Chemosensitivity of neurons in the dorsal motor nucleus of the vagus that responded to portal infusion of hypertonic saline in rats

Neural responses in the dorsal motor nucleus of the vagus (DMV) to topical administrations of sodium and portal infusions of hypertonic saline were investigated electrophysiologically by using multibarrel electrodes in anesthetized rats. Of 102 neurons that showed antidromic response to electrical stimulation of the ventral gastric vagus or the accessory celiac vagus, 51 neurons increased and 13 neurons decreased their discharge rates in response to the electrophoretic administration of sodium. The other 38 neurons did not respond to this stimulation. The portal infusion of hypertonic saline elicited neural responses of some DMV neurons whose axons are involved into either the ventral gastric or the accessory celiac vagus. Further, effects of the topical administration and the portal infusion of hypertonic saline were examined on 33 neurons. Typical response was characterized by an increase in discharge rate responding to both of the portal infusion and the topical administration. In conclusion, the DMV neurons receiving the afferent inputs from hepatoportal osmoreceptors may have an enteroceptor function detecting the change in osmotic pressure of their environment.     

Clinical and immunological studies on patients with Graves' disease preoperatively treated with corticosteroids and iodides

The purpose of this study was to evaluate the acute effects of corticosteroid and iodide preoperative therapy in patients with Graves' disease in terms of thyroid function and immunological parameters. The above combination was prescribed for 4 patients who had experienced severe side effects from antithyroid drugs (ATD) in order to reduce the possibility of post-thyroidectomy thyroid storm. Corticosteroids were employed daily for four days, and iodides were given daily for two weeks prior to thyroidectomy. The free T₃ values decreased rapidly to euthyroid levels following the administration of both drugs, although the free T₄ values were still much higher than normal in 3 of the 4 patients at the time of surgery. By comparison, 3 of 8 patients treated with ATD also had thyroid hormone levels above normal. Studies of lymphocyte subsets revealed that the percentage of helper T cells was significantly less in the corticosteroidiodide treatment group than in the control and ATD groups. It is thus possible that postoperative thyroid storm might be prevented through corticosteroid-iodide therapy by virtue of the reduction of free T₃ values to within the normal range by the time of surgery. The acute suppression of helper T cells was another result of this form of therapy observed.     

Effects of iomeprol,a new nonionic contrast medium,vis a vis iopamidol and nitroglycerin,on coronary diameter and blood flow in chronically instrumented dogs

The effects of an intracoronary administration of iomeprol, a new nonionic tri-iodinated water-soluble contrast medium, on coronary circulation were compared to those of iopamidol and those of nitroglycerin in 6 chronically instrumented conscious dogs. A pair of 10 MHz piezoelectric crystals and an electromagnetic flow probe were placed on the left circumflex coronary artery (LCCA) to measure the epicardial coronary diameter (CD) and coronary blood flow (CBF). Polyethylene tubing for drug administration was inserted into the LCCA proximal to the sonomicrometers. Iomeprol at the dose of 1 ml and 3 ml/min for 1 min significantly increased CD by 0.6±0.1% and 1.4±0.3%, respectively and CBF by 44.5±9% and 70±10%, respectively. Iopamidol at the same rates also significantly increased CD by 0.8±0.1% and 1.5±0.3% and CBF by 50±11% and 82±14%, respectively. There was no statistically significant difference between iomeprol-and iopamidol-induced increases in CD and CBF. However, the duration of the increase in CD was significantly shorter (p<0.05) after iomeprol than after iopamidol. Nitroglycerin (10 μg/kg) significantly increased CD by 4.5±1% and CBF by 105±10%. The increases in CD and CBF in response to iopamidol and iomeprol were significantly smaller (p<0.01) than to nitroglycerin. We conclude that vasodilating effects of iomeprol and iopamidol on the large epicardial coronary artery and coronary blood flow are comparable in conscious dogs and significantly lower than after nitroglycerin in the doses used by us. This study was supported by a grant from the EI-ZA1 Pharmaceutical Co., Tokyo, Japan.     

Regeneration of periodontal ligament and cementum by BMP-applied tissue engineering

Previously, we demonstrated that the inductive properties of bone morphogenetic protein (BMP) highly depend on the nature of the carrier material used for implantation. In this paper, we show that administration of BMP incorporated in a fibrous collagen membrane can help to regenerate periodontal ligament and cementum both in cat canines and in monkey molars. The partially purified bovine BMP was combined with one or two layers of a fibrous collagen membrane. Although the single layer approach showed partial regeneration of periodontal defects, it also quite often led to ankylosis. The double layer technique in artificially prepared class III furcation defects in monkey molars gave favorable results. After 12 wk, not only the alveolar process but also the periodontal ligament and cementum had regenerated along the entire treated dentin surface. Collagen fibers were arranged more or less perpendicular to the surface of the new cementum. Ankylosis was not seen. It is concluded that the double-layer approach is superior to the single-layer technique in regenerating cementum.     

Systemic chemotherapy using cisplatin plus 5-fluorouracil for inoperable gallbladder cancer

We report a case of advanced gallbladder cancer in a 37-year-old man who presented in June 1993 with malignant obstructive jaundice. After percutaneous transhepatic biliary drainage and several diagnostic imaging examinations, the patient underwent laparotomy under a diagnosis of extremely advanced gallbladder cancer involving the confluence of the hepatic ducts. The tumor, however, was judged to be unresectable because of its massive spread into the liver along Glisson's sheath, and because of histologically proven peritoneal dissemination. After exploratory laparotomy, one course of anticancer chemotherapy (cisplatin, 100 mg/body IV, on day 1, and 5-fluorouracil, 1000 mg/body, on days 1–5, by continuous infusion) was administered and the completely obstructed hepatic duct was dramatically re-canalized. Four courses of chemotherapy were administered over a 16-month period until jaundice recurred. For these 16 months, the patient's quality of life was well maintained without biliary drainage. He died of increased peritoneal dissemination approximately 2 years after the first course of anticancer chemotherapy.     

The effects of problem-solving training on two problem-solving tasks

The present study assessed the effects of problem-solving (D'Zurilla & Goldfried, 1971) training on two problem-solving tasks. Sixty-one subjects were assigned randomly to and trained in one of the following groups: general orientation (GO)-problem definition (PD)-generation of alternatives (GA)-decision making (DM), GO-PD-GA, GO-PD-DM, GO-GA-DM, GO, and a control group. The six groups did not differ significantly at pretesting on the measures of selecting the best alternative solution and describing problem-solving behaviors used to solve problems. Training was significantly effective on selecting the best alternative solution for all groups compared with the control group at the time of posttesting. The GO-PD-GA-DM and GO-PD-DM groups described significantly more problem-solving behaviors than the GO-PD-GA, GO-GA-DM, and GO groups. All five treatment groups performed significantly better than the control group at the time of post-testing. At follow-up 1 month after posttesting, groups trained with the PD component selected significantly better alternatives than the groups without PD training. Groups trained with the DM component described significantly more problem-solving behaviors at follow-up than the groups trained without the DM component.     

Primary Adenocarcinoma in the Urethrorectal Fistula

A 60-year-old Japanese man was hospitalized because of urinary leakage from the anus on October 3, 1994. Retrograde urethrography detected a fistula between the bulbous urethra and the rectum. Urethrocystoscopy revealed a tumor on the urethrorectal fistula. Tumor biopsy showed a well differentiated adenocarcinoma. Cystourethrectomy with fistulectomy, and ileal conduit urinary diversion were performed. Pathological examination revealed primary adenocarcinoma in the fistula with invasion to the prostatic urethra and bladder wall. The patient showed no evidence of a recurrence as of August, 1996.     

Silicone-Coated Polypropylene Hollow-Fiber Oxygenator: Experimental Evaluation and Preliminary Clinical Use

Background. A membrane oxygenator consisting of a microporous polypropylene hollow fiber with a 0.2-μm ultrathin silicone layer (cyclosiloxane) was developed. Animal experimental and preliminary clinical studies evaluated its reliability in bypass procedures.

Methods. Five 24-hour venoarterial bypass periods were conducted on dogs using the oxygenator (group A). In 5 controls, bypass periods were conducted using the same oxygenator without silicone coating (group B). As a preliminary clinical study, 14 patients underwent cardiopulmonary bypass with the silicone-coated oxygenator.

Results. Eight to 16 hours (mean, 12.2 hours) after initiation of bypass, plasma leakage occurred in all group B animals, but none in group A. The O₂ and CO₂ transfer rates after 24 hours in group A were significantly higher than at termination of bypass in group B (p < 0.005 and p < 0.03, respectively). Scanning electron microscopy of silicone-coated fibers after 24 hours of bypass revealed no damage to the silicone coating of the polypropylene hollow fibers. In the clinical study, the oxygenator showed good gas transfer, acceptable pressure loss, low hemolysis, and good durability.

Conclusions. This oxygenator is more durable and offers greater gas transfer capabilities than the previous generation of oxygenators.