Hyalinizing clear cell carcinoma of the base of tongue: A distinct and rare entity.

Hyalinizing clear cell carcinoma (HCCC) of tongue is a rare neoplasm originating from minor salivary glands. We present a case of HCCC involving the base of tongue, in a 73-year-old male, clinically diagnosed as fibroma. Laser excison of the mass was done. Histopathological examination showed an infiltrating lesion composed predominantly of clear clear. The differential diagnosis included other salivary gland lesions having a clear cell component and metastatic clear cell renal carcinoma. lmmunohistochemistry was useful in ruling out these lesions exhibiting clear cell component from clear cell carcinoma. imaging studies revealed no lesion in either kidney. Since, HCCC has a better prognosis and the adequate treatment is wide excision, it needs to be differentiated from other carcinomas with clear cells. No further therapy was given to the patient. One year after the surgery, the patient is symptom free without local recurrence and on regular follow up.

Hypothalamic digoxin and regulation of body mass index.

The hypothalamus produces digoxin, an endogenous membrane Na+-K+ ATPase inhibitor and regulator of neurotransmission. Digoxin being a steroidal glycoside, is synthesised by the isoprenoid pathway. In view of the reports of elevated digoxin levels in metabolic syndrome X with high body mass index, the isoprenoid pathway mediated biochemical cascade was assessed in individuals with high and low body mass index. It was also assessed in individuals with differing hemispheric dominance to find out the relationship between digoxin status, body mass index and hemispheric dominance. The isoprenoid pathway metabolites, tryptophan / tyrosine catabolic patterns and membrane composition were assessed. In individuals with high body mass index an upregulated isoprenoid pathway with increased HMG CoA reductase activity, serum digoxin and dolichol levels and low ubiquinone levels were observed. The RBC membrane Na+-K+ ATPase activity and serum magnesium levels were decreased. The tyrosine catabolites (dopamine, morphine, epinephrine and norepinephrine) were reduced and the tryptophan catabolites (serotonin, quinolinic acid, strychnine and nicotine) were increased. There was an increase in membrane cholesterol : phospholipid ratio and a reduction in membrane glycoconjugates in individuals with high body mass index. The reverse patterns were seen in individuals with low body mass index. The patterns in individuals with high body mass index and low body mass index correlated with right hemispheric dominance and left hemispheric dominance respectively. Hemispheric dominance and digoxin status regulates the differential metabolic pattern observed in individuals with high and low body mass index.

Endogenous sodium-potassium ATPase inhibition related biochemical cascade in trisomy 21 and Huntington's disease: neural regulation of genomic function.

The isoprenoid pathway related cascade was assessed in trisomy 21 and Huntington's disease. Membrane Na+-K+ ATPase activity, serum magnesium and ubiquinone were decreased while HMG CoA reductase activity, serum digoxin and dolichol levels were increased in both the disorders. There were increased levels of tryptophan catabolites (nicotine, strychnine, quinolinic acid and serotonin) and decreased levels of tyrosine catabolites (dopamine, noradrenaline and morphine) in both trisomy 21 and Huntington's disease. There was an increase in dolichol levels, carbohydrate residues of glycoproteins, glycolipids, total/individual GAG fractions and lysosomal enzymes in both disorders. Reduced levels of ubiquinone, reduced glutathione and free radical scavenging enzymes as well as increased lipid peroxidation products and nitric oxide were noticed in both the disorders. The role of hypothalamic digoxin and a disordered isoprenoid pathway in the pathogenesis of trisomy 21 and Huntington's disease is discussed.