Lower-limb coordination changes following a 6-week training intervention that elicited enhancements to maximum velocity sprint performance.

Alterations to intra- and inter-limb coordination with improved maximal velocity performance remain largely unexplored. This study quantified within-day variability in lower-limb segmental coordination profiles during maximal velocity sprinting and investigated the modifications to coordination strategies in 15 recreationally active males following a 6-week period comprised of a multimodal training programme [intervention group (INT); n=7] or continued participation in sports (control group; n=8). The INT demonstrated a large decrease (effect size=-1.54) in within-day coordination profile variability, suggesting potential skill development. Thigh-thigh coordination modifications for the INT were characterised by an earlier onset of trail thigh reversal in early swing (26 versus 28% stride) and lead thigh reversal in late swing (76 versus 79% stride), rather than increases in overall time spent in anti-phase. Moreover, an increase in backward rotation of thigh relative to shank (effect size, 95% CIs: 0.75, 0.17 to 1.33) and shank relative to foot (0.76, -0.17 to 1.68) during late swing likely facilitated more aggressive acceleration of the limb, contributing to reduced touchdown distance and more favourable lower-limb configuration at initial ground contact. These novel findings provide empirical support for the role of longitudinal coordination modifications in improving maximal velocity performance.

Detection and characterization of hepatic engraftment of embryonic stem derived cells by fluorescent stereomicroscopy.

BACKGROUND: Embryonic stem (ES) cells have been investigated as a potential replacement therapy for failed organs, such as the liver. However, detection of hepatic engraftment from candidate stem cells has been difficult due to low engraftment efficiency. Previous detection methods required that the graft be processed by molecular and/or immunohistochemical techniques, limiting further functional studies. This study evaluated the use of three-dimensional fluorescent stereomicroscopy for gross detection of ES cell derived hepatic engraftment. MATERIAL AND METHODS: Murine ES cells expressing the enhanced green fluorescence protein (EGFP) underwent directed endodermal lineage differentiation. Three days after two thirds partial hepatectomy, cells were injected into the liver parenchyma, and livers were harvested at 10 to 20 d and examined by fluorescence stereomicroscopy with a GFP2 long pass filter (100447084; Leica Microsystems AG, Wetzlar, Germany). The sensitivity and reliability of the test was evaluated using quantitative polymerase chain reaction (q-PCR) to assay for the presence of EGFP mRNA in the tissue. RESULTS: Fluorescent microscopy detected EGFP-positive cells engrafted with normal histology in 5 of 11 specimens. EGFP mRNA was confirmed in all five specimens by q-PCR. Only one of the 11 specimens was negative by fluorescence stereomicroscopy and positive by q-PCR, P < 0.02, Fisher's exact test. CONCLUSION: Utilization of three-dimensional stereomicroscopy with a GFP2 long pass filter is a powerful and fast screening tool for GFP-ES derived hepatic engraftment.

Microsatellite instability testing in colorectal carcinoma: choice of markers affects sensitivity of detection of mismatch repair-deficient tumors.

PURPOSE: Microsatellite instability (MSI) is found in 10% to 15% of sporadic colorectal tumors and is usually caused by defects in DNA mismatch repair (MMR). In 1997, a panel of microsatellite markers including mononucleotide and dinucleotide repeats was recommended by a National Cancer Institute workshop on MSI. We investigated the relationship between instability of these markers and MMR protein expression in a cohort of sporadic colorectal cancer patients. EXPERIMENTAL DESIGN: Paraffin sections of normal and tumor tissue from 262 colorectal cancer patients were examined for MSI status by PCR amplification and for MMR protein expression using antibodies against hMLH1, hPMS2, hMSH2, and hMSH6. RESULTS: Twenty-six (10%) of the patients studied had tumors with a high level of MSI (MSI-H). The frequencies of MSI were the same in African-American and Caucasian patients. Each of the MSI-H tumors had mutations in both mononucleotide and dinucleotide repeats and had loss of MMR protein expression, as did two tumors that had low levels of MSI (MSI-L). These two MSI-L tumors exhibited mutations in mononucleotide repeats only, whereas eight of the other nine MSI-L tumors had mutations in just a single dinucleotide repeat. There was not a statistically significant difference in outcomes between patients whose tumors were MMR-positive or MMR-negative, although there was a slight trend toward improved survival among those with MMR-deficient tumors. CONCLUSIONS: The choice of microsatellite markers is important for MSI testing. Examination of mononucleotide repeats is sufficient for detection of tumors with MMR defects, whereas instability only in dinucleotides is characteristic of MSI-L/MMR-positive tumors.

Upregulation of focal adhesion kinase (FAK) expression in ductal carcinoma in situ (DCIS) is an early event in breast tumorigenesis.

Focal adhesion kinase (FAK) is a protein tyrosine kinase that is overexpressed in a subset of invasive breast cancers. FAK transmits signals that mediate several functions including tumor cell proliferation, migration, adhesion and survival. We used immunohistochemical techniques to assess FAK expression in patients with fibrocystic disease (FCD), atypical ductal hyperplasia (ADH), ductal carcinoma in situ (DCIS) and infiltrating ductal carcinoma (IDC). Formalin-fixed, paraffin-embedded (FFPE) tissue sections were obtained from 119 patients (12 FCD, 38 ADH, 51 DCIS and 18 IDC). The anti-FAK 4.47 monoclonal antibody was used to detect FAK expression. FAK expression was scored as high (3 or 4 intensity and > or =90% positive cells) or low. The DCIS tissue sections demonstrated high FAK expression in 34/51 (66%) of the sections. High FAK expression was demonstrated in 6/18 (33%) of the IDC tissue sections and 8/38 (21%) of the ADH tissue sections. None (0/12) of the FCD tissues sections stained high for FAK. The pattern of FAK expression in DCIS was significantly higher than ADH (p < 0.0001) and IDC (p = 0.02). We conclude that FAK overexpression in preinvasive, DCIS tumors precedes tumor cell invasion or metastasis, suggesting that FAK may function as a survival signal and be an early event in breast tumorigenesis.

A decade of tyrosine kinases: from gene discovery to therapeutics.

Tyrosine kinases are key regulators of breast cancer cell survival and proliferation. Ten years ago, we conducted a screen for protein kinases expressed in primary human breast tumors and cultured cancer cells. Here, we review the progress from the last ten years in understanding the functions of these kinases with a focus on breast cancer. Three themes emerge: (1). tyrosine kinases regulate proliferation through the MAP Kinase pathway, (2). tyrosine kinases regulate cellular survival through the PI3 Kinase-Akt pathway, and (3). the cell cycle is regulated through a complex series of serine-threonine kinases. Our improved understanding of these signaling cascades has led to novel strategies for therapeutic intervention in breast cancer.

Laparoscopic incisional hernia repair in liver transplant and other immunosuppressed patients.

We report the early results of laparoscopic incisional hernia repair in a small group of immunosuppressed patients and compare these results with a cohort of patients with open repair. We describe a modification used to secure the cephalad portion of the Gore-Tex mesh in high epigastric incisional hernias often encountered after liver transplantation. Data were gathered retrospectively for all incisional hernia repairs by our group from March 1996 to January 2001. Twelve of 13 attempted patients had successful completion of their laparoscopic hernia repairs with no reported recurrences to date. Two of these procedures were performed for recurrent hernias. We completed nine of nine attempted laparoscopic hernia repairs in liver transplant patients with epigastric incisional hernias. We repaired two of three attempted lower midline incisional hernias in renal disease patients. One of these patients was soon able to reuse his peritoneal dialysis catheter. A total of 15 patients, 12 with liver transplants, underwent open repair of their incisional hernias. These patients had seven recurrences and/or serious mesh infections with five patients electing repeated operations. In our initial series, laparoscopic mesh repair of incisional hernias is practical and safe in the abdominal organ transplant population with a low incidence of early recurrence and serious infections.