Nonabsorbable marker and single, random stool samples used for measuring intestinal absorption of macronutrients in infants and children

To measure intestinal absorption by using a single, random stool sample, polyethylene glycol (PEG), 1 g/d, and a constant diet were given to healthy infants, with a constant PEG-to-macronutrient ratio. After 10 d equilibration, apparent intestinal absorption of macronutrients was estimated from a standard 3-d metabolic balance and compared with that estimated by using the ratio of PEG to macronutrients in a single random sample of feces. Correlation coefficients for this comparison were 0.649, 0.715, and 0.924 for nitrogen, carbohydrate, and fat, respectively. Additionally, apparent intestinal absorptions estimated from two separate consecutive 3-d metabolic-balance studies were compared, showing correlation coefficients of 0.106, 0.653, and 0.463 for nitrogen, carbohydrate, and fat, respectively. The random sample-marker technique appears to be acceptable for measuring apparent absorption of macronutrients and is at least as accurate as a standard 3-d metabolic-balance study.     

Effects of heterozygosity for the E180 splice mutation causing growth hormone receptor deficiency in Ecuador on IGF-I, IGFBP-3, and stature.

CONTEXT & OBJECTIVE: The Ecuadorian GH receptor deficiency (GHRD)/Laron syndrome population is the only large cohort with a single GHR mutation (E180 splice), permitting identification of numerous carrier and noncarrier first-degree relatives, to ascertain effects of heterozygosity on GH-dependent IGF-I and IGFBP-3 concentrations and on growth. DESIGN: First-degree relatives (n=212) of GHRD patients had specimens taken for IGF-I, IGFBP-3, and GHR genotyping. Normal statured (n=40) and short statured (n=40) unrelated controls had measurement of IGF-I, IGFBP-3, and stature. RESULTS: There were no significant differences between heterozygous and homozygous normal relatives in IGF-I or IGFBP-3 standard deviation scores (SDS). Heterozygous relatives had lower mean height SDS than did homozygous normals, but with extensive overlap between genotype groups in both child and adult relatives. Height SDS in general did not relate to IGF-I or IGFBP-3 concentrations. CONCLUSIONS: GH-dependent IGF-I and IGFBP-3 secretion is not affected by heterozygosity for the E180 splice mutation that causes GHRD/Laron syndrome in the Ecuadorian population. Heterozygosity is associated with reduction in mean statural SDS, but this is not sufficient to be clinically important and not mediated through measurable differences in circulating IGF-I or IGFBP-3 related to genotype.     

Postmenopausal Women With Colles'' Fracture Have Lower Values of Bone Mineral Density Than Controls as Measured by Quantitative Ultrasound and Densitometry

Measurement of ultrasonographic parameters provides information concerning not only bone density but also bone architecture. We investigated the usefulness of ultrasonographic parameters and bone mineral density (BMD) to evaluate the probability of Colles' fracture. Two-hundred eighty-nine postmenopausal women (62.3 +/- 8.7 yr) with (n = 76) and without (n = 213) Colles' fracture were studied. BMD of lumbar spine and proximal femur was evaluated in all women by dual-energy X-ray absorptiometry (DXA) and speed of sound (SOS), broadband ultrasound attenuation (BUA), and stiffness in the calcaneus were measured by a Sahara ultrasonometer (Hologic). Patients suffering from Colles' fracture had lower values of BMD adjusted by height at the lumbar spine, L2-L4 (0.797 g/cm2 vs 0.860 g/cm2), femoral neck (0.685 g/cm2 vs 0.712 g/cm2 ), SOS (1518 m/sg vs 1525 m/sg), and stiffness (74.6 vs 77.7) (p < 0.05). Nevertheless, BUA values were similar in both groups. After stepwise logistic regression analysis, the area found under receiver operating characteristic (ROC) curves was 0.60 for L2L4 and 0.63 for a formula combining L2L4 and height. Our data suggest that patients suffering from Colles' fracture have lower values of BMD by DXA, SOS, and stiffness. However, the ability of these techniques to discriminate is low because the values for the area under ROC curve are 0.60 for L2-L4 and 0.63 for a formula derived of the combination of L2-L4 and height.     

Astroglial alterations in rat hippocampus during chronic lead exposure.

The present study was performed in order to follow the response of astroglial cells in the rat hippocampus to chronic low-level lead exposure. The experiments combined immunohistochemistry using anti-glial fibrillary acidic protein (GFAP) antibody and conventional transmission electron microscopy (EM). Chronic administration with drinking water [1 g% w/v (subclinical dose) of lead acetate dissolved in distilled water] was started through the mother's milk when pups were 7 days old. Following weaning, experimental offspring were treated for 3 months with the same concentration of adulterated water. The group of intoxicated animals and their controls were sacrificed by perfusion-fixation at 30, 60, and 90 days of exposure. After 60 days of lead treatment, staining of GFAP-positive cells demonstrated an astroglial transformation from the quiescent to the reactive state, characterized by an increase in GFAP. In control rats no changes in GFAP immunostaining were observed. The intensity of the astroglial response was enhanced after 90 days of lead intoxication, showing an increment of GFAP immunoreactivity. Quantification of these changes was made by computerized image analysis, confirming that the sectional areas of the astroglia in lead-exposed animals were larger than those in controls. These results are consistent with the ultrastructural alterations. Simultaneously with the increment in gliofilaments, intranuclear inclusions were seen in some astrocytes. The mechanisms by which lead affects astrocytes are unknown. Probably the astroglial changes induced by lead intoxication produce microenvironmental modifications that may disturb the neuronal function.     

Relationship between digestive and killing abilities of neutrophils against Paracoccidioides brasiliensis.

Peripheral blood neutrophils (PMN) from patients with paracoccidioidomycosis killed and digested Paracoccidioides brasiliensis much less than did PMN from normal individuals or from patients with other diseases. However, deficiency in killing ability was less specific than digestive deficiency and correlated poorly with it. We conclude that the capacities of PMN to digest and kill P. brasiliensis are not intimately related phenomena, and that in paracoccidioidomycosis the key deficiency of neutrophil function is that of digestion of P. brasiliensis.     

Carcinogenesis in rats by nitrosodialkylureas containing methyl and ethyl groups given by gavage and in drinking water

The carcinogenic effects in male and female F344 rats of four nitrosodialkylureas containing methyl or ethyl groups have been compared by two modes of administration, gavage in oil solution or dissolved in drinking water. Weekly doses of 20 and 40 mumol were given to each rat by either route and treatment lasted usually 30 wk, resulting in a total dose per rat of 0.6 or 1.2 mmol. Nitrosodimethylurea and nitroso-1-methyl-3-ethylurea gave rise primarily to tumors of the nervous system, whereas nitrosodiethylurea and nitroso-1-ethyl-3-methylurea gave rise to tumors of the mammary gland, lung, intestinal tract, nervous system, and testicular mesotheliomas. The effect of nitrosodimethylurea was weaker than that of the other three compounds, as measured by rate of mortality with tumors. Drinking water treatment was less effective than treatment by gavage, by the same criterion. The tumorigenic effects paralleled those of the corresponding monoalkylnitrosourea, suggesting the presence in the target organs of receptors for which ethylnitrosoureas or methylnitrosoureas, respectively, have affinity.     

Common bile duct calculi: updated experience with dissolution with methyl tertiary butyl ether

The authors describe their experience with methyl tertiary butyl ether (MTBE) in a larger series of patients than previously reported in order to acquaint physicians with both its effectiveness for dissolution of common bile duct calculi and the limitations of its use. Ten patients with 13 biliary calculi underwent percutaneous stone dissolution treatment with the experimental cholesterol solvent, MTBE. Three stones completely dissolved within 30 minutes, seven were reduced in size, and three were visibly unaffected. All stones not completely dissolved were easily extracted by means of a stone basket except for one in a patient taken to surgery. Although MTBE perfusion is an effective technique for management of biliary calculi, practitioners should be aware that its use is quite time consuming and its odor difficult to control.     

Analgesia produced by intrathecal administration of the kappa opioid agonist, U-50,488H, on formalin-evoked cutaneous pain in the rat

The antinociceptive activity of the selective k opioid agonist U-50,488H, given intrathecally (i.t.) against chemically induced cutaneous pain in rats, was assessed from cumulative dose-response experiments and the formalin test. Three successive i.t. doses of 5, 10 and 35 nmol of U-50,488H produced a gradual reduction of pain scores which was statistically significant at all observation periods. This effect was antagonized significantly by 3 mg/kg i.p. of the opiate antagonists, naloxone and WIN 44,441-3. The analgesia profile showed a clear dose-response relationship. A dose producing 50% ‘maximum posible analgesia’ of 6.20 nmol (95% confidence interval: 3.05–12.59 nmol) was calculated. The results indicated that cutaneous pain of a chemical/inflammatory nature is highly sensitive to activation of k receptors of the spinal cord dorsal horn.     

Axonal transport of dopamine D1 receptors in the rat brain

Binding of a specific dopamine D₁ receptor antagonist,¹²⁵I-SCH 23982, was measured in rat brain sections by quantitative autoradiography at various time intervals, following a knife cut through the striatonigral pathway. Twenty-four hours after lesioning, accumulations of D₁ receptor binding sites were found in sagittal sections both rostral and caudal to the lesion site. No other regions studied (caudate-putamen, nucleus accumbens, olfactory tubercle, and substantia nigra pars reticulata) showed any change in D₁ receptor binding 24h after the lesion. In brain sections obtained 10 days after lesioning, only the substantia nigra pars reticulata had a significant decrease in D₁ receptors ipsilateral to the lesion. These findings suggest the possibility of a presence of bidirectional axonal transport of D₁ receptors in rat striatonigral pathway.     

Segmental intestinal muscular thinning: a possible cause of intestinal obstruction in the newborn

Intestinal obstruction proximal to a transition zone without an interposed physical barrier usually indicates Hirschsprung disease. The authors report one case of focal small bowel muscular thinning just distal to a transition zone that produced clinical and radiographic findings that simulated long-segment Hirschsprung disease in a 2-day-old infant.