Revisiting Bone Marrow Core Biopsy Adequacy Criteria in the Era of Extensive Ancillary Testing.

BACKGROUND: Bone marrow core biopsy is a routine component of comprehensive marrow evaluation, and adequacy criteria have been recommended. However, the effectiveness of these adequacy criteria for diagnostic bone marrow evaluation needs to be reassessed in the current era of extensive ancillary testing. We aimed to determine the impact of core biopsy length and intertrabecular area of evaluable bone marrow on overall adequacy for diagnostic marrow evaluation at our tertiary care institution. METHODS: Five hundred sequential cases of iliac crest bone marrow sampling were identified by retrospective re-view at our tertiary care institution. In this cohort, 470 core biopsies were obtained for histologic evaluation. Data including gross core biopsy length, number of intertrabecular 40x high power fields of evaluable marrow, and other pathologic/clinical parameters were compiled. RESULTS: The mean core biopsy length was 1.2 cm, and only 23% measured the recommended ≥ 1.5 cm. However, 96% of the core biopsies were interpretable and contributed to the comprehensive bone marrow evaluation. Notably, 100% of biopsies with ≥ 5.5 intertrabecular areas were contributory. Ancillary testing including immunophenotypic, cytogenetic, and/or molecular studies were performed in > 99% of cases. CONCLUSIONS: When histology was integrated with ancillary testing, the overall diagnosis was substantially limited in only 0.4% of cases and material deemed entirely insufficient in 0.4%. The number of intertrabecular 40x areas of evaluable marrow is a better predictor of adequacy than core biopsy length, and adequacy criteria should be revised in this era of extensive ancillary testing.

Low Levels of Physical Activity Among Older Persons Living with HIV/AIDS Are Associated with Poor Physical Function.

Antiretroviral therapy (ART) has prolonged lives of persons living with HIV/AIDS (PLWHA), resulting in greater incidence of aging-related diseases and disability. Physical activity (PA) is recommended for healthy aging, but little is known about PA in older PLWHA. The purpose of this study was to objectively assess PA levels in older PLWHA and the associations with physical function. Twenty-one PLWHA, ≥50 years old, on ART with undetectable HIV-1 viral loads, wore an accelerometer to assess PA, including number of steps, activity intensity, and energy expenditure over 7 days. A physical function performance battery assessing aerobic capacity, strength, and gait speed was also completed. Average age was 66, and 67% were male. An average of 3,442 (interquartile range: 4,613) steps were walked daily, with 254.9 kcals expended. Participants spent most waking hours (75%) sedentary, with minimal hours (24%) in light-intensity activity. Only 5 min per day (35 min per week), on average, were spent in moderate-to-vigorous physical activity (MVPA). Maximal gait speed and 6-min walk test significantly correlated (p < .05) with all PA outcomes. Usual gait speed significantly correlated with all PA outcomes, except for daily kcals and light-intensity activity. Greater PA was associated with better physical performance, while high sedentary time was associated with poorer performance. To our knowledge, this is the first study to objectively measure PA in older PLWHA. Our findings indicate that older PLWHA accumulate substantial sedentary time. Most (86%) do not achieve recommended MVPA levels. This activity profile was associated with poor physical function. Providers should promote PA among PLWHA.

Spectrum of variations in dog-1/FANCJ and mdf-1/MAD1 defective Caenorhabditis elegans strains after long-term propagation.

BACKGROUND: Whole and partial chromosome losses or gains and structural chromosome changes are hallmarks of human tumors. Guanine-rich DNA, which has a potential to form a G-quadruplex (G4) structure, is particularly vulnerable to changes. In Caenorhabditis elegans, faithful transmission of G-rich DNA is ensured by the DOG-1/FANCJ deadbox helicase. RESULTS: To identify a spectrum of mutations, after long-term propagation, we combined whole genome sequencing (WGS) and oligonucleotide array Comparative Genomic Hybridization (oaCGH) analysis of a C. elegans strain that was propagated, in the absence of DOG-1 and MDF-1/MAD1, for a total of 470 generations, with samples taken for long term storage (by freezing) in generations 170 and 270. We compared the genomes of F170 and F470 strains and identified 94 substitutions, 17 InDels, 3 duplications, and 139 deletions larger than 20 bp. These homozygous variants were predicted to impact 101 protein-coding genes. Phenotypic analysis of this strain revealed remarkable fitness recovery indicating that mutations, which have accumulated in the strain, are not only tolerated but also cooperate to achieve long-term population survival in the absence of DOG-1 and MDF-1. Furthermore, deletions larger than 20 bp were the only variants that frequently occurred in G-rich DNA. We showed that 126 of the possible 954 predicted monoG/C tracts, larger than 14 bp, were deleted in unc-46 mdf-1 such-4; dog-1 F470 (JNC170). CONCLUSIONS: Here, we identified variants that accumulated in C. elegans' genome after long-term propagation in the absence of DOG-1 and MDF-1. We showed that DNA sequences, with G4-forming potential, are vulnerable to deletion-formation in this genetic background.

Cyclin B3 and dynein heavy chain cooperate to increase fitness in the absence of mdf-1/MAD1 in Caenorhabditis elegans.

Spindle assembly checkpoint (SAC) ensures genome stability by delaying anaphase onset until all the chromosomes have achieved proper spindle attachment. Once correct attachment has been achieved, SAC must be silenced. In the absence of mdf-1/MAD1, an essential SAC component, Caenorhabditis elegans cannot propagate beyond 3 generations. Previously, in a dog-1(gk10)/FANCJ mutator background, we isolated a suppressor of mdf-1(gk2) sterility (such-4) which allowed indefinite propagation in the absence of MDF-1. We showed that such-4 is a Cyclin B3 (cyb-3) duplication. Here we analyze mdf-1 such-4; dog-1, which we propagated for 470 generations, with freezing of samples for long time storage at F170 and F270. Phenotypic analysis of this strain revealed additional suppression of sterility in the absence of MDF-1, beyond the effects of such-4. We applied oligonucleotide array Comparative Genomic Hybridization (oaCGH) and whole genome sequencing (WGS) and identified a further amplification of cyb-3 (triplication) and a new missense mutation in dynein heavy chain (dhc-1). We show that dhc-1(dot168) suppresses the mdf-1(gk2), and is the second cloned suppressor, next to cyb-3 duplication, that does not cause a delay in anaphase onset. We also show that amplification of cyb-3 and dhc-1(dot168) cooperate to increase fitness in the absence of MDF-1.

Cytoplasmic cAMP-sensing domain of hyperpolarization-activated cation (HCN) channels uses two structurally distinct mechanisms to regulate voltage gating.

Voltage gating of hyperpolarization-activated cation (HCN) channels is potentiated by direct binding of cAMP to a cytoplasmic cAMP-sensing domain (CSD). When unliganded, the CSD inhibits hyperpolarization-dependent opening of the HCN channel gate; cAMP binding relieves this autoinhibition so that opening becomes more favorable thermodynamically. This autoinhibition-relief mechanism is conserved with that of several other cyclic nucleotide receptors using the same ligand-binding fold. Besides its thermodynamic effect, cAMP also modulates the depolarization-dependent deactivation rate by kinetically trapping channels in an open state. Here we report studies of strong open-state trapping in an HCN channel showing that the well-established autoinhibition-relief model is insufficient. Whereas deletion of the CSD mimics the thermodynamic open-state stabilization usually associated with cAMP binding, CSD deletion removes rather than mimics the kinetic effect of strong open-state trapping. Substitution of different CSD sequences leads to variation of the degree of open-state trapping in the liganded channel but not in the unliganded channel. CSD-dependent open-state trapping is observed during a voltage-dependent deactivation pathway, specific to the secondary open state that is formed by mode shift after prolonged hyperpolarization activation. This hysteretic activation-deactivation cycle is preserved by CSD substitution, but the change in deactivation kinetics of the liganded channel resulting from CSD substitution is not correlated with the change in autoinhibition properties. Thus the liganded and the unliganded forms of the CSD respectively provide the structural determinants for open-state trapping and autoinhibition, such that two distinct mechanisms for cAMP regulation can operate in one receptor.

Air-inflated magnetic resonance colonography in patients with incomplete conventional colonoscopy: Comparison with intraoperative findings, pathology specimens, and follow-up conventional colonoscopy.

BACKGROUND: To assess the usefulness of air-inflated magnetic resonance colonography (MRC) in patients with incomplete conventional colonoscopy (CC). METHODS: From September 2001 to December 2004, 51 patients (25 male and 26 female, age range 32 to 85 years) with incomplete colonoscopy were recruited to have MRC performed. Half-fourier single short turbo spin echo (HASTE) axial, coronal, and three dimensional fat suppressed gradient echo sequence (VIBE) coronal images in both the prone and supine positions were performed for each patient. MRC was reviewed by two radiologists for detection of synchronous colonic lesion. The location and size of lesions were recorded and were compared with the findings of CC. Patients were managed according to the clinical situation and intraoperative findings were compared with MRC findings. Follow-up colonoscopy was performed in 29 patients. The follow-up colonoscopy findings were then compared with the MRC findings. RESULTS: Forty-four patients had incomplete colonoscopy because of an obstructing tumor. The other seven patients had incomplete colonoscopy because of excessive bowel looping. Apart from one patient suffering from chronic obstructive airway disease with resulting nondiagnostic MRC, all other patients had MRC successfully performed. Each colon was divided into six bowel segments for analysis. All 300 segments were of diagnostic quality and were assessed by the MRC. MRC correctly identified all 44 obstructing tumors demonstrated by initial CC. Synchronous tumors in proximal colonic segments were identified in two patients by MRC. In addition, MRC identified two colonic tumors located in bowel segments inaccessible by CC because of excessive looping. CONCLUSIONS: MRC is useful for detection of colonic pathology and assessment of proximal colon in patients with colonic cancer after incomplete colonoscopy.

Sonography of plantar fibromatosis.

OBJECTIVE: Plantar fibromatosis is a rare benign fibroproliferative disorder of the plantar fascia that can be evaluated on sonography. Our study details the sonographic appearances of plantar fibromatosis. MATERIALS AND METHODS: We conducted a retrospective review of the clinical presentation, sonographic appearances, and clinical progress in 14 patients (range, 35-85 years; mean age, 53.1 years;) with plantar fibromatosis. Sonography was performed using either a 13-5-MHz multidimensional or 12.5-MHz linear array transducer. The location, sonographic appearances, and size of the plantar fibromatosis nodules were noted and correlated with symptom duration and clinical outcome. RESULTS: A total of 25 fibromatosis nodules in 19 feet were examined. On sonography, plantar fibromatosis was seen as a discrete fusiform nodular thickening of the plantar fascia, separate from the calcaneal insertion. Approximately one third (36%) of lesions were bilateral, and one quarter (26%) were multiple. All lesions were located either medially (60%) or centrally (40%) in the fascia. Most were hypoechoic (76%), were well defined (64%), and showed no acoustic enhancement (80%) or intrinsic vascularity (92%). No correlation was found between the echogenicity and size of plantar fibromatosis nodules or duration of symptoms (p < 0.01). One quarter of the affected feet had coexistent thickening of the plantar fascia at the calcaneal insertion with no related symptoms. CONCLUSION: Although the sonographic appearances of plantar fibromatosis vary, the appearances are characteristic enough to allow a specific diagnosis to be made. No clear relationship was found among the sonographic appearances, duration of symptoms, or clinical outcome.