Signal transducing molecules and glycosyl-phosphatidylinositol-linked proteins form a caveolin-rich insoluble complex in MDCK cells

GPI-linked protein molecules become Triton-insoluble during polarized sorting to the apical cell surface of epithelial cells. These insoluble complexes, enriched in cholesterol, glycolipids, and GPI-linked proteins, have been isolated by flotation on sucrose density gradients and are thought to contain the putative GPI-sorting machinery. As the cellular origin and molecular protein components of this complex remain unknown, we have begun to characterize these low-density insoluble complexes isolated from MDCK cells. We find that these complexes, which represent 0.4-0.8% of the plasma membrane, ultrastructurally resemble caveolae and are over 150-fold enriched in a model GPI-anchored protein and caveolin, a caveolar marker protein. However, they exclude many other plasma membrane associated molecules and organelle-specific marker enzymes, suggesting that they represent microdomains of the plasma membrane. In addition to caveolin, these insoluble complexes contain a subset of hydrophobic plasma membrane proteins and cytoplasmically-oriented signaling molecules, including: (a) GTP-binding proteins--both small and heterotrimeric; (b) annex II--an apical calcium-regulated phospholipid binding protein with a demonstrated role in exocytic fusion events; (c) c-Yes--an apically localized member of the Src family of non-receptor type protein-tyrosine kinases; and (d) an unidentified serine-kinase activity. As we demonstrate that caveolin is both a transmembrane molecule and a major phospho-acceptor component of these complexes, we propose that caveolin could function as a transmembrane adaptor molecule that couples luminal GPI-linked proteins with cytoplasmically oriented signaling molecules during GPI-membrane trafficking or GPI-mediated signal transduction events. In addition, our results have implications for understanding v-Src transformation and the actions of cholera and pertussis toxins on hetero-trimeric G proteins.

[The changes in free radical and prostaglandin metabolism in newborn infants with asphyxia]

Blood plasma thromboxane-B2 (TXB2) and 6-keto-PGF1 alpha levels were determined by radioimmunoassay technique during the first six to sixteen hours of life in 16 newborn infants with severe asphyxia, 18 newborn infants with mild asphyxia and 27 normal term neonates. Plasma lipid peroxidation (LPO) content was measured by TBA-colour-contrast method in 15 infants with severe asphyxia, 17 infants with mild asphyxia and 24 healthy term newborn infants. The results showed that blood plasma LPO, TXB2 and 6-keto-PGF1 alpha levels in infants suffering from severe asphyxia were higher than those in infants with mild asphyxia and normal infants (P < 0.01), but no significant difference was noted between the mild asphyxia group and normal control group (P > 0.01). These suggest that production of free radicals is increased and prostaglandin metabolism is triggered in the infants with severe asphyxia, that cerebral ischemia and hypoxia caused by asphyxia contributes to the augmented production of prostaglandins and free radicals, and that accumulation of free radicals and prostaglandin enhances brain damage and the metabolism of arachidonic acid appears to be an important source of the free radicals in infants with intrauterine asphyxia.

Negative regulation of the wee1 protein kinase by direct action of the nim1/cdr1 mitotic inducer

The wee1 protein kinase suppresses the entry into mitosis by mediating the inhibitory tyrosine phosphorylation of p34cdc2. Genetic studies have suggested that the nim1 protein kinase (also known as cdr1) acts as a positive regulator of mitosis by down-regulating the wee1 pathway in yeast cells. We have overexpressed the nim1 protein in both bacteria and insect cells. The recombinant nim1 protein autophosphorylates on both tyrosine and serine residues and can phosphorylate the isolated wee1 protein directly in a cell-free system. The nim1-catalyzed phosphorylation of the wee1 protein occurs in its C-terminal region and leads to a substantial drop in its activity as a cdc2-specific tyrosine kinase. This nim1-dependent inhibition of the wee1 protein kinase can be reversed readily in vitro by treatment with a protein phosphatase. These experiments provide direct biochemical evidence that the wee1 protein is subject to negative regulation by phosphorylation and indicate that the nim1 protein acts as an inhibitory, wee1-specific kinase.

[The influence of neonatal hyperbilirubinemia on neonatal behavior]

Two groups of neonates, 30 cases with hyperbilirubinemia (307.8 +/- 99.86 mumol/L) and 30 normal newborns (control group with bilirubin 80.37 +/- 35.74 mumol/L), were evaluated with Neonatal Behavioral Assessment Scale (NBAS) and followed up at the age of 2 months and 5 months. All cases in the two groups were evaluated with NBAS at ages of 2-3 days, 12-14 days and 26-28 days. The results showed that there were statistically significant differences between the two groups in the aspects of attention and social responsiveness, the ability to modulate state of consciousness, the motor integrity and the reflexes. We also found that while the level of bilirubin was below 205.2 mumol/L, there was no correlation between the level of bilirubin and NBAS (r = -0.095, P > 0.02), but when bilirubin was at or above the level of 205.2 mumol/L, there was significant negative correlation (r = -0.53, P < 0.001) between the two. The follow-up revealed that 9 of 23 jaundiced infants had abnormal auditory reactions or abnormal muscle tonus at the age of 2 months; 8 of the 9 infants recovered, but 1 still had abnormal muscle tonus by the age of 5 months. The study suggests that hyperbilirubinemia above the level of 205.2 mumol/L would affect neonatal behavior and the greater the severity of jaundice, the more significant the influence on neonatal behavior. The effects on some jaundiced infants may last 5 months or more. NBAS is a valuable scale for early detection of mild brain dysfunctions which are less obvious on clinical examination.

[Construction of clone about major DNA fragment coding for 150kd phosphoprotein of human cytomegalovirus and its restriction site analysis]

Human cytomegalovirus (HCMV) DNA EcoRI-Y fragment, which is major DNA fragment coding for 150kd phosphoprotein (pp150) of HCMV, was separated and recovered from recombinant cosmid pCM1015. The recombinant plasmids pHCY1 and pHCY2, which contain major DNA fragment coding for pp150, were constructed successfully, using the plasmid pUC19 as vector. The recombinant plasmids were analysed by restriction endonucleases and determined by Southern hybridization. The restriction sites of DNA encoding region for immunodominant epitopes of HCMV pp150 were analysed by GENEPRO system. The region could be digested by 76 kinds of restriction endonucleases. The sizes of cleaved fragments were between 4-2667 bp.

Radioiodinated anti-hepatocellular carcinoma (HCC) ferritin. Targeting therapy, tumor imaging and anti-antibody response in HCC patients with hepatic arterial infusion

Radioimmunoimaging and radioimmunotherapy with radioiodinated anti-(hepatocellular carcinoma ferritin) antibody (131I- or 125I-FtAb) have been applied in patients with primary liver cancer. A total of 41 patients with surgically unresectable hepatocellular carcinoma (HCC) and receiving hepatic artery ligation and cannulation during exploratory laparotomy were treated with this regimen by intrahepatic arterial infusion. Compared with the control group, a decline of serum alpha-fetoprotein (65.7% versus 42.9%) and shrinkage of tumor (68.3% versus 33.9%) were observed in the treated group, and a higher second-look resection rate (31.7% versus 5.1%) and longer survival (1-year: 61.0% versus 37.3%, 3-year: 25.0% versus 6.9%) resulted. The administration of antibody through a hepatic arterial catheter (n = 16) was compared with intravenous injection (n = 17) in terms of the tumor-imaging sensitivity in 33 patients with liver cancer. The results indicated that hepatic arterial infusion was superior to intravenous injection. The sensitivity 7 days after the administration was 100% in the i.a. group and 76.5% in the i.v. group, the uptake ratio of tumor to liver being 1.74 +/- 0.57 in the former and 1.34 +/- 0.29 in the latter. Furthermore, intrahepatic arterial infusion revealed a lower anti-antibody detection rate than intravenous injection (0/14 versus 4/11).

[Influence of moxibustion on TXA2 and PGI2 in plasma of rat infected epidemic hemorrhagic fever virus (EHFV)]

In this paper, the model of rat infected EHFV was made and the influence of moxibustion on TXA2 and PGI2 in its plasma was observed. The results show that the content of TXA2 increased and PGI2 decreased in rat significantly after the abdominal inoculation of EHFV, and the content of TXA2 decreased and PGI2 increased markedly in rat infected EHFV to normal level after treatment with moxibustion, suggesting that the regulative function of moxibustion on TXA2 and PGI2 is one of its nerve-endocrine-immune regulations to the body, and there is an important significance. This study provides an important reference for mechanism exploration of moxibustion preventing and treating EHF.

[Copper, iron and zinc content of preterm and term human milk and cow's milk]

Sixty-eight samples of preterm human milk and 39 samples of term human milk were obtained during 4 weeks postpartum from 7 mothers delivering prematurely and 9 mothers giving birth at term. Eleven cow's milk samples were obtained at random from 11 healthy cows. Samples were measured by flame method using an atomic absorption spectrophotometer (Type WYX-402). The three trace elements content of PT and FT milks decreased significantly with duration of lactation, and the content of each mineral was higher during the first week than that measured during the fourth week. PT and FT milk did not differ significantly in the content of the three elements during the first month of lactation. Copper content of PT milk at each week, iron content of PT milk at the first week and zinc content of PT milk during the first two weeks of lactation are higher than those of cow's milk respectively. The intake of copper, iron and zinc of the preterm infant fed his own mother's milk or cow's milk was calculated. Comparison of the intake level of copper and zinc of breastfed and cow's milk-fed preterm infant with the recommended intake level of the two minerals was made. The results show PT milk is superior to cow's milk for copper, iron and zinc; may be helpful for promoting breast feeding and feeding the preterm infant with supplemental trace elements.

[Consecutive study of nutritional composition of milk from mothers of preterm delivery]

The content of protein, fat, lactose, potassium, sodium, calcium, phosphorus, magnesium, copper, iron, zinc in preterm human milk was determined from the longitudinal samples during the first 8 weeks of lactation. Changes in content, over time were tested by analysis of variance. Protein, potassium, sodium, copper, iron, zinc content decreased significantly as lactation progressed. Based upon these data, a preterm infant fed 200 ml per kg per day of its own mother's milk would receive an excess of all substrates except calcium, phosphorus and iron over the estimated intrauterine accretion rates. Within 4 weeks the first in the postpartum period, the average intake of calcium, phosphorus, magnesium and copper was lower than the recommended intake. Iron intake is not adequate. After 4 weeks, the average intake of protein, sodium and zinc was lower than the recommended intake. The results may offer a basic datum for establishing premature infant feeding and formulation of human milk fortifiers (HMF).

Prothrombin expression in the adult and fetal rabbit liver

Plasma prothrombin levels in newborn humans are lower than in adults. The same is true of many newborn and fetal mammals, including the rabbit. To determine if the lower levels are due to less expression of the protein, we have compared mRNA for prothrombin in fetal and adult rabbit liver. Northern blots were hybridized with a cDNA for rabbit prothrombin revealing a single mRNA of approximately 2 kb in both adult and fetal animals. mRNA specific for prothrombin was quantitated by slot blotting of RNA prepared from adults and fetuses aged 21 d to term (31 d). Prothrombin-specific mRNA in fetuses was greater than 50% of that in adults even when the fetal plasma prothrombin was only 15% of the adult level. This suggests that low plasma levels in the fetuses are not the result of less transcription. Examination of liver sections revealed that the predominant tissue in the fetus is hematopoietic, not hepatic. In the youngest fetuses, less than 20% of the liver consisted of hepatocytes, yet these fetuses expressed more than 50% of the adult level of prothrombin-specific mRNA. Thus, transcription of prothrombin mRNA may be proceeding at a greater rate in the fetal hepatocyte than in the adult, or hematopoietic cells may be expressing the protein. We conclude that in fetal rabbit liver, prothrombin is expressed at a high level relative to the hepatocyte content and that the cause of the low plasma levels is posttranscriptional.

[Application of polymerase chain reaction in amplification of human cytomegalovirus B gene code region]

A nucleic acid amplification procedure, the polymerase chain reaction (PCR), has been used to amplify the human cytomegalovirus (HCMV) B gene code region, and its glycoprotein 52 kd antigenic domain. The primers used in the PCR assay were based on a conserved region of the HCMV B gene sequence. By using primer 1 (5'-AAAGAATTCATGGAATCCAGGATCTG-3', upstream nucleotides 157 to 2877), primer 2 (5'-AAAGAATTCATGAACGTGAAGGAATCG-3', upstream nucleotides 1846 to 2877), and primer 4(5'-ATAAAGCTTAATCAGACGTTCTCTTCTTC-3', downstream nucleotides 157 to 2877 and 1846 to 2877), the HCMV B gene code region sequence and its glycoprotein 52 kd antigenic domain sequence were amplified from the recombinant plasmid pBH1 DNA containing the HCMV B gene. Amplification cycles consisted of denaturation at 92 degrees C for 1 min, annealing at 55 degrees C for 1 min, and extension at 72 degrees C for 1.5 min. The cycles were carried out 30 times in three different water baths, respectively. After the last extension, 10 microliter of each reaction mixture was removed and subjected to electrophoresis on 1.2% agarose gel. Ten microgram of PCR products were obtained from 0.2 microgram of template DNA after the 30 times cycles, and were enough for being used in the restriction site analysis and the construction of clones.

[Clinical effects of nifedipine on blood pressure and left ventricular performance in patients with isolated hypertension]

17 patients with isolated systolic hypertension (ISH) and 8 with diastolic hypertension (DH) were treated with 10 mg of nifedipine sublingually. In ISH group the blood pressure decreased on the average from 180.2/87.4 to 166.2/84.2, 161.9/82.6, 163.4/83.7 mmHg after 5.20 and 60 minutes, while in DH group the blood pressure decreased on the average from 139.2/102.0 to 138.0/100.0, 137.6/97.6, 134.4/97.2 mmHg. With pulsed Doppler echocardiography, we found that early diastolic time-velocity integral increased (P less than 0.001) and E time prolonged (P less than 0.01) after 20 and 60 minutes in ISH group; and 1/3 filling fraction increased (P less than 0.05) after 20 minutes in DH group. With M-mode echocardiography we found that cardiac index and ejection fraction were improved in both groups. No obvious side effects were noted. From above-mentioned findings we are of the opinion that sublingual nifedipine is effective in reducing blood pressure and improving left ventricular performance especially in ISH patients.

Hb Westmead: an alpha 2-globin gene mutation detected by polymerase chain reaction and Stu I cleavage

Hb Westmead or alpha 2 122(H5)His----Gln beta 2 is one of the most common hemoglobin variants in Guangxi, a province in Southern China. The alpha 2-globin DNA sequence of a carrier for this variant was selectively amplified by the polymerase chain reaction and analyzed with the restriction enzyme Stu I. We found that this mutant globin was encoded at the alpha 2 locus and that the CAC----CAG mutation at codon 122 created a new Stu I restriction site. It is easy to detect this mutation by these methods.

[Construction of the human cytomegalovirus B gene clone and its restriction site analysis by computer]

We constructed two clones of the human cytomegalovirus strain AD169, using the plasmid pBR322 and the recipient bacterium Escherichia coli strain HB101. The human cytomegalovirus B gene was isolated from the recombinant plasmid pAT153 that contained the 20.7-kb Hind III F fragment of the human cytomegalovirus genome. The recombinant plasmid pAT153 was digested with BamHI and a 8.5-kb fragment was isolated and ligated with BamHI-digested pBR322 to form the recombinant plasmid pB1. pB1 was further digested with BamHI-Hind III and a 5.1-kb fragment was isolated, and ligated with BamHI-Hind III digested pBR322 to form the recombinant plasmid pBH1. The human cytomegalovirus B gene sequence was analysed by Beckman Microgenie Systems. The results indicated that the human cytomegalovirus B gene could be further digested by 13 kinds of restrict endonucleases. The size of the restrict fragments was between 22 base pairs to 2.9 kilobase pairs. The construction of the expression plasmid that contained human cytomegalovirus B gene is now in progress.

[Transformation and identification of recombinant plasmid pAT153 containing HCMV gene Hind III F fragment and its clinical application]

Transformation of the recombinant plasmid pAT153 containing human cytomegalovirus (HCMV) gene Hind III F fragment into E.coli strain HB 101 was made by the CaCl2 method with a 24% of transformation efficiency. The bacterial colonies containing the recombinant plasmid were selected in colony hybridization with 32P-labelled HCMV Hind III F fragment. The recombinant plasmid was isolated by the modified alkaline lysis method which is characterized by high quality, great quantity, and time-saving. HCMV Hind III F fragment has no homology to the other herpes virus. The 32P-labelled HCMV Hind III F fragment probe could detect 0.25 pg homological sequences of HCMV DNA. The use of this probe allows the detection of HCMV in clinical specimens with the advantages of quickness, good sensitivity and specificity.

Primary glomerulonephritis in China. Analysis of 1001 cases

The morphologic classification and clinical spectrum of 1,001 cases of primary glomerulonephritis (GN) in Jinling Hospital during 1980-1988 were analysed. It was found that the incidence of mesangial type lesion including mesangial proliferative GN, IgA nephropathy and IgM nephropathy ranks first (21.5%, 32.1% and 10.1% respectively), which is not only the commonest cause of patients clinically manifesting nephrotic syndrome and gross hematuria but also the predominant type of nephritis causing uremia and hypertension.

Hb Duan [alpha 75(EF4)Asp----Ala], Hb Westmead [alpha 122(H5)His----Gln], and alpha-thalassemia-2 (-4.2 Kb deletion) in a Chinese family

Detailed data are presented concerning the relative amounts of Hb A and two alpha chain variants (Hb Duan with alpha 75 Asp----Ala, and Hb Westmead with alpha 122 His----Gln), and the occurrence of an alpha-thalassemia-2 heterozygosity in five members of a small Chinese family. The three children who have the three abnormalities inherited the alpha-Duan and alpha-thalassemia-2 heterozygosities from their father, and the alpha-Westmead heterozygosity from their mother. The base substitution which leads to the synthesis of the alpha-Duan chain occurred at codon 75 of the alpha 1 globin gene of the chromosome which also carried the alpha-thalassemia-2 deletion; the concentration of alpha-Duan (37% of total alpha) is similar to that observed for other alpha chain variants, linked to an alpha-thalassemia-2 condition.

The study of spectra and X-ray crystal structure of a novel bionics insecticide--(CH3)2NHCH(CH2S2O3)2Na X H2O

IR and NMR spectra of novel bionics insecticide--C5NS4O6H12Na X H2O have been studied. The molecular and crystal structures of the compound also have been determined. The compound crystallizes in the monoclinic space group C5(2)h-P21/n with a = 8.0972(9)A, b = 16.262(4)A, c = 10.370(3)A, beta = 94.26(2)degrees and z = 4. The result shows that N atom in this compound captures a proton to form HN+ group, Na+ is in statistical disorder. Therefore, the structural formula of the compound is (CH3)2HN+-CH(CH2S2O3-)2 X 1/2(Na+)2 X H2O.