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Biomedical subjects

J Mann

Publications and source records attributed to J Mann.

At least 415 records · Page 23Linked to original sources
PubMed1967

Growth and intracellular development of a new respiratory virus.

The multiplication of a new, ether-sensitive, ribonucleic acid virus, 229E, isolated from the human respiratory tract, has been studied in cultures of WI-38 human diploid cells. In thin sections of these cells examined with the electron microscope, particles appeared in vesicles in the cytoplasm of cells at a time corresponding to the initial increase in infectious virus. Antigen was also detected in the cytoplasm of cells by the immunofluorescent technique. Extracellular particles of similar morphology were prominent soon after. These events preceded a detectable cytopathic effect. Later, an electron-dense particle appeared within vacuoles in the cytoplasm but was never found extracellularly. Its role in virus development is not known. Complement-fixing antigen developed along with the increase in infectious virus.

Cell Line↗
PubMedDate not supplied

Assessing tumor angiogenesis using macromolecular MR imaging contrast media.

MRI enhanced with a macromolecular contrast medium (MMCM) has previously been shown to estimate tumor microvascular characteristics that correlate closely with histologic microvascular density, an established surrogate of tumor angiogenesis. A similar MMCM-enhanced MRI technique has now been used to investigate the acute tumor microvascular effects of antibody-mediated inhibition of vascular endothelial growth factor (VEGF), a well-studied and potent angiogenesis stimulator. Athymic rats xenografted with a human breast carcinoma (MDA-MB-435) were imaged after administration of albumin-gadolinium diethylenetriamine pentaacetic acid (Gd-DTPA30) using a heavily T1-weighted three dimensional-spoiled gradient-refocused acquisition in a steady-state pulse sequence before and 24 hours after treatment with anti-VEGF antibody (single dose of 1 mg). Changes in longitudinal relaxivity (delta R1) were analyzed using a bidirectional two-compartment kinetic model to estimate tumor fractional blood volume (fBV) and permeability surface area product (PS). Data showed a significant decrease (P < 0.05) of tumor PS with respect to macromolecular contrast medium at 24 hours after treatment with anti-VEGF antibody. No significant change was observed in fBV. Suppression of tumor microvascular permeability induced by anti-VEGF antibody can be detected and quantified by MMCM-enhanced MRI. MRI grading of tumor angiogenesis and monitoring of anti-angiogenesis interventions could find wide clinical application.

Animals↗
PubMedDate not supplied

Synthesis and evaluation of analogues of 4-androstene-3,17-dione as aromatase inhibitors.

Twenty-three synthetic analogues of 4-androstene-3,17-dione (androstenedione) have been evaluated as inhibitors of human placental microsomal aromatase enzyme. Among the most potent of these compounds were the 4-hydroxy, 6 alpha-fluoro, 6 beta-fluoro, and 4-fluoroandrostenediones and 4-fluoro-19-nor-4-androstene-3,17-dione. 4-Hydroxy-4-androstene-3,17-dione (4HAD) is an irreversible inhibitor of aromatase in vitro, whereas the four fluoro analogues are reversible inhibitors. 4HAD and 4-fluoro-4-androstene-3,17-dione caused significant regression of the nitrosomethylurea-induced mammary tumor in rats, but the other fluoro derivatives were inactive.

Androstenedione↗
PubMedDate not supplied

Rational drug treatment of the hypertensive diabetic with nephropathy.

Development of hypertension in Type I diabetics parallels evolution of nephropathy. In Type II diabetics, excessive prevalence of hypertension prior to the appearance of proteinuria suggests that factors other than nephropathy are operative in its pathogenesis. On the other hand, the risk of nephropathy in Type II diabetics is higher than previously appreciated. Recent evidence suggests that angiotensin II plays an important role in the induction and progression of diabetic nephropathy. This provides a rationale for antihypertensive therapy with converting enzyme inhibitors in nephropathic diabetics in whom they have been shown to lower blood pressure and diminish proteinuria. Furthermore, in a retrospective study of patients with various renal diseases (including diabetic nephropathy), the authors found suggestive evidence that converting enzyme inhibitors may also attenuate progression of renal failure to a greater extent than other antihypertensive drugs.

Antihypertensive Agents↗
PubMedDate not supplied

Oral health status and dental needs of an autistic population of children and young adults.

Behavior of patients with autistic syndrome makes delivery of oral hygiene and dental treatment a problem. In this study, the oral health and needs of two groups of patients with autism were evaluated: noninstitutionalized children with a mean age of 11 and institutionalized adults with a mean age of 22. The latter group had severe periodontal problems; almost half required periodontal surgery. Many of the children also needed periodontal treatment. Adults were found to have lower decayed, missing, and filled teeth (DMFT) scores than functionally independent Israeli persons of the same age. This finding was surprising because institutionalized adults are predisposed to development of dental caries; they frequently consume sweets, have poor oral hygiene, and do not use fluoride. Noninstitutionalized children with autism had caries rates that were similar to rates of functionally independent peers.

Adolescent↗
PubMedDate not supplied

Caries levels, Streptococcus mutans counts, salivary pH, and periodontal treatment needs of adult Down syndrome patients.

The prevalence of dental caries and periodontal treatment needs in an institutionalized Down syndrome (DS) population was examined as well as the relationship between caries prevalence, salivary pH and salivary levels of Streptococcus mutans. Twelve patients with DS, aged 20 to 48, were compared with two similar age and gender control groups: healthy, and non-Down institutionalized mentally retarded patients. The pH levels did not differ significantly among the three groups. As to periodontal needs expressed by the CPITN, the institutionalized groups had the highest needs compared with the healthy group. Down adults, who were cariesfree, had significantly lower S. mutans counts compared with the patients with caries. In addition, the cariesfree patients with DS had much lower CPITN scores compared with the patients with caries.

Adult↗
PubMedDate not supplied

Caries experience, periodontal treatment needs, salivary pH, and Streptococcus mutans counts in a preadolescent Down syndrome population.

The prevalence of dental caries and periodontal treatment needs in an institutionalized population with Down syndrome was examined and the relationship between caries prevalence, salivary pH, and salivary levels of Streptococcus mutans was studied. Thirty-two children with Down syndrome, aged 8 to 13, were compared with two control groups of similar age ranges: healthy children and non-Down mentally retarded (MR) children living in the same institution as the Down syndrome population. The gender ratio mixtures in each group also matched the study sample. Caries experience as indicated by decayed, missing, and filled surfaces (DMF-S) showed significantly lower mean scores for the Down syndrome group compared with both control groups. A similar pattern was found when evaluating the mean numbers of decayed surfaces. Streptococcus mutans counts, expressed as number of colony-forming units on mitis salivarius agar plates among the Down syndrome group, were the lowest, although not statistically significant compared with the counts of the healthy children. Both groups had bacterial counts which were significantly lower than those of the MR group. Significant differences between the two institutionalized groups and the healthy group were recorded for the salivary pH levels. The periodontal treatment needs as evaluated by the Community Periodontal Index of Treatment Needs showed significant difference between the MR group versus both the healthy population and the Down syndrome group. On the whole, 84% of the Down syndrome children were cariesfree.

Adolescent↗