Biochemical evaluation in human saliva with special reference to ovulation detection.

Aim : The aim of the present study was to investigate the level of salivary sialic acids and glycosaminoglycans with reference to salivary hormones during the normal menstrual cycle. Settings and Design: Fifty women volunteers were selected for the present study. Materials and Methods : Saliva was collected from 50 women and ovulation was detected in women with normal menstrual cycles through basal body temperature (BBT), ultrasound and salivary ferning. Samples were divided into five categories, as prepubertal (6-9 years), pre-ovulatory phase (6-12 days), ovulatory phase (13-14 days), postovulatory phase (15-26 days) and menopause (above 45 years). Each sample was subjected to evaluation of the sialic acids and glycosaminoglycans along with salivary hormones. Results : The result revealed that the ovulatory phase has increased sialic acid and glycosaminoglycans during the menstrual cycle when compared with that of the other phases. Consequently, an increased level of hormones such as luteinizing hormone and estrogen during the ovulatory period when compared to that of the pre-ovulatory and postovulatory periods appeared to be noteworthy. Statistically, analysis was performed using one way-ANOVA (LSD; post hoc method) to determine the significance as P < 0.001, 0.01, 0.05 in between the reproductive phases of the menstrual cycle. Conclusion : This study concluded that saliva-specific carbohydrates in the ovulatory saliva make the possibility to develop a biomarker for detection of ovulation by non-invasive methods.

A re-evaluation of plasma sialic acid determination using the periodate resorcinol method versus the enzymatic method.

The concentration of plasma sialic acid was estimated using the modified chemical method and the more sensitive enzymatic method in 20 subjects with impaired glucose tolerance and 20 control subjects. The mean sialic acid concentration values of the control subjects and subjects with impaired glucose tolerance using the enzymatic method were 1.747 +/- 0.047 and 2.583 +/- 0.070 mmole/l and 1.753 +/- 0.067 and 2.591 +/- 1.02 mmole/l for the chemical method. The intra-assay coefficient of variation for the control subjects and for the subjects with impaired glucose tolerance were 1.963% and 1.583%, respectively, for the enzymatic assay and 2.728% and 2.431%, respectively, for the chemical assay. The inter-assay coefficient of variation for the control subjects and for the subjects with impaired glucose tolerance were 2.686% and 2.723% for the enzymatic assay, and 3.819% and 3.95% for the chemical assay. Since the values do not differ significantly, the chemical assay is a cost effective method that can be used in large epidemiological studies.

Alterations and pathology of thalassemic red cells: comparison between alpha- and beta-thalassemia.

Two main types of thalassemia have been categorized according to defective production of the globin gene ie alpha-thalassemia and beta-thalassemia. We report different red cell abnormalities between these two types. The study included 139 thalassemic patients including 91 patients with hemoglobin (Hb) H disease (52 cases with the classical genotype and 39 cases with Hb Constant Spring) and 48 were beta-thalassemia/Hb E disease. The deformability index of thalassemic red cells measured by laser diffractometer was significantly lower than that of normal red cells. Increased susceptibility of the thalassemic red cells to monocyte phagocytosis was markedly noted. Few sialic acid molecules were scattered on red cell surface of thalassemic red cells. Reticulocytes with delayed maturation stage were also observed in thalassemia indicating enhanced release from the bone marrow. The alpha-thalassemic red cells had relatively better deformability, increased susceptibility to phagocytosis, reduced sialic acid content and greater degree irregular distribution of sialic acid on red cell surface as compared to beta-thalassemic red cells. The alpha-type with hemoglobin Constant Spring (Hb CS) had increased percentage of reticulocyte and young reticulocyte (high fluorescent intensity) as compared to beta-thalassemic red cells. The different abnormalities between alpha- and beta-thalassemic red cells may lead to different mechanism of red cell destruction and different severity of the disease.

Sialic acid variants in benign versus malignant colorectal lesions

The histochemical mucin structure of colorectal lesions has been subject to several studies. Some reports relate changes in mucin pattern to the grade of epithelial dysplasia. Alterations in sialomucin with both its O-and N-residues have been described in colonic malignancy. This work was, thus, carried out on 50 benign and malignant colorectal lesions to study the histochemical structure of sialic acid, by applying the PAT/KPH/PAS technique [introducing a counterstain to the original method described] and the mPAS technique for demonstrating the O-and N-acetyl residues respectively. The PAT/KOH/PAS technique was more informative. It gave a spectrum of colours ranging from red through purple to blue, reflecting normal, partial loss and absence of the O-acetyl residue respectively. In contrast, however, were the results of the mPAS technique. Positive cases have shown only scattered foci of mild positivity in the form of pale, red granular deposits. Among all non-neoplastic lesions examined [n = 9], the PAT/KOH/PAS technique gave a red reaction reflecting normal pattern. In adenomatous polyps without atypia [n = 10] 70% gave a normal, red, reaction while in 30% the reaction was purple. Polyps with atypia [n = 12] revealed more loss of O-residue in cases showing atypia. There was also a notable loss of O-residue with higher grades of malignancy. None of the malignant cases examined revealed a normal red reaction [n = 19], while 25% of well, 75% of moderately and 100% of poorly differentiated adenocarcinomas gave a blue mucin reaction. Results confirm higher loss of O-acetyl residue with severe dysplasia and less differentiated malignant tumors of the colon. The PAT/KOH/PAS technique can, thus, be helpful in predicting the outcome of colonic adenoma by assuming that a red colour reaction reflects its benign nature, while a purple to blue reaction implies the danger of malignant transformation. It can also be used in the interpretation of equivocal malignancies in small colonoscopic biopsies

Detection of sialic acid in trophozoites of Entamoeba histolytica (NIH:200).

In two successive experiments detection of sialic acid was achieved from trophozoites of axenically grown E. histolytica (NIH:200) using silicic acid column chromatography for the separation of sialosylated lipids and asialosylated lipids from total lipids. Sialic acid of the sialosylated lipids was detected through thiobarbituric acid assay followed by acid hydrolysis. These findings indicate that presence of sialic acid is not only a character of the cystic stage but also that of trophozoites of E. histolytica. Detection of sialic acid confirmed the electronegative charge of the surface membrane (glycocalyx) of E. histolytica trophozoites.

Differential diagnostic value of sialic acid and L-fructose in pleural effusion

In order to discriminate between malignant, tuberculous pleural effusions and that due to cardiac failure,Sialic acid and L- fucose were determined in pleural fluid and serum in 44 patients; 16 with malignant, 21 with tuberculous effusion and 7 with effusion due to cardiac failure. Serum and pleural fluid levels of Sialic acid were significantly higher in malignant and tuberculous effusions than in those with effusions due to cardiac failure and insignificantly higher in malignant than in tuberculous effusions The levels of L-fucose were significantly higher in malignant effusions than in the other two types of effusion.Pleural fluid concentration of sialic acid showed the highest sensitivty and diagnostic accuracy in differentiating tuberculous effusion from that due to cardiac failure while pleural fluid concentration of L-fucose showed the highest sensitivity and diagnostic accuracy in differentiating malignant effusion from that due to cardiac failure. An obvious overlap in evaluating each of the two markers was observed on comparing malignant and tuberculous effusions. However, it was less marked on comparing either of them with that due to cardiac failure. Because serum and pleural fluid levels of the two markers were highest in malignant effusions, they seem promising in the differential diagnosis of pleural effusion in spite of the overlap with tuberculous effusion

Sialemia en personas aparentemente sanas de la tercera edad / Sialemic in aged people

Se determinó la concentración de ácidos siálicos séricos en 30 personas del sexo masculino aparentemente sanas entre 55 y 75 años de edad y en 80 del sexo femenino cuyas edades estaban entre 50 y 75 años. Lasmuestras de suero se obtuvieron de personas del Hogar Central Iganacia Rodolfo Vda de Canevaro. El método usado para la cuantificación fue el de Ayala, Moore y Hess. En los varones, los ácidos siálicos alcanzan una media de 53,76ñ0,881 mg por ciento y valores extremos de 42-63 mg por ciento. En las mujeres, la media fue 54,08ñ0,639 por ciento y valores extremos de 42-68 mg por ciento.

Ultrastructural and biochemical changes in epididymis and vas deferens of gossypol treated rats.

Adult male Wister rats when administered with 15 mg/kg body weight/day of gossypol acetic acid proved to be sterile by 10 weeks of treatment. The weight of the whole epididymis did not deviate from the controls but when the caput, corpus and cauda epididymidis were considered separately, the cauda epididymidis weight was significantly reduced. The major changes were observed in the motor apparatus of the sperm. The most common defects in the sperm were the vacuolization and complete degeneration of the midpiece mitochondria and plasma membrane. The total LDH activity of caput and cauda epididymidis were within the range of control values. Sialic acid levels of the epididymis were not affected after the treatment. These results suggest a more proximal site of action of the drug than at the epididymal level.

Fucose and sialic acid contents of intestinal microvillus membranes from different animal species.

Fucose and sialic acid contents of intestinal microvillus membranes isolated from different animal species have been analysed. Expressed on protein basis, brush borders from fish contained considerably high amounts of sialic acid (298 +/- 16 nmole/mg protein), while rat, goat, sheep and guinea pig membranes showed 41-61 nmole/mg protein. Pig, frog, monkey rabbit and chicken membranes exhibited low levels of sialic acid (10-13 nmole/mg protein). Fucose content of the brush borders was quite high (203-212 nmole/mg protein) in frog and fish intestines. It was least in rabbit (54 +/- 3) and of intermediate levels (80-122 nmole/mg protein) in various other animal species analysed. Fucose to sialic acid molar ratio was less than 1 in fish microvillus membranes. In all other animal species, the ratio was however, greater than one and ranged between 1.65 and 15.20.

Estudo do ácido siálico em cordöes umbilicais humanos de recém-nascidos a termo, pré-termo e pós-termo / Study of sialic acid in human umbilical cord of term, pre-term and post-term newborn infants

Analisaram-se 30 cordöes umbilicais de recém-nascidos humanos divididos igualmente em funçäo de sua idade gestacional e pela presença ou näo de infiltrado inflamatório, com a finalidade de estudar a presença, concentraçäo e a distribuiçäo do ácido siálico na substância intercelular do tecido conjuntivo. Após o emprego de técnicas histoquímicas adequadas concluiu-se: a) ácido siálico está presente em quantidade variável nos cordöes umbilicais sem infiltrado inflamatório, sendo maior sua concentraçäo nos cordöes umbilicais de recém-nascidos a termo; b) na presença de infiltrado inflamatório, houve acentuada reduçäo de ácido siálico em todos os grupos estudados

Sialic acid in human semen.

Sialic acid of seminal fluid of eighty two human subjects has been studied in relation to infertility. Normozoospermic group had highest sialic acid content (94 mgm/100 ml of the fluid) and was significantly different from other groups. The lowest sialic acid level was observed in necrozoospermic group (54 mgm/100 ml of the fluid). Azoospermic (62 mgm/100 ml) and vasectomised group (73 mgm/100 ml) had 33 and 22 percent less sialic acid level respectively than normozoospermic group. For the pooled observation sialic acid was found to be correlated (r = 0.282, significant at 5 percent level) with the total sperm count.