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Biomedical subjects

R Neiger

Publications and source records attributed to R Neiger.

At least 19 recordsLinked to original sources
PubMed2006

Study of the effects of once daily doses of trilostane on cortisol concentrations and responsiveness to adrenocorticotrophic hormone in hyperadrenocorticoid dogs.

The effects of trilostane, a 3beta-hydroxysteroid dehydrogenase inhibitor on basal cortisol concentrations and the results of ACTH stimulation tests in dogs with pituitary-dependent hyperadrenocorticism were investigated. In eight of nine dogs trilostane suppressed the concentration of cortisol below the lower limit of the reference range (<50 nmol/l) for a mean (sd) of 3.5 (2.3) hours during the day, but for no longer than 13 hours. In another 10 dogs, there was a clear difference between the post ACTH cortisol concentrations observed four and 24 hours after the administration of trilostane. Furthermore, in the six dogs whose clinical signs were poorly controlled the post-ACTH concentrations observed four and 24 hours after the administration of trilostane were always higher than the equivalent cortisol concentrations in the four dogs whose clinical signs were controlled. A short duration of drug action may be responsible for the failure of some dogs to respond adequately to once daily trilostane administration.

Adrenocortical Hyperfunction↗
PubMed2006

Nasal bone assessment in prenatal screening for trisomy 21.

A small nose is a common facial feature of individuals with trisomy 21. Evidence based on radiologic, histomorphologic, and sonographic studies shows that nasal bone abnormalities are significantly more common in trisomy 21 fetuses than in euploid fetuses. These abnormalities, which include both nasal bone absence and short nasal bone length, can be detected by prenatal ultrasound. In this article we review the evidence and discuss the potential value of assessment of the fetal nasal bone in screening for trisomy 21.

Down Syndrome↗
PubMed2006

Changes in the threshold of fetal lung maturity testing and neonatal outcome of infants delivered electively before 39 weeks gestation: implications and cost-effectiveness.

OBJECTIVE: To compare the neonatal outcome of infants delivered before 39 weeks' gestation following documentation of fetal lung maturity before and after the lamellar body count (LBC) threshold was increased from 30,000 to 50,000 LB/ul. We discuss the algorithm employed for testing fetal lung maturity, the cost of testing and potential savings. MATERIAL AND METHODS: We studied the outcome of infants delivered electively before 39 weeks' gestation after fetal lung maturity was documented by amniotic fluid analysis. We compared the outcome of neonates born before and after the LBC threshold was increased. RESULTS: Our cohort included 527 neonates who were divided into two groups: 264 who underwent fetal lung maturity studies before the change in LBC threshold and 263 who underwent testing after the change. In the first group, 158 neonates met the criteria of LBC >30,000 LB/ul and were delivered without further testing. The second group included 154 neonates who were mature by LBC >50,000 LB/ul and were delivered. Seven of the neonates born in the first group required admission to the neonatal intensive care unit (NICU), whereas in the second group only two neonates required admission (P = 0.02). Additionally, 16 neonates in the first group required respiratory assistance compared with six in the second group (P = 0.04). The overall neonatal complication rate was significantly higher in the first group (P = 0.001). CONCLUSION: Changing the LBC threshold resulted in a significant decrease in neonatal morbidity. Employing the algorithm, we described for testing fetal lung maturity is cost effective, and more importantly, represents sound evidence-based medical management.

Algorithms↗
PubMed2006

Gender-related differences in fetal heart rate during first trimester.

OBJECTIVE: Many expecting parents wish to ascertain fetal gender early in pregnancy. Our goal was to determine whether fetal heart rate (FHR) of males and females during the first trimester is significantly different. MATERIALS AND METHODS: From November 1997 to February 2003 we enrolled pregnant women with singleton gestations who underwent obstetric sonography at less than 14 weeks of gestational age. Indications for the sonographic study included first-trimester bleeding, uncertain gestational dating, poor obstetrical history, and aneuploidy screening by nuchal translucency. The sonographic studies were performed by a single sonographer and reviewed by the first author. The FHR was determined by m-mode. All subjects underwent second-trimester sonography at 18.0-24.0 weeks' gestation by the same team, and fetal gender was recorded. Multiple gestations, miscarriages and pregnancies with uncertain fetal gender were excluded. Sonographically assigned fetal gender was confirmed at delivery. RESULTS: Of the 966 first-trimester studies performed, 477 met the inclusion criteria. Of these, 244 (51%) were female and 233 (49%) were males. There were no statistical differences in mean maternal age, gravidity, parity, and mean gestational age at the time of the first study (9.0 +/- 2.3 weeks for female fetuses and 9.0 +/- 2.3 weeks for males, p = 0.7). The average female FHR was 151.7 +/- 22.7 bpm and male FHR was154.9 +/- 22.8 bpm (p = 0.13). DISCUSSION: Contrary to beliefs commonly held by many pregnant women and their families, there are no significant differences between male and female FHR during the first trimester.

Female↗
PubMed2006

Nasal oncocytoma in a domestic shorthair cat.

An oncocytoma was diagnosed in the nasal cavity of a 12-year-old Domestic Shorthair cat who presented with periocular swelling and sneezing. Histologic examination from biopsy material revealed monomorphic sheets, anastomosing cords, tubules, and acini composed of large polygonal to oval cells that contained abundant finely granular eosinophilic cytoplasm. No vascular or lymphatic invasions were noted. Histochemical stains revealed positive staining of tumor cells with periodic acid-Schiff (PAS) (before and after diastase digestion) and phosphotungstic acid-hematoxylin. Immunohistochemical evaluation of the tumor cells demonstrated positive staining for cytokeratin and negative staining for vimentin, desmin, S-100, glial fibrillar acidic protein, and neuronal specific enolase. Ultrastructurally, the tumor cells contained large numbers of mitochondria within their cytoplasm, which confirmed a diagnosis of oncocytoma.

Adenoma, Oxyphilic↗
PubMed2005

Primary hyperparathyroidism in 29 dogs: diagnosis, treatment, outcome and associated renal failure.

OBJECTIVES: To review the records of 29 dogs diagnosed with primary hyperparathyroidism and see if any factors correlate with renal failure. METHODS: Dogs were selected retrospectively from case files from the QVSH and the QMH. RESULTS: The majority of dogs were middle-aged and four were keeshonds. The primary presenting complaints were polyuria and polydipsia. All dogs had an elevated total and ionised plasma calcium concentration. Plasma phosphate concentrations were variable. Ultrasonography of the parathyroid gland revealed nodular enlargement which was found to correlate well with surgical findings. The majority of dogs underwent surgical parathyroidectomy. Five cases were treated by ultrasound-guided chemical ablation of the parathyroid gland, of which only two cases showed a partial response. Three dogs were euthanased within a week of presentation. Seven other dogs had renal failure diagnosed either at presentation or up to six months after parathyroidectomy. The development of renal failure was correlated with total calcium concentration but did not correlate with any other factor, including the calcium phosphate product. Thirteen treated dogs were known to be alive at the time of writing, which was six months to 3.5 years after parathyroidectomy. CLINICAL SIGNIFICANCE: Primary hyperparathyroidism cases with high total calcium were more likely to develop renal failure in this group of dogs; however, the calcium phosphate product did not seem to be a useful predictor. Ultrasound-guided chemical ablation seemed to have limited advantage over surgery.

Animals↗
PubMed2004

Trilostane treatment of bilateral adrenal enlargement and excessive sex steroid hormone production in a cat.

A 14-year-old neutered female cat was presented for the investigation of aggression and male-type behaviour. Bilateral adrenal enlargement together with elevated plasma concentrations of oestradiol and testosterone were identified, with no evidence of hypercortisolaemia. These findings are similar to the syndrome of hyperadrenocorticism recognised most commonly in ferrets. The cat was treated for six months with the enzyme inhibitor drug, trilostane, and showed a moderate improvement in clinical signs.

3-Hydroxysteroid Dehydrogenases↗
PubMed2004

Adrenal necrosis in a dog receiving trilostane for the treatment of hyperadrenocorticism.

Clinical and biochemical changes suggestive of hypoadrenocorticism were observed in a 10-year-old male neutered Staffordshire bull terrier shortly after beginning therapy with trilostane for the treatment of hyperadrenocorticism. The dog's condition was stabilised with intravenous fluids, fludrocortisone and prednisolone. An exploratory laparotomy and excisional biopsy of the left adrenal gland were performed. Histopathological analysis showed adrenal cortical necrosis with reactive inflammation and fibrosis. Trilostane is a reversible inhibitor of steroid synthesis and this complication has not been reported previously. Clinicians should be aware that trilostane therapy may result in adrenal necrosis but that prompt treatment might correct a life-threatening situation.

3-Hydroxysteroid Dehydrogenases↗
PubMed2004

Serum insulin concentrations in horses with equine Cushing's syndrome: response to a cortisol inhibitor and prognostic value.

REASONS FOR PERFORMING STUDY: Serum insulin concentration and its use as a prognostic indicator in horses with equine Cushing's syndrome (ECS) have been poorly documented. OBJECTIVES: To examine daily insulin variations in horses with ECS and the effect of treatment using trilostane, a competitive inhibitor of 3beta-hydroxysteroid dehydrogenase. Further, we aimed to examine the relationship between baseline serum insulin concentration and survival in horses with ECS. METHODS: Basal serum insulin concentrations were measured in 20 confirmed ECS cases by taking blood at regular 4 h intervals for 24 h (1200, 1600, 2000, 2400, 0400 and 0800 h) before treatment (Day 0) and 10 days, and 30 days and 1-2 years after the onset of trilostane therapy. The temporal pattern of insulin was analysed using a linear mixed model approach, and the prognostic value of measurements on Day 0 assessed using receiver-operating characteristic analysis. RESULTS: Horses with ECS showed a diurnal pattern of serum insulin concentration, highest value at 1200 h, and this pattern was not altered by treatment with trilostane. Furthermore, despite a mild increase of serum insulin concentrations after 10 days of trilostane therapy, insulin concentration was unaffected in the long-term. Low serum insulin concentrations at the beginning of the trial were significantly associated with improved survival to 1-2 years. The 1200 h sampling before treatment had the highest prognostic value for prediction of survival with a sensitivity and specificity of at least 90% for serum insulin at < 62 and > 188 microu/ml to predict survival and nonsurvival, respectively. CONCLUSIONS AND POTENTIAL RELEVANCE: Insulin is a useful prognostic indicator for ECS, but potentially large variations can occur throughout a 24 h period, indicating a single sample may not be representative. Serum insulin concentration did not increase over 1-2 years in horses receiving trilostane therapy.

3-Hydroxysteroid Dehydrogenases↗
PubMed2003

Cardiac troponin I in cats with hypertrophic cardiomyopathy.

The molecular structure of cardiac troponin I (cTnI) is highly conserved across mammalian species and assays developed for its measurement in human patients have been validated in a number of veterinary species. A raised concentration of circulating cTnI is a sensitive and specific marker of cardiac myocyte injury. Raised levels have been documented in a variety of cardiac diseases in both human and veterinary patients. This study compared serum cTnI concentrations between 16 cats diagnosed with hypertrophic cardiomyopathy (HCM) using echocardiography and 18 control cats. The results show that cats with HCM have significantly higher concentration of serum cTnI (median 0.95 ng/ml, range 0.2-4.1 ng/ml) than control cats (median <0.2 ng/ml, range <0.2-0.25 ng/ml) [P<0.0001]. Furthermore in cats with cardiomyopathy a weak correlation was found between the thickness of the left ventricular freewall in diastole measured by ultrasound and serum cTnI concentration (r(2)=0.28;P=0.036). These results suggest that measurement of serum cTnI concentration may enable cats with cardiomyopathy to be distinguished from normal cats using the assay described here.

Animals↗
PubMed2003

The urinary corticoid:creatinine ratio (UCCR) in healthy cats undergoing hospitalisation.

Thirty-one healthy pet cats had voided urine samples collected prior to, during and after a brief period of hospitalisation. Urinary corticoids were measured, both prior to and following an extraction technique, and the urinary corticoid:creatinine ratio (UCCR) was calculated. Associations between the UCCR and age, sex, breed and time of urine collection were investigated. There was no significant relationship established between age, sex and breed and the UCCR. A significant increase in the UCCR, however, did occur between the first home collected and first hospitalised urine sample, but only when comparing extracted corticoid results. A normal range for feline UCCR is established for the chemiluminescent immunoassay used in this study.

Animals↗
PubMed2003

Efficacy of trilostane for the treatment of equine Cushing's syndrome.

REASONS FOR PERFORMING STUDY: Trilostane, a competitive 3-beta hydroxysteroid dehydrogenase inhibitor, has been used successfully to control clinical signs and cortisol excess in canine pituitary dependent hyperadrenocorticism. OBJECTIVES: Trilostane was evaluated for its efficacy in resolving clinical and clinicopathological abnormalities of equine Cushing's syndrome (ECS) and to assess its safety. METHODS: Twenty horses (mean age 21 years) diagnosed with ECS were followed for 1 or 2 years. Affected horses received 0.4-1 mg/kg (mean 0.5 mg/kg) trilostane once daily. RESULTS: Clinical signs assessed over 1 or 2 years, showed a reduction in lethargy in all horses post treatment. Polyuria and/or polydipsia, present in 11 horses, was reduced in all after treatment. Recurrent or chronic laminitis, present in 16 horses, improved in 13/16 (81%) of cases. There were no side effects reported. Combined dexamethasone suppression and thyrotropin releasing hormone (TRH) stimulation tests were significantly different before and 30 days following therapy. There was a significant reduction (P = 0.01) of cortisol following TRH administration before (160 +/- 53.0 nmol/l) and after (130 +/- 46.1 nmol/l) trilostane. CONCLUSIONS: Trilostane caused improvement in clinical signs in horses, without side effects, and a corresponding decrease in cortisol response to TRH administration. POTENTIAL RELEVANCE: Trilostane may be a useful therapy for the treatment of ECS. Further work comparing the effects of trilostane and pergolide is warranted.

3-Hydroxysteroid Dehydrogenases↗
PubMed2002

Trilostane treatment of 78 dogs with pituitary-dependent hyperadrenocorticism.

The efficacy of trilostane in the treatment of canine pituitary-dependent hyperadrenocorticism (PDH) was evaluated in 78 dogs with the condition which were treated for up to three years. The drug appeared to be well tolerated by almost all the dogs, and only two developed clinical signs and biochemical evidence of hypoadrenocorticism. Polyuria and polydipsia completely resolved in 70 per cent of the dogs that had these problems, and skin changes resolved in 62 per cent of the dogs that had skin abnormalities. There was a significant reduction (P<0.001 in each case) in both the mean basal and post-adrenocorticotrophic hormone (ACTH) cortisol concentrations after a mean of 12.3 days of treatment. The post-ACTH cortisol concentration decreased to less than 250 nmol/litre in 81 per cent of the dogs within one month of the start of treatment and in another 15 per cent at some later time. The median survival time of the 26 dogs which died was 549 days, and 51 of the dogs were alive at the completion of the study. One was lost to follow up after 241 days treatment.

Abortifacient Agents, Steroidal↗
PubMed2002

Differentiation of dogs with regenerative and non-regenerative anaemia on the basis of their red cell distribution width and mean corpuscular volume.

The red blood cell distribution width (RDW), which provides a quantitative measure of the heterogeneity of the red cell population (anisocytosis) in the peripheral blood, the mean corpuscular volume (MCV) and a regression model combining both variables were used to assess their predictive accuracy in differentiating 51 dogs with regenerative anaemia from 92 dogs with non-regenerative anaemia, which had been diagnosed on the basis of the corrected reticulocyte count A classification tree analysis was constructed to generate an optimum set of diagnostic rules to differentiate between the two types of anaemia. Seventy-four dogs with a normal haemogram were used as controls. An increase of 1 per cent in the RDW and of 1 fl in the MCV increased the odds of an anaemic dog suffering from regenerative anaemia by factors of 1.3 and 1.14, respectively. By the classification tree, 78 per cent of anaemic dogs with a RDW of 16.25 per cent or less would be expected to have non-regenerative anaemia. With a RDW over 16.25 per cent, an MCV of 68.2 fl was the cut-off between dogs expected to have regenerative (71 per cent) or non-regenerative (75 per cent) anaemia. The RDW and MCV are measured by most automatic haematology analysers and may give the first indication of the bone marrow response of an anaemic dog. However, different electronic counters give different normal values of the RDW and MCV.

Anemia↗