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Biomedical subjects

J Fritsch

Publications and source records attributed to J Fritsch.

At least 109 records · Page 6Linked to original sources
PubMed1988

Do skin tags constitute a marker for colonic polyps? A prospective study of 100 asymptomatic patients and metaanalysis of the literature.

Several reports have suggested that skin tags may be a marker for the presence of colonic polyps in symptomatic patients referred for colonoscopy. In a prospective study of 100 asymptomatic patients, we found no association between skin tags and colonic polyps. A review of the literature and results of a metaanalysis show a significant association between skin tags and colonic polyps in 777 symptomatic patients, but no association in 268 asymptomatic patients. To explain this discrepancy, several possible biases are analyzed. As skin tags constitute a marker for colonic polyps only in symptomatic patients for whom a colonoscopy is already indicated, their detection is of no diagnostic value in asymptomatic patients.

Aged↗
PubMed1988

Voltage-gated sodium and calcium currents in rat osteoblasts.

1. The whole-cell voltage-clamp mode of the patch-clamp technique was used to investigate the presence of voltage-gated inward currents in osteoblasts from newborn rat calvaria. 2. In K+-free solutions, three kinds of inward currents could be activated by depolarization: a voltage-gated Na+ current and two different types of Ca2+ currents. 3. The Na+ current was activated by depolarization above -40 mV in all the cells. It was reduced by half by 10 nM-TTX (tetrodotoxin). 4. In an isotonic Ba2+ external solution containing TTX, and with a Cs-EGTA internal solution buffered at pCa 8, depolarizing jumps induced both a transient Ba2+ current and a sustained Ba2+ current. The relative proportions of these two currents varied greatly among cells. 5. The transient and sustained Ba2+ currents differ with respect to their time course and their voltage dependence. 6. The depolarization-activated inward currents were also observed under more physiological conditions, in the presence of only 2 mM-external Ca2+ and with a K+ internal solution buffered at pCa 7. 7. A few records obtained in current clamp showed that it is possible to induce action potentials in osteoblasts.

Animals↗
PubMed1988

[Lithiasis of the common bile duct in the aged subject treated with endoscopy (227 patients)].

One hundred and sixteen patients aged from 65 to 80 years (first group including 39 previously cholecystectomized patients) and 161 patients aged over 80 years (second group, including 31 previously cholecystectomized patients) underwent endoscopic papillotomy for choledocholithiasis. We compared clinical, biochemical and morphological features of choledocolithiasis with early results of endoscopic papillotomy. Clinical symptoms were not different between the old and very old patients, cholecystectomized or not. Charcot's triade was observed in one third of patients. Biochemical data just before endoscopic retrograde cholangiography were not different according to groups: 21 p. 100 of the 277 patients had a biological cholestasis without elevation of bilirubin and 10 p. 100 of the patients had no abnormality of the liver function. Diagnosis of choledocholithiasis was accurately suspected in 90 p. 100 of patients. Complete removal of gallstones after endoscopic papillotomy was obtained in 95 p. 100 of patients in the first group and 93 p. 100 of patients in the second group. Morbidity and mortality rates related to endoscopic papillotomy were not different between the 2 groups (6.9 and 0.8 p. 100 in the first group and 8.7 and 3.1 p. 100 in the second group, the first group and 8.7 and 3.1 p. 100 in the second group, respectively). These results suggest that clinical and biochemical features of choledocholithiasis, and early results of endoscopic treatment do not present any particularities in the elderly.

Aged↗
PubMed1988

[Dilatation of the common bile duct without visible obstruction at endoscopic retrograde cholangiography. Description and development].

The aim of this study was to specify the signs and course of patients with a dilated common bile duct without obstruction. We included patients with a dilated common bile duct of more than 12 mm on endoscopic retrograde cholangiography, and we excluded patients with stones, tumor or other visible obstruction. Two hundred and seven patients (8.4 p. 100 of endoscopic retrograde cholangiography) were included. One hundred and nineteen (57.5 p. 100) had undergone cholecystectomy. Sixty-five p. 100 of patients had signs suggesting biliary tract disease, and 78 p. 100 had biological signs of cholestasis. The size of the common bile duct was not different whether the patient had been cholecystectomized (16.2 +/- 0.3 mm.M +/- SEM) or not (16.2 +/- 0.4 mm). Forty-one patients in the non cholecystectomized group had gallbladder stones. Thus, 47 of our 207 patients (23 p. 100) had neither gallbladder stones nor previous cholecystectomy. Endoscopic retrograde cholangiography was completed by endoscopic sphincterotomy in 130 patients, either in the intent of not missing obstruction, or for therapeutic purposes. Follow-up more than one month after endoscopic retrograde cholangiography was available for 159 patients (77 p. 100). The median survival was 73 months. One hundred and ten patients (69 p. 100) were asymptomatic, 36 (23 p. 100) had atypical abdominal pain while 13 (8 p. 100) patients had episodes of biliary colic and/or fever and/or jaundice. During follow-up, an initially unrecognized obstacle was discovered in 8 patients: 5 common bile duct stones, 2 ampullary tumors and one pancreatic tumor.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1987

Comparative studies of membrane potentials of rat osteoblasts in situ and in primary culture.

The aim of the present study was to compare the membrane potential, Vm, of rat calvarium osteoblasts in situ and during primary culture using electrophysiological techniques. For osteoblasts studied in situ the Vm (mean +/- S.D.) was found to be -42.0 +/- 10 mV, n = 32. Comparable values (-46.8 +/- 9.n, n = 152) were found for cultured osteoblasts during the first week. Thereafter when cells began to form multilayers an increase in Vm negativity was observed (-58.6 +/- 12.8, n = 82). The Vm of osteoblasts in situ and during the first week of culture were highly dependent on the Na+ diffusion potential and slightly influenced by the increase in extracellular [K+]. In contrast, the more negative Vm of the cells cultured 2 weeks were highly dependent on the K+ diffusion potential and were not influenced by changes in external [Na+]. Parathyroid hormone (bPTH(1-34], 240 nM, in the external solution, induced a rapid membrane depolarization in situ (+10.2 +/- 5.0, n = 18) as it does in cultured cells. Additional investigation on the possible effects of Ca2+ and PO4(2-) (since, in situ, mineralized matrix prevents such an approach) showed that low external [Ca2+] only slightly hyperpolarizes the membrane, whereas cell Vm was highly sensitive to changes in external [PO4(2-)].

Animals↗
PubMed1986

Short-term effects of PTH on cultured rat osteoblasts: changes in membrane potential.

The introduction of parathyroid hormone [bPTH (1-34)], 10(-8) M, into the medium of cultured rat osteoblasts results in rapid (less than 1 min) depolarization of the osteoblast membranes. Conventional and pH-sensitive microelectrodes were used to assess the mechanism underlying this change. PTH depolarized cell membrane independently of steady-state membrane potential (Vm). Blocking K+ conductance (Ba2+) and Ca2+-dependent K+ conductance (quinine) depolarized Vm by +13.1 +/- 4.6 (n = 6) and +14.8 +/- 6.7 mV (n = 6), respectively, and both abolished the effect of PTH on Vm. The rate of depolarization was reduced in low-Ca2+ medium. PTH inhibited low Na+-induced cell hyperpolarization, but intracellular pH was not altered by hormone addition. PTH-induced depolarization occurred even when the Na+-K+ pump was blocked with ouabain. A second slower response was seen in cells having a Vm lower than -60 mV, with an increase in negativity 5-15 min after hormone application. The results indicate that PTH rapidly modifies Vm by changes of K+ conductance, which may be the first step in hormonal stimulus-response coupling, and induces delayed, long-term changes in cell status.

Animals↗
PubMed1986

Response to parathyroid hormone and 1,25-dihydroxyvitamin D3 of bone-derived cells isolated from normal children and children with abnormalities in skeletal development.

In order to evaluate the role of intrinsic defects in osteoblast function in the pathogenesis of diseases of skeletal development, we developed techniques which permit the evaluation of the metabolic properties of bone-derived cells in vitro. Cells from control children demonstrated a variety of properties classically attributed to osteoblasts (presence of alkaline phosphatase positive cells and synthesis of bone gla protein) and responded to PTH (cAMP production) and to 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) ([3H]25-hydroxyvitamin D3 conversion into [3H]24,25-dihydroxyvitamin D3 and bone gla protein secretion). Using these techniques we evaluated the function of cultured bone cells from patients with three rare diseases of skeletal development. Cells from a patient with rickets resistant to 1,25(OH)2D3 were resistant to 1,25(OH)2D3 but responded normally to PTH. Cells from a patient with acroosteolysis with osteoporosis responded normally to PTH and 1,25(OH)2D3. Cells from a patient with hyperphosphatasia with osteoectasia responded normally to 1,25(OH)2D3 but did not respond to PTH. The results demonstrate that bone cell cultures can provide information about the role of osteoblast dysfunction in such diseases.

Alkaline Phosphatase↗
PubMed1986

[Pancreas divisum: clinical and therapeutic study in man. Apropos of 87 cases].

In order to evaluate the responsibility of pancreas divisum in the occurrence of pancreatitis, we studied retrospectively 1,808 endoscopic retrograde pancreatograms. Eighty-seven pancreas divisum (4.8 p. 100) were found in 50 males and 37 females, mean age 53.3 +/- 16.8 yrs. Acute pancreatitis was significantly more frequent (p less than 0.001) in this group (19.6 p. 100) than in the patients with fused pancreas (4.3 p. 100). The difference was also significant (p less than 0.01) for idiopathic recurrent acute pancreatitis. Histologic lesions in the dorsal pancreas were in favor of a retentional mechanism of pancreatitis. Sphincterotomy of the accessory papilla, proposed to improve the drainage of the dorsal pancreas, was performed in 11 patients (10 endoscopic, 1 surgical). This treatment, repeated in case of secondary stenosis of the accessory papilla, was successful in 5 out of 8 patients with acute pancreatitis followed up from 12 to 30 months. After reviewing the literature, secondary stenosis of accessory papilla was found significantly less frequently (p less than 0.05) after surgical sphincterotomy or sphincteroplasty (4 out of 46, 8.6 p. 100) than after endoscopic sphincterotomy (6 out of 22, 27.2 p. 100). Treatment, preferentially surgical, should be proposed only to patients with idiopathic recurrent pancreatitis before constitution of chronic non reversible pancreatitis.

Acute Disease↗
PubMed1985

1,25 Dihydroxyvitamin D3 is required for growth-independent expression of alkaline phosphatase in cultured rat osteoblasts.

Osteoblastic cells were isolated from periosteum-stripped parietal bones of neonatal rat calvaria, seeded at low density (5,000 cells/35 mm of Falcon dish), and cultured for 6 days in BGJ medium supplemented with 20% of vitamin D-depleted FCS or vitamin D and calcium-depleted FCS, with daily addition of 1,25 dihydroxyvitamin D3 (10(-9) M) or 24,25-dihydroxyvitamin D3 (10(-9) M). Plating efficiency, clonal growth (number and size distribution of the colonies formed), and the alkaline phosphatase phenotype were evaluated on days 2 and 6 of culture. (1) Culture for 6 days in media not supplemented with 1,25(OH)2D3 led to a significant (P less than 0.001) loss of the alkaline phosphatase phenotype of the osteoblastic cells; the loss was greater in proliferating cells than in nonproliferating ones and occurred in both 0.12 mM or 1.1 mM ionized calcium concentrations. (2) Daily addition of 1,25(OH)2D3 (10(-9) M) but not 24,25(OH)2D3 maintained the basal percentage of Alk Pase positive cell units in non-proliferating cells and significantly reduced the loss of this phenotype in proliferating colonies. (3) This effect did not stem from an action of the hormone on cell growth. 1,25(OH)2D3 was also found to enhance the adhesiveness of the seeded osteoblasts, irrespective of the medium calcium concentration.

Alkaline Phosphatase↗
PubMed1985

Vitamin D metabolite effects on membrane potential and potassium intracellular activity in rabbit cartilage.

In rabbit cartilage growth plates, the membrane potential, Vm, and potassium intracellular activities, alpha iK, were determined in order to study the effects of long-term (48 h) and short-term (1-2 min) exposures to vitamin D metabolites. Results are as follows: (i) in proliferative cells, Vm was -55.6 +/- 0.2 mV, n = 30, and alpha ik = 50.8 +/- 4.2 mM, n = 22; (ii) in hypertrophic cells, Vm was -35.5 +/- 0.8 mV, n = 88, and alpha iK = 85.1 +/- 5.4 mM, n = 20; (iii) Vm (-44.0 +/- 1.0 mV, n = 33) and alpha iK (114.7 +/- 8.7 mM, n = 14) were increased in metatarsal hypertrophic cells incubated with 10(-10)M of 1,25(OH)2D3 but were unaffected by the presence of 24,25(OH)2D3; (iv) an hyperpolarization of Vm was observed after short-term exposure of the hypertrophic cells to 10(-10)M of 1,25(OH)2D3 (-2.2 +/- 0.2 mV, n = 34) and 24,25(OH)2D3 (-2.2 +/- 0.7 mV, n = 17) but not to 25(OH)D3 (+0.3 +/- 0.8 mV, n = 10).

24,25-Dihydroxyvitamin D 3↗
PubMed1984

Bone ultrastructure and x-ray microanalysis of aluminum-intoxicated hemodialyzed patients.

In hemodialyzed patients aluminum (Al) intoxication may induce osteomalacic lesions which are mainly observed when plasma immunoreactive parathyroid hormone (iPTH) concentrations are low, and osteitis fibrosa absent. In this study, the bone tissue of eight hemodialyzed patients with elevated plasma and bone Al concentrations was examined by histomorphometry, electron microscopy, and x-ray microanalysis. Five patients (group 1) had osteomalacia and minimal osteitis fibrosa, three patients (group 2) had severe osteitis fibrosa. In group 1, Al was concentrated at the mineralizing front, in hexagonal structures measuring 200 to 1,000 A which also contained phosphorus, but not calcium. Hydroxyapatite needles had a normal aspect. Osteoblasts appeared inactive. In group 2, Al was also present at the mineralizing layer of osteoid, but, in these cases, in small clusters next to abnormal calcium deposits. Osteoblasts appeared very active. Their mitochondria contained calcium and phosphorus granules, or amorphous material, measuring 1,500 to 2,000 A, emitting x-rays characteristic for Al and phosphorus. These results suggest that secondary hyperparathyroidism, by stimulating the cellular activity, may increase the uptake and release of Al by the osteoblasts. The presence of Al within the mitochondria of these cells may be one of the factors inducing the mineralization defect.

Adult↗
PubMed1983

[Esophageal fistulas in mediastinal tuberculous adenopathies in adults].

An adenopathy perforated into the esophagus in a thirty-two-year old woman from black Africa with mediastinal and abdominal tuberculous adenopathies. The fistula was disclosed upon endoscopic examination in the absence of esophageal symptoms. The characteristics of such fistulas are recalled: location in the middle third of the esophagus, inconspicuousness of symptoms, scarcity of complications among which digestive hemorrhage is the most significant, usually favorable course under medical management alone. The latency of fistulas between tuberculous adenopathies and the esophagus warrants routine fiberoptic endoscopy in patients with mediastinal tuberculous adenopathies.

Adult↗
PubMed1983

[Acute alcoholic hepatitis and death of cirrhotic patients].

Alcoholic hepatitis (AH) seems to be less frequent and to play a lesser role in the death of cirrhotic patients than previously acknowledged. The purpose of this work was: 1) to study the cause of death of cirrhotic patients 2) to determine the prevalence of AH among these patients and 3) to describe the clinical and laboratory features of cirrhotic patients with AH. The data were collected from a series of 107 necropsies in cirrhotic patients without hepatocellular carcinoma. The statistical analyses were carried out with an IRIS 80 computer. Severe liver failure with jaundice and encephalopathy, hemorrhage and uncontrolled infection with septic shock represented 84 p. 100 of the causes of death in patients with cirrhosis. Seventy-nine out of 107 patients (74 p. 100) had no AH (group 1), and 28 (26 p. 100) had AH (group 2): AH was mild in 15 cases and severe in 13 cases. All patients with AH died from a complication directly related to their liver disease while 21.5 p. 100 of patients without AH died from a complication not related to cirrhosis. The clinical and laboratory features of the patients without AH and cirrhosis differed from those of patients without AH by: a more frequent presence of fever (p less than 0.01), the absence of important weight loss (p less than 0.001), the total absence of abstinence (p less than 0.05), a higher value of ASAT/ALAT ratio, of serum levels of total bilirubin (p less than 0.01) and conjugated bilirubin (p less than 0.05), gamma glutamyl transpeptidase (p less than 0.001) and total cholesterol (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗