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Biomedical subjects

R R Hanson

Publications and source records attributed to R R Hanson.

28 records · Page 2Linked to original sources

Herniation of the abdominal wall in pregnant mares.

Abdominal wall hernia was detected in 4 pregnant mares. Antemortem diagnosis of the specific abdominal wall lesion was difficult. Ventral deviation of the abdomen, associated abdominal wall edema, and pain indicated rupture of the prepubic tendon. Three mares examined at necropsy did not have a rupture of the prepubic tendon but did have herniation of the abdominal wall. Abdominal pain was severe and was compounded by incarceration or entrapment of viscus.

Animals↗

Effects of xylazine on renal function and plasma glucose in ponies.

The intravenous administration of xylazine (1.1 mg/kg bodyweight) in six ponies resulted in a significant increase in urine output over two hours, with maximum flow occurring between 30 and 60 minutes after injection. Urine specific gravity, osmolality and glucose concentration decreased. Renal clearance of endogenous creatinine was unchanged. Significant increases in the excretion of potassium and chloride occurred. Plasma glucose concentration was increased 30 minutes after the administration of xylazine by a mean value of 37 per cent. Serum osmolality and sodium, potassium and chloride concentrations remained unchanged.

Animals↗

Transbronchial biopsy via flexible fiberoptic bronchoscope; results in 164 patients.

The diagnostic accuracy and complication rate of transbronchial forceps lung biopsy combined with bronchial brushing were analyzed in 164 consecutive patients, of whom 95 had nonmalignant disease and 51 had malignant disease. Eighteen patients with abnormal chest radiographs had normal transbronchial forceps lung biopsies and no established diagnosis. Satisfactory specimens were obtained in 153 patients (93 per cent), with diagnositc accuracies of 62, 64, and 67 per cent, respectively, in infectious, interstitial, and malignant lung disease. The over-all diagnostic accuracy was 57 per cent. Seven patients were diagnosed as having metastatic carcinoma to the lung by transbronchial forceps lung biopsy, but brush biopsy was psoitive in only 3. Of the 23 patients with primary lung carcinoma diagnosed by transbronchial forceps lung biopsy, 21 had positive brush biopsies. An additional 3 patients with bronchogenic carcinoma, however, were diagnosed only by brush biopsy. Fluoroscopy was essential for accurate positioning of the biopsy instrument. Increased risk factors were present in 83 patients (51 per cent), among whom the immunosuppressed group presented special problems. Significant bleeding in 15 patients (9 per cent) was controlled by conservative management. Pneumothorax occurred in 7 patients (4 per cent). There were no deaths. Transbronchial forceps lung biopsy in experienced hands is safe and well tolerated. The physician, nevertheless, must be prepared to handle major complications, especially bleeding. The procedure has a resonable diagnostic yield in high-risk patients who have a variety of lung lesions.

Adolescent↗

Mistaken diagnoses in continuous muscle fiber activity of peripheral nerve origin.

The syndrome of continuous muscle fiber activity of peripheral nerve origin has manifestations that resemble those of many other more common neurologic disorders during childhood and infancy. This similarity often leads to misdiagnosis when an adequate index of suspicion is not entertained and a comprehensive electromyographic examination is not performed. Two affected patients from 1 family are reported to illustrate the type of diagnostic errors that were made before the establishment of the correct diagnosis.

Arthrogryposis↗

Standing surgical repair of cystorrhexis in two mares.

Two surgical techniques were used to evert the bladder into the vagina for observation and repair of bladder tears that were associated with parturition. One technique involved an incision through the vaginal floor into the peritoneal cavity just caudal to the cervix, and prolapse of the bladder into the vagina. The second technique involved a 3-cm incision through the urethra, 5 cm cranial to the urethral orifice, and digital exploration of the tear and finger traction to evert the bladder through the urethral incision. In both mares, the bladder defects were repaired in two layers, with use of 2-0 polyglycolic acid in a simple continuous pattern. After repositioning, the vaginal and urethral incisions were closed in single layers using absorbable suture material. A standing vaginal approach eliminates the need for general anesthesia and allows excellent observation and repair of bladder tears in adult mares.

Animals↗

A comparison of laparoscopic and belt-loop gastropexy in dogs.

A simplified technique for laparoscopic gastropexy (group 1) was compared to belt-loop gastropexy (group 2) in eight adult male dogs randomly divided into two groups of four dogs each. Our hypothesis was that a satisfactory laparoscopic gastropexy would approximate the strength and operative time required for belt-loop gastropexy. Operative time, surgical complications, postoperative morbidity, gross and histological appearance, radiographic microvascularization, and maximal tensile strength were measured and compared between the two groups. All dogs recovered from surgery. No morbidity was associated with either procedure. The mean (+/- SD) duration of surgery was 69.75 +/- 7.23 minutes for group 1 and 58.75 +/- 7.63 minutes for group 2. Fifty days after surgery, the microvascular appearance of the gastropexy site was similar for both groups. Blood vessels were observed within each seromuscular flap but vascular ingrowth to the abdominal musculature was observed in only two dogs, one from each group. The maximum tensile strength at 50 days was 76.55 +/- 22.78 for group 1 and 109.21 +/- 22.29 N for group 2. Differences between surgical duration and maximum tensile strength were not statistically significant (P > .05). Histologically, all gastropexies consisted of an adhesion composed of dense fibrous connective tissue. The results of this study indicate that laparoscopic gastropexy provides a minimally invasive alternative to open abdominal prophylactic gastropexy in dogs.

Abdominal Muscles↗

Surgical reduction of ileal impactions in the horse: 28 cases.

OBJECTIVE: To evaluate the seasonal influence, signalment, type of hay consumed, clinical examination findings, and outcome after surgery for horses with ileal impaction. STUDY DESIGN: A retrospective study. RESULTS: Between 1988 and 1993, 28 horses had surgical correction of ileal impaction. There was a significantly higher rate of ileal impaction during the Fall (September-November, P = .0041 ). Mean duration of clinical signs of abdominal pain before referral was 15 hours. Transrectal palpation was used to localize the impaction in 11 horses. The ileal impaction was reduced by extraluminal massage aided by admixing of intestinal fluid oral to the impaction or injection of fluids intraluminally and then movement of the ingesta into the cecum alone in 24 horses. A total of 26 horses recovered from surgery; 24 horses were discharged from the hospital and eventually returned to previous use. Two horses had fatal postoperative complications: jejunocecostomy dehiscence and development of extensive small intestine adhesions after manual reduction of the impaction. One horse initially treated by manual reduction required jejunocecostomy twice for management of recurrent ileal impaction. Follow-up information was obtained for 21 horses, of which 20 were alive 1 year or longer after surgery. A total of 27 of 28 horses were fed Coastal Bermudagrass hay as the primary type of hay consumed. A total of 9 horses continued to be fed Coastal Bermudagrass hay as the only roughage source, whereas 6 horses were fed Coastal Bermudagrass with at least 50% other hay, and in 6 horses, Coastal Bermudagrass hay was entirely eliminated from the diet. CONCLUSION AND CLINICAL RELEVANCE: Ileal impactions can be successfully reduced by celiotomy and extraluminal massage and injection techniques to soften the ingesta for passage into the cecum without enterotomy or bypass techniques in most horses. Changes in weather and feeding practices in the Fall may account for an increased risk of ileal impaction in horses in the southeastern United States at that time of year.

Animals↗

Low-field magnetic resonance imaging of the equine tarsus: normal anatomy.

The objective of this study was to define the normal gross anatomic appearance of the adult equine tarsus on a low-field magnetic resonance (MR) image. Six radiographically normal, adult, equine tarsal cadavers were utilized. Using a scanner with a 0.064 Tesla magnet, images were acquired in the sagittal, transverse and dorsal planes for T1-weighted and the sagittal plane for T2-weighted imaging sequences. Anatomic structures on the MR images were identified and compared with cryosections of the imaged limbs. Optimal image planes were identified for the evaluation of articular cartilage, subchondral bone, flexor and extensor tendons, tarsal ligaments, and synovial structures. MR images provide a thorough evaluation of the anatomic relationships of the structures of the equine tarsus.

Animals↗

The pneumoconioses.

The pneumoconioses are by and large industrial diseases, although casual contact may be important on occasion, particularly with asbestos. The effect of dust on the lung ranges from only radiographic changes to severe functional impairment. Destruction and fibrosis of lung parenchyma may be the end result in severe disease. Great improvement has been made in recent years in the control of dust in the numerous situations where it may cause disease. We are still faced with evaluating existing standards of particle concentration in air breathed by workers and establishing safe limits and better control of the particles placed into the general environment. Undoubtedly, there are other particulates which potentially can cause lung disease of which we are not aware. Of even more concern is the realization that a latent period of 20 years or so may be necessary for physicians to become aware of the pathologic process. Every physician who sees patients with pulmonary problems must inquire regarding a history of dust exposure and be prepared to interpret that history.

Asbestosis↗