Direct evidence of H7N7 avian influenza virus mutation from low to high virulence on a single poultry premises during an outbreak in free range chickens in the UK, 2008

H5 and H7 subtypes of low pathogenicity avian influenza viruses (LPAIVs) have the potential to evolve into highly pathogenic avian influenza viruses (HPAIVs), causing high mortality in galliforme poultry with substantial economic losses for the poultry industry. This study provides direct evidence of H7N7 LPAIV mutation to HPAIV on a single poultry premises during an outbreak that occurred in June 2008 in free range laying hens in Oxfordshire, UK. We report the first detection of a rare di-basic cleavage site (CS) motif (PEIPKKRGLF), unique to galliformes, that has previously been associated with a LPAIV phenotype. Three distinct HPAIV CS sequences (PEIPKRKKRGLF, PEIPKKKKRGLF and PEIPKKKKKKRGLF) were identified in the infected sheds suggesting molecular evolution at the outbreak premises. Further evidence for H7N7 LPAIV preceding mutation to HPAIV was derived by examining clinical signs, epidemiological descriptions and analysing laboratory results on the timing and proportions of seroconversion and virus shedding at each infected shed on the premises. In addition to describing how the outbreak was diagnosed and managed via statutory laboratory testing, phylogenetic analysis revealed reassortant events during 2006-2008 that suggested likely incursion of a wild bird origin LPAIV precursor to the H7N7 HPAIV outbreak. Identifying a precursor LPAIV is important for understanding the molecular changes and mechanisms involved in the emergence of HPAIV. This information can lead to understanding how and why only some H7 LPAIVs appear to readily mutate to HPAIV.

Detection of endogenous and antibody-conjugated alkaline phosphatase with ELF-97 phosphate in multicolor flow cytometry applications

BACKGROUND

The fluorogenic alkaline phosphatase (AP) substrate 2-(5'-chloro-2'-phosphoryloxyphenyl)-6-chloro-4-(3H)-quinazolinone (ELF(R)-97 phosphate, for Enzyme-Labeled Fluorescence) has been used primarily in microscope-based imaging applications to detect endogenous AP activity, antigens and various ligands in cells and tissues, and nucleic acid hybridization. In a previous study, we demonstrated the applicability of ELF-97 phosphate for detecting endogenous AP activity by flow cytometry. In this study, we show that the spectral characteristics and high signal-to-noise ratio provided by the ELF-97 phosphate make it a useful label for immunodetection via flow cytometry. It can be combined with a variety of other fluorochromes for multiparametric flow cytometry analysis of both endogenous AP activity and intracellular and extracellular immunolabeling with AP-conjugated antibodies.

METHODS

ELF-97 phosphate detection of endogenous AP activity in UMR-106 rat osteosarcoma cells was combined with intracellular antigen detection using Oregon Green 488 dye-conjugated secondary antibodies and DNA content analysis using propidium iodide (PI) or 7-aminoactinomycin D (7-AAD). ELF-97 phosphate detection of endogenous AP was also tested for spectral compatibility with a variety of other commonly used fluorochromes. ELF-97 phosphate was then used to directly label intracellular antigens via AP-conjugated antibodies, again combined with the analysis of DNA content using PI and 7-AAD. ELF-97 phosphate was also used to directly detect extracellular antigens. It was combined with Oregon Green 488 dye, phycoerythrin (PE), and PE-Cy5 dye-labeled antibodies for simultaneous four-color analysis. All samples were analyzed on a dual-beam flow cytometer, with UV excitation of the ELF-97 alcohol reaction product.

RESULTS

Application of the ELF-97 phosphate to detect AP was found to be compatible with immunodetection and DNA staining techniques. It was also spectrally compatible with a variety of other fluorochromes. Endogenous AP activity could be detected simultaneously with both intracellular antigens labeled using Oregon Green 488 dye, PE, Cy5 dye and Alexa Fluor 568 dye-conjugated antibodies, and DNA content analysis with PI or 7-AAD. This multiparametric assay accurately delineated the distribution of AP in cycling cells and was able to identify cell subsets with varying endogenous AP levels. The ELF-97 alcohol reaction product was found to be an effective label for intracellular antigen immunolabeling with AP-conjugated reagents, and could also be combined with PI and 7-AAD. ELF-97 phosphate was also found to be a useful label for extracellular antigen immunolabeling with AP conjugates, and was compatible with Oregon Green 488 dye, PE, and PE-Cy5 dye-labeled antibodies for four-color surface labeling with minimal spectral overlap and color compensation.

CONCLUSIONS

ELF-97 phosphate was shown to be a useful label for both endogenous and antibody-conjugated AP activity as detected by flow cytometry. Its spectral characteristics allow it to be combined with a variety of fluorochromes for multiparametric analysis. Cytometry 43:117-125, 2001. Published 2001 Wiley-Liss, Inc.

A modified lateral approach for release of posttraumatic elbow flexion contracture

A modified lateral approach for release of posttraumatic flexion contracture of the elbow is described. The approach is a modification of the procedure described by Nirschl for resection and repair of lateral elbow tendinosis (tennis elbow). The modified approach allows visualization of the entire anterior elbow joint without disturbing the common extensor origin or the collateral ligaments. If necessary, a second, posterior triceps-splitting incision is used to access the olecranon fossa. Twelve consecutive patients were treated from 1988 to 1992. Mean flexion/deformity, which measured 41 degrees before operation, measured 8 degrees immediately after operation. The mean flexion/extension arc measured 70 degrees before operation and improved to 117 degrees after operation. With an average follow-up of 36.5 months, mean flexion contracture was 11 degrees and the mean flexion/extension arc of motion was 114 degrees. In no case was a medial approach or transhumeral perforation required. All patients were treated after operation with the elbow splinted in extension for 3 days, after which they were started on an aggressive physical therapy regimen. There were no wound complications, no neurovascular injuries, and no formations of heterotopic bone.

Permanent anatomic closure of the ductus arteriosus in newborn baboons: the roles of postnatal constriction, hypoxia, and gestation

Permanent closure of the ductus arteriosus requires loss of cells from the muscle media and development of neointimal mounds, composed in part of proliferating endothelial cells. We hypothesized that postnatal ductus constriction produces hypoxia of the inner vessel wall; we also hypothesized that hypoxia might lead to cell death and the production of vascular endothelial cell growth factor (VEGF), a hypoxia-inducible growth factor that stimulates endothelial proliferation. We mapped the distribution of hypoxia in newborn baboons and correlated it with the appearance of cell death (TUNEL technique), VEGF expression, and endothelial proliferation (proliferating cell nuclear antigen expression). In the full-term baboon (n=10), the ductus was functionally closed on Doppler examination by 24 h after delivery. Regions of the ductus where the lumen was most constricted were associated with moderate/intense hypoxia; VEGF expression was increased in the hypoxic muscle media, and luminal endothelial cells, adjacent to the hypoxic media, were proliferating. Cells in the most hypoxic regions of the ductus wall were undergoing DNA fragmentation. In contrast, regions of the ductus with mild degrees of hypoxia had no evidence of cell death, VEGF expression, or endothelial proliferation. Cell death and endothelial proliferation seemed to be limited to regions of the full-term ductus experiencing moderate/intense hypoxia. In the premature baboon (67% gestation) (n=24), only 29% closed their ductus by Doppler examination before d 6. None of the premature baboons, including those with a closed ductus by Doppler, had evidence of moderate/intense hypoxia; also, there was no evidence of cell death, VEGF expression, endothelial proliferation, or neointima formation by d 6. Therefore, the premature ductus is resistant to developing hypoxia, even when its lumen is constricted; this may make it susceptible to later reopening.

Canarypox virus-mediated interleukin 12 gene transfer into murine mammary adenocarcinoma induces tumor suppression and long-term antitumoral immunity

The antitumoral activity of recombinant canarypox virus vectors (ALVAC) expressing murine interleukin 12 (IL-12) was evaluated in the syngeneic, nonimmunogenic murine mammary adenocarcinoma model (TS/A). Seven-day preestablished subcutaneous tumors (5- to 6-mm mean diameters) were injected on days 7, 10, 14, 17, 21, and 24 with the vector ALVAC-IL12 at 2.5 x 10(5) TCID50 (50% tissue culture infective dose). Total tumor regression occurred in 40 to 50% of the treated mice. Furthermore, 100% of the cured mice were protected against a contralateral subsequent challenge with the TS/A parental cells on day 28. The ALVAC-IL12 treatment is not effective in nude mice, suggesting the critical role of T cells. CD4 and CD8 T cells infiltrated the tumors treated with ALVAC-IL12 in the BALB/c model. Furthermore, in vivo depletion of CD4+ T cells totally abrogated the induction of the long-term antitumoral immune response by ALVAC-IL12. Interestingly, some tumor growth inhibition was also observed with ALVAC-betaGal treatment and a vaccinal effect was found in 33% of the treated animals, suggesting an adjuvant effect of the vector itself. Other ALVAC vectors expressing murine cytokines (IL-2, GM-CSF, IFN-gamma) were evaluated in the same model. Major antitumoral activity was observed with ALVAC-GM-CSF. However, a combination of ALVAC-GM-CSF and ALVAC-IL12 had no synergistic effect. These results suggest that in vivo gene transfer with canarypox virus expressing IL-12 may provide an effective and safe strategy for the treatment of human cancers.

Heart health: treatment

Coronary heart disease (CHD) is the single most common cause of death in England and it has been estimated that about 26 per cent of all deaths each year are caused by CHD (Department of Health 1993). In light of this, it is important that all nurses understand the current investigations and treatment available for people with CHD.

Cardiology. Cardiomyoplasty

Cardiac transplantation is an excellent surgical option that offers positive results for many patients with end stage heart failure (Large 1995). However, the availability of donor hearts does not meet the demand, resulting in the exclusion of patients who, for example, are more than 60 years old and for whom transplantation is contraindicated. Dynamic cardiomyoplasty has been developed to help such a client group.

The effect of prosthetic alignment on relative limb loading in persons with trans-tibial amputation: a preliminary report

The prosthetic sockets of 14 independent persons with unilateral trans-tibial (BK) amputation were mounted on an adjustable alignment pylon. Vertical ground reaction forces were recorded in neutral prosthetic alignment and in 10 degrees of prosthetic socket varus, valgus, flexion, and extension. Stance phase time, peak vertical ground reaction force, and impulse were all found to be increased on the sound limb when compared to the amputated residual limb. Significant differences were found in stance phase time and peak vertical ground reaction force when comparing malaligned with neutrally aligned prosthetic limbs. Significant differences were also seen in impulse between neutrally aligned and malaligned prosthetic limbs. The results suggest that prosthetic malalignment in persons with trans-tibial amputation leads to increased loading of the contralateral limb.

Temperature differentials between treatment and pretreatment temperatures correlate with local control following radiotherapy and hyperthermia

PURPOSE

To evaluate the influence of pretreatment tumor temperatures and the temperature differential between treatment and pretreatment temperatures on local tumor control in patients who underwent combined radiation therapy and hyperthermia.

METHODS AND MATERIALS

Mapped intratumoral temperatures were measured immediately prior to and during hyperthermia in 138 hyperthermia fields among 59 patients with nodular (60 fields) or diffuse (78 fields) superficially-located tumors. In the nodular subgroup there were 40 fields with adenocarcinomas (31 breast, two prostate, seven other primary sites), six melanomas, nine squamous cell carcinomas, and five other histologies. The fields with diffuse tumor involvement consisted of 77 adenocarcinomas (67 breast, 10 other) and one melanoma. The maximum, minimum, and average temperatures were determined for both the pretreatment (pTmax, pTmin, pTave) and treatment (Tmax, Tmin, Tave) distributions and the differences, Dm = Tmin-pTmax, and Da = Tmin-pTave, computed. These quantities were averaged over treatments to produce the corresponding mean quantities for each hyperthermia field. Univariate and multivariate analyses were performed to determine treatment and pretreatment parameters which best correlated with the duration of local control.

RESULTS

Pretreatment tumor temperatures were significantly lower than the oral temperatures with mean pTmax, mean pTmin, and mean pTave of 36.2 degrees C, 34.2 degrees C, and 35.4 degrees C, respectively. For the adenocarcinomas with diffuse involvement within the hyperthermia field, the covariates best correlating with local control duration on univariate analysis were concurrent radiation dose (p = 0.0026), Dm (p = 0.009), pTmax (p = 0.012) and Da (p = 0.036). Lower pTmax and larger Dm and Da were predictive for longer local control. In multivariate analyses, all thermal parameters lost power, however, the best model included Dm which was significant at the p = 0.040 level. For the nodular subgroup, nonthermal parameters and dichotomized thermal parameters were of prognostic significance for local control.

CONCLUSION

For fields diffusely involved with adenocarcinoma significant correlations with duration of local control have been demonstrated both for a) low pretreatment temperatures and b) large differentials between treatment and pretreatment intratumoral temperatures. These correlations were also found in a dichotomized description for fields with nodular tumors. The results support the concept that pretreatment hypothermic conditions can lead to an increase in thermal sensitization and may help explain the excellent clinical results noted in the treatment of superficial tumors with radiation and hyperthermia. Further exploitation of this approach by planned cooling of superficially-located recurrent tumors prior to hyperthermia treatment warrants investigation.

The treatment of persistent wound leak after radial keratotomy

BACKGROUND

Macroperforation of the cornea during refractive keratotomy can result in persistent wound leak and may need treatment by suturing.

METHODS

We describe two eyes that developed a macroperforation during radial keratotomy with persistent leakage of aqueous. The wounds were sutured with 10-0 and 11-0 nylon sutures.

RESULTS

The sutures induced irregular astigmatism as shown by corneal topography. Removal of sutures improved the topography and led to an acceptable outcome.

CONCLUSION

Macroperforations with persistent aqueous leaks should be sutured. Suture removal within a few weeks after surgery can avoid persistent irregular astigmatism and lead to a good refractive result.

Postmortem cerebrospinal fluid pleocytosis

We show that postmortem cerebrospinal fluid (CSF) pleocytosis is a common event. Postmortem cerebrospinal or ventricular fluid was obtained from children and adults. The cells were counted and morphologically characterized using several histochemical markers. Infants exhibit a brisk postmortem CSF pleocytosis. Sudden infant death cases have relatively high CSF counts. Typeable cells are mononuclear and consist of approximately 60%-70% lymphocytes and 20%-40% macrophages. When postmortem duration is greater than 12 h, the cells become vacuolated and cannot be identified. The etiology of these findings requires further study.

Prenatal diagnosis and management of bleeding disorders with fetal blood sampling

The technique of fetal blood sampling for prenatal diagnosis has been shown to be both feasible and safe. The availability of fetal blood for direct evaluation has changed our attitude about the problems of both hereditary and acquired immune fetal bleeding disorders. We can continue with the classic approach and use fetal blood sampling for those conditions in which termination may be recommended, but we can also investigate less severe disorders in which the diagnosis allows us to plan the management of the pregnancy and minimize intrapartum and neonatal complications. We report our experience in prenatal diagnosis and management of 103 cases of hereditary and 18 cases of acquired immune bleeding disorders. We have developed specific management plans depending on the disorder under investigation, the severity of the condition in the fetus, and parental wishes. We have performed in utero transfusions of platelets and factor concentrate where appropriate. Efficacy of maternal therapy for fetal conditions can be directly assessed during gestation. Mode of delivery is determined by obstetric conditions and fetal status, directly assessed after appropriate therapy. Closer surveillance of the fetus by fetal blood sampling gives precise information on which to base clinical decisions to provide optimal maternal and fetal outcome.

Rabbit secretory components: identification of a third allotype, t63

A third allotype of rabbit secretory component has been identified. The allotype previously referred to as t62 by our laboratory can now be subdivided into two allotypes, t62 and t63, with alloantisera capable of discriminating between the two. Results of family studies are consistent with a three allele system (t61, t62 and t63) at the t-locus. By SDS PAGE, electrophoretic mobilities of the multiple SC bands for each of the three allotypes are characteristic of the allotype; the apparent molecular sizes of the bands of the t62 allotype are 2 to 3 kDa lower than those for the t61 allotype. The banding patterns of the t61 and t63, although similar, are not identical to each other. Results of serologic cross-reaction studies and of tryptic peptide mapping studies suggest multiple structural differences between the allotypes as well as a closer relationship between t62 and t63 than between either of these allotypes and t61.

Rabbit secretory components: identification of a third allotype, t63

A third allotype of rabbit secretory component has been identified. The allotype previously referred to as t62 by our laboratory can now be subdivided into two allotypes, t62 and t63, with alloantisera capable of discriminating between the two. Results of family studies are consistent with a three allele system (t61, t62 and t63) at the t-locus. By SDS PAGE, electrophoretic mobilities of the multiple SC bands for each of the three allotypes are characteristic of the allotype; the apparent molecular sizes of the bands of the t62 allotype are 2 to 3 kDa lower than those for the t61 allotype. The banding patterns of the t61 and t63, although similar, are not identical to each other. Results of serologic cross-reaction studies and of tryptic peptide mapping studies suggest multiple structural differences between the allotypes as well as a closer relationship between t62 and t63 than between either of these allotypes and t61.

The effects of image degradation on retinal illuminance and pattern responses to checkerboard stimuli

The contrast of a retinal image is less than that of the external stimulus owing to a process of optical degradation. Theoretical studies have shows that this affects the pattern and illuminance detectors of the retina differently and provides a new insight into the nature of contrast stimulation and the mechanisms responsible for the pattern electroretinogram. Consensus data on the optical transfer function of the eye are applied to the Fourier transform of the pattern stimulus and the retinal illuminance distribution is determined. The checkerboard image is shown to undergo substantial degradation for those check sizes used in experimental and clinical observations. Current concepts of contrast and modes of stimulation are examined and methods are described for quantifying the effects on stimulation of illuminance and pattern detectors. The findings are applied to experimental data on spatial tuning functions of electroretinograms elicited by checkerboard pattern stimulation. It is concluded that the signal predominantly originates from local illuminance, but that this can account for only part of the response with small check sizes. The remainder must be a highly selective response to spatial frequency. If the predicted degradation is accepted, a similar conclusion must be reached for many previously reported tuning functions of the pattern electroretinogram as well as to the present experiment on eight normal eyes.

Effect of hyaluronidase on acute spinal cord injury

Three control and five experimental dogs were subjected to 500 gm-cm injury of the midthoracic spinal cord by the weight dropping technique. Five hundred units per kilogram of hyaluronidase injected intravenously 20 minutes after injury in the experimental animals did not alter the loss of dorsal column evoked potentials (nonaveraged) or improve the pathological results up to three hours. These results imply that hyaluronidase will not significantly alter the functional outcome of trauma of the spinal cord in dogs.

Treatment of lumbar disks with chymopapain

Symptoms arising from a herniated disk appear when the nucleus pulposus or soft inner portion of the disk bulges against a nerve root. When conservative treatment fails to help the patient, the enzyme chymopapain is currently being used in the treatment of such conditions. Injected directly into the disk, the chymopapain dissolves the nucleus by enzymatic action which selectively breaks certain bonds within the nucleus. The pressure within the center is decreased, hence the pressure against the nerve root is relieved, alleviating the symptoms. Because back care is particularly important following such treatment, physical therapy is valuable in promoting continued relief. The major emphasis of the therapy back care program is on abdominal strengthening exercises and postural training.

Interrelations between Environmental Factors and Freezing Resistance of Cabbage Leaves

Rapid wilting of cabbage leaves (Brassica capitata L.), induced by excision of the shoot, induced as rapid and high a degree of freezing resistance as a similar period of hardening at low temperature. Maximum hardening in the leaf was generally associated with the maximum growth rate. On the other hand, exposure of the excised shoot to low temperature while immersed in aerated water failed to harden the plants. In the absence of light, abrupt wilting at room or low temperature induced little or no hardening. With the available equipment, which required the absence of light, freezing temperatures induced little or no hardening above that obtained by nonfreezing low temperature. In fact, the plant frozen at moderate temperatures showed a gradual but steady decrease in freezing resistance. Since these experiments were performed with plants grown in pots, and since they eventually became pot-bound, the results may not apply equally to field-grown plants.

Direct relation between growth and frost hardening in cabbage leaves

Potted cabbage plants were grown in growth chambers at 25 degrees day and 15 degrees night and hardened successively at 5, 0, and -3 degrees . Leaf growth was determined by measuring leaf area, hardiness by freezing at a series of temperatures and determining percent survival. Leaf growth increased progessively with leaf number, reaching a maximum rate of growth and final area in the tenth and eleventh leaves when the plants become potbound. Leaf growth continued at hardening temperatures of 5 or 0 degrees , the Q(10) being 2.0 to 2.5. Ability to harden also increased with leaf number, paralleling the growth rate of the leaves just before hardening as well as the growth rate and the total growth during hardening. The above results were similar whether prolonged (several weeks) or brief (24 hr) hardening was utilized.