Multidrug-resistant tuberculosis in New South Wales, Australia, 1999-2010: a case series report.

SETTING: The emergence of multidrug-resistant tuberculosis (MDR-TB) threatens the ongoing control of tuberculosis (TB). The Australian state of New South Wales (NSW) has low TB and MDR-TB incidence. OBJECTIVE: To examine the epidemiology and the clinical and public health management of MDR-TB in NSW. DESIGN: A retrospective case-series analysis of MDR-TB diagnosed in NSW between 1999 and 2010 was undertaken. A standardised questionnaire was used to collect information from the public health surveillance system, medical records and the State Mycobacterium Reference Laboratory about clinical features, drug susceptibility, treatment regimens, hospitalisation, risk factors for tuberculous infection, contact tracing and patient outcomes. RESULTS: Fifty-five cases of culture-confirmed MDR-TB, including two cases of extensively drug-resistant TB, were diagnosed. All cases were reviewed by an expert management panel. Fifty cases (91%) were foreign-born, and 50 cases (91%) had fully supervised treatment. Of the 55 cases, 46 (84%) successfully completed treatment, 3 (5%) died of TB and 3 (5%) required surgery. No MDR-TB cases were reported among contacts. CONCLUSION: Using a multidisciplinary, expert guided, case-management approach, the NSW TB Control Program achieved excellent MDR-TB outcomes. The impact of global increases in MDR-TB requires sustained commitment to TB in all settings.

Transcriptional control of brown adipocyte development and thermogenesis.

Brown adipose tissue (BAT) is a specialized endothermic tissue in eutherian mammals that protects against hypothermia. Heat production by BAT may also be stimulated by overfeeding as an apparent counter regulatory mechanism to prevent excessive adipose accumulation. Genetic studies in rodents have overwhelmingly demonstrated an antiobesity effect for BAT. There is thus substantial biomedical interest in developing methods to increase the amount or function of BAT as a means to combat obesity. Furthermore, the recent discovery that adult humans have rather significant amounts of active BAT raises speculation that this tissue may naturally affect body weight in humans. Recent advances in our understanding of the transcriptional regulation of brown adipocyte development and adaptive thermogenesis are reviewed here.

The potential of muscle stem cells.

Skeletal muscle contains two types of stem cells: satellite cells, which function as myogenic precursors, and a population of multipotent adult stem cells. Satellite cells are believed to form a stable, self-renewing pool of stem cells in adult muscle where they function in tissue growth and repair. An additional stem cell population in adult muscle displays a remarkable capacity to differentiate into hematopoietic cells as well as muscle following transplantation. This article discusses the characteristics and properties of these cell populations, the relationship between them, and the potential for stem cell-based muscle therapeutics.

Activation of JNK1 contributes to dystrophic muscle pathogenesis.

Duchenne Muscular Dystrophy (DMD) originates from deleterious mutations in the dystrophin gene, with a complete loss of the protein product. Subsequently, the disease is manifested in severe striated muscle wasting and death in early adulthood. Dystrophin provides a structural base for the assembly of an integral membrane protein complex. As such, dystrophin deficiency leads to an altered mechanical integrity of the myofiber and a predisposition to contraction-induced damage. However, the development of myofiber degeneration prior to an observed mechanical defect has been documented in various dystrophic models. Although activation of a detrimental signal transduction pathway has been suggested as a probable cause, a specific cellular cascade has yet to be defined. Here, it is shown that murine models of DMD displayed a muscle-specific activation of JNK1. Independent activation of JNK1 resulted in defects in myotube viability and integrity in vitro, similar to a dystrophic phenotype. In addition, direct muscle injection of an adenoviral construct containing the JNK1 inhibitory protein, JIP1, dramatically attenuated the progression of dystrophic myofiber destruction. Taken together, these results suggest that a JNK1-mediated signal cascade is a conserved feature of dystrophic muscle and contributes to the progression of the disease pathogenesis.

The synthesis of cyclic tetrapeptoid analogues of the antiprotozoal natural product apicidin.

A novel synthetic strategy is described which may be used to prepare analogues of the antimalarial, fungal metabolite apicidin. Compared to the natural product, one analogue shows potent and selective activity in vitro against the parasite Trypanosoma brucei and low mammalian cell toxicity.

Japanese Respiratory Society - 41st annual meeting. 6-9 April 2001, Tokyo, Japan.

This was a large meeting, attracting over 4000 delegates, the majority of whom came from Japan. For the first time, the meeting had an international program, featuring invited speakers from Europe, Asia and the US. The Japanese Respiratory Society plans to continue the international program to encourage its young scientists and clinical investigators to work closely with overseas collaborators. The program featured invited lectures, leading lectures, evening symposia, oral presentations and poster presentations.

Pax7 is required for the specification of myogenic satellite cells.

The paired box transcription factor Pax7 was isolated by representational difference analysis as a gene specifically expressed in cultured satellite cell-derived myoblasts. In situ hybridization revealed that Pax7 was also expressed in satellite cells residing in adult muscle. Cell culture and electron microscopic analysis revealed a complete absence of satellite cells in Pax7(-/-) skeletal muscle. Surprisingly, fluorescence-activated cell sorting analysis indicated that the proportion of muscle-derived stem cells was unaffected. Importantly, stem cells from Pax7(-/-) muscle displayed almost a 10-fold increase in their ability to form hematopoietic colonies. These results demonstrate that satellite cells and muscle-derived stem cells represent distinct cell populations. Together these studies suggest that induction of Pax7 in muscle-derived stem cells induces satellite cell specification by restricting alternate developmental programs.

A new look at the origin, function, and "stem-cell" status of muscle satellite cells.

Muscle satellite cells have long been considered a distinct myogenic lineage responsible for postnatal growth, repair, and maintenance of skeletal muscle. Recent studies in mice, however, have revealed the potential for highly purified hematopoietic stem cells from bone marrow to participate in muscle regeneration. Perhaps more significantly, a population of putative stem cells isolated directly from skeletal muscle efficiently reconstitutes the hematopoietic compartment and participates in muscle regeneration following intravenous injection in mice. The plasticity of muscle stem cells has raised important questions regarding the relationship between the muscle-derived stem cells and the skeletal muscle satellite cells. Furthermore, the ability of hematopoietic cells to undergo myogenesis has prompted new investigations into the embryonic origin of satellite cells. Recent developmental studies suggest that a population of satellite cells is derived from progenitors in the embryonic vasculature. Taken together, these studies provide the first evidence that pluripotential stem cells are present within adult skeletal muscle. Tissue-specific stem cells, including satellite cells, may share a common embryonic origin and possess the capacity to activate diverse genetic programs in response to environmental stimuli. Manipulation of such tissue-specific stem cells may eventually revolutionize therapies for degenerative diseases, including muscular dystrophy.

Caspase 3 cleavage of the Ste20-related kinase SLK releases and activates an apoptosis-inducing kinase domain and an actin-disassembling region.

We have demonstrated that a novel Ste20-related kinase, designated SLK, mediates apoptosis and actin stress fiber dissolution through distinct domains generated by caspase 3 cleavage. Overexpression of SLK in C2C12 myoblasts stimulated the disassembly of actin stress fibers and focal adhesions and induced apoptosis, as determined by annexin V binding and terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end labeling analysis. SLK was cleaved by caspase 3 in vitro and in vivo during c-Myc-, tumor necrosis factor alpha, and UV-induced apoptosis. Furthermore, cleavage of SLK released two domains with distinct activities: an activated N-terminal kinase domain that promoted apoptosis and cytoskeletal rearrangements and a C-terminus domain that disassembled actin stress fibers. Moreover, our analysis has identified a novel conserved region (termed the AT1-46 homology domain) that efficiently promotes stress fiber disassembly. Finally, transient transfection of SLK also activated the c-Jun N-terminal kinase signaling pathway. Our results suggest that caspase-activated SLK represents a novel effector of cytoskeletal remodeling and apoptosis.

Reduced differentiation potential of primary MyoD-/- myogenic cells derived from adult skeletal muscle.

To gain insight into the regeneration deficit of MyoD-/- muscle, we investigated the growth and differentiation of cultured MyoD-/- myogenic cells. Primary MyoD-/- myogenic cells exhibited a stellate morphology distinct from the compact morphology of wild-type myoblasts, and expressed c-met, a receptor tyrosine kinase expressed in satellite cells. However, MyoD-/- myogenic cells did not express desmin, an intermediate filament protein typically expressed in cultured myoblasts in vitro and myogenic precursor cells in vivo. Northern analysis indicated that proliferating MyoD-/- myogenic cells expressed fourfold higher levels of Myf-5 and sixfold higher levels of PEA3, an ETS-domain transcription factor expressed in newly activated satellite cells. Under conditions that normally induce differentiation, MyoD-/- cells continued to proliferate and with delayed kinetics yielded reduced numbers of predominantly mononuclear myocytes. Northern analysis revealed delayed induction of myogenin, MRF4, and other differentiation-specific markers although p21 was upregulated normally. Expression of M-cadherin mRNA was severely decreased whereas expression of IGF-1 was markedly increased in MyoD-/- myogenic cells. Mixing of lacZ-labeled MyoD-/- cells and wild-type myoblasts revealed a strict autonomy in differentiation potential. Transfection of a MyoD-expression cassette restored cytomorphology and rescued the differentiation deficit. We interpret these data to suggest that MyoD-/- myogenic cells represent an intermediate stage between a quiescent satellite cell and a myogenic precursor cell.

International Union Against Tuberculosis and Lung Disease (IUATLD)--20th Eastern Region conference. 4-7 June 1999, Wanchai, Hong Kong.

This biennial conference was hosted jointly by the Hong Kong Tuberculosis Chest and Heart Diseases Association (under the auspices of the Eastern Region of the IUATLD), the Hong Kong Thoracic Society and the American College of Chest Physicians (Hong Kong and Macau Chapter). It attracted over 1000 delegates, most of whom came from the Asian Pacific Region. There were 25 countries represented. The main themes of the meeting were strategies for dealing with common lung diseases such as asthma, chronic obstructive pulmonary disease (COPD), lung cancer and tuberculosis and human immunodeficiency virus (HIV).

Cutaneous vascular response to calcitonin gene-related peptide in psoriasis and normal subjects.

To determine whether cutaneous blood vessels in subjects with psoriasis possess a generalized inherently abnormal response to neuropeptides, the effect of three doses of intradermally injected calcitonin gene-related peptide (CGRP) on skin blood flow in normal subjects (n = 10), and on clinically normal skin (greater than 5 cm from psoriatic lesions) in subjects with psoriasis (n = 9) was measured using a laser Doppler technique. Calcitonin gene-related peptide caused a dose-dependent increase in local blood flow in both psoriatic and normal subjects, which was not statistically different between the two groups. This study has shown that the cutaneous vasculature at sites distant from lesions of psoriasis (> 5 cm) is not inherently different from normal skin in its response to CGRP.

GR138676, a novel peptidic tachykinin antagonist which is potent at NK3 receptors.

GR138676, a conformationally constrained analogue of neurokinin B, is a novel, potent NK3 receptor antagonist. GR138676 was a competitive antagonist of neurokinin B-dependent arachidonic acid mobilization from prelabelled Chinese hamster ovary cells stably transfected with a human NK3 receptor gene (pKB 8.3) and of contractions induced by senktide in rat portal vein (pKB 8.2). However, GR138676 was also a competitive antagonist of the increase in intracellular calcium evoked by the selective NK1 agonist, GR73632, in the human astrocytoma U373MG cell-line (pKB 8.3). GR138676 had little activity at NK2 receptors, inhibiting binding of the NK2 antagonist radioligand [3H]-GR100679 to Chinese hamster ovary cells transfected with the human ileum NK2 receptor with a pKi of 6.0. In summary, despite its activity at NK1 receptors, GR138676 will be a useful tool for characterizing NK3 receptors as well as defining the physiological and pathophysiological function of this receptor subtype.

Chloride secretion in response to guanylin in colonic epithelial from normal and transgenic cystic fibrosis mice.

1. Guanylin, a 15 amino acid endogenous gut peptide, increased the short circuit current (SCC) in the epithelium of the mouse colon, but only when applied to the apical and not the basolateral surface. 2. By use of selective blockers of epithelial ion transport and modification of the bathing solution, it was concluded that guanylin increased electrogenic chloride secretion but also had a minor effect on electrogenic sodium absorption. In addition there were small residual currents which remained unresolved. 3. The threshold concentration of guanylin causing a SCC increase was less than 50 nM, but at concentrations 40 times greater no indication of a maximally effective concentration was found. 4. Two guanylin isomers with the same amino acid sequence but with the disulphide bridges joined in an alternate fashion showed no activity. Thus only guanylin with the greatest structural homology to heat stable enterotoxin (STa) showed biological activity. 5. The action of guanylin was virtually eliminated in colonic epithelia from transgenic cystic fibrosis (CF) mice. As these animals lack the chloride channel coded by the CF gene sequence, it is likely that the final effector process in murine colonic epithelia involves the CFTR (cystic fibrosis transmembrane conductance regulator) chloride channel. 6. Opportunistic infections of the gut generating STa lead to diarrhoeal conditions via an action of the toxin on apical guanylin receptors. Thus, as discussed, the CF heterozygote may have a genetic advantage in this circumstance.

Solid-phase synthesis of O-mannosylated peptides: two strategies compared.

A comparison of the O-glycosylation of resin-bound assembled peptides with the incorporation of glycosylated amino acids using established chemistry is presented. Fmoc/tert-butyl-based protecting groups were used for the peptidic moieties in conjunction with acetyl sugar protection. Koenigs-Knorr glycosylations were carried out using protected bromomannose derivatives, the acceptor being threonine or serine, either in solution or within a resin-bound peptide. The characterisation of microgram quantities of glycopeptides by the use of glycosidases in combination with mass spectrometry is also described.

Solid-phase synthesis of a range of O-phosphorylated peptides by post-assembly phosphitylation and oxidation.

A completely general method for the O-phosphorylation of peptides of any given composition using solid-phase methodology is described. Peptides were assembled using Fmoc amino acid active esters, with base used for Fmoc deprotection. Unprotected amino acid side chain hydroxyl groups were phosphitylated and oxidised at the end of the assembly using bis(benzyloxy)(diisopropylamino)phosphine and tert.-butylhydroperoxide respectively. TFA was used for final deprotection of the amino acid side chains and for simultaneous cleavage from the resin. The synthesis of O-phosphopeptides of up to 15 residues in length is described.

Long-term psychosocial adjustment following burn injury.

Young adult survivors of severe childhood burn injuries were assessed for indicators of psychopathology and for factors that might enhance psychosocial adjustment. The results describe this group of burn victims as young people of average intelligence, still in school or otherwise employed and within normal limits on the measures of psychological adjustment. Some individuals, however, did evidence significant indicators of psychological disturbance. The only factors identified as significantly differentiating the most obviously disturbed subjects from the better-adjusted or well-adjusted victims were the perceptions held by those subjects that their families are less cohesive and less independent. These results emphasize the need to promote the familial support system and to encourage the values of autonomy and self-sufficiency. The results also affirm that severely injured burn victims can be expected to develop acceptably happy lives.