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Biomedical subjects

J M Weaver

Publications and source records attributed to J M Weaver.

At least 19 recordsLinked to original sources
PubMed2000

Hemicorporectomy.

In hemicorporectomy, or translumbar amputation, the bony pelvis, pelvic contents, lower extremities, and external genitalia are removed following disarticulation of the lumbar spine and transection of the spinal cord. Malignancies of the pelvic organs, skin, or musculoskeletal structures, usually locally advanced, may be indications for hemicorporectomy. The absence of systemic metastasis must be demonstrated before considering hemicorporectomy. Sacral decubitus ulcers and other complications of paraplegia represent the most frequent benign indications. Hemicorporectomy is a complex, multistep procedure with significant physiologic and psychologic implications. Postoperative morbidity and mortality rates are high, partly because of the complexity of the procedure itself and partly due to the underlying disease. Detailed planning, from preoperative evaluation to rehabilitation, is the key to a successful outcome. The procedure may be carried out in one stage or in multiple stages, depending on the clinical circumstances. Multidisciplinary collaboration of many health care professionals should be part of the planning process and must be carefully coordinated. Postoperative management requires particular attention to fluid replacement, temperature control, and pulmonary care. Posthospitalization rehabilitation includes the design and construction of a bucket prosthesis. Long-term management issues involve hypertension, weight gain, temperature control, stoma management, and skin care.

Amputation, Surgical↗
PubMed1999

Anesthesia for office-based oral and maxillofacial surgery.

This article is divided into two sections, each encompassing the various aspects of anesthesia used for dental procedures ranging from single tooth extraction to more complex reconstruction and tumor eradication. The various types of anesthesia used for each of these kinds of dental surgery are explored, and the effectiveness and cost efficiency of office-based anesthesia procedures are discussed.

Ambulatory Surgical Procedures↗
PubMed1998

Late follow-up and functional outcome after traumatic reproductive tract injuries in women.

The aim of this study was to assess female reproductive tract injuries and late effects on sexual and reproductive function. This was a review of women presenting to a Level I trauma center with reproductive tract injuries over 12 years. Thirty-one women (average age, 30 years) were divided into coital (19) and noncoital (12) injury groups. One-third of coital trauma presented late, one-fourth was abuse related, and seven women presented in shock. All had vaginal lacerations, and 15 required repair. Follow-up in 6 of 19 (32%) women averaged 4.5 years. Noncoital injuries resulted primarily from vehicular trauma, and two-thirds had associated abdominal injuries. Interventions included: vaginal laceration irrigation/repair (4), salpingectomy (2), ovariectomy (2), repair uterine perforation (1), and emergency cesarean section (2). The average Injury Severity Score was 25, with two deaths. Follow-up in 6 of 10 (60%) survivors averaged 6.1 years. The combined group has had seven subsequent pregnancies, and two women have minor dyspareunia after pelvic fracture. Women with coital injuries may develop shock, requiring rapid resuscitation and operative repair. Noncoital injuries are often associated with multiple severe injuries and require operative intervention. Late sequelae are minimal in both groups, and even severe injuries do not preclude normal pregnancy and sexual function.

Abdominal Injuries↗
PubMed1994

Correlation of human bladder tumor histoculture proliferation and sensitivity to mitomycin C with tumor pathobiology.

This study examined the in vitro proliferation and mitomycin C (MMC) sensitivity of patient bladder tumors as a function of the tumor pathobiology. Surgical specimens of transitional cell carcinoma of the bladder were maintained as histocultures on collagen gels. The thymidine labeling index (LI) was determined by autoradiography and the labeling for proliferating cell nuclear antigen (PCNA) by immunohistochemistry. There was a linear correlation between the thymidine LI and the PCNA LI, but the PCNA LI were quantitatively lower than the thymidine LI. The mean thymidine LI were 30.9, 32.4 and 51.5% for the grade I, II and III tumors, 33.6 and 56.3% for the superficial (Tis, Ta and T1) and invasive (T2-T4) tumors, and 28.9 and 50.9% for the diploid and aneuploid tumors. Analysis of variance indicates that these differences were statistically significant. These data indicate that the proliferation of tumor histocultures paralleled the tumor aggressiveness in vivo. The tumor sensitivity to MMC, measured by the inhibition of the thymidine LI of tumor cells, was studied in 31 tumors. At a 2 hour exposure, as is currently used in intravesical therapy, the MMC concentrations required for 50% inhibition of thymidine LI (IC50) showed a 120-fold intertumor variation (0.102 to 12.4 micrograms./ml.). The sensitivity to MMC inversely correlated with tumor aggressiveness. The IC50 increased with tumor LI (p < 0.05). The mean IC50 were 2.61 and 5.79 micrograms./ml. for superficial and invasive tumors (p < 0.05), 1.06, 3.05 and 4.49 micrograms./ml. for grade I, II and III tumors (p < 0.05), and 2.53 and 4.31 micrograms./ml. for diploid and aneuploid tumors (p = 0.14). These data indicate a large difference in sensitivity of human bladder tumors to MMC, with greater sensitivity for well-differentiated superficial tumors and lesser sensitivity for undifferentiated, invasive tumors.

Autoradiography↗
PubMed1993

Evaluation of a clinical recovery score after general anesthesia.

A clinical recovery score (CRS) assessing recovery after general anesthesia was compared with the Digit-Symbol Substitution Test (DSST), Trieger Test (TT), a patient-completed visual analogue scale for alertness (VAS), and an independent observer's evaluation of recovery. The CRS included ratings of the following parameters: activity, respiration, circulation, consciousness, ambulation, color, and nausea and vomiting. Forty patients requiring the removal of three or four third molars participated in the study. All patients received the same general anesthetic technique. Each patient was evaluated by the five methods preoperatively, on admission to the recovery room, and at 15-min intervals until discharge. The four recovery tests (CRS, DSST, TT, VAS) were evaluated using chi 2 analysis to determine if there was any overall difference among the tests using the observer's determination of home readiness as the standard for discharge. The CRS was significantly more in agreement with the observer's determination than were the paper and pencil tests. The recovery tests were also evaluated with regard to instances of early dismissal or prolonged retention of the patient, again using the observer's determination as the "gold standard." The CRS was the only recovery test devoid of early dismissals. We conclude that the CRS provides a valid, simple measure of recovery that can be readily used in offices providing outpatient anesthesia and in studies measuring clinical recovery from anesthesia or sedation.

Ambulatory Surgical Procedures↗
PubMed1988

Verapamil increases the toxicity of local anesthetics.

The calcium channel blocker verapamil has, in addition to its other properties, been shown to be a local anesthetic. Its concurrent use in a patient undergoing regional anesthesia may, therefore, increase the potential risk for local anesthetic toxicity. To evaluate this possibility, the effect of verapamil on the median lethal dose (LD50) of lidocaine and bupivacaine in mice was determined. Immediate pretreatment with verapamil increased the mortality of mice given the LD50 dose of lidocaine to 74%, and in mice given the LD50 doses of bupivacaine, to 82%. In animals pretreated with verapamil and calcium chloride, the mortality associated with the administration of LD50 doses of lidocaine and bupivacaine decreased to 43% and 48%, respectively, thus returning the mortality rate back to the LD50 of the local anesthetics when administered alone. It seems that the combined administration of local anesthetic and verapamil results in a significant drug interaction: the resulting blockade of sodium and calcium channels apparently impairs membrane function to a greater degree than with either drug alone. Additional investigation is warranted, and caution should be exercised in giving verapamil to patients during regional anesthesia. Should an adverse drug interaction ensue, the administration of calcium may be beneficial.

Animals↗
PubMed1988

The effectiveness of flurazepam as night sedation prior to the removal of third molars.

Anxiety prior to dental treatment is a well-recognized problem. Although oral sedation has been recommended the night before appointments to reduce this anxiety, there are no well-controlled studies to support this claim. The present double-blind cross-over study investigated the effect of 30 mg of flurazepam taken the night before the removal of impacted third molars. Preoperative anxiety, visuomotor performance and sleep patterns were investigated in 20 adult patients with similarly impacted third molars. While preoperative flurazepam led to a statistically significant improvement in sleep patterns, there was no reduction in pre-operative anxiety on the morning of surgery. In addition, the flurazepam-treated group demonstrated significantly impaired visuo-motor performance 60 min after intravenous sedation compared to this group where intravenous sedation was used only preceded by placebo. Patients had a significant preference for flurazepam over placebo as a night-time sedative.

Adult↗
PubMed1986

Sulfur influences on rumen microorganisms in vitro and in sheep and calves.

When continuously cultured ruminal microbes were given orchardgrass hay and sufficient sulfuric acid or hydrochloric acid to maintain a pH of 5.5, fermentation and numbers of protozoa were reduced compared with cultures whose pH was controlled with phosphoric acid. Likewise, when sulfur-deficient, purified diets were supplied to cultures, less methane (mmol X liter-1 X d-1), 3.2 vs 32.6, was produced and fewer cellulolytic bacteria (log10/ml), 5.8 vs 7.2 were present than when cultures were given the same diet supplemented with .3% elemental sulfur. The rumen of sheep fed the .04% sulfur diet had reduced digesta weights (1.69 vs 3.2 kg) compared with sheep fed the diet with .34% sulfur at the same intake. There also was reduced methanogenesis 12.3 vs 25.8 mmol X liter-1 X d-1) and reduced numbers of cellulolytic bacteria (7.4 vs 8.4 log10/ml) in sulfur-deficient sheep in comparison to sulfur-supplemented sheep. In growing calves, the same types of bacteria predominated in the rumen, but more facultative anaerobic bacteria were isolated from calves fed .04% sulfur than from calves fed diets with .34 to 1.72% sulfur. None of the dietary levels of sulfur appeared toxic. Regardless of treatment, volatile fatty acids were more predominant than lactic acid as end-products of fermentation of ruminal microbes in fermenters, sheep and calves. The greater methanogenesis and the greater cellulolytic bacterial numbers of sulfur-supplemented sheep compared with sulfur-deficient in vitro cultures, is interpreted to be the result of recycling of sulfur to the rumen in sheep where it is efficiently scavengered by ruminal bacteria.

Animal Feed↗