Expression of the leukemia-associated gene, p18, in normal and malignant tissues; inactivation of expression in a patient with cleaved B cell lymphoma/leukemia

p18 is a well conserved gene coding for an 18 kDa cytosolic phosphoprotein. Although the function of p18 is unknown, it is suspected of playing a role in regulation of cell proliferation or the proliferation-differentiation switch. Here we have found p18 mRNA expression highest in testis, brain, thymus and a multipotent hematopoietic stem cell line and lowest in liver. p18 was also expressed vigorously in all but one of 85 diverse tumor cell lines and primary human malignant specimens examined. In five primary tumors, expression was substantially elevated with respect to expression in contiguous normal tissue. Expression in chronic phase chronic myelogenous leukemia cells was far greater than in normal blood cells and increased with progression of disease. In liver material, the highest level of p18 was found in a primary hepatoblastoma, a stem cell tumor, whereas a benign adenoma demonstrated very low level expression. Cells from a cleaved B cell lymphoma/leukemia failed to express p18 whereas 18 specimens from other B lymphoid malignancies, including a second cleaved cell malignancy, expressed p18 at substantial levels. These data are consistent with p18 playing a role in control of cell proliferation in at least certain tissues. The questions arise if high level p18 expression in certain malignancies may play a primary role in driving cell proliferation or, based on chromosomal localization and inactivation of p18 expression in one lymphoma, if p18 may act as a tumor suppressor.

Equine cricoid cartilage densitometry

The density of the cricoid cartilage from 29 equine larynges collected from an abattoir was determined by dual photon absorptiometry (DPA). Densities of the right and left cricoid cartilages were highly correlated. No correlation was found between age of the horse and the density of the cricoid cartilage.

MHC restriction of T-cell proliferative responses in Xenopus

The MHC restriction of Xenopus allogeneic MHC- and antigen-specific T-cell proliferative responses was assessed. Xenopus MHC-specific monoclonal antibodies that recognize class I and class II molecules were tested for inhibitory effects on the generation of secondary T-cell proliferative responses. Antigen-specific T-cell lines were inhibited by anti-class II but not anti-class I monoclonal antibodies. Secondary alloantigen-specific proliferative responses also demonstrated MHC class II restriction. Allogeneic MHC- and antigen-specific T-cell lines demonstrated differential sensitivity to anti-class II monoclonal antibodies directed at discrete class II epitopes. These results indicate that Xenopus T cells interact with antigen-presenting cells similarly to mammals, and directly confirm previous data indicating that MHC class II restriction of proliferative responses is present in amphibians.

Summary report from the first international workshop on soluble HLA antigens. Paris, August 1992

The First International Workshop on Soluble HLA antigens focused on the comparison of immunoassay procedures for quantitation of soluble HLA (sHLA) class I antigens and the selection of a sHLA class I antigen international standard. Several sets of serum, plasma, and cell culture supernatant specimens were assayed blindly for levels of sHLA class I antigens by 15 participating laboratories using different immunoassay formats. The sandwich ELISA using (i) for antigen capture: an anti-HLA class I heavy chain monoclonal antibody (mAb) specific for a monomorphic epitope, and (ii) for antigen detection: an anti-beta 2 microglobulin antibody-enzyme conjugate, was the assay format of choice. There was a high inter-laboratory correlation among the majority of laboratories. All serum and plasma specimens from normal donors, and from a single transplant patient, had detectable levels of sHLA class I antigens. Paired serum and plasma specimens had similar levels of sHLA class I antigens, although plasma sHLA antigens seemed more stable than serum sHLA antigens. sHLA-A2 and sHLA-B7 antigens were detected in all specimens from HLA-A2 and HLA-B7 donors, respectively, using allele-specific ELISAs. No difference in reactivity was observed for quantitation of native sHLA class I antigens whether the capture mAb was TP25.99 (alpha 3 domain-specific) or W6/32 (alpha 2 + alpha 3-specific). However, a human-mouse chimeric sHLA class I antigen reacted weakly in assays which used TP25.99 mAb. The wide variation among laboratories in their reporting of micrograms/ml units pointed to the need for an inter-laboratory standardization based on a calibrated sHLA antigen preparation. T.sB7, an sHLA-B7 antigen derived from a cell line transfected within human beta 2 microglobulin and HLA-B7 genes, was accepted as the First sHLA class I Antigen International Standard at the workshop meeting.

Hypertension and a tumor of the glomus jugulare region. Evidence for epinephrine biosynthesis

Glomus jugulare tumors have been reported to secrete norepinephrine and cause severe hypertension with features similar to pheochromocytoma. In contrast, epinephrine secretion has not been observed in these neoplasms. This has been attributed to the absence of the norepinephrine-methylating enzyme, phenylethanolamine-N-methyltransferase (PNMT), required for epinephrine synthesis. We report a patient with severe hypertension caused by a glomus tumor that secreted norepinephrine and epinephrine. Following selective venous sampling, catecholamines were quantified by radioenzymatic assay. Marked elevations in norepinephrine and epinephrine release were localized to the glomus tumor. The enzymes involved in catecholamine biosynthesis, including PNMT and tyrosine hydroxylase, were identified immunocytochemically in the tumor. The glomus tumor had staining patterns identical to those observed within normal rat glomus cell. Hypertension resolved with resection of the functioning tumor. This is the first report of PNMT in a functioning paraganglioma of the glomus jugulare region. The factors that determine why functional activity is expressed only rarely by paraganglioma remain undefined.

Dissociation of blood pressure and albuminuria in normal subjects infused with angiotensin II and noradrenaline

1. Albuminuria is a predictor of diabetic renal disease and atherosclerosis. Changes in blood pressure (BP) may influence albuminuria. 2. The effect of acute BP elevation on albumin excretion rates (AER) using noradrenaline (NA) and angiotensin II (AII) infusions in six normal subjects was examined. 3. The average rise in BP during a 120 min infusion was 23 mmHg for AII and 16 mmHg for NA. 4. There was a marked dissociation between AER and BP levels in both AII and NA infusions. 5. Previously described correlations between BP and AER in ambulatory BP studies may be explained by other factors such as exercise and postural changes.

Hereditary angioneurotic edema with severe hypovolemic shock

Hereditary angioneurotic edema (HAE) is characterized by recurrent attacks of edema of the upper airways, face, and limbs, and/or abdominal pains sometimes mimicking surgical abdomen. Our patient, a 24-year-old woman, had undergone laparotomy on a previous attack, at which a large amount of serious peritoneal fluid and edema of the intestinal wall were found. This time she presented with severe abdominal pain and profound hypovolemic shock requiring replacement of great amounts of fluids in addition to fresh frozen plasma. There was no evidence of bleeding, and the patient recovered rapidly. Based on clinical and ultrasonographic grounds and findings on previous laparotomy, we concluded that the shock was produced by fluid sequestration in the peritoneal cavity and intestinal wall. We propose that patients with HAE who present with abdominal pain, hypotension, hemoconcentration, and leukocytosis form a distinct subgroup with a high risk of hypovolemic shock. This dangerous development should be anticipated in these patients.

The Drosophila Ras2 and Rop gene pair: a dual homology with a yeast Ras-like gene and a suppressor of its loss-of-function phenotype

The promoter of the Drosophila melanogaster Ras2 gene is bidirectional, regulating an additional gene oriented in the opposite polarity. The two divergently transcribed genes are only 93 bases apart and deletion analysis proved that common cis-acting elements within this promoter region are required for the transcriptional activity of both genes. We cloned the gene paired with Ras2 in the bidirectional promoter and isolated cDNAs corresponding to its mRNA. The Ras opposite (Rop) gene encodes for a 68 × 10(3) M(r) protein which shares sequence homology with the members of a novel Saccharomyces cerevisiae gene family, including the SLY1, SEC1 and VPS33 (SLP1) genes, all of which are involved in vesicle trafficking among yeast cellular compartments. A highly conserved motif in this family is also found in beta-COP, a coat protein isolated from rat Golgi-bound nonclathrin vesicles. Thus, the Rop protein may be a component of one of the vesicle trafficking pathways in Drosophila cells. The Rop gene expression during embryogenesis is restricted to the central nervous system (CNS) and the garland cells, a small group of nephrocytes that takes up waste materials from the haemolymph by endocytosis. Ras2 is also expressed in the embryonic garland cells. In postembryonic stages, the two genes are co-expressed in the larval salivary glands and the central nervous system, and in the adult CNS and reproductive systems. Interestingly, the S. cerevisiae SLY1-20 allele is a suppressor of the loss of the YPT1 gene, a ras-like gene implicated in vesicle translocation, suggesting that the two genes may interact with one another. Since Sec1p and beta-COP may also interact with small GTP-binding proteins of the ras superfamily, it is conceivable that the Rop and Ras2 gene products are not just co-expressed in common tissues, but may also functionally interact with one another in these tissues.

Exposure to conspecific alarm chemosignals alters immune responses in BALB/c mice

Male BALB/cJ mice were exposed for 24 h to odors from donor mice that were either footshocked or undisturbed. Mice exposed to odors from footshocked donors had suppressed splenic IL-2 production following in vitro concanavalin A (Con A) stimulation compared to home cage or apparatus controls. Stress odor exposure also resulted in reduced natural killer (NK) cell cytotoxicity against YAC-1 tumor target cells compared to controls. Stress odor exposure 24 h after intraperitoneal injection of keyhole limpet hemocyanin (KLH) increased IgM and IgG antibody titers relative to the response of home cage or apparatus control animals. These results demonstrate that exposure to olfactory cues from stressed rodents alters both cellular and humoral immune responses. This paradigm may provide an ethnologically appropriate model of psychosocial stress in rodents.

Transforming growth factor beta (TGF beta) is produced by and influences the proliferative response of Xenopus laevis lymphocytes

Both TGF beta 2 and 5 have been described in the South African clawed frog Xenopus laevis and have been cloned from the tadpole-derived fibroblast cell line, XTC. Because TGF beta has such a profound inhibitory effect on the mammalian immune system, this study was performed to determine whether TGF beta: (a) has any in vitro effects on the growth of Xenopus lymphoblasts, and (b) is produced by mitogen-activated Xenopus lymphocytes. Following stimulation with mitogen or alloantigen, T lymphocytes from Xenopus secrete a T-cell growth factor (TCGF) that is functionally homologous to mammalian interleukin-2 (IL-2). Both recombinant human TGF beta 1 and Xenopus TGF beta 5 inhibit TCGF-induced proliferation of Xenopus splenic blasts and this inhibition can be reversed with anti-pan TGF beta antiserum. The Xenopus mitogen-induced saturated ammonium sulfate precipitated TCGF-containing supernatant (SAS TCGF SN) also contains latent TGF beta as assayed on mink lung fibroblasts and Xenopus splenic blasts, and experiments utilizing anti-TGF beta antiserum showed that only TGF beta 5 is present in this supernatant.

Further characterization of an interleukin-2-like cytokine produced by Xenopus laevis T lymphocytes

A T-cell growth factor (TCGF) is produced by antigen- or mitogen-stimulated T lymphocytes from the South African clawed frog Xenopus laevis. This study further defines the physical and biological properties of this cytokine and demonstrates that TCGF is biochemically similar to mammalian interleukin-2 (IL-2). Biologically active TCGF eluted from SDS-PAGE displays a M(r) of 16 kD and lectin-affinity chromatography indicates that the three-dimensional configuration of carbohydrates on TCGF and human IL-2 is similar. Secretion of TCGF is detectable 1 day after stimulation of splenocytes with the T-cell mitogen phytohemagglutinin (PHA) and peaks following 2 to 3 days of stimulation. Finally, despite the biological and physical similarities between Xenopus TCGF and mammalian IL-2, anti-human IL-2 monoclonal antibodies do not recognize Xenopus TCGF.

Psychoneuroimmunology: conditioning and stress

The acquisition and extinction of the conditioned suppression or enhancement of one or another parameter of antigen-specific and nonspecific defense system responses have been documented in different species under a variety of experimental conditions. Similarly, stressful stimulation influences antigen-specific as well as nonspecific reactions. Moreover, both conditioning and stressful stimulation exert biologically meaningful effects in the sense that they can alter the development and/or progression of what are presumed to be immunologically mediated pathophysiologic processes. These are highly reproducible phenomena that illustrate a functional relationship between the brain and the immune system. However, the extent to which one can generalize from one stressor to another or from one parameter of immunologic reactivity to another is limited. Few generalizations are possible because the direction and/or magnitude of the effects of conditioning and "stress" in modulating immune responses clearly depend on the quality and quantity of the behavioral interventions, the quality and quantity of antigenic stimulation, the temporal relationship between behavioral and antigenic stimulation, the nature of the immune response and the immune compartment in which it is measured, the time of sampling, a variety of host factors (e.g. species, strain, age, sex), and interactions among these several variables. It seems reasonable to assume that the immunologic effects of behaviorally induced neural and endocrine responses depend on (interact with) the concurrent immunologic events upon which they are superimposed. Conversely, the efficacy of immunologic defense mechanisms seems to depend on the neuroendocrine environment on which they are superimposed. We seek to determine when and what immunologic (or neuroendocrine) responses could be affected by what neuroendocrine (or immunologic) circumstances. We therefore need studies that provide a parametric analysis of the stimulus conditions, the neuroendocrine and/or immunologic state upon which they are superimposed, and the responses that are being sampled. The neural or neuroendocrine pathways involved in the behavioral alteration of immune responses are not yet known. Both conditioning and stressor-induced effects have been hypothesized to result from the action of adrenocortical steroids, opioids, and catecholamines, among others. Indeed, all of these have been implicated in the mediation of some immunologic effects observed under some experimental conditions. We assume that different conditioning and stressful environmental circumstances induce different constellations of neuroendocrine responses that constitute the milieu within which ongoing immunologic reactions and the response to immunologic signals occur.(ABSTRACT TRUNCATED AT 400 WORDS)

Effect of dietary manipulations on glomerular filtration rate of mice offspring of nephrectomized mothers

We have previously reported that mice, offspring to uninephrectomized mothers, have greater than normal kidneys with supernumerary glomeruli. In this study we assessed glomerular filtration rate (GFR) in 40 mice offspring of nephrectomized mothers and 40 mice offspring of sham-nephrectomized animals aged 7 weeks. Each group was divided into 4 equal subgroups according to the following dietary manipulations: regular, high protein, high salt and high protein/high salt. At the end of 1 week, GFR was determined by 51Cr EDTA. In the first group, GFR was significantly greater in each experimental subgroup compared to control. In the offspring of sham-nephrectomized mothers, only the subgroup on the combined diet had a significantly greater GFR. We conclude that the capacity to raise GFR in response to dietary manipulations is greater in offspring of nephrectomized mothers. It remains to be elucidated whether the difference results from the increased number of nephrons or from an augmented single nephron GFR reserve.

[Cimetidine hepatitis]

A 41-year-old man with rheumatoid arthritis developed severe acute hepatitis 3 days after starting cimetidine for duodenal ulcer. Other causes were ruled out and he recovered after cimetidine was discontinued. Mild transient elevations of hepatic enzymes have been reported in 3.6% of patients taking cimetidine. However, only 12 cases of severe acute hepatitis associated with cimetidine, mostly secondary to idiosyncrasy, have been reported in the English literature. This rare but serious complication of cimetidine should be kept in mind.

High brain densities of the immunophilin FKBP colocalized with calcineurin

The immunophilins cyclophilin and FK506 binding protein (FKBP) are small, predominantly soluble proteins that bind the immunosuppressant drugs cyclosporin A and FK506, respectively, with high affinity, and which seem to mediate their pharmacological actions. The Ca(2+)-dependent protein phosphatase, calcineurin, binds the cyclophilin-cyclosporin A and FKBP-FK506 complexes, indicating that calcineurin might mediate the actions of these drugs. A physiological role for the immunophilins in the nervous system is implied by a close homology between the structure of NINA A, a protein in the neural retina of Drosophila, and cyclophilin, as well as by the high density of FKBP messenger RNA in brain tissue. Here we report that the levels of FKBP and mRNA in rat brain are extraordinarily high and that their regional localization is virtually identical to that of calcineurin, indicating that there may be a physiological link between calcineurin and the immunophilins. We also show that at low concentrations FK506 and cyclosporin A enhance the phosphorylation of endogenous protein substrates in brain tissue and in intact PC12 cells, indicating that these drugs may inhibit phosphatase activity by interacting with the immunophilin-calcineurin complexes.

Vestibuloocular reflex of rhesus monkeys after spaceflight

The vestibuloocular reflex (VOR) of two rhesus monkeys was recorded before and after 14 days of spaceflight. The gain (eye velocity/head velocity) of the horizontal VOR, tested 15 and 18 h after landing, was approximately equal to preflight values. The dominant time constant of the animal tested 15 h after landing was equivalent to that before flight. During nystagmus induced by off-vertical axis rotation (OVAR), the latency, rising time constant, steady-state eye velocity, and phase of modulation in eye velocity and eye position with respect to head position were similar in both monkeys before and after flight. There were changes in the amplitude of modulation of horizontal eye velocity during steady-state OVAR and in the ability to discharge stored activity rapidly by tilting during postrotatory nystagmus (tilt dumping) after flight: OVAR modulations were larger, and tilt dumping was lost in the one animal tested on the day of landing and for several days thereafter. If the gain and time constant of the horizontal VOR change in microgravity, they must revert to normal soon after landing. The changes that were observed suggest that adaptation to microgravity had caused alterations in way that the central nervous system processes otolith input.

Adjuvant effects of freely ingested cholera toxin on systemic antibody and DTH responses to protein antigen

Recent evidence suggests that immunological handling of antigen in the gut may be different when animals voluntarily ingest antigen in their drinking fluid. Therefore, we investigated whether the adjuvant effects of CT were evident in mice that voluntarily ingested CT together with keyhole limpet hemocyanin (KLH) in 1.0 ml chocolate milk. Initially, it was found that ingestion of 2 mg KLH for up to four times (one ingestion per week) did not induce serum IgG anti-KLH antibody; however, KLH-specific IgG was detected if KLH was ingested together with 10 micrograms CT. Furthermore, 50 days after only one ingestion of CT+KLH, the serum IgG response to intraperitoneal challenge with 100 micrograms KLH was significantly elevated with respect to the response of mice who previously had ingested either KLH alone, CT alone, or drinking fluid only. This observation was repeated in further experiments showing an enhanced IgG response to 100 micrograms KLH ip given 7 or 14 days after a single ingestion of 2 or 5 mg KLH mixed with different doses (0.5-20 micrograms) CT. The lowest effective CT dose for serum IgG anti-KLH adjuvanticity was found to be 1 microgram; the highest effective dose was 10 micrograms, there being no additive effect with 20 micrograms CT. It was also found that simultaneous ingestion of KLH (2 or 5 mg) with CT (0.5-20 micrograms) followed 7 or 14 days later by 100 micrograms KLH ip, increased the 24 hr footpad DTH response to 50 micrograms KLH administered 43 days after the ip challenge.(ABSTRACT TRUNCATED AT 250 WORDS)

Conditioned immunopharmacologic effects on cell-mediated immunity

One of the several lines of evidence documenting a relationship between the brain and the immune system is the research on behaviorally induced alterations in immune reactivity. The present review concentrates on the use of immunopharmacologic agents, stress, and antigenic stimuli as unconditioned stimuli (UCSs) in the classically conditioned suppression and enhancement of cell-mediated immune reactions including host-vs-graft and graft-vs-host reactions and delayed type hypersensitivity.

Mechanistic implications of alterations in HL-60 cell nascent DNA after exposure to 1-beta-D-arabinofuranosylcytosine

To improve our understanding of the mechanism of 1-beta-D-arabinofuranosylcytosine (ara-C) incorporation into DNA, we investigated the physical properties (size, position of nucleoside incorporation) of small fragments of nascent DNA (nDNA) obtained by pH-step alkaline elution of intact HL-60 cells following their exposure to ara-C. In the pH-step alkaline elution procedure, the smallest fragments of nDNA elute at pH 11. Anion-exchange high-performance liquid chromatography (HPLC) of nDNA obtained by 1 h elution at pH 11.0 of lysed HL-60 cells revealed a preponderance of nDNA fragments ranging from 0.5 to 40 kb in control ([3H]-dThd-labeled) cells. Exposure of cells to ara-C (0.8-1 microM) resulted in a loss of the preponderance of radiolabel in fragments of 0.5-40 kb along with redistribution of the radiolabel (from [3H]-dThd or [3H]-ara-C) into smaller nDNA fragments (predominantly < 100 bases in length) as determined by HPLC. We used the ability of pH-step alkaline elution to provide these small nDNA fragments produced by ara-C to investigate the paradoxical behavior of ara-C as a chain terminator in cell-free DNA synthetic systems while being incorporated into an internucleotide position in intact cells. Following the digestion of purified nDNA with micrococcal nuclease and spleen phosphodiesterase II, the proportion of radiolabel in 3'-dNMP (indicating an internucleotide position) or free nucleoside (indicating a chain terminus position) was determined by reverse-phase HPLC. In digests of prelabeled genomic DNA, as expected, > 90% of the radiolabel from [14C]-dThd or [3H]-ara-C was found to exist in an internucleotide position (as determined by co-chromatography with authentic 3'-dTMP or 3'-ara-CMP). In contrast, digests of nDNA that eluted at pH 11.0 revealed a significantly higher proportion of radiolabel in the chain terminus position (29%-35%) when the nDNA was obtained from cells exposed to 1 microM [3H]-ara-C as compared with cells exposed to [3H]-dThd or [3H]-dCyd alone (< 10%). These data obtained from pH-step alkaline elution of intact cells suggest that by causing the inhibition of chain elongation while failing to inhibit the formation of new nDNA replication intermediates, ara-C exposure leads to the production of very small nDNA fragments. This relative chain-terminating effect of ara-C is most apparent in the small nDNA replication fragments that elute at pH 11.0.(ABSTRACT TRUNCATED AT 400 WORDS)

Postnephrectomy mesangial cells secrete a factor(s) that stimulate(s) tubular cell growth in vitro

Rat kidney mesangial cells were procured from 5 sham-operated and 10 previously uninephrectomized rats. They were grown in cell culture medium supplemented with 20% fetal calf serum. Cell free conditioned medium was collected on the 10th day. Tubular cell cultures were then prepared from 18 normal unoperated 3-week-old rats. Tubular cells from each separate kidney sample were grown in pooled-mesangium conditioned medium from sham-operated or from nephrectomized rats, supplied with 20% pooled serum from either sham-operated or nephrectomized animals. 3H-thymidine incorporation of normal tubular cell cultures grown in nephrectomy mesangium conditioned medium supplemented with sera from nephrectomized animals proved to be significantly greater than that of any of the other three experimental variations. No statistically significant difference was evident when either preconditioned medium of postnephrectomy mesangial cells or postnephrectomy serum were used alone.