Evaluation of moldable, in situ hardening calcium phosphate bone graft substitutes.

OBJECTIVE: Moldable in situ self-stabilizing and hardening bone graft materials facilitate handling and may be suitable for membrane-free bone regeneration methods. This study aimed to compare two moldable synthetic calcium phosphate materials in a rabbit calvarial defect model. METHOD: In 12 New Zealand white rabbits, four evenly distributed 6 mm diameter defects were drilled in the calvarial bone. Three filler materials were randomly applied to 48 defects: an in situ hardening polylactide-coated ß-tricalcium phosphate (TCP), an in situ hardening polylactide-coated biphasic calcium phosphate (BCP), and a granular deproteinized bovine bone matrix (DBBM, positive control). One defect remained untreated and served as a negative control. Six animals were sacrificed after 4 weeks, and the remaining animals were sacrificed after 16 weeks. Biocompatibility, bone graft substitute integration and resorption, bone formation, defect bridging, and height of reconstructed hard tissue were assessed histologically and histomorphometrically. RESULTS: All tested materials showed good biocompatibility. Semi-quantitative analysis and pair-wise comparison suggested that BCP was more efficient in centripetal bone formation when compared with TCP. After 4 weeks, significantly more bone had formed in the defects treated with either TCP or BCP materials compared with the untreated sites. BCP and DBBM did not show macroscopic signs of degradation, whereas the TCP material was partially resorbed after 16 weeks. Otherwise, no major differences were detected between the three materials. CONCLUSION: The moldable, synthetic calcium phosphates are safe and suitable bone graft substitutes with outcomes that are comparable to the control material.

DNA methylation plays a crucial role during early Nasonia development.

Although the role of DNA methylation in insect development is still poorly understood, the number and role of DNA methyltransferases in insects vary strongly between species. DNA methylation appears to be widely present among the social hymenoptera and functional studies in Apis have suggested a crucial role for de novo methylation in a wide variety of developmental processes. The sequencing of three parasitoid Nasonia genomes revealed the presence of three Dnmt1 (Dnmt1a, Dnmt1b and Dnmt1c) genes and one Dnmt2 and Dnmt3 gene, suggesting a role of DNA methylation in Nasonia development. In the present study we show that in Nasonia vitripennis all Dnmt1 messenger RNAs (mRNAs) and Dnmt3 mRNA are maternally provided to the embryo and, of these, Dnmt1a is essential during early embryogenesis. Lowering of maternal Dnmt1a mRNA results in embryonic lethality during the onset of gastrulation. This dependence on maternal Dnmt1a during embryogenesis in an organismal group outside the vertebrates, suggests evolutionary conservation of the function of Dnmt1 during embryogenesis.

Bone regeneration in the presence of a synthetic hydroxyapatite/silica oxide-based and a xenogenic hydroxyapatite-based bone substitute material.

OBJECTIVES: A comparison of synthetic hydroxyapatite/silica oxide, xenogenic hydroxyapatite-based bone substitute materials with empty control sites in terms of bone regeneration enhancement in a rabbit calvarial four non-critical-sized defect model. METHODS: In each of six rabbits, four bicortical calvarial bone defects were generated. The following four treatment modalities were randomly allocated: (1) empty control site, (2) synthetic hydroxyapatite/silica oxide-based (HA/SiO) test granules, (3) xenogenic hydroxyapatite -based granules, (4) synthetic hydroxyapatite/silica oxide -based (HA/SiO) test two granules. The results of the latter granules have not been reported due to their size being three times bigger than the other two granule types. After 4 weeks, the animals were sacrificed and un-decalcified sections were obtained for histological analyses. For statistical analysis, the Kruskal-Wallis test was applied (P<0.05). RESULTS: Histomorphometric analysis showed an average area fraction of newly formed bone of 12.32±10.36% for the empty control, 17.47±6.42% for the xenogenic hydroxyapatite -based granules group, and 21.2±5.32% for the group treated with synthetic hydroxyapatite/silica oxide -based granules. Based on the middle section, newly formed bone bridged the defect to 38.33±37.55% in the empty control group, 54.33±22.12% in the xenogenic hydroxyapatite -based granules group, and to 79±13.31% in the synthetic hydroxyapatite/silica oxide -based granules group. The bone-to-bone substitute contact was 46.38±18.98% for the xenogenic and 59.86±14.92% for the synthetic hydroxyapatite/silica oxide-based granules group. No significant difference in terms of bone formation and defect bridging could be detected between the two bone substitute materials or the empty defect. CONCLUSION: There is evidence that the synthetic hydroxyapatite/silica oxide granules provide comparable results with a standard xenogenic bovine mineral in terms of bone formation and defect bridging in non-critical size defects.

Neutrophil-activating properties of the melanoma growth-stimulatory activity.

Melanoma growth-stimulatory activity (MGSA), a peptide reported to be mitogenic for Hs294T human melanoma cells, has extensive sequence similarity to the neutrophil-activating peptide NAP-1/IL-8, suggesting functional similarities. To test this hypothesis, MGSA was chemically synthesized and tested for its effects on human neutrophils. It was found to induce chemotaxis, exocytosis of elastase, and changes in cytosolic-free calcium to an extent and at concentrations similar to NAP-1/IL-8. However, MGSA was considerably less potent than NAP-1/IL-8 in inducing the respiratory burst. Intradermal injections in rats of MGSA resulted in a massive accumulation of neutrophils. Our data demonstrate that, apart from its growth-stimulatory activity, MGSA is a potent inflammatory agonist with neutrophil-stimulating properties.

Aneurysmal bone cysts of the jaws.

Aneurysmal bone cyst (ABC) is a osteolytic bone lesion that rarely involves the jaws. To date, a total of 92 cases of JABCs have been described in detail in English literature. They prevalently occur in the first 2 decades (72.8%) with slight female predilection. It affects the mandible more often (68.5%) with a predominant location in the mandibular ramus (31.3%) and its posterior regions (20.4%). A painless (54.7%) or painful (43.2%) bone swelling is the most frequent clinical sign. Radiologically 93.8% of the lesions present as a radiolucency; in 69.4% multilocular in appearance. 15.2% of JABCs were secondary in nature, including 8 cases associated with fibrous dysplasia. The recurrence rate (13.3%) did not differ significantly when comparing the surgical technique (curettage, 15.2%; resection, 11.8%). JABCs are known for their different clinical and radiographic features, therefore often posing a diagnostic dilemma. Some JABC's may be secondary in nature. Careful curettage is considered to be suitable as treatment for JABCs.

Quality of life and dyadic adjustment in oral cancer patients and their female partners.

The diagnosis of cancer affects not only the lives of patients, but also the lives of their family members. The purpose of this study was to examine the impact of oral cancer on quality of life (QoL), psychological distress and marital satisfaction in a sample of patients and their wives. Thirty-one men treated for oral cancer (mean time since diagnosis 3.7 years) and their female partners (n = 31) were assessed by questionnaires with regard to QoL (WHOQOL-BREF), anxiety and depression (Hospital Anxiety and Depression Scale, HADS), quality of relationship (Dyadic Adjustment Scale, DAS) and physical complaints (EORTC QOL-H&N35). Quality of life was remarkably high in patients and their partners. In patients, lower QoL was associated with more physical complaints and higher levels of psychological distress (HADS), whereas in wives, QoL was found to be related to marital quality (DAS) and levels of distress. In couples with highly discrepant ratings of marital satisfaction, wives reported more psychological distress. The findings indicate that overall QoL is considerably high in patients treated for oral cancer and their partners living in stable relationships. Quality of life correlates stronger with the quality of relationship in spouses than in patients. Generally, marital satisfaction appears to be an important moderating factor regarding QoL and psychological distress.

Three-dimensional pharyngeal airway changes in dento-skeletal class II patients after two-jaw orthognathic surgery with segmentation - a pilot study.

PURPOSE: To investigate short- and long-term post-surgical three-dimensional changes of pharyngeal airway morphology and hyoid bone position in dento-skeletal class II deformity patients after two-jaw surgery with segmentation. METHODS: Relations between skeletal movement, hyoid bone position and three-dimensional pharyngeal airway changes were retrospectively analyzed on pre- and post-surgical CBCTs in dento-skeletal class II patients who underwent orthognathic two-jaw surgery with segmentation. RESULTS: While long-term significant reductions in length (P= 0.003), surface area (P= 0.042) and volume (P= 0.004) were found in the nasopharynx, the highly significant increases in oropharyngeal airway length, surface area, volume and the minimal cross-sectional area (P < 0.05) prevailed only in the short-term. Although a significant antero-superior movement of the hyoid bone was detected both in short- and long-term follow-up CBCTs (P < 0.05), only its superior, but not the anterior movement was found to be associated with an increased lateral width of the oropharyngeal minimal cross-sectional area. CONCLUSION: Two-jaw orthognathic surgery with segmentations in dento-skeletal class II patients improved oropharyngeal airway parameters significantly in the short-, but not long-term.

Jaw osteonecrosis related to bisphosphonate therapy: a severe secondary disorder.

Bisphosphonate-related osteonecrosis of the jaws (BON), first described in 2003, is gaining importance due to the increasing indication spectrum of bisphosphonate therapy [S. Takeyama, M. Ito, H. Shinoda, A novel bisphosphonate, TRK-530, for periodontitis, Bone 38 (2006) 31-31; M. Tagil, A. W-Dahl, J. Astrand, D. Little, S. Toksvig-Larsen, Decreasing the catabolic response by a single bisphosphonate infusion shortens the healing time in hemicallotasis operations, Bone 38 (2006) 84-85; E. Rodriguez, M.C. Duran, L.M. Rodriguez, R. Ros, M.R. Aleman, M. Rodriguez-Gaspar, A.M. Lopez, E. Garcia-Valdecasas, F. Santolaria, Intravenous (IV) bisphosphonates for osteopenic cancer survivor women: an alternative treatment, Bone 38 (2006) 72-73; D.G. Little, K. Ward, P. Kiely, M.C. Bellemore, J. Briody, C.T. Cowell, Bisphosphonate rescue in distraction osteogenesis: a case series, Bone 38 (2006) 80-80; R. Marx, Pamidronate (Aredia) and zoledronate (Zometa) induced avascular necrosis of the jaws: a growing epidemic, J. Oral Maxillofac. Surg. 61 (2003) 1115-1118]. BON patients suffering from varying bony defects and symptoms are extremely restricted in their quality of life. Due to a limited knowledge of the aetiology of BON efficient evidence-based treatment strategies are lacking. Until now 23 patients with bisphosphonate-related osteonecrosis have been admitted to the Department of Cranio-Maxillofacial Surgery of the University of Zurich. A complete history has been recorded. All patients underwent clinical and radiographic examination. CT scans and MRI have been performed in selected cases. All patients had in common that, before signs of BON were observed, a local traumatic incidence had occurred. All patients showed signs of infection which could be remarkably reduced by antibacterial treatment. Furthermore, the period of bisphosphonate treatment was found to be one of the significant factors causing bisphosphonate-related osteonecrosis of the jaws. The aetiology of BON appears to depend on multiple factors: period and type of bisphosphonate therapy and trauma paving the way for an invasion of pathogens. Because evidence based therapy protocols for complete remodelling of bone defect are still missing, prevention in bisphosphonate-treated patients seems to be of utmost importance. A close interdisciplinary collaboration is required.

[Reported adverse reactions due to veterinary drugs in 2006]. / Gemeldete unerwünschte Wirkungen von Tierarzneimitteln im Jahr 2006.

We received 190 reports of suspected adverse events (SARs) following the use of veterinary drugs for the year 2006: 118 declarations for veterinary drugs and 72 declarations following the application of immunolgical medicinal products. Most of the 118 declarations relate to the use of antiparasitic drugs (48%) and every second declaration to drug use in dogs. Other drug classes concerned were, in decreasing order, antiinfectives (20%) and drugs used off-label (12%; other target species or other indication). For the vaccines, most of the reactions occurred in dogs (62%) followed by horses (11%) and cattle (10%). The most frequently reported reactions concerned the use of a vaccine against piroplasmosis. Another 349 requests for information were processed by the Swiss Toxicological Information center. We also present a case of a serious adverse reaction in form of a Stevens-Johnson syndrome in a cat as well as a case of ketamine abuse. We note the growing interest of practicing veterinarians with pleasure and are currently working on further adaptations to the system.

[Reported adverse reactions of veterinary drugs and vaccines in 2005]. / Gemeldete unerwünschte Wirkungen von Tierarzneimitteln im Jahr 2005.

We received 105 reports of suspected adverse events (SARs) following the use of veterinary drugs for the year 2005. This corresponds to a 35% increase compared to 2004. Practicing veterinarians sent most of these declarations. 73% of these concerned drugs used on companion animals. Antiparasitic drugs approved for topical use were the most frequently represented group with 48%, followed by drugs used to treat gastrointestinal disorders (11%) and drugs used off-label (14%; other target species or other indication). For the first time 2 declarations concerning the application of permethrin containing spot-on preparations used by mistake on cats were received. An overview of 20 declarations about adverse reactions following application of different vaccines is also presented with emphasis on the problem of fibrosarcoma in cats. We are pleased by the growing interest shown by practicing veterinarians for the vigilance system and hope to further develop this collaboration in the future.

Differences in the clinical appearances of white versus black patients with facial cleft deformities: a retrospective study of a South African clinic.

OBJECTIVE: The purpose of this study was to determine the difference in prevalence of the different categories of facial cleft deformities between the white and black patients in a database of 2806 cleft cases at the University of Pretoria. No variation of clefts between these two groups has ever been compared previously. For this purpose, the clefts were classified according to the system described by Bütow in 1985. MATERIAL AND METHODS: Records of 2806 patients attending the university's cleft lip and palate clinic, between August 1983 and February 2006, were reviewed. The study group included cleft patients with syndromic and nonsyndromic CL, CLA, CLAP, hP, hPsP, sP, COMBI clefts with or without oblique or transverse facial (or Tessier) clefts. Very few of the cases presented with speech problems only, but with no clefts. The cleft categories of cleft lip, cleft palate and cleft lip and palate, as well as their subdivisions, were analysed. RESULTS: Of these cleft patients, 2003 were white patients and 665 were black patients; the rest were Indian, Coloured and East-Asian patients. In the black and the white population groups (n = 2668), there were more males with cleft in the white group (58.2%), but more females with clefts in the black group (54.9%). The most common cleft type generally was the cleft lip, alveolus and palate cleft (CLAP) with a 434% prevalence of white patients and 296% of black patients. The most common cleft in the black patients was the cleft palate at 435%, which was only recorded in 35.0% of the white patients. The frequency of the other orofacial clefts in decreasing order was: sP 19.4% for white and 21.2% for black; hPsP 15.2% for white and 21.2% for black; CLA 9.7% for white and 19.8% for black; CL 5.9% for white and 4.5% for black and combinations of different orofacial clefts (COMBI), 6.0% for white and 2.6% for black. The isolated hard palate cleft (hP) occurred very rarely (0.4% for white and 1.1% for black). The left side of the face was more often afflicted (left to right 51.6% to 28.5% for white; and 35.0% to 37.9% for black). In 0.5% (white) and 3.9% (black) median clefts were observed. CONCLUSION: A retrospective study was done of 2806 facial black patients (2668 cases). There was a considerable variation between the groups of orofacial clefts occurring in the two groups.

The galea fascia flap in orbital reconstruction: innovative harvest technique.

AIM: To report the treatment of a recurrent adenoid-cystic carcinoma of the lacrimal gland required orbital exenteration with an en bloc resection of the lateral orbital rim and wall and an anterior portion of the temporal muscle. Reconstruction was planned with both the objectives of a shortened healing time for faster epithetic reconstruction and no visible scars. METHOD: After a cranially extended temporal approach, the dissection of the superficial galea layer was connected with the subcutaneous dissection of the upper and lower eyelid after subciliary incisions. RESULTS: Ample exposure of the temporal, frontal and orbital region was obtained, facilitating the orbital exenteration with en bloc resection of the lateral orbital rim and wall and the anterior portion of the temporal muscle. The epithelialization of the eye socket covered with the galea fascia flap was accelerated, providing faster epithetic reconstruction, without visible scars. CONCLUSIONS: Healing time is accelerated, providing faster epithetic rehabilitation without visible scars, which is important in the postoperative rehabilitation ladder after eye exenteration for both patient and surgeon. Further more ablative surgery within this region gets safer and easier due to the ample exposure of this innovative surgical technique. Further evaluation of the effectiveness and safety of this new approach is advisable.

Clinical experiences with bisphopsphonate induced osteochemonecrosis of the jaws.

QUESTION: Bisphosphonates are frequently used drugs in the adjuvant therapy of bone metastases and tumour-induced hypercalcaemia, but also for osteoporosis or Pagets disease. Several publications within the last three years considered osteonecrosis of the jaws to be connected with bisphosphonate therapy. Until today possible treatment strategies contain antibiotics, hyperbaric therapy and operative treatment. The tendency of healing however seems to be extremely poor. All clinicians should be aware of this new kind of side effect of bisphosphonate therapy. METHODS: 14 patients with this new kind of osteonecrosis were admitted to the department of Cranio-Maxillofacial Surgery of the University Hospital of Zurich. 8 men and 6 women all received bisphosphonates for cancer therapy. A complete analysis of patients' data was performed. RESULTS: Of 14 patients in 7 the underlying disease disease was multiple myeloma. In one patient it was prostate cancer and in all female patients it was breast cancer. All of them had prior dental treatment and showed inflammatory signs and bacterial colonisation with localisation in the upper or lower jaw or in both. CONCLUSION: The infectious part of the bisphosphonate-induced osteonecrosis (ONJ) is considered to be more important than thought before. We presume that antimicrobial treatment is of utmost importance in the treatment of this kind of osteonecrosis. Patients with current or previous bisphosphonate therapy should be treated multidisciplinary to assure ideal prevention and treatment.

Neutrophil accumulation and plasma leakage induced in vivo by neutrophil-activating peptide-1.

Neutrophil accumulation and plasma leakage induced in rabbit skin by neutrophil-activating peptide-1 (NAP-1, a 72 amino acid peptide produced by monocytes and a variety of tissue cells), E. coli endotoxin, and interleukin-1 (IL-1) were compared. Neutrophil accumulation at sites injected with NAP-1 was intense, rapid, and long-lasting; it reached a maximum rate during the first 30 min, continued at constant rate for 4-6 h, and remained detectable up to at least 8 h. In contrast, the neutrophil-attracting effect of endotoxin and IL-1 was slower in onset and more transient; it peaked in the first 2 h and declined to a very low level after 4 h. Plasma leakage induced by NAP-1 had a shorter time course than neutrophil accumulation and ceased after 6 h. Depletion of blood neutrophils by treatment with hydroxyurea prevented the plasma leakage induced by NAP-1 or endotoxin but not by histamine. Desensitization to NAP-1 was studied by restimulation of lesions. Following restimulation with NAP-1 after intervals from 6-10 h, there was diminished infiltration of neutrophils, while nearly normal responses were obtained after an interval of 24 h. Desensitization was dose dependent and affected both plasma leakage and neutrophil accumulation. In lesions initiated with NAP-1 there were normal responses following restimulation with endotoxin but marked desensitization to IL-1, suggesting that NAP-1 may contribute to inflammation induced by IL-1 but not by endotoxin. This study indicates that NAP-1 is a potent mediator of neutrophil accumulation in vivo, with characteristics similar to those reported for C5 fragments, but with a more protracted action.

Fc receptor expression, concanavalin A capping, and enzyme content of bovine neonatal neutrophils: a comparative study with adult cattle.

The increased susceptibility of newborns to infection may in part be related to impaired in vitro functions of neonatal polymorphonuclear neutrophils (PMNs). To evaluate early steps in the activation cycle of bovine PMNs we determined the expression of Fc receptors (FcRs) with an erythrocyte rosetting assay utilizing bovine anti-sheep immunoglobulin G2 IgG2 and the accumulation of ligand receptor complexes or "caps" with fluorochrome-coupled concanavalin A (Con A caps) on neutrophils from adult (A-PMN) and newborn (N-PMN) bovines. In addition, the levels of myeloperoxidase (MPO) and alkaline phosphatase (AP) were determined. FcR expression is reduced in N-PMNs (P less than .001), in contrast to results observed with human N-PMNs. Basal capping of Con A binding sites is reduced (P less than .05) in N-PMNs but is enhanced (P less than .001) upon pretreatment with colchicine (0.5, 5.0, and 50.0 microns). These findings are again contrary to results observed with human N-PMNs. Consistent with findings in human neonates, however, are reduced levels of cellular MPO (P less than .05) and elevated cellular AP (P less than .001) in the neonate. The functional significance of elevated AP levels and altered Con A capping in N-PMNs is unclear. However, diminished expression of FcR could potentially contribute to impaired adherence and phagocytosis of bacteria, and reduced activity of neutrophil MPO could indicate weaker microbicidal capacity of neonatal cells. The demonstrated impairment of N-PMN functions could potentially contribute to reducing the effectiveness of the cellular host defense system in neonatal calves.

Increased adhesiveness of complement-stimulated neonatal calf neutrophils and its pharmacologic inhibition.

Several in vitro functions of neonatal neutrophils (N-PMN) have been reported to be deficient and may be functionally related to the increased susceptibility of the newborn to infection. To evaluate an in vitro event corresponding to one of the early steps in the sequence of inflammation, we used zymosan-activated plasma as a source of activated complement fragments (Cf) and measured adherence of normal and Cf-stimulated bovine N-PMN to columns of Sephadex G-25. Adherence of control N-PMN and adult PMN (A-PMN) was comparable. When N-PMN and A-PMN were stimulated with a subaggregating dose of Cf, both responded with similar increases in adhesiveness. The stimulatory effect of Cf on N-PMN adhesiveness could be inhibited by pre-incubation of the N-PMN with either steroidal (0.05 mM dexamethasone) or non-steroidal (32 mM phenylbutazone) anti-inflammatory drugs. Ultrastructural observations correlated well with the results of the adhesiveness assays, and morphometric evaluation revealed an increase in the sectional circumference of Cf-stimulated N-PMN. Control cells were round with few short cytoplasmic projections, whereas Cf-stimulated cells exhibited marked shape irregularity, polarity, and prominent organelle-free lamellipodia development. There was a highly significant (P less than 0.001) increase in the measured circumference of Cf-stimulated cells. Thus, N-PMN were highly responsive to Cf stimulation, developed morphologic and functional changes indistinguishable from Cf-stimulated A-PMN, and were sensitive to pharmacologic inhibition.

[Suspected adverse drug reactions in 2004]. / Meldungen zu unerwünschten Wirkungen von Tierarzneimitteln im Jahr 2004.

We received 62 reports of suspected adverse events (SARs) for the year 2004. Their number and repartition according to affected animals and active substances were comparable with the previous year. The distributors or manufacturers submitted most of the declarations, but the proportion submitted by practicing veterinarians is slowly growing. 72% of the declarations dealt with adverse reactions in small animals (cats and dogs), followed by cattle and horses. Antiparasitics, anti-inflammatory drugs and immunologicals were the most frequently mentioned therapeutic classes, which are listed here according to the international ATCvet classification. A report from abroad about a fatality following injection of an antibiotic preparation for cattle prompted Swissmedic to review the security of this medication also sold on the Swiss market. It was decided to modify the package insert to warn about the danger of inadvertent self-injection in humans, to reduce the risk of similar accidents in Switzerland. We hope that the pharmacovigilance system will enjoy an increasing awareness by the practicing veterinarians.

[The locomotor activity of the squirrel (Sciurus vulgaris)]. / Die lokomotorische Aktivität des Eichhörnchens (Sciurus vulgaris).

The locomotor activity of Sciurus vulgaris has been observed in the field and in caged animals.Onset and cessation of activity (data from the cage only): Activity starts before sunrise and correlation with sunrise is very high (0.838≤r≤0.990). Cessation of activity normally lies before sunset, during summer late in the afternoon, in winter often already before noon. It is scatterd to a greater extent than onset of activity, correlation with sunset being 0.535≤r ≤0.798.Daily pattern: It is a bigeminus, although widely subject to seasonal variations. The afternoon peak is lacking from November till February, begins to form in March and reaches as much as 33.5% of total activity in September. The pause occurring at noon is most distinct during summer and vanishes gradually during the autumn months. Data from the field and from the cage show essentially the same pattern.Annual pattern: In the cage, activity is least during winter, increases gradually to a maximum in September followed by a sharp decrease to the winter minimum. The curve derived from the field observations shows a bimodal shape with a first peak in April and a second, more distinct one in September. A combination of the two groups of data shows three phases: December to May with irregular variations, May to September showing a conspicuous increase to maximal activity, September to December with sharp decrease to the winter minimum.

Chemotactic competence of neutrophils from neonatal calves. Functional comparison with neutrophils from adult cattle.

Neonates demonstrate an increased susceptibility to infection. Defects in locomotory functions of newborn neutrophils may play a crucial role in this context. We therefore compared the migratory response of newborn (N-PMN) and adult (A-PMN) bovine neutrophils in a microwell filter assay. Stimulation with four different endotoxins (E. coli O128B:4 and O55B:5; S. abortus equi; S. typhimurium), with zymosan-activated plasma (ZAP) and with C5a induced dose-dependent migration of A-PMNs and N-PMNs. Migration of unstimulated cells and of cells stimulated with diluted ZAP or C5a was higher (P less than 0.05) in N-PMNs. Migration of A- and N-PMNs towards C5a was inhibited (P less than 0.001) by preincubation with either a steroidal (122 microM flumethasone) or nonsteroidal (3.3 microM phenylbutazone) antiinflammatory drug. Migratory responses of N-PMNs were inhibited less by SAIDs than were responses of A-PMNs (P less than 0.05); indeed dexamethasone slightly enhanced N-PMN responses towards C5a, and 510 microM flunixin meglumine enhanced C5a-induced migration in both age groups. Endotoxins from E. coli O55:B4, S. abortus equi, and S. typhimurium induced a higher rate of migration (P less than 0.05) in N-PMNs. In contrast to the above findings, measurement of the maximal distance of migration by the leading-front method did not reveal age-related differences. Migration speed of PMNs was lower after stimulation with C5a than with ZAP, but could be restored partly by adding human vitamin D-binding protein (Gc-globulin). The demonstrated hyperirritability of bovine N-PMNs represents a major functional difference to neonatal neutrophils from other species, including man. It may additionally be related to altered PMN functions and neonatal disease susceptibility.

In vitro aggregation of bovine neonatal neutrophils. A comparative study with adult cattle.

Deficient in vitro functions of neonatal neutrophils have been reported in various species. They may be functionally related to the well-known susceptibility of newborn individuals to microbial infections. To evaluate an early step in the sequence of neutrophil activation, neutrophils from adult cows (A-PMN) and newborn calves (N-PMN) were stimulated with zymosan-activated plasma (ZAP) or with the lipid mediator platelet-activating factor (PAF): Aggregation was recorded kinetically in a standard aggregometer and measured quantitatively as the area under the aggregation curve (AUAC). The mean +/- SEM of the AUAC of the first 2.5 min of the reaction induced with ZAP was similar in N-PMN and A-PMN. However, N-PMN deaggregated only partially, whereas A-PMN deaggregated almost completely (P less than 0.05). This may indicate a mechanism of microvascular sequestration in vivo with the potential to inhibit chemotaxis. PAF (10(-5)-10(-10) M) aggregated N- and A-PMNs similarly and dose-dependently with a maximal reaction at 10(-6) M. Inhibition of aggregation induced by 10(-6) M PAF was evaluated by preincubation with four antiinflammatory drugs: dexamethasone (Dex: 5.1, 51.0, 510.0 microM), flumethasone (Flu: 12.2 and 122.0 microM), phenylbutazone (PB: 0.33 and 3.3 mM), and flunixin meglumine (Flxin: 51 and 510 microM). Dex and Flu each inhibited (P less than 0.05) PAF-induced N-PMN aggregation at the highest dose, and A-PMN aggregation at the two higher doses. PB and Flxin each inhibited aggregation of N- and A-PMNs at all doses used. We compared the inhibition rate in both age groups and could demonstrate that Dex, Flu, and Flxin each at the highest dose, and PB at all doses used, inhibited PAF-induced aggregation less (P less than 0.05) in N-PMNs than in A-PMNs. These functional differences indicate hyperirritability of N-PMNs, and they need further elucidation to help understand mechanisms of increased neonatal susceptibility.