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Biomedical subjects

R Pop

Publications and source records attributed to R Pop.

At least 19 recordsLinked to original sources
PubMed2000

[The neurogenic mechanisms of ocular inflammation and their modulation under local treatment with indomethacin].

Neurogenic modulation of the inflammation is an essential mechanism of initiate and conditionate an inflammatory reaction. SP, NKA and NKB--neurokinins are involved in the modulation of the local ocular inflammation initiated by the surgical perforating trauma of the anterior pole. They determine the increase of vascular permeability and the breakdown of the aqueous-humor-blood barrier by direct action on the endothelial vascular receptors and by indirect mechanism (releases prostaglandins). This effect is demonstrated by the increase of the blue Evans concentration in the aqueous-humor after local application of SP, NKA and NKB in a dose-dependent manner. Local treatment with non-steroidal-antiinflammatory drugs like Indomethacin stabilizes the aqueous-humor-blood barrier, by diminishing the local effect of neurokinins. By increasing the vascular permeability SP, NKA and NKB make an important linkage by which the nervous system mediators contribute to the modulation of eye inflammatory responses whose intimate mechanisms are not entirely known yet.

Animals↗
PubMed1999

Unfiltered sulfur colloid and sentinel node biopsy for breast cancer: technical and kinetic considerations.

BACKGROUND: There are few clinical data on technical limitations and radiocolloid kinetics related to sentinel lymph node (SLN) biopsy for breast cancer. METHODS: In 70 clinical node-negative patients, unfiltered 99mTc sulfur-colloid was injected peritumorally and cutaneous hot spots were mapped with a gamma probe. SLN biopsy was performed followed by axillary lymph node dissection. Missed radioactive nodes (nodes not under hot spots) were removed from axillary lymph node dissection specimens and submitted separately. RESULTS: At least one hot spot was mapped in 69 patients (98%) and SLNs were retrieved in 62 (89%). No radiolabeled nodes were found in five (7%) and only nodes not under hot spots were retrieved in three patients (4%). Residual nodes not under hot spots were retrieved in 17 patients (24%) in whom at least one SLN specimen had been found. Diffuse radioactivity around the radiocolloid injection site impeded identification of all radiolabeled nodes during SLN biopsy, and was responsible for one of two false negatives (20 node-positive patients; false-negative rate 10%). Hot spot radioactivity, number of radiolabeled nodes, and nodal radioactivity did not change with time interval from radiocolloid injection to surgery (0.75-6.25 hours). CONCLUSIONS: Although SLN localization rate is high, intraparenchymal injection may predispose to failure of radiocolloid migration, failure to identify SLNs because of high radiation background, and false-negative outcomes. Alternative routes of radiocolloid administration should be explored.

Adult↗
PubMed1999

A thousand points of light or just dim bulbs? Radiolabeled antibodies and colorectal cancer imaging.

Radioimmunoscintigraphy (RIS) is coming into its own as an imaging modality in clinical oncology. Early experience with indium-111-labeled intact murine monoclonal antibodies (MoAbs) in colorectal cancer suggested that RIS images hepatic metastases poorly. Moreover, an antimurine immune response was frequently provoked, precluding multiple follow-up RIS studies in individual patients due to reticuloendothelial sequestration of the radioimmunoconjugate before tumor targeting could occur. Recent trials of technetium-99m-labeled antibody fragments and human MoAbs have demonstrated significant improvement in imaging efficacy, and repeated or serial imaging is possible because of the absence of associated immunogenicity. RIS is demonstrably more sensitive than conventional diagnostic modalities (CDM) such as computed tomography (CT) for detection of extrahepatic abdominal and pelvic colorectal carcinoma and is complementary to CDM in imaging liver metastases. In a surgical decision-making analysis comparing CT, RIS (IMMU-4 99mTc-Fab'; CEA-Scan), and CT plus RIS in patients with recurrent or metastatic colorectal cancer, CT plus RIS improved correct prediction of resectability by 40% and correct prediction of unresectability by 100% compared with CT alone. At the present time, RIS used in combination with CDM contributes an incremental improvement in diagnostic accuracy in colorectal cancer patients with known or suspected recurrent disease. Basic and clinical research currently in progress promises to yield agents and methods that provide rapid high-resolution imaging, high tumor-to-background ratios in all organs at risk for tumor recurrence or metastasis, negligible immunogenicity and toxicity, and a significant further improvement in the accuracy of clinical decision making in oncology patients.

Antibodies, Monoclonal↗
PubMed1999

[The posterior chamber artificial crystalline lens implant in the diabetic patient].

UNLABELLED: The purpose of this study is to display the influence of diabetes on the course of the operation, postoperative complications and functional results in operated primary cataract. MATERIAL AND METHODS: We performed a study on 72 eyes with cataract and diabetes operated in the University Eye Hospital from Cluj-Napoca during 1992-1997. RESULTS: From the 72 cases, 58 had diabetes noninsuline dependent. Background diabetic retinopathy was present in only 18 cases. In 71 cases it was performed EEC + IOL-CP and 1 case with open angle glaucoma we made the triple procedure (EEC + CP-IOL + trabeculectomy). In 43 cases it was striate keratitis, in 30 eyes pigmentary migration and in 4 cases uveitis. As late postoperative complication we had 10 secondary cataract and i retinal detachment. Functional results were in majority cases between 0.1-0.3. CONCLUSIONS: Diabetes do not influence the course of planned extracapsular extraction with PC-IOL, which is the best choice for the patients with cataract and diabetes. Functional results depends on the presence of diabetic retinopathy.

Adolescent↗
PubMed1998

[The functional results in primary surgical cataract associated with diabetes mellitus].

UNLABELLED: The purpose of this study is to display the influence of diabetes on the course of the operation, postoperative complications and functional results in operated primary cataract. MATERIAL AND METHODS: We performed a study on 42 eyes with cataract and diabetes operated in the University Eye Hospital from Cluj-Napoca during 1992-1996. RESULTS: From the 42 cases, 32 had diabetes non-insulin-dependent. Background diabetic retinopathy was present in only 16 cases (38%). In 33 cases it was performed EEC + PC - IOL. Postoperative, in 38 cases it was striate keratitis, in 21 eyes pigmentary migration and in 3 cases uveitis. As late postoperative complications we had 5 secondary cataract and 1 retinal detachment. Functional results were in majority cases between 0.1-0.3. CONCLUSIONS: Diabetes do not influence the course of planned extracapsular extraction with PC-IOL, which is the best choice for the patients with cataract and diabetes. Functional results depends on the presence of diabetic retinopathy.

Aged↗
PubMed1998

[The functional prognosis of traumatic cataracts operated on for an artificial lens implant].

The authors shows the modern possibilities of rehabilitation of the vision in traumatic cataract on a group of 57 cases hospitalised and operated in the Department of Ophthalmology of the University of Medicine from Cluj-Napoca. The study includes the repartition of cases on age, sex, profession, the type of traumatic cataract, different techniques of surgery and the functional results. In all cases it were used intraocular lenses (pupillary, anterior chamber and posterior chamber).

Adolescent↗
PubMed1997

[Herpetic keratitis. Clinical and therapeutic aspects].

The authors have made a retrospective study of 161 cases of herpetic keratitis. 121 cases of them have been superficial herpetic keratitis and 40 of them discoid forms. 72 cases of superficial keratitis have been the first manifestation and 49 have relapsed. 53 cases of superficial herpetic keratitis and 39 cases of relapsed herpetic keratitis have been treated with specific antiviral medication. This treatment decreased significantly the hospitalisation period of first superficial attack herpetic keratitis. In relapsed and discoid forms the number of the hospitalisation days have not been influenced by the antiviral treatment, needing the association of nonsteroid anti-inflammatory drugs and vitamins.

Acyclovir↗
PubMed1997

[Postoperative uveitis in cataract surgery].

Postoperative uveitis is a complication of cataract surgery; this complication may compromise the functional outcome and sometimes loss of the eye ball. Between 1995-1996 in Ophthalmological Clinic from Cluj five hundred patients underwent one surgical procedure for cataract; from these in fifteen cases occurred postoperative uveitis. At thirty cases from them was practised the implant by posterior chamber and by anterior chamber at two cases. The debut and the clinical aspect shows the exogenic character in two cases and the endogenic character in thirty cases. The postoperative uveitis frequency in the cataract surgery was 0.4 per cent. In two cases the outcome was the functional loss of the eyeball. The endogenous uveitis answered favorable at the treat with topic and general corticotherapy. In none of the cases was the implant explantation effected.

Adrenal Cortex Hormones↗
PubMed1997

[Staphylococcal anatoxin, an alternative in the treatment of endogenous uveitis].

The paper presents one clinical study effected by fourty-four patients with endogenous uveitis which beneficiary of a general treatment with staphylococcal anatoxin. The conclusions of the study impose that one effective treatment is obtained at the young patients with anterior, acute uveitis with moderate inflammatory phenomenon and what present one effective answer of the lymphocyte T by interleukin 1. The application of the treatment suppose several exams reminiscent of the immunologic status especially of the cellular immunology.

Acute Disease↗
PubMed1996

High variability in drug pharmacokinetics complicates determination of bioequivalence: experience with verapamil.

PURPOSE: For the assessment of bioequivalence it is assumed that drug clearance in each subject on each of the study days is the same and any observed differences in AUC and/or Cmax between a brand and generic formulation are due to differences in bioavailability. We hypothesized that this assumption was invalid for highly variable drugs such as verapamil and tested it by comparing bioavailability for the brand vs itself. METHODS: To avoid any contribution from potential formulation differences, we evaluated bioavailability for isoptin SR 240 mg tablets in 9 healthy volunteers on 2 occasions separated by 1 week as part of a larger study. A validated HPLC assay was used to measure serial blood samples over 36 hours. RESULTS: The AUC0-1 varied 3.8 fold among subjects and 5/9 subjects had > 30% difference in AUC0-1 on the 2 days. After log transformation, the mean AUC0-1 +/- %cv (ng.h/mL) on Occasion 1 (878 +/- 38) was 23% greater (p = 0.031) than on Occasion 2 (713 +/- 41). The 90% confidence interval of Occasion 1/Occasion 2 was 106-143%. The Cmax varied > 9 fold (30-278 ng/mL) among subjects. The intrasubject difference between days ranged from -46% to +298%. The 90% confidence interval was 72-152% for Cmax. Since the same lot of Isoptin was used in the same subjects on 2 occasions, the observed differences must be due to biological variability in verapamil pharmacokinetics, not formulation differences. CONCLUSIONS: The intra-subject biological variability complicates bio-equivalence assessment and can lead to an erroneous assumption of bioinequivalence.

Adult↗
PubMed1987

Structural and catalytic properties of L-alanine dehydrogenase from Bacillus cereus.

Alanine dehydrogenase from Bacillus cereus, a non-allosteric enzyme composed of six identical subunits, was purified to homogeneity by chromatography on blue-Sepharose and Sepharose 6B-CL. Like other pyridine-linked dehydrogenases, alanine dehydrogenase is inhibited by Cibacron blue, competitively with respect to NADH and noncompetitively with respect to pyruvate. The enzyme was inactivated by 0.1 M glycine/HCl (pH 2) and reactivated by 0.1 M phosphate (pH 8) supplemented with NAD+ or NADH. The reactivation was characterized by sigmoidal kinetics indicating a complex mechanism involving rate-limiting folding and association steps. Cibacron blue interfered with renaturation, presumably by competition with NADH. Chromatography on Sepharose 6B-CL of the partially renatured alanine dehydrogenase led to the separation of several intermediates, but only the hexamer was characterized by enzymatic activity. By immobilization on Sepharose 4B, alanine dehydrogenase from B. cereus retained 66% of the specific activity of the soluble enzyme. After denaturation of immobilized alanine dehydrogenase with 7 M urea, 37% of the initial protein was still bound to Sepharose, indicating that on the average the hexamer was attached to the matrix via, at most, two subunits. The ability of the denatured, immobilized subunits to pick up subunits from solution shows their capacity to fold back to the native conformation after urea treatment. The formation of "hybrids" between subunits of enzyme from B. cereus and Bacillus subtilis demonstrates the close resemblance of the tertiary and quaternary structures of alanine dehydrogenases from these species.

Alanine Dehydrogenase↗