Occlusion Pressures of Tactical Pneumatic Tourniquet 2".

BACKGROUND: The Tactical Pneumatic Tournqiuet 2" (TPT2, 5.1cm-wide deflated) allows total average applied pressure measurement, which should be useful toward development of emergency-use limb tourniquet certification devices. METHODS: The TPT2 hand bulb was replaced with stopcocks and syringes, allowing filling with continuous pressure measurement. Forearm and mid-thigh applications involved two sets of five Doppler-based pulse gone/return pairs. Second set pulse gones were chosen a priori for occlusion pressures (preliminary work indicated greater consistency in second sets). RESULTS: All 68 forearms occluded (30 female, 38 male, median circumference 17.8cm, range 14.6-23.5cm; median second set of pulse gone tourniquet pressures 176mmHg, range 128-282mmHg). Fifty-five thighs occluded (median circumference 54.3cm, range 41.6-62.4cm; median systolic pressure 126mmHg, range 102-142mmHg; median second set of pulse gone pressures 574mmHg, range 274-1158mmHg). Thirteen thigh applications were stopped without occlusion because of concerning pressures combined with no indication of imminent occlusion and difficulties forcing more air into the TPT2 (3 female, 10 male, peak pressures from 958-1377mmHg, median 1220mmHg, p<.0001 versus occluded thighs; median circumference 63.3cm, range 55.0-72.9cm, p<.0001 versus occluded thighs; median systolic pressure 126mmHg, range 120-173mmHg, p<.019 versus occluded thighs). Thigh TPT2 impression widths on five subjects after occlusion were as follows: 3.5cm, occlusion 274mmHg; 2.8cm, occlusion 348mmHg; 2.9cm, occlusion 500mmHg; 2.8cm, occlusion 782mmHg; 2.7cm, occlusion 1114mmHg. CONCLUSIONS: Though probably useful to tourniquet certification, the required pressures for thigh occlusion make the TPT2 undesirable for any clinical use, emergency or otherwise.

Final efficacy and cost analysis of a fish skin graft vs standard of care in the management of chronic diabetic foot ulcers: a prospective, multicenter, randomized controlled clinical trial.

INTRODUCTION: DFUs remain a cause of significant morbidity. OBJECTIVE: This is the third of 3 planned articles reporting on a prospective, multicenter, randomized controlled trial evaluating the use of omega-3-rich acellular FSG compared with CAT in the management of DFUs. MATERIALS AND METHODS: A total of 102 patients with a DFU (n = 51 FSG, n = 51 CAT) participated in the trial as ITT candidates, with 77 of those patients included in the PP analysis (n = 43 FSG, n = 34 CAT). Six months after treatment, patients with healed ulcers were followed up for ulcer recurrence. A cost analysis model was applied in both treatment groups. RESULTS: The proportion of closed wounds at 12 weeks was compared, as were the secondary outcomes of healing rate and mean PAR. Diabetic foot wounds treated with FSG were significantly more likely to achieve closure than those managed with CAT (ITT: 56.9% vs 31.4%; P =.0163). The mean PAR at 12 weeks was 86.3% for FSG vs 64.0% for CAT (P =.0282). CONCLUSIONS: Treatment of DFUs with FSG resulted in significantly more wounds healed and an annualized cost savings of $2818 compared with CAT.

Evaluating the effect of omega-3-rich fish skin in the treatment of chronic, nonresponsive diabetic foot ulcers: penultimate analysis of a multicenter, prospective, randomized controlled trial.

OBJECTIVE: This is the second of 3 planned articles reporting on a prospective, multicenter, randomized controlled trial assessing the efficacy of fish skin graft in the management of diabetic foot ulcers in comparison with the standard of care (collagen alginate dressing). MATERIALS AND METHODS: The primary end point of this prospective randomized trial is the number of closed wounds at 12 weeks. RESULTS: As of the time of this writing, 94 patients had completed the protocol. At 12-week follow-up, healing was achieved in 63.0% of index ulcers (29 of 46 patients) in the acellular fish skin graft group compared with 31.3% in the control group (15 of 48 patients) (P =.0036). In both groups, the mean time to healing was 7 weeks. The median number of applications of the fish skin graft to achieve healing was 6. CONCLUSION: A clinically and statistically significant difference in healing was observed between patients treated with acellular fish skin graft and those treated with a collagen alginate dressing. The data support the completion of this prospective randomized trial.

Unusual presentation of lepidic adenocarcinoma in a healthy female.

BACKGROUND: Lepidic adenocarcinoma represents a histologic pattern of non-small cell lung cancer that characteristically arises in the lung periphery with tracking alongside pre-existing alveolar walls. Noninvasive and invasive variants of lepidic adenocarcinoma are dependent on parenchymal destruction, vascular, or pleural invasion. The lepidic-predominant lung malignancies are collectively recognized as slow growing with rare metastasis and excellent prognosis. The World Health Organization classification of lung malignancies depends on molecular and histopathological findings. CT findings most commonly include ground-glass characteristics, commonly mistaken for inflammatory or infectious etiology. These tumors are generally surgically resectable and associated with better survival given infrequent nodal and extrathoracic involvement. Rarely these tumors present with diffuse pneumonic-type involvement associated with worse outcomes despite lack of nodal and distant metastases. CASE PRESENTATION: A 63-year-old Caucasian athletic immunocompetent female presented with 2 months of progressive shortness of breath, fatigue, loss of appetite and 15 pound weight loss. History was only notable for well controlled essential hypertension and hypothyroidism. Contrast computed tomography angiogram and positron emission tomography revealed diffuse hypermetabolic interstitial and airspace abnormalities of the lungs without lymphadenopathy (or distant involvement) in addition to right hydropneumothorax and left pleural effusion. Baseline laboratory testing was unremarkable, and extensive bacterial and fungal testing returned negative. Bronchoscopy and video-assisted thoracoscopic surgery was subsequently performed with pleural fluid cytology, lung and pleural biopsies returning positive for lepidic adenocarcinoma with 2% programmed death ligand 1 expression and genomic testing positive for PTEN gene deletion. Prior to treatment, the patient perished on day 15 of admission. CONCLUSION: We present a rare case of lepidic predominant adenocarcinoma with extensive bilateral aerogenous spread in the context of no lymphovascular invasion in a healthy, low risk patient. This case presentation may add to the body of knowledge regarding the different behavior patterns of lepidic predominant adenocarcinomas.

A Multicenter, Blinded, Randomized Controlled Clinical Trial Evaluating the Effect of Omega-3-Rich Fish Skin in the Treatment of Chronic, Nonresponsive Diabetic Foot Ulcers.

INTRODUCTION: Omega-3-rich fish skin grafts have been shown to accelerate wound healing in full-thickness wounds. OBJECTIVE: The goal of this study was to compare the fish skin graft with standard of care (SOC) using collagen alginate dressing in the management of treatment-resistant diabetic foot ulcers (DFUs), defined as superficial ulcers not involving tendon capsule or bone. MATERIALS AND METHODS: Patients with DFUs who were first treated with SOC (offloading, appropriate debridement, and moist wound care) for a 2-week screening period were then randomized to either receiving SOC alone or SOC plus fish skin graft applied weekly for up to 12 weeks. The primary endpoint was the percentage of wounds closed at 12 weeks. RESULTS: Forty-nine patients were included in the final analysis. At 12 weeks, 16 of 24 patients' DFUs (67%) in the fish skin arm were completely closed, compared with 8 of 25 patients' DFUs (32%) in the SOC arm (P value = .0152 [N = 49]; significant at P < .047). At 6 weeks, the percentage area reduction was 41.2% in the SOC arm and 72.8% in the fish skin arm. CONCLUSIONS: The application of fish skin graft to previously nonresponsive DFUs resulted in significantly more fully healed wounds at 12 weeks than SOC alone. The study findings support the use of fish skin graft for chronic DFUs that do not heal with comprehensive SOC treatment.

Cost Effectiveness of Fish Skin Grafts Versus Standard of Care on Wound Healing of Chronic Diabetic Foot Ulcers: A Retrospective Comparative Cohort Study.

INTRODUCTION: Health care policy decision makers seek the highest quality products at the lowest cost for their patients. Cost-benefit analysis is a helpful tool and can be used together with other sources of information to ensure the most efficient use of medical resources. OBJECTIVE: The objective of this retrospective comparative cohort study is to evaluate the cost effectiveness of fish skin therapy compared with standard of care (SOC) on chronic diabetic foot ulcers (DFUs). METHODS: Retrospective patient data collected in a single wound care setting from 2014 to 2017 were included. In total, 59 DFUs treated with fish skin were used to calculate transition probabilities for a Markov model in which a hypothetical patient cohort treated with fish skin was compared with an identical hypothetical patient cohort treated with SOC. Cost was from the perspective of the payer, and the time horizon was set at 1 year. RESULTS: The model indicated that fish skin treatment could result in lower costs ($11 210 vs. $15 075 per wound), more wounds healing (83.2% vs. 63.4%), fewer amputations (4.6% vs. 6.9%), and a higher quality of life (0.676 vs. 0.605 quality-adjusted life year [QALY]) than the SOC. A probabilistic sensitivity analysis, based on a Monte Carlo simulation, indicated that the fish skin treatment (on DFUs) would be 93.6% likely to be cost effective for a willingness to pay at $100 000 per QALY and 71.4% likely to be cheaper than SOC. CONCLUSIONS: Including fish skin grafts in the SOC for DFU treatment has the potential to reduce costs while improving patient outcomes.

Acellular Fish Skin Graft Use for Diabetic Lower Extremity Wound Healing: A Retrospective Study of 58 Ulcerations and a Literature Review.

OBJECTIVE: This retrospective study evaluates the efficacy of acellular fish skin graft for the treatment of full-thickness diabetic foot ulcers (DFUs). The primary objective is to calculate the total wound surface area (cm2) healed over a 16-week period. The secondary objective is to provide a systematic review on acellular fish skin grafts. MATERIALS AND METHODS: There were 51 patients with a total of 58 DFUs treated with an acellular fish skin graft by the principal investigator. The initial wound surface area at first application was compared with the final wound surface area to conclude the percentage of total wound healed over a 16-week treatment period. RESULTS: At 16 weeks, there was a mean reduction of wound surface area by 87.57% and 35 wounds (60.34%) fully healed. The systematic literature review included 10 fish graft articles, 3 of which specifically evaluated lower extremity ulcers. The reviewed studies supported improved wound healing with fish graft application, with benefits noted in dentistry, neurology, and wound care. CONCLUSIONS: This retrospective study further supports previous evidence that acellular fish skin graft promotes wound healing in DFUs. In particular, a rapid increase in wound healing was observed during the initial 4 weeks following graft application. This study and review of the literature indicated that fish graft encourages wound healing by enabling the wound to transition from a chronic to an acute stage of healing.

Inhibition of the mitochondrial calcium uniporter prevents IL-13 and allergen-mediated airway epithelial apoptosis and loss of barrier function.

Mitochondria are increasingly recognized as key mediators of acute cellular stress responses in asthma. However, the distinct roles of regulators of mitochondrial physiology on allergic asthma phenotypes are currently unknown. The mitochondrial Ca2+ uniporter (MCU) resides in the inner mitochondrial membrane and controls mitochondrial Ca2+ uptake into the mitochondrial matrix. To understand the function of MCU in models of allergic asthma, in vitro and in vivo studies were performed using models of functional deficiency or knockout of MCU. In primary human respiratory epithelial cells, MCU inhibition abrogated mitochondrial Ca2+ uptake and reactive oxygen species (ROS) production, preserved the mitochondrial membrane potential and protected from apoptosis in response to the pleiotropic Th2 cytokine IL-13. Consequently, epithelial barrier function was maintained with MCU inhibition. Similarly, the endothelial barrier was preserved in respiratory epithelium isolated from MCU-/- mice after exposure to IL-13. In the ovalbumin-model of allergic airway disease, MCU deficiency resulted in decreased apoptosis within the large airway epithelial cells. Concordantly, expression of the tight junction protein ZO-1 was preserved, indicative of maintenance of epithelial barrier function. These data implicate mitochondrial Ca2+ uptake through MCU as a key controller of epithelial cell viability in acute allergic asthma.

Mitochondrial CaMKII inhibition in airway epithelium protects against allergic asthma.

Excessive ROS promote allergic asthma, a condition characterized by airway inflammation, eosinophilic inflammation, and increased airway hyperreactivity (AHR). The mechanisms by which airway ROS are increased and the relationship between increased airway ROS and disease phenotypes are incompletely defined. Mitochondria are an important source of cellular ROS production, and our group discovered that Ca2+/calmodulin-dependent protein kinase II (CaMKII) is present in mitochondria and activated by oxidation. Furthermore, mitochondrial-targeted antioxidant therapy reduced the severity of allergic asthma in a mouse model. Based on these findings, we developed a mouse model of CaMKII inhibition targeted to mitochondria in airway epithelium. We challenged these mice with OVA or Aspergillus fumigatus. Mitochondrial CaMKII inhibition abrogated AHR, inflammation, and eosinophilia following OVA and A. fumigatus challenge. Mitochondrial ROS were decreased after agonist stimulation in the presence of mitochondrial CaMKII inhibition. This correlated with blunted induction of NF-κB, the NLRP3 inflammasome, and eosinophilia in transgenic mice. These findings demonstrate a pivotal role for mitochondrial CaMKII in airway epithelium in mitochondrial ROS generation, eosinophilic inflammation, and AHR, providing insights into how mitochondrial ROS mediate features of allergic asthma.

CaMKII inhibition in type II pneumocytes protects from bleomycin-induced pulmonary fibrosis by preventing Ca2+-dependent apoptosis.

The calcium and calmodulin-dependent kinase II (CaMKII) translates increases in intracellular Ca(2+) into downstream signaling events. Its function in pulmonary pathologies remains largely unknown. CaMKII is a well-known mediator of apoptosis and regulator of endoplasmic reticulum (ER) Ca(2+). ER stress and apoptosis of type II pneumocytes lead to aberrant tissue repair and progressive collagen deposition in pulmonary fibrosis. Thus we hypothesized that CaMKII inhibition alleviates fibrosis in response to bleomycin by attenuating apoptosis and ER stress of type II pneumocytes. We first established that CaMKII was strongly expressed in the distal respiratory epithelium, in particular in surfactant protein-C-positive type II pneumocytes, and activated after bleomycin instillation. We generated a novel transgenic model of inducible expression of the CaMKII inhibitor peptide AC3-I limited to type II pneumocytes (Tg SPC-AC3-I). Tg SPC-AC3-I mice were protected from development of pulmonary fibrosis after bleomycin exposure compared with wild-type mice. CaMKII inhibition also provided protection from apoptosis in type II pneumocytes in vitro and in vivo. Moreover, intracellular Ca(2+) levels and ER stress were increased by bleomycin and significantly blunted with CaMKII inhibition in vitro. These data demonstrate that CaMKII inhibition prevents type II pneumocyte apoptosis and development of pulmonary fibrosis in response to bleomycin. CaMKII inhibition may therefore be a promising approach to prevent or ameliorate the progression of pulmonary fibrosis.

NEDD4 ubiquitin ligase is a putative oncogene in endometrial cancer that activates IGF-1R/PI3K/Akt signaling.

OBJECTIVE: The PI3K/Akt pathway is frequently dysregulated in endometrial cancer, the most common gynecologic malignancy. Emerging evidence identifies the ubiquitin ligase NEDD4 as a key regulator of the PI3K/Akt pathway via activation of insulin-like growth factor-1 receptor (IGF-1R). Our objective was to understand the role of NEDD4 in endometrial cancer. METHODS: NEDD4 expression was assessed by immunohistochemistry in a tissue microarray with 77 endometrial lesions ranging from normal benign endometrium to tumor specimens of varying stage and grade. Studies were extended to a panel of eight endometrial cancer cell lines phenotypically representing the most common endometrial patient tumors. RESULTS: Immunohistochemistry demonstrated robust staining of NEDD4 in endometrial tumor specimens, with greater NEDD4 expression in the most aggressive tumors. Expression of NEDD4 was detected in a majority of endometrial cancer cell lines surveyed. Exogenous overexpression of murine Nedd4 in endometrial cancer cell lines with modest endogenous NEDD4 expression resulted in a significant increase in the rate of proliferation. Nedd4 overexpression also promoted an increase in cell surface localization of IGF-1R and activation of Akt. Inhibition of PI3K/Akt signaling reversed the enhanced cell growth in Nedd4-overexpressing endometrial cancer cells. In addition, the expression of NEDD4 in endometrial tumors positively correlated with the Akt downstream effector FoxM1. CONCLUSIONS: This study identifies NEDD4 as a putative oncogene in endometrial cancer that may augment activation of the IGF-1R/PI3K/Akt signaling pathway.

Mitochondrial-targeted antioxidant therapy decreases transforming growth factor-ß-mediated collagen production in a murine asthma model.

Asthma is a disease of acute and chronic inflammation in which cytokines play a critical role in orchestrating the allergic inflammatory response. IL-13 and transforming growth factor (TGF)-ß promote fibrotic airway remodeling, a major contributor to disease severity. Improved understanding is needed, because current therapies are inadequate for suppressing development of airway fibrosis. IL-13 is known to stimulate respiratory epithelial cells to produce TGF-ß, but the mechanism through which this occurs is unknown. Here, we tested the hypothesis that reactive oxygen species (ROS) are a critical signaling intermediary between IL-13 or allergen stimulation and TGF-ß-dependent airway remodeling. We used cultured human bronchial epithelial cells and an in vivo mouse model of allergic asthma to map a pathway where allergens enhanced mitochondrial ROS, which is an essential upstream signal for TGF-ß activation and enhanced collagen production and deposition in airway fibroblasts. We show that mitochondria in airway epithelium are an essential source of ROS that activate TGF-ß expression and activity. TGF-ß from airway epithelium stimulates collagen expression in fibroblasts, contributing to an early fibrotic response to allergen exposure in cultured human airway cells and in ovalbumin-challenged mice. Treatment with the mitochondrial-targeted antioxidant, (2-(2,2,6,6-Tetramethylpiperidin-1-oxyl-4-ylamino)-2-oxoethyl)triphenylphosphonium chloride (mitoTEMPO), significantly attenuated mitochondrial ROS, TGF-ß, and collagen deposition in OVA-challenged mice and in cultured human epithelial cells. Our findings suggest that mitochondria are a critical source of ROS for promoting TGF-ß activity that contributes to airway remodeling in allergic asthma. Mitochondrial-targeted antioxidants may be a novel approach for future asthma therapies.

Systematic dissection of the mechanisms underlying progesterone receptor downregulation in endometrial cancer.

UNLABELLED: Progesterone, acting through its receptor, PR (progesterone receptor), is the natural inhibitor of uterine endometrial carcinogenesis by inducing differentiation. PR is downregulated in more advanced cases of endometrial cancer, thereby limiting the effectiveness of hormonal therapy. Our objective was to understand and reverse the mechanisms underlying loss of PR expression in order to improve therapeutic outcomes. Using endometrial cancer cell lines and data from The Cancer Genome Atlas, our findings demonstrate that PR expression is downregulated at four distinct levels. In well-differentiated cancers, ligand-induced receptor activation and downregulation are intact. miRNAs mediate fine tuning of PR levels. As differentiation is lost, PR silencing is primarily at the epigenetic level. Initially, recruitment of the polycomb repressor complex 2 to the PR promoter suppresses transcription. Subsequently, DNA methylation prevents PR expression. Appropriate epigenetic modulators reverse these mechanisms. These data provide a rationale for combining epigenetic modulators with progestins as a therapeutic strategy for endometrial cancer. SIGNIFICANCE: Traditional hormonal therapy for women with endometrial cancer can be molecularly enhanced by combining progestins with epigenetic modulators, thereby increasing progesterone receptor expression and significantly improving treatment efficacy.

Epigenetic modification restores functional PR expression in endometrial cancer cells.

Endometrial cancer, the most common gynecologic malignancy, is a hormonally-regulated tumor. Response to progestin-based therapy correlates positively with progesterone receptor (PR) expression. However, many endometrial tumors have low levels or loss of PR, limiting the clinical application of progestin. We evaluated the ability of epigenetic modulators to restore functional PR expression in Type I endometrial cancer cells with low basal PR. Treatment with the histone deacetylase inhibitor (HDACi) LBH589 induced a profound upregulation of PR mRNA. LBH589 restored PR protein expression at 24 hours and sustained expression for 72 hours, even in the presence of progesterone. LBH589 promoted a dose-dependent increase in PR protein levels, with an obvious increase with 10 nM LBH589. To investigate if the restored PR is functional as a transcription factor, we examined PR nuclear localization and expression of PRE- or Sp1-containing target genes. After treatment with LBH589 in the absence or presence of progesterone, PR nuclear expression was increased as demonstrated by Western blotting of nuclear fractions and immunostaining. Next, restored PR upregulated FoxO1, p21, and p27 and downregulated cyclin D1 in a ligand-dependent manner. Finally, LBH589 treatment induced cell cycle arrest in G1 that was further augmented by progesterone. Regulation of PR target genes was also achieved with other HDAC inhibitors, indicating that agents in this class work similarly with respect to PR. Our findings reveal that epigenetic modulators can restore endogenous functional PR expression in endometrial cancer cells and suggest that strategies to re-establish PR expression will resensitize endometrial tumors to progestin therapy.

Clinical effectiveness of an acellular dermal regenerative tissue matrix compared to standard wound management in healing diabetic foot ulcers: a prospective, randomised, multicentre study.

This 12-week, prospective, randomised, controlled multi-centre study compared the proportion of healed diabetic foot ulcers and mean healing time between patients receiving acellular matrix (AM) (study group) and standard of care (control group) therapies. Eighty-six patients were randomised into study (47 patients) and control (39 patients) groups. No significant differences in demographics or pre-treatment ulcer data were calculated. Complete healing and mean healing time were 69.6% and 5.7 weeks, respectively, for the study group and 46.2% and 6.8 weeks, respectively, for the control group. The proportion of healed ulcers between the groups was statistically significant (P = 0.0289), with odds of healing in the study group 2.7 times higher than in the control group. Kaplan-Meier survivorship analysis for time to complete healing at 12 weeks showed a significantly higher non healing rate (P = 0.015) for the control group (53.9%) compared with the study group (30.4%). After adjusting for ulcer size at presentation, which was a statistically significant covariate (P = 0.0194), a statistically significant difference in non healing rate between groups was calculated (P = 0.0233), with odds of healing 2.0 times higher in the study versus control group. This study supports the use of single-application AM therapy as an effective treatment of diabetic, neuropathic ulcers.

A multicenter study involving the use of a human acellular dermal regenerative tissue matrix for the treatment of diabetic lower extremity wounds.

This multicenter, retrospective study presents the use of a human acellular dermal regenerative tissue matrix as an alternative treatment for 100 chronic, full-thickness wounds of the lower extremity in 75 diabetic patients. Comorbidities included cardiac disease (86.0%), neuropathy (86.0%), peripheral vascular disease (82.0%), infection (54.0%), obesity (51.0%), and osteomyelitis (37.0%). Wound locations included the foot (86.0%), ankle (8.0%), and lower extremity (6.0%). Mean wound age was 20.4 weeks (1.3-191.4 weeks). University of Texas (UT) wound classifications included 15 (15.0%) 1A, 1 (1.0%) 1B, 1 (1.0%) 1C, 2 (2.0%) 1D, 18 (18.0%) 2A, 8 (8.0%) 2B, 5 (5.0%) 2C, 3 (3.0%) 2D, 3 (3.0%) 3A, 7 (7.0%) 3B, 3 (3.0%) 3C, and 34 (34.0%) 3D. The mean time to matrix incorporation, 100% granulation, and complete healing was 1.5 weeks (0.43-4.4 weeks), 5.1 weeks (0.43-16.7 weeks), and 13.8 weeks (1.7-57.8 weeks), respectively. The overall matrix success rate, as defined by full epithelialization, was 90.0%. One failed wound subsequently healed approximately 7 weeks after matrix reapplication. The healing rate was 91.0%, as 91 of the 100 wounds healed. No statistically significant differences were observed between UT classifications and time to matrix incorporation, 100% granulation, and complete healing. Absence of matrix-related complications and high rates of closure in a wide array of diabetic wounds suggest that this matrix is a viable treatment for complex lower extremity wounds. Lack of any statistically significant differences between UT grades and wound outcome end points lends further support to the universal applicability of this matrix, with successful results in both superficial diabetic wounds and in wounds penetrating to the bone or joint.

Cl- channels in basolateral TAL membranes. XVI. MTAL and CTAL cells each contain the mRNAs encoding mmClC-Ka and mcClC-Ka.

BACKGROUND: Our prior data indicate that two separate but homologous basolateral chloride (Cl-) channels, mmClC-Ka and mcClC-Ka, are the principal mediators of net Cl- absorption in mouse medullary thick ascending limb (MTAL) and cortical thick ascending limb (CTAL) cells, respectively. In the present studies, we evaluated the possibility that there might be translational or post-translational suppression of mmClC-Ka and mcClC-Ka activity in CTAL and MTAL cells, respectively. METHODS: Polymerase chain reaction (PCR) fragments were prepared that were highly specific for either mmClC-Ka or mcClC-Ka, the cDNAs encoding mmClC-Ka and mcClC-Ka, respectively. RESULTS: Using reverse transcription (RT)-PCR with these highly specific products, mRNAs specific for non-homologous channel sequences in either mmClC-Ka or mcClC-Ka were present in both MTAL and CTAL cells. CONCLUSIONS: Both mouse MTAL and CTAL cells contain the mRNAs encoding mmClC-Ka and mcClC-Ka. There may be translational or post-translational suppression of mmClC-Ka activity in CTAL cells, and of mcClC-Ka activity in MTAL cells.