Thyroid hormone abnormalities and outcome in dogs with non-thyroidal illness

OBJECTIVES

To document thyroid hormone abnormalities in dogs with non-thyroidal illness and identify markers of prognostic value.

METHODS

Circulating total and free thyroxine, total triiodothyronine and thyrotropin concentrations were measured in 196 dogs with non-thyroidal illness. Clinical signs, previous medications and outcome were recorded in each case. Data were analysed to determine endocrine prognostic factors, and to document the prevalence of thyroid hormone abnormalities.

RESULTS

Total triiodothyronine, and total and free thyroxine concentrations were decreased in 75.9, 34.7 and 4.5 per cent of cases, respectively. Dogs which were euthanased had significantly decreased total triiodothyronine, and total and free thyroxine concentrations compared with those which made a full recovery. Total triiodothyronine concentrations were significantly lower in dogs that were euthanased compared with those which made a partial recovery.

CLINICAL SIGNIFICANCE

Thyroid hormone concentrations may be used as prognostic indicators in dogs with non-thyroidal illness. Low triiodothyronine syndrome may be more common in dogs than previously recognised.

Faecal near infrared reflectance spectroscopy (F.NIRS) measurements of non-grass proportions in the diet of cattle grazing tropical rangelands

Frequent faecal near infrared reflectance spectroscopy (F.NIRS) analyses of faeces from cattle grazing a range of tropical pastures were used to measure the non-grass component, and other aspects, of their diets. Seasonal profiles of non-grass and crude protein in the diet are presented for nine sites from the speargrass, Aristida–Bothriochloa, and Mitchell grass dominated pasture regions, and for three shrubland sites where browse was plentiful. In grass-dominated native pastures of the speargrass and Aristida–Bothriochloa pasture regions of Queensland where little browse was available, non-grass was usually only 5–15% of the diet. Diet non-grass was even lower for a buffel grass pasture. In uncleared eucalypt woodland in the speargrass region, browse may have contributed up to 20% of the diet in the late dry season when grasses were senesced. In regions with abundant browse (e.g. mulga lands and desert upland systems) cattle preferentially selected actively growing grasses and forbs when they were available. With diminishing availability or declining quality of the forbs and grass due to grazing selection and dry conditions, browse increasingly contributed to intake. In Mitchell grass dominated pastures forbs often comprised more than 50% of the diet, and there appeared to be strong selection for forbs during the dry season. Where browse was available in association with Mitchell grass dominated pastures, it appeared to contribute to intake only in the late dry season. Dry season sampling in monsoonal tallgrass and Mitchell grass dominated pastures indicated dietary crude protein to be linearly correlated with diet non-grass, demonstrating the importance of non-grass in the prevention or alleviation of dry season protein deficiency in cattle. Changes in diet selected by cattle in relation to season and rainfall were generally in accord with the previous limited information, largely with sheep, in comparable vegetation systems. The results demonstrate the value of F.NIRS technology to assist understanding of diet selection by grazing cattle in northern Australia.

Association of canine hypothyroidism with a common major histocompatibility complex DLA class II allele

Dogs exhibit a range of immune-mediated conditions including a lymphocytic thyroiditis which has many similarities to Hashimoto's thyroiditis in man. We have recently reported an association in Doberman Pinschers between canine hypothyroidism and a rare DLA class II haplotype that contains the DLA-DQA1*00101 allele. We now report a further series of 173 hypothyroid dogs in a range of breeds where a significant association with DLA-DQA1*00101 is shown.

Long-term survey of laryngoplasty and ventriculocordectomy in an older, mixed-breed population of 200 horses. Part 1: Maintenance of surgical arytenoid abduction and complications of surgery

REASONS FOR PERFORMING STUDY

Laryngoplasty (LP) is currently the most common surgical treatment for equine laryngeal paralysis, however, there have been no reports quantifying the degree of retention of arytenoid abduction following LP. Additionally, the complications of LP have been poorly documented.

OBJECTIVES

To record the degree of arytenoid abduction retention following LP and to accurately document all complications of surgery.

METHODS

A study (1986-1998) of 200 horses of mixed breed and workload, median age 6 years (prospective 136 cases and retrospective 64 cases) undergoing LP (using 2 stainless steel wires) and combined ventriculocordectomy was undertaken; 198 owners completed questionnaires, a median of 19 months following surgery. The degree of arytenoid abduction achieved was endoscopically, semi-quantitatively evaluated using a 5-grade system, at 1 day, 7 days, and 6 weeks after surgery.

RESULTS

On the day following LP, 62% of horses had good (median grade 2) arytenoid abduction, 10% had excessive (grade 1), and 5% had minimal (grade 4) abduction (overall-median grade 2). Due to progressive loss of abduction, moderate (median grade 3, range 1-5) abduction was present overall at 1 and 6 weeks after LP. Further surgery was required to re-tighten prostheses in 10% of cases with excessive loss of abduction, or to loosen prostheses in 7% of horses which had continuing high levels of LP abduction and significant post operative dysphagia. LP wound problems (mainly seromas and suture abscesses) were reported to last < 2 weeks in 9% of cases, < 4 weeks in 4% and > 4 weeks in 4%. The (partially sutured) laryngotomy wounds discharged post operatively for < 2 weeks in 22% of cases, < 4 weeks in 7% and for > 4 weeks in 2%. Coughing occurred at some stage post operatively in 43% of cases and its presence correlated significantly with the degree of surgical arytenoid abduction. This coughing occurred during eating in 24% of cases and was not associated with eating (or dysphagia) in the other 19% of cases. Chronic (> 6 months duration) coughing occurred in 14% of cases, but appeared to be due to intercurrent pulmonary disease in half of these horses.

CONCLUSIONS

Suturing the cricotracheal membrane allows most laryngotomy wounds to heal quickly. Laryngoplasty wound problems were of little long-term consequence when stainless steel wire prostheses were used.

POTENTIAL RELEVANCE

A significant loss of LP abduction occurs in most horses in the 6 weeks following surgery and efforts should be made to find ways to prevent such loss. However, excessive LP abduction is associated with post operative dysphagia and coughing.

Effects of supplement type and previous experience on variability in intake of supplements by heifers

Intakes, and variability in intakes, of a range of supplements were examined in groups (n = 10–20) of cattle grazing tropical native pasture in 24-ha paddocks. Intakes of supplement by individual animals were measured using lithium sulfate as a marker. In Expt 1, heifers (n = 160) were offered 1 of 4 supplements consisting of (i) a restricted amount of cottonseed meal (CSM); or ad libitum amounts of (ii) molasses containing 74 g urea/kg (M8U), (iii) a loose mineral mix (LMM) containing (g/kg) salt 390, urea 300, CSM 150, calcium phosphate 150, and sulfur 10, and (iv) feed block supplements containing (g/kg) molasses 494, urea 99, calcium phosphate 62, salt 62, bran 62, calcium oxide 148, and magnesium oxide 74. After 5 and 10 weeks the variation in supplement intake among heifers within a group was lower (P < 0.05) for CSM and M8U (coefficient of variation (CV) 24–37%) than for the LMM or block supplements (CV 55–118%). All heifers offered CSM or M8U consumed at least some supplement, but up to 5% and 20% of heifers were non-eaters of LMM or block supplement, respectively. Both the per�cent non-eaters of supplement and the variability in intake of these latter supplements tended (P < 0.10) to decline as the experiment progressed. In Expt 2 the same heifers were re-allocated to paddock groups and were offered ad libitum supplements of (i) M8U, (ii) molasses containing 107 g urea/kg (M12U), (iii) M8U mixed with monensin (M8U-M), or (iv) M8U mixed with meatmeal (M8U-MM). The CV of supplement intake ranged from 37 to 58%, and except in one paddock group offered M8U-MM, all heifers consumed at least some supplement. In Expt�3, paddock groups of heifers (n = 120) without, or with experience of LMM supplements during the previous dry season were offered LMM supplements containing either nil or 300�g CSM/kg. Voluntary intake of LMM supplement DM was increased (P < 0.001) by 93% by inclusion of CSM and decreased (P < 0.05) by 24% by previous experience of a similar LMM supplement. Neither variability in supplement intake (CV 66–150%) nor the per�cent non-eaters was significantly (P > 0.05) affected by previous experience of the heifers with LMM supplements or inclusion of CSM in the supplement. However, the per cent non-eaters of LMM supplement was inversely related to the mean voluntary intake of the supplement by the paddock group; when the average voluntary intake of the supplement by the paddock group exceeded 0.2 g DM/kg LW.day, then ≤10% of heifers were non-eaters of supplement. In conclusion, within groups of heifers offered LMM and block supplements the variability in intake and per cent non-eaters of supplement were higher than for cottonseed meal or molasses-urea supplements, and variability appeared to be associated with voluntary intake of the supplements.

Lithium salts as a marker of intake of supplements by cattle

In a series of experiments the appearance of lithium cation in plasma following ingestion or intravenous administration of lithium salts was measured in order to examine the suitability of lithium as a marker of supplement intake by cattle. In experiment 1, cattle were offered low quality hay ad libitum and 0.15, 0.4, 1.0 and 3.0 kg cottonseed meal (CSM) supplement per day. Following ingestion of lithium-labelled CSM, the lithium concentration in plasma reached a maximum after about 24 h and the subsequent decrease in concentration appeared to follow a single exponential relationship. The rate constant of this disappearance of lithium from plasma was greater (P<0.05) when 3.0 kg than when lesser amounts of lithium-labelled CSM were consumed. Plasma lithium concentrations 24 and 32 h after ingestion of lithium-labelled CSM were both linearly related to the amount of supplement consumed (r = 0.86 and 0.87, respectively, n = 32, P<0.001), indicating that the plasma lithium concentrations could be used to measure intakes of supplement by individual animals. In experiment 2, following intravenous administration of lithium chloride the disappearance of lithium from plasma over 96 h appeared to be best described by 3 exponential compartments. In experiment 3, cattle were offered molasses-based or loose mineral mix (LMM) supplement, or water, labelled with lithium and the rate constant of disappearance of lithium from plasma between 32 and 96 h was determined. The pattern of the decrease in plasma lithium concentration was similar to that observed in experiment 1. In experiment 4, the variation about the estimates of supplement intake was measured in heifers (n = 24) offered hay and water ad libitum and in addition a meal of 60 g of lithium-labelled molasses–urea supplement; between 20 and 28 h after ingestion of the lithium-labelled supplement the coefficient of variation (CV) among animals in plasma lithium concentration was about 15%. The likely errors associated with the use of lithium salts to measure intake of supplement are discussed. These experiments confirm that lithium salts can be used as a marker to estimate intake of supplement by individual animals.

Treatment and therapeutic monitoring of canine hypothyroidism

Thirty-one dogs with spontaneous hypothyroidism were treated with thyroid hormone replacement therapy (THRT) and monitored for approximately three months. Good clinical and laboratory control was ultimately achieved in all cases with a mean L-thyroxine (T4) dose of 0.026 mg/kg administered once daily. There was a significant increase and decrease in circulating total T4 and canine thyroid stimulating hormone (cTSH) concentrations, respectively, after starting THRT. After commencing treatment, 11 cases subsequently required an increase and three cases required a decrease in dose to achieve optimal clinical control. Median (semi interquartile range [SIR]) circulating six-hour post-pill total T4 (53.6 [27.91 nmol/litre) and cTSH (0.03 [0] microg/litre) concentrations were significantly increased and decreased, respectively, in treated dogs that did not require a dose change; corresponding values in treated dogs in which an increase in dose was required were 29.3 (12.7) nmol/litre and 0.15 (0.62) microg/litre, respectively. However, circulating cTSH measurement was of limited value in assessing therapeutic control because, although increased values were associated with inadequate therapy, reference range cTSH values were common in inadequately treated dogs. Lethargy and mental demeanour were typically the first clinical signs to improve, with significant bodyweight reduction occurring within two weeks of commencing THRT. Routine clinicopathological monitoring was of value in confirming a general metabolic response to THRT, but was of limited value in accurately monitoring cases or tailoring therapy in individual cases.

Urinary cortisol:creatinine ratios in healthy horses and horses with hyperadrenocorticism and non-adrenal disease

Urinary cortisol and creatinine concentrations, and the cortisol:creatinine ratio were compared between 12 healthy horses (group 1), 13 horses with Cushing's disease (group 2), and eight horses with dysautonomia syndrome (equine grass sickness) (group 3). The mean (sd) urinary cortisol concentrations were 112 (55.7), 250 (357) and 864 (526) nmol/litre in groups 1, 2 and 3, respectively; the mean (sd) urinary creatinine concentrations were 18.9 (7.3), 12.0 (6.7) and 45.2 (26.4) nmol/litre in groups 1, 2 and 3, respectively, and the mean (sd) ratios were 6.1 (2.6), 19.8 (23.8) and 21.3 (14.5) (x 10(-6)) in groups 1, 2 and 3, respectively. The urinary cortisol and creatinine concentrations were significantly greater in group 3 than in groups 1 and 2, but the ratios were not significantly different, although there was a trend (P=0.076) towards higher values in groups 2 and 3. A diagnostic cut-off in the cortisol:creatinine ratio for the confirmation of Cushing's disease of more than 6.9 x 10(-6) was associated with a diagnostic sensitivity and specificity of 92.3 and 75.0 per cent, respectively, when compared with healthy horses. However, when group 3 horses were included, a cut-off of more than 7.4 x 10(-6) was associated with a diagnostic sensitivity and specificity of 84.6 and 54.5 per cent, respectively.

Tolerability and immune responses in humans to a PowderJect DNA vaccine for hepatitis B

We are developing a DNA vaccine toward hepatitis-B virus (HBV) using PowderJect's proprietary needle-free technology to deliver DNA-coated gold particles directly into cells of the skin. Preclinical studies in animals showed that (i) microgram doses of the DNA vaccine were sufficient to immunize pigs and non-human primates to antibody levels comparable to those obtained with a commercial recombinant subunit vaccine; (ii) the DNA vaccine was effective in mouse strains that respond poorly to protein subunit vaccines; (iii) the vaccine induces robust cytotoxic T-cell responses, and (iv) the vaccine is non-toxic and well tolerated. Based on these findings, this DNA vaccine was evaluated for safety, tolerability, and the induction of immune responses in phase 1 clinical studies in healthy, hepatitis-naïve human volunteers. Preliminary results indicate that the vaccine is safe and well tolerated, and elicits both humoral and cellular immune responses in man.

Daytime liver glycogen accumulation, measured by 13C magnetic resonance spectroscopy, in young children with Type 1 diabetes mellitus

AIM

To examine daytime liver glycogen accumulation in prepubertal children with Type 1 diabetes mellitus (Type 1 DM) compared with non-diabetic controls.

METHODS

Liver glycogen content was ascertained in the fasting (morning) and fed (afternoon) state using 13C magnetic resonance (MR) spectroscopy. Data were analysed from six children with Type 1 DM (median (range) age 8.7 (6.3-12.2) years), who were all on conventional insulin regimens, and six healthy controls (age 8.9 (7-10.2) years).

RESULTS

Children with diabetes tended to have lower fasting glycogen values than controls but this did not reach statistical significance (median (range) 154 (70-177) vs. 178 (120-203) mM glycosyl units, Type 1 DM vs. controls respectively; P = 0.06). Glycogen increased in all children with diabetes during the day and concentrations were similar to those in controls by the afternoon (175 (157-299) vs. 172 (136-238) mM glycosyl units; P = 0.7).

CONCLUSIONS

The ability of young children with Type 1 DM to replace liver glycogen depleted after an overnight fast was at least as good as that in control subjects, suggesting that impaired glycogen storage is not a contributory factor in nocturnal hypoglycaemia.

Hypo-osmotic swelling-activated release of organic osmolytes in brain slices: implications for brain oedema in vivo

A decrease in the intracellular levels of osmotically active species has invariably been seen after swelling of mammalian brain tissue preparations. The exact identity of the species, and the manner of their decrease, remain to be described. We investigated the swelling-activated decrease of organic osmolytes in rat cortical brain slices using (1)H- and (31)P-magnetic resonance spectroscopy. We found that acute hypo-osmotic shock causes decreases in the levels of a range of intracellular amino acids and amino acid derivatives, N-acetyl-aspartate, creatine, GABA, glutamate, hypotaurine, and also in the levels of the methylamines glycerol-phosphorylcholine, phosphorylcholine and choline. Incubation of cortical slices with the anion channel blockers niflumic acid and tamoxifen caused inhibition of organic osmolyte efflux, suggesting that such osmolyte efflux occurs through anion channels. Intracellular phosphocreatine was also seen to decrease during acute hypo-osmotic superfusion, although intracellular ATP remained constant. In addition, the acidification of an intracellular compartment was observed during hypo-osmotic superfusion. Our results suggest a link between brain energy reserve and brain osmoregulation.

The Black Sea Tele-Diab System: development-implementation-clinical evaluation

This paper describes the application of the GEHR (Good European Health Record) architecture to develop a system to enable the storage and exchange of EHCRs (Electronic Health Care Record) of patients with diabetes, in the Black Sea area. The objectives of the Black Sea Tele Diab System (BSTD) were to develop and evaluate the use of a fully-computerised healthcare record system in a clinical setting, to promote the use of electronic data exchange of healthcare information and to provide a framework for the epidemiological study and monitoring of diabetes care.

Effect of biofeedback-assisted relaxation training on foot ulcer healing

A prospective, randomized study was conducted to determine the effect of biofeedback-assisted relaxation training on foot ulcer healing. For patients with chronic nonhealing foot ulcers, medical care was combined with a standardized biofeedback-assisted relaxation training program in the experimental group. The intervention was designed to increase peripheral perfusion, thereby promoting healing. A total of 32 patients with chronic nonhealing ulcers participated in the study. In the experimental group, 14 out of 16 ulcers (87.5%) healed, as compared with 7 out of 16 ulcers (43.8%) in the control group.

Effects of experience on voluntary intake of supplements by cattle

Experiments examined the effects of prior experience of young cattle on their voluntary intake of supplements, and variability among animals in intake of supplements. Variability was measured using supplement labelled with lithium salts. Experiment 1 examined the effects of offering a concentrate supplement to calves before and/or after weaning on their subsequent intake of the same supplement and of a loose mineral mix supplement. Experience of the concentrate supplement increased acceptance and reduced variability in intake of the loose mineral mix supplement. However, neither voluntary intake (mean is 105 g DM/head.day) nor variability in intake of loose mineral mix supplement was affected by prior experience. Experiments 2 and 3 examined variability in intake of loose mineral mix supplement by weaners in larger groups or offered molasses–urea supplement, respectively. Experiment 4 examined the effects of provision of supplements and/or exposure to human activity and handling on subsequent intake of loose mineral mix supplement. Supplementing grazing weaners with concentrates had a transient effect by increasing voluntary intake of loose mineral mix supplement, but increased exposure to supplements, and human activity and handling while held in yards after weaning had no effects. Variability among animals in intake of loose mineral mix supplement (CV is 52–103%) tended to be greater than with the concentrate or molasses-based supplements (CV is 23–43%), irrespective of previous experience. There were fewer than 1% non-eaters of concentrate supplement and 0–7% non-eaters of loose mineral mix supplement. In experiment 5, prior experience of loose mineral mix supplements increased intake of such supplements by weaners during weeks 1 and 2 but not from weeks 3 to 9. In experiment 6, intake of loose mineral mix supplement by adult cattle was not affected by their experience as weaners of a similar supplement. In conclusion, although prior experience of supplements by young cattle sometimes increased their initial acceptance and voluntary intake of supplements, longer-term intake of supplements was not affected.

N-Acetylaspartate and DARPP-32 levels decrease in the corpus striatum of Huntington's disease mice

Huntington's disease (HD) is an autosomal dominant condition involving progressive neurodegeneration, primarily the corpus striatum and cerebral cortex. We have used in vivo magnetic resonance spectroscopy (MRS) to assess specific neuronal markers in transgenic mice (R6/1 line) expressing exon I of the human huntingtin gene with an expanded CAG repeat. Levels of N-acetylaspartate (NAA), an indicator of healthy neuronal function, were significantly reduced (26%) in the corpus striatum of HD mice relative to wild-type littermates at 5 months of age. However, levels of cholines and creatine-phosphocreatine were not altered in the HD mice. Expression of dopamine- and cAMP-regulated phosphoprotein, 32 kDa (DARPP-32), was assessed by immunohistochemistry in the striatum of HD mice and found to be downregulated by 5 months and, even more dramatically, at 11 months of age. In contrast, expression of calbindin was not significantly decreased in HD mice. Our results suggest that the observed decreases in DARPP-32 and NAA may contribute to aberrant receptor signalling and neuronal dysfunction in HD.

Induction of antigen-specific CD8+ T cells, T helper cells, and protective levels of antibody in humans by particle-mediated administration of a hepatitis B virus DNA vaccine

A DNA vaccine against the hepatitis B virus (HBV) was evaluated for safety and induction of immune responses in 12 healthy, hepatitis-naïve human volunteers using the needle-free PowderJect system to deliver gold particles coated with DNA directly into cells of the skin. Three groups of four volunteers received three administrations of DNA encoding the surface antigen of HBV at one of the three dose levels (1, 2, or 4 microg). The vaccine was safe and well tolerated, causing only transient and mild to moderate responses at the site of administration. HBV-specific antibody and both CD4+ and CD8+ T cell responses were measured before and after each immunization. All the volunteers developed protective antibody responses of at least 10 mIU/ml. In volunteers who were positive for the HLA class I A2 allele, the vaccine also induced antigen-specific CD8+ T cells that bound HLA-A2/HBsAg(335-343) tetramers, secreted IFN-gamma, and lysed target cells presenting a hepatitis B surface antigen (HBsAg) CTL epitope. Enumeration of HBsAg-specific T cells producing cytokine indicated preferential induction of a Type 1 T helper cell response. These results provide the first demonstration of a DNA vaccine inducing protective antibody titers and both humoral and cell-mediated immune responses in humans.

Phase II study of the oxygen saturation curve left shifting agent BW12C in combination with the hypoxia activated drug mitomycin C in advanced colorectal cancer

BW12C (5-[2-formyl-3-hydroxypenoxyl] pentanoic acid) stabilizes oxyhaemoglobin, causing a reversible left-shift of the oxygen saturation curve (OSC) and tissue hypoxia. The activity of mitomycin C (MMC) is enhanced by hypoxia. In this phase II study, 17 patients with metastatic colorectal cancer resistant to 5-fluorouracil (5-FU) received BW12C and MMC. BW12C was given as a bolus loading dose of 45 mg kg(-1) over 1 h, followed by a maintenance infusion of 4 mg kg(-1) h(-1) for 5 h. MMC 6 mg m(-2) was administered over 15 min immediately after the BW12C bolus. The 15 evaluable patients had progressive disease after a median of 2 (range 1-4) cycles of chemotherapy. Haemoglobin electrophoresis 3 and 5 h after the BW12C bolus dose showed a fast moving band consistent with the BW12C-oxyhaemoglobin complex, accounting for approximately 50% of total haemoglobin. The predominant toxicities--nausea/vomiting and vein pain--were mild and did not exceed CTC grade 2. Liver 31P magnetic resonance spectroscopy of patients with hepatic metastases showed no changes consistent with tissue hypoxia. The principle of combining a hypoxically activated drug with an agent that increases tissue hypoxia is clinically feasible, producing an effect equivalent to reducing tumour oxygen delivery by at least 50%. However, BW12C in combination with MMC for 5-FU-resistant colorectal cancer is not an effective regimen. This could be related to drug resistance rather than a failure to enhance cytotoxicity.

Intravenous administration of levothyroxine for treatment of suspected myxedema coma complicated by severe hypothermia in a dog

A 7-year-old male English Coonhound with suspected myxedema coma complicated by severe hypothermia and metabolic abnormalities was treated with a combination of active external and core rewarming techniques, i.v. and oral administration of levothyroxine, supplemental oxygen, and administration of fluids (0.9% NaCl solution). Myxedema coma develops as a consequence of severe hypothyroidism and is characterized by a hypometabolic, stuporous state. Myxedema coma is associated with a high mortality rate, and most reported cases have involved Doberman Pinschers. Intravenous administration of levothyroxine can be used successfully in combination with oral administration to restore normal metabolic function and assist in warming and thermoregulation, although dosages should be conservative to avoid adverse cardiovascular effects.

Response of lambs fed low quality roughage to supplements based on urea, cereal grain, or protein meals

The intake and growth responses of lambs fed barley straw to a range of supplements provided on a 3- or 4-day cycle were examined. Supplements were urea and sulfur (N/S) added to the straw, or 3 increments of each of 3 approximately isonitrogenous supplements consisting of barley grain mixed with urea and sulfur (Bar/N), cottonseed meal (CSM), and a 0.4 : 0.6 mixture of fishmeal and lucerne hay (FM/L). Lambs fed straw alone consumed 38.3 g dry matter (DM)/kg W0.75 day of straw and an estimated 2.54 MJ metabolisable energy (ME)/day, and lost 20 g liveweight (LW)/day. Supplementation with N/S increased estimated ME intake by 32%. Substitution rates of Bar/N, FM/L, and CSM supplements for straw were 0.50, 0.36, and 0.25 g/g, respectively, but these rates did not differ (P > 0.05) between supplements. Digestibilities of organic matter (OM) and neutral detergent fibre (NDF) were affected differently depending on both the type and amount of supplement. Estimated ME intake was increased 7.1, 7.9, and 8.6 kJ/g supplement DM by Bar/N, FM/L, and CSM, respectively. LW gain and wool growth were increased (P < 0.01) by consecutive increments of each of the supplements, and were increased more (P < 0.01) by the FM/L and CSM than by the Bar/N supplement. The slopes of the linear relationships between LWgain and estimated ME intake were greater (P < 0.05) for CSM and FM/L than for Bar/N supplement, ingested ME being used with about twice the efficiency for LW gain when the protein meal supplements rather than the cereal grain–urea supplement was fed. However, across all supplement treatments, LW gain was correlated (r = 0 .9 1 ; P < 0.001) with the absorbed amino acid supply as estimated from feeding standards. In conclusion, although supplements based on either cereal grain or protein meals increased LW gain in these young lambs, there were much greater responses to the protein meals due principally to more efficient utilisation of ingested ME for LW gain.

Recombinant leptin for weight loss in obese and lean adults: a randomized, controlled, dose-escalation trial

CONTEXT

The protein hormone leptin is important to the homeostatic regulation of body weight. Treatment with exogenous leptin may affect weight loss.

OBJECTIVE

To determine the relationship between increasing doses of exogenous leptin administration and weight loss in both lean and obese adults.

DESIGN

A randomized, double-blind, placebo-controlled, multicenter, escalating dose cohort trial conducted from April 1997 to October 1998.

SETTING

Four university nutrition and obesity clinics and 2 contract clinical research clinics.

PARTICIPANTS

Fifty-four lean (body mass index, 20.0-27.5 kg/m2; mean [SD] body weight, 72.0 [9.7] kg) and 73 obese (body mass index, 27.6-36.0 kg/m2; mean [SD] body weight, 89.8 [11.4] kg) predominantly white (80%) men (n = 67) and women (n = 60) with mean (SD) age of 39 (10.3) years.

INTERVENTIONS

Recombinant methionyl human leptin self-administered by daily morning subcutaneous injection (0 [placebo], 0.01, 0.03, 0.10, or 0.30 mg/kg). In part A, lean and obese subjects were treated for 4 weeks; in part B, obese subjects were treated for an additional 20 weeks. Lean subjects consumed a eucaloric diet to maintain body weight at the current value, and obese subjects were prescribed a diet that reduced their daily energy intake by 2100 kJ/d (500-kcal/d) from the amount needed to maintain a stable weight.

MAIN OUTCOME MEASURES

Body weight, body fat, and incidence of adverse events.

RESULTS

Weight loss from baseline increased with increasing dose of leptin among all subjects at 4 weeks (P = .02) and among obese subjects at 24 weeks (P = .01) of treatment. Mean (SD) weight changes at 4 weeks ranged from -0.4 (2.0) kg for placebo (n = 36) to -1.9 kg (1.6) kg for the 0.1 mg/kg dose (n = 29). Mean (SD) weight changes at 24 weeks ranged from -0.7 (5.4) kg for the 0.01 mg/kg dose (n = 6) to -7.1 (8.5) kg for the 0.30 mg/kg dose (n = 8). Fat mass declined from baseline as dose increased among all subjects at 4 weeks (P = .002) and among obese subjects at 24 weeks of treatment (P = .004); more than 95% of weight loss was fat loss in the 2 highest dose cohorts at 24 weeks. Baseline serum leptin concentrations were not related to weight loss at week 4 (P = .88) or at week 24 (P = .76). No clinically significant adverse effects were observed on major organ systems. Mild-to-moderate reactions at the injection site were the most commonly reported adverse effects.

CONCLUSIONS

A dose-response relationship with weight and fat loss was observed with subcutaneous recombinant leptin injections in both lean and obese subjects. Based on this study, administration of exogenous leptin appears to induce weight loss in some obese subjects with elevated endogenous serum leptin concentrations. Additional research into the potential role for leptin and related hormones in the treatment of human obesity is warranted.

Epidemiological, clinical, haematological and biochemical characteristics of canine hypothyroidism

Hypothyroidism was diagnosed in 50 dogs and excluded in 86 dogs suspected of hypothyroidism, on the basis of the results of bovine thyrotropin response tests. Breed, pedigree, sex or neutering status did not significantly influence the likelihood of the dogs being hypothyroid. The hypothyroid dogs were significantly older than the non-hypothyroid dogs referred to the University of Glasgow during the same period. However, when dogs under two years of age were excluded from the statistical analyses there was no significant difference in age between the two groups. The most common clinical characteristics associated with hypothyroidism were metabolic signs (84 per cent of cases), particularly lethargy (76 per cent), obesity or weight gain (44 per cent), and exercise intolerance (24 per cent); and dermatological abnormalities (80 per cent), including alopecia (56 per cent), poor coat quality (30 per cent) and hyperpigmentation (20 per cent). When compared with the laboratory reference limits the most common biochemical and haematological abnormalities were increased concentrations of triglycerides (88 per cent), cholesterol (78 per cent), glucose (49 per cent), and fructosamine (43 per cent), and increased activities of creatine kinase (35 per cent), and decreased concentrations of inorganic phosphate (63 per cent), and a low red blood cell count (40 per cent). When compared with reference limits derived from the euthyroid dogs the most common abnormalities were increased concentrations of gamma-glutamyltransferase (21 per cent), cholesterol (18 per cent), and aspartate aminotransferase (15 per cent) and a decreased red blood cell count (29 per cent), and decreased neutrophils (18 per cent) and decreased activity of creatine kinase (15 per cent). Assessment of cholesterol, creatine kinase, aspartate aminotransferase, gamma-glutamyltransferase, and red blood cell and neutrophil counts may be particularly useful in distinguishing hypothyroid dogs from euthyroid animals with similar clinical signs.

Canine serum thyroglobulin autoantibodies in health, hypothyroidism and non-thyroidal illness

Thyroglobulin autoantibody (TGAA) was measured in serum from dogs with hypothyroidism (n = 42), non-thyroidal illness (NTI) (n = 77) and clinically healthy dogs (n = 70) using a commercially available enzyme immunoassay kit. Precision studies were consistent with good intra-assay and inter-assay repeatability. TGAA positive results occurred in 15 of the 42 (36 per cent) hypothyroid and four healthy dogs of the remaining 147 animals resulting in a lower incidence of false positive results than obtained with previous TGAA assays. The presence of TGAA was not influenced by age, sex, neutering or pedigree status. Of the four apparently healthy TGAA -positive dogs, two had additional clinicopathological evidence of hypothyroidism. TGAA was positive in 43 per cent of hypothyroid dogs with unexpectedly normal serum c TSH concentrations and was particularly useful in the classification of these cases.

31P magnetic resonance spectroscopy of the liver in HELLP syndrome

OBJECTIVES

Using magnetic resonance spectroscopy (MRS) to measure phosphorus-containing metabolites in the liver, this study aimed to investigate non-invasively whether or not women with haemolysis, elevated liver enzymes and low platelets (HELLP) have detectable abnormalities of hepatic energetics.

SETTING

John Radcliffe Hospital, Oxford.

DESIGN

Prospective study.

METHODS

After giving informed consent, patients with HELLP syndrome (n = 7) and controls with severe pre-eclampsia (n = 3), were studied by 31P MRS of the liver as soon as possible after delivery (range 2-4 days) and compared with normal nonpregnant controls (n = 6). Haematological and biochemical tests were performed serially and on the day of the MRS in all pregnant patients.

RESULTS

The severity of HELLP varied as follows: peak aspartate aminotransferase (range 129-2574), peak gamma glutamyl transferase (range 28-96), peak lactate dehydrogenase (range 305-2820), nadir platelets (range 25-114), peak international normalised ratio for prothrombin time (before fresh frozen plasma) (range 0.9-1.9). One pregnancy was terminated but all others resulted in live births and all mothers made uneventful, rapid recoveries. MRS-determined relative hepatic concentrations of phosphorus-containing metabolites and absolute concentrations of adenosine triphosphate did not differ significantly between groups. One patient with the most clinically severe HELLP syndrome (by laboratory criteria) exhibited magnetic resonance spectra which showed a relative increase in phosphomonoester and an absolute decrease in hepatic adenosine triphosphate (to 62% of control).

CONCLUSIONS

Enthusiasm for the conservative management of HELLP syndrome that develops remote from term has been tempered by the inability to identify patients at risk for progression to hepatic necrosis. We found that most patients with HELLP syndrome had normal liver metabolism as assessed by MRS. However, clinically severe HELLP syndrome can be associated with disturbed hepatic metabolism consistent with that seen in hepatic ischaemia and/or granulocytic infiltration of the liver.