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The clinical course and the postmortal pathological findings in a female newborn showing parental consanguinity are presented. One week afterbirth, the infant developed fever, hepatosplenomegaly and polyserositis. Rapidly progressing immunodeficiency due to pancytopenia led to pneumonia and untreatable respiratory distress with fatal outcome after 2 weeks. Autopsy findings revealed multisystem lymphohistiocytic infiltration with marked erythrophagocytosis. Neuropathological findings included lymphohistiocytic leptomeningitis, perivascular cuffing by lymphohistiocytic infiltrations in the cerebral white matter, predominantly in subependymal location, and multifocal lymphohistiocytic infiltrations of the cerebral grey matter and the cervical spinal cord. Erythrophagocytosis was the histopathological hallmark at all sites. Regarding the fatal clinical course, the medical history of parental consanguinity and the histopathological features, postmortem diagnosis was familial erythrophagocytic lymphohistiocytosis (FEL, Farquhar's disease). The present case is discussed with focus on CNS involvement in FEL by reviewing the relevant literature.

Aims: Ductal carcinoma in situ (DCIS) is a pre-invasive form of mammary carcinoma with no microscopic evidence of cancer cell invasion through the basement membrane. However, for initiation of invasion, tumour cells have to acquire and focus proteolytic activity on to the cell surface in order to infiltrate the surrounding extracellular matrix. The receptor (uPA-R or CD87) for the serine protease urokinase-type plasminogen activator (uPA) plays a central role in invasion and metastasis. This study was performed to determine and localize m-RNA and protein of uPA-R in ductal carcinoma in situ of the breast., Methods and Results: We analysed uPA-R mRNA and protein expression by in-situ hybridization and immunohistochemistry, respectively, in 50 formalin-fixed, paraffin-embedded specimens of DCIS. Three different antibodies were used to stain cell-associated uPA-R; chicken polyclonal antibody (pAb) HU277 and monoclonal antibodies (mAb) IID7 and 3936. In all cases, myoepithelial and stromal cells reacted with either antibody. Especially, reaction of macrophage-like cells with mAb 3936 resulted in a well-marked and bright staining. Applying mAb IID7, in 46 of the 50 breast specimens tumour cells showed a positive immunoreaction. Likewise pAb HU277 stained tumour cells in 40 of the 50 cases, whereas mAb 3936 reacted with only 24 of the 50 tissue sections. Endothelial cells were marked by both mAb IID7 and pAb HU277 (46/50 and 35/50, respectively); mAb 3936 did not label at all. All of the cell types stained by mAb IID7 and pAb HU277 also displayed reactivity with uPA-R mRNA-specific antisense oligonucleotides in in-situ hybridization., Conclusions: Our results reveal the presence of the tumour invasion-related receptor for the protease uPA not only in invasive ductal breast carcinoma but also in different types of DCIS.

Previous data have shown that the mRNA-expression of the serin/threonine-kinase polo-like kinase (PLK) is closely correlated with the survival of patients suffering from a subset of malignant tumors. PLK-mRNA and protein-expression are restricted to cells in the cell cycle. PLK-mRNA-transcripts are highly abundant in proliferating cells; no gene expression is found in G0-phase cells. Here we investigated the mRNA- and protein-expression of PLK- and estrogen-receptor (ER) in human breast-carcinoma by northern-blotting, RT-PCR and immunohistochemistry. The expression of MIB-I was determined on serial sections. Analysis of the immunohistochemical data revealed a close correlation between the ER and PLK-expression (r = 0.677; p = 0.001, n = 30). No relationship between the mRNA-expression of ER and PLK was found. Furthermore, no correlation for the protein expression of PLK and MIB-I exists. The influence of estrogen (ES) is known to have proliferative potential. The expression of ER correlates with the ES-plasma-level. In addition, the hormone cycle of premenopausal women undergoes rapid vacillations with varying effects on the proliferating tumor cells, e.g., growth induction. Our results therefore show that ER-expression is not only of therapeutic value for the clinician, but it may also be a tool for determining the tumor proliferation index more precisely by integrating the hormone-mediated proliferation stimulus.

Gonadoblastomas are seen almost exclusively in dysgenetic gonads of patients with a chromosomal mosaicism of 45,X and an additional Y-bearing cell line. This paper presents a case of a Turner mosaic patient with 45,X/46,X,+mar karyotype, who developed a unilateral microscopic gonadoblastoma. Cytogenetic and molecular analysis confirmed a Y-chromosomal origin of the marker chromosome, with a deletion of the distal Yq arm and the proposed region of a so far undefined gonadoblastoma locus (GBY) present. One of the candidate genes within the postulated GBY region is TSPY (testis-specific protein Y-encoded). To study the TSPY protein expression, an anti-fusion protein antibody was used for immunohistochemistry of the patient's gonads. In contrast to the dysgenetic gonad, an intense immunoreaction was found in gonadoblastoma tumour cells of the other gonad. These results confirm the high level of TSPY protein expression by these cells and demonstrate the value of this antibody as an additional marker to confirm the diagnosis of gonadoblastoma., (Copyright 1999 John Wiley & Sons, Ltd.)

The serine protease urokinase-type plasminogen activator (uPA) mediates cancer invasion and metastasis by binding to a cell surface receptor (uPA-R, CD87) on both tumor and stromal cells. In the present study we assessed uPA-R distribution in formalin-fixed, paraffin-embedded breast cancer specimens (n=50) and benign lesions (n=10) by immunohistochemistry employing a newly developed polyclonal chicken antibody to uPA-R (pAb HU277) in parallel with established monoclonal antibody (mAb) 3936 to uPA-R. In addition, uPA-R mRNA synthesis was investigated by in situ hybridization. In all of the sections analyzed, macrophage-like cells reacted with either antibody type. In 22 of the 50 cancer specimens, tumor cells reacted with pAb HU277 in contrast to mAb 3936 which only stained 9 of the 22 positive cases. Nevertheless, in 49 of the 50 cases, uPA-R mRNA was detected in cancer and in stromal cells by in situ hybridization suggesting posttranscriptional regulation of uPA-R expression in breast cancer cells. In 18 of 50 cases, uPA-R mRNA was also visualized in blood vessel lining endothelial cells by in situ hybridization and applying pAb HU277 in 14 of these 18 cases by immunohistochemistry. mAb 3936 did not stain any endothelial cells. pAb HU277 reacted with the breast gland epithelial cells of benign lesions as well, in contrast to mAb 3936 which did not. As for the cancer tissue, in benign lesions, endothelial cells were sporadically stained by pAb HU277. This antibody, but not mAb 3936, also stained myoepithelial cells in intraductal areas of invasive breast carcinoma. The results presented demonstrate the usefulness of pAb HU277 in locating uPA-R in tumor and normal cells with high sensitivity in formalin-fixed, paraffin-embedded breast tissue.

Objective: To determine if the production of proinflammatory cytokines by placentally derived macrophages changes with term and preterm labor and to examine if changes in antigen expression of these cytokines can be detected by immunohistologic methods., Methods: Enzymatically dispersed placental cell suspensions of the trophoblastic villi, obtained from 16 women with spontaneous term delivery, 16 women with elective cesarean delivery without any labor, and 22 preterm delivering women with labor unresponsive to tocolysis, were fractionated by magnetic-associated-cell-sorting, on the basis of CD11b-antigen expression. Positively and negatively sorted cell fractions were cultured and concentrations of interleukin-6, interleukin-1beta, and tumor-necrosis-factor-alpha were measured in the culture supernatants. Immunohistologic staining was used for identification of cytokine-producing cells within placental tissues., Results: Positively sorted cells obtained from term (median 2027 pg/mL, P = .037) and preterm (median 3628 pg/mL, P = .001) laboring women produced significantly elevated amounts of tumor-necrosis-factor-alpha compared with nonlaboring (median 1088 pg/mL) women at term. Negatively sorted cell fractions obtained from term (median interleukin-1beta 162 pg/mL, P = .031, median interleukin-6 3134 pg/mL, P = .004) and preterm (median interleukin-1beta 934 pg/mL, P = .003, median interleukin-6 5695 pg/mL, P = .001) laboring women produced significantly elevated amounts of interleukin-1beta and interleukin-6 compared with nonlaboring (median interleukin-1beta 29 pg/mL, median interleukin-6 135 pg/mL) women at term. Immunohistologic staining revealed that tumor-necrosis-factor-alpha activity was localized in isolated stromal cells, whereas interleukin-1beta and interleukin-6 were predominantly found in endothelial cells within placental villi., Conclusion: The source of labor-associated release of tumor-necrosis-factor-alpha from placental tissues are macrophages, whereas interleukin-1beta and interleukin-6 are released from placental endothelial cells.

Recent studies have shown that urokinase (uPA) is an independent prognostic marker in breast cancer. uPA plays a key role in the degradation of tumor matrix and promotes tumor progression. Macrophage expression of uPA appears to be important in this context. Our objective in the present study was to provide evidence that tumor growth factor-beta (TGF-beta) released from breast cancer cells markedly up-regulates uPA expression in tumor-associated macrophages (TAMs). TAMs from 32 breast carcinomas were cultured. Blood monocytes from healthy donors and breast cancer patients as well as tissue macrophages from patients with fibrocystic changes of the breast were also examined. After TGF-beta incubation, uPA levels were tested by ELISA, and uPA mRNA levels were determined by Northern blot analysis. TGF-beta receptor and uPA cell surface fluorescence intensities were determined by flow cytometry; TGF-beta receptors were determined by Western blot analysis. Protein kinase-C dependence was also examined, and immunohistochemical stainings for uPA and TGF-beta were performed. We have demonstrated that TGF-beta markedly up-regulates basal uPA expression (mRNA and protein) in TAMs but only modestly increases uPA production in blood monocytes and tissue macrophages. Exposure of macrophages to TGF-beta1 led to a rapid and sustained increase in uPA mRNA levels, which was independent of de novo protein synthesis and completely inhibited by actinomycin D. H7 markedly reduced the ability of TGF-beta to stimulate uPA expression. Likewise, okadaic acid potentiated the ability of TGF-beta to up-regulate macrophage uPA expression. We suggest that TAMs are more responsive to TGF-beta stimulation than are blood monocytes and tissue macrophages because of different TGF-beta receptor densities. TGF-beta stimulates transcription of the uPA gene, increases uPA-mRNA stability, and activates uPA expression via protein kinase-C-dependent mechanisms. The ability of TGF-beta to induce macrophage uPA expression may provide an indirect mechanism by which this growth factor stimulates angiogenesis. It may be, therefore, that TAMs promote tumor progression and tumor angiogenesis.

We have studied the effect of immune complexes (IC) on interleukin (IL)-12 secretion by human monocytes in vitro. Two experimental models of IC were used. IC formed of tetanus toxoid and polyclonal anti-tetanus toxoid antiserum as well as heat-aggregated human serum IgG almost completely inhibited IL-12 (p70 and p40) secretion induced by interferon-gamma and lipopolysaccharide in human blood-derived monocytes. Neutralizing anti-IL-10 antibodies plus indomethacin restored IL-12 secretion in the presence of IC to a high extent, indicating that IL-10 and prostaglandin (PG) partially mediate the IC-induced inhibition of IL-12 secretion. However, neutralization of tumor necrosis factor (TNF)-alpha by specific antibodies also incompletely restored IL-12 secretion. Indeed, monocytes secrete high levels of TNF-alpha upon stimulation by IC. We found that exogenously added TNF-alpha caused a profound inhibition of monocytic IL-12 secretion in the absence of IC, again mediated via the induction of IL-10 and PG. In summary, IC inhibit IL-12 secretion via TNF-alpha-induced IL-10 and PG synthesis. We conclude that IC, typically appearing in the course of chronic inflammatory processes, may influence the balance between Th1 and Th2 responses and may thus contribute to a deprivation of cell-mediated immune responses.

PLK (polo-like kinase) belongs to a family of serine/threonine kinases and represents the human counterpart of polo in Drosophila melanogaster and of CDC5 in Saccharomyces cerevisiae. It is strongly involved in spindle formation and chromosome segregation during mitosis. We have shown previously that PLK mRNA expression correlates with the mitotic activity of cells and the prognosis of lung cancer patients. In this report, the level of PLK protein was analyzed using immunohistochemical techniques. PLK protein was found expressed in the nuclei of tumor cells from lung and breast cancer as well as in several tumor cell lines. Furthermore, in peripheral lymphocytes treated with phytohemagglutinin, elevated proliferative activity of the cells correlated with the up-regulation of PLK protein expression. In contrast, in U937 and HL-60 cells after induction of differentiation with phorbol ester, PLK immunostaining disappeared under conditions of terminal differentiation. Most of the PLK protein was found in the nucleus of proliferating cells with diffuse but distinct staining also in the cytoplasm. Taken together, high levels of PLK protein are associated with cellular proliferation. Combined with other proliferative and oncogene markers, PLK may be useful for improved prediction of the clinical prognosis of cancer patients and for early cancer diagnosis. Due to its activity late in the cell cycle, it may be a target for cancer chemotherapy.

Our previous data indicate that the expression of the PLK gene which codes for a serine/threonine kinase is restricted to proliferating cells. In Northern blot experiments PLK mRNA expression was at the limit of detection in normal lung tissue but elevated in most samples of non-small cell lung cancer (NSCLC). A very low frequency of PLK transcripts was only found in bronchiolo-alveolar carcinomas. NSCLC patients whose tumors showed moderate PLK expression survived significantly longer (5 year survival rate=51.8%) than those with high levels of PLK transcripts (24.2%, P=0.001). No statistically significant correlation was found between PLK mRNA expression and age, sex, TNM status, histological type or degree of differentiation. Interestingly, the prognosis of patients in post-surgical stages I and II was correlated with PLK expression (5 year survival rates in stage I: 69.1% (moderate PLK) - 43.5% (high PLK), P=0.03 or in stage II: 51.9% (moderate PLK) - 9.9% (high PLK), P=0.006). These results suggest that PLK mRNA expression provides a new independent prognostic indicator for patients with NSCLC.

In this study, cytokine secretion capacity and maturation phenotype of human lymphoma-associated splenic macrophages (LASM) were evaluated in a long-term culture. Sixteen spleens from malignant lymphoma patients and five control spleens were investigated. Splenic macrophages (SM) were isolated by teflon adherence and cultured for 6-48 days. Secretion of IL-1 alpha, IL-6 and TNF alpha was measured by ELISA following maximal stimulation with LPS and IFN-gamma, and cytokine mRNA expression was detected by in situ hybridization. Immunohistochemical expression of maturation-associated antigens was evaluated semiquantitatively. Cytokine secretion capacity was significantly altered in LASM which exhibited reduced TNF alpha and IL-6, but elevated IL-1 alpha secretion when compared to control SM. Alterations of cytokine secretion capacity were associated with a modification of LASM maturation phenotype, showing impaired expression of early and chronic/late inflammatory markers. These findings obtained from a long-term culture model suggest that malignant lymphomas induce lasting modifications of cytokine secretion and maturation patterns in LASM.

Peripheral T-cell lymphomas (PTCL) represent a heterogeneous group of T-cell malignancies including subentities with favourable (large cell anaplastic) or unfavourable (pleomorphic) prognosis. The clinical outcome of PTCL has been controversially discussed, but a worse prognosis than high-grade B-cell Non-Hodgkin's lymphomas (NHL) has been postulated by most authors. In this report we summarize the results of a prospective comparative study investigating the therapy outcome of 27 patients (pts) with PTCL and 55 pts. with high grade B-cell NHL and give an overview of therapy studies in PTCL. The histological subtypes were 14 pleomorphic, 8 large-cell anaplastic (Ki-1+), 2 angioimmunoblastic (AILD) and 3 other PTCL. In three patients the PTCL was associated with non-tropical sprue (11%). Nineteen patients presented with an advanced stage of disease (stage III and IV, 70%), 17 (63%) pts. had B-symptoms. The patients were treated with vincristine 2 mg d1, adriamycin 25 mg/m2 d1-3, cyclophosphamide 800 mg/m2 d1, prednisone 60 mg/m2 d1-7 and etoposide 120 mg/m2 d1-3 (VACPE). In 77% of pts. with PTCL and 84% of patients with high-grade B-cell NHL a complete remission (CR) was achieved. 75% of the complete responders with PTCL and 70% with B-NHL are still in ongoing CR. The subgroup of large-cell anaplastic attained a CR in 88%. The median observation time is 44 months (1(+)-77+). The probability of 1-, 3- and 5-year overall and disease-free survival for the T-cell group were 76%, 54%, 48% and 76%, 62%, 62%, respectively according to Kaplan-Meier. There was no significant difference regarding the remission rate, the overall-, event-free or disease-free survival compared to high-grade B-cell lymphomas. In conclusion, the VACPE regimen is an effective and feasible regimen in the management of PTCL achieving complete remissions in a large proportion of patients.

We have used two experimental models of immune complexes to study the secretion of interleukin (IL)-10, IL-6 and their connection with the immune complex-induced synthesis of prostaglandin (PG) E2 by human monocytes in vitro. Immune complexes formed of tetanus toxoid and polyclonal anti-tetanus toxoid antiserum as well as heat-aggregated human serum immunoglobulins induced the release of IL-6 and IL-10 in a dose- and antigen: antibody ratio-dependent manner. Antigen-antibody complexes formed near equivalence were most effective in induction of a cytokine response. PGE2 could augment the immune complex-induced IL-6 and IL-10 secretion, but alone, did not induce cytokine secretion. IL-10 was capable of down-regulating the release of IL-6 and PGE2. Additionally, we demonstrated that endogenously synthesized IL-10 limited the immune complex-induced secretion of proinflammatory cytokines tumor necrosis factor-alpha and IL-1 beta. All three regulatory factors examined here share anti-inflammatory properties and are closely associated with the T helper type 2 (Th2) immune response. We conclude that immune complexes, besides their well-known ability no cause acute and chronic inflammation, can mediate immunosuppressive effects and influence the balance of Th1/Th2 responses.

The consequences of complexing an antigen with specific antibodies upon the antigen-induced immune response were studied with respect to secretion of interleukin-2 (IL2), interleukin-6 (IL6), interleukin-10 (IL10) and interferon-gamma (IFN gamma). We found that the tetanus toxoid antigen-induced cytokine pattern was mainly dependent on the antigen/antibody ratio. While tetanus toxoid antigen alone induced a typical Th1-like cytokine pattern with high levels of IL2 and IFN gamma, equivalent or antibody-excess immune complexes induced a marked secretion of IL6 and IL10 while failing to induce IL2 and IFN gamma secretion. As the cytokine pattern plays a crucial role in the development of specific immune responses towards infectious agents, our results indicate that immune complexes--typically occurring during the course of chronic infectious diseases--may play an important role in the modulation of immune responses. Since a shift from Th1 to Th2 immune responses has been discussed as a pathogenetic factor in HIV-induced immunodeficiency, the role of circulating immune complexes as a possible cause for this shift should be considered.

Two experimental models of immune complexes were used to study the secretion of interleukin (IL)-10, IL-6, IL-1 beta and TNF-alpha by human monocytes in vitro. Immune complexes formed of tetanus toxoid and polyclonal anti-tetanus toxoid antiserum as well as heat-aggregated human serum immunoglobulins induced the release of IL-6 and IL-10 in a dose- and antigen: antibody ratio-dependent manner. Antigen-antibody complexes formed near equivalence were most effective in induction of a cytokine response. Additionally, we demonstrated that endogenously synthesized IL-10 limited the immune complex-induced secretion of proinflammatory cytokines tumor necrosis factor-alpha, IL-6 and IL-1 beta. IL-10 is an anti-inflammatory cytokine and closely associated with the T helper type 2 (Th2) immune response. We conclude that immune complexes, besides their well known ability to cause acute and chronic inflammation, can mediate immunosuppressive effects and influence the balance of Th1/ Th2 responses.

Urokinase plasminogen activator (uPA) is a proteolytic enzyme implicated in cancer invasion and tumor progression. Urokinase PA and its inhibitor (PAI-1) appear to be new and independent prognostic markers in breast cancer. To investigate how uPA- and PAI-1-levels correlate with angiogenesis and tumor vessel invasion, we counted microvessels and their tumor invasion and determined the uPA- and PAI-1 levels in 42 primary invasive breast carcinomas. 20 Patients had no lymph node metastasis at the time of surgery, while 22 patients had positive nodes. Using light microscopy, we highlighted the vessels by staining their endothelial cells immunocytochemically for CD31 and Factor VIII. After gaining tumor tissue extracts, we determined the uPA- and PAI-1-levels by ELISA. A positive correlation between microvessel density, angioinvasion and uPA- and PAI-1-levels was found. We speculate that high uPA levels may induce tumor neovascularisation, angioinvasion and may cause tumor progression and metastasis. The degradation of the vessel wall by uPA causes a leak. This wall defect may, on the one hand, be the stimulus for endothelial cell proliferation and formation of new blood vessels and, on the other hand, it may be the place of tumor cell entry.

The pathogenesis of liver injury, which remains unclear in the course of human immunodeficiency virus infection, can be investigated in simian immunodeficiency virus-infected macaques, which develop an immunodeficiency disease resembling human acquired immune deficiency syndrome (AIDS). We studied the livers of 21 monkeys infected with simian immunodeficiency virus (SIVmac251) for 4 days to 39 months and detected viral antigens in Kupffer cells, macrophages, and lymphocytes in 65% of the livers tested. Virus-containing cells were present in 5 out of 9 livers tested as early as 4 days postinoculation. The number of positive cells as well as their content in viral proteins substantially increased in sinusoidal cells with the progression of the disease. Morphological features and double immunolabeling indicated that Kupffer cells constituted the predominant cell type containing viral antigens. The presence of multinucleated giant cells displaying the ultrastructural features of resident liver macrophages was another sign of the productive infection of Kupffer cells in vivo, which was attested by the observation of budding, immature, and mature SIV particles. Kupffer cell hyperplasia and hypertrophy were evident and appeared to be related to the development of SIV infection, because a close correlation was found between antigenemia and the surface area occupied by these cells. The Kupffer cells contained apoptotic lymphocytes, indicating that resident liver macrophages could play a role in the uptake of such cells from the blood. The production of tumor necrosis factor alpha (TNF alpha) and, possibly, interferon-alpha by Kupffer cells, the expression of vascular adhesion molecule-1, (VCAM-1), intralobular and periportal inflammation, and the proliferation and expansion of bile duct cells were other signs of liver involvement in SIV infection.

Phenotype and release of IL1 alpha, IL6 and TNF alpha were examined in monocytes derived from 14 healthy donors and 24 tumour patients in a long-term culture using immunohistochemical, RNA in situ hybridization and ELISA techniques. After stimulation with LPS and IFN-gamma, blood monocytes and resulting macrophages showed an overall decrease in cytokine release from the 6th to the 48th day of culture, both with and without HIV infection. HIV infection provided a strong stimulus for IL6 production and a weak stimulus for IL1 alpha production, whereas TNF alpha release decreased after HIV infection. Non-HIV-infected monocytes/macrophages from patients with malignancies showed significantly reduced cytokine production after stimulation, in comparison with monocytes/macrophages from healthy subjects. In vitro HIV infection of monocytes from tumour patients caused severe depression of cytokine production during the whole time of observation. In all experiments a parallel was observed between the extent of cytokine release and the presence of young/early inflammatory macrophages as identified by the antibody MAC387/27E10 in situ. In contrast, cytokine expression assessed semiquantitatively by immunohistochemical staining in situ showed discordant development, since it increased during long-term culture, while supernatant concentrations of cytokines declined. Simultaneously, significant cytokine RNA levels could be found in macrophages from the 6th to the 24th day of culture, as detected by in situ hybridization. After 48 days of culture, no more cytokine RNA was detectable, while macrophages continued to exhibit distinct immunohistochemical positivity for cytokine antibodies. From these results, it is concluded that macrophages kept in culture for a long period become inhibited in their secretion. HIV has an ambivalent effect on cytokine production in Mo/Mac, resulting in an increase in IL6 and IL1 as well as a decrease in TNF alpha production. Mo/Mac of non-HIV-infected tumour patients show significantly reduced cytokine production in comparison with Mo/Mac from healthy subjects. The sum of the HIV infection in vitro and the tumour burden results in a dramatic reduction in cytokine release in Mo/Mac. This finding may provide a possible explanation for the specific aggressive behaviour of non-Hodgkin's lymphoma and Hodgkin's disease in AIDS.

The livers of 21 rhesus monkeys inoculated with SIVmac251 were examined at 4 days to 39 months after infection. SIV antigens were detected in the cytoplasm of Kupffer cells (KC), macrophages and lymphocytes in two-thirds of the livers tested. The number of cells containing viral proteins substantially increased during the development of the disease, and KC were the main cell type displaying SIV proteins at an advanced stage of infection. Mature and immature lentiviral particles were found in cytoplasmic vacuoles or associated with worm-like structures in KC, indicating that SIV replication could occur within resident liver macrophages. Another sign of the permissiveness of KC was the formation of multinucleated giant cells within the hepatic sinusoids. Some of these cells containing 3-6 nuclei still retained ultrastructural features of KC. Most of them contained a high quantity of viral particles. Numerous lymphocytes displaying signs of apoptosis were taken up by KC, especially at the beginning of infection. Hyperplasia and hypertrophy of KC were noted in the course of SIV disease in the liver. The present data indicate that KC can be infected in vivo and may serve as a reservoir for SIV during the progression of the disease.

Monocytes of healthy donors were infected with HIV1 in vitro: 14-21 days after infection 50-70% of the cells produced p24 HIV1 antigen as detected with anti-p24 immunostaining; infected cultures showed enhanced secretion of interleukin-6 (IL6), interleukin-8 (IL8) and tumour necrosis factor alpha (TNF-alpha). The expression of cytokines on the single-cell level was further analysed by in situ hybridization using nonradioactive digoxigenin for detection. HIV1 (p24+) -producing cells were compared with non-HIV (p24-) -producing cells. All morphological subtypes of macrophages showed HIV production; no difference in cytokine expression was observed. Immunocytochemistry of HIV-infected and uninfected cultures also showed no difference in the pattern of IL1-beta, IL6, IL8 and TNF-alpha protein expression in the cells.

Using monoclonal antibodies against proliferating cell nuclear antigen or PCNA (PC10) and the Ki-67 antigen (MIB1), an immunohistochemical and morphometric study was performed on routinely processed splenic tissue from ten patients with primary (idiopathic) osteomyelofibrosis (OMF). To determine the proliferation capacity of erythroid precursors and the endoreduplicative activity of megakaryocytes, corresponding antibodies (Ret40f and CD61) were applied in combination with the cell-cycle markers (sequential double-immunostaining). Morphometric analysis revealed no significant differences in PCNA or Ki-67 reactivity in either cell lineages. In comparison with previous studies on normal bone marrow, in splenic tissue showing myeloid metaplasia, the numbers of PCNA-labelled proerythroblasts, erythroblasts and megakaryocytes were conspicuously increased. Considering the ineffective erythropoiesis in OMF, there seemed to be a disproportional enhancement in PCNA and Ki-67 immunostaining of the red cell lineage. Similarly, the small size of megakaryocytes in advanced, OMF-associated myeloid metaplasia was in keeping with an impairment of endoreduplicative activity. In addition to various other contributory factors, anaemia in OMF may be partially caused by secondary folate (haematinic) deficiency. From experimental studies this defect is known to cause an abnormal arrest in the S-phase of the cell-cycle, comparable to that characterising pernicious anaemia. As a sequel of this pathomechanism, an undue overexpression of PCNA and Ki-67 has to be assumed, that is not necessarily associated with DNA synthesis or cell cycling.

The in situ content of cells of the reticuloendothelial system and lymphatic cells was examined in the skin of eight symptom-free HIV-positive individuals, three AIDS patients and eleven healthy immunocompetent volunteers. The epidermis was obtained in vivo by the suction blister technique. The numbers of CD68+, CD3+, CD8+, CD25-(IL2R)+ and HLA-DR+ intraepidermal cells proved to be independent of the number of CD4+ peripheral blood lymphocytes. At the same time, the intraepidermal concentrations of these cells were generally low in symptom-free HIV-infected individuals. The strong inverse correlation between the number of epidermal Langerhans cells (LC) and the severity of immunodeficiency was quantitatively confirmed; an increase in LC in symptom-free HIV-infected individuals was found. Thus, the reduction in these cells which was observed in the epidermis of AIDS patients began at a significantly elevated level. In contrast to results from other studies, in AIDS patients, in the present study, the concentration of epidermal LC did not differ significantly from that of healthy immunocompetent volunteers. The immunohistochemical technique can be as effective as in situ hybridization for the detection of HIV in the skin. Our results suggest that the viral load of the skin is rather low in HIV-infected subjects. HIV was demonstrated in one cell of one AIDS case by in situ techniques and this result was confirmed by a polymerase chain reaction examination using the same amount of tissue as for the in situ techniques.(ABSTRACT TRUNCATED AT 250 WORDS)

A case of large cell lymphoma of B-cell lineage originating in the splenic sinuses is described. In addition to widening the spectrum of primary malignant lymphomas of the spleen, this case raises the possibility that variants of angiotropic large cell lymphomas may exist that do not involve blood vessels but do involve the spleen and lymph node sinuses.

A 44-year-old man developed bouts of fever (up to 40 degrees C) seven days after returning from a holiday in Kenya. Malaria prophylaxis with chloroquine had been correctly undertaken. Concentrations of lactate dehydrogenase and total bilirubin were raised (493 U/l and 3.55 mg/dl, respectively). Blood smear revealed the ring forms of Plasmodium falciparum. Thereupon the patient was given mefloquine in decreasing doses (750/500/250 mg) at intervals of 8 hours. The following night he had a circulatory collapse and complained of pain on pressure, especially in the left upper abdomen. Abdominal sonography showed a slightly enlarged spherical spleen with an echo-poor band and fluid collection in the rectovesicular pouch, indicating rupture of the spleen. A splenectomy was performed. Subsequently the number of malaria organisms in the blood smear gradually fell and signs of haemolysis disappeared. Splenic rupture is a very rare complication of acute malaria. It is presumably caused by marked stasis in the splenic sinuses with deformed parasite-containing red blood cells.

Primary biopsies from 149 patients with malignant lymphomas were examined by histological and immunohistochemical techniques. Twenty eight cases were classified as Hodgkin's disease and 121 as non-Hodgkin's lymphomas. The immunohistochemical distribution of cytokine expression (Il-1 alpha, Il-1 beta, Il-6 and TNF-alpha) was demonstrated in neoplastic cells and in tumor-associated macrophages (TAM). Neoplastic cells showed mostly weak positivity for TNF-alpha in 40% of Hodgkin's disease and in 20% of T cell lymphoma cases. Two groups of malignant lymphomas were established which differed in the numbers of cytokine expressing TAM. The first group consisted of malignant lymphomas which contained large quantities of cytokine-possessing TAM. In the second group significantly lower frequencies of cytokine expressing TAM were found. In both groups high and low grade malignant lymphomas were encountered. There was a significantly positive correlation between the number of Il-6 possessing TAM and the proliferation of lymphoma cells in only the non-Hodgkin's lymphomas. Our results suggest a paracrine tumor growth stimulating mechanism which is created by a self perpetuating cytokine production loop. A supposed cytokine produced by neoplastic cells dependent from their proliferative activity may induce Il-6 secretion by TAM. Il-6 in turn may stimulate the proliferation of the lymphoma cells without maturation thus leading to a self-sustaining growth.

In this study we examined the P170-expression (mdr-phenotype) in 42 non-Hodgkin's Lymphomas with variant entities immunohistochemically with the mab JSB1. The mdr-phenotype was related to the tumor proliferation as measured by Ki67-expression and AgNOR numbers. Furthermore the mdr-phenotype was related to the tumor associated T-lymphocytes. The mdr-phenotype showed no relation to histological type and the proliferation of the tumor. There was a positive correlation between the mdr-phenotype and CD2-reactive lymphocytes. There was also a significant positive correlation between CD4-reactive lymphocytes and the mean number of AgNOR's. Possibly P170-expression and proliferation of the tumor cells have a lymphotactic effect on T-lymphocytes. The latter could promote tumor progression by means of paracrine mechanisms.

An immunohistochemical and morphometric study has been performed on splenic tissue of 10 patients with primary (idiopathic) osteomyelofibrosis (OMF) to determine characteristic features of megakaryocytopoiesis in myeloid metaplasia. Using the periodic acid-Schiff reaction (PAS) and particularly the monoclonal antibody CD61 (Y2/51), all elements of this cell lineage including precursors could be identified. In comparison with bone marrow specimens from our file material (40 patients with OMF, 15 control cases) which were processed in a similar way, megakaryocytes in the spleen revealed significant differences. These differences included smaller cell sizes, a disturbed nuclear-cytoplasmic ratio, and a conspicuous increase in the relative frequency of promegakaryoblasts. In conclusion, extramedullary megakaryocytopoiesis in OMF did not only show more pronounced abnormalities of differentiation, but also a higher degree of immaturity. Our finding of a significant accumulation of megakaryocytic precursors in the spleen as opposed to the bone marrow, corroborates the so-called filtration theory which has been introduced to explain the evolution of splenic myeloid metaplasia in OMF.