Cystic variant of calcifying epithelial odontogenic tumor.

Calcifying epithelial odontogenic tumor (CEOT) is a benign, locally aggressive odontogenic neoplasm characterized by sheets and nests of epithelial cells with deeply eosinophilic or occasionally clear cytoplasm, calcifications, and eosinophilic amorphous material that stains positive for amyloid. Although many cases of CEOT are associated with impacted teeth and occasionally appear radiographically as dentigerous cysts, a true cystic variant has not been previously reported. We report a 15-year-old white male with a large cystic maxillary lesion that filled most of the left maxillary sinus. It deformed the medial wall, the inferior orbital floor, and caused narrowing of the left inferior meatus. Histologically, the cystic lining showed characteristics of CEOT. An intraluminal component that featured histologic characteristics of CEOT was identified during surgery. The lesion was enucleated and the postsurgical course of the patient was uneventful. Because follow-up has been for less than 1 year, a meaningful long-term prognosis cannot be determined at present. However, the patient has not reported any symptoms or signs of recurrence during the follow-up period.     

GALLSTONE CIRRHOSIS: ARE WE ONLY SEEING THE TIP OF THE ICEBERG?

Gallstones are common and their incidence increases with age.¹ Fifty per cent of these stones are in the common bile duct (CBD) in the elderly.² Most of them are silent but with time there is an increasing chance of developing symptoms which are more likely to be serious in the elderly.³ Failure to relieve mechanical obstruction of bile flow may lead to secondary biliary cirrhosis.⁴ It has been estimated that on average secondary biliary cirrhosis develops some seven years after the onset of obstruction from a stricture, four and half years after gallstone obstruction and 10 months after the onset of malignant stricture.⁵ The characteristic features are the pathological findings of portal-portal linkages, with a pattern of monolobular cirrhosis and the preservation of normal vascular relationships.⁶ Secondary biliary cirrhosis may lead to hepatic insufficiency and portal hypertension with the resultant complications, such as bleeding oesophageal varices, hypersplenism with pancytopenia, ascites and encephalopathy. We describe a patient in whom the diagnosis was not suspected until laparotomy and confirmed only at autopsy.     

Expression of alpha-melanocyte stimulating hormone and the invasive ability of the B16 murine melanoma.

The expression of alpha melanocyte stimulating hormone (MSH) has been investigated in two variants of the B16 murine melanoma. The presence of MSH was demonstrated by immunohistochemical methods using anti-MSH antibodies. The low metastasis variant B16-F1, which grows as an encapsulated non-invasive tumour, showed no alpha-MSH immunoreactivity. In contrast, the high metastasis variant BL6 was found to be alpha-MSH positive and the immunoreactivity was found predominantly in the peripheral invading zones of the tumour.     

Traumatic haemarthrosis causing femoral head subluxation

We report seven children in whom traumatic haemarthrosis of the hip had produced lateral subluxation of the femoral head, which is different from the apparent displacement seen in Perthes' disease. In all seven cases, aspiration of the haemarthrosis allowed reduction of the femoral head, and follow-up for a mean of 14 months revealed no evidence of avascular necrosis of the proximal femoral epiphysis. Traumatic haemarthrosis of the hip in children appears to be a clinical entity which can produce femoral head subluxation. Aspiration and traction is the treatment of choice and can cure the condition.     

Calcium antagonizes the magnesium-induced high affinity state of the hepatic vasopressin receptor for the agonist interaction.

1. The present study describes the role of Ca2+ in the regulation of the hepatic vasopressin V1 receptor. With low concentrations of Ca2+, there was a small increase in [3H]-arginine vasopressin [( 3H]-AVP) binding, but above 10 mM, Ca2+ decreased the binding of this agonist. In contrast, low concentrations of Mg2+ were associated with a dramatic concentration-dependent increase in [3H]-AVP binding, reaching a maximal effect of 650% above control at concentrations ranging between 1-5 mM. At higher concentrations of Mg2+, the stimulatory effect of this cation was less pronounced, falling to 210% of control at 100 mM Mg2+. Strikingly, Ca2(+)-inhibited the stimulatory effect of Mg2+ in a concentration-dependent fashion. 2. Saturation binding data revealed that Ca2+ (2 to 10 mM) per se promotes the high affinity conformation of the V1 receptor for the agonist binding with the KD decreased from a control value of 2.3 nM to 0.5 nM in the presence of 10 mM Ca2+. This effect was attenuated with an increase in Ca2+ above 10 mM. With an increase in Ca2+ to 20 mM, however, the Bmax for [3H]-AVP binding was decreased. Ca2+ also decreased the high affinity/high capacity state (KD 100 pM) of the receptor induced by 1 mM Mg2+ for agonist interaction. 3. [3H]-V1 antagonist binding was inhibited by both Ca2+ and Mg2+. The IC50 values (mean +/- s.e. mean) for Ca2+ and Mg2+ were 32 +/- 8 and 53 +/- 9 mM respectively. Maximal inhibition achieved at 100 mM was 29% for Ca2+ and 42% for Mg2+.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effect of nitric oxide on mitogenesis and proliferation of cerebellar glial cells

In the brain, nitric oxide (NO) has been identified as a messenger molecule and a mediator of excitatory amino acid-induced neurotoxicity. In this study, the effects of NO on serum-induced mitogenesis and cell proliferation of the cerebellar glial cells were assessed. NO-generating agent, S-nitroso-N-acetylpenicillamine (SNAP) increased intracellular cyclic guanosine monophosphate (cGMP) levels. Furthermore, 2 chemically dissimilar NO-generating agents, SNAP and sodium nitroprusside (SNP) inhibited serum-induced thymidine incorporation and cell proliferation. The antimitogenic effect of NO was mimicked by 8-bromo-cGMP and blocked by hemoglobin, a known inhibitor of NO. The effect of NO was not cytotoxic, since the cells were not stained with Trypan blue and did not show increased release of lactate dehydrogenase in the culture supernatants. However, NO-treated cells showed decreased conversion of tetrazolium to blue formazan suggesting that NO inhibited mitochondrial activity in the glial cells. These results demonstrate that NO inhibits serum-induced mitogenesis and cell proliferation of cultured rat cerebellar glial cells.     

Pleomorphic adenoma of the nasal septum

Despite the common occurrence of pleomorphic adenoma of major salivary glands, intranasal pleomorphic adenoma are rare. We present a ease of pleomorphic adenoma of the nasal septum along with a brief review of literature. The histological nature of this lesion in comparison to other salivary gland tumours and the importance of an accurate diagnosis has been stressed.