摘要:

ExtractThe lipid composition of erythrocytes, obtained from the cord blood of prematurely born, low birth weight infants, was compared with that obtained from term infants. Infants weighing less than 1,200 g at birth had increased total lipids, lipid phosphorus (P), and cholesterol per cell (total lipid = 7.60 ± 10-10mg; lipid P = 1.80 ± 10-11mg; cholesterol = 2.10 ± 10-10mg) when compared with controls (total lipid = 6.45 ± 10-10mg; lipid P = 1.54 ± 10-11mg; cholesterol = 1.79 ± 10-10mg). The lipid content per 100 ml packed cells and the percentageF of total lipid as phospholipid and cholesterol did not differ significantly over the range of birth weights studied. Phospholipid fractionation showed a higher percentage of phosphatidyl choline in infants under 1,200 g birth weight (30.0% of total lipid P) than that noted in term infants (27.7% of total lipid P). The higher levels of combined phosphatidyl serine and phosphatidyl inositol noted in term infant erythrocytes (compared with normal adult cells) were observed in the low birth weight infants. Fatty acids esterified to phos-pholipids showed an increasing percentage of oleic acid with decreasing birth weight (infants of less than 1,200 g had 16.0% total fatty acid; infants of more than 2,500 g had 11.9% total fatty acid).SpeculationThese studies suggest that the earliest embryonic erythrocytes have the greatest membrane lipid content although the overall membrane lipid distribution does not vary greatly during fetal life.

ISSN:0031-3998    

出版商:OVID    

年代:1971

数据来源: OVID

摘要:

ExtractFibroblast cultures from skin biopsy specimens of a girl with type II glycogenosis showed less than 5% of control activity of lysosomal acid α-glucosidase. These cells showed numerous intracellular vacuoles that resembled the abnormal lysosomes found in liver and other tissues of the patient. Their characteristic ultrastructural abnormality was seen in fibroblast and epithelial cells of the primary cultures and thereafter in all the subcultures of which to date eight passages have been examined. Control fibroblast cultures did not contain such inclusions.SpeculationDemonstration of the disease-specific ultrastructural abnormality indicates the usefulness of fibroblast cultures to study pathophysiology and potential treatment in type II glycogenosis. In addition, fibroblast cultures of other lysosomal diseases may serve a similar purpose.

ISSN:0031-3998    

出版商:OVID    

年代:1971

数据来源: OVID

摘要:

ExtractPregnant sheep of 110–140 days' gestation were used to determine the effect of intravascular coagulation in the mother upon her fetus and the effect of intravascular coagulation in the fetus upon its mother. Because fetal lambs can be delivered and left attached to the mothers via the umbilical cord without placental separation, coagulation studies on a mother and her corresponding fetus could be done simultaneously. When intravascular coagulation was induced in the mothers by administering thromboplastin infusions intravenously, the attached fetal lambs also developed intravascular coagulation with decreased levels in platelets, fibrinogen, and factor V, and prolongation of prothrombin, thrombin, and partial thromboplastin times. When intravascular coagulation was induced in fetal lambs, the dam had a drop in platelet count, a minimal drop in fibrinogen levels, and the appearance of fibrin breakdown products in serum and urine.The factor or factors that crossed the placenta initiating this transfer of coagulation abnormalities are not known. It has been demonstrated that the transfer was not due to fibrin or fibrinogen breakdown products, nor to the infused thromboplastin, and that the trauma of surgery or hypoxia did not contribute to the coagulation abnormalities. The mothers consistently developed fibrin breakdown products in the serum and urine when intravascular coagulation was induced. This was in contrast to the results observed in fetal lambs, which, with one exception, did not show evidence of fibrin breakdown products in serum or urine under identical experimental conditions. These observations suggest the fibrinolytic system of the fetus is inefficient compared with that of the adult; this could be a considerable disadvantage in the presence of intravascular coagulation.SpeculationAs a result of intravascular coagulation in the mother or the fetus a stimulus is produced on the opposite side of the placental barrier resulting in similar changes in the placental partner. This mechanism may be of significance in the etiology of fetal death in eclampsia.

ISSN:0031-3998    

出版商:OVID    

年代:1971

数据来源: OVID

摘要:

ExtractMinced samples of brown and white adipose tissue from young rats were incubated with various lipolytic agents. Both tissues responded well to norepinephrine (10 μg/ml buffer), theophyllin (2.5 or 5 mg/ml), and dibutyryl cyclic adenosine monophosphate (AMP) (10-3M) by releasing glycerol. Brown adipose tissue from newborn rats and rats older than 20 days was responsive to both glucagon and adrenocorticotropic hormone (ACTH) (10 μg/ml), but between days 2 and 20 did not react to these hormones. Responsiveness of brown adipose tissue to ACTH could be induced prematurely by injecting 5 mg cortisone acetate/100 g body weight on days 8 and 9. Such injections also enhanced the response to ACTH 30 days later. Subcutaneous white adipose tissue became responsive to glucagon after day 18 but later in life did not react to this hormone. Ovarian and epididymal adipose tissues, however, showed an increase in responsiveness to glucagon.SpeculationOur results indicate that there are some basic differences in the responsiveness to lipolytic agents not only between brown adipose tissue and white subcutaneous tissue but also between those tissues and epididymal and ovarian fat. It appears that a developmental approach to explain these differences might clarify the mechanisms responsible for differences in the responsiveness of the adenyl cyclases of the various tissues studied.

ISSN:0031-3998    

出版商:OVID    

年代:1971

数据来源: OVID

摘要:

ExtractIn rats, supplied with an adequate dietary intake of magnesium, the mean fetal magnesium concentration in plasma was 2.4 mEq/liter compared with a maternal concentration of 1.6 mEq/liter. Equilibrium dialysis experiments resulted in a disappearance of the fetal to maternal gradient, with maternal levels becoming slightly higher than fetal levels. Determination of ultrafiltrable magnesium concentrations also demonstrated a slightly lower binding capacity for magnesium in fetal plasma so that the fetal to maternal gradient reflected the unbound magnesium.When a diet containing magnesium in a concentration of 0.88 mEq/kg (compared with a control diet containing 120 mEq/kg) was introduced on day 2 of gestation, only one of eight pregnant rats bore a litter to term. If the diet was introduced on day 10 of gestation, pregnancy continued until term but there was an increased resorp-tion rate and the surviving fetuses were small, weak, and anemic. Analyses of maternal muscle for magnesium, calcium, sodium, and potassium revealed normal concentrations, even though magnesium concentrations in plasma rapidly fell to 20% of the normal level. There appeared to be a reduction in bone magnesium. The significant changes in the fetus were a reduction in magnesium levels in plasma with a disappearance of the fetal to maternal gradient and an elevation in sodium levels. Analysis of the total fetus demonstrated a reduction in magnesium and potassium and an increase in calcium concentrations. The last was also evident in the placenta.Speculation“Fetal parasitism” as a general concept appears to be. an over-simplification which can be denned with accuracy only by the study of deprivations of specific nutrients, and eventually by the interaction of such nutrients.

ISSN:0031-3998    

出版商:OVID    

年代:1971

数据来源: OVID

摘要:

ExtractA case study of a 14-year-old female child who developed normally for 18 months but subsequently deteriorated rapidly in mental status and social behavior is reported. Histochemical studies of tissues removed at biopsy from liver, skin, and bone marrow showed changes similar to those found in the Hurler syndrome. Ultrastructural changes of the liver were also similar to those found in the above syndrome with the exception of the presence of mitochondrial crystalloids not observed to date in the Hurler disease. Heparitin sulfate constituted the bulk of the acid mucopolysaccharides in the urine with only traces of chondroitin sulfate B present. In view of these observations and the lack of clinical and radiological findings generally associated with the Hunter and Hurler syndromes the diagnosis of Sanfilippo disease was made.SpeculationOn the basis of the finding that the pattern of acid mucopolysaccharide (AMPS) excreted in urine in our patient differed from that of 12 other children with Sanfilippo disease [12], it is speculated that two subtypes of this disease exist characterized by different patterns of excretion of the AMPS in urine. Whether this difference will prove to be extended to other manifestations is not known at present, but it is conceivable that the difference in radiological findings (in our case minimal and nonspecific, in other cases resembling those of the Hurler and Hunter syndromes), degree of mental retardation, or morphological features, may parallel these biochemical differences. It would be important, therefore, to study other children with Sanfilippo disease in detail, to determine whether other variables are consistent with varying patterns of excretion of AMPS in urine.

ISSN:0031-3998    

出版商:OVID    

年代:1971

数据来源: OVID