Cortisol secretion and Alzheimer's disease progression

BACKGROUND

Mild hypercortisolemia is a frequent concomitant of Alzheimer's disease (AD). In an effort to ascertain the relationship between serum cortisol concentration (CORT) and disease progression, aging, and survival, we followed 9 persons with AD, ages from 56 to 84 years, from an original cohort of 19 enrollees with serial cognitive testing and CORT determinations.

METHODS

The cognitive instrument was a modification of the Alzheimer's Disease Assessment Scale-Cognitive (mADAS-COG). Serum cortisol determinations were performed at noon, and an Afternoon Cortisol Test (ACT) was used to obtain an estimate of average CORT.

RESULTS

Baseline 12:00 hours CORT but not ACT correlated significantly with the change in mADAS-COG (r = .90, p < .01). ACT levels increased as the mADAS-COG increased over time (p = .037), by 0.156 +/- 0.06 microgram/dL for each one-point increase (indicating greater impairment) in cognitive test score. ACT levels did not increase significantly simply with aging. For the entire cohort of 19 subjects, neither baseline ACT nor 12:00 hours CORT was significantly related to survival.

CONCLUSIONS

Hypercortisolemia in AD appears related to the clinical progression of the disease, but not to aging or length of survival.

Radiotelemetrically recorded blood pressure and heart rate changes in relation to plasma catecholamine levels during parturition in the conscious, unrestrained goat

The aim of this study was to investigate the extent of sympathetic nervous system activation during parturition in four unrestrained goats. Chronically implanted radiotelemetry devices registered heart rate and arterial blood pressure around the clock and blood was sampled for determination of plasma adrenaline and noradrenaline concentrations before, during and after labour. Two goats delivered two kids after moderately intensive abdominal contractions. A third goat had dystocia, and was treated with prostaglandin F2 alpha. One normal kid and one mummified foetus were delivered manually. After milking, a third kid was born spontaneously. The fourth goat experienced severe abdominal contractions and delivered one kid. Mean blood pressure was 69 +/- 2 mmHg the day before parturition, increased gradually during the labour pains, and reached a maximal value of 120 +/- 7 mmHg when the head of the first kid was visible (P < or = 0.05). Heart rate was 134 +/- 4 beats min-1 the day before parturition and peaked when the first kid was born (159 +/- 6 beats min-1, P < or = 0.05), as did plasma adrenaline concentration (from 0.4 +/- 0.2 nmol L-1 to 2.7 +/- 1.2 nmol L-1, P < or = 0.05). The concentration of noradrenaline increased from 4.8 +/- 2.3 nmol L-1 to 12.2 +/- 8.4 nmol L-1 (P < or = 0.05), when the head of the first kid was visible. Expulsion of the second and third kids caused relatively smaller increases in blood pressure, heart rate and catecholamines than those seen with the first born kid. It is concluded that changes in pressure, heart rate and catecholamines during parturition are related to the different phases of labour and not to its duration or severity.

Parathyroid hormone-related protein in neonatal and reproductive goats determined by a sensitive time-resolved immunofluorometric assay

OBJECTIVE

High concentrations of parathyroid hormone-related protein (PTHrP) have been found in goat milk but it is not known whether it can enter the circulation of the neonate. In this study we have developed a sensitive two-site lanthanide immunofluorometric assay (IFMA) using dissociation and enhancement time-resolved fluorometry to address this question.

METHOD

Affinity-purified anti-PTHrP 38-67 raised in rabbit was biotinylated and immobilized in streptavidin-coated microtitration wells as a 'capture' antibody. As a signal, affinity-purified anti-PTHrP 1-34, raised in sheep, was labeled with an europium chelate. A sensitivity of 0.3 pmol/l was achieved. PTHrP levels were determined in the plasma of eleven neonatal, seven parturient and six non-pregnant, non-lactating goats as well as in goat milk.

RESULTS

The circulating PTHrP levels (mean +/- S.D.) were significantly increased at day 1 (6.1 +/- 1.7 pmol/l: P < 0.01) and day 3 (3.5 +/- 0.6 pmol/l: P < 0.05) after birth in the male kids (n = 8) bottle-fed with milk from the dams, compared with before (2.2 +/- 0.7 pmol/l) and 30 min after (2.0 +/- 0.6 pmol/l) the first feeding and 14 days (2.4 +/- 0.8 pmol/l) later. In the female kids (n = 3) fed with formula there was no such increase and the concentrations remained between 1.6-1.9 pmol/l. In the parturient goats the mean +/- S.D. PTHrP levels before, during and after parturition were 2.9 +/- 1.7, 4.2 +/- 2.4 and 3.7 +/- 2.2 pmol/l respectively (n = 7) which demonstrated that plasma PTHrP was higher during and after parturition in comparison with before (P < 0.05). The levels in non-pregnant, non-lactating goats were 3.3 +/- 1.5 pmol/l (n = 6). PTHrP levels in goat milk were in the nanomolar range and were highest in the colostrum.

CONCLUSIONS

A significant increase of plasma PTHrP was observed in goat kids fed with milk from their dams and this increase was not found in kids fed with formula. Plasma PTHrP was also increased during parturition.

The goat mammary gland as a target organ for atrial natriuretic peptide

Milk secretion represents a major route for electrolyte and water excretion in the dairy goat. The aims of this study were to investigate whether the mammary gland is a target site for atrial natriuretic peptide (ANP) in the goat and whether ANP affects mammary sodium and water secretion. Receptor autoradiography using 125I-ANP as radioligand revealed specific binding sites in the secretory tissue of the mammary gland. The radioligand was totally displaced by unlabelled ANP, but not by brain natriuretic peptide or the ANP fragment c-ANP4-23, indicative of ANP-A receptor preference. To elucidate the role of ANP in milk secretion, ANP (30 ng kg-1 min-1; 120 min) or 0.15 M NaCl (control) were administered in vivo. The ANP infusions caused haemoconcentration, but did not change milk flow or the concentrations of sodium, potassium, lactose, fat and protein in the milk. The results show that the mammary gland of the goat expresses ANP-specific binding sites, however, a physiological role of ANP in goat mammary gland function remains to be elucidated.

The incidence and time-course of latanoprost-induced iridial pigmentation as a function of eye color

Latanoprost, a phenyl-substituted analogue of prostaglandin F2 alpha administered as eye drops, induces increased melanogenesis in the iridial melanocytes of monkeys. Similar effects were seen in 12, 23 and 11% of patients in the USA, United Kingdom (UK) and Scandinavia, respectively, during one year of treatment. The highest incidence of induced pigmentation was seen in green-brown, yellow-brown and blue/grey-brown eyes, in that order. The relatively high proportion of patients with green-brown eyes in the UK explains the larger number of affected patients in this country. Typically, a concentric increase of the iris pigmentation appeared after six months (range: 3-17) and was judged to be noticeable by the patient in about 2/3 of the cases. After cessation of latanoprost, no change of the induced pigmentation has been seen in patients followed for two years, and there have been no signs of dispersion of pigment into the anterior chamber. Irides, homogeneously blue, grey, green or brown, were seldom affected. Naevi or freckles on iris, conjunctiva, or eye lids were not affected. It is intriguing that many patients with mixed eye color, particularly the blue-brown eyes, have not developed increased pigmentation even during two years of treatment. This could be due to a relatively slow melanogenesis or to refractory melanocytes in these individuals.

Effects of naturally acquired decompensated mitral valve regurgitation on the renin-angiotensin-aldosterone system and atrial natriuretic peptide concentration in dogs

OBJECTIVE

To investigate activity of the renin-angiotensin-aldosterone system and N-terminal pro-atrial natriuretic peptide (NT-proANP) during development of clinical signs of decompensated mitral valve regurgitation (MR).

ANIMALS

11 Cavalier King Charles Spaniels with advanced MR attributable to chronic valvular disease.

PROCEDURE

Dogs were subjected to repeated examinations at 6-month intervals until signs of decompensation had developed (end point). Data acquired at end point were compared with data obtained from examinations 1 year and 1 to 6 months before decompensation. Each examination included physical examination, collection of venous blood, thoracic radiography, and echocardiography.

RESULTS

Echocardiographic measurements of left atrial-to-aortic root ratio and left ventricular end diastolic diameter increased considerably during the study, whereas left ventricular end systolic diameter remained unchanged. The increase in cardiac size was associated with increased plasma concentration of NT-proANP. In contrast, plasma concentrations of aldosterone and angiotensin II were reduced at decompensation (aldosterone compared with the 2 earlier examinations and angiotensin II compared with values obtained 1 to 6 months before), despite decreased plasma protein concentration and hematocrit, suggesting fluid retention. The urine-to-plasma creatinine ratio was reduced at end point.

CONCLUSION AND CLINICAL IMPLICATIONS

Early decompensated MR in dogs was not associated with increased circulating renin-angiotensin-aldosterone system activity, which may be caused by increased activity of ANP, and may be important for future therapeutic strategies of MR.

Effects of long-term treatment with enalapril or hydralazine on the renin-angiotensin-aldosterone system and fluid balance in dogs with naturally acquired mitral valve regurgitation

OBJECTIVE

To study long-term effects of enalapril, an angiotensin-converting enzyme inhibitor, and hydralazine, an arteriodilator, on renin-angiotensin-aldosterone system and fluid balance before and after administration of furosemide.

ANIMALS

22 dogs with clinical signs of congestive heart failure (CHF) attributable to mitral regurgitation.

PROCEDURE

After initial examination, 12 dogs received enalapril and 10 received hydralazine. Dogs were re-examined 3 weeks and 6 months after initial examination. Furosemide was added after the 3-week examination, and at 6 months, dogs had received furosemide for at least 4 months.

RESULTS

Angiotensin II and aldosterone plasma concentrations were low before treatment, and only aldosterone became significantly decreased after enalapril monotherapy. Concentrations of both hormones and heart rate increased in dogs receiving hydralazine monotherapy, and fluid retention was evident. After long-term treatment with either of the 2 drugs together with furosemide, angiotensin II and aldosterone values increased in both groups. Natriuresis and kaliuresis developed in all dogs, with greatest effect in those receiving enalapril and furosemide. These dogs had decreased plasma sodium concentration, whereas potassium concentration was equally decreased in both groups. After 6 months, the enalapril group, but not the hydralazine group, had increased cardiac size. All dogs had moderate reduction of weight and were azotemic, although changes were more pronounced in those of the hydralazine group.

CONCLUSION

The 2 drugs have different effects on the renin-angiotensin-aldosterone system and fluid balance in dogs with CHF.

Responses to systemic angiotensin II in lactating and non-lactating goats

This study aimed at investigating whether lactation affects the dipsogenic, hypertensive and volumetric effects of angiotensin II (Ang II) in a low-yielding goat adapted to arid conditions. Six black Moroccan goats were given intravenous infusions of Ang II at 8 ng kg-1 min-1 for 90 min during lactation and a non-lactation period. To further test the dipsogenic response, 5 of them were given Ang II at the consecutively increasing doses 10, 20, 50 and 100 ng kg-1 min-1 (10 min at each dose). The body weight was 32 +/- 1 kg in both periods and the daily milk production was 22 +/- 2 ml kg-1. No drinking was observed during infusions of Ang II in any of the goats. The rise of the mean arterial pressure to Ang II was attenuated in lactating animals and this was not steroid-dependent since the plasma progesterone level was low (< 0.2 nmol 1(-1)). Total plasma protein concentration decreased during Ang II infusions, and the ratio albumin/total proteins was unchanged, indicating that haemodilution had occurred. It is concluded that Ang II does not elicit drinking in the arid adapted Moroccan goats and we suggest that these goats have an elevated thirst threshold. However, haemodilution and an attenuated blood pressure response to Ang II occur in the lactating Moroccan goat, as has previously been observed in high-yielding Swedish domestic goats.

Keratouveitis--two families with a dominantly inherited disorder

Herein we describe a relapsing acute keratouveitis without known aetiology. The disorder has been found in two families and shows an autosomal dominant inheritance. Acute anterior uveitis can be traced for five generations in one of these families. In the same family there is also an association to an autosomal dominantly inherited vascular disorder (Osler-Rendu-Weber disease). The anterior uveitis has an acute onset, a recurrent pattern and a mild activity. The associated keratitis is seen as a midstromal thin flat disc in the central cornea, sometimes with folds in Descemet's membrane as a sign of oedema. This causes a change in refraction and a mild reduction of the corrected visual acuity. There is a prompt response to topical steroid treatment, but the corneal changes have in one case become permanent. Clinical documentation and the mode of inheritance is presented.

A long term study of goats naturally infected with caprine arthritis-encephalitis virus

The caprine arthritis-encephalitis virus (CAEV) is a big problem in dairy goat industry. Little is known about its characteristics in naturally infected goat herds. The aims of this study were: 1) to study how antibody expression, measured by agar gel immunodiffusion test (AGIDT), varied over time in naturally infected, seropositive goats, 2) to observe clinical signs in seropositive adult goats and 3) to follow seroconversion and gamma globulin concentration in goat kids artificially reared on cow milk replacement product only, compared to kids reared on untreated goat milk. The antibody expression pattern to the viral proteins gp135 and p28 varied in the individual goat and intermittent negative reactions were seen in 19 adult animals followed for 30-91 weeks. Four seropositive goats developed clinical symptoms with difficulties to move. However, no correlation between clinical signs and antibody expression pattern was seen. During the first 27 weeks of age no kid in the milk replacement reared group (N = 4) seroconverted, but 5 of the 7 kids fed goat milk occasionally showed a positive antibody reaction. The gamma globulin concentration was significantly higher in the goat milk fed group until the kids had become more than 19 weeks old. The results show that a great variation of the antibody pattern in individual goats occurs, and therefore the AGIDT is only reliable as a herd screening test. Frequent sampling is necessary to get reliable information about spreading of the CAEV in a naturally infected goat herd. Removing kids from their dams immediately after birth combined with segregation and artificial rearing protected them from CAEV infection. However their gamma globulin concentration was initially low.

The preference for warm drinking water induces hyperhydration in heat-stressed lactating goats

The aim of this study was to determine whether lactating goats regulate their water intake when given a choice between warm (35 degrees C) and cold (15 degrees C) water. Six lactating goats were kept individually in pens. At 07.00 h one bucket was filled with warm water and another with cold water. Water consumption was measured at intervals until 18.00 h. Water temperature was not controlled at night. Two experiments were made, one at normal room temperature (18-19 degrees C) and the other at 39-40 degrees C from 10.45 to 17.00 h. At normal room temperature the goats drank 6.0 +/- 1.4 L of the warm water but only 1.7 +/- 1.3 L of the cold water (P < 0.001). The total water consumption, including the following night, was 9.2 +/- 1.6 L. This differed from control days, when only cold water was available (5.9 +/- 0.4 L; P < 0.05). Neither the plasma Na concentration nor the osmolality changed, which indicate that the goats regulated their fluid balance. In the experiments involving heat stress the goats drank 11.5 +/- 1.7 L of the warm water but only 2.0 +/- 1.0 L of the cold water (P < 0.001). In total, including the following night, they drank 16.2 +/- 2.6 L (P < 0.001 vs. control days). Goats drank repeatedly despite falling plasma Na and osmolality, proving that their thirst was not induced by water losses. Their abdomens became distended, indicating that water was stored in the reticulo-rumen and explaining why their body weights increased. The goats appeared distressed. It is concluded that goats prefer to drink warm water. Nevertheless, our results suggest that, if possible, warm drinking water should not be given to lactating goats under hot ambient conditions.

Reproductive period affects water intake in heat-stressed dehydrated goats

Water intake following dehydration was studied in pregnant (N = 5), lactating (N = 4) and nonpregnant, nonlactating (N = 5) Swedish domestic goats (Capra hircus) to investigate if reproductive period affected drinking. Plasma cortisol concentration and the hematocrit value were measured to evaluate stress. The goats were water deprived from 9.00 h until 15.05 h the next day. They were fed at 7.00 and 15.20 h. On the second day, ambient temperature was increased from 20 degrees C to 38-39.5 degrees C for 5.15 h to accelerate water losses. Water temperature during rehydration was 35 +/- 1 degree C. Plasma Na concentration and osmolality increased most in dehydrated and heat-stressed pregnant and lactating goats. Pregnant goats lost 2.2 kg of their body weight. They drank 3.5 l immediately, followed by 2.5 l during afternoon eating. Lactating goats lost 4.9 kg and drank 6.3 l at once, and 3.9 l during feeding. Nonpregnant, nonlactating goats lost 1.7 kg and drank 2.6 l followed by 0.6 l. The large water consumption in pregnant and lactating goats caused hyponatremia and hemodilution, but they continued to drink during the night (0.5 +/- 0.2 l and 0.8 +/- 0.5 l, respectively). Renal free water clearance increased in all periods, with a long-lasting water diuresis during pregnancy. Plasma cortisol concentrations and the hematocrit values rose in connection with water intake. These results imply that the thirst center became less sensitive to inhibitory signals from the oropharyngeal tract and the diluted blood plasma during pregnancy and lactation. Catching sight of water was the most exciting procedure during these experiments.

Evaluation of platelet function using the in vitro bleeding time and corrected count increment of transfused platelets. Comparison between platelet concentrates derived from pooled buffy coates and apheresis

The functional capacity of transfused platelets was evaluated with in vitro bleeding time (IVBT) and corrected count increment (CCI) in order to compare platelet concentrates (PCs) derived from pooled buffy coats (BC-PCs) with PCs collected by apheresis (A-PCs). The suspension medium in the BC-PCs was 30% CPD plasma and 70% of an additive solution (containing sodium and potassium chloride, sodium citrate and phosphate, mannitol), and in the A-PCs the medium was 100% CPD plasma. IVBT was evaluated using a Thrombostat 4000/2. BC-PC and A-PC were transfused 57 and 41 times, respectively to 36 patients with chemotherapy-induced thrombocytopenia. PCs transfused within 2 days of donation were considered fresh, and those transfused within 3-5 days were considered stored. IVBT was determined before, as well as 10-30 min and 24 h after transfusion; CCI was determined 10-30 min and 24 h after transfusion. The median pretransfusion IVBT value was 486 s. It was measurable in 21 of 98 (21%) of the transfusions, i.e. below the cutoff limit of 486 s. Ten to 30 min after transfusion, the IVBT showed a measurable reduction in 90% of the transfusions with fresh BC-PCs, 92% of those with fresh a-PCs, 63% of those with stored BC-PCs and 79% of those with stored A-PCs. After 24 h, the corresponding values were 63% for fresh BC-PCs, 50% for fresh A-PCs, 26% for stored BC-PCs and 38% for stored A-PCs. The median value of CCI 10-30 min after transfusion was 20 for fresh BC-PCs, 17 for fresh A-PCs, 16 for stored BC-PCs and 14 for stored A-PCs. The difference in IVBT between fresh and stored BC-PCs was significant (p = 0.032), unlike that between fresh and stored A-PC. After 24 h the corresponding values were 7 for fresh BC-PCs, 4 for fresh A-PCs, 4 for stored BC-PCs and 3 for stored A-PCs. When all transfusions with fresh PCs (BC-PCs + A-PCs) were compared with all transfusions with stored PCs, a statistical difference was demonstrated in both CCI (p = 0.027) and IVBT (p = 0.043). Spearman's rank correlation coefficient (rs) was -0.41 between CCI and IVBT < 486 s 10-30 min after transfusion, and -0.55 between the posttransfusion platelet count and IVBT, indicating a relatively poor correlation between CCI and IVBT, and a slightly better correlation between platelet count and IVBT. In conclusion, BC-PCs showed a slightly higher CCI and a better response in IVBT than A-PCs. No statistical difference was demonstrated between BC-PCs and A-PCs transfused within 2 days after donation, with respect to function and recovery in vivo. BC-PCs stored for 3 days or more showed about the same CCI and IVBT as stored A-PC but significantly lower CCI and higher IVBT than fresh BC-PCs. This may indicate that the preparation and/or storage conditions were not optimal. IVBT seems to be a useful possibility to test the in vivo behavior of transfused platelets.

A long term study of goats naturally infected with caprine arthritis-encephalitis virus

The caprine arthritis-encephalitis virus (CAEV) is a big problem in dairy goat industry. Little is known about its characteristics in naturally infected goat herds. The aims of this study were: 1) to study how antibody expression, measured by agar gel immunodiffusion test (AGIDT), varied over time in naturally infected, seropositive goats, 2) to observe clinical signs in seropositive adult goats and 3) to follow seroconversion and gamma globulin concentration in goat kids artificially reared on cow milk replacement product only, compared to kids reared on untreated goat milk. The antibody expression pattern to the viral proteins gp135 and p28 varied in the individual goat and intermittent negative reactions were seen in 19 adult animals followed for 30-91 weeks. Four seropositive goats developed clinical symptoms with difficulties to move. However, no correlation between clinical signs and antibody expression pattern was seen. During the first 27 weeks of age no kid in the milk replacement reared group (N = 4) seroconverted, but 5 of the 7 kids fed goat milk occasionally showed a positive antibody reaction. The gamma globulin concentration was significantly higher in the goat milk fed group until the kids had become more than 19 weeks old. The results show that a great variation of the antibody pattern in individual goats occurs, and therefore the AGIDT is only reliable as a herd screening test. Frequent sampling is necessary to get reliable information about spreading of the CAEV in a naturally infected goat herd. Removing kids from their dams immediately after birth combined with segregation and artificial rearing protected them from CAEV infection. However their gamma globulin concentration was initially low.

Influence of amino acids on the formation of mutagenic/carcinogenic heterocyclic amines in a model system

Mixtures of creatinine, glucose and various single amino acids were heated at 180 degrees C for 10 min in an aqueous model system. The heated mixtures all showed mutagenic activity, ranging from 80 to 2400 TA98 revertant colonies/mumol creatinine with metabolic activation. Testing of HPLC fractions for mutagenic activity showed each mixture to contain several mutagenic components, some of which corresponded to known heterocyclic amines and others to unknown compounds. The presence of 2-amino-3-methyl-imidazo[4,5-f]quinoxaline, 2-amino-3,8-dimethylmidazo[4,5-f]quinoxaline and 2-amino-3,7,8-trimethylimidazo[4,5-f]quinoxaline in most of the samples was established using HPLC with photodiode array detection and liquid chromatography/mass spectrometry with electrospray interface and single ion monitoring. In addition, 2-amino-3,4,8-trimethylimidazo[4,5-f]quinoxaline, 2-amino-1-methyl-6-phenylimidazo[4,5-f]quinoxaline, 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine, 3-amino-1,4-dimethyl-5H-pyrido[4,3-b]indole and 3-amino-1-methyl-5H-pyrido[4,3-b]indole and the co-mutagenic compounds 9H-pyrido[3,4-b]indole and 1-methyl-9H-pyrido[3,4-b]indole were detected in some samples.

Heat stress causes excessive drinking in fed and food deprived pregnant goats

Water intake was studied in six goats during late pregnancy to investigate if heat stress induces primary polydipsia. The goats were fed twice daily or deprived of food for 24 hr to avoid postprandial drinking and induce hyponatremia. Signs of stress was evaluated by determination of plasma cortisol concentration. Ambient temperature was increased from 20 degrees C to 38.0-39.5 degrees C for 5.15 hr. Water temperature was 35 +/- 1 degree C during heat stress. Fed goats started to drink 13 +/- 3 min after the heaters were turned on and water diuresis developed in five of them. The body weight increased simultaneously with decreased plasma Na concentration and osmolality showing that the goats also stored water. During food deprivation, plasma Na concentration and osmolality fell, and plasma aldosterone concentration increased. Despite hyponatremia, food deprived goats started to drink 44 +/- 15 min after the heaters were turned on and then they drank repeatedly. Three of them underwent water diuresis. Hemodilution was observed both in fed and food-deprived goats during heat stress. These results show that heat stress induced primary polydipsia in pregnant goats. It is suggested that stimulating signals from warmth receptors overrode inhibiting influences from receptors signalling hyponatremia and hypoosmolality at the "thirst center" in the hypothalamus. Heat stress did not increase plasma cortisol concentration, but catching sight of food caused an abrupt, short-lasting elevation.

Intraruminal fluid administration to goats: effects of handling and fluid temperature

Physiological stress response to intraruminal fluid administration was studied in 5 female goats. The fluid was given through a stomach tube. The water was cold (10 degrees C) or warm (38 degrees C) and in an amount of 7.5-10% of body weight. Plasma concentrations of adrenaline, noradrenaline and cortisol increased significantly after both treatments. Adrenaline and noradrenaline responses were greater and more longlasting after cold water administration, but there was no difference in cortisol response between cold and warm water. Haematocrit and plasma protein concentrations increased also and the effects of cold water lasted longer. Blood pressure showed a sharp rise of short duration and was independent of water temperature. The immediate tachycardiac response was similar with both treatments, but cold water caused an additional peak 15 min later. The cooling did not increase plasma histamine level. The results suggest that stomach intubation and administration of water into the rumen leads to strong activation of hormonal and cardiovascular stress parameters even in goats well adapted to handling. Low temperature of the fluid further heightens the effect. Warming of fluids to near body temperature before their administration is thus recommended.

Preoperative evaluation of primary hemostasis in patients with thrombocytopenia using the Thrombostat 4000

It is difficult to estimate the risk of hemorrhage that may follow an invasive or surgical procedure in patients with thrombocytopenia or platelet dysfunction. Conventional functional tests for the evaluation of primary hemostasis have been questioned. We have evaluated the in vitro bleeding time (IVBT) using the Thrombostat 4000 in 25 patients with thrombocytopenia in order to estimate the risk of bleeding following an invasive or surgical procedure. Using the IVBT, it was possible to suggest and evaluate preoperative treatment in order to restore primary hemostasis. All patients studied had their operations without bleeding complications. From these observations we conclude that the IVBT is a convenient and useful tool in the evaluation of primary hemostasis in these patients.

Tendon arthroplasty for treatment of trapeziometacarpal arthrosis

Trapeziometacarpal arthrosis is common among middle-aged women, and the surgical treatment options include arthrodesis, excision of the trapezium, prosthetic replacement of the trapezium, reconstruction of the ligaments, and various tendoplasties. We have prospectively studied a simple tendoplasty in which a strip of abductor pollicis longus tendon was anchored to the flexor carpi radialis tendon, the intact part of the abductor pollicis tendon, and the joint capsule, after excision of the trapezium, and carried out 27 operations in 25 patients. The thumb was immobilised for only eight days. Systematic exercises were started on the day of operation. Complete pain relief was obtained in 17 patients and partial relief in eight. Grip strength improved. The mobility was unaltered and functionally satisfactory. Three patients were reoperated on for cutaneous nerve entrapment and one for carpal tunnel syndrome. The procedure is simple, and the patients' symptoms improved without failures. The intensive supervised postoperative physiotherapy was essential to achieve the final results.

Plasma concentration of atrial natriuretic peptide in relation to severity of mitral regurgitation in Cavalier King Charles Spaniels

Plasma concentration of immunoreactive atrial natriuretic peptide (ir-ANP) was investigated in 83 Cavalier King Charles Spaniels with variable severity of mitral regurgitation caused by chronic valvular disease (CVD). Severity of mitral incompetence was assessed by echocardiography. Significant differences in plasma concentrations of ir-ANP were not found between clinically normal dogs (New York Heart Association functional class O), dogs with only cardiac murmur (class I), and dogs with echocardiographic evidence of slight to moderate left atrial and ventricular dilatation (class II). Dogs with severe left atrial and ventricular dilatation and clinical signs of congestion (classes III and IV) were found to have significantly (P < 0.001) increased plasma concentration of ir-ANP. Overall, moderate degree of association was found between plasma concentration of ir-ANP and left atrial and left ventricular diameters (Pearson's r = 0.65, 0.60, respectively, P < 0.001), as well as heart rate (r = 0.47, P < 0.01). However, left atrial enlargement was found to have the predominant effect on plasma ir-ANP concentration. It is concluded that the plasma concentration of ir-ANP did not become markedly increased before decompensation of chronic mitral regurgitation associated with severe enlargement of the left atrium and ventricle in Cavalier King Charles Spaniels.

Discrepant effects of angiotensin II and phenylephrine on plasma volume in conscious goats

Pressor doses of angiotensin II induced haemodilution in goats despite renal fluid losses. This study was undertaken to determine if this response is dose-dependent and correlated to the vasoconstrictor action of angiotensin II. Angiotensin II at the doses 0.025, 0.05 and 0.1 micrograms min-1 was given intravenously to five goats. Mean arterial blood pressure increased by 3, 10 and 20 mmHg, respectively, and the renal Na excretion rose. The haematocrit decreased by 7, 10, and 9% (percentage of control values) and the plasma protein concentration by 1% (n.s.), 4.5, and 3.5%, respectively. Infusions of phenylephrine (40 micrograms min-1; n = 6) caused an equivalent increase of blood pressure and renal Na excretion as angiotensin II (0.1 micrograms min-1), but the haematocrit increased by 16% and the plasma protein concentration by 6.5%. Infusions of atrial natriuretic peptide (1 microgram min-1) alone or together with angiotensin II (0.1 microgram min-1), or phenylephrine were also given (n = 6). Infusions of atrial natriuretic peptide alone did not change blood pressure, but renal Na excretion increased. The haematocrit rose by 10.5% and the plasma protein concentration by 7.6%. Adding atrial natriuretic peptide to the angiotensin II solution attenuated the rise of MAP and counteracted the haemodilution, but did not decrease the natriuresis. Infusions of phenylephrine plus atrial natriuretic peptide caused similar elevations of blood pressure and renal Na excretion as phenylephrine alone. The haematocrit rose by 24% and the plasma protein concentration by 13%. These results show that in the intact conscious goat rapid and marked changes in haematocrit and plasma protein concentration can be provoked by intravenous infusions of vasoactive agents and that these effects are not correlated to changes in arterial blood pressure or renal Na excretion.

Intraruminal fluid administration to goats: effects of handling and fluid temperature

Physiological stress response to intraruminal fluid administration was studied in 5 female goats. The fluid was given through a stomach tube. The water was cold (10 degrees C) or warm (38 degrees C) and in an amount of 7.5-10% of body weight. Plasma concentrations of adrenaline, noradrenaline and cortisol increased significantly after both treatments. Adrenaline and noradrenaline responses were greater and more longlasting after cold water administration, but there was no difference in cortisol response between cold and warm water. Haematocrit and plasma protein concentrations increased also and the effects of cold water lasted longer. Blood pressure showed a sharp rise of short duration and was independent of water temperature. The immediate tachycardiac response was similar with both treatments, but cold water caused an additional peak 15 min later. The cooling did not increase plasma histamine level. The results suggest that stomach intubation and administration of water into the rumen leads to strong activation of hormonal and cardiovascular stress parameters even in goats well adapted to handling. Low temperature of the fluid further heightens the effect. Warming of fluids to near body temperature before their administration is thus recommended.