A cost-benefit analysis of foot and mouth disease control program for smallholder cattle farmers in Cambodia.

The Cambodian government is attempting to mobilise government, donor and private sector funding to implement a coordinated FMD vaccination program (FMDVP). A necessary first step is to convince the farmers of the benefits of participating in and potentially financially supporting this program. Information was collected from 300 farmers in order to estimate the on-farm benefits and costs of their participation in an FMDVP. Implementing a successful vaccination program is difficult, and farmers understand from previous experience that there may be institutional, social, technical and financial constraints which limit its success. A benefit-cost analysis needs to take into account that outbreaks do not occur every year, not all cattle will be successfully vaccinated, not all sick animals successfully treated and sometimes sick animals simply sold. This study sensitises these variables in order to give a realistic estimation of the farmer participation benefits in an FMDVP. A general result is that it is worthwhile for farmers to participate in the FMDVP if there are average annual outbreaks, or at least two major outbreaks, in the ensuing 5 years. However, the results are influenced by the interaction of vaccination success and treatment success and coverage. Ineffective coverage and poor treatment of sick animals reduce the benefits of an FMDVP. It is also important that farmers do not sell sick stock and, if they do, that they are able to breed replacements rather than purchase replacements. There are many factors in the smallholder cattle farming system that will influence the success of an FMDVP; farmers will only choose to participate if they can be convinced of the short and long-term economic benefits.

Histological evaluation of combined platelet-rich fibrin membrane and piezo-incision application in orthodontic tooth movement.

The aim of this study was to evaluate the effect of platelet-rich fibrin (PRF) membrane on tooth movement in comparison with shunt control and piezoelectric surgery. Sixteen White Vienna rabbits were included in the study and divided into two groups. Reciprocal forces (20 g) were applied on the maxillary incisors by an orthodontic appliance. In group 1, PRF membrane was placed sub-periosteally on the distal alveolar bone surface of the right central incisors and the left side was kept as control. In group 2, piezo-incisions 3 mm in depth were performed and combined with PRF membrane on the distal alveolar bone surface of the right central incisors, while the left side was kept as control. All rabbits were euthanized on day 21 and bilateral alveolar bone segments from the distal regions were removed for histological evaluation. Isolated PRF membrane application increased the blood vessel (8.3 ± 1.0; P = 0.026), osteoblast (6 ± 0.8; P = 0.027), and osteoclast (2.3 ± 0.8; P = 0.026) counts significantly compared to shunt control. Combined application of PRF membrane + piezo-incision increased the blood vessel (15.3 ± 0.8; P = 0.027), osteoblast (9.8 ± 1.4; P = 0.026), and osteoclast (3.3 ± 0.8; P = 0.024) counts significantly compared to shunt control. The increases in blood vessel count and osteoblast cell count were more evident in the combined application group (both P = 0.002). PRF membrane application significantly increased bone turnover, and the combined application of PRF membrane + piezo-incision was found to be the best method for increasing bone turnover.

Effect of ruminal administration of Escherichia coli wild type or a genetically modified strain with enhanced high nitrite reductase activity on methane emission and nitrate toxicity in nitrate-infused sheep.

The effects of two kinds of Escherichia coli (E. coli) strain, wild-type E. coli W3110 and E. coli nir-Ptac, which has enhanced NO(2) reduction activity, on oral CH(4) emission and NO(3) toxicity in NO(3)-treated sheep were assessed in a respiratory hood system in a 4 x 6 Youden square design. NO(3) (1.3 g NaNO(3)/kg(0.75) body weight) and/or E. coli strains were delivered into the rumen through a fistula as a single dose 30 min after the morning meal. Escherichia coli cells were inoculated for sheep to provide an initial E. coli cell density of optical density at 660 nm of 2, which corresponded to 2 x 10(10) cells/ml. The six treatments consisted of saline, E. coli W3110, E. coli nir-Ptac, NO(3), NO(3) plus E. coli W3110, and NO(3) plus E. coli nir-Ptac. CH(4) emission from sheep was reduced by the inoculation of E. coli W3110 or E. coli nir-Ptac by 6 % and 12 %, respectively. NO(3) markedly inhibited CH(4) emission from sheep. Compared with sheep given NO(3) alone, the inoculation of E. coli W3110 to NO(3)-infused sheep lessened ruminal and plasma toxic NO(2) accumulation and blood methaemoglobin production, while keeping ruminal methanogenesis low. Ruminal and plasma toxic NO(2) accumulation and blood methaemoglobin production in sheep were unaffected by the inoculation of E. coli nir-Ptac. These results suggest that ruminal methanogenesis may be reduced by the inoculation of E. coli W3110 or E. coli nir-Ptac. The inoculation of E. coli W3110 may abate NO(3) toxicity when NO(3) is used to inhibit CH(4) emission from ruminants.

Effects of yeast culture and galacto-oligosaccharides on ruminal fermentation in holstein cows.

Four nonlactating, ruminally cannulated Holstein cows were used in a 4 x 4 Latin square design, balanced for residual effects, to evaluate the effects of supplementing dairy cow diets with yeast culture (Trichosporon sericeum; YC), galacto-oligosaccharides (GOS), or the mixture of YC and GOS on ruminal fermentation, microbial N supply, in situ degradation, and energy and nitrogen metabolism. Treatments were arranged in a 2 x 2 factorial as follows: 1) basal diet, 2) basal diet plus 10 g/d YC, 3) basal diet plus 2% GOS, 4) basal diet plus a mixture of 10 g/d YC and 2% GOS. Nitrogen losses in urine were lower, and retained N was higher, for cows supplemented with a mixture of YC and GOS. Ruminal pH was lower in cows supplemented with GOS alone compared with other treatments. Total VFA concentration was higher in cows fed control and GOS-supplemented diets than in those fed YC containing diets. The molar proportion of propionate was higher, and the molar proportion of acetate was lower, in cows fed control diets. Microbial N supply was higher in cows fed control diets. There were no major positive effects of supplements observed in this study. However, supplementation of a mixture of YC and GOS had a tendency for synergistic effects on N metabolism and in situ degradation of a soluble fraction of oat straw DM and CP of concentrates compared with supplementation of YC or GOS alone.

Effect of Escherichia coli wild type or its derivative with high nitrite reductase activity on in vitro ruminal methanogenesis and nitrate/nitrite reduction.

The effects of two kinds of Escherichia coli strains, wild-type E. coli W3110 or E. coli nir-Ptac, which has enhanced nitrite reduction activity, on in vitro CH4 production and nitrate and nitrite reduction in cultures of mixed ruminal microorganisms was investigated using continuous incubation systems. Escherichia coli nir-Ptac, a derivative of wild-type E. coli W3110, was constructed by replacing self promoter of nir BD operon encoding subunits of nitrite reductase in E. coli W3110 by tac promoter to make the expression of nir BD higher and constitutive. The nitrite reductase activity of E. coli nir-Ptac was approximately twice as high as E. coli W3110. The culture media consisted of 400 mL of strained ruminal fluid taken from two nonlactating Holstein cows receiving a basal diet of orchardgrass hay at maintenance level (55 g of DM/kg of BW0.75 daily), and 400 mL of autoclaved artificial saliva. Treatments were arranged in two separate 3 x 3 factorials consisting of nitrate (NaNO3; 0, 5, or 10 mM) without E. coli or inoculated with E. coli W3110 or E. coli nir-Ptac, or nitrite (NaNO2; 0, 1 or 2 mM) without E. coli or inoculated with E. coli W3110 or E. coli nir-Ptac. The control culture contained no chemical or microbial additives. Escherichia coli cells were inoculated into in vitro mixed ruminal cultures at approximately 2 x 10(8) to 10(9) cells/mL. Methane production by ruminal microorganisms was decreased markedly (P < 0.001) by the addition of nitrate and nitrite, and by the inoculation of cultures with E. coli W3110 or E. coli nir-Ptac (P < 0.01). With mixed nitrite-containing cultures, E. coli nir-Ptac inhibited (P < 0.001) in vitro nitrite accumulation and CH4 production more than E. coli W3110, which may be due to the tac promoter-enhanced nitrite reductase activity of E. coli nir-Ptac accelerating electrons to be consumed for nitrite reduction rather than CH4 biosynthesis. In conclusion, anaerobic cultures of E. coli W3110 or E. coli nir-Ptac may decrease CH4 production in the rumen. The inoculation of E. coli W3110 or, especially, E. coli nir-Ptac to mixed ruminal microorganisms may decrease nitrite toxicity when ruminants consume high-nitrate-containing forages and when nitrite is applied to abate ruminal CH4 production.

Transoral resection and reconstruction for primary osteogenic sarcoma of the second cervical vertebra.

STUDY DESIGN: A case of primary osteogenic sarcoma at the second cervical vertebra is reported. OBJECTIVES: To document an osteogenic sarcoma of the second cervical vertebra and its treatment, and to review the literature. SUMMARY OF BACKGROUND DATA: Primary osteosarcoma of the cervical spine is encountered infrequently, and its location in the upper cervical spine is extremely rare. Two cases of osteosarcoma in the second cervical vertebra have been reported previously in the literature. METHODS: A 15-year-old boy with a mass lesion in the axis was treated surgically by anterior transoral resection, fusion, and reconstruction of the defect with a Harms cage. The resection was completed by posterior excision of the remaining vertebral elements, and by occipitocervical instrumentation and fusion between the occiput and the fourth cervical vertebra. The therapy was completed by adjuvant chemotherapy and radiotherapy. RESULTS: At this writing, 40 months after the initial diagnosis, the patient was in a good state of health with his underlying disease. CONCLUSIONS: The axis is a very rare location for the occurrence of primary osteosarcoma. Osteosarcoma may histologically mimic chondroblastoma. The axis can be surgically exposed, resected, and instrumented transorally. The stabilization must be augmented by posterior occipitocervical fusion.

Surgical treatment of distal intraarticular humeral fractures in adults.

We reviewed 17 patients with distal intraarticular humeral type C fractures, treated by open reduction and internal fixation, followed by an early rehabilitation programme. The results, as judged by the criteria of Jupiter, were excellent in ten, good in five and fair in two. Non-union of the olecranon osteotomy occurred in one patient.

Anterior instrumentation for adolescent idiopathic scoliosis.

Thirty-two patients with adolescent idiopathic scoliosis underwent anterior fusion with rigid single rod (third generation instrumentation) and titanium mesh cages. The mean follow-up was 31 (24-45) months and the mean age was 14.9 years. There were 8 patients with King type I, 10 with type II, 6 with type III, 4 with type IV and 4 with lumbar curves. Titanium mesh cages were used in all the lumbar procedures and at the cranial and caudal ends of the instrumented area in thoracic cases. All the patients were immobilized in an orthosis for 3-6 months postoperatively. Mean preoperative primary coronal Cobb angle of 56 degrees was improved to 8.6 degrees. Average correction rate was 84%. Sagittal balance was restored with a mean thoracic kyphosis of 28 degrees and a mean lumbar lordosis of 38 degrees. Spontaneous secondary curve decompensation did not occur and postoperative thoracolumbar junctional kyphosis was not seen. One case had to be revised due to proximal screw pull out and loss of correction.

An anterior approach to the cervicothoracic junction of the spine (modified osteotomy of manubrium sterni and clavicle).

Standard anterior approaches to the cervicothoracic junction of the spine provide inadequate exposure. For this reason, various techniques of exposure are developed. One of these is Sundaresan's technique in which a part of the manubrium sterni and medial clavicle is resected. This technique provides good visibility and working area at the lesion level but causes a significant bony defect. We modified Sundaresan's technique and did not damage the sternoclavicular joint. After decompression and fusion was completed, the osteotomized segment was replanted. We performed this technique in a case of Pott's disease and had no problem with union at the osteotomy sites.

Studies of structure-activity relationship of nitroxide free radicals and their precursors as modifiers against oxidative damage.

The protective effects of stable nitroxides, as well as their hydroxylamine and amine precursors, have been tested in Chinese hamster V79 cells subjected to H2O2 exposure at fixed concentration or exposure to ionizing radiation. Cytotoxicity was evaluated by monitoring the viability of the cells assessed by the clonogenic assay. The compounds tested at fixed concentration varied in terms of ring size, oxidation state, and ring substituents. Electrochemical studies were carried out to measure the redox midpoint potentials. The studies show that in the case of protection against H2O2 exposure, the protection was determined by the ring size, oxidation state, and redox midpoint potentials. In general the protection factors followed the order nitroxides > hydroxylamines > amines. Both the six-membered ring nitroxides and substituted five-membered ring nitroxides were efficient protectors. For six-membered ring nitroxides, the compounds exhibiting the lowest midpoint potentials exhibited maximal protection. In the case of X-radiation, nitroxides were the most protective though some hydroxylamines were also efficient. The amines were in some cases found to sensitize the toxicity of aerobic radiation exposure. The protection observed by the nitroxides was not dependent on the ring size. However, the ring substituents had significant influence on the protection. Compounds containing a basic side chain were found to provide enhanced protection. The results in this study suggest that these compounds are novel antioxidants which can provide cytoprotection in mammalian cells against diverse types of oxidative insult and identify structural determinants optimal for protection against individual types of damage.

Synthesis of alpha-aryl N-adamant-1-yl nitrones and using them for spin trapping of hydroxyl radicals.

alpha-Aryl N-adamant-1-yl nitrones were synthesized and evaluated with respect to the stability of the hydroxyl radical adduct. The polarity and water solubility of nitrones were altered with changing the alpha-aryl groups. Introduction of adamantane ring instead of tert-butyl group resulted in a reasonable good stability of hydroxyl radical adduct for biological measurements.

A novel electron paramagnetic resonance spin label and its application to study the cross-bridge cycle.

We have used a novel alpha-iodoketone spin-label (IKSL) to study myosin head orientation and cross-bridge dynamics in the putative pre-powerstroke state. Possible perturbation of the cross-bridge cycle by the label was assayed by the sinusoidal analysis method (Kawai and Brandt, 1980; Kawai and Zhao, 1993), which determines the rate constants of the elementary steps in the cycle. A comparison of the rates obtained from unlabeled and IKSL fibers revealed small (10-20%) changes in the ATP hydrolysis rate and in the rate constants of the elementary steps. The labeling induced small changes (< 13%) in the distribution of the cross-bridges among the various intermediate states. Pre-powerstroke cross-bridges were induced by aluminum fluoride in the presence of Ca2+ and ATP. In this state, force development is inhibited, but a large proportion (40%) of the cross-bridges are still attached to the thin filament. We have used conventional electron paramagnetic resonance to measure orientation, and have found that the pre-powerstroke heads are as disordered as in relaxation. Their mobility, as determined by saturation transfer electron paramagnetic resonance, was significantly restricted. Assuming that stiffness is proportional to the fraction of strongly attached heads, the rotational correlation time of the bound heads is estimated to be tau r = approximately 150-400 microseconds.

Myosin catalytic domain flexibility in MgADP.

Conventional EPR studies of muscle fibers labeled with a novel alpha-iodoketo spin label at Cys-707 of the myosin head revealed substantial internal domain reorganization on the addition of ADP to rigor fibers. The spin probes that are well-ordered in the rigor state become disordered and form two distinct populations. These orientational changes do not correspond to rotation of the myosin catalytic domain as a whole because other probes (maleimide and iodoacetamide nitroxides attached to the same Cys-707 of myosin head) report only a small (5-10 degrees) torsional rotation and little or no change in the tilt angle [Ajtai et al. (1992) Biochemistry 31, 207-17; Fajer (1994) Biophys. J. 66, 2039-50]. In the presence of ADP, the labeled domain becomes more flexible and executes large-amplitude microsecond motions, as measured by saturation-transfer EPR with rates (tau r = 150 microseconds) intermediate between the rotations of detached (tau r = 7 microseconds) and rigor heads (tau r = 2500 microseconds). This finding contrasts with an absence of global motion of the myosin head in ADP (tau r = 2200 microseconds) as reported by the maleimide spin label. Our results imply that the myosin head in a single chemical state (AM.ADP) is capable of attaining many internal configurations, some of which are dynamic. The presence of these slow structural fluctuations might be related to the slow release of the hydrolysis products of actomyosin ATPase.