The effect of fertilizer nitrogen input to grass-clover swards and calving date on the productivity of pasture-based dairy production.

The objective of this systems-scale study was to investigate grazing season timeframes on pasture and milk production and on milk processability of dairy systems with compact spring-calving dairy cows grazing white clover (Trifolium repens L.) based grassland. Fifty-four primiparous and multiparous Holstein-Friesian dairy cows were used in a one-factor study with 3 systems (n = 18) and repeated over 2 yr (2008/09 and 2009/10). The 3 systems were: early spring calving with annual fertilizer N input of 100 kg·ha-1 applied in spring (ES100N; 2.1 cows·ha-1; grazing February to November), early spring calving without fertilizer N (ES0N; 1.6 cows·ha-1; grazing February to November) and late spring calving without fertilizer N (LS0N; 1.53 cows·ha-1; grazing April to January). Annual pasture production was affected by an interaction between grazing system and year: Mean annual pasture yields for 2008 and 2009 were ES100N; 10.35 and 9.88, ES0N; 8.88 and 8.63, LS0N; 9.18 and 10.31 t of dry matter (DM)·ha-1 (SEM 0.39). LS0N had higher pasture DM yield in 2009 due to higher clover DM production and biological N fixation compared with the other systems. Clover stolon and root mass in the following February was correlated with stolon and root mass in the previous November with 64% of stolon mass present on LS0N in February (R2 = 0.84). There were no detectable differences in per-lactation milk yield (6,335 kg·cow-1), fat, protein and lactose yields (271, 226, 297 kg·cow-1, respectively), cow liveweight (585 kg) or body condition score (3.02). Although winter grazing favored subsequent clover DM production, biological N fixation and pasture DM production, delaying calving date in spring and extending lactation into the following winter led to inefficient use of this pasture by the grazing herd and lowered the quality of late-lactation milk for processing purposes. Hence, a mean calving date in mid- to late-February is recommended for zero-fertilizer N input clover-based grassland.

Controlling anoxic tolerance in adult Drosophila via the cGMP-PKG pathway.

In this study we identify a cGMP-dependent protein kinase (PKG) cascade as a biochemical pathway critical for controlling low-oxygen tolerance in the adult fruit fly, Drosophila melanogaster. Even though adult Drosophila can survive in 0% oxygen (anoxia) environments for hours, air with less than 2% oxygen rapidly induces locomotory failure resulting in an anoxic coma. We use natural genetic variation and an induced mutation in the foraging (for) gene, which encodes a Drosophila PKG, to demonstrate that the onset of anoxic coma is correlated with PKG activity. Flies that have lower PKG activity demonstrate a significant increase in time to the onset of anoxic coma. Further, in vivo pharmacological manipulations reveal that reducing either PKG or protein phosphatase 2A (PP2A) activity increases tolerance of behavior to acute hypoxic conditions. Alternatively, PKG activation and phosphodiesterase (PDE5/6) inhibition significantly reduce the time to the onset of anoxic coma. By manipulating these targets in paired combinations, we characterized a specific PKG cascade, with upstream and downstream components. Further, using genetic variants of PKG expression/activity subjected to chronic anoxia over 6 h, approximately 50% of animals with higher PKG activity survive, while only approximately 25% of those with lower PKG activity survive after a 24 h recovery. Therefore, in this report we describe the PKG pathway and the differential protection of function vs survival in a critically low oxygen environment.

Allosteric effects of Pit-1 DNA sites on long-term repression in cell type specification.

Reciprocal gene activation and restriction during cell type differentiation from a common lineage is a hallmark of mammalian organogenesis. A key question, then, is whether a critical transcriptional activator of cell type-specific gene targets can also restrict expression of the same genes in other cell types. Here, we show that whereas the pituitary-specific POU domain factor Pit-1 activates growth hormone gene expression in one cell type, the somatotrope, it restricts its expression from a second cell type, the lactotrope. This distinction depends on a two-base pair spacing in accommodation of the bipartite POU domains on a conserved growth hormone promoter site. The allosteric effect on Pit-1, in combination with other DNA binding factors, results in the recruitment of a corepressor complex, including nuclear receptor corepressor N-CoR, which, unexpectedly, is required for active long-term repression of the growth hormone gene in lactotropes.

Drosophila Hsc70-4 is critical for neurotransmitter exocytosis in vivo.

Previous in vitro studies of cysteine-string protein (CSP) imply a potential role for the clathrin-uncoating ATPase Hsc70 in exocytosis. We show that hypomorphic mutations in Drosophila Hsc70-4 (Hsc4) impair nerve-evoked neurotransmitter release, but not synaptic vesicle recycling in vivo. The loss of release can be restored by increasing external or internal Ca(2+) and is caused by a reduced Ca(2+) sensitivity of exocytosis downstream of Ca(2+) entry. Hsc4 and CSP are likely to act in common pathways, as indicated by their in vitro protein interaction, the similar loss of evoked release in individual and double mutants, and genetic interactions causing a loss of release in trans-heterozygous hsc4-csp double mutants. We suggest that Hsc4 and CSP cooperatively augment the probability of release by increasing the Ca(2+) sensitivity of vesicle fusion.

Inherited propionyl-Coa carboxylase deficiency in "ketotic hyperglycinemia".

Cultured fibroblasts from a young girl with ketotic hyperglycinemia were unable to oxidize propionate-(14)C to (14)CO(2), but oxidized methylmalonate-(14)C and succinate-(14)C normally. This block in propionate catabolism was shown to result from a lack of propionyl-CoA carboxylase activity. The carboxylase deficiency was not due to the presence of an intracellular inhibitor and it was not corrected by biotin, a known cofactor for the enzyme. Both of her parents' fibroblasts had approximately 50% of normal propionyl-CoA carboxylase activity. These results demonstrate that ketotic hyperglycinemia and propionicacidemia are the same disease, caused by a mutation of the propionyl-CoA carboxylase apoenzyme, which is inherited as an autosomal recessive trait. This enzymatic localization provides an explanation for the remarkable clinical and chemical similarity between ketotic hyperglycinemia and methylmalonicaciduria and offers a potential means of antenatal detection of this disorder.

Role of estrogen receptor-alpha in the anterior pituitary gland.

Targeted insertional disruption of the mouse estrogen receptor-alpha (ER alpha) gene has provided a genetic model in which to test hypotheses that estrogens exert important effects in development and homeostatic functions of the anterior pituitary gland, particularly in the lactotroph and gonadotroph cell types. Analysis of ER alpha gene-disrupted mice reveals a marked reduction in PRL mRNA and a decrease in lactotroph cell number, but normal specification of lactotroph cell phenotype. Gonadotropin mRNA levels in ER alpha gene-disrupted female mice are elevated, consistent with previously described transcriptional suppression of gonadotropin subunit gene expression in response to sustained administration of estrogen in wild type mice. These results provide genetic evidence that ER alpha plays a critical role in PRL and gonadotropin gene transcription and is involved in lactotroph cell growth, but is not required for specification of lactotroph cell phenotype.

Heat shock protects synaptic transmission in flight motor circuitry of locusts.

We investigated the effects of heat shock on the temperature sensitivity of synaptic transmission in the motor circuit for flight in Locusta migratoria. In heat shocked animals synaptic transmission failed at 5-6 degrees C higher than in control animals and recovery of transmission was more than three times faster upon return to room temperature. We also found that synaptic delay was rendered insensitive to increases in temperature by heat shock. Thus we have shown in the locust that heat shock has important protective effects on synaptic transmission, thereby extending the upper temperature limit for the motor patterns that generate flight. This is the first description of an effect of heat shock that preserves neuronal communication under subsequent stressful conditions.

Forewing asymmetries during auditory avoidance in flying locusts

Flying locusts orient to sounds in their environment. Sounds similar to those produced by echolocating bats cause a flying locust to change its flight path. We used high-speed cinematography and videography to study changes in body posture and wing kinematics of tethered locusts in response to stimulation with bat-like sounds. Locusts showed both negative and positive phonotaxis to this stimulus. Within a few wingbeats of stimulus onset (between 126 and 226ms), locusts deflected their abdomens to one side, and the angle of the left and right forewings with respect to the dorsal­ventral body axis became asymmetrical during the downstroke. This forewing asymmetry, in which the forewing on the inside of the turn became more depressed, ranged from 20 to 45° (37±9.7°, mean ± s.d.) and was correlated with the direction and magnitude of abdomen deflection, a measure of steering in tethered, flying locusts. Hindwing stroke angle asymmetries were minimal or non-existent after stimulation. Coincident with changes in forewing asymmetry and abdomen deflection was a decrease in stroke amplitude (19±6.5°) of the forewing on the inside of the attempted turn. Motor patterns from forewing first basalar (M97) muscles showed an asymmetry in the timing of left and right depressor activation that ranged from 10.4 to 1.6ms (4.23±2.85ms). The number of spikes per depressor burst increased to a maximum of three spikes in the muscle on the inside of the attempted turn, and depressor frequency (wingbeat frequency) increased by approximately 2Hz (2.17±0.26Hz). We suggest that the asymmetry in forewing first basalar activity is causally related to the asymmetry in the timing of the initiation of the downstroke, resulting in an asymmetry in the ranges of the stroke angles of the forewings, which would impart a roll torque to the locust. This would augment the steering torques generated by concurrent changes in the angle of attack of the fore- and hindwings and changes in abdomen position to effect rapid avoidance manoeuvres.

Reliable fifteen-minute assay for theophylline.

We describe a reliable, rapid high pressure liquid chromatography assay for serum theophylline which can be performed on 0.5 ml or smaller samples. The procedure involves extraction, centrifugation and sampling all in the same disposable centrifuge tube. In the therapeutic range the coefficients of variation for within-day and day-to-day assays are 1.0% and 2.6%, respectively. The sensitivity of the method is better than 1 microgram/ml in serum. The minimum number of steps, rapid elution and use of only peak heights contribute to the reliability and rapidity of the assay.

Hepar lobatum associated with chemotherapy and metastatic breast cancer.

Hepar lobatum is now a rarity in developed countries. In this article, we describe three cases with typical liver morphology associated with carcinoma of the breast metastatic to the liver, treated with combination chemotherapy. The pathogenesis of hepar lobatum in our cases is multifactorial with tumor-related desmoplasia and effects of chemotherapy, with resultant tumor necrosis and fibrosis playing a major role.

The characteristic appearance of non-alcoholic duct destructive chronic pancreatitis: a report of 2 cases.

We report 2 patients with an unusual form of chronic pancreatitis, both of whom were treated for clinical suspicion of pancreatic malignancy. The surgical specimens revealed a dense lymphoplasmacytic infiltration of the main and interlobular branches of the pancreatic duct, causing sclerosis of the duct wall, diffuse irregular lumenal narrowing, extensive parenchymal fibrosis, and organ enlargement. Neither case showed calcifications, fat necrosis, or cyst formation, features usually seen in alcoholic pancreatitis, nor was there any evidence of neoplasia. One patient had an unusual form of acalculous cholecystitis, but without cystic duct inflammation or fibrosis. Both patients recovered well from the surgical procedure and have not had any complications or relapse of their symptoms. To the best of our knowledge, these cases are representative of the recently described non-alcoholic duct destructive chronic pancreatitis, which is thought to be immune-mediated.

Early visual recovery after excimer laser surgery for myopia: the Melbourne OmniMed results.

BACKGROUND AND OBJECTIVE: Although the refractive outcome can change for months after photorefractive keratectomy (PRK), early visual results are of particular importance during pre-operative counseling of prospective PRK candidates. The expected vision in the first week post-operatively, following 6.0 mm or larger zone photoablation for myopia with the Summit OmniMed (Apex) laser, has not been analyzed in the literature to date. This study is intended to provide an indication of the early visual acuity that may be experienced by a patient undergoing PRK for myopia. PATIENTS AND METHODS: The visual acuity recorded for 123 consecutive patients, (79 low myopes [-1.00 to -5.90 diopters (D)], 44 high extreme myopes [-6.00 to -19.00 D]), one week after they had undergone PRK, was analyzed. All patients included in the study had undergone PRK with the Summit OmniMed (Apex) excimer laser, leaving small degrees of astigmatism uncorrected. RESULTS: One week after PRK, uncorrected visual acuity was better for low myopes than high myopes. Of the low myopes, 83.0% were 20/40 or better compared with high myopes of whom 61.4% were 20/40 or better. CONCLUSION: Patients can be counseled that functional vision will be present in the period immediately after re-epithelialization.

Case study: a data warehouse for an academic medical center.

The clinical data repository (CDR) is a frequently updated relational data warehouse that provides users with direct access to detailed, flexible, and rapid retrospective views of clinical, administrative, and financial patient data for the University of Virginia Health System. This article presents a case study of the CDR, detailing its five-year history and focusing on the unique role of data warehousing in an academic medical center. Specifically, the CDR must support multiple missions, including research and education, in addition to administration and management. Users include not only analysts and administrators but clinicians, researchers, and students.

Adding value to clinical data by linkage to a public death registry.

We describe the methodology and impact of merging detailed statewide mortality data into the master patient index tables of the clinical data repository (CDR) of the University of Virginia Health System (UVAHS). We employ three broadly inclusive linkage passes (designed to result in large numbers of false positives) to match the patients in the CDR to those in the statewide files using the following criteria: a) Social Security Number; b) Patient Last Name and Birth Date; c) Patient Last Name and Patient First Name. The results from these initial matches are refined by calculation and assignment of a total score comprised of partial scores depending on the quality of matching between the various identifiers. In order to validate our scoring algorithm, we used those patients known to have died at UVAHS over the eight year period as an internal control. We conclude that we are able to update our CDR with 97% of the deaths from the state source using this scheme. We illustrate the potential of the resulting system to assist caregivers in identification of at-risk patient groups by description of those patients in the CDR who were found to have committed suicide. We suggest that our approach represents an efficient and inexpensive way to enrich hospital data with important outcomes information.

Customizing a clinical data warehouse for housestaff education in practice-based learning and improvement.

We developed Systems and Practice Analysis for Resident Competencies (SPARC), a Web-based tool to support teaching the practice-based learning and improvement (PBLI) ACGME competencies. SPARC allows Department of Medicine residents to explore de-identified, population-based data about their patient panels with peer comparisons. Data primarily comes from an existing data warehouse that has been customized for this application. Our preliminary evaluation suggests that it improves residents' abilities in PBLI, is easy to use, and perceived as important and useful by the housestaff.

Mucinous syringometaplasia.

This is a clinicopathologic study of six patients with mucinous syringometaplasia, which was diagnosed histologically. Biopsies revealed a focal invagination of the epidermis lined by squamous epithelium, with one or several eccrine ducts leading into the vagination. The eccrine duct epithelium contained mucin-laden goblet cells, and there was mucinous syringometaplasia of the underlying eccrine coils. This histopathologic change was associated with two types of clinical lesions: (1) verrucous lesions, consistent with those described by previous authors, and (2) lesions suggestive of basal cell carcinoma, which have not been described with this pathologic entity in previous publications.

Drug-specific antibodies in human serum?

In view of the fact that all drugs possess the potential to stimulate an immunological response when administered to man, it was proposed that certain individuals in the general population may have developed high antibody titres to certain commonly used drugs. Human serum samples were incubated with radioactively-labelled drugs and the amount of IgG antibody present was determined by coprecipitation. Using the method outlined, we were unable to detect any antibodies specific for acetylsalicylic acid, ampicillin, erythromycin, lidocaine, penicillin, procainamide or tetracycline, and conclude that drug-specific immunoglobulins are not one of the major factors involved in the equilibrium between the free and bound drug forms.

Solitary fibrofolliculoma.

We present a case of solitary fibrofolliculoma. Histopathologic findings of this entity are characteristic: in the dermis a central hair follicle is surrounded by a thick mantle of fibrotic and mucinous stroma, and numerous thin, anastomosing bands of follicular epithelium extend into this stroma. This entity has been described as occurring only multiply; to our knowledge, this is the first case report of a solitary fibrofolliculoma.