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Biomedical subjects

L Ma

Publications and source records attributed to L Ma.

At least 595 records · Page 33Linked to original sources
PubMed1983

Sclerosing stromal tumor of the ovary: case report and review of the literature.

A case of sclerosing stromal tumor of the ovary in a Chinese girl of 17 years is reported. She presented with metrorrhagia and an abdominal mass in the right lower quadrant. At operation, a large unilocular cyst was found in the right ovary. Light microscopic and ultrastructural study established the diagnosis of sclerosing stromal tumor of the ovary. To date, 63 cases have been recorded in the literature, 33 of which have been described in detail.

Adolescent↗
PubMed1983

A scanning electron microscope study of isolated glomeruli in glomerulonephritis.

Glomeruli from 48 cases of glomerulonephritis (Gn) were isolated and studied by means of the scanning electron microscope (SEM). Overall glomerular loss due to processing was 2.4%. SEM of these isolated glomeruli showed good preservation of glomerular structure. Changes of the podocyte cell body and its foot processes were noted and correlated with light microscopic morphology. Individual podocyte necrosis, variable foot process fusion and cell body swelling were seen in IgA nephropathy. Podocyte degeneration with separation from the glomerular basement membrane was evident in idiopathic minimal change Gn while idiopathic membranous Gn was characterized by globular swelling of the podocyte cell bodies. In focal sclerosing Gn, large spherical bodies arising from swollen podocyte cell bodies were frequently encountered. Innumerable microvilli and small spherical bodies characterized membranoproliferative Gn. Variable podocyte cell body swelling, microvilli and small spherical bodies were seen in cases of lupus nephritis. Taken alone, none of the SEM changes were diagnostic. However, when the type of the change, the severity and the combination of the changes were considered as a whole, they were indicative of what light microscopy might reveal and helpful in differentiating between idiopathic minimal change Gn and focal sclerosing Gn.

Basement Membrane↗
PubMed1983

Is sclerosing hemangioma of lung an alveolar mixed tumour?

A case of a peripheral lung tumour histologically categorized as a sclerosing hemangioma of the lung is presented. Ultrastructurally, the tumour is composed of a mixture of epithelial and mesenchymal elements in varying stages of differentiation. Type II pneumocytes are identified as one epithelial component, while primitive mesenchymal cells with a tendency to develop into pericytes are the predominant mesenchymal component. The tumour appears to differentiate along the line of the pulmonary alveolar septa, and should be designated as a 'pulmonary alveolar mixed tumour'.

Child↗
PubMed1982

Preparation of Epon-embedded renal tissue for scanning electron microscopy.

A method for the preparation of Epon-embedded renal tissue for scanning electron microscopy (SEM) is described. This involves careful removal of Epon by potassium hydroxide in absolute methanol to expose the embedded kidney tissue. The method is simple and gives good surface morphology of the sectioned and trimmed surfaces of the tissue block. Both sectioned and intact glomeruli are well shown. The method also allows SEM observation of tubules and blood vessels.

Epoxy Resins↗
PubMed1981

Serum alpha-fetoprotein in rats after ligation of the common bile duct: relation to ductular cell (oval cell) proliferation.

Serum AFP levels were measured by radio-immunoassay in rats at various periods after ligation and section of the common bile duct and after sham-ligation. Transient elevations of serum AFP reaching statistically significant levels occurred at 3 to 10 days, 17 days and 28 days after ligation of the common bile duct but not in sham-operated rats. The peak elevations of serum AFP followed waves of mitosis in both the ductular cells and the hepatocytes as measured by autoradiography. Proliferation of hepatocytes, however, remained minor when compared to ductular cell multiplication. Ultra-structural and histochemical studies of the liver clearly distinguished ductular (oval) cells from hepatocytes and provided no evidence of transition from ductular cells to hepatocytes. Our findings suggest that ductular cell proliferation in the rat induced by ligation of the common bile duct may produce elevations in the serum AFP.

Animals↗
PubMed1981

Non-endocrine carcinoid tumour of the uterine cervix: aspects of diagnosis and treatment. Case report.

A case of primary well-differentiated carcinoid tumour of the uterine cervix in a Chinese woman of 62 years without endocrine symptoms is reported and its clinico-pathological features, ultrastructure and response to radiotherapy discussed. To our knowledge, it is the first of such cases seen in Hong Kong. Clinically, it presented as a polypoid lesion. The initial diagnosis was squamous carcinoma of cervix stage Ib and the patient was treated with radiotherapy. The tumour disappeared after application of first intracavitary irradiation of 4500 mg h. After completion of 9000 mg h, Wertheim hysterectomy followed and no residual tumour was found. Retrospective staining of the pre-irradiation cervical tumour by Grimelius method was positive for argyrophil granules and electron microscopic study demonstrated neurosecretory granules in the cytoplasm and established the diagnosis.

Carcinoid Tumor↗
PubMed1979

Changes in adrenocorticotropic hormone (ACTH) and cortisol levels in drug addicts treated by a new and rapid detoxification procedure using acupuncture and naloxone.

Plasma ACTH, cortisol, and cyclic-AMP levels of eleven heroin addicts were dertermined before and after treatment with a fast detoxification procedure using acupuncture and electrical stimulation (AES) together with the administration of limited doses of naloxone. At the end of the treatment period, the average plasma ACTH, cortisol, and cyclic-AMP level rose 130,83, and 24 percent, respectively. In view of the appearance of mild withdrawal signs during this method of treatment, the observed increases in ACTH and cortisol levels probably reflect the inability of AES to suppress withdrawal symptoms induced by naloxone completely. The mechanism underlying this new method of treatment is discussed in relation to AES's ability to stimulate the secretion of endorphins.

Acupuncture Therapy↗
PubMed1979

The influence of electro-acupuncture on naloxone-induced morphine withdrawal. II. Elevation of immunoassayable beta-endorphin activity in the brain but not the blood.

The effect of electro-acupuncture in the treatment of naloxone precipitated morphine withdrawal in mice was studied. Thirty minutes of acupuncture was enough to suppress withdrawal behaviors by more than 60%. Concomitant to the decrease of withdrawal behavior, there was a significant increase of brain beta-endorphin level in the acupunctured animals. Plasma beta-endorphin level of the treated and untreated group was not significantly different.

Acupuncture Therapy↗
PubMed1978

Reduction of adrenocorticotropic hormone (ACTH) and cortisol in drug addicts treated by acupuncture and electrical stimulation (AES).

Forty-two heroin addicts and 31 normal persons were examined for the effect of acupuncture and electrical stimulation (AES) on plasma ACTH, cortisol and cyclic-AMP levels. Both ACTH and cortisol levels were reduced significantly in the addicts after treatment whereas no such significant reduction was observed in the normals. Plasma cyclic-AMP level was not affected in either group. Taken together, results from the present study suggest that the mechanism of AES in the treatment of addiction may have a neuroendocrinological basis. This hypothesis is particularly attractive in view of the isolation of opiate-like peptides from the brain.

Acupuncture Therapy↗