Amino sugars such as galactosamine are hepatotoxic. It has been verified that toxic hepatitis induced by galactosamine is similar to that of CCl4 poisoning, and that both were inhibited by O2* scavengers. Fructosamine results from the union of glucose with the epsilon-amine of lysine. A test for fructosamine quantification is based on nitroblue tetrazolium (NBT) reduction, in which O2- is involved, the reduction being inhibited in the presence of superoxide dismutase (SOD). Given these facts, we attempted to elucidate if galactosamine and glucosamine reduce NBT and if that reduction is inhibited by SOD. This was confirmed. Subsequently, we incubated aminoacids (glycine, lysine, alanine) with glucose and galactose for 7 days and studied the action of the incubation products on NBT, using amino acids and sugars as controls. We found that NBT reduction increases proportionally to the length of incubation time of glucose/galactose with lysine, but not with other amino acids. Reduction of NBT by the Amadori compounds formed is inhibited by SOD. We suggest that oxygen radical generation by Amadori compounds must be taken into consideration as one cause of damage in diabetes of long duration.

Amino Sugars↗

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Gastric pseudotumor.

The authors present a case report of a pseudotumor of the stomach and a brief discussion about this very unusual entity. A 75-year-old female patient was admitted with melena and a large epigastric tumor; she underwent upper gastrointestinal endoscopy, abdominal ultrasound, magnetic resonance imaging, guided needle aspiration and angiography. Preoperative diagnostic hypothesis included a partially thrombosed aneurysm of the splenic artery, pancreatic cystic neoplasm with gastric invasion and pancreatic pseudocyst complicated with hemorrhage. Laparotomy revealed a gastric tumor and the patient was submitted to a radical subtotal Billroth II gastrectomy. Only the pathologic examination revealed the unexpected definitive diagnosis of an organized intramural gastric hematoma. There were no postoperative complications and she remains asymptomatic 10 months after surgery.

Aged↗

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[Alcohol and resistance to infections].

The main defense mechanisms of the human body are described. The essential steps of the immune responses are summarized, emphasising the importance of cytokines, especially II-1, TNF and TGF. Alcohol acts as an immunosuppressor in different ways, namely through suppression of TNF synthesis. The consequence is the appearance of respiratory infections, including pneumonia, tuberculosis, AIDS, infections and cancer of the digestive tract and a status of chronic inflammation which leads to hepatic cyrrhosis.

Ethanol↗

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[Activity of beta-N-acetylglucosaminidase in chronic alcoholic liver disease].

Serum N-acetyl-B-glucosaminidase (NAG) activity was determined in a control group of 76 normal people and in 23 patients with hepatic cirrhosis: 15 non-compensated patients and 8 with compensated chronic liver fibrosis. NAG is significantly increased in the non-compensated group--mean value of 931.67 units vs 637.71 units for the controls (p less than 0.001). There is no significant elevation regarding the compensated group. No significant correlations were observed between NAG activity and hepatic functional tests. In the follow-up of the non-compensated group, NAG activity returned to normal with the clinical improvement; in 7 cases where this goal was not achieved there was elevation of NAG activity, with higher values in photo-systemic encephalopathy.

Acetylglucosaminidase↗

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[Paraquat and diquat: mechanisms of toxicity].

The authors review the mechanisms of paraquat and diquat toxicity. They discuss the generation of multiple toxic active forms of oxygen. The pulmonary concentration of paraquat seems to be due to a mechanism of active concentration, which seems to be used by polyamines and diamines in normal situations. Considerations on therapeutics attempts are made.

Animals↗

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[Relation of thyroid hormones with the total and specific serum activity of N-acetyl-beta-D-glucosaminidase].

Total serum N-acetyl-beta-D-glucosaminidase (NAG), isoenzyme A (labile) and isoenzyme B (stable) activities were determined in euthyroid controls and in thyroid disease. In twenty hyperthyroid individuals total NAG (856.9 +/- 122,676 nmols/h/ml and isoenzyme A (490.3 +/- 93.592) as well as isoenzyme B (361.6 +/- 66,371), were higher than the levels in nineteen hypothyroid [total NAG = 533.105 +/- 97.927 (p less than 0.001); isoenzyme A = 280.263 +/- 61.463 (p less than 0.001); isoenzyme B = 251,580 +/- 50,530 (p less than 0.001)] or in twenty euthyroid [total NAG = 555.55 +/- 75.59 (p less than 0.001); isoenzyme A = 316.85 +/- 55.0 (p less than 0.001); isoenzyme B = 238.95 +/- 39.60 (p less than 0.001)]. Monthly assays were performed in seven hypothyroid and eleven hyperthyroid over the course of their corrective treatment with L-thyroxine (LT4: 0.1-0.2 mg (day) and propylthiouracil (PTU: 0.3-0.4/day), respectively. Total T4 was taken as the criterion for thyroid status. The reduction of hormone activity in seven hyperthyroid was accompanied by a significant decrease in enzyme activity (NAG = p less than 0.02; isoenzyme A = p less than 0.02). Isoenzyme B displayed no significant variation. In four hyperthyroid submitted to treatment with PTU there was no reduction in NAG activity and although T4 came down to normal levels. These patients still displayed symptoms of hyperthyroidism.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetylglucosaminidase↗

PubMedDate not supplied