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H Vogt

Publications and source records attributed to H Vogt.

At least 19 recordsLinked to original sources
PubMed2006

[Radioiodine therapy for combined disseminated and nodular thyroid autonomy. Results after using a correction term for the disseminated part].

AIM: In combined focal and disseminated thyroid autonomy a variety of concepts in the treatment with radioiodine are used. The difference lies mainly in the calculation of the autonomous volume. This retrospective study shows a new method of calculating the autonomous volume. PATIENTS AND METHODS: In 398 patients with combined thyroid autonomy and good correlation of scintigraphically hot nodules and lesions defined by ultrasound the volume of the nodules is ascertained from scintigraphic and ultrasound parameters and the volume of the disseminated autonomous tissue is assessed with a weighting factor (VF). This factor is the ratio of impulse density in a ROI over the disseminated volume divided by the corresponding impulse density over the nodular volume of the thyroid scintigraphy. The sum of nodular volume and weighted perinodular volume gives the total autonomous volume. A standard radioiodine test gives the maximum iodine-131-uptake and effective half-life to calculate the activity to obtain a treatment dose of 400 Gy. RESULTS: The rate of success with and without thyrostatic medication was 97% with an 18.6% rate of hypothyroidism observed from 4 months post therapy onwards. CONCLUSION: The use of the weighting factor VF in the treatment of combined autonomy leads to an excellent rate of success in patients with good correlation of functional imaging and ultrasound findings.

Humans↗
PubMed2004

Technical considerations for microstructural analysis of human trabecular bone from specimens excised from various skeletal sites.

The purpose of this study was to test the effect of repositioning, systematic displacements of the region of interest (ROI), and acquisition parameters (scan mode and integration time) on quantitative analysis of human trabecular bone microstructure at various skeletal sites, using microcomputed tomographic (microCT) technology. We investigated 28 cylindrical specimens of human trabecular bone (length 14 mm, diameter 8 mm) from four skeletal sites (femoral neck, greater trochanter, second lumbar vertebra, and distal radius). These specimens were selected from over 200 microCT measurements, in order to cover a large range of bone volume fraction (BV/TV) observed at each site. Cylindrical ROIs (length 6 mm, diameter 6 mm) were examined twice at an isotropic resolution of 26 microm, 8 weeks apart. In addition, comparative analyses were performed for displacements of the volumes of interest (VOIs) by 1, 2, 3, and 4 mm (83.4%, 66.6%, 50%, and 33.3% overlap), respectively. Eventually, comparative measurements were obtained at different resolution scan modes and integration times. The results show that microCT measurements are highly reproducible (range of the root mean square coefficient variation % (RMS CV%) = 0.64% to 1.29% for BV/TV at different sites). Displacements of the VOI of up to 4 mm generally led to non significant systematic differences in mean values of < 10%. When comparing various combinations of resolution scan modes and integration times, the use of an integration time of 100 ms was found to be preferable for determining microstructural parameters from human samples with this microCT scanner.

Aged↗
PubMed2003

[Dissociative stupor as a postoperative consequence of general anesthesia].

A 31-year-old woman failed to awaken after an uneventful general anesthesia (propofol, alfentanil and 65% N2O in oxygen) for laparoscopic resection of an ovarian cyst. After the operation she was extubated and vital signs were stable. However, the patient remained unresponsive even to painful stimuli for about 2 h. Just before we performed a computed tomogram of the brain to exclude a cerebral lesion we noticed that she blinked. We hypothesized that unconsciousness was due to a dissociative stupor. After administration of sublingual lorazepam the patient woke up promptly and was alert and normal for the rest of the hospital stay. In conclusion, after exclusion of a pharmacological or organic cause for postoperative unconsciousness, dissociative stupor may be a reason for apparent coma after general anesthesia.

Adult↗
PubMed2002

[Sentinel lymph node diagnosis in prostatic carcinoma: II. Biokinetics and dosimetry of 99mTc-Nanocolloid after intraprostatic injection].

AIM: To visualise the sentinel lymph nodes (SLNs) of the prostate we injected the radiotracer into the parenchyma of the prostate. The activity was deposited in liver, spleen, bone marrow, urinary bladder and regional lymphatic system. The aim of this work is to determine biokinetical data and to estimate radiation doses to the patient. METHODS: The patients with prostate cancer received a sonographically controlled, transrectal administration of 99mTc-Nanocoll, injected directly into both prostate lobes. In 10 randomly selected patients radionuclide distribution and its time course was determined via regions of interest (ROIs) over prostate, urinary bladder, liver, spleen and the lymph nodes. The uptake in the SLNs was estimated from gamma probe measurements at the surgically removed nodes. To compare tumour positive with tumour free lymph nodes according to SLN-uptake and SLN-localisation we evaluated 108 lymph nodes out of 24 patients with tumour positive SLN. For calculating the effective dose according to ICRP 60 of the patients we used the MIRD-method and the Mirdose 3.1 software. RESULTS: The average uptake of separate organs was: bladder content 24%, liver 25.5%, spleen 2%, sum of SLN 0.5%. An average of 9% of the applied activity remained in the prostate. The residual activity was mainly accumulated in bone marrow and blood. Occasionally a weak activity enrichment in intestinal tract and kidneys could be recognized. The effective dose to the patient was estimated to 7.6 microSv/MBq. The radioactivity uptake of the SLN varied in several orders of magnitude between 0.006% and 0.6%. The probability of SLN-metastasis was found to be independent from tracer uptake in the lymph node. The radioactivity uptake of the SLNs in distinct lymph node regions showed no significant differences. CONCLUSION: The radiotracer is transferred out of the prostate via blood flow, by direct transfer via the urethra into the bladder and by lymphatic transport. Injecting a total activity of 200 MBq leads to a mean effective dose of 1.5 mSv. It is not recommended to use the tracer uptake in lymph nodes as the only criterion to characterize SLNs.

Biological Transport↗
PubMed2002

[Sentinel lymph node diagnosis in prostatic carcinoma: I: Method and clinical evaluation].

AIM: Evaluation of the significance of lymphoscintigraphy and intraoperative probe measurement for the identification of the sentinel lymph node (SLN) in prostate cancer. PATIENTS AND METHOD: In 117 patients with prostate cancer scintigrams in various projections were acquired till approximately 6 hours p.i. after ultrasound guided transrectal intraprostatic injection of 99mTc-Nanocoll. On the following day the SLNs were identified in the operation theatre with a gamma probe and removed. Pelvic standard lymph node dissection followed SLNE. RESULTS: In three of 117 patients with preoperative lymphoscintigraphy no SLN was scintigraphically detectable. These three patients had antecedent transurethral resection of the prostate. In 113 of the residual 114 patients SLN could be intraoperatively localized. In the mean four SLNs per patient were removed. 28 of 117 patients had pelvic lymph node metastases. In 25 cases SLN were right-positive, in one false-negative and in one intraoperatively not detectable. In one patient we found macrometastasis of up to 4 cm diameter (one SLN was tumour positive). In 15 cases only the SLN was bearing tumour. CONCLUSION: The SLNE with preoperative lymphoscintigraphy and intraoperative gamma probe measurement is suitable for detecting lymph node metastasis in prostate cancer. SLNE is superior to the surgical techniques commonly used in pelvic lymphadenectomy.

Aged↗
PubMed2001

The predictive value of the sentinel lymph node in malignant melanomas.

At the beginning of a lymphogenous metastasizing process in malignant melanomas, the first tumor cells are found in the so-called sentinel lymph node (SLN), defined as the first tumor-draining lymph node. Its removal and histopathological examination enable us to discover metastases of malignant melanomas long before their possibility of detection by any other method. Since the beginning of 1995, we have performed more than 350 gamma-probe-guided sentinel lymphonodectomies (gamma-SLNE), without any clinical evidence of metastases as determined by lymphoscintigraphy. Using gamma-SLNE, the detection and excision of the SLN succeeded in nearly all patients. The SLNs were fixed in formalin, completely cut into 1-mm thin slices and stained for routine H&E histology and with S-100 and HMB-45. In persons with melanomas thinner than 0.75 mm, we never found micrometastases. However, the SLNs were positive in melanomas from 0.76 to 1.50 mm in about 7% of patients, in melanomas from 1.51 to 4.00 mm in about 21% and in tumors thicker than 4 mm in about 44%. In primary melanomas with satellite or in-transit metastases, the SLNs contained metastases in 75% of patients. Normally, a radical lymph node dissection (RLND) follows, as it is considered to be the necessary consequence following detection of tumor cells. The lymph nodes of the RLNDs contained further metastases in about 30% of patients. The probability of the involvement of lymph nodes other than the SLN correlates with the extension of tumor cells in the SLN. During our 4-year-follow-up, we observed only a single lymph node recurrence in a patient with a negative SLN (false negative rate of about 0.4%). The development of systemic metastasis correlates not only with the Breslow tumor thickness, but also with the extent of the involvement of the melanoma metastasis in the SLN. Summarizing, it can be said that gamma-SLNE has revolutionized melanoma surgery. Based on our data, it is absolutely necessary in the staging of malignant melanoma. In our opinion, the existing classification systems for staging lymph node involvement have to be revised in light of the results of SLNE.

Adolescent↗
PubMed2001

[New anticonvulsants].

Eight new antiepileptic drugs were licensed in the last decade in Switzerland for the treatment of epilepsies, more will follow. Their efficacy as add-on in comparison with placebo was shown in controlled studies. Comparative studies with the new anticonvulsive drugs are lacking. In the daily work after bringing into the market there was shown that the best indications were not always recommended in the approval studies. Other seizure types or epilepsy syndromes showed partially a better response. Also was detected that the recommended dosages and titration velocities were either too slow or too high. Consequences were partially a suboptimal treatment or too much side effects. Rare in some circumstances severe side effects which require a strong indication are seen only after a lot of patients are treated. In this review I deal with the pharmacological properties and interactions, the actual indications, important side effects and strength and weakness of the single compounds.

Anticonvulsants↗
PubMed2001

Radioisotope guided pelvic lymph node dissection for prostate cancer.

PURPOSE: The localization of lymph node metastases in prostate cancer varies enormously. Due to high morbidity complete pelvic lymphadenectomy is often decreased to modified staging lymphadenectomy, resulting in loss of sensitivity for detecting micrometastases. Based on the promising results of intraoperative gamma probe application for identifying sentinel lymph nodes in malignant melanoma, breast and penis cancer, we identified sentinel lymph nodes in prostate cancer using a comparable technique. MATERIALS AND METHODS: In 117 patients 99mtechnetium nanocolloid was transrectally injected directly into the prostate under ultrasound guidance 1 day before pelvic lymphadenectomy. Thereafter dynamic lymphoscintigraphy was done. Initially lymph nodes identified as sentinel lymph nodes by the gamma probe were removed and subsequently modified pelvic lymphadenectomy was performed. RESULTS: Lymphatic metastasis was detected in 28 cases. An average of 4 sentinel lymph nodes were identified per patient in 25 of 27 patients with micrometastasis, of which those in 24 contained micrometastasis for 96% sensitivity. In contrast, sensitivity of modified pelvic lymphadenectomy was 81.5%. In 16 patients only sentinel lymph nodes were positive. An average of 21.8 lymph nodes (range 10 to 51) was dissected per patient at pelvic lymphadenectomy. Lymph node metastasis was noted in 6 of the 46 patients with a prostate specific antigen between 4 and 10 ng./ml. and in 8 of the 64 with a stage pT2 tumor. CONCLUSIONS: Our study shows individual variability of lymphatic drainage of the prostate and limited sensitivity for detecting positive lymph nodes when the pelvic dissection area is limited. Furthermore, our experience implies that the identification of sentinel lymph nodes is feasible, not only in breast cancer and malignant melanoma, but also in prostate cancer using a comparable technique.

Aged↗
PubMed2000

[Clinical value of scintigraphy for gastrointestinal bleeding. Experiences in a large community hospital].

BACKGROUND AND OBJECTIVE: In the majority of cases of gastrointestinal bleeding the site and cause can be determined by gastroscope. If this is unsuccessful, radiological and nuclear-medical tests are available. This study was undertaken to determine the value of scintigraphy in diagnosing of the site of gastrointestinal bleeding. PATIENTS AND METHODS: The data on 155 patients who, between 1984 and 1988, had undergone 161 scintigraphies (with 99mTc-labelled erythrocytes, 5 with 99mTc-Sn colloid) were retrospectively analysed. The results were compared with other diagnostic tests that had been performed, with the definitive diagnosis and, where applicable, the findings at surgery. RESULTS: 78 scintigrams (47%) provided positive results. The site of bleeding had been demonstrated ca. 20 hours after the diagnostic studies had begun. In 47 of the cases the diagnosis was confirmed by additional tests. The intestine was the most common site of bleeding. Localization of the source of bleeding by scintigraphy and other diagnostic tests succeeded in 34 cases, with a 82% concordance between the tests. No bleeding was demonstrated in 88 scintigrams (53%), including all those done with Sn-colloid. In 13 cases the final diagnosis suggested that there had been no previous bleeding and in 43 cases the source of bleeding could not be determined. In 32 scintigraphically negative cases the source of bleeding was demonstrated by other tests. But only 2 of the 13 angiograms and none of the 33 double-contrast studies of the small intestine gave positive results. Among the total number of cases in which bleeding was demonstrated, scintigraphy had a sensitivity of 71%. CONCLUSION: Because of the long duration of observation, scintigraphy with 99mTc-labelled erythrocytes proved superior to other diagnostic tests in the demonstration of the bleeding. By localizing the source of bleeding in a definite part of the gastrointestinal tract, scintigraphy points the way to choosing other diagnostic methods or treatment. If the initial endoscopy has failed, scintigraphy, a method of low invasiveness, should be included when further tests are planned.

Angiography↗
PubMed2000

A magnetoencephalographic study of brain activity related to recognition memory in healthy young human subjects.

Neural activity associated with recognition memory was investigated using magnetencephalography (MEG) in healthy young subjects. At sensor sites overlying frontal and temporoparietal cortices, magnetic evoked fields (MEFs) revealed a difference between studied and unstudied stimuli, which onset about 400 ms following stimulus onset and lasted about 600 ms. MEG yielded reliable source information revealing the activity of three independent dipoles, located in the right medial temporal lobe (MTL), the right inferior frontal and the left inferior parietal cortices. Our findings suggest that neural activity underlying recognition memory from both superficial and deep brain structures can be monitored by MEG.

Adult↗
PubMed2000

First experience with gamma probe guided sentinel lymph node surgery in penile cancer.

Because of the curative approach, the detection of lymph node metastases in squamous cell carcinoma (SCC) of the penis is of significant clinical relevance. Sentinel lymph node (SLN) identification by means of lymphangiography has been proven to be insufficiently safe. However, the high morbidity of inguinal lymphadenectomy and the considerable individual variability regarding the location of lymph node metastases justify the necessity of a technique that enables the identification of SLNs. Since 1998, SLNs have been intraoperatively identified and selectively dissected, after peritumoral injection of technetium-99m nanocolloid and using lymphoscintigraphy, in three patients (one with malignant melanoma and two with SCC). At least one SLN could be detected in each patient. The maximum surgical time was 30 min. There were no severe complications. Lymph node metastases did not occur in any patient. Upon a mean follow-up of 10 months, all patients are currently free of tumor. Owing to the long-term results of sentinel lymphadenectomy in malignant melanoma of other locations and our preliminary results with respect to penile carcinoma. we consider the current method appropriate as the only primary operation for lymph node staging in early stages and, in combination with modified inguinal lymphadenectomy, in locally advanced stages.

Aged↗
PubMed2000

Human testicular mast cells contain tryptase: increased mast cell number and altered distribution in the testes of infertile men.

OBJECTIVE: To determine whether human testicular mast cells contain the potent fibroblast growth factor tryptase and to examine changes in mast cell morphology and intratesticular distribution in testes with normal spermatogenesis versus abnormal spermatogenesis. DESIGN: Retrospective evaluation of testicular biopsies with the use of immunohistochemistry, morphometry, and electron microscopy. SETTING: University research and clinical institutes. PATIENT(S): Infertile men (total of 24) with severe hypospermatogenesis, germ cell arrest syndrome, or Sertoli cell only syndrome, and men without pathologies. INTERVENTION(S): Diagnostic testicular biopsy. MAIN OUTCOME MEASURE(S): Location, number, and distribution of testicular mast cells. RESULT(S): All groups showed tryptase-positive mast cells. In specimens with normal spermatogenesis, mast cells were round and located mainly in the interstitial spaces close to Leydig cells. In germ cell arrest syndrome, a 2-fold increase was evident, and in Sertoli cell only syndrome, a >3-fold increase of tryptase-immunoreactive mast cells became evident. Moreover, there was a statistically significant shift of the cells from the interstitium to the tubular walls in Sertoli cell only syndrome and germ cell arrest syndrome. Mast cells in specimens of Sertoli cell only syndrome and germ cell arrest syndrome were heterogeneous, with rounded or elongated shapes and signs of degranulation. The thickness of the tubular walls was doubled in specimens of germ cell arrest syndrome and Sertoli cell only syndrome in comparison with normal specimens, and this increase was positively correlated with the number of mast cells in these patients. CONCLUSION(S): Our results suggest that mast cell products, including the potent fibroblast growth factor tryptase, are involved in the thickening of the tubular wall and other changes in infertile testes.

Adult↗
PubMed2000

Navigation system for interstitial brachytherapy.

PURPOSE: To develop a computed tomography (CT) based electromagnetic navigation system for interstitial brachytherapy. This is especially designed for situations when needles have to be positioned adjacent to or within critical anatomical structures. In such instances interactive 3D visualisation of the needle positions is essential. METHODS AND MATERIALS: The material consisted of a Polhemus electromagnetic 3D digitizer, a Pentium 200 MHz laptop and a voice recognition for continuous speech. In addition, we developed an external reference system constructed of Perspex which could be positioned above the tumour region and attached to the patient using a non-invasive fixation method. A specially designed needle holder and patient bed were also developed. Measurements were made on a series of phantoms in order to study the efficacy and accuracy of the navigation system. RESULTS: The mean navigation accuracy of positioning the 20.0 cm length metallic needles within the phantoms was in the range 2.0-4.1 mm with a maximum of 5.4 mm. This is an improvement on the accuracy of a CT-guided technique which was in the range 6.1-11.3 mm with a maximum of 19.4 mm. The mean reconstruction accuracy of the implant geometry was 3.2 mm within a non-ferromagnetic environment. We found that although the needles were metallic this did not have a significant influence. We also found for our experimental setups that the CT table and operation table non-ferromagnetic parts had no significant influence on the navigation accuracy. CONCLUSIONS: This navigation system will be a very useful clinical tool for interstitial brachytherapy applications, particularly when critical structures have to be avoided. It also should provide a significant improvement on our existing technique.

Brachytherapy↗
PubMed2000

[Melanoma. Results with "sentinel node" sampling].

Since June 1995 we have practised a gamma probe guided sentinel lymphadenectomy (SLNE) in 274 patients after injecting a colloidal 99 m-Tc labelled solution around the tumor. By this technique the detection and excision of the SLN succeeded in 99.3% of all cases. We found micrometastases in about 53.1% of patients with pT3 and pT4 melanomas. The specimen of the radical lymph node dissection contained in 30% further metastases. A regional recurrence after SLNE occurred only in one case, a SLN-negative patient.

Adolescent↗
PubMed1999

Secondary lymph node involvement from primary cutaneous large B-cell lymphoma of the leg: sentinel lymph nodectomy as a new strategy for staging circumscribed cutaneous lymphomas.

BACKGROUND: Primary cutaneous large B-cell lymphoma of the leg (LBCLL) is a recently defined type of non-Hodgkin's lymphoma. It forms a separate category in the new classification of primary cutaneous lymphomas elaborated by the European Organization for Research and Treatment of Cancer. It is associated with a less favorable prognosis than the most frequently occurring types of primary cutaneous B-cell lymphoma. METHODS: The authors present four patients with the typical clinicopathologic constellation of LBCLL. Three of them died during the years 1993-1996. The authors reviewed their courses. The fourth patient was staged by sentinel lymph nodectomy (SLNE), i.e., the selective surgical removal and histologic examination of the first draining lymph node associated with the cutaneous tumor. RESULTS: The courses of the three previous patients were characterized by secondary involvement of regional lymph nodes followed by systemic dissemination of the lymphoma in a third step. Although the conventional staging of the fourth patient had been negative for any extracutaneous lymphoma manifestation, the SLNE revealed initial regional lymph node involvement, which had decisive implications for the choice of therapy. CONCLUSIONS: SLNE may gain a prominent role in the staging of circumscribed cutaneous lymphomas, in addition to its already established position in melanoma management. Further positive effects of SLNE are 1) better distinction of primary cutaneous lymphomas with secondary lymph node involvement from primary lymph node lymphomas with skin manifestation, and 2) better insight into the biology of different primary cutaneous lymphoma types.

Aged↗