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Biomedical subjects

M Luna

Publications and source records attributed to M Luna.

At least 19 recordsLinked to original sources
PubMed1992

Adenoid cystic carcinoma of the palate.

We reviewed the clinical records of 41 patients who received definitive treatment for adenoid cystic carcinoma arising from the palate. Tumors were divided into three categories depending on local extension and pattern of growth. Surgery, either alone or in combination with post-operative radiation therapy, yielded satisfactory local regional control of the cancer. Patients who had adenoid cystic carcinoma with diffuse microscopic spread into adjacent tissues had the highest propensity for the development of distant metastases.

Adult↗
PubMed1991

Cadmium determination in Mexican-produced tobacco.

Exposure to cadmium by inhalation or ingestion is dangerous for human health. This metal induces damage to the kidneys, the bones, the prostate, and the lungs. In the lungs, cadmium can produce cancer, emphysema, and fibrosis. It is well known that tobacco leaves are contaminated with cadmium, a metal that has been related to pulmonary damage. In this paper we report the concentration of cadmium in tobacco leaves and in cigarettes produced for domestic consumption. Fifty-five cigarettes of different brands, prices, and stocks were analyzed as well as 48 samples from four different types of tobacco. The average concentration of cadmium in cigarettes was 4.41 +/- 0.67 micrograms/g, and 2.65 +/- 0.99 micrograms/g for tobacco leaves; the content of cadmium was 2.8 +/- 0.4 micrograms/cigarette. It was estimated that a person that smokes 20 Mexican cigarettes per day can increase his (her) cadmium burden by 1.4 to 2.8 micrograms per day.

Cadmium↗
PubMed1991

Increased transcription and translation of heme oxygenase in Chinese hamster fibroblasts following photodynamic stress or Photofrin II incubation.

Porphyrin mediated photosensitization can enhance the transcription and translation of several oxidative stress genes. In this study, we report on the enhanced expression of the gene encoding for heme oxygenase in Chinese hamster fibroblasts by; (1) incubation in Photofrin II; (2) Photofrin II mediated photosensitization; and (3) photosensitization induced by Rose Bengal. Increased expression of heme oxygenase mRNA was accompanied by a concomitant increase in the synthesis of the 34 kDa heme oxygenase protein. Western blot analysis using antibody to heme oxygenase confirmed the immunoreactivity of the 34 kDa protein induced by Photofrin II and PDT. These results demonstrate that heme oxygenase can be activated by non-metalloporphyrins as well as by photosensitization associated with singlet oxygen mediated subcellular injury.

Animals↗
PubMed1991

Neuroendocrine regulation of adrenal 5'-monodeiodination during acute cold exposure in the rat. I. Effects of hypophysectomy.

Circulating levels of T4, T3, corticosterone, noradrenaline, and adrenaline, as well as 5'-monodeiodinase activity (5'-MA) were measured in control and hypophysectomized rats acutely exposed to cold environment (15-120 min, 4 C). In addition to the well known activation of the sympathoadrenomedullary system and the hypothalamic-pituitary-adrenal and-thyroid axes, cold exposure was followed by a rapid and sustained increase of 5'-MA in the hypothalamus, and a byphasic course of activation in the adrenal gland in control rats. The adrenal rapid activation (30 min) corresponded to the medulla and the slower activation (120 min) to the cortex. Both, the basal adrenal 5'-MA and the response to cold in adrenal and hypothalamus were 2-fold higher in hypophysectomized rats compared to control. The time course of enzyme activation in these structures suggests that: 1) organ-specific increases in 5'-MA may be associated to a simultaneous rise in their metabolic and/or functional activity, 2) the triggering mechanisms involves an immediate sympathetic signal activating the hypothalamic-adrenal medulla response and a pituitary signal eliciting a slower adrenocortical response, and 3) the compensatory sympathetic hyperactivity after panhypopituitarism contribute to enhance both the adrenal enzyme basal activity and the hypothalamic and adrenal hyperresponse to cold stress.

Adrenal Cortex↗
PubMed1990

Submandibular gland tumors. Adverse histologic factors and therapeutic implications.

We reviewed our 41-year experience with tumors of the submandibular gland to determine what factors influence outcome and their implications for treatment. The most common benign neoplasm was pleomorphic adenoma (21), while among malignant tumors the adenoid cystic variety (37) predominated. For the 86 patients who had malignant tumors, the 2- and 5-year survivals by the life table method were 82% and 69%, respectively. For patients with malignant tumors, histology, size, perineural invasion, and prior treatment did not affect overall survival. Factors adversely affecting outcome were extraglandular soft-tissue extension and lymph node metastasis. Local-regional control was enhanced in patients with soft-tissue extension if they were treated by surgery followed by radiotherapy rather than by surgery alone.

Adenocarcinoma↗
PubMed1989

Light chain deposition disease derived from the kappa I light chain subgroup. Biochemical characterization.

The authors biochemically analyzed the nonamyloidotic light chain deposits, the first studied in this way, from a patient with systemic kappa light chain deposition disease (LCDD). The light chain deposits from myocardium were extracted in 6 M guanidine-HCl under reducing conditions, partially purified by column chromatography, and analyzed by immunoblotting and amino-terminal sequencing. The extracted material contained four main bands reactive with anti-kappa antibody: intact kappa light chain (MW, 28 kd), under reducing conditions, and 3 fragments (MW, 20, 16, and 15 kd). As revealed by the aminoterminal sequencing performed on three of the four bands, the intact light chain molecule and two fragments belong to the kappa I subgroup. Thus, similar to light chain amyloid (AL), the deposits in LCDD are derived from both intact light chain and fragments. Unlike in AL, amyloid P component was not detected in the deposits of this patient or those examined previously. The differences demonstrated thus far between AL and LCDD are the lack of fibrils and amyloid P component in LCDD, suggesting that local tissue factors may be responsible for different processing of the light chain deposits in LCDD.

Adult↗
PubMed1987

Concentrations of calmodulin in sperm in relation to their motility in fertile euspermic and infertile asthenozoospermic men.

The relationship between calmodulin and sperm motility was assessed in euspermic and asthenozoospermic men using radioimmunoassay and time-lapse photography, respectively. There was a significant decrease in the % sperm motility, mean sperm velocity, motility index and % of progressively motile sperm in the asthenozoospermic group when compared with euspermic men. The former also exhibited a higher % of sperm with erratic or circular motility. Calmodulin concentration in sperm from the asthenozoospermic men was 4.8 +/- 1.4 micrograms/mg protein compared with 12.6 +/- 2.3 in euspermic men (P less than 0.0005). The differences observed in sperm motility characteristics between the two groups may, thus, be due to the observed differences in the concentration of calmodulin.

Adult↗
PubMed1987

Review of the literature and a recommended system of malignancy grading in oral squamous cell carcinomas.

A review of histologic classification systems for grading of malignancy in squamous cell carcinomas of the head and neck region is presented. Reasons behind the varying results obtained in studies using histomorphologic grading schemes are presented and potential errors involved in this type of clinical research are discussed. Requirements for the study of correlations between malignancy grade scoring, and recurrence and survival rates are presented. These include factors as patient selection, clinical staging, and follow-up principles. Special attention must be given to treatment modalities, establishment of negative surgical margins and occurrence of regional lymph node and/or distant metastases.

Carcinoma, Squamous Cell↗
PubMed1986

Fusarium. A newly recognized fungal pathogen in immunosuppressed patients.

Two cases of disseminated fungal infection due to Fusarium species, that occurred during a 4-month period, are reported. Both patients had a myeloproliferative disorder for which they had received intensive cytotoxic and immunosuppressive therapy, and both died despite treatment with amphotericin B. This report and review of the recent literature suggest that Fusarium is emerging as a newly recognized fungal pathogen in immunosuppressed patients.

Adult↗
PubMed1986

Malignancy grading of squamous cell carcinoma in the floor of the mouth related to clinical evaluation.

A multifactorial grading system was used for histologic classification and grading of malignancy in 89 patients with squamous cell carcinoma in the floor of the mouth. All patients had been treated with surgery alone and only those patients were included in the study who at the initial diagnosis had no clinically suspected regional lymph node or distant metastatic involvement. There was a statistically significant correlation between the mean total malignancy scoring, on the one hand, and clinical staging, frequency of recurrences, and death from the first primary oral carcinoma, on the other.

Carcinoma, Squamous Cell↗
PubMed1985

Vimentin and glial fibrillary acidic protein in human brain tumors.

Using the peroxidase-antiperoxidase (PAP) technique, we examined 35 primary brain tumors for expression of vimentin and GFAP. Both low-grade and high-grade astrocytomas contained vimentin-positive and GFAP-positive cells. Ependymomas also stained for both markers. In gliosarcomas, the glioblastomatous portions stained like astrocytomas, while only vimentin stain was seen in the fibrosarcomatous portions. Medulloblastomas and oligodendrogliomas were negative for both vimentin and GFAP, while meningiomas contained scattered areas of vimentin-positive cells. These results suggest that the expression of vimentin and GFAP is mostly confined to glial-derived tumors, and that vimentin can potentially be a useful marker for distinguishing undifferentiated GFAP-negative glial tumors and mesenchymal tumors from primitive neuroectodermal tumors.

Astrocytoma↗
PubMed1985

Liposomal amphotericin B for the treatment of systemic fungal infections in patients with cancer: a preliminary study.

Twelve patients with hematologic malignancies complicated by fungal infections were treated with liposomal amphotericin B (L-AmpB). Nine patients were granulocytopenic; the three additional patients with normal granulocyte counts were immunosuppressed. All patients had biopsy findings or cultural evidence of the progression of their fungal infection while being treated with conventional amphotericin B. Doses of 0.8-1.0 mg/kg of L-AmpB were administered intravenously every 24-72 hr. Three patients had a complete remission, five had a partial remission, and four showed no improvements. A total of 161 doses of L-AmpB were administered. Fever and chills occurred on seven occasions. No hematologic or blood chemistry abnormalities related to L-AmpB treatment were observed.

Adolescent↗
PubMed1984

Systemic candidiasis in cancer patients.

Two hundred thirty-five fungal infections occurred in patients with malignant diseases over a four-year period. One hundred eighty-eight were due to Candida species and Torulopsis glabrata and are reviewed herein. The frequency was highest in patients with acute leukemia (11.9 per 100 registrations) with a frequency of 0.8 per 100 registrations in all cancer patients at this institution. Three or more predisposing factors were present in more than 50 percent of the cases; antecedent myelosuppression, chemotherapy, and antibiotic therapy were most common. Blood cultures were positive in only 35 percent of patients with disseminated candidiasis. Twenty-nine of 55 patients (53 percent) had candidemia without identifiable organ infection recovered. Eleven were given no systemic antifungal therapy and recurrence of infection was documented in two patients. Only six (4.5 percent) of 133 patients with proved deep organ infections recovered. Respiratory failure was the clinical cause of death in 62 percent of patients. Clinical features, cultures, and serologic tests were usually of no assistance in establishing the diagnosis early in the course of the infection.

Acute Disease↗
PubMed1984

Flow-cytometric analysis of DNA content in postmortem tissue.

In order to determine the heterogeneity of ploidy in disseminated cancer, we assessed the suitability of postmortem tissue for flow-cytometric analysis of cellular DNA content. Forty tissue samples from various tumor-bearing sites in 12 patients with widely metastatic cancer were analyzed. In eight cases studied there was a single unimodal ploidy level in all disease sites studied. The remaining four cases revealed bimodal tumor populations present in different proportions in the various sites studied. No difference in ploidy could be detected between irradiated and nonirradiated sites in patients who had received radiation therapy. Samples taken from normal tissues all revealed diploid DNA content, suggesting that DNA fluorescence is not altered in the immediate postmortem period. Systematic analysis of cellular DNA content in autopsy material is feasible and may contribute to our understanding of patterns of metastatic spread in patients with cancer.

Autopsy↗
PubMed1984

Human tissue distribution of 4'-(9-acridinylamino)-methanesulfon-m-anisidide (NSC 141549, AMSA).

Concentrations of AMSA were determined by HPLC in autopsy tissue samples from five patients who had received the drug antemortem. Relative organ concentrations of AMSA varied from patient to patient; however, concentrations were generally highest in gallbladder, liver, and kidney, while low levels were generally but not invariably found in lung, testicle, muscle, fat, spleen, bladder, pancreas, colon, prostate, and brain. One patient with ventricular fibrillation and seizures had high tissue AMSA concentrations in myocardium, but low concentrations in brain. Another patient with seizures during treatment had high brain concentrations of AMSA. Relative organ concentrations were similar to those found in mice, except that mice have high AMSA concentration in their spleens whereas our patients did not, even when the spleen was infiltrated with leukemic cells. High tissue concentrations of AMSA were still present 2 weeks after treatment. AMSA concentration was lower in a renal oncocytoma (1.1 micrograms/g) than in surrounding kidney (2.4 micrograms/g).

Adult↗
PubMed1984

Mycobacterial pulmonary infections after allogeneic bone marrow transplantation.

Allogeneic bone marrow transplant recipients are prone to pulmonary infections caused by a wide spectrum of organisms. Nonetheless, the recognition of lung disease caused by Mycobacterium tuberculosis in two patients and Mycobacterium avium-intracellulare in a third patient at the University of Texas M. D. Anderson Hospital represents the first report of these agents occurring in allogeneic marrow recipients. Diagnosis can be difficult due to atypical presentations, initial negative culture results, and the presence of more than one pathogen in these compromised hosts. In the case involving Mycobacterium avium-intracellulare infection, culture of material obtained by bronchoscopy established the diagnosis when repeated sputum samples showed no growth. A vigorous search for mycobacteria is suggested in allogeneic bone marrow transplant recipients with pulmonary infections.

Adult↗