Luteal phase decrease in packed cell volume in healthy non-pregnant and pregnant bitches.

OBJECTIVES: To establish packed cell volume (PCV) ranges for non-pregnant, pregnant and post-partum bitches from day 10 of proestrus, investigating any relationship with parity and litter size. METHODS: This prospective cohort study used 37 healthy breeding bitches to examine PCV counts from routine blood samples collected every 4 weeks, from day 10 of proestrus, as part of routine PCV monitoring. RESULTS: For pregnant (n = 19) and non-pregnant (n = 18) bitches, PCV decreased until week 8 (corresponding to 8.5 ± 1.1 days before whelping for pregnant bitches) and recovered by 16-20 weeks after the initial sample; bitches that whelped average and large litters showed greater declines. PCV began to recover sooner for bitches that had previously whelped one or two litters compared to bitches that had previously whelped three or more litters. There was a significant three-way interaction between time after the onset of proestrus, litter size and the number of previous litters which demonstrated that the large decrease in PCV for bitches that had previously whelped three or more litters only occurred in bitches that were expecting an average or large sized litter. CLINICAL SIGNIFICANCE: Chronological variation in PCV for pregnant and non-pregnant bitches was established during the reproductive cycle. There was no evidence to suggest that routine PCV measurement for normal, healthy bitches would be beneficial. However, knowledge from this study may be useful when deciding whether to prospectively monitor a bitch where there is a history of previous pregnancy-related anaemia, when performing a caesarean section due to the anticipated blood loss during surgery, or when examining blood profiles for post-litter bitches.

Herbivory and Time Since Flowering Shape Floral Rewards and Pollinator-Pathogen Interactions.

Herbivory can induce chemical changes throughout plant tissues including flowers, which could affect pollinator-pathogen interactions. Pollen is highly defended compared to nectar, but no study has examined whether herbivory affects pollen chemistry. We assessed the effects of leaf herbivory on nectar and pollen alkaloids in Nicotiana tabacum, and how herbivory-induced changes in nectar and pollen affect pollinator-pathogen interactions. We damaged leaves of Nicotiana tabacum using the specialist herbivore Manduca sexta and compared nicotine and anabasine concentrations in nectar and pollen. We then pooled nectar and pollen by collection periods (within and after one month of flowering), fed them in separate experiments to bumble bees (Bombus impatiens) infected with the gut pathogen Crithidia bombi, and assessed infections after seven days. We did not detect alkaloids in nectar, and leaf damage did not alter the effect of nectar on Crithidia counts. In pollen, herbivory induced higher concentrations of anabasine but not nicotine, and alkaloid concentrations rose and then fell as a function of days since flowering. Bees fed pollen from damaged plants had Crithidia counts 15 times higher than bees fed pollen from undamaged plants, but only when pollen was collected after one month of flowering, indicating that both damage and time since flowering affected interaction outcomes. Within undamaged treatments, bees fed late-collected pollen had Crithidia counts 10 times lower than bees fed early-collected pollen, also indicating the importance of time since flowering. Our results emphasize the role of herbivores in shaping pollen chemistry, with consequences for interactions between pollinators and their pathogens.

Risk factors and the natural history of accelerated knee osteoarthritis: a narrative review.

BACKGROUND: Osteoarthritis is generally a slowly progressive disorder. However, at least 1 in 7 people with incident knee osteoarthritis develop an abrupt progression to advanced-stage radiographic disease, many within 12 months. We summarize what is known - primarily based on findings from the Osteoarthritis Initiative - about the risk factors and natural history of accelerated knee osteoarthritis (AKOA) - defined as a transition from no radiographic knee osteoarthritis to advanced-stage disease < 4 years - and put these findings in context with typical osteoarthritis (slowly progressing disease), aging, prior case reports/series, and relevant animal models. Risk factors in the 2 to 4 years before radiographic manifestation of AKOA (onset) include older age, higher body mass index, altered joint alignment, contralateral osteoarthritis, greater pre-radiographic disease burden (structural, symptoms, and function), or low fasting glucose. One to 2 years before AKOA onset people often exhibit rapid articular cartilage loss, larger bone marrow lesions and effusion-synovitis, more meniscal pathology, slower chair-stand or walking pace, and increased global impact of arthritis than adults with typical knee osteoarthritis. Increased joint symptoms predispose a person to new joint trauma, which for someone who develops AKOA is often characterized by a destabilizing meniscal tear (e.g., radial or root tear). One in 7 people with AKOA onset subsequently receive a knee replacement during a 9-year period. The median time from any increase in radiographic severity to knee replacement is only 2.3 years. Despite some similarities, AKOA is different than other rapidly progressive arthropathies and collapsing these phenomena together or extracting results from one type of osteoarthritis to another should be avoided until further research comparing these types of osteoarthritis is conducted. Animal models that induce meniscal damage in the presence of other risk factors or create an incongruent distribution of loading on joints create an accelerated form of osteoarthritis compared to other models and may offer insights into AKOA. CONCLUSION: Accelerated knee osteoarthritis is unique from typical knee osteoarthritis. The incidence of AKOA in the Osteoarthritis Initiative and Chingford Study is substantial. AKOA needs to be taken into account and studied in epidemiologic studies and clinical trials.

Adults With Incident Accelerated Knee Osteoarthritis Are More Likely to Use Pharmacological Treatment Options and Receive Arthroscopic Knee Surgery: Data From the Osteoarthritis Initiative.

OBJECTIVE: To determine if people with incident accelerated knee osteoarthritis (AKOA) were more likely to receive a pharmacological treatment or arthroscopic knee surgery than those with typical knee osteoarthritis (KOA) or no KOA. METHODS: We conducted a nested cohort study using data from baseline and the first 8 years of the Osteoarthritis Initiative. Eligible participants had no radiographic KOA at baseline (Kellgren-Lawrence [KL] < 2). We classified three groups using KL grades: 1) AKOA: knee progressed to advanced-stage KOA (KL 3/4) in 4 years or less, 2) typical KOA: knee increased in KL grade by 8 years (excluding AKOA), and 3) No KOA: no change in KL grade by 8 years. The outcome was self-reported arthroscopic knee surgery or a pharmacological treatment option: nonsteroidal anti-inflammatory drugs (NSAIDs), hyaluronic acid injections, intra-articular corticosteroid injections, or prescription analgesics. Between-group differences in therapeutic use were evaluated with Chi-square tests. RESULTS: Adults who developed AKOA (n = 92) were more likely to report arthroscopic knee surgery (AKOA: 32%, KOA [n = 380]: 8%, no KOA [n = 875]: 3%; P < 0.001), hyaluronic acid injections (AKOA: 10%, KOA: 4%, no KOA: 1%; P < 0.001), intra-articular corticosteroid injections (AKOA: 30%, KOA: 7%, no KOA: 4%; P < 0.001), and NSAID use (over the counter: AKOA: 65%, KOA: 48%, and no KOA: 46%; P = 0.003; prescription: AKOA: 61%, KOA: 43%, no KOA: 41%; P = 0.002). CONCLUSION: Adults with AKOA are more likely to receive pharmacological treatment or arthroscopic knee surgery than their peers. Adults with AKOA are an important patient population that is understudied in clinical research despite their use of greater health care resources.

Association Between Declining Walking Speed and Increasing Bone Marrow Lesion and Effusion Volume in Individuals with Accelerated Knee Osteoarthritis.

OBJECTIVE: To determine whether a decline in walking speed during the year prior to disease onset is associated with concurrent changes in cartilage, bone marrow lesions (BMLs), or effusion in adults who develop common knee osteoarthritis (OA), accelerated knee OA, or no knee OA. METHODS: We identified 3 groups from the Osteoarthritis Initiative based on annual radiographs from baseline to 48 months: accelerated knee OA, common knee OA, and no knee OA. We used the cartilage damage index (CDI) to assess tibiofemoral cartilage damage and used a semiautomated program to measure BML and effusion volume. Walking speed was assessed as an individual's habitual walking speed over 20 meters. One-year change in walking speed and structural measures were calculated as index visit measurements minus measurements from the year prior visit. Logistic regression models were used to determine whether change in walking speed (exposure) was associated with change in each structural measure (outcome) for the overall group and then separately for the accelerated knee OA, common knee OA, and no knee OA groups. RESULTS: Adults who slowed their walking speed were almost twice as likely to present with increased BML volume, with a significant association (odds ratio 3.04 [95% confidence interval (95% CI) 1.03-8.95]) among adults with accelerated knee OA. Adults with accelerated knee OA who slowed their walking speed were approximately 3.4 times (95% CI 1.10-10.49) more likely to present with increased effusion volume. Walking speed change was not significantly associated with CDI change. CONCLUSION: A change in an easily assessable clinical examination (i.e., 20-meter walk test) was associated with concurrent worsening in BML and effusion volume in adults who developed accelerated knee OA.

Accelerated Knee Osteoarthritis Is Characterized by Destabilizing Meniscal Tears and Preradiographic Structural Disease Burden.

OBJECTIVE: To determine whether accelerated knee osteoarthritis (KOA) is preceded by, and characterized over time by, destabilizing meniscal tears or other pathologic changes. METHODS: We selected 3 sex-matched groups of subjects from the first 48 months of the Osteoarthritis Initiative, comprising adults who had a knee without KOA (Kellgren/Lawrence [K/L] radiographic grade <2) at baseline. Subjects in the accelerated KOA group developed KOA of K/L grade ≥3, those with typical KOA showed increased K/L radiographic scores, and those with no KOA had the same K/L grade over time. An index visit was the visit when the radiographic criteria for accelerated KOA and typical KOA were met (the no KOA group was matched to the accelerated KOA group). The observation period was up to 2 years before and after an index visit. Radiologists reviewed magnetic resonance (MR) images of the index knee and identified destabilizing meniscal tears (root tears, radial tears, complex tears), miscellaneous pathologic features (acute ligamentous or tendinous injuries, attrition, subchondral insufficiency fractures, other incidental findings), and meniscal damage in >2 of 6 regions (3 regions per meniscus: anterior horn, body, posterior horn). In addition, bone marrow lesions (BMLs) and cartilage damage on MR images were quantified. Linear mixed regression models were performed to analyze the results. RESULTS: At 1 year before the index visit, >75% of adults with accelerated KOA had meniscal damage in ≥2 regions (odds ratio 3.19 [95% confidence interval 1.70-5.97] versus adults with typical KOA). By the index visit, meniscal damage in ≥2 regions was ubiquitous in adults with accelerated KOA, including 42% of subjects having evidence of a destabilizing meniscal tear (versus 14% of subjects with typical KOA). These changes corresponded to findings of larger BMLs and greater cartilage loss in the accelerated KOA group. CONCLUSION: Accelerated KOA is characterized by destabilizing meniscal tears in a knee compromised by meniscal damage in >2 regions, and also characterized by the presence of large BMLs and greater cartilage loss.

Folding of Fibroblast Growth Factor 1 Is Critical for Its Nonclassical Release.

Fibroblast growth factor 1 (FGF1), a ubiquitously expressed pro-angiogenic protein that is involved in tissue repair, carcinogenesis, and maintenance of vasculature stability, is released from the cells via a stress-dependent nonclassical secretory pathway. FGF1 secretion is a result of transmembrane translocation of this protein. It correlates with the ability of FGF1 to permeabilize membranes composed of acidic phospholipids. Like several other nonclassically exported proteins, FGF1 exhibits ß-barrel folding. To assess the role of folding of FGF1 in its secretion, we applied targeted mutagenesis in combination with a complex of biophysical methods and molecular dynamics studies, followed by artificial membrane permeabilization and stress-induced release experiments. It has been demonstrated that a mutation of proline 135 located in the C-terminus of FGF1 results in (i) partial unfolding of FGF1, (ii) a decrease in FGF1's ability to permeabilize bilayers composed of phosphatidylserine, and (iii) drastic inhibition of stress-induced FGF1 export. Thus, folding of FGF1 is critical for its nonclassical secretion.

The Your Disease Risk Index for colorectal cancer is an inaccurate risk stratification tool for advanced colorectal neoplasia at screening colonoscopy.

Tailoring the use of screening colonoscopy based on the risk of advanced colorectal neoplasia (ACN) could optimize the cost-effectiveness of colorectal cancer (CRC) screening. Our goal was to assess the accuracy of the Your Disease Risk (YDR) CRC risk index for stratifying average risk patients into low- versus intermediate/high-risk categories for ACN. The YDR risk assessment tool was administered to 3,317 asymptomatic average risk patients 50 to 79 years of age just before their screening colonoscopy. Associations between YDR-derived relative risk (RR) scores and ACN prevalence were examined using logistic regression and χ(2) analyses. ACN was defined as a tubular adenoma ≥1 cm, tubulovillous or villous adenoma of any size, and the presence of high-grade dysplasia or cancer. The overall prevalence of ACN was 5.6%. Although YDR-derived RR scores were linearly associated with ACN after adjusting for age and gender (P = 0.033), the index was unable to discriminate "below average" from "above/average" risk patients [OR, 1.01; 95% confidence interval (CI), 0.75-1.37]. Considerable overlap in rates of ACN was also observed between the different YDR risk categories in our age- and gender-stratified analyses. The YDR index lacks accuracy for stratifying average risk patients into low- versus intermediate/high-risk categories for ACN.

An estrogen-platinum terpyridine conjugate: DNA and protein binding and cellular delivery.

A platinum metal complex in which terpyridine joins estradiol (via an ethynyl link) to a platinum with a labile ligand (chloride) has been designed, synthesised and its X-ray crystal structure determined. The aim of this work was to link a targeting motif (in this case estrogen) to a metal-based biomolecule recognition unit (the platinum moiety). The target molecule: 17alpha-[4'-ethynyl-2,2':6',2'-terpyridine]-17beta-estradiol platinum(II) chloride (PtEEtpy) has been shown to bind to both human and bovine serum albumin (SA) and to DNA. FTICR mass spectrometry shows that the bimolecular units are in each case linked through coordination to the platinum with displacement of the chloride ligand. Circular dichroism indicates that a termolecular entity involving PtEEtpy, SA and DNA is formed. A range of electrospray mass spectrometry experiments showed that the PtEEtpy complex breaks and forms coordination bonds relatively easily. A whole cell estrogen receptor assay in an estrogen receptor positive cell (MCF-7) confirms binding of both EEtpy and PtEEtpy to the estrogen receptor in cells. The work demonstrates the concept of linking a targeting moiety (in this case estrogen) to a DNA binding agent.

Pharmacokinetics of oral cyclosporine (Neoral) in heart transplant recipients during the immediate period after surgery.

Neoral cyclosporine has better absorption characteristics than the original Sandimmun formulation. This has allowed Neoral to be administered orally in circumstances where Sandimmun had been ineffective, including the postoperative phase of liver transplantation. Sampling strategies, such as the measurement of drug concentration 2 h after oral administration, have been used in a variety of settings to estimate systemic exposure to Neoral (measured as the area under the blood concentration curve (AUC) of the drug) in blood. We conducted a pilot study to determine whether Neoral could be administered orally immediately after heart transplantation and to determine which pharmacokinetic parameters reflect systemic drug exposure in this setting. Eight male patients (mean age 50 years) undergoing a first heart transplant were studied. Neoral was administered orally before surgery and at 12-h intervals via a nasogastric tube after surgery. Twelve-hour pharmacokinetic profiles were obtained on postoperative days 1, 3 and 5. Cyclosporine concentrations were measured with the Dade Behring Emit assay, which is specific for the parent drug. Drug concentrations were dose-normalised and drug exposure was measured by the AUC. Drug exposure following administration (AUC(0-12)) was low on day 1 but increased by 99% between postoperative day 1 and day 5 ( P<0.05), indicating more complete absorption of cyclosporine; exposure in the first 4 h post-dose (AUC(0-4)) increased by 126% ( P<0.01), reflecting more rapid cyclosporine absorption, and the maximum blood concentration observed increased by 137% ( P<0.05) during the same period. The correlation between the cyclosporine trough concentration and AUC(0-12) was low on all days. Due to the changing pattern of cyclosporine absorption, concentration measurements at a single time point could not accurately predict 12-h exposure to the drug on all study days. However, the drug concentration at 2 h post-dose had a high correlation with drug exposure during the first 4 h (correlation of C(2) to AUC(0-4): r(2)>0.93 on all days). Absorption of Neoral was low immediately after heart transplantation but improved substantially during the first 5 days after surgery. No single timed measurement of drug concentration reflected cyclosporine exposure; however, the 2-h concentration did provide an accurate measure of the early phase of drug absorption (AUC(0-4)). Oral administration of Neoral may result in inadequate immunosuppression immediately after heart transplantation unless it is supplemented either by intravenous cyclosporine or by the use of an induction agent.