Spermiogenesis is impaired in mice bearing a targeted mutation in the protein phosphatase 1cgamma gene

Type 1 protein phosphatases (PP1) are involved in diverse cellular activities, ranging from glycogen metabolism to chromatin structure modification, mitosis, and meiosis. The holoenzymes are composed of two or more subunits, including a catalytic subunit (PP1c) and one or more regulatory subunits. Many eukaryotes possess several catalytic subunit genes which encode highly conserved isoforms. In rodents, one of these isoforms, PP1cgamma2, appears to be expressed predominantly in testes. Whether PP1cgamma2 performs a testis-specific function is unclear. To address this and other questions, the PP1cgamma gene was disrupted by targeted insertion in murine embryonic stem cells. Mice derived from these cells were viable, and homozygous females were fertile. However, males homozygous for the targeted insertion were infertile. Histological examination revealed severe impairment of spermiogenesis beginning at the round spermatid stage. In addition, defects in meiosis were inferred from the presence of polyploid spermatids. Immunohistochemistry revealed the presence of PP1calpha protein on condensing spermatids in both wild-type and mutant testes, suggesting that this closely related isoform is unable to compensate for the loss of PP1cgamma. These defects are discussed in the light of known functions of protein phosphatase 1.

The cdr2(+) gene encodes a regulator of G2/M progression and cytokinesis in Schizosaccharomyces pombe

Schizosaccharomyces pombe cells respond to nutrient deprivation by altering G2/M cell size control. The G2/M transition is controlled by activation of the cyclin-dependent kinase Cdc2p. Cdc2p activation is regulated both positively and negatively. cdr2(+) was identified in a screen for regulators of mitotic control during nutrient deprivation. We have cloned cdr2(+) and have found that it encodes a putative serine-threonine protein kinase that is related to Saccharomyces cerevisiae Gin4p and S. pombe Cdr1p/Nim1p. cdr2(+) is not essential for viability, but cells lacking cdr2(+) are elongated relative to wild-type cells, spending a longer period of time in G2. Because of this property, upon nitrogen deprivation cdr2(+) mutants do not arrest in G1, but rather undergo another round of S phase and arrest in G2 from which they are able to enter a state of quiescence. Genetic evidence suggests that cdr2(+) acts as a mitotic inducer, functioning through wee1(+), and is also important for the completion of cytokinesis at 36 degrees C. Defects in cytokinesis are also generated by the overproduction of Cdr2p, but these defects are independent of wee1(+), suggesting that cdr2(+) encodes a second activity involved in cytokinesis.

A physical map of 30,000 human genes

A map of 30,181 human gene-based markers was assembled and integrated with the current genetic map by radiation hybrid mapping. The new gene map contains nearly twice as many genes as the previous release, includes most genes that encode proteins of known function, and is twofold to threefold more accurate than the previous version. A redesigned, more informative and functional World Wide Web site (www.ncbi.nlm.nih.gov/genemap) provides the mapping information and associated data and annotations. This resource constitutes an important infrastructure and tool for the study of complex genetic traits, the positional cloning of disease genes, the cross-referencing of mammalian genomes, and validated human transcribed sequences for large-scale studies of gene expression.

Accuracy of medical records in hip fracture

OBJECTIVE

To determine the accuracy of diagnoses and procedure codes in medical records for hip fracture patients.

DESIGN

A validation sample of hip fracture medical records was used to compare the facesheet data with progress notes, operative reports, and discharge summaries for patients in a prospective study of functional recovery.

SETTING

Eight Baltimore hospitals with the highest volume of older hip fracture patients.

PATIENTS

Study subjects were 343 community-dwelling patients, 65 years of age and older, admitted to one of eight Baltimore hospitals between January 1990 and June 1991 with a diagnosis of hip fracture.

MAIN OUTCOME MEASURES

Facesheet diagnosis codes were compared with admitting notes, discharge summary, and/or progress notes. The abstracted surgical procedure was compared with postoperative radiographs.

RESULTS

Excess coding of diagnoses on the hospital facesheet was evident in 12% of charts. In 17% of charts, a complication identified in the chart was not coded on the facesheet. More complications with low severity were omitted. Agreement between the abstractor's procedure review and radiograph readings for arthroplasty was 84%. In 15% of patients, the abstractor coded total arthroplasty when hemiarthroplasty was done.

CONCLUSIONS

Discrepancy between the hospital facesheet and the medical record and between the abstracted surgical procedure and radiographs was found for hip fracture patients. This may make findings from health outcomes research relying on administrative databases uncertain and reimbursement inaccurate.

Measurement of elastic-like behaviour in the power squat

Because traditional procedures of evaluating elastic-like behaviour have yielded mixed results, the purpose of this work was to explore two methods of measuring elastic-like behavior in the power squat. The entire concentric time method was based on traditional procedures. The initial concentric time method was developed to examine elastic-like behavior for the beginning 0.2 s of concentric movement. The present study compares a power squat performed maximally by nine subjects at 70% of their 1 repetition maximum. Squats were performed with rebound (REB) and without rebound (NRB). For the entire concentric time method only concentric time was significantly greater (p < 0.05) in the NRB than the REB. For the initial concentric time method the relative displacement, velocity, net work, & peak power of the center of mass were significantly greater (p < 0.05) in the REB than the NRB. Some subjects had theoretically infeasible negative results for elastic enhancement in the entire concentric time method, but not the initial concentric time method. It seems that measuring elastic-like behavior near the end of the movement can be confounded by the constraints of the task. Based on its success, the initial concentric time method appears to be more appropriate for measurement of elastic-like behavior in lifting.

Effect of fenfluramine challenge on cocaine craving in addicted male users

The authors studied the effects of a challenging dose of the serotonin (5-HT)-releaser/reuptake inhibitor d,l-fenfluramine (FEN) on spontaneous cocaine craving in a group of cocaine-addicted users in order to evaluate the involvement of serotonergic pathways in the modulation of craving for cocaine. Nineteen cocaine-dependent male inpatients received 60 mg of FEN or placebo (double-blind). Data were compared with those obtained in a previous study of another serotonergic probe, the partial postsynaptic agonist meta-chlorophenyl-piperazine (m-CPP). FEN significantly reduced cocaine craving and increased cortisol and prolactin when compared with placebo. When the responses to the two drugs were compared, there were no differences in the cortisol and prolactin rises, but m-CPP was a more potent inhibitor of cocaine craving than FEN. These data suggest that 5-HT releasers/reuptake inhibitors and serotonergic agents with greater postsynaptic activity should be further examined.

Does the Composite International Diagnostic Interview underdiagnose the eating disorders?

OBJECTIVE

A study was undertaken to assess the procedural validity of the Composite International Diagnostic Interview (CIDI) for the diagnosis of eating disorders.

METHOD

The CIDI was administered to 44 patients consecutively admitted to an eating disorders unit. CIDI-generated diagnoses were compared with clinical diagnoses documented in patient files. Discrepancies between diagnoses were examined in detail.

RESULTS

A significant level of disagreement was apparent, particularly for anorexia nervosa patients. A large number of patients with symptoms requiring inpatient treatment did not reach criteria using CIDI's diagnostic algorithm.

CONCLUSION

Considerable difficulties remain in the use of standardized assessments, such as the CIDI, to diagnose eating disorders. While presenting features of the illness, for example, ego syntonic nature of the illness, secrecy, and denial, may be part of the reason, the questions used by the CIDI appear to be in need of some refinement.

Outcome after hemiarthroplasty for femoral neck fractures in the elderly

A prospective outcome study was performed on 270 patients, 65 years of age and older, who sustained a femoral neck fracture and underwent hemiarthroplasty. The treatment compared was the use of a noncemented unipolar versus either a cemented or a press fit bipolar prosthesis. The outcome variables assessed included the occurrence of a postoperative complication, length and cost of hospitalization, and function in various quality of life measurements. Patients who underwent bipolar hemiarthroplasty with either a cemented or a press fit prosthesis had better pain relief and function than patients who had a noncemented unipolar prosthesis at a minimum of 24 months after surgery. However, the mean hospitalization cost for patients who had a bipolar prosthesis was $12,290 compared with $8876 for a unipolar prosthesis.

A first-generation whole genome-radiation hybrid map spanning the mouse genome

We have assembled a first-generation anchor map of the mouse genome using a panel of 94 whole-genome-radiation hybrids (WG-RHs) and 271 sequence-tagged sites (STSs). This is the first genome-wide RH anchor map of a model organism. All of the STSs have been previously localized on the genetic map and are located 8.8 Mb apart on average. This mouse WG-RH panel, known as T31, has an average retention frequency of 27.6% and an estimated potential resolution of 145 kb, making it a powerful resource for efficient large-scale expressed sequence tag mapping. [All of the mapping data for the maps presented here have been deposited at the Research Genetics, Inc., web site and can be freely accessed and downloaded at http://www.resgen.com/.]

Severe aplastic anaemia in association with a unique constitutional translocation 46,XY,t(6;10)(q13;q22)c

Severe aplastic anaemia (SAA) is an uncommon disorder which may be associated with several congenital syndromes. However, it has rarely been described in association with a constitutional karyotypic abnormality. The breakpoint of the balanced t(6:10)(q13:q22) translocation described here does not disrupt any currently recognized gene of haemopoietic or stromal importance. This report also highlights the problems inherent in the use of bone marrow transplantation (BMT) for treating multiply transfused aplastic anaemia patients.

The meta-chlorophenylpiperazine challenge test in cocaine addicts: hormonal and psychological responses

We report on the neuroendocrine and psychological responsivity of 31 cocaine addicts and 14 controls to the serotonergic agonist, meta-chlorophenylpiperazine (m-CPP) (0.5 mg/kg p.o.). Cocaine addicts were subdivided into subjects with aggressive tendencies and other features similar to those found in type 2 alcoholics and subjects without these features. Following m-CPP, aggressive and nonaggressive patients had a significantly blunted prolactin response compared to controls, but there was no difference between the two patient subgroups. There was no difference between the cortisol responses of nonaggressive patients and controls, but aggressive patients had a significantly blunted cortisol response compared to controls and nonaggressive patients. Both patient subgroups reported more intense "activation-euphoria" and "high" responses following m-CPP than controls. These results could indicate the existence of alterations along serotonergic pathways in cocaine addicts taken as a group. In addition, a subgroup of patients who could be described as type 2 cocaine addicts appear to be biologically different from healthy subjects and from other cocaine addicts as indicated by a greater cortisol blunting following m-CPP.

Hormonal, psychological, and alcohol craving changes after m-chlorophenylpiperazine administration in alcoholics

To assess the serotonergic function of alcoholics, their neuroendocrine and psychological responsivities to the serotonergic partial agonist meta-chlorophenylpiperazine (m-CPP) was compared with the responsitivity of healthy subjects. The effect of m-CPP on craving for alcohol was also assessed in the alcoholics. Sixteen patients and 14 controls were tested under double-blind, placebo-controlled conditions. m-CPP (0.5 mg/kg of body weight) was given orally. Alcoholics were tested after a period of abstinence of 15 to 39 days. The two groups of subjects did not differ in their cortisol response to m-CPP, but the prolactin response of alcoholics was significantly blunted. Alcoholics reported a significantly more intense "high" feeling after m-CPP than the healthy subjects. m-CPP induced also a decreased craving for alcohol. Our data thus provide further evidence for the existence of a serotonergic dysfunction in alcoholics and a modulation of craving for alcohol by serotonergic systems.

Does Behaviour After Weaning Affect the Dominance Status of Adult Male Mice (Mus Domesticus)?

Abstract

To investigate whether behaviour in the litter predicted later dominance status, male mice were observed whilst within their litters from three weeks old, and when paired with an unrelated male as an adult. We found that males that were dominant in their litter were not more likely to become dominant as an adult. The best predictor of adult dominance status was the relative scent marking rate when with littermates, males that marked more than their adult partner were more likely to become dominant. The high scent mark rate of dominant males may be the cause not the consequence of dominance, they scent mark at a higher rate before becoming dominant. It was also shown that there are strong family resemblances for scent mark rate, body weight and most urogenital gland weights. This indicates that scent mark rate and urogenital gland weights may be determined genetically, or partly determined by parental effects. As found in previous work the preputial gland was heavier in dominant males than subordinates. Furthermore, dominant males were lighter than subordinates at the end of the experiment indicating that there may be a cost to maintaining dominance.

Safety and immunogenicity of UBI HIV-1MN octameric V3 peptide vaccine administered by subcutaneous injection

Twenty-four HIV-seronegative men, at high risk of HIV infection, were recruited into a phase I/II safety and immunogenicity trial of a prototype HIV vaccine. The immunogen was a synthetic, monovalent, octameric HIV-1MN V3 peptide in an aluminum hydroxide (alum) adjuvant. The vaccine had been evaluated previously using a standard 0-, 1-, 6-month intramuscular schedule and was found to stimulate neutralizing antibody in 60-90% of volunteers. Participants were randomized to receive either 500 micrograms (n = 10; high dose) or 100 micrograms (n = 10; low dose) of immunogen or placebo (alum alone; n = 4) at 0, 1, and 6 months by subcutaneous injection. Responses to the immunogen were evaluated by enzyme-linked immunosorbent assay (ELISA)-detectable antibody and by proliferative responses. Safety was monitored by both clinical assessment and regular review with a clinical psychologist. No serious adverse experiences were observed following administration of the assigned medication. One individual (placebo) seroconverted while on study, following exposure to HIV. After the vaccination course only four individuals (three high dose and one low dose) had ELISA-detectable antibody against the immunogen. In the evaluable samples, from 19 volunteers, only 7 vaccine recipients (3 high dose and 4 low dose) had demonstrable lymphoproliferative responses to preparations of the immunogen. Subcutaneous administration of its candidate vaccine was safe but did not result in uniform or robust immunological responses.

Craving for cocaine in addicted users. Role of serotonergic mechanisms

Very few studies have examined the role of serotonin (5-HT) in the modulation of craving for cocaine in cocaine-addicted persons. The authors evaluated whether the acute increase in serotonergic neurotransmission after the administration of a challenging dose of the 5-HT partial agonist meta-chlorophenylpiperazine (m-CPP) had an effect on spontaneous cocaine craving. Male inpatients (N = 31) who met DSM-III-R criteria for cocaine dependence completed 2 days of testing (separated by 48 hours) that involved the oral administration of m-CPP (0.5 mg/kg of body weight) or placebo in random order and under double-blind conditions. Patients' craving for cocaine was found to decrease significantly after the administration of m-CPP. These data could provide evidence for a modulation of cocaine craving by 5-HT systems.

Severity of radiographic findings in hip osteoarthritis associated with total hip arthroplasty

OBJECTIVE

The decision to perform total hip arthroplasty (THA) in patients with osteoarthritis (OA) of the hip is based largely on patients' reports of pain and disability and not on radiographic findings of OA. We determine the severity of radiographic OA and its association with disability in patients undergoing THA.

METHODS

Individual radiographic features (osteophytes, joint space narrowing, sclerosis, cysts, deformity) and global severity of hip OA were assessed in 95 consecutive elderly patients with hip OA undergoing THA who were enrolled in a Patient Outcome Research Team (PORT) project.

RESULTS

Eighty-seven patients (91.5%) had either severe or moderate OA in the hip to be replaced; 17% of these had a previous contralateral THA. Only 8 patients (8.4%) had mild or no signs of OA in the hip to be replaced and 4 (50%) of these patients had their opposite hip replaced previously.

CONCLUSION

These data indicate that radiographic features of moderate to severe hip OA are associated with clinical findings and the necessity to perform THA in the majority of patients. Patients who have had a prior hip replacement, however, may be more likely to have a contralateral replacement done earlier (p = 0.03), before radiographic signs are evident.

Antibody ligation of CD9 modifies production of myeloid cells in long-term cultures

The KMC8.8 monoclonal antibody was made by immunizing rats with the BMS2 stromal cell clone, and was selected for further study because its ability to inhibit production of myeloid cells in Dexter cultures but not that of lymphoid cells in Whitlock-Witte cultures. The influence on myeloid progenitors might have been indirect, since the antibody did not prevent responsiveness to colony-stimulating factors in semisolid agar cultures. Furthermore, there was no inhibition, and some augmentation, of cell production when the antibody was added to established Dexter cultures. A cDNA clone that encoded the KMC8.8-recognized molecule was isolated by expression cloning and found to be identical in sequence to a previously published murine CD9 homologue. The antibody and cDNA clone were used to establish that CD9 is expressed by stromal cells, megakaryocytes, platelets, myeloid cells, and subpopulations of mature lymphocytes in mice. Treatment with the KMC8.8/CD9 antibody slightly augmented adhesion between myeloid cells and stromal cells, consistent with previous reports that this member of the tetraspan family of proteins can transmit proadhesive signals to human platelets and lymphoid cells. CD9 might participate in cell-cell interactions critical for correct orientation and movement of maturing myeloid cells in bone marrow.

Effect of ultraviolet-B light on lymphocyte activity at doses at which normal bone marrow stem cells are preserved

Ultraviolet B (UVB) light is known to be immunosuppressive, but, probably because of a small UVC component in the emission spectra of some of the UVB lamps used, reports vary on effective dose levels. To prevent potentially lethal graft-versus-host disease (GVHD) after allogeneic bone marrow transplantation, alloreactive donor T-cell activity must be suppressed. In this study, a narrow wavelength UVB lamp (TL01, 312 nm peak emission) was used to determine what doses of UVB were required to abolish rat lymphocyte proliferation while simultaneously preserving rat bone marrow progenitor cell and primitive hematopoietic stem cell viability. Lymphocyte proliferation, as measured by 3H-Thymidine incorporation, in response to lectin stimulation was abolished below detection at doses greater than 3,500 J/m2. When T-cell clonogenicity was measured in a limiting dilution assay, a small fraction (0.6%) was maintained at doses up to 4,000 J/m2. Cytotoxic T-lymphocyte (CTL) activity was reduced after treatment with 4,000 J/m2, but a significant level of cytotoxicity was still maintained. Natural killer cell cytolytic activity was not affected by doses up to 4,000 J/m2. At 4,000 J+m2 there was a 10% survival of colony-forming units-granulocyte-macrophage; a 1% and 4% survival of day-8 and day-12 colony-forming units-spleen, respectively; and 11% survival of marrow repopulating ability cells. Up to 25% of late cobblestone area forming cells (4 to 5 weeks), reflecting the more immature hematopoietic stem cells, were preserved in bone marrow treated with 4,000 J/m2, indicating that early stem cells are less sensitive to UVB damage than are more committed progenitor cells. Thus, a potential therapeutic window was established at approximately 4,000 J/m2 using this light source, whereby the potentially GVHD-inducing T cells were suppressed, but a sufficient proportion of the cells responsible for engraftment was maintained.

PCR amplification of short tandem repeat sequences allows serial studies of chimaerism/engraftment following BMT in rodents

Animal models of bone marrow transplantation (BMT) allow evaluation of new experimental treatment strategies. One potential strategy involves the treatment of donor marrow with ultra-violet B light to allow transplantation across histocompatibility boundaries without an increase in graft rejection or graft-versus-host disease. A major requirement for a new experimental protocol, particularly if it involves manipulation of the donor marrow, is that the manipulated marrow gives rise to long-term multilineage engraftment. DNA based methodologies are now routinely used by many centres to evaluate engraftment and degree of chimaerism post-BMT in humans. We report the adaptation of this methodology to the serial study of engraftment in rodents. Conditions have been defined which allow analysis of serial tail vein samples using PCR of short tandem repeat sequences (STR-PCR). These markers have been used to evaluate the contribution of ultraviolet B treated marrow to engraftment following BMT in rodents without compromising the health of the animals under study. Chimaerism data from sequential tail vein samples and bone marrow from selected sacrificed animals showed excellent correlation, thus confirming the validity of this approach in analysing haemopoietic tissue. Thus the use of this assay may facilitate experimental studies in animal BMT.

In vivo electrochemical studies of dopamine overflow and clearance in the striatum of normal and MPTP-treated rhesus monkeys

Rapid chronoamperometric recordings, using Nafion-coated carbon-fiber electrodes (30-90 microns o.d.), were used to investigate overflow and uptake of dopamine (DA) in the striatum of normal and 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-treated rhesus monkeys. The monkeys were anesthetized with isoflurane and placed in a stereotaxic apparatus. Magnetic resonance imaging-guided sterile stereotaxic procedures were used for implantations of the electrochemical electrodes coupled with single-barrel micropipettes that were used to apply potassium or DA locally. Potassium evoked a robust overflow of DA-like electrochemical signals into the brain extracellular space in the unlesioned or normal putamen and caudate nucleus of the rhesus monkeys. In contrast, potassium did not produce any detectable changes (> 97% depletion) of DA in the MPTP-lesioned striatum. In addition, the diffusion/clearance of locally applied DA was markedly altered in the lesioned caudate nucleus and putamen compared with unlesioned striatum. Cell counts of the number of residual tyrosine hydroxylase-positive neurons in MPTP-treated monkeys, in conjunction with whole-tissue levels of DA and its metabolites, showed that the MPTP lesions produced extensive damage of the nigrostriatal DA system. These data indicate that residual dopaminergic fibers remaining after MPTP lesions are dysfunctional and have a greatly diminished capacity for high-affinity DA uptake.

Extensive infiltration of bone with marrow necrosis in a case of hairy cell leukaemia

This 32-year-old patient with hairy cell leukaemia demonstrated extensive bony involvement in a pattern not previously described. Although the disease continued to progress during interferon treatment, a change to a regime of deoxycoformycin resulted in an excellent response.

Glial cell line-derived neurotrophic factor augments midbrain dopaminergic circuits in vivo

Recently, a novel glial cell line-derived neurotrophic factor (GDNF) has been identified, cloned, and shown to have potent survival- and growth-promoting activity on fetal rat midbrain dopaminergic neurons in cell culture. In this study, we document marked and long-lasting effects on adult rat midbrain dopaminergic neurons in vivo after intracranial administration. A single injection of this factor into the substantia nigra elicited a dose-dependent increase in both spontaneous and amphetamine-induced motor activity, and a decrease in food consumption, lasting 7-10 days. Using immunocytochemistry, we found sprouting of tyrosine hydroxylase-positive neurites towards the injection site, and increased tyrosine hydroxylase immunoreactivity of the ipsilateral striatum was produced by GDNF. There was also a marked and dose-dependent increase in dopamine turnover in the substantia nigra and striatum, and in ipsilateral dopamine levels in the substantia nigra. Little or no effects of GDNF were seen on norepinephrine or serotonin levels. The neurochemical changes on dopaminergic afferents persist for at least 3 weeks after a single intracranial injection of 10 micrograms. Taken together, these data suggest that this glial cell line-derived factor has a potent influence on adult rat dopamine neurons and may have a potentially important role as a trophic factor for these neurons.

Glial cell line-derived neurotrophic factor reverses toxin-induced injury to midbrain dopaminergic neurons in vivo

Fischer 344 rats were unilaterally injected into the medial forebrain bundle with 6-hydroxydopamine (6-OHDA). Apomorphine-induced rotational behavior was used to select animals whose rotation exceeded 300 turns/h, corresponding to greater than 95% dopamine (DA) depletion in the ipsilateral striatum. Four weeks later, glial cell line-derived neurotrophic factor (GDNF) or vehicle was injected intranigrally ipsilateral to the lesion (0.1-100 micrograms). The highest dose of GDNF tested produced a marked decrease in rotational behavior. This dose also produced levels of DA in the ipsilateral substantia nigra (SN) which were not statistically different from the contralateral side. Vehicle-treated animals showed a marked DA depletion in the ipsilateral SN. These results demonstrate neurochemical and behavioral improvements in unilaterally DA-lesioned rats following intranigral administration of GDNF, suggesting that GDNF may develop into a useful therapy for Parkinson's disease.

Requirements for Langerhans' cell depletion following in vitro exposure of murine skin to ultraviolet-B

Langerhans' cells found within the skin and mucous membranes are critical regulators of antimicrobial and allergic responses. Therefore, the depletion of these cells following exposure of skin to solar ultraviolet radiation (UV) has direct functional consequences on immunity within this tissue. In order to understand how Langerhans' cell depletion is regulated following exposure of skin to medium-wave UV (UVB), the role of second messengers in these responses was investigated using a novel in vitro system. This was accomplished by analysing the expression of a specific marker associated with Langerhans' cells (ATPase) among the epidermal portion of cultured sections of mouse skin following treatment with inhibitors specific for second messenger components and subsequent exposure to UVB. In this study, inhibitors of guanosine triphosphate (GTP) binding proteins, H-8, pertussis toxin and cholera toxin as well as inhibitors of RNA and protein synthesis were all capable of blocking Langerhans' cell depletion in response to UVB treatment. In contrast, an inhibitor of protein kinase C (H-7) was incapable of specifically blocking depletion following treatment with this physical agent. These results suggest that Langerhans' cell depletion mediated by UVB may involve a pertussis and cholera toxin-sensitive G protein as well as de novo protein synthesis.

Osteoblastic gene expression during adipogenesis in hematopoietic supporting murine bone marrow stromal cells

A growing body of data suggests that the bone marrow stroma contains a population of pluripotent cells capable of differentiating into adipocytes, osteoblasts, and lymphohematopoietic supporting cells. In this work, the murine stromal cell lines BMS2 and +/+ 2.4 have been examined as preadipocytes and adipocytes for evidence of osteoblastic gene expression. Adipocyte differentiation has been quantitated using fluorescence activated cell sorting. Within 7-10 days of adipocyte induction by treatment with glucocorticoids, indomethacin, and methylisobutylxanthine, between 40% to 50% of the cells contain lipid vacuoles and exhibit a characteristic adipocyte morphology. Based on immunocytochemistry, both the adipocytes and preadipocytes express a number of osteoblastic markers; these include alkaline phosphatase, osteopontin, collagen (I, III), bone sialoprotein II, and fibronectin. Based on biochemical assays, the level of alkaline phosphatase expression is not significantly different between preadipocyte and adipocyte cells. However, unlike rat cell lines, dexamethasone exposure causes a dose-dependent decrease in enzyme activity. The steady-state mRNA levels of the osteoblast associated genes varies during the process of adiopogenesis. The relative level of collagen I and collagen III mRNA is lower in adipocyte-induced cells when compared to the uninduced controls. Osteocalcin mRNA is detected in preadipocytes but absent in adipocytes. These data indicate that osteoblastic gene expression is detected in cells capable of undergoing adipocyte differentiation, consistent with the hypothesis that these cell lineages are interrelated.

Modulation of lymphohematopoiesis in long-term cultures by gamma interferon: direct and indirect action on lymphoid and stromal cells

Gamma interferon (IFN-gamma) is the product of multiple cell types within the bone marrow microenvironment and has been demonstrated to act as a potent inhibitor of myelopoiesis in vitro and in vivo. The action of this cytokine on lymphohematopoiesis has now been examined on both long-term bone marrow cultures and representative cloned cellular components of the bone marrow microenvironment. In myelopoietic (Dexter) cultures, the half maximal inhibitory concentration of IFN-gamma was between 1 and 10 U/mL. In comparable lymphopoietic (Whitlock/Witte) cultures, IFN-gamma inhibited the production of B-lineage lymphoid cells with a half maximal effective concentration of less than 1 U/mL. In a clonal assay for pre-B cells, IFN-gamma inhibited colony formation with a half maximal concentration of 1 to 5 U/mL. Not all B-lineage lymphoid cells displayed the same sensitivity, however. Growth of the IL-7-dependent B cell line (2E8) in methylcellulose assays was unaffected by IFN-gamma while the replication of other lymphoid lines was partially or completely inhibited. IFN-gamma induced the expression of cell surface proteins (MHC Class I and II) on both B-lineage cells and stromal cells. In cloned stromal cell lines, IFN-gamma increased the steady state mRNA levels for the cytokines interleukin-6 (IL-6) and JE, a member of the IL-8 family. These data indicate that IFN-gamma acts within the lymphohematopoietic microenvironment through both direct and indirect actions on the hemopoietic and stromal cell populations.

Alternatively spliced pp52 mRNA in nonlymphoid stromal cells

The 52-kDa phosphoprotein, also reported as lymphocyte-specific gene 1 and WP34, is transcribed as a 1.6-kb mRNA in B lymphocytes, B cell lines, and untransformed T cells. This gene encodes a cytoplasmic and plasma membrane-associated protein that is phosphorylated at a casein kinase II site and reportedly binds calcium. Based on these properties, it has been hypothesized that lymphoid form of the 52-kDa phosphoprotein protein may play a role in lymphocyte signal transduction. We show that alternatively spliced mRNA are expressed from this gene in nonlymphoid cell lines (myocytes, stromal cells, fibroblasts). These cell lines do not express the 1.6-kb lymphoid cell-specific transcript. Instead, mRNA of 2.0 and 2.8 kb are detected in varying abundance. A full-length 2.0-kb cDNA has been cloned and sequenced from the BMS2 stromal cell line by conventional screening and polymerase chain reaction-based methods. This cDNA clone, designated S37, has a single open reading frame encoding a 328 amino acid peptide. The nucleotide sequence of the S37 stromal cell cDNA is identical to that of the lymphocyte derived pp52 cDNA from the 3' poly(A) tail to the codon encoding the amino acid at residue 24. This region of the S37 cDNA clone encodes a protein that is identical to that encoded by the lymphoid pp52 cDNA and includes a casein kinase II phosphorylation site. However, the two clones differ in their 5' nucleotide sequence and their NH3 terminal amino acid sequence. This organization is consistent with alternative exon utilization. These results suggest that tissue-specific control mechanisms are used to generate different forms of lymphoid form of the 52-kDa phosphoprotein mRNA in lymphoid cells versus mesoderm-derived, nonlymphoid cell lineages.

Alternatively spliced pp52 mRNA in nonlymphoid stromal cells

The 52-kDa phosphoprotein, also reported as lymphocyte-specific gene 1 and WP34, is transcribed as a 1.6-kb mRNA in B lymphocytes, B cell lines, and untransformed T cells. This gene encodes a cytoplasmic and plasma membrane-associated protein that is phosphorylated at a casein kinase II site and reportedly binds calcium. Based on these properties, it has been hypothesized that lymphoid form of the 52-kDa phosphoprotein protein may play a role in lymphocyte signal transduction. We show that alternatively spliced mRNA are expressed from this gene in nonlymphoid cell lines (myocytes, stromal cells, fibroblasts). These cell lines do not express the 1.6-kb lymphoid cell-specific transcript. Instead, mRNA of 2.0 and 2.8 kb are detected in varying abundance. A full-length 2.0-kb cDNA has been cloned and sequenced from the BMS2 stromal cell line by conventional screening and polymerase chain reaction-based methods. This cDNA clone, designated S37, has a single open reading frame encoding a 328 amino acid peptide. The nucleotide sequence of the S37 stromal cell cDNA is identical to that of the lymphocyte derived pp52 cDNA from the 3' poly(A) tail to the codon encoding the amino acid at residue 24. This region of the S37 cDNA clone encodes a protein that is identical to that encoded by the lymphoid pp52 cDNA and includes a casein kinase II phosphorylation site. However, the two clones differ in their 5' nucleotide sequence and their NH3 terminal amino acid sequence. This organization is consistent with alternative exon utilization. These results suggest that tissue-specific control mechanisms are used to generate different forms of lymphoid form of the 52-kDa phosphoprotein mRNA in lymphoid cells versus mesoderm-derived, nonlymphoid cell lineages.

The wee1 protein kinase is required for radiation-induced mitotic delay

Cellular feedback or 'checkpoint' mechanisms maintain the order of completion of essential, cell-cycle related functions. In the budding yeast, for example, the RAD9 gene product is required to delay progression into mitosis in response to DNA damage. Similarly, in fission yeast, the cdc25 and cdc2 gene products influence the ability of cells to delay mitosis in response to the inhibition of DNA synthesis. Because these two checkpoint controls regulate the same event, mitosis, we observed the effect of gamma-irradiation on cell cycle progression in fission yeast, to test whether the two controls require the same cell-cycle regulatory elements. We show that gamma-radiation-induced mitotic delay requires functional wee1 protein kinase but does not seem to involve the cdc25 pathway. Mitotic delay in response to DNA damage is thus distinct from the delay induced by inhibition of DNA synthesis, which involves cdc25 but is not dependent on wee1.

A phase I trial of recombinant human macrophage colony-stimulating factor by rapid intravenous infusion in patients with refractory malignancy

Twenty patients with advanced cancer for which there was no effective standard therapy or whose disease was refractory to standard therapy were treated with recombinant macrophage colony-stimulating factor (rM-CSF). The rM-CSF was administered by intravenous bolus infusion for 5 consecutive days every other week for 2 treatment weeks. The doses administered ranged from 30 to 33,000 micrograms/m2/day. There was no intrapatient dose escalation. There were minimal to no systemic side effects seen, except for acute dyspnea noted in three patients. The dyspnea was felt to be related to the rate of infusion and did not recur in one patient given additional rM-CSF at a slower infusion rate. The major hematologic effect seen was a mild decrease in platelet count, which began to recover while the patients continued to receive the rM-CSF. The clearance of rM-CSF was dose dependent. Lower doses resulted in a saturable mechanism felt to represent cellular uptake. Clearance at higher doses demonstrated both a first-order mechanism at high serum rM-CSF concentrations, representing renal clearance, as well as a saturable mechanism at low serum concentrations. The maximum mean serum half-life was reached at dose levels of greater than or equal to 3,690 micrograms/m2 and was in the range of 234-258 min. By this route of administration, rises in absolute monocyte count were slight and seen only at doses of greater than or equal to 450 micrograms/m2 during the second therapy week. The maximum tolerated dose was not reached in this study because of lack of availability of rM-CSF.

Cloning and characterization of the promoter of the murine lipoprotein lipase-encoding gene: structural and functional analysis

The enzyme lipoprotein lipase (LPL) is responsible for the hydrolysis of triglycerides into free fatty acids and glycerol. Its synthesis is induced as the murine bone marrow stromal cell clone, BMS2, undergoes adipocyte differentiation. The murine genomic LPL promoter has been cloned, sequenced, and characterized by functional and structural assays. The transcriptional start points have been mapped by S1 nuclease and primer extension techniques. Comparison of the 1.7-kb of LPL 5'-flanking sequence between mouse and man reveals 65% identity or greater with conservation of many potential protein-recognition motifs. Using constructs linking this region to the luciferase-encoding reporter gene, transient transfection experiments have documented the promoter function of this sequence in a number of cell lines. Based on a battery of restriction endonucleases, at least 260 bp immediately adjacent to and including the 5'-untranslated region of the first exon are hypersensitive to exogenous nuclease digestion, consistent with an altered chromatin structure. Protein-DNA interactions are detected within this area at the octamer binding protein 1 site and immediately 5' to the translation initiation site based on ExoIII footprinting and gel retention assays.

Regulation of interleukin 6 expression in murine bone marrow stromal cells

The regulation of interleukin 6 (IL-6) expression in the B-lymphocyte-supporting murine stromal cell line BMS2 has been examined in response to exogenous cytokines and chemical agents. Kinetic analyses of IL-6 mRNA induction and decay are presented together with analysis of the IL-6 biological activity. The cytokines tumor necrosis factor, interleukin 1 (alpha and beta), and transforming growth factor beta, as well as forskolin and dibutyryl cyclic AMP, all induce a transient rise in the steady-state level of IL-6 mRNA and an increased release of IL-6 protein. To study its regulation at the chromatin level, the murine IL-6 genomic gene has been cloned. Induction of IL-6 expression correlates with increased DNA nicking, consistent with increased topoisomerase I and endogenous nuclease activity. This finding is supported by kinetic analyses using camptothecin, a topoisomerase I inhibitor. We conclude that IL-6 regulation in murine stromal cells capable of supporting B-lymphopoiesis is comparable to that observed in human diploid fibroblasts.

Tumor necrosis factor-alpha mRNA accumulation in human myelomonocytic cell lines. Role of transcriptional regulation by DNA sequence motifs and mRNA stabilization

The cytokine TNF mediates many of the pathologic signs of cachexia, inflammation, and sepsis. The current work describes the regulation of TNF in human myelomonocytic cell lines after PMA stimulation. The cell lines exhibit a low level of constitutive TNF mRNA expression. Within 2 to 4 h of PMA exposure, steady state levels of TNF mRNA are markedly elevated in all myelomonocytic cell lines studied. This rise is due to increased mRNA stability, which increased by almost twofold, and to an overall increase in transcription, which rises by more than sixfold. At the level of the genomic TNF gene, a DNase I hypersensitive site is detected within the TNF promoter between -200 to -100 bp relative to the transcription initiation site. Although absent in nonexpressing erythroleukemia cell lines, the DNase I site is present in uninduced myelomonocytic cell lines and is not changed after PMA induction. The PMA induction of c-fos mRNA correlated well with TNF gene induction; expression of genes encoding other proteins in the AP-1 complex (junB and junD) were also induced by PMA. The nuclear extracts from resting and induced ML-1 cells contain proteins binding specifically to the AP-1, AP-2, and NF kappa B sequence located within the TNF promoter. PMA induction increases the level of a number of specific binding complexes relative to the resting cells. The regulatory mechanisms of the human and murine TNF genes are discussed.

Tumor necrosis factor-alpha mRNA accumulation in human myelomonocytic cell lines. Role of transcriptional regulation by DNA sequence motifs and mRNA stabilization

The cytokine TNF mediates many of the pathologic signs of cachexia, inflammation, and sepsis. The current work describes the regulation of TNF in human myelomonocytic cell lines after PMA stimulation. The cell lines exhibit a low level of constitutive TNF mRNA expression. Within 2 to 4 h of PMA exposure, steady state levels of TNF mRNA are markedly elevated in all myelomonocytic cell lines studied. This rise is due to increased mRNA stability, which increased by almost twofold, and to an overall increase in transcription, which rises by more than sixfold. At the level of the genomic TNF gene, a DNase I hypersensitive site is detected within the TNF promoter between -200 to -100 bp relative to the transcription initiation site. Although absent in nonexpressing erythroleukemia cell lines, the DNase I site is present in uninduced myelomonocytic cell lines and is not changed after PMA induction. The PMA induction of c-fos mRNA correlated well with TNF gene induction; expression of genes encoding other proteins in the AP-1 complex (junB and junD) were also induced by PMA. The nuclear extracts from resting and induced ML-1 cells contain proteins binding specifically to the AP-1, AP-2, and NF kappa B sequence located within the TNF promoter. PMA induction increases the level of a number of specific binding complexes relative to the resting cells. The regulatory mechanisms of the human and murine TNF genes are discussed.

Altered hepatic clearance and killing of Candida albicans in the isolated perfused mouse liver model

The adherence of Candida albicans was studied in situ by using the perfused mouse liver model. After exhaustive washing, 10(6) C. albicans were infused into mouse livers. At the time of recovery, 62 +/- 5% (mean +/- standard error of the mean) of the infused C. albicans were recovered from the liver and 14 +/- 3% were recovered from the effluent for a total recovery of 76 +/- 4%. This indicates that 86 +/- 3% of the original inoculum was trapped by the liver and that 24 +/- 4% was killed within the liver. Chemical pretreatment of C. albicans with 8 M urea, 12 mM dithiothreitol, 2% beta-mercaptoethanol, 1% sodium dodecyl sulfate, 10% Triton X-100, or 3 M potassium chloride or enzyme pretreatment with alpha-mannosidase, alpha-chymotrypsin, subtilisin, beta-N-acetyl-glucosaminidase, pronase, trypsin, papain, or lipase did not alter adherence of C. albicans to hepatic tissue. By contrast, pepsin pretreatment significantly decreased hepatic trapping. Simultaneous perfusion with either 100 mg of C. albicans glycoprotein per liter or 100 mg of C. albicans mannan per liter also decreased trapping. Furthermore, both substances eluted previously trapped C. albicans from hepatic tissue. Chemical pretreatment with 8 M urea, 12 mM dithiothreitol, or 3 M KCI or enzymatic pretreatment with alpha-mannosidase, subtilisin, alpha-chymotrypsin, or papain increased killing of C. albicans three- to fivefold within hepatic tissue. The data suggest that mannose-containing structures on the surface of C. albicans, for example. mannans or glucomannoproteins, mediate adherence of C. albicans within the liver. Indirectly, chemical and enzymatic pretreatment renders C. albicans more susceptible to hepatic killing.

Interleukin 2 receptor expression in patients with head and neck squamous carcinoma. Effects of thymosin alpha 1 in vitro

Altered cellular immunity in patients with advanced head and neck cancer includes impairments in lymphokine production, blastogenesis, in vitro cytotoxicity, and T-cell levels. Recent evidence for the potential importance of in lymphokine interleukin 2 (IL-2) in patients with cancer prompted a study of the kinetics of IL-2 receptor expression on lymphocytes from patients with untreated advanced head and neck cancer and normal subjects and an evaluation of the in vitro effects of the T-cell immune-reconstituting peptide, thymosin alpha 1. Concanavalin A-stimulated IL-2 receptor expression was maximal after 72 hours and was higher in normal subjects than in patients. This was due to lower levels of helper/inducer (CD4) cells expressing IL-2 receptors in the patients compared with the normal subjects. Thymosin alpha 1 further decreased levels of IL-2 receptor-positive (both CD4 and CD8) cells at 48 and at 72 hours. At 96 hours, levels of IL-2 receptor-positive cells and proportions of cells in G2 and M phases of the cell cycle were similar among both groups of subjects. Simultaneous cell kinetic studies indicated that thymosin alpha 1 down regulation of IL-2 receptors was not due to an effect on proliferation and that differences in IL-2 receptor expression at 72 hours among normal subjects and the patients with cancer were more likely related to differences in cell proliferation kinetics.

Effect of diagnostic and therapeutic cordocentesis on maternal serum alpha-fetoprotein concentration

We investigated the affect of cordocentesis (n = 36) and intravascular transfusion (n = 14) performed with a fixed needle guide on maternal serum alpha-fetoprotein levels. In 50% of the procedures, the placenta was anterior and punctured. For all patients, maternal serum alpha-fetoprotein levels rose 70.8% +/- 28%. The magnitude of the rise was unrelated to the number of attempts necessary, gestational age, or the initial maternal serum alpha-fetoprotein levels concentration. The location of the placenta was the sole identified variable related to the rise. A total of 44% of the patients had a significant increase in maternal serum alpha-fetoprotein level when the placenta was anterior. In contrast, only 4% of the patients had a significant rise in maternal serum alpha-fetoprotein level when the placenta was other than anterior. There was no difference in the frequency of a significant rise in maternal serum alpha-fetoprotein level concentration between the patients who underwent cordocentesis and those who underwent intravascular transfusion. On the basis of these findings, we recommend that when maternal isoimmunization is a potential concern and the placenta is anterior, the umbilical cord should be approached either through a window or laterally from the placenta.

Ammonium ion sensitivity is a ribosomal phenotype associated with suppressor mutations in the suaC gene of Aspergillus nidulans

Ammonium ions are selectively toxic to strains containing mutations in the suaC gene which can mutate to a suppressor phenotype. This phenotype is associated with increased ribosomal misreading in vitro (Zamir and Martinelli 1987) and altered ribosomal proteins (Harvey and Martinelli 1983). Such ammonium-sensitivity is a feature of both strong and weak suppressor alleles, and segregates with suppressor ability in crosses. Suppressor mutations in the suaB and suaD genes are not affected, nor are those in suaA, another ribosomal suppressor gene. Thus, the ammonium-effect is locus specific. Mutations which act as anti-suppressors (asu-) of suppressor suaC109 also partially reverse the ammonium ion sensitivity associated with this mutation. This effect is in line with their restoration of other aspects of the pleiotropic phenotype to normal. The cations, lithium and rubidium, mimick the effects of ammonium ions. Only ribosomes from suaC strains are sensitive to the presence of NH+4 ions in vitro.

B cell activation in patients with active procainamide induced lupus

Cellular immune abnormalities have been described in asymptomatic patients receiving procainamide therapy, but not in patients with active procainamide induced lupus. We tested patients with active procainamide lupus for evidence of T or B cell activation similar to that observed in idiopathic lupus. Symptomatic patients had a significant increase in spontaneous IgG synthesis, but T cells bearing activation markers were not significantly different from age matched controls. Our results demonstrate that patients with active procainamide lupus have evidence for B cell activation, similar to idiopathic lupus.

Increased immunoglobulin response to gamma-interferon by lymphocytes from patients with systemic lupus erythematosus

The factors responsible for abnormal B-cell activation in systemic lupus erythematosus (SLE) are incompletely understood. This study tested the hypothesis that the abnormal B-cell activation observed in human SLE may be due to an augmented response to a helper signal. We demonstrated that non-T cells from 10 of 19 SLE patients increased IgG production in response to interferon-gamma (IFN-gamma) by a mean factor of 20.9 +/- 3.9 over resting levels, while controls stimulated a mean factor of 3.0 +/- 0.5 (P less than 0.005). We found no relationship of IFN-gamma responsiveness to disease activity. Serotyping for HLA A, B, C, and D loci suggested that the hyperresponsiveness may be genetically linked to HLA-Cw7. We conclude that IFN-gamma may contribute to the development and perpetuation of SLE in a subset of patients with SLE.