Long-term follow-up after aortic valve replacement with a small aortic prosthesis.

Although aortic valve replacement (AVR) is an effective treatment for patients with aortic valvular disease, the implantation of a small aortic prosthesis may result in residual left ventricular outflow stenosis and transvalvular gradient. In this study, the outcome in the long-term period of patients treated with a small aortic prosthesis was analyzed retrospectively. Twenty-four patients with AVR were divided into two groups, group A and group B. Group A consisted of 16 patients with 21 mm-sized prosthetic valves, and group B consisted of 8 patients with 19 or 16 mm-sized prosthetic valves. There were no significant differences in preoperative cardiac function or operative procedure in the two groups. The mean follow-up period (months) was 55.0 in group A and 51.3 in group B. RESULTS: One patient died of cerebral infarction in group A. There were no significant differences in cardiothoracic ratio (CTR), left ventricular ejection fraction (LVEF), and left ventricular mass index (LVMI) between the two groups. Postoperative physical activity according to the New York Heart Association (NYHA) classification showed no significant differences in the two groups. Despite using a small prostheses for AVR, the postoperative course was good in the long-term period, although careful follow-up is necessary.     

The evaluation of cystoscopy in the screening of asymptomatic microhematuria

As a prospective study on asymptomatic microhematuria, complete urological examinations including cystoscopy, IVP, ultrasound and urinary cytology were performed on 422 patients over 40 years old between January 1987 and December 1988 (group A). The results of group A was compared with that of retrospective study on 266 patients, who had incomplete urological examination between January 1984 and December 1985 (group B). Cystoscopy was performed on 321 patients (87.2%) in group A and on 108 patients (40.6%) in group B. Bladder tumor was found in 10 cases (2.4%) in group A, including 7 cases of male patients (5.7%), but in only 1 case (0.4%) in group B. Since the negative rate of abnormal urinary cytology was 50% and that of abnormal IVP was 90% in 10 cases of bladder tumor in group A, cystoscopy was considered to be an essential examination for the screening of patients with asymptomatic microhematuria over 40 years old patients.     

Overexpression of suppressor of cytokine signalling-5 augments eosinophilic airway inflammation in mice

BACKGROUND: Enhanced expression of the suppressor of cytokine signalling (SOCS)-5 might be of therapeutic benefit for T-helper type 2 (Th2) dominant diseases, as its expression is reported to result in a reduction of Th2 differentiation in vitro due to the inhibition of IL-4 signalling. OBJECTIVE: To investigate the regulatory role of SOCS-5 in vivo, we explored the phenotype of an experimental asthma model developed in SOCS-5 transgenic (Tg) mice. METHODS: The SOCS-5 Tg mice or wild-type (WT) mice were sensitized and repeatedly challenged with ovalbumin (OVA). We examined bronchoalveolar lavage fluid (BALF), lung specimens, and airway hyperresponsiveness (AHR) to methacholine. RESULTS: The production of IFN-gamma by CD4(+) T cells from unprimed SOCS-5 Tg mice was significantly increased in comparison with unprimed wild-type mice, indicating that SOCS-5 Tg mice have a Th1-polarizing condition under natural conditions. However, in an asthma model, significantly more eosinophils in the airways and higher levels of IL-5 and IL-13 in BALF were observed in the SOCS-5 Tg than the wild-type mice. AHR in the asthma model of SOCS-5 Tg was also more enhanced than that of wild-type mice. OVA-stimulated CD4(+) T cells from the primed SOCS-5 Tg mice produced significantly more IL-5 and IL-13 than CD4(+) T cells from wild-type mice. CONCLUSION: Our results demonstrate that the overexpression of SOCS-5 does not inhibit Th2 response, but rather augments the phenotype of the asthma model in vivo. This finding throws into question the therapeutic utility of using enhancement of SOCS-5 expression for Th2-dominant disease.     

Laparoscopic nephrectomy. Preliminary report]

Laparoscopic surgery has been widely performed for removing the gallbladder and the pelvic lymph-nodes in recent years. We have applied laparoscopy technique to nephrectomy and here we describe our procedures and the clinical results. The patient is placed in the supine position under general anesthesia. After a 4 liter CO2 pneumoperitoneum is induced, five trocars are inserted into the abdominal cavity through the ipsilateral abdominal wall. The patient is then turned to the lateral position to displace the bowel medially. The ipsilateral colon is reflected medially after incision of the parietal peritoneum was made along the line of Todt to expose the retroperitoneum. The ureter was identified and dissected. It was secured with 4 clips (2 clips on the renal side and 2 on the distal side) and then cut with scissors. The renal vein and artery were then dissected and separately ligated with clips as described above. These vessels were also cut. The upper pole of the kidney was dissected out and the adrenal gland was left in place. The kidney thus became completely free within the abdomen. It was then grasped by the forceps through a 10 mm sheath positioned below the umbilicus. After incising the abdominal wall, the kidney was removed from the abdominal cavity with the grasping forceps and the sheath. By this procedure right nephrectomy was completely performed in a 56-year-old female patient and left nephrectomy in a 56-year-old male patient. The underlying disease was recurrent pyelonephritis secondary to renal calculi in both cases. The operative times were 221 min and 346 min, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)     

K-ras activation and ras p21 expression in latent prostatic carcinoma in Japanese men.

Twenty-three clinically silent prostatic carcinomas discovered in Japanese men at autopsy were surveyed for ras proto-oncogene mutations by mutation-specific oligonucleotide probe hybridization after polymerase chain reaction (PCR) amplification from a section of formalin-fixed, paraffin-embedded tissue. Six of the 22 that were satisfactory amplified contained activating point mutations in codon 12 of K-ras, a significantly higher frequency than has been reported in patients with clinically advanced disease in the United States. Of the six cases with activating point mutations in codon 12 of K-ras, one had a GGT----GAT transition, four had GGT----GTT transversions, and one had both GGT----GAT and GGT----GTT mutations. Sections from the same tissues were immunohistochemically stained with an anti-ras p21 antibody. Carcinoma cells stained for ras p21 to some degree in 13 cases. Immunohistochemically detectable expression of p21 was always focal and was not necessarily associated with K-ras mutation. K-ras oncogene activation in prostatic carcinoma appears to merit additional study as a significant event in the pathogenesis of this neoplasm.     

Effects of KW-3635, a novel dibenzoxepin derivative of a selective thromboxane A2 antagonist, on human, guinea pig and rat platelets.

We examined the binding of [3H]U-46619, a thromboxane A2 agonist, to human and guinea pig platelets and the binding of [3H]SQ 29,548, a thromboxane A2 antagonist, to human, rat and guinea pig platelets. KW-3635 (sodium (E)-11-[2-(5,6-dimethyl-1- benzimidazolyl)ethylidene]-6,11-dihydrodibenz[b,e]oxepin-2-c arboxylate monohydrate) concentration-dependently inhibited the [3H]U-46619 binding to human and guinea pig platelets with inhibition constants of 1.2 nM and 2.7 nM, respectively. KW-3635 also potently inhibited the [3H]SQ 29,548 binding to human and guinea pig platelets with inhibition constants of 1.9 nM and 3.2 nM, respectively. In contrast, KW-3635 was less active against thromboxane A2/prostaglandin H2 receptors in rat platelets with an inhibition constant of 97 nM. KW-3635 at 10(-5) M did not antagonize various receptors including prostaglandin E2, prostaglandin I2 and neurotransmitters. In addition, 10(-5) M KW-3635 did not alter the prostaglandin D2-induced cAMP accumulation in EBTr cells. KW-3635 was inactive towards thromboxane synthase, cyclooxygenase and prostaglandin I2 synthase up to 10(-5) M. KW-3635 slightly inhibited 5-lipoxygenase with an IC50 value of 71 microM. These data indicate that KW-3635 is a potent and selective non-prostanoic thromboxane A2 antagonist, and it can recognize the species differences in thromboxane A2/prostaglandin H2 receptors.     

Tumorigenicity study in Syrian hamsters fed areca nut together with nitrite

In order to evaluate the effect of concurrent administrationof areca nut and sodium nitrite, a long-term feeding study wasconducted with 120 Syrian hamsters. The animals were dividedinto four treatment groups, each consisting of 15 males and15 females, and received 2 g/kg diet of sodium nitrite (groupI), 20 g/kg diet of powdered areca nut (group II), 2 g/kg dietof sodium nitrite plus 20 g/kg diet of areca nut (group III)or powdered diet only (group IV) throughout their lifetime.Urine samples from all groups were analysed for N-nitrosonipecoticacid (NNIP), a major urinary metabolite of areca-nut-derivednitrosamines. NNIP was only detected in the urine of hamstersfed nitrite plus areca nut (concentration: 1.9±0.9 ng/mlurine), indicating that areca nut alkaloids underwent in vivonitrosation to form arecanut-specific nitrosamines. The totaltumour response was not significantly elevated in groups IIand III. Hamsters of group III had a markedly, but also insignificantlyhigher frequency of malignant tumours than those of the othergroups, with a statistically significant increase in malignantlymphomas in the males. Although limited by the low number ofanimals per group, these results indicate that exposure to nitritetogether with areca nut constituents appears to enhance therisk of developing malignancies.     

Non-prostanoid thromboxane A2 receptor antagonists with a dibenzoxepin ring system. 2.

A series of 11-[2-(1-benzimidazolyl)ethylidene]-6,11-dihydrodibenz[b,e]oxep in-2- carboxylic acid derivatives and related compounds were synthesized and found to be potent TXA2/PGH2 receptor antagonists. Each compound synthesized was tested for its ability to displace [3H]U-46619 binding from guinea pig platelet TXA2/PGH2 receptors. Structure-activity relationship studies revealed that the following key elements were required for enhanced activities: (1) an (E)-2-(1-benzimidazolyl)ethylidene side chain in the 11-position of the dibenzoxepin ring system and (2) a carboxyl group in the 2-position of the dibenzoxepin ring system. The studies also indicated that the TXA2/PGH2 receptor binding affinities of this series of compounds in guinea pig platelet were poorly correlated with those in human platelet. Introduction of substituent(s) to the benzimidazole moiety was effective and sodium (E)-11-[2-(5,6-dimethyl-1-benzimidazolyl)ethylidene]- 6,11-dihydrodibenz[b,e]oxepin-2-carboxylate monohydrate (57) recorded the highest affinity for human platelet TXA2/PGH2 receptor with a K(i) value of 1.2 +/- 0.14 nM. It demonstrated potent inhibitory effects on U-46619-induced guinea pig platelet aggregation (in vitro and ex vivo) and human platelet aggregation (in vitro). Compound 57, now designated as KW-3635, is a novel, orally active, and specific TXA2/PGH2 receptor antagonist with neither TXA2/PGH2 receptor agonistic nor TXA2 synthase inhibitory effects. It is now under clinical evaluation.