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Biomedical subjects

L Crooks

Publications and source records attributed to L Crooks.

At least 19 recordsLinked to original sources
PubMed1995

Anxiety in community-based AIDS caregivers before and after personal construct counseling.

Personal construct counseling was provided for voluntary AIDS caregivers based in the community, with the goal of reducing their anxiety levels. Seventy-five caregivers participated in the project, 33 of whom received counseling. They were interviewed on three occasions--before, immediately after, and 3 months after counseling. Their responses to an open-ended question were subjected to six subscales of a content analysis scale in order to measure levels of anxiety from six different sources. At time 2, the anxiety of the counseled caregivers was significantly less than that of those not counseled, specifically their anxiety about bodily mutilation and guilt. These differences were not sustained at time 3 because the anxiety of those not counseled dropped. Some criticisms of the project are examined before the meaning of these findings for meeting the mental health needs of AIDS caregivers is discussed.

Acquired Immunodeficiency Syndrome↗
PubMed1992

CD3+ and CD4+ cells adoptively transfer experimental hypersensitivity pneumonitis.

To characterize the cells responsible for transfer of adoptive murine experimental hypersensitivity pneumonitis (EHP), we depleted Micropolyspora faeni (M. faeni)-sensitized C3H/HeJ spleen cell (SC) cultures of CD3+, CD4+, or CD8+ cells before administration to recipients. We determined the length of time sensitization persists, the ability of cultured lung-associated lymph node (LALN) cells to transfer EHP, and the ability of cultured SC from animals subjected to two, four, or eight weekly intratracheal challenges of M. faeni to transfer EHP. The extent of pulmonary inflammatory response after challenge with intratracheal M. faeni was used to determine adoptive transfer. Depletion reduced the proportion of CD3+ cells from 21 to 1%, CD4+ cells from 15 to 3%, and CD8+ cells from 7 to 1% in the cultured SC population. The proportion of B cells exhibited reciprocal changes. Cultured SC could transfer EHP. Depletion of CD3+ and CD4+, but not CD8+ cells, ablated or diminished the capacity to transfer EHP. Sensitized cells persisted in recipients for at least 8 wk. Cultured LALN cells could transfer EHP. Recipients of cultured SC from 4- and 8-wk donors exhibited less extensive pulmonary abnormalities than recipients of cultured SC from 2-wk donors. The proportion of CD3+, CD4+, CD8+, B cells, and macrophages was the same in cultured cells from 2-, 4-, and 8-wk donors. We conclude that the active cells in SC cultures are CD3+, CD4+, and CD8- T cells, and there are differences in the ability of cultured cells to adoptively transfer EHP that are dependent on the nature of the donor but not on the phenotype of the cell population.

Alveolitis, Extrinsic Allergic↗
PubMed1991

Psychological frailness and strength in an AIDS-affected community: a study of seropositive gay men and voluntary caregivers.

Addressed both the psychological frailness and strength in an AIDS-affected community. The gay community in Sydney, Australia, was represented by men who were seropositive (n = 60) and voluntary caregivers (n = 60). They were compared with two samples of men outside the gay community, who were ill with non-AIDS-related medical conditions (n = 30), and well (n = 30). Their psychological frailness and strength were measured by content analysis scales. Both the seropositive men and the caregivers showed the frailness of anxiety, indirectly expressed anger and helplessness, but also the compensating strength of greater personal competence and good feeling relative to the other men. The men who were seropositive or had other illnesses showed the predicted frailness of anxiety and depression but neither indirectly expressed anger nor helplessness. The seropositive men and caregivers of the gay community differed from each other only in the high levels of depression of the former.

Acquired Immunodeficiency Syndrome↗
PubMed1990

Experimental hypersensitivity pneumonitis: influence of donor sensitization.

Experimental hypersensitivity pneumonitis (EHP) can be transferred to strain 2 guinea pigs by lymphoblasts from lymph node cells from sensitized guinea pigs cultured in vitro with antigen. We sought to examine the relationship between characteristics of the donor animal and development of competence to transfer EHP. We also compared cell populations that were capable and incapable of transfer using flow cytometry and fluorescein conjugated anti-Ig to determine cell size and surface IgG + (SIg +: surface immunoglobulin-positive) cells. Lymph node cells from donor animals were cultured with a soluble extract of Micropolyspora faeni (10 micrograms/ml) for 72 hours; blasts were then isolated and transferred intravenously to syngeneic recipients. Control recipients received an equal volume of medium. Four groups of donors were used: animals systemically sensitized with Freund's adjuvant and M. faeni and challenged with two, four, or eight weekly intratracheal injections of M. faeni (2-, 4-, and 8-week group); and animals sensitized with Freund's adjuvant and normal saline and challenged with two weekly intratracheal injections of normal saline (NS group). Recipients were challenged intratracheally with M. faeni 48 hours after the cell transfer and killed 4 days thereafter. Randomly selected microscopic fields of the lung (250/animal) were judged to be normal or abnormal without knowledge of treatment. All animals were maintained in high efficiency particulate accumulator-filtered air. There was a low level of pulmonary response to an intratracheal challenge of M. faeni in animals that received media.(ABSTRACT TRUNCATED AT 250 WORDS)

Actinomycetales Infections↗
PubMed1989

The emotional reactions of HIV antibody positive men.

This study was concerned with the emotional reaction of men who are HIV antibody positive, and with whether their expression of enjoyment is better viewed as the result of rigid defending or flexible coping. A sample of these men was matched with samples of patients with other major illnesses and well controls. Enjoyment was found to be more frequently expressed in the two ill samples, as were anxiety, depression and helplessness. The HIV antibody positive patients expressed more anger, and yet more competence, than the other patients. These patterns of emotional reaction proved to be modified by different levels of enjoyment in a manner more indicative of coping than defending, because depressive emotions appeared to be reduced when some enjoyment of life was apparent. The implications of these findings for health professionals working with people who are HIV antibody positive are discussed.

AIDS Serodiagnosis↗
PubMed1989

Experimental hypersensitivity pneumonitis in guinea pigs. Kinetics and dose response.

Experimental hypersensitivity pneumonitis (HP) can be transferred by cells cultured in vitro with antigen, but not by noncultured cells. We determined the relationship between antigen concentration, time of culture, and development of competence to transfer HP and if separation of lymphoblasts from a noncultured cell population would allow transfer. We cultured lymph node cells from sensitized Strain II guinea pigs with a soluble extract of Micropolyspora faeni (10 micrograms/ml) for 48, 72, and 96 h, and isolated and transferred lymphoblasts intravenously to syngeneic recipients. Other animals received lymphoblasts from 72-h cultures exposed to 0, 0.1, 1, 10, or 30 micrograms/ml M. faeni. We also separated and transferred lymphoblasts from noncultured lymph node cell populations. Control animals received equal volumes of media. The animals were challenged intratracheally with M. faeni 48 h after the cell transfer, and they were killed 4 days after intratracheal challenge. Randomly selected microscopic fields of the lung (250/animal) were judged to be normal or abnormal without knowledge of treatment. All guinea pigs were maintained in HEPA-filtered air. There was a low level of pulmonary response to an intratracheal challenge of M. faeni in animals that received media and a substantial increase (p less than 0.01) in the extent of pulmonary abnormalities in the animals receiving lymphoblasts cultured for 72 and 96 but not for 48 h. Recipients of lymphoblasts cultured for 72 h with 1, 10, and 30 but not zero and 0.1 micrograms/ml M. faeni exhibited increased extent of pulmonary abnormalities.(ABSTRACT TRUNCATED AT 250 WORDS)

Alveolitis, Extrinsic Allergic↗
PubMed1988

Vulvar dermatofibrosarcoma protuberans.

Dermatofibrosarcoma protuberans of the vulva is an extremely rare neoplasm. This low-grade sarcoma of the dermis clinically appears to be encapsulated but microscopically has tumor projections well away from the central nodules. Wide local excision is the recommended treatment for dermatofibrosarcoma protuberans; however, a more radical surgical approach may be needed to obtain clear surgical margins. The following case study present the fifth reported patient with this unusual neoplasm on the vulva.

Clitoris↗
PubMed1988

Ovarian mucinous cystadenocarcinoma of low malignant potential associated with a mature cystic teratoma.

A 54-year-old female underwent exploratory laparotomy for evaluation of a large abdominopelvic mass. She was found to have a 29-pound multicystic tumor arising from the right ovary. There were no other gross intraabdominal abnormalities. Histologic examination of the mass revealed a mucinous cystadenocarcinoma of low malignant potential and a mature cystic teratoma. To our knowledge, this is the first case report of an ovarian epithelial adenocarcinoma of low malignant potential associated with a mature cystic teratoma.

Cystadenocarcinoma↗
PubMed1988

Signal-to-noise ratio and section thickness in two-dimensional versus three-dimensional Fourier transform MR imaging.

The efficiency and quality of three-dimensional Fourier transform (3DFT) magnetic resonance imaging were evaluated and compared with those of 2DFT imaging. For a fixed imaging time and number of sections, 3DFT imaging with conventional spin echoes always had a worse signal-to-noise ratio (S/N) than did 2DFT imaging, when both were optimized with respect to choice of repetition time (TR). With partial-flip magnetic resonance (MR) imaging, S/N was nearly equal for 2DFT and 3DFT imaging when both were optimized with respect to TR and flip angle. 3DFT imaging can have cross-section artifacts that exceed those of 2DFT imaging. For very thin sections these artifacts may be lessened, and 3DFT imaging can achieve this with smaller gradient pulses. Over-all, 3DFT imaging was found to be advantageous only for the very-thin-section imaging and in combination with partial-flip MR imaging.

Fourier Analysis↗
PubMed1986

Positive indium-111 leukocyte scan in Nocardia brain abscess.

We report a case of clinically unsuspected nocardia brain abscess detected by 111In-labeled autologous leukocytes. Clinical and computed tomographic findings supported the diagnosis of primary or metastatic tumor and the patient was treated with dexamethasone for 30 days prior to the leukocyte scan. Labeled leukocytes may provide a sensitive discriminator for brain abscess despite previous therapy with steroids.

Aged↗
PubMed1985

Abdominal venous system: assessment using MR.

Twenty-five patients with known or suspected evidence of venous disease based on results of computed tomography, angiography, or ultrasound were imaged with magnetic resonance (MR) to determine the MR characterization of venous abnormalities. MR findings were proved by laparotomy or autopsy in 18 of 25 cases. In seven of 25 patients in whom only biopsy was performed, the MR findings were correlated with findings from other radiologic tests. On MR, the inferior vena cava (IVC), portal vein, and their major tributaries were seen in all but two cases. In those two, identification of collaterals led to the correct diagnosis of splenic vein thrombosis in one case and left renal vein thrombosis in another. MR imaging helped identify intraluminal thrombi in the IVC (12 of 12 cases), portal vein (two of two cases), renal veins (seven of seven cases), superior mesenteric vein (one case), and iliac veins (seven of seven cases). Intraluminal signal intensity secondary to slow blood flow seen in five patients was always differentiated from the thrombus. MR imaging helped identify correctly the nature of the thrombus in 11 of 16 patients. In five patients, the differentiation between tumor thrombus and blood clot thrombus was not possible. Involvement of the IVC wall by tumor was seen in four cases. MR imaging also accurately depicted slow flow in obstructed or constricted veins; encasement, compression, or displacement of veins without intraluminal occlusions; and the presence of venous collaterals. The MR imaging evaluation of venous abnormalities is accurate, easily performed, and will probably become an important application.

Abdomen↗
PubMed1984

Pulsatile blood velocity in human arteries displayed by magnetic resonance imaging.

The authors describe a new method for magnetic resonance (MR) imaging of flowing protons which can illustrate relative blood velocity in the arteries supplying the brain. The magnetic gradient pulse sequence was synchronized to the cardiac cycle at 100-msec. increments to track pulsatile blood flow perpendicular to the image plane. The magnitude of the signal increased with the velocity of blood in major arteries flowing in the direction of the spatially offset refocusing plane. The blood velocity in the vertebral and internal carotid arteries varied as a function of the phase of the cardiac cycle, and the velocity profiles across the vascular lumina were compatible with laminar flow.

Blood Flow Velocity↗
PubMed1984

Imaging by nuclear magnetic resonance in patients with chronic ischemic heart disease.

Cardiac anatomy was defined by gated nuclear magnetic resonance (NMR) imaging at a magnetic field strength of 3.5 kGauss in eight normal subjects and 10 patients with chronic myocardial infarctions. Multisectional imaging was performed with the spin-echo technique and encompassed most of the left ventricle in an imaging time of 5 to 12 min. In all subjects internal cardiac structure was well delineated without the use of any type of contrast medium. The myocardial wall-blood interface was sharply defined, resulting in visualization of trabeculations, papillary muscle, and chordal structures in both ventricles. In patients with ischemic heart disease, the extent of postinfarctional wall thinning, aneurysms, and mural thrombi were depicted on NMR images. Images obtained with the second spin-echo (delay time = 56 msec) demonstrated high signal intensity in regions of the left ventricular chamber adjacent to the site of aneurysms or infarctions; this finding suggested stasis of blood in a region of akinesis or dyskinesis. The results of this study show that gated NMR is feasible as a technique for imaging the human heart and is capable of demonstrating a variety of left ventricular abnormalities associated with chronic myocardial infarction. NMR is a completely noninvasive technique for clinical imaging of the cardiovascular system.

Adult↗
PubMed1983

Nuclear magnetic resonance imaging of mammary adenocarcinomas in the rat.

A study of 24 rats implanted in the hind leg with mammary adenocarcinomas and five sham-implanted rats, followed from the second to the eight week postimplantation, showed nuclear magnetic resonance imaging capable of detecting all the tumors without yielding any false-positives in the control rats. The T1 relaxation time of tumors overlapped that of muscle, and the T2 times overlapped fat, but the combination was unique when comparing tumors to muscle and fat. Necrotic regions of the tumor and the bladder contents tended to have very long T1 and T2 relaxation times. The difference in relaxation time between tumors and muscle could be accounted for in terms of water content, which was approximately 8% higher for the tumors. The study corroborates data from previous studies indicating that NMR imaging is a highly sensitive modality, although T1 and T2 times are not exclusive indicators of malignancy.

Adenocarcinoma↗