Leucocytic Response Research Articles

The modulatory effect of carvacrol on viral shedding titer and acute phase response in broiler chickens experimentally infected with infectious bronchitis virus

Infectious bronchitis virus (IBV) is one of the major respiratory diseases of broiler causing huge economic losses. The inability to control IBV using different vaccination programs owing to the high mutation rate and recombination ability of the RNA genome generates IBV variants. This study was designed to give a specific perspective of carvacrol effect on early immune response, viral shedding titer, oxidative stress, serum biochemical parameters and clinical consequences in broilers experimentally infected by IBV. One hundred and twenty-one-day old commercial broiler chicks were equally divided into 4 groups. First group was considered as control. Second group was given carvacrol, third group was infected with IBV and fourth group was given carvacrol and infected with IBV. Infection with variant IBV induced significant upregulation of chicken interferon-inducible transmembrane protein 3 (chIFITM3) gene in trachea, elevations in serum levels of Alpha-1 acid glycoprotein (α1-AGP) and Interleukin 6 (IL-6), total leucocytic count (TLC), heterophil/lymphocyte (H/L) ratio and oxidative stress in lung and kidney tissues. Beside, histopathological changes in trachea, lung and kidney induced by IBV, elevation of kidney function tests was detected. The pretreatment with carvacrol significantly reduced viral shedding titer, chIFITM3 gene expression, IL-6 and α1-AGP levels, leucocytic response and H/L ratio with minimization of clinical signs intensity. Also, carvacrol relieved oxidative stress, ameliorated the increased uric acid level and histopathological alterations in kidney and lung caused by viral infection.

Splenic and Leucocytic Responses in Wistar Rats Exposed to Chronic Doses of Hydromethanol Extract of Helianthus annuus Leaf in Feed

Abstract To evaluate the effects of the hydromethanol extract of Helianthus annuus on leucocyte profile and spleen histology after prolonged exposure to Wistar rats. This study involved the incorporation of varied concentrations (2.50, 5.00 and 10.00 mg/10 g) of hydromethanol extract of H. annuus in feed and feeding same to Wistar rats for 90 consecutive days. Blood samples were collected from the retro-orbital plexus of the rats on days 30, 60 and 90, for leucocyte count. Histopathological examination of the spleen was also conducted. The extract treatment did not cause a significant (p >0.05) change in the leucocyte profile and the spleen histology in the treated rats when compared to the normal control rats. On day 90, the total leucocyte counts of 15.24 ± 1.47, 12.69 ± 0.84 and 16.29 ± 3.36 for the groups that were treated with extract 2.50, 5.00 and 10.00 mg/10 g feed respectively, were not significantly (p > 0.05) different when compared with the total leucocyte count (12.01 ± 0.77) of the control group. The findings suggest that hydromethanol extract of H. annuus do not have a significant effect on the leucocyte profile and the histology of spleen.

Biochemical and leucocytic response study of herbal immunomodulators against levamisole inToxocara canisinfected mice

Toxocara canis owns an exceptional ability to withstand host’s immune system by encystment of larval stages into host’s tissue and thus, paving way for anthelmintic ineffectiveness against the larval stages of the parasite. The aim of the present study was to evaluate the effect of three herbal (methanolic extracts of Hippophae rhamnoides, H. salicifolia and Piper longum) and one allopathic (levamisole) immunomodulators on the migratory behaviour of T. canis larvae in tissues of Swiss albino mice, experimentally infected with T. canis embryonated eggs on day 14 of immunomodulatory medication. On the basis of biochemical and leukocyte observations on days 14 and 28 post infection, H. salicifolia and H. rhamnoides were recorded as superior immunomodulators followed by levamisole and Piper longum in Swiss albino mice.

Leucocytic Response In Pigs Experimentally Infected With <i>Trypanosoma brucei</i> and Subsequently Treated With Diffluoromethylornithine (DFMO) alone and in Combination with Diminazene Aceturate

The effect of dl-%- Diffluoromethylornithine (DFMO) alone and its combination with Diminazene aceturate (Berenil®) treatments on the leucocytic response of T.b. brucei infected pigs was investigated. Weaning pigs were experimentally infected with T. b. brucei and monitored pre and post treatment with the test drugs for parasitaemia and leucogramic changes. The infection caused overall increases in leucocyte numbers which remained high even after treatment. The leucocytosis was characterized by lymphocytosis which did not normalize with treatment, neutropaenia which rose to pre-infection level with treatments, eosinophilia and monocytosis which slowly returned to pre-infection values following treatments. It is concluded that pigs's response to T.b. bruce i infections may include a lymphocyte dominated leucocytosis which is partially sensitive to DFMO or its combination with Berenil® treatments. Key Words: Trypanosoma brucei, pigs, diffluoromethylornithine, diminazene aceturate. Trop. Vet. Vol. 21: (4) 192-199 (2003)

Transport and Phagocytosis of Fresh Versus Aged Rabbit Sperm.

Published research indicates that few of the sperm deposited in the female tract are recovered after insemination. Experiments were performed in rabbits to determine if sperm recovery could be improved by intensive flushing, and to examine leucocytic response as a factor affecting recovery. Freshly ejaculated and washed sperm were compared with sperm aged for 10 to 12 h in vitro prior to insemination. More aged sperm (54%) were recovered from the uterus than fresh sperm (36%) within 10 to 15 min of uterine deposition. Use of whole semen instead of washed sperm reduced recovery of both types of sperm (33 to 37% recovery). Increasing concentrations of Triton X-100 and multiple flushes increased recovery of fresh sperm, but not of aged sperm. Only 6.6% of the aged sperm and 11.5% of the fresh sperm were engulfed by neutrophils after 12 h in ligated uteri, and many sperm were unaccounted for. A breakthrough in recovery was achieved by developing a method to solubilize neutrophils, leaving sperm heads intact. This increased recovery of sperm held for 12 h in the female from 48% before to 93 to 95% after neutrophil dissolution. This technique will enhance studies involving sperm interactions in the female.

The intensity and duration of primary Heligmosomoides polygyrus infection in TO mice modify acquired immunity to secondary challenge

The effect of dose and duration of immunizing infections of Heligmosomoides polygyrus on protection against homologous challenge was studied in female TO mice. Primary infections were terminated at various levels with pyrantel embonate (adult infections) or ivermectin (larval infections) and mice were then challenged with 500 infective larvae (L3). The level of protection to secondary challenge positively correlated with the intensity of the primary immunizing infection but truncation of larval infection produced significantly better protection than termination of the adult nematode infection. The duration of the primary larval infection (1-6 days) positively correlated with the level of protection to secondary challenge, antibody responses and the proportion of circulating eosinophils. Histological changes in the gastrointestinal tract, peripheral leucocytic changes and antibody responses of the mice to H. polygyrus adult somatic antigens indicate both a cellular and humoral basis of host immunity to secondary challenge. Although the TO mice are slow responders in that they harbour chronic infections, immunization by intramucosal killing of the larval stage produced strong protection against secondary challenge infection. The presence of dead immunogenic larval stages within the intestinal wall may well be an important factor, since it exposes the host to stage specific antigens at an appropriate location. The implications of the findings for the control of gastrointestinal nematode infections are also discussed.

Group Selection for Adaptation to Multiple-Hen Cages: Hematology and Adrenal Function ,

A selected line of White Leghorns that has shown improved survivability and productivity and reduced feather loss in multiple-hen cages was evaluated for hematological and adrenal responses under both stressed and unstressed conditions. It was hypothesized that hens selected for adaptation to multiple-bird cages would react less intensely to stressors. Three lines of chickens (selected, control, and commercial) were housed in either single-hen (1 hen) or multiple-hen cages (12 hens, social competition) at 16.7 or 17.1 wk of age. They were subsequently subjected to cold exposure at 33 wk of age and heat exposure at 44 wk of age.Genetic stock as a main effect, and the interaction of genetic stock with either a cold or heated environment or with cage size, had no effect on plasma levels of cholesterol and corticosterone. At the time of transfer to laying cages, the selected line of pullets, as indicated by a decrease in packed cell volume, appeared to adapt more quickly to the new waterer system of multiple-hen cages than did the control and commercial lines. At 33 wk of age, the control and commercial lines in multiple-hen cages experienced heterophilia and increased heterophil to lymphocyte ratios, whereas the selected line did not, when compared with these same lines in single-hen cages. This leucocytic response could be interpreted to mean that the selected line of chickens adapted better to social competition than either the control or commercial lines; however, a similar leucocytic response was not observed at 18 or 44 wk of age. In conclusion, the physiological characterization of the selected line of Leghorns showed evidence of improved adaptation to multiple-hen cages when compared to the other stocks. In some cases, the selected line responded less intensely to stress; however, trends were not always consistent.

Avian blood leucocyte responses to stress

This review on avian blood leucocyte responses to stress covers the literature from the early 1980s. It considers only non-infectious hormonal responses of leucocytes to stress mediated either by nutritional, parenteral, climatic/environmental (physical or social) or psychological stressors. The heterophil/lymphocyte (H/L) ratio after the administration of ACTH either in the diet or by injection and during food restriction studies has been studied. The ratio was found to be inadequate during severe food restriction studies, as some stressed birds responded with a heteropenia, lymphocytosis and a significant basophilia. Climatic and environmental stressors such as road transportation and heat stress produced significantly raised H/L ratios and basophilias, respectively. Psychological stressors such as fasting, frustration or noise showed different leucocytic responses and the times in which cells were mobilized also varied. Although the H/L ratio is a less variable indicator of avian stress than individual cell numbers and more reliable than corticosteroid levels in plasma, this rule applies only when mild to moderate stress exists. During extreme stress, as in life-threatening situations, a heteropenia and basophilia develop so the H/L ratio cannot always be accepted as an accurate measurement of stress in poultry. Thus, in some avian stress a two-phase cellular reaction may be present. This biphasic leucocytic response to stress may be unique to Aves.

Responses to isolation in Japanese quail genetically selected for high or low sociality

The adrenocortical, behavioral, and leucocytic responses to isolation, for 1, 3, or 72 h, of 7–10-day-old Japanese quail chicks, of lines selected for high (HSR) or low (LSR) levels of social reinstatement (SR) behavior, were studied. Isolation had no effect on plasma corticosterone levels of heterophil/lymphocyte measures in LSR line chicks. Conversely, circulating corticosterone levels were increased after 1 h of isolation in the HSR line, although they fell to control levels thereafter. Heterophil/lymphocyte ratios of HSR line chicks were also increased after 3 h of isolation but decreased to control levels thereafter. Isolated HSR line chicks were consistently more active and showed more peeping and jumping than LSR line chicks in which sitting and lying were more frequent. However, no such behavioral divergence was observed when HSR and LSR line chicks were housed in same-line groups. These results indicate that selection for SR behavior has influenced both underlying social motivation and responses to short-term isolation. Social separation appeared to be more stressful for HSR than LSR line chicks.

Cytometric Haematological Analysis of Experimental Yersinia pseudotuberculosis Infection at Temperatures of Cultivation of 25°C and 37°C

The dynamics of acute lethal infection with Yersinia pseudotuberculosis (serovar III) grown at 25 degrees C and 37 degrees C, respectively, were studied in guinea-pigs. Using an automated hematology analyzer, the quantity and quality of the host cellular response was determined at the primary site of infection (the peritoneal cavity) and in parallel in the blood. A much more intensive leucocytic response of monocytic type was observed in the animals infected with microorganism grown at 37 degrees C. This type of reaction was associated with a lower mortality rate and a relatively benign progression of the infection.

Haematological changes in buffalo calves inoculated with Escherichia coli endotoxin and corticosteroids

Haematological studies were conducted on 10 clinically normal water buffalo calves to determine leucocytic responses to Escherichia coli endotoxin, prednisolone and dexamethasone. Intravenous injection of 10 micrograms endotoxin induced minimal decreases in leucocyte numbers, whereas 20, 50 and 100 micrograms produced a marked leucopenia within one hour. Moderate to marked leucopenia, neutropenia and lymphopenia persisted for three to 14 hours. Significant rebound neutrophilia was evident at six to eight hours after inoculation in calves given only 10 and 20 micrograms. Intramuscular injection of prednisolone (100 mg) and dexamethasone (5 mg) produced increases in total leucocyte counts and neutrophil numbers within two hours. Moderate to marked leucocytosis and neutrophilia persisted for eight to 24 hours. Lymphocyte response was unlike that in other species in that lymphopenia was not a consistent feature of the corticosteroid response. A transient monocytosis was seen following administration of prednisolone but not of dexamethasone, while eosinopenia and basopenia developed in both cases. In conclusion, endotoxin and corticosteroid induced changes in total and differential leucocyte counts in water buffalo were largely similar to those seen in cattle.

Chronic stressors, tonic immobility and leucocytic responses in the domestic fowl

Tonic immobility (TI) fear reactions and heterophil/lymphocyte (H/L) ratios were measured in individually caged Brown Leghorn pullets before and after their exposure to one of three procedures lasting approximately 72 hr. These were: ad lib feeding (controls), fasting (removal of food) or frustration of feeding (fasting plus denial of access to visible food). H/L ratios were elevated after fasting or frustration, illustrating the stressful nature of these procedures, but remained unaltered in the controls. Pretreatment TI responses were similar in all groups. Susceptibility and response duration were reduced upon retesting presumably through habituation, but this effect was relatively homogeneous across groups. Any direct effect of fasting/frustration upon fearfulness seemed unlikely because the mean TI responses of control and stressed birds were similar. However, whereas a rank order based on TI durations was repeatable upon retesting in the controls, it was destabilised in the stressed groups. Positive intraindividual correlations were found between pretreatment TI durations and subsequent H/L responses to fasting/frustration. This suggests that leucocytic responses to chronic stressors may be greater in fearful pullets than in less fearful birds.

Immunohistochemical studies of fetal trophoblast and maternal decidua in hydatidiform mole and choriocarcinoma

The survival of the fetoplacental unit to term in a potentially hostile environment remains an immunological enigma. The development of trophoblast-reactive monocional antibodies (mAbs) has allowed in situ characterization of phenotypically distinct villous and extravillous fetal trophoblast populations in normal human pregnancy (Bulmer and Johnson, 1985). Maternal decidual leucocytes have also been defined by the same approach: macrophages are common throughout gestation, often closely associated with extravillous trophoblast (Bulmer and Johnson, 1984; Smith, Bulmer and Wells, 1986), whereas granulated lymphocytes expressing certain T-cell differentiation antigens are prominent only in early pregnancy tissues (Bulmer and Sunderland, I&; Bulmer, Johnson and Buimer, 1987). The immunobiological importance of both fetal trophoblast surface antigens and the local maternal leucocytic response in successful implantation and placentation are of current interest. The response of gestational choriocarcinoma to chemotherapy has highlighted the interrelationship between this tumour and the maternal host. It is often associated with a local host mononuclear cell response (Elston, 1978) and high serum levels of anti-paternal lymphocytotoxic antibodies (Shaw et al, 1979). In Caucasian populations, approximately equal numbers of cases of choriocarcinoma follow normal term delivery, molar pregnancy and non-molar abortion, although the proportion following hydatidiform mole is higher in Japan (World Health Organization, 1983). The risk of choriocarcinoma following a molar pregnancy is around one thousand times greater than after normal term delivery (Bagshawe et al, 1973). but it is likely that choriocarcinoma ensues in no more than 5 per cent of hydatidiform moles (World Health Organization, 1983). Complete hydatidiform moles are diploid and of androgenetic origin (Kajii and Ohama, 1977) and hence are fully allogeneic with the maternal host. Most are homozygous 46XX and may arise by fertilization of an empty egg by a haploid sperm which dupli-

Experimental chlamydial keratitis in rabbits. Correlation with chlamydia infected McCoy tissue culture cells.

Rabbit corneas were inoculated three times at weekly intervals with the agent of chlamydia trachomatis using the scratch method. Specimens of the corneal epithelium were obtained using the replica technique on the 1st, 2nd, 3rd and 4th day after each inoculation and at two weeks after the last inoculation. The development of chlamydial inclusions and the inflammatory cell response were monitored using Giemsa stain, acridine orange stain and direct immunofluorescent technique. Primary inoculation produced mild clinical disease associated cytologically with polymorphonuclear leucocytic cellular inflammatory response. Repeated inoculations produced more severe disease associated clinically with pannus formation and cytologically with the presence of lymphocytes and Leber cells in addition to polymorphonuclear leucocytes. Halberstaedter Prowazek inclusion bodies were detected in all the specimens. Additional intracytoplasmic and intranuclear inclusions of different morphological appearances were present. The cytological findings detected in the corneal epithelium of rabbits were correlated with the findings in McCoy tissue culture cells inoculated with chlamydia trachomatis.

Immunohistochemical studies of fetal trophoblast and maternal decidua in hydatidiform mole and choriocarcinoma.

Immunohistochemical techniques have been used to investigate the expression of fetal trophoblast antigens and the maternal leucocytic response in molar pregnancy and choriocarcinoma. The antigenic phenotype of morphologically defined trophoblast populations in complete, partial and invasive moles was analogous to that in normal pregnancy. All trophoblast phenotypes described in normal pregnancy were also identified in choriocarcinoma, suggesting that extensive differentiation into heterogeneous subgroups occurs in malignant trophoblast. The maternal leucocytic infiltrate in molar pregnancy consisted of T lymphocytes and class II MHC-positive macrophages. CD2-positive, CD3-negative lymphocytes were identified in molar decidua but not in uterine tissue in choriocarcinoma. Similarly, endometrial granulocytes were present in molar decidua but not in choriocarcinoma; these cells were associated with decidualization rather than with fetal trophoblast.

The Fate of Intraarticular Loose Bodies of Meniscus Origin in Canine Species

A potential risk of arthroscopic meniscectomy is the retention of debris of meniscus origin in the knee joint. This prospective study analyzes the fate of loose bodies of meniscus origin placed into the canine knee joint. At 12 weeks, 16.7% of the free fragments were completely degraded, 16.7% were absorbed by the synovium, and 66.6% were loose, located between synovial folds. At 12 weeks, 93.3% of the fragments had disappeared, and the remaining fragments had decreased 70% in length and 50% in width. A focus of calcification was present in one fragment at 12 weeks. By three weeks, all loose bodies had a pseudocapsule composed of cells with intense fibroblastic activity, occasional mitoses, and a loss of connective tissue matrix at the periphery. A mononuclear leucocytic response was present in the synovium at 12 weeks in four of the five dogs. Free fragments of meniscus origin are most commonly degraded completely by 12 weeks. Enzymatic digestion, mechanical abrasion, and synovial phagocytosis are processes that may contribute to this phenomenon.

Electron microscopic study of leucocytic infiltration of the mammary teat duct during infection with Staphylococcus aureus

Leucocytic response to Staphylococcus aureus infection was observed in the bovine mammary teat duct using transmission electron microscopy. Leucocytes migrating across the stratified squamous epithelium were observed in close association with areas colonised by cocci. Leucocytes gained access across the epithelium to the teat duct lumen by: passage as luminal cells desquamated; migration through degenerate cell cytoplasm; and penetration of cell junctions. The results provide evidence of marked leucocytic infiltration into ductal tissue which may participate in the cellular response to mastitis.

The site selected by the larvae of Heligmosomoides polygyrus.

Histological examination of the small intestine of mice infected with Heligmosomoides polygyrus indicates that the final site of the larvae is in the circular muscle layer of the muscularis externa of the anterior small intestine. The larvae become embedded in the muscle between the first and third days after infection and are subsequently sequestered by a localized leucocytic response. There is no evidence of a true cyst. Histological evidence suggests that the larvae actively feed on the tissues of the host during their development.

Leucocytic changes in cows given intravenous injections of Escherichia coli endotoxin

Single intravenous injections of Escherichia coli endotoxin into normal cows produced dose dependent leucocytic and febrile responses. Injections of 5 to 20 microgram endotoxin induced a neutrophilia between 4 and 8 h, whereas 50 to 500 microgram produced a severe neutropenia for 4 to 6 h followed by a gradual increase in neutrophils along with slight to moderate left shift. Higher doses caused progressively severe lymphopenia and greater increase in fever than the lower doses. It was concluded that blood leucocytic changes during the early part of endotoxin-induced mastitis are partly related to systemic absorption of endotoxin, and that the size of the bone marrow neutrophil reserve in the cow could be estimated by injecting 5 to 10 microgram of endotoxin intravenously.

A pathological study of the lungs of foals infected experimentally with Parascaris equorum

Eight pony foals 2 to 4 weeks old were infected with a single dose of 8000 P. equorum eggs. The animals were killed at intervals to investigate the pulmonary lesions produced. Two distinct lesions were found in the lungs. The migrating P. equorum larvae provoked a transitory eosinophilic bronchitis and bronchiolitis which was later replaced by a lymphocytic response. Large numbers of subpleural lymphocytic nodules were also present for a short period. In addition, there was a cranial lobe pneumonia with a mainly polymorphonuclear leucocytic response. It is suggested that this second lesion may be a form of enzootic pneumonia and that its pathogenesis is enhanced by the migrating P. equorum larvae.