[Lipopolysaccharide-induced apoptosis of rat hepatocyte in vitro]

OBJECTIVES

To investigate the effect of lipopolysaccharide(LPS) on hepatocyte in vitro.

METHODS

The hepatocytes were isolated in the way of liver perfusion with 0.05% collagenase type I and type IV, and cultured for 24 h in vitro before LPS was added directly into the culturing medium. Propidium iodide(PI) staining, and transmission electron microscopy techniques had been used to observe the morphological changes of hepatocyte treated with LPS. DNA-fragment assay was analyzed by the agarose gel electrophoresis to determine apoptotic level.

RESULTS

Hepatocytes incubated with LPS exhibited some typical apoptosis-specific morphological features. The DNA-fragment by agarose gel electrophoresis demonstrated the typical ladder pattern on the hepatocytes directly exposed to LPS, but it was absent in the group used ATA, an inhibitor of apoptosis. These morphological changes, accompanied by DNA fragmentation assay, confirmed that cells were dying through an apoptotic pathway. In addition, the hepatocyte number of apoptosis increased parallel with the dose of LPS and time within 24 h when hepatocytes were exposed to LPS alone.

CONCLUSIONS

LPS can induce apoptosis of hepatocyte in vitro.

Spontaneous regression of primary autoreactivity during chronic progression of experimental autoimmune encephalomyelitis and multiple sclerosis

Experimental autoimmune encephalomyelitis (EAE) is a widely used animal model for multiple sclerosis (MS). EAE is typically initiated by CD4(+) T helper cell type 1 (Th1) autoreactivity directed against a single priming immunodominant myelin peptide determinant. Recent studies have shown that clinical progression of EAE involves the accumulation of neo-autoreactivity, commonly referred to as epitope spreading, directed against peptide determinants not involved in the priming process. This study directly addresses the relative roles of primary autoreactivity and secondary epitope spreading in the progression of both EAE and MS. To this end we serially evaluated the development of several epitope-spreading cascades in SWXJ mice primed with distinctly different encephalitogenic determinants of myelin proteolipid protein. In a series of analogous experiments, we examined the development of epitope spreading in patients with isolated monosymptomatic demyelinating syndrome as their disease progressed to clinically definite MS. Our results indicate that in both EAE and MS, primary proliferative autoreactivity associated with onset of clinical disease invariably regresses with time and is often undetectable during periods of disease progression. In contrast, the emergence of sustained secondary autoreactivity to spreading determinants is consistently associated with disease progression in both EAE and MS. Our results indicate that chronic progression of EAE and MS involves a shifting of autoreactivity from primary initiating self-determinants to defined cascades of secondary determinants that sustain the self-recognition process during disease progression.

Ventilatory, lactate-derived and catecholamine thresholds during incremental treadmill running: relationship and reproducibility

Anaerobic threshold as a basic criterion of training recommendation can be estimated by various parameters. The purpose of this study was to investigate the relationship and the reproducibility of ventilatory, lactate-derived and catecholamine thresholds of an incremental treadmill exercise. Therefore, 11 male subjects underwent two incremental treadmill tests within 7 days. The lactate threshold (LT) was determined at the lowest value of the lactate-equivalent (ratio lactate/performance). The individual anaerobic threshold (IAT) was calculated at LT+1.5 mmol/L lactate. The ventilatory thresholds, using mass-spectrometry, were defined by the V-slope method (AT) and at the deflection point of end-tidal CO2 (ET-CO2) concentration (RCP). The thresholds of epinephrine (TE) and norepinephrine (TNE) were calculated in the manner of LT. The running velocities were highly reproducible at LT (test-retest correlation coefficient r=0.90), IAT (r=0.97), AT (r=0.88) and RCP (r=0.95). By contrast TE (r=0.49) and TNE (r=0.46) showed a poor reproducibility. TE and TNE occurred 5-11% below LT and AT with a low correlation to LT and AT. LT was found 4% below AT, both were correlated with r=0.70 (p<0.01, test 1) and r=0.95 (p<0.01, test 2). IAT occurred 7-8% above RCP, in both tests a close correlation was found between IAT and RCP of r=0.97 (p<0.01). In summary, the ventilatory and lactate-derived thresholds show a high and similar reproducibility, but the catecholamine threshold does not. In the present exercise protocol, there are systematic differences between the lactate-derived and ventilatory thresholds, in spite of a close relationship, and these must be taken into account in recommendations derived for training.

[A new cultivated technique of Rehmannia glutinosa by sprout cutting]

The traditional cultivated method of Rehmannia glutinosa is the asexual reproduction that small rhizomes are used as materials of reproduction. In this test, the small rhizomes germinated on seedbed, then young sprouts were picked for culture.

[Effect of recombinant human growth hormone with total parenteral nutrition on albumin synthesis in patients with peritoneal sepsis]

OBJECTIVE

To investigate the effect of recombinant human growth hormone (rhGH) in combination with total parenteral nutrition (TPN) on albumin synthesis in patients with peritoneal sepsis.

METHOD

17 patients with peritoneal sepsis were divided randomly into two groups. The control group received TPN only for 7 days, and the GH group received both rhGH (12 U/d) and TPN for 7 days. The TPN scheme and other treatment were the same in the two groups.

RESULT

Serum albumin, prealbumin, and transferrin concentration were increased in patients in the GH group (P < 0.01), but no apparent effect was observed in the control group (P > 0.05).

CONCLUSION

In condition of serious peritoneal sepsis, TPN can not increase albumin, prealbumin, and transferrin synthesis alone, whereas rhGH in combination with TPN significantly increase the synthesis of visceral proteins.

Host response to EBV infection in X-linked lymphoproliferative disease results from mutations in an SH2-domain encoding gene

X-linked lymphoproliferative syndrome (XLP or Duncan disease) is characterized by extreme sensitivity to Epstein-Barr virus (EBV), resulting in a complex phenotype manifested by severe or fatal infectious mononucleosis, acquired hypogammaglobulinemia and malignant lymphoma. We have identified a gene, SH2D1A, that is mutated in XLP patients and encodes a novel protein composed of a single SH2 domain. SH2D1A is expressed in many tissues involved in the immune system. The identification of SH2D1A will allow the determination of its mechanism of action as a possible regulator of the EBV-induced immune response.

A new candidate region for the positional cloning of the XLP gene

X-linked lymphoproliferative disease (XLP) is an inherited immunodeficiency characterised by selective susceptibility to Epstein-Barr virus and frequent association with malignant lymphomas chiefly located in the ileocecal region, liver, kidney and CNS. Taking advantage of a large bacterial clone contig, we obtained a genomic sequence of 197620 bp encompassing a deletion (XLP-D) of 116 kb in an XLP family, whose breakpoints were identified. The study of potential exons from this region in 40 unrelated XLP patients did not reveal any mutation. To define the critical region for XLP and investigate the role of the XLP-D deletion, detailed haplotypes in a region of approximately 20 cM were reconstructed in a total of 87 individuals from 7 families with recurrence of XLP. Two recombination events in a North American family and a new microdeletion (XLP-G) in an Italian family indicate that the XLP gene maps in the interval between DXS1001 and DXS8057, approximately 800 kb centromeric to the previously reported familial microdeletion XLP-D.

Human immunodeficiency virus type 1 replication is modulated by host cyclophilin A expression levels

Human immunodeficiency virus type 1 (HIV-1) Gag and the cellular protein cyclophilin A form an essential complex in the virion core: virions produced by proviruses encoding Gag mutants with decreased cyclophilin A affinity exhibit attenuated infectivity, as do virions produced in the presence of the competitive inhibitor cyclosporine. The A224E Gag mutant has no effect on cyclophilin A affinity but renders HIV-1 replication cyclosporine resistant in Jurkat T cells. In contrast, A224E mutant virus is dead in H9 T cells, although replication is rescued by cyclosporine or by expression in cis of a Gag mutant that decreases cyclophilin A-affinity. The observation that disruption of the Gag-cyclophilin A interaction rescues A224E mutant replication in H9 cells prompted experiments which revealed that, relative to Jurkat cells, H9 cells express greater quantities of cyclophilin A. The resulting larger quantity of cyclophilin A shown to be packaged into virions produced by H9 cells is presumably disruptive to the A224E mutant virion core. Further evidence that increased cyclophilin A expression in H9 cells is of functional relevance was provided by the finding that Gag mutants with decreased cyclophilin A affinity are dead in Jurkat cells but capable of replication in H9 cells. Similarly, cyclosporine concentrations which inhibit wild-type HIV-1 replication in Jurkat cells stimulate HIV-1 replication in H9 cells. These results suggest that HIV-1 virion infectivity imposes narrow constraints upon cyclophilin A stoichiometry in virions and that infectivity is finely tuned by host cyclophilin A expression levels.

The epitope spreading cascade during progression of experimental autoimmune encephalomyelitis and multiple sclerosis

We have made the following observations regarding self-recognition during the development and progression of murine experimental autoimmune encephalomyelitis (EAE) and human multiple sclerosis (MS): 1) chronic progression of EAE is accompanied by a sequential, predictable cascade of neo-autoreactivity, commonly referred to as epitope spreading, presumably caused by endogenous self-priming during autoimmune-mediated tissue damage; 2) there is an invariant relationship between the progression of EAE and the emergence of epitope spreading; 3) progression of EAE can be inhibited by the induction of antigen-specific tolerance to spreading determinants after onset of initial neurologic symptoms; 4) CD4+ Th 1 cells responding to spreading determinants are autonomously encephalitogenic; 5) epitope spreading occurs during the development of MS and in some cases involves HLA-DP class II-restricted self-recognition; and 6) progression of both EAE and MS is accompanied by the decline of primary T-cell autoreactivity associated with disease onset and by the concurrent emergence of the epitope spreading cascade. Our studies directly challenge the traditional view that EAE and MS are initiated and maintained by autoreactivity directed against a single predominant myelin protein or determinant. Our results indicate that progression of EAE and MS involves a shifting of T-cell autoreactivity from primary initiating self-determinants to defined cascades of secondary determinants that sustain the inflammatory self-recognition process during disease progression.

Continuing quality improvement procedures for a clinical PACS

The University of California at San Francisco (USCF) Department of Radiology currently has a clinically operational picture archiving and communication system (PACS) that is thirty-five percent filmless, with the goal of becoming seventy-five percent filmless within the year. The design and implementation of the clinical PACS has been a collaborative effort between an academic research laboratory and a commercial vendor partner. Images are digitally acquired from three computed radiography (CR) scanners, five computed tomography (CT) scanners, five magnetic resonance (MR) imagers, three digital fluoroscopic rooms, an ultrasound mini-PACS and a nuclear medicine mini-PACS. The DICOM (Digital Imaging and Communications in Medicine) standard communications protocol and image format is adhered to throughout the PACS. Images are archived in hierarchical staged fashion, on a RAID (redundant array of inexpensive disks) and on magneto-optical disk jukeboxes. The clinical PACS uses an object-oriented Oracle SQL (systems query language) database, and interfaces to the Radiology Information System using the HL7 (Health Languages 7) standard. Components are networked using a combination of switched and fast ethernet, and ATM (asynchronous transfer mode), all over fiber optics. The wide area network links six UCSF sites in San Francisco. A combination of high and medium resolution dual-monitor display stations have been placed throughout the Department of Radiology, the Emergency Department (ED) and Intensive Care Units (ICU). A continuing quality improvement (CQI) committee has been formed to facilitate the PACS installation and training, workflow modifications, quality assurance and clinical acceptance. This committee includes radiologists at all levels (resident, fellow, attending), radiology technologists, film library personnel, ED and ICU clinician end-users, and PACS team members. The CQI committee has proved vital in the creation of new management procedures, providing a means for user feedback and education, and contributing to the overall acceptance of, and user satisfaction with the system. Well developed CQI procedures have been essential to the successful clinical operation of the PACS as UCSF Radiology moves toward a filmless department.

[Uterine and placental vascular lesions in pregnancy induced hypertension and its relationship to pregnancy outcome]

OBJECTIVE

To study the vascular lesions of the uterus and placenta in severe pregnancy induced hypertension (SPIH) and its relationship to pregnancy outcomes.

METHODS

29 cases of SPIH and 29 cases of normal term pregnancies (NTP) were examined to observe the expressions of IgA, IgG, IgM and C3 in the vascular walls of placental villus and uterus placental bed by immunohistochemical technique.

RESULTS

(1) In SPIH, the positive expression rates of the IgA, IgG, IgM and C3 in the vascular wall of placental villus (20.1%, 24.1%, 72.4%, and 65.5%) and uterus placental bed (20.0%, 20.0%, 70.0% and 60.0%) were significantly higher than those of NTP (all P < 0.05), while there were no expression in NTP. (2) The thickening of endangium angiostenosis, fibronoid necrosis and acute arterial atherosis were found at the sites of positive expressions in SPIH. (3) In SPIH complicated by intrauterine growth retardation (IUGR), the positive expressions of the immunocomplex and complement in the vessel walls (76.2%) were significantly higher than those of the SPIH without IUGR (50%, all P < 0.05).

CONCLUSION

In SPIH, there are depositions of immunocomplex and complement on the vessel walls of placental villus and uteroplacenta. Immunological factor plays an important role in the development of PIH.

[Placental morphometriological study on prolonged and delayed pregnancy and its relationship to pregnancy outcome]

OBJECTIVE

To study the morphological characteristics of the placental villous vessels and uteroplacental spiral arteries in the prolonged and delayed pregnancy and its relationship to pregnancy outcome.

METHODS

Placentae from 20 cases of prolonged pregnancy (PP), 15 cases of delayed pregnancy (DP), and 29 cases of normal term pregnancy (NTP) were examined by morphometriological feature image analysis.

RESULTS

Significant differences were found between PP and NTP groups (P < 0.05) in the following findings: the placental weights, the numbers of the placental villus with the syncytial knots, cytotrophoblasts, thickening of basal lamina, fibrinoid necrosis, vasculosyncytial membranes, and the diameter, perimeter and area of the villi the spiral artery wall thickening of the uteroplacental bed, and the incidences of the oligoamnios and amniotic fluid meconium staining. Significant differences of the villus perimeter and oligoamnios were only found between DP and NTP (all P < 0.05). There was no significant differences in the indices between PP and DP. As the pregnancy delayed and prolonged, the placental weights gradually decreased and the low Apgar score of neonates gradually increased.

CONCLUSION

After term pregnancy the placental function is gradually lowered especially in PP. The situations of the placenta, amniotic fluid, and fetus should be frequently monitored after 40 gestational weeks.

Association of multiple endocrine neoplasia type 2 and Hirschsprung disease

In a few patients with Hirschsprung disease (HSCR) and no clinical symptoms of multiple endocrine neoplasia type 2 (MEN-2A) or medullary thyroid carcinoma (MTC), missense mutations in the cysteine residues 609 and 620 of the Ret gene have been identified. In several pedigrees with either MEN-2A or familial MTC (FMTC) a documented germline mutation in cysteine 618 or 620 follows the segregation of the disease phenotype. The appearance of the HSCR phenotype in such patients and pedigrees cannot be easily reconciled with the gain of function which is associated with the dominant oncogenic effect of MEN-2A mutations. Gastrointestinal manifestations are known to occur also in association with MEN-2B but, to the best of our knowledge, in only very few cases the intestinal phenotype of MEN-2B has been investigated by enzymo-histochemical techniques, as in the present work. We report an extensive molecular study of patients, two with HSCR and FMTC carrying a Cys620Arg or Ser mutation and two with MEN-2B and gastrointestinal symptoms carrying a Met918Thr mutation. One of the latter two patients showed aganglionosis of the last 5 cm of rectum which caused a congenital megacolon leading to the diagnosis and operation for HSCR. The mutation screening of all the exons of Ret in 3 of these patients did not reveal any additional mutation. Therefore these results do not support the hypothesis of additional constitutional Ret mutations in patients showing association of MEN-2 and HSCR, whilst the histochemical and clinical data in one of these patients indicate that MEN-2B can be associated with a true form of short segment HSCR.

Disruption of the Jak1 gene demonstrates obligatory and nonredundant roles of the Jaks in cytokine-induced biologic responses

Herein we report the generation of mice lacking the ubiquitously expressed Janus kinase, Jak1. Jak1-/- mice are runted at birth, fail to nurse, and die perinatally. Although Jak1-/- cells are responsive to many cytokines, they fail to manifest biologic responses to cytokines that bind to three distinct families of cytokine receptors. These include all class II cytokine receptors, cytokine receptors that utilize the gamma(c) subunit for signaling, and the family of cytokine receptors that depend on the gp130 subunit for signaling. Our results thus demonstrate that Jak1 plays an essential and nonredundant role in promoting biologic responses induced by a select subset of cytokine receptors, including those in which Jak utilization was thought to be nonspecific.

Breast implants and risk of neurologic disease: a population-based cohort study in Sweden

OBJECTIVE

To examine the risk of neurologic disorders among women with breast implants.

BACKGROUND

Case reports in the literature have raised concern about a possible link between silicone breast implants and some types of neurologic disorders, but there is a dearth of epidemiologic studies in this area.

METHODS

Through the nationwide Swedish hospital discharge register, we identified a population-based cohort of 7433 women with breast implants. A similarly identified cohort of 3351 women who underwent breast reduction surgery served as a comparison. The women were followed from 1972 (or date of breast surgery if it occurred later) through 1993 by means of record linkages and review of inpatient medical records. Ratios of observed to expected numbers, and relative risks (RR) with 95% confidence intervals (CI), were calculated as measures of the risk of neurologic diseases among women with implants.

RESULTS

A direct comparison of the exposed (implant) versus comparison (breast reduction) groups, after exclusion of patients with pre-existing disease or incorrect neurologic diagnoses, showed no excess risk among implant patients (RR = 0.8; 95% CI = 0.5 to 1.4). When external rates derived from the background population were used as comparison, we found a small, statistically nonsignificant excess of neurologic disorders both in the breast implant (RR = 1.3; 95% CI = 0.9 to 1.9) and the breast reduction (RR = 1.5; 95% CI = 0.9 to 2.4) cohorts.

CONCLUSION

Our results provide no support for the conjecture that breast implants cause neurologic disease.

Cytotoxicity of xenobiotics and expression of glutathione-S-transferases in immortalised rat hepatocyte cell lines

1. Immortalised rat hepatocyte cell lines are more sensitive to the cytotoxicity of 1-chloro-2,4-dinitrobenzene and ethacrynic acid than primary cultures of hepatocytes. 2. Class alpha glutathione S-transferases are not expressed in immortalised hepatocyte cell lines. Class pi glutathione S-transferase expression is elevated in the immortalised cell lines compared with freshly isolated hepatocytes, but it is not as high as in the HTC rat hepatoma cell line. 3. Immortalised hepatocyte cell lines may provide a sensitive model system for detecting cytotoxicity associated with xenobiotics which are detoxified by glutathione S-transferases.

Risk of connective tissue disease and related disorders among women with breast implants: a nation-wide retrospective cohort study in Sweden

OBJECTIVE

To examine the relation between connective tissue disease and related conditions and breast implants.

DESIGN

Retrospective cohort study of all women in the Swedish national inpatient registry who underwent breast augmentation surgery with artificial implants during 1964-93, compared with women who underwent breast reduction surgery during the same period.

SETTING

Sweden.

SUBJECTS

7442 women with implants for cosmetic reasons or for reconstruction after breast cancer surgery and 3353 women with breast reduction surgery.

MAIN OUTCOME MEASURES

Subsequent hospitalisation for definite connective tissue diseases (rheumatoid arthritis, systemic lupus erythematosus, systemic sclerosis, dermatomyositis, and Sjögren's syndrome) or related disorders.

RESULTS

29 women with implants were hospitalised for definite connective tissue disease compared with 25.5 expected based on general population rates (standardised hospitalisation ratio 1.1 (95% confidence interval 0.8 to 1.6)). There were no diagnoses of systemic sclerosis, and no significant excess in risk for polymyalgia rheumatica, fibromyalgia, and several related disorders. Among women who underwent breast reduction surgery, 14 were hospitalised for definite connective tissue disease compared with 10.5 expected (standardised hospitalisation ratio 1.3 (0.7 to 2.2)). Compared with the breast reduction group, women with breast implants showed a slight reduction for all definite connective tissue disease (relative risk 0.8 (95% confidence interval 0.5 to 1.4)).

CONCLUSIONS

This large nationwide cohort study shows no evidence of association between breast implants and connective tissue disease.

[Diagnosis and endovascular treatment of multiple thrombosis in cerebral venous sinus]

OBJECTIVE

To study 12 cases of multiple thrombosis in cerebral venous sinuses and the diagnosis and endovascular therapy.

METHOD

The long T2 and short T1 signals in the related region of multiple venous sinuses on MR were important characteristics for the diagnosis before angiography. In the 12 cases, the treatment consisted of intermittent injection of urokinase via common carotid artery and oral administration of warfarin.

RESULTS

Intracranial pressure of 11 cases reduced to lower than 300 mm H2O and clinical deficits were markedly improved in 10 days. Re-angiography of 4 cases found partial recanalization in 2 in one week after therapy.

CONCLUSION

Intraoarterial thrombolysis combined with general anticoagulation in the treatment of multiple thrombosis in cerebral venous sinuses may be an effective meansure.

Control of mouse hepatocyte proliferation and ploidy by p53 and p53ser246 mutation in vivo

The effect of expression of the p53 gene, in the presence or absence of the p53ser246 mutation (p53*), on ploidization (image cytometry), proliferation (expression of proliferating cell nuclear antigen and radioactive thymidine histoautoradiography), and apoptosis (in situ detection of DNA fragments) is determined in hepatocytes of p53-null and p53*-transgenic mice. The mouse p53ser246 mutation is equivalent to the p53ser249 mutation found in human hepatomas associated with hepatitis B virus infection and aflatoxin exposure. The hepatocytes of heterozygous or homozygous p53-knockout mice (p53+/-; p53-/-), as well as knockout mice expressing one allele of p53ser246 (p53+/-, p53*; p53-/-, p53*), do not undergo normal polyploidization with aging and show an increase in the number of cycling (G1-, S-, and M-phase) cells. In addition, p53ser246-transgenic mice (p53+/+, p53*; p53+/-, p53*; and p53-/-, p53*) have a greatly increased number of hepatocytes in the G1 phase. No differences in rates of apoptotic hepatocytes are found among any of the mouse groups studied, so the increased proliferation results in a hyperplasia manifested by a increased number of small periportal cells. We conclude that loss of p53 removes blocks in the cell cycle, leading to increased proliferation, whereas expression of the p53ser246 mutation stimulates G0 to G1 and/or M to G1 transition of hepatocytes. Increased proliferation of hepatocytes, combined with no concomitant increase in apoptosis, may in part explain the enhanced development of hepatocellular carcinomas in p53-knockout and p53*-transgenic mice exposed to aflatoxin.

Two pimarane diterpenoids from Ephemerantha lonchophylla and their evaluation as modulators of the multidrug resistance phenotype

Two new pimarane diterpenoids, lonchophylloids A (1) and B (2), were isolated from the stems of Ephemerantha lonchophylla. The structures of 1 and 2 were established predominantly through the application of extensive 1H-and 13C-NMR, 1D- and 2D-homonuclear and heteronuclear correlation NMR experiments, and X-ray diffraction methods. Consistent with structure--activity predictions, both compounds were capable of sensitizing cells that expressed the multidrug resistance phenotype to the toxicity of the anticancer drug doxorubicin.

[Inherent mdr-1 gene expression in fresh tumor tissue specimens from several high-incidence malignancies]

OBJECTIVE

To ascertain frequency of inherent mdr-1 gene expression in several common neoplasms.

METHODS

One hundred fifty one surgically resected tumor specimens confirmed pathologically to be malignant from preoperatively untreated cancer patients were studied. Expression of mdr-1 gene was examined by RT-PCR.

RESULTS

The frequency of primary mdr-1 gene expression was 33.3% for cancer of the stomach and gastric cardia (17/51), 37% for cancer of the esophagus (17/46), 31.3% for cancer of the colon and rectum (5/16), 13.2% for cancer of the breast (2/15), 40.0% for cancer of the thyroid (4/10), 55.0% for cancer of the lung (5/9) and 0% for cancer of the uterine cervix (0/4).

CONCLUSION

Primary mdr-1 gene expression is relatively of frequent occurrence as detected by RT-PCR technique.

[Spectrophotometric method for determination of protein in food with Hantzsch reaction]

A new spectrophotometric method for the determination of protein in food was developed. The method is based on the reaction of ammonia in Kjeldahl digest with acetylacetone for maldehyde reagent in pH4.8 acetate medium to yield a yellow compound 3,5-diacetyl-2,6-dimethyl-1,4-dihydropyridine. Beer's law is obeyed in the concentration range of 0-10.0 mg/L at 400 nm. The molar absorptivity in terms of nitrogen was 1.7 x 10(-3). The recoverites of the added standard samples were 99.6%-101.2%, and relative standard deviation was below 3.7%.

Apoptotic condensations in M-phase cells

BACKGROUND

Apoptosis is a morphologically distinctive form of programmed cell death/cell suicide in which genomic DNA degradation/fragmentation and variegated dense chromatin aggregates are characteristic hallmarks that have never been demonstrated in mitotic cells. Perceptions of mutual exclusivity between apoptosis and mitosis imply that M-phase cells cannot be apoptotic. However, in the present study we show apoptotic morphologies in M-phase cells after an acute oxidative stress and endonuclease digestion.

METHODS

Degradation of genomic DNA in human Chang liver cells (American Type Culture Collection, ATCC CCL13) was demonstrated by flow cytometric cell-by-cell evaluation of (a) propidium iodide intercalative binding to DNA and (b) terminal deoxynucleotidyl transferase (TdT)-mediated 3'OH nick end labeling (TUNEL) of fragmented DNA. Oxidative stress was imposed by a 30-min prepulse with 200 microM vanadyl(4), which produces hydroxyl free radicals (OH*), the most reactive of the free radical species. Oxidative stress in the cells was demonstrated by evaluating glutathione-S-transferase (GST)-mediated monochlorobimane-glutathione adduct fluorescence for glutathione content, the main reducing agent of a cell, and methylene blue redox metachromasia, which is a deep color when oxidized and colorless when reduced. Cells with DNA fragmentation were highlighted by TUNEL. Apoptotic morphologies were visualized by staining with Giemsa and neutral red dyes and by DNA-propidium iodide binding to chromatin. Direct endonuclease induction of apoptotic morphologies in permeabilized M-phase cells was produced by 1 hr incubation (37 degrees C) with 16 units/ml of micrococcal nuclease.

RESULTS

The genomic DNA of proliferative cells, namely in G2/M phase of the cell cycle, was degraded by vanadyl(4) prepulsing and by micrococcal nuclease digestion, concomitantly with DNA fragmentation shown by TUNEL. Cytological profiles showed GSH depletion and M-phase cells with particularly high oxidative reactivity indicated by methylene blue redox metachromasia. DNA fragmentation in M-phase cells was highlighted by TUNEL. Characteristic apoptotic condensations, ranging from single-ball condensations to "pulverized" aggregates of a mitotic catastrophe, buddings, and "apoptotic bodies," were found in prophase, metaphase, anaphase, and telophase mitotic cells. The observed separation of condensed chromatin aggregates from the main chromosome mass in prophase and metaphase cells could explain micronuclei, linking it with apoptosis. Direct endonuclease digestion readily produced apoptotic morphologies in interphase and in M-phase cells.

CONCLUSION

Apoptotic morphologies in M-phase cells can be induced indirectly via oxidative stress or directly via endonuclease activity, which has long been established as a pervading hallmark of apoptosis.

[Influence of intercellular adhesion molecule-1 transcription on nasal epithelial cell by airborne allergenic pollens]

Eleven patients with Artemisia allergic rhinitis were evaluated. Among them 8 were studied during pollen season and 3 out of pollen season. Intercellular adhesion molecule-1(ICAM-1) was detected on nasal epithelial cells by reverse transcription polymerase chain reaction (RT-PCR). The results showed that ICAM-1 was detectable from all samples in the pollen season. However, during off-pollen season 2 of the 3 samples were negative, 1 was positive (who was also positive to house dust). It is suggested that ICAM-1 is detectable on nasal epithelial cells during exposure to specific allergen.

Immune responses in mice deficient in Ly-GDI, a lymphoid-specific regulator of Rho GTPases

Ly-GDI (lymphoid-specific guanosine diphosphate (GDP) dissociation inhibitor), also called D4-GDI, is preferentially expressed in hematopoietic tissues including bone marrow, thymus, spleen and lymph nodes. It binds to the small guanosine triphosphate (GTP)-binding protein Rho and inhibits GDP dissociation from Rho proteins. To explore the function of Ly-GDI in lymphocytes, we have generated Ly-GDI-deficient mice by gene targeting. These mice showed no striking abnormalities of lymphoid development or thymocyte selection. The mice also exhibited, for the most part, normal immune responses including lymphocyte proliferation, IL-2 production, cytotoxic T lymphocyte activity, antibody production, antigen processing and presentation, immune cell aggregation and migration, and protection against an intracellular protozoan. However, Ly-GDI-deficient mice exhibited deregulated T and B cell interactions after in vitro cultivation of mixed lymphocyte populations in concanavalin A (Con A) leading to overexpansion of B lymphocytes. Further studies revealed that Ly-GDI deficiency decreased IL-2 withdrawal apoptosis of lymph node cells while dexamethasone- and T cell receptor-induced apoptosis remained intact. These data implicate the regulation of the Rho GTPase by Ly-GDI in lymphocyte survival and responsiveness, but suggest that these functions may be partially complemented by other Rho regulatory proteins when the Ly-GDI protein is deficient.

The morphology of the immature HIV-1 virion

Newly released HIV-1 particles exhibit an immature morphology, previously reported to be characterized by a doughnut/ring-shaped structure. In this study we showed that among immature extracellular virus particles not only were particles with doughnut-shaped morphology present, but particles with a crescent morphology were also observed. These particles occurred with different frequencies, depending on whether they were in the cell or in cell-free fractions. The crescent-shaped particles were more abundant in the cell-free fractions, whereas the particles in the cell fraction mainly exhibited doughnut-shaped morphology. The crescent-shaped structure may represent an assembly intermediate.

Energy Needs Are Poorly Predicted in Critically Ill Elderly

Changes in energy expenditure with age have been described, but this physiology is not routinely considered when managing critically ill elderly patients. To allow us to avoid the potential problems associated with underfeeding or overfeeding the critically ill elderly population, with approval of the human studies committee and appropriate consent from legal guardians, 25 critically ill patients over 65 years of age requiring mechanical ventilation underwent expired gas indirect calorimetry. If they had a pulmonary artery catheter in place for clinical reasons, reverse-Fick indirect calorimetry was also performed. Data obtained by indirect calorimetry was compared with commonly applied equations for predicting energy expenditure by statistical methods of correlation and limits of agreement. These 25 patients had an average age of 74 ± 1.23 (standard error of the mean) and an average APACHE II score of 15. Predictive equations correlated poorly with measured resting energy expenditure, and although they showed reasonable bias, they were imprecise in their estimation of resting energy expenditure. These data suggest that energy expenditure in critically ill, mechanically ventilated elderly patients is highly variable. Although generally overestimating energy needs, currently available equations for predicting energy expenditure in this population are associated with significant bias and imprecision, which may lead to both overfeeding and underfeeding. Although these equations may be suitable as a basis of initiating nutritional support, energy provisions should ideally be guided by indirect calorimetry.

The role of Gag in human immunodeficiency virus type 1 virion morphogenesis and early steps of the viral life cycle

The phenotypes of a series of mutant human immunodeficiency virus type 1 proviruses with linker insertion and deletion mutations within the gag coding region were characterized. These mutants, with mutations in the matrix, capsid, and p2 coding regions, produced replication-defective virion particles with defects in the early steps of the viral life cycle. To investigate this phenotype further, the abilities of mutant virion particles to enter T cells, initiate and complete reverse transcription, and transport the newly transcribed proviral DNA were investigated. Only 4 of 10 of the mutants appeared to make wild-type levels of viral DNA. Biochemical analyses of the mutants revealed the middle region of CA as being important in determining virion particle density and sedimentation in velocity gradients. This region also appears to be critical in determining the morphology of mature virion particles by electron microscopy. Particles with aberrant morphology were uninfectious, and only those mutants which displayed cone-shaped cores were capable of carrying out the early steps of the viral life cycle. Thus, the normal morphology of human immunodeficiency virus type 1 appears to be critical to infectivity.

Cyclosporine A-resistant human immunodeficiency virus type 1 mutants demonstrate that Gag encodes the functional target of cyclophilin A

The cellular peptidyl-prolyl isomerase cyclophilin A is incorporated into human immunodeficiency virus type 1 virions via contacts with the proline-rich domain of the Gag polyprotein. Cyclosporine A and nonimmunosuppressive analogs bind with high affinity to cyclophilin A, compete with Gag for binding to cyclophilin A, and prevent incorporation of cyclophilin A into virions; in parallel with the disruption of cyclophilin A incorporation into virions, there is a linear reduction in the initiation of reverse transcription after infection of a T cell. Passage of human immunodeficiency virus type 1 in the presence of the drug selects one of two mutations, either of which alters the proline-rich domain of Gag and is sufficient to confer drug resistance on the cloned wild-type provirus. Neither mutation alters Gag's cyclophilin A-binding properties in vitro, and cyclophilin A incorporation into drug-resistant virions is effectively disrupted by cyclosporine A, indicating that the drug-resistant mutants do not require virion-associated cyclophilin A to initiate infection. That Gag's functional dependence on cyclophilin A can be differentiated genetically from its ability to bind cyclophilin A is further demonstrated by the rescue of a mutation precluding cyclophilin A packaging by a mutation conferring cyclosporine A resistance. These experiments demonstrate that, in addition to its ability to package cyclophilin A into virions, gag encodes the functional target of cyclophilin A.

MoSearch: a radiologist-friendly tool for finding-based diagnostic report and image retrieval

The diagnostic reports generated in a radiology department contain a wealth of information. Although radiology information systems can greatly facilitate patient-based access to this information, they typically provide only limited finding-based access. A user-friendly personal computer-based software package that allows radiologists to conduct sophisticated real-time searches of diagnostic reports on the basis of patient characteristics, modality used, anatomy examined, and imaging findings and to easily review, refine, and output the results was designed and implemented in a large academic hospital. A notable feature of this system is the use of synonym-matching and syntactic cues, which allow it to identify findings within the text of a diagnostic report much more accurately than a simple keyword search can. This type of system is easily and inexpensively implemented and is a valuable tool in the support of various research and teaching applications in a radiology department.

Prevalence and parental origin of de novo RET mutations in Hirschsprung's disease

In contrast with the reported almost exclusive paternal origin of de novo mutations in MEN 2A, FMTC and MEN 2B, de novo mutations in Hirschsprung patients arise both on paternal and maternal chromosomes. This distinctive feature of RET mutations associated with Hirschsprung's disease and of the RET mutations associated with thyroid cancer indicates a basic biological difference between the mutational events leading to the different phenotypes.

Physical map and cosmid contig encompassing a new interstitial deletion of the X-linked lymphoproliferative syndrome region

The X-linked lymphoproliferative syndrome (XLP) is an inherited immuno-deficiency to Epstein-Barr virus infection that has been mapped to chromosome Xq25. Molecular analysis of XLP patients from ten different families identified a small interstitial constitutional deletion in 1 patient (XLP-D). This deletion, initially defined by a single marker, DF83, known to map to interval Xq24-q26.1, is nested within a previously reported and much larger deletion in another XLP patient (XLP-739). A cosmid minilibrary was constructed from a single mega-YAC and used to establish a contig encompassing the whole XLP-D deletion and a portion of the XLP-739 deletion. Based on this contig, the size of the XLP-D deletion can be estimated at 130 kb. The identification of this minimal deletion, within which at least a portion of the XLP gene is likely to reside, should greatly facilitate efforts in isolating the gene.

The physical map of the human RET proto-oncogene

The RET proto-oncogene, a transmembrane tyrosine kinase receptor, is involved in the development of at least five different disease phenotypes. RET is activated through somatic rearrangements in a number of cases of papillary thyroid carcinoma while germ-line point mutations are associated with three inherited cancer syndromes MEN 2A, MEN 2B and FMTC. Moreover, point mutations or heterozygous deletions of RET are found in the dominant form of Hirschsprung disease or congenital colonic aganglionosis. We cloned the entire RET genomic sequence in a contig of cosmids encompassing 150 kb, from the CA repeat sTCL-2 to the region upstream the RET promoter, and established the position of the 20 exons of the RET gene with respect to a detailed restriction map based on eight endonucleases. A new highly polymorphic CA repeat sequence was identified within intron 5 of RET (RET-INT5). Finally the orientation of RET on chromosome 10q11.2 made it possible to orientate three other genes rearranged with RET in papillary thyroid carcinomas, namely H4/D10S170 on 10q21, R1 alpha on 17q23 and RFG2/Ele1 on 10q11.2.

[The regulation of calmodulin in the cell cycle]

In order to study the role of calmodulin (CaM) in the cell cycle, RC 3 cells carring the CaM expression vectors which was constructed by joining the CaM cDNA with a plasmid of mouse mammary tumor virus (MMTV), were used in this experiment. The CaM expression vectors transcription is regulated by a dexamethasone (DXM) inducible MMTV LTR promoter. Upon addition of DXM, cells have transiently increased CaM mRNA and protein levels. Increased CaM caused a acceleration of proliferation. Flow cytometric analysis showed that progression though G1, G2 and metaphase was accelerated by increase in CaM levels, while treatment with the CaM antagonist trifluoperazine (TFP) blocked cell cycle progression at G1/S boundary and during G2/M and metaphase. The studies have shown that CaM is important in controlling progression at three points in the cell cycle: (1) The G1/S boundary to permit the initiation of DNA synthesis; (2) The G2/M boundary to permit the initiation of mitosis; (3) At the metaphase/anaphase transition of mitosis to permit chromosome segration and the completion of mitosis. This study indicates that the RC 3 cell is a useful experimental cell model for studing the effect of a transient increase of intracellular CaM levels on control of cell cycle.

Unconventional cytotoxic T lymphocyte recognition of synthetic peptides corresponding to residues 1-23 of Ras protein

A peptide corresponding to amino acids 1 through 23 of Ras protein containing a mutation at position 12 was used to induce cytotoxic T lymphocytes (CTL) in mice. Although the CTL were CD8+ and expressed alpha, beta T cell antigen receptors (TCR), their major histocompatibility complex (MHC)-restriction was unconventional. They recognized peptide-treated murine cells of different H-2 haplotypes, but not MHC class I-negative cells. Human HLA class I molecules did not present Ras peptides and hybrid human/mouse MHC molecules revealed that all three extracellular domains alpha 1, alpha 2 and alpha 3 were required for recognition by peptide-specific CTL. Shortening the 23-mer peptide by 5 residues at either the amino or carboxy terminus resulted in loss of CTL recognition. This demonstrates an unusual form of antigen recognition by mouse CTL in which peptide presentation requires murine H-2 class I molecules but is not class I allele restricted, and the peptides recognized are much larger than peptides in conventional class I-restricted responses.

Influence of in vitro methods, receptor fluids on percutaneous absorption and validation of a novel in vitro method

In vitro experiment using excised skin has been valuable for studying the mechanism of percutaneous absorption. Based on previously established static diffusion cell system in this laboratory, a novel model-perfused glass diffusion cell system is designed. The results of initial comparative study on percutaneous absorption between glass perfused diffusion cell and static diffusion cell, in vitro and in vivo permeation as well as factors affecting permeation with seven radiolabelled chemicals are presented. The results demonstrate that the perfused diffusion cell system, which used a perfusion fluid below the surface of skin to take up the materials which penetrated the skin, is more similar to physiologic condition, convenient and automatic than that of the static cell. It well predicts the in vivo percutaneous absorption if appropriate receptor fluid is chosen. The results also show that the selection of receptor fluid is critical for in vitro permeation of chemicals with different solubility.

Heterogeneity and low detection rate of RET mutations in Hirschsprung disease

Mutations in some exons of the RET proto-oncogene were recently observed in Hirschsprung patients. Using DNA polymorphisms and single-strand conformation polymorphism analysis for the whole coding sequence of the RET proto-oncogene, 82 unrelated Hirschsprung patients were screened systematically. A total of 4 complete deletions of RET and 12 point mutations were identified, each present in no more than one patient and distributed along the whole gene. De novo mutations could be documented in 4 patients. Southern blot and fluorescence in situ hybridization analysis carried out in a restricted number of patients did not reveal any deletion of RET. The low efficiency in detecting mutations of RET in Hirschsprung patients (20%) may originate mainly from genetic heterogeneity.

Few peptides dominate cytotoxic T lymphocyte responses to single and multiple minor histocompatibility antigens

Minor histocompatibility (H) antigens are T cell recognized self proteins which can cause graft versus host disease or organ transplant rejection. We have analysed the number of peptide epitopes involved in cytotoxic T lymphocyte (CTL) responses to single or multiple minor H antigens. Bulk CTL responses were generated in H-2b mice differing in one (H-1), two (H-1 and H-25), or multiple (> 29) minor H loci, and HPLC separation was used to analyse the complexity of CTL recognized peptides. Anti-H-1 CTL recognize one out of 50 HPLC peptide fractions and recognition is H-2Kb restricted. The same peptide fraction is also recognized by anti-H-1/H-25 CTL and no additional epitopes are detected, indicating that the H-25 locus does not stimulate CTL when combined with H-1. CTL generated to multiple minor H loci (including H-1 and H-25) recognize two HPLC peptide fractions which are presented by H-2Db and H-2Kb class I molecules, respectively. The H-2Kb presented fraction is the same as that recognized by anti-H-1 and anti-H-1/H-25 CTL, and it is shown to contain a H-1-derived peptide. Subfractionation of the CTL recognized HPLC fractions is consistent with the presence of only one peptide epitope. Thus, in the responses analysed here one minor H locus encodes probably only one CTL epitope. The study provides a molecular explanation for immunodominance among minor H antigens, suggesting that dominant loci encode single peptide epitopes which are presented efficiently by MHC class I molecules enabling them to readily stimulate CTL responses.

T cell recognition of a point mutation in the P21 Ras protein

Point mutations of p21 Ras proteins correlate with many human malignancies. To determine whether the mutations of Ras proteins generate immunogenic determinants which can be recognized by T cells and possibly serve as targets for immunotherapy, we studied the murine T helper responses to synthetic Ras peptides corresponding to amino acids 1-23 of normal or mutant Ras protein. Immunization of C3H/He and B10.BR mice with Ras peptides containing a valine mutation at position 12 stimulated MHC class II-restricted T helper cells which recognised specifically the Ras mutation. Surprisingly C57BL/10 mice generated T helper responses not only against mutant but also against normal Ras peptides. Importantly, natural processing of Ras protein was found to generate the epitopes recognized by the peptide-induced T cells.