Pregnancy rate and reproductive hormones in humpback whale blubber: Dominant form of progesterone differs during pregnancy.

To better understand reproductive physiology of humpback whales Megaptera novaeangliae that reside in Hawai'i and Alaska, enzyme immunoassays were validated for both progesterone and testosterone in free-ranging and stranded animals (n = 185 biopsies). Concentrations were analyzed between different depths of large segments of blubber taken from skin to muscle layers of stranded female (n = 2, 1 pregnant, 1 non-pregnant) and male (n = 1) whales. Additionally, progesterone metabolites were identified between pregnant (n = 1) and non-pregnant (n = 3) females using high pressure liquid chromatography (HPLC). Progesterone concentrations were compared between juvenile (i.e., sexually immature), lactating, and pregnant females, and male whales, and pregnancy rates of sexually mature females were calculated. Based on replicate samples from ship struck animals collected at 7 depth locations, blubber containing the highest concentration of progesterone was located 1 cm below the skin for females, and the highest concentration of testosterone was in the skin layer of one male whale. HPLC of blubber samples of pregnant and non-pregnant females contain different immunoreactive progesterone metabolites, with the non-pregnant female eluate comprised of a more polar, and possibly conjugated, form of progesterone than the pregnant female. In females, concentrations of progesterone were highest in the blubber of pregnant (n = 28, 28.6 ± 6.9 ng/g), followed by lactating (n = 16, 0.9 ± 0.1 ng/g), and female juvenile (n = 5, 1.0 ± 0.2 ng/g) whales. Progesterone concentrations in male (n = 24, 0.6 ng/g ± 0.1 ng/g) tissues were the lowest all groups, and not different from lactating or juvenile females. Estimated summer season pregnancy rate among sexually mature females from the Hawai'i stock of humpback whales was 0.562 (95 % confidence interval 0.528-0.605). For lactating females, the year-round pregnancy rate was 0.243 (0.09-0.59), and varies depending on the threshold of progesterone assumed for pregnancy in the range between 3.1 and 28.5 ng/g. Our results demonstrate the synergistic value added when combining immunoreactive assays, HPLC, and long-term sighting histories to further knowledge of humpback whale reproductive physiology.

ATP depletion, a possible role in the pathogenesis of hyperuricemia in glycogen storage disease type I.

Other investigators have shown that fructose infusion in normal man and rats acutely depletes hepatic ATP and P(i) and increases the rate of uric acid formation by the degradation of preformed nucleotides. We postulated that a similar mechanism of ATP depletion might be present in patients with glucose-6-phosphatase deficiency (GSD-I) as a result of ATP consumption during glycogenolysis and resulting excess glycolysis. The postulate was tested by measurement of: (a) hepatic content of ATP, glycogen, phosphorylated sugars, and phosphorylase activities before and after increasing glycolysis by glucagon infusion and (b) plasma urate levels and urate excretion before and after therapy designed to maintain blood glucose levels above 70 mg/dl and thus prevent excess glycogenolysis and glycolysis. Glucagon infusion in seven patients with GSD-I caused a decrease in hepatic ATP from 2.25 +/- 0.09 to 0.73 +/- 0.06 mumol/g liver (P <0.01), within 5 min, persisting in one patient to 20 min (1.3 mumol/g). Three patients with GSD other than GSD-I (controls), and 10 normal rats, showed no change in ATP levels after glucagon infusion. Glucagon caused an increase in hepatic phosphorylase activity from 163 +/- 21 to 311 +/- 17 mumol/min per g protein (P <0.01), and a decrease in glycogen content from 8.96 +/- 0.51 to 6.68 +/- 0.38% weight (P <0.01). Hepatic content of phosphorylated hexoses measured in two patients, showed the following mean increases in response to glucagon; glucose-6-phosphate (from 0.25 to 0.98 mumol/g liver), fructose-6-phosphate (from 0.17 to 0.45 mumol/g liver), and fructose-1,6-diphosphate (from 0.09 to 1.28 mumol/g) within 5 min. These changes, except for glucose-6-phosphate, returned toward preinfusion levels within 20 min. Treatment consisted of continuous intragastric feedings of a high glucose dietary mixture. Such treatment increased blood glucose from a mean level of 62 (range 28-96) to 86 (range 71-143) mg/dl (P <0.02), decreased plasma glucagon from a mean of 190 (range 171-208) to 56 (range 30-70) pg/ml (P <0.01), but caused no significant change in insulin levels. Urate output measured in three patients showed an initial increase, coinciding with a decrease in plasma lactate and triglyceride levels, then decreased to normal within 3 days after treatment. Normalization of urate excretion was associated with normalization of serum uric acid. We suggest that the maintenance of blood glucose levels above 70 mg/dl is effective in reducing serum urate levels and that transient and recurrent depletion of hepatic ATP due to glycogenolysis is contributory in the genesis of hyperuricemia in untreated patients with GSD-I.

Calcium-regulated biosynthesis of the parathyroid secretory protein, proparathyroid hormone, and parathyroid hormone in dispersed bovine parathyroid cells.

Dispersed bovine parathyroid cells were incubated in vitro with 3H-labeled amino acids for 30--120 min. Analysis of cell extracts by sodium dodecyl sulfate-urea-polyacrylamide gel electrophoresis revealed a calcium-regulated incorporation of 3H-labeled amino acids into three major peaks, one with a molecular weight (Mr) of 70,000 and two peaks in the 10,000 Mr region, and a minor 5,000 Mr peak. Furthermore, [3H]mannose was incorporated into the 70,000 Mr peak, which corresponds to the parathyroid secretory protein (PSP) recognized as a glycoprotein. The two peaks in the 10,000 Mr region had the electrophoretic mobility of [3H]bovine proparathyroid hormone (ProPTH) and [3H]bovine PTH (1--84), respectively. Immunoreactive PTH was only detected in a peak comigrating with [3H]PTH-(1--84). The nonimmunoreactive 5,000 Mr peptide was not further identified. The incorporation of radioactive amino acids into PSP, ProPTH, PTH-(1--84), and the 5000-daltons peptide was inversely related to the calcium concentration in the incubation medium. The incorporation of radioactive mannose into PSP was also greater at low extracellular calcium concentrations. Our findings provide evidence for an inverse relationship between the extracellular calcium concentration and the formation of PSP, ProPTH, PTH-(1--84), and a yet to be identified 5000-dalton peptide in dispersed bovine parathyroid cells.

Limited nerve impulse blockade by "leashed" local anesthetics.

To measure the depth of the local anesthetic binding site within the neuronal membrane, biotin-containing polyethylene glycols having zero, three, and six ethylene glycol subunits were added to the p-amino termini of tetracaine and procaine, thereby interposing a pharmacologically inert "spacer" molecule between the local anesthetic and the biotin moiety. These biotinyl-local anesthetic derivatives produced "tonic" inhibition of the compound action potential of split, desheathed frog sciatic nerves in a concentration-dependent, reversible manner. However, no inhibition of the action potential occurred when sufficient avidin, a 66,000-MW protein that binds four biotins, was present to bind and anchor the biotin-containing end of each derivative outside the plasma membrane. Increasing the "leashed" anesthetic derivative's concentration to 4 times that which reduced impulse height by 50% in the absence of avidin still produced no detectable block when equimolar avidin was present. Apparently, the "spacer" in the derivative compound was too short to permit the avidin-complexed anesthetic to reach its site of action on the sodium channel. In a similar fashion, the local anesthetic derivatives produced "use-dependent" block when drug-treated nerves were stimulated at 40 Hz in the absence of equimolar avidin, but failed to produce "use-dependent" block when equimolar avidin was present. In common with others, we assume that tertiary amine local anesthetics may reach their binding site via hydrophobic (transmembrane) pathways without necessarily entering the cytoplasm. Thus, since our longest local anesthetic derivative, that containing six ethylene glycol subunits, placed the local anesthetic group a maximum of 15-18 A from the surface of the avidin moiety, we conclude that the local anesthetic binding site for block of sodium channels of amphibian nerve must be greater than or equal to 15 A from the outer surface of the plasma membrane.

Use of a single solution for oral rehydration and maintenance therapy of infants with diarrhea and mild to moderate dehydration.

OBJECTIVE: To compare the efficacy of two commonly used solutions in the rehydration of infants with mild to moderate dehydration caused by acute diarrhea in the United States. DESIGN AND SETTING: Double-blind, parallel-group, randomized study performed at Children's Hospital Medical Center. PATIENTS: Sixty infant boys (< or = 2 years old), with mild (< or = 5%) or moderate (6 to 9%) dehydration caused by acute diarrhea of less than 1 week's duration were included in the study. INTERVENTIONS: Infants were randomly assigned to receive treatment with either a glucose-based oral rehydration solution (ORS) (Pedialyte, Ross Laboratories, Columbus, OH) or a rice syrup solids-based ORS (Infalyte, Mead Johnson Nutritional Group, Evansville, IN). After rehydration was achieved, patients entered a maintenance phase during which, in addition to a maintenance ORS, breast milk or a soy-based formula was offered; infants older than 1 year were also given a lactose-free diet. OUTCOME MEASURES: Rehydration was judged clinically. Infants remained on a metabolic bed during the study in to separate and quantitate urine and stool output. Therefore, in addition to clinical outcome, we compared intake, output and apparent absorption and retention of fluid, sodium, and potassium between groups. RESULTS: All patients were successfully rehydrated using an ORS without the use of intravenous fluids. No differences were detected between treatment groups in time to rehydration, percentage of weight gain after rehydration, consumption of ORS to achieve rehydration, or stool output. However, the apparent sodium absorption (net intake less fecal output) was greater in the Infalyte group than the Pedialyte group during the first 24 hours. CONCLUSION: The two maintenance oral electrolyte solutions (Pedialyte and Infalyte) most commonly used in the United States are effective as rehydration solutions for infants with mild to moderate dehydration. We speculate that a strategy for oral rehydration therapy in the United States, based on the use of a single solution during the rehydration and maintenance phase, might gain additional acceptance by practicing pediatricians and family physicians.

Histologic diagnosis of Hirschsprung's disease. The value of concurrent hematoxylin and eosin and cholinesterase staining of rectal biopsies.

False positive and negative results can complicate the diagnosis of Hirschsprung's disease (HD) with the acetylcholinesterase (AChE) stain. To improve the diagnostic value of this test, the authors evaluated the concurrent hematoxylin and eosin (H and E) staining of extra sections after the AChE procedure. Flash-frozen (FF), cryostat-cut (CC) sections of rectal suction biopsies from 96 patients with constipation were evaluated by AChE together with H and E staining of additional unstained sections. In 13 of 15 cases of HD with a diagnostic (positive-A) AChE pattern, the H and E sections confirmed the diagnosis. In five cases with other AChE patterns, the H and E sections were instrumental when the diagnosis was made. Of the 76 non-HD subjects with positive-B (n = 8), equivocal (n = 6), and negative (n = 62) AChE patterns, the H and E sections eliminated the diagnosis in 62 (81%). Neuronal and nerve fiber morphologic characteristics were excellent. Rebiopsies were needed in 14 subjects (19%) when there was failure in finding neurons. Simplicity, quickness, and the high quality of the histologic preparations make this procedure a useful adjunct to the AChE stain.

Preference diversity and the breadth of employee health insurance options.

OBJECTIVE: To examine the effect of worker heterogeneity, firm size, and establishment size on the breadth of employer health insurance offerings. DATA SOURCES: The data were drawn from the 1993 Robert Wood Johnson Foundation Employer Health Insurance Survey of 22,000 business establishments selected randomly from ten states. STUDY DESIGN: The analysis was cross-sectional, using ordered probit models to relate the breadth of plan offerings to firm characteristics. PRINCIPAL FINDINGS: Firms with more diverse workforces offered a more diverse set of health insurance options. Firm and establishment size independently influenced the breadth of plan offerings. CONCLUSIONS: Employers are responsive to worker heterogeneity when determining the breadth of their health insurance offerings. However, diseconomies of scale in the purchase and administration of health insurance appear to limit the extent to which small employers can accommodate diverse worker preferences.

The effects of severe zinc deficiency on intestinal amino acid losses in the rat.

To determine whether intestinal amino acid losses might occur during zinc deficiency, labeled aminoisobutyric acid was given parenterally to zinc deficient rats and to appropriate zinc-sufficient controls. After 24 hours, the aminoisobutyric acid loss into the intestinal lumen was measured by in situ perfusion of isolated intestinal segments under conditions of either net water absorption or water secretion. Net amino acid losses were larger in the jejunum of the zinc deficient rats and losses were exacerbated during net water secretion in the jejunum and colon segments. The contribution of amino acid losses to fecal nitrogen, particularly during osmotic diarrhea, may be important in the growth retardation of zinc deficiency. Further, these alterations may indicate defective enterocyte transport functions during severe deficiency.

Analysis of aggregate surgically induced refractive change, prediction error, and intraocular astigmatism.

PURPOSE: To demonstrate analytical methods for evaluating the results of keratorefractive surgical procedures and emphasize the importance of intraocular astigmatism. SETTING: University of Texas Medical School, Houston, Texas, USA. METHODS: A standard data set, provided by an editor of this journal, comprising the preoperative and postoperative keratometric and refractive measurements of 100 eyes that had keratorefractive surgery was evaluated by 2 methods, vector and spheroequivalent (SEQ) analysis. The individual and aggregate surgically induced refractive changes (SIRCs) and prediction errors were determined from the refractive and keratometric measurements using both methods and then compared. The refraction vertex distance, keratometric index of refraction, and corneal asphericity were used to make the results calculated from refractive data directly comparable to those derived from keratometric data. Doubled-angle and equivalency plots as well as frequency and cumulative histograms were used to display the data. Standard descriptive statistics were used to determine the mean and standard deviation of the aggregate induced astigmatism after converting the polar values (cylinder and axis) to Cartesian (x and y) values. RESULTS: The preoperative SEQ refractive errors were undercorrected by at least 0.25 diopter (D) in most cases (78%). Six percent were corrected within +/- 0.24 D, and 16% were overcorrected by at least 0.25 D SEQ. The mean SEQ was -6.68 D +/- 2.49 (SD) before and -0.61 +/- 0.82 D after surgery, reflecting a SIRC SEQ of -6.07 +/- 2.40 D. The defocus equivalent (DEQ) was 7.41 +/- 2.53 D before and 0.96 +/- 0.74 D after surgery; for a nominal 3.0 mm pupil, this corresponded to an estimated improvement in uncorrected visual acuity (UCVA) from worse than 20/200 to better than 20/25, respectively. The predictability of the treatment decreased as the attempted refractive correction increased. The average magnitude of the refractive astigmatism was 1.46 +/- 0.61 D before and 0.40 +/- 0.38 D after surgery. The centroid of the refractive astigmatism was +0.96 x 87.9 +/- 0.85 D, rho = 0.43 before and +0.11 x 83.1 +/- 0.37, rho = 0.49 after surgery. The decrease in the square root of the centroid standard deviation shape factor (rho1/2) indicated an 8% increase in the amount of oblique astigmatism in the population. The prevalence of preoperative keratometric irregular astigmatism in excess of 0.5 D in this group of patients was 13%. The correlation between keratometric and refractive astigmatism was extremely poor before (r2 = 0.26) and especially after surgery (r2 = 0.02), demonstrating the presence of intraocular astigmatism and the limitations of manual keratometry. The centroid of intraocular astigmatism at the corneal plane was +0.48 x 178 +/- 0.49 D, rho = 0.59, and was compensatory. CONCLUSIONS: The 2 analytical methods are complimentary and permit thorough and quantitative evaluation of SIRCs and allow valid statistical comparisons within and between data sets. The DEQ allows comparison of refractive and visual results. The decrease in refractive predictability with higher corrections is well demonstrated by the SEQ and doubled-angle plots of the SIRC. Doubled-angle plots were particularly useful in interpreting errors of cylinder treatment amount and errors in alignment. The correlation between refractive and keratometric astigmatism was poor for preoperative, postoperative, and SIRC data, indicating the presence of astigmatic elements beyond the corneal surface (ie, intraocular astigmatism). Sources of error in refractive outcome statistics include the use of multiple lens systems in the phoropter, errors in vertex calculations, difficulty in accurately defining the axis of astigmatism, and failure to consider measurement errors when working with keratometric data. The analysis of this particular data set demonstrates the significant clinical benefits of refractive surgery: an 8-fold increase in UCVA, an 11-fold decrease in SEQ refractive error, as well as a 9-fold and nearly a 2 1/2-fold decrease in the magnitude and distribution of astigmatism, respectively.

Prevention of alcohol misuse: a review of health promotion efforts among American Indians.

PURPOSE: The purpose of this review is to provide an overview of a wide range of potentially useful strategies to address the prevention of alcohol misuse among American Indians. This broad approach to the review is useful because the extreme heterogeneity of the American Indian population requires that health promotion professionals explore many options and tailor their activities to specific communities. SEARCH METHOD: A literature search was initiated through MEDLINE using the following key words: prevention, alcohol, substance abuse, American Indian, and Native American. The search yielded 29 articles from the years 1982 through 1994. These articles, along with 45 previously identified in three overview articles, form the basis of the review and discussion in this paper. SUMMARY OF FINDINGS: As a group, American Indians experience many health problems that are related to alcohol misuse. Comparison of Indians to non-Indians shows that the age of first involvement with alcohol is younger, the frequency and amount of drinking is greater, and negative consequences are more common. Health promotion programs that address these issues must take into account American Indian heterogeneity and should use a comprehensive approach that addresses both heavy drinking and the sequelae of problems related to alcohol misuse. MAJOR CONCLUSIONS: Important concepts for providing health promotion services to this population are: cultural relevance must be carefully planned and monitored; individuals in the local community must be involved; the drunken Indian stereotype must be addressed; and community empowerment should be an important goal.

Meeting lipid needs of infants with allergy and gastrointestinal diseases.

Infant formulas containing medium chain triglycerides (MTC) have been used for the nutritional management of infants with fat malabsorption. The optimal proportion of MTC in the formula remains to be determined. Three infant formulas with varying proportion of MTC in the fat blend were studied in children with cystic fibrosis, cholestasis or persistent diarrhea. The formula containing 48% of the total energy from fat and 55% of the fat component as MTC was found to be the most suitable for the needs of those infants. It leads to an adequate essential fatty acid status and to improved recovery in those conditions.

Synthesis and pharmacology of two new histamine receptor antagonists related to ranitidine.

Pyridyl and 1,6-dihydropyridyl ranitidine analogues 1 and 2 were obtained by applying an improved modification of ranitidine synthesis. Compound 1 shows a selective H2 antagonistic activity while compound 2 is a non-selective histamine antagonist.

Sources of sexual information and sexual attitudes and behaviors of Anglo and Hispanic adolescent males.

A survey of Anglo and Hispanic adolescent males' sources of sexual information and their attitudes and practices was conducted. A comparison of attitudes and behaviors revealed little difference by ethnicity; however, a more detailed analysis of sources of information resulted in some interesting findings. The relationship between completing a sex education class and condom use was statistically significant in a positive direction. In addition, this relationship was much stronger for Hispanic youth. The important implications of this finding are discussed.

PIP: This exploratory study examined the self-reported sexual attitudes and behavior of 28 Anglo and 69 Hispanic adolescent males from urban and rural areas of Colorado in 1987. 64.3% of the Anglos and 60.3% of the Hispanics were from urban areas. The mean age was 15.6 years for Anglos and 16.1 years for Hispanics. The education level was lower for Anglos. 29.6% of Anglos and 31.1% of Hispanics lived in 1-parent households. The results showed that sexual knowledge was learned from a variety of sources in both groups, with no statistical difference between groups. Of interest, however,is that sex education was ranked 1st by Anglos and 3rd by Hispanics. Statistical differences were found in the desire to postpone sex until marriage, i.e., 39.3% of Anglos vs. 20.9% of Hispanics desired postponement. There were no differences in actual engagement in sexual intercourse, i.e., 64.3% of Anglos and 70.8% of Hispanics with mean ages of 13.2 years and 13.6 years, respectively. Condom use was also similar with 38.9% of Anglos and 31.8% of Hispanics indicating use of condoms sometimes. 27.8% of Anglos and 20.5% of Hispanics reported no use ever. The most important finding was the effect of sex education classes. 53.6% reported sex education classes as a source of knowledge (60.7% of Anglos and 50.7% of Hispanics). An additional analysis showed that there was a very strong relationship between learning about sexuality in a sex education class and reports of condom use among those sexually active. 71.4% of those reporting condom use had learned about sexuality through a sex education class, while only 21.45 of those never having used a condom had attended a sex education class. It was also statistically significant that those who had learned about sexuality from sex education classes would choose sex education classes as a source of further information, both for Anglos and Hispanics. What is not answered is whether sex education was result of choice or access, i.e., considered important in light of the association between condom use and sex education. Timing of sex education is also important, and may explain the lack of association between age at 1st intercourse and sex classes. The study points out the cultural value of Hispanic "machismo" which also means accepting responsibility for contraception and providing for one's family, but in traditional households youth may not ask about sexuality. This study addresses cultural expectations, the nature of information desired by youth, and the multiple sources influencing knowledge and attitudes.

Comparison of oral rehydration solutions made with rice syrup solids or glucose in the treatment of acute diarrhea in infants.

An oral electrolyte solution made with rice syrup solids was found to reduce fecal output more effectively than a comparable glucose-based solution in the early hours of treatment of infantile diarrhea. Administration of the rice syrup solids solution was also more effective in promoting absorption of fluid, sodium, and potassium. In some infants, the rapid, effective rehydration offered by this solution may prevent the need for hospitalization.

[Prolonged neurologic deficiency after accidental spinal anesthesia]. / Déficit neurológico prolongado tras anestesia espinal accidental.

A case of severe prolonged neurological deficit following inadvertent spinal anesthesia is presented. Intradural block occurred after a test dose of Bupivacaine and vasoconstrictor when inserting an epidural catheter for post-thoracotomy pain-relief treatment. The likely triggering and etiological factors responsible for the neurological damage after spinal anesthesia were studied and evaluated, mainly those toxic and traumatic. Special mention of the local anesthetics and sodium bisulfite used is made. Preventive measures for this sort of complication are suggested.

Effects of prolonged exposure to partially hydrolyzed milk protein.

Formulas containing proteins with reduced potential to sensitize might be effective in reducing the risk of atopic disease, but such products should be nutritionally adequate. We designed a randomized, double-blind study to evaluate nutritional adequacy and sensitization potential of a formula containing partially hydrolyzed whey-predominant milk proteins. Subjects were term infants enrolled at birth. Infants in group A were fed human milk, and group B received the partially hydrolyzed formula; group C, fed a formula containing intact whey-predominant milk proteins, served as control subjects. We recorded anthropometric measurements and symptoms of formula intolerance at monthly intervals for 4 months in 205 infants. Milk IgE and IgG antibodies were measured until 8 months of age in 63 infants. Daily weight gain was not significantly different among the groups. Gastrointestinal symptoms attributed to feeding intolerance were also comparable. Increases in serum IgG antibodies were significantly greater in group C throughout the study. There were no significant differences in IgE antibodies. Thus a formula containing partially hydrolyzed whey-predominant milk protein promoted adequate growth and induced a lesser priming effect for IgG antibody response than did an intact whey-predominant formula.

Postnatal intestinal maturation in rats: alpha-aminoisobutyric acid loss during in vivo, perfusion by hypertonic solutions.

We investigated with an in vivo single pass perfusion technique net secretion of [14C]aminoisobutyric acid, a non-metabolizable amino acid, from the proximal, distal small intestinal segments and from the colon segments of suckling (14-15 day old), weanling (21-22 day old) and adolescent (42-43 day old) rats during perfusion with either isotonic (300 mOsm/Kg) or hypertonic (500 mOsm/Kg) solutions. During isotonic perfusion, net secretion of [14C]aminoisobutyric acid was significantly greater in all segments of the suckling rats compared to corresponding values in segments of the adolescent rats. Rates of net secretion of [14C]aminoisobutyric acid in all segments of the weanling rats were intermediate between corresponding mean values of the suckling and adolescent rats. When secretion of [14C]aminoisobutyric acid was compared between individual segments, the colon was the major site of secretion followed by the proximal and then the distal segments in all age groups. During perfusion with hypertonic solutions there was significant increase in net secretion of [14C]aminoisobutyric acid in all segments of the suckling rats compared to mean values with isotonic perfusion. In the weanling and adolescent rats, there were no significant differences in the rates of net secretion of [14C]aminoisobutyric acid with hypertonic perfusion. Our findings suggests greater permeability of the intestinal epithelium not only to water, electrolytes and minerals but also to amino acids in the suckling rats compared to adolescent rats. The implication is that during periods of osmotic diarrhea infant animals appear to be at risk of losing amino acids.(ABSTRACT TRUNCATED AT 250 WORDS)

The effects of severe zinc deficiency on intestinal permeability: an ultrastructural study.

Evidence suggests that intestinal transport of water and electrolytes may be altered in zinc deficiency. We examined the structural features of intestinal epithelial cells of zinc-deficient rats using electron microscopy and assessed the integrity of the junctional complexes using a heavy metal tracer, lanthanum hydroxide. The absorptive cells, as well as Paneth cells and chromaffin cells, were not found to have ultrastructural changes of a consistent nature in zinc deficiency. Moreover, the integrity of the junctional complexes was found to be preserved. These findings suggest that the abnormalities in intestinal transport previously reported are not secondary to increased tight junction permeability in zinc deficiency.

Rice-based oral electrolyte solutions for the management of infantile diarrhea.

BACKGROUND: In infants the treatment of acute diarrhea with glucose-based solutions results in rehydration but does not reduce the severity of diarrhea. Oral rehydration with solutions based on rice powder may reduce stool output as well as restore fluid volume. METHODS: We designed a prospective, randomized, double-blind study to evaluate the efficacy of two rice-based rehydration solutions and a conventional glucose-based solution. Solution A contained only rice-syrup solids, solution B contained rice-syrup solids and casein hydrolysate, and solution C, the glucose-based solution, served as control. The study subjects were 86 mildly to moderately dehydrated infant boys, 3 to 18 months old, who were admitted to a children's hospital with acute diarrhea. We measured fluid intake, fecal and urine output, and absorption and retention of fluid, sodium, and potassium at intervals for 48 hours in all 86 infants. RESULTS: The mean (+/- SE) fecal output was significantly lower in the infants given solution A (group A infants) than in the infants given solution C (group C) (29 +/- 4 vs. 46 +/- 7 ml per kilogram of body weight, P less than 0.05) during the first six hours of therapy. The infants in group A also had greater fluid absorption (221 +/- 16 vs. 167 +/- 9 ml per kilogram, P less than 0.05) over the entire 48 hours of therapy and greater potassium absorption (1.6 +/- 0.2 vs. 0.6 +/- 0.1 mmol per kilogram, P less than 0.05) during the first six hours than the infants in group C. Solution B offered no advantages over solution A. CONCLUSIONS: Solutions containing rice-syrup solids were effective in the rehydration of infants with acute diarrhea. They decreased stool output and promoted greater absorption and retention of fluid and electrolytes than did a glucose-based solution.