Endoscopic laser speckle imaging of tissue blood flow: applications in the human knee

This work represents the first clinical data acquired with the endoscopic laser speckle imaging (eLSPI) system, a new diagnostic tool developed for real-time imaging of tissue blood flow during endoscopic surgical procedures. eLSPI was used to image tissue perfusion in the medial compartment of the knee of five patients requiring arthroscopic knee surgery. The effectiveness of eLSPI as a diagnostic tool was tested by measuring changes in tissue perfusion resultant from tourniquet application, and intra-articular epinephrine. eLSPI produced real-time perfusion video images of tissue blood flow in the knee joint. Tourniquet applications produced consistent decreases in mean perfusion index measurements (29.3% +/- 5.1% in meniscus; 39.5% +/- 8.2% in synovium with an intra patient variability of 6%-9%). A dose-dependent vasoconstrictive response to the administration of intra-articular epinephrine was measured, with maximum dose producing a mean decrease in perfusion of 31.0%-9.3% in meniscus and 41.2%-10.9% in synovium. eLSPI consistently detects decreases in articular tissue blood flow resultant from tourniquet inflation or from the administration of increasing concentrations of epinephrine. These are the first in vivo results indicating physiologic changes in articular tissue as a function of two commonly applied practices in endoscopic joint surgery.

Upregulation of calcium-sensing receptor and mitogen-activated protein kinase signalling in the regulation of growth and differentiation in colon carcinoma

In the present study, we demonstrate that Ca²⁺-induced growth inhibition and induction of differentiation in a line of human colon carcinoma cells (CBS) is dependent on mitogen-activated protein (MAP) kinase signaling and is associated with upregulation of extracellular calcium-sensing receptor (CaSR) expression. When CBS cells were grown in Ca²⁺-free medium and then switched to medium supplemented with 1.4 mM Ca²⁺, proliferation was reduced and morphologic features of differentiation were expressed. E-cadherin, which was minimally expressed in nonsupplemented medium, was rapidly induced in response to Ca²⁺ stimulation. Sustained activation of the extracellular signal-regulated kinase (ERK) occured in Ca²⁺-supplemented medium. When an inhibitor of ERK activation (10 μM U0126) was included in the Ca²⁺-supplemented culture medium, ERK-activation did not occur. Concomitantly, E-cadherin was not induced, cell proliferation remained high and differentiation was not observed. The same level of Ca²⁺ supplementation that induced MAP kinase activation also stimulated CaSR upregulation in CBS cells. A clonal isolate of the CBS line that did not upregulate CaSR expression in response to extracellular Ca²⁺ was isolated from the parent cells. This isolate failed to produce E-cadherin or undergo growth inhibition/induction of differentiation when exposed to Ca²⁺ in the culture medium. However, ERK-activation occurred as efficiently in this isolate as in parent CBS cells or in a cloned isolate that underwent growth reduction and differentiation in response to Ca²⁺ stimulation. Together, these data indicate that CaSR upregulation and MAP kinase signalling are both intermediates in the control of colon carcinoma cell growth and differentiation. They appear to function, at least in part, independently of one another.

A laser speckle imaging technique for measuring tissue perfusion

Laser Doppler imaging (LDI) has become a standard method for optical measurement of tissue perfusion, but is limited by low resolution and long measurement times. We have developed an analysis technique based on a laser speckle imaging method that generates rapid, high-resolution perfusion images. We have called it laser speckle perfusion imaging (LSPI). This paper investigates LSPI output and compares it to LDI using blood flow models designed to simulate human skin at various levels of pigmentation. Results show that LSPI parameters can be chosen such that the instrumentation exhibits a similar response to changes in red blood cell concentration (0.1%-5%, 200 microL/min) and velocity (0-800 microL/min, 1% concentration) and, given its higher resolution and quicker response time, could provide a significant advantage over LDI for some applications. Differences were observed in the LDI and LSPI response to tissue optical properties. LDI perfusion values increased with increasing tissue absorption, while LSPI perfusion values showed a slight decrease. This dependence is predictable, owing to the perfusion algorithms specific to each instrument, and, if properly compensated for, should not influence each instrument's ability to measure relative changes in tissue perfusion.

Report of 34 patients with clonal chromosomal abnormalities in Philadelphia-negative cells during imatinib treatment of Philadelphia-positive chronic myeloid leukemia

Imatinib mesylate (Gleevec), an inhibitor of the BCR-ABL tyrosine kinase, was introduced recently into the therapy of chronic myeloid leukemia (CML). Several cases of emergence of clonal chromosomal abnormalities after therapy with imatinib have been reported, but their incidence, etiology and prognosis remain to be clarified. We report here a large series of 34 CML patients treated with imatinib who developed Philadelphia (Ph)-negative clones. Among 1001 patients with Ph-positive CML treated with imatinib, 34 (3.4%) developed clonal chromosomal abnormalities in Ph-negative cells. Three patients were treated with imatinib up-front. The most common cytogenetic abnormalities were trisomy 8 and monosomy 7 in twelve and seven patients, respectively. In 15 patients, fluorescent in situ hybridization with specific probes was performed in materials archived before the initiation of imatinib. The Ph-negative clone was related to previous therapy in three patients, and represented a minor pre-existing clone that expanded after the eradication of Ph-positive cells with imatinib in two others. However, in 11 patients, the new clonal chromosomal abnormalities were not detected and imatinib may have had a direct effect. No myelodysplasia was found in our cohort. With a median follow-up of 24 months, one patient showed CML acceleration and two relapsed.

Endoscopic laser imaging of tissue perfusion: new instrumentation and technique

BACKGROUND AND OBJECTIVES

New instrumentation, based on a previously established laser speckle perfusion imaging (LSI) technique is evaluated for its ability to capture and generate blood flow images during endoscopic surgery.

STUDY DESIGN/MATERIALS AND METHODS

Investigations are detailed in an in-vitro blood flow model simulating physiological properties of vascularized tissue, and in-vivo in rabbit joint capsule tissue.

RESULTS

In-vitro measurements showed a linear response of the instrument to blood flow in the range of 0-800 microl/minute, where data points were significantly correlated with an r(2) value of 0.96. In-vivo measurements showed a 58.7% decrease to the medial collateral ligament during occlusion of the femoral artery.

CONCLUSIONS

Blood flow images demonstrate that the endoscopic LSI technique is capable of measuring relative tissue blood flow changes at high resolutions and rapid response times and incorporates well with endoscopic surgeries.

Comparison of laser speckle and laser Doppler perfusion imaging: measurement in human skin and rabbit articular tissue

Laser Doppler perfusion imaging (LDI) is currently used in a variety of clinical applications, however, LDI instruments produce images of low resolution and have long scan times. A new optical perfusion imager using a laser speckle measurement technique and its use for in vivo blood flow measurements are described. Measurements of human skin and surgically exposed rabbit tissue made using this instrument were compared with a commercial laser Doppler perfusion imaging instrument. Results from blood flow measurements showed that the laser speckle imager measured an 11-67% decrease in blood flow under arterial occlusion. Under similar conditions, the laser Doppler imager measured blood flow decreases of 21-63%. In comparison with LDI, it was observed that the higher temporal resolution of the laser speckle imager was more sensitive to measuring the hyperaemic response immediately following occlusion. This in vivo study demonstrated some of the several advantages laser speckle imaging has over conventional LDI, making the new instrument more versatile in a clinical environment.

Therapy for anomia in semantic dementia

Semantic dementia is a commonly accepted term for a language disorder resulting from neurodegenerative changes due to frontotemporal dementia. An intervention program was designed to halt and/or decelerate the effects of progressive anomia in AK, a 63-year-old female with semantic dementia. Pictorial stimuli were selected and labeled with their respective names and a description most relevant to AK's experience. Daily homework assignments were carried out, during which AK looked at the picture, read the label aloud, and read the description. Positive short-term effects of treatment were observed on treated items.

Using focus group methods to develop multicultural cancer pain education materials

Methods to treat cancer pain effectively have existed for more than 2 decades. However, the effective treatment of cancer pain continues to elude many patients with cancer who suffer from poor management. Although efforts to address the problem of cancer pain in the United States have acknowledged the importance of patient education and advocacy, few endeavors, to date, have attended to the special needs of inner-city, low-literacy, or socioeconomically disadvantaged patients from minority cultural groups. From 1992 to 1995, the Boston Cancer Pain Education Program, funded by the National Cancer Institute and the American Cancer Society, worked collaboratively with community representatives using focus group methods to develop a culturally sensitive, linguistically appropriate cancer pain education booklet in 11 languages and for 11 ethnic groups. The booklet serves as a guide for patients and families and is to be used as a teaching tool by clinicians. The focus group approach was used to develop materials that would empower patients and families to more effectively participate in pain management when working with health care providers from cultures other than their own. Qualitative data analysis methods were used to analyze transcripts of taped focus group sessions. Themes emerged from the data regarding pain and its culturally competent management as well as the group process of booklet development.

Congenital muscular dystrophy with rigid spine syndrome: a clinical, pathological, radiological, and genetic study

Rigid spine syndrome is a term first proposed by Dubowitz to describe a subset of patients affected by myopathy with early spinal contractures as a prominent feature. While spinal rigidity is a nonspecific feature, found in Emery-Dreifuss muscular dystrophy and in some congenital myopathies, it is also a prominent feature in a group of patients with merosin-positive congenital muscular dystrophy, where it is generally associated with stable or only slowly progressive weakness and early respiratory insufficiency. Recently, the first locus for congenital muscular dystrophy in association with rigid spine syndrome was mapped to chromosome 1p35-p36 in consanguineous Moroccan, Turkish, and Iranian families. We present here a detailed phenotypic description of the familial syndrome linked to this locus, describing 4 siblings (3 boys and 1 girl) of Northern European-American heritage who are the offspring of a nonconsanguineous marriage. All 4 siblings were affected by hypotonia and prominent neck weakness in infancy, early spinal rigidity, and early scoliosis. After initial improvement, muscle strength stabilizes or slowly declines, and skeletal deformities and respiratory insufficiency supervene. Muscle biopsy in an affected child at age 9 months revealed minimal, nonspecific myopathic changes, leading to a diagnosis of "minimal change myopathy." Muscle biopsy in his sibling, at the age of 14 years, revealed chronic and severe myopathic (dystrophic) changes, with normal staining for laminin-2 and for proteins of the dystrophin-glycoprotein complex. A possible explanation for these biopsy findings is that magnetic resonance imaging of the thighs reveals stereotyped selective muscle involvement, with the selectivity more pronounced early in the disease course followed by widespread muscular signal abnormalities in the late stages of the disease. In this family, linkage to the chromosome 1p rigid spine syndrome locus (RSMD1) is supported by maximum LOD scores for several markers of 1.81 at theta = 0, representing the maximum statistical power possible for this family. In combination with the previous report, this syndrome is linked to the RSMD1 locus with a summated maximum LOD score of 6.29, and analysis of recombination events in our family narrows the previously reported RSMD1 locus to 3 centiMorgans.