Assessment of Epithelial Lining Fluid Partitioning of Systemically Administered Monoclonal Antibodies in Rats

For systemically administered monoclonal antibodies (mAbs) with pharmacological targets in the epithelial lining fluid (ELF), information on the partitioning of mAb between plasma and ELF is instrumental for dose predictions. Bronchoalveolar lavage (BAL) combined with measurements of urea as indicator of sample dilution is often used to estimate ELF concentrations of a drug. However, unbalanced extraction of mAb and urea could potentially lead to a systematic bias in the back-calculated ELF concentration. In the present study 0.5, 1, or 4 mL phosphate-buffered saline was instilled to lungs of rats to obtain lavage samples after systemic dosing of mAb and tool small molecule (n≥4/group). Furthermore, extraction of urea, mAb and the small molecule was assessed by repeatedly lavaging the lung (n = 4). There was no statistically significant difference in the calculated partitioning into ELF between the evaluated instillation volumes. Repeated BAL demonstrated that urea and the small molecule were extracted from other sources than the ELF. In contrast, there was limited to none in-flow of mAb into the lavage fluid. The unbalanced extraction of urea and mAb could theoretically result in underestimated ELF concentrations and the calculated partitioning of 0.17±0.062 might therefore constitute a lower boundary for the true partitioning.

A Randomized Placebo-Controlled Trial of Metformin for Frailty Prevention in Older Adults

Frailty is a progressive physical decline leading to higher morbidity and mortality in older adults. Previous studies have demonstrated shared mechanisms between insulin resistance, inflammation, and frailty. The purpose of this trial is to determine whether metformin prevents frailty in non-frail, community-dwelling older adults (≥65 years) with pre-diabetes, determined by 2-hour oral glucose tolerance test (OGTT). Frail individuals (Fried criteria) and those with renal impairment (glomerular filtration rate <45 mL/min) are excluded. Eligible participants are randomized to metformin or placebo and followed for two years. The primary outcome is frailty; secondary outcomes include physical function (short physical performance battery), systemic and skeletal muscle inflammation (plasma and muscle inflammatory markers), muscle insulin signaling (muscle biopsy), insulin sensitivity (insulin clamp), glucose tolerance (OGTT), and body composition (dual-energy x-ray absorptiometry) measurements. Participants are followed every 3 months for safety assessments, every 6 months for frailty assessment and OGTT, and every 12 months for muscle biopsy. Currently, 99 participants, including 53 (53.5%) male and 91 (91.9%) white, are active (54) or have completed the study (35). At baseline, mean age was 72.3 ± 5.5 years, body mass index was 30.7 ± 5.9 kg/m2, and Hemoglobin A1c was 5.73 ± 0.37%. Mean frailty score was 0.5 ± 0.6 and the proportion of non-frail and pre-frail participants were 58.6% (n = 58) and 41.5% (n = 41), respectively. Findings of this clinical trial may have future implications for the use of metformin in older adults with pre-diabetes in order to prevent the onset of frailty.

Fiber degradation and carbohydrate production by combined biological and chemical/physicochemical pretreatment methods of lignocellulosic biomass - A review

Sustainable biorefinery concepts based on lignocellulosic biomass are gaining worldwide research interest because of their inexpensiveness and abundance. The recalcitrance of lignocellulosic biomass poses a major hindrance to enhance biofuel production. Therefore, a pretreatment step is critical to prepare the substrates for the downstream process. Combining pretreatment steps help to lower the severity of the drawbacks of a single pretreatment step. This paper systematically reviews the combined biological and chemical/physicochemical pretreatment based on fiber degradation and sugar yield. An energy-efficient biological pretreatment method combined with a chemical pretreatment that accelerates the pretreatment times has been seen to be efficient for fiber degradation and sugar yields. However, fungal species, culture conditions, biomass type, the severity of chemical pretreatment and the order of sequential pretreatment influences the relative component contents and sugar yield. Even the same biomass from different sources undergoing similar pretreatment conditions could result in a varying amount of digestibility.

Rationale for the advancement of PI3K pathway inhibitors for personalized chordoma therapy

PURPOSE

Chordomas are rare and serious tumors with few effective treatments outside of aggressive surgery and radiation. Targeted therapies may present a more effective option for a subset of patients with lesions possessing certain genetic biomarkers.

METHODS

A small molecule inhibitor library was tested in patient-derived UM-Chor1 cells to identify targeted therapies with potential efficacy. Targeted exome sequencing of UM-Chor1 and UM-Chor2 cells was performed to investigate genetic aberrations in relevant pathways. Chordoma cell lines were treated with inhibitors of the phosphotidylinositol 3-kinase (PI3K), epidermal growth factor receptor (EGFR), and cyclin dependent kinase (CDK) pathways, and responses were determined using resazurin cell viability assays, Annexin V apoptosis assays, and western blotting. Pan-PI3K inhibitor BKM120 was also tested in five chordoma xenograft models.

RESULTS

Unbiased small molecule profiling nominated PI3K-AKT-mTOR pathway inhibitors as a promising therapy in chordoma, and genetic analyses of UM-Chor1 and UM-Chor2 cell lines revealed aberrations in PTEN, EGFR, and CDKN2A. Treatment of UM-Chor1 and UM-Chor2 with targeted PI3K, EGFR, and CDK inhibitors inhibited growth and proliferation and induced apoptosis more robustly than imatinib, a currently used chordoma therapy. Furthermore, BKM120 significantly inhibited tumor growth in a subset of the xenograft models tested.

CONCLUSION

Targeted therapies, especially those inhibiting PI3K, display promising effects in multiple chordoma cell line and xenograft models. Nevertheless, the limited effects of PI3K, EGFR, and CDK targeting agents in other models reveal the presence of resistance mechanisms, which motivates future research to both identify biomarkers of response and develop combination therapies.

Manipulating ligand–nanoparticle interactions and catalytic activity through organic-aqueous tunable solvent recovery

Tunable solvents are leveraged to recover dispersed, PVP-stabilized gold nanoparticles and to manipulate the amount of ligand passivating the surface thereby altering the catalytic activity.

HIV infection, sexual risk behaviour and condom use in the Belize defense force

This study is the first Biological and Behavioral Surveillance Survey to be conducted among personnel in the Belize Defense Force. The purpose of the study was to understand the prevalence of HIV infection and risk behaviours, and to identify key correlates of sexual risk behaviours. A representative sample of personnel underwent serological testing and an Audio Computer-Assisted Self Interview. Of those sampled, 351 completed a blood test and 334 completed a behavioural interview. The prevalence of HIV was 1.14%. Twelve percent had ever reported being diagnosed with a sexually transmitted infection (STI) or screened positive for HIV infection. The odds of ever having an STI/HIV were higher among those who had less education, those who had sex with a commercial sex worker (CSW), those who ever engaged in receptive anal sex and those with post-traumatic stress disorder (PTSD). Alcohol abuse and PTSD were prevalent and associated with HIV risk behaviours. These results are being used to inform current prevention efforts.

Gamma 3 gene-disrupted mice selectively deficient in the dominant IgG subclass made to bacterial polysaccharides. II. Increased susceptibility to fatal pneumococcal sepsis due to absence of anti-polysaccharide IgG3 is corrected by induction of anti-polysaccharide IgG1

Bacterial polysaccharides (PS) are type 2 T-independent Ags that elicit Abs restricted in isotype to IgM and predominantly IgG2 in humans and IgM, and IgG3 in mice. Humans with IgG2 subclass deficiency are susceptible to sinus and pulmonary infections with PS-encapsulated bacteria. We previously developed an IgG3-deficient mouse by disrupting the gamma3 H chain constant region gene via targeted mutagenesis. Mutant mice lacking IgG3 were backcrossed for 10 generations to wild-type (WT) BALB/c mice to generate BALB/c mice that have complete absence of IgG3. WT mice immunized with type 3 Streptococcus pneumoniae capsular PS made anti-PS IgM, IgG3, and small quantities of IgG1, which opsonized S. pneumoniae for killing by polymorphonuclear leukocytes. These mice were protected against death from lethal doses of type 3 S. pneumoniae. In contrast, IgG3(-/-) mice made similar titers of anti-PS IgM and IgG1 as WT mice but no IgG3, and had poorly opsonic sera with significantly increased mortality after S. pneumoniae challenge. Immunization of IgG3(-/-) mice with type 3 S. pneumoniae PS conjugated to carrier protein CRM(197)-elicited IgM and high-titer IgG1 Abs, restored serum opsonization, and gave protection from mortality after S. pneumoniae, challenge comparable to WT mice. We conclude that mice lacking the dominant IgG3 subclass made to bacterial PS are more susceptible to fatal S. pneumoniae sepsis than WT mice, but that IgG1 induced by a S. pneumoniae glycoconjugate can adequately protect against S. pneumoniae sepsis. This model suggests that IgG subclass of anti-PS Ab is an important component of immunity to encapsulated bacteria.

Phosphatidylinositol 3 kinase contributes to the transformation of hematopoietic cells by the D816V c-Kit mutant

Stem cell factor (SCF) binds the receptor tyrosine kinase c-Kit and is critical for normal hematopoiesis. Substitution of valine for aspartic acid 816 (D816V) constitutively actives human c-Kit, and this mutation is found in patients with mastocytosis, leukemia, and germ cell tumors. Immortalized murine progenitor cells (MIHCs) transduced with wild-type c-Kit proliferate in response to SCF, whereas cells expressing D816V c-Kit (MIHC-D816V) are factor-independent and tumorigenic. However, the mechanisms mediating transformation by D816V c-Kit are unknown. The objective of this study was to identify signaling components that contribute to D816V c-Kit-mediated transformation. SCF stimulates association of p85PI3K with phosphorylated tyrosine 721 of wild-type c-Kit. Phosphatidylinositol 3 kinase (PI3K) subsequently contributes to the activation of Akt and Jnks. In contrast, these studies demonstrated that the D816V c-Kit mutant was constitutively associated with phosphorylated p85PI3K, and, downstream of PI3K, Jnk 1 and Jnk 2 were activated but Akt was not. Interestingly, Erks 1 and 2 were not constitutively activated by D816V c-Kit. Thus, D816V c-Kit maintains the activity of PI3K but not of all signaling pathways activated by wild-type c-Kit. Further, all pathways downstream of PI3K are not constitutively active in MIHC-D816V cells. Studies with a PI3K inhibitor and D816V/Y721F c-Kit, a mutant incapable of recruiting PI3K, indicate that constitutive activation of PI3K through direct recruitment by D816V c-Kit plays a role in factor-independent growth of MIHC and is critical for tumorigenicity.

Adenocarcinoma of the stomach in an adolescent presenting as pneumoperitoneum: a brief report

BACKGROUND

Adenocarcinoma of the stomach is rare in children and adolescents. A unique case, presenting as an acute abdomen with pneumoperitoneum, is discussed.

METHODS

Case presentation and literature review.

RESULTS

A 13-year-old girl with perforated gastric adenocarcinoma treated by wedge resection developed metastatic disease within two months and died within six months despite chemotherapy.

CONCLUSION

Frozen section of all perforated gastric ulcers, with resection/postoperative chemotherapy for adenocarcinoma.

SUMMARY

A 13-year-old girl with gastric adenocarcinoma presented with pneumoperitoneum. Within two months of wedge resection widespread metastatic disease was documented by computerized tomography scan and laparoscopy and despite chemotherapy, the patient died within six months. Frozen section of all perforated gastric ulcers, even in children, and definitive formal gastrectomy with postoperative chemotherapy, offer the only chance of cure.

Outpatient transurethral resection of the prostate at a urological ambulatory surgery center

Transurethral resection of the prostate has been the standard treatment for patients with benign prostatic hyperplasia, and it has traditionally required 2 to 7 days of hospitalization. Since 1991 we performed outpatient transurethral resection of the prostate at a urological ambulatory surgery center on 125 select patients. Standard resection techniques were used with particular attention to hemostasis, since bladder irrigation was stopped before patients were discharged home. Transfer to a hospital was required for 3 patients because of hematuria, 1 for fever and suspected bacteremia, and 1 for cardiac dysrhythmia. No patient required hospitalization after he was discharged from the ambulatory surgery center. Outpatient transurethral resection of the prostate can be performed safely with excellent patient satisfaction and cost-effectiveness. Alternative treatment modalities for benign prostatic hyperplasia should be evaluated against outpatient transurethral resection of the prostate before they are broadly embraced.

Reliability of a functional mobility assessment tool with application to neurologically impaired patients: a preliminary report

The purpose of this preliminary study was to examine the intratester and intertester reliability of a functional mobility assessment tool (FMAT). Seven licensed physical therapists with varying amounts of clinical experience served as raters. Twelve patients with neurological deficits were subjects for this study. Raters were asked to provide eight possible ratings for each of eight critical mobility functions. Average weighted kappa coefficients ranged from .82 to .97. Intraclass correlation coefficients ranged from .73 to .97 for the first assessment and from .52 to .97 for the second (retest) assessment. A high degree of agreement between and within seven raters indicated that this tool may provide an effective assessment of stroke, brain injury, and spinal cord injury. Preliminary findings indicate the functional mobility assessment tool is reliable, thereby increasing the usefulness of this method for clinical assessment. The high resolution of the FMAT makes this tool ideally suited for use in future studies focusing on the prediction of mobility function following neurological insult.

A computerized kinematic diagnostic system

This paper describes the instrumentation developed for a clinical system that measures upper extremity kinematics in normal and cerebral palsied children. The ability to diagnose cerebral palsy during early and midinfancy is influenced by the fact that movement and postural abnormalities become apparent only over time, and are not readily detectable until there is sufficient abnormality so that it can be viewed by gross inspection during clinical examination. The methodology presented here serves to discriminate normal from deviant movement at an earlier age than what is presently possible, and may also result in alternative therapeutic intervention.

Teaching car passenger safety to preschool children

An educational curriculum entitled "Bucklebear" was designed to increase safety seat and seat belt use in young children enrolled in preschool programs (day care centers and nursery schools). Three basic concepts were emphasized: (1) "buckling up" is a good habit for everyone for every ride; (2) the back seat is the best seat; and (3) there are desirable passenger behaviors. The curriculum included training workshops with teachers, parent meetings, classroom lessons, sound filmstrip, puppet play, and many other activities. Six experimental programs and seven control programs with 402 and 427 enrolled children, respectively, participated. After their participation in the educational curriculum, children in the experimental program increased their use of a safety seat or seat belt from 21.9% to 44.3%. These children also increased their knowledge and simulated practice of car passenger safety.