Morphological differentiation of the conjunctival goblet cells in the chick (Gallus domesticus)

BACKGROUND: These is no consensus in the literature regarding the differentiation of conjunctival goblet cells in vertebrates. METHOD: The conjunctival epithelium of the chick was studied before and after hatching in order to demonstrate the morphological evolution of the goblet cells. The entire conjunctiva was processed for light microscopy either on semithin sections stained with toluidine blue-pironine or on traditional sections stained with Alcian blue pH 2.5-PAS. RESULTS: It was possible to demonstrate that goblet cells underwent remarkable changes in their secretory activity. At 12 h after hatching, isolated Alcian blue-positive cells were present in the fornix. At 24 h after hatching, cells positive for both Alcian blue and PAS were scattered among epithelial cells. Two days after hatching, cells which reacted positively only to PAS were also present. CONCLUSION: It is suggested that the differentiation of conjunctival goblet cells occurs first in the fornix, probably due to the particular vascular environment of this region, and then spreads all over the conjunctiva.     

Observations of hatching movements in the chick, Gallus domesticus.

Made a film analysis of the hatching movements of White Leghorn chicks placed in transparent glass "eggshells." During every hatching burst, each of the limbs first extended, then flexed beyond the original resting point, and finally extended again to the original resting point (as seen from the body). This suggests that all 4 limbs helped to hold the body of the embryo tightly in place inside the egg during a cracking phase, enabling the beak to perform the actual cracking of the shell. Subsequently during a turning phase, the limbs contributed to rotation of the embryo in the eggshell, bringing the animal in the right position for further breaking the shell during the next burst. The effective forces against the shell, leading to rotation of the animal in the egg, were probably performed by (a) the right leg during its flexion, (b) the right wing during its flexion, and (c) the left wing during its re-extension. (17 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Teratoma in a chicken (Gallus domesticus)

A large mass composed of multiple tissue elements was observed in the abdominal cavity of a chicken. The tumor mass was tridermic microscopically, and therefore classified as a teratoma.     

Reduction in numerical synapse density in chick (Gallus domesticus) dorsal hippocampus following transient cerebral ischaemia

BACKGROUND: The epidermal growth factor (EGF) signal transduction pathway, frequently activated in pancreatic cancer, is an important regulator of cellular growth and transformation. This study examined whether activation of the cyclic adenosine monophosphate protein kinase A pathway may inhibit the EGF signal transduction pathway in pancreatic cancer cell lines. METHODS: Human pancreatic cancer lines BxPC-3 and AsPC-1 were stimulated with EGF, forskolin, or both. Forskolin is a compound that increases cyclic adenosine monophosphate levels. Assays of cell lines were then obtained for cellular growth (MTT assay), anchorage-independent growth (soft agar), and EGF-induced mitogen-activated protein kinase activation as measured by an in-gel kinase assay. RESULTS: Treatment with forskolin resulted in inhibition of EGF-induced activation of mitogen-activated protein kinase activity (BxPC-3 78% inhibition and AsPC-1 70% inhibition, p < 0.005), diminished cellular proliferation (BxPC-3 92% inhibition and AsPC-1 86% inhibition, p < 0.001), and formation of colonies in soft agar (BxPC-3 98% inhibition and AsPC-1 76% inhibition, p < 0.001). Forskolin did not inhibit EGF receptor autophosphorylation or tyrosine kinase signaling in response to EGF. CONCLUSIONS: Forskolin-induced inhibition of mitogen-activated protein kinase is associated with diminished pancreatic cancer cell proliferation in vitro. Use of strategies to increase cyclic adenosine monophosphate levels may have therapeutic application in pancreatic cancer.     

A presumptive diagnosis in the fowl (Gallus gallus domesticus) from Assam (India)

In postmortem examination of carcasses of White Leghorn chickens, 3 had typical gross lesions of necrotic enteritis affecting the small intestines. The occurrence of avian necrotic enteritis was noticed after an outbreak of coccidiosis had subsided. On the basis of the gross and microscopic examination the disease was differentiated from coccidiosis and ulcerative enteritis.     

Potential for non-shivering thermogenesis in perfused chicken (Gallus domesticus) muscle

The state of Oregon decided to cover all potentially eligible Medicaid citizens to 100% of poverty. Previously, Oregon had covered persons up to 67% of poverty. In order to keep overall program costs in check. Oregon decided to limit the number of services that its Medicaid program would cover. Oregon's normative choice was to contain program costs by covering all eligible persons up to 100% of poverty, while at the same time uniformly limiting access to certain services for everyone in the overall group of eligible persons. The state developed a prioritization list of medical services and priced the components on the list. The amount of money ultimately available for the Medicaid program was a political decision informed by data about the cost of different services and influenced by the priorities set through an independent process of priority-setting. Physicians were asked to determine what works medically, how well it works, and what benefits accrue to patients. Recognizing that physician perspectives on efficacy might vary from patients' perspectives on valuation of benefits, Oregon's planners developed a method for valuing medical outcomes that stemmed from particular medical interventions. This blend of medical fact and value to patients allowed for comparing valuations by introducing cost considerations. Condition-treatment (CT) pairs linked a medical condition with one or more courses of treatment. The goal was to determine the likely incremental medical benefit from a given treatment. In addition, Oregon developed a Quality-of-Well-Being scale to determine the net patient benefit from medical intervention and used a telephone survey to value that net benefit. A cost-benefit ratio was derived, and a prioritization of CT pairs was developed. The article analyzes and evaluates Oregon's use of cost-benefit calculations in the allocation of Medicaid funds, noting that Oregon itself backed away from many of the implications of its cost-benefit analysis and that the Americans with Disabilities Act has constrained use of quality-of-life judgments in Medicaid resource allocation decision-making.     

Evidence of a thyrotropin-releasing activity of ovine corticotropin-releasing factor in the domestic fowl (Gallus domesticus)

New tools to prevent malaria morbidity and mortality are needed to improve child survival in sub-Saharan Africa. Insecticide treated bednets (ITBN) have been shown, in one setting (The Gambia, West Africa), to reduce childhood mortality. To assess the impact of ITBN on child survival under different epidemiological and cultural conditions we conducted a community randomized, controlled trial of permethrin treated bednets (0.5 g/m2) among a rural population on the Kenyan Coast. Between 1991 and 1993 continuous community-based demographic surveillance linked to hospital-based in-patient surveillance identified all mortality and severe malaria morbidity events during a 2-year period among a population of over 11000 children under 5 years of age. In July 1993, 28 randomly selected communities were issued ITBN, instructed in their use and the nets re-impregnated every 6 months. The remaining 28 communities served as contemporaneous controls for the following 2 years, during which continuous demographic and hospital surveillance was maintained until the end of July 1995. The introduction of ITBN led to significant reductions in childhood mortality (PE 33%, CI 7-51%) and severe, life-threatening malaria among children aged 1-59 months (PE 44%, CI 19-62). These findings confirm the value of ITBN in improving child survival and provide the first evidence of their specific role in reducing severe morbidity from malaria.     

Chick (Gallus domesticus) Approach Preferences for Natural and Artificial Sound Stimuli: Erratum.

Reports an error in the original article by Gloria J. Fischer (Developmental Psychology, 1976[Jan], Vol 12[1], 39-46). On page 41, the 1-sec designation was inadvertently cropped from Figure 1; .5 sec should be plotted 6.5 cm from 0 along the abscissa. (The following abstract of this article originally appeared in record 1979-25318-001.) Found that 2-day-old White Leghorn and New Hampshire chicks showed an unlearned preference for an ancestral maternal call over a brief, repetitive pure tone burst when choice preference tests were between stationary models emitting maternal call and tone burst sounds. However, other Ss of both breeds showed an unlearned preference for tone burst over maternal call when choice preference tests were between moving models emitting tone burst and call sounds. These same preferences were found in Ss that had been imprinted (exposed) to moving call and tone burst sounds on their 1st posthatch day. The tone bursts were briefer than the call note duration (25 vs 80 msec). Since very brief sound bursts are easier to localize, it is concluded that Ss preferred tone bursts over calls when sound sources were moving because of the greater ease of localizing tone bursts. Along with other recent data, the failure to find imprinting to a maternal call or to tone bursts (i.e., the call and tone burst preferences found were uninfluenced by a brief prior exposure to either sound) suggests the need to question whether or not auditory imprinting occurs in the domestic chick. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Furazolidone treatment suppresses pubertal testosterone secretion in male broiler breeder birds (Gallus domesticus)

We determined the effect of chronic administration of furazolidone (Fz) on sexual maturation of male broiler breeder birds (Ross 308; Gallus domesticus). A total of 20 15-w-old birds were randomly assigned to receive 0, 150, 250 or 350 mg Fz/kg feed daily for 5-w. Blood samples were taken at weekly intervals. The birds were challenged with 500 IU human chorionic gonadotropin (hCG) i.v. at the age of 24 w before slaughtering. Concentration of testosterone in the plasma was measured by a specific radioimmunoassay. Testicular tissue was processed for morphometric studies. Testicular weights of the groups fed 250 or 350 mg Fz/kg feed/d were decreased (P < 0.05). Plasma testosterone levels were affected by age (P < 0.001) and dose of Fz (P < 0.001). Mean plasma testosterone levels during and after drug administration were reduced (P < 0.05) by all Fz doses. Human chorionic gonadotropin administration led to poor testosterone response (P < 0.05) in all Fz-dosed groups, but not the control group (P < 0.05). As compared to the control, Fz-dosing reduced the seminiferous tubule diameter (P < 0.05) at the 350 mg/kg feed dose, seminiferous epithelial height (P < 0.05) at the 250 and 350 mg/kg feed doses, and Leydig cell nuclear diameter (P < 0.05) at the 350 mg/kg feed dose. This data suggest that sexual maturation in male broiler breeder birds is adversely affected by chronic Fz-administration. Actions of Fz on sexual maturation probably involve a direct effect at the testicular level.     

Histochemical studies of the development of alkaline and acid phosphatase activities in the ovary and oviduct of the fowl (Gallus domesticus)

Alkaline and acid phosphatase activities were studied in the ovary and oviducts of pullets from the age of 2-32 weeks. Adult fowls were similarly studied. Alkaline phosphatase activity was present only in the glandular grooves and crypts of the immature oviducts. Alkaline phosphatase activity appeared at the pits of epithelial evaginations as glandular formation commenced. The young, non-secreting glands also showed the enzyme activity. But in the mature oviduct, alkaline phosphatase activity was confined to only the uterovaginal glands or sperm host glands and the epithelium of the vagina. In the ovary, alkaline phosphatase activity in the theca interna increased as the diameter of the follicles increased. Acid phosphatase activity was not present in the ovary, but in the oviduct, the enzyme activity was present in the uterine (shell gland) glands and in the uterovaginal epithelium and glands (sperm host glands). Alkaline phosphatase activity in the ovarian follicles and in the immature oviduct is thought to be related to histodifferentiation of these structures.     

The thyroid hormone, 3,5,3'-triiodothyronine, is a negative modulator of domestic fowl (Gallus gallus domesticus) adrenal steroidogenic function

Previous work with chickens (Gallus gallus domesticus) suggests a relationship between depressed thyroid hormone status and enhanced adrenal steroidogenic function. In addition, in hypophysectomized chickens, replacement of the thyroid hormone, 3,5,3'-triiodothyronine (T3), maintains chicken adrenal steroidogenic cell sensitivity to adrenocorticotropin (ACTH) but decreases steroidogenic capacity further than that due to hypophysectomy alone. The present in vivo and in vitro studies were conducted to determine the influence of thyroid status and T3 per se on avian adrenal steroidogenic function. Chicks (1 day old) were thyroidectomized using combined surgical and chemical (6-propyl-2-thiouracil) treatments and were administered a replacement dose of T3 (0, 1.5, 4.5, 15, and 45 microg/kg body wt/day) for 5 weeks. Whereas thyroidectomy (TX) decreased adrenal weight (-20%), it increased relative adrenal weight (mg/100 g body weight) (+171%), trunk plasma corticosterone (+880%), and aldosterone (+124%). In addition, TX increased basal, maximal ACTH-induced, maximal 8-bromo-cyclic AMP-induced, and maximal 25-hydroxycholesterol-supported corticosterone production (+520, +93, +124, and +195%, respectively) and aldosterone production (+578, +288, +280, and +275%, respectively) by isolated adrenal steroidogenic cells. T3, in a dose-dependent manner, reversed the effects of TX on these in vivo and in vitro parameters of adrenal steroidogenic function. Restoration of most of these parameters to those in the sham-treated control was attained with 4.5-15 microg/kg body wt/day. Although some of the effects of TX and T3 replacement on adrenal steroidogenic function may have been mediated through changes in circulating levels of ACTH, other data suggest a direct effect on adrenal steroidogenic cell function. Adrenal steroidogenic cells from sham-treated and TX birds were preincubated (0, 4, and 12 hr) with various concentrations of T3 (0, 0.3, 3, and 30 nM), washed, and then incubated for an additional 2 hr in medium containing the same respective concentrations of T3, with or without a maximal steroidogenic concentration of ACTH (100 nM). T3 had no acute effects on TX-dependent enhancement of adrenal steroidogenic cell function (2-hr incubation). However, with preincubation (4 and 12 hr), T3 inhibited basal and maximal ACTH-induced corticosterone production in a dose-dependent manner. This concentration-dependent, direct effect of T3 was not observed with cells from sham-treated birds. In addition, the ostensibly inactive thyroid hormone metabolite, 3,3',5'-triiodothyronine [reverse T3; 30 nM], was without effect. Taken collectively, these studies indicate that T3 is a direct negative modulator of avian adrenal steroidogenic function.     

The inhibition of androstenedione production in mature thecal cells from the ovary of the domestic hen (Gallus domesticus): evidence for the involvement of progestins

In the 24 hours before ovulation, there is an abrupt decline in the ability of theca cells from the largest chicken preovulatory follicle to produce androstenedione from all substrates except dehydroepiandrosterone. In this study, we tested the hypothesis that progesterone from granulosa cells might inhibit andostenedione production by the adjacent theca cells. Physiological concentrations of progesterone inhibited andostenedione production by dispersed thecal cells from the substrate 17 alpha-hydroxyprogesterone but not dehydroepiandrosterone in both a dose- and time-dependent manner. In contrast, the metabolites of progesterone, 17 alpha-hydroxyprogesterone, and androstenedione at a high concentration (100 nM) failed to produce such an inhibitory effect. In addition, this inhibitory effect of progesterone was reversed by the protein synthesis inhibitor cycloheximide. The results of this study seem to suggest that progesterone acts indirectly through its nuclear receptor to induce the synthesis of a protein that possibly inhibits C17,20 lyase activity and/or C17,20 lyase gene expression.     

Calcium solubilization and retention in the gastrointestinal tract in chicks (Gallus domesticus) as a function of gastric acid secretion inhibition and of calcium carbonate particle size

In chicks, immature pullets and laying hens, the inhibition of gastric acid secretion by omeprazole, an H+,K(+)-transporting ATPase (EC 3.6.1.36) inhibitor, greatly increased proventricular and gizzard pH values. Consequently, gizzard soluble Ca concentration deceased and the insoluble Ca fraction increased. Inhibition of acid secretion increased duodenal pH values in immature pullets and laying hens but not in chicks. Duodenal soluble and ionic Ca concentrations were lowered by gastric acid inhibition in chicks and to a larger extent in immature pullets and laying hens. The use of Ca of coarse particle size increased the gizzard insoluble Ca fraction in chicks and pullets. However, it did not influence its soluble Ca fraction in chicks but tended to reinforce the negative effect of omeprazole on soluble Ca in the gizzard and duodenum of chicks and laying hens. Coarse particles of Ca led to an increase in gizzard and duodenal soluble Ca at the end of eggshell calcification in laying hens. An enhancement in the level of Ca in the diet from 10 to 36 g/kg increased gizzard soluble Ca and duodenal soluble and ionic Ca concentrations in immature and adult hens. Intestinal Ca retention and bone mineralization was unaffected by gastric acid inhibition in chicks but were largely diminished by the use of coarse particles of Ca. Gastric acid inhibition was associated in laying hens with decreased Ca retention to a small extent and with reduced eggshell quality. These observations confirm that gastric acid secretion is of importance for CaCO3 solubilization but question its role as a prerequisite for intestinal Ca retention in chicks and even in hens fed on a high Ca diet.     

2f1-f2 distortion product otoacoustic emissions in White Leghorn chickens (Gallus domesticus): effects of frequency ratio and relative level

The effects of primary tone frequency ratio (f2/f1 ratio) and relative level (L2/L1) on the amplitude of the cubic difference tone (CDT: 2f1-f2) distortion product otoacoustic emissions (DPOAEs) were investigated in adult White Leghorn chickens (Gallus domesticus). In experiment 1, 9 f2/f1 ratios ranging from 1.05 to 1.8 were investigated. Measurements were obtained from both ears of 4 chickens at 7 f1 frequencies ranging from 0.8 to 4.0 kHz. The primary tones were equal in level, and varied from 20 to 80 dB SPL. The mean CDT amplitude increased with increasing primary tone level once the measurement noise floor was exceeded. The input/ output functions assumed one of two shapes: one in which there was a systematic increase in DPOAE amplitude with increasing primary tone level, and the other in which there was a plateau in the input/output function near 65-70 dB SPL. At the highest primary tone level (80 dB SPL), there was a decrease in the CDT amplitude with increasing f2/f1 ratio. At high primary tone levels, the f2/f1 ratio which produced the largest CDT was 1.05 or 1.1, while at lower primary tone levels the largest CDT occurred at f2/f1 ratios of 1.2-1.3. In experiment 2, L2 was held constant at 70 dB SPL, and L1 varied from 50 to 80 dB SPL. For f1 frequencies of 0.8 and 3.2 kHz, there was an increase in the CDT amplitude with increasing L1, followed by an asymptote at higher levels. In contrast, for 1.6 and 2.0 kHz f1 frequencies, the amplitude increased, plateaued and then increased again at higher levels. Informal measurements suggest that spontaneous otoacoustic emissions (SOAEs) are rarely seen in chickens. However, a reliable SOAE was observed in 1 chicken, which could be suppressed by external sounds and anoxia.     

Apolipoprotein CII from chicken (Gallus domesticus). The amino-terminal domain is different from corresponding domains in mammals

The amino acid sequence of chicken apolipoprotein CII (apoCII) was determined from cDNA sequencing and from partial protein sequencing. The chicken sequence showed an overall identity of around 30% to all the other previously known apoCII sequences. Comparison of the carboxyl-terminal domain (residues 51-79, human numbering) showed at least 50% identity between species. By limiting the region to residues 51-70 the similarity was remarkably high, about 85%. This is in concert with the previous opinion that residues in the region 56-76 are directly engaged in binding to lipoprotein lipase and in activation of this enzyme. In contrast, in the amino-terminal end up to residue 50 (human numbering) less than 24% of the amino acid residues in chicken apoCII were identical to residues of any of the other species. In addition, chicken apoCII is four residues longer than human apoCII (83 versus 79 residues), probably due to an extension at the amino-terminal end. Although the sequence was completely different in the amino-terminal domain, the structures necessary for binding to lipid appear to be present in chicken apoCII. Secondary structure prediction showed that the amino-terminal domain could form two amphipathic alpha-helices in almost similar areas of the sequence as was previously predicted for human apoCII.     

Regularities and irregularities in the structure of the seminiferous epithelium in the domestic fowl (Gallus domesticus). II. Co-ordination between germ cell associations

It was investigated in the domestic fowl, whether a mechanism for a synchronous start of the proliferation of the differentiating spermatogonia in a transversely cut seminiferous tubule (called the "co-ordination" between germ cell association) operates effectively in this species. A trapezoid-shaped cellular association demarcated by two perpendiculars from the tubular lumen to the basement membrane was the unit of observation (provisionally called a "column" Each column is composed of a bundle of elongate spermatids and the neighbouring, various types of germ cells). The extent of closeness of the co-ordination was examined in a total of 2,650 columns, based on the continuity of the spermiogenic step-number of the youngest generation of spermatids within adjacent columns. In no case did all columns in a tubular cross section show the same-step spermatids. In most cases (50.2% of 2,650 columns), the same number was kept in only 2 to 6 adjacent columns. The arrangement of different but consecutive numbers (e.g., 1-2-3 or 1-2-1) was observed in a total of 882 columns. The co-ordination mechanism, therefore, is considered to work, albeit incomplete, among a limited number of adjacent columns in this species.