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Biomedical subjects

J L Carpenter

Publications and source records attributed to J L Carpenter.

At least 109 records · Page 6Linked to original sources
PubMed1978

An ultrastructural study of acinic cell carcinomas of the canine pancreas.

Four cases of spontaneous adenocarcinoma of the canine exocrine pancreas were studied by thin section and freeze-fracture electron microscopy. The neoplastic cells in all 4 cases were of acinar origin and showed many alterations of cytoarchitecture compared with normal acinar cells. In the neoplastic cells, zymogen granules varied in number and appearance and contained an abnormal secretory product characterized by 24-nm-thick microtubules. The nuclear volume and surface area and the nuclear cytoplasmic ratio were increased; although the nuclear pore density per nuclear surface area was significantly decreased, there was no change in the nuclear pore density per nuclear volume. There was a decrease in number and size of gap junctions; focal proliferation, fragmentation, and discontinuation of the tight junctions were also noted. The basal lamina (BL) of the neoplastic cells was discontinuous. The tumor microvasculature often appeared as sinusoids and had sparse discontinuous BL. Finally, the endothelium in both tumor and normal tissue contained "tubulo-reticular inclusions" (TRI) which simulated distemper virus and were located in the rough endoplasmic reticulum (RER) and the perinuclear cisternae.

Animals↗
PubMed1975

Hepatic arteriovenous fistula in two Saint Bernard pups.

Two saint bernard pups, 7 and 5 months old respectively, were examined because of anorexia, vomiting, and ascites. Exploratory laparotomy disclosed arteriovenous fistula of the right medial lobe of the liver in one dog, and in the right medial and quadrate lobes of the other one. Surgical removal of the affected lobes resulted in cessation of presenting signs. Both dogs remained healthy but had poor weight gain and vomited occasionally. After more than 2 years of apparently good health, both dogs were euthanatized and necropsied because of presumably unrelated gastrointestinal disturbances.

Animals↗
PubMed1975

Feline oncornavirus-associated cell membrane antigen. II. Antibody titers in healthy cats from household and laboratory colony environments.

Antibody titers to the feline oncornavirusassociated cell membrane antigen (FOCMA) were determined for 447 healthy cats from laboratory colony and household environments. Only 2.7 percent of 221 cats from colony environments were antibody positive as compared to 50.4 percent of 256 cats from household environments. Incidence of FOCMA antibody and geometric mean antibody titer for pet cats from New York City representing single cat apartment habitats were substantially lower than values for unscreened cats from the Boston, Glasgow, and Detroit suburban environments. Geometric mean antibody titer for young adults in the Boston population was significantly higher than titers for kittens or aged cats. This may be due to greater mobility resulting in increased exposure to other cats. In contrast to the high frequency of FOCMA antibody positivity in pet-cat populations, less than 2 percent of the same groups were positive for virus group-specific antigen in peripheral blood leukocytes and platelets. This was interpreted as an indication that many more cats became infected with feline leukemia virus under natural conditions that the number developing persistent virus infection and/or clinical leukemia.

Animals↗
PubMedDate not supplied

The admission urinalysis: impact on patient care.

Although urinalysis is one of the most frequently ordered tests in primary care, its usefulness in screening has not been demonstrated. A retrospective review of 1,607 admission urinalyses for inpatients in a referral/community hospital identified 861 as clinically indicated and 746 as routine. Routine urinalyses were abnormal less frequently than clinically indicated urinalyses (18.1% vs 39.6%) and when abnormal, were responded to less often (33.3% vs 75.4%). Forty-five (6.0%) of the routine urinalyses yielded an abnormality that led to diagnostic action. Of these, 18 were normal on repeat testing and 17 were considered unlikely to represent significant disease. Therefore, only ten (1.3%) of the routine urinalyses affected patient therapy. In eight of these cases, the abnormality was pyuria, of which six proved to be asymptomatic bacteriuria. The admission urinalysis as a routine test had little impact on patient care in the authors' institution.

Adolescent↗
PubMedDate not supplied

Klebsiella pulmonary infections: occurrence at one medical center and review.

Klebsiella pneumoniae is the species of aerobic gram-negative bacteria most commonly recognized as a cause of community-acquired pneumonia. The vast majority of articles concerning the epidemiology, frequency, and clinical and radiographic features of community-acquired pneumonias caused by this organism are over 20 years old. Experience with community-acquired pneumonias due to K. pneumoniae at one medical center over the last 20 years is reported and compared with the previously published literature. The recent experience at Parkland Memorial is quite similar to that in the literature. Salient features include the infrequency of K. pneumoniae as a cause of community-acquired pneumonia, the lack of specificity and sensitivity of most clinical and radiographic findings, and the similarity to and potential confusion with anaerobic pneumonitis and cavitary lung disease if only expectorated sputums are utilized for diagnosis in certain population groups such as alcoholics.

Acute Disease↗
PubMedDate not supplied

Perivalvular extension of infection in patients with infectious endocarditis.

Perivalvular extension of infection is a not-infrequent and potentially fatal complication of bacterial endocarditis. Because the efficacy of various modalities in the diagnosis of such complications is not well established, a selective review of the published literature on this issue is worthwhile. The electrocardiogram is the easiest study to obtain. It is quite specific in identifying perivalvular extension of infection when conduction system disease is demonstrated but has a low degree of sensitivity overall. Transthoracic two-dimensional echocardiography, transesophageal echocardiography, and color-flow Doppler echocardiography are the most practical and useful techniques for diagnosis of perivalvular extension of infection. Magnetic resonance imaging also appears to be an effective tool in this setting; however, because of a paucity of clinical data, its precise utility has not yet been determined. Nuclear medicine studies and computed tomography play a minimal role. Cardiac catheterization is as useful as the echocardiographic techniques but is invasive, not as readily available, and significantly riskier in terms of complications. An approach to the diagnosis of perivalvular extension of infection is proposed on the basis of the literature review.

Abscess↗
PubMedDate not supplied

Mycobacterium kansasii infections in patients positive for human immunodeficiency virus.

The experience with Mycobacterium kansasii infections in patients who are infected with human immunodeficiency virus (HIV) at Parkland Memorial Hospital in Dallas is presented, and the literature on such infections is reviewed. The absolute and relative paucity of reports of M. kansasii infections in HIV-positive patients is emphasized. M. kansasii infections in HIV-positive patients are classified as either pulmonary or disseminated. Evidence of the lack of therapeutic response in patients with disseminated infections and of the potential for therapeutic response in patients with infections limited to the lung is reviewed and documented. Other unresolved diagnostic and therapeutic issues concerning M. kansasii infections in HIV-positive patients are reviewed.

Adult↗
PubMedDate not supplied

Reliability model from the in vitro durability tests of a left ventricular assist system.

A reliability test of the Novacor N100PC left ventricular assist system (LVAS) with valved conduits, including a pump/drive unit with compact controller and LVAS monitor was performed. The initial test objective was to demonstrate sufficient reliability for clinical use as a long-term circulatory support system. The subsequent objective, a test to failure, was intended to provide an assessment of the durability of the design and to determine the LVAS wearout modes. Testing began in April 1993 and was performed with 12 systems on gravity-feed mock circulatory loops. The pump/ drive units were submersed in body temperature saline for the duration of the test. Each of the LVAS units was operated at nominal afterloads of 75, 90, and 105 mm Hg, with test conditions varied to yield nominal pump outputs of 5.6, 7.1, and 8.3 L/min. Failure was defined as the inability of the LVAS to maintain an average pump output of 4 L/min or an average output pressure of 60 mm Hg. After 3 years, all systems remained on test, with durations of 2.3 to 3.0 years. Analysis of the testing to that date, using a constant hazard rate model, indicated a minimum demonstrated reliability of 94% at a 60% confidence level, or 86% at a 90% confidence level, for a 2 year mission time. This greatly surpasses the reliability level included in the STS-ASAIO Long-Term Mechanical Circulatory Support System Reliability Recommendation (80% reliability, 60% confidence level for a 1 year mission time). In the subsequent test-to-failure protocol, all systems ran failure-free for at least 3 years. System failures occurring at longer durations were caused by a single common cause: wear of the energy converter's armature support bearings and shafts. The wearout mode was gradual and could be diagnosed noninvasively before failure. An analysis using a Weibull model was performed, using the test durations of those devices that failed, those that were electively removed from test for analysis of the wear mode, and those that continued on test. As of April 1998, the test results showed a reliability, at a 60% confidence level, of >99.9% for a 1 year mission time, 99.5% for a 2 year mission, and 92.0% for a 3 year mission (>99.9%, 98.3%, and 85.9% for equivalent mission times, at a 90% confidence level). Systems continue on test after as long as 4.9 years.

Equipment Failure Analysis↗
PubMedDate not supplied

Treatment of chancroid with erythromycin.

Chancroid is a sexually transmitted disease that is not often recognized in the United States. It has traditionally been treated with sulfonamides and/or tetracyclines. Recently, 14 active-duty U. S. Army personnel who acquired chancroid in the Far East were seen at the Madigan Army Medical Center, Tacoma, Wash. All of the organisms were isolated from clinical material on solid media without the use of a blood-clot tube. Because of dissatisfaction with conventional treatment and the demonstration of in vitro sensitivity of the organism to erythromycin, seven of the last eight patients were treated with erythromycin. All patients treated with erythromycin had rapid and favorable responses and none suffered recurrences. The results of this study led to three conclusions: chancroid is a relatively common disease in the Far East, the causative organism can be isolated by most clinical microbiology laboratories with proper technique, and erythromycin is an effective drug in the treatment of chancroid.

Adult↗
PubMedDate not supplied

Surgical treatment of idiopathic pericardial effusion in the dog: 25 cases (1978-1993).

Twenty-five cases of canine idiopathic pericardial effusion are described. All were treated surgically and underwent thoracotomy and pericardectomy, with histopathological evaluation of the resected pericardial sac. No tumor, infection, granulation tissue, or foreign body was found. Thirteen of the 25 dogs were golden retrievers, and all were large or giant breeds. Three (12%) died in the immediate postoperative period, and four (16%) died within one year of signs possibly related to the original condition. Eighteen (72%) survived at least 18 months; seven died or were euthanized for reasons unrelated to pericardial effusion (median, 44 months); and 11 were still alive at last contact (median, 61 months).

Animals↗