Supervision of the initial interview. A study of two methods.

Two methods of supervision of the initial evaluation of outpatients by psychiatric residents were compared. In condition 1, residents evaluated patients and then presented the case material to a supervisor in the traditional manner. In condition 2, the supervisor observed the interview directly. Supervisor and residents then independently completed ratings of psychopathology, motivation, insight, and prognosis of the patients. Significant differences in several variables between the two conditions were noted. Resident and supervisor ratings of patients were in clear agreement when both observed the interview.

Acromegaly and Cushing's syndrome associated with a foregut carcinoid tumor.

We report an 18-yr-old youth with a metastatic foregut carcinoid tumor, Cushing's syndrome, and hypersomatotropic gigantism. Administration of cyproheptadine caused a dramatic fall in urinary cortisol excretion and plasma ACTH levels associated with clinical remission of the Cushing's syndrome. GH secretion was not affected by cyproheptadine administration. Ectopic ACTH secretion was confirmed by RIA of tumor extracts and immunohistochemical demonstration of ACTH-containing cells in hepatic metastases. There were two sources of GH production demonstrated in this patient. Ectopic secretion of GH by the carcinoid hepatic metastases was documented by both RIA and immunohistochemical techniques. A somatotrophic pituitary tumor was also present. The histological characteristics of this tumor suggest adenomatous hyperplasia rather than de novo neoplastic change as the likely mechanism of its pathogenesis. GH releasing factor-like activity was demonstrated in extracts of plasma and in extracts of the carcinoid tumor. We conclude that cyproheptadine exerted an effect on the ectopic ACTH-producing cells but not on the ectopic GH-producing cells or on adenohypophyseal GH secretion. Production of a GH releasing factor-like activity by the carcinoid tumor may have caused the pituitary somatotrophic tumor.

Some fixation reagents reduce or abolish the detectability of Ia-antigen and HLA-DR on cells.

The effect of paraformaldehyde (PF), glutaraldehyde (GT), methanol (ME), ethanol (ET) and acetone (AC) fixation on the detectability of Ia antigens on murine and rat peritoneal exudate (PE) and resident peritoneal (RP) macrophages (M phi), and on detectability of HLA-DR antigens on human blood leukocytes (HBL) and human splenic M phi (HSM phi) was examined. Ia-antigen on Mø from H-2k mice was detected by a rosetting assay using erythrocytes (E) to which a monoclonal antibody (MoAb) reactive to Ia.2 (E anti-Ia.2) had been coupled, and by the direct binding of 125I-labeled anti-Ia.2. The antigen was detected on Wistar/Furth (W/Fu) rat RPMø splenocytes (SC) by rosetting with E coupled with a MoAb to the murine determinate Ia.17, which cross-reacts with an Ia-like molecule on cells from the W/Fu strain. HLA-DR framework determinants were detected on HBL and HSMø by the binding of 125I-labeled MoAb and by an avidin-biotinylated peroxidase procedure. Exposure of murine PEMø or RPMø to 1% PF or 0.5% GT for 15 min at room temperature reduced 125I-anti-Ia.2 binding and E anti-Ia.2 rosetting by at least 60%; the radioimmunoassay was more affected by the fixatives than was the rosetting assay. Further, PEMø were more sensitive to the effect of PF fixation than were RPMø. Treatment of freshly isolated RPMø with 1% PF reduced the proportion of Ia-bearing cells detected by the rosetting assay by greater than 50%. Culturing alone did not affect the detectability of Ia on RPMø as assessed by the rosetting test, but cultured RPMø were more sensitive to the effects of FX fixation than fresh cells except when lymphokine from Con A-stimulated murine SC was included in the culture medium. Similar losses of HLA-DR were recorded when HBL and HSMø were exposed to PF, GT, ME or ET, but brief (less than 20 s) treatment with cold AC did not appreciably reduce antigen detectability. Procedures in which fixation takes place after the primary antibody binding step did not result in an appreciable loss of detectable Ia. Thus, commonly used fixatives affect the detectability of Ia and Ia-like antigens on a variety of cells. Results obtained from assays on cells treated prior to the primary antibody binding step, therefore, must be interpreted with caution.

Isolation of human splenic macrophages and lymphocytes by countercurrent centrifugal elutriation.

Certain tissues, such as the spleen, are rich sources of mononuclear phagocytes (MP); however, separating the phagocytes from tissues and removing the contaminating cells have been difficult. We report here a method for the extraction and purification of human splenic MP that employs gentle homogenization of splenic fragments with a Tenbroeck tissue homogenizer, controlled digestion with purified collagenase to free MP from splenic stroma, incubation with DNase to dissociate cell clumps and purification by countercurrent centrifugal elutriation (CCE). With homogenization and enzymatic digestion most of the splenic nonspecific-esterase-positive cells are freed into suspension as determined by morphometric analysis of 2 micron sections from plastic embedded spleen stained for alpha-naphthyl butyrate esterase (ANB). Overall cell recovery after homogenization and enzyme treatment is 56 +/- 7%; no selective cell loss occurs as determined by differential cell counts at each purification step. CCE of up to 3 X 10(9) treated spleen cells results in recovery of 63 +/- 6% of the elutriated cells and separates nearly 50% of the recovered MP into enriched fractions. These MP are morphologically intact as determined by light and electron microscopy and are actively phagocytic. Highly purified (96%) autologous splenic lymphocytes are a useful by-product of this separation technique.

Idiopathic retroperitoneal fibrosis is a macrophage-rich process. Implications for its pathogenesis and treatment.

Idiopathic retroperitoneal fibrosis (IRF) is an uncommon disease of obscure etiology and pathobiology. Using sections of frozen and paraffin-embedded tissue, an immunohistochemical technique, and antibodies to a variety of macrophage- and lymphocyte-associated antigens, we studied six examples of IRF. The results showed a large population of spindle-shaped cells that expressed the immunophenotype of a tissue macrophage, that is, Leu 3a,b (CD4)+, MY7 (CD13)+, Leu M5 (CD11c)+, KP-1 and EBM-11 (CD68)+, human leukocyte antigen (HLA-DR)+, leukocyte common antigen (CD45)+, HAM-56+, and MAC387+. A subpopulation of these cells also reacted with an antibody to the "activation" antigen, interleukin 2R (CD25). A control group of "fibroblastic" lesions including keloids, desmoid tumors, and an aggressive fibromatosis displayed minimal reactivity with this panel of antibodies. The abundance of macrophages suggests that they may play an important role in the pathogenesis of IRF. If, as has been suggested by some studies, IRF is an immune-mediated phenomenon, the macrophages may be triggered to produce cytokines that stimulate fibroblast proliferation and subsequent fibrosis that characterize this disease.

Primary tumor of spleen with morphologic features of malignant fibrous histiocytoma. Immunohistochemical evidence for a macrophage origin.

We report a case of primary splenic malignant fibrous histiocytoma that occurred in a 41-year-old man. Adjacent to the tumor there was a large calcified intrasplenic cyst. Despite splenectomy, postoperative radiation, and systemic chemotherapy, the patient died with metastatic tumor 6 months after diagnosis. Electron microscopic analysis of the tumor demonstrated subpopulations of tumor cells with fibroblastic or histiocytic features. Immunoperoxidase studies of frozen tumor tissue showed positive staining of both spindle and histiocytelike tumor cells with a large panel of monoclonal antibodies against antigens associated with the mononuclear phagocyte system. Expression of these antigens by the tumor supports a mononuclear phagocyte origin.

Increased glomerular deposits of von Willebrand factor in chronic, but not acute, rejection of primate renal allografts.

BACKGROUND: In our previously described primate renal allograft model, T cell ablation leads to long-term graft survival. The role of endothelial cell alteration in chronic rejection was examined in our model. METHODS: Renal transplants were performed in rhesus monkeys using a T cell- depleting immunotoxin, FN18-CRM9. Sections from 10 rejected kidneys (5 acute and 7 chronic rejection) were examined after immunohistochemical staining for expression of endothelium-related proteins [von Willebrand factor (vWF), CD62P, and CD31], fibrinogen, and a macrophage marker (CD68). Glomerular staining for each antigen was graded on a semiquantitative scale. RESULTS: Intense staining for vWF was consistently observed in glomerular endothelium, subendothelium, and mesangium in all kidneys removed due to chronic rejection. vWF staining was weak in kidneys showing acute rejection. The difference in glomerular staining was statistically significant. Staining for vWF in extraglomerular vessels was nearly identical in kidneys showing acute and chronic rejection. Expression of CD62P was increased in extraglomerular vessels in allografts with chronic rejection, but the glomeruli showed little or no staining. There was no significant difference in the glomerular staining for CD62P or CD31 in organs showing acute and chronic rejection. Fibrinogen staining of glomerular mesangium was seen in kidneys with chronic rejection. Macrophages (CD68+) infiltrating glomeruli were more numerous in kidneys showing chronic rejection. CONCLUSION: Increased glomerular deposition of vWF in renal allografts showing chronic rejection, without increased staining for CD62P or CD31, suggests increased constitutive secretion of vWF from endothelial cells as a component of the mechanism of chronic rejection in our model.

Fatal cytomegalovirus bronchiolitis in a patient with Nezelof's syndrome.

A 4-year-old girl who had received a fetal thymus gland by intraperitoneal transplantation 41 months previously sustained acute, fatal bronchiolitis due to culture-proven cytomegalovirus despite the fact that a specific antibody response to this organism was detected. While the thymic transplantation had increased the number of circulating T lymphocytes and had permitted immune sensitization to delayed-hypersensitivity skin test antigens, there was still an incomplete state of T lymphocyte function. In particular, isolated lymphocytes failed to respond to stimulation with phytohemagglutinin at several concentrations and, more important, the pathologic examination demonstrated a severe anatomic deficiency of lymphoid tissue associated with T lymphocyte function. The unusual infection that caused the death of this child emphasized the necessity of acquiring sufficient T lymphocyte function in immunologic reconstitution attempts.

Monoclonal antibodies to T-helper/inducer and T-suppressor/cytotoxic lymphocyte subsets recognize antigens on splenic sinusoidal lining cells.

Most of the monoclonal antibodies (MoAbs) to T-lymphocyte subsets are, with few exceptions thought to recognize antigens (Ags) unique to T-cells. The authors examined the distribution of cells reacting with MoAbs to the helper/inducer (OKT4, anti-Leu-3a,b) and suppressor/cytotoxic (OKT8, anti-Leu-2a) T-lymphocyte subsets and to "pan T" Ags (anti-Leu-1, anti-Leu-4) in sections from frozen human spleen. In addition to recognizing lymphocytes in the T-zone (periarteriolar lymphoid sheaths), MoAbs to the helper/inducer and suppressor/cytotoxic T-cell subsets reacted distinctly with the red pulp sinusoidal lining cells. MoAbs to "pan T" Ags also reacted with T-zone lymphocytes but did not react with sinusoidal lining cells. MoAbs to the helper/inducer and suppressor/cytotoxic subsets of T-lymphocytes do not appear to identify Ags unique to these cells.

Value of CD23 determination by flow cytometry in differentiating mantle cell lymphoma from chronic lymphocytic leukemia/small lymphocytic lymphoma.

Mantle cell lymphoma (MCL) and chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) share many morphologic and immunophenotypic features. In addition to histomorphologic examination, it is customary to use the absence of CD23 to differentiate MCL from CLL/SLL, based primarily on reported comparisons of immunohistochemical staining of tissue sections. These findings are widely extrapolated to flow cytometric analysis, although available data are contradictory and not sufficiently detailed. We compared expression of CD23 by flow cytometry in 22 cases of MCL and 25 cases of CLL/SLL. Lymphoma cells in 12 of 22 MCLs were negative for CD23, and 10 showed dim expression. In contrast, none of 25 CLL/SLLs were negative for CD23, 4 were dimly positive, and 21 were moderately or brightly positive. Thus, a significant proportion of MCL exhibited overlap of CD23 expression in the low-intensity range with CLL/SLL. Clinically, there was no correlation between the intensity of CD23 expression and clinical stage at diagnosis or survival. These findings emphasize that by flow cytometry, MCL can be differentiated reliably from CLL/SLL using CD23 if negative expression is observed. However, with dimly positive expression, interpretation should be cautious.

Cytogenetic and molecular analysis of an unusual case of acute promyelocytic leukemia with a t(15;17;17)(q22;q23;q21).

We present a 52-year-old female with a clinical history of acute myelocytic leukemia, probable acute promyelocytic leukemia (APL). Flow cytometry results were somewhat unusual. Specifically, the promyelocytic population showed partial positivity for antigens not usually expressed in APL (HLA-DR and CD117). The interpretation of these results was that the abnormal population contained a proportion of very early promyeolocytes that had not completely lost all their "precursor" antigens. Cytogenetic analysis of a bone marrow aspirate showed a t(15:17;17)(q22;q23;q21) in all cells analyzed. Fluorescence in situ hybridization (FISH) analysis using the PML-RARA DNA probe showed a positive signal pattern (fusion) in 100% of 200 total interphase and metaphase cells examined, confirming the presence of the PML-RARA rearrangement. Multicolor FISH, which produces 24 colors to differentiate all chromosomes in a single hybridization, was applied. This study confirmed the cytogenetic interpretation of the rearrangement. No material from any other chromosome was detected on the second smaller derivative chromosome 17. Additional studies using the RARA(17q21) break-apart DNA FISH probe showed that 17q21 (RARA) was not rearranged on the derivative chromosome 17 that received the q22-->qter segment from chromosome 15. The RARA locus on the smaller derivative 17 was the allele involved in the fusion in this three-way rearrangement. The signal pattern was consistent in 100% of interphase and metaphase cells scored. This unusual t(15;17;17) prompted us to investigate further using reverse-transcription polymerase chain reaction with primers from the 3' and 5' regions of both the RARA and PML loci. These studies showed that the PML-RARA fusion was present, but the complementary fusion RARA-PML, which is usually detectable, was absent. The patient is responding well to standard treatment protocols.

Immunophenotypic characterization of sinus histiocytosis with massive lymphadenopathy (Rosai-Dorfman disease).

Histochemical and immunohistochemical studies have been reported in only a few cases of sinus histiocytosis with massive lymphadenopathy (SHML) to date. These indicate that SHML cells belong to the macrophage/histiocyte family, but their exact origin is still unknown. We determined the antigenic phenotype of SHML cells in sections from 20 cases of routinely fixed, paraffin-embedded tissue and from two cases of fresh frozen tissue using a broad panel of antibodies to macrophage/histocyte, B-, and T-cell antigens. SHML cells expressed the following: (1) S-100 protein, (2) "pan-macrophage" antigens such as EBM11, HAM 56, and Leu-M3, (3) antigens functionally associated with phagocytosis (Fc receptor for IgG, complement receptor 3), and lysosomal activity (lysozyme, alpha 1-antichymotrypsin, and alpha 1-antitrypsyn), (4) antigens associated with early inflammation (Mac-387, 27E10), (5) antigens commonly found on monocytes, but not tissue macrophages (OKM5, Leu-M1), and (6) "activation" antigens (Ki-1 and receptors for transferrin and interleukin 2). These data suggest that SHML cells are true functionally activated macrophages that may be recently derived from circulating monocytes.

Fracture characteristics of acrylic bone cement-bone composites.

In this study, the fracture properties of Perspex, acrylic bone cement prepared using a commercially available reduced pressure mixing system and a bone cement-bone composite were compared under different test conditions. The method used was the double-torsion (DT) test. The observations made from this investigation are as follows. The fracture toughness and critical crack length for Perspex significantly increased (ANOVA, p = 0.001) when tested in water compared to air. An increase in test temperature from 19 to 37 degrees C resulted in a decrease in the fracture properties in water, this reduction being also statistically significant (ANOVA, p = 0.02). The mean fracture toughness and standard deviation of CMW3 bone cement when mixed under reduced pressure was 2.19 +/- 0.11 MN m(-3/2) compared to 3.89 +/- 0.10 MN m(-3/2) for the cement-bone composite (ANOVA, p = 0.004). The crack length determined for CMW3 bone cement and the cement bone composite were 0.323 +/- 0.031 and 1.1434 +/- 0.61 mm respectively. The plateau loads of the composite material were higher than measured for the monolithic acrylic bone cement, 249.66 +/- 67.75 N compared with 140.83 +/- 6.82 N. The high level of variation recorded for the plateau loads of the bone cement bone composite is due to the orientation and volume fraction of the cancellous bone. It can be concluded from this investigation that acrylic bone cement interdigitation into the cancellous bone results in a superior material with respect to crack resistance in comparison with the bone cement as a lone entity. Therefore it is an advantage if there is sufficient cancellous bone stock available within the intermedullary canal to allow bone cement penetration to occur, for the transfer of loads during daily activity. Additionally, it is paramount that the clinician ensures that adequate pressure is applied and maintained for an appropriate time during cement injection and prosthesis insertion in order to ensure optimum cement penetration into the pore openings of the cancellous bone, thus improving the resistance of the cement mantle to fracture and ultimately improving the longevity of the joint replacement.

[Effect of femoral cementing technique on results. Comparison between retrograde technique and vacuum application]. / Einfluss der femoralen Zementiertechnik auf das Zementierergebnis. Vergleich von retrograder Technik und Vakuumapplikation.

METHODS: To evaluate the penetration depth of cement into trabecular femoral bone, femora of 14 sheep were subjected to simultaneous bilateral cementing. After femoral neck osteotomy, preparation of the bone cavities and jet lavage, cement was applied simultaneously using the conventional retrograde method for one side and vacuum application for the contralateral limb. Bilateral simultaneous pressurisation was then applied. All femoral specimens were X-rayed, sawed into standardised, horizontal, stereometric, identical slices and microradiographed. Cement penetration was assessed using a morphometric software system. RESULTS: No significant differences in depth of cement penetration between sheep femora cemented with the vacuum application method and the standard retrograde method could be found or between the ratio of cement-consolidated and non-cement-consolidated cancellous bone. CONCLUSION: The more complicated and technically challenging method of cement application under vacuum had no advantage in terms of cement interdigitation over the standard retrograde method.

Phenotypic subpopulations of macrophages and dendritic cells in human spleen.

Using immunohistochemical techniques and a large number of monoclonal antibodies, the presence and distribution of phenotypic subpopulations of macrophages (MOs) and dendritic cells in human spleen were assessed. The results of this study show that different subsets of MOs and dendritic cells are present in the spleen and that some of these occupy discrete microanatomic locations. In the red pulp (RP) certain antigens are expressed by different proportions of uniformly distributed MOs in the cords. On the other hand, some antigens are present on MOs that form clusters of variable size within the red pulp. These include CD11c, CD15 and alpha-1-anti-chymotrypsin. Another type of cell in the RP that is phagocytic under certain conditions is the splenic sinusoidal lining cell (SLC). These cells exhibit a phenotype that is unique: nonspecific esterase (NSE)+, lysozyme+, and HLA-DR+, CD36+, factor VIII-related antigen+, CD8+ and CD71+. MOs in the splenic marginal zone (MZ) share some antigens with red pulp MOs, but in addition express CD11b, CD14 (Mo2;63D3) and 61D3. These antigens are found on only a few RP MOs. MZ cells expressing one antigen shared with RP MOs (CD4) and one present largely on the MZ cells (CD14;63D3) form clusters around small vessels; these structures resemble the so-called splenic ellipsoids that may play a role in the trapping of circulating antigens. Phagocytic MOs (tangible body MOs) of the white pulp follicular germinal centers were also shown to differ from RP and MZ cells with respect to the expression of the antigens CD11b, CD14 (Leu M3;Mo2), CD16 and the antigen detected by antibody 25F9. The unique topographical and surface antigenic features of dendritic cells were confirmed by this study. Furthermore, these cells were found to share a number of antigens with RP, MZ, and white pulp MOs, which suggests that they may be derived from a common progenitor. The presence of phenotypic subpopulations and variation in distribution among human splenic phagocytic cells and dendritic cells may be indicative of functional specialization.

Mantle zone lymphoma in a gastric glomus tumor.

A 61-year-old man had an ileocolectomy for resection of an obstructing lesion of the terminal ileum, which proved to be a mantle zone variant of intermediate lymphocytic lymphoma. At laparotomy, an intramural nodule in the gastric antrum was observed; on resection, this was found to be a typical gastric glomus tumor, focally infiltrated by lymphoma. This combined tumor has not been described previously, to the knowledge of the authors, and could be misdiagnosed easily, although both components should be considered in the differential diagnosis of small cell gastric neoplasms and can be identified readily by immunohistochemical studies.

Diagnosis of gastrointestinal T-cell lymphomas in routinely processed tissues.

Diagnosis of primary gastrointestinal T-cell lymphomas is often problematic because lymphoma may not be suspected clinically or on resection, and tissue may not be frozen for immunophenotyping. Furthermore, ulceration and inflammation and the polymorphous character of the lesions makes evaluation difficult. Only approximately 150 cases have been reported, fewer than 20 from North America. We have tried to establish a reliable approach to the diagnosis of gastrointestinal lymphomas of T-cell phenotype in routinely processed tissue. Sections from five primary gastrointestinal T-cell lymphomas were stained with a panel of 13 antibodies reactive in routinely fixed, paraffin-embedded tissue. These included antibodies to pan-T- and pan-B-cell antigens (CD3, CD20), B- and T-cell-associated antigens (CD43, CD45R0; CDw75, CD74), antigens expressed by activated T-cells (HLA-DR, CD30), leukocyte antigens (CD45, CD15), and macrophage markers (MAC-387, HAM-56). All stained positively with T-cell markers MT-1 and Leu-22, four with UCHL-1, and three with anti-CD3 polyclonal antibody. B-cell markers identified by L-26 and LN-1 were negative in all five, whereas LN-2 was expressed in two. Two expressed HLA-DR; all were Ber-H2 negative. Two had an abnormal phenotype: one was Leu-M1 positive, and one LCA negative. Ten B-cell gastrointestinal lymphoma controls were negative for MT-1, Leu-22, and CD3, and nine were negative for UCHL-1. Nine were positive for the B-cell marker L-26, eight for LN-2, and seven for LN-1. All tumors were negative for monocyte-macrophage markers. This antibody panel provides a reliable means for identifying gastrointestinal T-cell lymphomas in paraffin sections. Use of a panel is advisable because of variation in expression and preservation of antigens, and to detect abnormal phenotypes. Application of this approach may facilitate the diagnosis of gastrointestinal T-cell lymphomas both prospectively and in archival material, and thereby encourage studies of the behavior and treatment of these neoplasms.

The immunologic approach to analysis of malignant lymphoma. Mantle zone lymphoma of the ileocecal region.

We studied an unusual type of lymphoma of the ileocecal region using an established protocol that combines morphologic, flow cytometric, and immunohistochemical analyses. This lymphoma grew as multiple submucosal nodules, some of which had coalesced into a mass in the terminal ileum. Histologically, the lesion resembled a lymphoma of follicular center-cell origin except for germinal centers that appeared reactive and greatly expanded follicular mantles. Flow cytometric studies showed that the lymphoma contained a monoclonal, kappa+ population of B-lymphocytes. Evaluation of sections of frozen tissue by an immunoperoxidase technique revealed that the germinal centers were polyclonal (nonneoplastic) and that the neoplastic cells were confined to the mantle zone. The additional information led to classification of the neoplasm as the mantle zone variant of intermediate lymphocytic lymphoma. This type of lymphoma may pursue a more aggressive course than a follicular lymphoma derived from the germinal center. We review our general approach to the analysis of hematolymphoid neoplasms and discuss how certain techniques may be useful adjuncts in the evaluation of these types of tumors.

Histiocytes in familial and infection-induced/idiopathic hemophagocytic syndromes may exhibit phenotypic differences.

Familial hemophagocytic syndrome (FHS) and infection-associated hemophagocytic syndrome (IAHS) usually present with fever, pancytopenia, hepatosplenomegaly, signs of hepatic dysfunction, bleeding diathesis, and neurological manifestations. FHS is almost uniformly fatal, and IAHS is associated with high mortality. The only distinguishing characteristics are lack of family history and association with infection in the latter. Despite this, sporadic cases of FHS and culture-negative examples of IAHS (idiopathic HS) can be difficult to distinguish and the distinction may have important implications for treatment and family planning. We evaluated the immunophenotype of the macrophages (M phi s) in frozen tissue sections from three cases of hemophagocytic syndrome using a very large panel of monocyte/M phi-associated monoclonal antibodies and an immunoperoxidase technique. The clinical and laboratory features suggested that two were examples of FHS (one with strong family history) and that the third was IAHS/idiopathic HS. The results supported the clinical impressions by showing that the antigenic phenotypes of the FHS cases were nearly identical and different from that of the case of presumed IAHS/idiopathic HS. Specifically, M phi s from the FHS cases expressed complement receptors, 1, 2, and 3 (CD35, CD21, and CD11b, respectively), the monocyte antigen CD36, and the "activation" antigens CD25 (IL2-R) and CD30 (Ki-1), while those from the IAHS/idiopathic case did not. These studies also demonstrated that the M phi s in these cases exhibited some phenotypic differences from those in control tissues, that is, expression of the pan-M phi antigen CD14, the M phi subset antigen identified by antibody G16/1, complement receptors, certain monocyte antigens, and M phi "activation" antigens.(ABSTRACT TRUNCATED AT 250 WORDS)

In vivo production of an RNA-DNA copolymer after infection of Escherichia coli by bacteriophage T4.

An RNA-DNA copolymer was isolated from Escherichia coli infected with bacteriophage T4. The RNA and DNA are covalently linked, and in the same polynucleotide strand. The DNA of the copolymer hybridizes specifically to the left strand of phage T4 DNA. The copolymer is produced in cells infected with amber mutants of phage T4 deficient in DNA replication and is not inhibited by the addition of chloramphenicol.