Fibroblastic Subtype has a Favourable Prognosis in Appendicular Osteosarcoma of Dogs.

Osteosarcoma (OS) is an aggressive malignant bone neoplasm that occurs mostly in the appendicular skeleton of dogs and people. OS is classified based on the presence of malignant stroma and the formation of extracellular matrix into osteoblastic, chondroblastic and fibroblastic forms. This study investigated the correlation between the three histological subtypes of canine OS and clinical outcome. Additionally, we examined whether there was any difference in the immunolabelling of desmin, S100 and neuron-specific enolase (NSE) between the three histological subtypes. Formalin-fixed and paraffin wax-embedded tissues from 87 dogs with primary OS were available for this study. The survival times were correlated with appendicular OS subtypes in dogs that were treated surgically, received adjuvant chemotherapy and had no pulmonary metastasis at the time of diagnosis. Dogs with an appendicular fibroblastic OS had significantly prolonged mean average survival times (546 ± 105 days) in comparison with dogs having appendicular osteoblastic (257 ± 48 days) or appendicular chondroblastic (170 ± 28 days) OS (P = 0.003, Log Rank). The results also revealed that the appendicular chondroblastic subtype is a significant indicator for poor prognosis in dogs compared with the fibroblastic or osteoblastic subtypes (P = 0.006, Cox regression). Moreover, the findings indicated that there was no significant correlation between the localization of desmin, NSE or S100 and histological subtypes. Importantly, dogs with appendicular fibroblastic OS were found to have a better prognosis when compared with dogs with other subtypes. This may suggest that histological subtypes of appendicular OS have diverse behaviour and could be used to categorize patients for risk-based assessment.

Immunohistochemical Validation of Spontaneously Arising Canine Osteosarcoma as a Model for Human Osteosarcoma.

Osteosarcoma (OS) originates from bone-forming mesenchymal cells and represents one of the primary bone tumours. It is the most common primary bone tumour in dogs and man. The characterization of an appropriate natural disease animal model to study human OS is essential to elucidate the pathogenesis of the disease. This study aimed to validate canine OS as a model for the human disease by evaluating immunohistochemically the expression of markers known to be important in human OS. The immunohistochemical panel included vimentin, alkaline phosphatase (ALP), desmin, S100, neuron-specific enolase (NSE), runt-related transcription factor 2 (Runx2) and bone morphogenetic protein 4 (BMP4). Immunohistochemistry was conducted on formalin-fixed, paraffin wax-embedded tissue sections from 59 dogs with confirmed primary OS. Vimentin, ALP, Runx2 and BMP4 were highly expressed by all tumours, while desmin, S100 and NSE were expressed variably. The findings were similar to those described previously for human OS and suggest that canine OS may represent a useful model for the study of the human disease.

[Erionite-induced pleural plaques. Exposition to urban pollution in a female Turkish migrant in Germany]. / Erionitinduzierte Pleuraplaques. Urbane Belastung bei einer türkischen Migrantin.

Erionite is a zeolite mineral of volcanic origin which contains no asbestos. It is found in different regions of the world, including southeast Turkey in ash and dust, from which it can cause inflammatory pleural plaques or malignant pleural mesothelioma (MPM). We report a female Turkish migrant exposed to urban pollution in her home country who decades later suffered from pleural plaques with a nonspecific chronic inflammatory disease. The differential diagnosis of inflammatory pleural plaques was assumed radiologically and confirmed by video-assisted thoracoscopic biopsy. Short-term clinical and radiologic control of the patient will be necessary because of the risk of MPM. For epidemiologic considerations discussed referring to current literature, a growing incidence of this type of disease in migrants from high-risk areas must be reckoned with in Germany, even without exposition to asbestos.

[Cerclage using hollow screws for internal arthrodesis in cases of pronounced osteoporosis and osteopenia]. / Hohlschraubenunterstützte Rahmencerclage zur internen Arthrodese bei ausgeprägter Osteoporose und -penie.

Osteosynthesis of osteoporotic or osteopenic bone poses a considerable challenge for the surgeon, the type of osteosynthesis performed, and the osteosynthesis material employed. In osteoporotic and osteopenic bone, especially when circulation is decreased or sensitivity reduced, the principle of tension banding places great demands on the bone and surgeon since insufficient tightening of the wire results in inadequate immobilization while overtightening of the tension band can cause the wire to cut through the soft bone. This contribution describes a surgical technique, which prevents the wire from cutting through the bone. Cannulated screws are inserted vertically into the bone in the traction direction and the wire of the tension banding is passed through the cannulated screws. This ensures that the wire traction is distributed across the entire cross section of the bone. Thus, it is possible to completely tighten the tension band in osteopenic and osteoporotic bone. This technique is illustrated using the example of internal screw and tension band arthrodesis of the ankle joint, which achieved stable arthrodesis with weight bearing and recovered ambulation in a patient with pronounced diabetic foot syndrome and peripheral arterial occlusive disease.

Impact of chronic airflow obstruction in a working population.

Data on the individual and collective impact of chronic airflow obstruction at a population level are scarce. In a nationwide survey, dyspnoea, quality of life and missed working days were compared between subjects with and without spirometrically diagnosed chronic airflow obstruction. Subjects aged > or =45 yrs were recruited in French health prevention centres (n = 5,008). Results of pre-bronchodilator spirometry and questionnaires (European Community Respiratory Health Survey-derived questionnaire and European quality of life five-dimension questionnaire) were collected. Adequate datasets were available for 4,764 subjects aged 60+/-10 yrs (only 2% were aged > or =80 yrs). The prevalence of airflow obstruction (forced expiratory volume in one second/forced vital capacity of <0.70) was 7.5%. The vast majority (93.9%) of cases had not been diagnosed previously. Health status was significantly influenced by dyspnoea. Both were associated with the number of missed working days. Despite mild-to-moderate severity, subjects with chronic airflow obstruction exhibited more dyspnoea, poorer quality of life and higher numbers of missed working days (mean 6.71 versus 1.45 days.patient(-1).yr(-1) in patients without airflow obstruction, for the population with no known heart or lung disease). In conclusion, even mild-to-moderate airflow obstruction is associated with an impaired health status, which represents an additional argument in favour of early detection in chronic obstructive pulmonary disease.

[Palliative bypass surgery]. / Bypasschirurgie zur Palliation.

Impaired intestinal passage considerably reduces quality of life irrespective of the underlying condition. Limited life expectancy and increased operative risk of advanced malignant disease add particular weight to this issue. The indication for operative therapy results from carefully weighing individual incapacity and potential gain vs operative risk and life expectancy. Exactly because life expectancy is quite limited, selection of an effective, low-risk procedure is of utmost importance to benefit the patient.

[Sun exposure and sun protection behavior and attitudes among the French population]. / Connaissances, attitudes et comportements des adultes vis-à-vis du soleil en France.

INTRODUCTION: The number of new skin cancers has constantly increased in France over the past two decades. The role of sun exposure can partly explain this phenomenon and justifies the development of information and prevention campaigns to change peoples' attitude towards sun bathing. To be effective, we need to know how much information and what attitudes the population currently has with regard to the sun. Although several studies in France have targeted children, little data is available regarding adults. This trial was aimed at pinpointing the knowledge, attitude and behavior of adults regarding sun exposure. MATERIAL AND METHODS: Data were collected during a randomized multicenter study on the prevention and early diagnosis of cutaneous tumors, conducted in 26 Health Centers from 1998 to 2000. Standardized questionnaires were handed to those consulting to assess their knowledge, attitudes and behavior towards sun bathing. The population was composed of 41 143 adults aged over 30, consulting one of the 26 Health Check-up units. Analysis of the data was made using SAS v 6.12 and STATA 7.0 software. Logistic regression identified the explicative factors of knowledge and behavior. All the statistical analyses were considered significant above a threshold of alpha<5%. RESULTS: A total of 33 021 persons filled-in the self-questionnaire. Forty-nine percent were women and 51% were men, with a mean age of 50 years. Geographically, 25% lived in the North-East, 16% in the North-West, 25 p.cent in the South-East and 34% in the South-West. Thirty percent claimed that they tanned without burning and 2% of the population studied had often suffered from sun burn, generally when they were adult. The risks related to sun burn were known, because 92% knew that the sun increased the risk of skin aging and 89% knew that it increased the risk of skin cancer. Regarding sun screens, knowledge was not so good; 42% thought that all products were the same and 53% that they allowed one to sun bathe longer. This knowledge was better in those with fair skins, in those who had a history of sun burn, in women and in those who lived in the northern areas of France. Conversely, knowledge decreased with age and was limited in those aged over 60. Regarding behavior, those with fair skin and who reddened under the sun without tanning, protected themselves more. The women declared they protected themselves more than the men, but they used less sun protective measures (clothing, hats...), other than sun screens, than men. Subjects aged over 60 protected themselves more than younger subjects. Lastly, a personal cutaneous history increased protective behavior, and those from northern France protected themselves more than those from the South. DISCUSSION: This analysis of 33 021 adults aged over 30 shows the good global knowledge of the consequences of sun bathing, but also the lack of knowledge on the interest of using external sun protection and the role of physical means of protection. Attitudes varied depending on gender, age and phototype and also depending on the area where they lived. Despite good knowledge, the most frequent behavior of adults aged over 30 is still not appropriate with differences depending on age, gender and area, which must prompt more appropriate targeting of prevention campaigns according to the populations concerned.

Retrieval of ureteral calculus using a new method of endoscopic assistance in a cat.

A 9-year-old female spayed domestic short-haired cat presented with ureteral obstruction due to a ureteral calculus 4 cm distal to the renal pelvis. Preoperative creatinine was 844 mmol/L. A novel approach to this condition was utilised whereby a flexible endoscope was passed through a hole made in the renal capsule into the renal pelvis and ureter. The calculus was visualised, and the endoscope was removed. A 1.4 mm flexible grasping forceps was introduced into the proximal ureter through the same hole in the renal capsule and the calculus was removed. The creatinine dropped to 282 micromol/L within 2 weeks of surgery. The cat died of apparently unrelated causes several months after surgery.

[Experimental testing of a new coil design for endoluminal MRI applied to the pig stomach]. / Experimentelle Erprobung eines neuen Spulendesigns zur endoluminalen MRT am Beispiel des Schweinemagens.

PURPOSE: Experimental feasibility study of a new MR-Coil concept for enhanced visualization of the gastric wall. MATERIAL AND METHODS: The newly developed single-loop receiver coil for endoluminal imaging (Fraunhofer Institute, St. Ingbert, Germany) was evaluated in 4 explanted pig stomachs in a 1.5T MR unit (Siemens Symphony, Erlangen, Germany) with T1 w and T2 w MR sequences in three planes. The new coil consists of a foldable and self-expanding single loop coil (receiver coil) of a shape memory metal (nitinol). It was covered with a biocompatible material (silicone) to prevent direct contact of the wire with stomach tissue. The coil assumes a circular configuration with a diameter of 8 cm because of its memory metal properties. The flexible characteristics of the material used allow the passage through the instrument channel (13 mm diameter) of a specially designed MR-compatible endoscope. The purpose of our study was to assess feasibility of the coil design as a first step in developing a new endoluminal MRI-concept. Additionally the number and signal intensity of visible gastric wall layers were evaluated and findings were correlated with histopathological results of a pig stomach. RESULTS: The new coil concept was a feasible system in all 4 cases and showed good image quality for analysis. On T1 w images, 3 layers were visible in all cases, and on T2 w images 4 different gastric wall layers were seen in 2 cases. Due to histopathological correlation, the different gastric wall layers were identified as follows: mucosa, submucosa and muscularis propria if three layers were depicted; in cases of 4 visible wall layers, serosa and subserosa could be detected additionally. For each gastric wall layer, a distinct signal intensity was found. CONCLUSION: The new MR coil concept for endoluminal imaging proved to be a feasible technique. Good differentiation of gastric wall layers in the pig stomach could be demonstrated. We have shown that endoscopic MR-imaging with our new coil concept is a valuable technique for the visualization of gastric wall layers. Due to this fact, follow-up studies including assessing safety aspects are necessary to finally conduct an experimental-clinical study on in-vivo human gastric specimens to detect tumor growth and morphology within the gastric wall. Endoscopic MRI may have the potential in the future to overcome today's limitations of diagnostic imaging in gastric cancer.

Influence of different gases used for laparoscopy (helium, carbon dioxide, room air, and xenon) on tumor volume, histomorphology, and leukocyte-tumor-endothelium interaction in intravital microscopy.

BACKGROUND: Previous studies indicate that helium pneumoperitoneum used for laparoscopic surgery suppresses whereas carbon dioxide pneumoperitoneum increases postoperative tumor growth. The pathomechanisms of decreased tumor growth by helium are unknown. This study was designed to examine the effect of the gases helium, carbon dioxide (CO(2)), and air, and xenon, which can be used to induce pneumoperitoneum in laparoscopy on tumor volume, histomorphology, and leukocyte-endothelium interaction measured by intravital microscopy in rats with implanted liver malignoma (Morris hepatoma 3924A). METHODS: In 46 rats, Morris hepatoma 3294A cells were implanted intrahepatically. After implantation, rats were randomized into two main groups. In the first main group, 10 animals were prepared for examination of leukocyte-endothelium interaction by intravital video microscopy and were randomized into two groups. Five days after implantation they underwent laparoscopy using either helium (n = 5) or CO(2) (n = 5). Ten days after implantation the rats underwent intravital video microscopy to assess leukocyte-endothelium interaction in the tumor and liver vessels. In the second main group 36 rats were prepared for examination of tumor volume arid histomorphology. They were randomized into five groups. Five days after implantation they underwent laparoscopy using helium (n = 7), carbon dioxide (n = 7), room air (n = 7), or xenon (n = 8). The control group (n = 7) received anesthesia only. Rats were killed 10 days after tumor implantation to assess tumor volume and histomorphology. RESULTS: Compared to the control group or groups that received CO(2), room air, or xenon for pneumoperitoneum, the establishment of helium pneumoperitoneum caused a significantly smaller tumor volume (Kruskal-Wallis test, p = 0.001; median tumor-volume: control group, 44 mm(3); helium 19 mm(3)). There was no significant difference in histomorphology between the groups. There was only a statistically significant difference in the development of central tumor necrosis in accordance to tumor volume (Mann-Whitney test, p = 0.03). In the tumor samples, roller counts were statistically significantly higher in the helium group compared to the CO(2) group (p = 0.04). For sticker counts, no statistically significant effects due to liver/tumor (p = 0.13) or treatment (p = 0.48) were observed. CONCLUSIONS: There was a significant decrease in tumor volume using helium pneumoperitoneum for laparoscopy compared to the other gases. Here, we demonstrate that suppression of tumor growth is not due to variation of histomorphology. It seems that helium pneumoperitoneum effects a higher leukocyte-endothelium interaction and thereby a higher immune activation. This could be one explanation for the statistically significantly smaller tumor volume after laparoscopy with helium compared to laparoscopy with CO(2).

Influence of different gases used for laparoscopy (helium, carbon dioxide, room air, xenon) on tumor volume, proliferation, and apoptosis.

BACKGROUND: Previous reports suggest that helium pneumoperitoneum used for laparoscopic surgery suppresses postoperative tumor growth. The present study was designed to determine the effects of gases used in laparoscopy on tumor volume, proliferation, and apoptosis in rats with implanted malignoma. METHODS: In 36 rats Morris hepatoma 3294A cells were implanted intrahepatically. Then, after 5 days, they underwent laparoscopy using helium ( n = 7), CO(2) ( n = 7), room air ( n = 7), or xenon ( n = 8). One group received anesthesia only ( n = 7). Rats were killed 10 days after implantation to assess tumor volume, proliferation, and apoptosis. RESULTS: Helium pneumoperitoneum caused a significant smaller tumor volume compared to other groups (Kruskal-Wallis test: p = 0.001; median tumor volume: control: 44 mm3; helium: 19 mm3). There was no significant difference in tumor cell proliferation (PCNA) and apoptosis (TUNEL reaction) between the groups. CONCLUSIONS: There was a significant decrease of tumor volume using helium pneumoperitoneum compared to the other gases, but no decreased tumor cell proliferation or increased tumor cell apoptosis.

Helium pneumoperitoneum reduces tumor recurrence after curative laparoscopic liver resection in rats in a tumor-bearing small animal model.

BACKGROUND: After exposure of neoplastic tissue to helium, a significant reduction of tumor growth has been detected in experimental studies, both in vitro and in vivo. This tumor-suppressive effect of helium is controversly discussed in the literature. It was therefore the aim of this study to investigate the influence of pneumoperitoneum with CO2, room air, or helium in a tumor-bearing small animal model comparing laparoscopic partial hepatic resection for hepatocellular carcinoma with conventional open partial hepatectomy. METHODS: One-hundred forty-eight male American Cancer Institute rats underwent partial hepatectomy for curative resection of previously induced hepatocellular carcinoma (Morris hepatoma 3924A). Resection was performed either in open laparotomy (n = 30) or laparoscopically under the employment of CO2 (n = 30), room air (n = 30), or helium (n = 30) for the pneumoperitoneum. Twenty-eight animals served as controls receiving anesthesia but no tumor resection. All animals were sacrificed on postoperative days 21, 35, or 56 for autopsy and evaluation of possible tumor recurrence and metastasis. RESULTS: Significant reduction of postoperative tumor recurrence and metastasis was observed in the group of animals receiving laparoscopic tumor resection under helium insufflation compared to open surgery or laparoscopic resection with air pneumoperitoneum. CONCLUSIONS: The results of this study suggest a suppressive effect of helium pneumoperitoneum on postoperative tumor growth and metastatic spread. Furthermore, tumor exposure to room air appears to have a stimulative influence on tumor recurrence and metastasis compared to a pneumoperitoneum established with CO2.

In vivo assessment of angioarchitecture and microcirculation in experimental liver cancer: a new model in rats.

The rising incidence of unresectable hepatocellular malignancies remains a therapeutic challenge. Little is known about the mechanisms of angiogenesis and immunological aspects of liver tumor vessels. The aim of this study was to investigate hepatic and tumor microcirculation and leukocyte-endothelium interaction by means of intravital microscopy in a rat model of hepatocellular carcinoma. Off-line analysis showed that the angioarchitecture as well as blood flow velocity in liver cancer is heterogeneous. The leukocyte-endothelium interaction is significantly reduced compared to normal liver tissue. The data suggest that the main mechanism is a reduced expression of adhesion molecules demonstrating an effective immune escape mechanism of this tumor. The model represents a useful experimental tool to explore angiogenesis inhibition or immunological therapeutic strategies in experimental liver cancer.

[Prospective comparison of hydrosonography, endosonography and specimen sonography for TN staging of gastric carcinoma]. / Prospektiver Vergleich von Hydrosonographie, Endosonographie und Präparatesonographie beim TN-Staging von Magenkarzinomen.

PURPOSE: To compare hydrosonography (HUS), endosonography (EUS) and experimental sonography (PUS) with respect to TN-staging accuracy of gastric carcinoma. MATERIAL AND METHODS: Thirty-six patients with gastric carcinoma underwent EUS (7.5/12 MHz transducer, Olympus GF-UM 20) and HUS (3.75 MHz transducer, Toshiba, Sonolayer SSA-270A) for TN-staging according to the UICC-classification. The resected specimens were reexamined (3.75/7.5 MHz transducer) and again TN-staging was performed. Findings were correlated with histopathological results. RESULTS: T- and N-staging accuracies were as follows: EUS 54 % (19/35) and 79 % (27/34); HUS 41 % (15/37) and 61 % (22/36); and PUS 51 % (19/37) and 72 %(26/36). Sensitivities and specificities for the detection of lymph node metastases were as follows: EUS 87 % and 54 %; HUS 57 % and 69 %; and PUS 83 % and 54 %. CONCLUSIONS: The accuracy of sonographic TN- staging is limited in patients with gastric carcinoma. Nevertheless, EUS may contribute to the preoperative management of patients with gastric carcinoma if indications are well defined. HUS is not suited for TN-staging of gastric carcinoma.

Comparison of laparoscopic versus conventional technique in colonic and liver resection in a tumor-bearing small animal model.

BACKGROUND: Laparoscopic procedures in oncological surgery are either done in curative or palliative intent. We present two experiments comparing laparoscopic to conventional surgery in the curative and palliative setting regarding short-term (stress and immune alteration) and long-term aspects (survival time and recurrence rate). METHODS: We established two syngenic tumor-bearing small animal models for curative liver resection (Morris hepatoma 3924A, ACI rats) and palliative colon resection (BSp73 ASML, BOX rats). Male rats were operated on, performing laparoscopic and conventional liver resection as well as laparoscopic and conventional colon resection; control groups (anesthesia) were included. The following parameters of the stress and immune system were measured: corticosterone, neopterine, Il-1-b, Il-6, and body weight as a parameter of postoperative recovery. Analyzed long-term parameters were survival time, tumor weight, and recurrence rate (histology). RESULTS: After colon resection, analysis of variance showed significant differences in all short-term parameters, including body weight after laparoscopic versus conventional colon resection (p <0.05). In the case of laparoscopic versus conventional liver resection, only Il-6 showed globally statistically significant differences for the short-term parameters (p = 0.05). Long-term parameters were not significantly different between the laparoscopic and conventional groups, regardless of the type of resection (colon or liver) or the operative setting (curative or palliative). However, there were differences after curative liver resection compared to the control group (anesthesia alone). CONCLUSION: These results suggest that the type of intraabdominal operation (colon or liver) may influence the degree of trauma of an operation more than the type of technique (laparoscopic or open). The perioperative alteration of stress and immune function has no implications on the long-term results, such as survival time or recurrence, neither in the curative nor in the palliative setting. The thesis that laparoscopic surgery results in less pain, which in turn means less stress and less alteration of the immune system and therefore results in a lower rate of postoperative metastasis is only valid for laparoscopic colonic resection in our model. The part of the thesis that states that fewer metastases should occur after laparoscopic oncological surgery cannot be confirmed in our study.

Effect of gas-plasma sterilization on the osteoinductive capacity of demineralized bone matrix.

The current study evaluated the effect of low-temperature hydrogen peroxide gas plasma sterilization on the osteoinductive capability of human demineralized bone matrix using a rat model. Twelve athymic rats received three separate implants consisting of steam-sterilized demineralized bone matrix (negative control), sterile-harvest demineralized bone matrix (positive control), and gas-plasma-sterilized demineralized bone matrix. A demineralized bone matrix pellet from each sterilization group was placed individually into one of three separate soft tissue pockets created in the epaxial musculature of each rat. All 12 rats were euthanized 9 weeks after implantation. Each implantation site was removed along with 0.5-cm normal tissue around the implant. Histologic examination was done on each implant site to determine the presence or absence of new bone, cartilage, or bone marrow elements. All 12 sterile harvest demineralized bone matrix sites histologically contained new bone elements, whereas none of the negative control or gas plasma sterilized demineralized bone matrix sites contained any of these same elements. The results of this study indicate that demineralized bone matrix sterilized with low-temperature, gas-plasma sterilization loses its osteoinductive capacity in a manner similar to that of steam-sterilized demineralized bone matrix, making low-temperature, gas- plasma sterilization unsuitable as a method of secondary sterilization of demineralized bone matrix.

Accuracy of radiography, nuclear scintigraphy, and histopathology for determining the proximal extent of distal radius osteosarcoma in dogs.

OBJECTIVE: To compare the accuracy of radiography, nuclear scintigraphy, and histopathology for determining the proximal extent of distal radius osteosarcoma in dogs. STUDY DESIGN: Retrospective clinical study. SAMPLE POPULATION: Twenty client-owned dogs taken to Colorado State University with osteosarcoma of the distal radius. METHODS: Medical records of 20 dogs with confirmed osteosarcoma that underwent a limb-salvage procedure were reviewed. Measurements were performed directly from the lateral view of each radius, from both the scintigram and the radiograph, to determine the length of the radius and the distance from the proximal extent of the tumor to the distal radiographic or scintographic extent of the radius. The ratio of distal radial involvement to total radius length was calculated. A similar ratio was also determined using the macroslide, which included the entire portion of bone that was excised during the limb-salvage procedure. All 3 methods of measurement were compared. RESULTS: Nuclear scintigraphy significantly overestimated tumor length when compared with macroslide specimen measurements. Radiography also overestimated tumor length, but these results were not significantly different from macroslide specimen measurements. CONCLUSIONS: Both radiography and nuclear scintigraphy overestimate the extent of distal radius osteosarcoma in dogs when compared with histopathologic macroslides of the same lesions. Nuclear scintigraphy overestimated tumor extent to a larger degree than did radiography. CLINICAL RELEVANCE: Although radiography is a more accurate method of measurement of the extent of distal radius osteosarcoma, because nuclear scintigraphy overestimates tumor length to a greater degree, scintigraphy may provide a larger margin of safety for determining the site of proximal osteotomy during a limb-salvage procedure. However, caution should be taken when utilizing scintigraphy, because this method may overestimate length of radius involved to such an extent as to cause the surgeon to believe that a patient is not a suitable limb-salvage candidate.

Monocytes influence the fate of T cells challenged with oxidised low density lipoproteins towards apoptosis or MHC-restricted proliferation.

Atherosclerosis has been implicated in myocardial infarction, stroke and a host of cardiovascular diseases. The presence of activated T lymphocytes and macrophages, and the increased expression of HLA-DR antigen are consistent with the notion of immune activity in the atherosclerotic plaque. The nature of the causative antigen has not been established although oxidised low density lipoproteins (oxLDL) that accumulate in atherosclerotic plaques could fulfil this role. Here, we report that monocytes play a key role in influencing the fate of purified peripheral human T lymphocytes from healthy donors when the cells are exposed to LDL oxidised under the controlled conditions of water radiolysis. Our data showed that oxLDL generated under these conditions were chemoattractants for T cells. However, they induced a state of apoptosis in T lymphocytes cultured in the absence of monocytes. The extent of apoptosis was related to the degree of oxidation of LDL and the time of T cell exposure to oxLDL. OxLDL-dependent apoptosis did not involve a scavenger-like receptor. CD4(+) cells were more sensitive to the apoptotic effect of oxLDL than CD8(+) cells. OxLDL-primed (12 h) autologous monocytes triggered a robust proliferation of T lymphocytes cultured in the absence of oxLDL. The strength of T cell stimulation was related to the degree of oxidation of the LDL used in priming. Heterologous monocytes exposed to oxLDL under similar conditions induced a response that was not different than monocytes exposed to untreated LDL (natLDL) which did not induce T cell proliferation. Fucoidan did not modify the oxLDL-, monocyte-dependent T cell response to proliferation, suggesting that a scavenger-like receptor was not involved. The expression of the HLA-DR marker and the B7.2 protein were up-regulated in monocytes exposed to oxLDL but not to natLDL. The levels of B7.1 were unchanged. Our data are consistent with the notion that monocytes are critical for T cell survival in the presence of oxLDL and MHC-restricted T cell proliferative response to oxLDL.

Surgical treatment of adrenocortical tumors: 21 cases (1990-1996).

Twenty-four adrenocortical tumors were surgically removed from 21 dogs. Histopathological examination confirmed 18 carcinomas and six adenomas. Four dogs died in the perioperative period. Fifteen of the 17 dogs that survived the perioperative period had long-term resolution of their clinical signs. Two dogs with incompletely resected tumors were treated with mitotane to control their clinical signs. Overall median Kaplan-Meier life-table survival for dogs with carcinomas was 778 days (range, one to 1,593 days). Median survival for dogs with adenomas was not reached (range, 11 to 730 days). Histopathological diagnosis, histopathological cellular features, age of the dog, and tumor size were not prognostic of outcome.