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Biomedical subjects

J Grass

Publications and source records attributed to J Grass.

9 recordsLinked to original sources
PubMed1999

Elimination of cytokine production in stored platelet concentrate aliquots by photochemical treatment with psoralen plus ultraviolet A light.

BACKGROUND: Cytokines generated in platelet concentrates (PCs) during storage have been implicated as possible mediators of febrile nonhemolytic transfusion reactions. Two potential methods of white cell inactivation were compared for their ability to reduce cytokine synthesis in pooled random-donor PC aliquots: treatment with gamma-radiation and photochemical treatment (PCT) using psoralens and ultraviolet A light. STUDY DESIGN AND METHODS: ABO-matched PC aliquots were pooled and divided into separate aliquots. Aliquots (20 mL) were taken from each pool to serve as an untreated control and to undergo gamma-radiation. Aliquots were treated by using either gamma-radiation (2500 or 5000 cGy) or virucidal PCT. PCT with the psoralens 8-methoxypsoralen (8-MOP), aminomethyltrimethyl psoralen (AMT), and S-59 was investigated. PC aliquots were stored for 7 days and analyzed for levels of interleukin 8 by use of an enzyme-linked immunosorbent assay. Levels of DNA adduct formation were determined by using 3H-labeled psoralens. RESULTS: Levels of interleukin 8 in the untreated random-donor PC aliquots increased with increasing white cell counts, but they were not affected by pooling. The untreated control aliquots and the aliquots treated with gamma-radiation had significant increases in levels of interleukin 8 after 5 to 7 days of storage (p<0.05). PCT with S-59 resulted in a significant reduction in cytokine synthesis (p<0.05). Day 5 to 7 levels of interleukin 8 did not differ significantly from Day 0 levels. Inhibition of interleukin 8 production by PCT increased with increasing levels of DNA modification (S-59 > AMT > 8-MOP). CONCLUSION: PCT that utilizes S-59 has been developed to inactivate potential viral and bacterial pathogens in PC aliquots while maintaining in vitro platelet function. These data demonstrate that PCT of aliquots of pooled PC aliquots before storage also prevents white cell cytokine synthesis during storage. PCT may therefore offer the potential for reducing cytokine-associated febrile nonhemolytic transfusion reactions.

Blood Preservation↗
PubMed1999

Predicting the difficult neuraxial block: a prospective study.

UNLABELLED: Anticipated technical difficulty is one factor that can influence the anesthesiologist's decision to perform neuraxial (spinal or epidural) blockade. Problems during the procedure may be associated with patient dissatisfaction, neurologic sequelae, or hematoma. We designed this study of 595 neuraxial blocks to determine whether any patient characteristics would be useful in predicting a difficult neuraxial block. Before the procedure, the following data were noted: demographic data, body habitus (normal, thin, muscular, obese), spinal landmarks (good = easily palpable spinous processes, poor = difficult to palpate spinous processes, none = unable to positively identify spinous processes), and spinal anatomy (assessed by inspection and examination as normal or deformed). We noted the technique, approach, needle type, needle gauge, etc. We also recorded whether the procedure was completed at the first (first-level success) or second spinal level and the total number of new skin punctures (attempts) necessary to complete the procedure. Of all the factors considered, the quality of landmarks best correlated with technical difficulty as measured by both first-level success and number of attempts. Abnormal spinal anatomy correlated with difficulty as measured by number of attempts. Body habitus also correlated with difficulty, but only as measured by number of attempts. There was no association between either measure of difficulty and any of the following: age, sex, spinal versus epidural, approach, needle type, needle gauge, or training level of the provider. Thoracic epidurals were less difficult than lumbar epidurals by both measures of difficulty. We conclude that body habitus does not seem to be the best predictor of technical difficulty. An examination of the patient's back for the quality of landmarks and obvious anatomical deformity better predicts the ease or difficulty of neuraxial block. Other factors seem to have little or no influence on the difficulty of neuraxial block procedures. IMPLICATIONS: We studied a number of factors, including equipment, technique, and patient characteristics, that may indicate the ease or difficulty of performing neuraxial (spinal and epidural) blocks. Of these factors, only patient characteristics had significant predictive value. We found that an examination of the patient's back for the quality of landmarks and obvious anatomical deformity better predicts the ease or difficulty of neuraxial block than does body habitus.

Adolescent↗
PubMed1997

Adjuvant chemotherapy for the treatment of intracranial ependymoma of childhood.

BACKGROUND: Current treatment for childhood intracranial ependymomas with surgery and radiation therapy (RT) yields 5-year survival rates ranging from 50-70% after complete resection to 0-30% after incomplete surgical resection. The role of chemotherapy in the treatment of ependymoma has not been established. In this pilot study, children with newly diagnosed intracranial ependymoma were treated with RT and chemotherapy using agents comparable to those found to be active in the treatment of intracranial ependymoma in infants. METHODS: Nineteen children age 3-14 years (median, 7.5 years) were treated with postoperative RT and chemotherapy. Chemotherapy was comprised of carboplatin, 560 mg/m2, with vincristine, 1.5 mg/m2, weekly for 3 weeks, alternating at 4-week intervals with ifosfamide, 1.8 g/m2, and etoposide, 100 mg/m2, for 5 consecutive days for a total of 4 cycles. RESULTS: The 5-year progression free survival (PFS) estimate was 74%. The extent of surgical resection was not a significant prognostic factor in this study. By contrast, ependymomas located in the posterior fossa were associated with a higher rate of progression (P = 0.036). Toxicity, limited predominantly to myelosuppression, was manageable. CONCLUSIONS: The PFS for children with postoperative residual ependymoma treated with RT and chemotherapy in this study was higher than published survival results for RT alone. These results suggest a role for multialkylator chemotherapy in incompletely resected intracranial ependymoma and provide the rationale for a randomized trial comparing this strategy with conventional postoperative RT.

Adolescent↗
PubMed1996

Cardiovascular collapse during anesthesia in a patient with preoperatively discontinued chronic MAO inhibitor therapy.

We describe a patient in whom long-term monoamine oxidase (MAO) inhibitor therapy was discontinued 20 days before surgery with general anesthesia. This patient developed severe perioperative hypotension after administration of 10 mg of bupivacaine through an epidural catheter, which was corrected only after potent vasopressor therapy. We attribute this hemodynamic instability to attenuation of this patient's sympathetic tone based on several mechanisms: (1) residual effect of long-term administration of MAO inhibitor that caused a decrease in the number of beta-adrenergic receptors (adrenergic subsensitivity due to receptor down-regulation), (2) recovered MAO activity causing effective degradation of sympathetic amines, and (3) combined attenuating effects of general and epidural anesthesia on sympathetic tone.

Aged↗
PubMed1981

The influence of early age mastectomy and unilateral ovariectomy on reproductive performance of the bovine.

The effects of mastectomy and unilateral ovariectomy and their interaction during the postpartum period were examined in 26 Angus heifers. At birth, the animals were assigned to a 2 x 2 factorial arrangement of treatments: mastectomy and unilateral ovariectomy, mastectomy, unilateral ovariectomy and unoperated suckled control. Surgeries were performed at approximately 2 months of age, and animals were observed through three consecutive postpartum intervals (PP1, PP2, and PP3). There were no significant influences of mastectomy or ovariectomy on age at puberty, age at first conception or services required for first conception. Mastectomy reduced the number of days from parturition to ovulation (PP1, 32.1 vs 52.5, P less than .01; PP2, 21.6 vs 59.9, P less than .01; PP3, 20.6 vs 46.7, P less than .01) The interval from parturition to first estrus was shorter for heifers in the mastectomized group (PP1, 45.3 vs 76.2, P less than .05; PP2, 28.7 vs 69.9, P less than .01; PP3, 32.4 vs 62.3, P less than .05) as was the interval from parturition to conception during PP2 (60.0 vs 104.9, P less than .05). The interval between calvings was shorter for heifers in the mastectomized group than for controls, but the difference was significant only between the second and third parturitions: 338.5 vs 399.2 (P less than .01). Mastectomy reduced the standard deviation for the interval between parturition 2 and parturition 3 (55.9 vs 15.9; P less than .01), the interval between parturition and return to estrus in PP2 (56.3 vs 11.4; P less than .01) and the interval from calving to conception PP1 (92.2 vs 31.4; P less than .01). Unilateral ovariectomy did not have a significant influence on any of the postpartum intervals, nor were there any significant interactions.

Age Factors↗