Jejunal and ileal adaptation to alterations in dietary calcium: changes in calcium and magnesium absorption and pathogenetic role of parathyroid hormone and 1,25-dihydroxyvitamin D.

Previous balance studies have shown that fractional calcium absorption is increased by a low and reduced by a high calcium diet. The present studies were done to determine which segment of the small intestine is most sensitive to alterations in dietary calcium, and to see if dietary calcium intake has an effect on the intestinal absorption of another divalent cation, magnesium. Absorption was measured during constant perfusion of 30-cm segments of jejunum and ileum of normal subjects after 4 or 8 wk of a high (1,900 mg/d) or a low (20 mg/d) calcium diet. We found that calcium absorption rate was higher when subjects had been on a low than when they had been on a high calcium diet; the ileum responded more rapidly and more completely than the jejunum. Similar results were obtained with magnesium, but only the difference in the ileum was statistically significant. Sodium and xylose absorption were not influenced by dietary calcium intake. The serum concentrations of parathyroid hormone and 1,25-dihydroxyvitamin D were higher on the low than on the high calcium diet. We conclude that the ileum is more sensitive than the jejunum to changes in dietary calcium intake, and that ileal adaptation probably plays a major role in protecting the body against a deficiency or excess of body calcium that otherwise would occur when dietary calcium is abnormally low or high. Calcium intake influences ileal magnesium absorption in a similar fashion; it is not known whether or not this serves a protective function. Our data are compatible with the concept that adaptation to dietary calcium intake is mediated by changes in the serum concentrations of parathyroid hormone and 1,25-dihydroxyvitamin D.

Nuclear factor NF-kappa B in myocardium: developmental expression of subunits and activation by interleukin-1 beta in cardiac myocytes in vitro.

OBJECTIVE: The aims of the study were to investigate the pattern of expression of the major subunits of the NF-kappa B transcription factor complex in human and rat heart development, and to characterise the timing of NF-kappa B activation by interleukin-1 beta (IL-1 beta) in rat neonatal cardiac myocytes. METHODS: The expression of NF-kappa B subunits p65 and p50 and the inhibitory subunits I kappa B-alpha and I kappa B-beta in human and rat myocardial samples was measured by immunoblotting, using antibodies, specific to each subunit. The activation of NF-kappa B was measured in neonatal rat cardiac myocytes that were treated with IL-1 beta for different times (0-60 min). Depletion of the inhibitory factors I kappa B-alpha and I kappa B-beta was assessed by immunoblotting. The presence of NF-kappa B DNA binding activity was measured directly in nuclear extracts by electrophoretic mobility shift assay (EMSA). RESULTS: p65, p50, I kappa B-alpha and I kappa B-beta are expressed at all stages of development analysed. In human myocardial samples, expression of p50, p65 and I kappa B-alpha show an apparent gradual decline relative to total protein. In contrast, the level of I kappa B-beta remained relatively constant, suggesting a significant shift in the ratio of beta and alpha subunits with development. In rat myocardium, p65, p50, I kappa B-alpha and I kappa B-beta showed a gradual decline during development, with a particularly pronounced decrease between the ten day post-natal and adult samples. Treatment of neonatal rat cardiac myocytes with IL-1 beta (5 ng/ml) caused a rapid and transient depletion of I kappa B-alpha (reducing to 16 +/- 1.6% of initial levels within 5 min, returning to 82 +/- 10% within 60 min). A slower, less marked depletion is observed for I kappa B-beta (24 +/- 6% by 30 min, returning to only 49 +/- 5% by 60 min). Rapid and transitory accumulation of NF-kappa B DNA binding activity was detected in the nucleus, with a pattern that correlated with the depletion of I kappa B-alpha. CONCLUSIONS: The principal NF-kappa B subunits p65, p50, I kappa B-alpha and I kappa B-beta are present throughout development, suggesting that this transcription complex may participate in myocardial gene regulation throughout development and in the adult. Activation by IL-1 beta demonstrates that NF-kappa B probably plays a direct role in the regulation of gene transcription in response to cytokine activation in cardiac myocytes.

A patient with pseudohypoparathyroidism with increased serum calcium and 1 alpha, 25-dihydroxyvitamin D after exogenous parathyroid hormone administration.

The cause for the normal calcemic response to exogenous parathyroid hormone (PTH) was explored in a case of pseudohypoparathyroidism. The diagnosis of pseudohypoparathyroidism in this 29-yr-old woman was well established, since she had hypocalcemia (6.6 mg/dl), hyperphosphatemia (5.0 mg/ dl), high serum immunoreactive PTH, and negligible urinary cAMP response to exogenous PTH. Treatment with Amphojel slightly increased serum calcium (to 7.4 mg/dl) and lowered serum phosphorus (to 4.1 mg/dl) without altering the serum concentration of 1 alpha, 25-dihydroxyvitamin D [1,25(OH)2D]. After im administration of parathyroid extract (400 U/day for 4 days), serum calcium increased to 9.2 mg/dl, commensurate with significant elevations in serum 1,25(OH)2D (from 1.2 to 2.6 ng/dl) and fractional (intestinal) calcium absorption (from 0.22 to 0.43). The results suggest that the synthesis of 1,25(OH)2D upon PTH challenge was relatively intact and may have accounted for the normal calcemic response.

Effect of 1,25-dihydroxyvitamin D3 on calcium and magnesium absorption in the healthy human jejunum and ileum.

In calcium deficiency states such as chronic renal failure, 1,25-dihydroxyvitamin D3 increases calcium and magnesium absorption toward normal levels. In the present study, the ability of exogenous 1,25-dihydroxyvitamin D3 to increase calcium and magnesium absorption above normal rates in healthy subjects was investigated. Steady-state perfusion studies were performed in 30 cm segments of jejunum and ileum before and after one week of 1,25-dihydroxyvitamin D3 administration (2 micrograms per day, 10 subjects). Serum 1,25-dihydroxyvitamin D concentration increased from 25.8 +/- 2.5 pg/ml to 56.4 +/- 6.6 (mean +/- SEM, p less than 0.05). In the basal state, calcium absorption was significantly higher in the jejunum than in the ileum. Vitamin D administration resulted in a significant increase in calcium absorption which was quantitatively similar in both the jejunum and ileum. The changes in net movement were due to an increase in lumen-to-plasma flux of calcium; the plasma-to-lumen flux remained unchanged. Jejunal magnesium absorption also was enhanced by 1,25-dihydroxyvitamin D3. These studies demonstrate that in healthy persons, exogenous 1,25-dihydroxyvitamin D3 increases calcium absorption in both the jejunum and the ileum, and increases magnesium absorption in the jejunum.

Ambulatory evaluation of nephrolithiasis. Classification, clinical presentation and diagnostic criteria.

Using the ambulatory protocol previously described, 241 patients with nephrolithiasis were evaluated. They could be categorized into 10 groups from the results obtained. Absorptive hypercalciuria type I (87 per cent male) comprised 24.5 per cent and was characterized by normocalcemia, normal fasting urinary calcium (less than 0.11 mg/100 ml glomerular filtration), an exaggerated urinary calcium following an oral calcium load (greater than 0.20 mg/mg creatinine), normal urinary cyclic adenosine monophosphate (AMP) (less than 5.4 nmol/100 ml glomerular filtration) and serum parathyroid hormone (PTH), and hypercalciuria (greater than 200 mg/day during a calcium- and sodium-restricted diet). Absorptive hypercalciuria type II (50 per cent male) accounted for 29.8 per cent; its biochemical features were the same as those for absorptive hypercalciuria type I, except for normocalciuria during a restricted diet and low urine volume (1.42 +/- 0.55 SD liter/day). Renal hypercalciuria (56 per cent male), disclosed in 8.3 per cent, was represented by normocalcemia and high values for fasting urinary calcium (0.160 +/- 0.054 mg/100 ml glomerular filtration), urinary cyclic AMP (6.80 +/- 2.10 nmol/100 ml glomerular filtration) and serum PTH. Primary hyperparathyroidism (57 per cent female), accounted for 5.8 per cent, typically included hypercalcemia, hypophosphatemia, hypercalciuria and high urinary cyclic AMP. Hyperuricosuric calcium urolithiasis (100 per cent male) comprised 8.7 per cent, and was characterized by hyperuricosuria (776 +/- 164 mg/day) and urinary pH exceeding pK for uric acid (5.91 +/- 0.33). In enteric hyperoxaluria (60 per cent female), encountered in 2.1 per cent of cases, urinary oxalate was increased (6.29 +/- 13.2 mg/day). Noncalcium-containing stones were found in 2.1 per cent of the patients with uric acid lithiasis (100 per cent male) and in another 2.1 per cent of the patients with infection lithiasis (60 per cent female). These conditions were typified by low urinary pH (5.29 +/- 0.12) and high urinary pH (6.69 +/- 1.16), respectively. Renal tubular acidosis was found in one patient (male, 0.4 per cent). In 10.8 per cent of the patients (81 per cent male), no metabolic abnormality could be found, although urine volume was low (1.41 +/- 0.51 liter/day). Hypercalciuria could not be differentiated between absorptive hypercalciuria and renal hypercalciuria in 5.4 per cent of the patients. Thus, this ambulatory protocol disclosed a physiologic disturbance in nearly 90 per cent of the cases and provided a definitive diagnosis in 95 per cent of the patients.

A representational analysis of numeration systems.

This article explores the representational structures of numeration systems and the cognitive factors of the representational effect in numerical tasks, focusing on external representations and their interactions with internal representations. Numeration systems are analyzed at four levels: dimensionally, dimensional representations, bases, and symbol representations. The representational properties at these levels affect the processes of numerical tasks in different ways and are responsible for different aspects of the representational effect. This hierarchical structure is also a cognitive taxonomy that can classify nearly all numeration systems that have been invented across the world. Multiplication is selected as an example to demonstrate that complex numerical tasks require the interwoven processing of information distributed across internal and external representations. Finally, a model of distributed numerical cognition is proposed and an answer to the question of why Arabic numerals are so special is provided.

An apparent 1,25-dihydroxyvitamin D-independent stimulation of intestinal calcium absorption in patients with Paget disease of bone during a short-term diphosphonate therapy.

Six patients with Paget disease of bone were treated with a 6-mo course of disodium-ethane-1-hydroxy-1, 1-diphosphate (EHDP) at a dosage of 5 mg/kg/day (one patient) or 20 mg/kg/day (five patients). In addition to symptomatic and biochemical improvement which persisted 3 mo after discontinuance of therapy, EHDP resulted in a significant increase in intestinal calcium absorption that was not correlated with a change in serum 1 alpha, 25-(OH)2-vitamin D concentration. EHDP appears to stimulate intestinal calcium transport by either a vitamin D independent process or by an increased intestinal mucosal cell sensitivity to vitamin D.

Retropharyngeal infection in a pregnant diabetic. A case report.

A retropharyngeal infection occurred in a pregnant class C diabetic at 31 weeks' gestation. Early diagnosis, prompt therapy with antibiotics and possibly surgery for drainage if an abscess develops constitute optimal management.

The 'problem' with automation: inappropriate feedback and interaction, not 'over-automation'.

As automation increasingly takes its place in industry, especially high risk industry, it is often blamed for causing harm and increasing the chance of human error when failures do occur. I propose that the problem is not the presence of automation, but rather its inappropriate design. The problem is that the operations under normal operating conditions are performed appropriately, but there is inadequate feedback and interaction with the humans who must control the overall conduct of the task. When the situations exceed the capabilities of the automatic equipment, then the inadequate feedback leads to difficulties for the human controllers. The problem, I suggest, is that the automation is at an intermediate level of intelligence, powerful enough to take over control that used to be done by people, but not powerful enough to handle all abnormalities. Moreover, its level of intelligence is insufficient to provide the continual, appropriate feedback that occurs naturally among human operators. This is the source of the current difficulties. To solve this problem, the automation should either be made less intelligent or more so, but the current level is quite inappropriate. The overall message is that it is possible to reduce error through appropriate design considerations. Appropriate design should assume the existence of error, it should continually provide feedback, it should continually interact with operators in an effective manner, and it should allow for the worst situations possible. What is needed is a soft, compliant technology, not a rigid, formal one.

Isolation, sequence, and chromosomal localisation of the human IkappaBR gene (NFKBIL2).

The inhibitors of NF-kappaB (IkappaBs) play an important role in the regulation of the NF-kappaB pathway. IkappaBR (for IkappaB-Related) is proposed to be a novel member of this family. We report the cloning and characterization of the region of the human gene encoding the previously reported mRNA. This region contains 13 exons, spread over 6550 bp of genomic sequence. The coding sequence is only weakly similar to other IkappaBs and the exons display a more complicated structure than has been found in other members of the IkappaB gene family. Moreover, the positions of intron-exon junctions are different from those found in other IkappaB genes, even within the otherwise conserved ankyrin-like repeat region, suggesting that the IkappaBR gene is not a member of this extended gene family. We report a revised mRNA and protein sequence for IkappaBR, which predicts that the protein is larger than originally described. We also report the chromosomal localisation of the human IkappaBR gene (approved gene symbol NFKBIL2) to 8q24.3 using PCR-based somatic cell hybrid panel analysis and fluorescence in situ hybridization (FISH) mapping.

Gastrointestinal systemic sclerosis in serologic mixed connective tissue disease.

Mixed connective tissue disease is a clinical entity defined by overlapping features of progressive systemic sclerosis, systemic lupus erythematosus, polymyositis, rheumatoid arthritis, and distinct serologic findings. Esophageal dilatation and dysmotility have been the only gastrointestinal manifestations reported. Three patients with serologic findings of mixed connective tissue disease and extensive gastrointestinal involvement compatible with the changes found in progressive systemic sclerosis are presented. Gastrointestinal manifestations of progressive systemic sclerosis are reviewed and were found to be indistinguishable from the findings in these patients.

Direct current electrotherapy of internal hemorrhoids: an effective, safe, and painless outpatient approach.

Hemorrhoid disease is one of the most frequently occurring, disabling conditions of man. We report the results of 120 patients with symptomatic internal and mixed hemorrhoid disease treated with direct current (d.c.) via a dual-tipped disposable needle probe (negative electrode). Evaluation and treatment utilized an operative anoscope which visualized one-eighth of the anal canal. Five hundred ninety segments revealed hemorrhoid disease (grade 1 = 114, 2 = 222, 3 = 178, 4 = 76). One or more segments (highest grade) were treated per office visit. Symptoms, frequency, and mean number of treatment applications per patient for complete symptom resolution were: bleeding, 85%, 4.0; protrusion, 58%, 3.9; pain, 52%, 3.6; and pruritus, 49%, 3.9. Ablation of hemorrhoid disease grade was directly correlated with milliampere current and time of application. No major complications occurred. All patients were successfully treated and remained symptom-free at a mean duration of follow-up of 23 months. Direct current electrotherapy is an effective, painless, and safe outpatient treatment approach to all grades of internal and mixed hemorrhoid disease.

Massive gastrointestinal hemorrhage from a diverticulum of the appendix.

A patient with massive gastrointestinal hemorrhage found to be bleeding from a diverticulum of the appendix is presented. Appendectomy was curative and pathologic changes were those associated with colonic diverticular hemorrhage. A review of the literature reveals this to be a previously unreported cause of gastrointestinal bleeding.

Influence of glucose, fructose, and water movement on calcium absorption in the jejunum.

The first experiment demonstrated that glucose stimulated calcium absorption. Possible mechanisms include: (a) glucose stimulation of active calcium absorption, (b) glucose stimulation of water absorption with enhanced calcium absorption by solvent drag, or (c) glucose stimulation of water absorption caused an increased luminal calcium concentration with resultant increased active and/or passive calcium absorption. In a second experiment, neither glucose, fructose of water absorption stimulated calcium absorption when luminal calcium concentration was maintained at a constant level. These results suggest: (a) glucose and fructose indirectly enhance calcium absorption via an effect on water movement, (b) water absorption enhances calcium absorption by virtue of concentrating unabsorbed calcium within the intestinal lumen, not by solvent drag, and (c) bulk water movement and passive calcium ion movement take place via separate channels.

Simultaneous hepatic and renal involvement in acute syphilis. Case report and review of the literature.

An unusual case of simultaneously occurring acute syphilitic hepatic and renal disease is presented and a concise literature review of both the pathological and clinical findings in this disease is included. Hepatic and renal biopsies were useful in excluding other diagnostic possibilities and in establishing the correct diagnosis in the case presented.