Gamma knife radiosurgery for hemangioblastomas

Thirteen patients (11 males, 2 females) with cerebral hemangioblastomas (HABs) were treated with Gamma Knife radiosurgery (GKR). Four patients had multiple lesions in the brain. The remainder had a single lesion. The total number of lesions was 20. Eight cases had recurrent or residual HABs after surgery. In one case diagnosis was confirmed following surgical resection 22 months after GKR. One case was diagnosed by computed tomography (CT), magnetic resonance imaging (MRI) and digital subtraction angiography (DSA). Three patients had von Hippel Lindau (VHL) disease. The mean tumor diameter was 20 mm (range 7.5 to .55 mm). The mean margin dose was 18 Gy (range 12 to 24 Gy). In 5 cases, there was an improvement of symptoms and reduction in tumor volume. In 4 cases the tumor volume and clinical status remained unchanged. In 3 patients, there was clinical deterioration. The cause of this was an increase in tumor cyst volume in 2 cases. Subsequent surgery resulted in clinical improvement. In a third patient with multiple lesions, deterioration was the result of adverse radiation effects in the medulla oblongata. Three patients were subjected to post GKR-surgery with subsequent histopathology. In one, this was due to cyst expansion. In one, it was at the patient's insistence in the presence of a stable clinical and radiological picture. In a third patient with a temporal lobe tumor, it was because of late-developing epileptic seizures. The histopathological findings in these patients showed varying degrees of small vessel thickening and occlusion together with loss of tumor cells. The observations varied in degree according to the time between GKR and the secondary operation. These findings indicate the effectiveness of the treatment. The reduction in vascularity suggests that GKR could make subsequent surgery less hazardous. The observations of this study suggest that while GKR is not adequately reliable for the control of HAB cysts, it can be an effective treatment for solid tumors, especially those in eloquent regions.

Ultrasonic and viscoelastic properties of skin under transverse mechanical stress in vitro

Ultrasound properties of rabbit and human skin tissues under transverse stress have been studied in vitro over the frequency range from 15 MHz to 40 MHz. B-scan images show significant increases in average dermal grey-scale levels for increasing strain. Quantitative measurements show that ultrasound attenuation coefficients decrease significantly with increasing strain. A linear decrease of 0.109 dB/mm/strain% in rabbit skin and 0.069 dB/mm/strain% in human breast reduction skin was observed at 30 MHz. Experimental results show that backscattering coefficients only exhibit minor variation with strain. The speed of sound in human skin appears to be age-dependent. The viscoelastic and mechanical properties of skin, including stress relaxation, creep and Young's modulus as a function of strain were also studied.

High frequency of CagA+ Helicobacter pylori infection in high-grade gastric MALT B-cell lymphomas

A high incidence of Helicobacter pylori infection has been found in patients with gastric MALT (mucosa-associated lymphoid tissue) B-cell lymphoma. Recent studies have indicated that the aggressive strains of the bacterium containing the CagA gene may have direct effects on tumourigenesis. To investigate the involvement of CagA+ strains in MALT lymphomagenesis, a sensitive polymerase chain reaction (PCR)-based detection assay for the gene was developed. DNA extracts from paraffin sections of 123 H. pylori-related gastric biopsies from Italy were analysed, including 56 cases of chronic gastritis, 37 low-grade, and 30 high-grade MALT lymphomas: 30.3 per cent (17/56) of the gastritis cases, 37.8 per cent (14/37) of the low-grade, and 76.7 per cent (23/30) of the high-grade MALT lymphomas were found to contain the CagA gene. The frequency of CagA+ strain infection was significantly higher (P < 0.05) in high-grade than in low-grade MALT lymphoma or gastritis. These results suggest that high-grade gastric MALT lymphoma transformation may be more likely to occur following infection by CagA+ strains of H. pylori.

Functional replacement of the mouse E2A gene with a human HEB cDNA

The mammalian E2A, HEB, and E2-2 genes encode a unique class of basic helix-loop-helix (bHLH) transcription factors that are evolutionarily conserved and essential for embryonic and postnatal development. While the structural and functional similarities among the gene products are well demonstrated, it is not clear why deletion of E2A, but not HEB or E2-2, leads to a complete arrest in B-lymphocyte development. To understand the molecular basis of the functional specificity between E2A and HEB/E2-2 in mammalian development, we generated and tested a panel of E2A knockin mutations including subtle mutations in the E12 and E47 exons and substitution of both E12 and E47 exons with a human HEB cDNA. We find that the alternatively spliced E12 and E47 bHLH proteins of the E2A gene play similar and additive roles in supporting B lymphopoiesis. Further, we find that HEB driven by the endogenous E2A promoter can functionally replace E2A in supporting B-cell commitment and differentiation toward completion. Finally, the postnatal lethality associated with E2A disruption is fully rescued by the addition of HEB. This study suggests that the functional divergence among E12, E47, and HEB in different cell types is partially defined by the context of gene expression.

Polymerase chain reaction in the assessment of lymphomas

The polymerase chain reaction (PCR) offers a practical means of studying the molecular genetic features of lymphomas. The method is rapid and, as formalin-fixed, paraffin processed samples can be used, does not require special tissue handling procedures. PCR amplified immunoglobulin and T cell receptor gene rearrangements can be exploited as markers of clonality and lineage and genetic abnormalities such as chromosome translocations and mutations of oncogenes and tumour suppressor genes can be used to identify specific lymphoma types. Polymorphic X linked loci may also be used as markers of clonality in females. Direct sequencing of PCR amplified IGH variable regions has provided insights into the developmental stages, susceptibility to antigen drive and dissemination patterns of lymphomas. The role of oncogenes and tumour suppressor genes such as MYC and TP53 in lymphomas can be studied by PCR amplification of mutation hotspots and direct sequencing of products. Known viral and bacterial DNA can readily be identified using PCR and unknown organisms sought using conserved primers to amplify polymorphic sequences. PCR analysis of the lymphomas and related disorders has accelerated our understanding of their molecular biology and provides a practical tool with diagnostic and prognostic applications. Future development of in situ PCR methods will provide cellular localization of genetic defects and infectious agents.

Comparison of two high-performance liquid chromatographic methods for monitoring plasma concentrations of haloperidol and reduced haloperidol

Two high-performance liquid chromatographic methods for monitoring haloperidol (HAL) and reduced haloperidol (RHAL) plasma concentrations were compared. In one method ultraviolet detection and a C18 column were used (UV method); in the other method electrochemical detection and a CN-column were used (EC method). Both methods are accurate and precise. For plasma samples spiked with HAL or RHAL, an excellent correlation was observed between the concentrations of HAL and RHAL found with both methods (r < or = 0.99, p < 0.01). However, for plasma obtained from patients treated with HAL the correlation between the two methods was poor (r > or = 0.71, p < 0.01). The main reason for the discrepancy between the two methods is probably interference of comedications or their metabolites, mostly in the EC method. Although the quantitation limit of the UV method (2 ng/ml for HAL and RHAL) is higher than that of the EC method (0.5 ng/ml for HAL and RHAL), the UV method is to be preferred for monitoring plasma levels in psychiatric patients because there is less interference from comedication.

Cloning and sequence analysis of the 5'-flanking region of goat beta-lactoglobulin gene

We were the first to report 5'-flanking sequences of goat beta-lactoglobulin (beta LG) gene (867 bp) including a promoter (770 bp) and part of the first exon (97 bp). The fragment was isolated from Chinese goat tissue with PCR, and then cloned and sequenced. Sequence comparison showed 94.6% homology with sheep and 88% homology with cattle, respectively. There are highly conserved transcription factor binding sites as well. It suggested that the proximal 406 bp of 5'-flanking sequences of sheep beta LG possess strong tissue-specific DNAaseI-hypersensitive sites. Sheep beta LG transgenes containing only the 406-bp 5'-flanking sequences were efficiently expressed in the mouse mammary gland at a high level. These goat beta LG 5'-flanking sequences could possibly direct heterologous protein expression in the milk of transgenic animals.

Total body irradiation and acute graft-versus-host disease: the role of gastrointestinal damage and inflammatory cytokines

The influence of bone marrow transplantation (BMT) conditioning regimens on the incidence and severity of graft-versus-host disease (GVHD) has been suggested in clinical BMT. Using murine BMT models, we show here an increase in GVHD severity in several donor-recipient strain combinations after intensification of the conditioning regimen by increasing the total body irradiation (TBI) dose from 900 cGy to 1,300 cGy. Increased GVHD was mediated by systemic increases in tumor necrosis factor alpha (TNF alpha). Histologic analysis of gastrointestinal tracts showed synergistic damage by increased TBI and allogeneic donor cells that permitted increased translocation of lipopolysacharide (LPS) into the systemic circulation. In vitro, LPS triggered excess TNF alpha from macrophages primed by the GVH reaction. In addition, macrophages isolated within 4 hours of conditioning were primed in proportion to the TBI dose itself to secrete TNF alpha. Thus, the higher TBI dose increased macrophage priming and increased gut damage after allogeneic BMT, causing higher systemic levels of inflammatory cytokines and subsequent severe GVHD. These data highlight the importance of conditioning in GVHD pathophysiology and suggest that interventions to prevent LPS stimulation of primed macrophages may limit the severity of GVHD after intensive conditioning for allogeneic BMT.

Molecular analysis of T-cell clonality in ulcerative jejunitis and enteropathy-associated T-cell lymphoma

Ulcerative jejunitis (UJ) and enteropathy-associated T-cell lymphoma (EATL) are closely related conditions both associated with celiac disease. Benign-appearing inflammatory ulcers are seen in both, which has led to the suggestion that UJ is a manifestation of EATL. The aim of this study was to investigate this relationship using the polymerase chain reaction (PCR) to detect T-cell gene rearrangement. PCR amplification of the T-cell receptor gamma-chain gene was performed on DNA extracted from lymphoma, associated inflammatory ulcers, and intervening mucosa in six EATL cases and from ulcers and intervening mucosa of seven cases of UJ. In two of these cases, DNA from a subsequent lymphoma was also studied. The PCR products from the tumor and an ulcer from one EATL case, two ulcers from one case of UJ, and one ulcer and subsequent cutaneous lymphoma from one UJ case were sequenced. Twenty-five ulcers from twelve cases of Crohn's disease, twenty sections of normal bowel, and nine celiac biopsies were included as controls. A monoclonal T-cell population defined by a dominant band equal in size to that amplified from the lymphoma was identified in at least one ulcer from four informative EATL cases and from intervening mucosa in three. Monoclonality was demonstrated in at least one, and up to thirteen, ulcers from all seven cases of UJ, in intervening mucosa in five, and in the two subsequent lymphomas. Sequencing showed the same clone was present in the tumor and the ulcer in the EATL case, in two of three ulcers from the UJ case, and in an ulcer and subsequent cutaneous lymphoma in one UJ case. All Crohn's disease ulcers and all sections of normal bowel were polyclonal. One of nine celiac biopsies showed a dominant band. In conclusion, we have shown that T-cell monoclonality is a feature of the ulcers in both UJ and EATL and that the same clone is present in EATL and its associated inflammatory ulcers and in UJ and subsequently developing lymphoma.

c-myc gene abnormalities in mucosa-associated lymphoid tissue (MALT) lymphomas

c-myc gene abnormalities associated with lymphomagenesis, including rearrangements and mutations in the regulatory region between exon I and intron I, have been studied in 54 MALT lymphomas (43 low and 11 high grade) and 36 nodal lymphomas (27 low and 9 high grade). By Southern blot analysis, none of the 54 MALT lymphomas but 2 of 36 nodal lymphomas had c-myc gene rearrangements. Defined tumour cell populations from all MALT lymphoma cases were isolated by microdissection from frozen tissue sections and analysed by polymerase chain reaction-single-strand conformational polymorphism (PCR-SSCP) and direct sequencing for somatic mutations in the exon I/intron I region of the gene. Point mutations in this region were identified in nine cases of MALT lymphomas (7/43 = 16.2 per cent of low grade; 2/11 = 18.1 per cent of high grade). These mutations were located at either the exon I/intron I border of myc intron factor (MIF) binding sites, which are critical in the negative regulation of c-myc expression. Of the nodal lymphomas, only the two cases (5-6 per cent) with c-myc gene rearrangement showed scattered or clustered mutations. These results suggest that c-myc mutations in MALT lymphomas are unlikely to be associated with chromosome translocation, which is the main cause of somatic mutations observed in other types of lymphomas. The mutations involving the c-myc regulatory regions may play a pathogenetic role in at least a proportion of MALT lymphomas.

Genetic evidence for a clonal link between low and high-grade components in gastric MALT B-cell lymphoma

High-grade MALT lymphomas often contain low-grade tumour components; both cell populations have been shown to express the same immunoglobulin light chain previously. However, the clonal link between the low and high-grade components has not been established at the genetic level. To investigate this link, we have examined low- and high-grade components micro-dissected from tissue sections of four high-grade gastric MALT lymphomas. PCR and sequence analyses were performed to identify clone-specific rearranged immunoglobulin heavy chain gene sequences. In each of these cases, the PCR products from the two components were identical in size by electrophoresis. Direct sequencing revealed common clone-specific immunoglobulin heavy chain gene rearrangements in both lesions of each case, providing genetic evidence for a clonal link. These results support the proposal that high-grade MALT lymphomas generally evolve from low-grade clones.

Immersion-histo polymerase chain reaction: a practical tool for visualization of single-copy genes in tissue sections

A method, immersion-histo polymerase chain reaction (IH-PCR), was developed for visualization of single-copy DNA sequences in cells in paraffin-embedded tissue sections. Sections were mounted on coverslips, cut into small pieces, and immersed in reaction mixtures in micro-tubes for specific DNA amplification using a conventional thermal cycler. This was followed by in situ hybridization, in micro-tubes, with PCR-generated, digoxigenin-labeled probes. Epstein-Barr virus, chromosomal translocations, and rearranged immunoglobulin genes were clearly demonstrated in individual cells in human lymphomas. The use of a standard thermal cycler, the ease of probe preparation, and the high specificity and sensitivity of target localization make IH-PCR a practical and powerful tool for the study of genetic events within individual cells.

c-myc gene abnormalities in mucosa-associated lymphoid tissue (MALT) lymphomas

c-myc gene abnormalities associated with lymphomagenesis, including rearrangements and mutations in the regulatory region between exon I and intron I, have been studied in 54 MALT lymphomas (43 low and 11 high grade) and 36 nodal lymphomas (27 low and 9 high grade). By Southern blot analysis, none of the 54 MALT lymphomas but 2 of 36 nodal lymphomas had c-myc gene rearrangements. Defined tumour cell populations from all MALT lymphoma cases were isolated by microdissection from frozen tissue sections and analysed by polymerase chain reaction-single-strand conformational polymorphism (PCR-SSCP) and direct sequencing for somatic mutations in the exon I/intron I region of the gene. Point mutations in this region were identified in nine cases of MALT lymphomas (7/43 = 16.2 per cent of low grade; 2/11 = 18.1 per cent of high grade). These mutations were located at either the exon I/intron I border of myc intron factor (MIF) binding sites, which are critical in the negative regulation of c-myc expression. Of the nodal lymphomas, only the two cases (5-6 per cent) with c-myc gene rearrangement showed scattered or clustered mutations. These results suggest that c-myc mutations in MALT lymphomas are unlikely to be associated with chromosome translocation, which is the main cause of somatic mutations observed in other types of lymphomas. The mutations involving the c-myc regulatory regions may play a pathogenetic role in at least a proportion of MALT lymphomas.

[Study on time-resolved fluorimetry of samarium]

In this paper, a simple and highly sensitive laser fluorimetric system is described, and the value of time discrimination for suppressing unwanted signals and decreasing the minimum detectable concentration is demonstrated. It is confirmed that time discrimination is very useful for ultratrale determination of fluorescent complex. This technique is successful with the combined use of a pulsed laser and a pulse-gate signal detection system for samarium complex. The linear range and the detectin limit of the method are 0. 01-10microg/ml and 3.3ng/ml, respectively. The RSD for Sm3+ (0. 5microg/ml) ( n =12) is 3.7%. The method was used to detemine samarium in rare earth mixtures. The recovery was in the range of 90.0-110.0%, and the mean recovery was 101.4% ( n = 6 )

Clonality analysis in tumours of women by PCR amplification of X-linked genes

Modifications have been made to two polymerase chain reaction (PCR) methods for clonality analysis based on the inactivation patterns of two highly polymorphic X-linked genes encoding the androgen receptor (AR) and monoamine oxidase A (MAOA). These methods have been used to examine the clonal nature of frozen tissues from 42 tumours and 25 non-tumour controls from female subjects. Unbalanced inactivation patterns of the genes, which indicate monoclonality, were frequently observed in tumours of heterozygous (informative) cases (18/35 = 51.4 per cent for the AR gene, 9/30 = 30 per cent for the MAOA gene, and 21/38 = 55.2 per cent for both). Among 23 informative non-tumour controls, only one (4.3 per cent), a reactive lymph node, showed skewing in the AR gene. Successful detection of monoclonality was found to depend on the proportion of tumour cells in the tissues examined. None of the AR or MAOA informative cases containing less than 50 per cent of tumour cells showed imbalance in inactivation patterns. With more than 50 per cent of tumour cells in the samples, 66.6 per cent (18/27) of AR and 39.1 per cent (9/23) of MAOA informative cases showed allelic imbalance, with a combined frequency of 72.4 per cent (21/29) of both genes. Our results demonstrate that the methods described are useful for clonal analysis of tissue samples from female patients.

Trauma-induced striatal CNTF and BDNF mRNA in hemiparkinsonian rats

Surgical implantation of tissues into the brain causes trauma to the region receiving the graft. This study shows that real or simulated striatal trauma in hemiparkinsonian rats leads to increased expression of two trophic factor mRNAs: ciliary neurotrophic factor (CNTF) and brain-derived neurotrophic factor (BDNF). The baseline expression of BDNF mRNA was also markedly lower in dopamine-depleted striatum than in normal striatum in non-traumatized (control) hemiparkinsonian rats. Striatal CNTF message was relatively symmetrical in the non-traumatized (control) hemiparkinsonian rats. Host production of these and other trophic factors may play important roles in the response to tissue grafting, to enhance graft survival and as a stimulus to regenerative collateral axonal sprouting.

[Sequence alterations in p53 gene of hepatocellular carcinoma from high aflatoxin risk area in Guangxi]

OBJECTIVE

Check on the sequence alterations of the p53 gene of hepatocellular carcinoma (HCC) in some areas of Guangxi.

METHODS

40 cases of archival HCC samples were divided into two groups. One includes 26 cases from Fusui--an area notorious for high risk in HCC, AFB1 and HBV; The other includes 14 cases from Yulin where both HCC and HBV were high but AFB1 may be low because rice low in AFB1 was the staple food. Exon 7 were sequenced by DNA direct sequencing. p53 mutational protein and HBsAg were examined by immunostaing.

RESULTS

In the Fusui group, 16/26 (61.5%) cases showed mutation at codon 249 third position G to T transversion to form a hot-spot which is generally considered to be caused by AFB1. In the Yulin group, only one single place-Guigang showed p53 mutation clustered at the hot-spot like Fusui in 3/5 cases (60%), while the other cases demonstrated mutational points in various positions.

CONCLUSION

Besides Qidong and South Africa, a third AFB1 high risk area was demonstrated where HCC is accompanied by p53 gene specific mutation.

Transplantation of polarized type 2 donor T cells reduces mortality caused by experimental graft-versus-host disease

Acute graft-versus-host disease (GVHD) is thought to be initiated by alloreactive type 1 T cells that secrete gamma-interferon (IFN-gamma). IFN-gamma induces the production of inflammatory cytokines, e.g., tumor necrosis factor-alpha and interleukin (IL)-1, which are the distal mediators of GVHD. We demonstrate that the transplantation of polarized type 2 murine T cells (i.e., cells secreting IL-4 but not IFN-gamma) together with T-cell-depleted bone marrow results in a significant increase in survival (P<0.001) after bone marrow transplantation across minor histocompatibility barriers (B10.BR-->CBA/J). Further analysis demonstrated that increased survival in recipients of polarized type 2 T cells correlated with diminished production of both IFN-gamma and tumor necrosis factor-alpha but with increases in IL-4 2 weeks after transplantation. Despite improved survival, histologic changes of GVHD were evident in oral mucosal and hepatic tissues at 7 weeks after bone marrow transplantation. These data provide further evidence that inflammatory cytokines in the immediate posttransplant period are pivotal to the development of mortality but that they do not correlate with individual target organ damage.

Long-term engraftment, graft-vs.-host disease, and immunologic reconstitution after experimental transplantation of allogeneic peripheral blood cells from G-CSF-treated donors

Peripheral blood cells (PBPC) are an alternative source of bone marrow for allogeneic transplantation. Reports from recent clinical trials granulocyte colony-stimulating factor (G-CSF)-mobilized PBPC for allogeneic transplantation show incidence and severity of graft-vs.-host disease (GVHD) similar to those observed in conventional bone marrow transplantation (BMT), despite the presence of 10- to 20-fold more T cell in the PBPC inoculum. In the present study, we examined the effects of pretreatment of donors with G-CSF on GVHD, long-term engraftment, and lymphocyte reconstitution in a murine parent-->F1 model (B6.Ly-5a-->B6d2F1) using splenocytes as a source of peripheral progenitor cells. Recipients of splenocytes from G-CSF-treated donors experienced less mortality from acute GVHD and showed sustained weight gain by day 100 after transplantation. At that time, there was no histological evidence od GVHD in either liver or gut. Recipients of splenocytes from G-CSF-treated donors showed complete donor engraftment within 1 month, which was sustained until the end of the observation period. In contrast, recipients of T cell-depleted splenocytes showed slower donor engraftment and persistent donor/host chimerism. In addition, lymphocyte phenotype and function in mice receiving splenocytes from G-CSF-treated donors was significantly restored by day 100 after transplantation. Thus, the use of G-CSF-mobilized PBPC may provide significant advantages to conventional BMT by reducing GVHD without impairing long-term engraftment and immunologic reconstruction.

[Study on small intestinal lumenal and membrane flora of 30 healthy Chinese]

Lumenal and membrane flora were investigated using ileum and jejunum samples obtained through endoscopy. 10 kinds of representative anaerobic or aerobic bacteria were cultured for quantitative and qualitative analysis. The result showed there were significant differences between lumenal and membrane flora on Clostridium of ileum, Lactobacillus and Bacillus bifudus in jejunum (P < 0.05). Enterococci were not found in all of these 30 patients. In jenumum, E. Coli was found in 53.3% (16/30) of lumenal flora and 33.3% (10/30) of membrane flora, Bacteroides were found in 40.0% (12/30) of lumenal flora and 33.3% (10/30) of membrane flora respectively.

The immunopathophysiology of acute graft-versus-host-disease

The major complication after allogeneic bone marrow transplantation (BMT) is the development of graft-versus-host-disease (GVHD). This disease is initiated during the conditioning of the recipient, when host tissues are damaged. During the afferent phase of the disease, alloreactive donor T cells recognize foreign major and minor histocompatibility antigens of host tissues. The efferent phase includes activation of inflammatory effector cells as well as the secretion of cytopathic molecules which induce pathology in skin, gastrointestinal tract, liver, lung, and the immune system. Substantial experimental and clinical evidence now indicates a central role of cytokines in the immunopathophysiology of acute GVHD, which forms the basis of this review. The balance between cytokines released by T helper 1 (Th1) cells (interleukin 2, interferon-gamma) or by T helper 2 (Th2) cells (interleukin 4, interleukin 10) after allogeneic BMT is hypothesized to govern the extent of the systemic inflammatory response. Because Th2 cytokines can inhibit the production of proinflammatory cytokines such as interleukin 1 and tumor necrosis factor-alpha, a Th1-->Th2 shift in the initial response of donor T cells may interrupt the cytokine cascade and thus offer a new approach to the prevention and treatment of acute GVHD. Successful interventions to modify the response of donor T cells may obviate the need for T cell depletion and thereby avoid the increased risk of relapse of malignancy and impairment of donor cell engraftment.

Positive correlation between apoptotic and proliferative indices in gastrointestinal lymphomas of mucosa-associated lymphoid tissue (MALT)

To understand the role of deregulation of apoptosis in the pathogenesis of gastrointestinal MALT lymphoma, apoptosis has been quantitatively studied in paraffin sections from 40 cases (19 low grade, 21 high grade). The extent of apoptosis was correlated with histological grade, proliferative activity as measured by immunostaining of Ki67 proliferation antigen, and the expression of bcl-2 and p53 oncoproteins, which are known to participate in the regulation of apoptosis. Both apoptotic and proliferative indices were significantly (P < 0.00001) higher in high-grade than in low-grade tumours. Overall, apoptotic indices were negatively correlated with bcl-2 expression, particularly in low-grade tumours in which both strong bcl-2 expression and low levels of apoptosis were observed. Thus, the slow expansion of low-grade MALT lymphoma may partly result from a prolonged life-span of tumour cells, due to bcl-2-mediated blockage of apoptosis. No difference in apoptotic indices was found between p53-positive and p53-negative cases. Furthermore, correlation analysis revealed a significantly positive association between apoptotic and proliferative indices. This supports the current belief that the mechanisms controlling apoptosis and proliferation are both activated during the cell cycle and whether a cell enters the proliferation cycle or the apoptotic process depends on survival factors.

[Relationship between the state of intravascular bubbles and microcirculation system]

To confirm the hypothesis that air bubbles were unable to block the blood vessels and that the state of the intravascular bubbles was determined by the function of the circulatory system, 35 guinea pigs were pressurized then were decompressed to normal pressure. Microscopic observation was made of the bulbar conjunctival, dorsum auricular and subcutaneous vessels in 33 surviving animals. Air bubbles of different amounts, sizes and shapes were found in the dorsum auricular and subcutaneous vein of all the amimals and in the bulbar conjunctival oriridal artery of 16 animals, and in some cases the vessels were even filled with bubbles. The bubbles ran in the same direction and at the same speed as the blood flow. They could run in a backward, to-and-fro or sluggish flow. The bubbles looked shapeless and tended to break and divided into branch flows where the vessel branches. The bubbles were motionless at the proximal end of the artery occluded due to spasm or when the blood was stagnated. Under the action of the blood pressure the bubbles could expand the vessel and push forward. The bubbles showed a tendency of flowing with ease with the function of the vessel recovered. The results suggest that bubbles of any size in the vessel could easily change their shape under the action of the blood flow and pressure, and pass through vessels of any diameter and circulate with the blood. Only when a vessel was occluded due to spasm or the blood in a vessel was stagnated could the bubbles be motionless, but it was not that the bubbles blocked the vessel.

Eph receptors and ligands comprise two major specificity subclasses and are reciprocally compartmentalized during embryogenesis

We report that the many Eph-related receptor tyrosine kinases, and their numerous membrane-bound ligands, can each be grouped into only two major specificity subclasses. Receptors in a given subclass bind most members of a corresponding ligand subclass. The physiological relevance of these groupings is suggested by viewing the collective distributions of all members of a subclass. These composite distributions, in contrast with less informative patterns seen with individual members of the family, reveal that the developing embryo is subdivided into domains defined by reciprocal and apparently mutually exclusive expression of a receptor subclass and its corresponding ligands. Receptors seem to encounter their ligands only at the interface between these domains. This reciprocal compartmentalization implicates the Eph family in the formation of spatial boundaries that may help to organize the developing body plan.

Ongoing mutation in MALT lymphoma immunoglobulin gene suggests that antigen stimulation plays a role in the clonal expansion

Indirect antigenic stimulation by H. pylori-specific T cells is implicated in the development of low-grade gastric lymphoma of mucosa-associated lymphoid tissue (MALT), however, the role of direct antigen stimulation is unknown. To study the role of direct antigen stimulation in MALT lymphomagenesis and its relationship with the pathogenesis of distinct pathological lesions, which represent different stages of the tumour progression, we cloned and sequenced the rearranged immunoglobulin (Ig) heavy chain gene in three low-grade (two from the lung, one from the stomach) and one high-grade (from the stomach) cases. In the low-grade gastric case, we studied the Ig sequence in primary as well as its disseminated and recurrent tumours. In the high-grade gastric case, we analysed the Ig sequence in tumour cell populations microdissected from the residual diffuse low-grade lesions, diffuse high-grade areas from follicles colonized by high-grade blasts. Compared with the published germline sequences, the heavy chain variable (VH) genes of three MALT lymphomas, in which the putative germline was identified, contained frequent somatic mutations, showing a much higher ratio of replacement/silent mutations in the complementarity determining regions (CDRs) than the framework regions (FRs). Ongoing mutation as indicated by intraclonal variation of the Ig sequence clearly existed in low-grade tumour including its dissemination and recurrence, but was not evident in high-grade tumour cell populations including those microdissected from independent colonized follicles. In addition, the germlines of VH genes used by the three MALT lymphomas are frequently found in autoreactive antibodies. Our results suggest that MALT lymphoma derives from postgerminal centre memory B cells, possibly autoreactive B cell clones, and that direct antigen stimulation may play an important role in the clonal expansion of low-grade MALT lymphoma.

Evidence for specific annexin I-binding proteins on human monocytes

Recombinant human annexin I and a monoclonal antibody specific for this protein (mAb 1B) were used to investigate surface binding of this member of the annexin family of proteins to peripheral blood monocytes. Flow cytometric analysis demonstrated trypsin-sensitive, saturable binding of annexin I to human peripheral blood monocytes but not to admixed lymphocytes. A monoclonal antibody that blocks the anti-phospholipase activity of annexin I also blocked its binding to monocytes. These findings suggest the presence of specific binding sites on monocytes. Furthermore, surface iodination, immunoprecipitation and SDS/PAGE analysis were used to identify two annexin I-binding proteins on the surface of monocytes with molecular masses of 15 kDa and 18 kDa respectively. The identification and characterization of these annexin I-binding molecules should help us to better understand the specific interactions of annexin I with monocytes that lead to down-regulation of pro-inflammatory cell functions.

Biological characteristics of an immunoregulatory activity secreted by an autoreactive CD4+ T cell clone that suppresses autoimmune diabetes in non-obese diabetic mice

We previously reported the generation and characterization of a panel of CD4(+) autoreactive T cell clones that suppress development of autoimmune diabetes in non-obese diabetic (NOD) mice. We showed that the protective capacity of the T cell clones correlated with secretion of an activity that potently inhibits allogeneic mixed lymphocyte reaction (allo-MLR). In this report, we describe the biological characteristics of the allo-MLR inhibitory activity (MLR-IA, short for mixed lymphocyte reaction inhibitory activity) secreted by the protective T cell clone, NOD-5. MLR-IA has little effect on initiation of proliferation in an allo-MLR, but it potently inhibits the maintenance and amplification of the proliferative response. MLR-IA is also capable of inhibiting concanavalin A (Con A) stimulated splenic responder T cell proliferation. MLR-IA is reversible in vitro and is not restricted by MHC class I or II proteins. MLR-IA does not affect IL-2 receptor expression of responding T cells and has no effect on IL-2-dependent proliferation of CTLL-20 T cells. Partially purified MLR-IA inhibits IL-2 production in a primary allo-MLR, and decreases IFN-gamma production during secondary allo-MLR and Con A activation, whereas it enhances IL-4 production in both primary and secondary Con A activation. MLR-IA is not neutralized by combination of antibodies specific for transforming growth factor-beta, IL-10, tumor necrosis factor-alpha/beta or IFN-gamma, suggestive of a novel activity. MLR-IA is ammonium sulfate precipitable, sensitive to protease digestion and is destroyed by boiling, indicating that a protein moiety is part of its active structure. Our work suggests that a potentially novel immunoregulatory activity, capable of inhibiting T lymphocyte proliferation and IFN-gamma production, and stimulating IL-4 production, may regulate development of autoimmune diabetes in NOD mice.

Positive correlation between apoptotic and proliferative indices in gastrointestinal lymphomas of mucosa-associated lymphoid tissue (MALT)

To understand the role of deregulation of apoptosis in the pathogenesis of gastrointestinal MALT lymphoma, apoptosis has been quantitatively studied in paraffin sections from 40 cases (19 low grade, 21 high grade). The extent of apoptosis was correlated with histological grade, proliferative activity as measured by immunostaining of Ki67 proliferation antigen, and the expression of bcl-2 and p53 oncoproteins, which are known to participate in the regulation of apoptosis. Both apoptotic and proliferative indices were significantly (P < 0.00001) higher in high-grade than in low-grade tumours. Overall, apoptotic indices were negatively correlated with bcl-2 expression, particularly in low-grade tumours in which both strong bcl-2 expression and low levels of apoptosis were observed. Thus, the slow expansion of low-grade MALT lymphoma may partly result from a prolonged life-span of tumour cells, due to bcl-2-mediated blockage of apoptosis. No difference in apoptotic indices was found between p53-positive and p53-negative cases. Furthermore, correlation analysis revealed a significantly positive association between apoptotic and proliferative indices. This supports the current belief that the mechanisms controlling apoptosis and proliferation are both activated during the cell cycle and whether a cell enters the proliferation cycle or the apoptotic process depends on survival factors.

Diagnosis and posttreatment follow-up of Helicobacter pylori-positive gastric lymphoma of mucosa-associated lymphoid tissue: histology, polymerase chain reaction, or both?

The differential diagnosis between Helicobacter pylori (H pylori-associated chronic gastritis and low-grade B-cell gastric lymphoma of mucosa-associated lymphoid tissue (MALT) and the assessment of endoscopic biopsy specimens after treatment of lymphoma can be problematic. Although immunocytochemistry can be used to identify clonal B-cell populations, which are characteristic of MALT lymphoma, its application to small biopsy specimens and the subsequent interpretation can be difficult. The polymerase chain reaction (PCR) can detect clonal B-cell populations by analysis of the Ig heavy chain gene in routinely fixed paraffin-embedded material and might provide a useful tool in the assessment of these specimens. We have investigated the value of histology and PCR in the diagnosis of lymphoma and its followup in formalin-fixed paraffin-embedded gastric endoscopy biopsy specimens from 69 sequential patients selected on the basis of a dense mucosal lymphoid infiltrate associated with H pylori infection. Histologic evidence of MALT lymphoma was identified in 13 cases, 9 of which showed PCR-detected monoclonality. In 12 of 13 cases, H pylori was eradicated, and in 11 of 12 cases, histologic regression of the lymphoma followed. PCR evidence of monoclonality disappeared in 6 of 9 originally monoclonal cases. This was synchronous with histologic remission in 1 case, but lagged in the remaining 5 cases by up to 28 months. Two of the 3 of the 9 cases originally monoclonal by PCR that have not shown molecular regression have monoclonal-amplified products 17 and 24 months after negative histology. In 3 cases, the histology of the biopsies was considered indeterminate or discordant. In 1 of these cases, the histologic features were obscured by crush artefact. In a second case, there was molecular evidence of monoclonality in the absence of histologic features suggestive of lymphoma; this persisted after H pylori eradication. An additional single case originally diagnosed as reactive developed a PCR detectable clonal population 29 months after original evaluation in the absence of histologic features of lymphoma but in the presence of persistent H pylori infection. These findings suggest that the histologic assessment of gastric biopsies remains the method of choice for the diagnosis of lymphoma in gastric endoscopic biopsies with a dense mucosal lymphoid infiltrate. PCR provides a useful technique to support the diagnosis if clonal amplification products are found. The significance of PCR detected clonality in the absence of histologic evidence of lymphoma in uncertain but may represent a stage of tumor progression/regression when the clonal population is insufficient to be detected by conventional histology. This is supported by the evidence that PCR-detectable monoclonality can persist after treatment and the disappearance of histologically detectable lymphoma.

Low grade gastric B-cell lymphoma of mucosa associated lymphoid tissue in immunocompromised patients

An increased incidence of non-Hodgkin's lymphoma is seen in patients with immunodeficiency from any cause. The majority of these are high grade B-cell lymphoma and most are associated with the Epstein-Barr virus (EBV). In post-transplant lymphoma/lymphoproliferative disorders the tumour may regress following reduction of immuno-suppression but in AIDS the lymphomas show a characteristic aggressive course and poor prognosis. We describe low grade B-cell gastric lymphoma of mucosa associated lymphoid tissue (MALT) in three immunocompromised patients (two post-transplant, one HIV positive). In each case, the tumour showed classical morphological features of gastric MALT lymphoma and was not associated with EBV. Helicobacter pylori was identified in each case. Clinical follow-up suggests that the behaviour in these tumours is similar to that seen in MALT lymphomas in immunocompetent patients and not typical of the lymphomas usually associated with immunosuppression. Although the finding of MALT lymphoma in immunosuppressed patients might be coincidental, the association of some MALT lymphomas with autoimmune disease suggests that dysregulation of the immune system might play a role in the pathogenesis of these tumours.

[Cardiotoxicity of 5-fluorouracil]

OBJECTIVE

To determine the possibility and magnitude of cardiotoxicity following high dose intravenous infusion of fluorouracil (5-FU).

METHODS

A prospective clinical study was performed on 104 patients with choriocarcinoma and invasive mole. 5-FU was administered by slow intravenous infusion in 5% glucose 500 ml for 8 hours at doses of 28-30 mg.kg-1.day-1 when used as a single agent treatment or 24-26 mg.kg-1.day-1 when used in combination with kengshengmycin (KSM). The total cycles of treatment with 5-FU + KSM were 109 and those of 5-FU or KSM each used as a single agent were 71 and 12 respectively. The cardiac functions were monitored by cardiac symptoms, ECG and serum cardiac enzymes before and after 5-FU infusion.

RESULTS

Among the 192 treatment cycles tachycardia, palpitation or cardiac distress were observed in 14 cycles. ECG showed changes of ST or T waves in 8 cycles, sinus tachycardia in 3 cycles. The results of serum cardiac enzyme determinations were variable. The diagnostic criteria of cardiotoxicity were appearances of abnormalities manifested in any two of the three monitor items. The incidence of cardiotoxicity was 4.2% in 5-FU group, 4.6% in 5-FU + KSM group and 0% in KSM group. All episodes were mild, reversible spontaneously after cessation of chemotherapy and did not reappear in subsequent chemotherapeutic cycles. Seven patients with definite cardiac diseases before chemotherapy were given 5-FU treatment, but no obvious aggravation of cardiotoxicities were observed even with repeated 5-FU treatments.

CONCLUSION

Only occasional cardiotoxicities were observed in 5-FU treatments. They were rather mild and reversible. The incidence of cardiotoxicity might be reduced with emphasis on strict observance of the treatment regimen in regard to the dosage used, the speed of the infusion and attention to the treatment of any side-effects.

Replication error phenotype and p53 gene mutation in lymphomas of mucosa-associated lymphoid tissue

Low grade mucosa-associated lymphoid tissue (MALT) lymphomas commonly arise from a background of chronic inflammatory lesions and can transform into high grade tumors at a late stage. Because chronic inflammation is closely associated with genetic instability, which is one of the mechanisms leading to activation of oncogenes and inactivation of tumor suppressor genes, it is possible that genetic instability plays an important role in MALT lymphomagenesis. In this study, we have examined the frequency of replication error (RER+) phenotype, a newly defined manifestation of genetic instability, and its relationship to p53 mutations in 40 MALT lymphomas (16 high grade and 24 low grade). RER+ phenotype was detected in 21/40 (52.5%) MALT lymphomas (12/24, 50% in low grade; 9/16, 56.2% in high grade). Five of seven reactive lymphoid infiltrates adjacent to tumors also showed one microsatellite alteration, four of which were identified in the corresponding lymphoma lesions in the same patient. In five RER+ high grade lymphomas with low grade lesions, homogeneous and heterogeneous microsatellite alterations were observed between the two components. The same 40 cases were investigated for p53 gene mutations at exons 5 to 8 by PCR-SSCP and direct sequencing. p53 point mutations were found in 11 (27.5%) of the 40 cases. These mutations were statistically related to RER+ phenotype (P < 0.05). Our results demonstrate that the RER+ phenotype is a common genetic feature of MALT lymphomas. Genetic instability occurs throughout the spectrum of the lymphoma development and may be related to the accumulation of genetic aberrations such as p53 mutations. The observation of identical microsatellite alterations between the adjacent lymphoid infiltrates and their corresponding lymphomas provides genetic evidence for evolutionary link of the two lesions. The homogeneous and heterogeneous microsatellite alterations observed between low and high grade components indicate their clonal lineage and genetic diversity.

Stereotactic Gamma thalamotomy for the treatment of parkinsonism

From September 1994 to June 1995, eight patients with intractable parkinsonism underwent gamma thalamotomy in our hospital. All of these patients were male, with an average age of 59.3 years. The duration of the disease from initial diagnosis was 2-10 years (mean 6.8 years). All had failed or had serious side effects with antiparkinsonian medicine. Seven cases had tremor-dominant symptoms, while the other had mainly rigidity. Six cases had bilateral symptoms. Computed tomography or magnetic resonance imaging (MRI) was undertaken prior to treatment in all cases to exclude focal brain lesions. Stereotactic MRI was taken with the Leksell frame in place and both T1- and T2-weighted images were obtained. The targets were located in the area of Vim/Voa/Vop based on the Schaltenbrand atlas. In seven cases, two plugged 4-mm-collimator shots were used. The maximum dose was 160 Gy in six cases and 180 Gy in one case. In another case, a single 4-mm-collimator shot was used, and a maximum dose of 160 Gy was delivered to the target center. The border of the internal capsule was outside the 20-30% isodose line. We intended the 50% isodose line to have an oval-shaped region with the use of two shots and should correspond to the shape of Vim. Follow-up data were available for six patients (mean: 4.5 months, range: 2-9 months). Tremor disappeared in three cases and improved in the other three. In one of these six cases, the tremor disappeared just 3 days after gamma thalamotomy. Rigidity improved in four of these six cases. In only one patient, treated with a maximum dose of 180 Gy, was there any contralateral limb weakness, which developed 3 months after treatment and has been recovering gradually. Follow-up MRI T2-weighted images in this case showed that the diameter of the lesion was larger than intended and there was a region of diffuse edema in the thalamus and upper brain stem. No other complications occurred in this series.

Preliminary application of Gamma Knife in the treatment of nasopharyngeal carcinoma

Nasopharyngeal carcinoma is a malignant tumor which occurs frequently in China. Currently, radiotherapy using 60Co is the main method of treatment. However, the 5-year survival rate is only 49.5%. There is no effective method today for treating residual or recurrent tumor following radiotherapy. In principle, the Leksell Gamma Knife could contribute to better results. Since December 1993, we have treated 36 patients suffering from nasopharyngeal carcinoma with the Gamma Knife: 32 were relapses after radiotherapy and 4 were primary cases. Treatment was very effective for a short period. The rate of improvement of such symptoms as headache, facial paralysis, reduced vision, nasal obstruction and nasal bleeding was 70-100%. After treatment, tumors became smaller or even disappeared. A new nasopharyngeal biopsy was performed in 12 patients and demonstrated that the pathological tissue had returned to normal. The short duration of the survey precludes conclusions about the long-term effects of the treatment.

The accumulation of p53 abnormalities is associated with progression of mucosa-associated lymphoid tissue lymphoma

The genetic mechanisms underlying the genesis of low-grade mucosa-associated lymphoid tissue (MALT) lymphomas and their transformation into high-grade lymphoma are poorly understood. p53 inactivation, commonly caused by mutation and allele loss, has been shown to play an important role in the early development and/or the late disease progression of many human tumors including lymphoid malignancies and, thus, may also be important in MALT lymphomagenesis. We examined 75 cases (48 low grade and 27 high grade) of MALT lymphoma for p53 allele loss and mutation as well as protein accumulation. DNA samples prepared from microdissected cell populations were used for the detection of p53 gene abnormalities. Loss of heterozygosity (LOH) of the gene was detected by polymerase chain reaction-based analysis of p53 CA repeat polymorphism, whereas p53 mutation was studied by single-strand conformation polymorphism analysis and direct sequencing. p53 expression was assessed by immunostaining with CM1 polyclonal antibody. p53 allele loss and mutation, which resulted in the alteration in the amino acid sequence, were found in both low-grade (LOH, 3 of 44 [6.8%]; mutation, 9 of 48 [18.8%]) and high-grade (LOH, 6 of 21 [28.6%]; mutation, 9 of 27 [33.3%]) MALT lymphomas, particularly in the latter group. p53 staining was not observed in any low-grade tumors but in 6 high-grade cases that harbored missense mutations. There were also differences in the extent of p53 abnormalities, between low- and high-grade tumors. Of the 11 low-grade tumors showing p53 abnormalities, only 1 tumor showed the concomitance of p53 mutation and allele loss, whereas in high-grade tumors, 6 of 9 affected cases displayed both p53 mutation and allele loss. Our results suggest that p53 partial inactivation may play an important role in the development of low-grade MALT lymphomas, whereas complete inactivation may be associated with high-grade transformation.

Pretreatment of donor mice with granulocyte colony-stimulating factor polarizes donor T lymphocytes toward type-2 cytokine production and reduces severity of experimental graft-versus-host disease

The incidence and severity of acute graft-versus-host disease (GVHD) after allogeneic transplantation using peripheral blood progenitor cells mobilized by granulocyte colony-stimulating factor (G-CSF) appear to be no worse than those after bone marrow transplantation, despite the presence of large numbers of T cells in the donor infusion. Experimental studies have shown that type-1 T cells (secreting interleukin-2 [IL-2] and interferon-gamma) mediate acute GVHD, whereas type-2 T cells (secreting IL-4 and IL-10) can prevent acute GVHD. We tested the hypothesis that G-CSF modulates T-cell function toward a type-2 response and thus reduces the severity of acute GVHD. B6 mice were injected with G-CSF or diluent for 4 days, and their splenic T cells were stimulated in vitro with alloantigen or mitogen in the absence of G-CSF. T cells from G-CSF-treated mice showed a significant increase in IL-4 production, with a simultaneous decrease in IL-2 and interferon-gamma production in response to both stimuli. We also examined the effect of G-CSF pretreatment of donors in a GVHD model (B6-->B6D2F1). Survival was significantly improved in recipients of G-CSF-treated donors. Concanavalin-A-induced cytokine production at day 13 after transplantation also showed an increase in IL-4 along with a decrease in IL-2 and IFN-gamma production by splenocytes from recipients of G-CSF-treated bone marrow and T cells. These data show that pretreatment of donors with G-CSF polarizes donor T cells toward the production of type-2 cytokines, which is associated with reduced type-1 cytokine production and reduced severity of acute GVHD.

On the role of ligand in retinoid signaling: positive cooperativity in the interactions of 9-cis retinoic acid with tetramers of the retinoid X receptor

Previously, we have shown that the retinoid X receptor (RXR) forms tetramers with a high affinity and that interactions of the receptor with its ligand, 9-cis retinoic acid (9cRA), result in dissociation of protein tetramers. Here it is shown by fluorescence anisotropy studies that ligand-induced tetramer dissociation displays a pronounced positive cooperativity. The binding affinity of RXR for 9cRA at low saturation levels of the receptor with ligand was found to be significantly weaker than the affinity observed at higher levels of saturation. In addition, the rate of dissociation of 9cRA from RXR was found to be faster at low vs. high saturation levels of the receptor. These data suggest that the observed positive cooperativity of the ligand-induced dissociation of RXR tetramers stems from positive cooperativity in binding of 9cRA by the receptor. Kinetic studies showed that dissociation of RXR tetramers upon ligand binding is a rapid reaction characterized by a t1/2 of 80 ms, which is about 5 orders of magnitude faster than the rate of dissociation in the absence of ligand. The data indicate that the oligomeric state of RXR is tightly regulated by the precise concentrations of 9cRA and that it rapidly responds to changes in the ligand's concentrations. These findings further substantiate the hypothesis that modulation of the oligomeric state of RXR by 9cRA is an important regulatory step in the pathway by which retinoids affect gene transcription.

Role of ligand in retinoid signaling. 9-cis-retinoic acid modulates the oligomeric state of the retinoid X receptor

Many of the effects of retinoids on cells are mediated by the transcription factors known as retinoid nuclear receptors, but the mechanisms by which retinoids regulate the activity of the receptors are not known. It was previously shown that the retinoid X receptor (RXR) forms tetramers with a high affinity. In the present work it is demonstrated that binding of 9-cis-retinoic acid to RXR leads to rapid dissociation of receptor tetramers. In addition, fluorescence anisotropy studies indicate that ligand-binding results in a significant conformational change such that holo-RXR is more compactly folded as compared to the apo-protein. These findings suggest that the initial event in signaling by 9-cis-retinoic acid is a change in the oligomeric state of RXR. The data also imply that tetramer formation is a regulatory feature of the pathway by which RXR mediates the effects of retinoids on gene transcription.

Mice lacking the CNTF receptor, unlike mice lacking CNTF, exhibit profound motor neuron deficits at birth

Ciliary neurotrophic factor (CNTF) supports motor neuron survival in vitro and in mouse models of motor neuron degeneration and was considered a candidate for the muscle-derived neurotrophic activity that regulates motor neuron survival during development. However, CNTF expression is very low in the embryo, and CNTF gene mutations in mice or human do not result in notable abnormalities of the developing nervous system. We have generated and directly compared mice containing null mutations in the genes encoding CNTF or its receptor (CNTFR alpha). Unlike mice lacking CNTF, mice lacking CNTFR alpha die perinatally and display severe motor neuron deficits. Thus, CNTFR alpha is critical for the developing nervous system, most likely by serving as a receptor for a second, developmentally important, CNTF-like ligand.

Satellite remote sensing of tropospheric CO and CH(4): forward model studies of the MOPITT instrument

The Measurements of Pollution in the Troposphere (MOPITT) instrument is designed to measure tropospheric CO and CH(4) from a spaceborne platform by the use of infrared gas correlation radiometers. We describe the forward model that is used as the basis for the retrieval algorithm. We present the techniques used to model the instrument and describe the radiative transfer involved in the measurement process. Calculations have been performed to assess the sensitivity of the measured radiance to changes in the target-gas concentration profiles, changes in the concentration of contaminating constituents, and to variations in the parameters that describe reflection and emission of radiation at the Earth's surface.

High-resolution SSCP analysis using polyacrylamide agarose composite gel and a background-free silver staining method

We describe here an improved methodology for single-strand conformation polymorphism (SSCP) analysis of PCR products. The method utilizes a polyacrylamide agarose composite gel and background-free silver staining. In comparison with conventional pure polyacrylamide gel for PCR-SSCP analysis, the composite gels have a much greater mechanical strength and improved resolution. The background staining commonly seen in many silver staining protocols has been eliminated by incorporation of thiosulfate, which can prevent nonspecific deposits of silver salts. As shown in our titration tests, the composite gel and background-free silver staining together have allowed clear identification of point mutations in samples containing as little as 5% of the target sequences, the same sensitivity achieved by radioactive labeling methods.

Neuronal deficits, not involving motor neurons, in mice lacking BDNF and/or NT4

Nerve growth factor and other neurotrophins signal to neurons through the Trk family of receptor tyrosine kinases. TrkB is relatively promiscuous in vitro, acting as a receptor for brain-derived neurotrophic factor (BDNF), neurotrophin-4 (NT4) and, to a lesser extent, NT3 (refs 3-5). Mice lacking TrkB show a more severe phenotype than mice lacking BDNF, suggesting that TrkB may act as a receptor for additional ligands in vivo. To explore this possibility, we generated mice lacking NT4 or BDNF as well as mice lacking both neurotrophins. Unlike mice lacking other Trks or neurotrophins, NT4-deficient mice are long-lived and show no obvious neurological defects. Analysis of mutant phenotypes revealed distinct neuronal populations with different neurotrophin requirements. Thus vestibular and trigeminal sensory neurons require BDNF but not NT4, whereas nodose-petrosal sensory neurons require both BDNF and NT4. Motor neurons, whose numbers are drastically reduced in mice lacking TrkB, are not affected even in mice lacking both BDNF and NT4. These results suggest that another ligand, perhaps NT3, does indeed act on TrkB in vivo.

B-cell monoclonality, Epstein Barr virus, and t(14;18) in myoepithelial sialadenitis and low-grade B-cell MALT lymphoma of the parotid gland

Low-grade mucosa-associated lymphoid tissue (MALT) type B-cell lymphomas of the salivary gland arise in a background of myoepithelial sialadenitis (MESA), usually in association with Sjögren's syndrome. The distinction between benign MESA and early lymphoma has proved difficult using histological criteria alone and the significance of B-cell monoclonality in this respect is controversial. We have used immunohistochemistry and polymerase chain reaction (PCR) amplification of immunoglobulin heavy-chain VDJ regions to assess clonality in biopsies from 45 patients with lymphoid infiltration of the parotid. Sequential biopsies spanning 3-18 years were available from seven patients, three of whom had developed disseminated nodal B-cell lymphoma. In light of previous studies, each biopsy was additionally analyzed for the presence of t(14;18) and Epstein Barr Virus (EBV) DNA using PCR. Monoclonality was detected in 34/45 cases. Comparison of histology with clonality confirmed earlier suggestions that the emergence of an identifiable population of centrocyte-like B cells around ducts or epithelial islands correlated with monoclonality. In six of seven patients with sequential biopsies PCR fragments of identical size were amplified from each biopsy, suggesting that demonstrable monoclonality in "lymphoepithelial" lymphoproliferative lesions of the salivary gland is indicative of lymphoma. No t(14;18) chromosome translocations were identified; EBV sequences were detected in three of 45 cases.

[A clinical and experimental study of L-form bacteria in 66 cases]

In order to study the relationship between the time for establishing the diagnosis of infectious diseases and L-form bacteria, a series of clinical specimens taken from 321 cases of patients suspected to have infection were collected. Besides routine bacterial culture, special culture for L-form bacteria was also performed. The results were as follows: the rate of positive routine bacterial culture was 10.90% (35/321); the rate of negative routine bacterial culture but positive L-form bacterial culture was 20.56% (66/321). In this study, L-form bacteria infection was treated with sensitive antibiotics and a satisfactory result was obtained. It is shown that L-form bacterial culture is very useful in detection of pathogenic bacteria and helpful to the therapy of infectious diseases. Ultrastructure organization of these bacteria was studied by using transmission electron microscope.

Suppression of collagenase gene expression by all-trans and 9-cis retinoic acid is ligand dependent and requires both RARs and RXRs

Retinoic acids (RA) are active metabolites of vitamin A which affect the expression of many genes involved in embryonic development, cell differentiation, and homeostasis. One important target gene for RA is matrix metalloproteinase (MMP-1, collagenase), the only enzyme active at neutral pH that can degrade interstitial collagen, a major component of extracellular matrix. Using a cell line of normal rabbit synovial fibroblasts, HIG82 cells, as a model, we report that both all-trans- and 9-cis-RA inhibit collagenase synthesis. This inhibition occurs at a transcriptional level and is ligand-dependent. Constitutive levels of retinoic acid receptor (RAR) mRNA levels are low, but are increased by all-trans and by 9-cis RA. In contrast, constitutive levels of retinoid X receptor (RXR) mRNA are higher and are not affected by RA. To measure DNA/protein interactions, we used a gel mobility shift assay with oligonucleotides containing either an AP-1 site or a 40 bp region between -182/-141, nuclear extracts from RT-treated cells, and antibodies to RARs and RXRs. We found that both RARs and RXRs interact with these regions of the collagenase promoter, perhaps as part of a complex with other proteins. Our results suggest that heterodimers between RARs and RXRs mediate suppression of the collagenase gene by RA, and that RAR is a limiting factor in this negative regulation.

Mature polymorphonuclear leukocytes express high-affinity receptors for IgG (Fc gamma RI) after stimulation with granulocyte colony-stimulating factor (G-CSF)

The high-affinity receptor for the constant region of immunoglobulin G IgG (Fc gamma RI; CD64) is virtually undetectable on mature polymorphonuclear neutrophils (PMNs) in healthy individuals but is expressed on PMNs in patients with certain infections and in patients treated with recombinant human granulocyte colony-stimulating factor (rhG-CSF). The induction of Fc gamma RI by rhG-CSF has previously been reported to result from effects on immature granulocyte progenitors. To evaluate the G-CSF effect on mature PMNs, we studied the correlation between G-CSF plasma concentration and expression of Fc gamma RI on PMNs in vivo as well as the effect of G-CSF on Fc gamma RI expression on mature PMNs in vitro. Fc gamma RI expression on PMNs correlated (R = 0.79; p < .001) with plasma concentrations of endogenous or recombinant G-CSF in healthy volunteers and in patients undergoing high-dose chemotherapy and autologous bone marrow transplantation. PMNs exhibited a unimodal distribution for elevated Fc gamma RI expression, suggesting that G-CSF induced increased expression of Fc gamma RI on mature as well as on immature PMNs. In vitro, incubation of mature PMNs with G-CSF induced mRNA for Fc gamma RI. Significant Fc gamma RI surface expression was induced in a time- and dose-dependent manner. Thus, G-CSF can act on mature PMNs to increase Fc gamma RI expression and may be useful for stimulating antibody mediated immune functions of PMNs in vivo.

Insulin enhances glucocorticoid receptor-mediated induction of gene expression independent of a specific insulin response element

We have established a system in which we observe a synergistic interaction between insulin and glucocorticoids. This includes chimeric genes constructed to contain synthetic glucocorticoid-responsive elements, 5' of the HSV thymidine kinase promoter and the chloramphenicol acetyltransferase reporter gene. The magnitude of induction of gene expression by glucocorticoid was dependent on the number of GREs. Insulin alone had virtually no effect on the expression of any of these genes but together with dexamethasone acted in a synergistic manner. This synergy diminished as the number of GREs in the promoter increased. The synergy is independent of promoter sequences other than the GREs and a functional TATAA box. Three different approaches demonstrate that the effect of insulin is not directly on the glucocorticoid signal transduction pathway. Insulin does not change the dose-response relationship for dexamethasone. The effect of insulin is independent of the intracellular concentration of glucocorticoid receptor. The effect is independent of any specific domain of the glucocorticoid receptor. The target of insulin action is likely to be part of the normal host cell transcriptional initiation complex or a putative adaptor molecule.

[Personal characteristics as risk factors of endometriosis]

203 patients with pelvic endometriosis, all Beijing resident, were collected from the Peking Union Medical College Hospital and the Beijing Obstetrical and Gynecological Hospital. The diagnosis of endometriosis was confirmed by pathological examination of surgical specimens in 186 patients and by aspiration of chocolate substance under laparoscopy in 17. Two population controls, age matched +/- 1 year, were randomly selected for each patient from the same residential area, after careful pelvic examinations and ultrasonographies. A questionnaire for any possible risk factors to endometriosis was developed and with this questionnaire a face to face interview for each subject was carried out by the trained interviewers. All interviews were tape recorded and calculated in a AST 386 computer. The continuous logistic regression for matched sites was used to obtain a maximum likelihood point and to control the potential confounding effects of selected variables. Relative risk (RR) substituted for odds ratio together with the 95% confidence intervals was estimated. All the results were adjusted for the variables of the model including some relevant factors of menstruation, pregnancy and contraception. An increased risk for endometriosis was found to be related to women who had a higher level of education. Even it was adjusted for age of first marriage and pregnancy, gravidity, parity, contraception and all other variables of the model, the relative risk was 1.84 for endometriosis. Therefore, it is the education level itself that plays a true role in development of endometriosis. Although there was a trend in risk for endometriosis in height, it was statistically insignificant.(ABSTRACT TRUNCATED AT 250 WORDS)

Time course of ciliary neurotrophic factor mRNA expression is coincident with the presence of protoplasmic astrocytes in traumatized rat striatum

Adrenal grafting for Parkinson's disease has led to modest functional improvement despite poor graft survival. One explanation is a neurotrophic response within the traumatized striatum. This study was undertaken to investigate the time course of the astrocytic response in vivo and in vitro, and the expression of ciliary neurotrophic factor (CNTF) mRNA following striatal injury. Unilateral stereotaxic biopsy of the rat striatum was performed and gelatin sponge (gel-foam) was immediately placed into the biopsy cavity. Rats were sacrificed on days 1, 3, 5, 7, 14, and 28 post biopsy. Immunohistochemical staining of the traumatized striatum with antibodies to glial fibrillary acidic protein (GFAP) was carried out. The reactive astrocytes which appeared within 7 days after trauma were mostly protoplasmic on the basis of morphology, and maximal on day 7, being 30 times the level in the normal striatum. After day 7, fibrous astrocytes appeared and increased up to day 28, while protoplasmic astrocytes decreased. In addition, immunocytochemical double staining of short term cultured astrocytes from the traumatized striatum with anti-A2B5 and anti-GFAP antibodies revealed that 84% and 90% of astrocytes were type 1 astrocytes on days 3 and 7, respectively; however, by day 28 47% of astrocytes were type 2. Northern blot analysis revealed that CNTF mRNA expression was up-regulated and peaked on day 7, coincident with a predominance of protoplasmic astrocytes in vivo and type 1 astrocytes in vitro, respectively. These findings suggest that the expression of CNTF mRNA is part of the early astrocytic response to trauma, particularly associated with protoplasmic astrocytes in vivo and type 1 astrocytes in vitro.(ABSTRACT TRUNCATED AT 250 WORDS)