Temperature Effects on the Transmission of Bursaphelenchus xylophilus (Nemata: Aphelenchoididae) by Monochamus alternatus (Coleoptera: Cerambycidae)

The object of this research was to investigate the effects of ambient temperature on the transmission of the pinewood nematode, Bursaphelenchus xylophilus, by its vector, Monochamus alternatus. Ninety M. alternatus were reared individually at one of three constant temperatures (16, 20, and 25 degrees C). As the ambient temperature decreased from 25 to 16 degrees C, longevity of vectors decreased, nematode transmission efficiency decreased, and the peak period of nematode transmission was delayed and its peak height decreased. Low temperature may inhibit the transmission process, and this inhibition could be partially responsible for preventing pine wilt disease from devastating pine forests in cool regions.

A Simple Method for Determining Aphelenchoides besseyi Infestation Level of Oryza sativa Seeds

A simple extraction method was developed for obtaining the white tip nematode, Aphelenchoides besseyi Christie, from single seeds of rice, Oryza sativa. The method was as follows: Individual rice seeds were split longitudinally and then transferred into single pipet tips. Tips containing a split seed were then singly placed upright in glass vials with water to extract the nematodes. This method was more efficient than the Baermann funnel technique and allowed nearly 100% recovery of living A. besseyi from single rice seeds within 4 hours.

Efficacy of magnifying endoscopy in the differential diagnosis of neoplastic and non-neoplastic polyps of the large bowel

PURPOSE

We have introduced magnifying colonoscopy into clinical practice and analyzed its diagnostic efficacy, especially regarding the ability to distinguish neoplastic from non-neoplastic polyps.

METHODS

The materials consisted of 923 polyps. After identifying the lesions during normal colonoscopy, a dye was sprayed, and then the zoom apparatus of the colonoscope was used to make a magnified observation at a maximum 100 times magnification. We classified the crypt orifices into six categories and labeled them A to F as follows: A, a medium round appearance; B, an asteroid appearance; C, an elliptic appearance; D, a small, round appearance; E, a cerebriform appearance; F, no apparent structural appearance.

RESULTS

Forty-two of 923 polyps did not reveal any clear images of crypt patterns. The percentage of histologically neoplastic change in the lesions classified as A, B, C, D, E, and F were 10, 15.9, 93.7, 100, 94.8, and 87.5 percent, respectively. When we considered types A and B to represent a crypt pattern of non-neoplastic lesions, and types C, D, E, and F to represent neoplastic lesions, and when the lesions that did not show any clear images were classified as a misjudgment, the diagnostic accuracy of neoplastic lesions (sensitivity) was 92 percent and that of non-neoplastic lesions (specificity) was 73.3 percent. Overall, the diagnostic accuracy in differentiating neoplastic from non-neoplastic lesions was 88.4 percent. Twenty-three neoplastic lesions that were misjudged to be non-neoplastic were histologically adenoma with mild atypia in 22 and adenoma with moderate atypia in 1.

CONCLUSION

Magnifying colonoscopy was considered to be useful in determining the indications for colonoscopic removal.

Prospective observation of small "flat" tumors in the colon through colonoscopy

PURPOSE

No prospective observations of "flat" tumors of the colon have yet been reported. The purpose of this study was to investigate the progression of small flat tumors by prospective observations using colonoscopy.

METHODS

The shapes of flat tumors were classified into three types, including slightly elevated lesions with a flat top (flat-top type), slightly elevated lesions with a wide depression in the center (wide-depressed type), and slightly elevated lesions with a slit-like depression in the center (slit-depressed type). A total of 14 flat tumors of the colon in 13 patients (2 women; median age, 58; range, 46-72 years) were examined in this project. All cases were followed up prospectively using colonoscopy, and all underwent a resection using the submucosal saline injection and snaring technique.

RESULTS

Because two patients were eventually dropped from the follow-up, only 12 lesions were studied. The observation period ranged from 11 to 26 (median, 19) months. At the time the observations started, the diameter of the tumors varied from 2 to 6 (median, 4) mm, and the shapes were flat-top type in five lesions, wide-depressed type in three lesions, and slit-depressed type in four lesions. Of the 12 flat tumors, 8 showed various changes in their shape. However, only two lesions demonstrated an increase in diameter of the tumor from 2 to 4 mm. In the other ten tumors any change in size was less than 2 mm. No lesions were carcinomas according to the final histologic diagnosis, but all were adenomas.

CONCLUSIONS

Flat tumors of the colon did not rapidly progress when they measured approximately 5 mm in diameter. Such flat tumors did tend to change their shapes; however, such changes did not indicate invasion to the submucosal layer.

[Assessment of induction therapy and resection in stage IIIb non-small cell lung cancer]

Twelve patients with stage IIIb non-small cell lung cancer underwent induction therapy and resection from January 1990 to July 1998. They were divided into two groups; group A (n = 5) received two (to four) preresectional cisplatin and videsine chemotherapy, group B (n = 7) received chemoradiotherapy (radiation with concurrent low-dose-daily cisplatin). All patients in both groups had clinically down-stage and had no major side effects preventing surgery. 3 patients underwent radical pneumonectomy and 9 patients had radical lobectomy with no operative mortality. In 9 patients the disease was pathologically downstaged. Overall five-year survival was 27%, while in group A it was 50%. In group B 2-year survival was 18% and the longest survivor had pulmonary recurrence four years after surgery. Our data show better prognosis in group A than in group B. This results suggest that chemotherapy may be superior pre-resectional therapy to chemoradiotherapy.

Intraoperative localization of colorectal tumors in the early stages using a marking clip detector system

In laparoscopic colectomy the identification of the site of a tumor is often difficult. The topical injection of india ink or blue dye by preoperative colonoscopy is the most prevalent method to mark the tumor site; however, such a procedure also includes the intrinsic danger of possibly injecting dye into the peritoneal cavity. In addition, the injected marker may also spread so widely that the intended site may become obscure. A marking clip detector system was used to detect metallic marking clips in the luminal side that had been applied to the mucosa adjacent to the lesion during the course of preoperative colonoscopy. This method was able to identify the marked site in 40 percent of cases in which only one clip was applied to the mucosa. However, when the lesion sites were marked with two or three clips, then the detection rate increased to 100 percent. Based on our findings, this procedure was found to be a safe and reliable method for identifying lesions during laparoscopic-assisted colectomy.

Unusual appearances of uterine leiomyomas: MR imaging findings and their histopathologic backgrounds

Typical appearances of uterine leiomyoma at magnetic resonance (MR) imaging are well established, and diagnosis is usually easy. However, cases that, are extremely difficult to differentiate from other conditions are occasionally encountered. To understand the wide spectrum of MR imaging findings, such unusual appearances can be classified into three categories: degeneration and other histopathologic findings, specific types of unusual leiomyomas, and unusual growth patterns. The common types of degeneration are hyaline (>60% of cases), cystic (approximately 4%), myxoid, and red. Edema is not a phenomenon of degeneration but is a common histopathologic finding (approximately 50% of cases). Hemorrhage, necrosis, and calcification (approximately 4% of cases) may also be observed. Specific types of unusual leiomyomas include lipoleiomyoma and myxoid leiomyoma, which may have MR imaging features characteristic enough to allow differentiation from other gynecologic and nongynecologic diseases. Intravenous leiomyomatosis, metastasizing leiomyoma, diffuse leiomyomatosis, and peritoneal disseminated leiomyomatosis represent unusual growth patterns; other unusual growth patterns are retroperitoneal growth, parasitic growth, and the pattern that may occur in cervical leiomyoma. Because leiomyomas are the most common gynecologic tumors and are exclusively benign, it is important to be familiar with the variety of MR imaging appearances of uterine leiomyomas to distinguish them from other significant diseases.

Detection of porcine circovirus from lesions of a pig with wasting disease in Japan

A wasting disease characterized by progressive weight loss and dyspnea has been observed in weaning pigs on a farm in Yamagata Prefecture in 1998. Histopathologic findings in an affected pig were bronchointerstitial pneumonia and intracytoplasmic clusters of basophilic inclusions in macrophages of lymph nodes, which were similar to those in pigs with postweaning multisystemic wasting syndrome (PMWS) recently reported in North America and Europe. Porcine circovirus (PCV)-like particles were observed in bronchial lymph node of the pig by electron microscopy, and PCV antigens were detected in the lesions by immunohistochemical staining. PCV DNA was also detected in the lung and tonsil by PCR, and restriction fragment length polymorphism analysis of the PCR products with HinfI showed the same type of the PCV associated with PMWS (pmws PCV). Homology of nucleotide sequences between the PCR product and corresponding regions of published pmws PCV genomes was very high. These results indicated that virus detected in this study was pmws PCV. To our knowledge, this is the first report on the presence of pmws PCV in Japan.

[Effect of preoperative chemotherapy for bulky N2 non-small-cell lung cancer]

The effect of chemotherapy as the adjuvant therapy to bulky N2 disease (stage IIIA) non-small-cell lung cancer was examined. From January 1992 to December 1996, 464 patients with non-small-cell lung cancer underwent surgery. Seven patients (1.5%) with N2 disease (stage IIIA) received two cycles of preresectional cisplatin and vindesin chemotherapy, followed by standardized surgical resection (Group A). 46 patients (9.9%) had pathological N2 disease (T1-3, M0) after surgery (Group B). In Group A a complete resection was accomplished in two patients (28.6%), and five patients had incomplete resection with a deseased margin, followed thoracic irradiation 60 to 75 Gy. In three patients in Group A the N2 disease was pathologically downstaged to N1 or N0 disease. Overall survival at five years in Group A and in Group B was 48% and 39%, and median survival time was 49 months and 38 months. Although complete resection rate was lower in Group A (28.6%) than in Group B (78.2%), there was no significant difference between five year survival and median survival time in Group A and Group B. These data may be thought to suggest that induction chemotherapy in Group A was effective on occult micrometastatic disease.

Evaluation of ectopic pregnancy by magnetic resonance imaging

Patients (n = 37) suspected of ectopic pregnancy were prospectively evaluated with magnetic resonance (MR) imaging to assess the capability of MR imaging in the diagnosis of ectopic pregnancy. Five levels of confidence were defined: diagnostic, suspicious, equivocal, questionable, and negative. Tubal wall enhancement and presence of tubal haematoma or gestational sac-like structure were considered diagnostic findings. There were 21 diagnostic, two suspicious, eight equivocal, and six negative findings. MR findings were compared with the surgical findings in 18 patients. Surgical confirmation was obtained in 12 diagnostic, two suspicious, and four equivocal studies. Using the MR diagnostic criteria for tubal pregnancy, MR had 12 true positive, three true negative, three false negative, and no false positive results for the diagnosis of tubal pregnancy. Retrospective analysis of the signal intensity of haematoma and ascites was performed for these 18 surgically confirmed cases. The predominant signal intensity of tubal haematoma was an intermediate signal on T1-weighted image (WI) and a low signal on T2WI. Ascites showed signal intensity higher than that of urine on T1WI in 100% of 13 cases. In conclusion, MR imaging with use of intravenous contrast material allows a specific diagnosis of tubal pregnancy, recognizing tubal wall enhancement and fresh tubal haematoma.

MR imaging of endometrial stromal sarcoma: correlation with pathologic findings

OBJECTIVE

This study describes MR imaging of eight patients with endometrial stromal sarcoma and correlates the imaging findings with histopathologic findings. To our knowledge, the radiologic findings of this entity have not been reported in the literature.

CONCLUSION

Endometrial stromal sarcoma typically presents with extensive myometrial involvement, which is either sharply demarcated or diffusely infiltrative. Bands of low signal intensity are observed within the areas of myometrial involvement on T2-weighted images. These bands correspond to the preserved bundles of myometrium on pathologic examination. Tumor extension along the vessels or ligaments is another characteristic of MR imaging of endometrial stromal sarcoma.

Sclerosing stromal tumor of the ovary: MRI

The MR and pathologic findings of a case of sclerosing stromal tumor (SST) are presented. MR findings reflecting pathological features of SST include pseudolobulation, which consists of low-intensity nodules set against high-intensity stroma on T2-weighted images, and striking enhancement on postcontrast images.

The significance of microsatellite instability in predicting the development of metachronous multiple colorectal carcinomas in patients with nonfamilial colorectal carcinoma

BACKGROUND

Patients with metachronous multiple colorectal carcinomas have been reported to have a higher frequency of a family history of colorectal carcinoma, associated colorectal adenomas, and extracolonic malignancies. These clinicopathologic factors also are considered to be related to the development of metachronous multiple colorectal carcinomas after surgery for colorectal carcinoma. In this article, the authors investigated whether genetic markers such as microsatellite instability (MSI) were helpful in predicting the development of metachronous multiple colorectal carcinomas.

METHODS

Between 1990-1997, 312 colorectal carcinoma patients underwent yearly surveillance colonoscopy after surgery. Among these patients, there were 19 with nonfamilial colorectal carcinoma in whom metachronous multiple colorectal carcinomas were diagnosed during the yearly surveillance colonoscopy. A control group was comprised of 28 patients who did not demonstrate either synchronous or metachronous carcinomas over a period of > or =5 years. Six microsatellite markers (D2S123, D3S1029, D3S1611, TP53, Mfd26, and Mfd36) were used to determine MSI by polymerase chain reaction.

RESULTS

The frequency of MSI positive cases was significantly higher in patients with sporadic metachronous multiple colorectal carcinomas than in those with a single carcinoma (17/19 [89%] vs. 4/28 [14%]; P<0.0001). In tumors occurring in the distal colon and rectum, the percentage of MSI positive carcinomas was significantly higher in the patients with metachronous multiple carcinomas than in those with a single carcinoma (13/15 [87%] vs. 0/19 [0%]; P<0.0001). No such difference was observed in the proximal colon.

CONCLUSIONS

Based on the findings of the current study, the analysis of MSI in sporadic carcinomas of the distal colon and rectum may be helpful in predicting the development of metachronous multiple colorectal carcinomas.

Inhibition of human telomerase activity by alterperylenol

Human telomerase is a ribonucleoprotein that maintains telomeres by adding TTAGGG tandem repeat sequences using RNA template of the enzyme. Telomerase activity is highly expressed in immortalized cells but not in most somatic cells, except for some renewal tissues, such as hematopoietic stem cells. Therefore, telomerase can be a target for anticancer drugs. Here we show that a fungus metabolite, alterperylenol, inhibits human telomerase activity. Alterperylenol inhibited telomerase activity (IC50 = 30 microM), but altertoxin I, a structurally related compound, did not affect it at 1 mM. Moreover, alterperylenol did not affect the activity of viral reverse transcriptase at 1 mM.

[Two cases of descending necrotizing mediastinitis]

Descending necrotizing mediastinitis (DNM) is relatively rare inflammatory lesion with high mortality unless an appropriate surgical treatment is undertaken. Recently we successfully treated two surgical cases of DNM. In both cases, the disease started with pharyngeal abscess, and the mediastinal swelling followed. The surgery consisted with neck drainage and the mediastinal drainage through thoracotomy at the same time. A continuous mediastinal irrigation was performed postoperatively, and both patients recovered well. Immediate drainage of the primary lesion and the mediastinum is important once the diagnosis of DNM is established.

Dermoid cysts of the ovary with malignant transformation: MR appearance

OBJECTIVE

This study presents the MR appearances of five women with a total of six proven dermoid cysts of the ovary with malignant transformation. To our knowledge, the MR findings of this entity have not been reported.

CONCLUSION

The lesions appeared to be fat-containing tumors with a solid component (4/6) that extended transmurally (4/6) and extensively invaded neighboring pelvic organs (3/6). The supervening malignancy was squamous cell carcinoma in four tumors, melanoma in one, and transitional cell carcinoma in one. The mode of spread differed from that of common ovarian tumors in that it included transmural extension and local invasion, reflecting squamous cell carcinoma.

Role of reducing co-factor in cerulenin-insensitivity of 6-hydroxymellein synthase in carrot cell extract

The activity of 6-hydroxymellein synthase, a multifunctional polyketide biosynthetic enzyme of carrot, was not inhibited by cerulenin in the presence of NADPH. However, cerulenin showed a marked inhibitory activity to the synthase if the reducing co-factor was omitted from the assay mixture. The synthase was also sensitive to the antibiotic even in the presence of NADPH when the acyl condensation site and the reducing domain at the reaction center of the enzyme were dissociated under the high ionic strength condition. In addition, the synthase activity was appreciably inhibited when NADH was employed instead of NADPH. These observations strongly suggest that a phosphate group attached to 2'-position of adenosyl moiety of NADPH molecule plays an important role in the apparent insensitivity of 6-hydroxymellein synthase toward cerulenin.

Asymptomatic hyponatremia due to inappropriate secretion of antidiuretic hormone as the first sign of a small cell lung cancer in an elderly man

A 72-year-old man was hospitalized with asymptomatic hyponatremia. Despite hyponatremia, urinary sodium excretion with urine osmolality exceeding plasma osmolality persisted. Plasma vasopressin levels were high and independent of plasma osmolality during hypertonic saline infusion. Computed tomography of the chest showed enlarged mediastinal and right hilar lymph nodes. Microscopically, a specimen of lymph nodes obtained by biopsy represented vasopressin-producing small cell lung carcinoma. Chemotherapy plus irradiation improved the hyponatremia. Thus, careful evaluation is necessary to determine the cause of hyponatremia disorders in elderly patients.

MRI of adenomyotic cyst of the uterus

The radiologic and pathologic features of three cases of adenomyotic cysts are presented. Two cases were subserosal and one was intramyometrial. All three cases had cystic spaces filled with hyperintense fluid on T1-weighted images, which were surrounded by hypointense tissue on T2-weighted images.

Cervical cancer

The stage estimated by clinical FIGO staging is the main determinant in guiding the treatment decisions. However, clinical FIGO staging does have inherent inaccuracies, because it does not include significant prognostic factors. Presently, MRI is not officially incorporated in the staging workup system; however, it is widely accepted as the most reliable imaging modality in evaluating cervical cancer and in treatment planning. MRI offers direct tumor visualization, accurate assessment of the depth of stromal invasion and tumor volume, lymph node evaluation, and reliable staging accuracy. Published reports show the superiority of MRI over clinical staging, and several recent works on dynamic MRI suggest further improvement of MRI in evaluating cervical cancer.

[Nodular bronchioloalveolar carcinoma with multiple small air spaces caused by bronchiolectasis]

A 67-year-old man was admitted to our hospital with a faint abnormal shadow in the right S2 on January 1995. Chest CT showed a faint abnormal shadow about 3 cm in diameter with multiple small air spaces. He was admitted again 18 months later for surgical treatment because the shadow on chest X-ray had grown. Right upper lobectomy was performed in June 1996 and pathohistological examination revealed bronchioloalveolar carcinoma. Tumor cells along the walls of the alveolus were recognized only in the periphery of the lesion. The center of the lesion was fibrotic and multiple small air spaces ranging from 0.5 mm to 10 mm in diameter were present. One cause of these air spaces was considered to be the "check valve" mechanism, but the majority of the air spaces were derived from ectatic bronchioli. These results suggested that bronchiolectasis had developed with central fibrosis only in the tumor. Central fibrosis in this case had played a significant role in determining the radiographic appearance of the lesion.

[A role of limited operation for non-small cell lung cancer at present]

Our indication of limited operation is passive. Twenty-three patients with stage I non-small-cell lung cancer underwent a limited resection from 1983 to 1995. They were divided into two groups: group A (n = 12) included the elderly patients with the smaller nodule (< or = 2 cm), group B (n = 11) included the patients with decreased pulmonary function or important heart disease. Overall four-year survival was 67%, while the survival in group A was better than that in group B. The rate of local recurrence was 30.4% in both groups and second primary lung cancer occurred in two cases. We conclude that the limited operation played an important role in surgical treatment of patients with non-small cell lung cancer, especially with the smaller nodule (< or = 2 cm).