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Biomedical subjects

A Montoya

Publications and source records attributed to A Montoya.

At least 91 records · Page 5Linked to original sources
PubMed1977

Refractory ventricular arrhythmia: the role of intraoperative electrophysiological study.

Thirty patients with drug refractory ventricular tachycardia (RVT) were studied between 1 week and 5 years after myocardial infarction with coronary agniography and left ventriculography. They were divided into four groups: (1) inoperable, five patients; (2, a) operated, with primary left ventricular failure, five patients; (2, b) operated with primary RVT, not mapped, 15 patients; (2, c) operated, with mapping, five patients. The mortality rate in group 1 was 100%, and in group 2, a it was 80%. In group 2, b, despite aggressive drug therapy and operation, including aneurysmectomy, coronary revascularization, and intra-aortic balloon pumping when appropriate, the mortality rate wad intraoperative mapping in group 2, c. Arrhythmogenic foci were identified and removed in four. There was one operative death (20%) and four patients are alive from 12 to 27 months after operation, three of whom are asymptomatic. Intraoperative epicardial mapping is an important adjunct to surgery for RVT.

Aged↗
PubMed1976

Disc variance: a potentially lethal complication of the Beall valve prosthesis.

During 1975, 4 patients with erosion of the disc in Beall valve prostheses were seen. In one case the eroded disc was found loose in the distal aorta at postmortem examination. In 3 other cases, clinical diagnoses were made and successful reoperations performed. Because disc variance represents a potentially lethal complication, patients with disc prostheses should be examined at frequent intervals. When signs and symptoms of mechanical malfunction develop, the valve prosthesis should be replaced immediately to prevent death.

Female↗
PubMed1970

Possible inhibitory effect of teichoic acid on Bacillus subtilis transfer ribonucleic acid.

1. tRNA of Bacillus subtilis was found to be variably contaminated with membrane teichoic acid. 2. Samples with high contents of teichoic acid showed no accepting activity for tRNA(Phe) and tRNA(Tyr). 3. Removal of teichoic acid restored accepting activity and fractions containing teichoic acid, separated on Sephadex G-150, inhibited the charging of tRNA(Tyr). 4. The presence of teichoic acid did not inhibit the charging of tRNA(His).

Bacillus subtilis↗
PubMedDate not supplied

Effects of benorylate and impacina on the metabolism of cultured hepatocytes.

To directly evaluate the effects of benorylate and impacina on liver metabolism, we have adapted the use of cultured adult rat hepatocytes as a biological model. Cells were exposed to sub-toxic levels of the xenobiotic which were incorporated into the culture media. This was followed by the evaluation in treated cultures of some biochemical functions typical of the liver, namely, gluconeogenesis, glycogen metabolism, synthesis of plasma proteins and ureogenesis, and a comparison made with non-treated controls. Benorylate impaired glucose release by hepatocytes to the medium and net accumulation of glycogen was detected. Urea production also diminished (20%) in benorylate-treated cells. Impacina significantly increased the synthesis of albumin and tranferrin when added at therapeutic levels into the culture medium and did not alter other biochemical functions of the hepatocytes.

Animals↗
PubMedDate not supplied

Right-sided heart failure in a dog with primary cardiac rhabdomyosarcoma.

A seven-year-old, female German shepherd mixed-breed dog was presented with weakness, inappetence, and a distended abdomen. Right-sided heart failure with pleural, pericardial, and abdominal effusions; dyspnea; and tachycardia were identified. The radiographic and electrocardiographic examinations did not allow a conclusive diagnosis. Echocardiographic findings included a mass in the wall of both the right atrium and right ventricle, partially occupying the right heart cavities. A diagnosis of cardiac tumor was made, and the owner elected euthanasia. The necropsy confirmed a tumor mass located in the right atrium and right ventricle. A definitive diagnosis of primary cardiac rhabdomyosarcoma was based on histopathological and immunohistochemical analyses.

Animals↗
PubMedDate not supplied

Determination of thiabendazole in fruit juices by a new monoclonal enzyme immunoassay.

A competitive, indirect enzyme-linked immunosorbent assay (ELISA) for thiabendazole has been developed and applied to the analysis of fruit juices spiked with this fungicide. The immunoassay is based on a new monoclonal antibody derived from a hapten functionalized at the nitrogen atom in the 1-position of the thiabendazole structure. To our knowledge, such a structure has not been previously used to obtain antibodies to thiabendazole. The I50 value and the detection limit of the ELISA for standards were 0.2 and 0.05 ng/mL, respectively. Fruit juices were analyzed by diluting samples in assay buffer, without extraction or cleanup. Samples were not even centrifuged or filtered to remove fruit pulp. Under these conditions, the immunoassay was able to accurately determine thiabendazole down to 1 ng/mL in orange and grapefruit juices, down to 5 ng/mL in banana juice, and down to 20 ng/mL in apple and pear juices. Sensitivity differences of the ELISA were caused by the minimum dilution required by each juice to minimize matrix effects: 1/10 for orange and grapefruit juices, 1/50 for banana juice, and 1/100 for apple and pear juices. In an attempt to further increase the sensitivity of the immunoassay for matrixes showing the strongest interferences, apple and pear juices spiked with thiabendazole at low levels (1-20 ng/mL) were extracted with ethyl acetate before analysis. This simple procedure entailed a significant reduction of matrix effects, which in fact allowed us to determine accurately as low as 5 ng/mL thiabendazole in apple and pear juices. Irrespective of whether samples were analyzed by the direct dilution method or after extraction, the simplicity, sensitivity, and sample throughput of this monoclonal immunoassay makes it a very convenient method for the routine monitoring of thiabendazole residues in fruit juices.

Antibodies, Monoclonal↗
PubMedDate not supplied

Successful use of the total artificial heart as a bridge to transplantation with no mediastinitis.

UNLABELLED: High rates of infection, especially mediastinitis, have been reported with the use of the total artificial heart (TAH), thereby limiting its usefulness. We have used the TAH as a bridge to transplantation with only minor infectious complications and a zero incidence of mediastinitis. Between February 1988 and August 1990, the TAH was inserted at Loyola University Medical Center in 19 patients, ages 16 to 64 years (mean, 44 years). Seventeen patients (89%) underwent transplantation within 1 to 34 days (mean, 9.8 days). Of the patients who did not undergo transplantation, one was brain dead and the other died of bleeding diathesis. Early (30-day) deaths occurred in two patients (11.7%): acute rejection at 18 days and multiple cerebral infarcts at 14 days. Three late deaths (17.6%) occurred: one patient, cytomegalovirus and pneumocystis pneumonia at 4 months; one patient, bronchopneumonia and multisystem failure at 9 months; and one patient, chronic rejection at 14 months. Minor infectious complications during the TAH implantation included Enterobacter pneumonia treated with antibiotics and positive sputum cultures (Escherichia coli; Candida), with no clinical evidence of infection in two patients. No cases of mediastinitis occurred either while the TAH was implanted or after transplantation. All patients were on antibiotics while the device was in place. CONCLUSION: Our experience with the TAH shows this to be an excellent device for successful bridging of patients for heart transplantation. We have had minimal infectious complications and none directly attributed to the use of this device. This device should continue to be used safely as a bridge to transplantation.

Adult↗
PubMedDate not supplied

Comparison of results after heart transplantation: mechanically supported versus nonsupported patients.

Between March 1984 and July 1990 our team transplanted 168 hearts. One hundred twelve patients did not require mechanical support (group I). Fifty-six patients required mechanical support (group II). Intraaortic balloon counterpulsation was used in 37 patients (66%). The total artificial heart (TAH) was used in 16 patients (29%), and the ventricular assist device (VAD) was used in three patients (5%). The time spent on the device ranged from 1 to 35 days. No statistical difference was noted on the survival between the two groups. The 30-day and 1-year survival rate was 95% (106 patients) and 71% (79 patients) in group I and 91% (51 patients) and 68% (38 patients) in group II. As of July 31, 1990, 70% in group I and 68% in group II are alive. No significant differences were found between the two groups for the following variables (after heart transplantation): length of stay, 30-day survival, 1-year survival, and complications. The only significant difference found between the two groups was the incidence of infections: group I, 23%; group II, 51.7% (p = 0.001). Mechanical support as a bridge to transplantation provides excellent support until a donor becomes available. No difference was found in the 30-day and 1-year survival between the two groups.

Cause of Death↗
PubMedDate not supplied

[Comparison of the effect of alprazolam, imipramine and placebo in the treatment of panic disorders in Cali, Colombia].

A comparison of safety, and efficiency of Alprazolam, Imipramine, and placebo in the treatment of panic disorder shows that both active drugs are significantly superior to placebo as regards therapeutic effectiveness. On a 77 patient sample, 62 completed an 8-week treatment, and 66 were considered as "assessable" for efficiency results after completing a 3-week treatment. Significantly, more placebo-treated patients than either Alprazolam, or Imipramine-treated patients dropped out trial, while the number of panic attacks was significantly reduced in both Alprazolam-, and Imipramine-treated groups. When trial was over, 96% of patients in Alprazolam group, and 95% of patients in Imipramine group were free from panic attacks, if compared to 65% in the placebo group. Generally speaking, drugs were well tolerated, and no serious adverse effects or life-threatening events were observed.

Adolescent↗
PubMedDate not supplied

Use of the total artificial heart and ventricular assist device as a bridge to transplantation.

The proliferation of transplant programs has not been paralleled by a similar increase in the availability of organ donors. This has significantly prolonged the waiting period and consequently has resulted in increased mortality of the patients with end-stage heart disease who are awaiting transplantation. Between 1984 and 1987, 104 orthotopic heart transplants were performed at Loyola University Medical Center. During the same period, 25 patients died while waiting for a suitable donor. To reduce the mortality of our patients waiting for transplantation, we began using the total artificial heart and a ventricular assist device as a bridge to transplantation in 1988. Of 29 patients who underwent transplant procedures in 1988, 18 required either a total artificial heart (15) or a ventricular assist device (3) as a bridge to transplantation. The underlying heart conditions were ischemic cardiomyopathy (11), dilated cardiomyopathy (5), giant cell myocarditis (1), and allograft failure (1). The average duration of mechanical support was 10 days (range, 1 to 35 days). Seventeen of the supported patients had successful transplants. One patient had brain death and did not receive a heart transplant. Of the 17 patients who survived surgery, two died within 30 days: one at 17 days because of acute rejection, the other at 14 days because of a cerebral vascular event. Fifteen patients (83%) were long-term survivors. Nine of the supported patients required reoperation because of bleeding after device implantation. There was no mediastinal or incisional infection. While the mechanical device was in place, the activated clotting time was maintained between 170 and 200 seconds with the administration of heparin (400 to 1000 units per hour).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMedDate not supplied

Optimal size matching in single lung transplantation.

BACKGROUND: Single lung transplantation for patients with end-stage obstructive lung disease has been highly effective in providing symptomatic relief, and it has been performed at a much increased frequency since 1983. However, there still lacks a convincing study showing the effect of size match and other preoperative variables in predicting functional outcome of patients after transplantation. METHODS: We evaluated 23 single lung transplantations performed for obstructive lung disease over a 34-month period. Multiple physiologic variables and size match criteria were evaluated for their contribution in determining the postoperative forced expiratory volume in 1 second at 3 months after transplantation. RESULTS: The size match ratio that was based on inframammary chest wall circumference was the most useful criterion to adopt, and the optimal donor/recipient size match ratio was 0.89. Furthermore, forced expiratory volume in 1 second at 3 months after transplantation could be predicted with a simple mathematical model that was based on the size match ratio and the recipient's calculated vital capacity of the transplanted hemithorax. CONCLUSIONS: This model could be applied in a clinical setting to maximize functional outcome of the recipients undergoing single lung transplantation.

Adult↗