Treatment of a malignant esophageal fistula with a Gore-Tex-covered flexible nitinol stent

In order to treat fistulated esophageal cancer using a flexible stent, a covered flexible stent was constructed by wrapping a nitinol stent with a thin sheet of Gore-Tex, preserving the stents original advantages of flexibility and a low-profile introducer system. This stent was used to perform standard radiotherapy in a case of fistulated esophageal cancer.     

Research review: DNA polymerases as molecular markers of the regenerating capacity of hepatocytes

Hepatocyte regeneration has been widely investigated, with the mitotic index and the incorporation of [³H]thymidine being used as regeneration markers. We focused on the induction of DNA replication enzymes, particularly DNA polymerases (pol) α, δ, and ε. Using rat models, we have shown that the activity of pol α in crude liver extract well represents the regenerating capacity of hepatocytes. Using pol α as an indicator, we analyzed liver regeneration in rat models under various conditions: obstructive jaundice, external or internal biliary drainage, and the obstruction of portal vein branches. It has been revealed that the ligation of the common bile duct alone induces a certain amount of hepatocyte proliferation. It was striking that external biliary drainage suppressed regeneration capacity in cholestatic rat liver after partial hepatectomy. The strong regeneration in nonligated lobes induced by portal branch ligation was similar to the liver regeneration seen after partial hepatectomy with respect to the induction of DNA polymerases. Taken together, the aspects of DNA replication, particularly the induction of DNA polymerases, may contribute to shedding new light on the regeneration of human liver. This work was supported in part by a Grant-in-Aid for General Scientific Research and for Cancer Research from the Ministry of Education, Science and Culture, Japan, and by grants from the Uehara Memorial Foundation     

The results and problems of reoperation for coronary artery disease]

In six hundred and six consecutive patients undergoing coronary artery bypass grafting (CABG) within the past 17 years (May 1974 to March 1991), repeated CABG were performed on 10 patients (1.65%). The main reasons for repeated CABG were graft failure (GF) in 8, progression of native disease (NP) in 5 and incomplete revascularization (IR) in 3 patients. The incidence of GF was high either within a half year or around 5 years after CABG. Although all patients survived from reoperation, four patients continued to have mild angina pectoris. When the recurrence of angina is noted after CABG, coronary arteriography and if necessary PTCA should be done as soon as possible. If a second surgery is inevitable, maximum utilization of arterial graft and accomplishment of complete revascularization are emphasized.     

Late results after total correction of tetralogy of Fallot: over 10 year follow-up

Late results after total correction of tetralogy of Fallot over ten year follow up of 84 patients were discussed. No late death was experienced and 95.1% of these patients are now in NYHA class I. Reoperations were performed in 7 cases (8.3%) in which six had had residual shunt and one had had sick sinus syndrome and had VVI pacemaker implantation. Ten cases had over 90% of ratio of right ventricular pressure to systemic pressure in systole in their cardiac catheterization about 40 days after correction. In spite of this high pressure ratio, all cases are now in NYHA class I. We conclude that there is a possibility of enabling to preserve pulmonary valve function by adopting smaller criteria than the Pacifico's criteria.     

A successful surgical case of aortic arch aneurysm associated with aortic regurgitation

A 57-year-old male patient with aortic regurgitation and aneurysm of the ascending aorta and the aortic arch underwent aortic valve replacement and graft replacement from the ascending aorta to the aortic arch. The operation was done using cardio-pulmonary bypass and selective cerebral perfusion with deep hypothermia. Postoperative DSA revealed no dilatation of the sinus Valsalva and a good configuration of the anastomosis. It seems that selective cerebral perfusion with deep hypothermia is a safe method to prevent cerebral damage in a case of arch aneurysm.     

Effect of 24-hour ureteral obstruction on subsequent ischemic damage in rat kidney

The effects of prior 24-hour ureteral obstruction on ischemic renal damage were studied in rats. Rats were divided into 6 groups with different times of ischemia (0, 60 and 90 min) and with or without 24-hour ureteral obstruction. Following a 4-week recovery period, contralateral nephrectomy was performed and the rat was sacrificed 24 h later for the determination of serum creatinine and for histologic examination of the affected kidney. A preceding ureteral obstruction for 24 h made no difference to the renal damage with 60 min of ischemia or without ischemia. However, kidneys with 90 min of ischemia and 24 h of ureteral obstruction were more damaged than those with 90 min of ischemia only. These results suggested that the hydronephrotic kidney was more susceptible to long periods of ischemia than the normal kidney.     

Effects of low-caloric diet in puerperium on prolactin, TSH estradiol and milk secretion

Ten puerperal women were put on a 1,200 kcal diet per day for 3 days followed by an ordinary 1,800 kcal diet per day for 3 days [Low-Caloric (LC) group]. Fifteen puerperal women were put on an ordinary 1,800 kcal diet per day for 6 days[Ordinary-Caloric (OC) group]. All of the women took breakfast at 7:30 am, blood was drawn at 9:30 am and then the breasts were milked for 2 minutes with an electric breast pump starting on the day of delivery (Day 0) and continuing to Day 5. Four women in the LC and OC groups underwent a thyrotropin-releasing hormone (TRH) stimulation test on Days 1 and 3. Serum prolactin (PRL) and TSH levels in the LC group tended to be much lower than those of the OC group during the test period. Serum PRL and TSH release response to TRH in the OC group were much higher than in the LC group on Days 1 and 3. No significant difference was noted between the OC and LC groups in serum estradiol (E2) and cortisol levels from Day 0 to Day 5. The milk volume in the LC group was significantly less than in the OC group on Day 1. Analysis of milk specimen components revealed little difference between the OC and LC groups. These results suggested that a low-caloric diet may suppress PRL, TSH and milk secretion and may not be useful for breast-feeding.     

A pH-sensitive microsphere system for the colon delivery of tacrolimus containing nanoparticles.

Nanoparticles (NP) are known to accumulate at the site of inflammation in inflammatory bowel disease. In order to avoid premature uptake or degradation of NP during their passage through the small intestine, it appeared necessary to devise a form of local delivery system for NP. Tacrolimus (FK506) loaded poly(lactic-co-glycolic acid) NP entrapped into pH-sensitive microspheres (NPMS) were designed to achieve greater selectivity to their site of action when administered orally. The therapeutic efficacy of this drug delivery system was tested in an experimental colitis in rats. The in vitro characterization showed a successful incorporation of FK506-NP and strongly pH-sensitive release kinetics of both NP and drug. During the in vivo studies, clinical activity, colon/body weight index, and myeloperoxidase activity were determined to assess the severity of inflammation. Systemic availability of a fluorescent dye entrapped in the microspheres was measured in order to determine possible adverse effects. The NPMS as well as the controls of NP and MS formulations exhibited significant mitigating effects in the clinical activity index after 3 days of treatment with similar levels for the various therapies. When observing colon/body weight index and myeloperoxidase activity, only the NPMS group reached statistically significant differences (P<0.05) compared to the colitis control group while other groups did not (colitis control: 21.94+/-4.97; FK506 solution: 15.81+/-3.42; FK506-NP: 17.03+/-5.52; FK506-MS: 15.17+/-7.81; and FK-NPMS: 10.26+/-7.76 U/mg tissue). Moreover, the NPMS system reduced the systemic absorption of the entrapped dye compared to the dye solution or simple NP formulation (relative biovailability-solution: 100+/-14.9%; NP: 46.8+/-8.6%; and NPMS: 29.4+/-3.3%). The results suggest that the NPMS system can provide selective delivery of NP in the colon and develop a significant mitigating effect, while the control group treatments appeared to be insufficient.