Efficacy of Humalog injections before an afternoon meal and their acceptance by children and adolescents with type 1 diabetes

AIMS

To evaluate the acceptability and efficacy of an injection of insulin lispro, before an afternoon meal.

METHODS

The subjects, 43 patients with Type 1 diabetes, 16 boys and 27 girls, aged 12.4 +/- 2.4 years, were randomly assigned to the treatment (n = 20) or the untreated control group (n = 23). The treatment was an injection of insulin lispro immediately before the afternoon meal. The control group had no injection. The treatment and the control group consumed identical types of meals for 2 months. The mean before-dinner blood glucose was measured during the last 2 weeks of the study.

RESULTS

Injection of insulin lispro resulted in a significant reduction in the before-dinner blood glucose compared with the untreated control group (10.4 +/- 3.8 mmol/l vs. 14.7 +/- 3.9 mmol/l, respectively). The number of days on which the blood glucose was > 10 mmol/l was reduced by half in the insulin lispro group. The difference in HbA1c between baseline and endpoint differed slightly but significantly between the two groups, in boys. Treated patients ate the meal less frequently (11.4 +/- 3.0 times per 15 days) than the control patients (14.4 +/- 0.6 times per 15 days) and injected themselves with insulin 8.9 +/- 3.6 times per 15 days. The HbA1c increased significantly with the number of meals taken without injection. There was no statistically significant difference in the frequency of hypoglycaemia or changes in weight between the two groups.

CONCLUSIONS

We conclude that an injection of insulin lispro before the afternoon meal can effectively lower the before-dinner blood glucose, and in boys also lowers the HbA1c. Patients were satisfied with the lower blood glucose before dinner, and did not find the insulin lispro injection difficult. However, compliance with the protocol procedures decreased during a subsequent 6-month period.

Reduced risk of liver-function-test abnormalities and new gallstone formation with weight loss on 3350-kJ (800-kcal) formula diets

Weight loss in obese subjects ingesting very-low-energy (VLE; < 2510 kJ/d), low-fat (< or = 1 g/d) formula diets is associated with liver-function-test abnormalities and gallstone formation. It is unknown whether these abnormalities develop during treatment with diets higher in energy and fat. We prospectively studied liver-function tests and gallstone formation in 73 obese patients ingesting approximately 3500 kJ and 15-25 g fat daily for 10 wk. Two of 53 patients completing the protocol developed ultrasonographic gallstones during weight loss, a rate substantially lower than that observed with VLE diets. Trend analysis demonstrated significant increases in AST and ALT activities, but changes were less than those observed with VLE diets. Patients who developed gallstones had a significantly greater weight loss rate and larger increases in AST and ALT than did nonstone-forming patients. These results suggest that the risk of developing hepatobiliary abnormalities with dieting is lowered when subjects ingest greater amounts of energy and fat than that administered in earlier VLE-diet studies. Our results also highlight potential risk factors and markers of new gallstone formation.

Glutamine metabolism in healthy adult men: response to enteral and intravenous feeding

To assess the effect of feeding on glutamine kinetics, six healthy men received 4-h intravenous infusions of L-[2-15N]glutamine and L-[1-13C]leucine on 3 separate days: 1) in the postabsorptive state, 2) over the course of an 8-h nasogastric infusion of a small peptide-based nutrient mixture, and 3) during an 8-h isonitrogenous, isoenergetic intravenous infusion (1.5 g amino acid.kg-1.d-1; 130 kJ.kg-1.d-1, or 31 kcal.kg-1.d-1; 58% carbohydrate and 42% fat). Regardless of the route, nutrition increased leucine appearance rate (Ra) and oxidation, stimulated protein synthesis, and improved leucine balance; apparent rates of protein breakdown decreased during enteral nutrition only. Glutamine Ra increased 16.8% (NS) and 26.2% (P < 0.01) with parenteral and enteral feeding, respectively, over postabsorptive values. The present findings are consistent with a major role of glutamine in interorgan nitrogen transport in the fed state and further suggest that increased availability of precursors may stimulate glutamine synthesis de novo, and enteral infusion of peptide-bound amino acids may be an effective route to provide free glutamine to the rest of the body.

Postobstructive enteropathy in infants with transient enterostomy: its consequences on the upper small intestinal functions

Repeated or prolonged organic obstruction of the small intestine in the neonatal period can lead to severe refeeding problems, despite a transient ostomy. These problems are thought to result from a postobstructive enteropathy (POE) of the apparently normal small intestine segment above the obstruction. Ten infants with a POE, characterized by limited oral caloric and carbohydrate intakes and increased ostomy effluent, were compared with 8 controls with an enterostomy and a normal postoperative refeeding pattern. There was no statistical difference in the histomorphometric appearance of the mucosa or its digestive or absorptive capacity (brush-border hydrolases, glucose transport) between the two groups. The effluent and duodenal floras of the two groups were similar. However, all POE patients showed significant abnormal peristalsis characterized by barium and carmin transit times. This suggests that repeated or prolonged obstruction in the neonatal period could lead to a POE, caused by chronic motricity abnormalities of the small intestine above the obstruction. Although this POE is more frequent after small bowel atresia, it may also occur with other conditions causing prenatal and postnatal intestinal obstruction.

[Research of factors for glucose intolerance in mucoviscidosis]

Glucose tolerance has been assessed in cystic fibrosis (CF) children using HbA1C and plasma glucose and insulin determinations during an oral glucose tolerance test (OGTT), along with the determination of HLA-DR and islet-cell (ICA) and anti-insulin (IAA) antibodies. Of 49 patients (25 males, 24 females), aged 2 to 21 years (mean = 10.9 years), 29 had normal glucose tolerance (WHO criteria) during OGTT, 14 had impaired glucose tolerance (IGT) and 6 had an isolated hyperglycemia at 120 min. Fasting plasma glucose and HbA1C were significantly higher in IGT than in normoglycemic patients. However, these two parameters showed poor individual predictive value of disturbance in glucose tolerance. Of 14 patients with abnormal OGTT, 7 were aged below 10 years, with 2 as young as 5 years; 8 patients were females. HLA antigens characteristic of type I diabetes tended to be found less frequently in CF patients than in the general population: 9% were DR3, 7% were DR4 and none was DR3/DR4. There were no HLA differences according to glucose tolerance. ICA and IAA were respectively detected in only one patient. Stimulated plasma insulin was low but did not correlate with glucose tolerance. In conclusion, impaired glucose tolerance is common in cystic fibrosis and can be found early in life. Although insulin secretion is decreased in this population, it does not seem to be the only factor responsible for impaired glucose intolerance. The absence of the genetical and immunological characteristics of type I diabetes confirms that glucose intolerance in cystic fibrosis is due to other pathogenetic mechanisms.

Effects of dietary whey proteins, their peptides or amino-acids on the ileal mucosa of normally fed and starved rats

The effects of three liquid diets, differing only in the molecular form of the nitrogen source (whole whey proteins, WP; trypsic whey protein hydrolysate, WPH, and amino-acid mixture, AAM) were studied on the mucosa morphology and brush border hydrolase (BBH) activities (disaccharidases, peptidases) of the ileum of normally fed male Wistar rats (controls) and during refeeding of rats starved for 72h. All three diets produced repair of the fasting induced mucosal atrophy; the AAM diet gave the most rapid response and highest villus height (p < 0.01). This was correlated with an increase in crypt mitoses (p < 0.01). Similar results were obtained in controls with AAM. The sucrase (S) and acid amino peptidase (AAP) specific activities of controls were higher (p < 0.01) on the WPH diet; neutral amino peptidase (NAP) was unaffected. Dipeptidyl peptidase IV (DDP) was lowest on AAM while glucoamylase (G) highest on WP. Fasting increased S and DDP activity, and produced no change in the other BBH. Large variations in BBH occurred during refeeding except for NAP which remained stable. Control values were restored at 96h, except for AAP. The results show that BBH and mucosa morphology of the ileum in the rat can be modified by the molecular form of the nitrogen source and that the nutritional status interferes with this adaptation. These data could have implications for the therapy of small bowel disease.

VIP receptors and control of short circuit current in the human intestinal clonal cell line Cl.19A

At the maximally effective concentration of 10 nM, VIP induced a marked (12.5-fold stimulation above basal), and sustained increase in short circuit current in the human intestinal epithelial cell line Cl.19A grown on permeable filters and placed in Ussing chambers. Half-maximal increase of Isc was observed for 0.1 nM VIP. This was well correlated with the VIP-stimulated adenylate cyclase activity (ED50:0.07 nM). Binding studies using 125I-VIP indicated that Cl.19A cells express a peptide-specific VIP receptor with a dissociation constant of 0.07 nM. Covalent labeling of receptors followed by SDS-PAGE analysis of membrane proteins resulted in the identification of a 63,000 dalton binding protein in Cl.19A cells.

Functional VIP receptors in the human mucus-secreting colonic epithelial cell line CL.16E

A polarized human clonal intestinal cell line exhibiting mucus secretion (Cl.16E) was used to study the expression and function of vasoactive intestinal peptide (VIP) receptors in mucus-secreting cells. Cl.16E cells expressed one class of receptors with a KD of 0.13 nM and a capacity of 67 fmol/mg protein. Covalent labeling of receptors followed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed a receptor protein with a Mr of 63,000 in Cl.16E cells. VIP stimulated adenylate cyclase activity in membranes from Cl.16E cells with an ED50 of 0.06 nM. In conditions where carbachol stimulated mucin secretion from filter-grown Cl.16E cells, VIP, dibutyryl adenosine 3',5'-cyclic monophosphate (DbcAMP), or forskolin did not alter basal secretion. However, VIP strongly potentiated carbachol-induced mucin secretion, since carbachol alone and VIP plus carbachol induced a 1.6- and 3.6-fold increase of mucin secretion above basal, respectively. This potentiating effect of VIP was mimicked by DbcAMP or forskolin. It was observed for VIP concentrations in the 0.1-100 nM range (ED50, 2 nM). VIP elicited a dramatic increase of intracellular cAMP levels in filter-grown Cl.16E cells with a dose-response curve (ED50, 4 nM) very similar to that observed for the modulation of mucin secretion. These studies suggest that the clonal cell line Cl.16E may be an invaluable cellular model for evaluating the neurohormonal control of mucus secretion.

Antigen absorption by the jejunal epithelium of children with cow's milk allergy

To establish if intestinal permeability to exogenous antigens is involved in cow's milk allergy (CMA) in infants, 33 children 1 to 24 months old (18 controls and 15 with CMA) were tested for intestinal permeability to the protein marker horseradish peroxidase (HRP). Jejunal biopsies were performed either during the initial period of diagnosis, at the mean (and SE) age of 3 +/- 1 months, and/or 1 yr later, at the age of 13 +/- 2 months, just before and after a milk challenge. A small fragment of the biopsy was studied for histology and the remainder was mounted in an Ussing chamber for simultaneous measurement of mucosal to serosal transport of HRP in its intact and degraded forms and electrical parameters including short-circuit current and conductance. No modification in HRP absorption was noted in control children aged from 2 months to 11 yr, indicating that gut closure probably occurred earlier in life. During the initial period of CMA, transepithelial HRP fluxes were significantly higher, about 8-fold, in children with CMA (intact HRP flux = 48.5 +/- 15.2, 95% confidence interval, 11.2 to 85.7 versus 5.9 +/- 1.2, 95% confidence interval 2.9 to 8.3, in control children). In addition, short-circuit current was increased but conductance was unchanged. After several months on a milk-free diet, HRP flux and short-circuit current returned to control values. Just after the milk challenge and independently of the clinical issue, a slight rise in HRP permeability was observed but it was not significant and remained within control values.(ABSTRACT TRUNCATED AT 250 WORDS)

Congenital selective malabsorption of glucose and galactose

We review here the case histories and results of in vivo and in vitro tests for eight children with congenital selective glucose and galactose malabsorption (GGM) whom our laboratory has followed up since 1971. Clinically, GGM was manifested by intractable, acidic, sugar-containing diarrhea that started during the neonatal period. Diarrhea only abated when glucose and galactose were removed from the diet. The disease was notable for the absence of other symptoms, although mellituria was a common finding. Defective sugar transport was permanent, but sugar tolerance appeared to increase with age. In vitro, intracellular mucosal glucose concentration (C) was significantly below control level in GGM intestinal tissue for concentrations (M) of 10 and 0.1 mM glucose in the medium. C/M for galactose also decreased, while the C/M ratios for alanine and xylose were within the control range. Glucose influxes across the luminal membrane, net glucose transepithelial fluxes, and electrical parameters were all consistent with defective sodium and glucose cotransport at the brush border membrane of jejunal epithelial cells. However, the present results are also consistent with a small residual active transport system observed only at low glucose concentration in the medium. Further observations are needed to establish the role of glucose transport systems in absorption of other monosaccharides, the relationship between kidney and intestinal sodium-glucose cotransport systems, and their genetic control.

Epithelial properties of human colonic carcinoma cell line Caco-2: effect of secretagogues

Human colonic carcinoma Caco-2 cells grown in vitro form epithelial layers of highly polarized cells. Unlike colonic adsorptive cells they possess a mucosal membrane with very limited ionic conductance, even after exposure to aldosterone. When grown on filters, Caco-2 cells were sensitive to various secretagogues; these included 10(-5) M dibutyryl adenosine 3',5'-cyclic monophosphate (DBcAMP) and 10(-10) M vasoactive intestinal peptide, both of which, added serosally, enhanced the short-circuit current. The same applied to mucosal forskolin. Caco-2 cell sensitivity to serosal epinephrine was lower. Ion substitutions and 22Na-36Cl flux measurements indicated the possibility of secretagogue-dependent chloride secretion. Measurements on cells grown on Petri dishes and exposed to 1 mM DBcAMP for 1 h enabled detection of more profound modifications. Sustained 20-mV cell depolarization and a large reduction in the relative electrical resistance of the mucosal membrane were concomitant with a sizable decrease in 36Cl accumulation. These results suggest that Caco-2 cells, which to some extent resemble colonic crypt cells, possess the cAMP-dependent mucosal chloride conductance characteristic of secretory cells.

Epithelial properties of human colonic carcinoma cell line Caco-2: electrical parameters

Human colonic carcinoma Caco-2 cells grown in vitro undergo epithelial differentiation. Electrical measurements showed that they form resistant monolayers of polarized cells. On millipore filters, transepithelial electrical resistance (154 +/- 6.5 omega X cm2) was accompanied by a small potential difference (0.29 +/- 0.02 mV, serosal side positive) and by short-circuit current (1.9 +/- 0.14 microA X cm-2), both of which were ouabain sensitive. Micropuncture of domes formed on plastic supports under standard culture conditions revealed electrical polarity similar to that of filter-grown cells (0.8 +/- 0.2 mV, serosal side positive) combined with a highly negative cytoplasm (-57 +/- 1 mV) and very marked cell asymmetry (76% of total electrical cell resistance was located in the mucosal membrane). These parameters were not affected by the diuretic amiloride nor the hormone aldosterone, suggesting that sodium conductance is very limited in the mucosal membrane. Addition to the mucosal side of the ionophore nystatin or amphotericin B unmasked the possibility of high electrical transport activity. Electrical measurements made it possible to define the epithelial properties of Caco-2 cells, which may resemble those of colonic crypt or fetal cells. These measurements also confirmed that functional differentiation is homogeneous in Caco-2 cells. It is suggested that dome cell micropuncture may be useful in investigating the functional properties of other dome-forming cell lines.

Effects of Na-coupled alanine transport on intracellular K activities and the K conductance of the basolateral membranes of Necturus small intestine

Intracellular electrical potentials and K activity, (K)c, were determined simultaneously in Necturus small intestine before and after the addition of alanine to the mucosal solution. As noted previously (Gunter-Smith, Grasset & Schultz, 1982), the addition of alanine to the mucosal solution resulted in a prompt depolarization of the electrical potential difference across the apical membrane (psi mc) and a decrease in the slope resistance of that barrier (rm). This initial response was followed by a slower repolarization of psi mc associated with a decrease in the slope resistance of the basolateral membrane (rs) so that when the steady state was achieved (rm/rs) did not differ significantly from control values in the absence of alanine. In the absence of alanine, psi mc averaged -32 mV and (K)c averaged 67 mM. When a steady state was achieved in the presence of alanine these values averaged -24 mV and 50 mM, respectively. The steady-state electrochemical potential differences for K across the basolateral membrane in the absence and presence of alanine did not differ significantly. Inasmuch as the rate of transcellular active Na transport or "pump activity" was increased two- to threefold in the presence of alanine, it follows that, if active Na extrusion across the basolateral membrane is coupled to active K uptake across that barrier with a fixed stoichiometry then, the decrease in rs must be due to an increase in the conductance of the basolateral membrane to K that parallels the increase in "pump activity". This "homocellular" regulatory mechanism serves to (i) prevent an increase in (K)c due to an increase in pump activity; and, (ii) repolarize psi mc and thus restore the electrical driving force for the rheogenic Na-coupled entry processes.

[Intestinal malabsorption of glucose and galactose. Study of a family]

A girl with congenital glucose-galactose malabsorption and her two parents were studied. Hydrogen breath tests performed on the child during glucose and galactose tolerance tests (0.5 g/kg) were positive (increase in expired pH concentration of 21 p.p.m. and 32.5 p.p.m. from the basal level respectively). This was negative for fructose (2 g/kg). In vitro intestinal transport studies showed: 1) a selective decrease in active glucose accumulation (intracellular concentration 0.34 mM in 0.1 mM glucose bathing solution - controls: 1.58 +/- 0.56 (means +/- SD), and 12.1 mM in 10 mM bathing solution - controls: 38.4 +/- 12.4). 2) absence of net glucose absorption during in vitro Ussing chamber measurements with a marked decrease in mucosal membrane glucose permeability. For the parents, the hydrogen breath test was negative after glucose and galactose ingestion (2 g/kg) and intestinal transport was normal (father; intracellular concentration 1.32 mM and mother 2.04 for 0.1 mM bathing glucose concentration). The marked decrease in brush border permeability explains the absence of net glucose absorption in the child. The parents who are presumed to be heterozygotes did not exhibit any detectable transport defect.

Relationship between transport of D-xylose and other monosaccharides in jejunal mucosa of children

In order to clarify the relationship between the transport of D-xylose, D-glucose, and Na in human gut, several characteristics of D-xylose uptake were examined in jejunal biopsies from 47 children (45 with normal intestinal function and 2 with glucose-galactose malabsorption). Standard in vitro techniques were used, with the following results: In tissue accumulation experiments with Ringer solution, the intracellular D-xylose concentration (C) was not significantly different from the medium D-xylose concentration (M) (C/M = 1.10 +/- 0.08). D-Xylose uptake was not affected by the disappearance of the Na electrochemical gradient in the presence of ouabain or DNP (C/M = 1.02 +/- 0.16 and 0.96 +/- 0.04, respectively). However, in Na-free solution, D-xylose uptake decreased (C/M = 0.47 +/- 0.08). The influx of 10 mM D-xylose across the luminal membrane (Jmcxyl = 1.34 mumol/h . cm2) was not significantly influenced by 2 mM phlorizin (Jmcxyl - 1.25 mumol/h . cm2), which is a competitive inhibitor of D-glucose transport. Removal of Na from the incubation medium, reduced Jmcxyl by 55%. Galactose (40 mM) and fructose (40 mM) did not inhibit Jmcxyl (2.18 and 2.27 mumol/h . cm2, respectively). In Ussing chambers, D-xylose did not stimulate the short-circuit current (Isc), neither did it interfere with the increase in Isc induced by glucose. In the congenital absence of glucose and galactose active transport, D-xylose entry into the cell was unaltered. These results support the concept that in jejunal mucosa of children, D-xylose is at least in part, transported by a system that is different from those for fructose and Na-dependent D-glucose (hexose) transport.

Cystinuria: reduced lysine permeability at the brush border of intestinal membrane cells

Na-dependent L-lysine epithelial transport was assessed in vitro by measuring the intracellular accumulation and unidirectional influx across the enterocyte brush border membrane. Pieces of jejunum were obtained by peroral biopsies from 27 "control" children and 2 cystinuric patients. In these patients, the following observations are recorded: 1) Na-dependent lysine intracellular accumulation is eliminated; 2) Na-independent accumulation persists (the accumulation ratio is 1.69 +/- 0.34); 3) Na-intracellular concentration is significantly higher in cystinuric patients (60.2 +/- 4.2 mEq/liter) than in controls (42.0 +/- 4.2 mEq/liter), and 4) lysine influx at the luminal membrane is measurable only in tracer amounts, both in the presence of Na (0.17 +/- 0.03 mumole/h cm2) and in it absence (0.22 +/- 0.09 mumole/h cm2). These results suggest a specific loss of Na-dependent L-lysine transport at the luminal membrane of the enterocyte in both the patients with cystinuria. The basolateral membrane is probably permeable to L-lysine.

Possible sodium and D-glucose cotransport in isolated jejunal epithelium of children

Some experimental data in human jejunum suggest a Na dependence for glucose absorption and a glucose dependence for Na absorption. However, the relationship between these two transport processes is not yet known. Na+ and D-glucose absorptions were, therefore, measured simultaneously, in vitro, in isolated jejunal mucosa of children. The results are as follows: 1) the steady-state accumulation of D-glucose (C/M glucose) is a function of the Na concentration gradient between cell and medium (C/M Na). In Ringer solution, C/M glucose = 3.97 and C/M Na = 0.29; in the presence of 10(-4) M ouabain, C/M glucose = 1.63 and C/M Na = 0.60, and in Na free solution, C/M glucose = 0.99. In the presence of phloridzin, C/M Na is not statistically different from that in Ringer, but C/M glucose is significantly decreased. 2) The influx of D-glucose at the luminal membrane is a function of Na concentration in the bathing solution; it has the value of 4.41 mumole/hr cm2 in the presence of Na and of 1.65 mumole/hr cm2 in absence of Na. 3) The short-circuit current is a saturable function of D-glucose and of 3-O-D-methylglucose. The Kt for glucose is 8.01 mM. These results support the concept of a coupling between Na and D-glucose absorptions at the luminal membrane of jejunal mucosa of children.

Immunological Studies on Scorpions

These investigations on scorpions constitute a further contribution to the experimental studies carried out by one of us (Grasset and Zoutendyk, 1931; Grasset, 1931) on the immunity of the lower vertebrata, such as reptiles, compared with mammals.

The following immunological aspects were investigated: Susceptibility of scorpions to bacterial toxins such as tetanus, diphtheria, dysentery, and the persistence of the toxin in the system of the scorpion.The immunity response of scorpions to bacterial toxins and toxoids and to bacterial somatic antigens.Susceptibility of scorpions to homologous and heterologous scorpion venoms, and to a variety of snake venoms.

The bulk of these investigations have been done on the 3 most common genera of South African scorpions: Hadogenes, Opisthophthalmus and Parabuthus, the venoms of which have made the subject of previous investigations by the authors (Grasset, Schaafsma and Hodgson, 1945). For zoological taxonomy see Hewitt (1918) and Lawrence (1942).