Transarticular invasion of iliopelvic sarcomas into the sacrum: Radiological analysis of 47 cases

Joint cartilage functions as a barrier against the extension of bone tumors. However, transarticular invasion by iliopelvic sarcomas across the sacroiliac (SI) joints into the sacrum sometimes occurs. We made a radiological analysis (CT and/or MRI) of 47 bone sarcomas which originated in the ilium and extended nearly to the SI joint. 8 of 17 chondrosarcomas and 3 of 30 other sarcomas (2 of 23 Ewing's sarcomas and 1 of 7 osteosarcomas) invaded the sacrum through the SI joint.     

Ewing's sarcoma of the femur: Prognosis in 69 patients treated by the CESS group

We reviewed the treatment outcome of 69 patients with Ewing's sarcoma of the femur. The patients received chemotherapy according to the CESS 81 (n 14), CESS 86 (n 43), and CESS 91P (n 12) protocols. The 10-year relapse-free survival rates were 36%, 65%, and 65% (p = 0.01). 68 patients received local treatment. The primary tumor was treated by surgery without radiotherapy in 28 patients; 1 developed a local recurrence and 7 metastases. 10 patients received radiotherapy alone; 4 developed metastases and 4 local recurrences and metastases. 30 cases had a combination of surgery and radiotherapy; 7 developed metastases and 1 a local recurrence and metastasis. The survival of patients after radiotherapy alone was worse than that of patients after surgery with/without radiotherapy (p = 0.005). Pathological fractures (n 16) did not influence the prognosis.     

A retrospective mortality study of workers exposed to arsenic in a gold mine and refinery in France

A historical mortality study of a cohort of employees of a gold mining and refining company was carried out in Salsigne, France. A major goal of the study was to investigate the relationship between lung cancer mortality and exposure to arsenic, radon, silica, and other contaminants of the working environment. A twofold excess of lung cancer was found both among miners and smelters, mainly concentrated among workers who had experienced exposure to past levels of arsenic, radon, and silica. The consistency of the results in the mine and the refinery are suggestive of a carcinogenic risk from both soluble and insoluble arsenic, although the potential role of other factors cannot be dismissed. © 1994 Wiley-Liss, Inc.     

Ritually induced growth disturbances and deformities of the orofacial system – A contribution to cranial morphogenesis

Numerous ritual acts involving the skull result in orofacial changes. The present study focuses on ritual acts of Brazilian Zoé Indians. A distinct deformation effect of the ritual act (wearing a lip-plug) on the morphology of the orofacial system is demonstrated and documented using jaw models. The studies show that the lip-plug significantly influences tooth position and jaw growth. While the maxilla displays palatal displacement of the lateral incisors and elevation of the palate, retraction occurs in the mandible depending upon plug size. Additionally, both the plug and the nutritional habits of the Indians induce marked abrasion of all teeth. Moreover, it is shown that the duration of lip-plug wear is an essential determinant of sustained orofacial changes.     

The siderophore iron transporter of Candida albicans (Sit1p/Arn1p) mediates uptake of ferrichrome-type siderophores and is required for epithelial invasion

The human fungal pathogen Candida albicans contains a close homologue of yeast siderophore transporters, designated Sit1p/Arn1p. We have characterized the function of SIT1 in C. albicans by constructing sit1 deletion strains and testing their virulence and ability to utilize a range of siderophores and other iron complexes. sit1 mutant strains are defective in the uptake of ferrichrome-type siderophores including ferricrocin, ferrichrysin, ferrirubin, coprogen, and triacetylfusarinine C. A mutation of FTR1 did not impair the use of these siderophores but did affect the uptake of ferrioxamines E and B, as well as of ferric citrate, indicating that their utilization was independent of Sit1p. Hemin was a source of iron for both sit1 and ftr1 mutants, suggesting a pathway of hemin uptake distinct from that of siderophores and iron salts. Heterologous expression of SIT1 in the yeast Saccharomyces cerevisiae confirmed the function of Sit1p as a transporter for ferrichrome-type siderophores. The sit1 mutant was defective in infection of a reconstituted human epithelium as a model for human oral mucosa, while the SIT1 strain was invasive. In contrast, both sit1 and SIT1 strains were equally virulent in the mouse model of systemic infection. These results suggest that siderophore uptake by Sit1p/Arn1p is required in a specific process of C. albicans infection, namely epithelial invasion and penetration, while in the blood or within organs other sources of iron, including heme, may be used.     

A Golgi deimpregnation study of neurons in the rhesus monkey visual cortex (Areas 17 and 18)

Summary The morhological features of 298 neurons impregnated according to Golgi-Kopsch in areas 17 and 18 of Macaca mulatta were analyzed, and the same neurons were deimpregnated to visualize structural details of the somata in different types of neurons. The following cell types were investigated: Pyramidal and pyramid-like cells, spiny stellate cells, double bouquet cells, bipolar cells, chandelier cells, neurogliaform cells, basket and related cells. This procedure allows the evaluation of the nuclear-cytoplasmic proportion and the position of the nucleus besides shape and size of the cell body. Pyramidal and pyramid-like cells (N=43), spiny stellate cells (N=26), basket and related cells (N=126) are variable in these features. A positive correlation between soma size and width of the cytoplasm is found in pyramidal, pyramid-like cells and spiny stellate cells. With the exception of some large somata in both these types of neurons the nucleus is found in a central position. Double bouquet cells (N=6), bipolar cells (N=13) and chandelier cells (N=11) exhibit small cytoplasmic rims and centrally located nuclei. The small somata of neurogliaform cells (N=37), however, and the small to very large somata of basket and related cells show broad cytoplasmic portions surrounding the eccentrically located nuclei. These findings allow the identification of different neuronal types in Nisslstained sections on the basis of these soma features. This is a prerequisite for further detailed quantitative studies on the laminar distribution of different neuronal types in the visual cortex of the monkey.     

Alloreactive T-cell clones raised in an HLA-B/D crossing-over family dissect HLA-DR5 and HLA-DQw3 subtypes.

This study was undertaken to resolve a positive mixed lymphocyte reaction between HLA-ABC identical, HLA-D different siblings. Three CD3+ CD4+ CD8- alloreactive T-lymphocyte clones, called 2/6, 7/1, and 7/2, were generated and extensively studied. Proliferation of 2/6 cells and 7/2 cells was blocked by anti-DQ monoclonal antibodies (mAbs), whereas anti-DR and DP were not effective. Stimulation of 7/1 cells was inhibited by anti-DR, but not by anti-DQ and DP mAbs. Testing on a well-characterized panel of reference B-lymphoblastoid cell lines showed that the DQ-specific clones 2/6 and 7/2 were able to proliferate upon stimulation by cells carrying the DQw7 and DQw8 but not the DQw9 subtype of DQw3. Clone 7/1 was proliferative towards cells expressing DRw11.1 but not towards DRw11.2- or DRw12-positive cells. Moreover, this clone detected determinants present on some DRw8 cells. Correlation of the reactivity of clone 7/1 with available sequence data suggests that amino acids 67, 71, and 86 of DR beta 1 molecules played a crucial role in forming the epitope recognized by this clone. In contrast, sharing of T-cell epitopes between DQw7 and DQw8 subtypes was not inferable from specific amino acid residues. The implication of these findings for T-cell allorecognition is discussed.     

Significance of polyploidy in megakaryocytes and other cells in health and tumor disease

Summary Polyploidy — the doubling of chromosome sets of cells caused by a stop of mitosis at different levels of the mitotic cycle — is a phenomenon widely observed in plants, protozoa, metazoa, and animals. In man obligate polyploid tissues are found in liver parenchyma, heart muscle cells, and bone marrow megakaryocytes. Polyploidy occurs mostly in stable and highly differentiated cells and tissues. Besides age, stimulation of proliferation and increased metabolic function lead to polyploidization in these organs. Aneuploidy, however, is exclusively found in tumor cells.Megakaryocyte differentiation and polyploidy are controlled by thrombopoietin-like activities, of which the loci of production are still unknown. Megakaryocytes are unique among polyploid mammal cells. On the precursor level they maintain their proliferative activity independently of the mammal's age. Once having entered the incomplete mitotic cycle they stop cytokinesis and develop into highly polyploid cells. Polyploidization of megakaryocytes is the basic requirement for establishing highly effective hemostasis in mammals, which exhibit blood circulation based on high blood pressures.Every polyploidization results in increased production of membrane materials with which the platelet becomes endowed. By shedding cytoplasmic fragments approximately 3000 platelets are set free from a 32c megakaryocyte, compared with only 16 nucleated thrombocytes by mitotic division. There is further evidence that the heterogeneity of platelets mostly depends on the different polyploidy classes of the megakaryocytes from which they are derived. Changes in the polyploidy pattern of megakaryocytes could therefore have consequences for hemostatic disorders in several human diseases, particularly in malignancy.Abbreviations n haploid chromosome set (number of chromosomes actually counted) - c haploid DNA content (measured by cytophotometry) - M mitosis - C-Mitosis colchicine mitosis - G₀, G₁, G₂, S phases of the mitotic cycle - Meg CSF megakaryocyte colony stimulating factor(s) - TSF thrombocytopoiesis stimulating factor(s) - CFU-Meg megakaryocyte colony forming unit This work was supported by Deutsche Forschungsgemeinschaft, grant Wi 806/1-1     

Thoracoscopic interventions in deformities of the thoracic spine

AIM OF THE STUDY: We prospectively studied 9 patients with deformities of the thoracic spine who underwent thoracoscopic surgery to critically evaluate the benefits and limitations of thoracoscopy. METHODS: Seven patients with deformities of the thoracic spine (5 scoliosis, 2 kyphosis) underwent a thoracoscopic release and posterior correction and fusion in a single stage. In one case of a crankshaft-phenomenon a thoracoscopic epiphyseodesis und in another case of a posttraumatic kyphosis a thoracoscopic instrumentation and fusion were performed. The average age was 21 years, the follow-up was 18 months with a minimum of 12 months. The perioperative data including complications were collected and a radiographic analysis concerning curve correction was carried out. RESULTS: The scoliotic curves measured preoperatively 84 degrees on average with a Cobb angle of 62 degrees on the traction films and were corrected by 57% to averagely 36 degrees at follow-up. In the two cases of Scheuermann kyphosis a preoperative kyphosis of 94 degrees respectively 82 degrees was corrected to 52 degrees respectively 58 degrees. Between 4 and 5 discs were excised with an average operative time of 160 min and a blood loss of 380 ml. A conversion to open thoracotomy was not necessary in any case. There were no intraoperative neurovascular complications. CONCLUSIONS: Thoracoscopic procedures in deformities of the thoracic spine are technically demanding; however, it is a minimally invasive procedure with a reduced approach-related morbidity compared to open thoracotomy. The indications for a thoracoscopic release are rigid kyphosis and scoliosis with rigid curves between 80 and 90 degrees Cobb angle in which an anterior correction and instrumentation alone is not considered.     

Ultrasound Densitometric Analysis: Comparison Between an Online Digital Acquisition Acoustic Program and an Offline Analog Program

Videodensitometric analysis of myocardial contrast echocardiography is traditionally performed off line. Recently, an online contrast ultrasound analysis system, Acoustic Densitometry (Hewlett-Packard), was introduced. We compared pixel intensities acquired with Acoustic Densitometry to pixel intensities derived from videodensitometry. A tissue phantom was imaged in phase I using three transducer frequencies (2.5, 3.5, and 5.0 MHz). In phase II, an in vitro flowing tube model with various concentrations of Albunex® was imaged at two flow rates, 0.6 and 1.2 m/sec, and at two transducer frequencies, 2.5 and 3.5 MHz. The relationship between pixel intensities yielded by the two systems for identical ultrasound signals was determined with linear regression. Intensities derived with Acoustic Densitometry strongly correlated with those derived from the offline videodensitometry system. The intensities were related by a predictive multiplicative factor based on display characteristics of the two systems. These results suggest that semiquantitative, online perfusion analysis with Acoustic Densitometry is as sensitive as analysis offline with videodensitometry.