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Biomedical subjects

B Gerber

Publications and source records attributed to B Gerber.

At least 73 records · Page 4Linked to original sources
PubMed1999

[Rating of transvaginal sonography in the evaluation of postmenopausal bleeding].

OBJECTIVE: The purpose of this study was to evaluate transvaginal ultrasonography (TVS) in differential diagnosis of vaginal bleedings in postmenopausal patients. MATERIAL AND METHODS: Between January 1990 and December 1996, 1198 postmenopausal patients with vaginal bleedings were sent to our clinic for a histological evaluation. Eight hundred and seventy-nine patients (73.4%) were preoperatively scanned by transvaginal probe, and endometrial thickness (< 5, 5-7, 8-10, > 10 mm) was measured. RESULTS: Atrophy was found in 46.3%, endometrial polyps in 19.8%, endometrial cancer in 17.5%, and hyperplasia in 6.7%. An endometrial thickness of lower than 5 mm (p < 0.0001) was shown in TVS patients with atrophy in 71%, with endometrial polyps in 10.9%, with endometrial cancer in 3.9% and hyperplasia in 6.8%. In 55.2% of these eases with endometrial cancer the preoperatively estimated thickness was 10 mm or more. The additionally morphologic examination in cases with an endometrium smaller than 5 mm was false positive in 75% (9/12). Thus an endometrial thickness of > 5 mm had a sensitivity of 92.5%, specificity of 71.0%, positive and negative predictive value of 75.6, respectively 90.9% for the detection of endometrial pathology. CONCLUSIONS: TVS allows the detection of an endometrial pathology in the vast majority of patients with postmenopausal bleedings. In cases with a single postmenopausal bleeding and an endometrium smaller than 5 mm we recommend expectative procedures with repeated ultrasound examination of the endometrium.

Aged↗
PubMed1999

Pharmacological dissociation between the reinforcing, sensitizing, and response-releasing functions of reward in honeybee classical conditioning.

Reserpine depletes biogenic amines from their stores in the honeybee (Apis mellifera carnica) brain and leads to impaired appetitive conditioning using sucrose as a reinforcer. Compensatory injection of octopamine or dopamine directly into the brain restores these behavioral losses. Dopamine rescues the slowing-down effect on motor patterns, but not sensitization or conditioning. Octopamine leaves the motor patterns as well as sensitization unchanged but rescues conditioning. Specifically, octopamine rescues acquisition but not retrieval. Serotonin has no significant effect on sensitization but impairs conditioning. The authors conclude that octopamine is involved in selectively mediating the reinforcing but not the sensitizing or response-releasing function of the sucrose reward, whereas dopamine is selectively involved in the expression of the motor response.

Adrenergic Uptake Inhibitors↗
PubMed1999

[An old disease with a new face: canine leptospirosis does not lose its relevance].

The clinical features of the disease are presented based on retrospective analysis of the records of eleven dogs diagnosed with leptospirosis using clinical signs and results of the microagglutination test (MAT) between 1991 and 1996. Additionally, Leptospira titres were determined in 30 healthy dogs and 20 hospitalised dogs without clinical or laboratory evidence of leptospirosis. A positive titre for L. grippotyphosa, L. pomona, L. bratislava, L. australis, L. icterohaemorrhagiae and/or L. canicola was found in 16 normal dogs and only one hospitalised patient. Eight of these dogs had titres of > or = 1:800. Only one of them had been vaccinated shortly before sampling. These results suggest that many dogs from the surroundings of Bern, Switzerland have contact with various Leptospira interrogans serovars. In ten healthy dogs, the Leptospira titre was determined before and four weeks after vaccination with leptospiral antigen. Only two of the dogs showed a serologically measurable response to the antigen contained in the vaccine. In dogs MAT titers presumably do not reliably reflect the immune status against leptospiral infections.

Agglutination Tests↗
PubMed1998

Temporal determinants of olfactory long-term retention in honeybee classical conditioning: nonmonotonous effects of the training trial interval.

The question of which acquisition parameters govern long-term retention is important to an understanding of memory function. We investigate the effects of the time interval between learning trials on mediate (1 day)- and long-term (4 days) retention. In classical conditioning of the proboscis extension reflex, we train honeybees to associate an odorant with a sucrose reward using intertrial intervals of either 30 s, 1 min, 3 min, or 20 min. Intervals of 20 and 1 min result in stable retention but 3-min and 30-s intervals result in reduced retention after 4 days compared to that seen after 1 day. Thus, stability of long-term retention depends nonmonotonously on the intertrial interval. Reduced retention with 3-min intervals might be caused by a disruption of memory consolidation which is known to be especially sensitive to interference 3 min after a conditioning trial. Habituation and backward inhibitory learning are discussed as explanations for reduced retention with 30-s intervals.

Animals↗
PubMed1998

Short communication: long- but not medium-term retention of olfactory memories in honeybees is impaired by actinomycin D and anisomycin.

Although work in a wide variety of species and paradigms has demonstrated that long-term memory is sensitive to the blocking of protein synthesis, previous studies have suggested that the honeybee might represent an exception to this rule. Retention tested one day after training was not impaired by the inhibition of translation by cycloheximide. Using blockers of either transcription (actinomycin D) or translation (anisomycin), we present experiments that reconcile this unusual finding by testing over longer retention periods. Honeybees were conditioned to associate an odourant with a sucrose reward. Typically, this leads to stable retention over days. However, injection of either drug led to lower retention after 4 days, whereas retention after 2 or sometimes even 3 days was unaffected. This dissociates two forms of memory: a protein synthesis-independent, medium-term memory (up to 3 days) and a protein synthesis-dependent, long-term memory lasting for at least 4 days.

Animals↗
PubMed1998

Visual modulation of olfactory learning in honeybees.

We use classical conditioning of the honeybee (Apis mellifera) proboscis extension reflex with a visual (A) and an olfactory (X) conditioned stimulus in a blocking paradigm. Typically, learning about one element (X) of a compound (AX) is decreased (blocked) if the other component (A) has previously been rewarded alone. Our results show that visual pretraining did not produce blocking in honeybees: instead, forward pairings of A with a reward increased subsequent learning about X relative to a backward pairing control. This finding violates the independence assumption, which holds that elements of inter-modal compound stimuli change associative strength independently of each other. Furthermore, it is at odds with common theories of conditioning that predict blocking and assume that the elements of a compound stimulus rely on one common internal reinforcing signal. Taking the functional anatomy of the honeybee brain into account, we suggest that vision and olfaction may not rely on the same internal reinforcing signal; compound interactions might thus reflect the wiring of the honeybee nervous system and the biological significance of different sensory modalities during natural behaviour.

Animals↗
PubMed1997

Simple ovarian cysts in premenopausal patients.

OBJECTIVE: To compare clinical, ultrasonographical, and cytological findings with the histopathological diagnosis of unilocular, anechoic smooth-walled cystic ovarian tumors ('simple ovarian cysts'). METHOD: In 140 premenopausal women simple ovarian cysts were removed by laparoscopy following ultrasound evaluation. In this retrospective study the histopathological diagnosis was correlated with clinical data, sonographic characteristics, macroscopic impression and with cytological findings. RESULTS: Histopathology revealed 21 (15.0%) functional cysts, 31 (22.1%) retention cysts, 9 (6.4%) endometriomas, 3 (2.1%) cystic teratomas, 12 (8.6%) undifferentiated cysts and 64 (45.7%) cystadenomas. No mentionable differences were correlated with the patient's age or the size of the cyst as determined by ultrasound. Classically, 'chocolate-like' cystic fluid characterizes endometriomas. However, in the present study cysts with different histopathological classifications exhibited similar fluid characteristics. The cytological diagnosis was correct in only 53 (37.9%) of all 140 cases. CONCLUSION: In premenopausal women differential diagnosis of ovarian cysts is not possible by clinical characterization, either by ultrasound or cytological evaluation. Simple ovarian cysts should be observed for at least 8 weeks or 2 menstrual cycles, respectively. If persisting over that period, the ovarian cyst should be removed by laparoscopy, but not by cyst aspiration.

Adult↗
PubMed1997

Correlation of functional recovery with myocardial blood flow, glucose uptake, and morphologic features in patients with chronic left ventricular ischemic dysfunction undergoing coronary artery bypass grafting.

OBJECTIVE: Our objective was to investigate the influence of preoperative myocardial ultrastructure and metabolism on recovery of contractile function after coronary artery bypass grafting in patients with coronary artery disease and left ventricular dysfunction. METHODS: Dynamic positron emission tomography with 13N-ammonia and 18F-deoxyglucose was used to assess myocardial perfusion and glucose uptake in 53 patients scheduled for coronary revascularization because of coronary artery disease and left ventricular dysfunction. The degree of tissue fibrosis and the presence of potentially reversible alterations of cardiomyocytes (loss of myofilaments and accumulation of glycogen) were quantified from transmural biopsy specimens. These were harvested from the center of the dysfunctional area during the operation and analyzed with a light microscope. The recovery of contractile performance was assessed from the changes in left ventricular function at contrast ventriculography or echocardiography before and 6 months after the operation. RESULTS: According to postoperative changes in regional wall motion, left ventricular function was considered to have improved in 34 patients, whereas dysfunction persisted in 19 patients. In patients with improved wall motion, ejection fraction rose by 12% and end-systolic volume decreased by 28%. By contrast, in patients with persistent dysfunction, ejection fraction decreased by 6% and end-systolic volume increased by 25%. Before revascularization, myocardium with reversible dysfunction displayed higher levels of absolute myocardial blood flow, higher myocardial glucose uptake, less tissue fibrosis, and more altered cardiomyocytes than myocardium with persistent dysfunction. Significant correlations were found between regional blood flow and the surface of the biopsy specimen covered by fibrosis, as well as between glucose uptake and the density of altered cardiomyocytes. CONCLUSION: In patients with left ventricular ischemic dysfunction, the recovery of regional and global left ventricular function after surgical revascularization is associated with higher preoperative blood flow and glucose uptake, with less tissue fibrosis and a higher amount of viable cardiomyocytes in the dysfunctional area. The current study thus confirms the value of noninvasive preoperative metabolic imaging for identification of residual viable myocardium and for prediction of the functional outcome after revascularization.

Adult↗
PubMed1997

Odorant intensity as a determinant for olfactory conditioning in honeybees: roles in discrimination, overshadowing and memory consolidation.

Stimulus intensity is an important determinant for perception, learning and behaviour. We studied the effects of odorant concentration on classical conditioning involving odorants and odorant-mechanosensory compounds using the proboscis-extension reflex in the honeybee. Our results show that high concentrations of odorant (a) support better discrimination in a feature-positive task using rewarded odorant-mechanosensory compounds versus unrewarded mechanosensory stimuli, (b) have a stronger capacity to overshadow learning of a simultaneously trained mechanosensory stimulus, and (c) induce better memory consolidation. Furthermore, honeybees were trained discriminatively to two different concentrations of one odorant. Honeybees are not able to solve this task when presented with rewarded low versus unrewarded high concentrations. Taken together, our results suggest that high concentrations of odorant support stronger associations (are more 'salient') than low concentrations. Our results, however, do not indicate that honeybees can treat two different concentrations of one odorant as qualitatively different stimuli. These findings fill a gap in what is known about honeybee olfactory learning and are a first step in relating behaviour to recent advances in the physiological analysis of coding for odorant concentration in honeybees.

Animals↗
PubMed1997

Estradiol, gonadotropins, and tumor markers in ovarian cyst fluid.

BACKGROUND: The study was designed to improve the discrimination between functional and neoplastic ovarian cysts in order to avoid unnecessary surgery. METHODS: Concentrations of tumor markers (CA 125, CEA, CASA, CA 72-4) and hormones (estradiol, FSH, LH) in cyst fluid were detected by enzyme immuno- or immunoradiometric assays. Wilcoxon test was used to evaluate the correlation of cyst fluid markers and histology. RESULTS: One hundred and thirty-eight ovarian cyst aspirates were investigated. Seventy-one patients (51.5%) had functional cysts whereas 67 (48.5%) had benign (n=59) or malignant (n=8) cystic tumors. Statistically significant correlations of CA 125 (p<0.0005) and CASA (p<0.02) with neoplastic histology were found. No significant correlation could be detected between CA 72-4, CEA, or hormone values and histology. Elevated estradiol concentrations are suspicious for functional cysts in premenopausal age. Low FSH and LH levels seem to be an indicator for functional cysts in peri- and postmenopausal age. CONCLUSIONS: The assessed analytes could not reliably distinguish between functional and neoplastic ovarian cysts. Our results indicate that CA 125 is a marker for neoplastic histology in a proportion of ovarian cysts. The use of FSH and LH in the diagnosis of postmenopausal blastomas needs further investigation.

Adolescent↗
PubMed1997

[Quality of life in relation to patient education regarding surgical procedures in primary breast carcinoma].

Breast conserving therapy is seen as a profit according to life quality. The patients have been subjected to the surgeon suggestions during decision-making about the primary therapy. The purpose of this study was to examine the relationship between the degree of preoperative information of breast cancer therapy and patients' choices of treatments in cases suited for breast conserving therapy. 138 recurrence free patients after breast conserving therapy (BCT) or mastectomies (ME) due to a breast cancer staged as pT1-2N0-1M0 and missing contraindication to BCT were interviewed using an observer checklist. The degrees of preoperative information, reasons for decision to mastectomy, though BCT was possible, were correlated with the postoperative life quality. Patients decided for BCT were averaging 56.0 + 12.3 years and significantly (p < 0.05) younger than patients decided for ME (60.4 + 10.5), whereas tumor size, nodal status and adjuvant therapies were comparable. The results indicate, that subjects' choice of treatment was unrelated to the amount of information. 87% (BET) respectively 78.3% (ME) patients evaluated, that preoperative information was enough (p = 0.19). The most frequent reasons for preference of mastectomy were the "perception that survival would be diminished if mastectomy was not done" (93.5%), "avoidance of radiotherapy" (60.9%) and "no partner" (34.8%). According to expectation the body image in the BCT-group (84.8%) was significantly (p = 0.0007) more positive than in the ME-group (58.9%). Nevertheless only 5 (10.9%) patients after ME have felt sorry for their earlier decision. There were no significant differences between the two groups with regard to partner- and sexual adjustment as well as physical well-being. Despite being fully informed of treatment possibilities and no medical contraindications to BCT nearly one third preferred mastectomy due to different reasons. When the patient was involved in the clinical decision-making process the mastectomy indicates not generally a loss of life quality, though nearly 40% are dissatisfied with their nude body image.

Adult↗
PubMed1997

[Role of isotopic techniques in the evaluation of myocardial viability in man].

Modern management of coronary artery disease is increasingly based on techniques of myocardial revascularisation. The introduction of coronary bypass surgery, percutaneous coronary angioplasty and thrombolysis has radically changed the prognosis, reducing the morbidity and mortality related to myocardial infarction and chronic ischaemic heart disease (when associated with left ventricular dysfunction). In this case, the beneficial effects of revascularisation are probably due to improved contractility of dysfunctional tough viable myocardium in response to improved perfusion. Several methods are available for predicting the reversible character of segmental dysfunction after revascularisation. Most are based on fundamental cellular mechanisms thought to contribute to cellular viability and postoperative contractile recovery. These include adequate tissue perfusion for providing energetic substrate and the elimination of metabolic waste; the maintenance of essential membrane functions, the conservation of metabolic pathways for the aerobic use of glucose and fatty acids, and the maintenance of a contractile function capable of ensuring efficacious mechanical activity after surgery. Thallium or MIBI myocardial scintigraphy and position emission tomography (PET) allow the non-invasive evaluation of some of these mechanisms. These techniques are capable of detecting viable myocardium with a high sensitivity (> 80%). They are limited by a lack of specificity (+/- 55% for thallium and +/- 75% for PET). However, all have an additive prognostic value with respect to usual functional (ejection fraction) and anatomical (coronary angiography) parameters.

Coronary Circulation↗
PubMed1996

Chemokine receptor specific for IP10 and mig: structure, function, and expression in activated T-lymphocytes.

A human receptor that is selective for the CXC chemokines IP10 and Mig was cloned and characterized. The receptor cDNA has an open reading frame of 1104-bp encoding a protein of 368 amino acids with a molecular mass of 40,659 dalton. The sequence includes seven putative transmembrane segments characteristic of G-protein coupled receptors. It shares 40.9 and 40.3% identical amino acids with the two IL-8 receptors, and 34.2-36.9% identity with the five known CC chemokine receptors. The IP10/Mig receptor is highly expressed in IL-2-activated T lymphocytes, but is not detectable in resting T lymphocytes. B lymphocytes, monocytes and granulocytes. It mediates Ca2+ mobilization and chemotaxis in response to IP10 and Mig, but does not recognize the CXC-chemokines IL-8, GRO alpha, NAP-2, GCP-2. ENA78, PF4, the CC-chemokines MCP-1, MCP-2, MCP-3, MCP-4, MIP-1 alpha, MIP-1 beta. RANTES, 1309, eotaxin, nor lymphotactin. The exclusive expression in activated T-lymphocytes is of high interest since the receptors for chemokines which have been shown so far to attract lymphocytes, e.g., MCP-1, MCP-2, MCP-3, MIP-1 alpha, MIP-1 beta, and RANTES, are also found in monocytes and granulocytes. The present observations suggest that the IP10/Mig receptor is involved in the selective recruitment of effector T cells.

Amino Acid Sequence↗
PubMed1996

[Prognostic significance of micrometastases in axillary lymph nodes in breast carcinoma].

We looked for micrometastases in the axillary lymph nodes of 163 women with breast carcinoma, using monoclonal anticytokeratin antibodies. We found 26 micrometastases (2.1%) in node-negative patients (n = 17). Life-table analysis after 3 years detected the conformity of this group with the N1 group with regard to overall survival and distant-metastasis-free survival.

Adult↗
PubMed1996

A study of second-look laparoscopy after acute salpingitis.

Acute salpingitis (AS) has a major impact on the reproductive health of women. In this study second-look laparoscopy was assessed for its ability to predict reproductive function after AS. We questioned 158 women who had had a second-look laparoscopy with tubal dye insufflation after laparoscopically proven AS between September 1984 and August 1989. The answers of 69 women with at least two years of involuntary infertility were analyzed. The mean follow-up period was 76 months (range 53-108 months). Second-look laparoscopy revealed bilateral tubal occlusion in 21.7% (15/69). Bilateral tubal occlusion was found in 9.5% (2/21) after mild stage, 20% (4/20) after moderate stage and 32.1% (9/28) after severe stage AS. The rate of infertility during follow-up was 9.5% (stage I), 35% (stage II) and 39.9% (stage III). Eighty per cent (12/15) of women with proven bilateral tubal occlusion after treated AS had involuntary infertility, and 14.8% (8/54; P = 0.000001) of women with one or both tubes patent also had infertility. Specificity, sensitivity and positive predictive value for subsequent infertility were 85.2%, 80% and 84.1%, respectively. Pelvic adhesions (21/69) were strongly correlated with bilateral tubal occlusion (8/21; 38.1%; P = 0.029), a history of chronic pelvic pain (14/21; 66.7%; P = 0.00024), as well as failure to achieve an intrauterine pregnancy (10/21; 47.6%; P = 0.024). Recurrent pelvic infections occurred in 16% (12/69) and ectopic pregnancies in 7.3% (5/69). Operations for infertility and pelvic pain (excluding ectopic pregnancy), were carried out in 11.6% (8/69). We conclude that second-look laparoscopy after treated AS have accurate evaluation of reproductive function.

Acute Disease↗
PubMed1996

Epidermal growth factor receptor gene and c-erbB-2 gene amplification in ovarian cyst fluid.

OBJECTIVE: To test for a significant difference between functional and neoplastic ovarian cyst with respect to epidermal growth factor (EGF) receptor and c-erbB-2 proto-oncogene amplification rates. METHODS: We determined amplification of EGF-receptor and c-erbB-2 genes by differential polymerase chain reaction (PCR) on 138 ovarian-cyst aspirates. The semiquantitative differential PCR is based on simultaneous co-amplification of a target gene and a reference gene. Amplification rates were detected by densitometry of silver-stained polyacrylamide gels and were scored as single-, low-, or high-copy numbers. Wilcoxon ranked sum test, Pearson correlation coefficient, and multiple logistic regression were used to evaluate the differences in oncogene amplification and to predict histology. RESULTS: There were 71 (51.5%) women with functional cysts, whereas 67 (48.5%) had benign (n = 59) or malignant (n = 8) tumors. Low-copy (two- to fourfold copy numbers) EGF-receptor gene amplification was found in 22 of 67 (33%) women with neoplastic cysts, but in only eight (11%) of those with functional cysts. Neoplastic histology differed significantly from functional histology in correlation to EGF-receptor low-copy gene amplification (r = .279, P < .001). There was no significant difference in c-erbB-2 gene amplification with respect to functional and neoplastic histology (r = .083, P = .32). CONCLUSIONS: Low-copy EGF-receptor gene amplification seems to be a market for neoplastic histology. Epidermal growth factor receptor gene amplification may be involved in proliferation and growth in an early stage of tumorigenesis. However, further studies are required to investigate this gene structure abnormality on a gene function level. Amplification of c-erbB-2 proto-oncogene does not appear to be a common factor in the development of ovarian tumors.

Adolescent↗
PubMed1996

Nuclear and echocardiographic imaging for prediction of reversible left ventricular ischemic dysfunction after coronary revascularization: current status and future directions.

Modern therapy of coronary artery disease (CAD) increasingly involves interventional strategies aimed at restoring blood flow to the ischemic myocardium. The emergence of coronary artery bypass surgery, percutaneous transluminal coronary angioplasty, and more recently thrombolytic therapy, has helped to change the natural course of ischemic heart disease and contribute to the overall reduction in the mortality from both acute myocardial infarction and chronic CAD. Presumably, the beneficial effects of revascularization result from improving blood supply to dysfunctional but viable regions with subsequent improvement in regional and global left ventricular function. Over the past decade, several approaches have been proposed to predict the reversibility of left ventricular dysfunction after coronary revascularization. For the most part, these methods rely on assessment of basic cellular mechanisms that are known to play a central role in the recovery of systolic function after coronary revascularization. These include sufficient resting perfusion to provide metabolic fuels and to allow wash-out of toxic metabolites, maintain membrane integrity (which includes the ability to generate transmembrane ionic gradients and to transport energy providing substrates), preserve metabolic machinery (to allow glucose, fatty acid and oxygen consumption), and recruitable inotropic reserve. Among the available modalities, thallium imaging, positron emission tomography, and low-dose dobutamine echocardiography are currently the most frequently used in the clinical setting. All allow prediction of reversible dysfunction with a high degree of sensitivity (greater than 80%). They seem to vary, however, in terms of specificity, thallium imaging showing the lowest (50-55%) and dobutamine echocardiography the highest (80-85%) specificity. New promising modalities, such as FDG or MIBI SPECT imaging, contrast echocardiography and integrated backscatter imaging are just ahead and will likely strengthen further our ability to identify jeopardized but viable myocardium.

Angioplasty, Balloon, Coronary↗