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Biomedical subjects

M J Murray

Publications and source records attributed to M J Murray.

At least 73 records · Page 4Linked to original sources
PubMed1996

A direct relationship between thyroid enlargement and breast cancer.

Despite extensive study, evidence to support a direct relationship between diseases of the thyroid and breast has not been established. In this study thyroid volume was assessed by ultrasound in 200 patients with breast cancer and 354 with benign breast disease. Results were compared to appropriate female control groups. Both mean thyroid volume (21.1 +/- 1.4 mL) and the percentage of individual patients with enlarged (> 18.0 mL) thyroid glands (41.5%) were significantly greater in the breast cancer group than equivalent values (13.2 +/- 0.5 mL and 10.5%, respectively) in age-matched controls (P < 0.01 in both cases). The mean thyroid volume of 14.5 +/- 0.34 mL in patients with benign breast disease was also significantly greater than that of 12.5 +/- 0.38 mL in younger controls (P < 0.01). The results support a direct association between breast cancer and increased thyroid volume as mean thyroid volumes and the percentage of individual patients with enlarged thyroid glands were similar in those studied both before (20.8 +/- 1.3 mL and 43.0%) and after (21.4 +/- 1.6 mL and 40.0%) therapies for breast cancer. Although there is no evidence that thyroid enlargement represents a risk factor for breast cancer, the results emphasize the importance of raising the consciousness of the coincidence of both disorders.

Adult↗
PubMed1996

How should hospitals relate to Medicare HMOs?

With the increased emphasis on the development of Medicare managed care plans, healthcare organizations should explore Medicare managed care products and structures available in the marketplace and assess how they best fit with their overall strategy and strengths. An organization's Medicare strategy might involve protecting the organization's current Medicare population, increasing network linkages, and gaining experience with managed care and capitated payment contracting. Medicare, however, is only one of many potential payers for organizations. A strategy developed around Medicare, therefore, also must support the organization's overall managed care strategy.

Aged↗
PubMed1996

Sudden exertional death in a soldier with sickle cell trait.

Most family physicians regard sickle cell trait (SCT) as a benign condition. But in special circumstances SCT can have deadly consequences. SCT affects 8% of the black population. Most of the cases of sudden exertional death (SED) in those with SCT have occurred during military basic training. A retrospective review of all soldiers in basic training found that those with SCT had a 40-fold increased risk of SED. This paper discusses an individual case of SED that occurred at Fort Sill, Oklahoma. A literature review makes comparisons to our index case. The current Army Medical Corps recommendations for prevention of SED as well as the current military SCT screening policy will be discussed. Prospective studies are needed to evaluate the efficacy of the currently recommended preventative guidelines as well as to more fully evaluate the potential for SCT to cause significant morbidity and mortality during military basic training.

Adult↗
PubMed1996

Effects of intermittent feed deprivation, intermittent feed deprivation with ranitidine administration, and stall confinement with ad libitum access to hay on gastric ulceration in horses.

OBJECTIVES: To determine the effect of decreasing gastric acidity in a feed-deprivation protocol on induction of gastric ulcers, and to determine whether stall confinement may be a factor contributing to gastric ulceration in horses. ANIMALS: 8 adult horses, 4 geldings and 4 mares, 3 to 8 years old, and 7 adult horses, 5 geldings and 2 mares, 4 to 11 years old. PROCEDURE: Gastric ulceration was induced in horses by alternating 24-hour periods of feed deprivation and ad libitum access to hay, for a total of 96 hours' feed deprivation. This protocol was repeated with the horses receiving the histamine type-2 receptor (H2) antagonist ranitidine (6.6 mg/kg of body weight, PO, q 8 h). In another group of horses, severity of gastric lesions was compared after 7 days' pasture turnout and 7 days' stall confinement with ad libitum access to hay. Gastroscopy was performed after each feed-deprivation protocol was completed, and total lesion area in the gastric squamous epithelial mucosa was measured. Gastroscopy was performed at the beginning and end of 7 days' pasture turnout and 7 days' stall confinement. RESULTS: Alternating periods of feed deprivation resulted in erosion and ulceration of the gastric squamous epithelial mucosa of each horse. Concurrent treatment with ranitidine resulted in significantly (P < 0.05) less area of ulceration in the gastric squamous epithelial mucosa. After 7 days' stall confinement, 6 of 7 horses had ulceration in the gastric squamous epithelial mucosa, and 1 horse had a lesion in the glandular mucosa, whereas after 7 days' pasture turnout, 2 horses had reddening of the gastric squamous mucosa along the lesser curvature (P < 0.05). CONCLUSIONS AND CLINICAL RELEVANCE: Severe ulceration of the gastric squamous epithelial mucosa, caused by excess acidity, can develop rapidly in horses deprived of feed or not consuming feed. Suppression of gastric acidity with the histamine type-2 receptor antagonist ranitidine effectively minimized the area of ulceration caused by feed deprivation. Compared with being turned out to pasture, stall confinement alone appears to be an important factor in the development of gastric ulcers in horses, probably as a result of altered eating behavior.

Animals↗
PubMed1995

Evaluating contrast-enhancing brain lesions in patients with AIDS by using positron emission tomography.

OBJECTIVE: To determine whether a noninvasive method for evaluating contrast-enhancing brain lesions in patients with the acquired immunodeficiency syndrome (AIDS) can accurately differentiate between lymphoma and nonlymphoma diagnoses. This method is based on Toxoplasma serologic testing and positron emission tomography. DESIGN: Prospective, nonrandomized, criterion-standard clinical study. SETTING: An academic center in the mid-southeastern United States. PATIENTS: 20 patients with AIDS and contrast-enhancing brain lesions. INTERVENTIONS: Positron emission tomographic scanning and Toxoplasma serologic testing. MAIN OUTCOME MEASURE: Diagnoses were confirmed by clinical response, autopsy, or brain biopsy. RESULTS: Eight patients had a confirmed diagnosis of toxoplasmosis, six had lymphoma, four had other diagnoses, and two were not evaluable. Seven of eight patients with toxoplasmosis had positron emission tomographic scans; all of these scans showed hypometabolic lesions consistent with a nonlymphoma diagnosis. The six patients with lymphoma all had hypermetabolic lesions on positron emission tomographic scans. The difference between these two sets of results was statistically significant (P < 0.001, Fisher exact test, two-tailed). The anti-Toxoplasma titer was greater than or equal to 1:4 in all patients with confirmed toxoplasmosis who had serologic testing and in three of six patients with lymphoma. CONCLUSIONS: Evaluating contrast-enhancing brain lesions in patients with AIDS by using Toxoplasma serologic testing and positron emission tomography can accurately guide therapy and obviate the need for most brain biopsies in these patients. A larger, national, multicenter study is needed to confirm our findings and to determine the effect of earlier diagnosis and treatment on morbidity and mortality in patients with AIDS and primary central nervous system lymphoma.

AIDS-Related Opportunistic Infections↗
PubMed1995

The size of the anterior spinal artery in relation to the arteria medullaris magna anterior in humans.

We studied the anterior spinal artery (ASA) in 25 cadaveric human spinal cords to determine the cross-sectional area of the ASA cephalad and caudal to the entry of the arteria medullaris magna anterior (AMMA). Spinal cords were removed en bloc and latex was injected into the AMMA. The preparations were then fixed in formalin, embedded in paraffin, sectioned, mounted, and stained with hematoxylin and eosin. The diameter and cross-sectional area of the ASA 1 cm above and 1 cm below the entry of the AMMA were measured. The mean radius of the ASA above the entry of AMMA was 0.14 +/- 0.03 mm compared to 0.28 +/- 0.05 mm below the entry of the AMMA (P < 0.001). According to Poiseuille's equation, the resistance to blood flow in the ASA cephalad to the AMMA would be 14.8 times greater than the resistance to blood flow caudal to the AMMA. This resistance could affect the distribution of blood flow in the distal spinal cord whenever flow in the AMMA or distal ASA is altered.

Adult↗
PubMed1995

Determination of normal versus abnormal activated partial thromboplastin time and prothrombin time after cardiopulmonary bypass.

OBJECTIVE: The study's objective was to determine the prothrombin time (PT) and activated partial thromboplastin time (aPTT) values that differentiated normal from excessively bleeding patients immediately after cardiopulmonary bypass (CPB). DESIGN: A prospective blinded study. SETTING: A large academic medical center. PARTICIPANTS: 148 patients were studied. INTERVENTIONS: aPTT and PT were determined by the hospital laboratory and the Biotrack 512 Coagulation Monitor (Ciba Corning Diagnostics, Medfield, MA) from an arterial whole blood sample obtained 10 minutes after protamine administration. Patients were subjectively and objectively defined as "bleeders" or "nonbleeders" with blinded observers. MEASUREMENTS AND MAIN RESULTS: The specificity and sensitivity were determined by a receiver operating characteristic (ROC) analysis. Twenty-three of 148 patients (14.9%) were characterized as bleeders. The laboratory PT had a maximal specificity and sensitivity of 78% and 75%, respectively, at a value of 15.4 s, with a negative and positive predictive value of 93% and 33%, respectively. The maximal specificity and sensitivity of the laboratory aPTT was 64% and 76%, respectively, at a value of 46 s, with a negative and positive predictive value of 89% and 33%, respectively. aPTT and PT approached normal values after 12 hours in the intensive care unit. CONCLUSION: The aPTT and PT values that produce the maximal sensitivity and specificity in the ROC analysis may be helpful to differentiate patients who are bleeding excessively from those patients who are not after CPB and to guide transfusion of blood products. New whole blood coagulation devices with rapid turn-around times had similar predictive value for bleeding tendency compared with standardized laboratory tests.

Adult↗
PubMed1995

Outcome of extracorporeal shockwave lithotripsy monotherapy for large renal calculi: effect of stone and collecting system surface areas and cost-effectiveness of treatment.

The treatment options for large renal calculi are controversial. We report on our experience with 65 treatments of renal calculi > 3 cm using extracorporeal shockwave lithotripsy (SWL) monotherapy. We stratified our results according to stone and collecting system surface areas (measured by computer image analyses), stone location, and stone type. The overall success rate of SWL monotherapy was 27% at 3 months. The best stone-free rate (60%) was obtained for stones < 500 mm2 and located primarily within the renal pelvis. The stone-free rate for stones with surface areas > 1000 mm2 was only 8%. None of the cystine stones was treated successfully, whereas 80% of patients with uric acid stones became stone free. We estimated an average cost of $67,048 to render a patient with a large renal calculus stone free using SWL monotherapy. We recommend that other treatment options, such as percutaneous nephrolithotomy, be considered as first-line therapy for large renal calculi.

Adult↗
PubMed1995

Comparison of the infusion requirements and recovery profiles of vecuronium and cisatracurium 51W89 in intensive care unit patients.

The selection and administration of neuromuscular blocking (NMB) drugs in intensive care unit (ICU) patients remain controversial. We compared the dose-response and recovery pharmacodynamics of a new intermediate-acting NMB drug, cisatracurium besylate, to the intermediate-acting NMB drug, vecuronium (VEC), in a prospective, randomized, double-blind, multicenter study in critically ill adults. After informed consent, 58 mechanically ventilated ICU patients from five medical centers were randomized to receive either cisatracurium or VEC. Fifty-four of the 58 patients received NMB drugs before entering this study but demonstrated at least partial recovery (> or = one twitch) in the train-of-four (TOF) response before initiation of the NMB study drug. NMB drug infusion was titrated by peripheral nerve stimulation to maintain at least one twitch in the TOF response. NMB drugs were infused for 1-5 days. After discontinuation of NMB drug infusion, recovery of neuromuscular transmission was monitored with an accelerometer. NMB drug infusion for 28 cisatracurium patients averaged 2.6 +/- 0.2 (mean +/- SEM) micrograms.kg-1.min-1 with a mean duration of 80 +/- 7 h. After discontinuing cisatracurium administration, recovery to 70% TOF ratio averaged 68 +/- 13 min. The mean infusion rate for 30 VEC patients was 0.9 +/- 0.1 micrograms.kg-1.min-1 with a mean duration of 66 +/- 12 h. Neuromuscular recovery after VEC averaged 387 +/- 163 min, which was significantly longer (P = 0.02) than that after cisatracurium. Prolonged recovery of neuromuscular function after discontinuation of NMB drug infusion (identified by the primary investigator at each medical center) was reported in two cisatracurium patients and 13 VEC patients (P = 0.002), and occurred despite the routine use of neuromuscular twitch monitoring. Seven VEC and one cisatracurium patients died during the infusion of study drug or within 48 h after discontinuation of the NMB drug infusion. In summary, we found recovery of neuromuscular function after discontinuation of NMB drug infusion in ICU patients is significantly faster with cisatracurium than with VEC. In addition, routine neuromuscular monitoring was not sufficient to eliminate prolonged recovery and myopathy in ICU patients.

Adult↗
PubMed1995

Analgesia after thoracotomy: effects of epidural fentanyl concentration/infusion rate.

After thoracotomy some patients have discomfort, primarily in the rostral portion of their incisions. In this prospective, randomized study in 66 patients after lateral thoracotomy we evaluated whether, for equal fentanyl dosage in micrograms per kilogram, epidural infusion (lumbar catheter) of fentanyl 5 micrograms/mL provided better segmental analgesia (including the rostral portion of the incision) than a 10-micrograms/mL concentration infused at a rate half that used in the 5-micrograms/mL group. Ketorolac was used as an analgesic adjunct for nonincisional pain. Postoperative epidural fentanyl infusion included a 1-microgram/kg initial dose and an initial infusion rate of 1 microgram.kg-1.h-1 in both the 5-micrograms/mL and 10-micrograms/mL groups. Patients were evaluated for comfort level and pain relief while resting, taking a deep breath, coughing, and ambulating at eight times over 3 days using two visual analog scales for overall comfort and a verbal rating score (VRS) for segmental analgesia. There were no significant differences in demographics, surgical procedure, intraoperative fentanyl dose, side effects, rates of epidural fentanyl infusion, or total epidural fentanyl doses at 12, 24, 36, 48, and 60 h postbolus. Analgesia was effective in both groups. Although overall comfort levels were lower (i.e., indicated greater comfort) in the 5-micrograms/mL group in 6 of 8 visual analog scores (VASs) for comfort level and 20 of 24 VRSs for comfort level scores, and mean VRSs for the rostral portion of the incision were lower (i.e., indicated greater comfort) in the 5-micrograms/mL group at 21 of 24 evaluation subsets (one statistically significant), statistical significance was achieved in only six evaluation subsets.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1995

Double-blind, randomized, multicenter study of doxacurium vs. pancuronium in intensive care unit patients who require neuromuscular-blocking agents.

OBJECTIVE: To compare the neuromuscular-blocking and hemodynamic effects of doxacurium vs. pancuronium administered by intermittent bolus to intensive care unit (ICU) patients who required neuromuscular block to facilitate mechanical ventilation for > or = 24 hrs. DESIGN: A multicenter, prospective, double-blind, randomized study comparing doxacurium, a new benzylisoquinolone neuromuscular-blocking agent, with pancuronium. SETTING: ICUs of three tertiary care hospitals. PATIENTS: Forty critically ill patients (29 male, 11 female) with an average age of 52.5 yrs (range 19 to 80). INTERVENTIONS: With approval of our Institutional Review Boards and after obtaining informed consent, 40 critically ill patients were entered into the study. Histories and the results of physical examinations were recorded, laboratory data were collected, and Acute Physiology and Chronic Health Evaluation (APACHE) II scores were calculated during the 8 hrs before the start of the study medication. Patients received either doxacurium (initial dose of 0.04 mg/kg) or pancuronium (initial dose of 0.07 mg/kg) by bolus injection with continuous measurement of vital signs every minute for 15 mins. We measured the degree of neuromuscular blockade using a peripheral-nerve stimulator to measure the Train-of-Four count. Patients were rebolused (doxacurium dose of 0.025 mg/kg, pancuronium dose of 0.05 mg/kg) based on clinical criteria, which were substantiated by measurement of the Train-of-Four count. The neuromuscular-blocking drugs were stopped when the patient no longer required paralysis or after 5 days of therapy, whichever came first. Group comparisons were made using repeated measures analysis of variance, Fisher's exact test, and two sample t-tests, when appropriate. Spearman's rank-correction coefficients were calculated to assess the relationship of onset time and recovery time with all baseline laboratory values and the APACHE II scores. A p < .05 was used to establish statistical significance. MEASUREMENTS AND MAIN RESULTS: There were no differences between the two groups with respect to age, gender, or APACHE II scores. There were no differences between groups in terms of adverse experiences, nor with respect to time of onset of block, number of doses, or the duration of neuromuscular blockade (2.6 vs. 2.2 days for doxacurium vs. pancuronium, respectively). There was a statistically significant increase in heart rate after the initial dose of pancuronium (120 +/- 23 vs. 109 +/- 22 beats/min postinjection vs. preinjection, respectively; p < .05) without any differences noted after doxacurium (107 +/- 21 vs. 109 +/- 21 beats/min, respectively). Furthermore, once neuromuscular block was discontinued, the pancuronium group had a more prolonged and variable recovery time (279 +/- 229 mins) compared with the doxacurium group (138 +/- 46 mins, p < .05). CONCLUSIONS: In critically ill patients requiring neuromuscular block for > 24 hrs, doxacurium was well tolerated without evidence of tachycardia and with a relatively prompt recovery profile.

APACHE↗