Effects of high fat diets or prednisolone treatment on femoral head separation in chickens.

1. The effects of high fat diets and prednisolone treatment were studied to understand the etiology of femoral head separation (FHS) in fast growing broiler chickens. Dietary effects on production parameters such as growth, feed conversion ratio (FCR) and blood chemistry were also measured. 2. Three groups of chickens, consisting of 30 birds each, in two replicate pens, were fed isonitrogenous diets containing 40 (control), 60, or 80 g poultry fat supplements per kg feed. The birds were fed a starter diet containing the fat supplements for the first three weeks, then switched to a grower diet containing the same supplements for the rest of the experimental period. Two groups of birds were also raised with the control diets, but were administered either cholesterol or prednisolone intramuscularly at 30 and 32 days of age to evaluate their effects on FHS incidences. 3. The chickens were euthanised and necropsied at 37 d of age. The presence of femoral head weakness was determined by applying mild pressure on the pelvic joint to cause the growth plate to become detached from its articular cartilage in affected cases. 4. High fat diets did not change FHS incidences, but increased 28 d body weights (BW) and FCR. At 37 d of age the BW differences were not significant but the FCR (gain: feed ratio) remained higher in high fat fed groups. Prednisolone treatment, by contrast, resulted in decreased BW, decreased feed efficiency, increased FHS index, and elevated blood lipid levels. 5. The results suggest that high dietary fats do not affect FHS incidence in broilers. Prednisolone treatment causes hyperlipidaemia and increases FHS index, and may therefore provide a suitable experimental model of FHS pathogenesis in growing chickens.

Histopathology and serum clinical chemistry evaluation of broilers with femoral head separation disorder.

Femoral head separation (FHS) and necrosis is a sporadic leg problem of unknown etiology in broiler breeders. To determine the underlying physiology of FHS, the blood chemistry and histopathology of the femoral growth plates of the affected chickens were compared with their age-matched controls and with birds having tibial dyschondroplasia. Femoral problems were categorized on the basis of 1) femoral head separating from articular cartilage without any visible damage to the growth plate (FHS) and 2) FHS with significant tearing and lesions in the growth plate (FHSL). Tibial dyschondroplasia was identified by a widening of the growth plate with an unresorbed plug of cartilage at the proximal end of the tibia. Control birds were without any femoral or tibial problems. The histopathology of FHSL growth plates revealed occasional chondrocyte death, hypocellularity, dysplasia in the prehypertrophic zones, and the absence of inflammatory infiltrates in the lesion areas. Hematoxylin and eosin staining showed brown chromogenic deposits in the metaphyseal bone marrow areas. Blood chemistry of chickens with FHSL showed a modest but significant elevation of cholesterol, triglycerides, and low-density lipoproteins. Only cholesterol and low-density lipoproteins were moderately elevated in FHS-affected chickens. Other blood parameters, such as protein, magnesium, and iron levels, showed differential changes in birds with leg problems, but there were no specific trends. Neither blood ovotransferrin, a marker of chronic inflammation, nor corticosterone, a marker of stress, showed any significant differences from the controls. These results indicate that FHS may be a metabolic problem in poultry, one that is related to fat metabolism disorders, possibly contributing to an unbalanced growth in the articular-epiphyseal complex that leads to its separation under sheer stress.

Novel Jeff=1/2 Mott state induced by relativistic spin-orbit coupling in Sr2IrO4.

We investigated the electronic structure of 5d transition-metal oxide Sr2IrO4 using angle-resolved photoemission, optical conductivity, x-ray absorption measurements, and first-principles band calculations. The system was found to be well described by novel effective total angular momentum Jeff states, in which the relativistic spin-orbit coupling is fully taken into account under a large crystal field. Despite delocalized Ir 5d states, the Jeff states form such narrow bands that even a small correlation energy leads to the Jeff=1/2 Mott ground state with unique electronic and magnetic behaviors, suggesting a new class of Jeff quantum spin driven correlated-electron phenomena.

Observation of strong spin valve effect in bulk Ca3(Ru1-xCrx)2O7.

The spin-valve effect is a quantum phenomenon so far only realized in multilayer thin films or heterostructures. Here we report a strong spin-valve effect existing in bulk single crystals of Ca3(Ru1-xCrx)2O7 having an anisotropic, bilayered crystal structure. This discovery opens new avenues to understand the underlying physics of spin valves, and fully realize its potential in practical devices.

Colossal magnetoresistance by avoiding a ferromagnetic state in the Mott system Ca3Ru2O7.

Transport and magnetic studies of Ca3Ru2O7 for temperatures ranging from 0.4 to 56 K and magnetic fields B up to 45 T lead to strikingly different behavior when the field is applied along the different crystal axes. A ferromagnetic (FM) state with full spin polarization is achieved for the B//a axis, but colossal magnetoresistance is realized only for the B//b axis. For the B//c axis, Shubnikov-de Haas oscillations are observed and followed by a less resistive state than that for B//a. Hence, in contrast with standard colossal magnetoresistive materials, the FM phase is the least favorable for electron hopping. These properties together with highly unusual spin-charge-lattice coupling near the Mott transition (48 K) are driven by the orbital degrees of freedom.

Infectious keratitis after laser refractive surgery.

PURPOSE: To report two cases of infectious keratitis, one fungal after photorefractive keratectomy (PRK) and the other bacterial after laser in situ keratomileusis (LASIK). DESIGN: Two interventional case reports. PARTICIPANTS: Case 1 is a male who was seen 3 weeks after PRK with a corneal ulceration. Case 2 involves a female who was seen 7 weeks after LASIK with interface granularity. RESULTS: Cultures in case 1 were identified as Scopulariopsis species, and despite intensive treatment, a therapeutic penetrating keratoplasty (PK) was eventually performed. Case 2 had cultures identified as Mycobacterium chelonae and also ultimately required a therapeutic PK. CONCLUSIONS: Two unusual infectious keratitides are reported after different laser refractive surgery techniques.

The predictability of corneal flap thickness and tissue laser ablation in laser in situ keratomileusis.

OBJECTIVE: To evaluate the relationship between predicted flap thickness and actual flap thickness and between predicted tissue ablation and actual tissue ablation. DESIGN: Prospective, nonrandomized comparative (self-controlled) trial. PARTICIPANTS: A total of 60 patients (102 eyes) who underwent laser in situ keratomileusis (LASIK). MAIN OUTCOME MEASURES: Subtraction pachymetry was used to determine actual corneal flap thickness and corneal tissue ablation depth. Other measurements included flap diameter and keratometry readings. RESULTS: Actual flap thickness was significantly different (P < 0.0001) from predicted flap thickness. Fifteen eyes had a predicted flap thickness of 160 micrometer and a mean actual flap of 105 micrometer (standard deviation [SD], +/-24. 3 micrometer range, 48-141 micrometer). Sixty-four had a predicted flap of 180 micrometer with an actual flap mean of 125 micrometer (SD, +/-18.5 micrometer range, 82-155 micrometer). Seventeen eyes had a predicted flap of 200 micrometer, with an actual flap mean of 144 micrometer (SD, +/-19.3 micrometer range, 108-187 micrometer). In addition, we found that significantly more tissue (P < 0.0001) was ablated than predicted. Linear regression of the observed ablation on predicted ablation yielded the following relationship: actual ablation = 14.5 + 1.5 (predicted ablation). Neither flap diameter nor flap thickness were found to increase with respect to steeper corneal curvatures. CONCLUSIONS: Actual corneal flap thickness was consistently less than predicted regardless of the depth plate used; actual tissue ablation was consistently greater than predicted tissue ablation for the laser used in this study.

Adrenal cortical function and reserve in lepromatous leprosy.

22 chronic Lepromatous Leprosy patients of over 10 years duration, 17 non-reactional and 5 in reactional state who have not taken steroids as part of treatment were selected for the study. Serum cortisol was estimated by Radio-immuno-assay. Samples for basal values were collected at 8.00 A.M. Stimulated values were estimated in samples collected 8 hours after ACTH gel 40 units IM or 2 hours after 0.15 unit/kg BW Plain Insulin I.V. Basal cortisol values are: Normal controls 123.06 +/- 57.33 ng/ml. Non-reactional: 100.47 +/- 30.33 ng/ml; Reactional 141.4 +/- 43.15 ng/ml. Stimulated values are: Normal controls: 207.6 +/- 72.57 ng/ml. Non-reactional: 175.33 +/- 57.07 ng/ml, Reactional: 230 +/- 40.92 ng/ml. Basal serum cortisol in the non-reactional state is slightly lower than in normals but not statistically significant (P greater than 0.1). The basal cortisol in reactional subjects is slightly higher than in normals but not significant statistically (P greater than 0.05). The percentage rise over the basal value after stimulation test is found to be significantly low in both the reactional and non reactional states (P greater than 0.05) and also there is no statistically significant difference between these two groups (p greater than 0.5). Hence it is concluded that the Adrenal cortical reserve is low both in the non-reactional and reactional states of Lepromatous Leprosy.