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Biomedical subjects

T Anderson

Publications and source records attributed to T Anderson.

At least 145 records · Page 8Linked to original sources
PubMed1993

Cerebral abnormalities in myotonic dystrophy. Cerebral blood flow, magnetic resonance imaging, and neuropsychological tests.

OBJECTIVE: To study cerebral abnormalities in myotonic dystrophy (MD) and determine the different patterns of cerebral function in patients with MD with maternal (mMD) vs paternal (pMD) inheritance. DESIGN: Patients with MD and normal controls were studied with neuropsychological testing, magnetic resonance imaging, and single photon emission computed tomography. SETTING: Studies were done at Harbor-UCLA Medical Center, Torrance, Calif. PATIENTS AND OTHER PARTICIPANTS: Twenty-two consecutive-patients with MD, 11 of whom had pMD and eight mMD, and 10 normal controls were studied. Diagnoses were made on the basis of family history, electromyography, and clinical examinations. Normal subjects in the same age distribution were studied for comparisons. RESULTS: We found significantly lower neuropsychological performance and cerebral blood flow in the patients with MD compared with the controls. Patients with mMD had statistically lower scores on IQ tests and more extensive cerebral hypoperfusion when compared with those with pMD. Changes in cerebral blood flow were most severe in the frontal and temporoparietal association cortex. Cerebral blood blow measures strongly correlated with IQ. CONCLUSIONS: Patients with mMD had earlier onset of disease and lower IQs than the pMD group. The pattern of cerebral perfusion in the mMD group was consistent with a diffuse brain injury, while cerebral perfusion in pMD showed more minor changes. These findings emphasize the cognitive differences between mMD and pMD.

Adolescent↗
PubMed1993

Measurement of mean velocity during pulsatile flow using time-averaged maximum frequency of Doppler ultrasound waveforms.

It has been suggested that mean velocity of flow could be estimated by the time-averaged maximum frequency over an integral number of cardiac cycles (Gill 1985). The present study verified this theory experimentally with a computer-controlled flow phantom. The effects of some parameters on the relationship between mean velocity and time-averaged maximum frequency were also studied. Parameters investigated included beam-vessel angle, diameter of tubing, pulsatility, flow rate and stenosis. The velocities measured by the Doppler system were compared with the actual velocities. A simple theoretical model was also developed to compare with the experimental results. The results showed that, in a long straight tube, the mean velocity can be estimated to within about 5% from the time-averaged maximum Doppler shift at various flow rates and pulsatilities. The error due to geometrical spectral broadening, especially for large beam-vessel angles, can be estimated to within 3% and therefore corrected.

Blood Flow Velocity↗
PubMed1993

The factor structure of the Rorschach for adolescent inpatients.

The factor structure of the Rorschach inkblot test was examined using a sample of 268 adolescent inpatients (including 105 with conduct disorders and 105 with depressive disorders). An initial analysis found a four-factor solution for both the conduct-disordered and depressive-disordered groups. However, examination of the factor patterns suggested that these groups did not yield significantly different factor structures. Thus, for the final analysis all inpatients were combined, and a single three-factor solution was found. These factors were substantively similar to the initial analysis and were interpreted as consisting of (a) struggles with affective expression, (b) general psychological health, and (c) perceptual organization.

Adaptation, Psychological↗
PubMed1993

A phase I trial of protracted 5-fluorouracil infusion and oral calcium leucovorin.

This phase I study of 36 patients was performed to identify the maximal tolerated dose of oral calcium leucovorin (CLV) that could be concomitantly administered with protracted 5-fluorouracil (5-FU) infusion (greater than 30 days). Administration of CLV in very small doses (5 mg p.o. q8h) with 5-FU, 200-300 mg/m2/day, resulted in excessive toxicity requiring treatment interruption in all patients. Subsequent reduction in the dose of 5-FU to 100 mg/m2/day with simultaneous administration of CLV, 5 mg p.o. q8h, decreased the toxicity and allowed for protracted administration of the combination. In subsequent patients the dose of oral CLV was increased to 22.5 mg p.o. q8h, which resulted in treatment-limiting toxicity in the majority of patients. Toxicity consisted almost exclusively of mucositis. No myelosuppression or significant organ toxicity was observed. We conclude that even low doses of oral CLV potentiate the biological effect of infusion 5-FU. If the combination is to be given on a protracted basis, 5-FU must be administered at a much smaller dosage than has been traditionally utilized.

Aged↗
PubMed1993

Eosinophil adhesion and maturation is modulated by laminin.

Eosinophils (Eo) participate in the inflammatory response to parasites, allergins, toxins, and epitopes recognized by autoimmune antibodies. Nonetheless, little attention has heretofore been paid to the interactions of Eo with extracellular matrix (ECM) proteins during their migration through the subendothelial basement membrane and into the surrounding tissue. Therefore, we have studied the adhesion of Eo to specific ECM proteins and the effect of this adhesion on Eo viability and maturation. Control Eo (from normal donors) adhere no better to substrates coated with laminin (LM), fibronectin (FN), cytotactin (CT), or collagen types I or IV (Col IV) than they do to human serum albumin coated substrates. In contrast, Eo activated in vitro with IL-5 or in vivo in patients with eosinophilia bind well to LM, FN and Col IV. LM is by far the most avid ligand among these molecules. For example, 43% of input cells bind to a substrate bearing 200 fmol/cm2 of LM; a similar level of adhesion to FN requires 30 times as much absorbed protein. Antibody inhibition experiments suggest that the alpha 6 beta 1 integrin heterodimer is the predominant LM receptor on these cells. Flow cytometry showed similar levels of these subunits on control and activated Eo, suggesting that Eo adhesion to LM is not regulated simply by cell surface integrin concentration. The effects of ECM proteins on Eo behavior were also examined. A LM-coated substrate (with no added cytokine) was found to be almost as effective as IL-5 in maintaining Eo viability while an equally adhesive FN-coated substrate had much less effect. Normally, even in the presence of 10% serum, no Eo survive a 5-day incubation in vitro unless IL-3, IL-5, or GM-CSF is added to the medium. Conditions that inhibit adhesion to LM (anti-integrin antibodies in the medium or CT on the substrate) and certain anti-cytokine antibodies inhibited the promotion of Eo viability by LM. During incubation on LM, Eo become hypodense, as they do in the presence of IL-5, indicating that they have become activated. These observations suggest that the interactions of Eo and ECM proteins may be important both for their potential to direct Eo migration and for their ability to regulate Eo viability, cytokine production, and maturation.

Animals↗
PubMed1992

UV exposure reduces immunization rates and promotes tolerance to epicutaneous antigens in humans: relationship to dose, CD1a-DR+ epidermal macrophage induction, and Langerhans cell depletion.

Increasing UVB radiation at the earth's surface might have adverse effects on in vivo immunologic responses in humans. We prospectively randomized subjects to test whether epicutaneous immunization is altered by prior administration of biologically equalized doses of UV radiation. Multiple doses of antigens on upper inner arm skin (UV protected) were used to elicit contact sensitivity responses, which were quantitated by measuring increases in skin thickness. If a dose of UVB sufficient to induce redness (erythemagenic) was administered to the immunization site prior to sensitization with dinitrochlorobenzene (DNCB), we noted a marked reduction in the degree of sensitization (P less than 0.0006) that was highly dose responsive (r = 0.98). Even suberythemagenic UV (less than a visible sunburn) resulted in a decreased frequency of strongly positive responses (32%) as compared to controls (73%) (P = 0.019). The rate of immunologic tolerance to DNCB (active suppression of a subsequent repeat immunization) in the groups that were initially sensitized on skin receiving erythemagenic doses of UV was 31% (P = 0.0003). In addition, a localized moderate sunburn appeared to modulate immunization with diphenylcyclopropenone through a distant, unirradiated site (41% weak responses) as compared to the control group (9%) (P = 0.05). Monitoring antigen presenting cell content in the epidermis revealed that erythemagenic regimens induced CD1a-DR+ macrophages and depleted Langerhans cells. In conclusion, relevant and even subclinical levels of UV exposure have significant down modulatory effects on the ability of humans to generate a T-cell-mediated response to antigens introduced through irradiated skin.

Antigens, CD↗
PubMed1992

Inefficacy of extracorporeal photochemotherapy in the treatment of B-cell chronic lymphocytic leukemia: preliminary results.

Because extracorporeal photopheresis has been shown to be clinically effective in Sezary syndrome, a disease characterized by a circulating malignant clone, we initiated a pilot study of its use in B-cell chronic lymphocytic leukemia (B-CLL) to see if it could be similarly effective. We treated three patients with Rai stage III and IV B-CLL with photopheresis (3 consecutive days a week every 3 weeks) and followed serial clinical and immunologic parameters. While we noted no major toxicity, there was neither clinical response to treatment nor marked improvement in white counts or mitogen assays. We conclude that photopheresis was not effective in inducing remission in this pilot study of advanced stage B-CLL patients.

Adult↗
PubMed1992

Medieval example of metastatic carcinoma: a dry bone, radiological, and SEM study.

An elderly male skeleton from medieval Canterbury displayed evidence of DISH and metastatic carcinoma. The dry bone findings, SEM, and radiography suggest a primary focus in the prostate. A review of the palaeopathological literature has shown that such a finding is extremely rare in archaeological remains. This is the first reported case of prostatic carcinoma from medieval England.

Bone Neoplasms↗
PubMed1992

Immature teratoma of the ovary--an unusual case.

A 30-year-old female was found to have a malignant immature teratoma of the ovary 14 years ago. This was treated with surgery followed by chemotherapy. Two years later, hepatic metastasis was discovered and treated with different multiple-agent chemotherapy, resulting in transformation or evolution into a mature teratoma form of disease. Twelve years later, this disease underwent malignant degeneration and transformed into a metastatic adenocarcinoma. This case report illustrates that malignant ovarian immature teratoma, teratocarcinoma, like its testicular counterpart, can evolve or differentiate into an apparently benign form of disease, but ultimately leads to death due to subsequent malignant transformation into new forms of malignancy arising from any of the three primordial germ cell layers.

Adenocarcinoma↗
PubMed1992

Experience with rigid fixation of mandibular fractures and immediate function.

The results of using rigid fixation for 75 mandibular fractures in 52 patients and allowing immediate function were retrospectively analyzed. Sixteen percent of fractures developed postoperative infection. All infections were in fractures associated with teeth; none occurred in fractures fixed within 24 hours of injury. Angle and posterior body fractures were most likely to become infected. Fractures with improperly applied rigid fixation also were subject to a high infection rate. It was unusual for infection involving this type of treatment to prolong the course of therapy or affect the final outcome.

Adolescent↗
PubMed1992

Use of ciprofloxacin in an infant with ventriculitis.

Ciprofloxacin was used successfully in a neonate with ventriculitis caused by a multiply resistant strain of Enterobacter cloacae. Limited pharmacokinetic data indicated that adequate concentrations of drug could be attained in cerebrospinal fluid.

Cerebral Ventricles↗
PubMed1992

Systematic bias in successive movement repetitions.

In three separate studies, independent groups of subjects made either 10 subjectively defined steps of the same length, 10 subjectively defined linear arm movements of the same extent, or 10 successive movements of a single experimenter defined linear arm movement. In each case, the repetitions of these movements became increasingly longer. This is an initial report of what may be a ubiquitous phenomenon.

Journal Article↗
PubMed1992

Periocular lymphoproliferative diseases: natural history, prognostic factors, and treatment.

A study was undertaken to assess the natural history of periocular lymphoproliferative diseases, identify key prognostic factors, and clarify the role of orbital irradiation. Thirty-four patients with periocular lymphoproliferative disease were treated with orbital irradiation between 1975 and 1990. Eight patients had atypical lymphoid infiltrate, and 26 had malignant lymphoma. Forty-three eyes were irradiated with en-face electrons or 6-MV photons. Five-year disease-free survival for all stages was 65%; it was not significantly affected by bilaterality or site. Stage, distinction between atypical lymphoid infiltrate and malignant lymphoma, and working formulation grade were important prognostic indicators. A complete response during irradiation was achieved in 24 of 43 (56%) eyes at a median dose of 2,400 cGy, and a partial response was achieved in 19 (44%), with resolution at a median of 2.8 months. Patients with periocular reactive lymphoid hyperplasia or atypical lymphoid infiltrate may have or are at significant risk of developing lymphoma and dissemination. Local treatment remains important; orbital irradiation achieves prompt local control with acceptable morbidity.

Adult↗
PubMed1992

Does Calcium Supplementation Reduce the Risk of Urinary Oxalate Calculi after Jejunoileal Bypass for Morbid Obesity?

Twelve patients having received an end-to-side jejunoileal bypass operation for morbid obesity 6-10 years previously were studied over three periods of 2 weeks each. The first period was used for baseline observations without any treatment. For the second period patients were randomly assigned to equimolar (75 mmol/day) oral calcium supplements administered either as a slow release or as a bolus calcium preparation. During the third period these treatments were crossed over. The calcium preparations used caused equal reductions in frequency of bowel movements. Both preparations increased serum calcium and serum phosphate, but significance (p < 0.05) was reached only during supplementation with the slow-release preparation. Despite the Intended raising of serum calcium levels, none of the preparations influenced the 24-hour urine oxalate to creatinine ratio or the urine stone index. There are several other reasons for supplying extra calcium after intestinal bypass procedures, but our data do not support the concept of preventing renal stone formation by means of calcium supplementation.

Journal Article↗
PubMed1992

Physiological response to water aerobics.

Heart rate (HR) and oxygen uptake (VO2) measured during water aerobics (WA) were compared to maximal values obtained during an incremental treadmill test to assess the energy demand and potential cardiorespiratory (CR) training effects of WA. Sixteen college-age females served as subjects (mean +/- SD = 20.4 +/- 1.6 years). WA elicited a mean HR of 162 b.min-1 and a mean VO2 of 18.4 ml.kg-1.min-1 which represented 74% of HR reserve, 82% of maximal HR, and 48% of VO2 max. Average caloric expenditure was 5.7 kcal.min-1. HR values for WA were consistent with guidelines established by the American College of Sports Medicine for developing and maintaining CR fitness in healthy adults. However, the VO2 fell just below the recommended minimum threshold level. It was concluded that WA may provide an attractive alternative to traditional modes of exercise for improving CR fitness, however, HR measures may overestimate the metabolic intensity of the exercise.

Adult↗
PubMed1991

The B lymphocyte adhesion molecule CD22 interacts with leukocyte common antigen CD45RO on T cells and alpha 2-6 sialyltransferase, CD75, on B cells.

Functional maturation of B lymphocytes correlates with expression of the B lineage-specific cell surface glycoprotein CD22. Two CD22 polypeptides have been characterized and suggested to play a role in B cell-B cell interaction as well as in B cell adhesion to monocytes. In this work we provide evidence that CD22 is directly involved in the cognate interaction between B and T cells. One of the two CD22 polypeptides, CD22 beta, interacts with a specific ligand on a subpopulation of CD4+ T cells. Our results suggest that the T cell ligand of CD22 is CD45RO, an isoform of the leukocyte common antigen class of phosphotyrosine phosphatases associated with the helper T cell phenotype. We further demonstrate that CD22 recognizes a second ligand, CD75, expressed predominantly on activated B cells and shown to be a cell surface alpha 2-6 sialyltransferase.

Antibodies, Monoclonal↗