Vision-based estimation of manipulation forces by deep learning of laparoscopic surgical images obtained in a porcine excised kidney experiment

In robot-assisted surgery, in which haptics should be absent, surgeons experience haptics-like sensations as "pseudo-haptic feedback". As surgeons who routinely perform robot-assisted laparoscopic surgery, we wondered if we could make these "pseudo-haptics" explicit to surgeons. Therefore, we created a simulation model that estimates manipulation forces using only visual images in surgery. This study aimed to achieve vision-based estimations of the magnitude of forces during forceps manipulation of organs. We also attempted to detect over-force, exceeding the threshold of safe manipulation. We created a sensor forceps that can detect precise pressure at the tips with three vectors. Using an endoscopic system that is used in actual surgery, images of the manipulation of excised pig kidneys were recorded with synchronized force data. A force estimation model was then created using deep learning. Effective detection of over-force was achieved if the region of the visual images was restricted by the region of interest around the tips of the forceps. In this paper, we emphasize the importance of limiting the region of interest in vision-based force estimation tasks.

Extracellular vesicles secreted from bone metastatic renal cell carcinoma promote angiogenesis and endothelial gap formation in bone marrow in a time-dependent manner in a preclinical mouse model

Introduction

Bone is a major metastatic site of renal cell carcinoma (RCC). Recently, it is well recognized that bone metastatic tumor cells remodel bone marrow vasculature. However, the precise mechanism underlying cell-cell communication between bone metastatic RCC and the cells in bone marrow remains unknown. Extracellular vesicles (EVs) reportedly play crucial roles in intercellular communication between metastatic tumor cells and bone marrow. Therefore, we conducted the current study to clarify the histological alteration in vascular endothelium in bone marrow induced by EVs secreted from bone metastatic RCC cells as well as association between angiogenesis in bone marrow and bone metastasis formation.

Materials and methods

We established a bone metastatic RCC cell line (786-O BM) by in vivo selection and observed phenotypic changes in tissues when EVs were intravenously injected into immunodeficient mice. Proteomic analysis was performed to identify the protein cargo of EVs that could contribute to histological changes in bone. Tissue exudative EVs (Te-EVs) from cancer tissues of patients with bone metastatic RCC (BM-EV) and those with locally advanced disease (LA-EV) were compared for in vitro function and protein cargo.

Results

Treatment of mice with EVs from 786-O BM promoted angiogenesis in the bone marrow in a time-dependent manner and increased the gaps of capillary endothelium. 786-O BM EVs also promoted tube formation in vitro. Proteomic analysis of EVs identified aminopeptidase N (APN) as a candidate protein that enhances angiogenesis. APN knockdown in 786-O BM resulted in reduced angiogenesis in vitro and in vivo. When parental 786-O cells were intracardially injected 12 weeks after treatment with786-O BM EVs, more bone metastasis developed compared to those treated with EVs from parental 786-O cells. In patient samples, BM-EVs contained higher APN compared to LA-EV. In addition, BM-EVs promoted tube formation in vitro compared to LA-EVs.

Conclusion

EVs from bone metastatic RCC promote angiogenesis and gap formation in capillary endothelium in bone marrow in a time-dependent manner.

The efficacy of sequential therapy with docetaxel and cabazitaxel for castration-resistant prostate cancer: A retrospective multi-institutional study in Japan

OBJECTIVE

This study investigated the efficacy of docetaxel (DOC) and cabazitaxel (CBZ) and examined the factors associated with the prognosis of patients with castration-resistant prostate cancer (CRPC) receiving DOC-CBZ sequential treatment in Japanese real-world data.

METHODS

We retrospectively evaluated data for 146 patients who received DOC followed by CBZ. The correlations of prostate specific antigen (PSA) decrease rate and time to progression between DOC and CBZ treatment were examined. Combined progression-free survival (PFS) of DOC-CBZ and overall survival (OS) from the initiation of DOC and the diagnosis of CRPC were evaluated and compared between patients with high and low PSA levels at the start of DOC and CBZ treatment.

RESULTS

No correlations of PSA decrease rate and time to progression were observed between DOC and CBZ. The patients for whom DOC was started in higher PSA levels had significantly shorter combined PFS (p = 0.003) and OS from the initiation of DOC (p = 0.002). In patients who started DOC at high PSA levels, those who switched to CBZ at low PSA levels had longer OS than those who switched at high PSA levels (p = 0.048). The OS from CRPC of patients who started DOC at low PSA levels was significantly longer than those that started at high PSA levels (p = 0.030).

CONCLUSIONS

For patients for whom DOC was not effective, sequential CBZ might have change to be effective. The PSA levels at the start of DOC and CBZ might be a potential prognostic biomarker.

[Testicular Preservation in a Patient with a Testicular Epidermoid Cyst Achieved by Preoperative Diagnosis : A Case Report]

Testicular epidermoid cysts are relatively rare, accounting for about 1% of all testicular tumors, and are often treated by high orchiectomy. We describe here the case of a testicular epidermoid cyst treated by testicle-sparing surgery due to a preoperative diagnosis. A 23-year-old man complained of a painless mass in the right scrotum. Physical examination revealed a firm little fingertip-sized smooth-surfaced mass in the right testis. Ultrasonography showed a hypoechoic lesion with an echogenic rim in the right testis. A T2-weighted magnetic resonance image showed a well-demarcated mass with a low signal outline. On the basis of a preoperative diagnosis of epidermoid cyst, intraoperative testicular frozen section was performed, and the mass was resected surgically while preserving the testis.

Mucinous tubular and spindle cell carcinoma with a high nuclear grade and micropapillary pattern: A case report

Mucinous tubular and spindle cell carcinoma (MTSCC) is rare in renal cell carcinoma (RCC) and usually demonstrates a low nuclear grade and a better prognosis compared with other RCCs. The authors present a case report of MTSCC containing an area of Fuhrman nuclear grade 3, in addition to an area with a micropapillary pattern. An 82-year-old man consulted a hospital due to macrohematuria, and a tumor in the right kidney was detected. The tumor was resected and histologically examined. The tumor consisted of various growth patterns: Elongated tubular structure, a papillary structure containing a micropapillary pattern and solid pattern with spindle cells. The tumor cells demonstrated Fuhrman nuclear grades 2 and 3. Invasion into the lymph vessel and metastasis into the regional lymph node were observed. Thus, the tumor was diagnosed as a high grade MTSCC. Five months following resection, a computed tomography scan suggested metastasis of the tumor into the para-aortic lymph nodes and liver, and the patient succumbed to brain metastasis. When MTSCC of kidney is observed, careful histological observation is important to avoid missing a high nuclear grade area.

Safe and effective administration of BCG for bladder carcinoma in situ after umbilical cord blood stem cell transplantation

Although intravesical Bacillus Calmette-Guérin (BCG) instillation is the standard treatment for carcinoma in situ of the bladder, it is generally contraindicated in immunocompromised patients. Here we report the first case, to our knowledge, of BCG treatment for a bladder cancer patient who had received umbilical cord blood stem cell transplantation (UCBSCT). BCG can be given safely and effectively in select cases where reconstitution of the immune system has been achieved at least 2 years after UCBSCT.

A 45,X/46,XY Male with Orchidopexy Diagnosed with Mixed Germ Cell Tumor After 21-year Follow-up

A case of a 45,X/46,XY boy with gonadal dysgenesis is presented. The patient showed hypospadias and right undescended testis. He underwent underwent repair surgery for hypospadias, right orchidopexy, and bilateral testicular biopsy. Testicular biopsy revealed no malignant finding. He was followed-up annually by scrotum palpation. When the patient grew up to 24 years old, he was diagnosed to have right testicular tumor. High orchiectomy revealed pT1 seminoma. The management of undescended testis in men with gonadal dysgenesis and disordered sexual development is discussed.

Nephrogenic adenoma in elderly patients: Three case reports

Nephrogenic adenoma (NA), referred to as nephrogenic metaplasia, is a rare benign lesion of the urinary tract. NA is histologically characterized by tubular and papillary formations lined by low cuboidal to columnar epithelial cells. NA is also immunohistochemically characterized by positivity for paired box (PAX) 2, PAX8 and cytokeratin 7, and negative for p63 and prostate-specific antigen. In this study, we present 3 cases of NA arising in the urinary bladder of elderly male patients with predisposing factors: patient 1 had undergone transurethral lithotripsy due to a ureteral stone; patient 2 had undergone transurethral resection of a urothelial carcinoma in the urinary bladder; and patient 3 had been treated with Bacillus-Calmettle-Guérin due to a urothelial carcinoma in the urinary bladder. The characteristics of the NAs of our 3 cases were histologically and immunohistologically consistent with previously reported cases, although 1 patient exhibited a pseudoinvasive pattern. Since NA is a tumor-like benign lesion, it should be clearly differentiated morphologically and immunohistologically from other tumors arising in the urinary tract and from invasion by prostate cancer.

[Clinical study of enterovesical fistulas]

We conducted a retrospective review of 16 patients who were diagnosed with enterovesical fistula in our hospital between January 2000 and July 2013. The patient's median age was 74 years old and 4 were female. Most of the chief complaints were pneumaturia and fecaluria. There was a vesicosigmoidal fistula in 12 patients, an ileovesical fistula in 2, and a rectovesical fistula in 2. The main underlying cause was diverticulitis in 9 patients and a sigmoid colon carcinoma in 3. Diagnoses were made based on the findings of cystoscopy, barium enema, abdominal computed tomography and so on. Treatment varied in each case depending on the etiology and the patient's condition. The procedure was mostly open surgery, but laparoscopic sigmoidectomy was performed preserving the bladder in the two most recent cases.

Effects of cardiotrophin-1 on hemodynamics and endocrine function of the heart

Cardiotrophin-1 (CT-1), a member of the interleukin-6 superfamily of cytokines, possesses hypertrophic actions and atrial natriuretic peptide (ANP)-producing activity in vitro. The goal of our study is to elucidate whether CT-1 affects the cardiovascular system in vivo. Intravenous injection of CT-1 (4-100 microg/kg) in conscious rats evoked significant declines in blood pressure and reflex increases in heart rate (HR) in a dose-dependent manner. CT-1 induced no significant change in cardiac output (from 260.7 +/- 11.0 to 264.7 +/- 26.6 ml. min(-1). kg(-1), P = not significant), which was compatible with the results from isolated perfused rat hearts; HR, change in pressure over time, left ventricular developed pressure, and perfusion pressure were unaffected. Northern blot and RT-PCR analyses revealed that CT-1 increased expression of inducible nitric oxide synthase (iNOS) in lung and aorta but not in heart or liver. Pretreatment with aminoguanidine, a specific iNOS inhibitor, inhibited both iNOS mRNA production and the depressor effect of CT-1. Interestingly, CT-1 increased ventricular expression of ANP and brain natriuretic peptide (BNP). The data demonstrate that CT-1 elicits its hypotensive effect via a nitric oxide-dependent mechanism and that CT-1 induces ANP and BNP mRNA expression in vivo.

The effects of atrial natriuretic peptide infusion on hemodynamic, renal, and hormonal responses during gastrectomy

Atrial natriuretic peptide (ANP) antagonizes the reninangiotensin-aldosterone, adrenocorticotropic hormone-cortisol, vasopressin, and endothelin systems. Surgical injury stimulates these systems and causes vasoconstriction and antidiuresis. We assessed the hemodynamic, renal, and endocrine effects of continuous intravenous infusion of ANP in patients anesthetized with sevoflurane undergoing gastrectomy. ANP (0.1 microgram.kg-1.min-1; ANP group, n = 9) or saline (control group, n = 9) was infused continuously for 3 h from the start of the operation. The ANP group showed much higher urinary volume and sodium, potassium, and chloride excretion than the control group, although the former had lower arterial blood pressure. ANP infusion slightly inhibited aldosterone secretion and initially tended to inhibit renin secretion stimulated by surgery, but it did not affect surgery-induced increases in the plasma concentrations of vasopressin, adrenocorticotropic hormone, cortisol, or endothelin. Two patients in the ANP group experienced excessive hypotension, one experienced bradycardia, and two experienced mild hypoxemia, which required treatment but were resolved easily. These findings suggest that ANP infusion may be used with caution for controlling renal function and arterial blood pressure during surgery.

IMPLICATIONS

Continuous intravenous infusion of atrial natriuretic peptide, 0.1 microgram.kg-1.min-1, during gastrectomy was associated with higher water and sodium excretion and lower arterial blood pressure. It tended to inhibit the renin-angiotensin-aldosterone system compared with saline infusion, which suggests that atrial natriuretic peptide may be useful for intraoperative circulation control.

[Are we legally allowed to administer blood for lifesaving to a patient who refuses it?]

We surveyed the literatures and discussed the legal issues whether we should administer blood for lifesaving to a patient who refuses it. The valid refusal of the transfusion requires the distinct intention of a competent patient. Minors below fifteen years of age are incompetent and their parents make a substituted judgement. Anyone must not give priority to the parents' belief and blood ought to be transfused if necessary for the children's benefits. We could evade liability for withholding blood only when we manage an operation arranged to succeed without blood transfusion, undergoing the sufficient treatments to avoid the risks, as well as on the basis of the valid refusal of a patient. The release deed and the intervention of hospital directors, ethics committees and courts are invalid for the immunity from liability. Anesthesiologists have to take the responsibility on themselves of administering blood or not. A statute law should be established to define what is a patient's valid intention and who is responsible.

Immunohistochemical detection of truncated APC protein in sporadic human colorectal adenomas and adenocarcinomas

Mutations of the APC gene frequently occur in sporadic forms of colorectal adenomas and adenocarcinomas. Phenotypically, the vast majority of these mutations result in the truncation of the APC protein. To demonstrate the defective APC gene product in human colorectal tumors, rabbit region-specific antisera raised against the APC protein of amino acid sequences between 371 and 390 (SPI) and between 1821 and 1840 (SP3) were used to exhibit the truncated APC protein. In all, 86 lesions from 67 cases of sporadic adenoma and adenocarcinoma were examined; abnormal staining patterns were distinguished in 43 lesions (50%); the incidence of abnormalities was not significantly different between adenomas and carcinomas. The majority, 75% exhibited epitopic change with the SPI-positive and SP3-negative phenotype (type P1), and 25% exhibited neither of these phenotypes (type P2). The staining pattern in all lesions was uniform, and studies of carcinomas arising in adenomas showed the same pattern of staining. These findings supported the view that the APC lesion is a very early event in colorectal carcinogenesis. Furthermore, this simple immunohistochemical approach demonstrated that different adenomas from the same patient showed different staining patterns.

Perioperative plasma concentrations of endothelin and natriuretic peptides in children undergoing living-related liver transplantation

To investigate the clinical significance of endothelin (ET), natriuretic peptides, and the renin-angiotensin-aldosterone system in pediatric liver transplantation, we measured plasma levels of ET, atrial and brain natriuretic peptides (ANP, BNP), aldosterone, and plasma renin activity in 18 patients (aged 0.5-12 yr; median 1 yr) undergoing living-related liver transplantation due to congenital biliary atresia and severe liver cirrhosis. Before transplantation, the plasma ET level (28.9 +/- 2.5 [mean +/- SEM] pg/mL) was increased compared with that of healthy children (10-18 pg/mL), but decreased during the anhepatic phase (22.5 +/- 1.6 pg/mL). It increased again after reperfusion and remained at high levels in the early postoperative period (postoperative day 3, 27.8 +/- 3.0 pg/mL). Plasma levels of ANP and BNP and aldosterone and plasma renin activity were also high before surgery. Plasma ANP and BNP did not change significantly during surgery. After transplantation, plasma BNP significantly increased, and plasma ANP tended to increase. Plasma aldosterone increased markedly during the anhepatic phase, although plasma renin activity decreased. After transplantation, plasma aldosterone and plasma renin activity both decreased to within normal levels. Mean arterial blood pressure increased gradually after reperfusion and surgery (postoperative day 3, 35.7 +/- 5.2% increase). No substantial differences in these variables occurred between the younger (< or = 1.0 yr, n = 9) and older patients (> 1.0 yr, n = 9). These results suggest that ET production in the cirrhotic liver is augmented and ET, natriuretic peptides, and the renin-angiotensin-aldosterone system all play some role in the circulatory regulation during perioperative periods of pediatric liver transplantation.

Effects of anesthesia and surgery on plasma endothelin levels

To investigate the clinical significance of endothelin (ET), a potent and long-acting vasoconstrictor peptide in anesthesia and surgery, we measured plasma ET-like immunoreactivity (ET-LI) levels by using radioimmunoassay in patients undergoing various kinds of surgery under general anesthesia. No significant changes in plasma ET-LI levels were observed in patients undergoing relatively minor surgery under general anesthesia with nitrous oxide and halothane (n = 6), enflurane (n = 6), or isoflurane (n = 5). Although plasma ET-LI levels after surgery in patients undergoing total knee replacement (12.4 +/- 0.9 [mean +/- SEM] pg/mL, n = 7), hysterectomy (11.4 +/- 0.6 pg/mL, n = 8) or cholecystectomy (14.8 +/- 1.2 pg/mL, n = 9) were no different from those before surgery, plasma ET-LI levels after surgery in patients undergoing gastrectomy (20.4 +/- 1.9 pg/mL, n = 15), esophagectomy (24.7 +/- 2.5 pg/mL, n = 12), hepatectomy (27.5 +/- 3.4 pg/mL, n = 12), or heart surgery (43.1 +/- 4.1 pg/mL, n = 18) were higher than those before surgery (P < 0.05). Changes in plasma ET-LI levels during surgery had positive correlations with the duration of the operation (n = 100, r = 0.51, P < 0.01) and intraoperative blood loss (n = 100, r = 0.30, P < 0.01). In patients undergoing subtotal esophagectomy, the plasma ET-LI level did not increase during the initial 2 h, but increased gradually during surgery, reached a peak within a few hours after surgery, and declined slowly thereafter.(ABSTRACT TRUNCATED AT 250 WORDS)

Changes of endothelin concentration in cerebrospinal fluid and plasma of patients with aneurysmal subarachnoid hemorrhage

To investigate the clinical significance of endothelin (ET), a potent vasoconstrictor peptide, in subarachnoid hemorrhage (SAH) and SAH-related cerebral vasospasm, we measured the ET-like immunoreactivity (ET-LI) in plasma and cerebrospinal fluid (CSF) obtained serially from patients with SAH due to ruptured cerebral aneurysm who underwent aneurysmal surgery. The normal ET-LI levels in plasma and CSF (n = 24) were 12.4 +/- 2.0 (mean +/- s.d.) and 9.1 +/- 1.2 pg.ml-1, respectively. Plasma ET-LI levels in patients with SAH before surgery (16.8 +/- 7.8 pg.ml-1, n = 8) were higher than the normal values (P < 0.05), and became further elevated after surgery (22.5 +/- 9.4 pg.ml-1). ET-LI levels in plasma and CSF one day after surgery were 18.7 +/- 5.5 and 18.4 +/- 6.8 pg.ml-1 (P < 0.01 vs. normal values), respectively, and declined thereafter. The plasma and CSF ET-LI levels in patients who showed symptomatic vasospasm became concomitantly elevated again. These results suggest that ET is involved in SAH-related vasospasm and raise the possibility that surgical stress influences the vasospasm.

Positive end-expiratory pressure ventilation decreases plasma atrial and brain natriuretic peptide levels in humans

To investigate the possible role of atrial and brain natriuretic peptides (ANP and BNP) in the renal effects of mechanical ventilation with positive end-expiratory pressure (PEEP), we measured changes in plasma ANP and BNP levels during PEEP in patients undergoing subtotal esophagectomy. Application of 15 cm of H2O PEEP for 1 h decreased the levels of plasma ANP and BNP from 24.4 +/- 5.5 (mean +/- SEM) and 19.0 +/- 3.5 fmol/mL to 14.4 +/- 2.1 and 15.3 +/- 3.0 fmol/mL, respectively (P < 0.05). The level of plasma cyclic guanosine monophosphate, an intracellular second messenger of ANP and BNP, also decreased from 8.4 +/- 1.5 to 5.7 +/- 0.8 pmol/mL (P < 0.05). PEEP increased the levels of plasma arginine vasopressin from 2.0 +/- 0.5 to 4.2 +/- 1.2 pg/mL, aldosterone from 36.1 +/- 4.9 to 65.3 +/- 12.7 pg/mL, and plasma renin activity from 1.4 +/- 0.5 to 2.7 +/- 0.7 ng.mL-1.h-1. During PEEP ventilation, urine output, urinary sodium and potassium excretion, osmolar clearance, and cardiac index all decreased. PEEP increased free water clearance, right atrial pressure, pulmonary arterial pressure, and pulmonary capillary wedge pressure. The level of plasma endothelin, mean blood pressure, and heart rate did not change significantly. These results suggest that not only hemodynamics and the vasopressin and renin-angiotensin-aldosterone system, but also the natriuretic peptide system (ANP and BNP), are involved in the renal effects of PEEP.

Low doses of endothelin-1 inhibit atrial natriuretic peptide secretion

To clarify the interaction between endothelin-1 (ET-1) and atrial natriuretic peptide (ANP), the effects of ET-1 on ANP secretion were investigated in isolated perfused rat hearts and in conscious unrestrained rats. Perfusion with 10(-9) M ET-1 stimulated ANP secretion from the isolated perfused rat heart. However, 10(-10) M ET-1 significantly decreased ANP secretion for the initial 15 min of the perfusion period. The perfusion with 10(-11) M ET-1, which is near the plasma level of ET-1 (2 x 10(-12) M), inhibited ANP secretion throughout the perfusion period. The perfusion of 10(-12) M ET-1 slightly decreased ANP secretion. After the ET-1 perfusion period, ANP secretion increased in proportion to ET-1 dose. The inhibitory action of ET-1 on ANP secretion was almost abolished by simultaneous perfusion of indomethacin, a cyclooxygenase inhibitor, but not by methylene blue, an inhibitor of soluble guanylate cyclase. In conscious unrestrained rats the iv infusion of 1 pmol/kg.min ET-1, which doubled the plasma ET-1 level, slightly but significantly decreased the plasma ANP level 5 and 10 min after the initiation of the infusion. The infusion of 10 and 30 pmol/kg.min ET-1 increased the plasma ANP level. These results demonstrate that low doses of ET-1 exert an inhibitory and short-acting action on ANP secretion from the heart, although high doses of ET-1 exert stimulating and long-lasting action, and suggest that prostanoids are involved in this inhibitory action.

Effects of the new anti-ulcer agent 12-sulfodehydroabietic acid monosodium salt on healing of acetic acid-induced gastric ulcers in rats

The macroscopic and microscopic effects of 12-sulfodehydroabietic acid monosodium salt (TA-2711, CAS 86408-72-2) on the healing of acetic acid-induced gastric ulcers in rats were compared with those of sucralfate and carbenoxolone. Test compounds were given orally twice a day for 10 consecutive days from the day after the injury with glacial acetic acid. TA-2711 (50 and 100 mg/kg) dose-dependently decreased the macroscopic ulcer index (mm2). In addition, at a dose of 100 mg/kg, this drug decreased the length of mucosal defect in the ulcerated region and increased the mucosal regeneration index estimated by microscopic observation. Furthermore, the mucosa surrounding the ulcerated area and the regenerated epithelium in the TA-2711 administered group contained more PAS (periodic acid-Schiff)-positive material than those in the control group. On the other hand, neither sucralfate nor carbenoxolone (100 mg/kg) showed any significant effects on ulcer healing.

Acute pulmonary alveolar hypoxia increases lung and plasma endothelin-1 levels in conscious rats

To investigate the effect of pulmonary alveolar hypoxia on the synthesis and release of endothelin (ET)-1, ET-1-like immunoreactivity (-LI) levels of the lung and plasma were measured in conscious unrestrained rats under hypoxic conditions. Sixty-min exposure to alveolar hypoxia (10% O2 or 5% O2) increased the ET-1-LI level in the lung. The plasma ET-1-LI level in hypoxic rats also increased significantly. The increase of plasma and lung ET-1-LI levels were parallel to the severity of hypoxia. These results demonstrates that acute pulmonary alveolar hypoxia increases lung and plasma ET-1-LI levels in conscious unrestrained rats, suggesting a possible physiological or pathophysiological significance of ET in alveolar hypoxia.

[Granulocyte beta-adrenoceptor density increased with methylprednisolone in patients receiving dopamine infusion]

Methylprednisolone (MP) is frequently used in shock states, its antishock mechanisms, however, have not been clarified. Effect of MP 10 mg.kg-1 on granulocyte beta-adrenoceptor density was studied in two patients who required dopamine infusion postoperatively. The granulocyte beta-adrenoceptor density was calculated from the binding of [3H] dihydroalprenolol. Arterial blood pressure and cardiac output increased 1 hr after MP administrations. Beta-adrenoceptor densities were low in both cases prior to the administration of MP (16.1 and 24.6 fmol.mg-1 protein), which increased 11 hr after MP (31.2 and 35.8 fmol.mg-1 protein, respectively). The effects of MP to improve status of cardiovascular system in patients receiving catecholamine-infusion may be associated with the increase in the density of myocardial "down-regulated" beta-adrenoceptor.

Effects of the new anti-ulcer agent 12-sulfodehydroabietic acid monosodium salt on duodenal alkaline secretion in rats

Alkaline secretion was measured by pH-stat titration (pH 7.4) during circulation of 0.15 mol/l NaCl through the duodenal lumen in urethane-anesthetized rats. 12-Sulfodehydroabietic acid monosodium salt (TA-2711), at concentrations of 5 and 10 mg/ml, instilled into the circulating fluid at pH 7.4 caused a slight increase in alkaline secretion. When the duodenal lumen was acidified to pH 2.0 for 5 min by instillation of HCl into the circulating fluid, a remarkable increase in alkaline secretion occurred. Addition of TA-2711 (5 and 10 mg/ml) to the circulating fluid considerably enhanced the acid-induced alkaline secretion, with a concurrent increase in prostaglandin E2 release into the circulating fluid. These effects of TA-2711 were inhibited by the pretreatment with indometacin (10 mg/kg s.c.). The results indicate that TA-2711 has an enhancing effect on acid-induced alkaline secretion and endogenous prostaglandins may be involved in the alkaline secretion enhanced by TA-2711.

Effects of 12-sulfodehydroabietic acid monosodium salt (TA-2711), a new anti-ulcer agent, on gastric mucosal lesions induced by necrotizing agents and gastric mucosal defensive factors in rats

Effects of TA-2711 on gastric mucosal lesions induced by various necrotizing agents and several defensive factors of gastric mucosa were investigated in rats. Oral administration of TA-2711 at 12.5 to 200 mg/kg prevented the formation of gastric mucosal lesions induced by 99.5% ethanol, 0.6 N HCl, 0.2 N NaOH and boiling water with ED50 values of 24, 58, 16 and 101 mg/kg, respectively. Oral TA-2711 at 100 mg/kg increased the gastric mucosal prostaglandin E2 (PGE2) level without any change in transmucosal potential difference. A sustained decrease in gastric mucosal blood flow produced by intragastric administration of 99.5% ethanol was inhibited by oral TA-2711 (50, 100 mg/kg) and 16,16-dimethyl PGE2 (10 micrograms/kg). The effect of TA-2711 on ethanol-induced decrease in blood flow was suppressed by indomethacin (10 mg/kg, s.c.). Oral TA-2711 (25-100 mg/kg) dose-dependently increased the amount of mucus adherent to the gastric mucosa. In addition, gastric HCO3- secretion was increased by intragastric TA-2711 at 2.5 and 5.0 mg/ml. These results suggest that TA-2711 enhances gastric mucosal resistance by increasing mucus and HCO3- secretion and by maintaining mucosal blood flow, and protects the gastric mucosa against various irritants. The effects of TA-2711 appear to be mediated by mucosal prostaglandins such as PGE2.

Effects of 12-sulfodehydroabietic acid monosodium salt (TA-2711), a new anti-ulcer agent, on gastric secretion and experimental ulcers in rats

Effects of 12-sulfodehydroabietic acid monosodium salt (TA-2711), a new anti-ulcer agent, on gastric secretion and experimental ulcers were investigated in rats. Oral administration of TA-2711 at doses of 25 to 100 mg/kg immediately after pyloric ligation markedly reduced pepsin activity and slightly lowered acid concentration without affecting the volume of gastric juice. Addition of TA-2711 (0.25-16 mg/ml) directly to gastric juice also reduced pepsin activity in vitro. Oral TA-2711 dose-relatedly inhibited the formation of pylorus-ligated ulcers (50-200 mg/kg), aspirin-induced gastric erosions (25-100 mg/kg) and cysteamine-induced duodenal ulcers (100-800 mg/kg). In addition, this drug prevented both the formation of gastric lesions (6.3-100 mg/kg, p.o.) and the fall in gastric potential difference (100 mg/kg, p.o.) induced by ethanol. The preventive effect against ethanol-induced lesions was suppressed by pretreatment with indomethacin (10 mg/kg, s.c.). Intravenous dosing of TA-2711 (10-100 mg/kg) never produced such effects on ethanol-induced lesions and pepsin activity as observed by oral administration. These results indicate that TA-2711 exerts its anti-ulcer effect by a local action, and it is suggested that both reduction of pepsin activity and a mucosal prostaglandin-mediated process are involved in the anti-ulcer action of TA-2711.

Possible activation of intracellular beta-adrenoceptors by extraneuronally accumulated isoprenaline in perfused rat heart

Two rat hearts were perfused in series by a modified Loewi's method. The recipient heart was perfused with the perfusate collected from the donor heart. 1. After perfusion with 3H-isoprenaline in the presence of tropolone, an inhibitor of catechol-O-methyltransferase, the donor heart was washed out with amine-free medium containing tropolone and corticosterone. The heart rate of the recipient heart increased after the change to the perfusate from the donor heart during the wash-out. After wash-out the heart rate of the donor heart (which had accumulated 43.4 pmol.g-1 3H-isoprenaline) was higher than that of the recipient heart (which had accumulated 0.44 pmol.g-1 3H-isoprenaline), and the rates of efflux of 3H-isoprenaline from both hearts were similar. 2. After perfusion with 3H-isoprenaline and corticosterone in the absence of tropolone, the enhanced heart rate of the donor heart decreased during wash-out with amine-free medium in the presence of corticosterone. The heart rate of the recipient heart increased after the medium change to the perfusate from the donor heart, and the heart rates in both hearts were similar after wash-out. Only small amounts of 3H-isoprenaline remained in both hearts after wash-out, and the rates of efflux of 3H-isoprenaline from both hearts were similar. 3. After perfusion with 3H-isoprenaline in the presence of tropolone, the effects of propranolol and atenolol on the heart rate during wash-out with amine-free medium containing tropolone and corticosterone were compared. The inhibitory effect of propranolol on the heart rate was significantly greater than that of atenolol.(ABSTRACT TRUNCATED AT 250 WORDS)

Extraneuronal accumulation of isoproterenol in atria and ventricle of perfused rat heart

Extraneuronal accumulation of isoproterenol in atria and ventricle of perfused rat heart was investigated. Rat hearts were perfused with various concentrations of 3H-isoproterenol for 30 min in the absence and the presence of catechol-O-methyltransferase (COMT) inhibitor (tropolone). When COMT was intact, the accumulation of 3H-isoproterenol in both atria and ventricle after perfusion with low concentration of 3H-isoproterenol (0.01 to 1 mumol/l) was less than that of perfusing concentration; the tissue/medium ratio (T/M) of isoproterenol for artia was lower than that for ventricle. The T/M of isoproterenol after perfusion with 10 and 20 mumol/l of 3H-isoproterenol were 0.94 and 1.76 for atria and 3.25 and 2.95 for ventricle, respectively. When COMT was inhibited by tropolone, the T/M increased 6.3-9.0 folds for atria and 5.1-6.7 folds for ventricle after perfusion with 3H-isoproterenol (0.01 to 1 mumol/l). From these results, it was concluded that both atria and ventricle of the rat heart have an extraneuronal O-methylating system as reported in rat whole heart, and was suggested that there might be different capacities of extraneuronal uptake and COMT between them.

Chloropolysporins A, B and C, novel glycopeptide antibiotics from Faenia interjecta sp. nov. V. Comparative studies of the biological properties

Chloropolysporins A, B and C, as well as derivatives prepared from this group and alpha- and beta-avoparcins by enzymatic and mild acid hydrolysis, were active against Gram-positive bacteria including clinically isolated methicillin-resistant Staphylococci (MIC 0.39-6.25 micrograms/ml) and anaerobic enterobacteria (MIC 0.10-1.56 micrograms/ml). Derhamnosyl and demannosyl derivatives from both groups of antibiotics showed stronger activities than the parent compounds. The MIC and MBC values against Staphylococci were similar and were not effected by the presence of serum. Moreover, chloropolysporin C exhibited very strong synergistic effects with various beta-lactam antibiotics against methicillin-resistant strains of Staphylococcus aureus. Some of these compounds also protected mice from experimental infection with S. aureus. Acute toxicities of chloropolysporin by intravenous administration ranged from 215-290 mg/kg in mice. Chloropolysporin B as well as other glycopeptide antibiotics, showed distinctive growth promoting activity in broiler chickens.

Differential effects of hypoxia on the turnover of norepinephrine and epinephrine in the heart, adrenal gland, submaxillary gland and stomach

The authors examined the effects of hypoxia (8% O2 in N2) on the turnover rates of norepinephrine (NE) and epinephrine (E) in the heart, adrenal gland, submaxillary gland and stomach. The turnover rates were estimated by measuring the decrease in the content of NE and E after an i.p. injection of alpha-methyl-p-tyrosine (250 mg/kg), an inhibitor of tyrosine hydroxylase. After a 4-h exposure to hypoxia, the turnover rate of NE in the heart and those of NE and E in the adrenal gland were increased, whereas that of NE in the submaxillary gland was decreased. The turnover rate of NE in the stomach was unchanged. Pretreatment with hexamethonium, a ganglionic nicotinic receptor blocker, abolished the hypoxia-induced changes in the turnover rate of NE or E in the heart, adrenal gland and submaxillary gland. Furthermore, transection of the spinal cord at the level of C5-6 abolished hypoxia-induced alterations in the turnover rate of NE and E in the adrenal gland and submaxillary gland. In contrast, the hypoxia-induced changes seen in the heart persisted, although at a lower level, even after transection. These results show that the effects of hypoxia on the activities of the sympathoadrenal system differ depending on the organs; activities are increased in the heart and adrenal gland, decreased in the submaxillary gland and unchanged in the stomach. Furthermore, the present data suggest that hypoxia-induced alterations in the activities of cardiac sympathetic nerves originate in both the brain and spinal cord, including preganglionic neurons, whereas changes in the activities of the sympathetic nerves to the adrenal gland and submaxillary gland originate mainly in the brain.

Effects of extraneuronal uptake inhibitors on the positive chronotropic response to isoprenaline and on the accumulation of isoprenaline in perfused rat heart after inhibition of catechol-O-methyl transferase

Experiments were carried out in isolated perfused rat hearts. The presence of tropolone (100 mumol/l), an inhibitor of catechol-O-methyl transferase (COMT), significantly potentiated the positive chronotropic response to isoprenaline (0.1, 1, 3 and 10 nmol/l). Two uptake2 inhibitors, 3-O-methylisoprenaline (100 mumol/l) and normetanephrine (100 mumol/l), induced a positive chronotropic response, but corticosterone (100 mumol/l) and hydrocortisone (100 mumol/l) had no such effect. 3-O-methylisoprenaline (100 mumol/l) and normetanephrine (100 mumol/l) enhanced the positive chronotropic response to isoprenaline (0.1, 1, 3 and 10 nmol/l). Corticosterone (100 mumol/l) potentiated the positive chronotropic response to isoprenaline (0.1 and 1 nmol/l). Hydrocortisone (30 mumol/l) enhanced the response to 0.1 nmol/l isoprenaline but did not affect the positive chronotropic responses to 1, 3 or 10 nmol/l isoprenaline. The addition of uptake2 inhibitors (3-O-methylisoprenaline, 100 mumol/l; normetanephrine, 100 mumol/l; corticosterone, 100 mumol/l) to the perfusion medium significantly reduced the positive chronotropic response to the perfusion with isoprenaline (3 nmol/l) and tropolone (100 mumol/l). The accumulation of 3H-isoprenaline in the heart perfused with 3H-isoprenaline (1, 10 and 100 nmol/l) was significantly increased by the presence of tropolone (100 mumol/l): the accumulation for 1, 10 and 100 nmol/l of 3H-isoprenaline was 5.07, 47.0 and 500 pmol/g, respectively. The high accumulation observed during perfusion with 3H-isoprenaline (3 nmol/l) and tropolone (100 mumol/l) was significantly decreased by the addition of an uptake2 inhibitor, 3-O-methylisoprenaline (100 mumol/l), normetanephrine (100 mumol/l) or corticosterone (100 mumol/l), but not by hydrocortisone (30 mumol/l).(ABSTRACT TRUNCATED AT 250 WORDS)

Intestinal bacteria antagonistic to Clostridium difficile in mice

Overgrowth by Clostridium difficile has been reported in conventional mice injected intraperitoneally with ampicillin. In this study, we aimed to determine which types of indigenous intestinal bacteria were eliminated by ampicillin to allow overgrowth by C. difficile. C. difficile overgrowth was associated with a decrease in the numbers of lactobacilli, an increase in bacteroidaceae and a slight decrease in the frequency of isolation of fusiform-shaped bacteria (clostridia). C. difficile cytotoxin was detected in caeca from mice in which the numbers of C. difficile were greater than 10(5) per gram of faeces. Gnotobiotic mice were inoculated with various groups of intestinal anaerobes to determine which members of the indigenous flora would antagonize C. difficile. Gnotobiotic mice inoculated with three strains of lactobacilli, 37 strains of bacteroides or 46 strains of clostridia isolated from limited-flora mice were unable to eliminate C. difficile. C. difficile was eliminated, however, from the gastrointestinal tracts of gnotobiotic mice inoculated with whole faeces or chloroform-treated faeces from conventional mice or whole faeces from limited-flora mice containing only clostridia.

Antibacterial activity of cefmetazole alone and in combination with fosfomycin against methicillin- and cephem-resistant Staphylococcus aureus

In vitro and in vivo antibacterial activities of cefmetazole alone and in combination with fosfomycin against methicillin- and cephem-resistant (MR) strains of Staphylococcus aureus were investigated, and the mechanism of synergistic effect between cefmetazole and fosfomycin was also studied. Cefmetazole inhibited the growth of 71 strains of MR S. aureus at concentrations ranging from 1.56 to 50 micrograms/ml; the antibacterial activity of cefmetazole against these strains was enhanced approximately 4 times with the addition of fosfomycin at a concentration of 1.56 micrograms/ml. The binding affinity of cefmetazole for the penicillin-binding protein 2' fraction specific for MR S. aureus was higher than that of methicillin, cloxacillin, cefazolin, and cefotaxime. A synergy experiment in vitro was performed by checkerboard titration with Mueller-Hinton agar plates containing various concentrations and ratios of cefmetazole and fosfomycin. The fractional inhibitory concentration index ranged from 0.09 to 0.75. Exposure of cefmetazole plus fosfomycin to exponentially growing cultures at a concentration at which both antibiotics had no bactericidal effect when given alone exerted bactericidal action. Combined administration of cefmetazole with fosfomycin at a ratio of 1:1 against systemic MR S. aureus infections with mice showed an excellent therapeutic efficacy as compared with administration of either antibiotic alone. Penicillin-binding protein 2', 2, and 4 fractions were scarcely detectable in MR S. aureus strains grown in the presence of fosfomycin at concentrations of 0.25 MIC and 0.5 MIC, respectively.

Isolation of Clostridium difficile from various colonies of laboratory mice

An attempt was made to isolate Clostridium difficile from a total of 565 mice from nine different conventional mouse colonies and six different specified-pathogen-free mouse colonies. C. difficile was isolated from all the conventional colonies but from none of the specified-pathogen-free colonies. Ampicillin injected intraperitoneally increased the isolation rate of C. difficile from mouse faeces to 63.6% compared with 19.4% from untreated mice.

Effects of trimebutine maleate (TM-906) on the spontaneous contraction of isolated duodenum and ileum in both guinea pigs and rabbits

Effects of trimebutine maleate (TM-906) on the spontaneous contraction of isolated duodenum and ileum were studied in both guinea pigs and rabbits. In the duodenum and ileum of both guinea pigs and rabbits, TM-906 (10(-6) g/ml, 10(-5) g/ml) produced a potentiation of the spontaneous contraction in preparations with low contractile activity (low tone or small contraction), while it caused an inhibition of the spontaneous contraction in preparations with high contractile activity (high tone or large contraction). The potentiation of spontaneous contraction by TM-906 was more pronounced in the ileum than in the duodenum of both guinea pigs and rabbits. When the spontaneous contraction of duodenum and ileum was decreased by atropine, the potentiation of spontaneous contraction by TM-906 was further augmented and was more pronounced in the ileum than in the duodenum. When the spontaneous contraction was remarkably potentiated by physostigmine or acetylcholine, TM-906 markedly inhibited the potentiated spontaneous contraction, and the potentiation by TM-906 seen in preparations with low contractile activity disappeared. From these results, it is concluded that TM-906 produces, depending on the contractile activity of the preparations, a potentiation or an inhibition of the spontaneous contraction of duodenum and ileum in both guinea pigs and rabbits and that the potentiation by TM-906 is more pronounced in the ileum than in the duodenum. It is suggested that the endogenous acetylcholine partly modifies the effects of TM-906, but that it does not relate to the more pronounced potentiation by TM-906 in the ileum than in the duodenum.

A new model of ventricular fibrillation induced by isoprenaline and catechol-O-methyl transferase inhibitor at a high perfusion temperature in isolated rat hearts

Isolated rat hearts were perfused with various concentrations of isoprenaline (0.01-10 mumol/liter) for 30 min at a constant flow rate (6.5 ml/min) at 37-44 degrees C. The occurrence of ventricular fibrillations was isoprenaline concentration dependent and also perfusion temperature dependent in the combined treatment with various concentrations of isoprenaline and high perfusion temperatures. When the hearts were perfused with isoprenaline (1 mumol/liter) in the presence of tropolone (100 mumol/liter) at 40-41 degrees C, the duration of ventricular fibrillations was significantly prolonged, but the incidence of ventricular fibrillations was similar to that produced with isoprenaline (1 mumol/liter) alone. The antiarrhythmic drugs such as quinidine sulfate, lidocaine hydrochloride, dl-propranolol hydrochloride, carteolol hydrochloride, atenolol, dl-verapamil hydrochloride, and diltiazem hydrochloride, given at a concentration of 10 mumol/liter, significantly suppressed the incidence and duration of such ventricular fibrillations. Bretylium tosylate (10 mumol/liter) significantly suppressed the duration of the ventricular fibrillations but not their incidence. These results indicate that ventricular fibrillation induced by combined treatment with a high concentration of isoprenaline and tropolone at a high perfusion temperature in isolated rat hearts is a more useful experimental model of arrhythmia than conventional models.

Serological analysis of ureaplasmas isolated from various animals

Ureaplasmas from various animal species were serologically characterized by the growth inhibition test as well as by the metabolism inhibition test. The animals positive for ureaplasmas included 9 common squirrel monkeys, 9 green monkeys, 164 cynomolgus monkeys, 58 chimpanzees, 73 goats, 11 sheep, 102 dogs, 116 cats, 64 cattle, 290 chickens, 3 red jungle fowls and 5 Japanese bantams. Simian ureaplasmas were divided into four serogroups in accordance with the zoological classification of the primates' families. Caprine ureaplasmas were all similar antigenically, and ovine ureaplasmas cross-reacted with the caprine ones, except for one strain. Canine, feline and bovine ureaplasmas were divided into groups of four, two and three, respectively. Avian ureaplasmas contained only one serogroup. All these ureaplasma serogroups were remarkably unrelated antigenically to each other, as shown by the growth inhibition test. Ureaplasmas could not be isolated from rhesus monkeys, Japanese monkeys, orangutans, gorillas, mice, rats, mongolian gerbils, hamsters, guinea pigs, rabbits, opossums, pigs, quails and turkeys.

[Effects of trimebutine maleate (TM-906) on the gastrointestinal motility in anesthetized dogs]

Effects of trimebutine maleate (TM-906) on the spontaneous motility of the gastrointestinal tracts were investigated in anesthetized dogs by means of force transducers. TM-906, administrated intravenously or intraduodenally, produced an inhibition followed by a potentiation of the spontaneous motility in the stomach, and caused a potentiation of the spontaneous motility in the duodenum, jejunum, ileum and colon. These effects of TM-906 were observed also in the vagotomized dogs as in the intact dogs. From these results, it is suggested that TM-906 modulates the spontaneous motility of the gastrointestinal tracts primarily through the peripheral mechanism.

Effects of trimebutine maleate (TM-906) on the smooth muscles of isolated guinea pig gallbladder

Effects of trimebutine maleate (TM-906) on the smooth muscles of isolated guinea pig gallbladder were investigated. TM-906 inhibited the contractile responses to cholinergic nerve stimulation (5 Hz) and to acetylcholine (3 X 10(-8) g/ml) to the same extent, both of which produced much the same amplitude of contraction. TM-906 noncompetitively antagonized the contractile response to methacholine, and it caused a parallel shift of dose-response curves for the contractile response to CaCl2 to higher concentrations. Moreover, TM-906 inhibited the contractile response to 50 mM KCl in a dose-dependent manner. On the other hand, TM-906 itself evoked a slight contractile response in a dose-dependent manner. The contractile response induced by TM-906 was prevented by exposure to Ca++-free solution, but not by tetrodotoxin or atropine. From these results, it was suggested that TM-906 inhibited the contractile responses to cholinergic nerve stimulation, acetylcholine, methacholine and 50 mM KCl by reducing the influx of calcium ion across the cell membrane, while it was assumed that TM-906 itself evoked a slight contractile response by increasing in some way the concentration of the intracellular free calcium ion available for the contractile systems.

Effects of trimebutine maleate (TM-906) on the spontaneous contraction of isolated guinea pig colon

Effects of trimebutine maleate (TM-906) on the spontaneous contraction of isolated guinea pig colon were investigated. TM-906 in the concentrations of 10(-6) g/ml and 10(-5) g/ml increased the tone without affecting the amplitude of the spontaneous contraction in the preparations with low tone, whereas it decreased the tone and the amplitude of the spontaneous contraction in the preparations with high tone. At the higher concentration (10(-4) g/ml). TM-906 decreased the tone and finally abolished the spontaneous contraction in any preparation. The increase in tone induced by TM-906 was prevented by diltiazem and exposure to Ca++-free solution, but not by tetrodotoxin, atropine, phentolamine or propranolol, and depended on the extracellular concentration of CaCl2. On the other hand, the decrease in tone and amplitude of the spontaneous contraction produced by TM-906 were not prevented by tetrodotoxin, phentolamine or propranolol. TM-906 further increased the tone increased by 10 mM KCl, while it decreased the tone increased by 30 mM KCl. From results described above, it is suggested that TM-906 possesses both a relaxing effect and an excitatory effect which seem to be due to its direct action on the smooth muscle.

Selective bronchial suctioning in the adult using a curve-tipped catheter with a guide mark

Our results of previous and successive studies indicate that torque control of curve-tipped catheters is easily accomplished by placing a guide mark on the catheter. Thus, a guide mark was made on a curve-tipped 14 FG Portex suction catheter using a felt pen. The efficacy of selective bronchial suctioning using this catheter was studied in 50 patients. Directed suctioning of the left and right bronchial passages was performed in each patient 3 times and once, respectively, with the head in the midline position. The success rate of left bronchial suctioning was 92% (138/150 attempts) and success in right bronchial suctioning 98% (49/50 attempts). The curve-tipped catheter with a guide mark significantly improved the success rate of left bronchial entry over the previous rate from 50% to 92%.

[Effects of trimebutine maleate on the gastrointestinal motility in conscious dogs]

Trimebutine maleate is known to have beneficial effect in the treatment of gastrointestinal disorders. In conscious dogs with implanted force transducers, effects of trimebutine maleate on the gastrointestinal motility were investigated by intravenous injection, and the results were compared to those with metoclopramide and hyoscine-N-butylbromide. When trimebutine maleate was administered during the motor quiescence in the interdigestive state, contractions were evoked or the quiescent time was shortened in the gastrointestinal tract. In the digestive state, the gastric antral contractile activity was reduced, and duodenal activity was somehow suppressed by trimebutine maleate; but in the jejunum, ileum or colon, the activity was augmented. Injection of metoclopramide evoked a continuous contraction in the gastric antrum and duodenum during the period of motor quiescence in the interdigestive state. In the digestive state, metoclopramide caused a slight enhancement in the contractile activity of the gastric antrum. On the other hand, hyoscine-N-butyl-bromide produced no effect during the period of motor quiescence in the interdigestive state and suppressed the activity of the gastrointestinal tract during the digestive state. Thus, the pattern of action of trimebutine maleate was different from metoclopramide and hyoscine-N-butylbromide. It was concluded that trimebutine maleate produces dual actions, suppression and acceleration, on the gastrointestinal motility in conscious dogs.

[Effects of trimebutine maleate (TM-906) on the spontaneous contraction of the isolated guinea pig stomach]

Effects of trimebutine maleate (TM-906) on the spontaneous contraction were investigated in the isolated circular smooth muscle of the antrum region of the guinea pig stomach. TM-906 dose-dependently reduced the amplitude of the regular spontaneous contraction without any marked change in its frequency and basal tension. This effect of TM-906 was also observed in the presence of phentolamine, propranolol, atropine, and tetrodotoxin. However, the inhibitory effect of TM-906 was overcome by increasing the extracellular concentration of CaCl2. On the other hand, in preparations which exhibited irregular spontaneous contraction, TM-906 regularized it, and spontaneous contraction with regular frequency and amplitude was elicited. In addition, this regularizing effect of TM-906 was also observed in the presence of atropine and tetrodotoxin. It was concluded that TM-906 has dual effects on the spontaneous contraction, reducing the amplitude of regular contraction and regularizing the irregular contraction. These effects of TM-906 may be attributed to the direct action on the smooth muscle.

[An attempt for eradication of respiratory diseases in breeding mice by sanitary improvement of care]

An attempt was made to eradicate respiratory diseases developed in about 1,000 mice of 19 congenic inbred strains which were maintained in a mouse breeding room. The contagious diseases with respiratory signs were found to be caused by mixed infections with Mycoplasma pulmonis and Sendai virus. The eradication of the diseases was mainly made by sanitary improvement in care of the mice such as intensive disinfection, culling some diseased mice and so on, instead of destroying all colonies. As the result, mycoplasma infection decreased gradually, resulting in a complete eradication about one and half years later and remarkable increases in litter size and weaning rate of mice were obtained. Sendai virus infection failed to be eradicated.

Isolation of ureaplasmas from poultry and experimental infection in chickens

Ureaplasmas were isolated from the oropharynxes of 47 of 247 (19 per cent) Leghorn chickens (Gallus gallus domesticus) and from five Japanese bantams but none was isolated from the oropharynx or cloaca of other poultry comprising 10 Japanese game, 75 common quails (Coturnix coturnix japonica), 17 turkeys (Meleagris gallopavo) and 10 guinea fowls (Numida galeata). In apparently healthy chickens, ureaplasmas were found at various sites, including the conjunctiva, nasal cavity, oropharynx, upper and lower tracheas, but not from the air sac, lungs, yolk, oviduct, urine or cloaca. All the isolates were antigenically similar but had no serological relation to those isolated from man, monkey, cattle, goat, sheep, dog and cat. In chickens experimentally infected with an avian ureaplasma, the organisms infected the oropharynx and nasal cavity but none of the birds inoculated demonstrated any clinical signs or macroscopic lesions.