[Chemical constituents of Euphorbia nematocypha Hand.-Mazz]

Four compounds were isolated from the roots of Euphorbia nematocypha. Three of them were identified as A'-neogammacer-22(29)-en-3 beta-ol (18 beta.21 alpha) (II), jolkinolide E (III) and beta-sitoesterol (IV). Among them, II was obtained from the genus Euphorbia and III from this plant for the first time.

Multiple members of the E2F transcription factor family are the products of oncogenes

The retinoblastoma gene product (pRB) is a known tumor suppressor, capable of arresting growth in mid-to-late G1. Part of its growth suppression action arises from interaction(s) with one or more members of the E2F family of transcription factors. These proteins most likely contribute to progression from G0 to S phase in mammalian cells, and pRB binding most likely inhibits aspects of their suspected growth-promoting function. Given their growth-stimulating potential, we asked whether one or more E2F alleles can function as oncogenes. Uncloned pools of NIH 3T3 cells producing the pRB binding target E2F-1, E2F-2, or E2F-3 grew in semisolid medium. In addition, they grew to much higher saturation density than controls. From the study of cells producing selected E2F-1 mutant species, it appears that E2F DNA-binding function contributes to, and pRB/E2F binding suppresses, soft-agar growth. Thus, three E2F family members can act as oncogene products, suggesting that part of the normal role of pRB is to down-modulate this potential activity.

Purification and stabilization of mouse DNA methyltransferase

Cytosine methylation within DNA has been implicated in genetic imprinting, X-chromosome inactivation, regulation of tissue-specific gene expression, aging, and cancer. Unfortunately, DNA (cytosine-5)-methyltransferases (EC 2.1.1.37) from various mammalian sources have been difficult to isolate and stabilize, precluding investigations of these critical enzymes. We describe a novel FPLC purification of the 190,000 Mr DNA methyltransferase from mouse Friend erythroleukemia cells. The homogeneous 190 kD Mr form of the enzyme is the only polypeptide detected at various stages of cell growth and has not undergone detectable N-terminal proteolysis.

[Enhancing effects of the supernatant of pulmonary alveolar macrophages stimulated by BCG on proliferation on pulmonary fibroblasts]

The supernatant of pulmonary alveolar macrophages (PAM) stimulated by 7.5-60mg/L of BCG could significantly enhance proliferation of pulmonary fibroblasts (PFB), and the supernatant contained high level of TNF. This result indicated BCG could stimulate PAM to produce TNF in vitro. On the other hand, the supernatant of PAM stimulated by 50mg/L of SiO2 could also enhance proliferation of PFB, but the level of TNF in the supernatant was very low and it demonstrated the ingredient in the supernatant enhancing proliferation was not TNF. TNF showed synergistic effect with this ingredient for enhancing proliferation of PFB. Therefore, TNF produced by tuberculosis bacteria-stimulated PAM might be an important factor enhancing the development of fibrosis of silicotuberculosis.

Tyrosine phosphorylation of p95Vav in myeloid cells is regulated by GM-CSF, IL-3 and steel factor and is constitutively increased by p210BCR/ABL

Vav is a recently described proto-oncogene expressed only in hematopoietic cells which contains an SH2 and two SH3 domains and shares homology with the Dbl GDP-GTP exchange factor and BCR. p95Vav is phosphorylated on tyrosine residues in response to stimulation of the T cell antigen receptor, cross-linking of IgE or IgM receptors and stimulation of immature hematopoietic cells by Steel factor. Monoclonal antibodies to human Vav were generated and used to examine the events which regulate tyrosine phosphorylation of p95Vav in myeloid cells. In the factor-dependent MO7e cell line, p95Vav was rapidly phosphorylated on tyrosine residues in a dose- and time-dependent manner by GM-CSF, IL-3 and Steel factor. Introduction of the BCR/ABL oncogene into this cell line resulted in factor-independent proliferation and constitutive phosphorylation of p95Vav. Tyrosine phosphorylation of p95Vav was also substantially increased by treatment of cytokine-deprived cells with the tyrosine phosphatase inhibitor sodium vanadate. Since many of the cytokines known to induce tyrosine phosphorylation of p95Vav are also known to activate JAK family tyrosine kinases, we looked for an interaction of p95Vav with JAK kinases. p95Vav co-precipitated with JAK2 in MO7e cells stimulated with GM-CSF, but not in unstimulated cells. Also, JAK2 was found to be constitutively associated with p95Vav in vivo when expressed at high levels in insect cells using baculovirus vectors. A fusion protein consisting of glutathione-S-transferase and the SH2 domain of p95Vav (GST-Vav-SH2) precipitated JAK2, suggesting that this interaction is mediated by the SH2 domain of p95Vav.(ABSTRACT TRUNCATED AT 250 WORDS)

[Taxonomic studies on original plants of radix Euphorbiae ebracteolatae]

It has been discovered through investigation across the country that, thus far, the Radix Euphorbiae Ebracteolatae is derived from 12 species (varieties, forms) of 3 families. Their classification characters are discussed and a key is given in this paper.

[Anatomical relationship of the ethmoid-sphenoid areas to the optic canal and the internal carotid artery]

The anatomical relationships and morphologic features of the optic canal and the internal carotid artery to the lateral wall of the most posterior ethmoidal cell and the sphenoid sinus in 100 half-skulls swan middle-saggitally were investigated. The results showed: (1) The whole optic canals neighboured with the most ethmoidal cell in 39 cases, with the sphenoid sinus in 43 cases and with both of them in 18 cases; (2) The bulgings of the optic canal formed on the lateral wall of the most posterior ethmoidal cells and the sphenoid sinus were demonstrated in 48 and 47 cases respectively; (3) The marks of the internal carotid artery formed on the lateral wall of the sphenoid sinus were demonstrated in 53%-77% of all cases. The height and the thickness of the bony wall of the bulgings and marks of the optic canal and the internal carotid artery were measured. From our observation it was suggested that the variations of development and composition of the sphenoid-ethmoid sinuses, the bulging or mark of the optic canal and the internal carotid artery on the lateral wall of the most posterior ethmoidal cell and the sphenoid sinus might be the anatomical factors of severe complications in endoscopic ethmoid-sphenoid surgery.

Genomic organization of the neurofibromatosis 1 gene (NF1)

Neurofibromatosis 1 maps to chromosome band 17q11.2, and the NF1 locus has been partially characterized. Even though the full-length NF1 cDNA has been sequenced, the complete genomic structure of the NF1 gene has not been elucidated. The 5' end of NF1 is embedded in a CpG island containing a NotI restriction site, and the remainder of the gene lies in the adjacent 350-kb NotI fragment. In our efforts to develop a comprehensive screen for NF1 mutations, we have isolated genomic DNA clones that together harbor the entire NF1 cDNA sequence. We have identified all intron-exon boundaries of the coding region and established that it is composed of 59 exons. Furthermore, we have defined the 3'-untranslated region (3'-UTR) of the NF1 gene; it spans approximately 3.5 kb of genomic DNA sequence and is continuous with the stop codon. Oligonucleotide primer pairs synthesized from exon-flanking DNA sequences were used in the polymerase chain reaction with cloned, chromosome 17-specific genomic DNA as template to amplify NF1 exons 1 through 27b and the exon containing the 3'-UTR separately. This information should be useful for implementing a comprehensive NF1 mutation screen using genomic DNA as template.

Reproducing abnormal cholesterol biosynthesis as seen in the Smith-Lemli-Opitz syndrome by inhibiting the conversion of 7-dehydrocholesterol to cholesterol in rats

The Smith-Lemli-Opitz syndrome is a recessive inherited disorder characterized by neurologic developmental defects and dysmorphic features in many organs. Recently, abnormal cholesterol biosynthesis with impaired conversion of 7-dehydrocholesterol to cholesterol has been discovered in homozygotes. To reproduce the biochemical abnormality, BM 15.766, a competitive inhibitor of 7-dehydrocholesterol-delta 7-reductase, the enzyme that catalyzes the conversion of 7-dehydrocholesterol into cholesterol was fed by gavage to rats. After 14 d, plasma cholesterol concentrations declined from 48 mg/dl to 16 mg/dl and 7-dehydro-cholesterol levels rose from trace to 17 mg/dl. Hepatocytes surrounding the central vein developed balloon necrosis. Stimulating cholesterol synthesis with cholestyramine followed by BM 15.766 produced an additional 40% decline (P < 0.05) in plasma cholesterol and 34% increase in 7-dehydrocholesterol levels compared to the inhibitor alone. Adding 2% cholesterol to the diet during the second week of BM 15.766 treatment increased plasma cholesterol threefold and decreased 7-dehydrocholesterol concentrations 55%. Hepatic 3-hydroxy-3-methylglutaryl co-enzyme A (HMG-CoA) reductase activity increased 73% with a 3.9-fold rise in mRNA levels but cholesterol 7 alpha-hydroxylase activity decreased slightly though mRNA levels increased 1.4 times with BM 15.766 treatment. These results demonstrate that BM 15.766 is a potent inhibitor of 7-dehydrocholesterol-delta 7-reductase. The model reproduces abnormal cholesterol biosynthesis as seen in the Smith-Lemli-Opitz syndrome and is useful to test different treatment strategies. Stimulating early steps of cholesterol synthesis worsens the biochemical abnormalities while feeding cholesterol inhibits abnormal synthesis, improves the biochemical abnormalities and prevents liver damage.

Effect of chronic vanadate administration in partially depancreatized rats

The effects of vanadate on B-cell function and replication in rats after 90% partial pancreatectomy (Px) were compared with insulin therapy. At the age of 4 weeks, male Wistar rats were subjected to sham operation or Px. Vanadate (0.2 mg/ml) was given in drinking water for 3 weeks starting at 2 weeks after surgery. Regular insulin (2.4 units/day) was administered as a continuous subcutaneous infusion through an osmotic pump. Plasma glucose levels were significantly higher in the Px rats than in the sham rats from 1 week after surgery. Vanadate lowered plasma glucose levels to near normal values in the Px rats as early as 2 days. The effect was sustained throughout the experiment. The hypoglycemic effect of insulin was less than that of vanadate. During an i.p. glucose tolerance test, plasma glucose levels were decreased in the Px rats treated with vanadate or insulin, while plasma insulin levels were not affected. The insulin content in the Px rats treated with vanadate was significantly (P < 0.01) greater than in the insulin-treated Px rats. Histological examination showed fibrotic degeneration in the enlarged islets of Px rats, whereas the normal structure was retained in most islets of the Px rats treated with vanadate and insulin. In addition, B-cell areas within the islet were restored to normal levels not only in the insulin-treated Px rats but in the vanadate-treated Px rats. However, both vanadate and insulin failed to stimulate proliferative activity of the B-cells. These data suggest that vanadate is a new therapeutic option to ameliorate the diabetic state after Px.

Primary care and non-primary care physicians: a longitudinal study of their similarities, differences, and correlates before, during, and after medical school

PURPOSE--To investigate similarities and differences between physicians in primary care and non-primary care specialties on performance measures prior to, during, and after medical school, and on demographic characteristics, professional plans and preferences in medical school, professional activities, career satisfaction, perceived problems and research activities, and to predict primary--non-primary care career choices from information obtained in medical school. A questionnaire was mailed to 1,076 physicians who graduated from Jefferson Medical College between 1982 and 1986. Of those who responded (62%), 232 were primary care and 406 were non-primary care physicians (29 physicians in mixed specialties were excluded). Data from the questionnaire concerning professional activities, satisfaction, problems, and research productivities were merged with the college's longitudinal study database. RESULTS--Comparisons of primary care--non-primary care physicians indicated no significant difference between them on performance measures before, during, and after medical school, with the exception that non-primary care physicians had higher scores on quantitative tests before medical school, and primary care physicians scored higher on a licensing examination of general clinical skills and patient management taken during residency training. Also, compared with non-primary care physicians, those in primary care were less likely to be employed full-time, were less likely to locate in metropolitan areas, had a lower rate of academic appointment, and had a higher rate of board certification. Other results showed differences between the groups in terms of age at entrance to medical school, proportion of women, estimates during medical school of anticipated income, career plans during medical school, satisfaction with career and income, and research and scientific activities. A logistic regression model could predict primary care--non-primary care status from specialty interest, professional plans and interests expressed in medical school.

Lack of effect of CS-045, a new antidiabetic agent, on insulin secretion in the remnant pancreas after 90% pancreatectomy in rats

We assessed the effect of CS-045, a new hypoglycemic agent, on B-cell function in partially pancreatectomized rats. At the age of 4 weeks, male Wistar rats were subjected to 90% pancreatectomy (Px). For 2 weeks starting at 6 weeks after surgery the Px rats were treated with CS-045 (CS rats) mixed with chow pellets in a proportion of 0.2% (w/w). To compare the efficacy of CS-045 with that of insulin therapy, an osmotic pump was implanted to release insulin (1.2 units/day) into the intraperitoneal cavity of the Px rats (Is rats). Plasma glucose levels in the CS and Is rats were significantly lower than in the control Px rats; however, no marked improvement in plasma glucose or insulin levels was observed in glucose tolerance test (2 g/kg, i.p.) in the CS rats. Insulin secretion by the isolated perfused pancreas in response to 16.7 mM glucose showed a biphasic pattern, but was slightly reduced in the Px and CS rats compared with the Is rats. Insulin secretion induced by 19 mM arginine was unaffected by the treatment. The insulin content of the CS rats was significantly greater than in the Px and Is rats. Histological observations suggested regranulation of the pancreatic islets of the CS rats. B-cell areas within the islet were restored to normal levels in the Cs and Is rats. These findings indicate that the hypoglycemic effect of CS-045, which is not mediated by insulin secretion from the residual pancreas, prevents destruction of the islet.

A comparison of flow cytometry and microcytotoxicity for the evaluation of alloimmune therapy in patients with recurrent spontaneous abortions

PROBLEM

There is substantial data that support the efficacy of paternal leukocyte immunization (PLI) for the treatment of alloimmune mediated miscarriage; however, there is confusion regarding the laboratory test that should be performed to determine levels of maternal anti-paternal leukocyte antibodies (MAPLA).

METHOD

Popular methodologies employed include: 1) microcytotoxicity (MCX), 2) mixed lymphocyte culture (MLC), and 3) cell flow cytometry crossmatch (FCXM). Cell flow cytometry crossmatch correlates well with the more difficult MLC assay although the former proves the more sensitive study. This work compares the MCX assays with FCXM. The study group consisted of ten women who had a history of three or more spontaneous abortions (SABs). All ten had very low levels (< 10%) of MAPLA as measured by FCXM. Following PLI all subjects demonstrated elevated levels (> 50%) of MAPLA by FCXM. At 12 weeks gestation, sera were simultaneously measured for MAPLA by MCX and FCXM.

RESULTS

Although all ten patients had very high levels of MAPLA by FCXM during pregnancy, five of ten had antibodies to HLA Class I and two of ten had antibodies to HLA Class II paternal antigens by MCX. Furthermore, all patients who were positive by MCX to paternal Class I antigens were also positive to Class I antigens not seen in either parent. Both patients who were positive by MCX to paternal Class II antigens were also positive to maternal Class II antigens. Notable is that all ten women eventually delivered healthy infants.

CONCLUSION

Based on this preliminary study, the MCX assay is neither sensitive or reliable enough to determine the need and/or to monitor the effectiveness of PLI. Flow cytometry should be the modality of choice when determining the need for alloimmunotherapy and to monitor the effectiveness of treatment.

[Assay of R-plasmid and antibiotic resistance spectrum in 286 strains of gram-negative bacteria]

This paper reports the results of the sensitivity test to 10 antibiotics and the assay of R-plasmid on 286 strains of Gram-negative bacteria isolated from hospitals. It was found that the main prevalent resistant bacteria are Pseudomonas aeruginosa, Escherichia coli and Klebsiella pneumoniae. Their major antibiotic resistance spectrum is: Ampicillin, Carbenicillin, Chloramphemicol, Gentamicin, Furbenicillin. The results showed that 272 of 283 strains resisted to 1-9 antibiotics (95.1%). One-hundred and seventy-eight of 286 strains resisted to more than 4 antibiotics (62.2%). One-hundred and fifty-one of 286 strains carried R-plasmid in resistant bacteria (53.3%). 13.3% resistance markers were transferred with the whole R-factor. But 86.7% resistance markers were transferred with only a part of R-factor.

Primary care and nonprimary care physicians' concerns in practice and perceptions of medical school curriculum

The purpose of the present study is to address the issue of physicians' concerns in practice and their perception of a medical school's curriculum with an emphasis on comparisons between primary and nonprimary care physicians. The sample consisted of 663 physicians who graduated from Jefferson Medical College (JMC) between 1982 and 1986, and also responded to a mailed questionnaire. Comparisons were made between physicians in primary care (n=234) and in nonprimary care (n=429) specialties on their responses regarding concerns in medical practice and evaluation of the medical school curriculum. Primary care physicians were more concerned about the time for their professional development whereas nonprimary care physicians were more concerned about an oversupply of physicians in their specialties, prospective hospital payment, and malpractice litigation. Regardless of the specialties, the physicians overall seemed very concerned about their personal time. Interpersonal skills were regarded by all respondents as an important aspect of the medical school's curriculum. The importance of psychological, social, and cultural factors in the curriculum was strongly supported by these physicians' responses, particularly among primary care and women physicians.

E2F-4, a new member of the E2F transcription factor family, interacts with p107

The E2F family of transcription factors has been implicated in the regulation of cell proliferation, and E2F-binding sites are present in the promoters of several growth-regulating genes. E2F family members are functionally regulated, in part, by complex formation with one or more members of the nuclear pocket protein family, RB, p107, and p130. Pocket protein regulation of E2F likely contributes to normal cellular growth control. While the three cloned species of E2F, E2F-1, E2F-2, and E2F-3, are known to be targets of RB interaction, no E2F species has yet been shown to be a specific p107 or p130 target. Here, we describe the cloning of a new member of the E2F family, E2F-4, which forms heterodimers with a member(s) of the DP family and, unlike some family members, is present throughout the cell cycle and appears to be a differentially phosphorylated p107-binding partner. p107 binding not only can be linked to the regulation of E2F-4 transcriptional activity, but also to suppression of the ability of E2F-4 to transform an immortalized rodent cell line.

Emergency medicine career change: associations with performances in medical school and in the first postgraduate year and with indebtedness

OBJECTIVE

Emergency medicine has been identified as the specialty that has gained the most young physicians who have changed their careers. To identify factors that may have contributed to such career changes, the authors compared the characteristics of three groups of physicians trained at their medical school: those who chose and stayed in emergency medicine, those who migrated into emergency medicine from other specialties, and those who moved out of emergency medicine.

METHODS

A prospective longitudinal study was conducted. The sample consisted of physicians who chose emergency medicine as their careers at graduation and stayed in the specialty (n = 24), those who migrated from other specialties into emergency medicine (n = 51), and those who moved out of emergency medicine (n = 10). This sample was obtained from a total of 2,173 graduates of Jefferson Medical College between 1978 and 1987. The three groups of physicians were compared according to their academic performances both during medical school and after graduation. The dependent variables were freshmen and sophomore grade point averages (GPAs), written clinical examination scores, scores on National Board of Medical Examiners examination (Parts I, II, and III), and residency program directors' ratings. Age and indebtedness at medical school graduation and board certification status also were examined.

RESULTS

Those physicians who stayed in emergency medicine and those who migrated from other specialties into emergency medicine had similar measures of academic performance, but both of these groups had higher academic performance measures and higher board certification rates than did the physicians who moved out of emergency medicine. Those who stayed in emergency medicine had the highest mean debt in the senior year of medical school.

CONCLUSIONS

High academic performance and high indebtedness are factors associated with choosing or staying in the specialty of emergency medicine.

Random-amplified-polymorphic DNA markers in sorghum

Conditions have been identified that allow reproducible amplification of RAPD markers in sorghum. High resolution of RAPD markers was accomplished by radiolabeling PCR-amplified DNAs followed by separation on denaturing 5% polyacrylamide gels. Reaction parameters including MgCl2 concentration and temperature significantly influenced yield and the type of amplification products synthesized. Unexplained amplified DNAs increased when more than 35 cycles of PCR amplification were used. Under standard conditions, approximately 80% of the primers tested amplified DNA, and most revealed 1-5 polymorphisms between BTx 623 and IS 3620C. Primers were used to amplify RAPDs in 32 genotypes of sorghum. In addition, 8 primers detected RAPDs in a population previously used to create an RFLP map for sorghum. These RAPDs were mapped successfully using a population of 50 F2 plants.

Immunotherapy with anti-CD3 monoclonal antibodies and recombinant interleukin 2: stimulation of molecular programs of cytotoxic killer cells and induction of tumor regression

Adoptive cellular immunotherapy, infusions of interleukin 2 (IL-2) in conjunction with in vitro-activated killer cells, has brought new hope to patients with cancer. The broad application of this strategy, however, is constrained by the need for repeated leukapheresis and by the labor-intensive process of in vitro activation of cells. Also, current protocols generally use nonphysiological and toxic concentrations of IL-2. Identification of an in vivo stimulant that renders T cells responsive to physiologic concentrations of IL-2 represents a potential improvement over existing approaches. We have determined whether in vivo administration of monoclonal antibodies (mAbs) directed at the T-cell surface protein CD3 induces T-cell responsiveness to IL-2, stimulates cytolytic molecular programs of natural killer cells and cytotoxic T cells, and induces tumor regression. These hypotheses were explored in a murine hepatic MCA-102 fibrosarcoma model. We report that in vivo administration of anti-CD3 mAbs plus IL-2 results in intrahepatic expression of mRNA-encoding perforin, cytotoxic T-cell-specific serine esterase, and tumor necrosis factor alpha. Anti-CD3 mAbs alone or IL-2 alone failed to induce or induced minimal expression of these molecular mediators of cytotoxicity. The anti-CD3 mAbs plus IL-2 regimen also resulted in a significantly smaller number of hepatic metastases and a significantly longer survival time of tumor-bearing mice, compared to treatment with anti-CD3 mAbs alone or IL-2 alone. Our findings suggest that a regimen of anti-CD3 mAbs plus IL-2 is a more effective antitumor regimen compared with anti-CD3 mAbs alone or IL-2 alone and advance an alternative immunotherapy strategy of potential value for the treatment of cancer in humans.

LRG1 is expressed during sporulation in Saccharomyces cerevisiae and contains motifs similar to LIM and rho/racGAP domains

We here report the sequence of a yeast gene LRG1 whose deduced amino acid sequence contains sequence motifs similar to LIM domain proteins in the amino-terminal, and to rho/rac GTPase activating proteins (rho/racGAP's) in the carboxy-terminal part. LRG1 expression is differentially regulated showing a peak of expression in sporulating cells. Gene disruption experiments indicate that the gene is not essential and may play a role during mating.

RFLP mapping of partially sequenced leaf cDNA clones in maize

We report here the results of mapping a set of 92 leaf cDNA clones in maize. The ends of each of these cDNA clones have previously been partially sequenced, and the sequence comparison has revealed the putative function for 28 clones. It is expected that the RFLP map developed using these expressed sequence tags will be of great importance for future maize genome analysis, such as for PCR-based gene mapping or gene function identification.

[Nosocomial respiratory infection caused by Xanthomonas maltophilia in immunocompromised hosts]

Between January 1988 and December 1992, 68 patients admitted to our Department of Internal Medicine with hematological malignancies or solid tumors showed colonization of the respiratory tract with Xanthomonas maltophilia (X. maltophilia). To characterize the significance of respiratory tract colonization by X. maltophilia, we retrospectively reviewed the medical records of the 68 patients colonized with this organism. Twenty-seven of these 68 patients developed pneumonia, with X. maltophilia being implicated in 10 cases. The majority of the 10 patients showed lobular infiltration on chest X-ray. Pleural effusion was observed in 2 (20%) of the 10 patients. All 68 strains of X. maltophilia were resistant to imipenem/cilastatin. Most strains (98.5%) were sensitive to latamoxef, while all strains were sensitive to minocycline. This report describes the clinical features of nosocomial X. maltophilia pneumonia in immunocompromised patients.