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Biomedical subjects

J A Graham

Publications and source records attributed to J A Graham.

At least 109 records · Page 6Linked to original sources
PubMed1979

A scanning electron microscope study of developing hamster tracheal epithelium in organ culture.

The ultrastructural surface features of tracheal epithelium at various times of development in organ culture were compared with those in the trachea of Syrian golden hamsters of similar age using scanning electron microscopy. Whole tracheal organ cultures, prepared from 3-day-old hamsters, were maintained in HEPES buffered CMRL 1066 medium with 0.2% bovine serum albumin. The ventral epithelial surface of trachea from 3-day-old animals was characterized by numerous microvillous cells, occasional well-developed cilia, and cells containing short cilia representing various stages of ciliary differentiation. After seven days in culture, an increased number of ciliated cells as well as developing cilia were seen. The epithelium after 14 days in culture appeared to have equal numbers of ciliated and microvillous cells, a pattern strikingly similar to that observed in vivo. After 21 days in culture, groups of well-developed cilia were interspersed with nonciliated cells covered with short, poorly developed surface microvilli. A similar pattern was found in the trachea of comparable age (24 days), with the exception of the microvillous cells; many being dome-shaped containing cluster of microvilli with prominent outlines. The tracheal organ culture, as developed in this investigation, appears to represent an excellent model for studying age-related effects of toxic and infectious agents on ciliated epithelial cells.

Age Factors↗
PubMed1977

Conservative treatment of gastrointestinal fistulas.

Conservative measures were instituted as the primary treatment of 39 consecutive patients with high output fistulas of the gastrointestinal tract and related organs. Nutritional status was maintained by an intravenous feeding regimen, using peripheral vein infusion sites and supplying 60% of the calorie intake by a fat emulsion. This regimen had no serious complications. These patients died during treatment. The fistulas healed spontaneously in 35 of the remaining 36 patients. None of these patients had obstruction distally or other factors tending to prevent spontaneous closure. Under these circumstances, nonoperative treatment is safest and best. Surgical closure was necessary in one patient after two months of conservative treatment and was successful.

Adolescent↗
PubMed1976

Human deficiency of the eighth component of complement. The requirement of C8 for serum Neisseria gonorrhoeae bactericidal activity.

The serum of a 23-yr-old woman with prolonged disseminated gonococcal infection syndrome failed to normally promote hemolysis of sensitized sheep red blood cells (RBC). The patient's serum was deficient in the eight component of complement (C8) as determined by functional assays, immunoelectrophoresis, and quantitative immunoprecipitation. Functional titers of each of her other complement components were normal. No serum inhibitors of C8 were detected. The patient's serum supported activation of both the classical and alternate complement pathways. Her fresh serum lacked any bactericidal activity against Neisseria gonorrhoeae, but addition of purified C8 or complement donor serum restored bactericidal activity as well as RBC hemolytic activity. Her serum gave normal opsonization of yeast particles and staphylococci and had normal capacity to coat sensitized RBC with C8 and C4 and to generate chemotactic activity. No defects were observed in the patient's blood coagulation mechanisms. Complement-mediated bacterial lysis may be important in human defense against bacteremic Neisseria infections.

Adult↗
PubMed1975

Effect of trace metals on phagocytosis by alveolar macrophages.

Experiments were performed to measure the effect of trace metals on a vital function of the alveolar macrophage (AM), phagocytosis. Since certain trace metals were found to reduce the viability of AMs, a technique was developed to permit examination of live cells only for phagocytosis. Evidence is presented that Ni(2+) selectively altered the phagocytic activity of AMs at concentrations lower than those which caused cell death. It is further shown that a level of VO(3) (-) that caused extensive lysis and death did not reduce phagocytosis in surviving cells. The effects of Cd(2+), Cr(3+), and Mn(2+) on AMs were also examined.

Animals↗
PubMed1975

Effect of nickel chloride on primary antibody production in the spleen.

Mice immunized intraperitoneally with sheep erythrocytes were treated with nickel chloride, a common particulate air pollutant. Primary antibody production in the spleen was examined using a hemolytic plaque technique. A negative linear dose-response relationship (p is less than 0.05) was observed between the logarithm of (plaques/10(6) cells) and the nickel concentration administered. Mice injected with 3.09 mug Ni2+/g body weight displayed lymphocyte function similar to that of control mice. However, injection of 9.26-12.34 mug Ni2+/g caused significant immunosupression (p is less than 0.05).

Animals↗
PubMed1973

Technique for differentiating particles that are cell-associated or ingested by macrophages.

Phagocytosis is a two-step process involving attachment and ingestion of particulate material. It is often difficult to determine under a light microscope whether the particles are actually ingested or are merely attached to the cell. A more accurate, easy to perform technique with the use of xylene has been developed for determining the difference between the attachment and ingestion of polystyrene latex spheres. The xylene treatment dissolves the extracellular spheres, leaving only the intracellular spheres to be counted by the experimenter to obtain a more accurate phagocytic index. This technique also allows an investigator to get an ingestion index, an attachment index, or both.

Animals↗
PubMed1971

Body water and electrolyte composition in acute renal failure.

Body water and electrolyte contents have been measured by means of muscle biopsy analysis in 11 patients with untreated acute renal failure and in one patient during the diuretic recovery phase of his illness. Patients with acute oliguric renal failure show two main types of imbalance. One group shows evidence of a reduction in extracellular sodium and chloride with normal intracellular water and electrolytes. These findings are thought to be due to a combination of excess urinary salt loss during the development of oliguric renal failure, and inadequate replacement of extrarenal electrolyte losses. A second group shows overhydration of both extra- and intracellular phases, associated with an excess of sodium and chloride. The intracellular potassium concentration is reduced, owing to the intracellular water excess. The patient studied during the diuretic recovery phase of acute renal failure showed a marked loss of sodium and chloride, which emphasizes the necessity to replace urinary electrolyte losses at this stage of the illness. It is often extremely difficult to assess fluid and electrolyte balance in patients presenting with acute renal failure, and muscle biopsy analysis or isotope dilution studies may be required before accurate replacement therapy is possible.

Acute Kidney Injury↗