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Biomedical subjects

R Valenzuela

Publications and source records attributed to R Valenzuela.

At least 55 records · Page 3Linked to original sources
PubMed1989

Two-color immunofluorescence flow cytometric analysis of lymphocytes in long-term renal allograft recipients.

We used 2-color immunofluorescence flow cytometry (FACS 440) and monoclonal antibodies (Becton-Dickinson) to study peripheral blood lymphocytes subsets from 26 patients with well functioning renal allografts for longer than 5 years. Comparisons were made to a group of 25 healthy volunteers and 25 dialysis patients awaiting renal transplantation. As anticipated, there was no significant difference with respect to the absolute number or percentage of activated (T11+ and HLA-DR+) and cytotoxic (Leu-2+ and Leu-15-)T lymphocytes among the 3 groups. However, there was a significantly decreased absolute number (p equals 0.0001) and percentage (p equals 0.0001) of suppressor cells (Leu-2+ and Leu-15+) in the transplant patients compared to the healthy control group. No significant differences existed between the transplant and dialysis groups. There also was an increase in the percentage (p equals 0.000) but not in the absolute number of T helper lymphocytes (Leu-3+ and Leu-8-) in the transplant population compared to healthy controls. No significant difference existed between the transplant and dialysis groups. These findings suggest that a normal value of cytotoxic (Leu-2+ and Leu-15-) and activated (T11+ and HLA-DR+) T lymphocytes may be a good prognostic indicator of long-term survival of renal allografts. Also, the highly significant decrease in the number of Leu-2+ and Leu-15+ cells in long-term, well functioning allografts indicates that additional functional characterization of this subset may be necessary.

Adult↗
PubMed1989

Lack of mixed agonist-antagonist properties of [Gln8-Gly31]-beta h-EP-Gly-Gly-NH2 and [Arg9,19,24,28,29]-beta h-EP in the rat vas deferens neuroeffector junction: studies with naloxone, beta-funaltrexamine and ICI 174,864.

The 1-27 truncated fragment of beta h-endorphin (beta h-EP) as well as [Gln8,Gly31]-beta h-EP-Gly-Gly-NH2 or [Arg9,19,24,28,29]-beta h-EP exhibited opiate agonist activity in the rat vas deferens bioassay; the potency of these peptides was 3 to 6 times less than that of beta h-EP. None of these compounds exhibited any degree of antagonism towards the inhibitory action of beta h-EP. Naloxone antagonized and reversed the inhibitory action of beta h-EP and its analogues though with varying potencies. The apparent naloxone-pA2 value for beta h-EP was 8.94; that for [Gln8-Gly31]-beta h-EP-Gly-Gly-NH2 was 8.08 and that for [Arg9,19,24,28,29]-beta h-EP was 8.38. beta-Funaltrexamine (beta-FNA) potently antagonized the inhibitory action of beta h-EP following non-equilibrium kinetics. Tissue preincubation with 10 nM beta-FNA for 60 min followed by extensive washing caused a 10-fold increase in the beta h-EP IC50. However, 10 nM beta-FNA caused only a 1.2 increase in the IC50 of [Gln8,Gly31]-beta h-EP-Gly-Gly-NH2 and a 4.1-fold increase in the IC50 of [Arg9,19,24,28,29]-beta h-EP. In contrast, preincubation of the tissue with 3 microM ICI 174,864 did not modify the potency of beta h-EP or its structural analogues. However, a 60 min pretreatment with 10 microM beta-FNA followed by the addition of 3 microM ICI 174,864 revealed a further decrease in the potency of the opiopeptins compared with tissues exposed to beta-FNA alone or ICI 174,864 alone. In conclusion, the inhibitory action of these peptides is remarkably sensitive to beta-FNA antagonism; in addition the peptides act as pure opiate agonists in marked contrast with the agonist-antagonist properties described in the CNS.

Animals↗
PubMed1989

The ANA profile: quality and cost-effective laboratory utilization.

The ANA Profile was introduced in 1981 and computerized in 1984 as a means of facilitating follow-up testing for specific antibodies (anti-nDNA, anti-Sm, anti-RNP, anti-La/SS-B) in sera found to contain antinuclear antibodies (ANA). A second purpose was to avoid unnecessary specific antibody testing on negative or low-titer sera. This study was done to evaluate the effectiveness of the computerized ANA Profile reporting system in accomplishing these purposes. The authors compared ordering practices during two two-week periods, one in 1984 and a second in 1988, and found that follow-up testing on positive sera had improved from 27% to 70% with a reduction in unnecessary specific-antibody testing of ANA-negative or low-titer sera from 11% to 1.6%. In 1988 dollars, the annual savings from eliminating unnecessary testing was calculated to be $12,000. The ANA Profile has been partially successful in accomplishing the purposes for which it was introduced.

Antibodies, Antinuclear↗
PubMed1987

Linear IgA bullous dermatosis mimicking erythema multiforme in adult.

This report describes a 49-year-old woman with an erythema multiforme--like rash and direct immunofluorescence showing linear IgA deposits at the dermoepidermal junction. Light microscopy revealed features of bullous pemphigoid, dermatitis herpetiformis, and erythema multiforme; immunoelectron microscopy demonstrated IgA deposition beneath the lamina densa about anchoring fibrils. These data provide additional information about the variable clinical and histologic manifestations of the adult linear IgA bullous dermatosis and emphasize the diagnostic dilemmas of light microscopy, which are resolved by immunohistochemical methods.

Dapsone↗
PubMed1987

[Results of the double J catheter as an internal urinary bypass].

A catheter in double J was used as an endoureteral prosthesis for internal urinary shunt in 118 patients (136 catheters), including 35 with malignant and 83 with benign affections. Catheterization was unilateral in 100 cases and bilateral in the remaining 18. The catheter was left in situ for between 1 and 645 days (mean 93 days), introduction being endoscopic in 72 cases, surgical in 50, percutaneous in 11 and combined endoscopic/percutaneous in 3. Complications related to introduction of prosthesis were ureteral perforation (1 case) and absence of bypass of obstacle (4 cases). Complications related to retention of prosthesis were mictional symptomatology or lumbar pain in 18 cases and urinary infection in 11. Results were rated as good in 99 cases (84%) the catheter fulfilling its mission of tutor and drainage, while in 19 cases (16%) results were poor due to bad insertion or obstruction.

Adolescent↗
PubMed1986

Depression, immunocompetence, and prostaglandins of the E series.

Plasma prostaglandin E1 and E2, and quantitative and qualitative measures of immune function, were determined in depressed patients and healthy controls. Prostaglandin E2 was significantly elevated in the depressed group, and prostaglandin E1 showed a trend in the same direction. Lymphocyte stimulation responses, as measured by phytohemagglutinin, concanavalin A, and pokeweed mitogen, were significantly lower in the depressed group. Helper and suppressor T cell percentages did not significantly differ in the two populations. In the depressed group, prostaglandin E1 showed a significant inverse correlation with concanavalin A, and prostaglandin E2 showed a similar trend. These preliminary data suggest prostaglandins of the E series may be related to abnormalities of cellular immunity previously documented in depression.

Alprostadil↗
PubMed1986

Immune reactivity in Bell's palsy.

Although the pathogenesis of acute facial (Bell's) palsy is probably multifactorial, some investigators believe that the disorder results from autoimmune demyelination and is perhaps related to previous viral infection. The purpose of this study was to identify immune mechanisms which might contribute to Bell's palsy. The lymphocyte transformation test and immunofluorescence were evaluated with a soluble homogenate of unrefined peripheral nerve antigens. Three antigen-nonspecific tests were also studied. Results in 14 patients with Bell's palsy were compared with those in 21 controls. To be eligible for study, patients with Bell's palsy had to be seen within 10 days of onset of weakness. The control group included 5 patients with facial nerve dysfunction from other causes and 16 normal volunteers. No patient or control had previously received steroids. Five patients with Bell's palsy and one normal volunteer had abnormal lymphocyte transformation (p less than .05). Virtually all other tests were normal. These results. suggest that some instances of Bell's palsy result from cell-mediated immunity against peripheral nerve antigens. They also encourage further research in steroid and other immunotherapy.

Adult↗