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M el-Salhy

Publications and source records attributed to M el-Salhy.

At least 19 recordsLinked to original sources
PubMed2002

The possible role of the gut neuroendocrine system in diabetes gastroenteropathy.

Gastrointestinal symptoms such as nausea and vomiting, heartburn, abdominal pain, diarrhoea, constipation and faecal incontinence are common in patients with diabetes. Diabetes gastroenteropathy is a clinically relevant problem. In addition to the increased morbidity it causes, it results in severely impaired metabolic control, which in turn increases the risk of hyper-/hypoglycaemia. Moreover, the poorly controlled blood glucose level increases the risk of secondary diabetes complications, namely, retinopathy, nephropathy, neuropathy and cardiovascular affection. Gastrointestinal symptoms may also cause malnutrition in patients with diabetes, which, together with the disturbed immune defence in diabetes, may cause intercurrent infections. Gastrointestinal symptoms in patients with diabetes are attributed to disturbed gastrointestinal motility. Gastrointestinal dysmotility in diabetes is believed to be caused by autonomic neuropathy and/or hyperglycaemia. The neuroendocrine system of the gut secretes peptides/amines that play an important role in regulating gastrointestinal motility. It is conceivable, therefore, to assume that a disturbance in this regulatory system may contribute to the pathogenesis of gastrointestinal complications in diabetes. The present review gives an updated overview of the abnormalities in the gastrointestinal neuroendocrine system in diabetes, speculates upon the possible role of these abnormalities in the pathogenesis of diabetes gastroenteropathy and, finally, predicts the possible clinical implications of these findings.

Animals↗
PubMed2000

Does diabetic state affect co-localization of peptide YY and enteroglucagon in colonic endocrine cells?

BACKGROUND: Changes in the numbers of PYY- and enteroglucagon-immunoreactive cells in colon of animal models of human diabetes have been reported. As these peptides co-localize in the same cells it is possible that the observed changes are a result of changes in co-localization. METHODS: Animal models of human type 1 and type 2 diabetes, namely the non-obese diabetic (NOD) mouse and the obese (ob/ob) mouse, were studied. As controls for the NOD mice, BALB/cJ mice were used and for ob/ob mice, homozygous lean (+/+) mice were used. Tissue samples from colon were double-immunostained for PYY and enteroglucagon according to the indirect immunofluorescence method. RESULTS: Co-localization of enteroglucagon and PYY was found in colonic endocrine cells in all groups investigated. Compared with controls, pre-diabetic NOD mice showed a decreased proportion of enteroglucagon/PYY co-localization. There was no difference in diabetic NOD mice or diabetic ob/ob mice when compared with controls. CONCLUSIONS: Whereas the number of cells containing solely enteroglucagon and solely PYY increases in pre-diabetic NOD mice, production of enteroglucagon in PYY-immunoreactive cells decreases. Although the numbers of PYY and enteroglucagon cells have been reported to be changed in both diabetic NOD mice and in obese mice, the balance between co-expressing and mono-expressing cells seems to be preserved.

Animals↗
PubMed1999

Human rectal endocrine cells and aging.

Endocrine cells of the human rectum were investigated by immunocytochemistry and quantified by computerized image analysis in three different age groups. The age intervals were 20-29, 40-49 and 60-69 years. No statistically significant differences were found between the age groups, regarding the numbers of all endocrine cell types investigated, namely peptide YY (PYY)-, pancreatic polypeptide (PP)-, enteroglucagon-, somatostatin- and serotonin-immunoreactive cells. Nor was there any difference regarding the cell secretory index. Nuclear volume was significantly greater in the 40-49 year olds than the other age groups. There was no statistically significant difference between females and males regarding numbers of the endocrine cell types investigated. It is concluded that age does not affect the endocrine cells of the human large intestine as it was earlier found in animal models of aging. It is imperative that caution should be taken when applying results obtained in animal models of aging in humans.

Adult↗
PubMed1999

Age-related changes in antral endocrine cells in mice.

Antral endocrine cells in four age groups of mice, namely prepubertal (1 month old), young (3 months old), ageing (12 months old) and senescent (24 months old), were detected by immunocytochemistry and quantified by computerized image analysis. A statistical difference was detected between the different age groups regarding the numbers of gastrin-, somatostatin-, and serotonin-immunoreactive cells. The number of gastrin-immunoreactive cells significantly increased between 1 and 12 months, whereas they became significantly fewer between 12 and 24 months. Somatostatin-immunoreactive cell number increased significantly in 1-, 12- and 24-month-old mice, compared with young mice (3 months old). The number of serotonin-immunoreactive cells also increased significantly in 1- and 12-month-old mice as compared with young mice. There was a statistical difference between different age-groups regarding the cell secretory index (CSI) of somatostatin- and gastrin-immunoreactive cells, the CSI of both somatostatin- and serotonin-immunoreactive cells increased significantly in 1-, 12-, and 24-month-old mice, compared with young mice. There was no statistical difference between the different age-groups regarding the CSI of gastrin-immunoreactive cells, nor between males and females regarding the number and CSI of all the endocrine cell types investigated. It is suggested that the large number of somatostatin-immunoreactive cells in ageing and senescent mice might have an impact on the gastric delay seen in the elderly. It was concluded also that the changes in the antral endocrine cells could be involved in the development of dysfunction of the gastrointestinal tract inherent in ageing, or could be secondary to structural and functional changes in the alimentary tract caused by ageing.

Aging↗
PubMed1999

Changes in intestinal endocrine cells in the mouse after unilateral cervical vagotomy.

The effect of right or left unilateral cervical vagotomy on the intestinal endocrine cells was studied in 23 mice at 2 and 8 weeks after operation, respectively. The results were compared with that from 10 sham operated mice. Various types of endocrine cells in duodenum and proximal colon were detected by immunohistochemistry and quantified by computerized image analysis. In mouse duodenum, chromogranin-, CCK/gastrin-, GIP- and somatostatin-cells were significantly decreased at 2 weeks after right vagotomy, but returned to the control levels at 8 weeks. Serotonin-cells were reduced at both 2 and 8 weeks after right vagotomy. The amount of the duodenal endocrine cells did not change after left vagotomy with the exception of secretin-cells, which were diminished at 8 weeks after both right and left vagotomy. In the proximal colon, chromogranin-cells were also decreased at 2 weeks after right vagotomy. Serotonin-cells were reduced at 8 weeks after left vagotomy but not right vagotomy. There was no significant difference between the unilaterally vagotomized and the sham operated mice with regard to PYY- and glucagon-cells. It was concluded that vagotomy affected the intestinal endocrine cells in mouse. The influence was more pronounced in the small intestine than the proximal colon. The right vagus nerves seemed to exert more effect on the intestinal endocrine cells than the left ones.

Animals↗
PubMed1999

Effects of unilateral cervical vagotomy on antral endocrine cells in mouse.

The present study was carried out to investigate the effect of unilateral cervical vagotomy on the antral endocrine cells in mouse. Fifty-four mice were randomly divided into three groups, 18 in each, for left or right cervical vagotomy, or sham operation as controls. The animals were sacrificed 2, 4, and 8 weeks after the operation, respectively. Chromogranin-, gastrin/CCK-, serotonin-, and somatostatin-cells were detected by immunohistochemistry and quantitated by computerised image analysis. The results showed that the number of chromogranin-cells was decreased in both left and right vagotomized mice after 4 weeks and remained at the same level after 8 weeks. The numbers of gastrin-, serotonin- and somatostatin-cells did not change after right vagotomy. However, the numbers of gastrin- and somatostatin-cells were decreased after left vagotomy, whereas no change was found in serotonin-cells. Endocrine cells with vacuolated cytoplasm and pyknotic nuclei were also observed during the course of time. The alteration in the antral endocrine cells observed in this study seemed to be dynamic and depended on the observation time after the operation as well as the denervated branches of the vagus nerve. This may explain, at least partially the contradictory results obtained earlier by different investigators.

Animals↗
PubMed1999

Endocrine cells in the upper gastrointestinal tract in relation to gastrointestinal dysfunction in patients with familial amyloidotic polyneuropathy.

Gastrointestinal (GI) dysfunction is a common complication of familial amyloidotic polyneuropathy (FAP). In previous reports, a decreased content of small and large intestinal endocrine cells has been found in patients with FAP and it has been suggested that this may contribute to the development of GI disturbances. The aim of the present study was to investigate the endocrine cell content in the stomach and duodenum of FAP patients, and to correlate the findings with gastric emptying. Fifteen patients with FAP were included in the study. Twenty-eight subjects with macroscopically and histologically normal mucosa were used as controls for endocrine cell contents and 14 healthy subjects for gastric scintigraphy. The endocrine cells were identified by immunohistochemistry and quantified with image analysis. Gastric emptying time was detected by scintigraphy and endoscopy. The number of chromogranin A-immunoreactive (IR) cells was reduced in all investigated parts of the GI tract except bulbus duodeni. Gastrin/CCK cell content was reduced in duodenum, but tended to be increased in antrum of the stomach (P = 0.07). Otherwise, the content of all other endocrine cells types in the upper GI tract was reduced compared with controls. A correlation with malnutrition was found for gastric inhibitory polypeptide and secretin cell content in bulbus duodeni. Gastric scintigraphy disclosed delayed gastric emptying of solid food, but the finding was not correlated to the decreased content of neuroendocrine cells. The severity of endocrine cell depletion was not correlated to duration of GI disturbances. The present study showed that the endocrine cells of the stomach are affected in FAP patients and that the abnormalities in the upper GI endocrine cells occur early during the course of the disease.

Adult↗
PubMed1999

Intestinal endocrine cells in myotonic dystrophy: an immunocytochemical and computed image analytical study.

OBJECTIVES: To study intestinal endocrine cell types in patients suffering from myotonic dystrophy (MD) and diarrhoea. DESIGN: Comparative study between MD patients and matched controls. SETTING: Departments of Medicine, Central Hospital, Boden, and University Hospital, Umeå, Sweden. SUBJECTS: Ten patients with MD (four males and six females) and suffering from diarrhoea. Ten healthy volunteers served as controls for the duodenal study and 13 patients under investigation for rectal bleeding and with endoscopically normal mucosa were controls for the rectal study. MEASUREMENTS: The duodenal and rectal endocrine cell types were identified by immunohistochemical investigation and quantified by computed image analysis. RESULTS: The total endocrine cell area in the duodenum as demonstrated by chromogranin A-immunoreactivity was significantly increased in MD as compared with the controls (126 +/- 58 vs. 48 +/- 22 x 10(3) micron 2 mm-2 in crypts and 230 +/- 183 vs. 28 +/- 22 in villi, respectively, P < 0.01). The increase included all types of endocrine cells studied, namely those positive for serotonin, cholecystokinin (CCK)/gastrin, secretin, gastric inhibitory peptide (GIP) and somatostatin. In the rectum, the total endocrine cell area as determined by chromogranin A-immunoreactivity was also significantly increased, but there was no statistical difference between the controls and patients with respect to the area of serotonin-, peptide YY (PYY)-, pancreatic polypeptide (PP)- or somatostatin-immunoreactive cells. CONCLUSIONS: The increase in endocrine cell area indicates a disturbed endocrine regulation of the gastrointestinal tract that may contribute to the development of gastrointestinal symptoms encountered in MD patients.

Adult↗
PubMed1998

The nature and implication of intestinal endocrine cell changes in coeliac disease.

Coeliac disease is associated with intestinal lesion. This lesion causes architectural derangement of the mucosa in the form of villus atrophy, increased crypt length and increased volume of the lamina propria. Several changes in the intestinal endocrine cells have been reported over the years, e.g. the number of secretin cells and increased numbers of GIP, CCK/gastrin, motilin, and serotonin cells. There is no consensus about the nature of the changes in somatostatin-cells. It has been postulated that the changes in the endocrine cells are a selective process to meet the new demands exerted by the dramatic decrease in intestinal absorptive area. It has been speculated further that the changes in the endocrine cells would cause an incomplete digestion of the ingested food and its rapid elimination from the intestine. These changes may be responsible for the diarrhoea and steatorrhoea that occur in patients with coeliac disease.

Celiac Disease↗
PubMed1998

Oxidative stress and amyloidosis.

From recent findings concerning free radical injury in several types of amyloidosis, it appears that free radical injury is involved either amyloid formation or in post-fibrillar modification. As we show in this review, among the more than 20 different types of amyloidosis, only a few types of amyloidosis present direct evidence of free radical involvement in amyloid formation. However, if we search further for other types of amyloidosis, other important information on free radical injury may be forthcoming. Free radical injury is probably central for the toxic properties of amyloid deposits.

Alzheimer Disease↗
PubMed1998

Myenteric plexus in the gastrointestinal tract of non-obese diabetic mice.

The myenteric plexus was investigated in the gastrointestinal tract of pre-diabetic and diabetic non-obese diabetic (NOD) mice. The plexus was immunostained by the avidin-biotin complex method, using a general marker for nerve elements, namely protein gene-product 9.5. The nerve fibres were quantified by point-counting and the number of ganglia and their area were determined by image analysis. The relative volume density of the nerve fibres in duodenal muscularis propria was found to be significantly reduced in of both pre-diabetic and diabetic NOD mice. There was no statistical difference between controls and NOD mice regarding relative volume density of nerve fibres in antral and colonic muscularis propria. The number of myenteric ganglia/mm baseline was significantly decreased in the duodenum of diabetic NOD mice, and showed a non-statistically significant tendency to decrease in pre-diabetic mice. In the antrum and colon, there was no difference between the controls and NOD mice regarding the number of ganglia/mm baseline. Nor was there any significant difference between controls and NOD mice in the area of myenteric ganglia in either antrum, duodenum or colon. It is concluded that the changes in the duodenal myenteric plexus of NOD mice are prior to the onset of diabetes. It is suggested that the absence of changes in the antral and colonic myenteric plexus when using a general marker for neuroelements does not preclude a possible change in cholinergic, adrenergic or peptidergic innervation.

Animals↗
PubMed1998

Colonic neuroendocrine peptide levels in patients with chronic idiopathic slow transit constipation.

The motility disorders in patients with slow-transit constipation have been attributed to a disturbance in the peptidergic innervation of the colonic enteric nervous system. The nature of this disturbance is, however, controversial. In the present study 7 patients with long-standing severe slow- transit constipation were included, and normal tissues from the colon of 6 patients, which had undergone colonectomy because of polyp, chronic diverticulitis, prolapsis and volvulus were used as controls. The concentrations of several neuroendocrine peptides were measured in tissue extracts by radioimmuno-assays. The level of pancreatic polypeptide was high in 2 patients and low in one patient. Peptide YY level was high in 3 patients and low in one patient, and that of neuropeptide Y was high in 4 patients. Somatostatin and vasoactive intestinal polypeptide levels were high in 3 patients and substance P concentration was low in 3 patients. Neurotensin level was high in one patient and low in another patient. Galanin concentration was low in 2 patients and high in one patient. Gastrin-releasing peptide level was high in one patient and that of enkephalin was high in 2 patients. All patients had altered concentrations of several neuroendocrine peptides except one, who had only a low level of galanin. It is concluded that patients with slow-transit constipation have disturbed neuroendocrine peptides in common, though the nature of this disturbance varies between patients and in most patients several neuroendocrine peptides were affected. This may explain the controversial results obtained in previous studies.

Adult↗
PubMed1997

Evaluation of immunohistochemical staining of human duodenal endocrine cells after microwave antigen retrieval.

The effect of microwave antigen retrieval on the immunostaining of human duodenal endocrine cells in formaldehyde-fixed, paraffin-embedded material was investigated. The sections were immunostained by the avidin-biotin complex (ABC) and immunogold-silver autometallography (IGSS) methods with and without prior microwave treatment. Dilutions of up to 1:30,000 of the following antisera/antibodies were used: anti-chromogranin A, anti-chromogranin AB, anti-secretin, anti-gastrin, anti-gastric inhibitory polypeptide, anti-somatostatin and anti-serotonin. The detection threshold for all the antibodies was lower after antigen retrieval, and the primary antibody could be used in higher dilutions. The dilutions varied for different antibodies and were between two and ten times the optimal dilution without antigen retrieval. At extremely high dilutions of, or without, the primary antibody, non-specific staining of some lymphocytes and the mucus of some goblet cells was observed when the avidin method was applied, but not with the immunogold technique. This phenomenon was not observed when optimal dilution or a lower dilution was used. This seems to have been caused by the binding of the avidin-biotin complex to epitopes in these structures unmasked by microwave treatment when competition with specific binding sites was absent.

Adult↗
PubMed1997

Application of computer image analysis in endocrine cell quantification.

Computer image analysis was applied for quantifying endocrine cells by using an automatic standard sequence analysis operation. Two parameters were used, namely the number of cells per mm3 of epithelial cells and the cell secretory index (the volume of the immunoreactive secretory granules per cell). The first indicates the variation in the anatomical peptide-producing unit and the second the synthesis and secretion activity of the cell. The endocrine cells chosen in this study were chromogranin-immunoreactive cells and secretin-immunoreactive cells in the human duodenum. The measurements were made by five different investigators with different backgrounds in order to evaluate the effect of the intra- and inter-individual variation. This study showed that the intra- and inter-individual variation had no impact on the results. Comparisons with the classical point-counting method considered to be easy and most efficient in volumetry showed that the present approach is between two and three times faster and less strenuous for the performer. It is concluded that this approach seems to be suitable for adaptation in morphometric studies when information is required about the changes in the number of endocrine cells and about changes in secretory activities.

Adult↗
PubMed1997

Image analysis of the duodenal endocrine cells in mice with particular regard to optical densitometry.

The endocrine cells in the murine proximal duodenum have been investigated by means of immunohistochemistry and computerized image analysis. Five endocrine cell types were identified, namely secretin-, gastric inhibitory polypeptide (GIP)-, gastrin-CCK-, somatostatin- and serotonin immunoreactive cells. The number of endocrine cells/mm3 epithelial cells was estimated and the cell secretory index (CSI) for different endocrine cell types was determined. Furthermore, the optical density of the cellular immunoreactivity and the immunoreactive area in the cell were determined and an index, cell immunoreactivity content was estimated as the optical density multiplied by the immunoreactive area. It has been suggested that the use of this index might better reflect the cellular peptide/amine content than does the CSI. Serotonin-immunoreactive cells were the predominant endocrine cell type, followed by gastrin/CCK-immunoreactive cells. The numbers of secretin-, GIP- and somatostatin immunoreactive cells were almost identical. All endocrine cell types were present both in crypts and in villi, but were, more numerous in the crypts, except for secretin which was more frequent in the villi.

Animals↗
PubMed1996

Peptidergic innervation of the human gallbladder.

The human gallbladder was investigated by means of immunohistochemical methods for the occurrence of peptidergic nerve fibres. In the gallbladder 11 types of peptidergic nerve fibres were observed. These were somatostatin-, pancreatic polypeptide (PP)-, peptide YY (PYY)-, neuropeptide Y (NPY)-, vasoactive intestinal peptide (VIP)-, gastric inhibitory peptide (GIP)-, neurotensin-, cholecystokinin (CCK)/gastrin C-terminus, substance P-, galanin- and serotonin-immunoreactive nerve fibres. NPY- and GIP-containing neurones were occasionally observed in the ganglionated plexus in the fibromuscular coat. Somatostatin-, NPY-, neurotensin-, and galanin-immunoreactive nerve fibres were abundant. The other nerve fibres were few. Peptidergic nerve fibres occurred in the lamina propria mucosae around and in close contact with the basement membrane of the epithelial cells. In the fibromuscular coat, they lied mainly around the muscle bundles. They showed no special arrangement in the perimuscular connective tissue. In both arteries and veins somatostatin-, neurotensin, and galanin nerve fibres were detected in both tunica media and tunica adventitia. NPY-nerve fibres were found in tunica media and substance P- and GIP- nerve fibres in tunica adventitia. The peptidergic nerve fibres observed in the gallbladder outnumbered those observed with the peripheral nerve markers used in this study. It has been speculated that this might be due to the coexistence of several neuropeptides in the same nerve fibre and/or the coexistence of these neuropeptides with a classical neurotransmitter.

Adult↗