Determination of isometric points for placement of a lateral suture in treatment of the cranial cruciate ligament deficient stifle.

Complete or partial rupture of the cranial cruciate ligament (CCL) is a common injury of the canine stifle. While numerous techniques have been developed for surgical treatment, extra-articular methods with placement of a lateral suture remain a popular treatment method. The purpose of this study was to determine the potential isometry of the six suture-paired sites; two on the femur and three on the tibia. In six femoro-tibial specimens with intact passive joint restraints, femoral sites adjacent to the proximal (F1) and distal (F2) poles of the fabella, and tibial sites adjacent to the patella insertion (T1), immediately cranial to (T2) and caudal to (T3) the long digital extensor tendon, were identified. A suture from one femoral site to one tibial site was placed under 0 or 5 N of preload, and tension was measured at joint angles of 150 degrees , 130 degrees , 90 degrees and 50 degrees . The F2-T3 combination was found to be most isometric. Isometry was re-assessed in the same specimens with the suture in the F2-T3 position, and under 5 N, 10 N and 15 N of preload, and after transection of the CCL. The suture pair retained its isometric pattern in the CCL transected specimens. There was no effect of preload on isometry patterns.

Prevalence of the dog nematode Spirocerca lupi in populations of its intermediate dung beetle host in the Tshwane (Pretoria) Metropole, South Africa.

Spirocerca lupi (Spirurida: Spirocercidae) is a cosmopolitan parasite, principally of domestic dogs and dung beetles are its main intermediate hosts. In South Africa there has recently been growing concern over the upsurge of reported cases of clinical spirocercosis in dogs, while little is known or understood about the dynamics of the host-parasite associations between dung beetles and this nematode. We determined and compared the prevalence of infection in dung beetles between rural, urban and peri-urban areas of Tshwane (Pretoria) Metropole. Dung beetles were sampled during April and October 2006, at various localities in each of these areas. Localities were selected on the basis of being focal areas of high infection with S. lupi in dogs. Pig, dog and cow dung-baited pitfall traps were used for sampling the beetles. Trap contents were collected 48 h after the traps had been set and only dung beetles were collected from the traps. In total, 453 specimens belonging to 18 species were collected from 63 pitfall traps in all three areas. The numbers of species that were collected varied among the three areas. Dung beetles, irrespective of species (18) and numbers (447), predominantly preferred pig dung. The prevalence of dung beetles infected with the larvae of S. lupivaried considerably in the three areas. In the urban area 13.5% of the dung beetles dissected were infected, while the prevalence of S. lupi in dung beetles in the rural area was 2.3%. All the dung beetles that were infected with this nematode showed a preference for omnivore (pig and dog) dung.

Cellular immune profile of patients with advanced cancer before and after taxane treatment.

The purpose of this study is to determine immune recovery and function after treatment with docetaxel or paclitaxel. Peripheral blood mononuclear cells were harvested before chemotherapy and at weekly times afterwards for cycle 1. Leukocyte subsets ICD45hiCD14lo polymorphonuclear neutrophils, CD45hiCD14hi monocytes, CD45hiCD14- lymphocytes, CD3+CD4/CD8+ T cells, CD3-CD19+ B cells, CD3-CD16/CD56+ natural killer (NK) cells], and circulating cytokine levels [tumor necrosis factor-alpha, gamma-interferon (gamma-IFN), and interleukins (IL-2, IL-10, IL-12)] were followed. In addition, T-cell mitogenic function, NK function, and lymphokine activated killer (LAK) function was assessed. Ten patients were entered in the trial. T-cell frequency, B-cell frequency, and CD4/CD8 ratio did not change. IL-10 serum levels significantly decreased in paclitaxel-treated patients (4.4+/-1.3 pg/ml at week 4 versus 7.8+/-2.1 pg/ml at baseline; p < 0.05). IL-2, IL-12, and gamma-IFN levels were not detectable. NK cytotoxic activity decreased in docetaxel-treated patients. LAK cell activity was not altered. Four patients achieved a partial or complete response. They demonstrated higher than normal CD4:CD8 T-cell ratios and an improved phytohemagglutinin stimulation index (SI = 2.5). In conclusion, our findings suggest that immune function was affected more significantly after docetaxel treatment. Investigational approaches, which enhance cellular immunity, may be of greater relevance after treatment with docetaxel. Additional studies monitoring NK function after chemotherapy are recommended.

Flystrike prevention on Merino lambs with the insect growth regulator dicyclanil.

The efficacy of a ready-to-use 5% dicyclanil pour-on formulation as a preventative of natural flystrike on Merino lambs was investigated in a field trial involving 5 sites in the southern Cape Province. A total of 1,804 lambs treated with dicyclanil were compared with 882 untreated control lambs for up to 25 weeks after treatment. Efficacy was assessed by calculating the weekly cumulative strike rate at each site and aggregated for all sites, as well as by calculating the percentage reduction achieved in treated lambs. Cumulative strike rates for the untreated controls aggregated for all sites at Weeks 9,14 and 19 after treatment reached 6.2, 12.8 and 17.8%, respectively, compared with 0.4, 1.7 and 3.6% for the dicyclanil treated lambs. Percentage control aggregated for all sites at Weeks 9,14 and 19 after treatment was 93, 87 and 80%, respectively. Heavy rains during the 1st half of the trial did not substantially reduce the efficacy of the product.

Randomized, double-blind, placebo-controlled trial to evaluate the hematopoietic growth factor PIXY321 after moderate-dose fluorouracil, doxorubicin, and cyclophosphamide in stage II and III breast cancer.

PURPOSE: To measure the effect of PIXY321 (granulocyte-macrophage colony-stimulating factor/interleukin-3 S. cerevisiae fusion protein) on the incidence, duration, and complications of neutropenia and thrombocytopenia after moderate-dose fluorouracil 600 mg/m(2), doxorubicin 60 mg/m(2), and cyclophosphamide 750 mg/m(2) (FAC) chemotherapy in patients with stage II and III breast cancer. PATIENTS AND METHODS: In this multicenter, randomized, double-blind placebo-controlled trial, 71 women were to receive four 21-day cycles of treatment with moderate-dose FAC chemotherapy by short intravenous infusion on day 1, followed by either placebo or PIXY321 (375 microg/m(2) subcutaneously twice a day) on days 3 to 15. All patients were to receive prophylactic oral ciprofloxacin when the absolute neutrophil count was less than 1,000/microL. RESULTS: PIXY321 significantly reduced the incidence and duration of grade 3 and grade 4 neutropenia in cycles 1 and 2 and the duration of grade 3 neutropenia in cycles 1 through 4. In cycles 3 and 4, grade 3 thrombocytopenia was significantly more common with PIXY321 (P <.05). Two patients, both in the PIXY321 group, required platelet transfusions. Fever and hospitalization for intravenous antibiotics were significantly more common in the PIXY321 group during cycle 1 only. More patients in the PIXY321 group achieved hematologic recovery by day 22 in cycles 1 through 3, and time to recovery was significantly shorter with PIXY321 in all cycles. FAC dose intensity was roughly 2% higher in the PIXY321 group (P = NS). Nonhematologic events of any intensity occurring with significantly greater overall frequency in the PIXY321 group included injection-site reactions, fever, chills, abdominal pain, and arthralgia. No patient died on study or within 30 days of her last dose of study drug. CONCLUSION: PIXY321 decreased the incidence and duration of FAC-induced grade 3 and 4 neutropenia in cycles 1 and 2 and significantly shortened the time to hematologic recovery in all cycles. However, it produced more systemic toxicity as well as thrombocytopenia in cycles 3 and 4.

SK&F107647: a synthetic hematoregulatory peptide in patients with solid tumor malignancies: a phase I trial.

SK&F107647 is a synthetic hematoregulatory peptide (HP) increases both the number and function of progenitor cells, enabling improved survival after lethal myelosuppression, lethal fungal infection, and lethal herpes simplex virus infection in murine models. This Phase I single-blind placebo-controlled dose-rising crossover trial examined the efficacy of SK&F107647 in patients who had incurable solid tumor malignancies. Sixteen patients were treated. Six adverse events in 3 patients were considered to be possibly related to SK& F107647; all were mild to moderate in nature (mild nervousness and agitation at 0.01 ng/kg, moderate fever and mild nausea at 0.1 ng/kg, elevated hepatic enzymes at 0.1 ng/kg, and mild vomiting at 1.0 ng/kg). Plasma half-life was 2.44 hours (+/-1.07 standard deviation). The observed area volume of distribution was 16.7 L (+/-7.7 standard deviation) and clearance was 5.04 L/hour (+/-1.83 standard deviation). When administered as a single 2-hour intravenous infusion at doses ranging from 0.01 to 100 ng/kg, SK&F107647 is safe and well tolerated.

Reduction in plate strain by addition of an intramedullary pin.

OBJECTIVE: The purpose of this study was to determine the strain sparing effect of a bone plate and rod system compared with a bone plate alone. STUDY DESIGN: Mathematical analysis and in vitro modeling of implant-bone constructs. Implants were instrumented with uniaxial strain gauges. ANIMALS OR SAMPLE PREPARATION: Five pairs of canine femurs. METHODS: Bone plates were instrumented with two 350-ohm strain gauges. The bone plates were used to bridge a simulated fracture gap in five pairs of canine femurs. In one femur of each pair, a bone plate alone was used to bridge the gap; in the opposite femur, a bone plate and intramedullary rod combination was used. Each specimen was mounted on a custom jig and loaded in an axial servohydraulic testing machine. A constantly increasing compressive load was applied at the rate of 0.7 cm/sec. Strains at 400.5 N were recorded and analyzed using Wilcoxon's signed rank test. Mathematical modeling was done using parallel beam theory. RESULTS: Stress reduction in the plate and rod system was twofold compared with the plate alone (P = .059). As important, based on stress reduction in the plate, the fatigue life of the plate/rod system increased 10-fold over the plate system alone and was greater than 10-fold at higher absolute stress values. Mathematical analysis of the plate/rod system was similar to that seen with the in vitro analysis. CONCLUSIONS: The combination of a bone plate and intramedullary pin was superior in reducing plate stress when compared with the plate alone and functioned as two beams acting in concert. CLINICAL RELEVANCE: Stabilization of comminuted fractures by bridging the zone of fragmentation with a bone plate without anatomic reduction of each fragment is a useful method of managing this type of injury. Addition of an intramedullary pin reduces the stress applied to the plate and thereby extends the fatigue life of the bone plate.

Efficacy and tolerability of oral ondansetron versus prochlorperazine in the prevention of emesis associated with cyclophosphamide-based chemotherapy and maintenance of health-related quality of life.

This study compared the efficacy and tolerability of oral ondansetron (8 mg twice daily [BID] for up to 3 days) with those of phenothiazine prochlorperazine (10 mg BID for up to 3 days) in 133 cancer patients receiving cyclophosphamide-based chemotherapy. In addition, the study evaluated the impact of these treatments on patients' health-related quality of life, measured with both the Functional Living Index-Cancer and the Functional Living Index-Emesis questionnaires. The first dose of study drug was administered 30 minutes before initiation of chemotherapy. Patients received a rescue antiemetic at their request or if the investigator deemed it necessary. There was a statistically significant difference in the number of patients with no emetic episodes over the 3-day study period: 60% in the ondansetron group compared with 21% in the prochlorperazine group. Twenty-five percent of ondansetron-treated patients compared with 68% of prochlorperazine-treated patients experienced three or more emetic episodes, rescue medication use, or withdrawal from the study due to emesis or adverse events. Among patients with at least one emetic episode, the mean time to emesis was significantly longer (13 hours and 37 minutes) in the ondansetron group compared with the prochlorperazine group (9 hours and 30 minutes). Nausea and appetite scores did not differ significantly between groups. The score on the vomiting subscale of the Functional Living Index-Emesis was significantly more favorable in the ondansetron group compared with the prochlorperazine group, indicating better maintenance of health-related quality of life in ondansetron-treated patients. Both treatments were well tolerated. The most common potentially drug-related adverse event was headache, which occurred in significantly more (16%) ondansetron-treated patients compared with prochlorperazine-treated patients (3%). The results of this study demonstrate that oral ondansetron 8 mg BID for up to 3 days is more effective than prochlorperazine 10 mg BID for up to 3 days in the prevention of emesis associated with moderately emetogenic chemotherapy.

Efficacy and tolerability of oral ondansetron versus prochlorperazine in the prevention of emesis associated with cyclophosphamide-based chemotherapy and maintenance of health-related quality of life.

This study compared the efficacy and tolerability of oral ondansetron (8 mg twice daily [BID] for up to 3 days) with those of phenothiazine prochlorperazine (10 mg BID for up to 3 days) in 133 cancer patients receiving cyclophosphamide-based chemotherapy. In addition, the study evaluated the impact of these treatments on patients' health-related quality of life, measured with both the Functional Living Index--Cancer and the Functional Living Index--Emesis questionnaires. The first dose of study drug was administered 30 minutes before initiation of chemotherapy. Patients received a rescue antiemetic at their request or if the investigator deemed it necessary. There was a statistically significant difference in the number of patients with no emetic episodes over the 3-day study period: 60% in the ondansetron group compared with 21% in the prochlorperazine group. Twenty-five percent of ondansetron-treated patients compared with 68% of prochlorperazine-treated patients experienced three or more emetic episodes, rescue medication use, or withdrawal from the study due to adverse events or lack of efficacy of the study drug. Among patients with at least one emetic episode, the mean time to emesis was significantly longer (13 hours and 37 minutes) in the ondansetron group compared with the prochlorperazine group (9 hours and 30 minutes). Nausea and appetite scores did not differ significantly between groups. The score on the vomiting subscale of the Functional Living Index--Emesis was significantly more favorable in the ondansetron group compared with the prochlorperazine group, indicating better maintenance of health-related quality of life in ondansetron-treated patients. Both treatments were well tolerated. The most common potentially drug-related adverse event was headache, which occurred in significantly more (16%) ondansetron-treated patients compared with prochlorperazine-treated patients (3%). The results of this study demonstrate that oral ondansetron 8 mg BID for up to 3 days is more effective than prochlorperazine 10 mg BID for up to 3 days in the prevention of emesis associated with moderately emetogenic chemotherapy.

Holding power of threaded external skeletal fixation pins in the near and far cortices of cadaveric canine tibiae.

We compared the pin-bone interfaces at the near and far cortical penetration sites of positive-profile end-threaded external fixation pins in cadaveric canine tibiae. The holding power of the pins in each cortical surface was independently measured in 21 pin-bone sections. Scanning electron microscopy (SEM) was used to compare subjectively the microstructural appearance of the pin-bone interfaces at the near and far cortical penetration sites in eight pin-bone sections. The far cortical penetration site provided greater holding power than did the near cortical site. SEM evaluation suggested more bony microfractures and debris with less pin-bone SEM evaluation suggested more bony microfractures and debris with less pin-bone interlock in the near cortical penetration sites than in the corresponding far cortical penetration sites. This study showed that after low-speed power insertion of positive-profile end-threaded pins in canine cadaveric tibiae, the near cortical penetration site contributes approximately 25% less to the overall holding power of the pin than does the far cortical penetration site.

Device-related litigation & clinical engineering.

The investigation of patient-related incidents often must include consideration of the role of the associated medical devices. In addition to being good practice from quality review perspectives, federally mandated MDR requirements generally need to include clinical engineering input. Medical devices also play a significant role in patient litigation aimed at medical providers, hospitals and device manufacturers. Clinical engineering has an important role to play in supporting and tracking litigation as it relates to medical equipment. This role requires an understanding of the litigation process and active participation as a claim progresses. It also should include careful evaluation of the assertions and defenses raised by the various parties both during and at the conclusion of litigation.

Desoxycorticosterone pivalate in the management of canine primary hypoadrenocorticism.

Primary hypoadrenocorticism in dogs may be poorly responsive to oral fluorocortisone treatment. Desoxycorticosterone pivalate is a suggested alternative treatment in these and all other cases of hypoadrenocorticism. Primary hypoadrenocorticism was diagnosed in a 3-year-old Cocker Spaniel bitch. Treatment with oral fluorocortisone at a dose rate of 0.13 mg 5 kg-1 d-1 was ineffective at maintaining serum electrolyte concentrations within normal limits. Administration of DOCP at a dose of 1.6-2.2 mg kg-1 intramuscularly every 28 d over a 5-year period, successfully maintained normal serum sodium and potassium concentrations. Side-effects encountered were minimal and were dose- or disease-related.

Pressure wave fidelity in catheter introducers.

Pressure waveform fidelity was examined in two sizes of the Bard catheter introducer. The purpose of this endeavor was to determine whether accurate blood pressure measurements could be achieved directly via the catheter introducers. The introducers were incorporated into a mock circulatory system for the study. The effects of supporting dilators and catheters within the introducer sheath during pressure measurements were also considered. Parameters used to explain pressure waveform response within the catheter introducers included the damping coefficient and the natural frequency of the catheter introducer, and the effects of impedance mismatching between the transducer and the mock circulatory system. Overall, the pressure measurements obtained from the catheter introducer were distorted. Mean pressure levels measured in the introducers were up to 15 mmHg higher than the true mean pressure. The distortion in the pressure measurements can be attributed for the most part to impedance mismatching. In sum, the pressure measurements obtained from catheter introducer-manometer systems should be used only referentially, and not as an absolute standard.

Principles of bone healing and biomechanics of external skeletal fixation.

External skeletal fixation is being used to treat an increasing number of orthopedic conditions in veterinary medicine. Study of the variables affecting the biomechanics of external fixation and bone healing is vital if patient morbidity is to be minimized. These are reviewed and incorporated into strategies that can be applied to decision making using external fixation in the clinical setting.

Information sources for medical equipment risk management.

An effective risk management program must include specific consideration of medical equipment, and must address hazard identification, incident prevention, and the coordination of efforts to minimize losses when incidents do occur. The hazard identification and prevention components require an organized effort to utilize external and internal information sources to determine both generic and device-specific hazards, recalls, alerts and related data. Equally important is the effective processing of this information so that it is integrated into the routine activity of the hospital. Attention to these information sources can contribute to the broad clinical engineering goal of helping to assure the safe and effective use of medical equipment throughout the hospital.

Legal liability in the development and use of medical expert systems.

The application of medical expert systems is likely in some instances to result in patient injury litigation. Such legal action will be based on the same principles now applicable to medical practice and products liability. These principles define legally wrongful acts, product defects, and theories of recovery: negligence, breach of warranty and strict liability. The resolution of such litigation will depend on whether the clinician should have relied on the advice of the expert system when the advice and patient treatment is alleged to have been wrong, as well as the overall quality of the expert system, its functional design, and claims made for it. Clinical engineers who become involved with expert system development, selection or implementation should understand the risk management implications of this technology.

Regulatory and other public policy issues.

Regulatory and other public policy issues in the future of biomedical engineering, as they relate to the development and use of medical devices, are discussed. At the federal level, agencies that directly influence the application of medical technology include the Food and Drug Administration (FDA), with its clinical trials and premarket and regulatory authority, and the Health Care Financing Administration (HCFA), with its reimbursement policy. The Occupational Safety and Health Administration (OSHA), the Environmental Protection Agency (EPA), and the Department of Commerce can have a considerable impact on corporate profitability, which is a driving force for most new technology and new product introductions. Another area of public policy that has been cited as significantly influencing health care and medical device development, namely, civil litigation, is also considered. To illustrate the issues, the impact of the regulatory environment on the application of computer software to a wide variety of medical products is examined. The humanistic and ethical problems brought about by technological advances are discussed. Ten key technologies that are likely to have the greatest importance in the next few years and ten external influences on the future of the medical device technology industry that have been identified by the Health Industry Manufacturers Association are described.