Noninvasive blood glucose monitoring using the optical signal of pulsatile microcirculation: a pilot study in subjects with diabetes

OBJECTIVE

The objective of this study was to determine the conditions for optimizing measurements obtained with a noninvasive blood glucose monitor using the optical signal of pulsatile microcirculation (OSPM) in both prediabetic and diabetic subjects receiving medication.

RESEARCH DESIGN AND METHODS

Eighteen subjects (3 prediabetic, 15 diabetic) aged 61.8 [15.9] years (mean [S.D.]) were studied. OSPM was the pulsatile component (P) of the signal obtained and analyzed by a blood glucose monitor. The measurement was calibrated to the fingerstick meter for each subject for personal calibration. Data were obtained from all subjects using both meters.

RESULTS

A total of 179 data pairs were measured and analyzed. The validity of the position of the tested finger was assessed using the position criterion, which resulted in the removal of 38 data pairs. The criterion for the intensity of the P signal was satisfied by 141 data pairs, with nonconforming data (with a much lower P signal) mainly occurring below 26 degrees C. A total of 113 data points passed both criteria, and 100% of them fell within Zones A and B of the Clarke error grid. Data in Zones A and B exhibited a linear relationship (r=.81; slope=0.82; intercept=28.0) between noninvasive and fingerstick measurements.

CONCLUSIONS

Environmental temperature has the greatest influence on the capability of the OSPM technique to monitoring blood glucose concentration, which is subject dependent. The position of the tested finger is the second major factor, hence a carefully designed finger adaptor is essential.

Gene expression profile comparison of Barrett's esophagus epithelial cell cultures and biopsies

Barrett's esophagus (BE) is a metaplastic process in which the normal squamous epithelium of the distal esophagus is replaced by columnar lined epithelium. The aim was to gain more insight in the process of metaplasia and to identify which genes are specifically expressed by the epithelial cells and the surrounding tissues in BE. Hereto, the gene expression profile of a BE epithelial primary cell culture was compared to that of a BE biopsy. To specifically obtain the epithelial cell layer, epithelial cells from biopsies of BE were cultured using a Barrett specific culturing medium. Serial analysis of gene expression was applied to obtain a transcription library of the primary epithelial cell culture. The transcriptome was analyzed and compared to a previously described transcriptome of a BE biopsy. Validation of results by reverse transcriptase-polymerase chain reaction was performed using tissues of 16 BE patients and 16 primary cell cultures. Over 43,000 tags were sequenced. Genes specifically expressed by the Barrett epithelial cells were for instance Lipocalin 2 and Cyclin D1, whereas annexin A10, trefoil factor (TFF)1 and TFF2 were specifically expressed in the BE biopsies. The comparison of the gene expression profiles of BE primary cultured epithelial cells with BE biopsy defines a subset of genes that are specifically expressed by the epithelial cells and another subset that most likely is expressed by the underlying stromal tissues in the BE biopsy specimens.

Phase I trial of oral MAC-321 in subjects with advanced malignant solid tumors

PURPOSE

MAC-321 is a novel taxane that has demonstrated exceptional activity in human xenograft models when administered intravenously and orally. Preclinical studies of MAC-321 have shown antitumor activity in MDR-expressing and paclitaxel-resistant tumors. This phase I dose escalation study was performed to determine the safety, tolerability, and pharmacokinetic profile of orally administered MAC-321 given once every 21 days. Preliminary antitumor activity of MAC-321 was also examined.

METHODS

Key eligibility criteria included adult subjects with refractory solid tumors or solid tumors for which conventional therapy was unsuitable or did not exist, good performance status (ECOG ( 2), and adequate hematologic, hepatic, and renal functions. Plasma pharmacokinetic (PK) sampling was performed during the first cycle of therapy.

RESULTS

Five dose levels of MAC-321 ranging from 25 to 75 mg/m(2) were evaluated in 18 subjects (four women and 14 men). MAC-321 was well tolerated at the first three dose levels (25, 37, 50 mg/m(2)). Two subjects developed dose-limiting toxicities (DLTs) at 75 mg/m(2); one subject with grade 3 and one subject with grade 4 neutropenia with fever. Three subjects treated at an intermediate dose level of 60 mg/m(2) had no DLTs. However, the study was terminated prior to completion of the maximal tolerated dose cohort after subjects treated with intravenous MAC-321 in a concurrent study experienced life-threatening toxicities. Other common toxicities included grades 1-2 fatigue and grades 1-2 diarrhea. There was substantial interpatient variability in the PK parameters. MAC-321 was rapidly absorbed with a mean C (max) value of less than 1 h. Mean C (max) and AUC values generally increased in a dose-related manner. The median terminal phase elimination half-life was 45 h (range 20-228 h). Disease stabilization was seen in four subjects with the following tumors: mesothelioma (14 cycles), chondrosarcoma (12 cycles), small cell carcinoma (10 cycles), and prostate carcinoma (6 cycles).

CONCLUSIONS

MAC-321 can be safely administered orally once every 21 days up to a dose of 60 mg/m(2). The major DLT was neutropenic fever. Four subjects had disease stabilization.

Impact of endoscopist withdrawal speed on polyp yield: implications for optimal colonoscopy withdrawal time

BACKGROUND

In 2002, a U.S. Multi-Society Task Force on Colorectal Cancer recommended that the withdrawal phase for colonoscopy should average at least 6-10 min. This was based on 10 consecutive colonoscopies by two endoscopists with different adenoma miss rates.

AIMS

To characterize the relationship between endoscopist withdrawal time and polyp detection at colonoscopy, and to determine the withdrawal time that corresponds to the median polyp detection rate.

DESIGN

Procedural data from out-patient colonoscopies performed at the Mayo Clinic, Rochester during 2003 were reviewed. Endoscopists were characterized by their mean withdrawal time for a negative procedure and individual polyp detection rate.

RESULTS

A total of 10 955 colonoscopies performed by 43 endoscopists were analysed. Median withdrawal time was 6.3 min (range: 4.2-11.9); polyp detection rate was 44.0% (all polyps), 29.8% (< or = 5 mm), 5.9% (6-9 mm), 6.7% (10-19 mm), 2.1% (> or = 20 mm). Longer withdrawal time was associated with higher polyp detection rate (r = 0.76; P < 0.0001); this relationship weakened for larger polyps (r = 0.19 for polyps 6-9 mm, r = 0.28 for polyps 10-19 mm, r = 0.02 for polyps > or = 20 mm). Overall median polyp detection rate corresponded to a withdrawal time of 6.7 min.

CONCLUSION

Our findings support a colonoscopy withdrawal time of at least 7 min, which correlates with higher colon polyp detection rates.

Serum insulin, insulin resistance, beta-cell dysfunction, and gallstone disease among type 2 diabetics in Chinese population: a community-based study in Kinmen, Taiwan

AIM

To explore the association of serum insulin, insulin resistance, and beta-cell dysfunction with gallstone disease (GSD) in type 2 diabetics.

METHODS

We used a community-based study conducted between 1991 and 1993 in Kinmen, Taiwan to identify type 2 diabetics. A screening program for GSD was performed in 2001 by a panel of specialists who employed real-time ultrasound sonography to examine the abdominal region after the patient had fasted for at least 8 h. Screening was conducted in 2001 on 848 patients diagnosed with type 2 diabetes. The HOMA method was used to compare the profile differences for insulin resistance (HOMA IR) and beta-cell dysfunction (HOMA beta-cell).

RESULTS

We studied 440 type 2 diabetics who attended sonography check-ups. After excluding eight insulin-treated diabetics, the prevalence of GSD among the remaining 432 was 13.9% (26/187) among males and 14.7% (36/245) among females. After adjustment for other GSD-associated risk factors in addition to age and obesity, GSD risk increased among females with levels of serum insulin [4(th) vs 1(st) quartile odds ratios (OR) = 4.46 (95%CI: 1.71-11.66)] and HOMA IR [4(th) vs 1(st) quartile OR = 4.46 (95%CI: 1.71-11.66)]. Better HOMA beta-cell function was significantly related to decreased risk of GSD [4(th) vs 1(st) quartile OR = 0.16 (95%CI: 0.03-1.70)]. Among males, age and central obesity were the most significant risk factors for GSD. No association of GSD with serum insulin, HOMA IR, and HOMA beta-cell was observed among males.

CONCLUSION

Serum insulin, insulin resistance, and beta-cell dysfunction are risk factors for GSD in females, but not males with type 2 diabetes.

Inhibition of p38 kinase mimics survival signal-linked protection against apoptosis in rat cerebellar granule neurons

The mitogen-activated protein kinase (MAPK) cascades are thought to be important mediators in the transduction of extracellular signals into cellular responses. The p38 kinase, a member of the MAPK superfamily, is activated by a wide variety of extracellular stimuli and has been implicated in neuronal apoptosis induced by glutamate. In this study we have examined the role of p38 kinase in the potassium deprivation model of apoptosis in rat cerebellar granule neurons (CGN). An increase in p38 kinase activity was observed with a 15-minute potassium deprivation when compared to the basal level. We also found that SB203580 and PD169316, specific p38 kinase inhibitors, significantly attenuated apoptosis in potassium-deprived cells in a dose dependent manner. A decrease in caspase-3 mediated DEVD-MCA, substrate hydrolysis and the appearance of the 120 kDa-spectrin breakdown product in cells treated with SB203580 further suggests that the p38 kinase acts upstream of caspase-3 in the apoptosis cascade. The data provides evidence for an essential role of p38 kinase in mediating apoptotic cell death in CGN and the inhibition of p38 kinase mimics the suppression of apoptosis provided by natural survival signals.

Combined endoscopic mucosal resection and photodynamic therapy for esophageal neoplasia within Barrett's esophagus

BACKGROUND

Endoscopic mucosal resection (EMR) and photodynamic therapy have been proposed as treatments for early stage cancers. EMR is limited by its focal nature whereas photodynamic therapy is dependent on precise staging. The combination of EMR and photodynamic therapy were studied in the treatment of superficial cancer in patients with Barrett's esophagus.

METHODS

Seventeen consecutive nonsurgical patients with superficial cancers underwent EMR followed by photodynamic therapy with a porphyrin photosensitizer. Photoradiation was performed at 630 nm for a total dose of 200 J/cm of diffuser.

RESULTS

Seventeen patients (15 men; mean age 69 +/- 13 years) underwent EMR. The mean diameter of mucosal resection was 1 cm. The margins were involved by cancer in 3 cases. EMR improved staging in 8 patients (47%). Sixteen (94%) patients remained in remission (median follow-up 13 months). Complications included minor bleeding after EMR in 1 patient (6%), stricture in 5 (30%), cutaneous phototoxicity in 2 (12%), and supraventricular tachycardia in 1 patient (6%).

CONCLUSIONS

Combined EMR and photodynamic therapy appears to be an effective and safe therapy for superficial esophageal cancer within Barrett's esophagus. This combination improves cancer staging, removes the superficial cancer, and eliminates remaining mucosa at risk for cancer development.

Novel synthesis of 4,5-diarylphenanthrenes via C2-C6 cyclization of benzannulated enyne-allenes

A new synthetic pathway to the 4,5-diarylphenanthrenes 8 having a helical twist in their structures was developed. The synthetic sequence involves condensation of the diketone 5 with 2 equiv of the lithium acetylides derived from the diacetylenes 4 followed by protonation to produce the propargylic alcohols 6. Reduction of 6 with triethylsilane in the presence of trifluoroacetic acid furnished the tetraacetylenic hydrocarbons 7 in nearly quantitative yields. Treatment of 7 with potassium tert-butoxide under refluxing toluene at 110 degrees C for up to 10 h then furnished the 4,5-diarylphenanthrenes 8. Apparently, the transformation from 7 to 8 involves initial prototropic isomerizations to form the benzannulated enyne-allenes 9. Two subsequent formal intramolecular Diels-Alder reactions via the biradicals 10 and 12 derived from the C(2)-C(6) cyclizations then led to 13, which in turn underwent tautomerizations to give 8. The structure of 8a was established by the X-ray structure analysis, showing that the two phenyl substituents are bent away from each other and the central aromatic system is severely distorted with a helical twist. The existence of a helical twist in 8 imposed by the aryl groups at the 4- and 5-positions was also revealed with a set of AB (1)H NMR signals for the diastereotopic methylene hydrogens on the five-membered rings.

The novel calpain inhibitor SJA6017 improves functional outcome after delayed administration in a mouse model of diffuse brain injury

A principal mechanism of calcium-mediated neuronal injury is the activation of neutral proteases known as calpains. Proteolytic substrates for calpain include receptor and cytoskeletal proteins, signal transduction enzymes and transcription factors. Recently, calpain inhibitors have been shown to provide benefit in rat models of focal head injury and focal cerebral ischemia. The present study sought to investigate, in experiment 1, the time course of calpain-mediated cytoskeletal injury in a mouse model of diffuse head injury by measuring the 150- and 145-kDa alpha-spectrin breakdown products (SBDP). Secondly, in experiment 2, we examined the effect of early (20 min postinjury) administration of the novel calpain inhibitor SJA6017 on functional outcome measured 24 h following injury and its effect on posttraumatic alpha-spectrin degradation. Lastly, in experiment 3, we examined the effect of delayed (4 or 6 h postinjury) administration of SJA6017 on 24-h postinjury functional outcome. In experiment 1, isoflurane-anesthetized male CF-1 mice (18-22 g) were subjected to a 750 g-cm weight drop-induced injury and were sacrificed for SBDP analysis at postinjury times of 30 min, and 1, 2, 6, 24 and 48 h (plus sham). In experiments 2 and 3, mice were injured as described, and delivered a single tail vein injection of either SJA6017 (0.3, 1, or 3 mg/kg) or vehicle (administered immediately, 4 or 6 h postinjury [3 mg/kg]). Functional outcome was evaluated in both studies, and, in experiment 2, 24-h postinjury assessment of SBDPs was determined. Following injury, the level of SBDP 145 was significantly different from sham at 24 and 48 h in cortical and at 24 h in the hippocampal tissues and at 48 h in the striatum. Immediate postinjury administration of SJA6017 resulted in a dose-related improvement in 24-h functional outcome (p < 0.05 at 3 mg/kg). Significance was maintained after a 4-h delay of the 3 mg/kg, but was lost after a 6-h delay. Despite improvement in functional outcome at 24 h, SJA6017 did not reduce spectrin breakdown in cortical or hippocampal tissues. These results support a role for calpain-mediated neuronal injury and the potential for a practical therapeutic window for calpain inhibition following traumatic brain injury. However, measurements of regional spectrin degradation may not be the most sensitive marker for determining the effects of calpain inhibition.

Concurrent assessment of calpain and caspase-3 activation after oxygen-glucose deprivation in primary septo-hippocampal cultures

The contributions of calpain and caspase-3 to apoptosis and necrosis after central nervous system (CNS) trauma are relatively unexplored. No study has examined concurrent activation of calpain and caspase-3 in necrotic or apoptotic cell death after any CNS insult. Experiments used a model of oxygen-glucose deprivation (OGD) in primary septo-hippocampal cultures and assessed cell viability, occurrence of apoptotic and necrotic cell death phenotypes, and protease activation. Immunoblots using an antibody detecting calpain and caspase-3 proteolysis of alpha-spectrin showed greater accumulation of calpain-mediated breakdown products (BDPs) compared with caspase-3-mediated BDPs. Administration of calpain and caspase-3 inhibitors confirmed that activation of these proteases contributed to cell death, as inferred by lactate dehydrogenase release. Oxygen-glucose deprivation resulted in expression of apoptotic and necrotic cell death phenotypes, especially in neurons. Immunocytochemical studies of calpain and caspase-3 activation in apoptotic cells indicated that these proteases are almost always concurrently activated during apoptosis. These data demonstrate that calpain and caspase-3 activation is associated with expression of apoptotic cell death phenotypes after OGD, and that calpain activation, in combination with caspase-3 activation, could contribute to the expression of apoptotic cell death by assisting in the degradation of important cellular proteins.

Biradicals from benzoenyne-allenes. Application in the synthesis of 11H-benzo[b]fluoren-11-ols, 1H-cyclobut[a]indenes, and related compounds

New synthetic pathways to 11H-benzo[b]fluoren-11-ols, 1H-cyclobut[a]indenes, and related compounds via biradicals generated from benzoenyne-allenes were developed. Treatment of the diacetylenic propargylic alcohols 13, derived from condensation between benzophenones and the lithium acetylide of 1-(2-ethynylphenyl)-2-phenylethyne, with thionyl chloride produced the 11-chloro-11H-benzo[b]fluorene 14 and, after hydrolysis, the corresponding 11H-benzo[b]fluoren-11-ols 15. The transformation involved a sequence of reactions, including a biradical-forming C2-C6 cyclization (Schmittel cyclization) reaction of the chlorinated benzoenyne-allene intermediates followed by an intramolecular radical-radical coupling to form the formal Diels-Alder adducts. Interestingly, in the case of the diacetylenic propargylic alcohol 26, obtained from dibenzosuberenone (25), an intramolecular [2 + 2] cycloaddition reaction of the chlorinated benzoenyne-allene intermediate occurred, furnishing the 1H-cyclobut[a]indene 27 exclusively. The dramatic change of the reaction pathway could be attributed to the emergence of a steric strain due to the nonbonded interactions with the chloro substituent along the pathway toward the formal Diels-Alder adduct 31. On the other hand, the non-chlorinated benzoenyne-allene, derived from prototropic isomerization of the diacetylenic hydrocarbon 60, underwent a formal Diels-Alder reaction to furnish the 11H-benzo[b]fluorene-type hydrocarbon 61 exclusively.

Accumulation of non-erythroid alpha II-spectrin and calpain-cleaved alpha II-spectrin breakdown products in cerebrospinal fluid after traumatic brain injury in rats

Although a number of increased CSF proteins have been correlated with brain damage and outcome after traumatic brain injury (TBI), a major limitation of currently tested biomarkers is a lack of specificity for defining neuropathological cascades. Identification of surrogate biomarkers that are elevated in CSF in response to brain injury and that offer insight into one or more pathological neurochemical events will provide critical information for appropriate administration of therapeutic compounds for treatment of TBI patients. Non-erythroid alpha II-spectrin is a cytoskeletal protein that is a substrate of both calpain and caspase-3 cysteine proteases. As we have previously demonstrated, cleavage of alpha II-spectrin by calpain and caspase-3 results in accumulation of protease-specific spectrin breakdown products (SBDPs) that can be used to monitor the magnitude and temporal duration of protease activation. However, accumulation of alpha II-spectrin and alpha II-SBDPs in CSF after TBI has never been examined. Following a moderate level (2.0 mm) of controlled cortical impact TBI in rodents, native alpha II-spectrin protein was decreased in brain tissue and increased in CSF from 24 h to 72 h after injury. In addition, calpain-specific SBDPs were observed to increase in both brain and CSF after injury. Increases in the calpain-specific 145 kDa SBDP in CSF were 244%, 530% and 665% of sham-injured control animals at 24 h, 48 h and 72 h after TBI, respectively. The caspase-3-specific SBDP was observed to increase in CSF in some animals but to a lesser degree. Importantly, levels of these proteins were undetectable in CSF of uninjured control rats. These results indicate that detection of alpha II-spectrin and alpha II-SBDPs is a powerful discriminator of outcome and protease activation after TBI. In accord with our previous studies, results also indicate that calpain may be a more important effector of cell death after moderate TBI than caspase-3.

Caspase-mediated calcineurin activation contributes to IL-2 release during T cell activation

Calcineurin, a Ca(2+)/calmodulin-dependent Ser/Thr phosphatase (protein phosphatase 2B), plays a critical role in IL-2 production during T cell activation. It has been previously reported that IL-2 release in activated Jurkat T requires caspase-like activity (Posmantur et al. (1998) Exp. Cell. Res. 244, 302-309). We report here that the 60-kDa catalytic subunit of calcineurin A (Cn A) was partially cleaved to a 45-kDa form in phytohemagglutinin A (PHA) or phorbol ester + ionomycin (P + I)-activated Jurkat cells. In parallel, proteolytic activation of upstream caspases (caspase-8 and -9) as well as effector caspase-3 was also observed. Cn A cleavage was caspase mediated, since it was inhibitable by pan-caspase inhibitor Cbz-Asp-CH(2)OC(O)-2,6-dichlorobenzene (Z-D-DCB). Cn A cleavage was also observed when purified calcineurin was digested in vitro with caspase-3. Truncated Cn A was associated with enhanced phosphatase activity and reduced calmodulin sensitivity. Furthermore, in PHA or P + I-activated Jurkat cells, dephosphorylation of calcineurin substrate NFATc (a transcription factor known to be involved in transactivation of the IL-2 gene), was also suppressed by Z-D-DCB. Taken together, our results suggest that caspase-mediated cleavage of Cn A contributes to IL-2 production during T cell activation.

The calpain family and human disease

The number of mammalian calpain protease family members has grown to 14 on last count. Overactivation of calpain 1 and calpain 2 (and their small subunit) has long been tied to acute neurological disorders (e.g. stroke and traumatic brain injury) and recently to Alzheimer's disease. Loss-of-function mutations of the calpain 3 gene have now been identified as the cause of limb-girdle muscular dystrophy 2A. Calpain 10 was recently identified as a susceptibility gene for type 2 diabetes, whereas calpain 9 appears to be a gastric cancer suppressor. This review describes our current understanding of the calpain family members and their mechanistic linkages to the aforementioned diseases as well as other emerging pathological conditions.

Temporal and spatial profile of caspase 8 expression and proteolysis after experimental traumatic brain injury

Recent studies have demonstrated that the downstream caspases, such as caspase 3, act as executors of the apoptotic cascade after traumatic brain injury (TBI) in vivo. However, little is known about the involvement of caspases in the initiation phase of apoptosis, and the interaction between these initiator caspases (e.g. caspase 8) and executor caspases after experimental brain injuries in vitro and in vivo. This study investigated the temporal expression and cell subtype distribution of procaspase 8 and cleaved caspase 8 p20 from 1 h to 14 days after cortical impact-induced TBI in rats. Caspase 8 messenger RNA levels, estimated by semiquantitaive RT-PCR, were elevated from 1 h to 72 h in the traumatized cortex. Western blotting revealed increased immunoreactivity for procaspase 8 and the proteolytically active subunit of caspase 8, p20, in the ipsilateral cortex from 6 to 72 h after injury, with a peak at 24 h after TBI. Similar to our previous studies, immunoreactivity for the p18 fragment of activated caspase 3 also increased in the current study from 6 to 72 h after TBI, but peaked at a later timepoint (48 h) as compared with proteolyzed caspase 8 p20. Immunohistologic examinations revealed increased expression of caspase 8 in neurons, astrocytes and oligodendrocytes. Assessment of DNA damage using TUNEL identified caspase 8- and caspase 3-immunopositive cells with apoptotic-like morphology in the cortex ipsilateral to the injury site, and immunohistochemical investigations of caspase 8 and activated caspase 3 revealed expression of both proteases in cortical layers 2-5 after TBI. Quantitative analysis revealed that the number of caspase 8 positive cells exceeds the number of caspase 3 expressing cells up to 24 h after impact injury. In contrast, no evidence of caspase 8 and caspase 3 activation was seen in the ipsilateral hippocampus, contralateral cortex and hippocampus up to 14 days after the impact. Our results provide the first evidence of caspase 8 activation after experimental TBI and suggest that this may occur in neurons, astrocytes and oligodendrocytes. Our findings also suggest a contributory role of caspase 8 activation to caspase 3 mediated apoptotic cell death after experimental TBI in vivo.

Molecular cloning and characterization of a novel caspase-3 variant that attenuates apoptosis induced by proteasome inhibition

Caspase-3 plays an important role in programmed cell death as an execution-phase caspase in degradation of many substrate proteins. We identified a naturally occurring short caspase-3 variant (caspase-3s) from a human carcinoma cell line that is resulted from alternative mRNA splicing. Analysis of nucleotide sequence reveals a deletion of the exon 6 in this variant that resulted in an altered reading frame in the C-terminus, leading to an altered amino acid sequence and a truncated protein. Caspase-3s shares the same amino acid sequence as caspase-3 in the N-terminus containing the prodomain and the majority of the large subunit. The variant is 95 amino acid residues shorter at the C-terminus and is missing the conserved QACRG sequence in the catalytic site. Caspase-3 and caspase-3s are coexpressed in all human tissues examined. Several cancer cell lines also show coexpression of caspase-3 and caspase-3s, both at the mRNA and protein levels. Overexpression of caspase-3s in 293 cells is more resistant to apoptosis induced by proteasome inhibition. Furthermore, we identified that proteasome inhibition stabilized the level of caspase-3s.

Extent of high-grade dysplasia in Barrett's esophagus correlates with risk of adenocarcinoma

BACKGROUND & AIMS

The identification of any high-grade dysplasia (HGD) in Barrett's esophagus has been considered to be an indication for esophagectomy because of the increased risk of cancer. The aim of this study was to determine if a limited extent of HGD has the same potential for cancer as diffuse HGD.

METHODS

A retrospective cohort study was performed to assess the risk of developing adenocarcinoma in relationship to the extent of HGD found on endoscopic surveillance. The extent of HGD was defined as focal if cytologic and/or architectural changes of HGD were limited to a single focus of 5 or fewer crypts and diffuse if more than 5 crypts were involved in a single biopsy specimen or if HGD involved more than one biopsy fragment. The relative risk of cancer was assessed using a Cox proportional hazard model, and cancer-free survival was determined using survival curves.

RESULTS

Sixty-seven patients with diffuse HGD and 33 with focal HGD satisfied selection criteria. Cancer-free survival rates at 1 and 3 years were 93% and 86% for focal HGD compared with 62% and 44% for diffuse HGD (P < 0.001). On univariate analysis, extent of HGD (relative risk, 5.36; 95% confidence interval, 1.84-15.56), nodularity on endoscopy (relative risk, 3.98; 95% confidence interval, 1.97-8.04), and lack of acid suppression (relative risk, 2.48; 95% confidence interval, 1.16-5.28) were associated with an increased risk of esophageal adenocarcinoma. Diffuse HGD had a 3.7-fold increase in the risk of esophageal cancer compared with focal HGD (P = 0.02) on multivariate analysis.

CONCLUSIONS

Patients with focal HGD are less likely to have cancer during the first year after diagnosis or on subsequent follow-up compared with diffuse HGD.

Impact of EUS-guided fine-needle aspiration on lymph node staging in patients with esophageal carcinoma

BACKGROUND

Preoperative identification of lymph node metastases associated with esophageal carcinoma may influence treatment. EUS is the most accurate method for locoregional staging of these tumors. The impact of EUS-guided fine-needle aspiration (EUS-FNA) on lymph node staging in esophageal carcinoma is unclear.

METHODS

From May 1996 to May 1999, 74 patients with esophageal carcinoma underwent preoperative EUS. After October 1998 EUS-guided FNA was performed on nonperitumoral lymph nodes greater than 5 mm in width. The results of EUS with and without FNA were retrospectively reviewed and compared. Final diagnosis was based on surgical results or EUS-guided FNA malignant cytology. Ten of the 74 patients had to be excluded for lack of lymph node stage confirmation. Final diagnosis was obtained in the remaining 64 patients (33 from the EUS only group and 31 from the EUS-FNA group).

RESULTS

The results of EUS versus EUS-FNA for lymph node staging were sensitivity 63% versus 93% (p = 0.01), specificity 81% versus 100% (not significant), and accuracy 70% versus 93% (p = 0.02), respectively. Complications comprised 1 patient who developed self-limited bleeding after dilation that did not preclude completion of the EUS (1%, 95% CI [0%, 7%]).

CONCLUSIONS

EUS-FNA is more sensitive and accurate than EUS alone for preoperative staging of locoregional and celiac lymph nodes associated with esophageal carcinoma. EUS-FNA of nonperitumoral lymph nodes in patients with esophageal carcinoma is safe and should be routinely performed when treatment decisions will be affected by nodal stage.

TNF-alpha stimulates caspase-3 activation and apoptotic cell death in primary septo-hippocampal cultures

Primary septo-hippocampal cell cultures were incubated in varying concentrations of tumor necrosis factor (TNF-alpha; 0.3-500 ng/ml) to examine proteolysis of the cytoskeletal protein alpha-spectrin (240 kDa) to a signature 145 kDa fragment by calpain and to the apoptotic-linked 120-kDa fragment by caspase-3. The effects of TNF-alpha incubation on morphology and cell viability were assayed by fluorescein diacetate-propidium iodide (FDA-PI) staining, assays of lactate dehydrogenase (LDH) release, nuclear chromatin alterations (Hoechst 33258), and internucleosomal DNA fragmentation. Incubation with varying concentrations of TNF-alpha produced rapid increases in LDH release and nuclear PI uptake that were sustained over 48 hr. Incubation with 30 ng/ml TNF-alpha yielded maximal, 3-fold, increase in LDH release and was associated with caspase-specific 120-kDa fragment but not calpain-specific 145-kDa fragment as early as 3.5 hr after injury. Incubation with the pan-caspase inhibitor, carbobenzosy- Asp-CH(2)-OC (O)-2-6-dichlorobenzene (Z-D-DCB, 50-140 microM) significantly reduced LDH release produced by TNF-alpha. Apoptotic-associated oligonucleosomal-sized DNA fragmentation on agarose gels was detected from 6 to 72 hr after exposure to TNF-alpha. Histochemical changes included chromatin condensation, nuclear fragmentation, and formation of apoptotic bodies. Results of this study suggest TNF-alpha may induce caspase-3 activation but not calpain activation in septo-hippocampal cultures and that this activation of caspase-3 at least partially contributes to TNF-alpha-induced apoptosis.

EUS-guided fine-needle aspiration combined with flow cytometry and immunocytochemistry in the diagnosis of lymphoma

BACKGROUND

Limited information is available regarding the use of EUS-guided fine-needle aspiration (EUS-FNA) in the diagnosis of lymphoproliferative disorders. The aim of this study was to evaluate the yield of this technique in the primary diagnosis of lymphoma.

METHODS

The records were reviewed of 38 consecutive patients with GI lesions and/or enlarged lymph nodes identified on imaging studies that raised a suspicion of lymphoma who underwent EUS-FNA of lymph nodes or the gut wall. Final diagnosis was based on clinical follow-up, imaging studies, or surgical findings.

RESULTS

Twenty-three patients with lymphoma and 15 patients with benign disease or reactive lymphadenopathy were identified. The overall sensitivity, specificity, and accuracy of EUS-FNA cytology with flow cytometry/immunocytochemistry (FC/IC) for the diagnosis of lymphoma were, respectively, 74%, 93%, and 81%. When comparing patients who had EUS-FNA with FC/IC versus those who had EUS-FNA without FC/IC, sensitivity was 86% versus 44% (p = 0.04), specificity was 100% versus 90% (not significant), and accuracy was 89% versus 68% (not significant).

CONCLUSION

EUS-FNA can provide cytology specimens diagnostic for lymphoma. Selective use of FC/IC in patients with suspected lymphoma improves the yield of EUS-FNA and may guide diagnostic evaluation and treatment decisions.

Endoscopic application of photodynamic therapy for cholangiocarcinoma

BACKGROUND

Previous studies indicate that photodynamic therapy provides effective relief from biliary obstruction in advanced cholangiocarcinoma. This report describes a method of applying photodynamic therapy in the biliary tract by using accessories available in the United States.

METHODS

Endoscopic retrograde cholangiography was performed to define the proximal and distal extent of intraductal tumor. Patients were injected with 2 mg/kg of sodium porfimer. Forty-eight hours later a commercially available cylindrical diffusing laser fiber was inserted into an 8F biliary catheter equipped with a 0.038 inch side-hole at its distal tip. After positioning of a 0.035 inch guidewire proximal to the biliary stricture, the preloaded catheter was advanced over the guidewire by using the monorail technique. Laser light was applied at a power of 400 mW/cm fiber for a total energy of 180 J/cm.(2)

RESULTS

Fourteen treatments were performed on 6 patients with tumors of Bismuth types IV (n = 2), III (n = 3), or II (n = 1). By using the preloaded biliary catheter, adequate positioning of the laser fiber was achieved in all patients. A fracture of the diffuser tip occurred during 1 of the treatments. Two patients developed acute cholangitis and 2 patients experienced skin phototoxicity.

CONCLUSIONS

Photodynamic therapy for cholangiocarcinoma is safe and technically feasible with a preloaded biliary catheter and a monorail technique for catheter positioning.

Biomarkers in Barrett esophagus

Barrett esophagus is a premalignant condition that may progress to adenocarcinoma. The risk of developing cancer has been estimated to be approximately 1 in 250 patient-years of observation; however, there appear to be subsets of patients at much higher risk. Risk stratification has previously been determined by histological identification of dysplasia. Several new biomarkers are being tested to help clinicians better determine the risk of cancer development. Although none of these biomarkers has been proven in a prospective study to predict the onset of cancer, they have been correlated with cancer development. Most of these are factors that have been associated with cancer development in other organs. These include assessment of cell proliferation, expression of cyclooxygenase 2, growth factors and oncogenes, secretory factors, cell cycle proteins, adhesion molecules, and aneuploidy and other genetic abnormalities. In addition to their role as potential cancer biomarkers, these factors have increasingly been reported as surrogate markers to monitor the effectiveness of conservative treatments for Barrett esophagus. In this article, biological markers are reviewed for their relevance in Barrett esophagus. Although most biological markers need to be evaluated further and, for most, prospective follow-up studies are lacking, at present abnormal ploidy status, P16 and P53 gene abnormalities, or allelic losses are the most extensively documented.

Mucosal ablation therapy of barrett esophagus

Barrett esophagus is defined by the metaplasia of existing squamous mucosa into a specialized intestinal-type mucosa. The importance of this metaplasia is the association of this condition with the development of adenocarcinoma of the esophagus. Elimination of the metaplastic mucosa may decrease the cancer risk. Currently, several forms of therapy have evolved with the goal of replacing the specialized mucosa with normal squamous mucosa. These proposed treatments include photodynamic therapy and thermal techniques. The effectiveness of photodynamic therapy varies depending on the pharmaceutical photosensitizer used and the wavelength of light applied to activate the drug. Thermal techniques include multipolar coagulation, argon plasma coagulation, KTP:YAG laser therapy, Nd:YAG laser therapy, and argon laser therapy. Finally, mucosal resection has been attempted through the endoscope to remove large areas of the Barrett mucosa. All of these ablative strategies attempt to destroy the metaplastic mucosa and promote the regrowth of squamous epithelium. These therapies have demonstrated the ability to "reverse" the metaplasia to varying degrees, but a decrease in cancer risk has not been demonstrated conclusively with any of these treatment methods.