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Biomedical subjects

M Harris

Publications and source records attributed to M Harris.

At least 793 records · Page 44Linked to original sources
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A study of spindle cell sarcomas showing myofibroblastic differentiation.

Five diagnostically problematic spindle cell sarcomas showing invasive character, cellular pleomorphism, and high mitotic rate were studied clinically and histopathologically by conventional light microscopy, immunohistochemistry, and transmission electron microscopy. They showed varied clinical courses, with two causing death within 5 years and three showing recurrent and metastatic behavior. All lacked a clearly defined line of differentiation by conventional light microscopy. By immunohistochemistry, all were positive for vimentin and alpha-smooth muscle actin; in addition, one showed focal S-100 protein positivity, and one stained for desmin. All were cytokeratin negative. By electron microscopy, the great majority of spindle cells in all cases showed abundant rough endoplasmic reticulum and fine myofilaments with focal densities; collagen secretion granules were also found in all cases but in fewer cells. The fine structure and immunophenotype were considered consistent with myofibroblastic differentiation; these tumors, therefore, were designated as sarcomas of myofibroblasts or myofibrosarcomas. The suitability of the alternative diagnostic label of myofibroblastic or matrix-secreting variant of leiomyosarcoma is discussed. Comparisons with similar tumors documented in the literature are drawn.

Actins↗
PubMedDate not supplied

Malignant epithelial mesothelioma of the peritoneum: observations on a problem case.

A 71-year-old asbestos-exposed male with symptoms suggestive of asbestosis for the previous 8 years presented with abdominal distension and ascites. Clinically, a diagnosis of mesothelioma carcinoma was made. Light microscopy of an omental biopsy failed to advance the diagnosis: The tumor was a solid, papillary, and glandular neoplasm lacking mucin and hyaluronidase-sensitive Alcian blue staining material. Immunohistochemistry gave positive results for Ber-EP4, LeuM1, and CEA, markers, favoring carcinoma. Electron microscopy revealed processes in channels and lumina, which were long, slender, and uncoated with a length: diameter ratio of 19.7. A few possessed small rootlets. A glycocalyx and glycocalyceal bodies were not seen. Other features included tonofibrils, a basal lamina, and desmosomes. The patient died 3 months following the onset of abdominal symptoms. Autopsy findings included solid and papillary tumor throughout the peritoneum, but no intrinsic tumor of the gastrointestinal tract or elsewhere. Arriving at a final diagnosis was complicated by immunohistochemistry, which favored carcinoma, and ultrastructure, which suggested mesothelioma. Taking into account all lines of evidence, it was concluded that the tumor was probably a mesothelioma but one with some features developed to an extent more typical of carcinoma.

Aged↗
PubMedDate not supplied

Intranodal myofibroblastoma: report of a case.

Palisaded myofibroblastoma (hemorrhagic spindle cell tumor) is a recent addition to the group of benign primary spindle cell lesions of lymph nodes. These tumors are characterized histologically by hemorrhage, palisading, and foci of collagen called amianthoid fibers. We report a further typical example with the aim of discussing its differentiation. Tumor cells were positive for smooth-muscle actin and vimentin. The cytoplasm contained moderate numbers of rough endoplasmic reticulum cisternae and some smooth-muscle type myofilaments. Subplasmalemmal densities and plasmalemmal caveolae, as well as material interpreted as external lamina, were identified at the cell surface, whereas the fibronexus junctions typical of myofibroblasts were not seen. Immunostaining for type IV collagen was positive. Intranodal myofibroblastomas have largely been considered as myofibroblastic, but the observations presented here raise the alternative possibility of simple smooth-muscle differentiation. The foci of collagen widely referred to as amianthoid fibers contained fibrils mostly of conventional diameter, 50-83 nm. The giant collagen fibrils typical of true amianthoid change were absent. It is suggested that the term amianthoid be used only after ultrastructural confirmation of the presence of giant collagen fibrils.

Humans↗
PubMedDate not supplied

[Idiopathic facial pain. Part 2: Treatment and prognosis].

The present paper introduces a new concept in the physiopathology and treatment of the called "temporomandibular disfunction". This paper was divided into two parts, the first explained the definition, etiology and hypothesis of the idiopathic facial pain. In this second part, its treatment, prognosis and recommendations are explained. The treatment consists basically in counselling, and, in a second stage, the use of tricylic antidepressants or similar drugs is used. Occlusal devices are some times used, but have been of less value. Arthroscopy can be used in resistant patients, and surgery is usually not indicated. The present management is based on a working model developed in this department and in other world centres, and is revolutionising the clinical management of the patients with idiopathic facial pain.

Facial Pain↗
PubMedDate not supplied

Successful combined orthotopic liver transplant and transcatheter management of atrial septal defect, patent ductus arteriosus, and peripheral pulmonic stenosis in a small infant with Alagille syndrome.

We report on a 4-kg infant with Alagille syndrome and congenital heart disease consisting of atrial septal defect (ASD), patent ductus arteriosus (PDA), and severe peripheral pulmonic stenosis. He underwent successful orthotopic liver transplant along with catheter closure of the ASD and PDA using the Amplatzer device and placement of Palmaz stents in both pulmonary arteries.

Alagille Syndrome↗
PubMedDate not supplied

Cryopreservation of Mediterranean fruit fly embryos.

In this paper we present a procedure to cryopreserve the embryos of a tephritid, the Mediterranean fruit fly (Ceratitis capitata), by vitrification. Developmental stages between 24 and 32 hours after oviposition were examined for tolerance to cryopreservation. Embryos, 27-hr-old and incubated at 29 C, were found to be at the most suitable stage for treatment. Effects of the previtrification steps of our protocol, dechorionation, permeabilization, cryoprotectant loading, and dehydration, on survival to hatching were also assessed. Dechorionation did not affect viability, while isopropanol and a hexane treatment used in the permeabilization step of the protocol reduced hatching by about 15%. This reduction was dependent on the amount of isopropyl alcohol carried over into the hexane rinse. The remaining previtrification steps reduced hatching by an additional 10%. After optimization of the procedure, normalized hatching was 44% after vitrification in liquid nitrogen vapor followed by storage under liquid nitrogen for a test period of 7 days. Post cryopreservation larval diets containing wheat bran, corncob grits, or agar as the base were examined for survival to pupation and emergence. A yield of 34% egg to adult emergence was obtained when the agar-based diet was used for rearing larvae that had experienced cryopreservation during the embryonic stage.

Animals↗
PubMedDate not supplied

Massive gastrointestinal bleeding in a patient with AIDS.

Cytomegalovirus enteritis can lead to gastrointestinal bleeding in patients with the acquired immune deficiency syndrome. The commonest site of involvement is the colon, followed by the stomach and terminal ileum. Most of these lesions can be diagnosed by colonoscopy or gastroscopy. We present our experience of a patient with cytomegalovirus infection involving only the proximal jejunum causing massive lower gastrointestinal bleeding. Conventional endoscopy and imaging had failed to locate the source of bleeding. Enteroscopy performed at the time of laparotomy showed an ulcerated lesion in the jejunum. Resection followed by histological examination of the resected area confirmed the diagnosis of cytomegalovirus infection. In addition to highly active antiretroviral therapy, ganciclovir was given for 14 days in a dose of 5 mg/kg twice a day and tapered over a period of 3 months. There has been no further episode of gastrointestinal bleeding over a follow up of 9 months.

Acquired Immunodeficiency Syndrome↗
PubMedDate not supplied

Conscious sedation and analgesia with rectal ketamine in the Macaca fuscata monkey.

Conscious sedation is commonly utilized in pediatric dentistry. Although opioid analgesics are often employed, patient safety would be enhanced if nonopioid drugs were used. The purpose of this study was to determine if rectal ketamine could produce plasma concentrations that would achieve both conscious sedation and analgesia to gingival needle puncture. Five 2-year-old male Macaca fuscata monkeys were given rectal ketamine at a dosage of 60 mg/kg and 90 mg/kg one week apart. Blood was drawn at selected times after administration, and vital signs, level of sedation, and consciousness were assessed. Plasma ketamine concentrations ranged from 240 to 820 ng/mL and from 390 to 3120 ng/mL after rectal administration at doses of 60 mg/kg and 90 mg/kg, respectively. Two monkeys after the high dose showed analgesia to a gingival needle puncture at plasma ketamine concentrations that ranged from 1390 to 3120 ng/mL. A good level of sedation was consistently observed in four monkeys (80%) following rectal ketamine at a dosage of 90 mg/kg, whereas one monkey showed a consistently good level at a dosage of 60 mg/kg. Sedation and dose were significantly (P less than 0.001) associated with plasma ketamine concentrations; physiologic parameters were not (P greater than 0.05). The results of this study suggest that rectal ketamine can produce plasma concentrations of the drug sufficient to achieve sedation in the monkey. The attainment of concomitant analgesia to a gingival needle puncture was not as predictable.

Analysis of Variance↗
PubMedDate not supplied

Anne Affeman.

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Cultural Characteristics↗