Integration-Free Reprogramming of Lamina Propria Progenitor Cells.

Producing induced pluripotent stem cells (iPSCs) from human tissue for use in personalized medicine strategies or therapeutic testing is at the forefront of medicine. Therefore, identifying a source of cells to reprogram that is easily accessible via a simple noninvasive procedure is of great clinical importance. Reprogramming these cells to iPSCs through nonintegrating methods for genetic manipulation is paramount for regenerative purposes. Here, we demonstrate reprogramming of oral mucosal lamina propria progenitor cells from patients undergoing routine dental treatment. Reprogramming was performed utilizing nonintegrating plasmids containing all 6 pluripotency genes (OCT4, SOX2, KLF4, NANOG, LIN28, and cMYC). Resulting iPSCs lacked genetic integration of the vector genes and had the ability to differentiate down mesoderm, ectoderm, and endoderm lineages, demonstrating pluripotency. In conclusion, oral mucosal lamina propria progenitor cells represent a source of cells that can be obtained with minimal invasion, as they can be taken concurrently with routine treatments. The resulting integration-free iPSCs therefore have great potential for use in personalized medicine strategies.

Pulmonary artery sarcoma diagnosed by endobronchial ultrasound-guided transbronchial needle aspiration.

Pulmonary artery sarcoma is a rare disease with poor prognosis that has not been reported in Hong Kong. Its clinical and radiological presentation frequently mimics pulmonary embolism. Diagnosis is usually delayed until surgery, which is the treatment option that provides the best survival. Endobronchial ultrasound-guided transbronchial needle aspiration is an effective non-surgical technique for lymph node staging of lung cancer and diagnosis of mediastinal lesions via bronchoscopy. Here we discuss a case of pulmonary artery sarcoma diagnosed by this method, the second one in the literature, which serves to illustrate its potential use for early and minimally invasive diagnosis of the condition. Although such aspiration is a safe procedure, tissue sampling of extravascular extensions is advisable wherever possible.

Hepatocyte-specific activation of NF-kappaB does not aggravate chemical hepatocarcinogenesis in transgenic mice.

The NF-kappaB signalling pathway plays important roles in liver organogenesis and carcinogenesis. Mouse embryos deficient in IKKbeta die in mid-gestation, due to excessive apoptosis of hepatoblasts. Although activation of the NF-kappaB signalling pathway has been demonstrated in human hepatocellular carcinoma, the role of NF-kappaB is controversial. Here, we have generated transgenic mice in which a constitutively active form of IKKbeta was expressed in a hepatocyte-specific manner. Using electrophoretic mobility shift assay, we documented increased NF-kappaB activities and up-regulated levels of NF-kappaB downstream target genes, Bcl-xL and STAT5, in the transgenic mouse livers. These results confirmed that the NF-kappaB pathway was activated in the livers of the transgenic mice. However, there was no significant difference in tumour formation between transgenic and wild-type mice up to an age of 50 weeks. When we treated the transgenic mice with the chemical carcinogen diethylnitrosamine (DEN), we observed no significant differences in the incidence and size of liver tumours formed in these mice with and without DEN treatment at 35 weeks of age, suggesting that the activated NF-kappaB pathway in the livers of the transgenic mice did not enhance hepatocarcinogenesis. Interestingly, some of the transient transgenic embryos (E12.5) had abnormal excessive accumulation of nucleated red blood cells in their developing livers. In summary, NF-kappaB activation in hepatocytes did not significantly affect chemical hepatocarcinogenesis. In addition, the TTR/IKKCA transgenic mice may serve as a useful model for studying the role of NF-kappaB activation in hepatocarcinogenesis as well as inflammatory and metabolic diseases.

The spectrum of pathological changes in severe acute respiratory syndrome (SARS).

AIMS: To analyse the lung pathology of severe acute respiratory syndrome (SARS) and correlate the findings with the time sequence of the disease. METHODS AND RESULTS: Ten patients with a clinical diagnosis of SARS, and virological confirmation of SARS coronavirus infection were identified. Histology in most cases showed diffuse alveolar damage, from early to late phases, and the changes corresponded to the time sequence. Other variable features include multinucleated giant cells, pneumocytes with cytomegaly and variable amounts of inflammatory cells and foamy macrophages. One case showed superimposed bronchopneumonia. No viral inclusions were found. Coronavirus particles were identified in pneumocytes by electron microscopy. CONCLUSIONS: The predominant pathological process of SARS is diffuse alveolar damage and, in patients who die from the disease, there is evidence of organization and fibrosis. There are apparently no histological features specific for this disease, and the aetiological diagnosis depends on virological and ultrastructural studies.

Review article: the management of pelvic floor disorders.

Anorectal disorders, such as faecal incontinence, defecation difficulty and conditions associated with anorectal pain, are commonly encountered in the practices of gastroenterologists, urogynaecologists and colorectal surgeons. The evaluation of these disorders has been very much improved by the development and wider availability of diagnostic tests, such as manometry, endo-anal ultrasound, static and dynamic pelvic magnetic resonance imaging and electromyography. After briefly reviewing the normal anatomy and physiology of the anorectum, the pathophysiology and diagnostic approaches to faecal incontinence, defecation disorders and functional anorectal pain are discussed. Until recently, the management of these disorders has been largely anecdotal. However, our therapeutic armamentarium has been expanded by pharmacological agents, such as nitrates, calcium channel blockers and botulinum toxin, as well as the development of novel techniques, such as sacral nerve stimulation. These and other pharmacological, behavioural and surgical approaches are reviewed with respect to the robustness of evidence to support their efficacy in patients with these disorders.

Transthyretin, thyroxine, and retinol-binding protein in human cerebrospinal fluid: effect of lead exposure.

Transthyretin (TTR), synthesized by the choroid plexus, is proposed to have a role in transport of thyroid hormones in the brain. Our previous studies in animals suggest that sequestration of lead (Pb) in the choroid plexus may lead to a marked decrease in TTR levels in the cerebrospinal fluid (CSF). The objectives of this study were to establish in humans whether TTR and thyroxine (T(4)) are correlated in the CSF, and whether CSF levels of Pb are associated with those of TTR, T(4), and/or retinol-binding protein (RBP). Eighty-two paired CSF and blood/serum samples were collected from patients undergoing clinical diagnosis of CSF chemistry. Results showed that the mean value of CSF concentrations for TTR was 3.33 +/- 1.60 microg/mg of CSF proteins (mean +/- SD, n = 82), for total T(4) (TT(4)) was 1.56 +/- 1.68 ng/mg (n = 82), for RBP was 0.34 +/- 0.19 microg/mg (n = 82), and for Pb was 0.53 +/- 0.69 microg/dl (n = 61 for those above the detection limit). Linear regression analyses revealed that CSF TTR levels were positively associated with those of CSF TT(4) (r = 0.33, p < 0.005). CSF TTR concentrations, however, were inversely associated with CSF Pb concentrations (r = -0.29, p < 0.05). There was an inverse, albeit weak, correlation between CSF TT(4) and CSF Pb concentrations (r = -0.22, p = 0.09). The concentrations of TTR, TT(4), and Pb in the CSF did not vary as the function of their levels in blood or serum, but RBP concentrations in the CSF did correlate to those of serum (r = 0.39, p < 0.0005). Unlike TTR, CSF RBP concentrations were not influenced by PB: These human data are consistent with our earlier observations in animals, which suggest that TTR is required for thyroxine transport in the CSF and that Pb exposure is likely associated with diminished TTR levels in the CSF.

Pulmonary infection with nontuberculous mycobacteria.

Nontuberculous mycobacterial infections (NTM) are being increasingly recognized as a cause of chronic pulmonary disease. We recently reviewed the clinical, radiologic, and bacteriologic presentation of 89 adult patients ill enough to have been hospitalized between 1981 and 1985 with the diagnosis of NTM. Preexisting lung disease was present in 82% and alcohol abuse in 40%. Although M. avium complex was identified in 51% of the patients, M. xenopi, which is usually reported to occur infrequently, accounted for 38% of our cases and M. kansasii for only 9%. Treatment was limited by a high incidence of associated disease, in vitro drug resistance, drug toxicity, and a mortality rate of 32% within 18 months of admission. Nevertheless, bacteriologic conversion occurred in 29% of those treated. M. xenopi appears to be an important pathogen in southern Ontario. It differs from the other NTM by having a different pattern of in vitro drug resistance but not by its clinical or radiologic presentation.

Tuberculosis--a review of 498 recent admissions to hospital.

To document the changing clinical spectrum of tuberculosis among inpatients, 498 consecutive admissions to the tuberculosis unit of West Park Hospital, Toronto between January 1977 and March 1980 were reviewed. The results were compared with those of a study at this hospital two decades earlier. The recent patients were older, had a shorter stay in hospital, were more often alcoholic and more often had nontuberculous mycobacterial pulmonary disease.

Immune responses to soluble antigens of treponemes.

Sonicates from five cultivable treponemes were used as antigens in delayed hypersensitivity tests and macrophage inhibition assays. Immunodiffusion analysis showed that the sonicate comprised two major antigenic components which were not distinguishable in the skin tests. The sonicate antigens elicited significant cell-mediated immunity in guinea-pigs. Treponema refringens biotype Nichols proved to induce the strongest delayed response. Delayed skin hypersensitivity to the antigens of Treponema pallidum was found in eight rabbits without orchitis, but not in six rabbits with T. pallidum orchitis. In contrast, the rabbits with syphilitic orchitis gave the strongest reactions with the non-pathogenic spirochetes. In terms of the cell-mediated immunity responses, Treponema phagedenis Reiter was found to be related to T. phagedenis Kazan 4 and Treponema denticola. Treponema scoliodontum was related to T. phagedenis Kazan 5, and T. refringens biotypes Nichols and refringens. The antigens of T. pallidum had the closest relationship to T. refringens biotypes refringens and Nichols ,T. phagedenis biotype Reiter, and T. scoliodontum. It was also demonstrated that some three of 12 human syphilitic sera reacted with the antigens of T. pallidum but not with control sera.

Drug resistance in patients with pulmonary tuberculosis.

A review of the records of 984 patients admitted to hospital from 1970 through 1973 with bacteriologically proven pulmonary tuberculosis showed bacterial resistance to one or more antituberculosis drugs in 103 (10.5%). Among the patients who had had previous drug treatment for tuberculosis the prevalence of drug resistance was 20% in the Canadian-born patients and 69.4% in the recent immigrants. Among the patients who had had no previous drug treatment the prevalence of drug resistance (primary resistance) was 2.7% in Canadian-born patients but 11.4% in recent immigrants. Because of the higher prevalence of drug resistance among recent immigrants and the finding in recent years that increasingly more tuberculosis patients in Ontario are recent immigrants, drug resistance in this group is likely to assume even more importance in the future.