Influence of somatostatin on acute pancreatitis in rats

Previously, we purified a protein with a molecular mass of 10 kDa (p10) that increases transiently during the regeneration of legs in the nymphal American cockroach Periplaneta americana, and showed that it is localized exclusively in the cytosol and on the external side of the newly formed epidermis of the regenerating legs [Nomura, A. et al. (1992) Int. J. Dev. Biol. 36, 391-389]. We isolated p10 cDNA and analyzed the expression of the p10 gene. The results indicated that p10 is synthesized as a precursor protein with a putative prosegment including a signal sequence at its N-terminal. The deduced amino acid sequence of p10 showed 53% and 47% identities with those of A10 (a Drosophila antennal protein) and CLP-1 (a moth, Cactoblastis cactorum labial palp protein), respectively. Expression of the p10 gene was shown to be significantly enhanced in regenerating Periplaneta legs. Immunoblotting analysis revealed that p10 was expressed not only in the regenerating legs, but also in the antennae and heads of nymphal and adult cockroaches.     

Changes in blood sugar, and insulin levels induced by somatostatin in normal, diabetic and acromegalic subjects

The effect of somatostatin on plasma sugar and insulin levels was determined in 8 normal, 7 diabetic and 5 acromegalic subjects. An absolute fall in blood sugar values on the order of about 20% was noted, though during administration of the drug only, in all cases. Normal and diabetic subjects also showed an approximately 40% decrease in blood insulin, whereas no such fall was observed in the acromegalic. In spite of the simultaneous fall in insulin levels, it was clear that the reduction in blood sugar was ascribable to a drug-induced block of glucagon secretion. The part possibly played by somatostatin in the regulation of glucide homeostasis is examined in the light of these results.     

Chronic pancreatitis, acute pancreatitis

MRCP has been recognized as a safe and noninvasive diagnostic method. In the present study we evaluated the usefulness of MRCP in diagnosis of chronic and acute pancreatitis. Two-dimensional fast asymmetric spin-echo (FASE) MRCP was performed in 40 patients with chronic pancreatitis and 13 with acute pancreatitis. In 29 patients (72.5%) with chronic pancreatitis and 9 (66.7%) with acute pancreatitis, main pancreatic duct (MPD) was visualized entirely. MRCP could demonstrate the characteristic findings of chronic pancreatitis such as dilatation and irregularity of MPD in most cases. In acute pancreatitis, MRCP indicated that MPD was normal in diameter, but irregular in configuration compared with that of the control group. MRCP may facilitate the diagnosis of chronic and acute pancreatitis.     

Influence of food on glycemia, insulin, C-peptide and glucagon levels in diabetic patients treated with antidiabetic metformin at steady-state

Seventeen diabetic patients (5 males and 12 females) treated with long-term metformin therapy received their morning dose after an overnight fast or after one of four types of breakfast: low protein, low fat, low carbohydrate or standard. Mean (+/- SD) and median areas under the serum concentration curves (AUC), maximum concentrations (Cmax) and time to reach the maximum concentrations (tmax) were calculated for the major biological parameters (glycemia, C-peptide, insulin and glucagon levels). None of the diets were bioequivalent to the fasting condition and only the low carbohydrate diet gave comparable results. A strong relationship was found between the carbohydrate intake (in g) and the AUC of the various markers except glucagon.     

C-peptide levels in secondary sulfonylurea resistant diabetics

In the presence of clinical features of secondary drug failure--even after reeducation on diet and intensive control of patients--is difficult to make a decision to switch on insulin. Therefore the serum C-peptide concentrations were assessed in order to get supporting data. From 35 patients with suspected secondary drug failure the therapy of 11 patients was continued with insulin, 24 patients remained on glibenclamide therapy. The decision based on clinical criteria. All of the patients were studied in i.v. glucagon test and with a test meal to evaluate their basal and stimulated serum C-peptide concentrations. There were only three patients with subnormal basal C-peptide (< or = 0.30 nmol/l), on the other hand nine patients had lower post-glucagon serum C-peptide level than 0.60 nmol/l. The basal and stimulated C-peptide concentrations from i.v. glucagon test and test-meal indicated the need of insulin therapy with a sensitivity of 81.8 percent and with specificity of 70.8 percent. The further glibenclamide treatment on the basis of C-peptide concentrations in 89.5 percent of cases could be accurately established. The statistical analysis showed that the glucagon-stimulated C-peptide concentration was the most characteristic feature to discriminate the patients in order to make a decision on the further diabetes therapy.     

Significance of monitoring cytokine levels in the prognosis of acute pancreatitis

Dupuytren's disease and its treatment have always been a fascinating subject. The operation technique, Guillaume Dupuytren performed the 12th of June 1831, does not appear obsolete, even today more than 150 years later (1). Almost the same technique as described in the original text was used. Guillaume Dupuytren was, in his time, a surgeon of true genius.     

Leptin inhibits in vitro hypothalamic somatostatin secretion and somatostatin mRNA levels

Leptin, the product of the ob gene, is a recently discovered hormone secreted by adipocytes that regulates food intake and energy expenditure. The site of action of leptin is likely to be the hypothalamus, since this area is important in the control of food intake and leptin receptor mRNA is particularly abundant in this area. In order to further unravel the mechanisms by which leptin acts, we have studied the effect of leptin on in vitro somatostatin synthesis and secretion. Leptin administration to fetal rat neurones in monolayer culture led to a time dependent decrease in basal somatostatin secretion and somatostatin mRNA levels, the maximal effect being observed with 6x10(-8) M leptin after 24 h incubation. Furthermore, leptin completely blunted 10(-7) M Neuropeptide Y-induced increase in somatostatin secretion and somatostatin mRNA levels as well as 10(-3) M (Bu)2-cAMP and 10(-6) M A23187-induced somatostatin secretion. Finally, leptin (3x10(-8) M M) also inhibited low glucose (1.1 mM) induced-somatostatin secretion in perifused adult hypothalami. This data indicates that leptin can influence the neuroendocrine system by regulating hypothalamic somatostatin gene expression.     

Behavior of C-peptide, insulin and glucose levels in blood during conditions of evaluating selected antihypertensive drugs in patients with hypertension and non-insulin-dependent diabetes (type 2)

In 60 patients divided in three groups, each of 10 non-diabetic patients with essential hypertension (h) and of 10 hypertensive type 2 (non-insulin-dependent) diabetics (h+c), aged 31-63 years, the effect of 2-week treatment with nifedipine, captopril and prazosin on glycaemia, serum insulin (IRI) and C peptide (CP) after oral and i.v. glucose loading was compared. Nifedipine resulted in higher glycaemia levels in the oral test in both groups. This drug caused in group (h), but not in group (h+c), reduction of the glucose-dependent early increases of serum IRI and CP, more marked in respect to CP, what was expressed by the decrease of the serum CP:IRI ratio. These results prove that in non-diabetic patients nifedipine reduces the early response of the B-cells to glucose, but this effect is partly compensated by decreased insulin uptake by the liver. In patients with type 2 diabetes this phenomenon has not become manifest because of absence or reduction of early glucose-dependent insulin release. After captopril in both groups lower values of glycaemia and serum IRI and CP were found. Prazosin did not change the determined blood parameters. Conclusion: nifedipine, captopril, prazosin have a small influence on secretory function of pancreatic B-cells and may be recommended for the treatment of hypertension in patients with type 2 (non-insulin-dependent) diabetes.     

Reversal of somatostatin inhibition of insulin and glucagon secretion

These studies were designed to elucidate the mechanism of inhibitory action of somatostatin (SRIF) on glucagon (IRG) and insulin (IRI) secretion. Studies were carried out in the unrecirculated isolated rat pancreas perfusion with arginine 19.2 mM and glucose 5.5 mM as stimulus primarily for IRG but also IRI secretion. The effects of excess Ca++ (15.2 mEq./L.) and excess K+ (12.8 mEq./L.) on IRG, IRI, and the SRIF-inhibited pancreas were studied. Ca++ excess in five perfusions strikingly stimulated IRG secretion (+92 per cent) but only stabilized IRI secretion compared with control perfusions. K+ excess (in seven perfusions) markedly inhibited IRG secretion (-39 per cent) while stimulating IRI secretion (+16 per cent). Restoration of normal concentrations of K+ resulted in a rebound of IRG to levels 120 per cent that of controls. SRIF, at concentrations from 0.1-20 ng./ml., produced inhibition of both IRG and IRI. In 11 perfusions, with SRIF at 10 ng./ml., IRG decreased more than IRI (-75.2 per cent IRG and -46.9 per cent IRI). In five perfusions, addition of Ca++ (15.2 mEq./L.) 10 minutes after SRIF was started resulted in a reversal of IRG inhibition to 69.4 per cent and IRI to 73.2 per cent of the arginine controls. The reversal by Ca++ of SRIF effect on IRG was greater at higher concentrations of Ca++, suggesting some form of competition. In four perfusions, excess K+ reversed SRIF-induced IRI inhibition to 79.6 per cent that of controls but had no effect on IRG inhibition. Studies in vitro with isolated islets revealed that SRIF (2 mug./ml.) inhibited 45Ca uptake of islets as did epinephrine (10(-5) M). It was concluded that SRIF-induced inhibition of hormone release appears related to an action on Ca++ uptake.     

Slowly deteriorating insulin secretion and C-peptide production characterizes diabetes mellitus in infantile cystinosis

Infantile cystinosis, a rare lysosomal storage disease of cystine, leads to Fanconi syndrome and end-stage renal failure. After renal transplantation, no recurrence of the disease occurs in the graft, but other organ involvement becomes evident later in life. Diabetes mellitus has been associated with cystinosis, but the mechanisms of impaired glucose tolerance have not yet been characterized. Here, we studied glucose tolerance, glucose constant decay (k-values), insulin and C-peptide by intravenous glucose tolerance test (IVGTT) in eight patients with infantile cystinosis (three with impaired GFR (CRF) and five after kidney transplantation (KTX)). For comparison, 15 age-matched children with CRF and 15 age-matched KTX patients were analysed. Both early and second insulin secretion phases were diminished in patients with infantile cystinosis, whereas in CRF, k-values were no different from control patients. After renal transplantation, k-values were significantly lower in cystinotic patients with a markedly reduced early insulin secretion phase. There was a significant negative correlation between k-values and age in patients with cystinosis. Repetitive IVGTTs in these patients demonstrated progressive but rather slow loss of first phase insulin secretion and C-peptide production, suggesting a slowly reducing secretion potential of the beta cell due to cystine storage. CONCLUSION: Unlike type I diabetes mellitus, glucose intolerance in patients with infantile cystinosis is characterized by a slow, progressive loss of insulin secretion and C-peptide production. For these patients, the data indicate a 50% risk of developing glucose intolerance by the age of 18 years. We recommend to perform intravenous glucose tolerance tests at 5-year intervals.     

Plasma levels of TNF and IL-6 following induction of acute pancreatitis and pentoxifylline treatment in rats

Activation of cytokine cascade is a decisive factor in determining the pathobiology of different inflammatory processes including acute pancreatitis. The purposes of this study were to determine the TNF and IL-6 levels after the induction of acute necrotizing pancreatitis, and to establish the effects of pentoxifylline on the cytokine production and the severity of pancreatitis. Acute necrotizing pancreatitis was induced by the retrograde injection of 200 microliters taurocholic acid into the pancreatic duct in male Wistar rats. TNF was titrated in a bioassay on cell line WEHI clone 164. IL-6 was measured via its proliferative action on the IL-6 dependent mouse hybridoma cell line B-9. Seven mg/kg pentoxifylline was administered intraperitoneally at the time of operation and/or 24 hours later. Rats were sacrificed, 48 or 72 hours after the operation. The TNF bioassay revealed high levels of TNF (36.6 +/- 6.0 U/ml) in the control group whereas levels decreased to zero in the pentoxifylline-treated group. The IL-6 bioassay likewise demonstrated high levels of IL-6 in the control group and markedly decreased levels in the pentoxifylline treated group (7083 +/- 2844 pg/ml, 6463 +/- 1307 pg/ml vs. 137.5 +/- 85.5 pg/ml, respectively, p < 0.05). The high mortality observed in the control group (43%) was sharply decreased by pentoxifylline administration to 11%. The data suggest that pentoxifylline is capable of modifying the cytokine production after 48 hours of induction of acute pancreatitis.     

Plasma lipase, C-peptide reactivity and human pancreatic polypeptide responses after ingestion of elemental diet in patients with chronic pancreatitis

Plasma lipase, C-peptide reactivity (CPR) and human pancreatic polypeptide (HPP) responses after ingestion of elemental diet were studied in 27 patients with chronic pancreatitis. These subjects were classified into 3 groups according to ERP findings; minimum or mild (MIP, n = 17), moderate (MOP, n = 6) and advanced (ADP, n = 4). Basal plasma lipase levels in the MIP and MOP patients were significantly higher than that in the controls (P < 0.05). Plasma CPR response (sigma delta CPR) in MIP cases were significantly higher than that in controls (P < 0.05). Also, plasma HPP (response (sigma delta HPP) in MIP cases were significantly higher than that in controls (P < 0.05). Plasma CPR and HPP responses correlated with the severity of chronic pancreatitis. Fourteen of the 17 MIP patients (82%) showed higher levels of basal lipase or sigma delta HPP in comparison to the respective normal ranges. This study suggested that the ED test may be more sensitive for detection of mild chronic pancreatitis and that it may be useful for evaluating exocrine and endocrine pancreatic functions in various stages of chronic pancreatitis.     

Therapy of acute pancreatitis

Therapy in patients with acute pancreatitis (AP) is primarily conservative and follows the rules of generally accepted principles. A very important basis in the treatment of AP is the interdisciplinary approach to this disease which demands teamwork between clinicians, intensive care specialists and surgeons. Patients with a necrotising course should be hospitalised on the ICU and should receive maximum intensive care measures and antibiotics. Indications for surgical interventions in severe AP are infected pancreatic necrosis and non-response to intensive care therapy.     

Practical imaging in acute pancreatitis

This paper outlines the "voxel reconstruction" technique used to model the macroscopic human anatomy of the cranial, abdominal and cervical regions directly from CT scans. Tissue composition, density, and radiation transport characteristics were assigned to each individual volume element (voxel) automatically depending on its greyscale number and physical location. Both external beam and brachytherapy treatment techniques were simulated using the Monte Carlo radiation transport code MCNP (Monte Carlo N-Particle) version 3A. To obtain a high resolution dose calculation, yet not overly extend computational times, variable voxel sizes have been introduced. In regions of interest where high attention to anatomical detail and dose calculation was required, the voxel dimensions were reduced to a few millimetres. In less important regions that only influence the region of interest via scattered radiation, the voxel dimensions were increased to the scale of centimetres. With the use of relatively old (1991) supercomputing hardware, dose calculations were performed in under 10 hours to a standard deviation of 5% in each voxel with a resolution of a few millimetres--current hardware should substantially improve these figures. It is envisaged that with coupled photon/electron transport incorporated into MCNP version 4A and 4B, conventional photon and electron treatment planning will be undertaken using this technique, in addition to neutron and associated photon dosimetry presented here.     

Therapy of acute pancreatitis

The mortality rate in acute pancreatitis (AP) is significantly lower in patients hospitalized directly at the intensive care unit than in patients admitted to hospital in 2 weeks after the assessment of diagnosis, prophylactic administration of low-molecular protease inhibitor reduces the occurrence of post ERCP pancreatitis a well a coincident complications. Despite rational considerations concerning the significance of pryphylactic administration of antibodies (ATB) in severe AP, there still not enough convincing data which could be recommended a standard therapy. One of the concepts of causal therapy of AP. Suggest that inhibition of exocrine pancreatic enzymatic secretion reduces autodigestion of the gland (setting the gland at rest). The reports on success of secretin-inhibiting substances a glucagon, calcitonin, atropine and somatostatin require confirmation in randomized or accurately defined comparable groups. The initial studies on the therapeutic significance of lexipanphate-antagonist of platelet activating factor (PAF) in acute pancreatitis is promising. A long-term lavage had reduced the mortality.