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Biomedical subjects

D J Doran

Publications and source records attributed to D J Doran.

At least 19 recordsLinked to original sources
PubMed1988

A response algorithm for the low-pressure alarm condition.

A response algorithm consists of a logical sequence of maneuvers to be performed in response to a specific condition. With the advent of alarm-equipped monitors that alert anesthesiologists to the presence of potentially hazardous clinical conditions, a need has arisen to develop the corresponding alarm-oriented responses expected from anesthesiologists; this problem, however, has not been satisfactorily addressed in the literature. An algorithm is proposed that guides the anesthesiologist through the three limbs of the ventilation system--gas supply system, breathing circuit, and mechanical ventilator--in response to a low-pressure alarm condition during automatic mechanical ventilation. The three-limbed algorithm rapidly and efficiently localizes the likely cause of the low-pressure condition without compromising patient safety; in the event that the search for a cause is fruitless, a default mode of ventilation is employed. A discussion is provided of common causes (e.g., disconnections), alarm-defeating circumstances (false negatives), and potential algorithm-defeating situations (multiple faults).

Algorithms↗
PubMed1980

Eimeria meleagrimitis Tyzzer in turkeys: the life cycle and effects of inoculum size and time on severity of infection and intestinal distribution.

Developmental stages of Eimeria meleagrimitis Tyzzer were found throughout the intestine and ceca of turkeys given inocula ranging from 10(4) to 7.5 x 10(5) sporulated oocysts/bird. Infection initially occurred in the duodenum and upper jejunum but later moved down the intestine and into the ceca. The speed with which the infection moved into these areas was rougly proportional to the inoculum size. Heaviest infections were in the ileum, neck of the cecum, and large intestine. The life cycle consisted of 5 asexual generations before gametogony, a 6th asexual generation developing simultaneously with gametogony. First- and 2nd-generations were located along the sides of villi in the upper intestine rather than in the crypts of Lieberkühn, as previously described in England for this species. Transitory first-generation stages that were abnormally large and usually degenerate were found in the neck of the cecum.

Animals↗
PubMed1978

Development of Eimeria meleagrimitis Tyzzer from sporozoites and merozoites in turkey kidney cell cultures.

Sporozoites and 1st-, 2nd-, and 3rd-generation merozoites of Eimeria meleagrimitis were inoculated into primary cultures of turkey kidney cells. In vitro-excysted sporozoites developed into mature macrogamonts in 8 days; in vivo-excysted sporozoites developed into 2nd- or 3rd-generation schizonts within 5 to 7 days. First-generation merozoites obtained from infected turkeys produced mature 2nd-generation schizonts within 24 h. Second-generation merozoites from turkeys produced mature macrogamonts and oocysts within 72 h, whereas 3rd-generation merozoites produced these stages within 48 h. The oocysts that developed from 3rd-generation merozoites sporulated at 25 C and were infective for turkeys. The timing of the early stages and the intervals between schizogonic generations in cultures were comparable with those in turkeys. Morphologic parameters, however, indicated that some differences existed between in vitro and in vivo development. Second- and 3rd-generation schizonts and gamonts that developed after inoculation of cultures with merozoites were similar to stages in turkeys. Oocysts, however, were significantly smaller (P less than 0.05) in cultures. All stages that developed after inoculation of cultures with sporozoites were smaller (P less than 0.05) than their in vivo counter parts.

Animals↗
PubMed1978

Eimeria tenella: vitamin requirements for development in primary cultures of chicken kidney cells.

Development of Eimeria tenella was studied in primary cultures of chicken kidney cells maintained in Medium 199 lacking each of the following: vitamin A, biotin, p-aminobenzoic acid, folic acid, nicotinamide, Ca pantothenate, pyridoxine, pyridoxal, riboflavin, thiamin, ascorbic acid, calciferol, alpha-tocopherol, and menadione. Data obtained concerning numbers of mature schizonts or total numbers of parasites or both indicated that all of the vitamins are needed for 1st- and 2nd-generation schizogony, and all except calciferol and folic acid are needed for gametogony.

Animals↗
PubMed1978

The life cycle of Eimeria dispersa Tyzzer 1929 from the turkey in gallinaceous birds.

The life cycle of a turkey strain of Eimeria dispersa was studied in chickens, Chukar partridge, Ring-necked pheasant, and Bobwhite quail. Endogenous development in partridge and quail differed from development in chickens and pheasant. In partridge and quail, mature 1st-, 2nd-, and 3rd-generation schizonts, macrogamets, and oocysts were found in tissue sections at an earlier time interval, mature 1st-generation schizonts were larger, and mature 1st-, 2nd-, and 3rd-generation schizonts contained a greater number of merozoites that were longer. The only apparent similarity among the 4 hosts was the size of mature 2nd- and 3rd-generation schizonts. The life cycle was completed in all 4 species of birds. The prepatent period was approximately 6 hr shorter in partridge and quail than in chickens and pheasant. Two partridge and 2 quail given 50,000 sporulated oocysts each shed a total of 23 million and 135 million oocysts, respectively, during 4-day interval. Two chickens and 2 pheasant given the same dosage shed a total of only 70,000 and 1 million oocysts, respectively, during the same interval. Oocysts from partridge and quail sporulated more quickly and were slightly larger than those from chickens and pheasant.

Animals↗
PubMed1977

Eimeria dispersa and Eimeria gallopavonis: infectivity, survival, and development in primary chicken and turkey kidney cell cultures.

Eimeria dispersa (turkey strain) and Eimeria gallopavonis sporozoites were inoculated into primary cultures of chicken kidney (CK) and turkey kidney (TK) cells. Eimeria dispersa sporozoites were more infective in either cell type than those of E. gallopavonis: at 4 hr, the percentage of infection was 67-98 for E. dispersa but only 23-56 for E. gallopavonis. E. dispersa also survived better in culture: at 2 days, losses of E. dispersa in both cell types were only 4-19%, whereas losses of E. gallopavonis were 35-47% IN TK cells and 60-95% CK cells. However, E. gallopavonis developed further than E. dispersa. Location and increase in numbers of intracellular stages at 4 days indicated that E. dispersa proceeded through 2 schizogonic generations before development stopped.

Animals↗
PubMed1975

Ultrastructure of cytoplasmic and nuclear changes in Eimeria tenella during first-generation schizogony in cell culture.

Eimeria tenella sporozoites were inoculated into primary cultures of chick kidney cells. Cells fixed from 1 1/2 to 54 hr later were examined with the electron microscope. At 1 1/2 and 24 hr, most intracellular sporozoites were fusiform and retained organelles typical of extracellular sporozoites. However, at 35 hr, rounded trophozoites were present without these structures; only a refractile body, nucleus, mitochondria, and endoplasmic reticulum remained. Binucleate parasites were also present at that time, but at 48 hr many multinucleate schizonts were present. Nuclei, with adjacent conoids, were at the periphery of these schizonts. Partly developed merozoites, each containing a conoid and a nucleus, protruded into the parasitophorous vacuole. At 54 hr, fully developed merozoites were separated from the residual body. Merozoites resembled sporozoites but lacked the large refractile bodies seen in sporozoites. Linear inclusions were present near the merozoite nucleus and in the residual body. Round vacuoles and ribosomes were also found in the residuum. Nucleoli were first seen in sporozoite nuclei at 1 1/2 hr. They were also present in merozoites but were more prominent in trophozoites and schizonts. Peripheral and scattered nuclear heterochromatins were prominent in intracellular sporozoites and diminished in trophozoites, but increased after several nuclear divisions and were again prominent in the merozoite. Small, distinct interchromatin granules were found in all stages. Intranuclear spindles, centrocones, and centrioles were found in connection with nuclear divisions. Ultrastructure of first-generation schizogony in cell culture was similar to that described for second-generation E. tenella in the chicken and to schizogony of other species of Eimeria.

Animals↗