Structural characterization of self-assembled ZnO nanoparticles obtained by the sol-gel method from Zn(CH3COO)2·2H2O.

Zinc oxide nanopowders were synthesized by the sol-gel method from an ethanol solution of zinc acetate dihydrate. Detailed structural and microstructural investigations were carried out using x-ray diffraction, Raman spectroscopy, thermogravimetric and differential thermal analyses, as well as high-resolution transmission electron microscopy (TEM) and field-emission scanning electron microscopy. The intermediate compound of the reaction was layered zinc hydroxide acetate that further transforms into hexagonally shaped ZnO crystalline nanoplates (d(m) = 4 nm), which aggregate into larger spherical particles. According to the TEM analysis the ZnO nanoparticles were self-assembled into larger particles with the same orientation, i.e. aligned lattice planes of the particles. A further solvothermal treatment resulted in hexagonal, prismatic ZnO mesocrystals.

Microstructural characterization of mechanically activated ZnO powders.

In this paper, changes of microstructural characteristics of disperse systems during mechanical activation of zinc oxide (ZnO) have been investigated. ZnO powder was activated by grinding in a planetary ball mill in a continuous regime in air during 300 min at the basic disc rotation speed of 320 rpm and rotation speed of bowls of 400 rpm but with various balls-to-powder mass ratios. During ball milling in a planetary ball mill, initial ZnO powder suffered high-energy impacts. These impacts are very strong, and large amounts of microstructural and structural defects were introduced in the milled powders. The morphology and dispersivity of particles and agglomerates of all powders were investigated by scanning electron microscopy and scanning transmission electron microscopy. The specific surface area of initial ZnO powder was determined as 3.60 m(2) g(-1) and it increased to 4.42 m(2) g(-1) in mechanically activated powders. An increase of the ball-to-powder mass ratio led to a decrease of particle dimensions as well as increased the tendency for joining into quite compact agglomerates, that is aggregates, compared with the very loose, soft initial agglomerates. The obtained results pointed out that activation of ZnO powders produces a highly disperse, nano-scaled mixture of small particles, that is crystallites with sizes in the range of 10-40 nm. Most of these particles are in the form of aggregates with dimensions of 0.3-0.1 mum. The crystallite and aggregate size strongly depend on milling conditions, that is ball-to-powder mass ratio, as shown in this investigation.

Short-term effect of acarbose on specific intestinal disaccharidase activities and hyperglycaemia in CBA diabetic mice.

The purpose of this study was to examine the short-term effects of 75, 100 and 150 mg of acarbose mixed in 100 g standard laboratory chow on specific intestinal disaccharidase activities and on hyperglycaemia in diabetic CBA strain mice on standard diet. The small intestine was excised and divided into three segments, from pylorus to duodenum, and two equal lengths of the jejunum and ileum of control and diabetic mice with or without added acarbose. Specific maltase and sucrase activities were determined using maltose and sucrose as substrates respectively. Increased specific activities of maltase and sucrase were detected in the intestines of CBA mice on standard laboratory diet seven days after alloxan-induced diabetes. Feeding for 7 days with 75, 100 or 150 mg acarbose uniformly mixed in 100 g standard laboratory chow, induced a decrease in the specific maltase and sucrase activities, compared with diabetic mice on standard laboratory diet. Feeding with 75 mg acarbose mixed in 100 g standard laboratory chow caused a statistically significant decrease of maltase in the duodenum and of sucrase in duodenum and jejunum, without a antihyperglycaemic effect. Feeding with 100 or 150 mg caused statistically significant decreases in specific maltase and sucrase activities in duodenum, jejunum and ileum. An antihyperglycaemic effect was observed only in the group of diabetic mice fed with 100 mg acarbose. This indicates that the antihyperglycaemic effect of acarbose involves factors other than these, related only to its inhibitory effect on disaccharidase activities.

Ectopic supernumerary kidney, a cause of para-aortic mass: case report and review.

Ectopic supernumerary kidney is a rare congenital urinary tract abnormality. Because of the scarcity of published cases and atypical presenting symptomatology this entity frequently causes a diagnostic as well as therapeutic dilemma. We report a case of an unusually symptomatic supernumerary kidney that presented as back pain. Noncontrast CT scan showed a suspicious left-sided para-aortic mass, which prompted a percutaneous biopsy. Intravenous contrast CT scan revealed an anatomically and functionally free supernumerary kidney. The approach to diagnosis as well as management of supernumerary kidneys is discussed herein.

Palliative treatment of recurrent obstructing gastric cancer. A case report of successful treatment with three self-expanding metallic stents.

Patients with advanced or recurrent gastric cancer affecting the upper and lower gastrointestinal tract usually experience obstructive symptoms, causing a severe compromise in their quality of life. Surgery may not be feasible because of the patient's precarious medical condition and multilevel tumor infiltration. When faced with these circumstances, surgeons have few options. Parenteral nutrition and comfort measures are utilized when surgical bypass is not a tenable option. We herein describe a unique case of multilevel upper and lower gastrointestinal obstruction secondary to recurrent gastric cancer. The patient was treated palliatively through a combined surgical, radiological, and endoscopic approach by implanting a series of self-expanding metallic stents. To our knowledge, there are no previous reports of successful management of simultaneous strictures of the upper and lower gastrointestinal tract using this technique.

Colon cancer cell vaccine prepared with replication-deficient vaccinia viruses encoding B7.1 and interleukin-2 induce antitumor response in syngeneic mice.

A replication-deficient recombinant vaccinia virus, NYVAC, was developed by deleting 18 open reading frames in the vaccinia virus genome. Recombinant NYVAC, encoding the murine T cell co-stimulatory gene B7.1 (CD 80) (NYVAC-B7.1) and the murine interleukin-2 gene (NYVAC-IL-2), were prepared and the expression of B7.1 and the secretion of IL-2 were respectively confirmed in vitro. The use of these viruses to prepare a potent tumor cell vaccine was studied in a syngeneic murine CC-36 colon adenocarcinoma model. Mice were immunized on days 1 and 8 with 10(6) irradiated CC-36 cells that were infected with 10(7) plaque-forming units of either NYVAC-B7.1, NYVAC-IL-2 or a control virus, NYVAC-HR, which encodes a vaccinia virus host-range gene. These mice were then challenged with 10(8) viable CC-36 tumor cells on day 15. All mice (10/10) in a group that had received no vaccination and all mice (20/20) in a group that had received a control vaccine of CC-36/NYVAC-HR developed tumor 4-weeks after tumor cell challenge. Interestingly, only 16/20 mice in a group that had received CC-36/ NYVAC-B7.1 showed the development of tumor after the same interval. The protection against tumor development and the reduction in tumor burden (as mean tumor diameter, 4 weeks after tumor challenge) were significant in this group when compared to groups that were either unvaccinated or vaccinated with CC-36/NYVAC-HR (mean tumor diameter = 6.51+/-3.2 mm compared to 26.5+/-0.9 mm or 26.2+/-1.8 mm respectively) (P = < 0.05). The protection against tumor in a group of mice that received CC-36/ NYVAC-IL-2 vaccination was similar to that in the unvaccinated group or the group receiving a CC-36/NYVAC-HR control vaccination. However, in a survival experiment, mice that received either CC36/NYVAC-B7.1 or CC-36/ NYVAC-IL-2 vaccination on the day of tumor transplantation survived significantly longer than mice that had not been vaccinated (median survival 60+ days, 60+ days or 23.5 days respectively) (P = < 0.05). Interestingly, when a therapeutic tumor vaccination was performed on day 4 after tumor transplantation, mice that had been vaccinated with either CC36/NYVAC-B7.1 or CC-36/NYVAC-IL-2 did not show an improved survival when compared to mice in the control that had not been vaccinated (median survival 28 days compared to 26 days or 25 days respectively). However, mice that had received a therapeutic vaccination with CC-36 cells infected with both NYVAC-B7.1 and NYVAC-IL-2, 4 days after tumor transplantation, survived significantly longer than control mice that had not received any vaccination (median survival 29.5 days compared to 25 days respectively) (P<0.05). These results suggest that a replication-deficient recombinant NYVAC encoding the B7.1 gene and NYVAC encoding the IL-2 gene can be used to produce an effective vaccinia-virus-augmented tumor cell vaccine.

Primary gastrointestinal non-Hodgkin's lymphoma: increasingly AIDS-related.

A retrospective study was conducted to determine the influence of the acquired immunodeficiency syndrome (AIDS) epidemic on the incidence, clinical presentation, and outcome of primary gastrointestinal lymphoma (stages I and II) over a 20-year period at a single institution. Between 1971 and 1981, there were seven cases. Fifty-eight patients were diagnosed between 1983 and 1993, and 81 per cent were AIDS-related. The mean age overall was 50 years; 81 per cent were male, and 35 per cent presented with acute complications. All tumors were high or intermediate grade B cell lymphomas, and 48 per cent had bulky or advanced disease at presentation. The overall actuarial 5-year survival was 9 per cent. Human immunodeficiency virus status and stage were significant independent prognostic factors. The AIDS-related subgroup had a mean age of 43 years, and 91 per cent were male. Tumor resection was performed in 38 per cent, and the 5-year survival was 2 per cent. The mean age for the non-AIDS-related subgroup was 71 years, and 55 per cent were male. Resection was performed in 39 per cent, and 5-year survival was 28 per cent. AIDS-related disease accounted for the dramatic increase in incidence of primary gastrointestinal lymphoma since 1983. The prognosis for these patients is poor and is dominated by the underlying immunocompromise.

Carcinoma of the breast during pregnancy: a review and update on treatment options.

Gestational breast cancer is occurring with increasing incidence because more women are delaying childbirth into their thirties and forties. Although breast cancer during pregnancy or within the first year postpartum is occurring more often, there is still some confusion regarding its treatment. Although breast conservation therapy has evolved as the major treatment in breast cancer, it has been thought that pregnancy was a contraindication for this type of breast cancer therapy due to risks imposed on the fetus by chemotherapy and radiation. However, recent studies have shown that the use of chemotherapeutics during the second and third trimesters is possible. Also, if chemotherapy is initiated after a lumpectomy, radiation can be withheld until after the birth of the baby when the cancer is detected in the second or third trimester.

Adjuvant immunotherapy for patients with melanoma: are patients with melanoma of the head and neck candidates for this therapy?

BACKGROUND: Although a wealth of information is available on adjuvant immunotherapy for melanoma, little is known about adjuvant immunotherapy for head and neck melanoma. Interestingly, a few immunotherapy clinical trials report the observation of clinical responses in a subset of patients with head and neck melanoma. METHOD: An up-to-date literature search was performed to identify the current information on adjuvant immunotherapy for patients with melanoma, including head and neck melanoma. Moreover, a retrospective analysis of a subset of primary head and neck melanoma was performed using data from a phase III, randomized, double-blind, multi-institutinal, vaccinia melanoma oncolysate adjuvant immunotherapy trial that was performed in our laboratory for patients with stage III (AJCC) melanoma. RESULTS: In a passive immunotherapy trial with an antibody to melanoma ganglioside antigen GM2, a complete regression was observed in one patient with lesions of the right cheek. In three active specific immunotherapy trials, including our phase III trial, a subset of patients with head and neck primary melanoma showed a longer disease-free and overall survival with immunotherapy. Moreover, these clinical responses were correlated to the induction of immune response, delayed-type hypersensitivity response and melanoma-specific antibody response. CONCLUSIONS: The above results therefore suggest that patients with head and neck melanoma clinically respond to immunotherapy. However, these results need to be confirmed in a prospectively randomized trial for patients with head and neck melanoma.