Search PubMed⌕ Search

Biomedical subjects

C Cruz

Publications and source records attributed to C Cruz.

At least 163 records · Page 9Linked to original sources
PubMed1990

Serum angiotensin converting enzyme activity and plasma renin activity in experimental models of rats.

1. Serum angiotensin converting enzyme activity (ACEA) and plasma renin activity (PRA) were determined in rats under different experimental conditions such as: nephrotic syndrome (NS), bilateral nephrectomy (BN), renovascular hypertension (RH), dehydration (DEH), anaesthesia (AN), low sodium diet (LSD) and high sodium diet (HSD), and injection with propranolol (PRO) and isoprenaline (ISO). 2. PRA increased in LSD, AN, NS, RH, DEH and IPT groups, and decreased in HSD, BN, and PRO groups. Serum ACEA did not change in RH, HSD, IPT, DEH, AN, and PRO groups, increased in NS group, and decreased in LSD and BN groups. 3. Serum ACEA changed in the opposite direction to PRA only in the LSD group. This finding suggests that ACE may limit the full expression of the renin-angiotensin system in the LSD group, but not in the other groups.

Animals↗
PubMed1989

Underreporting of AIDS cases in South Carolina, 1986 and 1987.

An evaluation of the completeness and accuracy of case reporting of the acquired immunodeficiency syndrome (AIDS) for the 18-month period from January 1, 1986, through June 30, 1987, was conducted for South Carolina. A total of 596,585 hospital discharge billing records were searched by computer for conditions defining AIDS. The resulting 1513 records were manually reviewed. Of these, 349 discharges for 163 individuals were classified as being definitely AIDS related, the clinical features of these cases meeting Centers for Disease Control criteria for AIDS diagnosis. Of these cases, 153 were reportable to the South Carolina AIDS registry at the time of their diagnosis. Comparison of this case list with registry records revealed that only 91 (59.5%) had been reported. Reporting was significantly poorer for cases among blacks (53.1%) than for cases among whites (71.6%). These findings may have important implications for the interpretation of AIDS surveillance data and for planning activities in which awareness of complete case counts may be critical.

Acquired Immunodeficiency Syndrome↗
PubMed1989

Porencephalic cyst in pycnodysostosis.

We describe a case of pycnodysostosis with porencephaly and suggest an explanation for the porencephaly by a mechanism of imbalance between brain growth and its vascular supply and a normal but unopposed cerebrospinal fluid pressure.

Adult↗
PubMed1988

Effects of bepridil on calcium release from rat heart mitochondria.

Bepridil at concentrations above 10 microM, and at pH 7.2 stimulates calcium release from rat heart mitochondria. However this action is different from that of ClCCP, an uncoupler of oxidative phosphorylations, since it is ruthenium red insensitive. At lower concentrations bepridil may inhibit the Na-induced calcium release. The effects of bepridil depend on the pH and indicate that the protonated form of the drug is more efficient on calcium release than the basic form.

Animals↗
PubMed1988

Abnormal Papanicolaou smears after earlier smears with atypical squamous cells.

From November 1984 to January 1986, 138 women were seen in our cervical clinic with atypical squamous cells in a referring cervical Papanicolaou smear. We obtained a second smear and performed a careful pelvic examination, microscopic examination of the vaginal secretions and endocervical culture for the gonococcus. The time interval between the smear showing atypical squamous cells and the one performed in our clinic ranged from 1 to 12 months. The Papanicolaou smear from 59 (50%) of the 117 women who had it repeated within four months returned abnormal as compared to 5 (24%) of the 21 repeated after four months (P = .04). Of 41 women with persistent atypical squamous cells, 10 (24%) had a clinically detectable vaginal infection, while only 3 (4%) of the 74 women with a normal repeat smear had an infection (P less than .01). These findings suggest an association between cervical cytology showing atypical squamous cells and vaginal infections. Nevertheless, this cytologic diagnosis should not be dismissed lightly since a high percentage of women with atypical squamous cells on cytology are found to have dysplasia on colposcopically directed biopsies. The most appropriate method of evaluating these patients has yet to be determined. If the clinician elects to follow these patients with serial Papanicolaou smears, the ideal interval between smears needs to be defined. Our data suggest that an interval of four to six months would be the most efficient.

Adolescent↗
PubMed1987

Protective effects of bepridil on calcium injury of anoxic myocytes isolated from adult rat heart ventricular muscle.

Cardiac myocytes allowed to recover after the isolation procedure in a well-oxygenated medium were resistant to an extracellular Ca++ concentration of 1.5 mM. At least 90% of the isolated myocytes maintained their initial rod-shaped form after a 1-hr incubation, as well as 85% of their ATP and a low cellular content of calcium. At concentrations less than 10(-5) M, bepridil had no effect on these cells. On the other hand, when the myocytes were incubated in anaerobic conditions, 1.5 mM Ca++ was deleterious: the number of viable cells decreased by about 50%, ATP levels were lowered by 70% and the total cell calcium content increased by more than 100%. Bepridil had a biphasic effect on anaerobic cells. At concentrations below 10(7) M, the drug had a beneficial action. It restored cell viability and cellular ATP to 77 and 100% when compared to their respective level in the absence of Ca++. However, at concentrations higher than 10(-6) M, bepridil decreased the number of viable cells as well as their ATP content. At optimal concentrations, bepridil lowered the cellular calcium to its level in aerobic conditions. Without calcium addition, anoxic cells accumulated Na+ and lost K+. Calcium addition decreased Na+ accumulation by 68% and prevented the loss of K+. The Na+ and K+ content of the cells were not affected by bepridil. However, it is noteworthy that, at 10(-4) M, bepridil decreased dramatically the potassium content of the cells. In aerobic conditions, the calcium resistance of isolated ventricular myocytes may still be enhanced by Fluozol, a fluorocarbon compound which increases oxygen solubility in water.

Adenosine Triphosphate↗
PubMed1986

Clinical and CSF cyto-proteic findings in 23 patients with CSF eosinophilia.

Clinical diagnosis and cerebrospinal fluid (CSF) protein pattern were studied in 23 patients who had eosinophilic granulocytes in the CSF. Clinical data revealed that an inflammatory disorder of the central nervous system (CNS) was evident in 20 cases. A lymphoid reaction and elevated CSF total protein were found in most of the cases, but the most important finding was an increase of CSF gamma-globulin in 12 patients, of whom 10 had oligoclonal patterns. Our results may give support to a relationship between intrathecal eosinophilic reaction and inflammatory diseases of the CNS with subacute or chronic course accompanied by intrathecal synthesis of immunoglobulins.

Cerebrospinal Fluid Proteins↗
PubMed1986

Contrast media for angiography: effect on renal function.

A total of 125 patients with severe peripheral vascular disease were examined with translumbar aortography. The mean dose of contrast medium injected was 65 ml of Angio Conray (containing 31.2 g of iodine). Forty patients were pretreated with mannitol, and 32 received furosemide. Thirty-eight patients (30%) had diabetes and, presumably, diabetic nephropathy. Eleven of them had significant azotemia (creatinine values greater than or equal to 4 mg/dl). Administration of contrast material did not significantly reduce renal function in any patient group. We conclude that acute renal failure following the injection of contrast material is uncommon, is reversible, and almost always occurs when avoidable complicating factors are present.

Adolescent↗
PubMed1986

Blood pressure response to changes in serum ionized calcium during hemodialysis.

The effect of an increasing serum ionized calcium concentration on blood pressure during hemodialysis was studied in a prospective cross-over trial. Twelve patients were dialyzed three times with a dialysate Ca concentration of 5.5 mg/dL and three times with one of 7.5 mg/dL. Dialysis with the high Ca dialysate was associated with less fall in the mean arterial pressure (p less than 0.001). No statistically significant changes occurred in serum osmolality, body weight, or heart rate after dialysis at the two dialysate Ca levels. Increasing the Ca concentration in dialysate may protect against intradialytic hypotension in some patients.

Adult↗
PubMed1986

Reduced phosphate reabsorption unrelated to parathyroid hormone after renal transplantation: implications for the pathogenesis of hyperparathyroidism in chronic renal failure.

We measured nephrogenous cyclic adenosine monophosphate (NcAMP) excretion, an in vivo bioassay for endogenous parathyroid hormone (PTH) secretion, and renal phosphate threshold (TmP/GFR) in 33 renal allograft recipients with stable renal function (creatinine clearance greater than or equal to 60 ml/min/1.73 m2 body surface area, 6 months or more post-transplant) and in 9 kidney donors. Sixteen patients had normal parathyroid function, 8 had hypercalcemic hyperparathyroidism and 9 had normocalcemic hyperparathyroidism; the latter were apparently resistant to the hypercalcemic actions of endogenous PTH, but the cause for this was not apparent. In all four subject groups, TmP/GFR was significantly and similarly lower (by 0.8-1.0 mg/dl) than predicted by multiple regression on age, sex, corrected plasma calcium and NcAMP (determined in 306 subjects spanning a wide range of parathyroid function) indicating a major PTH-independent mechanism for reducing phosphate reabsorption in the presence of a single kidney. In all four groups the contribution of this mechanism to the observed depression of TmP/GFR was substantially greater than the contribution of increased PTH secretion. In all groups, but more so in the recipients than in the donors, fasting urinary phosphate excretion/GFR was increased, so that fasting plasma phosphate, although reduced, did not accurately reflect the severity of the defect in phosphate reabsorption. We conclude that the dominant mechanism for the adaptive decrease in renal tubular phosphate transport in response to nephron reduction does not require the participation of PTH and is manifest in the presence of fasting hypophosphatemia.

Absorption↗
PubMed1985

Taurine and hypotaurine inhibit light-induced lipid peroxidation and protect rod outer segment structure.

Exposure of isolated frog rod outer segments to light (5000 lux) induces membrane disorganization and swelling. An increase of about 50% on lipid peroxidation, measured by the extent of malonaldehyde formation, accompanied the light-induced damage. Taurine and hypotaurine (25 mM) prevented the increase in lipid peroxidation, and provided an entire protection of rod outer segment structure.

Animals↗
PubMed1985

Double infection of the CNS with herpes simplex and mumps viruses. Serological and ultrastructural studies.

Clinical, serological and ultrastructural features are described in a case of acute encephalitis. The ultrastructural study of brain biopsy specimens revealed herpes-and paramyxovirus-like particles in neurons and glial cells that were characterized as herpes simplex and mumps viruses by serological study in serum and CSF. Of the few cases previously reported with double encephalitis, this is the only one in which ultrastructural and serological evidence of combined brain infection has been found.

Antibodies, Viral↗
PubMed1985

Local immunoglobulin synthesis and blood-brain barrier assessment in subacute sclerosing panencephalitis.

The immunoglobulin synthesis within the central nervous system and the blood-brain barrier (BBB) function were evaluated in 6 patients with subacute sclerosing panencephalitis (SSPE) using the IgG index and a graphic method based on serum/CSF albumin, alpha 2-macroglobulin, and IgG quotients. A strong local production of IgG was documented by both methods in all 6 cases of SSPE. Concerning the graphic analysis, the decrease in the serum/CSF alpha 2-macroglobulin ratio disclosed BBB dysfunction in 2 cases of SSPE, suggesting, in the absence of the serum/CSF albumin quotient abnormalities, that a homeostatic mechanism for CSF proteins can cause changes in the CSF protein profile.

Adolescent↗
PubMed1984

Protective effect of taurine and zinc on peroxidation-induced damage in photoreceptor outer segments.

Exposure of isolated frog rod outer segments (ROS) to ferrous sulfate in a Krebs-bicarbonate medium causes a time-dependent disruption of the membrane organization of the discs. Ferrous sulfate also causes ROS swelling and aggregation. Addition of taurine (5-20 mM) and zinc sulfate (250 microM) to the incubation medium markedly protected ROS from the disrupting effect of ferrous sulfate. Of other amino acids tested, only beta-alanine had a protective effect on ROS structure. Ferrous sulfate caused an increase in lipid peroxidation, measured by malonaldehyde formation. The protective effect of taurine and zinc is not accompanied by a reduction of lipid peroxidation. Water accumulation occurs as a consequence of the peroxidative action of ferrous sulfate, and this effect was counteracted by taurine and zinc. Ferrous sulfate did not cause damage to ROS structure when incubation was carried out in sucrose-HEPES. Sodium, chloride, and bicarbonate ions caused ferrous sulfate to disrupt ROS structure. It is concluded that taurine and zinc protect ROS membranes from ion and/or water entry occurring as a consequence of membrane lipid peroxidation.

Animals↗
PubMed1983

Cerebellar cortex ultrastructure in ataxia-telangiectasia.

An ultrastructural study of a biopsy fragment from the cerebellar cortex of a patient with ataxia-telangiectasia was performed. There was a sharp reduction in the number of Purkinje cells and an increase in the number of Golgi epithelial cells. Despite the degeneration of Purkinje cell dendrites, the volumetric density of parallel fiber varicosities and the number of synapses in the molecular layer were only slightly reduced. No qualitative nor quantitative abnormalities were noted in the granular layer. An analysis is made of the severe changes in cerebellar circuitry of this patient and their probable functional implications.

Ataxia Telangiectasia↗