Endoscopic argon plasma trimming of biliary and gastrointestinal metallic stents

BACKGROUND AND STUDY AIMS

The aim of this study was to assess the feasibility and efficiency of plasma argon trimming of gastrointestinal and biliary metallic stents.

PATIENTS AND METHODS

A total of 31 patients underwent plasma argon trimming of their metallic stents (14 women, 17 men; mean +/- SD age 73 +/- 12.2 years, range 46 - 96 years). Of these 31 patients, 24 had had covered or noncovered Unistep Wallstents placed in the biliary tract (13 patients with pancreatic neoplasms, five patients with Vater ampulloma, five patients with biliary tract carcinoma and one patient with chronic calcifiying pancreatitis); three patients had noncovered Enteral Unistep Wallstents (pyloroduodenal); two patients with obstructive colorectal carcinoma had a noncovered Bard Memotherm stent inserted; and two patients had noncovered Ultraflex stents placed for esophageal carcinoma. Endoscopic trimming of the stents was performed under propofol-induced general anesthesia, with the power set at 70 - 80 watts and an argon flow of 0.8 liters/minute.

RESULTS

Complete and satisfactory trimming of the stents was possible, without complications (mean follow-up 15.8 months), in all patients except one, a patient with a covered biliary Wallstent. In 13 patients with biliary or Enteral Wallstents the trimming procedure was preventive. In eight patients with ulceration and/or hemorrhage (duodenal or rectal), healing was achieved after stent trimming and epinephrine (adrenaline) injection followed by electrocoagulation. Stent trimming restored patency of the duodenal lumen in six patients and of the esophageal lumen in two patients, and was done to allow insertion of a biliary stent in one patient whose duodenal stent was covering the papilla. In one patient with rectal tenesmus, stent shortening resulted in complete resolution of symptoms.

CONCLUSIONS

Endsocopic plasma argon trimming of metallic stents is an efficient procedure which allows easy, reproducible and well-tolerated correction of complications that arise due to these prostheses.

Argon plasma endoscopic section of biliary metallic prostheses

We report our recent experience of using argon plasma to endoscopically cut biliary Wallstent prostheses in these patients. The first patient had a bleeding duodenal ulceration caused by the impaction of the prosthesis meshes whereas the second patient had an ill-positioned biliary stent with impaction into the opposite duodenal wall. Both prostheses were shortened using argon plasma. In the third patient, the lower extremity of a obstructed biliary Wallstent was positioned in the third duodenum preventing its endoscopic catheterization. After shortening using argon plasma, a new plastic stent could be inserted to allow drainage. The outcomes in these cases demonstrate the feasibility of endoscopically shortening metallic Wallstents after release using argon plasma.

A new source of drug-induced acute pancreatitis: codeine

A variety of drugs have been reported to cause acute pancreatitis during the past 40 years. We report the first series of four cases of acute pancreatitis related to codeine ingestion. Four patients (three female, mean age 50.2 yr) presented with clinical, biochemical, and radiological evidence of acute pancreatitis. All four had ingested a therapeutic dose of codeine 1-3 h before the onset of abdominal symptoms. Unintentional rechallenge occurred in three cases and was followed by recurrence of acute pancreatitis in all three. All patients made a full recovery. All four patients had had a previous cholecystectomy. The likely underlying pathophysiological mechanism is codeine-induced spasm of the sphincter of Oddi combined with sphincter of Oddi dysfunction related to a previous cholecystectomy. Codeine ingestion leads to acute pancreatitis in some individuals. Previous cholecystectomy seems to predispose to codeine-induced pancreatitis.

[Palliative endoscopic treatment of malignant duodenal stenosis by metal prosthesis]

PURPOSE

To evaluate the efficacy of through-the-scope metal stents for palliation of malignant duodenal stenosis.

MATERIAL AND METHODS

Fourty two patients with malignant primary or secondary duodenal stenoses who were treated with a through-the-scope metal stent were analysed. When obstructive jaundice occurred either before, during, or after the initial episode of gastrointestinal luminal obstruction, a biliary stent was inserted.

RESULTS

Duodenal metal stents were deployed in 40 patients. Endoprosthesis insertion led to restoration of oral intake in 39 patients. The procedure was not associated with morbidity or mortality. During a mean follow-up of 9.7 weeks, adequate oral intake was maintained in 38/39 cases. Tumour in-growth led to stent occlusion in 4 cases and re-cannulation was obtained by placement of another stent within the original stent. Obstructive jaundice occurred during the course of the illness in 32 patients and was successfully treated with a biliary metal stent in all cases.

CONCLUSIONS

Endoscopically placed metal stents offer an effective, well-tolerated alternative to surgical palliation in case of incurable malignant obstruction to gastric outflow.

Agenesis of the horizontal segment of the left portal vein demonstrated by magnetic resonance imaging including phase-contrast magnetic resonance venography

Two cases of agenesis of the horizontal segment of the left portal vein are reported. This very rare vascular anomaly probably corresponds to an embryological variation rather than to an obstruction of the left portal vein. In almost all cases liver ultrasonography is sufficient for identifying such vascular abnormalities. It shows a large aberrant vessel emerging from a right anterior segmental portal branch and running transversely in the quadrate lobe towards the teres ligamentum from which the portal supply to the left lobe arises. It is important to be able to recognize the magnetic resonance imaging features of this vascular variation, as magnetic resonance imaging may be the initial imaging study, and ultrasound may be technically challenging. To our knowledge, we present the first description of these features, including an enhanced gradient-echo T1-weighted sequence, a turbo spin-echo T2-weighted sequence with fat saturation, and a three-dimensional phase-contrast magnetic resonance portography.

Endoscopic bilateral metal stent placement for malignant hilar stenoses: identification of optimal technique

BACKGROUND

The aim of this study was to identify factors that facilitate bilateral insertion of metal stents in malignant hilar stenoses, for which plastic stents often result in incomplete drainage and subsequent cholangitis.

METHODS

Between January 1994 and April 1998, we collected 45 cases of advanced (Bismuth stage II or higher) hilar malignant stenoses. The insertion technique was progressively modified and the success rate in the early period (1994 to 1995) was compared with that of a later period (1996) and the most recent period (1997 to 1998).

RESULTS

Overall success rate was 73.3% (33 of 45). The success rates for the three periods were 50%, 67%, and 88% (p = 0.008), respectively. Cholangitis occurred in 3 of the patients with unilateral stents compared with 1 with bilateral stents.

CONCLUSION

We have described a technique for endoscopic insertion of bilateral metallic stents for malignant hilar stenoses that results in high (>88%) and reproducible success rates.

Endoscopic management of sump syndrome after choledochoduodenostomy: retrospective analysis of 30 cases

BACKGROUND

Side-to-side choledochoduodenostomy is a frequently performed operation. Postoperative biliary "sump syndrome" is infrequent, a complication for which endoscopic sphincterotomy is regarded as the treatment of choice.

METHODS

We retrospectively analyzed 30 cases of sump syndrome and describe the symptoms, the delay before the appearance of symptoms, laboratory abnormalities, the nature of the biliary obstruction, and the outcome of endoscopic sphincterotomy including its efficiency and complications.

RESULTS

The median clinical latency was 5 years (range 1 month to 28 years), the median delay between surgery and diagnosis was 6 years (range 1 month to 28 years). Fourteen patients had abdominal pain with fever, 5 had isolated abdominal pain, 4 had post-prandial pain, 4 had hepatic abscesses, and 3 had acute pancreatitis. Liver function tests were abnormal in 79%. During endoscopic retrograde cholangiopancreatography, food debris was identified in 18 patients in the biliary sump, biliary calculi in 10 patients, and a mixture of food and calculi in 2 patients. All patients underwent endoscopic sphincterotomy without complication. Recurrence during a median follow-up of 36 months (range 3 months to 11 years) was not observed.

CONCLUSIONS

Sump syndrome most often becomes symptomatic only after a long delay. Abdominal pain with fever was the most frequent symptom. Liver function tests were abnormal in the majority of patients. Food debris was the most frequent cause. Endoscopic sphincterotomy appeared to be a safe, reliable treatment.

Extensive aetiological investigations in acute pancreatitis: results of a 1-year prospective study

BACKGROUND

Epidemiological data on acute pancreatitis are poorly defined.

AIMS

To prospectively evaluate the aetiology of acute pancreatitis and to assess the benefits of intensive investigations.

METHODS

In a prospective, 1-year study all cases of acute pancreatitis in the Nice catchment area were enrolled. Subjects underwent routine (serum calcium, phosphate and triglycerides; abdominal ultrasonography and CT scan) and additional, delayed intensive investigations (ERCP with bile sampling and/or endoscopy ultrasonography).

RESULTS

One hundred and twenty-one cases were included. After routine investigations, a biliary, alcoholic, miscellaneous or unknown origin was diagnosed in 43%, 31.4%, 9.9% and 15.7%, respectively. In subjects with biliary pancreatitis, 43% had no previous history of biliary disease. In the alcohol-related subgroup, pancreatitis recurred in 18.5% during 114.5 days mean follow-up. In subjects with a first episode of alcoholic pancreatitis, delayed supplemental investigations revealed underlying chronic pancreatitis in 92.8%. After routine investigations, a diagnosis of pancreatitis of unknown origin was made in 15.7% (n = 19) of subjects. Additional investigations revealed an underlying cause in 57.8% of these patients (n = 11), including malignancy (n = 3) and biliary disease (n = 4), reducing the overall rate of pancreatitis with no apparent cause to 6.6%.

CONCLUSIONS

Investigative techniques, particularly ERCP, will reveal the underlying aetiology of pancreatitis in the majority of patients presenting with 'idiopathic' pancreatitis and should be considered when routine tests are negative.

Gallbladder volume in adults and its relationship to age, sex, body mass index, body surface area and gallstones. An epidemiologic study in a nonselected population in France

BACKGROUND/AIMS

The role of a large gallbladder volume with regard to a predisposition for gallstones is unknown. It is possible that an increase in gallbladder volume could result in impaired gallbladder motility and bile stasis. We looked for factors affecting gallbladder volume in a random population in the southeast of France.

METHODS

To assess the relationship between gallbladder volume and gallstones, 528 subjects over the age of 30 were studied (72 with lithiasis). Age, sex, body mass index, body surface area and gallbladder volume were collected for each subject. A linear regression analysis was performed to look for significant variables.

RESULTS

The overall adjusted prevalence of cholelithiasis was 13.9% in our population. On linear regression analysis, two variables (age and surface area) were found to be independently correlated with gallbladder volume. Gallbladder volume was significantly increased in subjects over 50 years (p < 0.001). There was a positive correlation between gallbladder volume and body surface area (r = 0. 33, p < 0.001). In this study, the presence or absence of gallstones did not significantly affect the gallbladder volume.

CONCLUSIONS

We report that there is dilatation of the gallbladder with age and with an increase in body surface area. Whether this could represent risk factors for the occurrence of gallstone remains uncertain.

Prevalence of cholelithiasis: results of an epidemiologic investigation in Vidauban, southeast France. General Practitioner's Group of Vidauban

Cholelithiasis leads to 80,000 cholecystectomies being performed every year in France, but its prevalence is still unknown. The aim of this study was to assess the prevalence and risk factors of cholelithiasis in a random population of 1027 women and 727 men over the age of 30 in a small town in the southeast of France. Detailed clinical history, dietary investigation, and gallbladder ultrasound were collected for each subject and assessed by univariate analysis. A regression model was used in the multivariate analysis to detect the relative risk of cholelithiasis. Cholelithiasis was found in 130 individuals (global prevalence 13.9%). The relative risk for lithiasis was higher in women compared to men (1.89). Age (P<0.0001) and body mass index (BMI) >25 (P = 0.013) were also significant risk factors. Neither pregnancy nor oral contraceptive use proved to be risk factors. Typical biliary colic pain was the only symptom significantly associated with cholelithiasis (P<0.0001). These results show that the prevalence of gallstones in France is similar to that in Denmark and Italy.

Long term treatment of biliary stricture due to chronic pancreatitis with a metallic stent

The exact role of endoprostheses in the management of chronic pancreatitis-associated biliary strictures has not yet been clearly established. We report an unusual case of a patient with this condition who was treated for an unexpectedly long term with a self-expanding metallic endoprosthesis. There has only been one previous report of the use of metallic stents in this situation. It appears that metallic endoprostheses may have a role to play in the management of selected patients who have chronic pancreatitis-associated bile duct stricture.

A prospective study of pancreatic disease in patients with alcoholic cirrhosis: comparative diagnostic value of ERCP and EUS and long-term significance of isolated parenchymal abnormalities

BACKGROUND

The prevalence of pancreatic disease in patients with alcohol-related liver cirrhosis is uncertain. We assessed the prevalence of pancreatic abnormalities in patients with alcoholic cirrhosis, and we compared endoscopic ultrasonography (EUS) and endoscopic retrograde cholangiopancreatography (ERCP) for the detection of chronic pancreatitis and other pancreatic lesions. In addition, we assessed the long-term significance of isolated pancreatic parenchymal abnormalities detected at EUS.

METHODS

EUS and ERCP were performed in each patient. Subjects with minimal parenchymal changes at initial EUS underwent clinical follow-up and subsequent EUS and/or ERCP to document the occurrence, absence, or progression of these changes.

RESULTS

Seventy-two patients with alcoholic cirrhosis were recruited. Chronic pancreatitis was diagnosed in 14 patients (19%) by both methods independently. Isolated parenchymal lesions were observed in 18 patients by EUS alone. After a mean follow-up of 22 months the EUS appearance was unchanged. Ten of the 18 patients underwent follow-up ERCP and this was normal in all cases.

CONCLUSIONS

This study demonstrated that (1) 19% of patients with alcoholic cirrhosis have chronic pancreatitis, (2) an additional 25% have isolated pancreatic parenchymal changes at EUS, and (3) these parenchymal abnormalities do not progress during follow-up.

Inferior vena cava hypoplasia with intrahepatic venous continuation: sonographic, angiographic and MR features including MR angiography

In cases of inborn or acquired obstacles on the inferior vena cava (IVC), the derived blood flow usually goes through collaterals in the azygos or the hemiazygos venous systems. Exceptionally, a collateral pathway through the portal system or through an anastomosis in between hepatic veins, shunting the IVC interruption, is encountered. In the present paper, the authors describe the fortuitous discovery of a IVC hypoplasia in its retrohepatic segment. MR venography, correlated with fluoroscopic angiography, clearly depicted an intrahepatic collateral circulation consisting of a double aneurysmal communication between an inferior right hepatic vein and the main right hepatic vein.

Right-sided sciatalgia complicating Crohn's disease

Neurological complications of Crohn's disease due to involvement of the extradural space are extremely rare. A 40-yr-old woman with Crohn's disease affecting the terminal ileum presented with a right-sided sciatalgia. The patient did not complain of diarrhea or constipation. The serum fibrinogen and the C-reactive protein were elevated. Magnetic resonance imaging and computed tomography scan of the abdomen and pelvis demonstrated a mass in front of the sacrum up to but not including the first sacral vertebra. Surgical intervention, with resection of 15 cm of terminal ileum, led to the complete resolution of symptoms. In this case, the underlying cause of the neurological symptoms was most likely an infiltration of the right lumbosacral nerve caused by edema and inflammation of the terminal ileum in the vicinity of the presacral space. Unexplained lumbosacral neurological symptoms in a patient with Crohn's disease necessitate a magnetic resonance imaging or computed tomography scan to detect potential neurological compression.

Cholelithiasis and dietary risk factors: an epidemiologic investigation in Vidauban, Southeast France. General Practitioner's Group of Vidauban

Dietary risk factors have been implicated in the development of cholelithiasis. The aim of this study was to determine in a homogeneous French population whether a particular type of diet may be lithogenic. Seventy-six subjects over 30 years of age (26 men, 50 women) with cholelithiasis detected by ultrasound were selected from a population sample of 830 subjects by drawing lots using the polling list. These were matched by 76 control subjects without cholelithiasis randomly selected from the same population. Univariate analysis was significant for a high calorie diet >2500 kcal/day (OR = 3.62, P = 0.0065), a diet rich in carbohydrates with a consumption > or = 55 g/day (OR = 2.98, P = 0.0067), and a diet rich in total lipids (OR = 4.97, P = 0.023) or saturated fatty acids (OR = 3.06, P = 0.0146). An alcohol consumption equivalent to 20-40 g/day was protective (P = 0.018). Multivariate analysis confirmed these results. Our study suggests that a change in dietary habits by limiting excess calories, saturated fats and carbohydrates could reduce the incidence of cholelithiasis.

The role of therapeutic endoscopy associated with extracorporeal shock-wave lithotripsy and bile acid treatment in the management of Caroli's disease

BACKGROUND AND STUDY AIMS

Caroli's disease causes relapsing episodes of cholangitis due to the presence of intrahepatic lithiasis. Strategies for cholangitis prevention are still widely debated. Ursodeoxycholic acid, hepaticojejunostomy, partial hepatectomy, or transplantation, have all been proposed as therapeutic options. The aim of this study was to evaluate the role of therapeutic endoscopy, and especially endoscopic sphincterotomy (ES), in the management of Caroli's disease.

PATIENTS AND METHODS

Between 1983 and 1995, six patients with Caroli's disease (mean age 52, range 17-75) underwent endoscopic retrograde cholangiopancreatography (ERCP) for acute cholangitis. Sphincterotomy was performed if common bile duct stones were present. Extracorporeal shock-wave lithotripsy, (ESWL) or intraductal electrohydraulic lithotripsy (IEL) were performed if necessary.

RESULTS

The mean number of endoscopic sessions per patient was four (range three to seven). Sphincterotomy was performed in five patients and cholangioscopy in three. ESWL was performed twice in each of four patients. A Strecker expandable metal stent was placed in one patient to maintain sphincterotomy patency. In one patient, two sessions of IEL and pulsed laser were carried out. Complete clearance of intrahepatic stones was achieved in four of the six subjects (66.6%) and partial clearance in two patients. No morbidity or mortality was observed. During the follow-up (mean 6.2 years; range: 2.1-16.3), only two patients had acute cholangitis at nine months and three years, respectively, after the endoscopic treatment. Both had residual intrahepatic stones left after the initial endoscopic attempt at clearance.

CONCLUSION

ERCP is a necessary diagnostic procedure which should always be carried out in patients with Caroli's disease. Our experience shows that ES does not result in an increased incidence of cholangitis and that therapeutic endoscopy allows complete clearance of intrahepatic stones in the majority of patients with unresectable symptomatic Caroli's disease. Nevertheless, the oncological risk in these patients remains unchanged, and they still have an increased risk of cholangiocarcinoma.

Relationships between mesangial cell proliferation and types I and IV collagen mRNA levels in vitro

Changes in the composition of the mesangial extracellular matrix (ECM) and cell turnover are present in glomerular disease. To determine if ECM changes play a role in perpetuating mesangial cell dysfunction, we examined a line of mouse mesangial cells cultured on films or gels of several ECM components and also on methyl cellulose, an inert substrate that prevents attachment. Cells on films of fibronectin or type IV or I collagen had persistently high growth rates and high levels of alpha 1-I and alpha 1-IV collagen mRNAs. In contrast, on gels of type IV or I collagen or matrigel, the growth rate was low. The alpha 1-IV collagen mRNA levels were low on type IV collagen gel or matrigel, whereas the alpha 1-I collagen mRNA levels remained high. In contrast, the alpha 1-I collagen mRNA levels were low on type I collagen gel, and the alpha 1-IV collagen mRNA levels were high. Cells on methyl cellulose formed floating aggregates, did not proliferate, and had a 5- to 10-fold decrease in both alpha 1-I and alpha 1-IV collagen mRNA levels. These phenotypic changes were largely reversible. Finally, when matrigel was layered over cells on fibronectin films, alpha 1-IV collagen mRNA levels decreased, but alpha 1-I collagen mRNA levels and proliferation remained high. Thus proliferation and alpha 1-I and alpha 1-IV collagen mRNA levels in mesangial cells were independently regulated and depended on attachment and the nature of the adjacent matrix.

Collagen and collagenase mRNAs in normal and sclerotic glomeruli: predictors of progression and response to therapy

Progressive glomerulosclerosis is associated with decreasing kidney function, eventuating in end-stage renal failure. There are multiple components of the extracellular matrix, and the exact composition in various renal diseases is not known. Thus, we examined some of the major components of the extracellular matrix (ECM) in murine and human glomerular diseases. We studied matrix synthesis and degradation at the level of gene expression and ECM composition in the intact glomerulus. To determine whether the composition of sclerosis was similar among diseases, we examined a normal mouse strain and compared it with strains which spontaneously developed glomerulosclerosis. The baseline levels of matrix components varied between different mouse strains, and this level correlated with their propensity to develop glomerulosclerosis. In addition, when glomerulosclerosis was induced, the baseline ECM mRNA level predicted the subsequent outcome. We studied mice transgenic for bovine growth hormone, since they develop progressive glomerulosclerosis. Treatment with heparin substantially decreased the lesions without changes in type IV collagen mRNAs. However, there was an up-regulation of both the mRNA and enzyme activity for the 92 kD matrix metalloproteinase. In contrast, when these mice were treated with either angiotensin converting enzyme inhibitors or angiotensin II (Ang II) receptor antagonists, the glomerulosclerosis was accentuated histologically and the ECM synthetic and degradative mRNAs were elevated. These data suggest that the mRNA levels reflect response to therapy.(ABSTRACT TRUNCATED AT 250 WORDS)

Assessment of 72-kilodalton gelatinase and TIMP-1 gene expression in normal and sclerotic murine glomeruli

Mice transgenic for bovine growth hormone (bGH) develop progressive diffuse glomerulosclerosis. Because murine mesangial cells in vitro were found to express the genes for 72-kd gelatinase and the metalloproteinase inhibitor TIMP-1, the expression of these genes in vivo in isolated whole glomeruli from bGH mice and normal control littermates was examined. Intact glomeruli were isolated by microdissection and subjected to reverse transcription. TIMP-1 cDNA was not detected by standard polymerase chain reaction (PCR) in glomeruli from bGH or control mice. In contrast, cDNA for 72-kd gelatinase was detected by standard PCR in both bGH and control mice, and the level was subsequently measured by quantitative competitive PCR. The gelatinase cDNA level was 14.7 +/- 2.8 x 10(-4) attomoles/glomerulus in 2- to 3-month-old control mice and was unchanged in 6-month-old controls. The bGH mice had 3.5-fold and 4.5-fold higher cDNA levels at 2 to 3 months and 6 months of age, respectively. Finally, zymography of glomerular extracts revealed increased levels of 72-kd and 96- to 100-kd gelatinase activity in bGH glomeruli in comparison to that in controls. In summary, whereas the genes for both TIMP-1 and 72-kd gelatinase are expressed in vitro in cultured mesangial cells, only the gelatinase gene appeared to be expressed in vivo in intact glomeruli. In addition, there was an up-regulation in the glomerular expression of the 72-kd gelatinase in bGH mice, a murine model of glomerulosclerosis.

The molecular basis of increased glomerulosclerosis after blockade of the renin angiotensin system in growth hormone transgenic mice

BACKGROUND

Angiotensin converting enzyme inhibitor (ACEi) therapy delays the onset of renal failure in diabetic nephropathy and inhibits or delays the onset of proteinuria in several animal models.

MATERIALS AND METHODS

We examined this question using a transgenic model of chronic glomerulosclerosis caused by an excess production of growth hormone (GH) in which there is progressive glomerular scarring leading to uremia. In addition, since GH mice do not have systemic hypertension or an elevated glomerular filtration rate, we could address the question of whether ACEi or angiotensin II receptor antagonists (AII RA) had an effect on the development of glomerulosclerosis under these conditions. Since excess matrix accumulates in glomerulosclerosis because of alterations in the balance between its synthesis and degradation, we examined the effect of ACEi and AII RA on these parameters.

RESULTS

Systemic blood pressure was unaffected by ACEi treatment, but the glomerular filtration rate decreased 85%. ACEi-treated mice had increased mesangial deposition of type I collagen and decreased 105 kD complex collagenase activity. In addition, ACEi-treated GH mice had increased glomerular alpha 1 type I collagen, alpha 1 type IV collagen, and alpha-smooth muscle cell actin mRNAs. No changes were noted in beta actin, or 72 kD metalloproteinase mRNAs. The result of these changes was a net increase in sclerosis. Surprisingly, GH mice treated with ACEi or AngII RA developed marked renal arteriolar lesions.

CONCLUSIONS

In some forms of glomerulosclerosis, the lesions develop independently of angiotensin II. Pharmacological inhibition of angiotensin II, in this circumstance, may aggravate the lesions through disregulation of the levels and the balance between glomerular matrix synthesis and degradation.

Advanced glycation end products up-regulate gene expression found in diabetic glomerular disease

Several lines of evidence suggest that the excessive accumulation of extracellular matrix in the glomeruli of diabetic kidneys may be due to reactive intermediates forming between glucose and matrix proteins called advanced glycation end products (AGEs). Normal mice received AGE-modified mouse serum albumin i.p. for 4 weeks, and glomerular extracellular matrix, growth factor mRNA levels, and morphology were examined. We found that AGE induced an increase in glomerular extracellular matrix alpha 1(IV) collagen, laminin B1, and transforming growth factor beta 1 mRNA levels, as measured by competitive PCR, as well as glomerular hypertrophy. The AGE response was specific because the coadministration of an AGE inhibitor, aminoguanidine, reduced all these changes. We conclude that AGEs affected expression of genes implicated in diabetic kidney disease and may play a major role in nephropathy.

Progression of glomerular diseases

The nature and slope of progression of glomerular diseases is the subject of considerable discussion. The use of renal biopsies has been accompanied by considerable improvement in the classification of glomerular disease. However, the clinical and histological tools available to assess prognosis in individual patients lack accuracy, especially in slowly progressive glomerular diseases such as diabetes mellitus. The development of molecular biology tools provides a new approach to the analysis of glomerulosclerosis. The accumulation of extracellular matrix in the glomerulus results from an exaggerated synthesis of collagens and other molecules forming the basement membranes, and is accompanied by an increase in the corresponding mRNAs. The measure of local glomerular gene activation can therefore provide a dynamic view of glomerular scarring. Utilizing a method combining microdissection of the glomeruli, reverse transcription in situ and a competitive polymerase-chain-reaction assay we were able to measure minute amounts of mRNAs in single mouse and human glomeruli. Both in mouse models and in human glomerulosclerosis we found upregulation of basement membrane collagen genes in the glomeruli. The increase appeared to be parallel to the slope of progression of glomerulosclerosis in experimental animals. This new approach may therefore provide a quantitative and sensitive method to define the propensity to sclerosis in human disease.

Mesangial cells from diabetic NOD mice constitutively secrete increased amounts of insulin-like growth factor-I

Experimental evidence has suggested that insulin-like growth factor-I (IGF-I) may contribute to diabetic complications. Previously, we and others have shown that normal glomerular mesangial cells have receptors for, synthesize, and exhibit a mitogenic response to IGF-I. We investigated the IGF-I response in cells derived from a genetic model of diabetes, the nonobese diabetic (NOD) mouse. Mesangial cell lines were derived from diabetic (D-NOD) and nondiabetic adult mice. D-NOD cells released more IGF-I into the supernatant and had a decreased binding of IGF-I to surface receptors. Analysis according to Scatchard revealed a decreased number of receptor sites on D-NOD cells, although the structure of the IGF-I receptor visualized by cross-linking was identical for both cell types. Preincubation of D-NOD cells with an antibody to IGF-I resulted in an increase in the number of receptor sites. This suggested that autocrine IGF-I was responsible for the decrease in D-NOD receptor number and that diabetes had resulted in a stable phenotypic change.

Human glomeruli express TIMP-1 mRNA and TIMP-2 protein and mRNA

Alterations in the balance between synthesis and degradation of extracellular matrix may result in glomerulosclerosis. The interaction between metalloproteinases and their inhibitors presumably modulates the rate of glomerular matrix degradation. We examined the gene expression of tissue inhibitor of metalloproteinases (TIMP)-1 and TIMP-2 in human glomeruli and TIMP-2 protein in tissue sections. Kidney tissue was obtained from adults undergoing nephrectomy for renal tumor (n = 9) or biopsy for nephrosis and renal failure (n = 1). Glomeruli were microdissected and subjected to reverse transcription. TIMP cDNAs were quantitated by competitive polymerase chain reaction assays. Five nephrectomy specimens had normal glomeruli and four had diffuse glomerulosclerosis. TIMP-1 and TIMP-2 cDNA levels, detected in glomeruli from all patients, were increased fourfold and threefold, respectively, in patients with glomerulosclerosis. The elevated TIMP cDNA levels could not be attributed to an increased number of glomerular cells. TIMP-2 protein was detected within normal and sclerotic glomeruli. In conclusion, both TIMP genes were expressed in normal glomeruli, and their level of expression was increased in glomerulosclerosis associated with renal carcinoma, suggesting that expression of these inhibitors may correlate with the development of sclerosis.

Glomerulosclerosis and body growth are mediated by different portions of bovine growth hormone. Studies in transgenic mice

BACKGROUND

Mice transgenic for bovine growth hormone (bGH) gene have increased body weight and severe glomerulosclerosis leading to death in uremia.

EXPERIMENTAL DESIGN

The aim of this study was to determine if body growth and glomerulosclerosis were mediated by different bGH regions. Amino acid substitutions in the bGH alpha-helix III were generated, and lines of transgenic mice that expressed these products were developed. Female transgenic mice carrying the native bGH gene (bGH mice), a mutated bGH gene that encodes a destabilized alpha-helix III (bGH-L121P, E126G; bGH-m11 mice), or a mutated bGH gene that encodes a perfect amphiphilic alpha-helix III (bGH-E117L, G119R, A122D; bGH-m8 mice) were examined at 2-3 months and 6-9 months of age. Body, kidney, and heart weights were measured. Urinary glucose, albumin, creatinine, and serum glucose were measured in all mice. Serum levels of insulin-like growth factor I (IGF-I) were measured in the 2-3 month group. Whole blood hemoglobin A1 was measured in some mice of the 6-9 month group. Kidney sections were examined by light and immunofluorescence microscopy. Glomerular volume was measured and related to body weight by allometry.

RESULTS

The bGH-m11 mice developed glomerulosclerosis indistinguishable from that seen in bGH transgenic mice, even though they had normal body size. Glomerular growth exceeded body growth by allometry in both bGH and bGH-m11 strains. bGH-m8 mice had glomeruli of appropriate size and normal histologic appearance; however, they were dwarfs. IGF-I was increased in bGH mice; they also had an increased albumin/creatinine ratio at 6-9 months. None of the mice were hyperglycemic.

CONCLUSIONS

These data indicated that development of glomerulosclerosis and body growth promotion were mediated by different regions of the growth hormone molecule. The glomerular response to bGH was unique and consisted of increased size and glomerulosclerosis.

Studies by competitive PCR of glomerulosclerosis in growth hormone transgenic mice

We have shown that the glomerulosclerotic lesions of mice transgenic for bovine growth hormone (bGH mice) consisted of a change in the phenotype of glomerular collagens and an elevation of the mRNAs for these collagens in whole kidney. The purpose of this study was to determine whether these phenotypic and quantitative changes were present in the glomeruli. We used the increased sensitivity afforded by reverse transcription followed by the polymerase chain reaction (RT-PCR) to detect type I collagen mRNA and a quantitative PCR assay to quantitate type IV collagen mRNA in microdissected glomeruli. There was a six- to eightfold increase in alpha 1IV collagen mRNA in the glomeruli of bGh mice. alpha 1(I) collagen mRNA was present in glomeruli of bGH mice, which is consistent with our previous findings that the sclerotic mesangium contained type I collagen peptides by immunofluorescence microscopy. Normal glomeruli did not contain detectable amounts of alpha 1I collagen mRNA. In summary, we found a phenotypic change in glomeruli of mice transgenic for bGH consisting of increased type IV collagen mRNA levels and the appearance of type I collagen mRNA. Thus, the development of glomerulosclerosis appeared to be at least partially regulated at a pretranslational level.

Glomerulosclerosis in mice transgenic for native or mutated bovine growth hormone gene

Mice transgenic for bovine growth hormone (bGH) develop an increase in body weight and glomerular lesions characterized by a disproportionate increment in glomerular volume and progressive mesangial sclerosis. The relationship between glomerular size and body growth in bGH mice was further investigated by examining mice transgenic for a mutated GH gene (bGH-m11) which failed to enhance body growth. The glomeruli in bGH-m11 mice exhibited an increase in size and glomerulosclerosis comparable to those found in bGH mice. The levels of alpha 1 type IV collagen mRNA, as measured by the competitive polymerase chain reaction in isolated microdissected glomeruli, were markedly elevated in mice transgenic for both bGH and bGH-m11 genes. These data suggest that body growth on one hand, and glomerular hypertrophy and sclerosis on the other hand, are mediated by different portions of GH or different second messenger signaling systems.

The contribution of increased collagen synthesis to human glomerulosclerosis: a quantitative analysis of alpha 2IV collagen mRNA expression by competitive polymerase chain reaction

We previously reported that one of the main components of the sclerotic material in human glomerular diseases was type IV collagen. In this study we examined the contribution of increased synthesis to this process at the gene expression level. Sufficient material has not been available to study type IV collagen synthesis by normal or sclerotic glomeruli in humans. We took advantage of the availability of nephrectomy specimens from patients with renal carcinoma, and of the observation that approximately 50% of these patients develop varying degrees of glomerulosclerosis. We microdissected glomeruli from 10 patients and analyzed them using in situ reverse transcription coupled with polymerase chain reaction (PCR) analyses (in situ RT-PCR). alpha 2IV collagen mRNA, after reverse transcription into cDNA, was detected in all patients and appeared to be increased in those with glomerulosclerosis (n = 5). A competitive PCR assay was developed to quantitate this change. There was an average 3.7-fold increase in glomerular type IV collagen cDNA in patients with significant sclerosis. This change was not due to an increased number of glomerular cells. Thus, glomerulosclerosis in humans is associated with an elevation of glomerular type IV collagen gene expression, suggesting that increased synthesis of type IV collagen may represent one component of this process.

Age-related changes in alpha 1- and alpha 2-chain type IV collagen mRNAs in adult mouse glomeruli: competitive PCR

Studies of age-related changes in glomerular extracellular matrix (ECM) synthesis in normal mice have been hampered by the difficulty of isolating sufficient numbers of intact glomeruli and by the inability to quantify different mRNA species. The purpose of this study was to identify and quantitate the individual mRNAs coding for alpha 1- and alpha 2-chains of type IV collagen in isolated, single glomeruli of normal mice at different ages. These data on normal ECM synthesis were necessary for the understanding of glomerulosclerosis, a condition characterized by excess deposition of collagen. Pools of freshly microdissected adult mouse glomeruli were reverse transcribed in situ, and alpha 1-IV and alpha 2-IV collagen mRNAs were individually amplified by means of specific primers and the polymerase chain reaction (PCR), according to a previously published method. A competitive PCR assay, based on utilization of mutated cDNAs, allowed the reproducible, quantitative, and separate determination of the absolute amounts of both alpha 1-IV and alpha 2-IV mRNAs measured, as their respective cDNAs, in one-tenth of one glomerulus. The levels of alpha 1-IV and alpha 2-IV collagen mRNA were 208 +/- 36.0 x 10(-4) and 161.2 +/- 18.6 x 10(-4) amol/glomerulus in 5-wk-old mice. There were no significant age-related differences at 8, 12, and 24 wk. The mean levels over this period were 60.2 +/- 4.9 x 10(-4) for alpha 1-IV collagen mRNA and 63.9 +/- 5.8 x 10(-4) amol/glomerulus for alpha 2-IV collagen mRNA. Two of three 24-wk-old mice had mild glomerulosclerosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Glomerulosclerosis in mice transgenic for growth hormone. Increased mesangial extracellular matrix is correlated with kidney mRNA levels

Mice transgenic for growth hormone (GH) develop progressive glomerulosclerosis. The compositions of kidney extracellular matrix (ECM) and ECM mRNA were examined. The glomerulosclerotic areas in GH mice contained types I and IV collagen, laminin, and basement membrane heparan sulfate proteoglycan (HSPG), which increased with age. The type IV collagen, laminin B2, and HSPG mRNA levels in GH mice, measured by a solution hybridization RNase protection assay, were increased over normal littermates. These findings suggest that the accumulation of ECM components in the glomeruli of GH mice is regulated at the transcriptional level and that glomerulosclerosis is, in part, due to the excess production of ECM rather than simply a reduction in its turnover. The glomerular lesions in GH mice resemble diabetic nephropathy and may allow further dissection of the molecular basis of certain forms of glomerulosclerosis.