The membrane immunoglobulin receptor utilizes a Shc/Grb2/hSOS complex for activation of the mitogen-activated protein kinase cascade in a B-cell line

Ligation of membrane immunoglobulin M (mIgM) receptor in the Ramos B-cell line induced tyrosine phosphorylation of several intracellular substrates, including the adaptor protein. Shc. Phosphorylated Shc could be seen to associate with Grb2 in a complex which included hSOS. Inasmuch as hSOS is involved in p21ras activation, we also demonstrated that mIgM ligation activated a Ras-dependent kinase cascade in which sequential activation of Raf-1 and MEK-1 culminates in the activation of p42 mitogen-activated protein (MAP) kinase (ERK-2). The tumour promoter and protein kinase C agonist, phorbol 12-myristate 13-acetate (PMA), also activated Raf-1, MEK-1, and MAP kinase in Ramos cells, but did not induce tyrosine phosphorylation of Shc or Shc/Grb2 association. Okadaic acid, another tumour promoter and serine/threonine phosphatase inhibitor, activated p42 MAP kinase without activating Raf-1 or MEK-1, suggesting the existence of a serine/threonine phosphatase which directly regulates MAP kinase activity.

Evidence for LFA-1/ICAM-1 dependent stimulation of protein tyrosine phosphorylation in human B lymphoid cell lines during homotypic adhesion

JK32.1 and SKW6.4 are Epstein-Barr virus (EBV)-positive human B cell lines that undergo spontaneous, lymphocyte function-associated antigen 1 (LFA-1) dependent homotypic adhesion in culture. This process is associated with induction of tyrosine phosphoproteins of molecular mass 90, 106, and 120 kDa and could be reproduced when these cells were centrifugationally aggregated. Antibodies to the beta 2 (CD18) chain of LFA-1 interfered with induction of p120, p106, and p90 during cellular aggregation. Response induction was abrogated when cells were incubated with protein tyrosine kinase (PTK) inhibitors (erbstatin, genistein, and geldanomycin) or cytochalasin B prior to aggregation. An in vitro kinase assay did not reveal activation of focal adhesion kinase. Although the role of LFA-1-dependent tyrosine phosphorylation in B cells is uncertain, patients with the leukocyte adhesion defect (LAD) exhibit humoral abnormalities. Moreover, aggregation did not induce specific tyrosine phosphoproteins in an EBV-transformed B cell line from a LAD patient. These results suggest that an LFA-1-dependent PTK pathway may play an important role in human B cell function.

Comparative in vitro cytotoxic effects of taxol and its major human metabolite 6 alpha-hydroxytaxol

Taxol is metabolized by the liver microsomal cytochrome P450 enzyme system into its principal metabolite 6 alpha-hydroxytaxol (6HT). In the present in vitro studies 6HT was compared to taxol with respect to its effects on tubulin depolymerization, mitotic arrest, clonogenic survival and apoptosis in HL-60 cells. 6HT was generated by incubating taxol with human liver microsomes in a NADPH-generating system. HL-60 cells were incubated for 24 h with either taxol or 6HT, washed and placed in drug-free suspension or cultured for colony growth in agarose. For the suspension and colony culture growth of the cells, the IC50 concentrations of 6HT were 500 +/- 46 and 350 +/- 37 nM, while those of taxol were 3.2 +/- 0.2 and 2.8 +/- 0.5 nM, respectively. Immediately after a 24-h exposure of HL-60 cells to 50 nM taxol, electrophoresis of genomic DNA from HL-60 cells revealed an internucleosomal DNA fragmentation 'ladder'. In addition, 39% of the cells were arrested in mitosis and 16% showed the morphologic features of apoptosis. In contrast, an identical treatment with 6HT resulted in the mitotic arrest of only 2.8% of the cells, with 4.0% displaying apoptosis (P < 0.01); internucleosomal DNA fragmentation was not observed. 6HT was also significantly less effective than taxol in inhibiting the temperature-induced depolymerization of microtubules in a cell-free system. However, at equipotent concentrations, the effect of 6HT on tubulin depolymerization, mitotic arrest or apoptosis was similar to that of taxol. In addition, at concentrations of taxol or 6HT at or below their IC50, there was little tubulin depolymerization, mitotic arrest or apoptosis. The results presented here show that the biotransformation of taxol to 6HT substantially detoxifies taxol.

Psychosocial correlates of suicidal ideation in adolescent psychiatric inpatients

The Beck Scale for Suicide Ideation (BSI) was administered to 121 inpatients between 12 and 17 years old who were diagnosed with mixed psychiatric disorders. Twelve background and clinical characteristics, previously found to be associated with adolescent suicidal ideation, were entered into a multiple regression to estimate the BSI scores, along with the Beck Anxiety Inventory, the revised Beck Depression Inventory (BDI), the Beck Hopelessness Scale (BHS), and the Youth Self-Report. The BHS and the BDI were the only two variables that contributed unique variance to the explanation of the BSI scores.

The effects of corticosteroid and reduced glutathione on the endothelial viability during culture in MK medium. A light microscopy study

The effect of addition of dexamethasone and reduced glutathione to MK medium, in a concentration of 10(-3) Molar and 0.92 g/l, respectively, was evaluated. The post preservation corneal endothelial viability was assessed using light microscopy. Our results showed that the addition of dexamethasone to MK medium increased the preservation time of dog cornea from 7 to 10 days and that reduced glutathione could further increase the storage period to 12 days. It can be concluded that the addition of reduced glutathione to MK medium is an excellent means for intermediate term corneal preservation.

Involvement of Janus kinases, p52shc, Raf-1, and MEK-1 in the IL-6-induced mitogen-activated protein kinase cascade of a growth-responsive B cell line

We have previously shown that the IL-6R in a growth-responsive B cell line, AF10, induces activation of mitogen-activated protein (MAP) kinase. Here we demonstrate the activation of Raf-1 and MEK-1, which act as a MAP kinase kinase kinase and a MAP kinase kinase, respectively, in the MAP kinase cascade induced by IL-6 in AF10 cells. IL-6 also induced tyrosine phosphorylation of the signaling transducing subunit of the IL-6R in AF10 cells, along with tyrosine phosphorylation of the gp130-associated tyrosine protein kinase JAK1 and the adaptor molecule p52shc. Although induction of tyrosine phosphorylation and activation of MAP kinase by IL-6 in a differentiation-responsive B cell line, SKW 6.4, were below the limits of detection, the phorbol ester PMA did activate Raf-1, MEK-1, and MAP kinase without inducing the phosphorylation of gp130, JAKs, or p52shc. These results suggest that JAK kinase family members associated with the IL-6R may participate in the activation of MAP kinase in AF10 cells by way of an adaptor protein and Ras-dependent kinase cascade.

Involvement of Janus kinases, p52shc, Raf-1, and MEK-1 in the IL-6-induced mitogen-activated protein kinase cascade of a growth-responsive B cell line

We have previously shown that the IL-6R in a growth-responsive B cell line, AF10, induces activation of mitogen-activated protein (MAP) kinase. Here we demonstrate the activation of Raf-1 and MEK-1, which act as a MAP kinase kinase kinase and a MAP kinase kinase, respectively, in the MAP kinase cascade induced by IL-6 in AF10 cells. IL-6 also induced tyrosine phosphorylation of the signaling transducing subunit of the IL-6R in AF10 cells, along with tyrosine phosphorylation of the gp130-associated tyrosine protein kinase JAK1 and the adaptor molecule p52shc. Although induction of tyrosine phosphorylation and activation of MAP kinase by IL-6 in a differentiation-responsive B cell line, SKW 6.4, were below the limits of detection, the phorbol ester PMA did activate Raf-1, MEK-1, and MAP kinase without inducing the phosphorylation of gp130, JAKs, or p52shc. These results suggest that JAK kinase family members associated with the IL-6R may participate in the activation of MAP kinase in AF10 cells by way of an adaptor protein and Ras-dependent kinase cascade.

A 70- to 80-kDa glial cell protein interacts with the AGGGAAGGGA domain of the JC virus early promoter only in the presence of the neighboring cis DNA elements

The neurotropic virus JC (JCV) causes the demyelinating disease progressive multifocal leukoencephalopathy. JCV is transcriptionally regulated by both positive and negative cis elements. Previous studies have shown that the AGGGAAGGGA sequence, in isolation, interacts with a 53- to 56-kDa cellular protein and acts as a silencer for the late promoter. We have reexamined the role of the AGGGAAGGGA element in the glial cell-specific transcriptional regulation of JCV by studying it in a longer natural context of elements of the JCV early promoter. Transcriptional analysis in C6 glial cells of selectively mutated AGGGAAGGGA domains within the nt 98-153 region of the JCV early promoter revealed that both GGG regions in the AGGGAAGGGA sequence are required for glial cell-specific transcription. The interactions of cellular proteins with the AGGGAAGGGA domain were also found to be dependent upon the presence or absence of neighboring cis elements. The TATA region was found to facilitate the interaction of specific proteins with the AGGGAAGGGA domain. Domain-specific photocrosslinking studies revealed the binding of a glial cell protein of approximately 70-80 kDa to the AGGGAAAGGGA domain only when it was flanked by its neighboring cis elements, the TATA and NF-1 domains of the JCV promoter.

Maturation of the cholinergic response of tracheal smooth muscle in the piglet

Maturational changes of the contractile properties of airway smooth muscle have been suggested to occur during the late prenatal and early postnatal period in the piglet. However, the timing and mechanisms involved remain elusive. Therefore, we studied isometric contraction of tracheal smooth muscle (TSM) to evaluate the effects of maturation on 1) the response of TSM to the muscarinic agonist acetylcholine (Ach); and 2) the regulatory activity of acetylcholinesterase (AChE) during the early postnatal period in the piglet. Studies were performed in 1-5-day-old (n = 6) and 14-22-day-old (n = 8) anesthetized, mechanically ventilated piglets. Changes in tracheal tension were measured in vivo from an open tracheal segment and normalized for both longitudinal length of the tracheal segment and cross-sectional area. Dose-response curves to locally applied Ach were obtained before and after the intravenous administration of the AChE inhibitor physostigmine (Phys). Ach-induced changes in tracheal tension significantly increased with maturation during the first 3 weeks of life (P < 0.01), regardless of normalization method. The addition of Phys significantly increased the cholinergic responses of TSM in both age groups (P < 0.02). However, this increase was comparable between age groups. There was also no difference in AChE activity measured in tracheal smooth muscle homogenates between the 1-5 and 14-22-day-old animals. These data indicate that maturation significantly enhances the cholinergic responses of tracheal smooth muscle in the early postnatal period in the piglet.(ABSTRACT TRUNCATED AT 250 WORDS)

The T-cell antigen receptor utilizes Lck, Raf-1, and MEK-1 for activating mitogen-activated protein kinase. Evidence for the existence of a second protein kinase C-dependent pathway in an Lck-negative Jurkat cell mutant

T-cell antigen receptor (TCR) ligation of an Lck-deficient Jurkat mutant, J.CaM1, with anti-CD3 or anti-TCR beta monoclonal antibodies failed to induce tyrosine phosphorylation and activation of p42MAPK. The same stimuli activated mitogen-activated protein (MAP) kinase in J.CaM1 cells transfected with Lck, demonstrating that Lck plays a critical role in MAP kinase activation. Utilizing immunocomplex kinase assays, we demonstrated that TCR/CD3 ligation activated a MAP kinase kinase kinase (Raf-1) as well as a MAP kinase kinase (MEK-1) in Jurkat but not in J.CaM1 cells. It was possible, however, to activate Raf-1, MEK-1, and p42MAPK in J.CaM1 cells during treatment with the phorbol ester phorbol 12-myristate 13-acetate, which activates protein kinase C (PKC). This demonstrates the presence of a PKC-dependent pathway which functions independently from Lck in MAP kinase activation. Stimulation of Jurkat cells with either anti-TCR beta or anti-CD3 monoclonal antibody failed to induce substantial tyrosine phosphorylation of Shc proteins or their association with Grb2 which forms a complex with the guanine nucleotide exchange factor hSOS. However, the same stimuli induced tyrosine phosphorylation of another putative guanine nucleotide exchange factor, p95Vav, in Jurkat but not J.CaM1 cells. Moreover, Lck was reversibly co-immunoprecipitated with p95Vav, and the stoichiometry of binding increased in anti-CD3-treated Jurkat cells. Phorbol 12-myristate 13-acetate did not induce tyrosine phosphorylation of p95Vav. These data show that the TCR activates MAP kinase by way of a signaling cascade, which depends upon Lck, and may be mediated by downstream events involving PKC or p95Vav which act on Raf-1 and MEK-1.

Expression and role of c-myc protooncogene in murine preimplantation embryonic development

PURPOSE

The present study was conducted to investigate the expression and possible role of the c-myc protooncogene in preimplantation embryos by using reverse-transcriptase/polymerase chain reaction (RT-PCR) technique and microinjection of synthetic antisense c-myc oligonucleotide probe, respectively. Total RNA was extracted from oocytes and two cell-, four cell-, early morula-, late morula-, early blastocyst-, and late blastocyst-stage embryos, and cDNA was constructed using MMLV reverse transcriptase. Sense primer (P1) and antisense primer (P2) used were based on the c-myc gene sequence bp 1609-1629 and bp 3279-3299, respectively, that span a 1.37-kb intron. PCR-amplified products of cDNA from oocyte-, two cell-, four cell-, early and late morula-, and blastocyst-stage embryos demonstrated the expected 313-bp product in Southern blot hybridization using a c-myc specific DNA probe, with an indication of lower levels in oocytes and early morulae.

RESULTS

Cytoplasmic injection of the antisense c-myc oligonucleotide probe (P2) and not the sense probe (P1) into pronuclear-stage zygotes caused a significant (P = 0.02 to 0.0001) inhibition of development to blastocysts in a concentration-dependent manner, with a maximal inhibition at the first cleavage of zygotes to two cell-stage embryos. There was no effect on the P2 antisense injection on pronucleus formation.

CONCLUSION

These results indicate that the c-myc protooncogene is expressed in preimplantation embryos and may have an essential role in normal embryogenesis in mice.

Self-reported suicidal ideation in adolescent psychiatric inpatients

In an investigation of the psychosocial correlates of suicidal ideation in adolescent inpatients, the Beck Scale for Suicide Ideation (BSI) was administered to 108 inpatients between 12 and 17 years of age who were diagnosed with mixed psychiatric disorders. A series of multiple regression analyses that controlled for gender, ethnicity, age, diagnosis of a mood disorder, and a history of a past suicide attempt were then used to examine the relationships of the Beck Depression Inventory, Anxiety Inventory, and Hopelessness Scale (BHS) with the BSI. Regardless of the series, the BHS contributed unique variance to the explanation of the BSI scores. The results are discussed as supporting the use of the BSI with adolescent inpatients and indicating that hopelessness is related to suicidal ideation when depression is controlled for.

Risk factors for stillbirths in a secondary level hospital at Ballabgarh, Haryana: a case control study

This study was conducted at a secondary level hospital at Ballabgarth, run by Centre for Community Medicine, All India Institute of Medical Sciences. The still birth rate during the study period 1987-1992 was 19.5 per 1,000 births. It showed a sudden decline during these six years probably reflecting the change in the admission policy of the hospital. A case control study of 72 still births and 144 controls was carried out to identify risk factors for still births. Maternal age, gravidity, previous history of still births or abortion were not found to be significantly associated with still births. Poor socio-economic status measured by parental literacy and occupation were significantly associated with still births. Lack of antenatal care [(OR 9.2 (2.5-37.9)], low birth weight (< 2500 gms) [OR-18.1 (4.4-74.5)], non-vertex presentation [(OR 41.2 (66-257.3)], maternal illiteracy [OR 2.75 (1.01-11.3)] were found to be the important predictors of still birth as identified by logistic regression analysis. The provision of good antenatal care and improvement of the socio-economic status, especially female literacy, will help in decreasing the still birth rate in the country.

Self-reported suicidal ideation in adolescent psychiatric inpatients

In an investigation of the psychosocial correlates of suicidal ideation in adolescent inpatients, the Beck Scale for Suicide Ideation (BSI) was administered to 108 inpatients between 12 and 17 years of age who were diagnosed with mixed psychiatric disorders. A series of multiple regression analyses that controlled for gender, ethnicity, age, diagnosis of a mood disorder, and a history of a past suicide attempt were then used to examine the relationships of the Beck Depression Inventory, Anxiety Inventory, and Hopelessness Scale (BHS) with the BSI. Regardless of the series, the BHS contributed unique variance to the explanation of the BSI scores. The results are discussed as supporting the use of the BSI with adolescent inpatients and indicating that hopelessness is related to suicidal ideation when depression is controlled for.

Epidemiological characteristics of new borns in a rural community

All births (1211) were recorded in a rural area for 1985 by monthly domiciliary visits and the sociological characteristics were collected from mothers within a month. The analysis of 1201 births is presented: 52.7% were male births, 95.7% were delivered in village itself, 80.4% were delivered by trained dais, 99.5% were live born, 12.9% were born before 37 weeks of gestation, 61.5% were put to breast feed within 6 hours, 35% were of gravida 4 and above, 68.9% did not receive any antenatal care, 67.1% had not received any tetanus toxoid, 70.8% did not receive any folifer tablet, 0.8% had abortion and another 0.8% had still birth in preceding outcome, 1.58% had lost a live born dead in preceding out come, 89.6% stopped breast feeding at conception, 31.7% had birth interval less than 2 years, but 2.2% had less than one year, 2/3rd were born in second half of the year, 17.8% had taken extra food during pregnancy, 21.2% reduced the work after becoming pregnant, 9.5% were born to mothers of less than 20 years age, 98.5% of mothers were housewives and 95.9% mothers were illiterate, 33.5% were born in nuclear family, 22.3% were living in 'Kacha' house, 34.8% had no electricity connection, 37.0% were born to land less, 42.2% had no radio in the house, 7.1% had no conveyance, 52.0% families had piped water supply. These findings have been discussed here.

Oncostatin-M stimulates tyrosine protein phosphorylation in parallel with the activation of p42MAPK/ERK-2 in Kaposi's cells. Evidence that this pathway is important in Kaposi cell growth

Oncostatin-M (OSM) is a potent mitogen for Kaposi's sarcoma (KS) cells. We studied signaling by the OSM receptor in three AIDS-related KS lines and show induction of tyrosine phosphorylation of 145-, 120-, 85-, and 42-kD substrates. The 42-kD substrate was identified as p42MAPK (mitogen-activated protein kinase), also known as ERK-2. This serine/threonine kinase relays mitogenic signals from receptor tyrosine protein kinases (TPKs) or receptor-associated TPKs to transcriptional activators. The OSM dose dependence for MAP kinase activation and induction of KS cell growth were almost identical, suggesting functional linkage. MAP kinase activation was dependent on tyrosine phosphorylation, and both OSM-induced MAP kinase activity and KS cell growth could be suppressed by TPK inhibitors, genistein and geldanomycin. OSM also stimulated tyrosine phosphorylation of similar substrates and MAP kinase activity in human vein endothelial cells. While it has been proposed that the OSM receptor may include the gp130 subunit of the IL-6 receptor and alpha-chain of leukemia inhibitory factor (LIF) receptor, neither LIF nor r.IL-6 induced tyrosine protein phosphorylation or p42MAPK activation in KS cells. However, r.IL-6 did stimulate tyrosine phosphorylation and p42MAPK activity in the human B cell line, AF-10, while OSM and LIF exerted no effects. Our results indicate that, although the OSM and IL-6 receptors share a common signaling pathway, this pathway is selectively activated by OSM in Kaposi's cells.

Recombinant IL-6 activates p42 and p44 mitogen-activated protein kinases in the IL-6 responsive B cell line, AF-10

IL-6 is a multi-functional cytokine that utilizes 80-kDa ligand-binding and 130-kDa signal-transducing subunits to stimulate diverse cellular responses. Although IL-6R ligation has been associated with tyrosine protein phosphorylation and activation of an unidentified serine/threonine kinase, very little is known about the intermediary signaling events between the cell membrane and the nucleus. rIL-6 treatment of the human B cell line, AF-10, induced MAP kinase (mitogen-activated protein kinase) activity as determined by in vitro phosphorylation of microtubule-associated protein-2 (MAP-2) and the synthetic peptide APRTPGGRR, corresponding to amino acids 95-98 of bovine myelin basic protein. The kinetics of the response was rapid and dependent on the dose of rIL-6. The response was cytokine specific, did not require the presence of extracellular Ca2+, and was minimally affected by the presence of staurosporine. MAP kinase activation in AF-10 cells occurred in parallel with appearance of 42- and 44-kDa tyrosine phosphoproteins (p42 and p44). Moreover, MAP kinase activation was diminished when AF-10 cells were stimulated with rIL-6 in the presence of tyrosine protein kinase inhibitors, genistein and geldanomycin. p42 and p44 co-electrophoresed on SDS-PAGE with extracellular signal-related kinase (ERK)-2, and ERK-1, respectively; both are members of the ERK family. In addition to p42MAPK and p44MAPK, rIL-6 also activated a MAP-2 kinase that eluted at a lower salt concentration (20 to 60 mM NaCl, peak I) from Mono-Q resin than p42MAPK (120 to 180 mM NaCl, peak II). The identify of this kinase is unknown but it is not an MPB kinase or a protein that exhibits immunoreactivity with anti-ERK antisera. In another IL-6-responsive B cell line, SKW6.4, rIL-6-activated peak I MAP-2 kinase but failed to activate ERK-2. The protein kinase C agonist, PMA, did, however, activate ERK-2 in SKW6.4 cells. These results show that the pleiotrophic cytokine, IL-6, activates p42MAPK/ERK-2 and at least one other serine/threonine kinase in B cell lines.

Recombinant IL-6 activates p42 and p44 mitogen-activated protein kinases in the IL-6 responsive B cell line, AF-10

IL-6 is a multi-functional cytokine that utilizes 80-kDa ligand-binding and 130-kDa signal-transducing subunits to stimulate diverse cellular responses. Although IL-6R ligation has been associated with tyrosine protein phosphorylation and activation of an unidentified serine/threonine kinase, very little is known about the intermediary signaling events between the cell membrane and the nucleus. rIL-6 treatment of the human B cell line, AF-10, induced MAP kinase (mitogen-activated protein kinase) activity as determined by in vitro phosphorylation of microtubule-associated protein-2 (MAP-2) and the synthetic peptide APRTPGGRR, corresponding to amino acids 95-98 of bovine myelin basic protein. The kinetics of the response was rapid and dependent on the dose of rIL-6. The response was cytokine specific, did not require the presence of extracellular Ca2+, and was minimally affected by the presence of staurosporine. MAP kinase activation in AF-10 cells occurred in parallel with appearance of 42- and 44-kDa tyrosine phosphoproteins (p42 and p44). Moreover, MAP kinase activation was diminished when AF-10 cells were stimulated with rIL-6 in the presence of tyrosine protein kinase inhibitors, genistein and geldanomycin. p42 and p44 co-electrophoresed on SDS-PAGE with extracellular signal-related kinase (ERK)-2, and ERK-1, respectively; both are members of the ERK family. In addition to p42MAPK and p44MAPK, rIL-6 also activated a MAP-2 kinase that eluted at a lower salt concentration (20 to 60 mM NaCl, peak I) from Mono-Q resin than p42MAPK (120 to 180 mM NaCl, peak II). The identify of this kinase is unknown but it is not an MPB kinase or a protein that exhibits immunoreactivity with anti-ERK antisera. In another IL-6-responsive B cell line, SKW6.4, rIL-6-activated peak I MAP-2 kinase but failed to activate ERK-2. The protein kinase C agonist, PMA, did, however, activate ERK-2 in SKW6.4 cells. These results show that the pleiotrophic cytokine, IL-6, activates p42MAPK/ERK-2 and at least one other serine/threonine kinase in B cell lines.

Localization of adjacent binding domains for cellular proteins over the minute virus of mice P4 promoter by site-specific photoaffinity labelling

A photoaffinity labelling (PHL) procedure was used to localize the specific binding sites for A92L fibroblast nuclear proteins on the minute virus of mice (MVM) P4 promoter. We describe a chemical and biochemical method for the construction of precisely modified photoreactive (phr) DNA probes. In this method, a phenylazide group is attached to the DNA fragment by coupling SASD [sulfosuccinimidyl-2-(p-azidosalicyl-amido)ethyl-1,3'-dithiopro pio nate] to the primary amino group of the linker arm present at any predetermined position. These phr probes would identify, upon photocrosslinking, only those proteins which bind to the location of the phr group. Specifically, two phr probes representing the 139-172 bp region of the MVM P4 promoter were constructed in which the highly phr phenylazide group was attached with a linker at nucleotide 168, towards the side of the GC box proximal to the TATA box. The PHL studies with these photoprobes revealed that although the proteins of 95 and 120-kDa bind near nt 168 of the P4 promoter, the 120-kDa protein requires the region between the TATA box and the GC box for binding to the MVM P4 promoter.

Hopelessness in adolescent psychiatric inpatients

To study hopelessness in adolescent inpatients, we administered the Beck Hopelessness Scale to 108 inpatients between 12 and 17 years old who were diagnosed with mixed psychiatric disorders. Moderate to severe pessimism about the future was described by 42.6%. A principal components analysis of the correlations among the scale's 20 items was conducted, and three components reflecting rejection of the possibility of a hopeful future, acceptance of the inevitability of a hopeless future, and resignation to the futility of changing the future were identified. These dimensions were comparable to those previously reported for adults, and the usefulness of the scale for evaluating hopelessness in adolescent inpatients was discussed.

Rare case of huge retroperitoneal liposarcoma presenting as a gynaecological problem

A large retroperitoneal liposarcoma presented clinically as an ovarian tumour in an infertile woman. The importance of computed tomography in the differential diagnosis and the appropriate management of retroperitoneal liposarcoma is presented with a review of the relevant literature.

S-antigen-like protein in porcine ciliary epithelium

A soluble protein with a molecular weight of approximately 52,000 Da (from SDS-polyacrylamide gel electrophoresis) was purified from porcine ciliary body, vitreous body and retina by ammonium sulfate fractionation, Sephacryl S-300 gel filtration, and DEAE-cellulose ion exchange chromatography. The protein has a higher molecular weight than bovine S-antigen which is a highly pathogenic retinal antigen, and was eluted from DEAE-cellulose at a slightly higher NaCl concentration than the concentration at which bovine S-antigen was eluted. By reaction with anti-bovine S-antigen polyclonal antibodies, the porcine protein and bovine S-antigen showed full immunological identity. Using a panel of five monoclonal antibodies (MAbs) directed against epitopes spanning the entire length of bovine S-antigen, the porcine protein was analyzed by the enzyme immunoassay and found to react with all MAbs except one that is specific for a species-specific epitope of bovine S-antigen. Immunocytochemical labeling of porcine ciliary body using all of the MAbs demonstrated that the 52,000-Da protein was primarily localized to the nonpigmented epithelial cells rather than the pigmented epithelial cells. Consistent with this localization, the 52,000-Da protein was synthesized by in vitro translation of mRNA extracted from the nonpigmented cells. When injected into Lewis rats, the porcine protein was found to be far less effective in inducing uveoretinitis than native bovine S-antigen.

Incorporation of BrdU in a DNA fragment may affect protein-DNA interactions in a site-dependent manner

DNA in which BrdU has been randomly incorporated is used to identify specific DNA-binding proteins. We show here that the location of BrdU incorporation in a DNA fragment can significantly affect specific protein-DNA interactions and thereby identification of DNA-binding proteins. We suggest that a radioactive labeled unmodified DNA, rather than BrdU-incorporated DNA, be used for identifying DNA-binding proteins by UV cross-linking.

Two cat expression vectors for cloning and generation of 3'- and 5'-deletion mutants

The construction of two versatile cat vectors, pGK0CAT and pGKA10CAT, is reported. These vectors possess multiple cloning sites derived from the Bluescript pKS(+) plasmid that allow the cloning of diverse DNA fragments. From a single cloned insert, i.e., a putative promoter element, one can use the exonuclease III (ExoIII) and S1 or mung-bean nuclease method to generate sequential deletion mutants of the 3' and 5' region. Linker-scanning and internal deletion mutants can thus be created by using appropriate 3'- and 5'-deletion mutants. These plasmids could thus be used for the identification of cis-acting promoter or enhancer elements by either in vivo or in vitro transcriptional analyses. The ability of these vectors to generate deletion mutants from the 3' end make them suitable to identify cis-acting elements in the 5'-noncoding region of the mRNA involved in the translational regulation of protein synthesis. Single-stranded circular mutant plasmids could also be generated from these vectors to study various protein-DNA interactions.

Presence and role of c-myc proto-oncogene product in mammalian sperm cell function

The presence and role of c-myc protein was investigated in mature sperm cells of the human, mouse, and rabbit. The monoclonal antibodies against c-myc protein (c-myc) reacted with the acrosomal region of the sperm of these mammalian species in the indirect immunofluorescence technique. The c-myc monoclonal antibody (MCA) recognized c-myc protein of 62 and 64 kDa on Western blots of lithium diiodosalicylate-solubilized sperm preparations of these species. The c-myc MCA showed a dose-dependent inhibition of human sperm penetration of zona-free hamster eggs, inhibition of murine in vitro fertilization, and reduced in vivo fertilization in rabbits. There was no effect of the antibody on percent sperm motility, though the antibody significantly affected various motility characteristics such as mean and maximum amplitude of lateral head displacement and curvilinear velocity involved in hyperactivation phenomenon of human sperm cells. These results suggest that c-myc or c-myc-like protein is present in mature sperm cells and may have a role in sperm cell function especially in capacitation and/or acrosome reaction.

A 53 kDa protein binds to the negative regulatory region of JC virus early promoter

Using gel retardation and photocrosslinking experiments, we have identified proteins of about 53 kDa in size in both rat glioma (C6) and cervical carcinoma (HeLa) cell extracts which bind to the negative regulatory region of JV virus (JCV) early promoter. The glial cell protein binds to its cognate promoter element with lesser affinity when compared to the protein present in HeLa cells. Further, these proteins interacted differentially to an oligonucleotide, containing the neighboring cis-acting domain, which is recognized by nuclear factor 1 (NF1). These findings suggest that the interactions of the 53 kDa HeLa protein may contribute to the negative regulation of JCV early promoter in HeLA cells.

Gender, differential mortality and development: the experience of Kerala

This study examines aspects of sex differentials in mortality in India. "The general question of sex bias and excess female mortality is first discussed.... Subsequently the reasons for the regional contrast in sex ratios are explored.... We then focus on the interesting exception to the Indian trend and attempt an explanation for the unusual sexual profile that Kerala displays.... The paper ends...with an attempt to draw some tentative conclusions from the Kerala experience with an eye towards more general issues concerning women and the development process."

Transcriptional analysis of minute virus of mice P4 promoter mutants

A series of 5' deletion, internal deletion, and linker-scanning mutants of the minute virus of mice P4 promoter were constructed and analyzed for transcriptional activity in nuclear extracts of mouse A92L fibroblasts. A GC box and a TATA box essential for in vitro transcription from the P4 promoter were localized between nucleotides 150 and 180 (-55 to -25 relative to the primary RNA start site). Although this region also exhibited homologies to other transcriptional control elements, the simian virus 40 enhancer, and the adenovirus E1A enhancer, only the GC box and TATA box appear functional. These two motifs also play an essential role in vivo, although additional upstream sequences (between -139 and -55) are required for optimal transcription. DNase I footprinting, competitive gel retardation assays, and UV-photocrosslinking were used to identify Sp1-like proteins of 95 and 120 kilodaltons in A92L extracts that interact with the GC box of the minute virus of mice P4 promoter.

Primary malignant fibrous histiocytoma of the stomach: (a case report)

A case of primary malignant fibrous histiocytoma (MFH) of the stomach is reported. The patient was a 51-year-old man who had a laparotomy for a malignant gastric tumour diagnosed by radiological studies and endoscopic examination. An inoperable gastric malignancy was found at operation. Histopathological studies of tissue biopsied at surgery showed characteristic light microscopic findings and strong positivity for alpha-1-antitrypsin by immunoperoxidase technique indicating the diagnosis of malignant fibrous histiocytoma. The absence of any other soft tissue or retroperitoneal tumour strongly indicated the stomach is the primary site.

Hemin and cyclic AMP stimulate message-dependent translation in lysates from Friend erythroleukemia cells

A message-dependent, cell-free translation system was prepared from both uninduced and N,N'-hexamethylene-bis-acetamide-induced Friend erythroleukemia cells following modification of standard protocols. Active extracts were prepared by lysing Friend erythroleukemia cells in hypotonic buffer containing 50 microM hemin and 10 mM cyclic adenosine monophosphate (cAMP), and assaying translation in vitro in the absence of exogenous nucleoside triphosphates. Both hemin and cAMP were required for full activity and appeared to act by prolonging initiation in vitro. Following treatment of cell extracts with micrococcal nuclease, brome mosaic virus, globin, equine herpesvirus type 1, and frog virus 3 mRNA were efficiently translated to yield full-sized products. Using brome mosaic virus as a test message, levels of translation equivalent to 30%-50% of that seen in mock-treated lysates were obtained. These results attest to the translational efficiency of extracts prepared and assayed in the manner described above, and suggest that such extracts may be useful both for routine translational studies, and as a tool to dissect translational changes accompanying erythroid differentiation in vitro.

Minimal change disease as the etiology of the nephrotic syndrome in a patient with angioimmunoblastic lymphadenopathy

Glomerular lesions have rarely been reported with angioimmunoblastic lymphadenopathy (AILD). A patient with histologically documented AILD developed the nephrotic syndrome. Renal biopsy demonstrated minimal change disease. Both the lymphadenopathy and the nephrotic syndrome spontaneously remitted in this patient. Prior reports of renal disease in AILD and atypical lymphoproliferative disorders are discussed. An association between the minimal change lesions and AILD is suggested.

Molecular cloning and regulated expression of the human c-myc gene in Escherichia coli and Saccharomyces cerevisiae: comparison of the protein products

mRNA from human HL-60 cells was used to prepare a cDNA library, from which two full-length clones that encompass the complete c-myc coding region were isolated. One clone, pM1-11, contains all three exons of human c-myc. The second clone, pM4-10, represents a relatively rare transcript that initiated in the first intron and includes the coding exons 2 and 3. The cDNA insert in pM1-11 was used to express the human c-myc protein in both prokaryotic and eukaryotic cells. Insertion of the coding sequences in exons 2 and 3 into the appropriate expression vectors yielded detectable c-myc protein in Escherichia coli lacking the Lon protease and in Saccharomyces cerevisiae upon induction. The protein produced in E. coli has an apparent size of 60 kDa and appears to be unmodified, as it is identical in size to the protein synthesized in an in vitro system. In contrast, yeast cells synthesize two myc proteins, of 60 kDa and 62 kDa. The difference in apparent molecular mass between the two proteins appears to be due, in part, to phosphorylation. Subcellular fractionation of yeast cells showed that the c-myc phosphoprotein is located predominantly in the nuclear fraction.

The peptidyltransferase center of Escherichia coli ribosomes: binding sites for the cytidine 3'-phosphate residues of the aminoacyl-tRNA 3'-terminus and the interrelationships between the acceptor and donor sites

The substrate specificity of the acceptor site of peptidyltransferase of Escherichia coli 70 S ribosomes was investigated in Ac-Phe-tRNA . poly(U) . 70 S ribosome (system A) and tRNC-A-Phe . poly(U) . C-A-C-C-A-Phe . 70 S ribosome (system B) systems by using C-C-A-Gly, C-C-A-Phe, C-A-Gly and C-A-Phe as analogs of the 3'-terminus of aminoacyl-tRNA. It was found that an addition of CP residue to C-A-Gly and C-APhe resulted in an increase of the acceptor activity in system A; the increase is more remarkable for C-A-Gly than for C-A-Phe, while the acceptor activities of C-C-A-Gly and C-C-A-Phe are roughly similar. On the other hand, dramatically increased binding affinities of C-C-A-Phe and C-C-A-Gly relative to C-A-Phe and C-A-Gly for the A site of peptidyltransferase were observed in system B using an inhibition assay; C-C-A-Phe binds much more strongly than C-C-A-Gly. The results indicate the important role of the third CP residue and the aminoacyl moiety of the 3'-terminus of aminoacyl-tRNA in the interaction with the acceptor site of peptidyltransferase, as well as the existence of cooperative effects between A and P sites of peptidyltransferase. These effects, depending on an occupancy of P site, may significant the specificity of the peptidyltransferase A site.