2-Thiazolylimino/heteroarylimino-5-arylidene-4-thiazolidinones as new agents with SHP-2 inhibitory action

SHP-2, a nonreceptor protein tyrosine phosphatase encoded by the PTPN11 gene, mediates cell signaling by growth factors and cytokines via the RAS/MAP kinase pathway. Somatic mutations in PTPN11 gene account for approximately 18% of juvenile myelomonocytic leukemia (JMML) patients. Moreover, SHP-2 mutations leading to continuously active enzyme were found in more than 50% of Noonan syndrome patients and are considered to be responsible for the high tendency of these patients to juvenile leukemias and other cancer types. Recently SHP-2 became a new drug target, but till now little has been done in this field. In the present study, 17 2-thiazolylimino/heteroarylimino-5-arylidene-4-thiazolidinones divided into three series of derivatives bearing thiazole-, benzo[d]thiazole-, and benzo[d]isothizole rings were tested for SHP-2 inhibitory activity. Most of the compounds were good SHP-2 inhibitors. Benzo[d]thiazole derivatives exhibited the best inhibitory action. Docking studies revealed that hydrophobic interactions and hydrogen bond formation stabilize enzyme-inhibitor complex.

Obesity and pregnancy

Obesity is reaching pandemic proportions worldwide. It is increasingly being recognised as a risk factor during pregnancy. Women should ideally be counselled preconceptionally about the increased risks and encouraged to lose weight actively, some may be candidates for bariatric surgery. Maternal risks include gestational diabetes, hypertension and pre-eclampsia, increased incidence of operative delivery, postpartum haemorrhage, anaesthetic risks as well as infective and thrombo-embolic complications while fetal risks include miscarriage, neural-tube defects, macrosomia and stillbirth. Obstetric units should institute appropriate guidelines for the management of pregnancy in this 'high-risk' group of women.

Internet resources in GPCR modelling

G-Protein coupled receptors (GPCRs), one of the most important families of drug targets, belong to the super family of integral membrane proteins characterized by seven transmembrane helices. Because they are difficult to crystallize, the three dimensional structure of these receptors have not yet been determined by X-ray crystallography, except one. In the absence of a 3-D structure, in-silico approaches for solving the structure of this class of proteins are widely used and provide valuable information for structure based drug design. There are several web servers and computer programs available that automate the modelling process of GPCRs. Some of these include Modeller, Swiss-Model server, Homer, etc. Using these tools reliable homology models of human histamine H1 receptor (HRH1) and thrombin receptor (PAR-1) have been generated which explain the binding mode of the standard antagonists of these receptors and may be useful in designing their novel antagonists.

Acquired von Willebrand's disease associated with gastrointestinal angiodysplasia: a case report

Acquired von Willebrand syndrome (AVWS) is a rare and probably underestimated bleeding disorder which mimics most of the clinical symptoms and laboratory features of hereditary von Willebrand disease (VWD) in patients devoid of both personal and family history of bleeding diathesis. In this study, we present a case of 55 yrs male patient, presented with gastrointestinal bleeds since three years, diagnosed to have AVWS with inhibitors. From this study it is concluded that AVWS is rare and it is important to diagnose this bleeding disorder so that appropriate treatment with plasmapheresis and IV:Ig can effectively correct the haemostatic defect and manage severe bleeding in these patients.

Clinical, haematological and histomorphological profile of adult myelodysplastic syndrome. Study of 96 cases in a single institute

Myelodysplastic syndromes (MDS) are clonal haematopoietic stem cell disorders characterised by ineffective and dyspoietic haematopoiesis. The natural history of these disorders is variable and ranges from a chronic to a rapid course towards leukaemic progression. Certain shortcomings have been encountered in the French-American-British (FAB) classification over the years, and therefore there is a need for an alternative method of classification. In 1999, the WHO published a revised classification of MDS. In the present study, we have analysed the clinical, haematological and histomorphological features in 96 cases of primary MDS seen in the department of haematology at the All India Institute of Medical Sciences (AIIMS) over a 6-yr period (1996-2001). Both FAB and WHO classifications have been incorporated and the Bournemouth scoring system applied in each case at presentation. The Bournemouth scoring system, in the absence of a cytogenetic study, offers a good prognostication and long-term survival estimate.

Synchronous occurrence of breast carcinoma and acute myeloid leukemia: case report and review of the literature

We present a case of breast carcinoma, which was followed by acute leukemia within 1 month of diagnosis of the former. She had undergone a modified radical mastectomy for her breast cancer and had not received chemotherapy or radiotherapy. Acute leukemia as a result of chemotherapy for breast carcinoma is well known. However, patients developing synchronous breast carcinoma and acute leukemia, in the absence of any chemotherapy or radiotherapy, are rare.

Geometric endo-ventricular patch repair of inferior left ventricular scars improves mitral regurgitation and clinical outcome

BACKGROUND

The surgical reconstruction of inferior left ventricular (LV) aneurysms and scars has been considered a difficult procedure and there has been little material published about this treatment option. In this study we report on our experience with reconstruction of the inferior wall and compare it to the outcome of anterior LV reconstructions.

METHODS

Seventeen patients (group 1) underwent geometric endo-ventricular patch repair (GER) of inferior LV aneurysms and dyskinetic scars between January 1998 and December 2000. In addition to poor LV function, 5 of these patients had severe mitral valve regurgitation (MR), 8 had moderate MR, and 4 had mild MR preoperatively. These patients also underwent coronary artery bypass graft surgery or valve surgery. The perioperative course, survival, and clinical status were evaluated in this group and was compared to those of 86 patients (group 2) undergoing anterior GER during the same period.

RESULTS

There was 1 early death in group 1 (5.8%) and 6 in group 2 (7%) (p = ns). At the conclusion of the operative procedure, all patients in group 1 were weaned off cardiopulmonary bypass with trivial to mild MR. There was 1 late death in group 1 (6.2%) and 2 in group 2 (2.8%) (p = ns). Eleven patients (73%) in group 1 were in New York Heart Association class 1 compared to 60 in group 2 (77%) (p = ns). Follow-up echocardiography showed that 80% of patients in group 1 had trivial MR.

CONCLUSIONS

The surgical reconstruction of inferior LV aneurysms and scars can be performed safely with the expectation of a reasonable early outcome similar to that achieved with anterior LV scars. When used in this setting GER improves MR, reducing the likelihood of heart failure decompensation.

D,L-alpha-difluoromethylornithine, an irreversible inhibitor of ornithine decarboxylase, induces differentiation in MEL cells

In the present study, the effect of D,L-alpha-difluoromethylornithine (DFMO), an irreversible inhibitor of ornithine decarboxylase (ODC), on Friend's murine erythroleukemia (MEL) cell differentiation is investigated. DFMO was able to induce differentiation of MEL cells in culture as determined by haemoglobin (Hb) content and percentage of cells synthesizing Hb detected by benzidine staining. DFMO at a concentration of 2 mM resulted in about 70% benzidine-positive cells on the fifth day. There was a time-dependent increase in the percentage of benzidine-positive cells starting from day three. However, only a 24 h presence of DFMO in the medium was required to induce differentiation suggesting that DFMO switches on a pathway during this period leading to terminal differentiation of MEL cells. DFMO induced differentiation of MEL cells was sensitive to dexamethasone and 5-bromo-2'-deoxyuridine.

Pulmonary hemorrhage in an infant following 2 weeks of fungal exposure

BACKGROUND

Exposure to indoor fungus growth and tobacco smoke has been epidemiologically linked to unexplained pulmonary hemorrhage in infants.

OBJECTIVE

To describe the 40-day-old male infant who had been exposed to fungi for a discrete 2-week period followed by acute exposure to environmental tobacco smoke prior to development of a life-threatening pulmonary hemorrhage.

PATIENT AND METHODS

History and clinical evaluation of the infant immediately followed the pulmonary hemorrhage. Air and surface sampling for isolation and identification of fungal growth in the dwelling where the infant resided before the acute hemorrhage was accomplished when the homeowner returned from vacation 4 months after the clinical event.

RESULTS

Two fungi associated with mycotoxin production were cultured from surface samples collected in the residence: Penicillium (possibly Penicillium purpurogenum) and a Trichoderma species. Stachybotrys atra was not isolated from air or surface samples. Environmental tobacco smoke exposure occurred over a discrete several-hour period prior to onset of the acute pulmonary hemorrhage.

CONCLUSIONS

Avoidance of unnecessary exposure of infants to fungus growth in water-damaged environments or exposure to tobacco smoke is prudent. Further investigation into the toxic effects of indoor fungi as causes of infantile pulmonary hemorrhage is warranted.

Factors associated with inadequate blood pressure control in hypertensive hemodialysis patients

Hypertension is common in hemodialysis patients and increases cardiovascular morbidity and mortality. We determined the prevalence of inadequate control of hypertension in 489 patients receiving hemodialysis and identified factors associated with uncontrolled hypertension. We interviewed the patients and abstracted demographic and clinical information from a computerized database. The prevalence of uncontrolled hypertension (average predialysis blood pressure, > or =160/90 mm Hg) was 62%. Ninety-one percent of patients with uncontrolled hypertension were receiving submaximal antihypertensive drug therapy, and 59% withheld their medications before dialysis. Uncontrolled hypertensives had a greater interdialytic weight gain (3.8% v 3.5%, P = 0.07) and a greater excess weight gain (3.1 +/- 1.6 kg v 2.5 +/- 1.4 kg; P < 0.05) compared with controlled hypertensives. Patients with uncontrolled hypertension showed higher interdialytic weight gain (2.7 +/- 0.06 kg v 2.2 +/- 0.13 kg; P < 0.05), were more likely to be black (94% v 81%; P < 0.05), were more likely to have hypertension as the cause of their end-stage renal disease (ESRD) (42% v 24%; P < 0.05), and had been receiving hemodialysis for a shorter time (4.3 +/- 2 yr v 6.1 +/- 0.9 yr; P < 0.05) compared with normotensive patients. There was significant correlation between diastolic blood pressure and both interdialytic weight gain (r = 0.31, P < 0.05) and percent weight gain (r = 0.34, P < 0.05) in the hypertensive but not in the normotensive patients (r = -0.21). Interdialytic weight gain and hypertension as a cause of ESRD were independent predictors of predialysis systolic blood pressure. We conclude that hypertension is uncontrolled in most patients undergoing hemodialysis. Submaximal antihypertensive therapy, excessive interdialytic weight gain, and withholding antihypertensive medication before dialysis are correctable factors potentially contributing to uncontrolled hypertension.

In vivo delivery of recombinant human growth hormone from genetically engineered human fibroblasts implanted within Baxter immunoisolation devices

Continuous delivery of therapeutic peptide to the systemic circulation would be the optimal treatment for a variety of diseases. The Baxter TheraCyte system is a membrane encapsulation system developed for implantation of tissues, cells such as endocrine cells or cell lines genetically engineered for therapeutic peptide delivery in vivo. To demonstrate the utility of this system, cell lines were developed which expressed human growth hormone (hGH) at levels exceeding 1 microgram per million cells per day. These were loaded into devices which were then implanted into juvenile nude rats. Significant levels of hGH of up to 2.5 ng/ml were detected in plasma throughout the six month duration of the study. In contrast, animals implanted with free cells showed peak plasma levels of 0.5 to 1.2 ng four days after implantation with no detectable hGH beyond 10 days. Histological examination of explanted devices showed they were vascularized and contained cells that were viable and morphologically healthy. After removal of the implants, no hGH could be detected which confirmed that the source of hGH was from cells contained within the device. The long term expression of human growth hormone as a model peptide has implications for the peptide therapies for a variety of human diseases using membrane encapsulated cells.

Benefits of pre-emptive dose reduction for Sandimmune to Neoral conversion in stable renal transplant recipients

In an effort to minimize nephrotoxicity resulting from greater exposure to cyclosporine after Sandimmune to Neoral conversion, we compared two conversion regimens using different dosing ratios. Serial serum creatinine concentrations and trough cyclosporine levels were measured in 26 patients converted from Sandimmune to Neoral using a 1:0.8 dosing ratio (Group 1) and compared to those of 26 patients converted using a 1:1 dosing ratio (Group 2). The percentage change in peak serum creatinine concentration after conversion was greater in Group 2. However, at last follow-up, the dose reductions in each group were comparable. Following conversion, patients in Group 1 required fewer dose adjustments and follow-up blood tests. Compared to conversion using a 1:1 dosing ratio, conversion from Sandimmune to Neoral using a 1:0.8 ratio results in comparable dose reductions and less short-term nephrotoxicity, while requiring less frequent laboratory monitoring.

Reoperation for recurrent coronary artery disease: results of 200 consecutive cases

BACKGROUND

It is well known that reoperation for recurrent coronary artery disease is more difficult than primary coronary artery bypass grafting. However, it is possible to reduce the morbidity and mortality of reoperation to the same level as the initial procedure with careful surgical technique.

METHODS

A retrospective study of the first 200 patients who underwent redo coronary bypass grafting was undertaken.

RESULTS

In the first 200 cases of redo coronary bypass grafting at St George Hospital, Sydney (August 1986-January 1995), there were five in-hospital deaths (2.5%). There was one case of sternal infection (0.5%), which required surgical debridement, three cases of stroke (1.5%), one case of postoperative bleeding (0.5%), which required a return to theatre and six cases (3%) required mechanical ventilation for more than 24 h. The need for major postoperative support (such as intra-aortic balloon pumping/adrenaline infusion) was significantly affected by the degree of urgency and the degree of pre-operative ventricular impairment.

CONCLUSIONS

The mortality rate of redo coronary artery bypass grafting in this series is similar to that of primary surgery described in other reports.

In vitro transcription of c-jun gene using fractionated nuclear extract from regenerating rat liver

Regenerating rat liver serves as a source of proliferating cells, such a system can be used to study the regulation of genes involved in proliferation. We have established an in vitro transcription capable of supporting accurate transcription of cloned c-jun gene using fractionated nuclear extract prepared from partially hepatectomized rat liver. EcoR I linearized plasmid -132/+170 jun-CAT containing c-jun gene promoter region (-132 to +170 nucleotides) was transcribed in an in vitro run-off transcription assay and a transcript of expected size i.e. 370 nucleotides was obtained. The intensity of the transcript was dependent on the concentration of fractionated nuclear extract as well as template. The transcription was alpha-amanitin sensitive indicating that it is directed by RNA polymerase II.

Production of the beta-subunit of human chorionic gonadotropin in Escherichia coli and its export mediated by the heat-labile enterotoxin chain-B signal sequence

The PCR-amplified beta-subunit of the human chorionic gonadotropin structural gene (betahCG) was cloned under the control of the tac promoter and the heat-labile enterotoxin chain B (LTB) signal sequence (LTBss). BetahCG was successfully produced, processed and exported to the periplasmic space in Escherichia coli. Expression of betahCG was confirmed by immunoblot analysis using an anti-betahCG polyclonal antibody. The processing of the protein was very efficient, as only the processed band could be detected at all time points during the course of induction. Expression was evident soon after the addition of the lactose analogue, IPTG. These results demonstrate that E. coli cells can synthesize, process and export betahCG using the LTBss.

Translational fusion of heat labile enterotoxin chain B and beta-subunit of human chorionic gonadotropin: periplasmic expression in Escherichia coli and its immunogenicity

A fusion gene was constructed consisting of heat labile enterotoxin chain B (LTB) of E. coli genetically linked at its C-terminus to the beta-subunit of human chorionic gonadotropin in translational fusion, under the control of tac promoter and LTB signal sequence. Expression of the fusion gene (about 5 microgram/ml) in E. coli was confirmed by immunoblot analysis using both anti-LTB and anti-betahCG polyclonal antibodies. The fusion protein was efficiently processed and exported to the periplasmic space. LTB in the fusion protein retained its ability to bind to GM1 ganglioside receptor. Mice immunized with the fusion protein produce antibodies that recognize recombinant betahCG and the native hCG suggesting its potential use as a contraceptive vaccine.

2-Mercaptopropionylglycine modulates the expression of c-jun and c-Ha-ras in regenerating rat liver

Changes in the expression of two proto-oncogenes, c-jun and c-Ha-ras and their modulation by MPG were studied in regenerating rat liver. A significant increase in c-jun and c-Ha-ras mRNA levels was noted after partial hepatectomy. However, the increase in c-Ha-ras mRNA was much less when compared with c-jun mRNA levels. Metallothionein (MT-I) mRNA levels showed a gradual decrease following partial hepatectomy. However, the decrease in MT-I mRNA levels was not significant when intertime comparisons were made. MPG caused a significant reduction in the levels of c-jun and c-Ha-ras mRNA in the regenerating rat liver compared to untreated controls, but had very little effect on MT-I mRNA levels. Selective reduction in the expression of proto-oncogenes by MPG suggests that MPG may affect the cell proliferation by modulating the expression of these genes.

Induction of differentiation in murine erythroleukemia cells by 1 alpha,25-dihydroxy vitamin D3

The Friend murine erythroleukemia (MEL) cells can be stimulated to differentiate in response to a variety of chemical inducing agents. In the present study, the effect of 1 alpha,25-dihydroxyvitamin D3 on differentiation of MEL cells was investigated. Vitamin D3 induced differentiation of MEL cells in culture as determined by elevated hemoglobin content, a rise in the number of benzidine-positive cells and increase in acetylcholine esterase activity. The optimum concentration of the vitamin required to induce differentiation of MEL cells was found to be 750 nM. The pattern of induction of differentiation was similar to that observed with DMSO and the induction of differentiation by vitamin D3 was inhibited by dexamethasone.