Massive left atrial thrombus: a possible paraneoplastic complication of breast carcinoma

We describe a patient with long-standing rheumatic mitral valve disease, left atrial dilatation, and a precommissurotomy history of left atrial thrombus. Following operation she was maintained on daily aspirin as an antithrombotic measure. For 6 years she had no evidence, echocardiographically, of left atrial thrombus. She underwent surgery for apparently nonmetastatic breast cancer in early 1986. In May 1986 the left atrium was echocardiographically clear. At approximately the same time, recurrence was found at the suture line. In October 1987, two metastatic lung lesions and a very large left atrial mass were detected by computed tomography. The atrial mass was surgically removed and found to be a thrombus. There was a striking temporal correlation between dissemination of carcinoma and development of a massive atrial thrombus.

Expression of ras oncogene p21 during human fetal development as determined by monoclonal antibodies RAP-5, Y13-259, and DWP

In this report we describe the expression of the ras proto-oncogene p21 protein in various tissues during normal fetal development. Conventional, formalin fixed and paraffin-embedded sections of normal organs were examined from fetuses ranging 9 to 42 weeks of gestation. Immunohistochemical localization of ras p21 was accomplished using the broadly reactive, mouse monoclonal antibodies RAP-5 and Y13-259. The monoclonal antibody DWP, which is specific for a mutated form of ras p21 having a valine/cysteine at amino acid position 12, was also used. Detectable expression of the p21 protein was seen at different time periods during fetal development depending on the tissue. The expression of ras p21 (as detected by RAP-5 and Y13-259) was noted in a wide range of cell types and tissues; intense immunostaining was noted in epithelial cells of the gastrointestinal tract, exocrine and endocrine pancreas, renal tubules and transitional urotheliem, as well as in other tissues. This immunostaining generally, but not invariably, corresponded with patterns previously reported in benign and/or malignant neoplasms of adult tissues. In most instances ras p21 expression, when present, occurred during periods of rapid growth in given organ systems. However, some actively proliferating fetal tissues such as thymus and spleen, failed to express detectable ras p21 suggesting that factors other than cell cycle may influence its expression. No reactivity with DWP was noted in any of the tissues, suggesting that the mutated forms detected by this monoclonal antibody are not expressed during normal human embryogenesis. These data show that there is regulated expression, and broad distribution of this gene product in normal developing human fetal tissue.

Immunohistochemical analysis of normal and mutated ras oncogene p21 expression in human pulmonary and pleural neoplasms

In this study we examined 214 cases of primary human pulmonary neoplasms for the expression of a mutated form of the ras oncogene p21 product, recognized by the monoclonal antibody (MCA) DWP. Adjacent serial sections from these same cases had previously been used to demonstrate the frequency of ras p21 expression using the broadly reactive anti-ras p21 MCA RAP-5. Confirmation of the increased expression of p21 was accomplished using MCA Y13-259. The use of adjacent tissue sections from these cases allows the direct comparison of the expression of the mutated and non-mutated forms of ras p21. If reactivity with DWP would prove to be significantly more restrictive than that of the "pan" ras MCAs, RAP-5 and Y13-259, it would lend support to the possibility that DWP (and similar MCAs which detect other specific mutations) could be used to define subsets of these neoplasms based on their specific ras p21 phenotype. Since one would anticipate that the valine/cysteine substitution at position 12 of the ras p21 would occur at only low frequencies in human tumors, our results with DWP are consistent with this hypothesis. As previously reported, RAP-5 reacted with a high proportion of lung tumors (100/214 or 47%). In this report, we demonstrate the selective expression of the mutation recognized by the MCA DWP in only 5% of these same tumors (13/214), and that the expression of this mutated form is not restricted to any of the conventional histological subclasses of pulmonary neoplasms.

Immunohistochemical identification of exocrine and neuroendocrine subsets of large cell lung carcinomas

Formalin fixed, paraffin embedded sections of 52 cases of pulmonary large cell undifferentiated carcinoma (LCUC) as defined in the current WHO classification were studied immunohistochemically to assess features of exocrine and neuroendocrine (NE) differentiation. Monoclonal antibody 44-3A6 was applied to detect a membrane association protein related to exocrine differentiation. A panel of ten neuroendocrine markers including antibodies to synaptophysin, chromogranin A, serotonin, and seven neuropeptides was used to assess NE differentiation. The broad spectrum anticytokeratin antibody PKK1 was used to confirm the epithelial differentiation of these tumors. Exocrine differentiation was detected in 40/52 (77%) of surgically resected LCUC, despite the absence of recognizable glands by light microscopy. Eighteen of 52 (35%) LCUC exhibited NE differentiation; synaptophysin was the most frequently detected NE marker. Cytokeratin immunostaining with PKK1 was demonstrated in 41/52 (79%) cases. Subsets of LCUC were defined based on their expression of exocrine or NE phenotypic markers. Accordingly, 28/52 (54%) LCUC displayed an exocrine phenotype, 6/52 (12%) a NE phenotype, 12/52 (23%) had combined exocrine and NE phenotypes, and 6/52 (12%) exhibited neither phenotype. In this surgical series, there were no significant differences in stage at presentation for the four subsets. Interestingly, two year survival appeared decreased in patients with tumors displaying the "pure" NE phenotype.

Mechanism of decreased insulinogenesis in manganese-deficient rats. Decreased insulin mRNA levels

Manganese-deficient rats exhibited seven-fold lower preproinsulin mRNA levels compared to control, as detected by dot blot hybridization of both total and poly(A)+ RNA using a preproinsulin cDNA probe. No differences in the size of the insulin mRNA were observed. Thus, decreased mRNA levels may be a major contributing factor to the decreased insulinogenesis observed in manganese-deficient rats.

Immunohistochemical evaluation of neuroendocrine cells and neoplasms of the lung

The dispersed neuroendocrine (NE) system is represented in the bronchopulmonary tract by submucosal nerves and ganglion cells and, in the mucosal lining by solitary NE cells and neuroepithalial bodies (NEB's). The latter two components variably express pan-NE markers including NSE, chromogranin (s) and, notably, synaptophysin. The expression of serotonin, bombesin, calcitonin and leu-enkephalin has been well established; additional eutopic materials include somatostatin and calcitonin gene-related peptide. Solitary NE cells and NEB's are epithelial structures as defined by their consistent cytokeratin expression. Hyperplasia and dysplasia of NE cells may be found in association with various forms of chronic injury; they have been noted in chronic bronchiectasis and in the vicinity of neoplasms of various types. Hyperplastic and dysplastic pulmonary NE cells frequently express ectopic materials particularly ACTH. NE neoplasms of the bronchopulmonary tract comprice a spectrum that includes a) carcinoids, b) well differentiated NE carcinomas, c) intermediate cell NE carcinomas and d) small cell NE carcinomas. The precise pathologic criteria defining these entities are discussed in detail as are their clinical implications. The entire spectrum of lung NE neoplasms express NE markers demonstrable by immunocytochemistry; these include pan-NE markers, serotonin and numerous neuropeptides. The expression of multiple hormonal materials is frequent. Within any given tumor, some variation in expression may be noted in different sites and in different periods of the "normal" or therapeutically modified lifespan of the tumor. The entire spectrum of lung NE neoplasms is epithelial for they express cytokeratin polypeptides and desmoplakin; subsets of the tumors coexpress cytokeratins and neurofilament proteins. Also, subsets of these NE neoplasms may be immunostained with monoclonal antibodies to antigens related to exocrine phenotype suggesting focal amphicrine features.

Elevated creatine phosphokinase MB in a patient with neuroendocrine carcinoma of the colon--evidence for a tumor marker. Report of a case

Elevated creatine phosphokinase (CPK) MB isoenzyme has become accepted as a highly specific criterion for the diagnosis of myocardial infarction (MI). A patient with metastatic neuroendocrine carcinoma of the colon who had marked and persistent elevation of CPK-MB isoenzyme, in the absence of clinical and cardiographic evidence for MI, is described. The CPK-MB level was 25 percent (normal, less than 3 percent) on admission, 39 percent postoperatively, and 57 percent on discharge. A prompt decline in serum CPK-MB activity (11 percent, less than 3 percent) paralleled chemotherapy-induced tumor regression. Resurgence of the isoenzyme heralded recurrent disease. These findings suggest that CPK-MB may be a valuable adjunct marker in the diagnosis and monitoring of neuroendocrine carcinomas.

Expression of the antigenic determinant recognized by the monoclonal antibody 44-3A6 on select human adenocarcinomas and normal human tissues

The IgG1 monoclonal antibody, 44-3A6, was raised against the human lung adenocarcinoma cell line, A549. It has been shown to react with a 40,000 MW protein found on the cell surface, which is preserved in formalin-fixed paraffin-embedded tissues. A recent study of pulmonary carcinomas utilizing immunohistochemical methods showed exclusive binding to lung adenocarcinomas, subsets of neuroendocrine tumors, some carcinoids and a subset of large cell carcinomas. Reactivity was not seen in squamous cell carcinomas and small cell neuroendocrine carcinomas. In addition, melanomas, sarcomas and hematologic malignancies do not express this antigen. We now report on the reactivity pattern of 44-3A6 in adenocarcinomas of nonpulmonary primary sites and in normal adults organs. Strong diffuse staining of neoplastic cells in adenocarcinomas of the stomach, colon, pancreas, gallbladder and breast was noted. Adenocarcinomas arising in the endometrium, ovary, kidney, prostate, thyroid and liver were either negative or showed weak and/or focal reactivity. Strong staining patterns were even noted in adenocarcinomas which had an 'undifferentiated' component; i.e., lacking well-defined glandular elements. Immunoreactivity was noted in epithelial cells in several tissues from which these adenocarcinomas arose including the bronchial tract, stomach, small intestine, pancreas and colon, whereas epithelial cells from the endometrium, kidney, ovary, prostate and thyroid were negative or showed diffuse weak immunoreactivity. Our finding indicate that monoclonal antibody 44-3A6 recognizes an epithelial antigen on subsets of normal as well as transformed glandular epithelia. The differential pattern of expression of its target antigen probably reflects differences in tumor genesis and/or differentiation.

Immunohistochemical evaluation of ras oncogene expression in pulmonary and pleural neoplasms

We undertook an immunohistochemical analysis of human bronchopulmonary epithelial neoplasms and pleural mesotheliomas using a monoclonal antibody which recognizes ras oncogene products (p21ras). The monoclonal antibody, RAP-5, recognizes both unaltered and certain mutated p21ras. Formalin fixed and paraffin embedded tissue samples of 187 lung epithelial tumors and 27 pleural mesotheliomas were investigated; normal and bronchiectatic lungs were similarly studied. Normal lung and pleural tissue did not immunostain except for occasional type II pneumocytes. Reactive type II pneumocytes adjacent to carcinomas and bronchiectasis immunostained consistently. Twenty four/34 (71%) squamous carcinomas immunostained. Only 8/50 (16%) adenocarcinomas immunostained focally and weakly whereas 19/24 (79%) bronchioloalveolar carcinomas immunostained. Eleven/18 (61%) large cell carcinomas immunostained with variable intensity. Eleven/13 (85%) carcinoids, 6/7 (85%) well differentiated neuroendocrine carcinomas, and 18/21 (86%) intermediate cell neuroendocrine carcinomas immunostained while none of 20 small cell neuroendocrine carcinomas immunostained. Only a few mesotheliomas were immunostained focally. Two/14 (14%) epithelial type and 1/9 (11%) biphasic type mesotheliomas immunostained weakly; none of 4 spindle cell mesotheliomas immunostained. We conclude that while at least occasional cases of most types of pulmonary epithelial neoplasms express p21ras, the frequency and intensity of the expression are distinctly greater in certain tumor types such as squamous, bronchioloalveolar, and neuroendocrine neoplasm except for the small cell type. Contrary to these lung epithelial neoplasms, most mesotheliomas did not immunostain for p21ras. Whether the enhanced p21ras expression may point to a different mechanism of transformation or may merely reflect differentiation features remains undetermined.

Effects of Fluosol DA 20% and carbogen on the radioresponse of SCK tumors and skin of A/J mice

The effect of Fluosol DA 20%, an emulsion of perfluorochemicals, in combination with carbogen (95% O2 and 5% CO2) breathing on the response of mouse tumors to radiation was studied. When A/J mice bearing SCK tumors in the right hind limb were injected iv with Fluosol DA 20% at 12 ml/kg and exposed to carbogen for 1 h before and during the irradiation of tumors, the response of tumors to a single dose of X irradiation was significantly enhanced. The dose modification factors for growth delay and cure of SCK tumors were 2.10 +/- 0.01 (SE) and 1.86 +/- 0.18 (SE), respectively. Such a treatment slightly increased the radiation-induced skin damage by a factor of 1.17 +/- 0.02 (SE), resulting in a therapeutic gain of 1.79 +/- 0.01 (SE) for the growth delay and 1.59 +/- 0.09 (SE) for the curability. Carbogen breathing alone also increased the response of tumor and skin to radiation, but it was far less effective than the combination of Fluosol DA 20% and carbogen breathing. It was concluded that iv injection of Fluosol DA 20% in conjunction with carbogen breathing significantly increased the O2 transport to hypoxic areas in the SCK tumors and thus significantly enhanced the tumoricidal effect of radiation on SCK tumors.

The mouse mammary tumor virus long terminal repeat directs expression in epithelial and lymphoid cells of different tissues in transgenic mice

A series of transgenic mice was developed that contained the simian virus 40 early region genes under the transcriptional control of the mouse mammary tumor virus long terminal repeat, including the promoter and glucocorticoid response elements. These mice all expressed the transgene in the epithelial cells of a number of different organs, such as lungs, kidneys, and prostate, salivary, and mammary glands, and in Leydig and lymphoid cells. Transcription of the chimeric gene was inducible by glucocorticoids, either after transfection into tissue culture cells or in cells cultured from animals carrying the transgene. Many, but not all, tissues which expressed the simian virus 40 sequences, as determined immunologically and by RNA analysis, developed into tumors, although they showed premalignant features. Since the mouse mammary tumor virus long terminal repeat is expressed in a number of different cell types when inherited through the germ line, the lactating mammary gland-specific transcription of endogenous proviruses must require other factors or sequences to achieve this specificity.

Synaptophysin expressed in the bronchopulmonary tract: neuroendocrine cells, neuroepithelial bodies, and neuroendocrine neoplasms

Synaptophysin is an integral membrane glycoprotein with an Mr of 38,000 that occurs in the small, clear vesicles present in neuronal cells and tumors as well as in pancreatic islet cells and various neuroendocrine (NE) carcinomas. We found that synaptophysin is also expressed in normal NE cells of the lungs of newborn rabbits and mice as well as of human fetuses. In bronchial ganglion cells and in nerves, synaptophysin is coexpressed with neurofilament proteins (NFPs), whereas in solitary NE cells and in at least some of the neuroepithelial bodies (NEBs) of the bronchial mucosal lining, synaptophysin coexists with cytokeratins. We also studied a series of NE neoplasms of the lung covering the entire spectrum of differentiation (i.e., from carcinoids to small-cell NE carcinomas), and found that synpatophysin was present in the majority of them. In these tumors, synaptophysin was invariably coexpressed with cytokeratin filaments and desmoplakin, as well as, occasionally, with NFP. Synaptophysin was identified throughout, the whole range of these NE neoplasms, i.e., from benign to low-grade to aggressive and rapidly metastasizing carcinomas; its presence was unaffected by the highly variable expression of serotonin and/or neuropeptides in these neoplasms, and was unrelated to the presence or absence of associated endocrine syndromes. Our findings indicate that synaptophysin occurs in the neural as well as in the epithelial components of the dispered NE system of the lung as well as in the majority of NE neoplasms of this organ, and that the expression of this protein is therefore independent of the cytoskeletal characteristics and other differentiation features of both normal and transformed NE cells of the lung. We emphasize the value of synaptophysin as an immunocytochemical marker of NE differentiation.

Immunocytochemical analysis of Ewing's tumors. Patterns of expression of intermediate filaments and desmosomal proteins indicate cell type heterogeneity and pluripotential differentiation

Examples of classical Ewing's tumors ("Ewing's sarcomas") of both skeletal and extraskeletal locations were analyzed for the expression of intermediate filament (IF) and cell junction proteins, with the use of immunofluorescence and immunoelectron microscopy as well as gel electrophoresis. In all 11 tumors examined vimentin filaments were abundant. A type of plaque-bearing small cell junction, which is common in these tumors but difficult to classify by morphologic criteria, was identified by antibodies to desmoplakins as true desmosomes. These were found in all cases, although in a very variable proportion of cells. Some of these junctions were associated with vimentin IFs. In addition, 9 of the cases examined showed scattered or clustered cells expressing the simple-epithelium type cytokeratins 8 and 18. Moreover, 3 cases displayed dispersed or clustered cells producing neurofilaments. The value of these observations, notably the cell type heterogeneity, for the diagnosis of tumors of this group is discussed. The results further indicate that Ewing's tumors are derived from a primitive, pluripotential cell that may differentiate, in variable proportions, into cells with mesenchymal, epithelial, and, more rarely, even neural features, suggesting that this tumor should be regarded as a blastoma, rather than as a true sarcoma.

Insertion of an intermediate repetitive sequence into a sea urchin histone-gene spacer

A common polymorphism of the early embryonic histone-gene repeat of Strongylocentrotus purpuratus is a 195-bp insertion within the H4-H2B spacer. The sequence, found as an insert in histone-gene repeats of 6 of 22 individuals screened, is also found at approximately 50 sites elsewhere in the genome of every individual. We compare the sequences of the histone-gene spacers that do and do not contain the insert. The insert is found not to have transposon-like features, and no sequence in the original spacer has been duplicated to flank the insert. There is, however, a hexanucleotide sequence that is repeated three times at one end of the insert, and the element has inserted between direct repeats of 5 bp that were present in the original spacer. One of the copies found outside the histone gene cluster was cloned and sequenced and is compared with the insert. Again, no transposon-like features are evident. Regions flanking the homologous sequence in this clone were used as hybridization probes in whole-genome blots. Results indicate that the 195-bp sequence insert is itself embedded within a larger element that is repeated within the genome. Therefore, only a portion of a larger repetitive sequence has integrated into the histone-gene spacer. The sequence features of the insert, although not typical of mobile elements, may be representative of other illegitimate recombination events.

Synaptophysin. A new marker for pancreatic neuroendocrine tumors

Synaptophysin (SYP) is a glycoprotein recently isolated from presynaptic vesicles of bovine neurons. Initial studies have demonstrated its presence in neurons in the brain, spinal cord and retina, and in adrenal medullary cells. A subsequent study demonstrated it in pancreatic islet cells and certain neuroendocrine (NE) neoplasms, including several pancreatic islet cell tumors. Based on these preliminary observations, we examined, by immunohistochemistry, conventionally fixed, paraffin sections of 57 pancreatic endocrine tumors with a monoclonal antibody to SYP. Furthermore, we compared the SYP immunoreactivity of 30 of these same tumors with that of neuron-specific enolase (NSE) and of chromogranin (CG). SYP was demonstrated in all but one of the 57 tumors. In the comparative study, for which material was available in only 30 cases, SYP and NSE were present in 29 of the tumors, whereas CG was seen in only 15 cases. We conclude that SYP is a highly sensitive and useful marker for pancreatic NE neoplasms. Moreover, in view of the increasingly evident limited specificity of NSE, SYP should be considered the marker of choice for pancreatic NE neoplasms.

Establishment and characterization of a neuroendocrine skin carcinoma cell line

A neuroendocrine skin carcinoma cell line MKL-1 has been established from a nodal metastasis in a 26-year-old patient. The line grows as irregularly outlined, loosely packed floating aggregates lacking central necrosis. MKL-1 is hyperdiploid and has a mean doubling time of 120 hours. Xenografts of 2 X 10(7) MKL-1 cells produce tumors in nude mice at 4 to 6 weeks after subcutaneous inoculation. The xenografts were morphologically indistinguishable from the original skin primary and the nodal metastasis. Electron microscopy revealed sparse membrane-bound neurosecretory granules, and conspicuous, paranuclear aggregates of intermediate filaments. Immunohistochemical study showed diffuse and consistent staining with neuron-specific enolase, while bombesin, adrenocorticotrophic hormone, Leu-enkephalin, substance P, and vasoactive intestinal polypeptide displayed heterogeneous and variable expression. Uniform staining of all cells appearing as cytoplasmic fibrils and paranuclear aggregates was noted with antibodies to cytokeratin. Appreciable amounts of cytokeratin polypeptides 8, 18, and 19 and IT protein were seen on two-dimensional gel electrophoresis of cytoskeletal preparations from MKL-1 cells and from tumor-rich frozen sections. Immunostaining also showed coexpression of neurofilaments arranged in paranuclear aggregates; gel electrophoresis and immunoblotting demonstrated the presence in MKL-1 cells of prominent amounts of the small neurofilament polypeptide. Focal expression of desmoplakin was noted in the xenografts. The cells reacted with monoclonal antibodies anti-Leu-7 and anti-Leu-M1 but did not react with antibodies to human lymphocyte antigens (HLA)-A, HLA-B, and HLA-C. Cytogenetic analysis revealed the presence of 3 chromosomally abnormal cell lines with the majority of metaphase cells demonstrating a gain of an isochromosome of the short arm of chromosome 5. Thus, MKL-1 cell line shares several characteristics with small cell neuroendocrine bronchopulmonary carcinoma cell lines but shows distinct cytogenetic abnormalities.

Immunohistochemical demonstration of lacto-N-fucopentose III in lung carcinomas with monoclonal antibody 624A12

Bronchopulmonary carcinomas were analyzed immunohistochemically using monoclonal antibody 624A12. The antibody was raised against a human "small cell carcinoma" cell line NCI-H69. It recognizes a particular sugar sequence in lacto-N-fucopentose III, which is preserved in formalin fixed and paraffin embedded tissue. Various bronchopulmonary carcinomas revealed characteristic patterns of immunoreactivity. Forty nine/50 adenocarcinomas were immunoreactive either diffusely or focally. The immunostaining was usually limited to the cell membranes with occasional intracytoplasmic immunostaining in large cells. The only negative case had been irradiated before surgical resection. Twenty seven/38 squamous cells carcinomas did not immunostain while the remaining 11 displayed focal immunoreactivity in areas of "loose cellular apposition" associated with necrosis and, rarely, in squamous pearls. All of six adenosquamous carcinomas showed immunoreactivity focally. Eleven/30 large cell carcinomas and 10/11 bronchiolo-alveolar carcinomas were either diffusely or focally immunoreactive. Seven/26 intermediate cell neuroendocrine carcinomas were focally immunoreactive while none of 33 typical small cell neuroendocrine carcinomas, 21 carcinoids, and 10 well differentiated neuroendocrine carcinomas was immunoreactive. An adenoid cystic carcinoma was diffusely immunoreactive, and a mucoepidermoid carcinoma was focally immunoreactive. We conclude that various bronchopulmonary neoplasms have characteristic patterns of distribution of this antigen, and that monoclonal antibody 624A12 may be useful for the differential diagnose among bronchopulmonary carcinomas, and their differential diagnosis from pleural mesotheliomas.

Synaptophysin expression in neuroendocrine neoplasms as determined by immunocytochemistry

Synaptophysin is an integral membrane glycoprotein originally isolated from presynaptic vesicles of bovine neurons. The authors have studied a wide spectrum of neuroendocrine (NE) neoplasms by immunofluorescence microscopy on cryostat sections of freshly frozen tissues using a monoclonal antibody to this protein (SY 38). Without exception, they found the identical--or a very similar--protein expressed in all neuroblastomas, ganglioneuroblastomas, ganglioneuromas, pheochromocytomas, and paragangliomas studied. In these "neural" type NE neoplasms, synaptophysin was coexpressed with neurofilament proteins. Synaptophysin was also demonstrated in NE neoplasms of "epithelial" type in which it was predominantly coexpressed with cytokeratins and desmoplakin. It was invariably found in all variants of islet cell neoplasms and in all medullary thyroid carcinomas. Synaptophysin was also demonstrated in several adenomas of the hypophysis and parathyroids, in the majority of carcinoids of the bronchopulmonary and gastrointestinal tracts, and in many, though not all, NE carcinomas of the same sites, and of the skin. Conversely, SY 38 did not immunostain any of a large number of benign and malignant non-NE epithelial neoplasms; nor was any immunostaining obtained in a group of mesenchymal tumors. It is remarkable that SY 38 did not immunostain a number of malignant melanomas, including several that were immunostained for neuron-specific enolase (NSE) and several neuropeptides. Parallel studies conducted on conventionally fixed, paraffin-embedded tissue sections immunostained by the use of the avidin-biotin complex technique yielded very similar results. The findings indicate that synaptophysin is expressed in the whole range of NE neoplasms without detectable relation to the expression of other NE markers such as NSE, serotonin, and neuropeptides. Nor could the expression of synaptophysin by these tumors be correlated with their epithelial and/or neural cytoskeletal characteristics, their clinical aggressiveness, or the presence or absence of endocrinologic abnormalities. While the consistent expression of synaptophysin by the "neural" type of NE neoplasms would seem predictable its presence in diverse benign and malignant NE tumors of "epithelial" type is remarkable. It is concluded that synaptophysin is a significant as well as novel NE marker, and the use of antibody SY 38 as a broad range marker for the study and diagnosis of NE neoplasms is proposed.

Increase in pO2 and radiosensitivity of tumors by Fluosol-DA (20%) and carbogen

The potential usefulness of i.v. injection of perfluorochemicals and breathing carbogen (95% O2 and 5% CO2) to improve the radiation-induced control of tumors was investigated. When C3H mice, bearing RIF-1 tumors in the legs, were given i.v. injections of Fluosol-DA (20%) at 12 ml/kg, and allowed to breathe carbogen for 1 h before and during a single dose of X-irradiation, the curability of tumors increased by a dose modification factor of 1.47 +/- 0.03 (SE). Such a treatment also increased the radiation-induced skin damage by a factor of 1.15 +/- 0.12, resulting in a therapeutic gain of 1.28 +/- 0.04. Measurement of intratumor pO2 by oxygen microelectrodes demonstrated small increases in pO2 when the animals breathed carbogen, and marked increases in pO2 when Fluosol-DA (20%) was injected into the animals and the animals breathed carbogen. It was concluded that i.v. injection of Fluosol-DA (20%) followed by carbogen breathing significantly improved the oxygen supply to hypoxic cells in the RIF-1 tumors and thus increased the control of tumors by radiation.

The intermediate filament complement of the spectrum of nerve sheath neoplasms

The intermediate filament complement of the spectrum of nerve sheath neoplasms including 12 typical benign schwannomas, 1 ancient schwannoma, 2 cellular schwannomas, 6 neurofibromas and 4 malignant schwannomas was investigated by immunofluorescence microscopy, two dimensional electrophoresis, and immunoblot analysis. Studies were performed on freshly frozen tumor tissue samples; a broad spectrum of antibodies against all classes of intermediate filaments was utilized. Samples were also studied by electron microscopy, and immunohistochemically for S-100 protein and desmoplakins. By immunofluorescence microscopy, all nerve sheath neoplasms revealed intense positivity for vimentin throughout the cytoplasm while 2 benign schwannomas displayed co-expression of vimentin and glial filament proteins. Two-dimensional gel electrophoresis and immunoblot analysis confirmed the presence of vimentin and showed that it was the predominant protein in all tumors. Electrophoretic analysis of the 2 benign schwannomas that immunostained for glial filament proteins confirmed the presence of this protein which was shown to comigrate with a known human control sample. Neither immunofluorescence microscopy nor biochemical analyses revealed cytokeratin polypeptides, neurofilament proteins, desmin, or desmoplakin in any of the tumors. We conclude that while vimentin is the predominant intermediate filament expressed by the entire spectrum of nerve sheath neoplasms, at least occasional benign schwannomas are capable of co-expressing glial filament proteins. It remains to be determined whether the subgroup of nerve sheath neoplasms that co-expresses vimentin and glial filament proteins is otherwise distinguishable from their more frequent counterparts that express vimentin exclusively.

Histologic variation in the skin lesions of the glucagonoma syndrome

Three cases of glucagonoma syndrome were seen in 1 year. Study of the skin biopsies from the first two cases led to a correct diagnosis from skin biopsy of the third case, although it was not suggested clinically. In each case serum glucagon levels were high and a pancreatic tumor was found, with complete remission of symptoms in cases 1 and 3 after resection; case 2 refused surgery and has died. A total of nine skin biopsies from the three patients showed a variety of findings: epidermal necrosis; subcorneal pustules, either isolated or associated with necrosis of the epidermis; confluent parakeratosis, epidermal hyperplasia, and marked papillary dermal angioplasia; and suppurative folliculitis. The clinical lesions in this syndrome vary from bright red macules to annular superficial erosions and flaccid pustules. Similarly, several histopathologic features of the disease can occur, which may represent the progression of the disease. No single histologic feature was specific for the disease, but a combination of the features is probably diagnostic. Therefore, multiple skin biopsies are recommended when this diagnosis is suspected.

Malignant mesotheliomas. Improved differential diagnosis from lung adenocarcinomas using monoclonal antibodies 44-3A6 and 624A12

Forty-three malignant pleural mesotheliomas and 10 known metastatic pulmonary adenocarcinomas to the pleura were studied by immunohistochemistry using monoclonal antibodies 44-3A6 and 624A12. Monoclonal antibodies 44-3A6 and 624A12 were raised against human pulmonary carcinoma cell lines; they recognize a membrane-associated protein of 40,000 mol wt and a specific sugar sequence of lacto-N-fucopentose III, respectively. Samples were also studied with a broad-spectrum antikeratin antibody and a polyclonal antibody to carcinoembryonic antigen (CEA). These investigations were performed on formalin-fixed and paraffin-embedded tissues. The mesotheliomas comprised only grossly evident, pleurectomized, or pneumonectomized cases; they included 22 epithelial, 15 biphasic, and 6 spindle cell types. Electron-microscopic study was also done on 9 cases. None of the mesotheliomas was immunoreactive to 624A12, while 9/10 metastatic pulmonary adenocarcinomas were convincingly immunoreactive. Monoclonal antibody 44-3A6 immunostained all of the metastatic adenocarcinomas strongly, whereas only 10/43 mesotheliomas were focally and weakly immunoreactive. The latter included 5 epithelial and 4 biophasic mesotheliomas and 1 spindle cell mesotheliomas; the immunoreaction was confined to scattered single cells, and the staining pattern was readily discernible from that of adenocarcinomas. Forty of 43 mesotheliomas were strongly immunoreactive with the broad-spectrum anti-keratin antibody, whereas 8/10 metastatic pulmonary adenocarcinomas showed focal and rather weak staining. Seven of 10 metastatic adenocarcinomas were immunoreactive to anti-CEA antibody, while only 15/43 mesotheliomas displayed weak immunoreactivity. It is concluded that monoclonal antibodies 44-3A6 and 624A12 are excellent phenotypic markers of metastatic pulmonary adenocarcinomas to the pleura and thus are useful for the differential diagnosis of pleural mesotheliomas. Given conventionally fixed and processed tissues, it appears that the combined use of these monoclonal antibodies may be more effective for that differential diagnosis than anti-CEA and anti-keratin antibodies.

The clonogenic response of bovine aortic endothelial cells in culture to radiation

The effect of ionizing radiation on the survival of bovine aortic endothelial (BAE) cells was determined by the in vitro colony formation method. The BAE cells were cultured in Dulbecco's modified Eagle's medium (DMEM) supplemented with 10% calf serum, antibiotics, and growth factors obtained from the culture of mouse S-180 cells. The cultured BAE cells were positive to the staining of antibodies against human factor VIII and formed clones in plastic culture flasks with a plating efficiency of about 11%. The survival curve of the BAE cells following an exposure to a single dose of X rays was characterized by D0 = 101 rad, Dq = 65 rad, and an extrapolation number (n) of 1.9. These parameters were not modified by the absence of growth factors at the time of irradiation. The response of BAE cells to radiation was dose-rate dependent. The split-dose studies demonstrated that the BAE cells were able to repair sublethal radiation damage within 1 h after irradiation.

Dose-response range of encainide for benign and potentially lethal ventricular arrhythmias

A multicenter, 2-week, double-blind, placebo-controlled, parallel group study was performed to determine the dose-response relation of encainide administered 3 times daily and to determine its onset of action. To be included in the study, patients with benign or potentially lethal ventricular arrhythmias were required to have an average of at least 30 ventricular premature complexes (VPCs) per hour on 48-hour Holter monitoring after a 48-hour washout period without antiarrhythmic drug treatment. Patients were randomly assigned to receive either placebo or 10, 25 or 50 mg of encainide 3 times daily (tid) for 2 weeks. Of the 125 patients who entered the study, 122 were available for efficacy analysis. Efficacy was determined using 24-hour Holter monitoring on days 1, 7 and 14. There was no difference in frequency of VPCs or of ventricular tachycardia events in the placebo and 10-mg-tid encainide arms. At doses of 25 and 50 mg of tid, encainide was effective in suppressing VPCs and in reducing the number of episodes of ventricular tachycardia. A positive dose-response relation was identified. The onset of effect of encainide was apparent at 3 hours and lasted for 24 hours with tid dosing. No difference in on-therapy conditions were found among the 4 study arms. No patients were discontinued from the study because of electrocardiographic changes. There was no statistically significant change in vital signs or physical examination data. In 1 patient an elevated serum glucose level developed. No symptomatic proarrhythmic events occurred and none required discontinuation of study medication.(ABSTRACT TRUNCATED AT 250 WORDS)

Immunohistochemical analysis of human pulmonary carcinomas using monoclonal antibody 44-3A6

A monoclonal antibody, 44-3A6, was raised against the human pulmonary adenocarcinoma cell line A549. This antibody recognizes a protein antigen at the cell surface, which is preserved after formalin fixation and paraffin embedding. Immunohistochemical staining of lung tissue with this antibody revealed diffuse immunoreactivity of type II pneumocytes. Bronchial epithelial cells were also focally immunoreactive. Immunostaining of various bronchopulmonary carcinomas demonstrated characteristic patterns of reactivity. All of the 42 adenocarcinomas and 18 carcinoids were strongly immunoreactive either diffusely or focally. The immunoreaction occurred at the cell membrane and/or in the cytoplasm. None of the 39 squamous cell carcinomas, 12 bronchioloalveolar carcinomas, and 30 small cell neuroendocrine carcinomas was immunostained. Ten intermediate cell neuroendocrine carcinomas and 8 well-differentiated neuroendocrine carcinomas were relatively weakly immunoreactive, while 7 and 2 of them were negative. Six adenosquamous carcinomas were focally positive in glandular and "basaloid" areas, whereas squamous areas were negative. Twenty-one large cell carcinomas were focally immunoreactive, while 6 were negative. It appears that MCA 44-3A6 is an effective marker for certain features of "glandular" differentiation, which may be present even in tumors lacking obvious glands, and that it may be useful for the differential diagnosis of various bronchopulmonary carcinomas.

Neuroendocrine markers in paragangliomas of the head and neck

Eighteen paragangliomas of the head and neck (11 carotid body tumors, four glomus tympanicum tumors, three glomus jugulare tumors) were studied retrospectively. Tissue from each of these tumors was immunostained for the presence of serotonin, a variety of neuropeptide hormones, and the enzyme neuron-specific enolase (NSE). Seven tumors were studied by electron microscopy. The clinical and laboratory records were reviewed for evidence of endocrine activity or metabolic imbalance. All tumors displayed diffuse and intense immunostaining for NSE. In addition, a wide variety of hormonal substances could be identified. Those most frequently demonstrated were serotonin and leu-enkephalin. Ten of the 11 carotid body tumors demonstrated immunoreactivity for multiple hormones. By electron microscopy all tumors contained a heterogeneous population of membrane-bound neurosecretory granules. None of these tumors was associated with a clinically apparent endocrine syndrome. We conclude that paragangliomas of the head and neck are neuroendocrine tumors that are capable of synthesizing a variety of hormonal substances. These hormonal substances rarely elicit a clinically apparent endocrine or metabolic imbalance. All of the tumors demonstrated immunostaining for NSE. Future studies on serum levels of NSE may provide useful diagnostic and follow-up data.

Monoclonal antibody 44-3A6 as a probe for a novel antigen found on human lung carcinomas with glandular differentiation

This paper describes an immunoglobulin G1 mouse monoclonal antibody (MCA) 44-3A6 directed against a human adenocarcinoma of the lung, cell line A549. This hybrid is a fusion product of the mouse myeloma SP 2/0.Ag14 and spleen cells from a BALB/c mouse which had been hyperimmunized with A549. Live cell radioimmunoassays, immunofluorescences, and fluorescent activated cell sorter analysis indicate that MCA 44-3A6 reacts with a cell surface antigen. Western blot analysis identifies a major antigen band with the apparent molecular weight of 40,000. Enzyme treatment of A549 target plates shows that the antigen is sensitive to proteases. This MCA does not react with carcinoembryonic antigen. Patients having a variety of different lung carcinomas do not appear to have detectable antigen in their serum, nor does the antigen appear to be shed into culture supernatants by human lung carcinoma cell lines. The antigen is preserved in formalin-fixed, paraffin-embedded tissue sections and shows a cell surface and/or cytoplasmic staining pattern. Immunohistochemical staining of various bronchopulmonary carcinomas demonstrated binding to be restricted to tumors with features of "glandular" differentiation. This MCA may have clinical and diagnostic utility due to its selective binding for a subset of carcinomas of the lung.

Application of monoclonal antibody 44-3A6 in the cytodiagnosis and classification of pulmonary carcinomas

Thirty-five pulmonary carcinomas were studied retrospectively with monoclonal antibody (MCA) 44-3A6 raised against a human adenocarcinoma cell line. The antibody was applied to cytologic smears of bronchial brushings originally stained with the Papanicolau method, and to conventional tissue sections. Ten of 12 adenocarcinomas (ADC) immunostained strongly in sections and smears, as did five of seven large-cell "undifferentiated" carcinomas (LCUC). Eight neuroendocrine carcinomas (NEC) and eight squamous-cell carcinomas (SCC) were negative, except for rare weakly positive foci. We conclude that MCA 44-3A6 can be effectively applied on cytologic smears, and that it could be valuable in the precise classification of pulmonary carcinomas. The immunoreactivity of the ADC and SCC was predictable. Positive immunostaining in some LCUC confirms that these constitute a heterogeneus tumor class that includes cases that are phenotypically ADC despite the absence of obvious glands. Occasional immunostaining in NEC suggests focal exocrine differentiation as previously noted by electron microscopy.

Increased radiosensitivity of tumors by perfluorochemicals and carbogen

The efficacy of an emulsion of perfluorochemicals (Fluosol-DA) to sensitize RIF-1 tumors of C3H mice to radiation was studied. An i.v. injection of 12 ml/kg of Fluosol-DA (20%) to tumor-bearing animals and keeping the animals in an atmosphere of a mixture of O2 (95%) and CO2 (5%) (carbogen) for 1 hr before and during irradiation of s.c. tumors in the thigh significantly enhanced the tumoricidal effect of radiation as measured with growth delay of the treated tumors. A lesser but significant enhancement of radiation damage in the tumors was also observed when the animals were kept in carbogen for 1 hr without injection of Fluosol-DA. It was concluded that Fluosol-DA increased the delivery of oxygen to hypoxic areas in the tumors and enhanced the response of hypoxic cells to radiation.

Coexpression of neuroendocrine markers and epithelial cytoskeletal proteins in bronchopulmonary neuroendocrine neoplasms

Neuroendocrine (NE) neoplasms of the human bronchopulmonary tract were examined by electron microscopy, immunocytochemistry, and gel electrophoresis of cytoskeletal proteins from microdissected tissue samples. All samples (carcinoids, well-differentiated NE carcinoma, NE carcinomas of intermediate type, NE carcinomas of the small cell type) contained significant numbers of cells that immunostained for one or more of the following neuroendocrine markers tested: bombesin, calcitonin, ACTH, leu-enkephalin, gastrin, serotonin, somatostatin, alpha-melanocyte-stimulating hormone, vasoactive intestinal peptide, glucagon, insulin, substance P, and neuron-specific enolase. Electron microscopy revealed typical NE cell features, including variable abundant and frequently heterogeneous neurosecretory granules. Tumor cells contained filaments specifically stained with different conventional and monoclonal antibodies to cytokeratins and displayed punctate plasma membrane staining with antibodies to desmoplakins, in agreement with the electron microscopic demonstration of tonofilament bundles and desmosomes. Immunocytochemistry for NE markers and cytoskeletal proteins on consecutive sections revealed both cytokeratins and neuroendocrine substances in single cells. Using gel electrophoresis of cytoskeletal proteins of tissue regions extracted with high salt buffer and detergent, we could detect, in the tumors tested, appreciable amounts of cytokeratin polypeptides 8, 18, and 19, i.e., major cytokeratins also found in certain other lung carcinomas such as adenocarcinomas. Tumor cells were not significantly stained with antibodies to other intermediate filament proteins such as vimentin, desmin, glial filament protein, and neurofilament protein. The results show that NE substances can be synthesized in cells containing a typical epithelial cytoskeleton, i.e., cytokeratin filaments and desmosomes. These findings support the notion of an epithelial character of these tumors and appear in contrast with recent reports that neurofilaments are the only type of intermediate filaments present in carcinoids and other pulmonary NE tumors. These observations may have important implications for the histogenesis of NE carcinomas and for diagnostic pathology.

Neuroendocrine skin carcinoma coexpressing cytokeratin and neurofilament proteins

Neuroendocrine (Merkel cell) carcinomas of the skin have been recognized as such for several years. Given the reported wide variability in the morphology and clinical evolution of these tumors, the notion that may they comprise several variants rather than a single type has been advocated. Electron microscopy has played a key role in the early recognition of these tumors while immunohistochemical studies for various neuroendocrine markers have facilitated their subsequent diagnosis and improved our understanding as to their complexity by the demonstration of immunoreactivity for NSE (neuron specific enolase) and a number of neuropeptides. There has also been considerable interest in the study of the cytoskeletal intermediate filament complement of neuroendocrine neoplasms in general and of those of the skin in particular. Early reports indicated that neuroendocrine skin carcinomas had neurofilaments while subsequent investigations determined that they had cytokeratin. However, more recent studies have indicated that at least some neuroendocrine skin carcinomas could in fact coexpress both aforementioned classes of intermediate filament proteins. This brief report is presented to confirm the latter investigations.

Bombesin in human neuroendocrine (NE) neoplasms

Bombesin is a 14 amino acid peptide isolated from amphibian skin which was found to have stimulatory effects upon gastric and pancreatic secretions, release of gastrointestinal hormones, gallbladder contraction and bronchoconstriction. It is present in amphibian gastric endocrine cells, avian proventriculus endocrine cells and avian brain. In mammals it is present mainly in nerve cells and fibers. The only mammalian endocrine cell shown to date to have bombesin is the P-cell in fetal lung. Bombesin is also found in mammalian brain, with its highest concentration in the hypothalamus. We examined several groups of human neuroendocrine neoplasms for the presence of bombesin by immunohistochemistry. Our findings indicate that bombesin is present 68% of bronchial carcinoids, 65% of pulmonary neuroendocrine carcinomas, 62% of neuroendocrine carcinomas of the skin, 5-10% of pheochromocytomas and extraadrenal paragangliomas and 35% of gastrointestinal carcinoids and neuroendocrine carcinomas. Parallel studies in a wide variety of non neuroendocrine neoplasms failed to reveal the presence of bombesin. We conclude that bombesin is a highly specific marker of neuroendocrine differentiation and thus a valuable tumor marker. Furthermore, its specificity compares favorably with another neuroendocrine marker, neuron specific enolase, an enzyme thought to be present only in neural tissues and neuroendocrine cells but recently found in non neural human tissues and non neuroendocrine neoplasms.

Paragangliomas of the head and neck: ultrastructural and immunohistochemical analysis

Eighteen head and neck paragangliomas were studied by light microscopy and light microscopic immunohistochemistry by the peroxidase technique for the presence of NSE (neuron-specific enolase), serotonin, and a battery of neuropeptides. Seven of these tumors were also studied by electron microscopy. All 18 cases demonstrated immunostaining for NSE; 10 of the 11 carotid body tumors had immunostaining for multiple hormones. Considering all 18 cases, the most frequently demonstrated hormonal substances were in order: serotonin, leu-enkephalin, gastrin, substance P, vasoactive intestinal polypeptide (VIP), somatostatin, bombesin, calcitonin, and alpha MSH. In several tumors, adjacent-step sections stained for different hormonal substances strongly suggested reactivity for more than one hormone in given tumor cells. By electron microscopy, all 7 cases studied displayed considerable heterogeneity of the neurosecretory granules with respect to size, shape, and electron density. This demonstrated that branchiomeric paragangliomas are capable of producing a spectrum of neuropeptides in addition to their known amine content. The presence of immunoreactive serotonin in most of these neoplasms was confirmed. In addition to these findings, neurofibrils within the substance of carotid body paragangliomas demonstrated immunoreactivity for somatostatin and a gastrinlike neuropeptide. The significance of the neuropeptides in these neoplasms and their possible presence and role in normal and hyperplastic paraganglia remain to be defined.

A comparison of subliminal, supraliminal and faded phobic cine-films in the treatment of agoraphobia

Thirty-two agoraphobic patients were randomly allocated to four groups and treated by repeated exposure to cine-films at twice weekly intervals for three weeks. Three of the groups saw the same cine-film, comprising a range of agoraphobic scenes, and a control group saw a potter working on his wheel. The three groups seeing the phobic cine-film included one who viewed it at an illumination level below the visual threshold (subliminal group), one seeing it under normal conditions (supraliminal group) and one which underwent graduated exposure from subliminal to supraliminal viewing levels as the study proceeded (faded group). The faded group showed significantly greater improvement than the control and supraliminal groups and this improvement was maintained over twelve weeks.

Blastogenic responsiveness of spleen cells from guinea pigs sensitized to Legionella pneumophila antigens

An in vitro leukocyte blastogenic assay was utilized to establish an in vitro correlate of cell-mediated immunity to Legionella pneumophila antigen with spleen cells from sensitized guinea pigs. Incubation of spleen cells from sensitized but not normal guinea pigs with graded amounts of killed whole cell Legionella bacteria or sonicate derived from the bacteria resulted in an antigen-induced blast cell proliferation as evidenced by an increased uptake of [3H]-thymidine into spleen cell cultures. Peak responses occurred approximately 4-6 days after incubation of the spleen cells with antigen. Sensitivity of spleen cells from animals immunized with Legionella vaccine in adjuvant persisted for at least 150 days, while responses after infection of guinea pigs with viable bacteria persisted about 4-6 weeks. The blastogenic responses of the spleen cells to Legionella antigen appeared to be a correlate of cell-mediated immunity.

Analgesic properties of meperidine, amitriptyline and phenelzine in mice

Sixty-three white Swiss Webster mice were divided into seven equal groups. Their tolerance to pain (heat applied to the tail by a test tube containing hot water at a temperature measured by telethermometry) was assessed before and after intraperitoneal injection of (1) physiologic saline; (2) meperidine 14 micrograms X g-1; (3) amitriptyline 6 micrograms X g-1 (4) amitriptyline 12 micrograms X g-1; (5) phenelzine 1.5 micrograms X g-1; (6) phenelzine 3 micrograms X g-1; and (7) amitriptyline 6 micrograms X g-1 plus phenelzine 1.5 micrograms X g-1. All post-injection tests were conducted 45 and 90 minutes after administration, and repeated 24 hours later. No significant difference in pain threshold was noted in any pre-injection test or in any test conducted with physiologic saline. By 90 minutes post-injection, all groups receiving drugs developed increased tolerance to pain. Mice which had received phenelzine plus amitriptyline, or either dose of phenelzine were more tolerant to pain for up to 24 hours than mice which had received physiologic saline. The most marked increases in tolerance to pain were seen with 1.5 micrograms X g-1 and 3 micrograms X g-1 of phenelzine and phenelzine plus amitriptyline. However, phenelzine was more effective and had a longer-lasting effect than either dose of amitriptyline, or meperidine. The combination of phenelzine plus amitriptyline was no more effective than phenelzine alone.

Cellular immunity to Legionella pneumophila in guinea pigs assessed by direct and indirect migration inhibition reactions in vitro

Spleen cell cultures from guinea pigs given legionella pneumophila vaccine in complete Freund adjuvant or as a sublethal infection were inhibited in their migration activity in vitro when incubated with specific antigen. Both direct and indirect migration inhibition assays revealed sensitization of the guinea pigs to the bacterium, with demonstrable reactivity 25 to 40 days or more after sensitization. No consistent reactions occurred when the guinea pigs were given the killed Legionella vaccine in incomplete Freund adjuvant in saline. However, spleen cells from guinea pigs injected with sublethal doses of the Legionella vaccine 3 to 4 weeks earlier showed positive migration inhibition factor reactivity. Cutaneous hypersensitivity and lymphocyte blastogenic responsiveness in vitro also developed in guinea pigs sensitized with killed Legionella vaccine in complete adjuvant or given a sublethal infection with the bacterium. These results indicate that in vitro assays for migration inhibitory activity may be utilized to monitor the development of the sensitization of guinea pigs to L. pneumophila, and such reactions correlate with skin reactivity and in vitro lymphocyte blastogenic responses.

Agar microdroplet assay for delayed hypersensitivity to Legionella pneumophila serogroup 1

An agarose microdroplet technique was utilized to assess the cellular immunity of guinea pig lymphoid cells to Legionella pneumophila antigen in vitro. Both direct and indirect migration inhibition procedures were shown to be capable of detecting sensitization of guinea pigs to L. pneumophila antigens. Animals injected with adjuvant alone or unrelated antigens did not yield spleen cells responsive to L. pneumophila, indicating the specificity of the response. Migration inhibition factor induction by Legionella antigen in vitro correlated well with skin test responses in vivo. The positive reaction detected by migration inhibition occurred at times similar to that of skin reactivity but later than that of the earliest serum antibody titers. The assay appears to be useful for monitoring sensitization to Legionella and may be applicable to the study of cell-mediated immunity to this bacterium in infected individuals.

Physiological characteristics of tremor after chronic lithium therapy

Twenty-three patients taking lithium carbonate alone in therapeutic dosage for a mean period of 43 months (range 6--108 months) and 23 control subjects matched for age and sex had the frequency and amplitude of postural tremor measured and extrapyramidal symptoms assessed by standard techniques. Patients on lithium had a significantly lower peak frequency of tremor than control subjects (P less than 0.05) and significantly greater extrapyramidal symptoms (P less than 0.01), indicating that tremor appearing after chronic lithium therapy is likely to be an extrapyramidal symptom. Such symptoms are common long-term adverse effects of lithium carbonate.