ATF2 confers radiation resistance to human melanoma cells

We have previously identified a U.V.-response element (URE; TGACAACA) and its bound proteins, members of the AP1 and ATF transcription factor families, in melanoma cells. Using a mutant form of cylic AMP response element binding (CREB), we found that CREB-associated-URE-bound proteins conferred characteristic melanoma phenotypes, including radiation resistance (Oncogene 12: 2223, 1996). In the present study we sought to determine which of the CREB-associated proteins confers radiation resistance on human melanoma cells. To this end we purified and identified via microsequencing ATF2 as a major URE- bound and CREB-associated protein in MeWo cells--a late stage human melanoma cell line. To determine the contribution of ATF2 to radiation resistance, MeWo cells were transfected with ATF2 cDNA lacking the trans-activation domain (ATF2(delta1-195)). MeWo cells that stably express ATF2(delta1-195) showed weaker transcriptional activities and an altered pattern of homo/hetero dimers. ATF2(delta1-195) clones exhibited up to tenfold lower resistance to irradiation by either U.V. or X-rays. The degree of resistance to radiation in the ATF2(delta1-195)-expressing clones could be increased upon transient transfection with ATF2(wt), but not with phosphorylation-defective mutant ATF2(69,71). Similarly, transfection of ATF2(wt) to WM3211, an early stage human melanoma cells line, increased resistance to radiation. Finally, changes elicited through ATF2(delta1-195) also led to reduced drug resistance, as shown for MMC, araC and cisplatinum. Our results suggest that ATF2 is a regulator of radiation and drug resistance in melanomas, and that tumor targeted ATF2 modulators may be useful sensitizers in the treatment of tumors of this type.

BFU-E colony growth in response to hydroxyurea: correlation between in vitro and in vivo fetal hemoglobin induction

Patients with sickle-cell anemia treated with hydroxyurea may have significant reduction in frequency and severity of pain episodes. However, previous clinical trials show a variable response to hydroxyurea. Criteria which can be used to select patients who are likely to respond to hydroxyurea treatment would be useful. Our laboratory has previously demonstrated an inverse linear relationship between the total number of burst-forming unit-erythroid (BFU-E) colonies and fetal hemoglobin levels in sickle-cell patients treated with hydroxyurea. In the present report, an in vitro cell culture system was established to evaluate the effects of hydroxyurea on BFU-E colony growth and induction of fetal hemoglobin production. Five Hb SS patients who were not previously treated with hydroxyurea and three Hb SS patients who failed to respond to hydroxyurea treatment were included in the study. The results show that the number of BFU-E colonies is decreased from 153.7 to 7.2 per 3 x 10(5) mononuclear cells, whereas fetal hemoglobin levels were increased from 5.1 to 19.4% in the presence of hydroxyurea in vitro in cultured erythroid progenitors, which were derived from 5 patients before treatment. The number of BFU-E colonies decreased from 153.7 to 2.0 per 3 x 10(5) mononuclear cells in the in vitro cultures obtained from serial peripheral blood samples over a 9- to 20-week period of oral hydroxyurea therapy. A simultaneous rise in fetal hemoglobin level from 10.2 to 28.6% in the peripheral blood over the same period of hydroxyurea therapy was also observed. Our results demonstrate that the increase in fetal hemoglobin levels in cells treated with hydroxyurea in vitro is comparable to the rise of fetal hemoglobin production following hydroxyurea therapy in these patients. On the contrary, these findings were not observed in three previously non-responsive sickle-cell patients. These results suggest that the changes in number of BFU-E colonies and fetal hemoglobin levels after in vitro exposure to hydroxyurea may be a useful approach to select sickle-cell patients who will respond to hydroxyurea therapy.

In vitro sensitivity of Plasmodium falciparum to eight antimalarials in China-Myanmar and China-Lao PDR border areas

In 1991-1995 by using the Rieckmann in vitro micro-method, susceptibilities of Plasmodium falciparum to eight antimalarials in the China-Lao PDR and China-Myanmar border areas were tested. The resistant rates of P. falciparum to chloroquinine were 95.0%-100%; IC50 114-240nmol/l. P. falciparum resistant rates to amodiaquine resistance accounted for 83.5%-100%, IC50 52-72nmol/l. All cases were sensitive to quinine, IC50 470-608nmol/l. P. falciparum isolates from the Lao PDR frontier were highly sensitive to artesunate, dihydroartemisinin, and arteether. Resistant rates from other areas were 0-11%. P. falciparum from China-Myanmar and Lao PDR border areas were also sensitive to mefloquine, IC50 68-88nmol/l. A longitudinal survey of the sensitivity of P. falciparum in vivo on the China-Lao PDR border showed that the average defervescent time of falciparum malaria was treated by pyronaridine increased from 32.7 +/- 16.0 hours during 1984-85 to 56.2 +/- 27.4 hours in 1995; the recrudescence rate rose up from 15.2% to 37.5%. The results monitored in vitro showed that all cases assessed in 1988 for response to pyronaridine were sensitive, but 36.4% of cases had emerging resistance, IC50 increased from 13nmol/l to 40 nmol/l. The above results suggested that P. falciparum in these areas has expressed resistance to chloroquine and amodiaquine. However, the parasites are still sensitive to artemisinin, pyronaridine, mefloquine, quinine, but with a declining sensitivities.

Mental disorders in children and adolescents with sickle cell disease

This study compares the rate of mental disorders in children and adolescents with sickle cell disease with the rate in a corresponding control population. Using the clinical interview, a diagnosis based on DSM-III-R criteria for the presence of 13 mental disorders common to childhood was considered in a sequential sample of 39 subjects with sickle cell disease and a convenience sample of 26 same-race control subjects. Thirty-one percent of the sickle cell group and 42% of the control group screened positive for one or more of the selected mental disorders. The difference was not significant. When subgroups of mental disorders were considered (anxiety disorders, depressive disorders, disruptive behavior disorders, psychotic disorders, and other selected disorders), the differences were still not significant. This study suggests that children and adolescents with sickle cell disease do not have a greater risk for clinically significant mental disorders than same-race outpatient clinic controls. This study supports other reports in the medical literature that suggest that children attending outpatient medical clinics are at a higher risk for mental disorder than is seen in epidemiologic studies of nonmedical populations.

Cellular uptake and antitumor activity of the new anthracycline analog DA-125 in human cancer cell lines

To predict the clinical usefulness of DA-125, a newly developed doxorubicin analog, we compared its antitumor activity against 20 different human cancer cell lines with that of doxorubicin using the MTT in vitro chemosensitivity test. We also measured and compared the cellular uptake of this drug and doxorubicin in two cancer cell lines and their doxorubicin-resistant sublines. In the MTT test, DA-125 showed lower IC50 values than doxorubicin for 14 of 20 cell lines. DA-125 was more potent than doxorubicin for hepatocellular cancer cells with high mdr 1 expression. Among cancer cells from the stomach and colon, DA-125 was more potent than doxorubicin in 12 of 14 cell lines. We also investigated the cross-resistance of this drug with doxorubicin using four doxorubicin-resistant cancer cell sublines. Except in one cell line, there was very low cross-resistance. Cellular drug-uptake experiments were performed for two gastric cancer cell lines and their doxorubicin-resistant sublines. In this experiment, DA-125 was found to be very rapidly and completely converted to its active metabolite, M1, in the culture media. After this conversion, M1 was incorporated into these cancer cells more rapidly and reached higher intracellular concentrations than doxorubicin, suggesting that DA-125 (as M1) could achieve earlier and higher levels of intracellular accumulation than doxorubicin in its target tissues from the bloodstream. As a possible alternative antineoplastic agent to doxorubicin, DA-125 awaits further evaluation for its antitumor activity and toxicity.

The cytotoxicity of psoralidin from Psoralea corylifolia

A cytotoxic coumestan derivative, psoralidin (1), was isolated from the seed of Psoralea corylifolia. The IC50 values of 1 against SNU-1 and SNU-16 carcinoma cell lines were 53 and 203 micrograms/ml, respectively, indicating cytotoxic activity against stomach carcinoma cell lines.

Tumoral calcinosis in an infant

We report tumoral calcinosis, an uncommon disease of uncertain origin, in an infant-only the sixth instance of the disease reported in this age group. The radiologic features are typical as illustrated by three modalities. The clinical, radiologic and pathologic features are discussed along with comments concerning possible etiologies and management.

Expression of dominant negative CREB reduces resistance to radiation of human melanoma cells

u.v.-responsive element (URE)-binding proteins were found to include members of the AP1 and ATF transcription factor families. To elucidate the functional contribution of URE-bound proteins to the characteristics of human melanoma, we have used a dominant negative CREB cDNA which is mutated within the DNA-binding domain and cloned into a mammalian expression vector driven by the RSV promoter (KCREB). As such, KCREB is still capable of heterodimerizing with its associated proteins, yet, due to its poor binding affinity to DNA it out competes transcriptional activity mediated by those proteins. Human melanoma cells (MeWo) were transfected with KCREB and three clones, designated K1, K2, and K10 which express KCREB transcripts were then selected for further characterization. When tested for binding activities in gel shift assays, proteins prepared from the three clones exhibited a different set of complexes than the parent MeWo and control MeWo(neo) cells (transfected with empty expression vector) under normal growth conditions, and after u.v.-irradiation. Using CAT vector, driven by a tetramer URE construct, revealed a striking decrease in transcriptional activity in each of the three clones before as well as after u.v.-irradiation. When tested for radiation resistance MeWo cells were found to exhibit 42% survival to a u.v.-dose of 16 J/m2, whereas, K1, K2 and K10 exhibited only 10.2, 3.9 and 4.2% survival, respectively. Exposure to 2 Gy of X-radiation led to 62.1% survival of MeWo as compared with 18.5% of K1 and 7.7% and 6.5% of K2 and K10, respectively. While no significant differences were noticed in their growth rate, all three clones exhibited fewer, and smaller colonies in soft agar, when compared with parent cells. These findings indicate that through their transcriptional activities, CREB and its associated proteins play an important role in the acquisition of characteristic phenotypes of human melanoma cells including resistance to u.v.-irradiation.

Systemic lupus erythematosus in a child with sickle cell disease

Although sickle cell disease (SCD) and systemic lupus erythematosus (SLE) are two distinct chronic diseases, many clinical features are common to both conditions. We describe a young patient who had a mild clinical course of SCD until SLE developed when he was 15 years old. His initial manifestations of SLE including fever, chest pain, and lung infiltration with pleural effusion were thought to be complications of SCD. However, a deteriorating clinical course, presence of facial and truncal rash, and persistent pleural effusion led to the diagnosis of SLE. We compare our case and the 10 previously reported cases and discuss the possible association of complement defects and the pathogenesis of SLE in patients with SCD. Our report illustrates the importance of considering other disease processes when clinical features are atypical of SCD.

Ultraviolet light-responsive element (TGACAACA)-binding proteins in cells of xeroderma pigmentosum patients

The ultraviolet light (UV)-responsive element (URE) is an octamer sequence, TGACAACA, that shares homology with cyclic AMP-responsive element and activator protein 1 target sequences. Because URE-binding proteins have been shown to play a role in cellular response to DNA damage, we determined their expression and DNA-binding activities in repair-deficient cells. Of the complementation groups tested, only xeroderma pigmentosum (XP)-C cells induced expression of c-jun after UV irradiation; this correlated with XP-C binding to the URE and resembled the pattern observed with normal human fibroblasts. In other cases either a decrease (XP-A) or no change (XP-D) in URE-binding activities was noticed, which may be associated with decreased c-fos and poor c-jun expression after UV irradiation. That XP-C cells were the only complementation group exhibiting URE-binding activities similar to those of repair-proficient cells points to the possible correlation between proper repair of transcriptionally active genes and the expression and activities of proteins implicated in the cellular response to UV irradiation.

Analysis of a repeat-containing family of Giardia lamblia variant-specific surface protein genes: diversity through gene duplication and divergence

Giardia lamblia trophozoites express on their surfaces one of a set of cysteine-rich antigenically variant proteins, called variant-specific surface proteins, which comprise the majority of proteins detected by surface labeling. While these VSP proteins may be immunodominant proteins important in the host immune response to G. lamblia, the ability to switch expression from one VSP to another may provide a means for the trophozoites to avoid the host immune response. The first VSP characterized, VSPA6 (from the A6 clone of the WB isolate, originally termed CRP170), contains 18-23 copies of a 65 amino acid repeat. We have now used the repeat as a probe to isolate from a WBA6 genomic library two genes related to vspA6 (called vspA6-S1, vspA6-S2). Sequence analysis of the vspA6-S1 gene revealed nearly two complete copies of the 195 bp repeat and substantial nucleotide and translated amino acid similarity in the coding regions 5' and 3' to the repeats. The vspA6-S2 gene, while still related, showed greater divergence from vspA6 than vspA6-S1 in the nonrepeat coding region and contained nearly four copies of a 201 bp repeat that was 75% identical to the 195 bp vspA6 repeat. These results suggest that gene duplication followed by divergence has played a key role in the generation of the vsp gene repertoire.

Toxicity of human recombinant interferon-gamma in rats and dogs

AIM

To study the acute and chronic toxicities of human recombinant interferon-gamma (Hu-rIFN-gamma) in mice, rats, and dogs.

METHOD

Twenty mice were administrated Hu-rIFN-gamma (i.m. or i.v.) 4.4 x 10(9) IU m-2 to observe the acute toxicity. In chronic studies, 1 x 10(7), 5 x 10(7), 1 x 10(8) IU m-2 d-1 were given to 80 rats and 5 x 10(5), 5 x 10(7) IU m-2 d-1 were injected to 14 dogs i.m. for 3 months, treatment-related changes were measured in the hematologic, chemical, urinalysis values, ECG and pathologic profile of organs and tissues.

RESULTS

The maximal tolerance dose (MTD) i.m. or i.v. in mice was 4.4 x 10(9) IU m-2, 4400 times the recommended clinical dosage (1 x 10(6) IU m-2). No adverse effects were found in chronic toxicity studies.

CONCLUSION

Human recombinant interferon-gamma did not produce toxic reaction in rats and dogs.

Comparison of costs to the health sector of comprehensive and episodic health care for sickle cell disease patients

Of 391 patients with sickle cell disease known to the health care facilities of the University of South Alabama, 194 patients used these facilities in 1989. In that year, 33.5 percent of patients seen at the University of South Alabama did not attend the Comprehensive Health Care Clinics developed for sickle cell patients. There were major differences in the patterns of use and in health care costs among sickle cell patients who attended the Comprehensive Health Care Clinics and those who did not. Patients not using these clinics, although they accounted for only 33.5 percent of the total patients, constituted 71.4 percent of visits to the emergency rooms and 42.3 percent of inpatient admissions. Patients enrolled in the Comprehensive Health Care Clinics used emergency rooms and inpatient units less frequently (P < 0.0001 and P = 0.0006, respectively) and were responsible for significantly smaller health care costs in each category (P < 0.0300). Evaluation of factors responsible for differences in the use patterns and patient education to improve use of comprehensive health care services should be considered.

Giardia lamblia trophozoites contain multiple alleles of a variant-specific surface protein gene with 105-base pair tandem repeats

Giardia lamblia trophozoites undergo antigenic variation of a variant-specific surface protein (VSP). All VSPs that have been reported have had high cysteine contents, including numerous copies of a CXXC motif. The first vsp gene described (vspA6; from the cloned line, WBA6), contained 21 copies of a 195 base pair tandem repeat, but other reported VSPs have not contained repeats. In this report, we describe the vsp gene from WBC5, a cloned line derived from WBA6. The vspC5 gene contains short 5' and 3' regions flanking 26 copies of a 105-bp tandem repeat, which comprises 93% of the coding region. In addition to the copy containing 26 repeats, the genome contains other copies of the vspC5 with fewer copies of the repeat. The sequences flanking the repeats are identical, and all copies map to the same location on chromosomal Band 5, suggesting that multiple alleles of the vspC5 gene are present.

Transformation of wheat (Triticum aestivum L.) through electroporation of protoplasts

Protoplasts isolated from embryogenic suspension cultures of wheat (Triticum aestivum cv. Hartog) were electroporated in the presence of plasmid pEmuGN and/or pEmuPAT, which contained the reporter gene gus and selectable marker gene bar, respectively. Under optimised electroporation conditions, up to 0.9% of viable protoplasts displayed gus activity two days after electroporation. To select for phosphinothricin (PPT) resistant colonies, electroporated protoplasts were incubated for six weeks in a medium containing 10 μg/ml PPT. The cells surviving the selection were maintained as individual colonies on solid medium or as suspension cultures. More than 60% of these colonies exhibited tolerance to 40 μg/ml PPT when tested 10 months after initial selection. To date, 57 green plants have been regenerated from these colonies and 24 have been transferred to soil. Southern blot analyses of colonies and plants, using the bar gene sequence as the probe, confirmed transformation of the cells. Positive PAT assays of both regenerated colonies and plants indicated the presence of the bar gene product. These results provide a basis for the establishment of routine procedures for transformation of wheat by direct gene transfer into protoplasts.

Relationship of burst-forming-unit-erythroid progenitors and their DNA-synthesis stage to fetal hemoglobin levels in hydroxyurea-treated patients with sickle cell anemia

DNA-synthesis stage and total number of circulating burst-forming-units-erythroid (BFU-E) have been inversely correlated with hemoglobin F levels in the peripheral blood, as well as in the cells from the BFU-E-derived colonies obtained from homozygous sickle cell anemia (SS) patients during steady state. Similar studies in SS patients treated with cytotoxic agents have not been reported. However, regeneration of the erythroid marrow that follows the cytoreduction phase of chemotherapy has been suggested as one of the mechanisms of stimulation of fetal hemoglobin synthesis. Therefore, a longitudinal study of hemopoiesis in hydroxyurea-treated SS patients was conducted. Thirty-two sets of hemopoietic studies, including total circulating BFU-E and S-phase BFU-E, were obtained from three patients treated with hydroxyurea. A dose-dependent decrease in total BFU-E colonies occurred in peripheral blood of all three patients (r = -0.58, -0.85, and -0.97, respectively, with each P < 0.05). There was a strong positive correlation between hydroxyurea dose and fetal hemoglobin levels in two of the three patients who responded clinically (r = 0.89618 and 0.88632, respectively, with each P < 0.01). When data from all patients were combined (n = 32), there was a strong, inverse, linear relationship between total number of BFU-E and percentage S-phase BFU-E with fetal hemoglobin levels (r = -0.6649 and -0.7404, respectively, with each P < 0.0001). A stronger, curvilinear, multiple relationship was detected between total BFU-E and percentage S-phase BFU-E with fetal hemoglobin levels (R = 0.8351 and 0.8602 with each P < 0.0001).

[Low-dose of processed rhubarb in preventing pregnancy induced hypertension]

A prospective randomized double blind study with processed rhubarb (low dose of 0.75g/day) was carried out in pregnant women at risk of pregnancy induced hypertension (PIH). Rhubarb (140 cases) or placebo (125 cases) was given to women at risk of PIH consecutively from the 28th week of gestation till delivery, and another 68 pregnant women as control. Results showed that 5.7% of rhubarb treated women developed PIH, a rate substantially lower than the 20.8% of the placebo group (P < 0.01). After 9-10 weeks of treatment, the plasma fibronectin (Fn) level and Plasminogen activator inhibiter (PAI) value were found significantly lower (P < 0.05) in the rhubarb treated group than in the placebo. Antithrombin III (ATIII) level also decreased significantly less in the rhubarb group as compared with the placebo (P < 0.05). It indicated that low dose of processed rhubarb has a good prophylactic effect on PIH. The mechanism may be related with the inhibition of PAI activity, reduced Fn synthesis and decreased damage to vascular endothelium.

Expression and transcriptional activity of AP-1, CRE, and URE binding proteins in B16 mouse melanoma subclones

The expression and DNA binding activity of members of the activating protein-1 (AP-1) and activating transcription factor (ATF) families of transcription factors were analyzed in sham and ultraviolet (UV)-irradiated subclones of the B16 mouse melanoma cell system. The four subclones we used represent sequential stages in the development and progression of malignant melanoma and exhibit differences in growth and metastatic potential. Western blot analysis revealed differential expression of some AP-1 (c-jun, jun-B, and jun-D) and ATF (43- and 47-kDa cyclic AMP-responsive element binding protein (CREB) family members) in the different subclones; while c-jun expression was noted in the subclones with the greater malignant potential, jun-D was expressed in those with the lesser malignant potential. Furthermore, a delicate balance between the two forms of CREB was noted; the 47-kDa CREB appeared, when expressed exclusively, in subclones that exhibit a greater malignant potential. Electrophoretic mobility shift assays using AP-1, CRE, and UV-responsive element (URE) consensus sequences indicated that distinct complexes were formed with extracts from each of the four subclones. The complexes were competitively inhibited by each of the target sequences used, suggesting that "cross-talk" occurs between some AP-1 and ATF family members in this cell system. Moreover, a multimer of the URE sequence, cloned upstream of a chloramphenicol acetyltransferase reporter gene, was transcriptionally active and responsive to UV irradiation in two of the four subclones. UV-related transcriptional activation was directly correlated with the expression of a 43-kDa CREB. Together, these observations identify members of AP-1 and CREB families whose expression and activities correlate with the malignant potential of subclones that represent different stages in melanoma development and progression.

Depression in children and adolescents with sickle-cell disease

OBJECTIVE

To look at the role of a standardized screening test for assessing depression in children and adolescents with and without sickle-cell disease and to compare findings with this instrument with clinical evaluations by child psychiatrists. In addition, to suggest the prevalence of clinical depression in children and adolescents with sickle-cell disease.

DESIGN

Nonrandomized, sequential sample of subjects, convenience control sample, prevalence study using the Children's Depression Rating Scale-Revised and an interview assessment by a child psychiatrist based on criteria from the Diagnostic and Statistical Manual of Mental Disorders, Revised Third Edition.

SETTING

Comprehensive Sickle Cell Center outpatient clinic and ambulatory Resident Practice Clinic at the University of South Alabama Children's Medical Center, Mobile.

STUDY PARTICIPANTS

Patients aged 6 through 18 years with homozygous sickle-cell disease (hemoglobin SS) served as study subjects. Subjects of the same age and race who did not have sickle-cell disease served as controls.

MEASUREMENTS AND RESULTS

The mean Children's Depression Rating Scale-Revised total scores were 27.1 and 22.1 in study and control groups, respectively (P = .0073). Eleven (29%) of 38 children in the study group had scores indicating a high risk for clinical depression. Four (12%) of 34 children in the control group were in this category. The four items accounting for most of this significant difference were excessive fatigue, physical complaints, self-esteem, and morbid ideation. This contrasted with the clinical evaluation by a child psychiatrist in a clinical interview in which 13% of study subjects and 15% of control subjects had evidence of clinical depression (P = .85).

CONCLUSION

Excessive fatigue and physical complaint factors contributed to a high false-positive rate when the Children's Depression Rating Scale-Revised was used to screen for depression among patients with sickle-cell disease. Based on the clinical interview by a child psychiatrist, the actual prevalence of clinical depression was not increased in children with sickle-cell disease compared with those without this chronic illness.

[Point mutation of K-ras gene in pancreatic carcinoma]

Direct sequencing using Taq enzyme was established for determination of point mutation of K-ras gene at codon 12 in 9 wax samples of pancreatic carcinoma (PC) and 1 of islet cell tumor. Point mutation occurred in 5 of 9 samples of PC and manifested two types of mutation, CCA-->CGA in 4 and CCA-->CAA in 1. The changes of amino acid included changes of glycine to alanine and glycine to valine. The causes of mutation frequency and the content differed from that of foreign reports were analysed in addition to the significance of determining point mutation of K-ras gene at codon 12.

Cell aggregates in wheat suspension cultures and their effects on isolation and culture of protoplasts

Fine embryogenic suspension cultures of wheat (Triticum aestivum cv Hartog and Timmo, and T. durum cv D6962) tend to grow into large cell clumps (1-3 mm), resulting in the formation of mixed suspension cultures consisting of both fine and large cell clumps. The cell clumps were separated according to their sizes and cultured as new lines to investigate their growth rate and differentiation potential and the effects of cell aggregate size on protoplast culture. The results showed that the fine clusters (<310 μm) had a higher growth rate but a lower differentiation frequency than the large cell aggregates (310-2000 μm). After 2-4 weeks incubation, all the new lines reformed mixed suspension cultures again. The large clumps (>1100 μm) released fine cell clusters into the medium so it was possible to initiate fine embryogenic suspension cultures from the large clumps. With regard to the isolation and culture of protoplasts, although the highest yield of protoplasts was obtained from the fine cell clusters, the protoplasts isolated from different sized cell aggregates all had similar potential for sustained cell division and plant regeneration.

UV-responsive element (TGACAACA) from rat fibroblasts to human melanomas

When taken together, several lines of evidence suggest that the URE-bound proteins are associated with DNA replication. (1) A trans-acting factor of 60 kDa (which may include the 68-kDa URE-binding proteins) was found to be induced by UV and to mediate polyoma DNA replication; (2) the URE was able to compete for the binding of factors that promote polyoma replication in rodent cells; (3) URE-bound proteins are expressed to a higher extent at the S phase of the cell cycle; and (4) they are induced following treatment with aphidicholin. These observations may suggest that the URE may play a role in growth "release" (as opposed to growth "arrest") which would assist in restoring normal growth following DNA damage. It is clear that URE-bound proteins consist of multiple transcription factors, some of which are well characterized (i.e., jun, CREB, and fos families); however, it is likely that the growth release phenomenon we relate to is also mediated by (1) other members of these transcription factor families which have not been identified as yet and (2) a specific combination of known transcription factors which bind to this response element under certain circumstances. This hypothesis is outlined in the enclosed model (Fig. 3).

A transcriptional inhibitor induced in human melanoma cells upon ultraviolet irradiation

Nuclear proteins from human melanoma cells exhibit strong binding activity to the UV response element (TGACAACA); however, this binding is inhibited following UV-C irradiation. In contrast, the binding of nuclear proteins from rodent fibroblasts and human keratinocytes to the UV-responsive element is initially weak and increases significantly upon UV irradiation. The addition of nuclear proteins from UV-irradiated melanoma cells to those prepared from nonirradiated cells inhibited the binding to the UV-responsive element in a concentration-dependent manner. Fast protein liquid chromatographic analysis of nuclear proteins from UV-irradiated melanoma cells revealed 12 and 14 kilodalton proteins within a fraction which also contained the inhibitory activity. The inhibitor blocks the binding of proteins to three other target sequences, AP1, CREB, and PEBP2, as well as the in vitro transcription of SV40 promoter sequences. The inhibitor was also found in UV-irradiated melanocytes, suggesting that it is tissue specific. The induction of a transcriptional inhibitor in response to UV irradiation represents a regulatory event that may play an important role in the transcriptional response of both normal and malignant melanocytes to UV irradiation.

Treatment of childhood acute lymphoblastic leukemia with protocol TCL-842 in Taiwan: the Taiwan Children's Cancer Study Group

From March 1984 to May 1988, 212 children with acute lymphoblastic leukemia were enrolled on Protocol TCL-842. In all, 68 patients were classified as standard risk (SR), 56 as intermediate risk (IR), and 88 as high risk (HR) groups. Remission induction for all three groups consisted of vincristine (VCR), prednisolone (PRED) and L-asparaginase (L-Asp). One consolidation course with cyclophosphamide (CP) and cytarabine (AraC) was used for the SR and IR groups, and two courses were given to patients in the HR group. Central nervous system prophylaxis was randomized using either cranial irradiation 18 Gy + 5 intrathecal methotrexate (IT MTX) or triple IT with maintenance. Reinforcement cycles were employed periodically during maintenance therapy (basically 6-mercaptopurine+MTX) and varied among the three groups. Four-week oral PRED every 16 weeks was the sole reinforcement agent for SR. Two-week VCR+dexamethasone (DEX)+adriamycin CP cycles were used to reinforce IR and HR at different intervals. Five third-form cycles with VCR+DEX+AraC were used only for HR. Treatment was discontinued after three years in patients who achieved continuous complete remissions (CCR). Eight patients died during the induction phase and eight failed to achieve complete remission (CR). The CR rate for SR was 97%, for IR was 98% and for HR was 83.3%; the overall rate was 91.8%. As of 30 June 1991, 33 patients had dropped out, 12 had died during remission, and 52 had relapsed. Twenty-eight SR, 26 IR, and 29 HR patients remained in CCR with a median follow-up duration of 66 months (38-88 months).(ABSTRACT TRUNCATED AT 250 WORDS)

Plant regeneration from protoplasts of durum wheat (Triticum durum Desf. cv. D6962)

Suspension cultures of durum wheat were established from embryogenic callus maintained in liquid medium for 30 months. Protoplasts were readily isolated from the suspension cultures with yields as high as 3 X 10(7) protoplasts per g fresh weight suspension cells. When incubated in a modified MS medium containing half strength of the macroelements, 5 μM 2,4-D (2,4-dichlorophenoxyacetic acid) and 0.6 M glucose, protoplast-derived cells divided at frequencies ranging from 1.4 to 10.0 %. After transfer to a solid subculture medium, the protoplast-derived colonies formed embryogenic protuberances, from which green plants have been regenerated.

Expression pattern of proteins that bind to the ultraviolet-responsive element (TGACAACA) in human keratinocytes

We previously identified an ultraviolet (UV)-responsive element (URE; TGACAACA) that plays a role in both transcription and replication of polyoma sequences. Mouse polyclonal antibodies were raised against affinity-purified URE-bound proteins to characterize their expression patterns. These antibodies specifically recognized two of four URE-bound proteins, of 40 and 68 kDa. The 68-kDa protein was constitutively expressed in human keratinocytes, while the expression of the 40-kDa protein was induced by UV irradiation. Of the two, the 68-kDa protein bound to the URE with greater affinity than the 40-kDa protein, as determined by southwestern analysis. The expression of the 40-kDa protein increased as early as 1 h after UV irradiation of both rat fibroblasts and human keratinocytes and correlated with increased binding to the URE in an electrophoretic mobility shift assay. Other types of damage, as well as heat shock and serum stimulation, also induced the expression of this protein, suggesting that it may play a role in cellular response to stress or damage. The 40-kDa protein was expressed at the highest levels in the S phase of the cell cycle and was induced by aphidicolin, suggesting that it has a role in DNA replication. All together, these results suggest that exposure of human keratinocytes to damage- and stress-inducing agents modulates the expression of proteins that may play a role in regulating cellular response to DNA damage.

Functional role of the ultraviolet light responsive element (URE; TGACAACA) in the transcription and replication of polyoma DNA

We have previously identified a novel 8 bp sequence (UV-responsive element, URE: TGACAACA) present in the regulatory region of polyoma DNA that interacts with protein factors induced in rat fibroblast cells by exposure to UV light. In the present study, we demonstrate through competitive binding assays that this sequence is distinct from the partially homologous AP1 and CRE target sequences. The proteins that bind to the URE appear to have transcriptional activity in UV-exposed rat fibroblasts. In addition, the URE appears to play a role in promoting the replication of polyoma DNA as determined through two different experimental approaches. Together, these findings suggest that the URE is a novel DNA binding element that interacts with proteins involved in the transcription and replication of polyoma sequences.

[Preliminary study on RFLPs for dystrophin gene in Chinese]

We have studied the RFLPs distribution and frequency of dystrophin gene in Chinese by using 14 subclones of complete 14 kb cDNA for the dystrophin gene as hybridization probes. Allelic fragments are detected in hybridization patterns of Pvu II/1a, Taq I/2b-3, Taq I/5b-7, Xba I/10. Among them, the allelic fragments (26 kb and 3.8 kb) in Pvu II/2b-3 patterns and the allelic fragments (10 kb and 8.4 kb) in Taq I/5b-7 patterns are the new RFLPs which have never been reported. From the comparison of our data with those of Caucasian and Japanese respectively and their statistical analysis, we can obtain the results as follows: There is remarkable difference (p less than 0.01) of the allelic fragment frequency in Taq I/2 b-3 (A1 = 3.4 kb, fre. 0.04; A2 = 3.2 kb, fre. 0.96) and Xba I/10 (A1 = 7.4 kb, fre. 0.41; A2 = 6.7 kb, fre. 0.59) between Chinese and Caucasian. The frequency of the allelic fragments A2 in Taq I/8 (A1 = 6.5 kb, A2 = 5.6 kb) and EcoR V/9 (A1 = 11.8 kb, A2 = 10.7 kb) are high in Caucasian, but have not been detected in Chinese. These differences are also highly significant. But the B1B2 allelic frequencies in Taq I/5 b-7 (B1 = 3.2 kb, B2 = 1.6 kb) are the same. There is no significant difference in the frequency of the allelic fragments A1A2 and B1B2 in Pvu II/1 a between Chinese and Japanese. Preliminary results suggest that there probably are high frequencies for spontaneous neutral mutations in the evolution process of the huge dystrophin gene (about 2,300 kb). In the meantime, the neutral mutation frequencies of various sectional sequences have remarkable differences, and that of some sectional sequences of the gene between Chinese and Caucasian may also have remarkable differences.

Splenic sequestration associated with sickle cell trait and hereditary spherocytosis

Coexistence of sickle cell trait and hereditary spherocytosis (HS) is unusual, and only 16 cases have been reported in the literature. These patients have the same clinical and hematological features as individuals having HS alone. We report a serious complication, acute splenic sequestration crisis (ASSC), occurring in two patients with sickle cell trait and HS. One patient experienced four episodes of ASSC during an 11-year span, while the other had two episodes of this complication during a 4-year period. Red blood cell studies and membrane protein analysis confirmed the diagnosis of HS as a consequence of spectrin deficiency. Splenectomy resulted in marked clinical and hematological improvement in both patients. Histological examination of spleens following splenectomy confirmed that significant erythrostasis and sickling had indeed occurred. ASSC can occur in patients with coexistence of sickle cell trait and HS, and this potentially life-threatening complication should be considered in this condition.

The cysteine-rich protein gene family of Giardia lamblia: loss of the CRP170 gene in an antigenic variant

Giardia lamblia trophozoites demonstrate variable expression of a repertoire of cysteine-rich surface antigens in vitro and in vivo. The size of the repertoire has been estimated at 20 to 184, and specific variants can be detected after approximately 12 generations of in vitro growth for the WB isolate. In earlier studies, we cloned a portion of the gene for a 170-kDa surface antigen (CRP170) and demonstrated by DNA sequencing that it was cysteine rich (12%) and contained 2.6 copies of a tandemly repeated 195-bp pair sequence. The clone hybridized to multiple bands on a Southern blot of G. lamblia DNA in a pattern that was variable among the cloned lines but did not correlate with expression of CRP170. We have now cloned a nearly full length cDNA as well as genomic clones for CRP170 from the WBA6 cloned isolate. In addition, we have isolated a cDNA clone from the WB1269 line (expressing CRP72), an antigenic variant which was derived from WBA6. Sequence analysis of the CRP170 and CRP72 genes revealed marked C-terminal amino acid homology, suggesting a conserved functional role such as membrane anchoring. The CRP170 repeat oligonucleotide hybridized to a stairstep of bands approximately 6 kb in size on HindIII-digested WBA6 DNA representing the expressed copy(ies) of CRP170. In contrast, there was no hybridization to a fragment of similar size in WB1269, suggesting that WB1269 trophozoites have lost the expressed copy of the CRP170 gene.

Acute splenic sequestration crisis in sickle cell disease: early detection and treatment

Acute splenic sequestration crisis (ASSC) in children with various forms of sickle cell disease can result in life-threatening circulatory collapse due to the loss of circulating blood volume. Over a 6-year period we have treated 12 patients ranging in age from 5 1/2 months to 7 years presenting with acute sequestration crisis. Eleven had homozygous sickle cell disease and the other had sickle-thalassemia. One patient died of acute circulatory collapse. Eight patients underwent splenectomy after a major episode of sequestration with no serious infectious complications up to 5 years following splenectomy. Three patients with minor episodes have been followed with no recurrences. To foster early detection of this potentially lethal complication of sickle cell disease, an educational program in our Comprehensive Sickle Cell Center instructs the parents to examine the spleen and bring their child in for evaluation if the spleen enlarges. A newly developed videotape describes the common symptoms of ASSC and illustrates the technique of palpating the spleen. With early detection of sickle cell disease by neonatal screening and the educational program, the morbidity and mortality from this complication of sickle cell disease can be reduced.

Plant regeneration from protoplasts of wheat (Triticum aestivum cv. Hartog)

Morphologically normal green plants have reproducibly been regenerated from protoplasts of an Australian wheat (Triticum aestivum cv. Hartog). The protoplasts were isolated from fine embryogenic suspension cultures which were initiated from embryogenic callus. Protoplasts were incubated in a modified liquid MS medium containing half strength of the macroelements, 5 μm 2,4-D and 0.6 M glucose. Colonies were formed at frequencies ranging from 0.1% to 5%. The frequency of colonies forming fully developed plants varied between 1% and 25%. More than eighty green plants with morphologically normal shoots and roots have been obtained and there was no difficulty in establishing these plants in soil. A cytological study of several randomly selected regenerated plants showed the normal chromosome complement for wheat (2n = 42).

Hierarchical distribution analysis for computer-assisted classifications of patient records

The many existing hierarchical classifications present opportunities for computer-aided classification of medical data. The authors evaluate lexical term mapping followed by hierarchical node activation to determine the semantic locality of diagnoses in the American College of Radiology (ACR) classification. The activated hierarchy exposes conceptual structures behind lexically matched categories and markedly narrows the alternatives for human review. Several distribution analyses are evaluated for narrowing the candidate search space, to reduce ambiguity. The methods were tested on a prototype system, using a set of 78 samples of Mayo radiology diagnoses; their relative effectiveness is illustrated.

The immortalization of thymic nurse cells by SV40 virus

Thymic nurse cells (TNCs) are stromal elements that contain between 20 and 200 T cells within their cytoplasm. Because of this unique feature they are believed to play a role in thymocyte development. Unfortunately, it has been difficult to obtain pure TNCs in quantities sufficient for extensive evaluation of their thymic function. As a result, only a limited amount of information is available that characterizes TNCs or the T cell population(s) found within their cytoplasm. We have now used SV40 to infect and immortalize TNCs from C57BL/6 mice. SV40-transformed TNCs were found to specifically bind and internalize cells from an immature thymocyte line isolated in our laboratory. These results describe a method of obtaining pure populations of TNCs for future studies of their thymic function, and suggest that binding to specific subpopulations of lymphoblasts may be necessary for internalization.

Corporectomy for intractable sickle-associated priapism

Priapism is a complication of sickle cell disease, and for those with severe prolonged attacks, it is serious, often resulting in permanent sexual impairment. Treatment is frustrating, and psychological consequences may be profound. A 20-year-old sickle cell patient with intractable priapism associated with intense pain and penile gigantism underwent multiple but unsuccessful medical and surgical treatment regimens. Finally, corpora cavernosa corporectomy was performed. The pathologic findings of extensive vascular thrombosis and stromal fibrosis underscore the irreversibility of this process and explain the inevitable impotence. Pain and sexual impairment were associated with serious psychological difficulties and suicide attempts. Counseling and close follow-up have improved his outlook considerably. He has been pain-free for 1 year, and future management includes consideration of placement of a penile prosthesis.

Magnetic resonance imaging of bone marrow in sickle cell disease: clinical, hematologic, and pathologic correlations

A longitudinal, prospective, controlled evaluation of magnetic resonance images (MRI) of long bones in sickle cell patients was undertaken simultaneously with assessment of clinical status and hematologic parameters, including dense erythrocytes. MRI of bone marrow in sickle cell patients during steady states appeared patchy and were markedly different from those in matched controls (P approximately 0). Patients with severe patchiness were older than those with mild or moderate patchiness (P less than .03). Sixty-nine MRI were performed during 28 painful episodes occurring in 14 subjects with sickle cell disease (SCD). Increased signals on intermediate and T2-weighted images were detected in 35.7% of painful episodes. These abnormalities were distinct and not observed to occur spontaneously during the steady-state examinations (P approximately 0). Bone marrow infarcts were confirmed by biopsy in two instances and autopsy in one instance. Dense red cells decreased by 40.81% of baseline during pain crises (P = .00005), more remarkably in those who had pain in the lower extremities (P = .0145). Patients with change in MRI during pain crises had a greater percentage change in the dense cells than those without the change in MRI (69.7% v 31.3%, P = .0120).

Pulmonary lipid nodules after intralipid infusion in a child with rhabdomyosarcoma and Staphylococcus epidermidis sepsis

Pulmonary lipid accumulation associated with intralipid infusion has been observed in autopsies of premature babies and a few adults. We report a 6-year-old boy with radiographically identifiable bilateral pulmonary nodules while he had Staphylococcus epidermidis sepsis. At the time, the child was receiving intralipid as a part of total parenteral nutritional support and was undergoing chemotherapy and radiotherapy for abdominal rhabdomyosarcoma. Pathological studies of the biopsied nodules revealed lipid deposits and foreign body type granulomatous vasculitis. Possible mechanisms for intralipid nodules in the lungs are discussed. Pulmonary intralipid accumulation can occur antemortem and should be included in the differential diagnosis of pulmonary nodules in patients with malignant tumors who are receiving intralipid infusion.

Maternal-fetal transport of vitamin K1 and its effects on coagulation in premature infants

We conducted a prospective study to determine (1) the maternal-fetal vitamin K1 transport in premature infants after vitamin K1 was given to the mothers antenatally and (2) the vitamin K1 effects on blood coagulation in the babies. Women in labor at less than or equal to 34 weeks of gestation were randomly selected to receive antenatal vitamin K1, 5 mg given intramuscularly (vitamin K1 group), or no vitamin K1 (control group). Eight infants, including one set of twins, were in the vitamin K1 group and six in the control group. Vitamin K1 concentrations were higher in the vitamin K1 group than in the control group (p = 0.06). Activated partial thromboplastin time was prolonged, and factor II coagulation activity and factor II antigen were proportionately decreased in cord plasma in both groups. The average ratio of factor II coagulation activity to antigen was not decreased in either group. Protein induced by vitamin K absence-II (PIVKA-II) was not detectable in any cord plasma sample in either group. These findings support previous reports that the decreased vitamin K-dependent coagulation activity in premature infants is the result of reduced synthesis of precursor proteins, rather than the result of vitamin K deficiency, and suggest that additional vitamin K1 is not likely to improve coagulation activity. Among those infants who underwent cranial ultrasonography, all four in the vitamin K1 group and one of five in the control group had mild intraventricular hemorrhage. Studies of a larger number of patients are necessary before it can be established that maternal antenatal administration of vitamin K1 results in improvement of coagulation and the prevention of intraventricular hemorrhage in premature infants.

[Study on leukemic-colony forming unit in 31 patients with acute non-lymphocytic leukemia]

Thirty-one patients with acute non-lymphocytic leukemia (ANLL) were studied with Dicke's soft agar marrow culture to identify leukemic colony forming units. Eighteen of them had leukemic colony formation, in those patients, the average survival period was shorter (65d), and none of them achieved remission after chemotherapy. The remaining thirteen patients had no colony formation and had a longer survival period of 119.8 d. In the latter group four out of six who had undergone more than two courses of chemotherapy went into complete remission. Our study showed that patients who had leukemic colony formation had a worse prognosis than those who had no leukemic colony formation.

Comparison of 252Cf plasma desorption mass spectrometry and fast atom bombardment mass spectrometry in identification of simple monoglucosyl conjugates

The fast atom bombardment (glycerol) and 252Cf plasma desorption mass spectra of 16 simple monoglucosyl conjugates have been compared. Plasma desorption mass spectrometry, in general, has been found to be the superior technique for characterizing these low molecular weight conjugates because of the relative absence of interfering matrix peaks.

Combined in-beam electron impact-B/E-linked scan mass spectrometry of oxazoline derivatives for the structure determination of long-chain unsaturated fatty acids

Long-chain unsaturated fatty acids (UFA) having up to six double bonds are derivatized to 2-substituted 4,4-dimethyloxazolines (DMOX) and then analyzed by combined in-beam electron impact (IBEI)-B/E-linked scan mass spectrometry. This technique provides highly characteristic mass spectra and may serve as an auxiliary means for direct structure determination of individual UFA in mixtures.

Magnetic resonance imaging of bone marrow in sickle cell patients

Assessment of the bone marrow in sickle cell patients with or without pain crises can be accomplished using a variety of imaging techniques. Conventional radiography is the least sensitive of all imaging modalities in the early stages of the bone marrow infarct. Radionuclide imaging using 99mTc sulfur colloid shows sharply demarcated photon-deficient regions that are slow to resolve. Cumulative exposure to ionizing radiation would be of concern if repeated examinations with conventional x-rays and radionuclides were carried out. Magnetic resonance imaging (MRI) is a noninvasive technique that differentiates the bone marrow of sickle cell patients from that of normal controls. Furthermore, at least in some patients, acute tissue changes can be detected during early stages of pain crises using magnetic resonance. Further investigations are necessary to optimize the use of MRI in sickle cell patients with pain crises.

Detection of trehalose monomycolate in Mycobacterium leprae grown in armadillo tissues

Trehalose-6-monomycolate (TMM) was isolated from the lipids of armadillo-derived Mycobacterium leprae. Only meagre amounts of this glycolipid were recovered, but its structure was unequivocally established. Only alpha-mycolates were detected in the TMM by 252Cf plasma desorption mass spectrometry. Electron impact mass spectrometry showed the alpha branch to be principally C20. Trehalose dimycolate (cord factor) was not detectable. Since we have also found TMM in M. lepraemurium and in every Mycobacterium species so far examined, we suggest that this glycolipid is truly ubiquitous amongst mycobacteria.