Decreased infectivity despite unaltered C3 binding by a DeltahbhA mutant of Mycobacterium tuberculosis

HbhA of Mycobacterium tuberculosis is a multifunctional binding protein, binding to both sulfated sugars such as heparin and to human complement component C3. HbhA may therefore interact with host molecules and/or host cells during M. tuberculosis infection and play a role in the pathogenesis of this bacterium. The purpose of this study was to use allelic exchange to create an M. tuberculosis strain deficient in expression of HbhA to determine whether this protein's C3-binding activity plays a role in the pathogenesis of M. tuberculosis. An in-frame, 576-bp unmarked deletion in the hbhA gene was created using sacB as a counterselectable marker. Southern blotting and PCR analyses confirmed deletion of hbhA in the DeltahbhA mutant. The DeltahbhA mutant strain grew at a rate similar to that of the parent in broth culture and in J774.A1 murine macrophage-like cells but was deficient in growth compared to the parent strain in the lungs, liver, and spleen of infected mice. In addition, the DeltahbhA mutation did not reduce binding of M. tuberculosis to human C3 or to J774.A1 cells in the presence or absence of serum, suggesting that in the absence of HbhA, other molecules serve as C3-binding molecules on the M. tuberculosis surface. Taken together, these data indicate that HbhA is important in the infectivity of M. tuberculosis, but its ability to bind C3 is not required for mycobacterial adherence to macrophage-like cells. Using the DeltahbhA mutant strain, a second M. tuberculosis C3-binding protein similar in size to HbhA was identified as HupB, but the role of HupB as a C3-binding protein in intact organisms remains to be determined.     

Polarimetric imaging of subsurface tissue-numerical results

Tissue images obtained at deeper depths lack significant contrast. To enhance the contrast of these images and to increase the visibility of subsurface tissues, a method is proposed. This technique is based on the principle that photons at longer wavelengths penetrate deeper than photons at shorter wavelengths. In this technique, images in the original and orthogonal polarized states are recorded with the source illumination in linear polarized state at two different wavelengths. Image subtraction of a fraction of the copolarized image from the perpendicular polarized state is done on these images. The images obtained after the first processing are subjected to the next image subtraction where the shorter wavelength image is subtracted from the longer wavelength image. Monte Carlo simulations show that the resultant image has marked contrast up to 2.5 cm.     

Laparoscopic Management of Prosthetic Infections Following Laparoscopic Groin Hernioplasty — Experiences from a Tertiary Care Center

Hellenic Journal of Surgery - Despite increasing trends towards laparoscopic groin hernioplasty, its early prosthesis-related complications have hardly been addressed. Although conventionally...     

The future of proteomics in the study of alcoholism

This article represents the proceedings of a workshop at the 2003 annual meeting of the Research Society on Alcoholism in Fort Lauderdale, FL. The workshop organizers/chairpersons were Chinnaswamy Kasinathan and Paul Manowitz. The presentations were (1) Introduction to the field of proteomics, by Kent Vrana; (2) Use of proteomics in the identification of urinary biomarkers for alcohol intake, by Chinnaswamy Kasinathan, Paul Thomas, and Paul Manowitz; (3) Proteomics screening illuminates ethanol-mediated induction of HDL proteins in macaques, by Kent Vrana, Randy Gooch, Travis Worst, Stephen Walker, Aaron Xu, Peter Pierre, Heather Green, and Kathleen Grant; and (4) Proteomics applied to the study of the liver, by Laura Beretta.     

Anihypercholesterolemic effect of Semecarpus anacardium Linn nut milk extract in high-cholesterol-fed rats

The present study was carried to bring about the hypolipidemic effect of the drug Semecarpus anacardium Linn nut milk extract (SA) in hypercholesterolemia-induced rat model. Adult male Wistar rats were divided into four groups which included control rats, hypercholesterolemia-induced rats (high-cholesterol diet (4 %) for 30 days), hypercholesterolemic rats treated with the drug SA (200 mg/kg/b. wt oil), and the control rats treated with the drug SA (200 mg/kg/b. wt). Increased level of ROS and lipid peroxides were observed in hypercholesterolemic rats, whereas the levels of activities of antioxidant enzymes were found to be decreased in animals fed with a high-fat diet. Simultaneous administration of SA to these rats reverted back the changes to near-normal levels. Similarly, an increase in the expression of iNOS and LOX-1 were observed in high-fat-fed rats when compared to normal rats. Upon treatment with the drug SA, their expressions were brought back to near-normal levels. No adverse effects were observed in SA-alone treated group of rats, indicating its protective nature. The present study suggests that SA could play a protective role against hypercholesterolemia, thereby preventing coronary heart disease.     

Immunomodulatory effect of Kalpaamruthaa on 7,12-dimethyl benz(a)anthracene-induced mammary carcinoma studied in rats

Kapaamruthaa is a modified Siddha preparation prepared in our laboratory. It has been proven to have therapeutic effect against arthritis and liver cancer. The present study was carried out to bring about the protective effect of Kalpaamruthaa on experimental mammary carcinoma in rats with special reference to cytokines, carcinoembryonic antigen (CEA), carbohydrate antigen 15–3 (CA 15–3), immunoglobulin levels, and glycoprotein components. Breast cancer was induced in rats by administering 7,12-dimethylbenz(a)anthracene (DMBA) orally (25 mg/rat) as a single dose. After 90 days of induction, Semecarpus anacardium Linn. (200 mg/kg body weight) and Kalpaamruthaa (KA) (300 mg/kg body weight) were administered for 14 days, by gastric intubation. In mammary carcinoma-bearing rats, the levels of interleukin-6, interleukin-8, and tumor necrosis factor-α were significantly increased (p?<?0.001) in serum when compared to control rats. The levels of CEA and CA 15–3 were found to be significantly increased (p?<?0.001) in mammary carcinoma-bearing rats. The levels of IgG and IgM were significantly decreased (p?<?0.001) whereas IgA levels were significantly increased (p?<?0.001) in mammary carcinoma-bearing rats. The levels of glycoprotein components namely hexose, hexosamine, and sialic acid were significantly (p?<?0.001) increased in the spleen and thymus of the mammary carcinoma-bearing (group II) rats when compared to control rats. Treatment with KA significantly altered the levels of cytokines, CEA, CA 15–3, immunoglobulins, and glycoprotein components to near normal levels when compared to breast cancer-induced rats. The present study suggests the therapeutic effect of KA in DMBA-induced mammary carcinoma in rats.