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Biomedical subjects

J Camps

Publications and source records attributed to J Camps.

At least 73 records · Page 4Linked to original sources
PubMed1995

Transportation of curved canals prepared with canal master U, canal master U niti, and stainless steel K-type files.

The purpose of this study was to evaluate and to compare root canal configuration after preparation with three different hand instruments and techniques: the canal master U preparation technique (Brasseler, Savannah, GA.), using stainless steel or nickel-titanium canal master U instruments, and the step-back technique using precurved conventional stainless steel K-type files. Sixty-three simulated curved canals were divided in three groups of 21 each. Each group was prepared using one of the three instruments. Comparison of root canal configuration was evaluated with pre- and postoperative photographs that measured the difference in canal diameter and the mesial and distal transportation of the canal walls at the canal length and at levels 1, 2, 3, 4, 5, 6, 7, and 8 mm coronal to the canal length. Data obtained were analyzed statistically using an analysis of variance. Instrument breakage was also recorded. Results showed that the final diameter of the prepared canals as well as canal transportation were significantly different between both canal master U instruments and the stainless steel K file. Three stainless steel canal master U instruments separated during instrumentation whereas none in the nickel-titanium canal master U and stainless steel K-type file groups separated. The results of this study show that the canal master U instruments and technique provide a better canal configuration than K files using the step-back technique and that the nickel-titanium canal master U and stainless steel K-type file offers a greater safety factor against breakage than the stainless steel canal master U.

Analysis of Variance↗
PubMed1995

Assessment of peripheral vascular effects of antimigraine drugs in humans.

The vascular beds of the forearm and finger can be used to study the peripheral effects of antimigraine drugs under normal and pathologic circumstances. We have investigated the novel antimigraine drug sumatriptan, a selective agonist for 5HT1 receptors. Its antimigraine effect may be attributed, at least in part, to constriction of cranial arteriovenous anastomoses (AVAs). In assessing the peripheral vascular effects of sumatriptan we used a forearm and finger blood flow model. Forearm blood flow (FBF) is mainly determined by resistance vessels, whereas finger blood flow (FiBF) mainly involves skin vessels, which contain many AVAs. Changes in FBF and FiBF can be assessed using venous occlusion plethysmography. Changes in AVA flow are determined by measuring the patency of the vascular beds of the forearm and hand to well-defined radiolabelled microspheres, which are injected into the brachial artery. We report the effects of sumatriptan on FBF, FiBF and AVA flow when administered into the brachial artery of healthy volunteers, and discuss the peripheral vascular effects of therapeutic doses of sumatriptan when given subcutaneously in migraine patients during and between attacks.

Adult↗
PubMed1995

Laparoscopic inguinal herniorrhaphy. Results of a multicenter trial.

OBJECTIVE: The purpose of this study was to determine if laparoscopic inguinal herniorrhaphy represents a viable alternative to the conventional repair and to assess whether a prospective randomized controlled trial comparing both procedures is warranted. METHODS: Three types of laparoscopic inguinal herniorrhaphies (transabdominal preperitoneal [TAPP], intraperitoneal onlay mesh [IPOM], and totally extraperitoneal [EXTRA]) were studied in a phase II design. Twenty-one investigators from 19 institutions participated. Approval from the local human research committee was required at each institution before patients could be enrolled. RESULTS: There were 686 patients with 869 hernias; 366 (42.1%) were direct, 414 (47.6%) were indirect, 22 (2.5%) were femoral, and 67 (7.7%) were combination hernias. The TAPP procedure was used for 562 hernias, the IPOM was used for 217 hernias, and the EXTRA was used for 87 hernias. Sixty-one patients had additional abdominal procedures performed at the time of laparoscopy without any adverse affects on their herniorrhaphies. The overall recurrence rate was 4.5%, with a minimum follow-up of 15 months. Complications were divided into the following three groups: 1) those related to laparoscopy, 2) those related to the patient, and 3) those related to the herniorrhaphy. Complications related to the laparoscopy occurred in 5.4% of patients; bleeding or abdominal wall hematomas occurred 31 times, (two patients required transfusion); one patient had bowel perforation, which was sutured laparoscopically; a bladder injury required laparotomy for management. Patient complications occurred in 6.7%. The majority involved the urinary tract (5.8%). Two patients required secondary abdominal procedures for adhesions, one for pain in the right lower quadrant and the other for adhesive small bowel obstruction. Postoperative myocardial infarction on day 5 resulted in the only operative mortality, for a rate of 0.1%. Complications related to the herniorrhaphy itself occurred in 17.1%. Most of these were minor, consisting of transient groin pain (3.5%), seroma (3.5%), transient leg pain (3.3%), hematoma (1.5%), or transient cord or testicular problems (0.9%). The incidence of leg pain decreased dramatically as surgeons became more familiar with the anatomy of the nerve supply to the groin when viewed laparoscopically. Ninety-three percent of patients were discharged within 24 hours of their operations. CONCLUSIONS: Laparoscopic inguinal herniorrhaphy is an effective method to correct an inguinal hernia. It can be offered safely to patients undergoing other abdominal procedures. The TAPP, IPOM, and EXTRA procedures appear to be equally effective. A controlled randomized trial is needed to compare this procedure with conventional inguinal herniorrhaphy.

Adolescent↗
PubMed1995

Pulmonary deposition and disappearance of aerosolised secretory leucocyte protease inhibitor.

BACKGROUND: The neutrophil elastase inhibitor, secretory leucocyte protease inhibitor (SLPI), is a potential therapeutic tool in inflammatory lung diseases such as cystic fibrosis and pulmonary emphysema. The distribution and disappearance in the lung of aerosolised recombinant SLPI (rSLPI) was investigated in healthy humans and in patients with cystic fibrosis or alpha 1-antitrypsin-associated emphysema. METHODS: To distinguish aerosolised rSLPI from endogenous SLPI the recombinant inhibitor was radiolabelled with 99m-technetium (99mTc) pertechnetate. Distribution and disappearance of aerosolised 99mTc-rSLPI in the lungs were studied by gamma radiation imaging. RESULTS: The deposition of 99mTc-rSLPI in normal volunteers was homogeneous in all lung lobes, while in patients with cystic fibrosis or emphysema only well ventilated areas showed deposition of the aerosol. The disappearance rate of 99mTc-rSLPI was biexponential. The half life of the rapid phase was 0.2-2.8 hours, while that of the slow phase was more than 24 hours. CONCLUSIONS: Future aerosol therapy with rSLPI will be most beneficial for well ventilated lung tissue that needs protection against neutrophil derived elastase. It may be more difficult to neutralise the burden of elastase in poorly ventilated, highly inflamed areas as are seen in cystic fibrosis.

Adult↗
PubMed1995

Influence of zinc intake on hepatic lipid peroxidation and metallothioneins in alcoholic rats: relationship to collagen synthesis.

Hepatic lipid peroxidation, metallothioneins, collagen and proline hydroxylase activity were investigated in 16 ethanol-fed rats and in 16 control animals. The rats were further divided into three groups to receive either a standard diet, a zinc-deficient diet or a zinc-supplemented diet. The animals were sacrificed at week 12 of the experiment for histological and biochemical assessments. Hepatic tissue examination indicated that oral zinc supplementation was associated with a decrease in lipid peroxidation, collagen deposition and proline hydroxylase activity together with an increase in metallothionein concentration in alcoholic rats. There were no significant differences in lipid peroxidation in the control group in relation to the diet. Zinc supplementation was associated with increased concentrations of hepatic metallothioneins together with decreased concentrations of proline-hydroxylase and collagen but to a lesser degree than in alcoholic animals. These results indicate that zinc is an efficient hepato-protective agent against lipid peroxidation in alcoholic rats and its effect may be, in part, mediated by the activation of metallothionein synthesis. Also, lipid peroxidation may be related to changes in hepatic collagen synthesis.

Alcoholism↗
PubMed1995

Accumulation of atherogenic remnants and lipoprotein(a) in the nephrotic syndrome: relation to remission of proteinuria.

Although lipoprotein abnormalities of the nephrotic syndrome are assumed to be related to the presence of proteinuria, this topic has not been investigated extensively. We measured lipoproteins from 19 nonuremic patients during and after remission of the nephrotic syndrome in an effort to determine the extent of their putative atherogenicity. As expected, disturbances involved primarily the apoprotein B-containing lipoproteins. No patient showed serum lipoprotein(a) [Lp(a)] < 300 mg/L during the acute phase. Lp(a) concentrations correlated significantly with those of apoprotein B, and both values decreased dramatically with the remission of the nephrotic syndrome. Surprisingly, despite the resolution of proteinuria, concentrations of intermediate-density lipoproteins and Lp(a) remained above normal in hypertriglyceridemic patients, suggesting a residual effect of nephrosis in the overall lipoprotein transport. Accumulation of atherogenic remnants should be considered a characteristic of the hyperlipidemia of the nephrotic syndrome, and aggressive treatment to reduce proteinuria is mandatory.

Adolescent↗
PubMed1995

Pathophysiology of hepatitis C virus infection.

Any physiopathological hypothesis of HCV infection must explain at least some of the most characteristic features of this infection, namely: 1) persistent infection in the majority of exposed individuals, associated with a wide spectrum of histological damages and fluctuating biochemical expression; 2) low tendency towards spontaneous recovery; 3) high tendency to progress to cirrhosis; 4) high prevalence of autoimmune phenomenons; 5) very weak or absent immunity to reinfection. A model is given taking into account the nature of the HCV genome, the immune response of the host to the infection and the potential mechanisms(s) involved in viral persistence.

Antibody Formation↗
PubMed1994

Response to repeated phlebotomies in patients with non-insulin-dependent diabetes mellitus.

Regardless of type, uncontrolled diabetes represents a serious disruption of fuel homeostasis with consequences throughout the body. This may hamper the applicability of predeposited autologous blood transfusion in diabetic patients because metabolic changes are expected as a consequence of repeated bleeding. We undertook this study to determine whether the presence of non-insulin-dependent diabetes mellitus (NIDDM) influences the erythropoietin (EPO) response to repeated phlebotomies with respect to normal subjects. We included 22 consecutive patients scheduled for major surgery during a 2-year period in which clinical and metabolic complications were excluded and renal and liver function was considered unaffected. Selected biochemical and hematologic variables were serially measured during donation of several units of blood in a 12- to 29-day period. Bleeding produced a significant decrease in serum glucose, cholesterol, triglyceride, and apoprotein B concentration in diabetic patients. Except for glucose, this effect was not observed in controls. Both groups were comparable with respect to initial hemoglobin concentrations and all hematologic variables measured. The decrease in hemoglobin concentration did not produce clinical symptoms in these patients, and recovery was regarded as normal in both groups. Serum EPO levels in diabetic patients were negatively influenced by the initial hemoglobin A1c (HbA1c) proportion. Moreover, three nonrespondent diabetic patients with poor glycemic control responded normally 6 to 13 months later, in a second operation, when glycemic control had improved significantly. In conclusion, NIDDM may limit the donation of requested units for major surgery only if poor glycemic control is present. When possible, phlebotomies should be delayed and metabolic control reinforced.

Adult↗
PubMed1994

Influence of tooth cryopreservation on human dentin permeability, in vitro.

OBJECTIVES: In order to use cryopreserved teeth in laboratory studies, cryopreservation must not modify the functional properties of teeth, in particular dentin permeability. The purpose of this study was to evaluate the effects of tooth cryopreservation on human dentin permeability. METHODS: Three hundred and sixty freshly extracted human noncarious third molars were used. The teeth were randomly assigned to two groups: 180 teeth were stored in phosphate-buffered saline at 4 degrees C and tested within 4 h of collection; 180 teeth were cryopreserved. Hydraulic conductance was calculated according to the method developed by Pashley (Outhwaite et al., 1976). RESULTS: Cryopreserved teeth presented a hydraulic conductance of 8.97 x 10(-3) +/- 4.21 x 10(-3) microL.cm-2.min-1.cm.H(2)0(-1) slightly higher than the hydraulic conductance of the freshly extracted teeth of 8.03 x 10(-3) +/- 3.87 x 10(-3) microL.cm-2.min-1.cm.H(2)0(-1). No statistically significant difference was found between the two groups. SIGNIFICANCE: Under the conditions of this study, cryopreservation did not modify dentin permeability.

Analysis of Variance↗
PubMed1994

Torsional and stiffness properties of Canal Master U stainless steel and nitinol instruments.

The purpose of this study was to compare stiffness and resistance to fracture of stainless steel and nickel titanium Canal Master U instruments. Instruments sizes 20 through 50 were tested according to ANSI/ADA Specification No. 28. Resistance to fracture was determined by twisting and measuring the maximum torque and angular deflection (rotation) at the failure point. Stiffness was determined by measuring the moment required to bend the instrument 45 degrees. Stainless steel and nickel titanium Canal Master U instruments satisfied and far exceeded specification standards for stiffness. They also satisfied and far exceeded the standards for angular deflection at the failure point. Stainless steel Canal Master U met or exceeded the maximum torque at failure standards in all sizes except 50, whereas the nickel titanium instruments met the standards in all sizes except 45 and 50. The mechanical properties of nickel titanium, especially its low bending moment and high angular rotation at failure, encourage further evaluation with clinical studies.

Alloys↗
PubMed1994

Fibrogenic and collagenolytic activity in carbon-tetrachloride-injured rats: beneficial effects of zinc administration.

Collagen synthesis and degradation in normal and carbon-tetrachloride-injured male Wistar rats at early and late stages of liver fibrosis, and the potential beneficial effects of zinc supplementation on liver fibrogenesis and collagenolysis have been assessed by measuring hepatic collagen content and prolyl hydroxylase and collagenase activities. No significant changes in hepatic collagen and prolyl hydroxylase activities were observed between control rats (82 +/- 25 cpm/mg protein) and rats with induced cirrhosis (107 +/- 23 cpm/mg protein) after 4 weeks of carbon tetrachloride injury. By this time, hepatic collagenase activity was significantly lower in rats with induced cirrhosis (61 +/- 9 micro units/mg protein) than in control rats (133 +/- 31 micro units/mg protein) (p < 0.05). This result was prevented by zinc administration, since hepatic collagenase activity was similar in zinc-supplemented, carbon-tetrachloride-injured rats and normal rats (148 +/- 19 micromicrons/mg protein). After 16 weeks, all carbon-tetrachloride-injured rats had cirrhosis. Hepatic collagen content and prolyl hydroxylase activity were significantly higher in carbon-tetrachloride-injured rats than in controls. These effects were partially prevented by zinc administration, since only two of the seven zinc-supplemented, carbon-tetrachloride-injured rats had cirrhosis. Moreover, prolyl hydroxylase activity was significantly lower in zinc-supplemented injured rats (263 +/- 27 cpm/mg protein) than in the non-supplemented respective controls (389 +/- 52 cpm/mg protein) (p < 0.05). No significant changes in hepatic collagenase activity were observed at this stage of liver injury.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

Prediction of sustained remission of chronic hepatitis C after a 12-month course of alfa interferon.

alpha-Interferon therapy normalizes aminotransferase levels in approximately 50% of the patients with chronic hepatitis C, but post-therapy relapses are common and predictive factors of sustained response remain largely unknown. We retrospectively assessed several parameters as predictors of sustained remission after a 12-month course of lymphoblastoid alpha-interferon: the Knodell histological activity index, serum levels of procollagen type III peptide, serum HCV-RNA, anti-alpha-interferon antibodies, and anti-HCV antibodies (C-100-3), all at month 12. Thirty-seven patients were studied. Fourteen patients were non-responders (38%), 15 patients experienced a sustained response (40.5%) and eight patients responded similarly but relapsed after alpha-interferon withdrawal (21.5%). A decrease in the histological activity index above 5, normalization of procollagen type III peptide levels (< 12 ng/ml) and the absence of viremia after treatment were all significantly associated with a sustained response (p = 0.008, p = 0.007 and p = 0.037, respectively). Anti-interferon antibodies were detected in only one non-responder patient. Anti-C-100-3 antibodies became undetectable at month 12 in 5 of the 15 sustained responders. The best prediction of sustained response was obtained from the three variables independent of multivariate analysis according to the following equation: F = 0.872 + 0.067 x K (decrease of histological index) -0.052 x P (procollagen type III peptide levels at month 12) -0.28 x R (HCV-RNA at month 12; R = 2 when present and R = 1 when absent). A score higher than 0 predicted sustained remission with a 100% sensitivity and specificity in this series of patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Plasma lipoprotein alterations in patients with chronic hepatocellular liver disease resulting from alcohol abuse: effects of alcohol intake cessation.

Cholesterol and triglyceride in plasma and lipoprotein fractions and serum apoprotein concentrations were measured in 51 chronic alcoholic subjects; 23 had minimal or mild hepatic changes (steatosis and/or fibrosis) and 28 had cirrhosis. Of the latter, 16 had stopped alcohol consumption at least 3 months before the study, while the other 12 and all the mildly affected patients had continued drinking. None of the patients presented with cholestasis or alcoholic hepatitis. The control group was composed of 15 healthy, non-drinking volunteers selected from the hospital staff with an age- and sex-distribution similar to that of the alcoholic group. Patients with minimal hepatic changes had plasma total cholesterol concentrations within the ranges of the normal population but with increased high density lipoprotein and decreased low density lipoprotein fractions. Total plasma triglyceride values were not significantly elevated but the distributions in the low density lipoprotein and high density lipoprotein fractions were significantly increased in patients compared to controls. This alteration was accompanied by a consistent increase in serum apolipoprotein C-III concentration. Conversely, in patients with cirrhosis, serum concentrations of apolipoproteins A-I and B were significantly lower and were reflected in the cholesterol concentrations in the lipoprotein fractions. Comparisons between abstainers and non-abstainers within the group with cirrhosis indicated that cessation of alcohol intake was not sufficient to rectify lipoprotein dysfunction following damage from cirrhosis.

Adult↗
PubMed1994

Effects of the Flexogates and Canal Master U on root canal configuration in simulated curved canals.

The purpose of this study was to compare the Canal Master U (CMU) instrumentation technique with that of a similar instrument, the Flexogates (FG). Forty simulated curved canals were divided in two groups of 20 each. One group was prepared using the CMU instrumentation technique and the other using the FG technique. Comparison was made by measuring the diameter of the prepared canals and transportation that occurred at the canal length and at levels 1, 3 and 5 mm coronal to the canal length. Data obtained were analysed statistically. Results showed that the final diameter of the prepared canals was not significantly different between the CMU or the FG. However, the FG transported the outer wall of the curvature more than the CMU at the canal length and at 1 mm from the CL. Although the difference in the canal transportation was statistically significant it may not be of clinical importance.

Analysis of Variance↗
PubMed1994

Laparoscopic inguinal herniorrhaphy.

Currently accepted laparoscopic inguinal herniorrhaphies are of three types: Trans-Abdominal Pre-Peritoneal (TAPP), Intra-Peritoneal Onlay Mesh (IPOM), and Totally Extra-peritoneal (EXTRA). The TAPP procedure is the most commonly performed operation. The peritoneum is opened transversely above the hernia defect and a radical dissection of the pre-peritoneal space accomplished. The hernia defect is widely covered with a large prosthesis, and the mesh is secured with staples. The peritoneum is then closed over the prosthesis. The IPOM technique has become the second most common laparoscopic inguinal herniorrhaphy. A prosthesis is placed on the intra-abdominal side of the peritoneum and stapled in place using the same landmarks as for the TAPP. This avoids an extensive dissection of the pre-peritoneal space. However, it must be considered as an experimental procedure because of the possibility of complications caused by adhesions to the intra-abdominally placed prosthesis. The third type of laparoscopic inguinal herniorrhaphy is the EXTRA. The hernia is repaired using laparoscopic instrumentation without violating the peritoneum by dissecting the space between the peritoneum and the transversalis fascia, beginning at the umbilicus. Once the inguinal region is entered, the procedure is similar to the TAPP. However, it is more difficult than the TAPP because of the small working space, especially for the inexperienced. Early results suggest that laparoscopic inguinal herniorrhaphy is an effective method for correcting an inguinal hernia. It can be performed with a reasonably low morbidity. Indications remain to be determined. A randomized prospective study comparing laparoscopic inguinal herniorrhaphy with conventional is warranted.

Hernia, Inguinal↗
PubMed1994

Limitations of the Friedewald formula for estimating low-density lipoprotein cholesterol in alcoholics with liver disease.

The accuracy of the Friedewald formula in estimating low-density lipoprotein (LDL) cholesterol was investigated in 47 alcoholic patients with liver disease (21 minimal-change, 26 cirrhotic) by comparing the results with those obtained by sequential preparative ultracentrifugation. In 14% of subjects with minimal-change disease, the error in the estimated LDL cholesterol was 50% +/- 9% (mean +/- SD; range 40-59%) and was related to the degree of attendant hypertriglyceridemia (r = 0.98; P < 0.001). A similar degree of error was observed in patients with cirrhosis, despite the absence of hypertriglyceridemia; an abnormal VLDL cholesterol: triglyceride ratio was the contributory factor in the discrepancy. We conclude that, as is the case in other clinical pathologies in which abnormalities of lipoprotein composition have been described (e.g., diabetes), the Friedewald formula to estimate LDL cholesterol may be inappropriate in chronic alcoholics, particularly those in whom a degree of hepatic dysfunction may be suspected.

Adult↗