[Effect of oral and intramuscular vitamin K on the factors II, VII, IX, X, and PIVKA II in the infant newborn under 60 days of age]

BACKGROUND

Neonates on exclusive breast feeding that do not receive vitamin K at birth are at higher risk hemorrhagic disease of the newborn.

AIM

To compare the effect of oral or intramuscular administration of vitamin K1 (VK1), on clotting factors II, VII, IX, X and PIVKA II, in children until the 60 days of age with exclusive breast feeding or mixed feeding.

PATIENTS AND METHODS

Forty healthy full term infants, distributed in two groups, A: 20 with mixed feeding (formula-feeding and breast-feeding) and B: 20 with exclusive breast feeding, were studied. Nine infants of each group received 1 mg of VK1 intramuscularly and eleven 2 mg VK orally 5 ml of cord blood was collected initially from each infant. Venous blood samples were taken on 15, 30 and 60 days of age.

RESULTS

All factors increased in a progressive form reaching levels over 50% at 60 days of age, in both groups. PIVKA II decreased significantly during the study period (p < 0.01). Factor II increased more in children with mixed feeding that received intramuscular vitamin K, than in the rest of study groups. No other differences between groups were observed. No infant had an abnormal bleeding during the study period.

CONCLUSIONS

Oral administration of vitamin K is as effective as the intramuscular route in the prevention of the hemorrhagic disease of the newborn.

[Effect of stress electrocardiogram on platelet function, concentration of von Willebrand factor and fibrinogen in hypertensive patients and healthy subjects]

The aim of the present study was to investigate the effect of the treadmill electrocardiogram (TMECG) on thrombotic risk factors in hypertensive patients and normal individuals. Twenty patients, 10 males and 10 females between 40 and 55 years of age, were studied and twenty normal persons of matching sex and age were chosen as controls. Blood samples were obtained before and immediately after the TMECG. Platelet counts and function as well as fibrinogen and von Willebrand factor (vWF) levels were determined in each sample. A significant increase in platelet number and aggregation with collagen and ristocetin was observed in all groups after the TMECG. Fibrinogen and von Willebrand factor levels were also significantly increased in all individuals. It is known that platelets play an important role in the formation of thrombi and the enhancement in their number and activity, in certain circumstances, might favor the development of a thrombotic episode. Elevated fibrinogen concentrations are considered an independent cardiovascular risk factor. The above changes in patients with other predisponent factors for cardiovascular events, such as arterial hypertension, enhances the possibility of a vasooclusive episode. It is recommended therefore, that before suggesting a physical activity to a hypertensive patient, other parameters, such as age, previous training and the existence of other cardiovascular risk factors should be considered.

[Prevalence of the activated protein C resistance in indigenous and Black populations of the western Venezuela]

The Activated Protein C Resistance (APCR) is the common phenotype of Factor V Leiden (arg506gln), which is considered as a thrombotic risk factor. The aim of this study was to determine the prevalence of APCR and its association with Factor V Leiden in indian and black populations from Zulia State in western Venezuela. Blood samples were taken from 80 Yukpa indians from Sierra de Perijá and 91 black individuals from the southeast of Lago de Maracaibo. APCR was determined by the Dahlback's method with the modifications of Jorquera et al. and Trossaert et al. The results were expressed as n-APC-SR (positive value < or = 0.75). Factor V Leiden genotype was identified by PCR and restriction analysis standard methods at the Institute of Human Genetics (Greifswald, Germany). No significative difference was found between n-APC-SR from indians (mean +/- SEM 1.13 +/- 0.02, CI 95% = 1.07-1.19) and black people (1.07 +/- 0.02, CI 95% = 1.03-1.12). APCR prevalence from indians was 1.25% (1 out of 80) who was heterozygote case for F V Leiden and 4.4% (4 out of 91) from blacks (one case was heterozygous for F V Leiden). No thrombotic event personal or familial was demonstrate. Our data represent the first report related to the association between APCR and F V Leiden in venezuelan indian and black individuals. APCR without the Factor V Leiden expression suggest a different type of mutation in the Factor V molecule. In spite of high endogamy in the indian group, we can not discard the role of foreign genes in both populations. The determination of the prevalence of this phenotype and its molecular marker in various ethnic groups is important for the interpretation of their role as risk factors for thrombotic disease.

[Anemia in indigenous population of the West of Venezuela]

The purpose of the study was to investigate the frequency of nutritional anemia among western venezuelan indians. Three hundred and ninety nine Yucpa indians from the communities of Aroy, Marewa and Peraya were studied. The concentrations of hemoglobin, serum iron, total iron binding capacity, serum ferritin, serum folate and serum vitamin B12 and the frequency of anemia and nutrient deficiency were determined. Anemia was found in 71.7% of people from Aroy, 52.25 from Marewa and in 74.4% from Peraya. No nutrient deficiencies were found in 48.1% of cases with anemia, while iron deficiency anemia was present in 39% of the population studied, and folate and or vitamin B12 deficiency were associated with anemia in only 12.9% of cases. The high frequency of anemia, unrelated to nutrient deficiency, among the Yucpa indians, is attributed to the prevalence of chronic infectious diseases such as hepatitis and parasitic infections, as well as skin and respiratory infectious processes.

Prevalence of anemia, iron, folic acid and vitamin B12 deficiency in two Bari Indian communities from western Venezuela

The hematological status of 406 Bari indians from two communities was studied. One hundred and seventy nine individuals were from Campo Rosario a village located in a low arid plain south to the Perijá mountain range and 287 were from Saimadoyi, a fertile valley in the heart of the mountain. Anemia was found in 54% and 31% of the people from Campo Rosario and Saimadoyi respectively. Low serum iron was present in 28% of the population in both communities while low serum ferritin levels were encountered in 20% of the population from Campo Rosario and 5% of the people from Saimadoyi. A high prevalence of serum folate and vitamin B12 deficiency (91% and 64% respectively) was found in Campo Rosario, in contrast only 5% of the population from Saimadoyi had low folate and none were vitamin B12 deficient. While there was a positive significant correlation between hemoglobin and serum iron concentrations (r = 0.517, p < 0.001), no significative correlation was found between the other parameters studied. The high prevalence of anemia and nutrient deficiency among the Bari indians, can be attributed to inadequate diets and the varied diseases encountered in the population.

[Hemoglobin and nutrient concentration in middle-class adolescents. Relationship with school performance]

Concentrations of hemoglobin and serum nutrients that participate in the erythropoiesis (iron, folic acid and vitamin B12) were studied in 213 adolescents (112 male, 101 female) belonging to a medium income group that assisted at a private secondary educational institution. The purpose of the present work was to observe the hematologic and nutrient status in this group and its relationship with the academic achievement. The level of academic performance was determined using the Final mean grades (0 to 20 points scale) and the Academic Achievement index (A.A.I.) calculated as the ratio of approved courses over the total. A high prevalence of iron (16.6%) and folate (14.2%) deficiency was found in the total group with predominance in the female adolescents. It was noted a relationship between anemic men and A.A.I. (p < 0.05) and no other difference was observed between individuals with nutritional deficiency and their academic achievement. Therefore, when it was established as cut-off point 20 micrograms/L for ferritin, a good correlation was found between iron status and academic achievement index (r = 0.411, p < 0.01). The hematologic and biochemical data were correlated with academic parameters. A positive correlation was obtained between A.A.I. and hemoglobin, total iron binding capacity (TIBC) in males. When using Final mean grades, a positive correlation was shown with folic acid (males) and vitamin B12 (females). This work reveals a high incidence of iron and folate deficiency, specially in the female adolescent group. These findings may be due to a inadequate dietary intake combined with an increase of nutritional requirements and probably parasitic infestation. These factors may contribute to an impairement of the academic achievement. It will be important the assessment of iron and folate status of the adolescent for the normal and integral development of his cognitive and psychomotor functions.

Platelet function in patients with lupus anticoagulant and thrombosis

In a group of 337 patients with a history of thrombotic episodes, pregnancy losses and/or thrombocytopenia, 66 cases of lupus anticoagulant (LA) were found. Spontaneous platelet aggregation and the aggregatory responses of platelet rich plasmas (PRP) from 14 patients, with a history of thrombotic episodes, with anticardiolipin (ACA) levels above 21 IgG antiphospholipid antibodies units and normal platelet counts were studied and compared with those of 8 patients with history of thrombosis and negative LA and ACA (controls). Epinephrine, adenosine diphosphate, collagen and ristocetin were used as platelet aggregation inducers. Early collagen-whole blood interaction (BASIC WAVE), as a measure of platelet recruitment, and the levels of von Willebrand factor were also determined. The results of each test were compared with those of nine patients, used as controls, with thrombotic antecedents but negative LA and ACA. None of the patients with LA, or the control group, showed spontaneous platelet aggregation. The aggregatory responses, when epinephrine, ADP or collagen were added to the patient's PRP, were within normal range in most cases (64.2%, 52% and 72% respectively). The highest rate of hyperaggregation after the above mentioned inducers, was 12% and corresponded to the response to collagen. On the contrary, platelet aggregation rate with ristocetin was higher than 100% in 61.0% of the problem group, with no significative difference from the controls. The BASIC WAVE was of low rate and similar in the two groups studied. The von Willebrand factor was significantly higher (150 +/- 55%) in the problem group than in the controls (98 +/- 25.6%) (p < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

[Genetic influence on energy requirements. I. Development of an experimental model]

In attempting to explore the mechanisms of interaction of genetic and environmental factors that affect the quantitative requirements of energy by man, the convenience of an animal model was considered and searched for. The idea was to start with male and female Wistar rats and through inbreeding segregate the highly effective users of energy from the poor users. The efficiency of dietary energy utilization was measured by the index of conversion (IC) defined as the dietary intake necessary to increase 1 g of body weight in a 32-day period, from day 21st to day 52nd of extrauterine life. The median value of the IC for all animals included in each experiment was the cut-off point to classify each individual as a good or a poor energy user. The first generation had three males and five females with a median IC = 2.90 and a range from 2.54 to 3.25. The proportion of males below the median was 3/3 while the proportion of females was 2/5. The difference in proportions was striking and led immediately to the consideration of a sex-link hypothesis, and to test it the, IC of 91 Wistar rats randomly selected at birth was obtained. The median value of the series was 2.99 with a range from 2.24 to 3.95. The proportion of male rats with values below the median was 33/38 while the corresponding proportion for females rats was 13/53. In other words, while nine of every ten male animals were good users of energy, only two out of ten females fell into this category.(ABSTRACT TRUNCATED AT 250 WORDS)

Association of pancreatic biotinidase activity and intestinal uptake of biotin and biocytin in hamster and rat

Pancreatic biotinidase activity was higher in hamster than in rat; these results were reversed in plasma. Uptake was studied in everted intestinal rings. Saturation kinetics at 37 degrees C were observed for biotin in hamster and for biocytin in rat, with a Vmax of 1.83 and 1.05 nmol min-1 ml-1 and an apparent Kt of 25.14 and 40.7 microM, respectively. Biotin uptake by hamster intestine was reduced at 4 degrees C and when choline or potassium replaced sodium; it was inhibited by biocytin only at very high concentrations. Biocytin uptake in the rat was small compared to passive diffusion and was not influenced by sodium or temperature; it was not inhibited by biotin. We observed only passive diffusion of biotin in rat and of biocytin in hamster. Our results suggest that protein-bound biotin may be absorbed mainly in its free form in the hamster. In the rat, on the other hand, at least part of the dietary biotin may be absorbed lysine-bound, as biocytin.