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Biomedical subjects

C M Allen

Publications and source records attributed to C M Allen.

At least 91 records · Page 5Linked to original sources
PubMed1991

Dolichol biosynthesis in human malignant cells.

Cholesterol, ubiquinone and dolichol biosynthesis from mevalonic acid was measured in non-malignant and malignant cultured human lymphocytes, freshly isolated human mononuclear leucocytes and in cultured human hepatoma cells. The relative flux of mevalonate into ubiquinone, dilichol and cholesterol was not significantly different between malignant and non-malignant cells, although the extent of labelling of each product was an order of magnitude greater in the malignant cultured cells. The most prominent dolichol isolated from total cellular lipid and synthesized in short-term labelling of cultured leukaemic cells had a chain length one isoprene unit shorter than that observed in normal human cells. Cultured human hepatoma cells and mononuclear leucocytes isolated from the peripheral blood of individuals with lymphoblastic and myelogenic leukaemia similarly synthesized shorter-chain dolichols. The dolichols made in cultured non-tumorigenic cells, freshly isolated mononuclear leucocytes from a normal individual or a patient with non-haematological malignancy had normal chain length.

Carcinoma, Hepatocellular↗
PubMed1991

Restraint stress differentially affects anti-viral cellular and humoral immune responses in mice.

Physical restraint administered to C57BL/6 mice significantly altered the inflammatory response to influenza virus infection and depressed anti-viral cellular immunity. Restraint-stressed animals showed a pattern of reduced mononuclear cell infiltration and lung consolidation which coincided with elevated plasma corticosterone levels. Furthermore, cellular immunity to virus was significantly depressed; interleukin-2 secretion was reduced by 96% and 59% in the mediastinal lymph nodes and spleens, respectively, as compared to a non-restrained group. However, the magnitude of the humoral immune response to influenza virus was unaffected by restraint stress. Anti-viral IgG antibody levels in restrained/infected mice did not differ when compared to a non-restrained/infected control group 14 days post-infection.

Animals↗
PubMed1991

Tuberculous broncho-oesophageal fistula in the acquired immunodeficiency syndrome.

Mycobacteria are the most common bacterial infections occurring in AIDS patients. Although the gastrointestinal tract is commonly involved, there has been only one case report of oesophageal infection. We report a patient in whom oesophageal tuberculosis was the presenting feature of AIDS and review the features of mycobacterial infections in AIDS. The incidence of extrapulmonary infection is common and mycobacterial oesophagitis should be considered in the differential diagnosis of oesophagitis in AIDS.

Acquired Immunodeficiency Syndrome↗
PubMed1990

Cheilitis granulomatosa: report of six cases and review of the literature.

Six cases of cheilitis granulomatosa, a rare inflammatory disorder of unknown origin, are reported. The condition produces nontender, persistent swelling of one or both lips and affects primarily young adults. Histologically, nonnecrotizing granulomatous inflammation is seen. The clinical findings and results of therapy in these six cases are presented. One patient was treated with hydroxychloroquine sulfate (Plaquenil) that stabilized the process. One of our patients had vesicular-appearing lesions. Microscopic examination showed the lesions to be dilated superficial lymphatic channels, a finding that to our knowledge has not been previously described.

Adult↗
PubMed1990

A method for counting leukocytes in filtered components.

Leukocyte-depleted components are being used more frequently. Quantitation of residual WRCs is needed for quality control and for establishing the critical level required to prevent alloimmunization. Electronic counting is not accurate at WBC levels below 100/microL (1) and previously proposed techniques are either tedious or require sophisticated equipment. We describe a simple hemacytometer procedure using Türks solution that gives 87-93% recovery at WBC levels below 40/microL.

Filtration↗
PubMed1990

Diphtheritic polyneuritis in an elderly woman: clinical and neurophysiological follow-up.

A 71-year-old English lady initially presented with a bulbar paralysis and, six weeks later, developed a generalised sensori-motor neuropathy. Corynebacterium diphtheriae mitis was cultured from her throat swab. Despite a good clinical recovery at one month, nerve conduction velocity was at its lowest. As far as the authors are aware, this is one of the few cases of neurophysiological and clinical follow-up in a British subject with diphtheritic peripheral neuropathy. This case emphasises the importance of giving antitoxin early.

Adrenocorticotropic Hormone↗
PubMed1989

Dehydrodolichyl diphosphate synthase in Sertoli and spermatogenic cells of prepuberal rats.

The specific activity of 2,3-dehydrodolichyl diphosphate synthase in homogenates of protease-treated seminiferous tubules, enriched spermatogenic cells, and Sertoli cells changed as a function of the age of prepuberal rats. The highest enzymatic activity occurred in each case in 23-day-old rats. Homogenates of pachytene spermatocytes, spermatids, or Sertoli cells had higher synthase activity than a whole testicular homogenate prepared by protease treatment of tubules. Enzymatic activity in pachytene spermatocytes expressed per mg of protein was about 1.7-fold higher than in spermatids, 5.3-fold higher than in spermatogonia, and about 8.3-fold higher than in spermatozoa. Therefore, the increase in spermatogenic cell synthase before day 23 can be accounted for by the appearance of the pachytene spermatocytes. Enzymatic activity decreased remarkably after the differentiation of spermatids into spermatozoa. Synthase activity in enriched Sertoli cell preparations was 1.5-2.3-fold higher than in spermatogenic cell preparations between days 15 and 30. Therefore, both spermatogenic cells and Sertoli cells contribute to changes in the enzymatic activity in seminiferous tubules during development. These changes may be important in regulating the availability of dolichyl phosphate for glycoprotein synthesis during early stages of differentiation.

Age Factors↗
PubMed1989

Early soft tissue ingrowth into porous block hydroxyapatite.

A dog model was used to determine the rate of soft tissue infiltration into porous block hydroxyapatite (PBHA) in order to provide a scientific basis for treatment of exposed implants. Ten mongrel dogs underwent alveolar ridge augmentation with PBHA and were killed at various times up to 21 days. Significant soft tissue ingrowth had occurred by 14 days and was complete by day 21. Bone formation was also seen as early as 14 days.

Alveolar Ridge Augmentation↗
PubMed1989

Clinical, histologic and scanning electron microscopic study of the development of chronic candidiasis of the rat tongue.

In order to examine the development of the chronic candidal lesion of the dorsal rat tongue, 210 rats were given a single oral inoculum of Candida albicans on Day 0 and were sequentially killed over a 20-wk period. Dorsal tongue changes were evaluated using clinical photographs, histologic sections and scanning electron microscopy (SEM). Clinically evident lesions became apparent at 2 wk post-inoculation, and inflammatory changes of the underlying connective tissue were observed by 3 wk post-inoculation. SEM showed a gradient of destruction of the dorsal tongue papillae at the periphery of the candidal lesions. Hyphae were seen infrequently on the lesional surface by SEM, a finding which correlated with the light microscopy.

Animals↗
PubMed1989

Dentinal dysplasia type I: a report of four cases.

Dentinal dysplasia type I is a relatively uncommon condition and four cases are described. The radiographic features in these patients are somewhat different to those reported in other cases in that anterior teeth appeared to be less affected than posterior, and tooth loss was less prevalent. These findings support the proposal that the characteristics of dentinal dysplasia type I can be divided into two subgroups.

Adult↗
PubMed1989

Pyostomatitis vegetans. Report of a case and review of the literature.

This report describes a 39-year-old woman with pyostomatitis vegetans and ulcerative colitis. Pyostomatitis vegetans is a rare eruption of the oral cavity characterized by tiny yellow pustules coating the surface of the friable eroded mucosa. It is considered a marker for inflammatory bowel disease. In a review of the literature, 19 of 26 cases (73%) reported were associated with gastrointestinal disturbances, predominantly inflammatory bowel disease.

Adolescent↗
PubMed1988

Cabbages and CABG.

Explore the source record for details and available documents.

Brain Diseases↗
PubMed1988

Changes in dehydrodolichyl diphosphate synthase during spermatogenesis in the rat.

The levels of dolichyl phosphate and 2,3-dehydrodolichyl diphosphate synthase were determined in seminiferous tubules of prepuberal rats to assess any changes occurring during early stages of spermatogenesis. Dolichyl phosphate increased in concentration two- to threefold from Day 10 to Day 23 after birth. A method was optimized to measure dehydrodolichyl diphosphate synthesis from delta 3-[14C]isopentenyl diphosphate and t,t-farnesyl diphosphate in homogenates of seminiferous tubules. Both dehydrodolichyl mono- and diphosphates were observed as products of the in vitro assay. The specific activity of tubular synthase increased twofold between Day 7 and Day 23 and decreased similarly between Day 23 and Day 60. Since there was a parallel increase in the concentration of tubular dolichyl phosphate and dehydrodolichyl diphosphate synthase activity during early stages of spermatogenesis, it is proposed that the level of dolichyl phosphate may be controlled at least in part by the regulation of de novo dehydrodolichyl diphosphate biosynthesis. The synthase was also solubilized from tubular membranes with deoxycholate and partially purified by chromatography.

Age Factors↗
PubMed1988

Resolution of candidal lesions of the dorsal rat tongue by ketoconazole.

The purpose of this study was to determine whether the mucosal alterations of the dorsal rat tongue produced by Candida albicans infection were reversible upon treatment with the antifungal drug ketoconazole. Following experimentally-produced infection, 17 rats showed clinical evidence of persistent lesions over a period of 20 weeks. Eight of these animals were then treated with ketoconazole daily for 2 weeks (20 mg/kg/day). Appropriate non-infected controls and ketoconazole-only controls were also maintained. Five weeks after the ketoconazole treatment, all animals were killed and the dorsal tongues evaluated clinically and histologically. Control groups showed no abnormalities. Of the 8 animals in the treated-lesion group, all showed lesional resolution, while only 2 of the 9 animals in the untreated-lesion group showed resolution of their lesions (p = 0.002). These findings indicate that the epithelial changes produced by this candidal isolate for this period of time are reversible.

Animals↗