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Biomedical subjects

R Lehner

Publications and source records attributed to R Lehner.

At least 55 records · Page 3Linked to original sources
PubMed1997

Contraceptive knowledge and attitudes of Austrian adolescents after mass media reports linking third-generation oral contraceptives with an increased risk of venous thromboembolism.

We performed a representative survey to determine the level of knowledge of 1,010 Austrian adolescents aged 14 to 24 years about selected facts relating to the recent massive news coverage of the increase in the risk of venous thromboembolism in users of third-generation oral contraceptives and to assess the contraceptive behavior of this population. The overall use rate of oral contraceptives and condoms had increased significantly between 1991 and 1996. Sixty-six percent of the adolescents surveyed stated not having heard or read any media reports on oral contraceptives. Only 8% of those who had knew that most reports focused on the pill as a possible cause of venous thromboembolism, whereas the majority of respondents indicated that the media conveyed doubts regarding the health safety of oral contraceptives in general. Nearly half of adolescents were unable to define what a thrombosis was. Thus, although the mass media play an important role in transmitting medical information, the dissemination of practical, accurate advice on the risks of a drug and competent patient counseling is reserved for the health care professionals.

Adolescent↗
PubMed1997

Fallopian tissue sampling with a cytobrush during hysteroscopy: a new approach for detecting tubal infection.

OBJECTIVE: To evaluate whether the transcervical approach for fallopian tissue sampling is a practicable and safe method to establish an etiologic diagnosis of salpingitis. DESIGN: Controlled clinical study. SETTING: Academic research environment. PATIENT(S): Twenty women with primary or secondary sterility undergoing hysteroscopy and laparoscopy. INTERVENTION(S): During hysteroscopy, fallopian tissue samples were obtained from the proximal parts of both tubes with a cytobrush inserted through the working channel of the hysteroscope. Diagnostic laparoscopy with assessment of tubal patency was performed in the same session. The specimens were split and used for chlamydial testing by both cell culture and polymerase chain reaction. Serum samples were evaluated for the presence of antichlamydial antibodies. MAIN OUTCOME MEASURE(S): Practicability and safety of the method. RESULT(S): The sampling procedure was performed in all patients without complications. Adequate samples were obtained from both tubes in all 20 patients. The fallopian specimens showed evidence of chlamydial infection in one patient. CONCLUSION(S): Those data indicate that transcervical fallopian tissue sampling with a cytobrush is a reliable and safe technique.

Cervix Uteri↗
PubMed1997

The diagnostic value of planar and SPET scintimammography in different age groups.

Planar scintimammography (SMM) with 99Tcm-sestamibi (99Tcm-MIBI) has proved to be a useful method in the evaluation of breast lesions. The aim of our study was to determine the diagnostic value of planar and single photon emission tomograpic (SPET) SMM in different age group. We investigated women with breast lesions for which the surgeon recommended biopsy or careful follow-up. Seventy consecutive patients underwent supine planar SMM, while supine SPET was performed in 68 of the patients. Twenty-seven carcinomas in 23 patients and 35 benign lesions in 31 patients were confirmed histologically. In the remaining 16 patients, the findings were classified as benign at follow-up. The carcinomas and benign lesions had a mean (+/- S.D.) diameter of 25 +/- 17 and 17 +/- 11 mm respectively (P < 0.05). A sensitivity/specificity of 67/96% and 88/91% was obtained with the planar and SPET techniques respectively. The accuracy of both techniques was 90%. In patients aged 40 years or less, SPET increased the sensitivity from 50 to 100% (P < 0.01), whereas it decreased the specificity and accuracy from 94 to 81% and 91 to 81% respectively (N.S.). In patients aged 41-50 years, the sensitivity increased from 63 to 100% (P < 0.01), whereas there was a small decrease in specificity and an increase in accuracy (from 91 to 89% and 86 to 91% respectively, N.S.) We conclude that, in younger patients, a negative SPET SMM study indicates the need for careful follow-up rather than biopsy. However, the addition of SPET in supine scintimammography does-not change the overall accuracy significantly.

Adult↗
PubMed1997

[Second look laparoscopy after fallopian tube perforation with the tubal endoscope].

In recent years, falloposcopic, visualization of the tubal lumen has become a topic of great interest. The development of a linear everting catheter system (Imagyn Medical Inc., Laguna Niguel, Calif., USA) allows cannulation of the fallopian tubes without exerting shear forces upon the tubal epithelium. We report the findings of a second-look laparoscopy after accidental tubal perforation at falloposcopy. Second-look laparoscopy was performed in a patient 6 months after tubal perforation with the falloposcope and no adhesions or signs of inflammation could be detected. On chromopertubation, no tubal fistula was found to be present. Two months after treatment, the patient got pregnant spontaneously. Pregnancy and delivery were without any complications. We conclude that technique of falloposcopy provides a safe access to the endotubal lumen. Even a perforation created by the microendoscope does not appear to be associated with any long-term complications.

Adult↗
PubMed1997

Preoperative assessment of the implantable middle ear pump system using CT scans and conventional X-rays of the temporal bone.

A completely implantable micropump system for drug delivery has recently been developed. After implantation in the temporal bone, this microdosage system enables application of drugs into the middle ear and round window area. Successful application of this new technology depends upon a suitable fit of the micropump within the patient's temporal bone. To obtain information about the fit before surgery, we analyzed 50 cadaver temporal bone specimens before total mastoidectomy, using conventional X-ray and spiral CT scans for water volume determination. Spiral CT is a feasible method for preoperative planning of the surgical implantation of the implantable middle ear micropump system (TI-DDS). The best parameter for a preoperative judgment is the volume of the mastoid cavity, as determined by CT. Implantation may be recommended when the mastoid volume, as measured by CT, is greater than 6.6 ml. To be certain that the implantable drug delivery system will be implantable, a cut-off value of 9.3 ml seems to be advisable. Spiral CT imaging is of great value as a tool for testing implantation preoperatively. The imaging is accomplished in approximately 30 seconds. Our preliminary results with cadaveric temporal bones are encouraging. Further studies are needed in order to transfer the results to a clinical implantation situation.

Ear, Middle↗
PubMed1997

A totally implantable drug delivery system for local therapy of the middle and inner ear.

Local therapy of middle and inner ear diseases is being used, but is restricted to cases of ear drum perforation or to repeated invasive intratympanic drug application by the physician. In accordance with the Medical Device Directive (class III), a bone-anchored, totally implantable drug delivery system (TI-DDS) has been developed. It includes a micropump for subcutaneous, patient-controlled activation, a drug reservoir and a septum port. A thin guide-wired catheter leads from the pump outlet to the point of application in the mastoid or middle ear cavities. Local inner ear therapy with suitable drugs is possible by positioning the catheter's end near the round window membrane. The system requires no battery and will offer a wide range of patient-controlled bolus applications (25 microliters per activation). We first analyzed the three-dimensional implantation geometry of the mastoid cavity. Basic micromechanical problems have been solved in order to create several prototypes. The TI-DDS has already undergone extensive in vitro testing. Recent results of pump rate precision and digital pressure force testing are promising. Local drug treatment for conditions such as lidocaine-sensitive tinnitus, secretory otitis media, Meniere's disease, localized pain and intralesional cancer is under discussion. Furthermore, local application of future biotechnological trophic factors for inner ear treatment is anticipated. The basic engineering is completed and initial animal tests are in preparation.

Animals↗
PubMed1996

Laparoscopic surgery in cases of ovarian malignancies: an Austria-wide survey.

The purpose of the study was to determine the frequency of discovering a malignant ovarian mass when laparoscopy is used to manage an adnexal mass. A countrywide survey was undertaken in Austria, comprising questions about ovarian malignancy detected or accidentally treated by laparoscopy. The response rate of 66.7% represented a total of 54,198 laparoscopies, 16,601 laparoscopic surgeries on adnexal masses, and 108 cases of ovarian tumors subsequently found to be malignant (96 well-documented). Twenty patients were treated with laparoscopy alone. In 22 cases, laparoscopy was followed by immediate laparotomy. A delayed laparotomy (3-1415 days) was performed in 54 cases. Staging revealed FIGO classifications from stages Ia to IV. The follow-up time ranges from 2 to 220 months. Four recurrences have been reported. Thirteen patients died of tumor progression. Laparoscopic surgery on ovarian malignancies is a rare situation (0.65% of all endoscopic surgeries on adnexal masses). In cases of malignancy, a laparotomy has to be performed to ensure optimal staging and treatment.

Adolescent↗
PubMed1996

[Varicella infection at the time of cesarean section].

Report on a twin pregnancy terminated by Caesarean section in the 35th pregnancy week due to retardation and pathological Doppler findings in the umbilical artery and fetal aorta. At the time of Caesarean section the mother suffered from florid varicella infection. The newborns treated with varicella hyperimmunoglobulin and acyclovir developed abortive varicella exanthema without further complications.

Acyclovir↗
PubMed1996

Diagnostic accuracy of 2 mm microlaparoscopy.

OBJECTIVE: To assess the diagnostic accuracy of a 2 mm microlaparoscope compared to the conventional 10 mm laparoscope. DESIGN: A prospective study. PATIENTS AND METHODS: Fifty-two patients underwent 2 mm and 10 mm laparoscopy in the same session. All procedures were videotaped and the quality of visualization for both methods was assessed by an independent investigator using a 3-step grading scale. RESULTS: Diagnostic information was found to be similar for both methods. CONCLUSION: In most cases undergoing laparoscopy for diagnostic purposes 2 mm microlaparoscopy yields sufficient information to abandon the conventional 10 mm technique.

Adolescent↗
PubMed1995

Triacylglycerol synthesis by purified triacylglycerol synthetase of rat intestinal mucosa. Role of acyl-CoA acyltransferase.

The activities of the proposed triacylglycerol synthetase complex, acyl-CoA ligase, acyl-CoA acyltransferase (AAT), monoacylglycerol acyltransferase (MGAT), and diacylglycerol acyltransferase (DGAT), coeluted upon Cibacron blue 3GA-agarose affinity chromatography of detergent-solubilized rat intestinal microsomes. The AAT activity is associated with a 54-kDa protein, that binds covalently an acyl group from acyl-CoA via a thiol ester linkage (Lehner, R. and Kuksis, A. (1993) J. Biol. Chem. 268, 24726-24733). Reagents that prevent the acyl-AAT formation inhibit triacylglycerol synthesis as does the removal of AAT from the complex by immunoprecipitation. In the absence of mono- and diacylglycerol acceptors, the acyl group is transferred to water. It is proposed that triacylglycerol synthesis proceeds via a sequential transfer of acyl groups from acyl-CoA ligase to the AAT, from which they are passed to the mono- and diacylglycerol acyltransferases for incorporation into the di- and triacylglycerols depending on the availability of the acyl acceptors.

Acyl Coenzyme A↗
PubMed1994

Three-dimensional video-endoscopy: clinical use in gynaecological laparoscopy.

We describe a system that displays the abdominal organs in three dimensions during laparoscopy. The system consists of a single-rod-lens endoscope and two integrated microchip cameras. The surgeon has to wear active-liquid-crystal shutter-glasses to obtain a three-dimensional impression during the operation. Improved orientation in the abdominal cavity allows exact handling of surgical instruments. The three-dimensional system permits surgery with more accuracy, speed, dexterity, and safety than conventional two-dimensional systems.

Female↗
PubMed1994

[Tuboscopy--an endoscopic approach to the intratubal lumen].

A linear everting catheter in combination with a 0.5-mm microendoscope enables the visualization of the tubal lumen. In 35 sterility patients, diagnostic tuboscopies were performed. Physiological and pathological results of tubal mucosa are described. Tuboscopy is a main tool in the diagnosis of the tubal factor. First steps are taken to use tuboscopy not only for diagnostic but also for therapeutic reasons. Yet, the role of this technique in cases of tubal pregnancies cannot be evaluated.

Endoscopes↗
PubMed1994

[Diagnosis of familial Holt-Oram syndrome].

Presented is one rare case in a family affected by a Holt- Oram-Syndrome. This syndrome is associated with an upper limb malformation and a congenital heart disease. In our case we found radiusaplasia on both sides, thenaraplasia on the left hand, a hypoplastic thumb on the right hand. The heart was malformed as a Fallot tetralogy, the left kidney was absent. Four additional affected members of the family are described. By routine ultrasound examination we could not find this malformation syndrome. In families with affected history ultrasound screening examination should be done on a center for prenatal diagnosis.

Abnormalities, Multiple↗