureus (MRSA)

Infections caused by methicillin-resistant Staphylococcus aureus (MRSA) very often complicate management of immunocompromised patients. We studied the effect of leukotriene B4 (LTB4) and epsilon-guanidino caproic acid methane sulfonate (GCA), on MRSA infection. Mice fed a 20% casein diet were intraperitoneally administered LTB4, GCA, or saline (control) daily for 30 days. On the 10th day of this treatment, mice were challenged with MRSA. The survival rate in the control group (20%) was significantly lower than the rates in the GCA (60%) and LTB4 (50%) groups, respectively (p < 0.05). There was a significant reduction of MRSA in the spleen and kidney of the survived mice in GCA group as against mice in the LTB4 and saline groups, indicating a better recovery in GCA group than the other groups. The results suggest that intraperitoneal administration of GCA and LTB4 may play a role in host defense mechanism during MRSA infections.

[A stick type filter unit for prevention of biohazard in a research laboratory]

It is important to prevent unexpected laboratory infections in a biosafety area. It is recommended that extreme caution should be used when handling needles and syringes to avoid autoinoculation, and that needles and syringes should be used only when there is no alternative. To remove cells and cell debris, a disk-type microfilter unit, which is recommended using a needle, has been used for filtrating supernatant from HIV-1-infected cell cultures. We compared a stick-type microfilter unit, which can be used without a needle, with a disk-type one for their safety and recovery of human immunodeficiency virus particle after filtration. To confirm the right of our comparison, we observed the filter electron microscopically for the virus particles and virus suspensions were carried out and discussed. In conclusion, the stick-type filter should be improved, since the filter unit is inferior to the disk-type filter unit in purification of the virus, but for the safety is superior to the disk-type.

Studies on pyridonecarboxylic acids. 1. Synthesis and antibacterial evaluation of 7-substituted-6-halo-4-oxo-4H-[1,3]thiazeto[3,2-a]quinoline-3- carboxylic acids

A series of [1,3]thiazeto[3,2-a]quinoline-3-carboxylic acids and their esters were prepared and evaluated for antibacterial activity. The derivatives with a hydrogen or methyl group at C-1, fluorine at C-6, and piperazinyl or 4-methyl-1-piperazinyl group at C-7 showed superior in vitro antibacterial activity, and the derivatives with 4-methyl-1-piperazinyl group at C-7 had potent in vivo activity. Compound 29a (NM394) showed excellent in vitro antibacterial activity and low toxicity but poor absorption from the gastrointestinal tract. Compound 29ee (NM441), an N-[(5-methyl-2-oxo-1,3-dioxol-4-yl)methyl] derivative of 29a, was found to possess a favorable pharmacokinetic profile and oral activity superior to that of ciprofloxacin in experimental animals.

In vivo evaluation of NM441, a new thiazeto-quinoline derivative

NM441 is a lipophilic prodrug of a new thiazeto-quinoline carboxylic acid derivative NM394, and when it is administered orally it is readily absorbed and hydrolyzed to its parent compound. After oral administration of NM441 at a dose of 20 mg/kg to dogs, the peak concentration of NM394 in plasma was 2.39 micrograms/ml, whereas it was 0.63 micrograms/ml for NM394 administered alone. The in vivo activity of NM441 was compared with those of ciprofloxacin, ofloxacin, and enoxacin in mouse protection studies. NM441 was as effective as ofloxacin and was twice as effective as ciprofloxacin against systemic infection with Staphylococcus aureus. Against infections with streptococci, NM441 was two to three times as effective as ofloxacin and five times as effective as ciprofloxacin. Against infection with Escherichia coli, NM441 was as effective as ciprofloxacin and ofloxacin, but against infections with Klebsiella pneumoniae, Serratia marcescens, and Pseudomonas aeruginosa, NM441 was two to four times as effective as ciprofloxacin and ofloxacin. NM441 was three to seven times as effective as enoxacin in systemic infections. Against urinary tract infections with E. coli, NM441 reduced the number of bacterial CFU per gram of kidney by 1 to 2 log10 more and, with P. aeruginosa, by 1 to 6 log10 more than did ciprofloxacin and ofloxacin. Against respiratory tract infections with K. pneumoniae, NM441 was as effective as ofloxacin and was twice as effective as ciprofloxacin.

In vitro antibacterial activity of a new quinolone, NM394

NM394 is a new 6-fluoroquinolone antibacterial agent with a tricyclic structure which has a bridge that connects the N-1 and C-2 positions of the quinolone. The antibacterial activity of NM394 against clinical isolates of staphylococci, streptococci, enterococci, members of the family Enterobacteriaceae, and Pseudomonas aeruginosa was equal to or one-half that of ciprofloxacin. NM394 was as active as ofloxacin against gram-positive bacteria and was two to eight times more active against gram-negative bacteria, including P. aeruginosa. NM394 was two to eight times more active than enoxacin against gram-positive and gram-negative bacteria. The MICs of NM394 against Escherichia coli and P. aeruginosa at pH 5.5 were reduced 4 to 16 times compared with those at pH 7.0. Ciprofloxacin, ofloxacin, and enoxacin were 2 to 32 times less active against these two bacteria and Staphylococcus aureus at an acidic pH than they were at pH 7.0. In the presence of 5 mM Mg2+, the MICs of all of these drugs increased 2 to 32 times, but they were only slightly affected by 5 mM Ca2+, type of medium, serum, or size of inoculum. NM394 showed potent bactericidal activity and inhibited the supercoiling activity of E. coli DNA gyrase. The in vitro antibacterial profile of NM394 is similar to that of other 6-fluoroquinolones.

New hypocholesterolemic abietamide derivatives. II. Synthesis and hypocholesterolemic activity of N-phenyl-delta 8-dihydroabietamides

A series of N-phenyl-delta 8-dihydroabietamide analogs were prepared and tested for hypocholesterolemic activity. The effects of substituents of the phenyl moiety on the activities were quantitatively analyzed by using various substituent parameters. The activities were enhanced by the electron-donating effect of ortho and para substitutents and the bulkiness of ortho substituents. A combination of 2,6-dimethylaniline with resin acids other than delta 8-dihydroabietic acid produced lower activities than N-(2,6-dimethylphenyl)-delta 8-dihydroabietamide, abietane-type carboxamides being somewhat stronger than pimarane-type carboxamides. The conversion of the carboxamide group to other groups resulted in more or less of a decrease in activity, giving evidence that the carboxamide group is important to hypocholesterolemic activity.