Vaccination with tumor cells expressing IL-15 and IL-15Rα inhibits murine breast and prostate cancer.

A number of antitumor vaccines have recently shown promise in upregulating immune responses against tumor antigens and improving patient survival. In this study, we examine the effectiveness of vaccination using interleukin (IL)-15-expressing tumor cells and also examine their ability to upregulate immune responses to tumor antigens. We demonstrated that the coexpression of IL-15 with its receptor, IL-15Rα, increased the cell-surface expression and secretion of IL-15. We show that a gene transfer approach using recombinant adenovirus to express IL-15 and IL-15Rα in murine TRAMP-C2 prostate or TS/A breast tumors induced antitumor immune responses. From this, we developed a vaccine platform, consisting of TRAMP-C2 prostate cancer cells or TS/A breast cancer cells coexpressing IL-15 and IL-15Rα that inhibited tumor formation when mice were challenged with tumor. Inhibition of tumor growth led to improved survival when compared with animals receiving cells expressing IL-15 alone or unmodified tumor cells. Animals vaccinated with tumor cells coexpressing IL-15 and IL-15Rα showed greater tumor infiltration with CD8(+) T and natural killer (NK) cells, as well as increased antitumor CD8(+) T-cell responses. Vaccination with IL-15/IL-15Rα-modified TS/A breast cancer cells provided a survival advantage to mice challenged with unrelated murine TUBO breast cancer cells, indicating the potential for allogeneic IL-15/IL-15Rα-expressing vaccines.

Chromosome 2 (2p16) abnormalities in Carney complex tumours.

Carney complex (CNC) is an autosomal dominant multiple endocrine neoplasia and lentiginosis syndrome characterised by spotty skin pigmentation, cardiac, skin, and breast myxomas, and a variety of endocrine and other tumours. The disease is genetically heterogeneous; two loci have been mapped to chromosomes 17q22-24 (the CNC1 locus) and 2p16 (CNC2). Mutations in the PRKAR1A tumour suppressor gene were recently found in CNC1 mapping kindreds, while the CNC2 and perhaps other genes remain unidentified. Analysis of tumour chromosome rearrangements is a useful tool for uncovering genes with a role in tumorigenesis and/or tumour progression. CGH analysis showed a low level 2p amplification recurrently in four of eight CNC tumours; one tumour showed specific amplification of the 2p16-p23 region only. To define more precisely the 2p amplicon in these and other tumours, we completed the genomic mapping of the CNC2 region, and analysed 46 tumour samples from CNC patients with and without PRKAR1A mutations by fluorescence in situ hybridisation (FISH) using bacterial artificial chromosomes (BACs). Consistent cytogenetic changes of the region were detected in 40 (87%) of the samples analysed. Twenty-four samples (60%) showed amplification of the region represented as homogeneously stained regions (HSRs). The size of the amplicon varied from case to case, and frequently from cell to cell in the same tumour. Three tumours (8%) showed both amplification and deletion of the region in their cells. Thirteen tumours (32%) showed deletions only. These molecular cytogenetic changes included the region that is covered by BACs 400-P-14 and 514-O-11 and, in the genetic map, corresponds to an area flanked by polymorphic markers D2S2251 and D2S2292; other BACs on the centromeric and telomeric end of this region were included in varying degrees. We conclude that cytogenetic changes of the 2p16 chromosomal region that harbours the CNC2 locus are frequently observed in tumours from CNC patients, including those with germline, inactivating PRKAR1A mutations. These changes are mostly amplifications of the 2p16 region, that overlap with a previously identified amplicon in sporadic thyroid cancer, and an area often deleted in sporadic adrenal tumours. Both thyroid and adrenal tumours constitute part of CNC indicating that the responsible gene(s) in this area may indeed be involved in both inherited and sporadic endocrine tumour pathogenesis and/or progression.

An observational study of 256 cases of vascular trauma in the north western province of Pakistan.

During the past 10 years Peshawar has dealt with increasing casualties with penetrating trauma inflicted by a wide variety of missiles. The aim of this study was to assess whether delay in arrival and mode of presentation affects the outcome of patients with penetrating vascular trauma. Prospective data were collected on 256 vascular injuries in 248 patients (median age, 29 years; range, 7-60 years) between January 1995 and June 1998. Early presentation (group A, 55 cases, < 12 h) was compared with late presentation (group B, 201 cases, > 12 h). The majority of injuries (93%) were caused by fire-arms. Arterial injuries accounted for 71% of the total, venous injuries accounted for 10% and 19% were mixed. The site of injury was the lower limb (61%), upper limb (32%), abdominal cavity (5%) and neck (2%). Patients presented with absent pulses (56%), haemorrhage (46%), false aneurysms (8%), A-V fistula (5%) and 11% presented with more than one sign. There were significantly more lower limb amputations in group A than group B (23% versus 5%; P < 0.05), with fractures having a positive association with lower limb amputations (odds ratio, 0.32; 95% CI, 0.13-0.94; P < 0.05). Group A had a higher mortality than group B (18% versus 7%; P < 0.05). This study shows that patients with vascular trauma can be managed successfully with clinical assessment alone. Patients with fractures were more likely to suffer eventually from lower limb loss. Due to self-selection, arrival at the hospital less than 12 h after sustaining vascular injury was associated with a higher mortality than those presenting after 12 h.

Duplication of the mutant RET allele in trisomy 10 or loss of the wild-type allele in multiple endocrine neoplasia type 2-associated pheochromocytomas.

Inherited mutations of the RET proto-oncogene are tumorigenic in patients with multiple endocrine neoplasia type 2 (MEN 2). However, it is not understood why only few of the affected cells in the target organs develop into tumors. Genetic analysis of nine pheochromocytomas from five unrelated patients with MEN 2 showed either duplication of the mutant RET allele in trisomy 10 or loss of the wild-type RET allele. Our results suggest a "second hit" causing a dominant effect of the mutant RET allele, through either duplication of the mutant allele or loss of the wild-type allele, as a possible mechanism for pheochromocytoma tumorigenesis in patients with MEN 2.

Replication of HIV-1 in dendritic cell-derived syncytia at the mucosal surface of the adenoid.

Human immunodeficiency virus-type 1 (HIV-1) replicates actively in infected individuals, yet cells with intracellular depots of viral protein are observed only infrequently. Many cells expressing the HIV-1 Gag protein were detected at the surface of the nasopharyngeal tonsil or adenoid. This infected mucosal surface contained T cells and dendritic cells, two cell types that together support HIV-1 replication in culture. The infected cells were multinucleated syncytia and expressed the S100 and p55 dendritic cell markers. Eleven of the 13 specimens analyzed were from donors who did not have symptoms of acquired immunodeficiency syndrome (AIDS). The interaction of dendritic cells and T cells in mucosa may support HIV-1 replication, even in subclinical stages of infection.

Coronary plaque erosion without rupture into a lipid core. A frequent cause of coronary thrombosis in sudden coronary death.

BACKGROUND: Coronary thrombosis has been reported to occur most frequently in lipid-rich plaques with rupture of a thin fibrous cap and contact of the thrombus with a pool of extracellular lipid. However, the frequency of coronary artery thrombosis with or without fibrous cap rupture in sudden coronary death is unknown. In this study, we compared the incidence and morphological characteristics of coronary thrombosis associated with plaque rupture versus thrombosis in eroded plaques without rupture. METHODS AND RESULTS: Fifty consecutive cases of sudden death due to coronary artery thrombosis were studied by histology and immunohistochemistry. Plaque rupture of a fibrous cap with communication of the thrombus with a lipid pool was identified in 28 cases. Thrombi without rupture were present in 22 cases, all of which had superficial erosion of a proteoglycan-rich plaque. The mean age at death was 53 +/- 10 years in plaque rupture cases versus 44 +/- 7 years in eroded plaques without rupture (P < .02). In the plaque-rupture group, 5 of 28 (18%) were women versus 11 of 22 (50%) with eroded plaques (P = .03). The mean percent luminal area stenosis was 78 +/- 12% in plaque rupture and 70 +/- 11% in superficial erosion (P < .03). Plaque calcification was present in 69% of ruptures versus 23% of erosions (P < .002). In plaque ruptures, the fibrous cap was infiltrated by macrophages in 100% and T cells in 75% of cases compared with 50% (P < .0001) and 32% (P < .004), respectively, in superficial erosions. Clusters of smooth muscle cells adjacent to the thrombi were present in 95% of erosions versus 33% of ruptures (P < .0001). HLA-DR expression was more often seen in macrophages and T cells in ruptures (25 of 28 cases) compared with expression in macrophages in superficial erosion arteries (8 of 22 cases, P = .0002). CONCLUSIONS: Erosion of proteoglycan-rich and smooth muscle cell-rich plaques lacking a superficial lipid core or plaque rupture is a frequent finding in sudden death due to coronary thrombosis, comprising 44% of cases in the present study. These lesions are more often seen in younger individuals and women, have less luminal narrowing and less calcification, and less often have foci of macrophages and T cells compared with plaque ruptures.

Localization of human immunodeficiency virus 1 RNA in thymic tissues from asymptomatic drug addicts.

Thymic tissue was collected from 11 human immunodeficiency virus 1 (HIV-1)-seropositive drug users who died suddenly of drug intoxication or trauma. None of the 11 individuals had symptoms related to HIV-1 infection or were known to be seropositive for HIV-1 before death. Secondary B-cell follicles were present in every thymus, and Warthin-Finckeldey giant cells were noted in three cases. These follicles were enlarged or fragmented and appeared similar to those in lymph nodes excised from the same individuals. Localization of viral RNA by in situ hybridization demonstrated abundant virus in a follicular center cell distribution within hyperplastic follicles and in scattered medullary lymphocytes. In nine thymus glands from seronegative drug addicts and five thymus glands from seronegative trauma victims who were not drug addicts, secondary follicles were absent and no hybridization signal was present. Other than the presence of germinal centers associated with HIV-1 RNA, there were no histologic differences among the thymus glands of seropositive drug addicts, seronegative drug addicts, and seronegative controls without a history of drug abuse. We conclude that the thymus gland in early stages of infection with HIV-1 is characterized by induction of secondary B-cell follicular hyperplasia in medullary tissues, the germinal centers of which contain abundant viral RNA.

Systemic lymphadenopathic histology in human immunodeficiency virus-1-seropositive drug addicts without apparent acquired immunodeficiency syndrome.

We examined lymph nodes from multiple sites in 50 individuals infected with human immunodeficiency virus (HIV-1) who died accidentally of drug overdoses and in whom there was no evidence of opportunistic infection. The size, histologic pattern, presence of Warthin-Finkeldey-type giant cells, and estimation of CD4 cell count of these lymph nodes were compared with those of 13 seronegative drug addicts (controls). Lymph nodes from seropositive individuals were slightly but significantly larger than those of controls. Lymph nodes from seropositive cases were much more likely to contain secondary follicles (90%) than were those from controls (20%). Unlike follicles in control nodes, most secondary follicles in the seropositive cases were in various stages of fragmentation and involution. As follicular changes progressed, there was a decrease in CD4 cells and an increase in intrafollicular and paracortical plasma cells. Plasmacytosis was much more prevalent in lymph nodes from seropositive individuals than in controls. Warthin-Finkeldey-type giant cells were present in at least one node in 29 of 50 seropositive cases, were most numerous in those showing follicular hyperplasia with fragmentation (45% of cases), and were especially numerous in Peyer's patches (61% of cases). There was generally good concordance of HIV-1-associated follicular morphology among diverse lymph node groups. There is prolonged generalized, mild hyperplastic lymphadenopathy with frequent syncytial cells in intravenous drug addicts with asymptomatic HIV-1 infection.

A comparison of double beta-lactam combinations with netilmicin/ureidopenicillin regimens in the empirical therapy of febrile neutropenic patients.

In a randomized trial ceftazidime plus piperacillin or azlocillin, and netilmicin plus piperacillin or azlocillin were used as initial empirical therapy in 202 febrile neutropenic episodes. Netilmicin plus azlocillin was the most effective combination with a clinical response rate of 81% in clinically and microbiologically documented infections compared with 63% for ceftazidime plus piperacillin. All of the episodes of Gram-negative bacteraemia treated with azlocillin responded compared with 43% of those treated with piperacillin. Gram-positive organisms accounted for 52% of all bacteriologically documented infections and 40% of the febrile episodes were treated with vancomycin for presumptive or documented Gram-positive infection. Patients treated with netilmicin had significantly more nephrotoxicity than those given the double beta-lactam combinations (14.8% vs 3.5%; P less than 0.05). However, this difference was not shown in those patients who did not receive concurrent vancomycin or amphotericin. The double beta-lactam combinations were associated with more hypokalaemia (58.2% vs. 37.7%; P less than 0.05) and more colonization with yeasts (24% vs. 10.4%; P less than 0.05) but there was no evidence that their use was associated with prolongation of neutropenia. These results indicate that ceftazidime plus a ureidopenicillin would be adequate empirical therapy in situations where the concomitant use of nephrotoxic agents precludes the use of aminoglycoside containing combinations.