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Biomedical subjects

J Cerda

Publications and source records attributed to J Cerda.

At least 19 recordsLinked to original sources
PubMed2000

Imaging the surface and the interface atoms of an oxide film on Ag111 by scanning tunneling microscopy: experiment and theory

High-resolution images of the vacuum oxide surface atomic structure of Ag111-p(4x4)-O reveal large terraces of a perfect (4x4) reconstruction. Under certain conditions, the surface Ag atoms at the interface between the reconstructed oxide layer and the underlying Ag111 lattice are also imaged, providing the structural registry. Scanning tunneling microscopy simulations reveal a strong sensitivity to structure and comparison with the experimental images, therefore providing an atom-by-atom model for the entire metal-oxide-vacuum structure.

Journal Article↗
PubMed2000

Basal and reserve renal artery blood flow: effect of endothelium-dependent and -independent vasoactive agonists and radiographic contrast medium in two patients.

This manuscript describes the results of invasive testing of renal artery and arteriolar reactivity in two patients using a panel of endothelium-dependent and -independent agents including radiographic contrast medium. We found that the renal artery and microcirculation dilate in response to graded acetylcholine infusions and to bolus nitroglycerin infusion; the renal microcirculation dilates in response to papaverine but constricts after adenosine and after radiographic contrast medium. Future indications for this testing are briefly discussed.

Acetylcholine↗
PubMed1999

The role of portosystemic shunting in children in the transplant era.

PURPOSE: Variceal bleeding in children generally presents in the setting of cirrhosis but may also occur in the absence of liver disease and after successful liver transplantation. The authors reviewed their experience with portosystemic shunting in children to better define its efficacy in sclerotherapy failures, as primary therapy, and its role before and after liver transplantation. METHODS: Between 1983 and 1997, 21 children with recurrent variceal bleeding underwent portosystemic shunting at the authors' institution. Patients were divided into two groups: 13 patients in group I presented with intrinsic liver disease (cirrhosis) as a cause for portal hypertension; eight patients in group II with no liver disease had extrahepatic portal venous thrombosis, five of which occured after successful liver transplantation. The mean age was 8.6 years (range, 3 to 18). Shunt procedures were semielective, and were performed successfully in all children without any operative morbidity or mortality. Follow-up ranged from 6 months to 15 years. RESULTS: Shunt procedures included splenorenal (n = 15), splenocaval (n = 1), side-to-side splenorenal (n = 1), inferior mesenteric vein to renal vein (n = 1), mesocaval (n = 1), and transcutaneous intrahepatic portosystemic shunt (TIPS; n = 2). All patients in group II are alive and well with no further bleeding or occlusions. Of the 13 patients in group I, three had bleeding postshunt, and three patients went on to require liver transplantation because of worsening liver disease. One child died of liver failure with encephalopathy 4 years after shunting. There were two shunt occlusions. CONCLUSIONS: Portosystemic shunting is effective therapy in patients with intrinsic liver disease, with salvage amenable by liver transplantation in the treatment failures. It is definitive therapy in patients with extrahepatic venous thrombosis.

Adolescent↗
PubMed1998

Orientation of the heme vinyl groups in the hydrogen sulfide-binding hemoglobin I from Lucina pectinata.

Hemoglobin I (HbI) from the claim Lucina pectinata is a unique heme protein that binds and transfers hydrogen sulfide (H2S) to a symbiotic bacteria. The metcyano, metaquo, carbon monoxy, oxy, and deoxy complexes of HbI were studies by resonance Raman (RR) spectroscopy, and the metacyano and carbon monoxy complexes were also studied by 1H-NMR. The results indicate a unique orientation of the heme 2-vinyl group relative to other heme proteins. The RR spectra of the HbICO, metHbICN, metHbIH2O, HbIO2 and deoxyHbI heme derivatives show a band at 1621 cm-1 and a shoulder at 1626 cm-1, indicative of an out-of-plane position for one of the vinyls relative to the other one. Spin-lattice relaxation properties of protons in the metHbICN complex also suggest a unique orientation for the heme 2-vinyl group of HbI. The longitudinal relaxation time (T1) for the 2-H alpha, 2-H beta c, and H beta t protons are 120 ms, 115 ms, and 135 ms, respectively. The data from both techniques suggest an out-of-plane and trans-oriented 2-vinyl group, and an in-plane and cis-oriented 4-vinyl group for the low-spin complexes of HbI. These results imply that the electron withdrawing character of the out-of-plane vinyl group contributes to the stability of the heme Fe+3 oxidation state, facilitates the binding of the H2S ligand, and promotes the stability of this ferric H2S complex.

Animals↗
PubMed1995

Cocket syndrome: thrombotic-septic disease post-appendicectomy complication.

The incidence of complications following treatment of acute appendicitis in childhood is lower than 5%, while thromboembolic disease at that age is exceptional. The case of a 13-year-old male who was operated on in our pediatric surgery department for acute gangrenous appendicitis is presented. His condition improved until the sixth day after the operation when he suffered thrombosis in both the left iliac vein and the inferior cava. Ultrasonography, plethysmography and computer tomography (CT) studies were carried out and a diagnosis of venous thrombosis was made with an underlying congenital vascular malformation where the iliac vein was compressed by the overlying iliac artery; known as the Cocket syndrome. The etiology diagnosis and treatment of this rare disease in childhood is reviewed.

Adolescent↗
PubMed1995

Microsurgical treatment of varicocele in adolescents.

Between March 1990 and November 1992, 22 adolescents with varicocele, 13 unilateral left and 4 bilateral, are presented. They were all treated with microsurgical techniques by shunting the venous drainage by means of a spermatic inferior epigastric end-to-side anastomosis. The results achieved have been optimum with the clinical disappearance of varicose veins in 100% of the cases and the elimination of the spontaneous reflux of the interna spermatic vein in 100% of the patients shown by echodoppler. This technique enables the establishment of an immediate and physiological testicular venous drainage fundamental for testicular growth and development.

Adolescent↗
PubMed1995

Correlation of plasma calcium with experimentally elevated cholesterol and triglycerides in laying hens.

An experiment was conducted to determine the relationship between plasma Ca, cholesterol, and triglycerides in commercial laying hens. A 2 x 2 factorial arrangement of treatments was used with two levels of dietary iodine (0 and 5,000 ppm) from KI and two levels of beta-estradiol (0 and 12 mg in a single subcutaneous injection), in a corn oil carrier. Feeding iodine or injecting beta-estradiol resulted in increased plasma Ca, cholesterol and triglycerides. The increases were additive for the two treatments. Plasma Ca and cholesterol was significantly correlated. Plasma Ca was negatively correlated with triglycerides when the hens were injected with beta-estradiol. Cholesterol and triglycerides were correlated when hens were injected with beta-estradiol. However, feeding KI decreased the correlation between Ca and triglycerides, and cholesterol and triglycerides.

Animals↗
PubMed1994

Periodontal disease in non-insulin dependent diabetes mellitus (NIDDM). The effect of age and time since diagnosis.

The association of periodontal disease with diabetes was studied in non-insulin dependent diabetes mellitus (NIDDM) patients. In a cross-sectional design, 100 patients (46 males and 54 females) were selected in 4 groups according to age and years since diagnosis of diabetes. The groups were: group 1, > 55 years old, diabetes diagnosed > or = 5 years; group 2, < or = 55 years old, diabetes diagnosed > or = 5 years; group 3, > 55 years, diabetes diagnosed < 5 years; and group 4, < or = 55 years, diabetes diagnosed < 5 years. Buccal and lingual pockets were deeper and lingual and buccal recessions greater for groups diagnosed 5 or more years ago, (P < 0.0001). In groups diagnosed less than 5 years, higher recession indices were found for patients older than 55. The loss of buccal insertion was also greater for groups diagnosed 5 or more years ago (P < 0.0001). For groups diagnosed less than 5 years ago, the loss was greater in the group older than 55 (P = 0.01). There was a marginal difference in gingival bleeding among the 4 groups (P = 0.047). Post-hoc analysis showed differences between the 2 groups who had been diagnosed less than 5 years, with lower indices for patients < or = 55. All groups were statistically different regarding bone loss (P < 0.0001), with higher indices for the groups with older age, and for groups with 5 or more years since diagnosis. There was no difference in dental mobility among the 4 groups (P = 0.0981). It was concluded that years since diagnosis of diabetes is more significant than age for severity of periodontal disease in NIDDM.

Adult↗
PubMed1992

Vascular changes in the dental pulp in the hypercholesterolemic miniature swine.

The aim of this study was to evaluate the effect of hypercholesterolemia and a cholesterol-lowering diet on the blood vessels of dental pulp. Eighteen miniature swine were assigned to three different groups on the basis of their diets: hog finisher; hog finisher with added fat and cholesterol, or hog finisher with added fat and cholesterol supplemented with grapefruit pectin. The cholesterol levels were monitored monthly for the duration of the experiment. Biopsy specimens of the aorta, coronary arteries, kidneys, and mandibular incisor teeth were prepared for histologic examination. The degree of narrowing of the central pulpal arterioles was measured with a Bioquant II digitizer attached to an Apple IIe computer and a Nikon Labophot light microscope. A few (9.8%) of the pulpal arterioles of the swine on a high-cholesterol diet had atheromatous plaques, but no complete vascular obstructions were observed. No degenerative changes were observed in any of the dental pulps examined.

Animals↗
PubMed1992

Drug poisoning patterns: the Albany experience, 1978 and 1988.

This study retrospectively compares the demography and patterns of poisonings and their local variations among patients admitted to Albany Medical Center Hospital in the years 1978 and 1988. An increase in the number of admissions during this period of time, and an apparent substantial change in the pattern of poisonings was observed; in addition, the gender difference observed in 1978 disappeared. Although street drugs were a common source of poisoning, the resulting morbidity and mortality was low. The use of extracorporeal drug removal procedures appears to have declined in this institution in the two years evaluated.

Adult↗
PubMed1989

Glomerulitis induced by cationized bovine serum albumin in the rat.

The effects of injected native and cationized bovine serum albumin (BSA- and BSA+ respectively) were evaluated in rats which subsequently received anti-BSA. Thrombocytopenia, low creatinine clearance (Ccr), increased proteinuria, capillary swelling, mild tuft necrosis and BSA+ deposits in glomeruli resulted within 24 h of BSA+ injection. Later BSA+ produced mesangial expansion glomerular capillary wall (GCW) thickening and deposits of BSA+ accompanied by rabbit anti-BSA and rat anti-BSA which correlated well with small mesangial, subendothelial and subepithelial electron-dense granular accumuli. These latter enlarged considerably after the injection of anti-BSA. BSA- controls showed minimal or no lesions. The disappearance from the blood (t1/2) of a single dose of immune complexes (IC) prepared with chromatography-purified, radioiodinated anti-BSA - BSA- and BSA+ was determined in another group of rats. The t1/2 of BSA- anti-BSA was 42.8 h (95% confidence: 39.8-46.2) while that of BSA+ anti-BSA was 52.5 h (48.1-57.8). These results suggested that serum sickness glomerulitis developed only in rats injected with BSA+, due to in situ IC which presumably grew by accretion of foreign anti-BSA. Circulating IC may have developed and colocated with the latter, with dissociation and recombination at these sites. It is postulated that the functional-immunomorphological changes and the slow removal of cationized IC reported herein could be explained by the highly positive net charge of the injected antigen.

Animals↗
PubMed1987

Congenitally corrected transposition with mirror-image atrial arrangement.

Congenitally corrected transposition (discordant atrioventricular and ventriculoarterial connexions) with mirror-image atrial arrangement is much less frequent than the same chamber combinations in the setting of usual atrial arrangement. This scarcity of cases has made their analysis difficult. In this study we have compared the anomalies found in 19 patients with congenitally corrected transposition in mirror-image arrangement with those in 39 patients having usual atrial arrangement. Absolute, relative and attributable risks were calculated for the presence of subvalvar pulmonary stenosis, ventricular septal defect, tricuspid regurgitation, atrioventricular block or the absence of these anomalies for each of the two groups. A greater absolute risk was found for both subvalvar pulmonary stenosis (68.4 vs. 43.6%, respectively) and ventricular septal defect (63.2 vs. 58.9%, respectively). The absolute risk for tricuspid regurgitation was 25.6% in those with usual arrangement as against 21.1% in those with mirror-image arrangement. Atrioventricular block was also more frequent in those with usual arrangement (25.6 vs. 10.5%) as was absence of associated cardiac defects (17.9 vs. 10.5%, respectively). The relative risks were greater for subvalvar pulmonary stenosis and ventricular septal defect in the patients with mirror-image as opposed to usual atrial arrangement (1.57: 1.00 and 1.07: 1.00, respectively), contrasting with greater relative risk for tricuspid regurgitation (1.26: 1.00), atrioventricular block (2.43: 1.00) and absence of associated anomalies (1.70: 1.00) in the patients with usual arrangement. The attributable risk for subvalvar pulmonary stenosis was estimated to be 24.8% and ventricular septal defect 4.3% for those having mirror-image atrial arrangement.(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiomyopathy, Hypertrophic↗
PubMed1986

Disseminated intravascular coagulation (DIC) induced by liquoid (polyanetholsulfonate) in the rat. V. Effects on circulating fibronectin.

Levels of plasma fibronectin (Fn) were 63% lower than normal 15 min after the intravenous injection of liquoid (P less than 0.01); 3 h later they were still low but rebounded to 35% above normal (P less than 0.01) by 24 h. Concurrently microthrombi containing fibrinogen, Fn and Factor VIII related-antigens (VIII:Ag) were detected in the kidneys and lungs by immunohistopathological studies. Ultrastructurally, thrombi were composed of dense granular and occasional fibrillar non-striated material. In liquoid-injected rats 125I-fibrinogen mainly localized in kidneys and lungs, especially in the latter (P less than 0.01), and the lungs had a higher wet-to-dry weight ratios than did controls (P less than 0.01). It is concluded that the polyanion (liquoid)-induced intravascular coagulation-like reaction sequestered Fn concomitantly with the precipitation of fibrinogen and VII:Ag in the microclots. The reduced concentration of plasma Fn may have impaired the disposal of coagulation products thus enhancing the expression of the coagulopathy-mediated renal and pulmonary histopathology. It is suggested that the liquoid-related coagulopathy may have resulted in enzymatic lysis of Fn.

Animals↗
PubMed1984

Unstirred water layers in rabbit intestine: effects of pectin.

Pectins have been shown to affect the absorption of several different nutrients in clinical studies; however, the mechanisms for decreased absorption have not been defined. A possibility not studied with regards to pectin, but previously demonstrated to be important in absorption, is the effect of change in the unstirred water layer. As the unstirred water layer increases in thickness, the rate of absorption decreases for certain nutrients. The effect of pectin on the unstirred water layer in the lumen of rabbit jejunum was examined by previously described techniques. It was observed that: (1) increases in pectin concentration resulted in an increased thickness of the unstirred water layer; (2) for any stir rate, the addition of pectin increased the thickness of the unstirred water layer; and (3) stir rate is inversely related to the thickness of the unstirred water layer. It was concluded from these results that pectin increases the thickness of the unstirred water layer in rabbit jejunum. This mechanism may explain, in part, the reduction of the rate of absorption of certain nutrients seen following pectin ingestion.

Animals↗
PubMed1984

Age-related renal, hematologic, and hemostatic abnormalities in FH/Wjd rats.

This longitudinal study compared the renal morphologic changes and hemostatic defects of FH/Wjd rats at different ages. A second aim was to determine whether the bleeding tendency becomes intensified in older animals by the concomitant renal disease. Results indicated that reduced capacity for platelet 14C-serotonin release (P less than 0.01) was found for each age group studied in comparison with Wistar controls. The nephropathy of old FH/Wjd male rats was more severe than that in either FH/Wjd females or age-matched Wistars of both sexes. The mesangial lesions showed abundant deposits of factor VIII-related antigen, fibronectin, and immunoglobulins, but not C3, along with tightly packed or loose electron-dense material. Polyethylene glycol precipitation and platelet aggregation tests detected small amounts of circulating immune complex-like material. Old FH/Wjd rats did not develop edema, and the glomerular filtration rate remained normal despite the persistent proteinuria, hematuria, and arterial hypertension characteristic of this strain. Our data indicated that the congenital platelet dysfunction does not become more severe in older animals and that the nephropathy seems unrelated, does not appear to be mediated by immune complexes, and, in contrast to the focal segmental glomerulosclerosis of persons, the lesions progress without a parallel impairment of renal function.

Aging↗