Diatom motility and nuclear alterations are affected by sediment elutriates of agricultural streams.

Diatoms respond to toxicants in lotic systems, and they are commonly considered to be sensitive indicators in environmental safety assessment. In addition to the structural characteristics of the algal populations, recent studies have shown that endpoints such as nuclear anomalies or diatom motility measures can be affected quickly by environmental changes. We sought to determine if cell density, cell size, nuclear anomalies and motility of the diatom Nitzschia palea were useful indicators of sediment quality from agricultural streams. For this purpose, we exposed cultures of the diatom to elutriates from sediments of a stream that flows through an intensive agricultural area, and measured the responses of the populations for 7 days in laboratory tests. The bioassays showed that motility measures in Nitzschia palea and the condition of their nuclear membranes rapidly reflected the effects of sediment quality after only 48 h of exposure; mean cell density and length were affected by day 7. The sediment elutriates affected cell movements by shortening the total path length and decreasing cell velocity; they also increased the number of cells with nuclear membrane breakage. Our results from these bioassays show that diatom motility measurements and the condition of the nuclei might be indicators that respond faster to impacts than the traditional structural parameters, such as cell density, specific composition of the assemblage or diversity metrics of the algal communities more often used in biomonitoring.

Morphology and Aquaporin Immunohistochemistry of the Uterine Tube of Saanen Goats (Capra hircus): Comparison Throughout the Reproductive Cycle.

The expression of six different aquaporins (AQP1, 2, 3, 4, 5 and 9), integral membrane water channels that facilitate bi-directional passive movement of water, was investigated by immunohistochemistry in the uterine tube of pre-pubertal and adult Saanen goats (Capra hircus), comparing the different phases of the oestrous cycle. Regional morphology and secretory processes were markedly different during the goat oestrous cycle. The tested AQP molecules showed different expression patterns in comparison with already studied species. AQP1-immunoreactivity was evidenced at the endothelium of blood vessels and in nerve fibres, regardless of the tubal tract and cycle period. AQP4-immunoreactivity was shown on the lateral plasmalemma in the basal third of the epithelial cells at infundibulum and ampulla level in the cycling goats, more evidently during follicular than during luteal phase. No AQP4-immunoreactivity was noticed at the level of the isthmus region, regardless of the cycle phase. AQP5-immunoreactivity, localized at the apical surface of epithelial cells, increased from pre-puberty to adulthood. Thereafter, AQP5-immunoreactivity was prominent during the follicular phase, when it strongly decorated the apical plasmalemma of all epithelial cells at ampullary level. During luteal phase, immunoreactivity was discontinuous, being weak to strong at the apex of the secretory cells protruding into the lumen. In the isthmus region, the strongest AQP5-immunoreactivity was seen during follicular phase, with a clear localization in the apical plasmalemma of all the epithelial cells and also on the lateral plasmalemma. AQP2, 3 and 9 were undetectable all along the goat uterine tube. Likely, a collaboration of different AQP molecules sustains the fluid production in the goat uterine tube. AQP1-mediated transudation from the blood capillaries, together with permeation of the epithelium by AQP4 in the basal rim of the epithelial cells and final intervening of apical AQP5, could be involved in fluid production as well as in secretory processes.

Can peri-surgical electroacupuncture relieve immunity suppression? A pilot study in dogs.

General anesthesia and surgical stress can suppress the immunological response by acting both directly on the immune system and indirectly on the hypothalamic-pituitary-adrenal axis and the sympathetic nervous system. Disturbance of the immune system during the perioperative period can lead to complications such as wound-healing disorders and infections up to sepsis. Effectiveness of acupuncture in regulating the immune function by increasing leukocyte numbers and inhibiting inflammatory response has been proven. This study aimed to explore the impact of electroacupuncture (EAP) on the dynamic balance of the immune system and immune cell populations in dogs undergoing surgery. Twelve healthy bitches scheduled for elective ovariectomy were divided into two groups according to whether (EAP, n=6) or not (CTR, n=6) a peri-operative electroacupuncture treatment was performed. Levels of leukocytes (neutrophils, monocytes, T- and B-cells) and immunoglobulins M (IgM) and A (IgA) were measured in blood samples collected before (T0), 1 h (T1) and 2.5 h (T2) after anesthesia induction. Leukocytes count decreased from T0 to T1 in both groups and restored within 1.5 h in EAP group whereas remained significantly lower in CTR group (P<0.02). In particular, neutrophils and monocytes increased in dogs receiving EAP (P<0.01) while T-cells decreased in CTR group (P<0.04) at T2. B-cells and cytotoxic T-cells decreased in EAP dogs (P<0.04) at T2. No differences in helper T-cells, IgM and IgA levels were recorded between groups and over time. Our results suggest a modulatory effect of EAP on the immune system which is early expressed on neutrophils, monocytes and T-cells.

Sialic acid and sialyltransferase activity in serum and tissues of dogs with mammary tumors.

In humans, the glycosylation pattern of serum and of membrane glycoproteins is associated with invasiveness of tumors: specifically, α2,6-sialylation and α2,3-sialylation are associated with metastasizing and nonmetastasizing tumors, respectively. In turn, the type of sialylation depends on the activity of α2,6 or α2,3 sialyltransferase (ST) enzymes. Because of the high prevalence of metastasizing tumors with biological behavior similar to the human counterpart, female dogs with metastasizing neoplasms could provide a good animal model for investigating the potential roles of sialic acid (Sia) and ST enzymes in the pathogenesis of metastatic tumors. The aims of this study were (1) to validate a solid-phase method based on lectin staining of serum and tissue homogenates to investigate sialylation and ST activity and (2) to compare the results obtained with this method and with lectin staining and to collect preliminary information on sialylation and ST activity in dogs with (n = 8) and without (n = 8) mammary tumors. The data recorded in healthy dogs revealed that serum and tissue glycoproteins are prevalently characterized by a α2,6 sialylation, but ST-α2,3 seems to be the most active enzyme in both samples. Sia-α2,3 and ST-α2,3 activity decreases in serum and tissues of dogs with tumors, especially in a dog with metastasis, suggesting that the equilibrium between ST-α2,6 and ST-α2,3 activity shifts toward the former, as reported in humans.

Effectiveness of electroacupuncture analgesia compared with opioid administration in a dog model: a pilot study.

BACKGROUND: Although opioid analgesics are the usual drugs to treat post-surgical pain, acupuncture has also been demonstrated to relieve various pain syndromes. The present pilot study aims to investigate the efficacy of electroacupuncture compared with a conventional opioid compound, butorphanol, for postoperative pain treatment in dogs undergoing elective ovariohysterectomy. METHODS: Twelve dogs were randomly allocated into two groups. Dogs received either electroacupuncture stimulation (16 and 43 Hz) at Shen Shu, Chang Shu, He Gu, Tai Yuan, Zu San Li, Yang Ling Quan, and Bai Hui acupoints, while control dogs were treated with butorphanol. Cardiovascular and respiratory parameters were recorded for both groups during operation. Plasma ß-endorphin concentrations were evaluated before surgery (baseline) and up to 24 h later. For each dog, pain was measured according to a dedicated subjective pain scoring system. RESULTS: Plasma ß-endorphin levels in dogs receiving electroacupuncture increased significantly against baseline values after 1 and 3 h after surgery. Moreover, the end-tidal isoflurane concentration needed for second ovary traction was significantly lower in acupuncture-treated dogs than control animals. All animals having electroacupuncture experienced prolonged analgesia, over 24 h at least, while four out of six dogs treated with butorphanol needed post-surgical ketorolac and tramadol supplementation to their pain relief. CONCLUSIONS: The results obtained from the present investigation showed some evidence for electroacupuncture as an alternative technique to provide postoperative analgesia in dogs.

Solitary and multiple simultaneous malignant epithelial mammary tumours in dogs: An explorative retrospective study.

Canine mammary tumours represent a hard-prognostic task for veterinary clinicians. TNM staging and grading systems refer to a single tumour. Significant limits come to light when these systems are applied to multiple mammary tumours due to the arbitrary criterion in determining which single tumour is representative of the patient's prognosis. This study explored some clinical features of 50 dogs affected by at least one malignant mammary tumour. Clinical features and staging, together with histological classification and grading, have been related to disease-free survival (DFS) with the purpose to evaluate their impact on prognosis. The prognosis was worse in 10-11-year-old dogs (P < 0.05), in dogs affected by complex carcinoma (P < 0.05), and in patients assigned to Peña grade I (P < 0.05). The bodyweight was not linearly related to DFS (P < 0.01), and patients with a low number of neoformations (n ≤ 2) showed a better prognosis than dogs with 3-5 tumours (P < 0.05). Both the average and the total size of malignant tumours were related to DFS (P < 0.05). Dogs assigned with stage I had the best DFS (P < 0.05). In conclusion, the Peña grade I alone would not seem to guarantee a favourable prognosis when applied to mammary tumours in dogs affected by multiple simultaneous presentations. Different characteristics, besides tumour grading, such as tumour immunophenotype and expression of hormonal receptors, could in the future, contribute to elucidate the clinical behaviour of multiple canine mammary tumours.

Ovarian Embryonal Carcinoma in a Dog.

A 17-month-old female doberman pinscher was referred for an abdominal mass and ascites. Exploratory laparotomy revealed the presence of a large neoplastic mass replacing the right ovary and associated with multiple mesovarian, mesometrial and peritoneal nodules. An ovariohysterectomy was performed. Grossly, the tumour was soft and multilocular with large areas of haemorrhage and necrosis. Microscopically, it was infiltrative and composed of round and polygonal cells arranged respectively in solid sheets or forming distorted tubular structures separated by thick fibrovascular septae. Tubules contained necrotic debris, proteinaceous fluid or small endoluminal papillary structures. Marked cellular atypia, multiple neoplastic emboli and high mitotic count were observed. Immunohistochemically, the round cells uniformly expressed placental alkaline phosphatase, while the polygonal cells arranged in tubules and papillae expressed cytokeratin (CK) AE1/AE3 and CK7. A final diagnosis of metastasizing ovarian embryonal carcinoma (EC), a primitive germ cell tumour characterized by rudimentary epithelial differentiation was made. Canine ovarian EC should be considered as a differential diagnosis for undifferentiated aggressive ovarian tumours in young dogs.

The role of birth weight on litter size and mortality within 24h of life in purebred dogs: What aspects are involved?

In humans, scientific evidence emphasizes the role of birth weight on neonatal welfare, morbidity and mortality. In canine species, defining normal ranges of birth weight is a harder issue due to a great morphological variability in size, body weight and breed. The aim of this study was to correlate birth weight with litter size and mortality within 24h of life in 789 pups from 140 litters of purebred dogs and to investigate the aspects that might affect these factors. Birth weight was influenced by maternal size, weight and age (P<0.001). The lightest pups were from toy sized or weighing up to 10 kg bitches. Conversely, bitches aged 2-8 years whelped heavier pups than younger and older mothers. Birth weight was also related both to litter size, with heavier pups in smaller rather than in larger litters from medium sized bitches, and breed (P<0.05). Unexpectedly, birth weight did not differ between live born and stillborn pups. However, birth weight was lower in pups dying within 24h of life (P<0.05). High mortality of pups was related both to short pregnancies (P<0.05), also showing lighter litters (P<0.001), and to dystocic parturitions (P<0.001). Litter size was associated with parity, type and number of mating, and length of pregnancy (P<0.001). Low birth weight appears to predispose to early neonatal mortality suggesting a predominant role of the breed rather than size and weight in determining birth weight in pups.

Breed-specific fetal biometry and factors affecting the prediction of whelping date in the German shepherd dog.

To date many studies have been published about predicting parturition by ultrasonographic fetal measurements in the bitch. Given that accuracy in such prediction is a key point for clinicians and breeders, formulas to calculate the whelping date were mainly obtained from small and medium sized dogs, which means poor accuracy when applied to large or giant breeds. Based on the evidence that ethnicity significantly affects fetal biometry in humans, this study aimed at developing a breed-specific linear regression model for estimating parturition date in the German shepherd dog. For this purpose, serial ultrasonographic measurements of the inner chorionic cavity diameter (ICC) and the fetal biparietal diameter (BP) were collected in 40 pregnant German shepherd bitches. The quality of the regression models for estimating parturition date was further verified in 22 other pregnant German shepherd bitches. Accuracy related to the prediction of parturition date was higher than previously reported: 94.5% and 91.7% within ±2 days interval based on ICC and BP measurements, respectively. Additional investigation was performed on the effects of maternal weight, age and litter size in relation to fetal biometry and to accuracy of parturition estimation. Moreover, the study included a comparison between hormonal and fetal ultrasound (ICC and BP) measurements connected to the estimation of whelping date. We suggest that specific equations from a single breed are likely to offer excellent accuracy, comparable to that of periovulatory progesteronemia, in parturition prediction and to avoid morphological variables present in dogs of different breeds even with the same size/weight.

Prognostic potential of amniotic fluid analysis at birth on canine neonatal outcomes.

Glucose, lactate and cortisol concentrations in amniotic fluid were measured at birth in 95 pups and related to neonatal viability based on Apgar scoring and to neonatal mortality. Neither amniotic parameters nor neonatal mortality were associated with the Apgar score. Stillborn pups showed high lactate (P < 0.001) and cortisol (P < 0.05) but low glucose amniotic concentrations (P < 0.001). No amniotic fluid differences were observed between normal and malformed pups. Amniotic glucose (P < 0.001), lactate (P < 0.05) and cortisol (P < 0.05) concentrations were higher in pups delivered by vaginal parturition than by Caesarean section. Birth weight was higher in live pups than in pups dying within 48 h (P < 0.05). Although these are preliminary results, the analysis of amniotic fluid collected at birth could be a valuable predictor of neonatal outcomes in dogs.

Periovulatory time in the bitch: what's new to know?: Comparison between ovarian histology and clinical features.

The ability to recognize specific events happening in the ovaries during periovulatory time allows optimal management of canine reproduction. The objective of this study was to assess the efficacy of vaginal cytology and blood progesterone (P4) assay to identify accurately the changes occurring at the ovarian structures, mainly during the fertile period. Tertiary follicles, corpora hemorrhagica (CHs) and corpora lutea (CLs) from forty healthy bitches undergoing ovariohysterectomy were evaluated by histo-morphometry based on their aspect, number and size. The tertiary follicles distribution (small, medium and large) was statistically different (P<0.002) among all the stages of the reproductive cycle, except for small follicles (<2mm), which were always observed from proestrus to anestrus. Very large follicles (>4mm) were predominant (P=0.008) around ovulation when P4 mean level was 6.1±1.7ng/mL. The early postovulatory estrous period was characterized by CHs (P<0.002) and P4 level of 16.7±5.9ng/mL. The end of the fertile period - start of diestrus - coincided with the development of CLs (P=0.001) associated with a P4 mean level of 73.9±9.9ng/mL. The small (P<0.001) and medium (P<0.05) follicle diameters were positively correlated with the bitch size. The number of follicles larger than 4mm was significantly lower in bitches younger than 4 years (P<0.02). This study provides insight into some critical steps in the canine reproductive processes in the periovulatory phase and the end of the fertile period, essential to plan breeding programs.

Comparison of the effects of histamine H2-receptor antagonists on prolactin secretion in the rat.

Various compounds with different blocking potencies on histamine H2-receptors were administered to rats both into the carotid (ia) and into the brain ventricles (icv) and their effects on PRL release were evaluated. The drugs were cimetidine, as reference compound, ranitidine, 5 to 7 times as potent, and oxmetidine, 8 to 10 times as potent. PRL was measured in blood samples collected at -15, 0 and +5, +10, +20 and +40 min after treatment. Cimetidine (80 mg/kg) and ranitidine (30 mg/kg), when injected ia as a single bolus, induced prompt increases (P less than 0.01) in PRL. On the contrary, oxmetidine (the most potent H2 antagonist), even at the high dose of 80 mg/kg ia, had no effect on PRL release. When the drugs were given icv (0.2 mumol/rat or 0.8 mumol/rat), none of them caused any significant PRL release. These results suggest that histamine H2-blocking potency is not correlated with PRL release. Furthermore, the PRL-releasing activity of the drugs seems not to be due to any action on the central neural control of PRL secretion. This comparative study shows that it is possible (as with oxmetidine) to achieve complete dissociation of the H2-receptor blocking action from the unwanted PRL-release stimulating effect.

High sensitivity to calcitonin of prolactin-secreting control in lactating rats.

The effects of intracerebroventricular (icv;25ng/rat) or iv (10 micrograms/kg) salmon calcitonin (sCT) on PRL secretion were determined in lactating rats and compared to the effects in intact or ovariectomized-estrogen-treated female rats. The icv or iv injections of sCT 9 days after estrogen treatment did not significantly lower the PRL levels in intact rats. In ovariectomized-estrogen-primed animals, sCT (icv or iv) did not modify the afternoon surge of PRL secretion when injected during the surge, nor did it delay or attenuate the increasing secretory activity when administered (iv) before the afternoon surge had begun. On the contrary, 30 or 60 min after the icv or iv administration of sCT to lactating rats, suckling-induced PRL secretion was prevented. These results and our previous evidence that a greater dose of sCT is needed to decrease the less intense morphine- or stress-induced PRL secretion indicate differential hypoprolactinemic properties of sCT, which are particularly striking during lactation. While the mechanisms underlying these selective activities deserve further investigation, the proposed participation of PRL in the regulation of calcium metabolism during lactation suggests that the potent PRL inhibitory effect of CT in this condition should be regarded as one factor in the complex mechanism that prevents bone loss and protects the maternal skeleton.

Antinociceptive activity of eel calcitonin, injected into the inflamed paw in rats.

This study examined the possible peripheral activity of eel calcitonin in the modulation of the response to noxious pressure on inflamed paws in rats (Randall and Selitto test). The intraplantar injection of eel calcitonin (20-200 ng/rat) but not the subcutaneous administration (200 ng and 2 micrograms/rat, s.c.), was able to significantly inhibit hyperalgesia induced by intraplantar injection of carrageenin. The development of oedema on the other hand was not inhibited. The intraplantar administration of eel calcitonin (200 ng/rat) in a non-inflamed paw did not modify paw pressure thresholds. Eel calcitonin (200 ng/rat, intraplantar, i.pl.) was also able to elicit an antinociceptive effect on formalin-induced hyperalgesia, both when the peptide was injected before or after (60 min) formalin. This effect, at difference with morphine (80 micrograms/rat, i.pl.), was not blocked by naloxone (10 micrograms/rat, i.pl.). These results demonstrate the local antinociceptive effect of eel calcitonin in inflammatory pain and might indicate a new way of using calcitonin in the control of pain.

Electrophysiological correlates for antinociceptive effects of histamine after intracerebral administration to the rat.

Data have been collected indicating possible functions for histamine in brain but there are only a very few data, collected exclusively with behavioural tests, about the effects of histamine on the perception of the pain, an important aspect in the homeostasis of the human body. The purpose of the present study was to investigate the effects of histamine, injected directly into the lateral cerebral ventriculi on the firing of nociceptive thalamic neurones, detected by electrophysiological techniques in rats rendered arthritic by injection of Freund's adjuvant into the left hindfoot. The noxious test stimuli used were either extension or flexion of the ankle or mild lateral pressure on the heel. With increasing doses of histamine (5, 10, 20, 40 micrograms) it was possible to observe an increasing inhibitory and long-lasting effects of the evoked activity, with a significant dose-effect linear regression. The inhibitory responses, induced by histamine, probably by a hyperpolarization phenomenon that decreased excitatory postsynaptic potentials, were clues for the presence of a histaminergic pathway in parallel with and/or in connection with other adrenergic, gabaergic, serotoninergic and opioidoergic pathways that regulate the transmission and the modulation of algogenic electrophysiological messages.

Evidence for an inhibitory role of central histamine on carrageenin-induced hyperalgesia.

The effects of intracerebroventricular (i.c.v.) injection of histamine, the H1 agonist 2-methyl-histamine and the H2 agonist dimaprit were tested on carrageenin induced hyperalgesia by the Randall-Selitto paw pressure test in the rat. Treatment with histamine (0.1, 0.2, 0.4 mumol/rat, i.c.v.) 150 min after intraplantar carrageenin (0.1 ml of 1% solution) caused a significant increase of paw pressure thresholds in inflamed (but not in non-inflamed) paws. The magnitude and the duration of the antinociceptive effects of histamine were dose-dependent. Administration of 2-methyl-histamine (0.2, 0.4, 0.8, 1.0 mumol/rat, i.c.v.) and dimaprit (0.1, 0.2, 0.4, 0.8 mumol/rat, i.c.v.) also displayed dose-dependent blockade of carrageenin-induced hyperalgesia. Antinociceptive ED50 values calculated 30 min after drug treatments were: histamine 0.18 mumol/rat; 2-methyl-histamine 0.65 mumol/rat; dimaprit 0.33 mumol/rat. These data indicate that histamine through central H1 and H2 receptors exerts an inhibitory role in the control of nociception in pain resulting from inflammation.

Protection by amylin of gastric erosions induced by indomethacin or ethanol in rats.

1. The effect of amylin on gastric ulcers induced by oral administration of indomethacin (Indo, 20 mg kg-1 at a dosing volume of 5 ml) or ethanol 50% (EtOH, 1 ml/rat) was investigated in conscious rats. 2. Amylin given intracerebroventricularly (0.22, 0.66 and 2.2 micrograms/rat, i.c.v.) demonstrated a dose-dependent cytoprotective effect against both Indo and EtOH-induced ulcers. In contrast, amylin, given subcutaneously at doses effective in inhibiting acid gastric secretion (2.5, 10 and 40 micrograms kg-1, s.c.), did not show any cytoprotective effect. 3. The interaction between amylin and endogenous nitric oxide (NO) in the maintenance of gastric mucosal integrity was investigated by pretreating the rats with a selective inhibitor of NO-synthesis, NG-nitro-L-arginine methyl ester (L-NAME, 25 and 70 mg kg-1, s.c.). Administration of L-NAME to rats did not significantly increase the degree of the Indo-induced ulcer index and was not able to remove the protective effect of amylin on Indo-induced ulcers, thus excluding a role for endogenous NO in mediating the protective effect of this peptide. 4. To determine whether the cytoprotective effect of amylin was mediated by endogenous prostaglandins, we studied the effect of amylin (2.2 micrograms/rat, i.c.v.) on EtOH- induced ulcers in rats pretreated with Indo (10 mg kg-1, s.c.) to inhibit prostanoid biosynthesis; Indo was injected 30 min before amylin and EtOH after a further 30 min. Pretreatment with Indo did not significantly increase the ulcer index induced by EtOH but counteracted the ability of amylin to prevent the ulcer formation. 5. These findings suggest that amylin exerts a gastroprotective activity that is not strictly related to inhibition of acid gastric secretion and can be partly explained through a prostaglandin-dependent mechanism mediated by receptors for the peptide in the brain. Amylin might be considered as a new brain-gut peptide.

Comparison between urinary pyridinium cross-links and hydroxylysine glycosides in monitoring the effects of ovariectomy and 17 beta-estradiol replacement in aged rats.

This study was undertaken to assess the sensitivity of hydroxylysylpyridinoline (HP), lysylpyridinoline (LP), galactosylhydroxylysine (GHyl) and glucosylgalactosylhydroxylysine (GGHyl) to monitor bone response to estrogen deficiency and replacement by comparing their excretory patterns in ovariectomized aged (11-14 months old) rats. The ovariectomized (OVX) rats were randomized into two groups: (1) OVX plus vehicle; (2) OVX plus 17 beta-estradiol (17-beta E, 10 micrograms/kg, s.c., 4 days/week). Treatment with 17-beta E started immediately after OVX and continued for 60 days. The collagen catabolites were measured in urine for 1 month before OVX and thereafter for 60 days. In temporal coincidence with urine collection, bone area and bone mineral density (BMD) of lumbar vertebrae, femoral diaphysis and distal metaphysis were measured by dual-energy X-ray absorptiometry. In the untreated rats, BMD of the femoral metaphysis and lumbar vertebrae decreased significantly and the urinary excretion of LP, HP, GHyl and GGHyl increased with different patterns. In the treated rats, 17-beta E replacement prevented the increment in LP excretion, partially prevented the increase in HP excretion, but had no effect on the excretion of GHyl and GGHyl. In conclusion pyridinolines and glycosides have different sensitivities to the bone response to OVX. Glycoside excretion after OVX also reflects metabolic processes not strictly related to bone loss and, in contrast with LP, is not sensitive to estrogen replacement.

Age-associated differences in neutrophil oxidative burst (chemiluminescence).

Phagocytic defensive functions consist of a sequence of events, including migration, phagocytosis, secretion, and the release of reactive oxygen species (ROS). The last of these (also called "oxidative burst") has not received due attention in the elderly, even though it can be considered the most important event in the process of killing an invading microorganism. The aim of the present study was to investigate the oxidative burst activity of polymorphonuclear neutrophil leukocytes (PMNs) in relation to age, using a technique that specifically identifies ROS production: luminol-amplified chemiluminescence (LACL). Besides the use of LACL, a particular feature of the study was the use of five rather than just one or two different stimulants: two particulate (Candida albicans and zymosan) and three soluble ones [N-formyl-methionyl-leucyl-phenylalanine (fMLP), phorbol 12 myristate 13 acetate (PMA), and polyanetholesulfonate (liquoid)]. This approach allowed us to observe a dichotomy between the effects of Candida and zymosan (particulates), which were not significantly different in the elderly subjects compared to the young controls, and those of fMLP, PMA, and liquoid (solubles), which showed a significant reduction in LACL in the elderly group. Considering the different results obtained with the various stimulants adopted that are all believed to have NADPH oxidase as a common final target of oxidative burst, it may be postulated that aging can influence the different transductional pathways in different ways.

Responsiveness of urinary markers of bone resorption to orchiectomy and clodronate treatment in mature rats: a comparative study.

OBJECTIVE: The aim of this study was to assess the responsiveness of two classes of bone resorption markers to the enhancement of osteoclastic activity induced by orchiectomy and to its inhibition by clodronate treatment in mature rats. DESIGN: Bone mineral density (BMD) at femural metaphysis, femural diaphysis, lumbar vertebrae, and the urinary excretion of pyridinoline (Pyr), deoxypyridinoline (D-Pyr), galactosylhydroxylysine (GHyl) and glucosylgalactosylhydroxylysine (GGHyl) were monitored at regular intervals for 30 days prior to and for 60 days following orchiectomy in eleven rats, divided into two groups: five rats untreated and the other six treated with clodronate. RESULTS: Prior to orchiectomy, a significant (P < 0.01) decrease in BMD was observed only at the distal femural metaphysis. This decrease appeared to be associated with a time-dependent increase in the urinary excretion of all markers. Following orchiectomy, the BMD of the untreated group decreased significantly (P < 0.01) at all bone sites. The bone loss was accompanied by a significant (P < 0.01) increase in Pyr and D-Pyr concentrations in urine, whereas urinary GHyl and GGHyl did not change significantly. In the clodronate-treated group, the BMD of the three skeletal sites did not change significantly, while the urinary excretion of all urinary biochemical markers decreased significantly (P < 0.001). CONCLUSION: This study showed that pyridinolines are able to monitor the bone response to orchiectomy and to clodronate treatment response in androgen-deficient mature male rat. whereas glycosides appear prone to confounding factors.