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J Ramp

Publications and source records attributed to J Ramp.

5 recordsLinked to original sources
PubMed1992

Affinity binding assay of glycohemoglobin by two-dimensional centrifugation referenced to hemoglobin A1c.

We describe an automated assay of glycohemoglobin performed with the Abbott Vision analyzer. The assay is based on batch affinity-extraction with 3-aminophenylboronic acid-derivatized agarose beads. Reagents are packaged in a disposable test pack. Whole-blood specimens are hemolyzed with saponin within a glass capillary tube inserted into the test pack. The sample is automatically diluted with, mixed with, and separated from the solid-phase reagent. Bichromatic absorbance readings are used to calculate the percentage of hemoglobin bound. Based on the linear correlation between affinity-measured glycohemoglobin and HPLC-measured hemoglobin A1c, the percentage of hemoglobin bound is converted to a "standardized %HbA1c" result by use of regression parameters stored during a calibration run. The combination of affinity methodology with standardization by reference to HPLC produces values directly comparable with those obtained by methods specific for HbA1c. The method produces 10 results within 15 min. The assay operates with CVs < 5%, and the results correlate highly with those by ion-exchange and affinity minicolumn methods, and by ion-exchange HPLC.

Autoanalysis↗
PubMed1986

Adaptation during surgical stress. A reevaluation of the role of glucocorticoids.

Pharmacologic doses of glucocorticoids are administered to patients with adrenal insufficiency during operative procedures to prevent hemodynamic instability, cardiovascular collapse, and death. Since these supraphysiologic doses might not be necessary and might have adverse effects, we examined the effects of different doses of glucocorticoids on hemodynamic adaptation during surgical stress in adrenalectomized primates. Sham-adrenalectomized placebo-treated animals served as controls. Adrenalectomized monkeys were maintained for 4 mo on physiologic glucocorticoid and mineralocorticoid replacement. The adrenalectomized monkeys were then stratified into three groups receiving, respectively, subphysiological (one-tenth the normal cortisol production rate), physiological, or supraphysiological (10 times the normal cortisol production rate) cortisol (hydrocortisone) treatment. 4 d later a cholecystectomy was performed. The intraoperative hemodynamic and metabolic parameters, perioperative survival rates, and postoperative wound healing were compared. The subphysiologically treated group was hemodynamically unstable before, during, and after surgery and had a significantly higher mortality rate than control. In this group, arterial blood pressure was low, and the cardiac index, systemic vascular resistance index, and left ventricular stroke work index were all reduced, suggesting decreased cardiac contractility and blood vessel tone. In contrast, the physiologically replaced group was indistinguishable from either supraphysiologically treated animals or sham-operated controls. All groups had similar metabolic profiles and normal wound healing. These findings suggest that the permissive actions of physiologic glucocorticoid replacement are both necessary and sufficient for primates to tolerate surgical stress. Supraphysiological glucocorticoid treatment has no apparent advantage during this form of stress in the primate.

Adaptation, Physiological↗
PubMed1978

Management of penetrating heart wounds.

The records of ninety-two patients treated between 1965 and 1976 at the Boston City Hospital for penetrating wounds of the heart were reviewed and the results were compared with a previous series of twenty-five patients admitted to the same institution between 1956 and 1964. The annual incidence rose from 2.8 cases during the first period to 8.0 during the more recent years. Gunshot wounds increased in frequency in the second period. The overall mortality was similar in the two series. However, there were more complex wounds and agonal patients subjected to immediate emergency room thoracotomy during the second phase of this experience. The salvage rate in the latter group of patients gradually improved and averaged 24% between 1965 and 1976. These data indicate that an aggressive approach, including the use of immediate thoracotomy, to the agonal patient with a heart wound will be rewarded with salvage of some patients.

Adolescent↗