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Biomedical subjects

A Meyers

Publications and source records attributed to A Meyers.

At least 37 records · Page 2Linked to original sources
PubMed1995

Wound healing after laser surgery.

Compared with scalpel wounds, CO2 laser wounds show delays in inflammation, collagen production, reepithelialization, and tensile strength in the early stages of healing. Some of these delays are similar to those seen with electrocautery and burn wounds. Later stages compensate for these early deficiencies, because scalpel and laser wounds become more similar in epithelialization and wound strength over time. Healed CO2 laser wounds tend to have less scar contraction than scalpel wounds. Débridement of initial laser wound char, tissue cooling techniques during lasering, and pulsed modes of laser delivery all seem to result in more rapid, favorable healing. Similar wound healing trends have been seen with the CO2 laser in bone, with other lasers, and with laser vascular and neural anastomosis. Biostimulation with low-level laser energy is a complex subject of ongoing investigations.

Anastomosis, Surgical↗
PubMed1994

Establishment of human parotid pleomorphic adenoma cells in culture: morphological and biochemical characterization.

This study reports the establishment of alpha-amylase-producing human parotid pleomorphic adenoma cell lines (2HP and 2HP1) which have been maintained in culture for over 1 yr. The procedures required preparation of cellular clumps from tumor tissue and plating them on plasma clot or precoated dishes. During the initial phase of growth they required modified MCDB-153 medium without serum. When cells showed signs of degeneration they were changed to MCDB-153 medium containing first 2% and then 10% heat inactivated fetal bovine serum. Although cells grew well in MCDB-153 containing 10% serum, the epithelial cell morphology was not distinct. Therefore, the growth and morphology of cells grown in MCDB-10% serum were compared with those in RPMI growth medium containing 10% fetal bovine serum and F12 containing 10% agammaglobulin newborn bovine serum. Although the growth of cells was a little slower in F12 medium than those in MCDB and RPMI, the epithelial cell morphology was maintained better than in other growth media. The cells of 2HP and 2HP1 produce low levels of alpha-amylase and relatively high levels of alpha-amylase mRNAs of 1176 and 702 bp and contain neurofilament-160, a neuronal-specific marker. The cells of 2HP1 are tumorigenic when tested in athymic mice, but the cells of 2HP are not. The establishment of amylase-producing human parotid adenoma cell lines of different characteristics in culture provides a new opportunity to study the mechanisms of differentiation and transformation, and regulation of alpha-amylase in these cells.

Adenoma, Pleomorphic↗
PubMed1994

Fluid and electrolyte therapy for children.

The major disorder of water and electrolyte metabolism in children is dehydrating diarrhea. The major advance in the treatment of this condition has been the development of oral rehydration therapy, ie, the enteral administration of a balanced glucose-electrolyte solution. This therapy is effective in patients of all ages, dehydration of all degrees short of hypovolemic shock, with gastroenteritis of all causes, and electrolyte disturbances including hypo- and hypernatremia. This review highlights current experimental and clinical studies that have focused on oral rehydration solutions that have the additional benefit of reducing the severity and duration of diarrheal disease. Recent results have been conflicting, however, and the search for the optimal solution continues.

Child↗
PubMed1993

Vitamins regulate gene expression and induce differentiation and growth inhibition in cancer cells. Their relevance in cancer prevention.

Although several hypotheses for human carcinogenesis have been proposed, the specific genetic changes that cause normal cells to become cancer cells have not been identified. In spite of uncertainties regarding the mechanisms of carcinogenesis, several vitamins such as beta-carotene and vitamins A, C, and E, which can reduce the risk of cancer, have been identified, using animal and in vitro models of carcinogenesis. These studies have led to a hypothesis that the supplemental intake of these vitamins may reduce the risk of cancer. This hypothesis in humans can be tested only by intervention trials that are in progress. Prospective and retrospective case-controlled experimental designs are not suitable for testing the above hypothesis. The fact that some vitamins induce cell differentiation and/or growth inhibition in tumor cells in culture suggests that the use of these vitamins in cancer prevention has a cellular basis. In addition to having a direct effect on tumor cells, vitamins such as alpha-tocopheryl succinate and beta-carotene enhance the effect of other agents that induce differentiation in tumor cells. Some vitamins like beta-carotene, retinoic acid, alpha-tocopheryl succinate, and vitamin D also regulate the expressions of certain oncogenes and cellular genes. These are exciting new functions of vitamins that nobody could have predicted only a few years ago.

Animals↗
PubMed1993

Chronic hyperplastic sinusitis: association of tissue eosinophilia with mRNA expression of granulocyte-macrophage colony-stimulating factor and interleukin-3.

BACKGROUND: We investigated the association among tissue eosinophilia, cellular infiltration, and cytokine mRNA expression in chronic hyperplastic sinusitis (CHS). METHODS: Percutaneous biopsies of the maxillary sinuses and nasal polyps were performed in 12 adult patients (six men and six women) of whom seven were nonallergic and 11 were asthmatic. Tissues were compared with biopsy specimens from the inferior and middle turbinates of normal control subjects. RESULTS: Histologically, an eosinophil-predominant inflammatory infiltrate was seen in 10 of 12 patients, whereas a mild to moderate neutrophilic infiltrate was seen in 4 of 12 patients. As determined by immunocytochemistry, diseased tissues and normal control tissues differed significantly in terms of the number of activated (EG2+) eosinophils (p = 0.005) but not in terms of CD3+ or CD4+ T lymphocytes, elastase-positive neutrophils or CD68+ macrophages. The number of eosinophils did not correlate with that of any other cell type. By in situ hybridization, CHS tissues showed significantly higher numbers of granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin (IL)-3 mRNA-positive cells than normal control tissues (p = 0.002 and 0.0005, respectively) per high-powered field. There was a significant correlation between the number of infiltrating EG2+ eosinophils and cells that expressed mRNA for GM-CSF (r = 0.60, p = 0.041) or IL-3 (r = 0.69, p = 0.013). Furthermore, epithelial cells did not show detectable mRNA expression for GM-CSF or IL-3. No significant correlation was found between IL-5 mRNA expression and infiltrating EG2+ eosinophils in diseased tissues. However, the IL-5 density was significantly higher in the five patients with CHS who had positive allergy skin test results than in the seven patients with negative skin test results (p = 0.017) or in normal control subjects. CONCLUSIONS: Our data support a role for GM-CSF and IL-3 in the eosinophilia characteristic of CHS and show that IL-5 mRNA expression is not a prominent feature of nonallergic inflammation. The cellular sources of GM-CSF and IL-3 in CHS remain to be definitely determined.

Adult↗
PubMed1993

The effect of protein kinase C modulators on endogenous protein phosphorylation in primate kidney.

The effects of modulators of protein kinase C on protein phosphorylation were studied in primate kidney. Phosphorylation of specific proteins, investigated using electrophoresis and autoradiography, indicated that in the absence of modulators eight major proteins were phosphorylated in membrane of baboon kidney; modulators enhanced a possible endogenous substrate of 41.8 +/- 2.3 kDa. In cytosol, eight major proteins were phosphorylated in the absence of modulators; a band of mass 110.4 +/- 13.8 kDa was enhanced with modulators added. Similar results were found in human kidney cytosol.

Animals↗