Anatomy of vasculature of 850 spleen specimens and its application in partial splenectomy

BACKGROUND

Anatomic knowledge of vasculature of the splenic lobe and segment is of great clinical significance in partial resections and transplantation of the spleen.

METHODS

The methods of two-colored corrosion casting, roentgenography, and anatomic dissection were used to evaluate the vasculature of the splenic hilum and intraspleen. On this basis splenic lobectomy and segmentectomy were performed on 42 patients with traumatized spleens.

RESULTS

In the observation of 850 spleen specimens the spleen showed a single lobar artery in 7 cases (0.8%), two lobar arteries in 730 cases (86%), three lobar arteries in 104 cases (12.2%), and multiple lobar arteries (i.e., more than three lobar arteries) in 9 cases (1%). In a subgroup of 276 specimens 17%, 53%, 24%, 4%, 1%, and 1% of spleen specimens had three, four, five, six, seven, and eight segmental arteries, respectively. The result from a subgroup of 280 specimens indicated that mean percentages of the existence of the superior and inferior polar arteries and of the coexistence of both polar arteries were 31.3%, 38.8%, and 13.3%, respectively. Relative avascular planes between segments or lobes were seen. Basic steps of splenic lobectomy or segmentectomy include mobilization of the injured spleen, ligation of vessels in the lobe or segment, transection of the splenic parenchyma, and sutures of the cut surface of the remaining spleen. The postoperative courses of all 42 patients undergoing partial splenectomy were uneventful. No postoperative bleeding and necrosis of the remaining spleen or infectious complications were registered.

CONCLUSIONS

Anatomically the spleen is defined with two primary lobes (the superior lobe and inferior lobe), one accessory lobe, and three to five segments. This new classification facilitates surgeons to perform partial resections of the spleen and allotransplantation of the hemispleen from a living related donor in human beings.

Localization of thyrotropin-releasing hormone mRNA expression in the rat heart by in situ hybridization histochemistry

Our laboratory has recently detected mRNA of thyrotropin-releasing hormone (TRH) in the rat heart. The density of mRNA for TRH is five-fold higher in the atria than in the left and right ventricle. We also found TRH receptor mRNA and 3H-TRH-binding sites in both ventricles. Cardiac contractility was stimulated after intracoronary administration of TRH. This study was performed to investigate the localization of TRH in the heart. We utilized in situ hybridization histochemistry (ISHH) to localize TRH mRNA expression in the rat heart. ISHH was performed on fresh frozen heart tissue sections which were hybridized with a specific 35S-TRH oligo probe and subsequently processed by autoradiography. The autoradiographic signals corresponding to TRH mRNA were analyzed with an image program. For positive controls TRH mRNA was identified in the hypothalamic paraventricular nucleus. This test confirms the specificity of the TRH oligo probe. Cardiac hybridization signals were observed predominantly in the atria and localized preferentially in atrial connective tissues, vascular adventitia and atrial cardiomyocytes. No hybridization signals were found in ventricular cardiomyocytes. These observations suggest that TRH is synthesized in atrial myocytes and atrial vascular structures. Based on studies which show synthesis of the TRH receptors in ventricular cardiomyocytes, we hypothesize that atrial TRH is an endocrine source for the stimulation of ventricular contractility and that endothelial and adventitial TRH may play a role(s) in the regulation of the growth and/or vasomotor tome of the cardiac vascular system.

Molecular basis of congenital erythropoietic porphyria: mutations in the human uroporphyrinogen III synthase gene

Congenital erythropoietic porphyria (CEP) is an autosomal recessive inborn error of metabolism that results from the markedly deficient activity of the fourth enzyme in the heme biosynthetic pathway, uroporphyrinogen III synthase (URO-synthase). To date, 17 mutations have been described including 11 missense, one nonsense, two mRNA splicing defects, one deletion and two coding region insertions. Most mutations have been identified in one or a few unrelated families with the exception of C73R and L4F which occurred in 29.6% and 9.3% of the 54 mutant alleles studied, respectively. Interestingly, analysis of the mutant alleles identified only 83% of the causative mutations, suggesting that about 20% of the mutations causing CEP lie elsewhere in the gene. Of note, mutation V82F, resulting from a G to T transversion of the last nucleotide of exon 4, caused both a missense mutation and an aberrantly spliced RNA transcript. Prokaryotic expression of the mutant URO-synthase alleles identified those with significant residual activity, thereby permitting genotype/phenotype predictions for this clinically heterogeneous disease.

Cocaine/sex type effects on T lymphocytes: a preliminary report

The influence of gender on the effects of cocaine (5 or 40 mg/kg) on immune function of sexually immature (35-day-old) C57BL/6J mice was assessed. The proliferation of T cells in thymus and spleen stimulated with phytohemagglutinin (PHA) and concanavalin-A(Con-A) was determined by 3H thymidine incorporation 24 hours after cocaine injections. The drug produced a dose-dependent reduction (25-51%) of Con-A and PHA-stimulated T cell proliferation in thymus from both male and female mice. Additionally, the impairment occurred at a lower cocaine dose for female than for male mice when the T cells were challenged with PHA. Under the experimental conditions, cocaine did not alter weights or cell numbers of thymus and spleen or T cell proliferation in spleen.

Analysis of interleukin-2-dependent signal transduction through the Shc/Grb2 adapter pathway. Interleukin-2-dependent mitogenesis does not require Shc phosphorylation or receptor association

The interleukin (IL)-2 receptor system has previously been shown to signal through the association and tyrosine phosphorylation of Shc. This study demonstrates that the IL-2 receptor beta (IL-2R beta) chain is the critical receptor component required to mediate this effect. The use of IL-2R beta chain deletion mutants transfected into a Ba/F3 murine cell model describes a requirement for the IL-2R beta "acid-rich" domain between amino acids 315 and 384 for Shc tyrosine phosphorylation and receptor association. COS cell co-transfection studies of IL-2R beta chain constructs containing point mutations of tyrosine to phenylalanine along with the tyrosine kinase Jak-1 and a hemagglutinin-tagged Shc revealed that the motif surrounding phosphorylated tyrosine 338 within the acid-rich domain of the IL-2R beta is a binding site for Shc. Deletion of this domain has previously been shown to abrogate the ability of IL-2 to activate Ras but does not affect IL-2-dependent mitogenesis in the presence of serum. Proliferation assays of Ba/F3 cells containing IL-2R beta chain deletion mutants in serum-free medium with or without insulin shows that deletion of the acid-rich domain does not affect IL-2-driven mitogenesis regardless of the culture conditions. This study thus defines the critical domain within the IL-2R beta chain required to mediate Shc binding and Shc tyrosine phosphorylation and further shows that Shc binding and phosphorylation are not required for IL-2-dependent mitogenesis. Neither serum nor insulin is required to supplement the loss of induction of the Shc adapter or Ras pathways, which therefore suggests a novel mechanism for mitogenic signal transduction mediated by this hematopoietin receptor.

Absence of linkage between human obesity and the mouse agouti homologous region (20q11.2) or other markers spanning chromosome 20q

Mutant alleles of the agouti gene cause obesity in the mouse and the homologous gene in humans has been mapped to chromosome 20q11.2. An allelic variant of the agouti gene could account for obesity in humans and we tested this hypothesis by genotyping 210 sibling pairs from 45 families segregating an obesity phenotype. Using sibling pair linear regression analysis, evidence for linkage between obesity and markers flanking the agouti locus and other markers spanning chromosome 20q was assessed. We found no correlation between identity-by-descent at these markers and obesity differences within pairs. In the mouse, obesity caused by mutations of the agouti gene develops later in life, so a subset of families with adult-onset obesity were also tested for linkage, with negative results. Although it is not possible to exclude alleles of the agouti gene as a contributor to obesity in humans, the absence of positive linkage in this study suggests that either the agouti gene has small effects or the allele frequency is low.

Variety of nonsense suppressor phenotypes associated with mutational changes at conserved sites in Escherichia coli ribosomal RNA

To screen for ribosomal RNA mutants defective in peptide chain termination, we have been looking for rRNA mutants that exhibit different patterns of suppression of nonsense mutations and that do not suppress missense mutations at the same positions in the same reporter gene. The rRNA mutations were induced by segment-directed randomly mutagenic PCR treatment of a cloned rrnB operon, followed by subcloning of the mutagenesis products and transformation of strains containing different nonsense mutations in the Escherichia coli trpA gene. To date, we have repeatedly obtained only two small sets of mutations, one in the 3' domain of 16S rRNA, at five nucleotides out of the 610 mutagenized (two in helix 34 and three in helix 44), and the other in 23S rRNA at only four neighboring nucleotide positions (in a highly conserved hexanucleotide loop) within the 1.4 kb mutagenized segment. There is variety, however, in the suppression patterns of the mutants, ranging from suppression of UAG or UGA, through suppression of UAG and UGA, but not UAA, to suppression of all three termination codons. The two helices in 16S rRNA have previously been associated both physically and functionally with the decoding center of the ribosome. The 23S region is part of the binding site for the large subunit protein L11 and the antibiotic thiostrepton, both of which have been shown to affect peptide chain termination. Finally, we have demonstrated that the 23S mutant A1093, which suppresses trpA UGA mutations very efficiently, is lethal at temperatures above 36 degrees C (when highly expressed). This lethality is overcome by secondary 23S rRNA mutations in domain V. Our results suggest that specific regions of 16S and 23S rRNA are involved in peptide chain termination, that the lethality of A1093 is caused by high-level UGA suppression, and that intramolecular interaction between domains II and V of 23S rRNA may play a role in peptide chain termination at the UGA stop codon.

[Medicinal plant resources of Berberis L. in Guizhou province]

Based on field investigation and identification of 19 species and one variety of medicinal plant of Berberis produced in Guizhou Province, it has been found out that among these species 3 is found to be new ,4 species and one variety are discovered for the first time in Guizhou province. Geographical distribution, perpendicular distribution and medicinal uses of these species are spelled out and a key for their identification is given.

Human glucose phosphate isomerase: exon mapping and gene structure

The structure of the gene for human glucose phosphate isomerase (GPI) has been determined. Three GPI clones were isolated from a human genomic library by using a full-length GPI cDNA probe and were characterized. Oligonucleotides based on the known cDNA sequence were used as primers in amplification and sequence analyses. This led to the identification of the exon-intron junctions. By this approach, 18 exons and 17 introns have been identified. The exons range in size from 44 to 431 nucleotides. The intronic sequences surrounding the exons provide useful information for the identification of mutations that give rise to human GPI deficiency associated with chronic hemolytic anemia.

Arabidopsis TCH4, regulated by hormones and the environment, encodes a xyloglucan endotransglycosylase

Adaptation of plants to environmental conditions requires that sensing of external stimuli be linked to mechanisms of morphogenesis. The Arabidopsis TCH (for touch) genes are rapidly upregulated in expression in response to environmental stimuli, but a connection between this molecular response and developmental alterations has not been established. We identified TCH4 as a xyloglucan endotransglycosylase by sequence similarity and enzyme activity. Xyloglucan endotransglycosylases most likely modify cell walls, a fundamental determinant of plant form. We determined that TCH4 expression is regulated by auxin and brassinosteroids, by environmental stimuli, and during development, by a 1-kb region. Expression was restricted to expanding tissues and organs that undergo cell wall modification. Regulation of genes encoding cell wall-modifying enzymes, such as TCH4, may underlie plant morphogenetic responses to the environment.

Identification of a candidate c-mos repressor that restricts transcription of germ cell-specific genes

The c-mos proto-oncogene is specifically expressed in female and male germ cells. Previous studies identified a negative regulatory element (NRE) upstream of the c-mos promoter that suppresses c-mos transcription in transfected NIH 3T3 cells. In this study, we used gel shift assays to detect proteins in nuclear extracts of NIH 3T3 cells that bind to the c-mos NRE in a sequence-specific manner. One protein was found to bind to a region of the NRE which was shown by site-directed mutagenesis to be required for suppression of c-mos transcription. This factor was present in nuclear extracts of several somatic cell lines and tissues but not in male germ cells in which c-mos is transcribed, suggesting that it is a somatic cell repressor of c-mos transcription. The binding site of the candidate repressor within the c-mos NRE consists of sequences related to putative NREs identified in two other male germ cell-specific genes (encoding protamine 2 and phosphoglycerate kinase 2). The c-mos repressor bound and could be UV cross-linked to these protamine 2 and phosphoglycerate kinase 2 gene sequences as a protein with an apparent molecular mass of approximately 30 kDa. The repressor binding site is also conserved in two other germ cell-specific genes (encoding testis-specific cytochrome c and heat shock-like protein 70), suggesting that the c-mos repressor may be generally involved in suppressing transcription of germ cell-specific genes in somatic cells.

[Hemodynamic study of distal splenorenal shunt (DSRS)]

Color-flow Doppler sonography (FDS) was used for assessing the hemodynamic changes in 8 patients undergoing distal splenorenal shunt (DSRS). Results were compared with 14 patients with portal-azygos disconnection (PAD). It was found that 3 weeks after DSRS portal venous flow (PVF) decreased by 50%, and at least in some patients the reduction of the PVF was a continuous process during the period of two years in the DSRS group. The postoperative decrease in PVF in DSRS patients was in sharp contrast to that in PAD patients (P < 0.001), hence PAD is superior to DSRS in remaining satisfactory PVF.

Flourishing health work in China

Great achievements have been made in China's medical and health work over the past 44 years. China now has become one of the leaders among the developing countries in respect of people's health conditions and health care service, and some of the fields have reached an advanced level. China owes its flourishing health work to the policy of 'put prevention first, rely on the progress of science and technology, strengthen rural health work, and give equal emphasis to both traditional Chinese and western medicine'. 'Health for all by the year of 2000' has been set as a strategic goal in China, and will be accomplished through increased governmental investment in health work and constant reforms of the medical systems.

Growth signal transduction by the human interleukin-2 receptor requires cytoplasmic tyrosines of the beta chain and non-tyrosine residues of the gamma c chain

To evaluate the possible role for receptor-based tyrosine phosphorylation in growth signaling induced by interleukin-2 (IL-2), a series of substitution tyrosine mutants of the IL-2 receptor beta and gamma c chains was prepared and analyzed. Concurrent mutation of all six of the cytoplasmic tyrosines present in the beta chain markedly inhibited IL-2-induced growth signaling in both pro-B and T cell lines. Growth signaling in a pro-B cell line was substantially reconstituted when either of the two distal tyrosines (Tyr-392, Tyr-510) was selectively restored in the tyrosine-negative beta mutant, whereas reconstitution of the proximal tyrosines (Tyr-338, Tyr-355, Tyr-358, Tyr-361) did not restore this signaling function. Furthermore, at least one of the two cytoplasmic tyrosines that is required for beta chain function was found to serve as a phosphate acceptor site upon induction with IL-2. Studies employing a chimeric receptor system revealed that tyrosine residues of the beta chain likewise were important for growth signaling in T cells. In contrast, although the gamma c subunits is a target for tyrosine phosphorylation in vivo, concurrent substitution of all four cytoplasmic tyrosines of this chain produced no significant effect on growth signaling by chimeric IL-2 receptors. However, deletion of either the Box 1, Box 2, or intervening (V-Box) regions of gamma c abrogated receptor function. Therefore, tyrosine residues of beta but not of gamma c appear to play a pivotal role in regulating growth signal transduction through the IL-2 receptor, either by influencing cytoplasmic domain folding or by serving as sites for phosphorylation and subsequent association with signaling intermediates. These findings thus highlight a fundamental difference in the structural requirements for IL-2R beta and gamma c in receptor-mediated signal transduction.

Oxygen sensors based on luminescence quenching: interactions of pyrene with the polymer supports

Oxygen quenching of pyrene has been studied in a diverse series of polymers. Most measurements were made using homo- or copolymers containing a poly(dimethylsiloxane) region. Systematic variations in the polymer properties have been made in order to delineate the structural features important for satisfactory use as supports for oxygen sensors. In particular, quenching behavior was examined as a function of the type and amount of copolymer cross-linkers; these were added to produce domains of different polarity and rigidity that would segregate the sensor molecule. A domain model (Xu, W.; et al. Anal. Chem. 1994, 66, 4133-4141) was used to explain the variations in oxygen-quenching properties as a function of additives and cross-linkers. The relative affinity of the different domains for the pyrene and the efficacy of the domains for oxygen quenching controls the overall behavior of the sensing response.

Human obesity does not segregate with the chromosomal regions of Prader-Willi, Bardet-Biedl, Cohen, Borjeson or Wilson-Turner syndromes

Prader-Willi, Bardet-Biedl, Cohen, Borjeson and Wilson-Turner syndromes are genetic disorders characterized by obesity and other diverse abnormalities. These disorders have been mapped to their respective chromosomal regions, and we hypothesize that each region contains a gene or genes important in the regulation of body weight. We tested this hypothesis by genotyping sibling pairs (n = 207; 17 markers) from 44 families who were segregating an extreme obesity phenotype but were otherwise clinically normal. The number of alleles shared between siblings from these chromosomal regions did not correlate with similarity in body mass index (kg/m2). If genes in these regions contribute to non-syndromal obesity, the prevalence is low and the corresponding alleles are rare.

[An investigation and design of apparatus for measuring fetal lung maturity]

Clinically, the authorized method for determing fetal lung maturity is the measurement of the ratio of surface-active L/S in amniotic fluid. To set up new, simple, rapid and accurate method, an apparatus for measuring fetal lung maturity was made. The paper describes the basic principle and working procedure of the apparatus. 148 amniotic fluid specimens from different pregnancies were measured by means of the apparatus. The result was compared with the L/S. The sensitivity of measurement was 95%, specificity 91%, and accuracy 93%. The operation of the apparatus is simple, convenient and rapid. A small quantity of amniotic fluid is needed. In conclusion, the expected result was attained. The apparatus is of great importance to clinical application.

[p53 gene point mutation in human colorectal carcinoma]

We introduced two modified assay systems, PCR-SSCP and PCR-direct sequencing for the identification of structure aberration at p53 exon 7 in 22 colorectal carcinomas and 1 metastatic lymph node. The data indicated that 27.2% (6/22) colorectal carcinomas and one metastatic lymph node were shown to contain the point mutations in codons 245, 251, 259 and 260 of exon 7. One half of all the mutations was G:c to A:T transition in codon 245. Other mutation patterns were base insertion and deletion. All positive point mutations of p53 exon 7 existed in colon carcinomas in this study. The point mutation in p53 exon 7 was usually associated with poorly differentiated primary carcinomas (P = 0.0178) and the mutation rate of was higher in Duckes C stage of the disease than in stage Duckes A and B (P = 0.0361). Thus p53 exon 7 point mutation in primary colorectal tumors and regional lymph nodes may identity a subgroup of colorectal cancer patients with more aggressive disease and may be as a new tumor markers for assessing the prognosis of colorectal carcinomas.

Signaling through the interleukin 2 receptor beta chain activates a STAT-5-like DNA-binding activity

To explore the possible involvement of STAT factors ("signal transducers and activators of transcription") in the interleukin 2 receptor (IL-2R) signaling cascade, murine HT-2 cells expressing chimeric receptors composed of the extracellular domain of the erythropoietin receptor fused to the cytoplasmic domains of the IL-2R beta or -gamma c chains were prepared. Erythropoietin or IL-2 activation of these cells resulted in rapid nuclear expression of a DNA-binding activity that reacted with select STAT response elements. Based on reactivity with specific anti-STAT antibodies, this DNA-binding activity was identified as a murine homologue of STAT-5. Induction of nuclear expression of this STAT-5-like factor was blocked by the addition of herbimycin A, a tyrosine kinase inhibitor, but not by rapamycin, an immunophilin-binding antagonist of IL-2-induced proliferation. The IL-2R beta chain appeared critical for IL-2-induced activation of STAT-5, since a mutant beta chain lacking all cytoplasmic tyrosine residues was incapable of inducing this DNA binding. In contrast, a gamma c mutant lacking all of its cytoplasmic tyrosine residues proved fully competent for the induction of STAT-5. Physical binding of STAT-5 to functionally important tyrosine residues within IL-2R beta was supported by the finding that phosphorylated, but not nonphosphorylated, peptides corresponding to sequences spanning Y392 and Y510 of the IL-2R beta tail specifically inhibited STAT-5 DNA binding.

[Total pelvic exenteration for local advanced rectal carcinoma: analysis of 20 patients]

20 patients of total pelvic extenteration (TPE) were performed from 1989 to 1995 for local advanced rectal carcinoma. The incidence of operative complications was 65% with a mortality of 5%. 19 patients were followed up for 3-42 months, 7 patients died with an average life-span of 14.1 months. It seemed to us that the results of conservative therapy was usually disappointing for local advanced rectal carcinoma and and TPE is the better management of choice for relieving patient's symptoms and improving their survival rates.

Molecular genetic analysis of the duplication of human inducible nitric oxide synthase (NOS2) sequences

In previous studies, we found multiple copies of inducible nitric oxide synthase gene (NOS2)-like sequences in the human genome and mapped them to the pericentric region of chromosome 17. Here, we describe the cloning and sequencing of exon22 regions from three of these NOS2-like sequences. We have also mapped another NOS2-like sequence to human chromosome 14. Since there are multiple NOS2-like sequences present in the human genome, we have also carried out Zoo Blot hybridisation analysis using a NOS2 cDNA probe. Our data suggest that duplication of NOS2-like sequences occurred very recently in primate evolution.

A microchip glucose sensor

A major problem in development of a glucose sensor for use in an implantable artificial pancreas is the lack of reproducibility in signals from sensor to sensor. Each glucose sensor fabricated with currently used methods has a unique response to varying levels of glucose concentration and thus needs to be individually calibrated before use. We have adapted microchip manufacturing techniques for the fabrication of electrochemically based glucose sensors with standardized and reproducible function. Scanning electron microscopic study of the resulting electrode surfaces shows them to be smooth and featureless at all levels of magnification. X-ray diffraction analysis of the electrodes indicates preferential exposure of the [1,1,1] crystal interface. Cyclic voltammetry evaluation of initial sensor response to varying glucose concentrations shows excellent sensor to sensor reproducibility for all sensors made with the same underlayment. Sensors made with titanium underlayment appear to be more differentiated and thus more sensitive to variations in glucose concentration than are sensors with chromium underlayment. Although the initial response of microchip glucose sensors appears to be standardized and reproducible, additional development of an appropriate electrical insulation material is required before long-term study of signal stability is feasible.

[Correlation study of allelic gene deletion of nm23-H1 and human colorectal carcinoma metastasis]

In recent years, a tumor suppressor gene nm23 has been found to be associated with decreased tumor metastatic potential. Allelic deletion, mutation and low expression of this gene has been correlated with tumor metastatic potential in a number of tumors. There are two known isotypes of human nm23 gene, named nm23-H1 and nm23-H2. We examined DNA from 23 cases of colorectal carcinomas and their corresponding normal mucosa using Southern blot hybridization with nm23-H1 cDNA probe. Five cases with allelic deletion of nm23-H1 gene were found, with allelic deletion rate of 57. 1% (4/7) in cases with metastasis to lymph node, liver or other organs, and 6.2% (1/16) in cases without metastases (P < 0.005). There is no correlation between allelic deletion and tumor size, location or differentiation. This result indicates that nm23-H1 gene plays an important role in the metastasis of colorectal carcinoma.

A micro carbon electrode for nitric oxide monitoring

A nitric oxide (NO) probe, consisting of a micro carbon fiber working electrode, 10 microns diameter, a platinum counter electrode, and a silver/silver chloride (Ag/AgCl) reference electrode, has been developed. The carbon fiber working electrode is covered with a Nafion cation exchange membrane. Using differential pulse voltammetry (DPV), we found the NO to N2O reduction current peak at approximately -1.35 V versus Ag/AgCl. This has been reported by others. The DPV current outputs are linearly related to dissolved NO concentrations [NO] in the 2-10 microM range. Catecholamines were found not to interfere with the reduction signal. The Nafion membrane also prevents interference by NO2-, NO3-, and amino acids at normal physiologic pH (pH 7.4). The effects of O2 are accounted for through sampling and subtracting background currents from the peak current. To increase sensitivity and shorten response time, a method of integrated pulse amperometry (IPA) was used for the study. The IPA charge outputs (delta C) are linear to the dissolved [NO] in the 50-350 nM range. The carbon fiber electrode has the potential of being miniaturized to a smaller electrode, allowing detection of NO released from the subendothelial space.