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Biomedical subjects

R Mendez

Publications and source records attributed to R Mendez.

At least 109 records · Page 6Linked to original sources
PubMed1985

Improved allograft survival in nonidentical living related donor transplants using donor-specific blood transfusions.

A total of 78 consecutive HLA nonidentical living related donor transplant recipients with moderate to high stimulating mixed lymphocyte culture indexes underwent a deliberate donor-specific blood transfusion protocol. Of the patients 67 were first and 11 were second allograft recipients. Patients were monitored for immunological responses by cytotoxic B-cold, B-warm and T-warm antibody responses to a random panel of 30 donors, and by serial crossmatches to their donor subset B and T lymphocytes at 5C and 37C before beginning the protocol and after each donor-specific blood transfusion. Patients were followed from 3 months to 2 1/2 years, with allograft survival rates reported by the actuarial method. Survival rates of first allograft recipients were 96.0 plus or minus 2.77, 93.97 plus or minus 3.37, 93.97 plus or minus 3.37 and 90.68 plus or minus 4.50 per cent at 3 and 6 months, and 1 and 2 years, respectively. Of the patients entering the protocol for a primary transplant 20.18 per cent had persistently positive crossmatches. With increasing numbers of previous random blood transfusions a statistically significant sensitization rate was noted. Patient sensitization showed a general pattern of initial development of B-warm lymphocytotoxins resulting in positive B-warm crossmatches, which progressed to T-warm lymphocytotoxins and positive T-warm crossmatches if donor-specific blood transfusions continued. However, on development of B-warm positive crossmatches reversion to a negative crossmatch with successful transplantation was possible upon cessation of transfusions. No patient in the study was rendered nontransplantable due to donor-specific blood transfusions. All 5 patients who were completely disparate suffered amnestic type rejection episodes but following control of the rejection the course mimicked that of mixed lymphocyte culture identical living related donor transplants. Donor-specific blood transfusion is highly successful among first allograft recipients and success in extending the procedure to more disparate relatives is noted.

Blood Transfusion↗
PubMed1985

Failure of B-cold lymphocytotoxins to enhance cadaveric renal allograft survival.

In a three-year period between January 1980 and December 1982, 242 consecutive cadaver transplant recipients in one center were tested before transplantation by cytotoxicity against a random panel of T and B lymphocytes at 5 degrees C and 37 degrees C incubation. They were also tested for HLA-A, B, and DR antigens. Kidney transplants were carried out with the primary objective of achieving a two-DR match. Kidney transplants were carried out only in the absence of T-warm positive cross-matches. All patients were followed for a minimum period of one year after transplant. There have been no exclusions, and all causes of failure, including death, have been counted as graft losses. Patients were stratified according to HLA-A, B, and DR matches and were also divided into high-antibody and low-antibody groups. The recipients with no antibodies had the best one-year graft survival (66%). Recipients with B-cold antibodies did not have enhanced one-year graft survival (51%). Recipients with B-warm antibodies did indifferently (56%). The worst results were seen in recipients who had pretransplant T-warm antibodies (42%) though the number of patients in this group was small.

B-Lymphocytes↗
PubMed1984

[Pharmacological characteristics of the acetylcholine and L-glutamate receptors of the subpharyngeal ganglion neuron in the mollusk Zachrysia guanensis].

The presence of acetylcholine and L-glutamate receptors sensitive to the cholinoreceptor-specific ligands cytizine and tubocurarine has been demonstrated by means of microapplication of acetylcholine and L-glutamate to the central parietal zone of the subpharyngeal ganglion of the mollusc Zachrysia guanensis. Azidocytizine inhibited the function of acetylcholine receptor but did not affect glutamate receptor. Based on the electrophysiological data and analysis of ligand conformations a model has been designed for a site where L-glutamine is recognized by glutamine receptor.

Acetylcholine↗
PubMed1983

The search for a digitalis substitute II milrinone (Win 47203). Its action on the heart-lung preparation of the dog.

Milrinone (Win 47203) is a dipyridine related to amrinone, which is about 20-50 times as effective as amrinone when assayed on cardiac contractility. In dog heart-lung preparations, milrinone in a concentration of 0.25-0.5 microM produced a near maximal positive inotropic effect on a variety of acute heart failures. This dosage produced a minimal increase in heart rate and reduced the PR interval. Large doses of milrinone did not produce cardiac irregularities and in Nifedipine heart failure with ventricular irregularities, it eliminated these irregularities. Papaverine-induced heart failure was resistant to ouabain, epinephrine and milrinone therapy. In the presence of positive inotropic amounts of papaverine or theophylline, a pentobarbital heart failure was superimposed. This heart failure responded poorly to milrinone, although it responded to both the addition of epinephrine and ouabain. It is thus possible that milrinone, papaverine and theophylline have closely related sites of action.

Animals↗
PubMed1983

Cardiac effects of six actodigin (AY-22,241)-related semisynthetic glycosides.

Six actodigin (AY-22,241)-related semisynthetic glycosides (with the C-3 natural linkage of the lactone ring to the steroid nucleus, transposed to C-2) were assayed in failing hearts of canine heart-lung preparations. Two compounds, with additional small modifications in the steroid nucleus, were incapable of reversing heart failure. Two others, an isodigoxigenin and an isogitoxigenin derivative, were only slightly active. However, the two other actodigin-derived compounds, with methyl groups at the lactone C-4, were very active. Compound 5 had the methyl group in beta position and was 2.5 times more potent than actodigin. Compound 6, with the methyl group in alpha position, had a potency similar to that of actodigin. In the anesthetized and vagotomized dog, their toxic effects (to the point of atrioventricular dissociation) were short lasting and completely reversible. Both of these agents had a wide margin of safety (relationship between the minimal therapeutic, irregularity and lethal doses).

Animals↗
PubMed1983

Leiomyoma of bladder.

A case of leiomyoma of the bladder is presented. The symptoms of this rare benign tumor depend on the size, location, or associated urinary tract infection. The diagnosis may be confirmed by transurethral biopsy, and, since these tumors are well encapsulated, the treatment of choice is total enucleation from the vesical wall. Transurethral resection as a definitive modality of treatment should be attempted only in small tumors.

Cystoscopy↗
PubMed1983

Prospective HLA-DR matching in cadaveric renal transplants: a single center study.

We reviewed 77 potential cadaveric allograft recipients who had undergone prospective HLA-A and B locus and HLA-DR antigen identification. Matching was accomplished, giving first priority to HLA-DR compatibility and relying on HLA-A and B antigen matching only in situations of total HLA-DR incompatibility. Complete HLA-DR identification occurred in 56 per cent of all patients. There were 15 patients (19.5 per cent) who received a 2/2 HLA-DR perfect match, with 86.7 plus or minus 8.8 per cent 1-year actuarial graft survival, and 41 (53 per cent) who received a 1/2 HLA-DR match, with 58.2 plus or minus 7.8 per cent 1-year actual allograft survival. Finally, 21 patients (27 per cent) received a 0/2 HLA-DR match, with 64.9 plus or minus 10.7 per cent actual survival. These results and their mirrored mismatching results showed statistically significant allograft success in only the HLA-DR 2/2 matches. Matching for HLA 2 DR donors proved a statistically significant success over the other HLA-DR allograft matches and the older controversial matching system based on HLA-A and B locus antigens. The restricted gene polymorphism of the HLA-DR systems allows for a relatively high percentage of perfect HLA-DR matches.

Cadaver↗
PubMed1983

Management of prostate carcinoma. Combination of pelvic lymphadenectomy, temporary Ir-192 implantation, and external irradiation.

Forty patients with prostate adenocarcinoma had bilateral pelvic lymphadenectomy, temporary Ir-192 implantation, and external irradiation. With the implant, the prostate received less than or equal to 3,000 rad (30 Gy) for A2 and B1 and 3,500 rad (35 Gy) for B2 and C lesions in 40-45 hours. Ten days to 2 weeks later, 4,000 rad (40 Gy) external irradiation was given in 4-5 weeks using AP and PA parallel opposed fields, a "box," or rotation. Patients with positive nodes were given 5,000 rad (50 Gy) to the pelvis with a midline block at 4,000 rad (40 Gy) so that the prostate received 7,000-7,500 rad (70-75 Gy). All patients were free of local recurrence. Treatment was tolerated well, with rapid regression and few complications.

Adenocarcinoma↗
PubMed1982

Effect of deliberate blood transfusions in cadaveric kidney allografts at a single center.

The effectiveness of deliberate pre-transplant blood transfusions was compared in randomly transfused and nontransfused patients who acted as controls at a single transplant center. The patients in the pre-transplant transfusion group who had never been transfused had better graft survival than all other groups. Next, were those patients who had previous random transfusions and were then placed in the deliberately transfused group. Those who had received random blood transfusions but were not in the protocol and those patients who never had transfusions did the poorest. Those patients never transfused previously who received the scheduled transfusions had far lower levels of antibodies than those who had had previous transfusions and those with previous transfusions who were then entered into the prospective transfusion protocol. The patients who had B cold cytotoxic antibodies had the highest graft survival rates. Timing was important, with the group receiving the last transfusions 3 to 6 weeks before transplantation doing significantly better than any other group. Histocompatibility locus-A and B antigen distribution among the groups did not bias the data.

Antilymphocyte Serum↗
PubMed1982

Staghorn calculis: its clinical presentation, complications and management.

There were 95 patients (105 kidneys) with staghorn calculi evaluated clinically and 84 kidneys were studied on a pathologic basis. Only 1 percent of the patients could be defined as having a silent stone calculus. Clinical complications occurred in 53 per cent of the patients. Of 84 kidneys submitted for a pathoanatomic study (surgical evaluation and/or histopathology) pyonephrosis was found in 20 per cent, xanthogranulomatous pyelonephritis in 8 per cent, end stage pyelonephritic kidney in 6 per cent, end state hydronephrotic kidney in 7 per cent, severe pyelonephritic changes in 7 per cent and a perinephric abscess in 5 per cent. The kidney was considered to be relatively undamaged in 51 per cent of the cases. Complete removal of the calculus and appropriate medical adjunctive therapy should be done early in the course of the disease in an attempt to prevent complications and renal deterioration. The results of treatment are discussed and compared to those obtained in a group of patients who initially were managed conservatively.

Adolescent↗
PubMed1980

Epidermoid cysts of testis.

Six cases of epidermoid cyst of the testis are presented. Conservative surgical treatment of this condition is discussed.

Adolescent↗
PubMed1980

Technetium-99m glucoheptonate renal scan in diagnosis of acute renal injury.

Twenty-four patients with suspected renal injury were evaluated using high-dose intravenous pyelography, technetium-99m glucoheptonate radionuclide studies (RNS), and selective renal arteriography. Critical examination of these three diagnostic modalities reveal that RNS are extremely accurate in renal trauma evaluation and are more sensitive than intravenous pyelography. When RNS are used in conjunction with high-dose intravenous pyelography in the third workup for renal trauma, 60 to 65 per cent of diagnostic angiograms may be avoided.

Adolescent↗
PubMed1979

Preoperative renal embolization as adjunct to radical nephrectomy.

Radical nephrectomy preceded by preoperative renal artery embolization using Gianturco-Anderson-Wallace steel coils has objective value as determined by comparing records of 15 patients who had adjunctive embolization with 15 patients who did not. Embolization of the major renal artery facilitated surgery allowing initial renal vein ligation resulting in reduction of blood loss and operative time. The described experience and current literature review support adjunctive embolization and document minimal risk to the patient.

Embolization, Therapeutic↗