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Biomedical subjects

F Garcia

Publications and source records attributed to F Garcia.

At least 55 records · Page 3Linked to original sources
PubMed2000

Comparison of T-cell subsets' reconstitution after 12 months of highly active antiretroviral therapy initiated during early versus advanced states of HIV disease.

UNLABELLED: This research comprised a pilot open prospective clinical study comparing T-cell subset reconstitution in antiretroviral-naive patients, after 12 months of HAART when treatment was initiated in early stages (ES; n = 18) of infection versus advanced stages (AS; n = 20). CONTROL GROUP: 10 healthy HIV-negative individuals. Immunophenotypic markers were evaluated before and after 6-and 12-months' therapy. Functional assays were performed in one subset. RESULTS: Viral load (VL) was < 200 copies/ml in all patients. Median percentages of CD4+ pretherapy were 33% and 6%, respectively, in the ES and AS groups, increment after 12 months of therapy was +15% and +13% respectively. Only the ES group achieved normal values. Declines of CD8+ percentage were significantly higher in the ES (-18%) than in the AS group (-2%). CD4+ memory and naive cells in the ES group were similar to those of controls before treatment and did not change after therapy. In contrast, CD4+ memory and naive cells in the AS group did not reach normal levels despite treatment. In the ES group, there was a significant increment in CD8+ naive cells (+8%) and a decrement in CD8+CD38+ cells (-17%), both populations reached values close to normal, whereas these subsets remained far from normal in the AS group. Improvement of lymphoproliferative response after therapy was observed in both groups. One patient in the ES group showed positive LPR against p24 after treatment. After 12 months' highly active antiretroviral therapy, only those who began such therapy in ES disease reached values within the range of healthy controls. To achieve a more complete immunologic reconstitution, early initiation of potent antiretroviral therapy should be recommended.

Adult↗
PubMed2000

Estrogen desensitizes 5-HT(1A) receptors and reduces levels of G(z), G(i1) and G(i3) proteins in the hypothalamus.

The present study investigated whether estrogen would desensitize hypothalamic serotonin(1A) (5-HT(1A)) receptors by examining the neuroendocrine response to 8-OH-DPAT, a 5-HT(1A) agonist. Rats were ovariectomized, allowed to recover for 5 days, then given 2 daily injections of estradiol benzoate or vehicle (10 microg/day, s.c.). Twenty-four hours after the second injection, rats were challenged with a sub-maximal dose of 8-OH-DPAT (50 microg/kg, sc) or saline 15 min prior to sacrifice. 8-OH-DPAT produced a significant increase in plasma oxytocin, ACTH and corticosterone levels in ovariectomized rats. While estrogen treatment for 2 days did not alter basal hormone levels, it did significantly reduce the magnitude of oxytocin, ACTH and corticosterone responses to 8-OH-DPAT. The reduction in hormone responses was accompanied by a significant reduction in hypothalamic levels of G(z), G(i1) and G(i3) proteins (by 50%, 30% and 50%, respectively). These findings suggest that a reduction in these G proteins may contribute to the mechanisms underlying estrogen-induced desensitization of 5-HT(1A) receptors. The desensitization of 5-HT(1A) receptors has been suggested to underlie the therapeutic effects of antidepressant 5-HT uptake inhibitors (SSRIs). Thus, the present results suggest that estrogen or estrogen-like substances in combination with SSRIs may prove effective in developing novel therapeutic strategies for neuropsychiatric disorders in women.

8-Hydroxy-2-(di-n-propylamino)tetralin↗
PubMed2000

Neurochemical changes in brain serotonin neurons in immature and adult offspring prenatally exposed to cocaine.

The present study investigates the age-dependent effects of prenatal cocaine exposure on changes in the neurochemical and functional status of brain serotonin neurons. Pregnant rats were administered either saline or (-)cocaine HCl (15 mg/kg, subcutaneously), twice daily from gestational days 13 through 20. Neurochemical changes in frontal cortex, hypothalamus, hippocampus, striatum and midbrain of prepubescent and adult offspring were determined by measuring: (1) the content of serotonin (5-HT) and its major metabolite 5-hydroxyindolacetic acid (5-HIAA), and (2) the ability of the serotonin releasing drug p-chloroamphetamine (PCA) to reduce brain serotonin levels. Brain catecholamine content was determined in progeny for comparative purposes. Prior to maturation, prenatal exposure to cocaine did not alter basal levels of brain 5-HT or 5-HIAA in any brain region examined. However, in adult progeny prenatally exposed to cocaine, basal 5-HT content was significantly reduced in the frontal cortex (-32%) and hippocampus (-40%), suggesting maturation-dependent effects of prenatal cocaine exposure on brain 5-HT neurons. Consistent with the maturational onset of changes in 5-HT, striatal dopamine was significantly reduced (-10%) by prenatal exposure to cocaine only in adult offspring. Reductions in 5-HT in most brain regions, produced by pharmacological challenge with p-chloroamphetamine (PCA), were comparable in prenatal saline versus cocaine offspring. One notable exception was the markedly greater reduction (-40%) in 5-HT in the midbrain of immature offspring prenatally exposed to cocaine, suggesting alterations in midbrain 5-HT neurons prior to maturation. Overall, these data demonstrate prenatal cocaine exposure produces region-specific changes in 5-HT neurons in offspring with some deficits occurring only following maturation.

Age Factors↗
PubMed2000

The structure of electromagnetic wave-induced 557.7-nm emission associated with a sporadic- E event over arecibo

We report observations of electromagnetic wave-induced 557.7-nm emission in correspondence with a sporadic low-altitude plasma layer (the sporadic- E layer, E(s)). We show that the structure of 557. 7-nm emission seen for some events results from a transformation of transmitted energy by ionization clouds, compiling the patchy type E(s), and presents a projection of the sporadic- E layer structure on the emission altitude. This allows us to propose the first method for visualizing a horizontal structure of sporadic- E layers.

Journal Article↗
PubMed2000

Quality indicators in ambulatory surgery. A prospective study.

Introduction: Ambulatory Surgery has emerged and developed in Spain in a similar way as in other occidental countries. Once established as a model for surgical care, results must be improved using objective quality indicators to assure minimal morbidity, efficient use of resources and satisfaction of patients and family. Objective: To provide a list of quality assessment indicators in Ambulatory Surgery and to discuss the necessity of obtaining a general consensus regarding the complexity of both the operations and the patients undergoing surgery. Design: Prospective and descriptive study. Patients and Methods: The study was performed on 833 ambulatory patients operated on in the Ambulatory Surgical Unit of the Can Misses Hospital of Ibiza. Surgical specialities involved were General Surgery, Ophthalmology, Orthopaedics, Urology, Gynaecology, and E.N.T. All diagnoses and proceedings were classified according to the CIE-9 and DGR systems, showing as an example the codes related to the General Surgery department. Quality Indicators evaluated were: (a) unplanned admission index; (b) re-admission index; (c) emergency department consultations; (d) cancellation index; (e) substitution index; and (f) postoperative pain evaluation. Results: Specialities involved were: Ophthalmology 277 patients (33.2%), General Surgery 189 (22.8%), Orthopaedics 142 (17%), Urology 90 (10.8%), E.N.T. 79 (9.5%) and Gynaecology 56 (6.7%). Unplanned Admission Index was 7.2%; Re-Admission Index 0.4%; Emergency department consultation 1.6%; Cancellation Index 3.3% and Substitution Index 70%. The reasons for unplanned admission were due to specific complications in 36 cases (60.1%), followed by those secondary to an inadequate selection of the patient in 22 cases (36.6%). Conclusions: It is necessary to apply a series of Quality Indicators in Ambulatory Surgery. Their systematic evaluation may help us define national standards in order to continuously improve our results.

Journal Article↗
PubMed2000

Evidence that G(z)-proteins couple to hypothalamic 5-HT(1A) receptors in vivo.

Using in situ hybridization and immunoblot analysis, the present studies identified G(z) mRNA and G(z)-protein in the hypothalamic paraventricular nucleus. The role of G(z)-proteins in hypothalamic 5-HT(1A) receptor signaling was examined in vivo. Activation of 5-HT(1A) receptors increases the secretion of oxytocin and ACTH, but not prolactin. Intracerebroventricular infusion (3-4 d) of G(z) antisense oligodeoxynucleotides, with different sequences and different phosphorothioate modification patterns, reduced the levels of G(z)-protein in the hypothalamic paraventricular nucleus, whereas missense oligodeoxynucleotides had no effect. Neither antisense nor missense oligodeoxynucleotide treatment altered basal plasma levels of ACTH, oxytocin, or prolactin, when compared with untreated controls. An antisense-induced decrease in hypothalamic G(z)-protein levels was paralleled by a significant decrease in the oxytocin and ACTH responses to the 5-HT(1A) agonist 8-hydroxy-dipropylamino-tetralin (8-OH-DPAT). In contrast, the prolactin response to 8-OH-DPAT (which cannot be blocked by 5-HT(1A) antagonists) was not inhibited by G(z) antisense oligodeoxynucleotides. G(z)-proteins are the only members of the G(i)/G(o)-protein family that are not inactivated by pertussis toxin. In a control experiment, pertussis toxin treatment (1 microgram/5 microliter, i.c.v.; 48 hr before the 8-OH-DPAT challenge) did not inhibit the ACTH response, potentiated the oxytocin response, and eliminated the prolactin response to 8-OH-DPAT. Thus, pertussis toxin-sensitive G(i)/G(o)-proteins do not mediate the 5-HT(1A) receptor-mediated increase in ACTH and oxytocin secretion. Combined, these studies provide the first in vivo evidence for a key role of G(z)-proteins in coupling hypothalamic 5-HT(1A) receptors to effector mechanisms.

8-Hydroxy-2-(di-n-propylamino)tetralin↗
PubMed2000

Long-term fluoxetine produces behavioral anxiolytic effects without inhibiting neuroendocrine responses to conditioned stress in rats.

The aim of the present study was to investigate the anxiolytic effects of long-term treatment with fluoxetine in rats. Selective serotonin reuptake inhibitors (SSRIs), such as fluoxetine, are used to treat anxiety and panic disorders, in addition to treating depression. A major concern with SSRIs is a 2-3-week delay in their therapeutic effects. SSRIs share with anxiolytic 5-HT(1A) agonists the ability to produce desensitization of post-synaptic 5-HT(1A) receptors. To investigate the anxiolytic effects of fluoxetine, rats were treated for 14 days with fluoxetine (10 mg kg(-1) day(-1), i.p. ). The rats were stressed using a conditioned stress procedure and tested one day after the last fluoxetine injection. Fluoxetine decreased stress-induced defecation (by 60%), reversed the stress-induced suppression of exploring behavior (by 59%) and shortened the duration of stress-induced freezing behavior (by 11. 5%). However, the stress-induced increase in plasma levels of ACTH, corticosterone, oxytocin, prolactin and renin were not inhibited by fluoxetine treatment. These findings suggest that neuroadaptive changes induced by sustained inhibition of serotonin (5-HT) reuptake, contribute to the mechanism of the anxiolytic effects of fluoxetine. In contrast, the neuroendocrine responses to conditioned stress are not affected by these neuroadaptive changes.

Adrenocorticotropic Hormone↗
PubMed2000

Chronic clomipramine alters presynaptic 5-HT(1B) and postsynaptic 5-HT(1A) receptor sensitivity in rat hypothalamus and hippocampus, respectively.

Clomipramine is a tricyclic antidepressant drug with a high affinity for the serotonin (5-HT) uptake site or transporter. Electrophysiological experiments have provided evidence that repeated administration of clomipramine induces an increase in the sensitivity of postsynaptic 5-HT(1A) receptors in the hippocampus. We have studied the effects of clomipramine, administered to rats at a dose of 10mg/kg/day for 28 days by osmotic minipumps, on presynaptic 5-HT(1A) and 5-HT(1B) autoreceptors in the hypothalamus, and on postsynaptic 5-HT(1A) receptors in the hippocampus, by using in vivo microdialysis to measure 5-HT and cyclic adenosine monophosphate (cAMP) levels. Postsynaptic 5-HT(1A) receptor sensitivity in the hypothalamus was determined by means of a neuroendocrine challenge procedure. Although the sensitivity of presynaptic 5-HT(1A) autoreceptors, as measured by the effect of a subcutaneous (s.c.) injection of 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT, 0.2mg/kg or 50 microg/kg) to reduce 5-HT levels, did not change, there was a reduction in sensitivity of presynaptic 5-HT(1B) receptors, as measured by the effect of an injection of the 5-HT(1B/1D) antagonist GR 127935 (5mg/kg, s.c.) to increase 5-HT levels. This effect probably accounted for the increase in basal 5-HT levels observed in the hypothalamus after chronic clomipramine administration. Postsynaptic 5-HT(1A) receptor sensitivity in the hippocampus, measured by the effect of 8-OH-DPAT to increase cAMP levels in the dialysate, was increased after chronic clomipramine. Animals that had received daily intraperitoneal injections of 10mg/kg clomipramine for 28 days did not show a change in postsynaptic 5-HT(1A) receptor sensitivity in the hypothalamus as measured by the ability of 8-OH-DPAT (50 microg/kg, s.c.) to stimulate secretion of corticosterone. Taken together with the results of previous experiments involving the cerebral cortex, these in vivo results show that chronic clomipramine exerts effects on both pre- and postsynaptic serotonin receptors, but that these effects are highly region-specific.

8-Hydroxy-2-(di-n-propylamino)tetralin↗
PubMed2000

Increased incidence of meiotic anomalies in oligoasthenozoospermic males preselected for intracytoplasmic sperm injection.

PURPOSE: Based on data from the literature, to detect the possible presence of an increased frequency of meiotic anomalies in oligoasthenozoospermic (OA) patients preselected for intracytoplasmic sperm injection. METHODS: Meiotic studies in as many successive patients with a clinical indication for a diagnostic testicular biopsy as needed to complete at least 100 cases with a severe OA (motile sperm concentration < or = 1.5 x 10(6)/ml). RESULTS: An increased incidence of meiotic anomalies was found in 102 patients with a severe OA (17.6%) compared to the mean for 105 patients with other etiologies in the series (5.7%) or the mean for patients reviewed in the literature (6.5%). CONCLUSIONS: Patients with a severe OA have a higher incidence of synaptic anomalies. This may result in the malsegregation of chromosomes at meiosis I, producing abnormal sperm, and could explain the high incidence of sterility and some cases of abortion (in two thirds of the couples with abortions the husband had meiotic anomalies) in this group.

Biopsy↗
PubMed2000

Forecasting physicochemical variables by a classification tree method. Application to the Berre Lagoon (south France).

The dynamics of the "Etang de Berre", a brackish lagoon situated close to the French Mediterranean sea coast, is strongly disturbed by freshwater inputs coming from an hydroelectric power station. The system dynamics has been described as a sequence of daily typical states from a set of physicochemical variables such as temperature, salinity and dissolved oxygen rates collected over three years by an automatic sampling station. Each daily pattern summarizes the evolution, hour by hour of the physicochemical variables. This article presents results of forecasts of the states of the system subjected to the simultaneous effects of meteorological conditions and freshwater releases. We recall the main step of the classification tree method used to build up the predictive model (Classification and Regression Trees, Breiman et al., 1984) and we propose a transfer procedure in order to test the stability of the model. Results obtained on the Etang de Berre data set allow us to describe and predict the effects of the environmental variables on the system dynamics with a margin of error. The transfer procedure applied after the tree building process gives a maximum gain in prediction accuracy of about 15%.

Environmental Monitoring↗
PubMed2000

Heterogeneity for mutations in the CFTR gene and clinical correlations in patients with congenital absence of the vas deferens.

Congenital absence of the vas deferens (CAVD) is a heterogeneous disorder, largely due to mutations in the cystic fibrosis (CFTR) gene. Patients with unilateral absence of the vas deferens (CUAVD) and patients with CAVD in association with renal agenesis appear to have a different aetiology to those with isolated CAVD. We have studied 134 Spanish CAVD patients [110 congenital bilateral absence of the vas deferens (CBAVD) and 24 CUAVD], 16 of whom (six CBAVD, 10 CUAVD) had additional renal anomalies. Forty-two different CFTR mutations were identified, seven of them being novel. Some 45% of the CFTR mutations were specific to CAVD, and were not found in patients with cystic fibrosis or in the general Spanish population. CFTR mutations were detected in 85% of CBAVD patients and in 38% of those with CUAVD. Among those patients with renal anomalies, 31% carried one CFTR mutation. Anomalies in seminal vesicles and ejaculatory ducts were common in patients with CAVD. The prevalence of cryptorchidism and inguinal hernia appeared to be increased in CAVD patients, as well as nasal pathology and frequent respiratory infections. This study confirms the molecular heterogeneity of CFTR mutations in CAVD, and emphasizes the importance of an extensive CFTR analysis in these patients. In contrast with previous studies, this report suggests that CFTR might have a role in urogenital anomalies.

Abnormalities, Multiple↗
PubMed2000

Distribution of open reading frames of plasticity region of strain J99 in Helicobacter pylori strains isolated from gastric carcinoma and gastritis patients in Costa Rica.

The plasticity region of Helicobacter pylori strain J99 is a large chromosomal segment containing 33 strain-specific open reading frames (ORFs) with characteristics of a pathogenicity island. To study the diversity of the plasticity region, 22 probes corresponding to 20 ORFs inside the plasticity region and two ORFs on its boundaries were hybridized to genomic DNA isolated from clinical strains of H. pylori from patients with gastritis or gastric adenocarcinoma. Highly variable hybridization patterns were observed. The majority of the clinical strains presented a hybridization profile similar to that of J99; thus, these ORFs are not J99 strain specific. No association was found between a particular hybridization pattern and the clinical origin of the strain. Nevertheless, two single ORFs (JHP940 and JHP947) were more likely to be found in gastric cancer strains. They may be new pathogenicity markers. An in vitro expression study of these ORFs was also performed for the J99 strain, under different conditions. Thirteen ORFs were consistently expressed, six were consistently shut off, and three were expressed differentially. Most of the constitutionally expressed genes were located on the 3' part of the plasticity region. Our results show that the plasticity region, rather than being considered a pathogenicity island per se, should be considered a genomic island, which represents a large fragment of foreign DNA integrated into the genome and not necessarily implicated in the pathogenic capacity of the strain.

Blotting, Southern↗
PubMed2000

Utilization of healthcare services by people living with HIV/AIDS in Europe. Eurosupport Group.

Our objective was to compare the utilization of healthcare/support services for people with HIV infection in Europe. Between August 1996 and September 1997 self-administered anonymous questionnaires were distributed by reference HIV treatment centres and HIV support organizations. The questionnaire was completed by 1366 people living with HIV/AIDS. A small number of people had received influenza or pneumococcal vaccinations (34% and 19% respectively). Many patients did not receive dental care (48% of participants from the southern countries) and only 72% of the women had a gynaecological examination. More participants from the south reported insufficient access to healthcare/support services, particularly for nursing care (19%), psychological support (33%), nutritional advice (45%), access to support organizations (36%), and legal advice (46%). In conclusion, many people living with HIV/AIDS in Europe do not benefit from certain annual medical procedures proposed by international guidelines and consider themselves to have insufficient access to health/support services.

Acquired Immunodeficiency Syndrome↗
PubMed2000

Evaluation of two reverse transcription polymerase reaction assays (GEN ETI-K HGV RNA and LCx GBV-C assay) for the detection of GB virus C/hepatitis G virus RNA in clinical samples.

Our study evaluates the analytical performance of two amplification methods in the detection of GB Virus C/Hepatitis G Virus, GEN ETI-K HGV RNA (GEN) and the LCx GBV-C Assay (LCx). GB Virus C RNA was detected by at least one test in 58/315 samples (18.41%). Fifty-five samples (17.46%) were positive by the GEN method and 51 samples (16.19%) by the LCx method. The same rate of detection was found for 71 haemodialysis patients and 18 non-A non-E hepatitis. Method based differences in prevalence were observed for patient samples from the general population, 8/106 (7.55%) positive by GEN vs 7/106 (6.60%) by LCx; and HIV infected patients, 26/98 (26.53%) vs 23/98 (23.46%). For chronic type C hepatitis 10/22 (45.5%) were positive by both methods, with two samples discordant. Overall, discordance was observed for ten samples, with seven positive only by the GEN ETI-K HGV RNA, and three positive only by the LCx GBV-C Assay. An additional evaluation of serial samples, from chronic type C hepatitis patients under interferon treatment, revealed three samples which were positive only by the GEN method. Results were 100% concordant for patients under haemodialysis and for non-A non-E hepatitis, 95.9% in the HIV positive group, 90.9% in the chronic type C hepatitis group, and 97.1% in the general population group. Overall, a 97.2% of concordance was found between methods. Both tests have a similar diagnostic performance, though in our opinion, LCx GBV-C Assay better suits the requirements of a clinical microbiology diagnostic laboratory.

Flaviviridae↗
PubMed2000

Coadministration of 5-hydroxytryptamine(1A) antagonist WAY-100635 prevents fluoxetine-induced desensitization of postsynaptic 5-hydroxytryptamine(1A) receptors in hypothalamus.

Treatment with selective serotonin reuptake inhibitors induces a desensitization of hypothalamic postsynaptic 5-hydroxytryptamine (5-HT)(1A) receptors in humans and rats. This study investigated whether fluoxetine-induced desensitization is due to overactivation of postsynaptic 5-HT(1A) receptors; whether blockade of somatodendritic 5-HT(1A) autoreceptors accelerates this desensitization; and whether desensitization is associated with a reduction of Gz proteins, which couple to 5-HT(1A) receptors. WAY-100635 was tested at low doses (0.03-0.3 mg/kg), which antagonize somatodendritic 5-HT(1A) autoreceptors in the raphe nuclei, and at a higher dose (1 mg/kg), which completely blocks postsynaptic 5-HT(1A) receptors. Plasma levels of oxytocin and adrenal corticotrophic hormone (corticotropin) were measured as peripheral indicators of hypothalamic 5-HT(1A) receptor function. Daily injections of fluoxetine (10 mg/kg/day i.p.) for 2 days did not desensitize 5-HT(1A) receptors but three daily injections of fluoxetine produced a partial desensitization of the hormone responses to (+/-)-8-hydroxy-2-dipropylaminoetetralin (50 microg/kg s.c.). WAY-100635 (0.03-0.3 mg/kg) did not accelerate or potentiate the fluoxetine-induced desensitization of 5-HT(1A) receptors. However, WAY-100635 at a dose that completely blocks postsynaptic 5-HT(1A) receptors (1.0 mg/kg) completely prevented the fluoxetine-induced desensitization of 5-HT(1A) receptors. These data demonstrate that at least 3 days of fluoxetine exposure is required to produce a homologous desensitization of hypothalamic 5-HT(1A) receptors. Although previous studies indicate that injections of fluoxetine for 14 days produce a reduction of Gz protein levels in the hypothalamus, the levels of Gz proteins were not affected by either fluoxetine or WAY-100635. Alternative mechanisms mediating the initial stages of 5-HT(1A) receptor desensitization could involve post-translational modifications in the 5-HT(1A) receptor-Gz protein-signaling cascade.

8-Hydroxy-2-(di-n-propylamino)tetralin↗
PubMed1999

Expanded polytetrafluoroethylene membrane for the prevention of peridural fibrosis after spinal surgery: an experimental study.

One of the most common complications of lumbar spine surgery is peridural fibrosis, a fibroblastic invasion of the nerve roots and the peridural sac exposed at operation. Peridural fibrosis may produce symptoms similar to those the patient experienced preoperatively and, if another spinal operation is necessary, may increase the risk of injury at reexposure. In a controlled study in dogs, we assessed the use of expanded polytetrafluoroethylene (ePTFE) as a barrier to postoperative invasion of fibrous tissue into the laminectomy defect. In 14 dogs, a two-level laminectomy was done, at L4-L5 and L6-L7. In 12 dogs, an ePTFE membrane was placed directly over the dorsal surface of the laminectomy defect at L4-L5 and within the defect (over the surface of the dura) at L6-L7. No material was implanted in two dogs (controls). Tissue for histologic studies was obtained from the controls and from ten dogs with the membrane 12 weeks postoperatively. Two dogs with the membrane underwent reoperation. The study found that there was no peridural fibrosis in seven of the ten specimens in which the ePTFE membrane had been placed directly on the dorsal surface of the laminectomy defect, some peridural fibrosis in all specimens in which the membrane had been placed within the defect, and extensive fibrosis in controls. The ePTFE membrane created an excellent plane of dissection for reoperation. No foreign-body reactions to the membrane or membrane-related infections occurred. We conclude that the ePTFE spinal membrane, when properly implanted, is an effective barrier to postsurgical fibrous invasion of the vertebral canal. Clinical studies of use of this material in spinal surgery are warranted.

Animals↗