Endoscopic thoracic sympathectomy for primary hyperhidrosis of the upper limbs. A critical analysis and long-term results of 480 operations.

OBJECTIVE: This evaluated the long-term outcome after endoscopic thoracic sympathectomy (ETS) from below D1 to D4, using a single-site access technique for primary hyperhidrosis of the upper limbs. SUMMARY BACKGROUND DATA: Primary hyperhidrosis of the upper limbs is a distressing and often socially disabling condition. Endoscopic thoracic sympathectomy is considered the treatment of choice, causing minimal morbidity and high initial success rates. However, data regarding long-term results are scarce. METHODS: Two hundred seventy of 323 patients (83.7%), in whom 480 sympathectomies were performed, answered a questionnaire after a mean of 14.6 years postoperatively regarding the early postoperative result, side effects, and complications caused by the operation and long-term results with particular emphasis on patient satisfaction. RESULTS: There was no postoperative mortality and no major complications requiring surgical reintervention. A majority of the patients (98.1%) were relieved, and 95.5% were satisfied initially. Permanent side effects included compensatory sweating in 67.4%, gustatory sweating in 50.7% and Horner's trias in 2.5%. However, patient satisfaction declined over time, although only 1.5% recurred. This left only 66.7% satisfied, and a 26.7% partially satisfied. Compensatory and gustatory sweating were the most frequently stated reasons for dissatisfaction. Individuals operated for axillary hyperhidrosis without palmar involvement were significantly less satisfied (33.3% and 46.2%, respectively).     

Receptive field scatter,topography and map variability in different layers of the hindpaw representation of rat somatosensory cortex

We recorded neurons extracellularly in layers II/III, IV, and V of the hindpaw representation of primary somatosensory cortex in anesthetized rats and studied laminar features of receptive fields (RFs) and representational maps. On average, RFs were smallest in layer IV and largest in layer V; however, for individual penetrations we found substantial deviations from this rule. Within the hindpaw representation, a distinct rostrocaudal gradient of RF size was present in all layers. While layer V RFs were generally largest independent of this gradient, layer IV RFs recorded caudally representing the proximal portions of the paw were larger than layer II/III RFs recorded rostrally representing the digits. The individual scatter of the locations of RFs across laminar groups was in the range of several millimeters, corresponding to about 25% of the average RF diameter. The cutaneous representations of the hindpaw in extragranular layers were confined to the areal extent defined by responsive sites in layer IV. Comparison between RFs determined quantitatively and by handplotting showed a reliable correspondence. Repeated measurements of RFs revealed spontaneous fluctuations of RF size of no more than 5% of the initial condition over an observation period of several hours. The topography and variability of cortical maps of the hindpaw representation were studied with a quantitative interpolation method taking into account the geometric centers of RFs and the corresponding cortical recording sites. On average, the overall topography in terms of preservation of neighborhood relations was present in all layers, although some individual maps showed severe distortions of topography. Factors contributing to map variability were overall position of the representation on the cortical surface, internal topography and spatial extent. Interindividual variability of map layout was always highest in the digit representations. Local topographic orderliness was lowest in layer V, but comparable in layers II/III and IV. Within layer IV, the lowest orderliness was observed in the digit representations. Our data emphasize a substantial variability of RF size, overlap and position across layers and within layers. At the level of representational maps, we found a similar degree of variability that often co-varied across layers, with little evidence for significant layer specificity. Laminar differences are likely to arise from the specific input-output pattern, layer-specific cell types and the connectivity between different layers. Our findings emphasizing similarities in the variability across layers support the notion of tightly coupled columnar interactions between different layers.     

Implementation of a Tc-99m and Ce-139 scanning line source for attenuation correction in SPECT using a dual opposing detector scintillation camera

Image degradation during single photon emission computed tomography (SPECT) due to attenuation and Compton scatter of photons can cause clinical image artifacts and will also result in inaccurate quantitative data. Therefore attenuation correction methods recently received wide interest. Transmission imaging can be performed to obtain the attenuation coefficients of a nonhomogeneous attenuating medium accurately. The aim of this study was firstly to evaluate the imaging characteristics of the scanning line source assembly. The results obtained with Tc-99m and Ce-139 were compared. Secondly the calculated attenuation coefficients were compared with known values from literature, using Tc-99m and Ce-139 as transmission sources. Lastly the method of acquiring simultaneous transmission and emission data was investigated. This study shows that an attenuation coefficient map can be obtained using a scanning line source for transmission imaging with a dual opposing detector camera. The imaging characteristics of Tc-99m and Ce-139 as transmission sources are similar. The resolution obtained with the Ce-139 line source was poorer than that obtained with the Tc-99m line source. A linear relationship was found between CT numbers and attenuation coefficients for transmission images using both Tc-99m and Ce-139 line sources. The attenuation coefficient value for water was underestimated by 1% using the Tc-99m transmission source and underestimated by 10% using Ce-139 as transmission source. This underestimation of attenuation coefficient values was also obtained in the human study. A myocardial perfusion study processed without and with attenuation correction clearly demonstrated the effect of the attenuation correction in the inferior myocardial region. The potential of using a scanning line source as transmission source with a dual opposing detector camera has been demonstrated in this study. The transmission source, Ce-139 was successfully introduced in this investigation for simultaneous acquisition of transmission and emission data.     

Voronoi Polyhedra Analysis of Optimized Arterial Tree Models

Topological and metric properties of Voronoi polyhedra (VP) generated by the distal end points of terminal segments in arterial tree models grown by the method of constrained constructive optimization (CCO) are analyzed with the aim to characterize the spatial distribution of their supply sites relative to randomly distributed points as a reference model. The distributions of the number N _f of Voronoi cell faces, cell volume V, surface area S, area A of individual cell faces, and asphericity parameter of the CCO models are all significantly different from the ones of random points, whereas the distributions of V, S, and are also significantly different among CCO models optimized for minimum intravascular volume and minimum segment length (p < 0.0001). The distributions of N _f , V, and S of the CCO models are reasonably well approximated by two-parameter gamma distributions. We study scaling of intravascular blood volume and arterial cross-sectional area with the volume of supplied tissue, the latter being represented by the VP of the respective terminal segments. We observe scaling exponents from 1.20 ± 0.007 to 1.08 ± 0.005 for intravascular blood volume and 0.77 ± 0.01 for arterial cross-sectional area. Setting terminal flows proportional to the associated VP volumes during tree construction yields a relative dispersion of terminal flows of 37% and a coefficient of skewness of 1.12. © 2003 Biomedical Engineering Society. PAC2003: 8719Uv, 8710+e, 4720Ky, 0260Pn, 0230Oz     

The repopulation of lymph nodes of dogs after 1200 R whole-body x-irradiation and intravenous administration of mononuclear blood leukocytes.

Fresh and cryopreserved autologous or allogeneic mononuclear blood cells (MBCs) intravenously injected in 1200 R total-body x-irradiated dogs repopulated lymph nodes within 10 days after tranfusion. Several parameters of the lymphopoietic regeneration were correlated with the number of cells transfused and with the number of colony-forming units contained in the cell suspension when they were cultured in agar (CFUc). Values within the normal or close to normal range were reached in the mesenteric nodes of most of the animals transfused with 10 X 10(9) MBC or more. These values were obtained when 5 X 10(5) CFUc or more were transfused. Axillary nodes showed lower values than mesenteric nodes. They were mostly under the normal range but well over those of the irradiated controls. Frozen and thawed MBCs seem to be as effective as fresh cells for lymphopoietic restoration. The mesenteric nodes of dogs transfused with allogeneic MBCs showed higher cellularity and larger cortical-paracortical areas than those of dogs tranfused with approximately the same number of autologous cells. The repopulation of lymph nodes parallels that of the marrow.     

Follicular dendritic cells are a major reservoir for human immunodeficiency virus type 1 in lymphoid tissues facilitating infection of CD4+ T-helper cells.

Human immunodeficiency virus type 1 (HIV-1) infection causes progressive depletion of CD4/HIV-receptor-positive T helper lymphocytes, ultimately leading to AIDS. The major HIV reservoir and site of T-helper cell infection in lymphoid tissues, however, has remained poorly defined. The authors used in situ hybridization in combination with immunohistologic labeling techniques to identify the phenotype of HIV-infected cells in lymph nodes from patients at different stages of HIV-infection. The number of HIV-infected macrophages, widely considered the major site of HIV replication, was extremely low. There was no evidence for HIV-infection of endothelial and interdigitating reticulum cells. However, HIV RNA was found in small but consistent proportions of CD45RO-positive T cells and in the vast majority of follicular dendritic cells (FDC) in a pattern suggestive of active infection in addition to HIV-immunocomplex trapping on cell membranes. FDC may therefore be a major HIV reservoir and since T-helper cells travel through the FDC meshwork during their migration within lymphoreticular tissues, it appears likely that HIV-replicating T cells may infect FDC, which then infect new T cells, thus causing a gradual dissemination of the virus to all FDC and thereby a steadily increasing infection of T-helper/memory cells within germinal centers. This results in CD4+ T cell depletion, and ultimately, in immunodeficiency.     

Epstein-Barr virus and carcinomas: undifferentiated carcinomas but not squamous cell carcinomas of the nasopharynx are regularly associated with the virus.

The Epstein-Barr virus (EBV) is consistently associated with undifferentiated nasopharyngeal carcinoma (NPC). There is, however, conflicting evidence as to whether squamous cell NPCs are also EBV-associated. Moreover, it has been proposed that other epithelial tumours, particularly thymomas and thymic carcinomas, should be included in the group of EBV-associated neoplasias. However, since the viral DNA in these studies was demonstrated only in extracted DNA, the cellular origin of the viral DNA is uncertain. We have therefore investigated 152 epithelial tumours from various sites for the presence of EBV-DNA by in situ hybridization with 35S-labelled probes. Sixty-eight of 77 undifferentiated NPCs showed an EBV-specific autoradiographic signal, thus confirming the strong association of this tumour type with EBV even in geographical areas where undifferentiated NPC is not endemic. None of eight squamous cell NPCs showed an EBV-specific signal. All of 15 carcinomas with a similar morphology to undifferentiated NPC but from different anatomic sites (thymus, tonsil, breast) were EBV-negative as were 9 thymomas, 26 squamous cell carcinomas of the palatine tonsil, and 14 cervical carcinomas. Our results therefore suggest a unique association of EBV with undifferentiated NPC and support concepts assigning different biological properties to undifferentiated NPC as compared with squamous cell NPC.