Dengue virus M protein C-terminal peptide (DVM-C) forms ion channels.

A chemically synthesized peptide consisting of the C-terminus of the M protein of the Dengue virus type 1 strain Singapore S275/90 (DVM-C) produced ion channel activity in artificial lipid bilayers. The channels had a variable conductance and were more permeable to sodium and potassium ions than to chloride ions and more permeable to chloride ions than to calcium ions. Hexamethylene amiloride (100 microM) and amantadine (10 microM), blocked channels formed by DVM-C. Ion channels may play an important role in the life cycle of many viruses and drugs that block these channels may prove to be useful antiviral agents.

Reproductive potential after methotrexate treatment of ectopic gestation in a community hospital.

OBJECTIVE: To compare the rates of ipsilateral tubal patency after methotrexate treatment versus conservative surgical treatment in a small community hospital lacking personnel dedicated to methotrexate management. STUDY DESIGN: From hospital and clinic records, cases of ectopic gestation within a six-year interval were identified. Method of treatment and location of the ectopic gestation were documented by review of records and confirmed by patient interviews. Women desiring fertility were offered hysterosalpingography (HSG) to evaluate tubal patency. HSG was performed under fluoroscopy with water-soluble contrast medium. RESULTS: HSG was completed in 11 cases of linear salpingostomy and 11 cases of ectopic gestations treated by methotrexate. Ipsilateral patency was documented in 8 of 11 (72%) tubes treated by linear salpingostomy and 9 of 11 (81%) methotrexate-treated tubes. One methotrexate case had a prior ipsilateral ectopic treated by salpingostomy, and two additional cases had a prior contralateral ectopic removed by salpingectomy. Each of these three cases had ipsilateral tubal patency after methotrexate for the most recent ectopic gestation. CONCLUSION: Data from this study suggest comparable tubal patency rates after methotrexate and conservative surgery. Comparable tubal patency outcomes were obtained in our community hospital despite a less-rigorous-than normal follow-up protocol.

Use of transvaginal ultrasonography to monitor the effects of tamoxifen on uterine leiomyoma size and ovarian cyst formation.

To evaluate the effects of tamoxifen on leiomyomas and ovarian cysts in postmenopausal breast cancer patients, uterine and leiomyoma volumes were monitored sonographically in 17 postmenopausal women receiving postoperative tamoxifen for breast cancer; patients were examined twice with a mean of 1.18 +/- 0.17 years between examinations. The mean increase in leiomyoma volume was 1.26 +/- 0.73 cm3. The mean myoma volume was significantly larger at follow-up evaluation than at initial ultrasonography (5.75 +/- 1.09 cm3 versus 4.36 +/- 0.817 cm3, respectively; Wilcoxon signed rank test, P = 0.0218). Six women developed new leiomyomas. Of the 21 leiomyomas initially detected, 13 increased, six decreased, and two were unchanged in volume. The mean increase in uterine volume was 17.45 +/- 8.49 cm3. Three patients had simple ovarian cysts at initial ultrasonographic examination, two of which remained unchanged in size, and the third resolved. Two patients had newly developed simple ovarian cysts. The increase in uterine and leiomyoma volumes with the development of new leiomyomas and the persistence or development of ovarian cysts in some patients support the existence of agonistic tamoxifen effects. Serial measurements of uterine and leiomyoma volumes and surveillance for ovarian cysts is recommended for tamoxifen users.

The use of transvaginal ultrasound and saline infusion sonohysterography for the evaluation of asymptomatic postmenopausal breast cancer patients on tamoxifen.

Tamoxifen has been shown to decrease the recurrence rate of breast cancer. Evidence that tamoxifen use may be associated with an increased risk of endometrial cancer has caused investigators to recommend routine invasive sampling. We have assessed a minimally invasive alternative for endometrial surveillance of tamoxifen-treated patients utilizing transvaginal ultrasound and saline infusion sonohysterography. Asymptomatic women (n = 44) with breast cancer on postoperative tamoxifen treatment were referred to our gynecological ultrasound unit. Initially, the endometrial echo was measured with unenhanced transvaginal ultrasound. If a distinct echo measured < or = 5 mm, no further procedure was performed. For thickened or inadequately visualized echoes, sonohysterography was performed. If a thin echo was noted on sonohysterography, no further procedure was performed. If focal changes were detected, hysteroscopy/dilatation and curettage (D&C) was performed. For generalized symmetrically thickened echoes, a blind biopsy was done. If sonohysterography was unsuccessful, hysteroscopy/D&C was performed. Eleven (25%) patients had thin unenhanced echoes of < or = 5 mm. Twenty-five (57%) patients had thickened endometrial echoes. Three (7%) had naturally occurring endometrial fluid outlining a polyp. An endometrial echo could not be visualized in five (11%) patients. Sonohysterography was successfully performed in 21 out of 30 (70%) patients with either thickened or non-visualized unenhanced echoes. Of these, two patients had thin endometria with coexisting myomas; seven had thin endometria with typical tamoxifen-induced subendometrial changes: and seven had focal polypoid thickening confirmed by hysteroscopy/D&C. Histology revealed carcinoma associated with two, proliferation in one and four polyps. Five patients had thickened unenhanced echoes with symmetrically thickened single-layer measurements on sonohysterography. Histology revealed that three were proliferative, one was inactive and one was hyperplastic. In the nine patients with unsuccessful sonohysterography, hysteroscopy/D&C revealed inactive endometria in six, and three polyps. Our paradigm of evaluating the endometrial response to tamoxifen is concluded to overcome the shortcomings of either unenhanced transvaginal ultrasound or blind biopsy alone while it kept the number of invasive sampling procedures to 55% (24 out of 44).

Ultrasonography-based triage for perimenopausal patients with abnormal uterine bleeding.

OBJECTIVE: Abnormal perimenopausal bleeding is common and accounts for much medical and surgical intervention. This study was undertaken to evaluate an ultrasonography-based triage paradigm for perimenopausal patients with abnormal uterine bleeding. STUDY DESIGN: Four hundred thirty-three perimenopausal patients with abnormal uterine bleeding (either metrorrhagia, menorrhagia, or both) were evaluated. In lieu of undergoing a sampling procedure they were brought back on days 4 to 6 of the subsequent bleeding cycle, when the endometrium was expected to be its thinnest. If a distinct endometrial echo < or = 5 mm (double layer) was imaged by endovaginal ultrasonography, dysfunctional uterine bleeding was diagnosed. If a thickened endometrial echo > 5 mm or no endometrial echo was reliably visualized, a saline infusion sonohysterography was performed. If saline infusion sonohysterography revealed a symmetric single-layer endometrial thickness < 3 mm, dysfunctional uterine bleeding was diagnosed. If focal lesions were noted (polyps, submucous myomas, focal thickening), the patient was scheduled for curettage with hysteroscopy. If the endometrium was globally thickened, nondirected office biopsy was performed. RESULTS: A total of 341 patients (79%) had ultrasonographic evidence of no anatomic abnormality, and dysfunctional uterine bleeding requiring no further studies was diagnosed. Fifty-eight patients (13%) had focal polypold masses, all of which were removed hysteroscopically and confirmed pathologically. Twenty-two patients (5%) had submucous myomas; 10 patients (23%) had globally thickened endometrium on saline infusion sonohysterography, and then nondirected office sampling revealed hyperplasia in 5 and proliferation in 5. Two patients had technically inadequate saline infusion sonohysterography, and thus we proceeded to hysteroscopy with curettage. CONCLUSION: Nondirected office biopsy alone without imaging would have potentially missed the diagnosis of focal lesions such as polyps, submucous myomas, and focal hyperplasia in up to 80 patients (18%). Our clinical algorithm for perimenopausal patients with abnormal uterine bleeding used unenhanced endovaginal ultrasonography followed by saline infusion sonohysterography for selected patients. This approach allowed for no endometrial sampling, nondirected sampling, or directed sampling depending on whether the ultrasonography-based triage revealed no anatomic abnormalities, globally thickened endometrial tissue, or focal abnormalities, respectively.

Relation of peri-infarction block to ventricular late potentials in patients with inferior wall myocardial infarction.

This study explores the relation of the presence of peri-infarction block to ventricular late potentials in patients with inferior wall myocardial infarction (MI). The hypothesis was that both the gross peri-infarction block pattern and subtle low-level ventricular late potentials are expressions of conduction abnormality associated with infarction. The consequent question arose whether peri-infarction block may have the same association with sustained ventricular arrhythmias that has been demonstrated in postinfarction patients with ventricular late potentials. Seventy patients with documented Q-wave MI were divided into those with (23) and those without (47) peri-infarction block. Signal-averaged electrocardiograms were obtained. Analysis of the vectormagnitude complex revealed that the total duration of that complex and the duration of terminal potential under 40 microV in the peri-infarction group exceeded that in the group without peri-infarction block (p less than 0.0001). The voltage in the last 40 ms of the vectormagnitude complex was also significantly less in the peri-infarction group (p less than 0.0005). There were 13 instances of sustained ventricular tachycardia, ventricular fibrillation or sudden death occurring subsequent to infarction not associated with the acute ischemic event, 11 of which occurred in the peri-infarction group. The significantly higher incidence of late potentials along with the significantly higher incidence of sustained ventricular arrhythmias in the peri-infarction block on the surface electrocardiogram may provide another marker for identifying persons at increased risk for these arrhythmias subsequent to MI.

Penlight test for glare disability of cataracts.

We describe an alternative glare test using a simple penlight. When the glare and decrease in vision created by the penlight were compared on Snellen chart recordings, 92% of eyes within 20/50 or less visual acuity were no longer able to see even the 20/200 Snellen figure. This penlight test is suggested as an adjunct to standard Snellen testing in the evaluation of the cataract surgery patient.