Development and physical characterization of chloramphenicol loaded biodegradable nanoparticles for prolonged release.

The objectives of our study were to prepare a biodegradable nanoparticulate system of chloramphenicol (CHL) and to evaluate its ability to prolong in vitro release of CHL compared to free drug suspension (FDS). CHL-loaded polylactide-co-glycolide nanoparticles (CHL-PLGA-NPs) were prepared by an emulsion/solvent evaporation method using ethyl acetate and polyvinyl alcohol. CHL-PLGA-NPs were characterized by particle size, zeta potential, infrared spectra, drug entrapment efficiency and in vitro release kinetics measurement. Sonication was done with an ultrasound pulse sonicator at 70 W, 30 kHz for 60 s to produce stable NPs of mean size range from 277 nm to 433 nm. Drug to polymer ratio (D:P) was selected as formulation variable and significantly influenced entrapment efficiency (approximately 30% to 66%) and release (p < 0.05). Entrapment of CHL in biodegradable NPs significantly prolonged drug release compared to FDS and thus implies potential antibiotic delivery system for ocular application.

Metal concentrations in water, sediment, and fish from sewage-fed aquaculture ponds of Kolkata, India.

The concentrations of lead, cadmium, chromium, copper, and zinc were investigated in the sewage-fed pond water, sediment, and the various organs of Labeo rohita, Catla catla, Cirrhinus mrigala, Oreochromis mossambicus, and Cyprinus carpio cultured in sewage-fed ponds, Kolkata, India. Among the metals, cadmium, lead, and zinc were detected in water and, except lead, were below the water quality guideline levels for the protection of freshwater aquatic life proposed by CEQG (Canadian Environmental Quality Guidelines) and AENV (Alberta Environment). Therefore, lead could pose danger to aquatic organisms. All the five metals were detected in the sediment and, except cadmium and lead, were below the sediment quality guideline levels for aquatic life proposed by EPA (Environmental Protection Agency). Therefore, these two metals could be toxic to aquatic organisms. Significant (P > 0.05) differences were observed among the five fish species for all these metals accumulation. Also, significant (P > 0.05) differences were noticed among these metals accumulation in fish organs. Cadmium showed the least bioaccumulation, while zinc showed the highest bioaccumulation in all the fish species. Though the metal concentration in the different fish tissues was variable, the highest concentration was found in kidney and the lowest in the muscle. Concentrations of these metals in the muscle tissue of all the fish species were well below the consumption safety tolerance in fish set by WHO/FAO, and thus, so far as these metals are concerned, these sewage-fed cultured fishes are safe and suitable for human consumption.

A validated UV spectrophotometric method for determination of duloxetine hydrochloride.

A simple, sensitive and accurate UV spectrophotometric method was developed for the assay of duloxetine hydrochloride in raw material and capsules. Validation of the method yielded good results concerning range, linearity, precision and accuracy. The absorbance was measured at 290 nm for duloxetine capsule solution. The linearity range was found to be 5-50 microg/mL for the drug. It was found that the excipients in the commercial formulation did not interfere with the methods.

A validated UV spectrophotometric method for estimation of nebivolol hydrochloride in bulk and pharmaceutical formulation.

A simple, sensitive and accurate UV spectrophotometric method was developed for the assay of nebivolol hydrochloride in raw material and tablets. Validation of the method yielded good results concerning range, linearity, precision and accuracy. The absorbance was measured at 282 nm for nebivolol hydrochloride tablet solution. The linearity range was found to be 5-50 microg/mL for the drug. It was found that the excipients present in the commercial formulation did not interfere with the method.

Oxidative DNA damage in prostate cancer patients consuming tomato sauce-based entrees as a whole-food intervention.

BACKGROUND: Human prostate tissues are vulnerable to oxidative DNA damage. The risk of prostate cancer is lower in men reporting higher consumption of tomato products, which contain high levels of the antioxidant lycopene. We examined the effects of consumption of tomato sauce-based pasta dishes on lycopene uptake, oxidative DNA damage, and prostate-specific antigen (PSA) levels in patients already diagnosed with prostate cancer. METHODS: Thirty-two patients with localized prostate adenocarcinoma consumed tomato sauce-based pasta dishes for the 3 weeks (30 mg of lycopene per day) preceding their scheduled radical prostatectomy. Serum and prostate lycopene concentrations, serum PSA levels, and leukocyte DNA oxidative damage (ratio of 8-hydroxy-2'-deoxyguanosine [8-OHdG] to 2'-deoxyguanosine [dG]) were assessed before and after the dietary intervention. DNA oxidative damage was assessed in resected prostate tissue from study participants and from seven randomly selected prostate cancer patients. All statistical tests were two-sided. RESULTS: After the dietary intervention, serum and prostate lycopene concentrations were statistically significantly increased, from 638 nM (95% confidence interval [CI] = 512 to 764 nM) to 1258 nM (95% CI = 1061 to 1455 nM) (P<.001) and from 0.28 nmol/g (95% CI = 0.18 to 0.37 nmol/g) to 0.82 nmol/g (95% CI = 0.57 to 1.11 nmol/g) (P <.001), respectively. Compared with preintervention levels, leukocyte oxidative DNA damage was statistically significantly reduced after the intervention, from 0.61 8-OHdG/10(5) dG (95% CI = 0.45 to 0.77 8-OHdG/10(5) dG) to 0.48 8-OHdG/ 10(5) dG (95% CI = 0.41 to 0.56 8-OHdG/10(5) dG) (P =.005). Furthermore, prostate tissue oxidative DNA damage was also statistically significantly lower in men who had the intervention (0.76 8-OHdG/10(5) dG [95% CI = 0.55 to 0.96 8-OHdG/10(5) dG]) than in the randomly selected patients (1.06 8-OHdG/10(5) dG [95% CI = 0.62 to 1.51 8-OHdG/10(5) dG]; P =.03). Serum PSA levels decreased after the intervention, from 10.9 ng/mL (95% CI = 8.7 to 13.2 ng/mL) to 8.7 ng/mL (95% CI = 6.8 to 10.6 ng/mL) (P<.001). CONCLUSION: These data indicate a possible role for a tomato sauce constituent, possibly lycopene, in the treatment of prostate cancer and warrant further testing with a larger sample of patients, including a control group.

DNA polymerase beta mutations in human colorectal cancer.

Increasing numbers of alterations have been found in protooncogenes (e.g., ras, myc), as well as tumor suppressor genes (e.g., p53, Rb) in various types of tumors. The multiple mutations cannot be explained by the spontaneous mutation rate. It has been suggested that mutator phenotypes leading to the accumulation of these mutations may be required in the early stages of tumorigenesis. To test this hypothesis, the entire coding region of DNA polymerase beta, a repair enzyme, mRNA from colorectal tumors, and corresponding normal mucosa were amplified by polymerase chain reaction, cloned, and sequenced. Mutations in the catalytic domain of DNA polymerase beta were detected in colorectal tumor specimens compared to the normal colorectal mucosa, placenta, and blood samples. Since these mutations changed the structure of polymerase beta, it is expected that the efficiency of the DNA repair system would be impaired and thus may account for the high mutation rate observed in colorectal carcinomas.

Mutation in the nm23 gene is associated with metastasis in colorectal cancer.

The human nm23 gene, a candidate metastatic suppressor gene, consists of two genes, nm23-H1 and nm23-H2. The potential mutation in the nm23-H1 gene was examined in colorectal cancer using a reverse transcription polymerase chain reaction amplification followed by DNA sequencing analysis. Genomic alterations in the nm23 gene were also examined by Southern hybridization. Genetic alterations either as a deletion in the coding sequence of nm23-H1 or as an allelic deletion were detected in four among eight colorectal adenocarcinomas associated with metastases in lymph nodes, lung, or liver. No alteration was observed in 12 additional colorectal cancer specimens without metastasis. These results provide first evidence for novel mutation in the nm23 gene and demonstrate a correlation between the mutation in the nm23 gene and metastasis in colorectal oncogenesis which suggests that the nm23 gene plays a role in the causation of metastasis.

Histochemical and ultrastructural study of lactic dehydrogenase in chemically induced lung cancer.

Light and electron microscopy studies of lactic dehydrogenase activity were carried out in embryonic, neonatal, and adult mouse lungs and in lungs undergoing chemically induced carcinogenesis. Embryonic mouse lungs were collected on the 6th, 12th, and 18th days of gestation; 1-day-old lungs were used for the neonatal model. These were compared with adult normal mouse lung and lungs of the animals treated with 4-nitroquinoline 1-oxide at a monthly interval until cancer developed. Enzymatic activity was seen in the embryonic, precancerous, and malignant lung tissues and was found diffusely in the cytoplasm of the epithelial cells.

Anomalous magnetic properties of mechanically milled cobalt oxide nanoparticles.

Defect induced magnetic properties of CoO nanoparticles produced via mechanical ball milling have been assessed by detailed magnetic measurements. A progressive decrease in the particle size and a concomitant increase in the induced strain have been observed with the milling times. The mechanically milled nanoparticles of CoO exhibit anomalous magnetic properties such as FM hysteresis when compared with the unmilled CoO sample. The presence of weak ferromagnetism, with a highest value of magnetization of 0.532 emu/g at 10 K in the 100 h milled sample, is attributed to the uncompensated surface spins resulting from induced surface defects via mechanical milling. The ZFC coercive force, measured at 10 K, increases with milling time reaching a maximum value of 1066 Oe for the 100 h milled sample. The temperature dependent field-cooled (FC) and zero-field-cooled (ZFC) magnetic measurements indicate a presence of an exchange bias field arising from uncompensated moments generated by mechanical strain and the antiferromagnetic (AFM) core. The exchange bias field measured at 10 K reaches a value 210 Oe for the 50 h milled sample and decreases upon prolonged milling. The exchange bias field vanishes at a temperature approximately 200 K, a temperature much lower than the Neel temperature of CoO (TN approximately 291 K). The observed anomalous magnetic behavior of CoO could be interpreted in terms of the exchanged bias FM-AFM model.

Structural changes of beta-lactoglobulin during thermal unfolding and refolding--an FT-IR and circular dichroism study.

We have quantitatively characterized by FT-IR spectroscopy the contents of secondary structure of beta-lactoglobulin during thermal unfolding and subsequent refolding. Our data clearly indicate that considerable amount of secondary structure, particularly beta-sheet, still remained intact even at 90 degrees C. Noticeable changes in secondary structure of beta-lactoglobulin were observed only above 70 degrees C. The refolded protein regained, within limits of experimental error, all of the secondary structure lost during thermal unfolding. The data also indicate that the refolding mechanism operating at pH 7.0 and 2.0 are the same. Identical secondary structure of native and refolded beta-lactoglobulin was also indicated by far-UV circular dichroic spectra of the two forms of protein. Near UV circular dichroic spectra of the same two forms showed considerable differences indicating less tertiary structure of refolded beta-lactoglobulin. The combined CD and FT-IR data indicated that refolded form of beta-lactoglobulin could be characterized as a molten globule state as it had native-like secondary structure and compromised tertiary structure.

Development of skeletal metastasis by human prostate cancer in athymic nude mice.

The biology of skeletal metastasis is poorly understood. In order to establish an animal model of bone metastasis, cells from a human prostate cancer cell line (PC-3) were injected into the tail veins of athymic nude mice while the inferior vena cava was occluded. This technique was used in order to divert cells into the vertebral venous plexus. A control group of animals received tumor cells without caval occlusion. Bone lesions developed in 3/16 (19 per cent) experimental mice and in none of the control mice. The incidence of lung metastasis was significantly decreased in the experimental mice (5/16) as compared with non-occluded control mice (14/16). Two tumor sublines were established from explant cultures of bone lesions. Injection of these cells resulted in bone metastasis in 19/36 (53 per cent) mice (P = 0.03 compared with the parent line). The incidence of lung lesions was also increased. The predominant site of bone metastasis was the lumbar vertebrae; other affected sites were the pelvis and femurs. All bone lesions resulted in extensive bone destruction. The successful development of bone metastasis using the technique of caval occlusion lends support to the hypothesis that entry of cells into the vertebral circulation is an important step in the development of these lesions. This model should be of value in understanding the pathogenesis of bone metastasis, and in studying the effects of various agents on the prevention and control of these lesions.

Myelolipoma and endocrine dysfunction.

Myelolipoma is an uncommon benign tumor of which the pathogenesis is unknown. It is rarely associated with endocrine disorders. We present a case of a myelolipoma in conjunction with congenital adrenal hyperplasia secondary to 21-hydroxylase deficiency. Nine previously reported cases of myelolipoma associated with endocrine dysfunction are reviewed with potential correlation of the hormonal imbalance to pathogenesis.

Effect of bioamines on uptake of promastigotes of Leishmania donovani by hamster peritoneal macrophages.

Epinephrine and norepinephrine inhibit attachment of Leishmania donovani promastigotes to cultured hamster peritoneal macrophages. The inhibition was significant at catecholamine concentrations of 10(-4) and 10(-5) M and occurred when they were added to the cell mixtures, or after pre-treatment of either macrophages or parasites. Inhibition of attachment after pre-treatment was less marked than when the catecholamines were added to parasite-cell mixtures. Similar results were obtained with dibutyryl cyclic AMP, cholera toxin, theophylline, and cadaverine which raise intracellular cyclic AMP (cAMP). Pretreatment of parasites or macrophages with the bioamines elevated the intracellular cAMP concentration. It is suggested that the inhibitory effect on the host-parasite interaction is mediated through cAMP.

Dysphagia caused by a fetus-in-fetu in a 27-year-old man.

Mechanical obstruction of the distal esophagus by a fetus-in-fetu is an extremely rare condition that has not been previously reported. We present the case of a 27-year-old man who presented with dysphagia caused by fetus-in-fetu contained within a retroperitoneal cystic cavity. The tumor, noticed since childhood, did not cause any symptoms until a year before presentation when symptoms of dysphagia developed. We propose including this entity in the differential diagnosis of a retroperitoneal mass.

Immunohistochemical localization of nephrocalcin, a kidney-specific glycoprotein, to renal cell carcinoma.

OBJECTIVES: Nephrocalcin (NC), an acidic glycoprotein produced by renal proximal tubule cells and functioning as an inhibitor of calcium oxalate monohydrate crystalization, has been previously shown to have increased urinary excretion in patients with renal cell carcinoma (RCC). The current study uses immunohistochemical techniques to localize NC to cells of primary RCC. METHODS: We studied 29 kidneys removed because of RCC. Slides were deparaffinized and stained after incubating with anti-NC antibody by using the avidin-biotin-peroxidase complex techniques. Uptake of stain by tumor cells and adjacent normal renal cells was compared. RESULTS: Twenty-seven kidneys (93%) showed positive staining for RCC tumor cells; 2 kidneys staining positive for normal proximal tubule cells failed to stain adjacent RCC tumor cells (7%). CONCLUSIONS: The data suggest that enhanced production of urinary NC in patients with RCC derives from cells of the primary tumor.

Thyroglossal duct carcinomas: light and electron microscopic studies.

Two cases of papillary carcinoma arising in thyroglossal duct cysts are reported. Electron microscopic studies were done on both cases and similar ultrastructural features were noted. When compared with a case of papillary adenocarcinoma arising in the thyroid gland proper, no difference was seen both at the light microscopic and ultrastructural levels.

Fibro-osseous, osseous, and cartilaginous lesions of the orbit and paraorbital region. Correlative clinicopathologic and radiographic features, including the diagnostic role of CT and MR imaging.

Fibro-osseous and cartilaginous lesions of the orbit and facial region share overlapping clinical, radiologic, and pathologic features that may lead to diagnostic confusion and possible misdiagnosis. The value of imaging studies in the histopathologic diagnosis of these lesions cannot be overemphasized. The histopathologic diagnosis of such lesions should not be rendered in the absence of radiographic correlation.

Intracellular demonstration of growth hormone in human mammary carcinoma cells.

Intracellular growth hormone has been demonstrated in human mammary carcinoma cells by using an unlabeled antibody enzyme technic with horseradish peroxidase and antihorseradish peroxidase complex. Intense reaction was seen in both male and female mammary carcinoma cells. Positive staining was observed in nuclei and cytoplasm and on cytoplasmic membranes.

Ultrastructural study of stroma in human mammary carcinoma.

This investigation was designed to study the origin of the stromal component of human mammary carcinoma. Tissues from 30 proved breast carcinomas were studied. Under a light microscope with special stains, an increased connective tissue component was seen in carcinoma. Gluteraldehyde-fixed tissue was examined under an electron microscope. The stroma appeared to be composed of fibroblastic, myofibroblastic, histiocytic and primitive mesenchymal cells. Elastic fibers were intimately intermingled with collagen and reticulin and seen in close association with carcinoma cells. In some areas they were seen inside the carcinoma cells with discontinuous cytoplasmic membrane, as if they were formed by the cancer cells. This observation suggests that breast carcinoma cells play an important role in the production of elastic fibers in association with stromal cells and also stimulate the proliferation of the stromal cellular component.

Effects of sodium hyaluronate on peridural fibrosis after lumbar laminotomy and discectomy.

Sodium hyaluronate, 1.9% solution, was evaluated for its ability to retard peridural fibrosis after unilateral lumbar hemilaminotomy, anular fenestration, and nuclectomy in dogs. Three materials: fat grafts, gelfoam, and sodium hyaluronate, were compared with empty controls for their ability to inhibit peridural fibrosis. Each dog served as his own internal control and the formation of fibrosis was evaluated at 2, 4, 12, and 26 weeks. Sodium hyaluronate was found to inhibit fibrosis more than the other materials on both a macroscopic and microscopic level. The area of fibrosis and tenacity of the adhesions on dissection were notably less in the sodium hyaluronate group. Microscopically, the thickness of collagen and number of fibroblasts were decreased with the use of 1.9% sodium hyaluronate. The peridural fibrosis occurred equally both anteriorly and posteriorly to the nerve roots and correlated with the area of surgical dissection. Fat grafts were not effective in preventing fibrosis anteriorly, especially in the region of the exiting nerve roots. Gelfoam did not inhibit but actually appeared to increase fibrosis formation. Interposition materials currently used in humans to prevent scar formation such as gelfoam and fat grafts have only addressed the posterior scar formation, which do little to alter the fibrosis anteriorly. The adhesions between the nerve root and the anulus fibrosus bind the nerve root down anteriorly, making it more vulnerable to recurrent disc herniation. Sodium hyaluronate, 1.9% solution, with its viscous semifluid properties, coats the nerve roots and dura anteriorly and posteriorly.(ABSTRACT TRUNCATED AT 250 WORDS)