Measurement of volatile organic compounds in the urban atmosphere of Harris County, Texas, USA.

Volatile organic compounds (VOCs) are a major component of urban air pollution. It is well documented that exposure to certain types of VOCs can cause adverse health effects such as cancer, immune and neurological damage, and reproductive and endocrine disorders. Urban air samples were collected at five locations in Harris County, Texas to determine the measurement of VOCs in the ambient air of residential areas in close proximity to industrial facilities that emit toxic air pollutants into the air.

Progressive multifocal leukoencephalopathy: unusual MR findings.

A case of progressive multifocal leukoencephalopathy (PML) with a classic clinical presentation but with unusual pathological and radiographic findings is reported. The pathology revealed evidence of prior hemorrhage, and imaging studies revealed focal cerebral atrophy as well as contrast enhancement on MR scans. The contrast enhancement was visible only by utilizing magnetization transfer pulses on T1-weighted scans.

Lymphocytes infiltrating the CNS during inflammation display a distinctive phenotype and bind to VCAM-1 but not to MAdCAM-1.

The nature of inflammatory lymphocytes recruited to the CNS has been studied in a model of chronic inflammation. Injection of killed Corynebacterium parvum into the cortex of the mouse brain produces a circumscribed inflammatory cellular infiltrate around the injection site, and recruited mononuclear inflammatory cells (IC) can be isolated for flow cytometric analysis. The majority of IC were T cells.

MHC class I gene(s) in the D/L region but not the TNF-alpha gene determines development of toxoplasmic encephalitis in mice.

Previous studies revealed that mice with the b or k allele at the H-2D region are susceptible to toxoplasmic encephalitis (TE); those with the d allele are resistant. To determine whether the b or d allele is dominant, F1 hybrids between susceptible C57BL/6 (H-2b) and resistant BALB/c (H-2d) mice were infected with T. gondii.

Antibody against interleukin-6 reduces inflammation and numbers of cysts in brains of mice with toxoplasmic encephalitis.

Treatment of toxoplasmic encephalitis in C57BL/6 mice with monoclonal antibody (MAb) against interleukin-6 (IL-6) resulted in a remarkable decrease in the number of foci of acute inflammation in their brains caused by proliferation of tachyzoites. In brains of mice treated with isotype control MAb and those treated with anti-IL-6 MAb, tachyzoites were observed only in foci of acute inflammation. Immunoperoxidase staining revealed a greatly diminished frequency of tachyzoites in brains of mice treated with anti-IL-6 MAb.

Cell adhesion molecules on vessels during inflammation in the mouse central nervous system.

The expression of endothelial cell adhesion molecules (CAMs) in the central nervous system (CNS) of the mouse was examined during an inflammation induced by intracerebral injection of killed Corynebacterium parvum (C. parvum). We showed that injection of killed C.

Susceptibility to chronic infection with Toxoplasma gondii does not correlate with susceptibility to acute infection in mice.

Resistance against acute and chronic infection with Taxoplasma gondii in BALB/c and CBA/Ca mice was compared. Intraperitoneal inoculation of either 20, 40, or 80 cysts of the ME49 strain resulted in mortality rates in BALB/c mice of 12% (2 of 17), 50% (6 of 12), and 75% (9 of 12), respectively, within 3 weeks after infection (acute stage). There was no mortality in the CBA/Ca mice for any of the doses.

Application of the disc angiogenesis system to tumor-induced neovascularization.

Solid tumors elaborate soluble substances that (directly or indirectly) induce angiogenesis by a step-wise process which ultimately results in a microvascular network that nourishes the growing tumor. To study angiogenesis induced by brain tumors we have used a rat glioma model. Modifying the disc angiogenesis system (DAS) we evaluated quantitatively the angiogenic response to cultured, live RT-2 rat glioma cells placed in the center of the discs.

Selective uptake of the somatostatin analog RC-160 across the blood-brain tumor barrier of mice with KHT sarcomas.

The development of somatostatin analogs with anti-tumor effects has raised hopes for their use in various cancers and tumors of the central nervous system. However, for many therapeutic agents, access to normal brain is retarded by the blood-brain barrier (BBB) and to tumor tissues by a blood-brain tumor barrier (BBTB). We examined the ability of RC-160, a somatostatin analog with known anti-tumor activity, to cross the normal BBB and the BBTB in mice with brain sarcomas.

A gene(s) within the H-2D region determines the development of toxoplasmic encephalitis in mice.

Studies were performed in a murine model to determine if there is genetic control of the development of toxoplasmic encephalitis. Ten weeks after infection with the ME49 strain of Toxoplasma gondii, mice with the H-2b haplotype (C57BL/6, C57BL/10) and H-2k haplotype (C3H/He, CBA/J) developed remarkable inflammatory changes in their brains, whereas mice with the H-2a haplotype (A/J) and H-2d haplotype (BALB/c, DBA/2) did not. In the area of acute focal inflammation in mice with the H-2b and H-2k haplotypes, tachyzoites and toxoplasma antigens were demonstrated by immunoperoxidase staining, suggesting that the focal inflammation was induced by toxoplasma organisms.

MR imaging in an experimental model of brain tumor immunotherapy.

A murine model of implanted CNS neoplasia was used to study a new form of brain tumor immunotherapy with intralesional Corynebacterium parvum (C. parvum). Assessment of treatment protocols has been limited by the inability to assess, noninvasively, tumor burden and/or the inflammatory reaction induced in the murine brain by treatment with C.

Treatment of toxoplasmic encephalitis in mice with recombinant gamma interferon.

The effect of exogenous gamma interferon (IFN-gamma) on toxoplasmic encephalitis in a murine model was evaluated. The brains of CBA/Ca mice chronically infected with the ME49 strain of Toxoplasma gondii have a remarkable inflammatory cell infiltrate. Intravenous administration of six doses (5 x 10(5) U each) of recombinant IFN-gamma (rIFN-gamma) resulted in a remarkable decrease in numbers and foci of inflammatory cells in murine brain parenchyma and perivascular areas 1 day after the last injection of IFN-gamma.

Intralesional immunotherapy of brain tumors with combined Corynebacterium parvum and recombinant interleukin-2 in mice.

Clinical observations and experimental work suggested that inflammatory cells attracted to the brain exert a nonspecific antineoplastic effect. Intralesional treatment of implanted malignant murine brain tumors (KHT sarcomas) with killed Corynebacterium parvum produced an inflammatory cell infiltrate and increased survival in C3H mice relative to that in untreated control C3H mice. This antitumor effect was enhanced when recombinant interleukin-2 was sequentially added as a second intralesional immunomodifier.

Decompression of lumbar spinal stenosis and stabilization with Knodt rods in the elderly patient.

We present a series of 25 elderly patients who exhibited signs and symptoms of neurogenic claudication and who were found to have one or two levels of spinal stenosis. At the time of decompressive surgery, excessive movement was found at the stenotic levels, so a simple stabilization procedure was performed using Knodt rods and a facet fusion. The expectation was that spine fixation would decrease the amount of postoperative back pain, which can be a result of continued abnormal mobility.

Reduction of vinblastine neurotoxicity in mice utilizing a collagen matrix carrier.

Vinblastine sulfate (VLB) suspended within a collagen matrix (CM) as a diffusion limiting drug delivery vehicle was examined in vitro, as well as in mouse subcutaneous and brain tumor models. Against RIF-1 and KHT subcutaneous tumors, there was enhancement of antitumor activity with intratumoral (i.t.

Effect of intracerebrally injected Corynebacterium parvum on the development and growth of metastatic brain tumor in mice.

Using KHT tumor in a mouse metastatic tumor model, we examined the effect of intracerebral and/or intraperitoneal injections of Corynebacterium parvum on the growth of metastatic brain tumor and the development of an inflammatory response in the central nervous system (CNS). C. parvum given intraperitoneally had no effect on the development and growth of CNS tumor, but did prolong the survival of mice by inhibiting the growth of systemic metastatic tumor, which was the cause of death in our tumor model.

Importance of endogenous IFN-gamma for prevention of toxoplasmic encephalitis in mice.

The importance of endogenous IFN-gamma for prevention of toxoplasmic encephalitis was studied in mice chronically infected with Toxoplasma gondii by using a mAb to this lymphokine. Control mice chronically infected with the ME49 strain that received saline or normal IgG had slight inflammation in their brains whereas those that received the mAb developed severe encephalitis. In contrast to control mice, the mAb-treated mice had many areas of acute focal inflammation and infiltration of large numbers of inflammatory cells in the meninges and parenchyma of their brains.