Mitsuaki Okita

A study on postoperative enteritis caused by methicillin-resistant Staphylococcus aureus

We investigated the production of staphylococcal enterotoxin (SE) with respect to coagulase types by methicillin-resistant Staphylococcus aureus (MRSA). A total of 138 strains of MRSA, which were isolated from clinical materials in the surgical ward between 1983 and 1990, were studied. Coagulase type IV strains produced SE A only, whereas coagulase type II strains were classified into four groups by SE production: SE B producing strains (32.7%), SE C producing strains (29.8%), SE B and C coproducing strains (12.5%), and SE A and C coproducing strains (25.0%). Almost all of the organisms (nine of ten) which were isolated from the feces of patients with MRSA enteritis were SE A and C coproducing strains. The coincidence in time of the prevalence of MRSA enteritis and the isolation SE A and C coproducing strains also demonstrated that these strains caused MRSA enteritis. Although SE C producing strains and SE A and C coproducing strains were simultaneously prevalent in 1990, the former tended to be sensitive while the latter tended to be resistant to minocycline. Considering the variety of antibiotic sensitivity in coagulase type II strains, it is thus considered to be of critical importance for epidemiologic purposes to further characterize isolates by SE typing.

Toxin involvement in methicillin-resistant Staphylococcus aureus enteritis in gastroenterological surgery

SummaryThe authors investigated the production of toxic shock syndrome toxin-1 (TSST-1) and staphylococcal enterotoxins (SE) by Methicillin-resistantStaphylococcus aureus (MRSA) isolates to clarify the pathogenesis of postoperative MRSA enteritis in patients undergoing gastroenterological surgery. Regarding the percentage of TSST-1-producing strains, there was a significant difference between type II MRSA strains (68.8%) and type IV MRSA strains (4.2%). Among type II strains, all those producing staphylococcal entorotoxin (SE) type C (SEC) also produced TSST-1, although other strains that produced SEB without TSST-1 were commonly isolated. Strains producing SEA were potent producers of SE which was considered to be responsible for enteritis. Therefore, we hypothesized that the strains which produced both SEA and SEC tended to cause enteritis associated with TSS-like symptoms owing to the high titer of these toxins.

Anomalous arrangement of the pancreaticobiliary ductal system without dilatation of the biliary tract.

A rare case of anomalous arrangement of the pancreaticobiliary ductal system without dilatation of the biliary tract (AAPBDS without DBT) associated with mucosal dysplasia of the biliary duct is described herein. A 53 year old male with a long history of diarrhea and right upper abdominal pain was diagnosed as having AAPBDS without DBT by endoscopic retrograde cholangiopancreatography and other examinations. Excision of the gallbladder and biliary duct with a Roux-en-Y hepatico-jejunostomy was performed and subsequent pathological examination of the surgical specimens showed mucosal hyperplasia of the gall-bladder and mucosal dysplasia of the biliary duct. Considering the dysplastic changes of the biliary duct as seen in our case, and the high incidence of AAPBDS without DBT developing into carcinoma of the biliary duct, being 12.2 per cent, we suggest that pancreaticobiliary ductal diversion with excision of the gall-bladder and biliary duct should also be performed for AAPBDS without DBT. However, further pathological investigations concerning the excised biliary duct in AAPBDS without DBT will be need to be carried out.

Mucin-producing pancreatic tumors: A study of nuclear DNA content by flow cytometry

Nuclear DNA content in eight surgically resected mucin-producing pancreatic tumors (MPPT) consisting of two mucinous intraductal adenocarcinomas (MIDAC), two mucinous intraductal adenomas (MIDA), one mucinous cystadenocarcinoma (MCAC), and three mucinous cystadenomas (MCA) were measured by flow cytometry using paraffin-embedded tissue samples. The technique of Shutte was used for the preparation of paraffin-embedded tissue into single dissociated nuclei, while the method of Vindelov was used for staining the isolated nuclei with propidium iodine. Clinicopathologically, the four patients with MIDAC or MIDA were all male and had cystic lesions with a dilated pancreatic duct at the head of the pancreas, while the four patients with MCAC or MCA were all females and had cystic tumors at either the body or tail of the pancreas. All eight patients with MPPT had no metastasis to the regional lymph nodes and were all still alive without recurrence. In an analysis of nuclear DNA content, seven of eight patients had DNA diploid tumors while one patient with a MIDAC perforating the duodenum and choledochus had a DNA aneuploid tumor. Thus, these findings suggest that DNA diploid patterns in MPPT might be associated with a favorable prognosis in MPPT although some patients whose MPPT invaded the surrounding organs might have DNA aneuploid tumors.

Severity and predicted outcome of postoperative Pseudomonas aeruginosa infections

The severity and predicted outcome of postoperative Pseudomonas aeruginosa (P. aeruginosa) infections (PPAI) was evaluated using a severity scoring system based on a simplification and modification of the APACHE II system. A total of 86 patients in whom P. aeruginosa was isolated from various sources were examined. PPAI developed in 50 patients, resulting in an overall mortality rate of 24%. An increased severity score (SS) correlated with an increased risk of developing PPAI. Thus, PPAI developed in 33% of the patients with an SS of 0–1, in 66.7% of those with an SS of 2–3, and in 100% of those with an SS of 6 or higher. Moreover, the mortality rate of the patients with an initial score of 6 or higher was 50%. The mean (±SD) initial severity score was 5.4±2.9 for survivors and 2.9±2.6 for nonsurvivors (P<0.01). In the patients who subsequently died, the SS remained high throughout the clinical course despite therapy, whereas in the survivors the SS decreased progressively, reflecting a favorable clinical course. These results suggest that our severity scoring system was useful for predicting outcome and monitoring the response of PPAI to therapy.

Studies of the Intraperitoneal Antibiotic Administration.

抗菌剤腹腔内1回投与が全身投与よりも術後感染予防に有用であるかを検討した. 消化器手術32例を対象にセフェム剤 (3剤) を1g点滴静注 (DI), 腹腔内投与 (IP) し体内動態を測定した. IP群での腹水中濃度は投与後30分, 1時間で1, 000,300μg/mlとDI群より有意に高い値が得られた. しかし, 投与後4, 6時間ではDI群と有意差のない値 (4-2μg/ml) となり, DI群に比べ有意の有効濃度の持続時間の廷長は得られなかった. 一方, flomoxef sodium (FMOX) は大腸菌に対し400, 40μg/mlでおのおの2, 4時間野接触時間で良好な殺菌効果を認めたが, 4μg/ml, 6時間接触では殺菌効果は得られなかった.緑膿菌, メチシリン耐性ブドウ球菌ではFMOX 400μg/ml, 6時間接触時間でも殺菌作用は得られなかった.高濃度の持続時間で期待できないので抗菌剤腹腔内1回投与では, 上記細菌.対象とした術後感染予防において全身投与以上の有用性は得られないと考えられた.

Clinicopathological Studies of Polypoid Lesions of the Gallbladder.

最近5年間に当科で経験した胆嚢隆起性病変21例 (腺癌6例, 腺腫3例, コレステロールポリープ5例, 過形成性ポリープ4例, 炎症性ポリープ2例, 異所性胃粘膜1例) の臨床病理学的検討を施行した.術前診断では, 超音波検査にて腺癌と他疾患の鑑別は困難で, コレステロールポリープのみ質的診断が可能であった.腺癌症例は, 高齢者の最大径10mm以上の隆起性病変に多く, 有茎性の腺腫内腺癌と広基性の進行癌に大別され, 後者はその最大径がより小さい時期に進行癌となる傾向を認めた.なお, 腺癌症例は, 全例, 無再発生存中で, DNA ploidy patternがdiploidであり, 予後良好な一因と考えられた.以上より, 胆嚢隆起性病変においては, 有茎性の症例は最大径10mm以上を, 広基性の症例は最大径5mm以上を手術適応とし, 手術術式としては, 全層胆嚢摘出術の後, 主病変, リンパ節の術中迅速病理診断の結果により, リンパ節郭清, 胆管切除, 肝切除を施行するのが妥当と考える.