Chromosome 18 suppresses prostate cancer metastases

Loss of heterozygosity and allelic imbalance data has shown that there are two distinct regions of loss on chromosome 18q associated with the progression of prostate cancer (CaP). To investigate the functional significance of chromosome 18q loci in CaP, we utilized the technique of microcell-mediated chromosome transfer to introduce an intact chromosome 18 into the human prostate cancer cell line, PC-3. Three of the resulting hybrid lines were compared to the PC-3 cells in vitro and in vivo. The hybrid cell lines, containing an intact copy of the introduced chromosome 18, exhibited a substantial reduction in anchorage-dependent and independent growth in vitro. These hybrid cell lines also made smaller tumors in nude mice following subcutaneous injection compared to PC-3 cells. Because tumor growth was not completely eliminated by introduction of chromosome 18, we assessed the ability of the hybrids to metastasize to bone after intra-cardiac inoculation in a nude mouse model. Mice inoculated with PC-3 hybrids containing intact copies of chromosome 18 had significantly fewer bone metastases and dramatically improved survival compared to PC-3 cells. In addition, the introduction of chromosome 18 significantly reduced tumor burden in extraskeletal sites. This was not because of differences in growth rates because mice bearing hybrids were monitored for metastases over twice as long as mice bearing PC-3 cells. Taken together, these data suggest that chromosome 18 has a functional role in CaP to suppress growth and metastases. Identification of the responsible gene(s) may lead to molecular targets for drug discovery.

Isolated iliac artery stenosis as a cause of kidney graft dysfunction post-transplant

We report the case of a kidney transplant recipient who, 1 yr post-transplant, presented with a serum creatinine level elevation secondary to iliac artery stenosis proximal to the graft anastomosis site. Stenosis of the transplant renal artery was initially suspected because of new onset of hypertension in addition to the rising creatinine level. Physical examination, however, revealed a diminished femoral pulse and a significantly lower ankle-brachial index on the right (versus left) lower extremity; these findings suggested a stenosis of the right iliac artery. Angiography confirmed a short stenotic lesion of the external iliac artery just proximal to the graft anastomosis site. The lesion--given its focal nature, its location, and the absence of disease elsewhere in the peripheral vascular system--was most consistent with a vascular clamp injury. The stenosis was managed by placement of an intravascular stent at the time of angiography. This resulted in normalization of the vascular examination findings, return to baseline of the serum creatinine level, and resolution of hypertension. This case demonstrates the value of physical examination in diagnosing this uncommon cause of an increased serum creatinine level post-transplant and the effectiveness of intravascular stents for its management.

Role in vivo for gamma interferon in control of pneumonia caused by Chlamydia trachomatis in mice

In a model of pneumonia caused by murine Chlamydia trachomatis, depletion experiments with monoclonal antibody to gamma interferon (IFN-gamma) made mice more susceptible. Repletion experiments giving exogenous recombinant murine IFN-gamma were not consistently protective. IFN-gamma may be necessary but not sufficient in host defense against the organism.

Gamma interferon-mediated cytotoxicity related to murine Chlamydia trachomatis infection

After infection with the mouse pneumonitis agent (MoPn; murine Chlamydia trachomatis), heterozygous (nu/+) but not nude athymic (nu/nu) mice produced enhanced amounts of gamma interferon (IFN-gamma) in vitro in response to MoPn antigen that exhibited cytotoxic activity when added to host cells already infected with chlamydiae. Antibody-complement lysis showed the cytotoxic activity to be dependent, at least in part, on L3T4+ T cells for production. The cytotoxic responses were directed primarily against Chlamydia-infected target cells, but a second type of toxicity was demonstrable against uninfected target cells after treatment of the generating cell population with anti-Lyt-2 antibody plus complement at certain time points after infection. This additional nonspecific cytotoxic activity was presumably due to a second factor (factor X) acting in concert with IFN-gamma. Lyt-2+ cells, however, also were shown to play a role in IFN-gamma production and cytotoxicity directed against infected targets at later time points after infection. Neutralization of IFN-gamma in the samples containing cytotoxic activity abrogated the cytotoxicity against both infected and uninfected targets, but cloned murine IFN-gamma exhibited toxicity in a dose-dependent manner only against infected target cells. The data provides evidence that cytotoxicity against infected targets is due to antigen-specific induction of IFN-gamma, but other cytokine activity, most demonstrable after removal of Lyt-2.2+ cells and cytotoxic to uninfected targets, also is present.

Primary murine Chlamydia trachomatis pneumonia in B-cell-deficient mice

Mice were rendered deficient in B-cell activity by treatment with anti-mu antibody from birth. These animals were then infected intranasally with murine Chlamydia trachomatis (murine pneumonitis agent [MoPn]). They produced neither local nor systemic antibody to MoPn but had intact delayed-type hypersensitivity to MoPn. Anti-mu-treated mice were not significantly more susceptible to primary invasive infection with MoPn than were control mice, and unrestricted multiplication with MoPn did not occur. The dominant immune response controlling this type of infection is not likely to be antibody.

Role of natural killer cells in infection with the mouse pneumonitis agent (murine Chlamydia trachomatis)

Natural killer (NK) activity is increased in both spleen and lung early in pulmonary infection by murine Chlamydia trachomatis in both susceptible nude and resistant heterozygous (nu/+) mice. Ablation of the rise in NK activity by giving the mice antiasialo GM-1 antibody or stimulation of NK activity by immunomodulators did not affect quantitative tissue counts of the mouse pneumonitis biovar of C. trachomatis or significantly affect survival. Studies are needed to further define the role of NK cells in host defense, immunoregulation, and immunopathology during chlamydial infection.

Antibody in host defense against mouse pneumonitis agent (murine Chlamydia trachomatis)

In a murine model of chlamydial pneumonia employing murine Chlamydia trachomatis, immune serum given intranasally delayed death in nude (nu/nu) mice and prevented death in nu/+ mice. Serum-derived immunoglobulin G and A fractions and immune lavage fluid fractions containing immunoglobulins G and A were effective in producing protection when used to opsonize the murine C. trachomatis inoculum. In hyperclean mice (previously made germfree and then colonized with a limited flora nonpathogenic to mice) antibody given intravenously was ineffective. The effects of antibody and nonspecific stimulation of cell-mediated immunity (after previous infection with Histoplasma capsulatum) were additive in increasing host resistance to murine C. trachomatis.

Cellular immunity to the mouse pneumonitis agent

During infection with the mouse pneumonitis biovar of Chlamydia trachomatis, heterozygous (nu/+) mice with relatively intact T cell function develop both delayed hypersensitivity to C trachomatis antigen and antigen-specific lymphocyte transformation, whereas athymic nude (nu/nu) mice do not. Nu/nu mice are protected against death from mouse pneumonitis by transfer of immune T cells from nu/+ mice, which are more resistant to C trachomatis. While this enables athymic mice to make antibody to C trachomatis (which does not occur without reconstitution), resistance correlates best with development of antigen-specific lymphocyte transformation in the recipient animals. During infection nu/+ mice develop activated alveolar macrophages (by both morphological and functional criteria) while nu/nu mice do not. Nu/+ mice that have been preinfected with Histoplasma capsulatum to activate cellular immunity become more resistant to C trachomatis than do nu/+ controls. Cell-mediated immunity to C trachomatis pneumonia is T cell dependent and is important in host defense.

The role of antibody in host defense against the agent of mouse pneumonitis

Athymic nude (nu/nu) mice, which are more susceptible to the agent of mouse pneumonitis (MoPn) (murine Chlamydia trachomatis) than are their heterozygous littermates (nu/+), do not develop significant IgG or IgA antibody to the MoPn agent. Nu/+ mice develop significant titers of both specific IgG or IgA antibodies after either intranasal or intrauterine challenge. Prior intranasal or intrauterine immunization protects nu/+ but not nu/nu mice against subsequent intranasal challenge with the MoPn agent. Resistance to pneumonia due to the MoPn agent can be transferred to nu/nu mice by nu/+ mouse immune serum (with high titers of IgG and IgA antibodies to the MoPn agent) but not by nu/+ mouse normal serum (with undetectable titers of IgG and IgA antibodies to the MoPn agent). Serum components, probably specific antibodies, are important in host defense against the MoPn agent.

Total parenteral nutrition for maintenance of growth, carcass mass and positive nitrogen balance in rats with a small transplantable tumor

This study evaluates the effects of 13 days of total parenteral nutrition (TPN) on body weight, carcass mass and nitrogen balance in rats with and without a transplanted Morris No. 7777 hepatoma. Groups of rats without a tumor as well as rats with a tumor of about 3% of body weight or less were shown to maintain carcass weight as well as maintain a positive nitrogen balance when fed totally by vein. The present experiment was done under the same conditions as a previously reported experiment except that the size of the tumor in the rats was considerably smaller. These past studies showed that as the hepatoma gets much larger than 3% of the body weight, it was inhibitory to carcass weight gain even when the rats were given TPN. Thus, the size of the tumor influences the ability of TPN to sustain carcass weight.

Total parenteral nutrition and inhibition of gluconeogenesis on tumor-host responses

Rats bearing the Morris hepatoma No. 7777 were randomized into three treatment groups. Two of the groups received a nutritionally complete liquid formula diet per os ad libitum. One of these two groups received hydrazine sulfate (HS; an inhibitor of gluconeogenesis) twice daily (15 mg/kg) for 5 days. A third group of tumorous rats received the HS therapy and was given the liquid diet parenterally for 5 days. Tumorous rats fed per os, especially with HS therapy demonstrated inhibition of tumor growth, reduction of body and carcass weight, anorexia and decreased nitrogen retention. The combination of parenteral feeding and HS therapy sustained body and carcass weight with high nitrogen retention but stimulated tumor growth and was associated with liver toxicity. These results support the concept that cancer cachexia involves 'a systemic energy-losing cycle dependent on an interplay of tumor glycolysis and gluconeogenesis'.