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Biomedical subjects

T G Nyland

Publications and source records attributed to T G Nyland.

At least 19 recordsLinked to original sources
PubMed2001

Use of percutaneous ethanol injection for treatment of bilateral hyperplastic thyroid nodules in cats.

OBJECTIVE: To determine the efficacy and safety of percutaneous ethanol injection (PEI) for the treatment of hyperthyroidism caused by bilateral hyperplastic thyroid nodules in cats. DESIGN; Prospective study. ANIMALS: 7 cats. PROCEDURE: Hyperthyroidism was diagnosed on the basis of clinical signs and increased serum total thyroxine (TT4) concentrations. The presence of 2 cervical thyroid nodules was confirmed by use of ultrasonography and technetium Tc 99m albumin thyroid scans. After the death of 1 cat that received PEI in both thyroid nodules at the same time, the protocol was changed to injecting ethanol into 1 nodule at a time, with at least 1 month between injections. Clinical signs, serum TT4 concentrations, serum ionized calcium concentrations, laryngeal function, findings on ultrasonographic examinations of the ventral cervical region, and results of thyroid scans were monitored. RESULTS: Serum TT4 concentrations transiently decreased in all 6 cats (into the reference range in 5 of 6 cats) within 4 days of the first staged ethanol injection. Each subsequent injection resulted in a transient decrease in serum TT4 concentration. The longest period of euthyroidism was 27 weeks. Adverse effects included Horner's syndrome, dysphonia, and laryngeal paralysis. One cat died of unrelated causes. One cat underwent bilateral thyroidectomy, 2 cats were treated with methimazole, and 2 cats that had increased serum TT4 concentrations were not treated further, because they remained clinically normal. CONCLUSIONS AND CLINICAL RELEVANCE: Percutaneous ethanol ablation of bilateral thyroid nodules as a treatment for cats with hyperthyroidism is not recommended. This treatment is not as efficacious as the medical and surgical treatments presently used.

Administration, Cutaneous↗
PubMed1999

Percutaneous ultrasound-guided chemical parathyroid ablation for treatment of primary hyperparathyroidism in dogs.

OBJECTIVE: To evaluate the efficacy, feasibility, and safety of ultrasound-guided chemical ablation of parathyroid masses in dogs with primary hyperparathyroidism. DESIGN: Prospective clinical trial. ANIMALS: 8 dogs. PROCEDURE: In all dogs, a solitary parathyroid mass was evident ultrasonographically. Dogs were anesthetized with propofol, and a 27-gauge needle was directed into the parathyroid mass under ultrasound guidance. Ethanol (96%) was injected into the mass until there was evidence of diffusion of fluid throughout the mass. Serum total calcium, ionized calcium, phosphorus, and parathyroid hormone (PTH) concentrations were monitored daily for 5 to 7 days after the ablation procedure and again 1, 3, and 6 months after the procedure. Dogs were also monitored for adverse effects. Follow-up ultrasonography was performed 5 days and 1 month after the ablation procedure. RESULTS: One injection was required in 7 dogs, and 2 injections were required in 1. Serum total and ionized calcium concentrations were within reference ranges within 24 hours after treatment in 7 dogs and within 5 days in 1 dog. Serum PTH concentration decreased and serum phosphorus concentration increased within 24 hours after treatment in all 8 dogs. Transient hypocalcemia developed in 4 dogs during the first 5 days after treatment, but only 1 dog required treatment for hypocalcemic tetany. Hypercalcemia recurred in 1 dog 1 month after the procedure and surgical removal of the parathyroid mass was required. Other adverse effects were not reported. CONCLUSIONS AND CLINICAL RELEVANCE: Ultrasound-guided chemical ablation of parathyroid masses is a safe and effective alternative to surgery for dogs with primary hyperparathyroidism.

Adenoma↗
PubMed1998

Ultrasonography of the adrenal glands in the dog, cat, and ferret.

Ultrasonography has become an important modality for imaging adrenal glands in small animals. Normal adrenal glands and structural abnormalities, such as changes in size, shape, and echogenicity, can be identified. In the case of adrenal tumors, ultrasonography is a valuable tool for identifying neoplastic masses with local and regional involvement, as well as potential abdominal metastases. When correlated with clinical findings and results of hematologic, serum biochemical and endocrine tests, ultrasonographic findings make a substantial contribution to the diagnosis of adrenal diseases in dogs, cats, and ferrets.

Abdominal Neoplasms↗
PubMed1998

Ultrasonography of the thyroid and parathyroid glands.

High-resolution thyroid and parathyroid ultrasonography can play an integral part in the diagnosis and management of patients with clinically undifferentiated cervical masses, thyroid carcinomas or adenomas, and primary parathyroid hyperplasia or neoplasia. Because the study is inexpensive, noninvasive, and easily performed, ultrasonography can be performed as a screening test early in the evaluation of a patient, and ultrasound findings can corroborate the results of other diagnostic procedures, leading to a more accurate diagnosis.

Adenoma↗
PubMed1995

Ultrasonographic evaluation of the adrenal glands in dogs.

OBJECTIVE: To determine normal adrenal gland size by means of ultrasonography in dogs and to determine the value of ultrasonography in the diagnosis of pituitary-dependent hyperadrenocorticism (PDH) in dogs. DESIGN: Prospective observational study. ANIMALS: 62 dogs: 20 healthy dogs, 20 dogs with non-endocrine disease, and 22 dogs with untreated PDH. PROCEDURE: Length and maximum and minimum diameter of the adrenal glands were measured ultrasonographically. Multiple regression and correlation analyses were used to determine whether body weight, kidney length, aortic diameter, or age was related to adrenal gland size. Two-tailed t-tests and multiple linear regression analysis were used to compare values between groups. Sensitivity and specificity of using ultrasonographic measurement of adrenal gland size as a diagnostic test for PDH were determined. RESULTS: There was a significant linear relationship between adrenal gland length, but not maximum and minimum diameters, and body weight, aortic diameter, and kidney length in healthy dogs and in dogs with nonendocrine diseases. Length, maximum diameter, and minimum diameter of the right adrenal gland and maximum and minimum diameters of the left adrenal gland were significantly greater in dogs with PDH than in healthy dogs and dogs with nonendocrine diseases. As a diagnostic test for PDH, ultrasonographic measurement of maximum or minimum diameter of the left adrenal gland gave the best combination of sensitivity and specificity. For maximum diameter of the left adrenal gland, sensitivity was 77% and specificity was 80%. For minimum diameter of the left adrenal gland, sensitivity was 73% and specificity was 85%. CLINICAL IMPLICATION: Ultrasonography of the adrenal glands is a valuable diagnostic procedure in dogs suspected of having pituitary-dependent hyperadrenocorticism.

Adrenal Glands↗
PubMed1994

Experimental induction of hepatic lipidosis in cats.

The effect of long-term voluntary fasting on hematologic variables, biochemical profiles, and liver histologic findings was assessed in 15 obese cats (> 40% overweight). Clinical signs and laboratory results consistent with hepatic lipidosis were observed in 12 of 15 cats after 5 to 7 weeks of fasting, and were associated with 30 to 35% reduction of initial body weight. Histologic examination of successive liver biopsy specimens revealed that obesity was not associated with liver parenchymal lipid accumulation, but that fasting resulted in lipidosis in all 15 cats. The long-term fast was associated with an early (after 2 to 4 weeks of fasting) and significant (P < 0.05) reduction in serum urea, glucose, and albumin concentrations, and RBC mass. Fasting for 5 to 7 weeks was associated with a significant (P < 0.05) increase in hepatic-associated enzyme activities and in total and direct serum bilirubin concentrations. Significant (P < 0.05) changes in serum alkaline phosphatase developed as early as 3 weeks before the onset of hyperbilirubinemia. Except for development of hepatic lipidosis, cats appeared to tolerate the fast without other adverse effect. This study confirmed that long-term fasting may induce clinical hepatic lipidosis in obese cats. Fasting appears to induce a syndrome of hepatic lipidosis that is indistinguishable from feline idiopathic hepatic lipidosis and may be an appropriate model to study the pathophysiologic features and treatment of hepatic lipidosis.

Alkaline Phosphatase↗
PubMed1993

Prostaglandin induction of abortion in pregnant bitches after misalliance.

Of 48 privately-owned bitches evaluated 30 to 35 days after a single, unplanned breeding, 30 (62%) dogs were determined not to be pregnant by abdominal ultrasonography and 18 dogs were confirmed to be pregnant. Each pregnant dog was hospitalized, allotted to a treatment group, and given prostaglandin F2 alpha, SC, at 1 of 3 dosages: group 1, 0.1 mg/kg of body weight, every 8 hours; group 2, 0.25 mg/kg, every 12 hours; and group 3, 0.1 mg/kg, every 8 hours for 2 days and then 0.2 mg/kg every 8 hours thereafter. Plasma from each dog was assayed for progesterone concentration before treatment and daily until abortion was completed. Physical examinations and abdominal ultrasonography were performed every 12 and 48 hours, respectively. Treatment was continued until abortion was complete as determined by results of abdominal ultrasonography. Ultrasonography was performed earlier than the scheduled 48 hours if abdominal contractions, fetuses, or bloody or dark colored vaginal discharge was observed. Dogs of 14 breeds were treated; body weight ranged from 5.4 to 37.7 kg. All dogs aborted all fetuses within 9 days of beginning treatment. Abdominal palpation was not satisfactory in confirming whether the abortion process had been completed; however, results of ultrasonography were a reliable indicator. Plasma progesterone concentrations prior to treatment were typical of the middle phase of gestation, with all concentrations > 6.0 ng/ml. The plasma progesterone concentration decreased significantly in each dog after the first 48 hours of therapy. None of the bitches aborted any fetal material until at least 24 hours after the plasma progesterone concentration was < 2.0 ng/ml.(ABSTRACT TRUNCATED AT 250 WORDS)

Abortion, Induced↗
PubMed1990

Comparison of two sample collection methods for quantitative bacteriologic culture of canine prostatic fluid.

Ejaculate, urine, urethral swab specimens, and ultrasonography-guided small-needle prostatic cyst aspiration and/or tissue core biopsy specimens were collected for bacteriologic culture from 25 dogs in which prostatic disease was suspected on the basis of history, clinical signs of disease, or results of physical examination. The prostate gland in each dog was examined ultrasonographically, and the tissue core biopsy specimens were examined histologically and bacteriologically. Two methods were used to assess bacterial prostatitis. In 5 dogs (20%), bacteriologic culture results of paired urethral swab and ejaculate specimens differed from culture results of specimens obtained by needle aspiration of prostatic cyst fluid or tissue core biopsy. The prostate gland in 17 dogs had 1 or more cystic, fluid-filled structures (0.5 to 4.0 cm in diameter). Ultrasonographic appearance of the prostate gland did not have obvious correlation with culture results from dogs of the study. Histologic results of prostatic tissue core biopsy specimens correlated well with culture results.

Animals↗
PubMed1989

Sonography of the liver, gallbladder, and spleen.

Focal hepatic and splenic lesions, vascular abnormalities, and disorders of the biliary system can readily be detected with ultrasonography. The sonographic diagnosis can be substantially narrowed when the presenting clinical signs are considered. Ultrasonography is less helpful when the liver or spleen is diffusely involved without parenchymal, abnormalities. However, certain diseases may also be eliminated from diagnostic consideration on the basis of this finding. Percutaneous ultrasound guided biopsy markedly improves the success and safety of obtaining a definitive diagnosis when either diffuse or focal lesions are present. Sonography has also been very beneficial for serially evaluating the response to therapy once focal lesions of the liver or spleen have been identified.

Animals↗
PubMed1987

Dissolution of gallstones using cholecystostomy tube in the pig.

Cholecystostomy catheters and human cholesterol gallstones were implanted surgically in the gallbladders of eight pigs. Through the catheters, mono-octanoin or sterile water (H2O) was infused from two to seven days. The mono-octanoin dissolved pure cholesterol gallstones smaller than 200 g. There was no stone dissolution with infusion of sterile water and only one stone larger than 250 g was dissolved with mono-octanoin. Side effects included moderate-to-severe inflammation and ulceration of the gallbladder with mono-octanoin instillation, which precludes its widespread use with the present treatment regimen. Infusion of water caused little gallbladder irritation.

Animals↗
PubMed1986

Splenic hematoma and abscess as a cause of chronic weight loss in a horse.

An 8-year-old gelding with a 3-month history of anorexia and weight loss was found to have a massive subcapsular splenic hematoma. At flank laparotomy, 36 L of fluid was removed from the hematoma. The horse's condition improved after drainage. Fifteen months later, the horse became depressed and febrile. A splenic abscess containing Bacteroides ruminicola and Clostridium sporogenes was found at necropsy.

Abscess↗
PubMed1985

Sonography of the liver, gallbladder, and spleen.

Focal hepatic and splenic lesions, vascular abnormalities, and disorders of the biliary system can readily be detected with ultrasonography. The sonographic appearance in certain cases may be nonspecific, but the differential diagnosis can be substantially narrowed when the presenting clinical signs are considered. Ultrasonography is less helpful when the liver or spleen is diffusely involved without parenchymal abnormalities. However, certain diseases may also be eliminated from diagnostic consideration on the basis of this finding. Percutaneous ultrasound guided biopsy markedly improves the success and safety of obtaining a definitive diagnosis when either diffuse or focal lesions are present. Sonography has also been very beneficial for serially evaluating the response to therapy once focal lesions of the liver or spleen have been identified.

Animals↗
PubMed1984

Ultrasonic assessment of fetal growth in the nonhuman primate (Macaca mulatta).

Serial ultrasound measurements of fetal growth were made during uncomplicated pregnancy in 28 time-mated rhesus monkeys. Gestational sac (GS) size, crown-rump length (CRL), biparietal diameter (BPD), head circumference (HC), head area (HA), abdominal circumference (AC), abdominal area (AA), and femur length (FL) were measured. Average longitudinal growth curves for each parameter were obtained from individual fetal growth curves. Data analysis indicated that the linear model was optimal for GS, CRL, HA, AA, and FL. The linear-quadratic model was optimal for AC, and the linear-cubic model was optimal for BPD and HC.

Animals↗
PubMed1984

Correction of congenital hydrocephalus in utero II: Efficacy of in utero shunting.

To study the effect of in utero ventricular decompression of hydrocephalus on brain development and prognosis, and to evaluate the function and possible complications of different shunt designs, we created fetal hydrocephalus in 28 fetal lambs and 17 fetal monkeys by injecting kaolin into the cisterna magna during the third trimester. One fetal lamb had indwelling intracranial subdural and amniotic cavity pressure catheters placed to study serial changes in the relationship of intracranial pressure (ICP) and amniotic fluid pressure (AFP) from the time of injection until term. Twenty hydrocephalic fetal lambs underwent ventricular decompression--ventriculoamniotic (V-A), N = 10; ventriculo-right atrial (V-RA), N = 9; and ventriculo-pleural (V-PL), N = 1--21 to 25 days after the kaolin was injected; seven hydrocephalic fetuses were left unshunted as controls (CON). Eight fetal monkeys underwent V-A decompression 14 to 21 days after kaolin injection; nine were left unshunted as controls. All animals were delivered by cesarean section near term, assessed for viability and their brains examined grossly and microscopically. After kaolin injection in the fetal lamb, ICP (r = 0.94) and ICP minus AFP (r = 0.93) rose in a linear fashion, while AFP showed no trend (r = 0.22). All unshunted newborn lambs and monkeys had split sutures, dilated ventricles, and thinned cortical mantle. Most shunted lambs showed anatomic improvement with decreased head circumference, overriding sutures, normal-sized ventricles, and improved survival. However, histopathology revealed marked white matter destruction. In contrast, most shunted monkeys showed little anatomic improvement. Both shunted and unshunted monkey brains showed a severe inflammatory ventriculitis. In both lambs and monkeys, shunting was associated with a variety of complications including subdural hematoma, subdural hygroma, shunt infection, shunt occlusion, and improper shunt tip placement. In this experimental model, in utero decompression of obstructive hydrocephalus improves overall survival, improves gross ventriculomegaly, does not improve histopathologic brain damage, and is associated with significant complications. The choice of the optimal shunt design and the effect on postnatal neurologic function requires further study. This work emphasizes the need for continuing research in an animal model prior to human application.

Amniotic Fluid↗