Vitamin D, Calbindin, and calcium signaling: Unraveling the Alzheimer's connection

Calcium is a ubiquitous second messenger that is indispensable in regulating neurotransmission and memory formation. A precise intracellular calcium level is achieved through the concerted action of calcium channels, and calcium exerts its effect by binding to an array of calcium-binding proteins, including calmodulin (CAM), calcium-calmodulin complex-dependent protein kinase-II (CAMK-II), calbindin (CAL), and calcineurin (CAN). Calbindin orchestrates a plethora of signaling events that regulate synaptic transmission and depolarizing signals. Vitamin D, an endogenous fat-soluble metabolite, is synthesized in the skin upon exposure to ultraviolet B radiation. It modulates calcium signaling by increasing the expression of the calcium-sensing receptor (CaSR), stimulating phospholipase C activity, and regulating the expression of calcium channels such as TRPV6. Vitamin D also modulates the activity of calcium-binding proteins, including CAM and calbindin, and increases their expression. Calbindin, a high-affinity calcium-binding protein, is involved in calcium buffering and transport in neurons. It has been shown to inhibit apoptosis and caspase-3 activity stimulated by presenilin 1 and 2 in AD. Whereas CAM, another calcium-binding protein, is implicated in regulating neurotransmitter release and memory formation by phosphorylating CAN, CAMK-II, and other calcium-regulated proteins. CAMK-II and CAN regulate actin-induced spine shape changes, which are further modulated by CAM. Low levels of both calbindin and vitamin D are attributed to the pathology of Alzheimer's disease. Further research on vitamin D via calbindin-CAMK-II signaling may provide newer insights, revealing novel therapeutic targets and strategies for treatment.

Recurrent implant fractures in total hip arthroplasty: a yes-you-yan case report

This case report describes a single patient with recurrent implant fractures of his left total hip replacement. According to our knowledge this is the first patient in literature with recurrent implant fractures. This is a rare phenomenon as reason for revision. Risk factors for implant failure of total hip replacement include a lack of proximal support, a distally well fixed stem with proximal debonding, malalignment of the stem and raised BMI.

Large Region of Homozygous (ROH) Identified in Indian Patients with Autosomal Recessive Limb-Girdle Muscular Dystrophy with p.Thr182Pro Variant in SGCB Gene

The sarcoglycanopathies are autosomal recessive limb-girdle muscular dystrophies (LGMDs) caused by the mutations in genes encoding the α, β, γ, and δ proteins which stabilizes the sarcolemma of muscle cells. The clinical phenotype is characterized by progressive proximal muscle weakness with childhood onset. Muscle biopsy findings are diagnostic in confirming dystrophic changes and deficiency of one or more sarcoglycan proteins. In this study, we summarized 1,046 LGMD patients for which a precise diagnosis was identified using targeted sequencing. The most frequent phenotypes identified in the patients are LGMDR1 (19.7%), LGMDR4 (19.0%), LGMDR2 (17.5%), and MMD1 (14.5%). Among the reported genes, each of CAPN3, SGCB, and DYSF variants was reported in more than 10% of our study cohort. The most common variant SGCB p.Thr182Pro was identified in 146 (12.5%) of the LGMD patients, and in 97.9% of these patients, the variant was found to be homozygous. To understand the genetic structure of the patients carrying SGCB p.Thr182Pro, we genotyped 68 LGMD patients using a whole genome microarray. Analysis of the array data identified a large ~1 Mb region of homozygosity (ROH) (chr4:51817441-528499552) suggestive of a shared genomic region overlapping the recurrent missense variant and shared across all 68 patients. Haplotype analysis identified 133 marker haplotypes that were present in ~85.3% of the probands as a double allele and absent in all random controls. We also identified 5 markers (rs1910739, rs6852236, rs13122418, rs13353646, and rs6554360) which were present in a significantly higher proportion in the patients compared to random control set ( $n=128$ ) and the population database. Of note, admixture analysis was suggestive of greater proportion of West Eurasian/European ancestry as compared to random controls. Haplotype analysis and frequency in the population database indicate a probable event of founder effect. Further systematic study is needed to identify the communities and regions where the SGCB p.Thr182Pro variant is observed in higher proportions. After identifying these communities and//or region, a screening program is needed to identify carriers and provide them counselling.

850 Surgical Versus Non-Surgical Treatment of Unstable Lateral Compression Injuries of the Pelvis with Complete Sacral Fractures (LC1) in Non-Fragility Fracture Patients: A Systematic Review

Background

Lateral compression type 1 (LC1) injuries comprise two-thirds of pelvic fractures. Approximately one third of LC1 fractures are unstable and may benefit from surgical fixation to improve stability but it is not clear if this leads to better clinical or cost-effectiveness outcomes.

Method

We performed a systematic review to determine whether surgical or non-surgical treatment yielded better clinical and cost-effectiveness for the treatment of unstable LC1 pelvic injuries with complete sacral fracture, excluding fragility fractures. We searched Medline, Embase and Cochrane databases from inception to June 2021, as well as clinical trials registries.

Results

Five observational studies met the inclusion criteria. 183 patients were treated surgically, and 314 patients treated non-surgically. Patients treated surgically had lower pain levels (Visual Analogue Scale) and fewer days to mobilisation. Quality of life (EQ-5D and SF-36 questionnaires) was better in the surgical group, but not statistically significant. No statistical differences in length of hospital stay or complication rates were found. Formal meta-analysis was not possible due to available study designs and heterogeneity.

Conclusions

This review highlights the low quantity and quality of existing data on patients with unstable LC1 pelvic fractures and the need for a definitive randomised controlled trial to determine whether surgical or non-surgical care should be the preferred treatment in terms of clinical and cost-effective care.

Enabling ultra-low-voltage switching in BaTiO3

Single crystals of BaTiO₃ exhibit small switching fields and energies, but thin-film performance is considerably worse, thus precluding their use in next-generation devices. Here, we demonstrate high-quality BaTiO₃ thin films with nearly bulk-like properties. Thickness scaling provides access to the coercive voltages (<100 mV) and fields (<10 kV cm^-1) required for future applications and results in a switching energy of <2 J cm^-3 (corresponding to <2 aJ per bit in a 10 × 10 × 10 nm³ device). While reduction in film thickness reduces coercive voltage, it does so at the expense of remanent polarization. Depolarization fields impact polar state stability in thicker films but fortunately suppress the coercive field, thus driving a deviation from Janovec-Kay-Dunn scaling and enabling a constant coercive field for films <150 nm in thickness. Switching studies reveal fast speeds (switching times of ~2 ns for 25-nm-thick films with 5-µm-diameter capacitors) and a pathway to subnanosecond switching. Finally, integration of BaTiO₃ thin films onto silicon substrates is shown. We also discuss what remains to be demonstrated to enable the use of these materials for next-generation devices.

Predicting the disaster - The role of CRP in acetabular surgery

OBJECTIVES

Acetabular fractures represent a complex surgical challenge. Given the heterogenous fracture pattern, the patient characteristics and spectrum of complications demand individual solutions. Surgical site infections (SSI) threaten osteosynthesis, and early detection of them and treatment remain crucial. What is the value of postoperative C-reactive protein (CRP) in this group of patients as well as its normal course?

DESIGN & METHODS

115 patients with isolated fractures of the acetabulum were retrospectively evaluated. CRP, white blood cell count (WBC) and fracture patterns as well as patient characteristics were assessed for 20 days following operative fixation of the acetabular fracture (n = 71) and in fractures that were managed conservatively (n = 44).

RESULTS

Twelve patients suffered an infectious complication. With a one-phase decay, 70.55% of the variance of postoperative CRP kinetics was predicted. To anticipate maximum CRP as well as an infection, the preoperative CRP represented the best prognostic parameter. To predict an infection, the single variable "peak CRP value above 100 mg/l" resulted in a sensitivity and specificity of 91.67% and 36.21%, respectively. Combining a second peak of CRP with maximum CRP and day 5 CRP value for receiver-operating characteristic (ROC) analysis resulted in 83.3% and 88.1%, respectively.

CONCLUSIONS

Predicting surgical site infections after an acetabular fracture is most predictive when analyzing the maximum overall CRP, the second peak and the CRP after day 5. With a combination of these parameters, a sensitivity and specificity of 83.3% and 88.1% to detect an infection was achieved.

Posterior wall acetabular fracture fixation: A mechanical analysis of fixation methods

Stable, anatomical fixation of acetabular fractures gives the best chance of successful outcome, while penetration of the acetabular articular surface with screws is associated with poor outcomes. Spring plates are an alternative to interfragmentary lag screws when penetration is a concern. A mechanical study comparing fracture stability and construct stiffness of three fixation methods for posterior wall acetabular fractures with transverse comminutions was performed. The three fixation methods tested were a posterior wall rim plate, a posterior wall buttress plate with separate lag screws and a posterior wall plate with two spring plates. Nine samples were tested, three for each fixation method. Two-dimensional motion analysis was used to measure fracture fragment displacement and construct stiffness. After two 6000 cycle-loading protocols, to a maximum 1.5 kN, the mean fracture displacement was 0.154 mm for the rim plate model, 0.326 mm for the buttress plate and 0.254 mm for the spring plate model. Mean maximum displacement was significantly less for the rim plate fixation than the buttress plate (p = 0.015) and spring plate fixation (p = 0.02). The rim plate was the stiffest construct 10,962 N/mm, followed by the spring plate model 5637 N/mm and the buttress plate model 4882 N/mm. Based on data obtained in this study, where possible a rim plate with interfragmentary lag screws should be used for isolated posterior wall fractures as this is the stiffest and most stable construct. When this method is not possible, spring plate fixation is a safe and a superior alternative to a posterior buttress plate method.

Atypical Location of an Atrial Myxoma: A Case Report

Here, we report a case of a right atrial myxoma attached to the lateral wall, which is seen in only 10% cases, impinging upon the tricuspid valve. A 57 year old male normotensive, non-diabetic, nonsmoker patient was presented to us on 5th of August 2018 with the complaints of cough, dyspnea and orthopnea for the last two years. This type of presentation is very rare. After excision of myxoma, there was a significant improvement in the signs and symptoms of the patient. In this report, we emphasize the rarity of myxoma in the Right Atrium, and its difficulty in diagnosis because of its uncommon location and atypical presentation, surgical management has shown to quickly alleviate the majority of symptom and expectant sequeale.

Right Atrial Myxoma: An Uncommon Presentation

There are two types of tumors found in the cardiac chamber. These are divided into primary intra-cardiac tumors and secondary intra-cardiac tumors. Primary intra cardiac tumors are rare and among them 29% are myxomas. Majority of them are found in the left atrium. Here, we report a case of a myxoma in the right atrium with hepatomegaly and Hepatitis B virus infection. The coexistence of all these conditions is very rare. A 52 years old patient presented with history of shortness of breath on exertion along with fever and generalized weakness for 6 months which aggravated lately for last 2 months. He was then taken for better medical care and hospitalization. On cardiac evaluation he had soft S1 and S2 over the tricuspid region on the right lower parasternal region. He had bilateral mild pitting pedal edema. On further examination, it was revealed that he had mild tender hepatomegaly with jaundice. His blood analysis for HBsAg was positive. Echocardiogram showed right atrial myxoma of 14.3cm² almost completely occupying the right atrium and even protruding into the Inferior Venacava however not fully obstructing it. The inferior vena cava size was mildly dilated (22mm). Abdominal ultrasound report showed hepatomegaly (17.6cm) with coarse hepatic parenchyma. In this report, we emphasize the rarity of myxoma in the Right Atrium, its difficult diagnosis because of the location and the atypical presentation in the echocardiograph.

8 ANTI-MÜLLERIAN HORMONE AT WEANING AND BREEDING AS A PREDICTOR OF BEEF HEIFER FERTILITY

This study examined the relationship between serum anti-Müllerian hormone (AMH) concentration at weaning and breeding to determine if either or both measures could predict subsequent fertility of beef heifers. Blood was collected from 71 Angus based heifers at ~7 and 14 months of age and serum stored frozen (−20°C) until analysis for AMH, using bovine AMH ELISA kits (AL115; Ansh Laboratories, Webster, TX, USA). Before breeding, transrectal ultrasonography was used to determine cyclic status of heifers. Heifers received 25 mg of prostaglandin F2α (PGF) and those detected in oestrus were AI ~12 h after detected oestrus. Heifers not detected in oestrus after 7 days received a second PGF injection and oestrus detection and AI continued for 4 days. Ten days later, the heifers were exposed to fertile bulls for a 45-days breeding season. At 50 to 60 days after insemination, transrectal ultrasonography was used to identify pregnant heifers and to confirm conception date based on fetal size. At 60 days after bull removal, ultrasonography was performed to determine pregnancy in heifers conceiving during the breeding season and confirm continuing pregnancy in heifers previously identified as pregnant. Based on fetal size at ultrasonography, the oestrous cycle after initiation of breeding when conception occurred was estimated. For comparison, AI pregnancies were considered cycle 1, and pregnancies initiated during subsequent 21-day intervals of the breeding season were classified as cycles 2, 3, and 4, respectively. For analysis, frequency distribution was used to assign serum AMH concentration measured at weaning, breeding, and the change from weaning to breeding, into quartiles. Comparisons were then made via Chi-squared analysis for heifers in each quartile that were cyclic at synchronization, detected in oestrus, conceived after AI, pregnant at the end of the breeding season, and the estimated cycle that conception occurred. Comparison of heifers based on serum AMH quartiles at weaning failed (P ≥ 0.35) to detect any effect of AMH on subsequent heifer cyclicity at breeding, oestrous response after synchronization, AI conceptions, overall pregnancy rate, or estimated oestrous cycle of the breeding season when conception occurred. Based on AMH concentration at breeding, heifers in the lowest quartile (Q1) had a lower (10%; P = 0.02) AI conception rate than heifers in other quartiles (43 to 73%), and conceived at a later oestrous cycle (P = 0.03) in the breeding season. Comparison of heifers based on the change in AMH concentrations from weaning to breeding revealed that none of the heifers in the lowest quartile (Q1) conceived after AI, compared with 80% in the highest quartile (Q4; P < 0.001). Heifers in the lowest quartile also conceived at a later oestrous cycle in the breeding season than heifers in the other quartiles (P = 0.01). Results indicate that either AMH concentration at breeding or the change in AMH from weaning to breeding can identify beef heifers more likely to conceive to AI and to conceive early in the breeding season.

21 EVALUATION OF SEMEN EXTENDERS FOR SHORT-TERM STORAGE OF RAM SEMEN AT 4°C

Preliminary studies found that progressive motility of ram sperm declined ~75% when stored at 4°C for 24 h, and continued to decline over time when using extenders supplemented with 5% egg yolk. The current study evaluated the effects of different combinations of extenders, ethylene glycol (EG), egg yolk, and penicillamine, hypotaurine, and epinephrine on ram sperm progressive motility during storage. Semen collected from 3 Katahdin and 2 Suffolk rams by electroejaculation was distributed across treatment combinations consisting of either TRIS citrate or milk extender supplemented with 5 or 20% (v/v) egg yolk, ± 1% ethylene glycol (EG) and ± 20 µM penicillamine, 10 µM hypotaurine and 2 µM epinephrine (PHE). For each semen collection, TRIS citrate extender was prepared from a 4× solution so that the TRIS, citric acid and fructose concentration were constant at 300, 94.7, 27.8 mM, respectively, regardless of semen dilution factor. A 4× milk extender was also used so that the extender contained 10% (w/v) milk powder, regardless of semen dilution factor. Both extenders were supplemented with 50 µg mL−1 of gentamicin. Semen was diluted in extender to a final concentration of 300 million sperm/mL in 1.5-mL tubes, and cooled to 4°C over a 2- to 3-h period. Semen was evaluated initially and daily for 3 days, using computer-assisted sperm analysis. Repeated-measures data were analysed using the mixed model (JMP 12.0 software; SAS Institute Inc., Cary, NC, USA) for main effects of extender, supplements, and their interactions. Nonsignificant interactions were removed from the model before reanalysis. Data are presented as LSMeans ± standard errors. Initially, sperm progressive motility averaged 41 ± 6.2% across treatments. After an initial decline, overall progressive motility did not change (P > 0.05) significantly (mean of 22.3 ± 1.6 and 23.05 ± 1.3% at 48 and 72 h, respectively). Over time and across treatment combinations, mean progressive motility was maintained to a greater extent (P < 0.01) by milk than TRIS-based extender (28.2 ± 1.1 v. 18.9 ± 1.1%, respectively). Across extenders, progressive motility of sperm was similar (P = 0.50) for 5 and 20% egg yolk (22.2 ± 1.4 v. 24.4 ± 1.4). Addition of 1% EG increased (P < 0.01) progressive motility (25.8 ± 1.05 v. 21.3 ± 1.05). Addition of PHE also increased (P < 0.01) progressive motility from 20.9 ± 1.04 to 26.3 ± 1.04%. There was an interaction between EG and % egg yolk, primarily due to an effect on sperm stored in TRIS citrate extender. Addition of 1% EG to extender containing 5% egg yolk improved (P < 0.01) progressive motility from 18.5 ± 1.5 to 26.9 ± 1.5%). Addition of 1% EG to TRIS citrate extender also increased (P < 0.05) progressive motility, from 14.6 ± 1.5 to 23.2 ± 1.5%. Results indicate that milk extender supplemented with 1% EG, PHE, and either 5 or 20% egg yolk is capable of maintaining progressive motility of ram semen at ~60% of its initial value when stored at 4°C for up to 72 h. Additional studies are needed to evaluate pregnancy rate after insemination of ewes with stored semen.

Examination of commercially available copper oxide wire particles in combination with albendazole for control of gastrointestinal nematodes in lambs

Control of gastrointestinal nematodes (GIN) remains a critical issue due to the prevalence of anthelmintic resistance. The objective of the experiment was to determine the efficacy of copper oxide wire particles (COWP) from three commercial sources and a combination of COWP and albendazole to control GIN and/or Haemonchus contortus in lambs. Naturally infected Katahdin lambs in early June 2014 and 2015 were randomly assigned to receive no COWP (CON; n=9 and 12) or 2g COWP in a gel capsule as Copasure(®) (COP; n=4 and 17; Animax Ltd.), copper oxide-wire form (AUS; n=7 in 2014 only; Pharmplex), Ultracruz™ (ULT; n=8 and 15; Santa Cruz Animal Health™), no COWP and albendazole (CON+alb; n=10 in 2015 only; 15mg/kg BW; Valbazen(®); Zoetis Animal Health), or COWP+alb (n=7 and 11; in 2014, lambs were administered alb on day 3). Lambs grazed grass pastures as a group and were supplemented with 227g/lamb daily of a commercial grain mix (15% crude protein) and the same amount of alfalfa pellets. Feces were collected on days 0 (day of COWP treatment), 7, and 14 for determination of fecal egg counts (FEC). Pooled (2014) or pooled treatment group feces were cultured on days 0, 7, and 14 (2015 only) to determine GIN genera. Data were analyzed using repeated measures in a mixed model, and FEC were log transformed. The predominant GIN on day 0 was H. contortus (87%) in 2014, and there was a mixed population in 2015. The mean FEC was reduced by day 7 in AUS and ULT lambs (treatment×day, P=0.001), and all of the COWP products were similar. By day 14, the AUS FEC were lower than the CON and COP groups. When examining the combination of COWP and synthetic anthelmintic, the FEC of COWP+alb were reduced to nearly 0eggs/g (back-transformed) and lower than the other groups (treatment×day, P=0.001). The percentage of H. contortus in cultured feces was reduced to a greater extent in the COWP than CON or CON+alb groups of lambs. In a mixed GIN population, the COWP products appeared to be similar in efficacy and using a combination of COWP+alb increased the efficacy not only against H. contortus, but all GIN genera present, offering options in the face of resistance to benzimidazoles.

The Pattern of Injury and Workload Associated with Managing Patients After Suicide Attempt by Jumping from a Height

PURPOSE

The aim of this study is to examine the pattern of injuries sustained and the hospital workload generated by patients who deliberately jump from height.

METHOD

One regional trauma centre's admissions were scrutinized to find all patients who jumped, or were suspected of jumping from one storey or greater over a four year period. Patients who died prior to admission were excluded.

RESULTS

41 patients were included. Each patient suffered a mean of 3 injuries. The probability of calcaneal fracture was 0.32, of ankle injury 0.2, tibial fracture 0.2, femoral fracture 0.17, pelvic fracture 0.34, spinal injury 0.51, upper limb injury 0.26, head injury 0.2 and trunk injury 0.32. The mean length of inpatient stay was 7.9 days, rising to 17.9 for the 11 patients requiring intensive care. The average number of operations per patient was 1.5.

CONCLUSION

Patients who jump from height generate large volumes of operative and inpatient workloads. Our data show that there may be a protective effect of limb trauma against lethal head, chest or pelvic injury. Injury to the upper limb is associated with a 4 times greater risk of head injury. The incidence of pelvic injury in this series is higher than in previous work. There was a high incidence of spinal fracture. Patients generated 64 surgical procedures and consumed a mean of 17.9 inpatient days, including prolonged stay in intensive care.

Survey on Street Dog Population in Pokhara Valley of Nepal

A survey was carried out to determine the population of street dogs and people’s opinion about their persistence in Pokhara Valley, Nepal. Information of street dog population was necessary to construct a future animal birth control (ABC) plans. For this, mark-resight survey method was used. Further, local residents were interviewed to know their opinion about the persistence of street dog population in that area. Among total 1767 dogs, 1072 (60.66%) were male, 641 (36.28%) were female and 54 (3.06%) were puppies. About 367 (57.25%) of the female street dogs were already spayed. A total of 371 local residents were interviewed to know their opinion about the causes of persistent street dogs in Pokhara Valley. Numerous reasons were put forward including unmanaged slaughter house (24.5%), abandoned due to disease (15.4%) and abandoned due to unmanageable estrus behavior (10.2%). Future ABC programs may need to consider these factors responsible for maintaining persistent street dog population, to enable control over street dog population in an efficient and sustainable manner.DOI: http://dx.doi.org/10.3329/bjvm.v13i1.23722Bangl. J. Vet. Med. (2015). 13 (1): 65-70

Effect of abiraterone acetate plus prednisone on the pharmacokinetics of dextromethorphan and theophylline in patients with metastatic castration-resistant prostate cancer

PURPOSE

To assess the effect of abiraterone acetate plus prednisone on the pharmacokinetics of dextromethorphan HBr (CYP2D6 substrate) and theophylline (CYP1A2 substrate) in patients with metastatic castration-resistant prostate cancer (mCRPC).

METHODS

Men with progressive metastatic mCRPC who failed gonadotropin-releasing hormone therapy and ≥1 lines of chemotherapy were enrolled. Patients received two doses of dextromethorphan HBr-30 mg (n = 18; group A) or theophylline-100 mg (n = 16; group B) under fasting conditions; one dose on cycle 1, day -8, and the other dose on cycle 1, day 8. Only patients with extensive CYP2D6 metabolizing status were assigned to group A. All patients received continuous daily oral abiraterone acetate (1,000 mg) plus prednisone (10 mg) starting on cycle 1, day 1.

RESULTS

Coadministration of abiraterone acetate plus prednisone increased the systemic exposure of dextromethorphan by approximately 100%. Ratios of geometric means for maximum plasma concentration (C(max)) (275.36%) and area under plasma concentration-time curves from time 0 to 24 h (AUC(24h)) (268.14%) of dextromethorphan were outside the bioequivalence limit. The pharmacokinetics of theophylline was unaltered following coadministration of abiraterone acetate plus prednisone. Ratios of geometric means [C(max); 102.36% and AUC(24h); 108.03%] of theophylline exposure parameters were within the bioequivalence limit. The safety profile of abiraterone acetate was consistent with reported toxicities.

CONCLUSION

Abiraterone acetate plus prednisone increased the exposure of dextromethorphan, suggesting a need for caution when coadministrating with known CYP2D6 substrates. The pharmacokinetics of theophylline was unaffected when coadministered with abiraterone acetate plus prednisone.

Open-label, phase I, pharmacokinetic studies of abiraterone acetate in healthy men

Purpose

To evaluate pharmacokinetics, safety, and tolerability of abiraterone acetate (AA) in healthy men.

Methods

Two phase I studies (dose-escalation study and dose-proportionality study) were conducted in healthy men aged 18–55 years. All subjects received 4 consecutive single doses of AA (250, 500, 750 and 1,000 mg). The dose-escalation study subjects (N = 33) received AA doses in a sequential manner, starting with the lowest dose. The dose-proportionality study subjects (N = 32) were randomly allocated (1:1:1:1) to receive each of the 4 doses in a four-way crossover design.

Results

A dose-related increase in abiraterone exposure was observed in both studies. Over the evaluated dose range, the mean abiraterone maximum plasma concentrations increased from 26 to 112 ng/mL in dose-escalation study and from 40 to 125 ng/mL in dose-proportionality study; the mean area under the plasma concentration–time curve from 0 to the last measurable plasma concentration increased from 155 to 610 ng.h/mL in dose-escalation study, and from 195 to 607 ng.h/mL in dose-proportionality study. In the dose-proportionality study, abiraterone exposure was dose proportional between 1,000 and 750 mg doses; however, the exposure was slightly greater than dose proportional when exposures at 500 and 250 mg doses were compared with the exposure at 1,000 mg. Single doses of AA were well tolerated in healthy men, and safety profile was consistent with its known toxicities in CRPC patients.

Conclusion

Systemic exposure to abiraterone increased with increasing doses of AA (250–1,000 mg) in healthy men; AA was well tolerated in this population.

Planococcus plakortidis sp. nov., isolated from the marine sponge Plakortis simplex (Schulze)

A novel coccoid-shaped strain, AS/ASP6 (II)T, was isolated from a sample taken from Plakortis simplex (Schulze), a marine sponge, collected at a depth of 30 m from the Bay of Bengal. This strain was identified by using a polyphasic taxonomic approach. The results of 16S rRNA gene sequence analysis showed that strain AS/ASP6 (II)T should be assigned to the genus Planococcus . Chemotaxonomic data (A4α-type peptidoglycan; MK-6, MK-7 and MK-8 menaquinones; mainly branched cellular fatty acids; and phosphatidylethanolamine, phosphatidylglycerol and diphosphatidylglycerol as cellular phospholipids) supported taxonomic placement in the genus Planococcus . Phylogenetic analysis of the 16S rRNA gene sequence showed that strain AS/ASP6 (II)T belonged to the genus Planococcus and was closely related to the type strains of Planococcus maritimus (99.1 %) followed by Planococcus rifietoensis (98.6 %), Planococcus maitriensis (98.5 %), Planococcus citreus (98.3 %), Planococcus salinarum (98.1 %), Planococcus columbae (97.9 %), Planococcus donghaensis (97.8 %) and Planococcus antarcticus (97.7 %); DNA–DNA hybridization values obtained were well below the threshold that is required for the proposal of a novel species. The G+C content of the genomic DNA was 51.0 mol%. The phenotypic and genotypic data showed that strain AS/ASP6 (II)T merits recognition as a representative of a novel species of the genus Planococcus , for which the name Planococcus plakortidis sp. nov. is proposed; the type strain is AS/ASP6 (II)T ( = MTCC 8491T = DSM 23997T).

CD23/FcεRII: molecular multi-tasking

CD23 is the low-affinity receptor for immunoglobulin (Ig)E and plays important roles in the regulation of IgE responses. CD23 can be cleaved from cell surfaces to yield a range of soluble CD23 (sCD23) proteins that have pleiotropic cytokine-like activities. The regions of CD23 responsible for interaction with many of its known ligands, including IgE, CD21, major histocompatibility complex (MHC) class II and integrins, have been identified and help to explain the structure-function relationships within the CD23 protein. Translational studies of CD23 underline its credibility as a target for therapeutic intervention strategies and illustrate its involvement in mediating therapeutic effects of antibodies directed at other targets.

SDF-1 and PDGF enhance alphavbeta5-mediated ERK activation and adhesion-independent growth of human pre-B cell lines

CD23 acts through the alphavbeta5 integrin to promote growth of human pre-B cell lines in an adhesion-independent manner. alphavbeta5 is expressed on normal B-cell precursors in the bone marrow. Soluble CD23 (sCD23), short CD23-derived peptides containing the arg-lys-cys (RKC) motif recognized by alphavbeta5 and anti-alphavbeta5 monoclonal antibodies (MAbs) all sustain growth of pre-B cell lines. The chemokine stromal cell-derived factor-1 (SDF-1) regulates key processes during B-cell development. SDF-1 enhanced the growth-sustaining effect driven by ligation of alphavbeta5 with anti-alphavbeta5 MAb 15F-11, sCD23 or CD23-derived RKC-containing peptides. This effect was restricted to B-cell precursors and was specific to SDF-1. The enhancement in growth was associated with the activation of extracellular signal-regulated kinase (ERK) and both these responses were attenuated by the MEK inhibitor U0126. Finally, platelet-derived growth factor also enhanced both alphavbeta5-mediated cell growth and ERK activation. The data suggest that adhesion-independent growth-promoting signals delivered to B-cell precursors through the alphavbeta5 integrin can be modulated by cross-talk with receptors linked to both G-protein and tyrosine kinase-coupled signalling pathways.

Incidence of MRSA surgical-site infection in MRSA carriers in an orthopaedic trauma unit

We examined the incidence of infection with methicillin-resistant Staphylococcus aureus (MRSA) in patients admitted to the Leicester Royal Infirmary Trauma Unit between January 2004 and June 2006. The influence of MRSA status at the time of their admission was examined, together with age, gender and diagnosis, using multi-variant analysis. Of 2473 patients, 79 (3.2%) were MRSA carriers at the time of admission and 2394 (96.8%) were MRSA-negative. Those carrying MRSA at the time of admission were more likely to develop surgical site infection with MRSA (7 of 79 patients, 8.8%) than non-MRSA carriers (54 of 2394 patients, 2.2%, p < 0.001). Further analysis showed that hip fracture and increasing age were also risk factors with a linear increase in relative risk of 1.8% per year.

MRSA carriage at admission, age and the pathology are all associated with an increased rate of developing MRSA wound infection. Identification of such risk factors at admission helps to target health-care resources, such the use of glycopeptide antibiotics at induction and the ‘building-in’ of increased vigilance for wound infection pre-operatively.

Prospective comparison of subcutaneous to intravenous administration of bortezomib in patients with multiple myeloma: Pharmacokinetics, efficacy and toxicity

8046

Bortezomib (Bz) is a novel proteasome inhibitor that is registered for treatment of relapsed or refractory MM as an IV bolus injection. Animal toxicology studies have indicated good local tolerability and an acceptable PK profile of SC injection of Bz supporting together with preliminary clinical data the exploration of this route of administration in humans. We conducted a randomized trial to compare pharmacokinetics/pharmacodynamics (PK/PD), toxicity and efficacy of SC and IV injections of Bz, both at standard dose of 1.3 mg/m2 twice weekly for 2 wks (day 1–4-8–11), with 1 wk rest, for up to 8 cycles. From 01/06 to 10/06, 24 pts with relapsed/refractory MM were randomized to receive Bz either IV (arm A, n = 12) or SC (arm B, n = 12); Patients received a median number of 5 cycles in both groups. The local tolerance of SC injections was good. Response rates were similar in both groups (CR+VGPR/PR/MR: 3/2/1 in arm A, vs 3/2/2 patients in arm B. Grade 3 / 4 adverse events occurred in 7 cases in arm A, vs 5 in arm B, leading to study discontinuation in 5 and 3 cases, respectively. PK analysis: average plasma Cmax values were lower for SC as compared to IV (15 ng/mL at day 1, and 23 at day 11, vs 130 and 127, p < .001), but overall systemic availability as measured by plasma AUC values were comparable between SC and IV administration for both day 1 & 11 (145 and 388 ng.h/mL, vs 133 and 386, p =.7 & .98, respectively). Average Tmax values were less than 1 hour for both routes. PD analysis (20S proteasome inhibition): average area under the curve for effect (AUE) values were comparable between SC and IV administration both for day 1 & 11 (761 and 1,324 %.h, vs 1,089 and 1,110, p = .29 & .54, respectively), while average Emax values were lower for SC administration (Emax day 1 & day 11 SC, 58 and 56%, vs 72 and 69% IV, p =.003 & .01 respectively). The overall systemic availability of Bz was comparable between SC and IV administration for both day 1 and 11. Similarly, the average AUE results were comparable between SC and IV, while average Emax was lower for SC administration. Response rates were identical in the 2 groups of patients, with similar toxicity profile. Given the good local tolerance of SC injection, this route of administration could be an alternative option to IV injection.

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