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Biomedical subjects

H Vogt

Publications and source records attributed to H Vogt.

At least 37 records · Page 2Linked to original sources
PubMed1999

The sentinel lymph node concept in prostate cancer - first results of gamma probe-guided sentinel lymph node identification.

OBJECTIVE: The goal of this study was to show lymphatic drainage and to verify the validity of lymphoscintigraphy for the identification of the sentinel lymph node (SLN) in prostate cancer. Furthermore, the question is to be raised whether the standardized pelvic lymphadenectomy is a sufficient means for also detecting solitary micrometastases. PATIENTS AND METHODS: Eleven patients with prostate cancer received a sonographically controlled, transrectal administration of a technetium-99m colloid injected directly into the prostate 1 day prior to pelvic lymphadenectomy. 20 min later the dynamic lymphoscintigraphy was carried out. During surgery, the SLNs were identified by using a gamma probe. The standard pelvic lymphadenectomy was performed after removal of the SLN. RESULTS: In 3 of 4 patients with micrometastasis the spread of the tumor could exclusively be found in those nodes which had been identified as SLNs by means of scintigraphy by combining preoperative lymphoscintigraphy and intraoperative gamma probe detection. In 2 cases, the pathologically proved SLNs were situated at the anteromedial region of the internal iliac artery, thus being located outside of the standard pelvic lymphadenectomy area. In 1 patient, however, the micrometastasis was found beyond those nodes which had been identified as SLN intraoperatively. CONCLUSIONS: In the future, we expect the restriction of pelvic staging lymphadenectomy to scintigraphically proved SLN. The perioperative morbidity may be reduced by increasing the sensitivity of the detection of micrometastases. Our data confirm earlier perceptions, according to which even modified standardized pelvic lymphadenectomy is considered insufficient in terms of the detection of micrometastases.

Aged↗
PubMed1999

[Sentinel lymph node detection by preoperative lymphoscintigraphy and intraoperative gamma probe guidance in malignant melanoma].

AIM: The purpose of this work was to prove the clinical significance of nuclear medical procedures in pre- and intraoperative detection of the SLN. METHODS: In the past 4 years, we did preoperative lymphoscintigraphy in 214 patients (pts.). Intraoperative localisation of the SLN with a hand-held gamma probe followed in 150 pts. RESULTS: In 214 pts. 247 lymphatic draining regions were found by preoperative scintigraphy. In 3 pts. with melanoma of the cheek no lymphatics/lymph nodes could be detected. 14 pts. showed interval lymph nodes. In 150 pts. gamma probe guided SLNE was done. In 2 pts. with supraclavicular primary tumor 4 SLN had been defined by preoperative scintigraphy but only 2 could be found intraoperatively. In all other cases (98.7%) the sentinel node was detected correctly by the gamma probe and then removed. In 19 of 150 pts. (12.7%) metastases were detected in the pathologic specimen. The incidence of lymph node metastases showed a continuous increase from 0% at tumor stage pT1 to 44% at stage pT4. CONCLUSION: SLNE is an accurate method to determine nodal involvement in melanoma and minimizes operative invasiveness in melanoma surgery.

Adolescent↗
PubMed1998

[Sentinel lymphadenectomy in malignant melanoma].

The sentinel lymph node dissection (SLND) is one of the most striking developments in the treatment of melanoma. Since the first report by Morton et al. in 1992, the method has been refined, and its use has increased. Introduced as an alternative to elective lymph node dissection (ELND), it has rapidly made its way into clinical practice. SLND allows precise pathologic staging through removal and analysis of a limited number of nodes (false-negative rate < 2%). It distinguishes patients with clinically occult nodal disease from those with tumor-free regional basin who would not benefit from radical dissection. However, the SLND is still an experimental procedure with yet unproven utility.

Humans↗
PubMed1998

Primary therapy of malignant melanomas: sentinel lymphadenectomy.

BACKGROUND: Each melanoma is drained by one or, occasionally, several individual lymph nodes within the nearest lymph node region (sentinel lymph node). OBJECTIVE: By histopathologic examination of the removed sentinel lymph node (SLN), it is possible to select patients clinically according to stage I or II (UICC classification), but who, microscopically, represent stage III. METHODS: Sentinel lymphadenectomies (SLNEs) were performed initially by the vital blue dye technique, and later by gamma-probe guidance only. The removed SLNs were examined by hematoxylin and eosin as well as immunohistochemical stains (S100, and HMB 45). RESULTS: We have performed 115 gamma-probe-guided SLNEs in 100 patients. The SLN could be found in all cases. In pT3 + 4 melanomas, 27.5% of the SLNs were positive; in only one patient with a pT2 tumor were micrometastases found. CONCLUSIONS: gamma-Probe-guided SLNE is a reliable procedure with minimal complications that should be performed in all pT3 + 4 (intraoperative frozen section histology) melanomas without clinically evident metastases.

Coloring Agents↗
PubMed1998

[Sentinel lymph nodes in breast carcinoma].

Aim of the experiment is to select patients with positive axillary lymph nodes by means of the sentinel lymph node concept. In this way all other patients who would not benefit from a lymph node dissection are spared from this procedure and its morbidity. Till now the sentinel lymphadenectomy is, however, still an experimental technic with yet unproven utility.

Axilla↗
PubMed1997

Biological activities of N6,C8-disubstituted adenosine derivatives as partial agonists at rat brain adenosine A1 receptors.

C8-substituted derivatives of the adenosine A1 receptor-selective agonist N6-cyclopentyladenosine (CPA) were evaluated as potential partial adenosine A1 receptor agonists in rat brain. Potencies and efficacies of 8-alkylamino-CPA derivatives were determined in G protein activation assays by their ability to stimulate binding of [35S]guanosine-5'-(gamma-thio)triphosphate ([35S]GTPgammaS) to rat forebrain membranes, by their ability to inhibit forskolin-stimulated adenylate cyclase, and by inhibition of evoked field excitatory postsynaptic potentials (field EPSPs) in hippocampal slices. EC50 values around 1 microM were determined for all C8-substituted CPA derivatives. Increase in chain length of the substituent gradually reduced agonist efficacy in [35S]GTPgammaS binding studies. Only C8-methylamino-, C8-ethylamino- and C8-propylamino-CPA inhibited forskolin-stimulated adenylate cyclase. In contrast, 8-methylamino- and 8-butylamino-CPA were the compounds of highest intrinsic activity in inhibition of field EPSPs in the hippocampus, followed by 8-ethylamino-CPA. 8-Cyclopentylamino-CPA was without effect in this tissue, and the propylamino derivative, when applied cumulatively, caused an inhibition which was smaller the higher the concentration used and the longer the application, which is suggestive of drug-induced desensitization. These data indicate that 8-aminoalkyl-substituted CPA derivatives act as partial agonists on the brain and may serve as valuable tools to dissect adenosine A1 receptor mediated signal trafficking in various organs.

Adenosine↗
PubMed1997

[Scintillation probe guided sentinel lymphadenectomy in malignant melanoma].

In cutaneous melanoma, biopsy of the first tumor-draining lymph node (Sentinel node, SLN) may replace routine elective lymph node dissection (ELND). The SLN has been shown to contain the first micrometastasis in early lymphatic tumor dissemination. As micrometastases were identified in 10-30% of stage I (AJCC/UICC) patients, sentinel lymphonodectomy (SLND) should enable us to select patients clinically in stages I and II, but histopathologically in stage III. This optimization of patient selection is mandatory as only this subgroup profits from ELND. Since the beginning of 1995 we was scintillation detector (gamma probe)-guided sentinel biopsy in patients with a melanoma > 1.0 mm and clinically negative lymph nodes. After injecting colloidal 99m-Tc-labelled tin(II)-sulfide solution around the tumor (or the biopsy scar), the SLN can be localized exactly. The technique is minimally invasive and easy to handle. If the SLN contains tumor, a standard en bloc lymphonodectomy is performed. Long-term follow-up, however, is needed to delineate the role of this procedure in melanoma treatment.

Adult↗
PubMed1997

[Breast carcinoma staging with sentinel lymphadenectomy].

The objective of our trial was to evaluate the significance and usefulness of sentinel lymphadenectomy (SLNE) for the staging of regional lymph nodes in breast cancer patients. The study presented illustrates the method and our results. As has been documented for melanoma, the first lymph node [sentinel node (SLN)] to receive lymphatic drainage from a primary tumor is the expected first site of lymph-node metastasis. The database presented includes 12 patients with operable breast cancer and clinically negative lymph nodes. In 11 cases the described method was applicable. In only one case was there no correlation between the histology of the SLN and the axillary specimen. Three SLN were tumor-positive. Successful completion of examination of a large number of patients with a long follow-up has the potential of reducing the number of axillary dissections and of significantly reducing morbidity in the majority of breast cancer patients.

Aged↗
PubMed1997

Chronic recurrent multifocal osteomyelitis: a radiological and clinical investigation of five cases.

OBJECTIVE: To make a detailed evaluation of the clinical and radiological course of five children with chronic recurrent multifocal osteomyelitis (CRMO). Emphasis was laid on the correlation between clinical data and radiological findings. DESIGN AND PATIENTS: Clinical data, histology (n = 11), bone scintigraphy (n = 17), and the plain radiographs (n = 198) of these patients were reviewed. The mean time of observation was 6.6 years (range 1-14.5 years). Thirty-two lesions seen at the time of primary diagnosis (n = 22) or during the course of the disease (n = 10) were evaluated. Twenty-seven foci were located in bone; in five cases the sacroiliac joints were involved. RESULTS: Bone scintigrams showed nearly all foci (31/32) and were especially helpful in clinically asymptomatic lesions (14/32) or foci which were radiographically difficult to detect or not seen at all (8/32). Only 14 of 32 foci were locally symptomatic clinically. In all cases with a short interval (< or = 3 weeks) between the onset of local symptoms and evaluation by plain radiographs (n = 5) osteolysis was shown without a sclerotic margin. All bone lesions with a longer duration of local symptoms (n = 7) revealed a variable radiographic pattern: osteolysis with sclerotic rim in three, a mixed lytic-sclerotic lesion in three and pure sclerosis in one. In two cases low back pain could be ascribed to sacroiliitis. CONCLUSION: Only careful correlation between clinical, scintigraphy and radiographic features permits an accurate assessment of disease activity in CRMO. The bone lesions detected radiographically soon after the onset of symptoms resemble those of acute osteomyelitis.

Bone Resorption↗
PubMed1996

Characterization of a novel adenosine binding protein sensitive to cyclic AMP in rat brain cytosolic and particulate fractions.

A novel binding site for the adenosine receptor agonist 5'-N-ethylcarboxamidoadenosine (NECA), which was enriched in rat forebrain, was characterized in cytosolic and particulate preparations. The site showed a pharmacological profile different from other [3H]NECA binding proteins and was named adenotin 2. [3H]NECA was bound in the presence of 100 microM 2-chloroadenosine with a Kd of 45.4 nM and a Bmax of 4711 fmol/mg in the cytosol and a Kd of 72.4 nM and a Bmax of 4844 fmol/mg in the crude membrane fraction. The presence of two different binding sites on adenotin 2 for [3H]NECA was shown in kinetic experiments. This protein showed identical pharmacological profiles in both subcellular preparations. [3H]NECA was displaced by purine analogues with a rank order of potency of NECA > 3'5' cyclic AMP (cAMP) > 5'-deoxy-5'-chloroadenosine > S-adenosylhomocysteine approximately 5'-deoxy-5'-methylthioadenosine (MeSA) > adenosine approximately adenine. cAMP inhibited [3H]NECA binding allosterically, whereas adenine and MeSA acted competitively. Inhibitors and activators of protein kinases such as N-(2-aminoethyl)-5-isoquinolinesulfonamide, Sp-adenosine cyclic monophophothioate and (8R*, 9S*, 11S*)-(-)-9-hydroxy-9-methoxy -carbonyl-8-methyl-2,3,9, 10-tetrahydro-8,11-epoxy-1H, 8H, 11H-2, 7b, 11a-triazadibenzo-(a,g)cycloocta(cde)-trinden-1-one (K 252a) interacted with [3H]NECA binding to adenotin 2 in nanomolar concentrations. Adenosine-5'-O-(3-thiotriphosphate) (100 microM) increased the affinity of [3H]NECA to a Kd of 9 nM and diminished the affinity of cAMP. The pharmacological characteristics of this novel binding site for [3H]NECA resemble those of the inhibition of phosphorylation processes by adenosine and its derivatives in heart and smooth muscle but are distinct from known adenosine receptors, adenosine binding proteins and protein kinases.

Adenosine↗
PubMed1996

["Sentinel" lymphonodectomy with scintillation detector. A new strategy in treatment of malignant melanoma].

For decades the results of elective lymph node dissection (ELND) are differently discussed, so that it is not definitely recommended at present the less so since the morbidity of this operation can't be neglected. Since the beginning of 1995 we practice a gamma-probe guided sentinel lymphonodectomy (SLNE) on patients with melanoma from a Breslow tumor thickness of 1 mm upward, after injecting a colloidal 99m-Tc labelled tin (II) - sulfide solution around the tumor or the scar, if the tumor has been excided before. By this method, that allows a selection of patients who according clinically to a stage I or II (UICC) but even histopathologically to a stage III and who are profiting of a removal of the regional lymph nodes, the sentinel node can be exactly localised, tissue-sparing removed at minimal complication rates and the completeness of the removal can be verified by measurements of the radioactivity. When finding metastases in the histopathological examination of the node a dissection of the whole region follows.

Adult↗
PubMed1996

Interaction of full and partial agonists of the A1 adenosine receptor with receptor/G protein complexes in rat brain membranes.

Full and partial agonists of the A1 adenosine receptor were characterized with respect to their influence on G protein activation and their thermodynamic parameters of receptor binding in rat brain membranes. G protein activation was determined through measurement of [35S]guanosine-5'-(gamma-thio)triphosphate ([35S]GTP[S]) binding, and receptor binding was studied under identical conditions through the displacement of [3H]-1,3-dipropyl-8-cyclopentylxanthine ([3H]DPCPX) in equilibrium binding studies. The intrinsic activity in stimulating [35S]GTP[S] binding did not correlate with the affinity of the ligands. 5'-Deoxy-5'-methylthioadenosine, 2-phenylaminoadenosine, and 2-chloro-2'-deoxyadenosine were identified as partial A1 agonists in the G protein activation assay. Depending on the temperature, these ligands showed agonistic and antagonistic properties to varying extents. EC50 values for G protein stimulation and KH and KL values of the partial agonists decreased when the incubations were performed at lower temperatures, indicating a mainly enthalpy-driven process of interaction with the receptor. Thermodynamic parameters of receptor binding of the partial agonists resembled the characteristics of the antagonist DPCPX more closely than those of the agonist 2-chloro-N6-cyclopentyladenosine. In addition, partial agonists detected fewer A1 adenosine receptors in the high affinity state than did full agonists. The lower efficacy in stimulation of the binding of [35S]GTP[S] is probably the consequence of an impaired ability of the partial agonists to release GDP from the G protein, as was shown by an impaired release of prebound [35S]GDP[S] from the membranes.

Animals↗
PubMed1995

[Vigabatrin and lamotrigin: experiences with 2 new anticonvulsants in the Swiss epilepsy clinic].

Vigabatrin and lamotrigine are two new antiepileptic drugs which have recently become available. Vigabatrin is a specific and irreversible inhibitor of the enzyme gamma-amino-butyric-acid (GABA) transferase. Its administration leads to a long lasting increase in GABA, the most important inhibitory neurotransmitter. Vigabatrin is effective in both adults and children in the treatment of partial and especially complex-partial seizures. After add-on in vigabatrin to their therapeutic drug regime in 116 of our own patients, 39% of previously therapy resistant patients reported a reduced seizure frequency of at least 50% and 6% of them became seizure free. In secondarily generalized epilepsies the best results were observed in axial (infantile) spasms. In addition there was some improvement in tonic and convulsive seizures. Single patients showed increased myoclonic and clonic seizures. Initial efficacy was not always maintained during follow-up. In the experience of other authors, vigabatrin is also effective in the treatment of infantile spasms. It is not suitable for the treatment of generalized epilepsies with absences and myoclonic seizures. Most patients tolerate vigabatrin very well, although psychotic episodes are sometimes reported. So far there have been no relevant hepatic or hematological side effects. Lamotrigine is also effective in the treatment of partial seizures, for which it is approved. However, uncontrolled studies and our own experience have shown that it is even more effective in generalized seizures. As add-on therapy in absences and tonic or tonic-clonic seizures, a significant reduction in seizure frequency--in individual cases seizure freedom--can be achieved.(ABSTRACT TRUNCATED AT 250 WORDS)

4-Aminobutyrate Transaminase↗
PubMed1995

T and B cell responses to mycobacterial 65-kDa heat-shock protein in sheep infected with maedi visna virus.

Sheep infected with maedi visna virus were tested for immune reactivity to recombinant HSP65 and tuberculin PPD from mycobacteria. The results showed that both naturally and experimentally infected animals had elevated IgM but not IgG or IgA antibodies to HSP65 from Mycobacterium leprae or M. bovis. In experimentally infected animals, the elevated IgM antibodies appeared in blood from about 3 to 4 weeks postinfection. Increased T cell proliferative responses to HSP65 and PPD were also found in both naturally and experimentally infected sheep. The T cell responses to HSP65 were substantially inhibited by antibodies to ovine major histocompatibility complex class II molecules, indicating that the responses were class II restricted. Increased expression of a putative HSP65 molecule was observed in synovial membranes from sheep infected with maedi visna virus and goats infected with the related, caprine arthritis encephalitis virus. The results thus show that lentivirus infection induces T and B cell anti-HSP65 immune responses and suggest that synovial inflammation may be due, at least in part, to T and B cell recognition of HSP65-like molecules expressed in joints.

Animals↗
PubMed1994

Embryological development of the arterial system of the forelimb in Tupaia.

BACKGROUND: The arterial system of the upper extremities in man shows drastic developmental changes and many individual variations related to interspecific variations in primates. The ontogenetic development in Tupaia was examined from the viewpoint of comparative embryology. METHODS: Histological specimens of 39 embryos were observed and reconstructed in three dimensions using a computer program. Four adult animals were dissected and examined with angiography to ascertain the end stage of development. RESULTS: At the proximal end of the upper arm the deep brachial artery appears first as a concomitant vessel with the radial nerve. It becomes reduced in size and is succeeded by the posterior circumflex humeral artery, which is accompanied initially by the axillary nerve and finally by the radial nerve. The main arterial passageway to the fingers consists of the brachial and interosseous arteries during early development. The superficial brachial artery and median artery are formed later, and their connection becomes the main route of blood supply for the finger arteries up to the adult stage. The ulnar artery is formed at the end of arterial development to form the ulnar end of the superficial palmar arch. The superficial antebrachial arteries are also recognized. CONCLUSIONS: All the arterial elements of the forelimb in Tupaia are observed in a variety of primates, including man, and the characteristics of Tupaia are thought to represent the primitive conditions of the common ancestor of tree shrews and primates.

Angiography↗