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Biomedical subjects

F J Hernandez

Publications and source records attributed to F J Hernandez.

At least 19 recordsLinked to original sources
PubMed2001

MCM2 is an independent predictor of survival in patients with non-small-cell lung cancer.

PURPOSE: Minichromosome maintenance protein 2 (MCM2) is a component of the prereplicative complex. It is essential for eukaryotic DNA replication and is only expressed in proliferating cells. The prognostic utility of MCM2 compared with Ki-67, another marker of proliferating cells, on survival of patients with non-small-cell lung cancer (NSCLC) was studied. PATIENTS AND METHODS: We examined the immunohistochemical expression of MCM2 and Ki-67 in primary pathologic tumor specimens from 221 NSCLC patients. For each marker, the fraction of tumor cells with positive staining was assessed as a percentage and categorized into four groups: 0% to 24%, 25% to 49%, 50% to 74%, and > or = 75%. MCM2 and Ki-67 immunoreactivities were compared with each other, and associations with pathologic and clinical parameters predictive of survival were analyzed with the chi(2) test. Cox regression models were used to assess associations between MCM2 and Ki-67 and survival while controlling for confounders. RESULTS: Independent variables significantly associated with survival were tumor stage, performance status, and staining category. Patients with less than 25% MCM2 immunoreactivity had a longer median survival time than patients with > or = 25% MCM2 immunoreactivity (46 v 31 months; P =.039) and a lower relative risk (RR) of death (RR, 0.55, 95% confidence interval, 0.34 to 0.88). There was no significant association between survival and Ki-67 expression. CONCLUSION: Immunostaining of tumor cells for MCM2 is an independent prognostic parameter of survival for patients with NSCLC. Interpretable results can be obtained on more than 96% of paraffin-embedded specimens, and approximately 35% will be in the favorable subgroup, with less than 25% positively stained tumor cells. Whether MCM2 is predictive of response to therapy needs to be studied.

Adenocarcinoma↗
PubMed2000

Self-tolerance and the composition of T cell repertoire.

T cell recognition of self-major histocompatibility complex-peptide complexes dictates the composition of the T cell receptor repertoire. Research projects in our laboratory deal with the mechanisms that regulate the composition of the repertoire specific for self-antigens and the defects that can result in autoimmunity. Two different types of disease models are under investigation: juvenile (type I) diabetes and cancer. Both of these diseases are impacted by the presence of anti-self CD8 cells, yet in opposite ways. By understanding the mechanisms of peripheral tolerance and the reasons they fail in autoimmunity, we may learn how to prevent undesirable autoimmunity and how to encourage an autoimmune response when it is needed to eliminate tumor cells.

Autoimmunity↗
PubMed1992

Effect of six organic acids on staphylococcal growth and enterotoxin production.

Four Staphylococcus aureus strains were incubated at 37 degrees C for 24 h in broth progressively acidified with lactic, citric, ascorbic, acetic, pyruvic and propionic acids, and their survival rate and enterotoxin producing ability was studied. Acids were chosen based on their frequent use by the food industry. Periodically, samples were withdrawn to determine counts, pH and the presence of enterotoxins A, B, C, and D. For a given acid, the effect on growth and enterotoxin synthesis was different. The most inhibitory acid for the growth of strains FRI-100 and FRI-472 was pyruvic acid, for strain FRI-137 was lactic acid, all six acids were equally effective on strain S6. Lactic acid was very inhibitory to enterotoxin synthesis, but the effect on this parameter of acetic and citric acids was almost nil. Enterotoxins were seen to be inactivated at acid pH values; enterotoxin B was the most resistant to inactivation.

Acetates↗
PubMed1987

Use of fine needle aspiration for detection of stage A prostatic carcinoma before transurethral resection of the prostate: a clinical trial.

The incidence of stage A prostatic carcinoma is approximately 10 per cent. We performed a clinical trial to determine if pre-prostatectomy fine needle aspiration could detect reliably stage A prostatic carcinoma. In 102 men with clinically staged benign disease by digital examination we performed a 4-quadrant fine needle aspiration of the prostate before prostatectomy. The cytological diagnosis of the aspirate was compared to the pathological diagnosis obtained at prostatectomy in all patients. The incidence of stage A prostatic carcinoma in this group of patients was 18.6 per cent (19 of 102 men). Sufficient aspirate material for cytological diagnosis was obtained in 98 of 102 men (96 per cent), including 17 with a diagnosis of carcinoma. When adequate diagnostic material was obtained, fine needle aspiration detected all cases of clinical stage A2 prostatic carcinoma but it did not detect stage A1 prostatic carcinoma. There were no false positive diagnoses. We conclude that routine pre-prostatectomy fine needle aspiration of the prostate can be safe, cost-effective and clinically useful.

Aged↗
PubMed1985

[Sutton's periadenitis mucosa necrotica recurrens. An optical-ultrastructural case study].

An optic-ultrastructural study is realized, emphazising the presence of: a) Intermediate lymphocytes, that we interpret as T-activated; b) Activated endothelial cells (prominent, rich in Weibel-Palade's bodies, well developed nuclei- and cytoskeletons); c) Classic and native myofibroblasts, partially responsible for the cicatricial contraction. We postulate that the changes in the connective-vascular tissue of the chorion represent an anarchic and reactive fibroangioblastic hyperplasia and favors the typical recurrences of this process.

Adolescent↗
PubMed1980

Legionnaires' disease. Postmortem pathologic findings of 20 cases.

From March 1977 to December 1978, postmortem examination was performed at Wadsworth Veterans Administration Medical Center for 20 patients who had had nosocomially acquired Legionnaires' disease. Seventeen patients died during the acute illness due to Legionnaires' disease, and three patients died after clinical resolution of the acute process. The only consistent postmortem findings were limited to the lungs. Confluent bronchopneumonia, and less frequently lobar pneumonia, was present in most cases. Although a spectrum of microscopic pulmonary findings was observed, the characteristic histologic features of acute Legionnaires' disease were an extensive intra-alveolar exudation of macrophages and neutrophils in varying proportions, erythrocytes, and fibrin. Lysis of the inflammatory cells was frequently found. Areas of coagulative necrosis of the lung parenchyma and edematous thickening of the alveolar septa were typically seen. Microscopy of lung tissue from the three patients who died after clinical resolution of the acute process revealed organized pneumonia, with patchy organization of the intra-alveolar exudate and focal obliteration of the alveolar septal framework. Associated postmortem findings were fibrinous endocarditis in one case and hemorrhagic infarction of the adrenal glands in two cases. Electron-microscopic examination of the lungs revealed as many as 23 separate bacillary profiles within a single macrophage. Septate binary fission or spore-like structures were not observed.

Adult↗
PubMed1979

Primary leiomyosarcoma of the aorta.

A case of primary leiomyosarcoma of the abdominal aorta is reported. The tumor replaced the full thickness of the aortic wall with formation of a large saccular aortic aneurysm filled with an admixture of tumor and mural thrombus. Electron microscopy of the surgical biopsy of the tumor revealed neoplastic smooth muscle cells with myofilaments and a discontinuous basal lamina. To our knowledge, leiomyosarcoma of the aorta has never been reported.

Adult↗
PubMed1978

Leiomyosarcoma of male breast originating in the nipple.

A case of leiomyosarcoma of the breast in a 53-year-old man originating in the erectile musculature of the nipple is presented. The tumor assumed roughly the conical configuration of the nipple musculature and was limited to the mammary gland. Ultrastructural study of the tumor revealed neoplastic smooth muscle cells with typical myofilaments.

Breast↗
PubMed1976

Multiple diffuse fibrosarcoma of bone.

Light and electron microscopic observations of a case of multiple diffuse fibrosarcoma of bone are presented. Two cases of diffuse fibrosarcoma of bone have been previously reported. Clinically the tumor presented as multiple osteolytic lesions involving the pelvis bone, vertebral bodies and skull with the radiologic appearance of a multiple plasma cell myeloma. Histologically the tumor was a spindle-cell fibrosarcoma. At the ultrastructural level the tumor cells represent fibroblasts separated by a scanty amount of collagen fibers. Electron microscopic findings substantiate the fibroblastic origin of multiple diffuse fibrosarcoma of bone.

Bone Neoplasms↗
PubMed1976

Mixed tumors of the skin of the salivary gland type: a light and electron microscopic study.

The light and electron microscopic features of two mixed tumors of the skin of the salivary gland type demonstrate eccrine differentiation of the epithelial component. The tumors were made up of tuboalveolar spaces lined by an eccrine duct type of epithelium with luminal cells showing numerous microvilli. The mesenchymal elements were fibroblasts and chondrocytes embedded in a mucous and chondroid matrix. Groups of undifferentiated cells without eccrine differentiation but with ultrastructural features suggestive of epithelial origin were seen among the mesenchymal and epithelial elements of the tumor.

Adenoma, Pleomorphic↗
PubMed1976

Poorly differentiated synovial sarcoma. A light and electron microscopic study.

Few studies of the ultrastructural features of synovial sarcoma have appeared in the literature. The case under study represented a poorly differentiated synovial sarcoma with a predominant fibrosarcomatous component and a few areas with epithelioid and pseudoacinar patterns. Ultrastructurally, the cellular elements of the varied histologic patterns were similar. Basement membranes and desmosomes were absent, and the cell surfaces facing the acinar lumen exhibited multiple microvilli. It appears from a comparison of our studies with the previous reports that the fine structure of this tumor varies according to the degree of histologic differentiation.

Adult↗
PubMed1975

Chemodectoma of the vagus nerve. Report of a case with ultrastructural study.

Light and electron microscopic studies of a chemodectoma of the vagus nerve are presented. Forty-four cases of vagal chemodectoma have been reported to date, but no electronmicroscopic studies have been published. The ultramicroscopic studies showed the presence of clear and dark cells and membrane-bound neurosecretory granules, and the absence of sustentacular cells and nerve endings. Similar findings have been reported in cases of carotid body and glomus jugulare tumors.

Cell Membrane↗
PubMed1975

Tubal ligation and pregnancy: mechanism of recanalization after tubal ligation.

The mechanism of recanalization after resection of a segment of the fallopian tube by the Pomeroy sterilization method is discussed. At the level of resection, the epithelial lining of the fallopian tube tends to regenerate, covering the split ends and planes of cleavage of the resected surfaces and forming slitlike spaces and blind pouches lined by tall columnar cells. Scarring and subsequent retraction of both severed ends of the tubes tend to result in approximation; in some cases, the resected ends and the epithelial lining bridge the gap between the lumina, re-establishing patency of the tube. Surgical procedures that prevent approximation of the resected ends of the fallopian tubes or methods that seal the lumina should produce failure rates lower than those obtained with the classic Pomeroy sterilization method.

Adult↗