The cerebrospinal fluid lactate is decreased in early stages of multiple sclerosis

BACKGROUND: The purpose of this study was to investigate if the concentration of lactate can provide additional information for pathologies that need examination of the cerebrospinal fluid (CSF) in their diagnostic controls or protocols. METHODS: A prospective study carried out in the year 2001 at the University Hospital of Bellvitge (Barcelona), on 92 samples of CSF from patients who needed this examination. The concentration of lactate, glucose, and the cell count was determined. One year later, the diagnosis revealed from the previous analyzed samples were sorted into groups according to the diagnosis. RESULTS: In the group with multiple sclerosis (MS) (n = 30), there was a significant decrease in lactate concentration (1.52 +/- 0.19 mmol/L) compared to the control group (1.89 +/- 0.11 mmol/L) (p < 0.001). The glucose concentration remained within the normal range and the cell count was < 4 cell/microL even in the relapses. CONCLUSIONS: In the early stages of MS, the lactate concentration in CSF is decreased and this could be related to alterations in sensitivity observed in those patients. Further studies are needed to evaluate if this lactate concentration is a prognostic indicator of the disease.

Annual rhythmic and non-rhythmic biological variation of magnesium and ionized calcium concentrations.

The annual inter- and intra-individual biological variation, including the circannual rhythmic variation, of the serum concentrations of magnesium and ionized calcium has been investigated in a group of 51 apparently healthy volunteers. Venous blood specimens were collected on intervals of once a month within a one-year period, using a standardized protocol. The inter-individual coefficients of variation were 5.12% for magnesium and 1.58% for ionized calcium. The medians of the intra-individual coefficients of variation were 1.93% for magnesium and 2.18% for ionized calcium. These data were used to determine the allowable imprecision, the allowable systematic error, the critical difference for significant change detection, and the usefulness of population reference values (index of individuality). Of the quantities studied, only the serum concentration of ionized calcium shows a significant annual rhythmic variation (amplitude 1.3%), although this result may be due to the between-run metrological variance, considering that the concentration of ionized calcium of the control material used during the study possesses a similar significant rhythmic variation.

Annual rhythmic variations of follitropin, lutropin, testosterone and sex-hormone-binding globulin in men.

The annual rhythmic variations of the serum concentrations of follitropin, lutropin, sex-hormone-binding globulin and testosterone, the ratio between the serum concentrations of testosterone and sex-hormone-binding globulin, and the salivary concentration of testosterone were investigated in a group of 20 apparently healthy men. Venous blood and salivary specimens were collected at 1-month intervals during 12 months. The annual rhythms were studied by using a periodic function resulting from the sum of three cosine functions with periods of 365, 182.5 and 121.66 days. For the salivary concentration of testosterone and for the ratio between the serum concentrations of testosterone and sex-hormone-binding globulin, only the cosine function with a period of 365 days was significant, and for the serum concentration of lutropin, only the cosine function with a period of 121.66 days was significant. Serum concentrations of follitropin, sex-hormone-binding globulin and testosterone were significantly affected by 365 and 121.66 rhythmic components. The salivary concentration of testosterone and the serum concentration of follitropin are the quantities with the greatest annual rhythmic variation of those studied.

Daily rhythmic and non-rhythmic variations of follitropin, lutropin, testosterone, and sex-hormone-binding globulin in men.

The circadian rhythmic variations of the serum concentrations of follitropin, lutropin, sex-hormone-binding globulin and testosterone, the ratio between the serum concentrations of testosterone and sex-hormone-binding globulin, and the salivary concentration of testosterone were investigated in a group of 13 apparently healthy men. Venous blood and salivary specimens were collected at 4-h intervals over a 24-h period. The circadian rhythms were studied by using a periodic function resulting from the sum of two cosine functions with periods of 24 and 12 h. The serum concentrations of follitropin and lutropin showed no significant rhythmic variations. For the salivary concentration of testosterone and for the ratio between the serum concentrations of testosterone and sex-hormone-binding globulin, only the cosine function with a period of 24 h was significant. Serum concentrations of sex-hormone binding globulin and testosterone were significantly affected by 24- and 12-h rhythmic components. Of the quantities studied, the salivary concentration of testosterone showed the greatest daily rhythmic variation (28.8% of the mean estimated over rhythm).

Within- and between-subject biological variations of follitropin, lutropin, testosterone, and sex-hormone-binding globulin in men.

The within-subject and between-subject biological variation of the serum concentrations of follitropin, lutropin, sex-hormone-binding globulin, and testosterone; the ratio between the serum concentrations of testosterone and sex-hormone-binding globulin; and the concentration of testosterone in saliva have been studied in a group of 20 men during 12 months. The between-subject coefficients of variation (CVs) were 36.0% for follitropin, 37.0% for lutropin, 42.7% for sex-hormone-binding globulin, 21.3% for testosterone in serum, 28.8% for testosterone in saliva, and 51.6% for the ratio between serum concentrations of testosterone and sex-hormone-binding globulin. The medians of the within-subject CVs for the respective analyses and ratio were 17.3%, 24.0%, 12.1%, 10.9%, 17.3%, and 9.4%. These data were used to calculate the desirable imprecision, the critical difference for significant change detection, and the index of individuality.

[Intestinal absorption of glucose in anesthetized rats. I. Standardization of a method for screening of oral hypoglycemic agents]. / Absorção intestinal de glucose em ratos anestesiados. I. Padronização de método para "screening" de drogas hipoglicemiantes orais (DHO).

This paper presents a method for the screening of natural hypoglycaemic drugs that interfere with the intestinal absorption of glucose. Luminal perfusion of the small intestine (whole length) was carried out on 24 h fasted adult Wistar rats, anaesthetized with sodium pentobarbital. Two rubber Nelaton cannulae were introduced into the organ, the first at the proximal end of the duodenum, just after the pylorus and a second larger one near the ileo-cecal valve. After a preliminary washing with warm physiological saline to remove any alimentary residues and secretions, warm saline containing glucose (plain or with added putative absorption inhibitors), was then introduced into the gut. Ten minutes later the contents was expelled with air and the preparation fully washed with plain warm saline. All perfusates were separately collected up to volume in graduated flasks kept in chipped ice. The glucose concentration was measured in triplicate samples by the specific glucose-oxidase method. The intestinal absorption of the sugar was calculated by difference from the glucose concentration found in the initial solution and in the final perfusate. The method is reliable and highly reproducible.