Bizarre parosteal osteochondromatous proliferation (Nora's Lesion) of the mandible. a rare bony lesion.

Bizarre parosteal osteochondromatous proliferation (BPOP) also eponymically called "Nora's lesion", is a rare benign reactive bone lesion first reported in 1983. BPOP occurs classically on the bones of the hands and feet and long bones. This lesion can easily be confused, both clinically and microscopically, with other benign and malignant lesions of bone, including osteochondroma, parosteal osteosarcoma, myositis ossificans and reactive periostitis. BPOP has been reported to have a high rate of recurrence. Only 3 cases of BPOP of the head and neck have been reported in the literature, of which one involved the maxilla. We present a rare case of BPOP involving the mandible in a 10 year old African American male. Microscopically, a fibro-cartilaginous cap giving rise to a proliferation of variably mineralized osteophytic finger-like projections of bone was seen. Multiple trabeculae of "blue bone" were noted as well as numerous atypical appearing chondrocytes. The lesion recurred within 4 months following the initial excision but has not recurred to date after the second local excision. To the best of our knowledge, this is the first report of BPOP arising in the mandible. In addition, we discuss the clinical and microscopic features, differential diagnosis, and prognosis of this rare entity. We present a case of BPOP of the mandible and believe this is the first report of such a case in the mandible.

Protective effects of green tea on intestinal ischemia-reperfusion injury.

OBJECTIVE: The intestinal mucosa is known to be adversely affected by ischemia-reperfusion (I/R). Previously we showed that green tea protects the intestinal mucosa from fasting-induced damage. The aim of this study is to determine whether green tea has any protective role in I/R of the intestine. METHODS: Three groups of male rats were used in this study. Group I (I/R) underwent I/R of the intestine (30 min of ischemia followed by 1 h of reperfusion). Group II (green tea + I/R) was given green tea for 2 wk before inducing I/R. Group III (control) had sham I/R. After the experiments, the jejunum was removed and the tissues were processed for histopathologic examination and immunohistochemical analysis for cell proliferation markers and antioxidant enzymes. RESULTS: The intestinal mucosa in group II was preserved compared with that in group I. The expressions of cellular proliferation markers (proliferating cell nuclear antigen and Ki-67) and cellular antioxidants (superoxide dismutase and catalase) in group II were similar to those in group III and much less than in group I, reflecting the protective effects of green tea in group II animals. CONCLUSION: In this animal model, administration of green tea before inducing I/R protects the intestinal mucosa from injury.

Transport kinetics of zinc, copper, selenium, and iron in perfused human placental lobule in vitro.

Transport characteristics of essential trace elements as zinc, copper, selenium and iron have been studied in maternal-fetal direction in normal pregnancies, using in vitro perfusion of human placental lobules. Solutions of trace elements corresponding to twice the physiological concentrations were injected (100 microl bolus) into the maternal arterial perfusate. Serial perfusate samples were collected every 30 sec from venous outflows for a study period of 5 min. Concentrations of these trace elements and their transport kinetics were determined. Transport fractions (TF) of zinc, copper, selenium and iron averaged 0.21, 0.49, 0.55 and 0.10% of maternal load respectively. Other parameters such as area under the curve, clearance, elimination constant, absorption and elimination rates showed some significant differences between the various elements. Copper and selenium appear to be transported passively in maternal-fetal direction, while for iron and zinc, role of active transport for transfer across the human placental membrane cannot be discounted. We speculate that alterations in copper: zinc TR50 (transport rate for 50% efflux) and TF ratios could serve as useful indicators for assessing placental transport status of these essential elements in complicated pregnancy states.

Expression of E-cadherin in human colorectal cancer.

AIM: To investigate the expression of E-cadherin, a calcium-dependent cell-cell adhesion molecule in colorectal carcinoma. Antibodies to E-Cadherin were used to establish the association of their expression with the clinicopathological characteristics of this disease using immunohistochemical methods. METHODS: Immunohistochemical analysis for E-cadherin was carried out in formalin-fixed, paraffin-embedded sections of neoplastic colorectal tissues and non-neoplastic ones adjacent to the lesion from 49 patients who underwent surgery, by the standard peroxidase-antiperoxidase method. Expression of this antigen in normal and malignant epithelium and stromal cells was compared. RESULTS: Both neoplastic and normal tissues showed expression of E-cadherin. There was, however, higher expression of E-cadherin in epithelial cells in both tumour and normal tissues than stromal cells. The percentage of expression in epithelial cells of well-differentiated tumours was significantly higher than moderately differentiated tumours. Loss of normal membranous expression and the presence of cytoplasmic and mixed staining were found frequently in tumour tissues (p = 0.004). This loss of membranous expression, however, did not correlate with Duke's staging, tumour grade, sex, size or site of the tumour. CONCLUSION: This study suggests that the lower expression of E-cadherin in less differentiated tumours may explain their aggressive nature, although loss of membranous expression was not significantly correlated to Duke's staging, tumour grade, sex, size and site of tumour.

Brain selenium accumulation in rat pups of selenium supplemented mothers.

Selenium is essential for normal mammalian development. Being a component of antioxidant enzyme, glutathione peroxidase, it plays a major role in protecting the cells from free radical damage. The level of glutathione peroxidase was directly related to the amount of selenium present in various tissues and organs. A decrease in selenium leads to various pathological changes in humans as well as in various laboratory animals. The aim of the present study was to understand whether there is an increase in the level of selenium in different brain regions of rat pups whose mothers were supplemented with selenium, either 2 or 4 mg/l of their drinking water throughout the period of their pregnancy. There was a significant increase in the level of selenium in the cerebellum, cortex and hypothalamic and hippocampal tissues of selenium supplemented mothers as compared with those of non-supplemented mothers. The brain stem of these animals did not show any significant difference in the level of selenium. Furthermore, the differences in the level of selenium between the rat pups of 2 mg/l selenium supplemented mothers and 4 mg/l selenium supplemented mothers were not statistically significant. These studies suggest that supplementation of selenium to mothers during the period of their pregnancy can selectively increase the level of this trace element in different brain regions. Further studies are necessary to understand the significance of selective accumulation of selenium in specific brain regions on brain development and function.

Level of superoxide dismutase, glutathione peroxidase and uric acid in thioacetamide-induced cirrhotic rats.

Levels of superoxide dismutase and glutathione peroxidase were determined in blood and hepatic tissues of thioacetamide-induced cirrhotic rats and compared to levels in age-matched control animals. The plasma level of uric acid was also determined in these animals. A general decrease was noticed in the level of all the antioxidants examined as compared to the control. This decrease was statistically significant in the level of all the antioxidants studied, except for the level of superoxide dismutase in blood. A decrease in the antioxidant level may indicate an increase in free radical level and thereby an increase in cellular damage in cirrhotic rats. The changes in the level of antioxidants showed a direct correlation with the changes in the level of trace elements observed in our previous studies. These studies suggest that antioxidants alone or in combination with trace elements may have beneficial effects in treating liver cirrhosis.

Maternal-fetal transport kinetics of copper, selenium, magnesium and iron in perfused human placental lobule: in vitro study.

Transport characteristics of certain inorganic elements such as copper, magnesium, selenium and iron have been studied in maternal-fetal direction in normal pregnancies, using in vitro perfusion of isolated placental lobules. Copper, selenium, magnesium and iron salts corresponding to twice physiological concentrations were injected as a 100 microl bolus, into the maternal arterial perfusate. Serial perfusate samples were collected from venous outflows for a study period of 5 min. Concentrations of various inorganic elements and their transport kinetics were determined. Transport fractions of copper, selenium, magnesium and iron averaged 0.14, 0.19, 0.06 and 0.23% of maternal load respectively. The pharmacokinetic parameters such as area under the curve, clearance, elimination constant, and time for maximum response showed some significant differences between the various elements. We speculate that copper and selenium share the same transport pathway along a concentration gradient in maternal-fetal direction, while for iron and magnesium, active transport plays a predominant role for element transfer across the human placental membrane.

Expression of CD44s in human colorectal cancer.

CD44s is a cell adhesion molecule, which belongs to the family of hyaluronan binding proteins. Anti-body to CD44s is used to establish the association of its expression with the clinicopathological characteristics of colorectal cancer using immunohistochemical methods. The aim of this study is to investigate the expression of the standard form of CD44 (CD44s) in colorectal cancer tissues as compared to adjacent normal colonic tissues. Furthermore, the level of expression of CD44s in colorectal cancer tissues was correlated with the degree of histological differentiation, Duke s classification, sex, size and site of the tumor. Immunohistochemical analysis for CD44s was carried out in 49 paraffin-fixed sections of neoplastic colorectal tissues and non-neoplastic ones adjacent to the lesion, by the standard peroxidase-antiperoxidase method. Expression of these antigens were compared in normal and malignant epithelium and stromal cells. The results show that the level of CD44s in the epithelial and stromal cells was significantly higher in the colorectal cancer tissues than the normal ones. However, there was no association between the percentages of expressions of CD44s and the degree of histological differentiation, Duke s classification, sex or size of the tumor. There was however, a significantly higher expression of CD44s in the epithelium of rectal cancer than that of colonic cancer. This study indicates that the expression of CD44s is significantly higher in colorectal cancer tissues. However, further studies are required to understand its role in tumor progression and metastasis of this disease.

Pre- and postnatal tissue selenium of the rat in the growing state.

The aim of this study is to quantify the selenium (Se) content (in microg/g) during different gestational periods in rat fetal tissues, and to follow up the changes in the Se content of the placenta, fetal head, liver and lung during gestation and postpartum periods. Locally reared virgin female Wistar rats were mated. Pregnant rats were sacrificed on days 15, 18 and 21 of pregnancy. Newborn pups at the age of 3 days and rats at the age of 1 month were also investigated. There was a gradual increase in placental and whole head Se content as gestation proceeded compared to day 15; however, the differences between the groups were not statistically significant. The liver Se content at day 18 of gestation was significantly higher than at day 21 of gestation and in rats at 3 days of age, but lower than the Se content of the liver of rats at the age of 1 month and the differences were statistically significant. The lung Se content was higher at day 18 of gestation than at day 21 and in the 3-day-old rats, and all differences between all groups were statistically significant except when the lung Se content at day 18 is compared to that of 1-month-old animals. The continuous increase in the Se content of the placental tissues and the whole head, although not significant statistically, may indicate that the fetus relies heavily on its supply of Se from the maternal blood and in part on the supply of thyroid hormones which are important for brain development, as evidence exists that T(4) and T(3) are present in the fetal brain in early fetal life before the onset of fetal thyroid function. The higher content of Se on day 18 and its decline on day 21 of gestation in the liver may imply that it is stored and being utilized partly in other tissues for other functions and particularly for thyroid hormone synthesis, metabolism and functions.

Effectiveness of laparoscopic fundoplication for gastro-oesophageal reflux.

BACKGROUND: Gastro-oesophageal reflux (GERD) is a common condition. Many patients respond to conservative therapy. Severe symptomatic cases and those who fail medical treatment are referred to surgery. The long-term results of open fundoplication surgery have been good with a more than 90% response after 10 years of follow-up. The introduction of laparoscopic fundoplication achieved the same results with shorter hospital stay, a better cosmetic result and less cost to the health care providers. PATIENTS AND METHODS: 74 patients who failed medical treatment for GERD were treated by laparoscopic fundoplication. The Toupet procedure was performed in 66 of these patients, the others patients had a Nissen-type fundoplication. The patients were followed up for a mean period (+/- SD) of 14.8 +/- 8.8 months (range 3-33 months). RESULTS: Most of the patients were males (n = 65). The mean age (+/- SD) of all the patients was 36.1 +/- 9.5 years (range 17-60 years). The majority (93.8%) reported disappearance of symptoms and are not using any antireflux medications. Five patients (6.7%) are considered failures of the procedures. Of these, three patients developed recurrence of reflux symptoms during the follow-up period. The other two patients developed complications, i.e. gas bloat, persistent vomiting and dysphagia which warranted taking down the wraps laparoscopically. Two patients developed a small incisional hernia at the site of the 10 mm port. The mean of hospital stay (+/- SD) was 3.1 +/- 1.3 days (range 1-7 days). CONCLUSION: Laparoscopic fundoplication is safe and effectively relieves reflux symptoms in patients who fail medical treatment.

Cholangiocarcinoma and liver cirrhosis in relation to changes due to thioacetamide.

Different doses of thioacetamide (0.05%, 0.1% and 0.15%) were used to induce liver cirrhosis in Wistar rats. Thioacetamide at 0.5% caused cirrhosis by the twelfth week of treatment. A severe bile duct proliferation and cholangiocarcinoma was seen at longer intervals. Animals treated with higher doses (0.1% and 0.15%) of thioacetamide developed more severe intense degenerative changes in the liver and died in the twelfth and eighth week respectively. The serum and tissue contents of Zn and Cu changed in a characteristic fashion that was consistent with the severity of the liver damage. Serum Zn and Cu concentrations were at their lowest in the animals that developed severe degenerative liver and died at higher dose (0.15%) of thioacetamide. This study indicates that treatment of rats with 0.05% thiocetamide is more effective and appropriate for the induction of liver cirrhosis. Continued administration of the drug at this dosage led to the development of further changes in the liver. This model may be suitable for studying these long term changes that occur in the liver and lead to cirrhosis. Events that precede the development of severe bile duct proliferation and cholangiocarcinoma may also be studied.

Thioacetamide toxicity and the spleen: histological and biochemical analysis.

Exposure to thioacetamide is associated with the development of liver cirrhosis in experimental animals. In addition to liver, thioacetamide toxicity has been observed in other organs. In this study, the toxic effect of thioacetamide on the spleen was investigated at 0, 4, 8 and 12 weeks post-treatment durations. The level of tissue copper and selenium increased until the eighth week when a significant drop was observed. The zinc level was also increased but returned back to normal by week 8, thereafter it showed further increase. Calculation of the copper/zinc ratio showed an increase, but, recovered and returned to normal value by week 12. The level of manganese fluctuated until the eighth week. It then increased rapidly. Histological studies of the spleen tissue showed a significant increase in extramedullary haematopoiesis in the red pulp region and marked hyperplasia in the marginal zone and follicles. The results of this study, demonstrate an intimate association between trace element levels and spleen pathology, as observed in studies of other organs.

Colitis-induced changes in the level of trace elements in rat colon and other tissues.

Trace elements constitute important prosthetic groups in a number of antioxidant enzymes which neutralize free radicals generated during inflammatory conditions such as colitis. However, the status of trace elements in colitis remains to be found. In the present study the concentrations of zinc, copper, manganese and selenium in the colon, liver and serum of rats with acetic acid (HAc)- or trinitrobenzenesulfonic acid (TNBS)-induced colitis were measured using atomic absorption spectrophotometer. Myeloperoxidase and glutathione peroxidase activities were measured spectrophotometrically. Our results show that the selenium concentration was significantly decreased by 33 and 37.5% in the colon and 69 and 78% in liver by HAc and TNBS treatment, respectively. Similarly the zinc concentration in the colon was decreased by 21 and 28% by HAc- and TNBS-induced colitis as compared to the controls, but manganese and copper, remained unaltered. The serum concentrations of copper, zinc and selenium also remained unaltered during colitis. The weight of HAc-treated rats did not decrease while there was a significant weight loss in the TNBS-treated rats. Myeloperoxidase activity was increased, whereas glutathione peroxidase activity was significantly decreased in the colon inflamed by HAc or TNBS as compared to the controls. These findings suggest that colitis induces a reduction in the tissue levels of trace elements which is independent of the way colitis is induced. Our findings of a reduction in Se and glutathione peroxidase activity together suggest that the reduction in the trace element concentrations is not due to dietary factors or malabsorption. The decrease may severely affect the antioxidant potential of the colon and therefore is a putative factor for the progression of disease.

Effect of dietary selenium, zinc and allopurinol supplements on plasma and tissue manganese levels in rats with thioacetamide [correction of thiocetamide]-induced liver cirrhosis.

The effect of thioacetamide-induced liver cirrhosis on plasma and tissue manganese levels and the protective role of selenium, zinc and allopurinol supplements was investigated in rats. Control plasma and liver manganese (Mn) levels were found to be (mean +/- SD): 8.4 +/- 2.4 mg/L and 5.7 +/- 1.5 mg/g wet weight respectively. Plasma manganese levels were significantly increased (p < 0.001) whereas liver manganese levels were significantly reduced (p < 0.05) in the cirrhotic rats. Treatment with selenium, zinc and allopurinol reversed this trend and restored the manganese levels close to the normal values. Lung, spleen, and kidney manganese levels under control conditions were considerably lower than that of the liver tissue. However, these levels registered a significant increase (p < 0.05) in cirrhotic rats and this change was normalized after selenium, zinc and allopurinol treatment. There were no significant differences in the comparative efficacy of each of these protective agents. Zinc supplement considerably increased the plasma zinc levels and plasma Zn/Mn ratio had a good correlation with plasma zinc concentration. This ratio was significantly reduced in cirrhotic rats, but returned to the control level after zinc, selenium and allopurinol treatment. The results of this study indicate that the trace element, manganese, plays an important role in stabilizing cell structure and that this effect is mediated possibly by preserving the antioxidant activity of the tissues.

Zinc and liver cirrhosis: biochemical and histopathologic assessment.

Experimental liver cirrhosis was produced by administration of thioacetamide. Cirrhotic animals were divided into two groups: one group was given zinc sulphate and the second kept as cirrhotic control. Zinc-treated animals showed a restoration of normal hepatic and plasma zinc and copper levels. Similarly, plasma levels of aspartate aminotransferase, alanine aminotransferase, gamma-glutamyl aminotransferase, and total bilirubin decreased significantly. Light microscopic studies showed that most of the hepatocytes appeared normal in zinc-treated as compared with untreated cirrhotic animals. The amount of fibrin, reticulin, and collagen, which was high in the cirrhotic livers, decreased following zinc treatment. Staining with periodic acid Schiff's reagent showed the ability of hepatocytes to store glycogen after zinc treatment. These results revealed that zinc may have some beneficial effect in the treatment of liver cirrhosis.

Interleukin-1 alpha (IL-1 alpha) production by alveolar macrophages in patients with acute lung diseases: the influence of zinc supplementation.

The relationship between zinc treatment and interleukin-1 alpha (IL-1 alpha) production by cultured alveolar macrophages (AM) in patients with pulmonary tuberculosis and bacterial pneumonia was investigated. AM (1 x 10(6) cells/ml) from 6 patients with pulmonary tuberculosis, 7 patients with bacterial pneumonia and 4 healthy volunteers were cultured with either two different concentrations of zinc chloride (Znl = 1 microgram/ml and Zn2 = 5 micrograms/ml) or cell culture media alone (control) for an initial period of 6 hours and then stimulated with 3 different immunomodulator agents and reincubated for a further 24 h. IL-1 alpha in culture supernatants was measured by enzyme-linked immunosorbent assay (ELISA). In the absence of Znl or Zn2 Polyinosinic:Polycytidylic acid (Poly I:C 1 microgram/ml), Lipopolysaccharide (LPS 100 ng/ml) and Tumour necrosis factor-alpha (TNF-alpha 10 ng/ml) significantly increased the production of IL-1 alpha from AM in both patients and healthy subjects (p < 0.001) compared to control (media only). Zn1 and Zn2 significantly increased the production of IL-1 alpha (p < 0.001) in culture supernatants in the absence of either Poly I:C, LPS or TNF-alpha in patients but not in healthy group. In contrast, the presence of LPS or TNF-alpha significantly reduced Zn1 or Zn2-stimulated release of IL-1 alpha from AM in patients and healthy subjects (p < 0.01). However, Poly I:C decreased only Zn1-stimulated release of IL-1 alpha. These results suggest that zinc can regulate the production of IL-1 alpha from AM in patients with pulmonary tuberculosis or bacterial pneumonia.

Liver cirrhosis induced by carbon tetrachloride and the effect of superoxide dismutase and xanthine oxidase inhibitor treatment.

Repeated administration of carbon tetrachloride (CCl4) induces liver cirrhosis, possibly because it involves the production of free radicals. In order to evaluate the effect of free radical scavengers such as superoxide dismutase (SOD) and allopurinol in the pathogenesis of liver cirrhosis, rats were subjected to repeated CCl4 administration with and without scavengers. Four groups of animals were studied: CCl4 plus SOD (group 1), CCl4 plus allopurinol (group 2), CCl4 alone (group 3) and olive oil (group 4, normal controls). Analysis of plasma and tissue concentrations of trace elements was performed and histopathological patterns were studied in all groups after 7 weeks of repeated intraperitoneal administration of the solutions. Plasma levels of zinc and selenium were significantly lower in all experimental groups, with reciprocal elevation of manganese and copper. Copper and manganese content in the liver tissue was significantly higher in all three experimental groups. The zinc content was elevated in groups receiving CCl4 alone (group 3) or with allopurinol (group 2). The liver selenium, however, was significantly lower in these two groups. The copper:zinc ratio for plasma was 0.78 in the control group, 1.6 in the CCl4 group, 1.3 in the allopurinol group and 1.5 in the SOD group. For liver tissue, the ratio was 0.07 for controls, 0.17 for CCl4, 0.11 for allopurinol and 0.28 for the SOD group. The changes in trace element content correlated with the severity of cellular damage observed microscopically in the liver. The higher the copper:zinc ratio, the more advanced and extensive was the microscopic evidence of liver injury after CCl4 challenge.

The early platelet uptake and distribution of platelets in small-diameter polytetrafluoroethylene (PTFE) vascular grafts in vivo.

Platelet deposition onto the surface of biomaterial is an important component of the interaction between blood and a prosthetic arterial graft. To understand the thrombotic process in small-diameter by-pass grafts, we used pigs to study the early in vivo uptake of 111In-oxine-labelled platelets in polytetrafluoroethylene (PTFE; GoreTex) grafts. In each experimental animal, 12 PTFE grafts (internal diameter, 3 mm; length, 5 cm) were placed in the femoral artery as interposition grafts. 111In-Labelled autologous platelets were injected. Sequential-scintillation camera images of the graft area were taken over a period of 3.5 h. Platelet deposition in vivo was calculated as an activity ratio for the entire grafts as well as for different segments of the graft. The grafts were harvested, cut into 0.6-cm pieces and weighed, and the 111In activity was measured. The distribution along the graft surface was calculated. Blood flow was measured continuously. The activity ratios rapidly increased, and a maximum was reached 60 min after the re-establishment of blood flow; thereafter the activity ratios slowly decreased. The distribution of platelets along the graft surface was found to be non-uniform where more platelets were deposited towards the distal anastomoses.