Early imaging of integration response to polypropylene mesh in abdominal wall by environmental scanning electron microscopy: comparison of two placement techniques and correlation with tensiometric studies

The repair of incisional hernias has taken advantage of the strength provided by prosthetic mesh grafts, but the best position for inserting the materials has not been conclusively established. Environmental scanning electron microscopy (ESEM) provides imaging of biologic samples with minimal manipulation. We used ESEM for early imaging of the integration response to polypropylene meshes placed in two anatomic positions in the abdominal wall and correlated results with tensiometric studies. Two macroporous polypropylene prostheses were implanted in a rat model--one on the abdominal aponeurotic layer and one on the peritoneal surface--without creating a wall defect. Studies were performed over implantation intervals of 7, 15, and 30 days in strips obtained from the polypropylene fiber-receptor repair tissue interface. Microscopic appearance, tensile strength, percent elongation, and stiffness were evaluated. Meshes implanted on the abdominal aponeurotic layer showed better early tissue incorporation (higher collagen deposition, capillary density, cell accumulation) and increased tensile strength, reflecting tighter anchorage to the abdominal wall. The percent elongation increased from day 7 to day 30 after implantation, mainly in the deep stratum. The ESEM images correlated well with biomechanical results, indicating the potential of this technique as a powerful, effective tool for use in wound-healing studies.

Expression of the HIV-1 co-receptors CCR5 and CXCR4 on placental macrophages and the effect of IL-10 on their expression

The chemokine receptors CCR5 and CXCR4 play a key role in HIV-1 infection as co-receptors for viral entry. In the placenta, an important natural barrier to HIV, the expression and regulation of these receptors has yet to be elucidated. In this study, we determined the expression of CCR5 and CXCR4 co-receptors on placental macrophages (PM) and the effect of interleukin-10 (IL-10) on co-receptor expression. PM were isolated from term placentae of HIV-uninfected mothers and cultured for up to 11 days. The cells were stimulated with IL-10 for 24 h and stained with specific antibodies to CCR5, CXCR4, CD4, CD3, CD11c and CD14 for flow cytometry. Unstimulated PM expressed significantly more CCR5 than CXCR4. Expression of both co-receptors was upregulated by stimulation with IL-10 at 24 h post-stimulation. In vivo expression of these co-receptors from frozen sections revealed a higher percentage of CCR5 positive cells. This is the first study in which expression of both co-receptors is detected on the PM membrane. These results are consistent with previous studies performed in our laboratory where PM were readily infected by CCR5-using HIV strains but could not be productively infected by HIV strains that exclusively use CXCR4 as a co-receptor.

Hemoperitoneum as a first manifestation of hepatocellular carcinoma in western patients with liver cirrhosis: effectiveness of emergency treatment with transcatheter arterial embolization

Hemoperitoneum is a well-known form of hepatocellular carcinoma presentation and represents a frequent complication in countries with a high incidence of hepatocellular carcinoma, but it is rarely seen in Western countries. Our aim was to report the results and describe the arteriographic and CT-scan characteristics in a series of seven consecutive patients. They were admitted to our hospital because of hemoperitoneum due to ruptured tumor as a first manifestation of hepatocellular carcinoma, and the rupture was effectively controlled by transcatheter arterial embolization. From April 1989 to April 1998, 440 consecutive patients were admitted to our liver unit with the diagnosis of hepatocellular carcinoma and liver cirrhosis. Fourteen patients (3%) presented with acute hemoperitoneum due to tumor rupture as a first manifestation of hepatocellular carcinoma. We here report our experience in the group of patients treated by transcatheter arterial embolization. Mean age was 67.1+/-5 years (range, 61-73). All patients presented with sudden abdominal pain, abdominal distension, and four patients had symptoms of acute anemia. In all cases the ruptured tumor was subcapsular. The procedure was effective in the control of bleeding in all cases, without significant impairment in liver function or treatment-related deaths. In six of the seven patients, a self-limited postembolization syndrome was observed. Mean survival time was 273+/-488.7 days (range: 15-1290). Three patients survived more than six months but at the time of evaluation, only one patient was alive. In conclusion, the present results confirm that transcatheter arterial embolization is an effective and well-tolerated treatment in the management of hemoperitoneum due to ruptured hepatocellular carcinoma in patients with liver cirrhosis.

Early effects of exogenous arginine after the implantation of prosthetic material into the rat abdominal wall

We have investigated the effects of high arginine (Arg) levels (7.5 mg/100 g body weight per hour) on the early integration of biocompatible mesh grafts into the rat abdominal wall. Studies were performed over implantation intervals of 6, 12, 24 or 48 hours (n=12, each). Arginine and related compounds were quantified in plasma, wound fluids and multiple tissues. Plasma nitric oxide (NO) production was studied. Strips were taken from the polypropylene fiber-host tissue interfaces (PTIs) for optical microscopic analysis and for immunohistochemical analysis using rat-specific antibodies against type I and type III collagens. Exogenous Arg was metabolized at the peripheral tissues but reliably reached the wound space. High amounts of Arg and ornithine (Orn) were detected in the specimens considered. No changes on citrulline (Ctr) or NO concentrations were observed, overall suggesting that, during the period studied, the arginase pathway predominated. The acute scarring response differed significantly in the two placements considered. The P-SS interface evidenced more extensive new tissue growth than the P-DS interface. Forty-eight hours after mesh implantation cellular infiltration, fibroblast proliferation, and mesh-surrounding angiogenesis were higher in the arginine-treated rats. Type III collagen staining was related to arginine treatment, being higher (++) in the study group. In conclusion, and independently of the site of mesh placement, supplemental Arg seemed to favorably affect early local collagen deposition. This could be potentially helpful to ameliorate the integration of biomaterials into the tissues and, consequently, to allow for the design of more selective therapeutic strategies to prevent hernia recurrence rates.

Relationship between lipoprotein(a) phenotypes and albumin excretion rate in non-insulin-dependent diabetes mellitus: protective effect of 'null' phenotype?

The possible association between lipoprotein(a) [Lp(a)] and albumin excretion rate (AER) is a topic that generates conflicting views. In addition, Lp(a) phenotypes have not previously been considered as factors influencing AER. In order to clarify this issue, we studied 70 non-insulin-dependent diabetes mellitus (NIDDM) patients without clinically detectable macroangiopathy, 27 with microalbuminuria and 43 without it. Both groups were matched for the known variables that could influence AER and serum Lp(a) levels. Lp(a) was determined by enzyme-linked immunosorbent assay (ELISA), and Lp(a) phenotypes were assessed by electrophoresis followed by immunoblotting. Lp(a) phenotypes were grouped as follows: 'small' (F, S1 and S2), 'big' (S3 and S4) and 'null'. The NIDDM patients with microalbuminuria presented higher serum Lp(a) concentrations than the patients without it [15.7 mg dL-1 (95% CI 0.5-36.5) vs. 4.5 mg dL-1 (95% CI 0.1-18.5); P < 0.001] and a direct correlation between Lp(a) and AER was observed (r = 0.34; P < 0.01). AER was significantly different when Lp(a) phenotypes were considered ['small': median 19 micrograms min-1 (range 1-195); 'big': median 9.5 micrograms min-1 (range 1-186); 'null': 4 micrograms min-1 (range 1-9); P = 0.04]. None of the NIDDM patients with a 'null' phenotype showed an AER of > 10 micrograms min-1. In conclusion, this case-control study provides evidence that microalbuminuria is associated with high serum Lp(a) in NIDDM without clinically detectable macroangiopathy. Furthermore, NIDDM patients with a 'null' phenotype could be considered at low risk for the development of microalbuminuria.

Prospective case control study to determine the effect of lovastatin on serum testosterone and cortisol concentrations in hyperlipidemic nephrotic patients with chronic renal failure

In order to investigate the effects of lovastatin on adrenal and gonadal function, we prospectively determined the basal and gonadorelin-stimulated concentrations of testosterone, follicle-stimulating hormone (FSH) and luteinizing hormone (LH) and the cortisol response to adrenocorticotropic hormone (ACTH) in a sample of 25 male patients with advanced chronic renal failure, hypercholesterolemia and proteinuria. Hormone studies were done prior to and after lovastatin treatment. The values of these patients were compared with those of a matched healthy control group. Before starting treatment with lovastatin, the patients showed significantly lower testosterone concentration and higher LH concentration than the control group. After stimulation with gonadorelin, they also showed a lower increase in testosterone and LH. After 12 months of lovastatin treatment, a significant decrease in the concentration of cholesterol, LDL C, VLDL C and apo B was observed, but neither the basal testosterone concentration nor the response to gonadorelin stimulation was modified. Before treatment, basal and ACTH-stimulated serum cortisol levels did not differ from those of the control group. After lovastatin treatment, neither the basal serum cortisol levels nor the response to ACTH was modified. We conclude that in the patients studied, although the decrease in testosterone concentration may be partially attributable to a decrease in its synthesis, lovastatin treatment does not increase testosterone deficit. This is either because this drug does not inhibit gonadal hydroxymethylglutaryl CoA reductase at the does given or because the cholesterol which LDL C provides the cell with is enough to maintain testosterone synthesis.

Serum lipoprotein (a) levels in patients with chronic renal failure--evolution after renal transplantation and relationship with other parameters of lipoprotein metabolism: a prospective study

In order to analyze the relationship between lipoprotein (a) [Lp (a)] and other lipoproteins during chronic renal failure and once renal function is restored after kidney transplantation, we determined the serum levels of total lipoprotein, high-density lipoprotein, low-density lipoprotein, and very-low-density lipoprotein cholesterols, total and very-low-density lipoprotein triglycerides, apolipoproteins A-I, B, C-II, C-III, and E, and E, and Lp (a) in 30 patients with chronic renal failure before and 12 months after renal transplantation. During the 1st year after transplantation, all patients were treated only with ciclosporin and prednisone and had serum creatinine levels < 1.6 mg/dl (140 mumol/l) and proteinuria < 500 mg/day. No patients had chronic hepatic disease. To determine reference values we studied a control group of 60 healthy volunteers. Before renal transplantation, the study group showed higher concentrations of triglycerides, very-low-density triglycerides, very-low density lipoprotein cholesterol, apolipoproteins, C-II and C-III, and Lp(a) than the control group. There was no correlation between Lp(a) and any of the studied variables. After renal transplantation, the serum levels of total lipoprotein, high-density lipoprotein, and low-density lipoprotein and apolipoproteins A-I and B increased significantly. Apolipoproteins C-II and C-III and Lp(a) decreased and normalized. After these changes had taken place, there was no relationship between Lp(a) and other parameters of lipoprotein metabolism. We conclude that the increase in Lp(a) during the chronic renal failure phase is basically related to the loss of renal function and does not depend on the resultant alterations which are produced in other lipoprotein variables.

[The percutaneous dissolution treatment of gallstones. Our initial experience]

OBJECTIVE

To describe our initial experience in direct contact dissolution of cholesterol gallstones with methyl-tert-butyl ether, a non surgical approach for high risk patients.

PATIENTS

Twenty symptomatic patients were preselected. They all had radiolucent stones in functioning gallbladders. Patients rejected elective surgery or were considered to be of high risk for anesthesia. Computerized tomography scan was performed to evaluate stone calcium content and liver-gallbladder anatomy. In selected patients, contact stone dissolution was carried out after transhepatic gallbladder catheterization.

RESULTS

Ten patients were excluded due to poor gallbladder contact to the liver (two patients) or stone density greater than 70 Hounsfield Units. Percutaneous transhepatic positioning of the catheter into the gallbladder was achieved in seven patients. Stone dissolution was complete in five patients and partial in one. Mean perfusion time was 6.15 hours (3.45-7.5); however, mean hospitalization stay was 7 days (4-10) mainly due to inexperienced management coordination. While on treatment, all patients experienced nausea, burning or abdominal discomfort that were easily controlled. Complications were related to catheter placement (intraperitoneal biliary leakage, external fistula) and in five patients to the dissolution procedure (severe abdominal pain, biliary colic, cholecystopancreatitis). Complications were all handled with non surgical treatment.

CONCLUSIONS

Percutaneous gallstone dissolution with methyl-tert-butyl ether is a rapid and efficacious procedure that can, nevertheless, induce relevant secondary effects and complications.

[Isotopic renogram after captopril administration: clinical experience in the assessment of the hypertensive patient]

BACKGROUND

Isotopic renogram allows renal function to be estimated in both kidneys independently. The glomerular filtrate in ischemic kidneys is largely dependent on the tone of the efferent glomerular arteriolae and therefore on the concentration of circulating angiotensin II.

METHODS

In 42 patients with severe high blood pressure in whom renal angiographic study was carried out for suspicion of vasculo-renal hypertension, an isotopic renogram using 99m Tc-DTPA as a tracer was performed in basal conditions and following the administration of 50 mg of oral captopril.

RESULTS

In 21 patients both the angiographic examination and the post-captopril renogram were normal. In 16 patients in whom uni or bilateral stenosis higher than 50% of the lumen of renal artery was observed on angiographic examination, the post-captopril renogram showed changes. In 5 patients the angiography was normal while the renogram showed evaluable changes. No false negatives were observed in the post-captopril renogram, however the basal renogram was not demonstrative in 6 patients with stenosis of the renal artery. Sensitivity of the test was thus 100% and specificity 80%. The positive predictive value was 76% and the negative predictive value 100%.

CONCLUSIONS

The post-captopril renogram may be a useful test in the functional study of renal behaviour in patients with vasculo-renal hypertension.

Carboplatin, methotrexate, vinblastine and epirubicin (Carbo-MVE) for transitional cell bladder carcinoma

BACKGROUND

MVAC is considered the most effective chemotherapy regimen for transitional cell bladder carcinoma. However, due to its significant toxic effects we substituted carboplatin for cisplatin and epirubicin for adriamycin in an attempt to produce the same response with less toxicity.

PATIENTS AND METHODS

Twenty-seven patients with invasive transitional cell bladder carcinoma received Carbo-MVE: carboplatin (300 mgr/m2 d2), methotrexate (30 mgr/m2 d1, 15, 22), vinblastine (3 mgr/m2 d2, 15, 22) and epirubicin (30 mgr/m2 d2) every 4 weeks.

RESULTS

There were 2 complete clinical responses (8.4%), 5 partial clinical responses (20.8%), 8 stabilizations (33.3%) and 9 progressions (37.5%). The overall clinical response rate was 29.2% (11%-47.4%, 95% CI), but 2 partial clinical remissions were not pathologically confirmed; were they to be considered as non-responses the response rate would fall even lower (20.8%). Toxicity was moderately severe, with 77.8% developing WHO grade III-IV granulocytopenia, 22.2% grade III-IV thrombocytopenia and 59.3% grade II-III vomiting. There were no toxic deaths nor any renal toxicity.

CONCLUSIONS

Our results suggest that Carbo-MVE is less active and at least as hematotoxic as multiagent CDDP-based regimens.

[Acute interstitial secondary to tricuspid endocarditis caused by Staphylococcus aureus]

The kidney diseases in patients with bacterial endocarditis and intravenous drug addicts (IVDA) tend to be of glomerular origin. Interstitial nephritis has been related to drug toxicity and only occasionally has it been described in other associations. We describe a 27-year-old patient IVDA with tricuspid endocarditis caused by S. Aureus whose first manifestations was acute renal failure. The renal biopsy showed an interstitial nephritis. It was treated with antibiotic and hemodialysis, obtaining the cure and normal levels of plasmatic creatinine.