Turbulence suppression by cardiac-cycle-inspired driving of pipe flow.

Flows through pipes and channels are, in practice, almost always turbulent, and the multiscale eddying motion is responsible for a major part of the encountered friction losses and pumping costs1. Conversely, for pulsatile flows, in particular for aortic blood flow, turbulence levels remain low despite relatively large peak velocities. For aortic blood flow, high turbulence levels are intolerable as they would damage the shear-sensitive endothelial cell layer2-5. Here we show that turbulence in ordinary pipe flow is diminished if the flow is driven in a pulsatile mode that incorporates all the key features of the cardiac waveform. At Reynolds numbers comparable to those of aortic blood flow, turbulence is largely inhibited, whereas at much higher speeds, the turbulent drag is reduced by more than 25%. This specific operation mode is more efficient when compared with steady driving, which is the present situation for virtually all fluid transport processes ranging from heating circuits to water, gas and oil pipelines.

CT coronary angiography as an alternative imaging method to ascertain cardiac output and its correlation with echocardiography.

AIM: To assess the feasibility and accuracy of cardiac output (CO) obtained using a test bolus in patients scanned with single-source prospective-gated cardiac computed tomography (CT), and comparing it with CO obtained from unenhanced two-dimensional (2D) echocardiography using biplane Simpson's method. MATERIALS AND METHODS: In the present study, 100 patients with a mean age of 55 ± 12 years who underwent coronary CT angiography with prospective electrocardiogram (ECG)-gated CT in which the scan delay was evaluated using a test bolus. The time-attenuation curves obtained from the test bolus were used to calculate the CO of the patients. The CO obtained was then compared with that obtained after follow-up 2D echocardiography using biplane modified Simpson method. RESULTS: Linear regression was calculated between the CO and contrast enhancement: CO = -0.16(HUmax) + 7.65. The study showed good correlation between the two methods with r=0.77, p<0.001. On Bland-Altman analysis, no significant difference was noted between the two methods. CONCLUSION: This less researched method for CO estimation appears feasible; however, the clinical usefulness of this parameter is uncertain in absence of further clinical and reference standard validation.

BA3338, a surface layer homology domain possessing protein augments immune response and protection efficacy of protective antigen against Bacillus anthracis in mouse model.

AIM: Category A classified Bacillus anthracis is highly fatal pathogen that causes anthrax and creates challenges for global security and public health. In this study, development of a safe and ideal next-generation subunit anthrax vaccine has been evaluated in mouse model. METHOD AND RESULTS: Protective antigen (PA) and BA3338, a surface layer homology (SLH) domain possessing protein were cloned, expressed in heterologous system and purified by IMAC. Recombinant PA and BA3338 with alum were administered in mouse alone or in combination. The humoral and cell-mediated immune response was measured by ELISA and vaccinated animals were challenged with B. anthracis spores via intraperitoneal route. The circulating IgG antibody titre of anti-PA and anti-BA3338 was found significantly high in the first and second booster sera. A significant enhanced level of IL-4, IFN-γ and IL-12 was observed in antigens stimulated supernatant of splenocytes of PA + BA3338 vaccinated animals. A combination of PA and BA3338 provided 80% protection against 20 LD50 lethal dose of B. anthracis spores. CONCLUSION: Both antigens induced admirable humoral and cellular immune response as well as protective efficacy against B. anthracis spores. SIGNIFICANCE AND IMPACT OF THE STUDY: This study has been evaluated for the first time using BA3338 as a vaccine candidate alone or in combination with well-known anthrax vaccine candidate PA. The findings of this study demonstrated that BA3338 could be a co-vaccine candidate for development of dual subunit vaccine against anthrax.

Characterization of liver specific promoters in a foamy viral vector pMD09.

Foamy viruses (FVs) or spumaviruses are retroviruses that are explored as vectors for gene therapy. The good feature of foamy viruses is its broad tropism; however, their infections result in non-targeted gene expression. Here, we attempted to design the liver targeted viral gene delivery by employing liver specific gene promoters like albumin (ALB), transthyretin (TTR) and hepatitis B virus (HBV) promoters. We compared the relative gene expression of liver specific promoters versus the U3 promoter in liver cell line (HepG2) and non-liver cell lines: human fibrosarcoma cell line (HT1080), baby hamster kidney cell line (BHK), human embryonic kidney cell line (HEK 293T) and cervical cancer cell line (HeLa). We have found that the promoter exchange didn't affect viral assembly. The ability to drive gene expression was best with TTR promoter which was followed by HBV and ALB promoter. The use of TTR, HBV and ALB promoters are helpful in achieving liver specific gene expression. Keywords: foamy virus; gene therapy; liver; albumin; transthyretin promoter; HBV promoter.

Syndrome of remitting seronegative symmetrical synovitis with pitting edema: a case series.

Remitting Seronegative Symmetrical Synovitis with Pitting Edema (RS3PE) is a rare clinical entity that is easily missed due to lack of knowledge. It was formerly considered as a subset of rheumatoid arthritis (RA), but is now regarded as a distinct disease/syndrome. The diagnosis of RS3PE is not easy, as it is always hindered by the lack of definite diagnostic criteria and presence of other much common rheumatological disorders that mimic it. We report a series of seven cases that attended our clinic in the last year, which highlight the salient features of the disease. The disease was found to have a heterogeneous presentation. Immunogenetic, clinical, laboratory, radiological, and possible etiological factors and associations with the neoplasm are described, as also other peculiar presentations. Finally, a comparison with other common rheumatological disorders is made to alert the clinician about this rare, but easily treatable disease.

Association of Sex Hormones and Androgens with Disease Activity in Premenopausal Females with Rheumatoid Arthritis.

Background: Gonadal sex hormone dysfunction is frequently reported in patients with Rheumatoid arthritis (RA). The relationship of these hormones with disease activity is still not clear and whether the hormone imbalance leads to increased severity of RA is not well studied in this part of the world. The present study aimed to elucidate this fact. Methods: It was a cross-sectional observational study performed in 80 premenopausal females with definite RA at a tertiary care hospital in New Delhi, India over one year. Patients were subjected to investigations as per the protocol and a fasting venous blood sample for hormone levels was collected in the follicular phase of their menstrual cycle. Results: A statistically significant correlation by linear logistic regression analysis was found between disease activity (as measured by DAS28) and serum progesterone, FSH, and prolactin, while serum testosterone and DHEAS showed an inverse relationship with disease activity. Low s. prolactin, and s. FSH as well as high s. testosterone and s. DHEAS were found to be associated with target clinical goals in RA (ie, remission and low disease activity). On multivariate logistic regression analysis, serum prolactin showed a direct association. (p=0.016, OR= 1.009. C.I.= 1.0021.017) and serum testosterone were found to have an inverse relationship (p=0.002, OR= 0.017, C.I.=0.001-0.237) with disease activity in this group of individuals. Conclusion: Serum levels of sex hormones may be helpful in predicting disease activity among patients with RA, and in future, may be used to guide treatment of severe refractory disease, unresponsive to conventional treatment with DMARDs, especially in resource-poor settings.

Phosphorous magnetic resonance spectroscopy-based skeletal muscle bioenergetic studies in subclinical hypothyroidism.

BACKGROUND: Subclinical hypothyroidism (sHT) is considered to be a milder form of thyroid dysfunction. Few earlier studies have reported neuromuscular symptoms as well as impaired muscle metabolism in sHT patients. AIM/OBJECTIVE: In this study we report our findings on muscle bioenergetics in sHT patients using phosphorous magnetic resonance spectroscopy (31P MRS) and look upon the possibility to use 31P MRS technique as a clinical marker for monitoring muscle function in subclinical thyroid dysfunction. SUBJECTS AND METHODS: Seventeen normal subjects, 15 patients with sHT, and 9 patients with hypothyroidism performed plantar flexion exercise while lying supine in 1.5 T magnetic resonance scanner using custom built exercise device. MR Spectroscopy measurements of inorganic phosphate (Pi), phosphocreatine (PCr), and ATP of the calf muscle were taken during rest, at the end of exercise and in the recovery phase. PCr recovery rate constant (kPCr) and oxidative capacity were calculated by monoexponential fit of PCr vs time (t) at the beginning of recovery. RESULTS: We observed that changes in some of the phosphometabolites (increased phosphodiester levels and Pi concentration) in sHT patients which were similar to those detected in patients with hypothyroidism. However, our results do not demonstrate impaired muscle oxidative metabolism in sHT patients based upon PCr dynamics as observed in hypothyroid patients. CONCLUSIONS: 31P MRS-based PCr recovery rate could be used as a marker for monitoring muscle oxidative metabolism in sub clinical thyroid dysfunction.

Clinical efficacy of a novel new injectable diclofenac formulation designed for intradeltoid use in post-operative pain management.

OBJECTIVE: A randomized study comparing efficacy and safety of a new 75 mg/1 ml formulation of injectable diclofenac sodium designed for intra-deltoid use with the conventional 75 mg/3 ml formulation given by the intra-gluteal route. DESIGN: This was an open-label, multicentric, randomized clinical trial. METHODS: A total of 250 adult patients with post-operative pain were randomized to receive either an injection diclofenac 75 mg/1 ml or diclofenac 75 mg/3 ml. Primary efficacy criteria were time to onset of analgesia and reduction in pain intensity. Severity of pain at site of injection and side effects were also evaluated. RESULTS: 232 patients completed the study. The mean times to onset of anal-gesia were comparable (16.17 ± 12.70 min in the diclofenac 75 mg/1 ml group and 19.16 ± 11.79 min in the diclofenac 75 mg/3 ml group). However, significantly more patients achieved analgesia in less than 5 min and had less pain at the site of injection with the 1 ml formulation. The need for rescue medication was also lower with the 1 ml formulation (2.5% vs. 9.82%). No side effects were reported. A significantly larger number of patients and physicians rated the efficacy and safety of injectable diclo-fenac 75 mg/1 ml as excellent. CONCLUSION: Both formulations were effective and safe in the management of post-operative pain with a significantly lower need for rescue analgesia and less pain at site of injection with diclofenac 75 mg/1 ml formulation. The 1 ml formulation had an added advantage of intra-deltoid use. This would be specially helpful in obese/overweight patients with a thick subcutaneous pad of fat over the gluteal region.

Effect of trifluoroethanol on native and acid-induced states of glucose oxidase from Aspergillus niger.

We have studied the effect of trifluoroethanol (TFE) on the native (pH 7.0), acid unfolded (pH 2.6), and molten globule (pH 1.4) states of glucose oxidase (GOX) by circular dichroism and fluorescence spectroscopy. In the presence of 50% TFE, at pH 7.0 and 2.6, GOX exhibited a transition from native coiled-coil and acid unfolded state to non-associating alpha-helical state. Interestingly, at pH 1.4, 15% TFE induced the formation of beta-structured intermediate by loss of 1-anilino-8-naphthalenesulfonate binding site and almost all tertiary contacts. The beta-structured intermediate converted into open helical conformation on further addition of TFE.

pH-Dependent urea-induced unfolding of stem bromelain: unusual stability against urea at neutral pH.

Equilibrium unfolding of stem bromelain (SB) with urea as a denaturant has been monitored as a function of pH using circular dichroism and fluorescence emission spectroscopy. Urea-induced denaturation studies at pH 4.5 showed that SB unfolds through a two-state mechanism and yields DeltaG (free energy difference between the fully folded and unfolded forms) of approximately 5.0 kcal/mol and C(m) (midpoint of the unfolding transition) of approximately 6.5 M at 25 degrees C. Very high concentration of urea (9.5 M) provides unusual stability to the protein with no more structural loss and transition to a completely unfolded state.

Resting membrane potential as a marker of apoptosis: studies on Xenopus oocytes microinjected with cytochrome c.

Observation of the electrical potential difference across the cell membrane is described as a new method for monitoring apoptosis of a single cell. The resting membrane potential (DeltaPsi) of Xenopus oocytes has been recorded in real time following microinjection of cytochrome c. Soon after microinjection, DeltaPsi becomes less negative and attains a new constant value with a half time, t(m), of about 35 (+ /- 5) min at all cytochrome c concentrations greater than 1 microM. The cytosol extract of cytochrome c-injected oocytes shows DEVD proteolytic activity characteristic of aspartate specific proteases, implicating an apoptotic death pathway. In response to the delivery of cytochrome c into the cytosol, caspases are activated within 7 min while the changes in DeltaPsi begin to occur after about 30 min. The method described here will be potentially useful to assess the effectiveness of cell death regulators and modulators of synthetic and biological origin, and the results presented shed light on the currently debated issue of the importance of the redox state of cytochrome c in the initiation of apoptosis.

Interaction of D,L- and D-tetraplatin with hyperthermia in vitro and in vivo.

The cytotoxicities of D,L-tetraplatin and D-tetraplatin were evaluated at 37 degrees C, 42 degrees C and 43 degrees C at normal pH, at pH 6.45 and under normally oxygenated and hypoxic conditions in EMT-6 cells in vitro. The D-isomer was also tested in FSaIIC cells in vitro. Under these various conditions the pure D-isomer was very similar in cytotoxicity with the racemic mixture. Like cisplatin, both D,L- and D-tetraplatin were selectively cytotoxic toward normally oxygenated cells under acidic pH (6.45) conditions at 37 degrees C. In both cell lines the cytotoxicity of D,L- and D-tetraplatin was markedly increased at hyperthermic temperatures. Under the same conditions platinum levels in EMT-6 cells exposed to D,L- or D-tetraplatin were higher than in cells exposed to cisplatin, and unlike cisplatin there was an increase in intracellular platinum levels when the cells were exposed to D,L- or D-tetraplatin at 42 degrees C compared with 37 degrees C. The tumour growth delay of the FSaIIC fibrosarcoma was the same for D,L- and D-tetraplatin. A dose of 10 mg/kg intraperitoneally of tetraplatin produced a tumour growth delay of about 4.3 days which was increased to about 6 days with the addition of local hyperthermia (43 degrees C, 30 min) to the drug treatment. The tumour cell survival assay also showed no difference between D,L- and D-tetraplatin and a log-linear increase in tumour cell killing with increasing drug dose which was increased 1.5-3-fold with local hyperthermia. D,L- and D-tetraplatin were relatively much more cytotoxic toward bone marrow colony forming units of granulocyte-macrophage progenitors (CFU-GM) than was cisplatin and this cytotoxicity was increased about 5-10-fold under hyperthermic conditions. There was an increase in DNA crosslink formation in tumours when hyperthermia accompanied tetraplatin treatment. Overall, D,L- and D-tetraplatin produced very similar responses under hyperthermic conditions in both tumour and normal tissues, and may be a useful agent in combination with local hyperthermia.

Cytoplasmic residues influence the voltage-dependence of the gating of human K+ channels.

Shaker type potassium channels are strongly voltage dependent and potassium selective. Kv1.4 channels from a variety of sources exhibit a much shallower voltage-dependence of activation than other members of the family. We have made a chimeric construct consisting of the N-terminal chain of hKv1.1 spliced onto the transmembrane portion of hKv1.4 (IN/4). When expressed in Xenopus oocytes, the chimeric channel exhibits a voltage dependence that is similar to hKv1.1 although the voltage sensing and transduction machinery presumably reside in the transmembrane portion of the channel. Loss of the N-terminal ball and chain from hKv1.4 is not responsible for this as a truncation construct, starting close to the splice junction, has the same voltage-dependence as full length hKv1.4. We suggest that residues from the N-terminal chain of hKv1.1 interact with the machinery that transduces movement of the voltage sensor into channel opening. If so, this chimeric construct could provide a handle to the identification of elements of this transduction machinery.

Transplanting the N-terminus from Kv1.4 to Kv1.1 generates an inwardly rectifying K+ channel.

A chimeric channel, 4N/1, was generated from two outwardly rectifying K+ channels by linking the N-terminal cytoplasmic domain of hKv1.4 (N terminus ball and chain of hKv1.4) with the transmembrane body of hKv1.1 (delta78N1 construct of hKv1.1). The recombinant channel has properties similar to the six transmembrane inward rectifiers and opens on hyperpolarization with a threshold of activation at -90 mV. Outward currents are seen on depolarization provided the channel is first exposed to a hyperpolarizing pulse of -100 mV or more. Hyperpolarization at and beyond -130 mV provides evidence of channel deactivation. Delta78N1 does not show inward currents on hyperpolarization but does open on depolarizing from -80 mV with characteristics similar to native hKv1.1. The outward currents seen in both delta78N1 and 4N/1 inactivate slowly at rates consistent with C-type inactivation. The inward rectification of the 4N/1 chimera is consistent with the inactivation gating mechanism. This implies that the addition of the N-terminus from hKv1.4 to hKv1.1 shifts channel activation to hyperpolarizing potentials. These results suggest a mechanism involving the N-terminal cytoplasmic domain for conversion of outward rectifiers to inward rectifiers.

Multiple modality treatment of carcinoma cells with Pt(Rh-123)2 plus x-ray plus light.

A complex of platinum tetrachloride with two molecules of rhodamine-123 (Rh-123), Pt(Rh-123)2, has been reported to act as hypoxic cell radiosensitizer of carcinoma cells in vitro and in vivo. In the present paper we report that Pt(Rh-123)2 photosensitizes human mammary carcinoma (MCF-7) cells and cis-platinum resistant human mammary carcinoma (MCF-7/CP) cells to 400-800 nm light in vitro. The efficiency of photosensitization by Pt(Rh-123)2 was 10 times greater than for Rh-123. Combination therapy using Pt(Rh-123)2 plus x-ray plus light was also much more effective compared to the combination therapy using Rh-123 plus x-ray plus light. After 15 microM of Rh-123 plus x-ray (0-8 Gy) plus light (5 J/cm2) treatment, cell survival curve was parallel to the x-ray cell survival curve with an initial decrease in the surviving fraction corresponding to the drug plus light mediated killing. Cell killing caused by Rh-123 (15 microM) plus x-ray (0-8 Gy) plus light (5 J/cm2) was additive as determined by the product of the surviving fraction after Rh-123 plus light and x-ray. In contrast, for 15 microM of Pt(Rh-123)2 plus x-ray (8 Gy) plus light (5 J/cm2) treatment, whereas additive killing predicts a survival fraction of approximately 0.024, in reality, the combination therapy caused the survival fraction to decrease to 0.0012, implying that the cell killing was enhanced by a factor of 20. Using Pt(Rh-123)2 plus x-ray plus light, supra-additive cell killing was also observed under hypoxic conditions, although compared to normally oxygenated conditions the degree of cytotoxicity was significantly reduced.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of hypoxia and acidosis on the cytotoxicity of mitoxantrone, bisantrene and amsacrine and their platinum complexes at normal and hyperthermic temperatures.

In an effort to synthesize drugs which would become much more cytotoxic at clinically achievable hyperthermic temperatures, complexes of the tetrachloro-platinum(II) dianion were made with two anthracene dye derivatives, MITOX and BISANT, and the acridine dye derivative m-AMSA. As compared with the parent drug, PtCl4(MITOX)2 was less cytotoxic at 37 degrees C and more cytotoxic at 42 degrees C and 43 degrees C especially at pH 6.45. In contrast, the PtCl4(BISANT)2 was more cytotoxic than BISANT under all conditions. M-AMSA was again shown to be less cytotoxic at elevated temperatures but PtCl4(m-AMSA)2 was more cytotoxic especially at 43 degrees C and pH 6.45. Platinum levels in cells treated for 1 hr with 25 microM at 37 degrees C, 42 degrees C and at pH 7.40 versus pH 6.45 demonstrated no significant differences depending on temperature or pH except for PtCl4(MITOX)2 where approximately 4 times higher intracellular platinum levels were present at pH 6.45 versus pH 7.40, although this finding did not correlate with cytotoxicity. These results suggest that PtCl4(MITOX)2 and PtCl4(m-AMSA)2 may be highly interactive drugs with local hyperthermia.

Exploring the architecture of potassium channels using chimaeras to reveal signal transduction.

The chimeric channel, 4N/1, generated from two outwardly rectifying K+ channels by linking the N-terminal cytoplasmic domain of hKv1.4 with the transmembrane body of hKv1.1, functions as an inward rectifier. The operating range of the channel is shifted to hyperpolarizing potentials and it is inactivated at resting membrane potentials. Co-expression of a truncated form of hKv1.1 with the N-terminal domain of hKv1.4 results in the same physiology as the chimaera implying specific interactions between the two segments.

Enriched collagen as coadjuvant therapeutic agent in experimental osteomyelitis in dogs.

Osteomyelitis was induced in the tibiae of dogs by injecting hemolytic strain of Staphylococcus aureus. Clinical, radiological and histomorphological reactions in the diseased tibiae were studied up to 15 weeks to evaluate the response of infected bone to parenteral oxytetracycline in cases of closed wounds and surgical curettage, antimicrobial irrigation along with parenteral oxytetracycline therapy in animals carrying open wounds. Enriched collagen as a constituent of therapeutic regimen was also administered locally and its efficacy during resolution of osteomyelitis was compared with other treatments. Surgical curettage along with irrigation of lesions was observed to be an effective method for bringing an early recovery in aggravated cases of osteomyelitis. The addition of collagen enhanced the healing process in comparison with non-collagen treated animals.