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.