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Biomedical subjects

V M Phillips

Publications and source records attributed to V M Phillips.

At least 37 records · Page 2Linked to original sources
PubMed1990

Odontoameloblastoma: a case report.

Confusion in the early literature regarding the odontoameloblastoma, resulted in this tumour being reported under a variety of names. Many of the reported cases fail to meet the clinical and histological criteria required for classification as odontoameloblastomata. This article attempts to present a case with clinical, radiological and histological features that meet the required criteria. In this case the ameloblastic component intermingled with the dental hard tissues.

Adult↗
PubMed1990

Collagen in submucous fibrosis: an electron-microscopic study.

A comparison of the electron-microscopic features of 11 examples of submucous fibrosis in its moderately advanced and advanced stages with 15 control specimens revealed no obvious abnormality of the collagen fibrils. The notable feature of the collagen in this disease is the densely packed bundles in the lamina propria, reaching close to the epithelial-connective tissue junction, to blood vessel walls, salivary glands and muscle fibers. The width and the periodicity of fibrils vary in both groups of specimens, noticeably so, next to the junction and close to blood vessels, salivary glands and muscles. This is due to the presence of the thinner Type III collagen fibrils in these sites and the natural variation of Type I fibrils. Immunofluorescent microscopy and special staining with sirius red and polarization microscopy demonstrate both types, confirming that Type I collagen forms the bulk of the collagen and that Type III is localized in the sites mentioned above. It is concluded that although there is an excessive increase of collagen, especially Type I, in submucous fibrosis, the fibrils are still morphologically normal.

Collagen↗
PubMed1990

Corticosterone 6 beta-hydroxylase in A6 epithelia: a steroid-inducible cytochrome P-450.

We found microsomal corticosterone 6 beta-hydroxylase (6 beta-OHase) from cultured A6 kidney epithelial cells to be a cytochrome P-450 enzyme with both similarities to and differences from the rat liver steroid 6 beta-OHase P-450p. Enzyme activity was inhibited by CO, alpha-naphthoflavone, metyrapone, and clotrimazole, well-known inhibitors of P-450 enzymes, and increased by known inducers of P-450 enzymes, including dilantin, phenobarbital sodium, and corticosteroids. Moreover, some additional, relatively specific inducers of P-450p (troleandomycin and pregnenolone-16 alpha-carbonitrile) also induced the A6 6 beta-OHase, whereas inducers of other forms of P-450 (aroclor, spironolactone, and isosafrole) appeared to repress the A6 enzyme. The time course of increase in enzyme activity and increased cellular cytochrome P-450 content were consistent with increased levels of enzyme protein. Induction of 6 beta-OHase by the substrate (corticosterone), the metabolite (6 beta-OH-corticosterone), dexamethasone, and aldosterone was biphasic as a function of inducer concentration, with approximate 50% effective concentration (EC50) values of 10(-8)-10(-9) M and 10(-5)-10(-6) M for the respective components of induction. Cortisol also induced the enzyme at 10(-8)-10(-6) M; however, its metabolite 6 beta-OH-cortisol was ineffective or decreased activity at higher concentrations.(ABSTRACT TRUNCATED AT 250 WORDS)

Aldosterone↗
PubMed1990

Comparison between fingerprint and dental concordant characteristics.

Twelve concordant characteristics are used in fingerprint identification. The South African courts of law are prepared to accept 7 concordant characteristics as being "beyond reasonable doubt" in the case of finger, hand and foot prints. In cases of identification by dental means, 12 concordant features have been advocated. In South Africa, with its mixed population in which a large majority have dental formulae containing normal decayed and missing teeth, these patterns show duplication and triplication. It is feasible to submit 7 concordant dental characteristics as positive identification in a mouth containing dental restorations, but in a mouth which features only missing teeth, pattern duplication demands more than 12 concordant characteristics for positive identification. Seven concordant dental characteristics have not been tested in the South African courts to date.

Dental Records↗
PubMed1990

A grave matter--dental findings of people buried in the 19th and 20th centuries.

The exhumed remains of 181 people, buried during the period 1848-1984 were examined. Because of the carelessness of exhumations, only 125 yielded sufficient information to compare the condition of skulls and jaws with the period in the grave, while 63 yielded information about the teeth. No correlation could be shown between the condition of the skulls and jaws and the period interred, but it was found that the better preserved remains belonged to younger people. Dental findings included the presence of healthy and decayed teeth, gold foil restorations, gold and porcelain inlays, amalgam and silicate fillings, and vulcanite and acrylic dentures. Amalgam restorations were present in people buried from 1875 (114 years ago) and vulcanite dentures from 1882 (107 years ago). The characteristics of the earliest amalgam restorations showed that they could have been placed before 1850. Findings of this study indicate that: (a) one cannot on the appearance of exhumed remains estimate the burial period, (b) dental features were well preserved and can be used for dental identification if antimortem data are available, (c) advanced dentistry could have been practised in South Africa during the last century, and (d) recovery of human skeletal remains from old cemeteries should be undertaken with care to preserve as much information as possible. A plea is made for closer co-operation between developers of old graveyard sites and scientists in order to preserve as much information as possible.

Burial↗
PubMed1989

Granulomatous cheilitis. A review and report of a case.

The Melkersson-Rosenthal syndrome (MRS) is a rare triad of unilateral facial paralysis, facial swelling, and fissured tongue; often only two of the components are manifest. The occurrence of swollen lips together with the characteristic microscopic appearance is called granulomatous cheilitis, which many believe is the oligosymptomatic form of MRS. This article reviews the literature on granulomatous cheilitis associated with MRS. An unusual case of a swollen upper lip together with a fissured tongue, strongly indicating the oligosymptomatic manifestations of MRS, is presented.

Adult↗
PubMed1989

The treatment and prognosis of oral precancer and cancer.

Oral cancer is an area of oncology that epitomises the need for a multidisciplinary approach. It involves many different sites, each with its own capacity to disseminate disease and to respond to medical therapy and rehabilitation. Within each site are various stages of spread that can be approached with different combinations and sequences of surgery, radiation and chemotherapy. In many areas various therapeutic options exist; however, it has not yet been clearly established which modality or sequence of modalities is optimal. Only continual clinical research will resolve the existing conflicts and questions.

Humans↗
PubMed1987

The effects on 4-aminoantifolates on 5-formyltetrahydrofolate metabolism in L1210 cells. A biochemical basis of the selectivity of leucovorin rescue.

This report describes studies designed to evaluate possible inhibitory effects of diaminoantifolates on folate-dependent biosynthetic enzymes in intact L1210 leukemia cells. A novel approach is described which involves an assessment of the metabolism of and biosynthetic flux of the one-carbon moiety from (6S)5-formyltetrahydrofolate in folate-depleted cells. Pretreatment with methotrexate (10 microM), resulting in the formation of methotrexate polyglutamates, or continuous incubation with trimetrexate (1 microM) inhibited growth of folate-depleted L1210 cells in the presence of folic acid or 5-formyltetrahydrolate. In both control and drug-treated cells, double-labeled (6S)-5-[14C]formyl[3H]tetrahydrofolate was rapidly metabolized with the loss of the [14C]formyl group. Under all conditions, the predominant metabolite was 10-formyl[3H]tetrahydrofolate, detectable both intracellularly and extracellularly. In drug-treated cells, there was a remarkably small decrease in the level of 10-formyl[3H]tetrahydrofolate (approximately 30%) and a 10-fold rise in the level of [3H]dihydrofolate to less than 20% of the total folate pool. The incorporation of [14C]formyl group from 5-[14C]formyltetrahydrofolate into thymidylate, serine, and methionine was unaffected by the presence of 1 microM trimetrexate, consistent with the generation of sufficient 5,10-[14C]methylenetetrahydrofolate to drive these reactions. Similarly, the presence of methotrexate polyglutamates had no effect at the level of amino acid synthesis; however, carbon transfer into thymidylate was markedly inhibited. Even though 10-formyltetrahydrofolate was readily formed from 5-formyltetrahydrofolate in this model, the net incorporation of 14C from 5-[14C]formyltetrahydrofolate into purine nucleotides was inhibited by both methotrexate and trimetrexate treatments. Similar findings were obtained when [14C]glycine incorporation into purine nucleotides was monitored in cells incubated with unlabeled 5-formyltetrahydrofolate. Finally, in antifolate-treated cells incubated with unlabeled 5-formyl-tetrahydrofolate, transfer of 14C from [14C]formate or [14C]serine into biosynthetic products or incorporation of [3H]deoxyuridine into nucleic acids was potently inhibited. These results suggest that insufficient levels of tetrahydrofolate and 5, 10-methylenetetrahydrofolate were formed to drive these reactions despite the presence of high levels of 10-formyltetrahydrofolate.(ABSTRACT TRUNCATED AT 400 WORDS)

Adenosine↗
PubMed1986

Percutaneous needle biopsy in the diagnosis and classification of lymphoma.

Results of percutaneous needle biopsies were evaluated retrospectively in 58 patients in whom a diagnosis of lymphoma was suspected. The biopsy specimen was diagnostic in 94% of the 36 patients with lymphoma, 20 of whom had recurrent disease and 16 of whom had newly diagnosed lymphoma. Sufficient tissue was obtained in 94% of these positive biopsy specimens to allow histologic subtyping of the lymphoma. Immunohistochemical studies performed on seven of the biopsy specimens allowed immunologic subclassification into B-cell and T-cell types of lymphoma. Our results suggest that the percutaneous needle biopsy is a useful and reliable tool in the diagnosis and classification of lymphoma.

Adolescent↗
PubMed1985

Percutaneous biopsy of pancreatic masses.

Forty-five percutaneous needle biopsies of pancreatic masses were performed in 41 patients in whom there was clinical or radiological concern for the diagnosis of cancer. Computed tomography (CT) was the imaging technique used in 41 of the 45 biopsies. An overall sensitivity of 85%, specificity of 100%, and accuracy rate of 88% were achieved, with serious complications in three of the 45 attempts (6.7%). These figures show that percutaneous pancreatic biopsies have the potential for greater accuracy than has been previously reported and are relatively safe when compared with surgery.

Adult↗
PubMed1985

Imaging guided percutaneous hepatic biopsy: diagnostic accuracy and safety.

During the 3-year period from May 1981 to June 1984, 145 patients with hepatic abnormalities demonstrated by computed tomography (CT) or ultrasonography (US) underwent 151 imaging guided percutaneous hepatic biopsies. These biopsies were performed with needles ranging in size from 21-gauge aspiration to 14-gauge cutting type. Histologic and cytologic results were correlated with subsequent surgical, autopsy, and clinical follow-ups ranging from 2 months to 3 years. The overall accuracy for imaging-guided biopsies was 92.1% and 98% for diagnosis of malignant lesions. Our complication rate of 1.3% is comparable to that reported in other studies. We discuss indications, techniques, and risks for imaging-guided percutaneous hepatic biopsy.

Adolescent↗
PubMed1985

CT densities in delayed iodine hepatic scanning.

Sixty patients underwent CT scanning of the liver prior to, immediately after, and four hours after intravenous administration of 60% meglumine diatrizoate. Twenty patients received a 50 ml bolus of contrast material (14.6 g of iodine), 20 received 100 ml (29.2 g of iodine), and 20 received 200 ml (58.4 g of iodine). In each group, delayed CT scanning safely raised the inherent density of the liver significantly (increase of 14.3% using 50 ml; 23.9% using 100 ml; and 40.7% using 200 ml). Thus, delayed scanning with doses presently used in abdominal and neurological CT examinations may be helpful in detecting hepatic lesions.

Diatrizoate↗
PubMed1985

CT-guided adrenal biopsy: accuracy, safety, and indications.

Fifty-eight percutaneous needle biopsies of adrenal masses were performed in 53 patients. The technique was initially successful in 44 (83%) of 53 patients. Five patients had second procedures because of initial failure or the possibility of sampling error. Fourteen biopsies were performed in nononcologic patients and 39 in patients with a known malignancy. None of the adrenal masses in nononcologic patients were malignant. Only 18 (46.1%) of the 39 masses in oncologic patients were metastases; the rest represented a variety of nonneoplastic conditions. Seven minor complications occurred in six patients. Two of these patients required transfusions for hypotension or decreases in hematocrit. No correlation was noted between needle size and complications. There were no pneumothoraces. The procedure is an accurate and safe alternative to surgical biopsy.

Adrenal Gland Diseases↗
PubMed1984

Percutaneous hepatic biopsy in suspected pancreatic carcinoma.

Pancreatic neoplasms often present with hepatic lesions as well as a pancreatic mass, as seen on abdominal computed tomography examination. To obtain histologic diagnosis, we advocate computed tomography-directed biopsy of the liver lesion instead of the pancreatic mass because of the increased accuracy and safety of hepatic biopsy as compared with pancreatic biopsy.

Adenocarcinoma↗