Activity of N-acetyl-beta-D-hexosaminidase (HEX) and its isoenzymes A and B in human milk during the first 3 months of breastfeeding.

PURPOSE: Milk contains free and bound oligo- and heteropolisaccharides, which protect newborns against pathogens and have nutritional value. N-acetyl-beta-D-hexosaminidase (HEX), the most active lysosomal exoglycosidase, modify and degrade oligo- and heteropolysaccharides. The objective of our study was to determine HEX activity and isoenzymes A and B in the progression of lactation. MATERIAL AND METHODS: Human milk samples were collected from 51 women on the 3rd, 21st and 100th day postpartum. Enzymatic activity was determined the Zwierz et al method modified by Marciniak et al. Protein and lactose concentrations were determined by a MilkoScan 4000 apparatus. RESULTS: The total HEX activity decreased by the 21st day in comparison to the 3rd day, and increased by the 100th day as compared to the 21st day. HEX A activity decreased by the 21st and the 100th day as compared to the 3rd day. HEX B activity decreased by 21st day and has the tendency to decrease by the 100th day as compared to the 3rd day. Protein concentration decreased and the lactose concentration increased in milk taken on the 21st day in comparison to concentration of protein and lactose on the 3rd day. HEX and its isoenzymes' activity significantly correlate with the progression of lactation. At the beginning of lactation, HEX A activity, which releases hexosamines from acidic oligosaccharides, dominates; later, HEX B releases hexosamines from neutral oligosaccharides. CONCLUSIONS: To better understand the degradation of human milk oligosaccharides, it would be useful to investigate and document their detailed structures and evaluate the activity of other exoglycosidases' activity in human breast milk over the course of lactation.

Saliva of patients with Type 1 diabetes: effect of smoking on activity of lysosomal exoglycosidases.

OBJECTIVE: The aim of our study was to evaluate the influence of smoking on the activity of N-acetyl-beta-hexosaminidase (HEX), its isoenzymes A (HEX-A) and B (HEX-B) and beta-galactosidase (GAL), in the saliva of patients with Type 1 diabetes. METHODS: In the supernatant HEX and its isoenzymes A and B, and beta-galactosidase were determined by the method of Chatteriee et al in modification of Zwierz et al (mKat kg(-1) of protein). Protein was determined by the Lowry et al method (mg ml(-1)). RESULTS: The results presented here suggest that diabetes and smoking modify activity of HEX and its isoenzymes, but only combination of diabetes and smoking give a significant increase in the specific activity of HEX and its isoenzymes. CONCLUSIONS: Type 1 diabetes slightly changes the composition of saliva. Smoking cigarettes significantly modifies the composition and properties of saliva in healthy individuals and patients with Type 1 diabetes.

The activity of cancer procoagulant in cases of uterine leiomyomas.

PURPOSE: It is currently believed that cancer procoagulant (CP), an enzymatic protein, is a product of malignant neoplastic cells. The present study was designed to test whether it is also synthesized by benign neoplastic cells, namely uterine leiomyomas. MATERIALS AND METHODS: We determined the activity of CP in the blood serum of women with uterine leiomyomas (N = 24), normal women (N = 15), and genital cancer patients (N = 6) by the coagulative method according to Gordon and Benson. Also, the CP activity in 10% tissue homogenates of uterine leiomyomas, normal uterine muscle and tissues of cervical and endometrial carcinoma was determined by the chromogenic method according to Colucci et al. RESULTS: The mean CP activity in the sera of women with uterine leiomyomas was 181.1 seconds (s) +/- 19.9 s, in healthy women--293.2 s +/- 33.8 s, and in genital cancer patients--78.8 +/- 18.5 s (all differences: p < 0.001). Similarly, in homogenates of uterine leiomyomas the CP activity was 19.6 +/- 3.8 nmoles pNa/ml, in normal uterine muscle it was 13.2 +/- 2.2 nmoles pNa/ml, and in cancerous tissue--28.0 +/- 6.6 nmol pNa/ml (all values being significantly different from each other). There was a strong correlation (r = -0.8122; p < 0.001) between the CP activity in uterine leiomyomas and serum activity, suggesting that the source of the serum CP activity was from the leiomyoma. The coagulation time of 120 to 240 s by the Gordon and Benson method supported the diagnosis of uterine leiomyoma, and a value below 120 s--the suspicion of genital cancer. CONCLUSIONS: Uterine leiomyomas, representing benign genital neoplasia, synthesize CP and are the likely origin of CP activity in blood, as has been described for malignant tumors, but to a lesser degree. There may be a role for CP as a tumor marker of genital neoplasia.