296 IN VITRO DIFFERENTIATION OF PORCINE BONE MARROW-DERIVED MESENCHYMAL STEM CELLS INTO HEPATOCYTE-LIKE CELLS

Mesenchymal stem cells (MSC) are isolated from bone marrow or other tissues, and have properties of self renewal and multilineage differentiation ability. The current study investigated the in vitro differentiation potential of porcine bone marrow derived MSCs into hepatocyte-like cells. The MSC were isolated from the bone marrow of adult miniature pigs (7 months old, T-type, PWG Micro-pig®, PWG Genetics, Seoul, Korea) and adherent cells with fibroblast-like morphology were cultured on plastic. Isolated MSCs were positive for CD29, CD44, CD73, CD90, and vimentin, and negative for CD34, CD45, major histocompatibility complex-class II (MHC-class II), and swine leukocyte antigen-DR (SLA-DR) by flow cytometry analysis. Further, trilineage differentiation of MSC into osteocytes (alkaline phosphatase, von Kossa and Alizarin red), adipocytes (Oil Red O), and chondrocytes (Alcian blue) was confirmed. Differentiation of MSC into hepatocyte-like cells was induced with sequential supplementation of growth factors, cytokines, and hormones for 21 days as described previously (Taléns-Visconti et al. 2006 World J. Gastroenterol. 12, 5834–5845). Morphological analysis, expression of liver-specific markers, and functional assays were performed to evaluate the hepatic differentiation of MSC. Under hepatogenic conditions, MSC acquired cuboidal morphology with cytoplasmic granules. These hepatocyte-like cells expressed α-fetoprotein (AFP), albumin (ALB), cytokeratin 18 (CK18), cytochrome P450 7A1 (CYP7A1), and hepatocyte nuclear factor 1 (HNF-1) markers by immunofluorescence assay. In addition, the expression of selected markers was demonstrated by Western blotting analysis. In accordance with these features, RT-PCR revealed transcripts of AFP, ALB, CK18, CYP7A1, and HNF-1α. Further, the relative expression levels of these transcripts were analysed by quantitative RT-PCR after normalizing to the expression of the endogenous control, glyceraldehyde-3-phosphate dehydrogenase (GAPDH). Data were analysed statistically by one-way ANOVA using PASW statistics 18 (SPSS Inc., Chicago, IL, USA), and significance was considered at P < 0.05. The results showed that the relative expressions of selected marker genes in hepatocyte-like cells were significantly increased compared with that in untreated MSC. The generated hepatocyte-like cells showed glycogen storage as analysed by periodic acid-Schiff (PAS) staining. Moreover, the induced cells produced urea at Day 21 of culture compared with control MSC. In conclusion, our results indicate the potential of porcine MSC to differentiate in vitro into hepatocyte-like cells. Further studies on the functional properties of hepatocyte-like cells are needed to use porcine MSC as an ideal source for liver cell therapy and preclinical drug evaluation. This work was supported by Basic Science Research Program through the National Research Foundation (NRF), funded by the Ministry of Education, Science and Technology (2010-0010528) and the Next-Generation BioGreen 21 Program (No. PJ009021), Rural Development Administration, Republic of Korea.

Carbon particles in airway macrophage as a surrogate marker in the early detection of lung diseases

BACKGROUND

It has been shown that inhalation of carbonaceous particulate matter may impair lung function in children.

OBJECTIVE

Using the carbon content of airway macrophages as a marker of individual exposure to particulate matter derived from fossil fuel, we sought direct evidence for this association.

METHODS

300 children from puffed rice industrial areas and 300 children from population living in green zone were selected randomly. Airway macrophages were obtained from healthy children through sputum induction, and the grading of ultrafine carbon particles in airway macrophages was measured. Pulmonary function was also measured by spirometry.

RESULTS

Pulmonary function tests showed that in industrial area 42.6% and 20.3% of children had moderate obstructive airway disease and restrictive airway disease, respectively. In the green zone area, 7% of children had obstructive airway disease and 6% had restrictive airway disease. Evaluation of airway macrophages for ultrafine carbon particles revealed that in industrial area there were ultrafine carbon particles of grade 2 in 23% of subjects and grade 3 in 8.33% of individuals with obstructive airway disease. In the green zone area, the rates were 1.67% and 0.7%, respectively.

CONCLUSION

The study provides a first evidence of the strong association between air pollution and development of airway diseases. Carbon particles in the sputum can be used as a marker for air pollution.

Functional characterization of a human aquaporin 0 mutation that leads to a congenital dominant lens cataract

The aquaporin (AQP) transmembrane proteins facilitate the movement of water across the plasma membrane. In the lens, AQP0 is expressed in fiber cells and AQP1 in the epithelium. Recently, two individuals were identified with congenital polymorphic autosomal dominant cataract, due to a single nucleotide base deletion mutation in the lens AQP0. The deletion modified the reading frame resulting in the addition of a premature stop codon. In the present study, we examined the water permeability properties, trafficking and dominant negative effects as well as cytotoxicity due to the mutant AQP0 (Delta213-AQP0) protein. The membrane water permeability (P(w)) of Delta213-AQP0 expressing oocytes (14+/-1 microm/s) was significantly lower than those expressing WT-AQP0 (25+/-3 microm/s). P(w) of water injected control oocytes was 13+/-2 microm/s. Co-expression of WT-AQP0 with Delta213-AQP0 significantly lowered the P(w) (18+/-3 microm/s) compared to WT-AQP0. With or without the EGFP tag, WT-AQP0 protein localized in the plasma membranes of oocytes and cultured cells whereas Delta213-AQP0 was retained in the ER. Forster Resonance Energy Transfer (FRET) showed that WT-AQP0 partly localized with the co-expressed Delta213-AQP0. Co-localization studies suggest that the mutant AQP0 gained its dominant function by trapping the WT-AQP0 in the ER through hetero-oligomerization. Incubating the cells with chemical chaperones, namely, TMAO and DMSO, did not correct the folding/trafficking defects. Cell death in the Delta213-AQP0 expressing cells was due to necrosis caused by the accumulation of Delta213-AQP0 protein in the ER in cytotoxic proportions. The data show that replacement of the distal end of the 6th TM domain and the C-terminal domain of AQP0 due to the deletion mutation resulted in the impairment of cell membrane P(w), localization of the mutant protein in the ER without trafficking to the plasma membrane, and cytotoxicity due to the accumulation of the mutant protein. Cataracts in patients with this mutation might have resulted from the above mentioned consequences.

Management of temporo-mandibular joint ankylosis in growing children

Although temporo-mandibular joint (TMJ) ankylosis is one of the most common pathologies afflicting the facial skeleton, it is also the most overlooked and under-managed problem in children. The TMJ forms the very cornerstone of cranio-facial integrity and hence its ankylosis in growing children adversely affects the growth and development of the jaws and occlusion. Impairment of speech, difficulty in mastication, poor oral hygiene, rampant caries and acute compromise of the airway pose a severe psychologic burden on the tender minds of children. The aim of this article is to present an overview of efficient management strategies, based on a case report, so as to increase its awareness among all dental surgeons involved in the treatment of children.

Effect of toothpaste with natural calcium carbonate/perlite on extrinsic tooth stain

OBJECTIVE

The current study was designed to determine the effect of natural calcium carbonate toothpaste containing Perlite and microgranules (Whitening toothpaste) on extrinsic tooth stain compared to a standard commercial toothpaste formulation with precipitated calcium carbonate (PCC) as abrasive and a commercial toothpaste with dicalcium phosphate dihydrate (DCPD) as abrasive.

METHODS

The toothpastes were evaluated in a double blind, three-cell, stratified (tobacco use; baseline tooth stain level), parallel group design study involving 600 subjects with extrinsic tooth stain. Subjects brushed twice daily with their allocated toothpaste for four weeks. Extrinsic tooth stain was measured using the Macpherson modification of the Lobene stain index.

RESULTS

ANCOVA showed significant differences between toothpastes (p=0.037). Subsequent multiple comparisons using pairwise t-tests, showed the Whitening toothpaste to be superior to the DCPD toothpaste (p=0.014) and the PCC toothpaste (p=0.067). When a Box-Cox transformation was made to the data (y0.6) to improve normality, these two differences were more accurately estimated at p=0.004 and p=0.03 respectively.

CONCLUSION

The Whitening toothpaste has been shown to be significantly more effective in tooth stain removal than the two standard commercial toothpaste formulations.

Reactive fibrous hyperplasia associated with a natal tooth

A natal tooth is that which is present in the oral cavity at the time of birth. Fibrous hyperplasia is a non-specific reactive lesion of soft tissues of unknown etiology usually associated with trauma or local irritation. Natal teeth can occur as an isolated dental finding, but many times they are associated wilh syndromes and developmental disturbances. This is a rare case, where in a natal tooth has led to the formation of a reactive fibrous hyperplasia in a four and half month old infant, a relationship not reported previously.

"Moebius syndrome": a case report

Moebius syndrome is an extremely rare disorder characterized by a lifetime facial paralysis, involving sixth and seventh cranial nerves with malformations of orofacial structures and the limbs. In this case, an 8 year old girl with Moebius syndrome is presented, clinical findings are described and management aspects are discussed. Early dental evaluation and parental counselling as a part of preventive dental regimen can go a long way in providing complete psychosocial rehabilitation for such physically disabled children.

Labial talon cusp on permanent central incisor: a case report

Talon cusp is a supernumerary crown structure, a developmental disturbance in the shape of teeth that causes various diagnostic, functional and esthetic problems. Some synonyms for talon cusp are dens evaginatus of anterior teeth, interstitial cusp, tuberculated tooth, odontoma of the axial core type, evaginated odontoma, enamel pearl, supernumerary cusp etc. The lingual location on incisors, which frequently affects occlusion, is pathognomonic of the talon cusp. This report describes a rare odontogenic, isolated anomaly rather than an integral part of any disorder, a case of talon shaped cusp projecting from the labial surface of a maxillary permanent central incisor.

Herniation of the buccal fat pad into the oral cavity: a case report

An interesting lesion is presented, wherein a tiny traumatic perforation of the buccal mucosa and buccinator muscle forced a large portion of the buccal fat pad to extrude into the oral cavity. Such a situation can alarm any clinician & reinforces the importance of careful history taking and thorough examination, before treating patients.

Congenital muscular dystrophy--a case report

A rare case of congenital muscular dystrophy with unique oro-facial manifestations is presented. Dental considerations and successful management techniques are discussed.

Patients' values for health states associated with hepatitis C and physicians' estimates of those values

OBJECTIVES

Hepatitis C is the leading cause of chronic hepatitis in the United States. Little information is available regarding how persons with hepatitis C view health with their disease. We studied patients' perceptions about the value of hepatitis C health states and evaluated whether physicians understand their patients' perspectives about this disease.

METHODS

A total of 50 consecutive persons with hepatitis C were surveyed when they presented as new patients to a hepatology practice. Subjects provided utility assessments (preference values) for five hepatitis C health states and for treatment side effects. They also stated their threshold for accepting antiviral therapy. Five hepatologists used the same scales to estimate their patients' responses.

RESULTS

On average, patients believed that hepatitis C without symptoms was associated with an 11% reduction in preference value from that of life without infection, and the most serious condition (severe symptoms, cirrhosis) was believed to carry a 73% decrement. Patients judged the side effects of antiviral therapy quite unfavorably, and their median stated threshold for accepting treatment was a cure rate of 80%. Physicians' estimates were not significantly associated with patients' preference values for hepatitis C health states, treatment side effects, or with patients' thresholds for accepting treatment. In multivariate analysis, patients' stated thresholds for taking treatment were significantly associated with their decisions regarding therapy (beta = -2.72+/-1.21, p = 0.025).

CONCLUSIONS

There was little agreement between patients' preference values about hepatitis C and their physicians' estimates of those values. Utility analysis could facilitate shared decision making about hepatitis C.

Adult living donor liver transplantation: Preferences about donation outside the medical community

An increasing number of transplant centers are performing adult living donor liver transplantation (LDLT). We evaluated peoples' perspectives on possible outcomes of living donation, thresholds for donating, and views regarding the donation process. One hundred fifty people were surveyed; half were from a medical care group serving an indigent population and half were from a private clinic. Preferences about outcomes of adult living donation were ranked and quantified on a visual analogue scale. Thresholds for donation to a loved one were quantified. Sixty percent of the respondents suggested they would prefer to donate and die and have the transplant recipient live rather than forego donation and have the potential transplant recipient die of liver failure. Participants' stated threshold for living donation was a median survival for themselves of only 79%. They would require that their loved one have a median survival of 55% with transplantation before they would agree to donate. Respondents from the medical care group reported higher survival thresholds for themselves and the transplant recipient, and race was the most statistically significant predictor of those thresholds. Sex was more predictive of threshold probabilities from the private clinic. Eighty-one percent of the respondents believed that the potential donor, not a physician, should have the final say regarding candidacy for living donation. In conclusion, the findings of this survey support the use of adult LDLT. Most respondents were willing to accept mortality rates that far exceed the estimated risk of donation and favored outcomes in which a loved one was saved.

Inducible expression of herpes simplex virus thymidine kinase increases sensitivity to ganciclovir but does not enhance bystander effect in breast cancer cells

Delivery of cancer chemotherapy directly to the cancer cell has great appeal. Previous studies using adenoviral transfer of the herpes simplex virus thymidine kinase (HSV-tk) gene followed by ganciclovir (GCV) in an ascites model of breast cancer was successful in reducing tumor burden and prolonging life. However, increasing the viral dose resulted in increased toxicity and host mortality emphasizing the need for an improved therapeutic ratio. To test the hypothesis that enhancement of HSV-tk gene expression would lead to increased sensitivity to GCV and improved bystander effect, we created breast cancer cells expressing HSV-tk under the control of the inducible tetracycline promoter. Using this system, we could inducibly increase gene expression and biochemical activation of HSV-tk. These increased levels of HSV-tk decreased the IC50 to GCV nearly 50-fold. However, the bystander effect was not enhanced by increasing HSV-tk gene expression. We conclude that increased HSV-tk gene expression improves sensitivity to CCV. However, additional measures, such as increased gap junction communication, will likely be needed to enhance the bystander effect and the therapeutic efficacy of this strategy.

Paraduodenal hernia presenting as unexplained recurrent abdominal pain

We present a case of a 29-yr-old female nurse who presented with an 8-h history of abdominal pain. She had had similar episodes (twice/yr) over the last 5 yr, and the pain had usually resolved spontaneously. Prior investigations including laboratory studies, plain films of the abdomen, an abdominal and pelvic ultrasound, and a CT scan yielded no diagnosis. Her pain was previously considered to be either psychosomatic or a variant of irritable bowel syndrome. On this admission, an evaluation and subsequent enteroclysis revealed a left paraduodenal hernia. The importance of considering paraduodenal hernias in the differential diagnosis of unexplained intermittent abdominal pain is discussed here.

Solid and papillary epithelial neoplasm of the pancreas. Report of a case with diagnosis by fine needle aspiration cytology

BACKGROUND

Solid and papillary epithelial neoplasm of the pancreas is a distinct clinicopathologic entity. It has a benign clinical course, and surgical resection can be curative.

CASE

A 17-year-old female presented with a mass measuring about 12 cm in the epigastrium and left hypochondrium. Fine needle aspiration cytology (FNAC) showed papillae with a central fibrovascular core and lined with many layers of bland-appearing cells exhibiting nuclear grooving. These features, along with ultrasound and computed tomographic findings, led to an accurate preoperative diagnosis.

CONCLUSION

In the setting of typical clinical and radiologic findings, it is possible to make a correct preoperative diagnosis by FNAC. Doing so has important implications for management.

Evaluation of an expert system on lymph node pathology

BACKGROUND

Pathfinder is an Expert System that assists pathologists in making accurate diagnoses in the domain of lymph-node pathology. Pathfinder provides a differential diagnosis based on the initial histological feature(s) observed by the pathologist, and suggests to the user additional histological features for observation that are likely to narrow the differential diagnosis.

PURPOSE

To evaluate the diagnostic accuracy of pathologists with and without the Pathfinder.

METHODS

Thirty H&E stained slides from 30 lymph node biopsy specimens on which a Consensus diagnosis was made by two experts were reviewed by 19 pathologists to evaluate Pathfinder. After a period of training, 10 pathologists using Pathfinder (Interactive Computer Method) and 9 pathologists using the Routine Method (diagnosis without computer) determined a differential diagnosis for 15 slides (Test 1). Pathologists were then crossed over, trained, and evaluated the remaining 15 slides (Test 2). For each test, the proportion of "correct" diagnoses was compared between methods. In addition, the information integration attributes (making logical diagnosis given a set of specific histologic features) of Pathfinder and pathologists were compared. Finally, feature identification and quantification skills of pathologists were determined and correlated with the percent correct diagnosis.

RESULTS

The diagnostic accuracy using Pathfinder was greater than that using the Routine Method (40% v 32%, P = .02). Diagnostic accuracy for the group of pathologists who made diagnosis using the Routine Method in Test 1 increased when they made diagnosis using Pathfinder in Test 2 (27% to 44%, P < .0001). The proportion of correct diagnosis for the group of pathologists who used Pathfinder in Test 1 remained virtually unchanged when they gave up Pathfinder in Test 2 (35% to 37%). The percentage of incompatible feature identification ("atypical proliferation" diagnosis) was significantly lower after using Pathfinder (P < .0001). In addition, information integration attributes of Pathfinder were significantly superior than that of the pathologists (P < .0001).

CONCLUSIONS

Pathfinder is a valuable tool that assists pathologists in making accurate diagnosis because it has superior attributes than pathologists to integrate information and to screen for observations incompatible with any specific disease.

Endoscopic removal of a toothpick from the transverse colon

We describe the case of a patient who presented with abdominal pain, weight loss, and night sweats of 8 wk duration due to the impalement of a toothpick in the transverse colon. The toothpick, which was inadvertently swallowed, was successfully removed during colonoscopy. Therapeutic colonoscopy has replaced or lessened to a significant degree the need for traditional open surgical procedures to extract foreign bodies from the colon. Unexplained abdominal pain and constitutional symptoms should alert the clinician to the possibility of a foreign body.

An Information Mediator Network for Tasks in Dynamic Environments

Coordination of activities among information workers and services, tracking and managing activities, and intelligent distribution of information are essential to the efficient operation of any large enterprise. This is particularly important in the healthcare domain, where many different organizations must cooperate to provide patient care reliably in a dynamically changing environment. In this review paper we present a distributed system that supports cooperative problem solving, activity management, and intelligent delivery of information in dynamic and unreliable environments. The system consists of a network of task/context managers (TCMs). Each TCM manages a group of related agents. It maintains up-to-date information on availability, operational status, and activities of participating agents, and it acts as a mediator between service requesters and service providers. In addition, the TCM acts as a representative for its agents with other TCMs, allowing different groups of agents to collaborate with one another. This paper describes the system architecture, its implementation and capabilities including matchmaking, plan monitoring, and failure recovery. Our system has been used in prehospital emergency patient information management applications.

An Information Mediator Network for Tasks in Dynamic Environments

Coordination of activities among information workers and services, tracking and managing activities, and intelligent distribution of information are essential to the efficient operation of any large enterprise. This is particularly important in the healthcare domain, where many different organizations must cooperate to provide patient care reliably in a dynamically changing environment. In this review paper we present a distributed system that supports cooperative problem solving, activity management, and intelligent delivery of information in dynamic and unreliable environments. The system consists of a network of task/context managers (TCMs). Each TCM manages a group of related agents. It maintains up-to-date information on availability, operational status, and activities of participating agents, and it acts as a mediator between service requesters and service providers. In addition, the TCM acts as a representative for its agents with other TCMs, allowing different groups of agents to collaborate with one another. This paper describes the system architecture, its implementation and capabilities including matchmaking, plan monitoring, and failure recovery. Our system has been used in prehospital emergency patient information management applications.

A rationale for gene targeting in glaucoma therapy

One of the mainstays of glaucoma treatment is the use of drugs that decrease the secretion of aqueous humor fluid from the ciliary epithelium. Unfortunately, many currently available drugs that decrease aqueous humor production such as beta-adrenergic antagonists, may cause serious systemic side effects such as cardiac arrhythmias and arrest, pulmonary dysfunction, and CNS side effects such as decreased libido and depression. Efforts to develop effective aqueous suppressants that offer decreased morbidity and mortality in comparison to those currently available will likely rely on the ability to alter the function of specific cellular events which underlie aqueous humor production by the ciliary epithelium. However, the secretory process which results in aqueous humor production is incompletely understood and the identification of precise cellular mechanisms which underlie this process remain to be established. We will present a rationale for genetic approaches to regulate gene expression so that aqueous humor production may be specifically targeted in glaucoma patients. Techniques of gene transfer including homologous exchange recombination, and expression of antisense genes, will be discussed.

Hemodynamic and oxygen transport patterns for outcome prediction, therapeutic goals, and clinical algorithms to improve outcome. Feasibility of artificial intelligence to customize algorithms

A generalized decision tree or clinical algorithm for treatment of high-risk elective surgical patients was developed from a physiologic model based on empirical data. First, a large data bank was used to do the following: (1) describe temporal hemodynamic and oxygen transport patterns that interrelate cardiac, pulmonary, and tissue perfusion functions in survivors and nonsurvivors; (2) define optimal therapeutic goals based on the supranormal oxygen transport values of high-risk postoperative survivors; (3) compare the relative effectiveness of alternative therapies in a wide variety of clinical and physiologic conditions; and (4) to develop criteria for titration of therapy to the endpoints of the supranormal optimal goals using cardiac index (CI), oxygen delivery (DO2), and oxygen consumption (VO2) as proxy outcome measures. Second, a general purpose algorithm was generated from these data and tested in preoperatively randomized clinical trials of high-risk surgical patients. Improved outcome was demonstrated with this generalized algorithm. The concept that the supranormal values represent compensations that have survival value has been corroborated by several other groups. We now propose a unique approach to refine the generalized algorithm to develop customized algorithms and individualized decision analysis for each patient's unique problems. The present article describes a preliminary evaluation of the feasibility of artificial intelligence techniques to accomplish individualized algorithms that may further improve patient care and outcome.

Metabolic studies with 'Nutrauxil', an enteral feed preparation

A metabolic study was carried out in 6 patients requiring enteral feeding to investigate the effectiveness and tolerance of 'Nutrauxil', a ready-made liquid nutritional preparation, over a period of 8 days. The results of anthropometric and laboratory measurements, made initially and at the end of two 4-day periods, showed that the basic provision of 2000 kcal and 60 g protein per day with 'Nutrauxil' maintained patients in metabolic, electrolyte and nitrogen balance. No adverse effects were noted and the preparation was easy to administer. It was concluded that 'Nutrauxil' compared favourably with other enteral feed preparations with respect to its nutritional effectiveness on clinical, biochemical and economic grounds.