Search PubMed⌕ Search

Biomedical subjects

J Allard

Publications and source records attributed to J Allard.

At least 55 records · Page 3Linked to original sources
PubMed1989

Three-dimensional reconstruction of human limbs from tomographic views.

The recently developed medical imaging technique of tomography can be used with amazing success to learn about the interior of a human body. Each tomograph, however, is limited to only one section of the specific human limb. A series of tomographs taken at irregular intervals and various angles would provide three-dimensional information of the interior of the limb. Currently available 3-D surface display algorithms have limitations, particularly when applied to clinically important image data requiring fast and flexible interactive analysis. In addition to the problem of computation time is the cost of specialized hardware. A new algorithm has been designed for use with three-dimensional medical images which attempts to overcome these limitations. A computer graphics system is described which reconstructs three-dimensional images from tomographic sectional data. This 3-D surface algorithm can be exploited in planning reconstructive bone surgery. An example which illustrates the versatility and speed of the new algorithm is presented.

Algorithms↗
PubMed1988

Respiratory cancer among orchardists in Washington State, 1968 to 1980.

A case-control investigation was conducted to evaluate the hypothesis that past exposure to the pesticide lead arsenate led to an excess mortality from respiratory cancer. Cases included all white male orchardists who died in Washington State between 1968 and 1980 from respiratory cancer. Orchardists who died of other causes during this period served as controls. Occupational and smoking data for 155 case subjects and 155 control subjects were obtained via telephone interview with next-of-kin/informants. Neither presence, intensity, nor duration of lead arsenate exposure differed between case and control subjects. Although cigarette smoking was unusually common among cases of respiratory cancer, smoking habits of the orchardists and a sample of non-orchardists who had died of other causes were quite similar. The cause of the excess mortality from respiratory cancer among Washington State orchardists remains unknown.

Aged↗
PubMed1987

Functional oncocytoma of the kidney: evaluation by dual tracer scintigraphy.

We report a case of renal oncocytoma with a unique scintigraphic pattern. The tumor showed strong avidity for [123I]iodohippurate, but no affinity for [99mTc] glucoheptonate. We offer an explanation for such exceptional scintigraphic finding, which may potentially enable us to make a pre-operative diagnosis of renal oncocytoma in the future.

Adenoma↗
PubMed1985

An outbreak of Yersinia enterocolitica infections caused by contaminated tofu (soybean curd).

The authors investigated 50 Yersinia enterocolitica infections during an outbreak of illness due to contaminated tofu (soybean curd) in Washington State between December 15, 1981 and February 22, 1982. The most common clinical syndrome (36 patients) was gastrointestinal infection for which two patients underwent appendectomies and one a partial colectomy. Of the remaining 14 patients, six had extraintestinal infections, two had fever alone, and six were asymptomatic. The patients with enteric infections were younger (median age three years) than those with extraintestinal infections (median age 28 years). In a case-control study of enteritis patients, illness was associated with ingestion of one brand of tofu (p less than 0.01). Ninety-two per cent of patients with gastrointestinal infections and 33% with extraintestinal infections recalled having eaten the implicated product. Y. enterocolitica serotype O:8, the most common serotype isolated from patients, was also isolated from tofu and the plant's untreated spring water. There was little clinical or laboratory evidence of secondary spread to family members who did not eat tofu. The outbreak demonstrates the transmission of Y. enterocolitica from nature to man and the potential of "natural" foods as vehicles for environmental pathogens.

Adolescent↗
PubMed1984

Brain abscess due to Petriellidium boydii.

A 22 year-old man died from multiple cerebral abscesses due to Petriellidium boydii 4 1/2 months after an episode of near drowning. The autopsy showed dissemination to heart and kidney. This patient had no immunocompromising disease but was treated with corticosteroids. The treatment of this condition with ventricular shunting and amphotericin B is discussed and compared with the experience of ten other cases reported in the literature.

Adult↗
PubMed1984

Legionella sainthelensi: a new species of Legionella isolated from water near Mt. St. Helens.

Six strains of a new species, Legionella sainthelensi, were isolated from freshwater in areas affected by the volcanic eruptions of Mt. St. Helens in the state of Washington. Strains of L. sainthelensi are culturally and biochemically similar to other legionellae. They grow on buffered charcoal yeast agar but not on media that lack cysteine. They are gram-negative, nonsporeforming, motile rods that are positive in reactions for catalase, oxidase, gelatin liquefaction, and beta-lactamase. They are negative in reactions for urease, hydrolysis of hippurate, reduction of nitrates, fermentation of glucose, and blue-white autofluorescence. Their cell wall fatty acid composition is qualitatively similar to those of other legionellae, with 50 to 62% branched-chain fatty acids. They contain the isobranched-chain 14- and 16-carbon acids and anteisobranched-chain 15- and 17-carbon acids and relatively large amounts of straight-chain 16-carbon acid. All strains of L. sainthelensi contain approximately equal amounts of ubiquinones Q9, Q10, Q11, and Q12, a pattern similar to those of Legionella bozemanii, Legionella dumoffi, and Legionella longbeachae. Serological cross-reactions were observed between L. sainthelensi, both serogroups of L. longbeachae, and Legionella oakridgensis. Three strains of L. sainthelensi were greater than 90% related by DNA hybridization. The type strain of L. sainthelensi, Mt. St. Helens 4, was 36% related to the type strain of L. longbeachae and 3 to 14% related to the other nine described Legionella species.

Disasters↗
PubMed1984

Misconceptions of homophobia.

Recent studies and analyses of social reactions to homosexuality are examined with the goal of linking them to general theories of deviance in the mainstream of sociology and social psychology. Homosexuality as an attitudinal object is classified as person, trait, and characteristic of collectivities and culture. The assumption of homosexuality as a "master status trait" is questioned. Foci of investigation are categorized as cognitive stereotypes, perceptions of threat to others and to valued aspects of society and culture, and the management of homosexuality. Ego-alien and phobic responses are distinguished. General problems of attitudinal research in the field are identified; chiefly, the overemphasis of cognitive elements and the neglect of affective and behavioral elements. The potential of this imbalance for the reification of homophobia among subjects and for the general public is noted. Other problems include the confounding of cognitive and affective dimensions and the assumption of stability of attitudes in different social settings. The need for concrete observations of responses to homosexuality in varying social settings and for the study of various types and phases of the disclosure process is specified. We call for grounded empirical observations of reactions to homosexuality within a model of the "social construction of reality" in order to place such studies within the mainstream of sociology and social psychology.

Attitude↗
PubMed1981

Mount St Helens eruptions, May 18 to June 12, 1980. An overview of the acute health impact.

Thirty-five known deaths were caused by the landslide and lateral blast of the May 18 eruption of Mount St Helens and at least 23 persons are missing. In 18 of 23 cases that reached autopsy, asphyxiation from ash inhalation was the cause of death. A rapidly established hospital surveillance system detected increases in the number of emergency room (ER) visits and admissions for asthma and bronchitis in communities with the heaviest ashfall after the May 18 eruption and the eruptions on May 25 and June 12. There were also increases in the number of ER visits for ash-related eye complaints in some areas. laboratory studies indicated that the May 18 ash was not acutely toxic, but the respirable portion contained 3% to 7% of crystalline free silica, a potential pneumoconiosis hazard to certain heavily exposed occupational groups. Continuing volcanic activity of Mount St Helens and future eruption of other volcanoes in the Cascade Range may pose a variety of health hazards, including blast, ashfalls, flooding, damage to public utilities, and possible psychosocial effects.

Asphyxia↗
PubMed1981

Multiple activities of a cloned cell line mediating natural killer cell function.

A special class of immunologic cells can lyse or damage a variety of target cells, notably malignant cells in vitro. These cells have been called natural killer (NK) cells because lysis does not require deliberate immunization by tumor cells. Although these cells can be distinguished from conventional T cells, B cells, and phagocytic cells, they have been difficult to define. We describe a representative cloned cell line that was obtained by cloning Ig -Ly-5+ cells from spleen. This clone, Cl.Ly-1-2-NK-1+/11, displays Thy-1, Ly-5, Qat-4, Qat-5 and NK-1 cell surface antigens and lyses the NK-sensitive YAC-1 lymphoma cells, but does not lyse RL-12 cells, an NK-resistant lymphoma. In addition, this clone lysed the P815 mastocytoma, EL4 lymphoma, and lipopolysaccharide-activated B lymphocyte targets. This cloned population therefore combined information for a unique display of cell surface antigens and specialized function similar to "activated" NK cells. Because this cloned population forms conjugates with susceptible but not resistant target cells, it may prove useful to identify the structure of cell surface molecules that recognize foreign cells. Finally, cells of this clone also specificity lysed target cells coated by antibodies to determinants on the target cell surface, demonstrating that a single cloned cell population can mediate two specialized immunologic functions: antibody-dependent cellular cytotoxicity and NK cell lysis.

Animals↗
PubMed1980

Differentiation between reperfusion and occlusion myocardial necrosis with technetium-99m pyrophospate scans.

Although infarct-avid scanning is used to diagnose myocardial infarction, no distinction is made between two very different mechanisms of myocardial cell death. These are occlusion necrosis and reperfusion necrosis. The former is the major form of cell injury after a sustained occlusion of a coronary artery; the latter occurs immediately after reperfusion of ischemic myocardium. The present study examines whether the technetium pyrophosphate scan becomes positive more rapidly with one form of injury rather than the other. Myocardial damage was produced in dogs by either sustained coronary occlusion (Group I, 6 dogs) or reperfusion (Group II, 18 dogs). Infarct-avid myocardial scans obtained with technetium-99m pyrophosphate were positive in only one of six animals in Group I when isotope was injected 4.5 hours after sustained coronary occlusion. In contrast, 12 or 13 animals (Group IIa) with reperfusion necrosis had a positive scan when isotope was injected 3.5 hours after reperfusion. When isotope was injected only 30 minutes after the onset of reperfusion (Group IIb), only two of five scans were clearly positive. The results indicate that if the interval between myocardial injury and a positive scan is known, inference can be made concerning the predominant type of injury.

Animals↗
PubMed1980

Neomycin absorption following Clagett procedure for postpneumonectomy empyema.

Following a Clagett stage II procedure, significant amounts of neomycin are absorbed when concentrations of 0.25% neomycin (8.9 micrograms milliliter) are used. If higher concentrations are employed, the neomycin can achieve toxic levels (40 micrograms per milliliter), with associated renal toxicity and respiratory suppression. The peel of the empyema cavity does not prevent absorption of drugs. Therefore, when drugs are inserted into an empyema cavity, due care must be exerted to prevent drug toxicity.

Absorption↗
PubMed1980

Causes of perioperative myocardial infarction: their identification and prevention.

Despite major technical advances in coronary bypass surgery and myocardial preservation, perioperative infarction remains a serious problem. The authors review the pathogenesis of the two different types of myocardial injury, occlusion necrosis and reperfusion necrosis. These two entities can be distinguished clinically by radioisotope scanning. Experimental studies have demonstrated that reperfusion necrosis can be prevented pharmacologically. Since the majority of perioperative infarcts are probably due to reperfusion, the importance of distinguishing between these two entities is evident.

Animals↗
PubMed1977

[Coronary thrombosis on oral contraception (author's transl)].

A case of myocardial infarction observed in a 27 years old female taking an oestrogen-progestogen combination for contraception, who died suddenly two months after the resection of a left ventricular aneurysm, provided unprecedented anatomical documents. Their histological examination allowed to state the thrombotic mechanism of the coronary occlusion and brought arguments in favour of an alteration of the coronary arterial wall in the form of thickening of the intima, likely to have been the starting point of this thrombosis.

Adult↗
PubMed1977

Concentric hemorrhagic necrosis of the myocardium. A morphological and clinical study.

Froty-nine cases of concentric hemorrhagic necrosis of the left ventricular myocardium were reviewed in a series of 97 autopsy studies in patients subjected to cardiopulmonary bypass for various types of cardiac surgery. The gross and microscopic findings were analyzed in order to define the morphologic evolution of the lesion. The extent of involvement was graded by gross examination of serial transverse sections of the heart. Microscopically there were five major histologic changes, probably representing the sequential evolution of the lesion, i.e., contraction bands, subendocardial hemorrhages, coagulative necrosis, healing by granulation tissue, and fibrosis. The location of the lesion conincided with the vulnerable region of the microcirculation. Owing to the implementation of new surgical techniques, the cases were subdivided into two groups, one covering the period from 1963 to 1970 and the other , 1971 to 1974. Concentric hemorrhagic necrosis was less frequent in the more recent group, but when it was present it was more pronounced in the individual heart. The lesion in the earlier group was milder but demonstrated a higher incidence of platelet microthrombi in the heart. In the recent cases concentric hemorrhagic necrosis tended to be more diffuse in aortocoronary bypass than in valvular replacement surgery. We discuss one possible explanation for the development of this lesion, i.e., transient hypoxemia occurring at the time of cardiopulmonary bypass, followed by reperfusion and accelerated necrosis with hemorrhage.

Adult↗