A yeast protein with homology to the beta-subunit of G proteins is involved in control of heme-regulated and catabolite-repressed genes

The product of the Saccharomyces cerevisiae AER2 gene is responsible for maintaining repression of at least two distinct regulatory pathways: heme activation/repression and catabolite repression. Mutations in the gene caused an eightfold increase in the expression of the heme-activated CYC1 gene in the absence of heme, a substantial increase in the expression of the heme-repressed ANB1 gene in the presence of heme, and a 13-fold increase in the expression of the catabolite-repressed GAL1 gene in the presence of glucose. Lesser or no increases in the expression of these genes were observed under derepressed or activation conditions. The aer2 mutations also caused a large increase in CYC7 gene expression under all conditions; this gene is subject to heme activation/repression, as well as catabolite repression. The AER2 gene was cloned and the sequence determined. The large open reading frame contiguous with the transcript from the complementing region encoded a 713-amino acid polypeptide chain with extensive homology to the beta-subunit of G proteins. The sequence revealed that AER2 is the TUP1 gene. A deletion mutation was constructed and the null phenotype was the same as the original mutants. The aer2 null mutant was shown to have increased aerobic and anaerobic levels of RNA encoding the ROX1 repressor, normally expressed only aerobically and responsible for the aerobic repression of ANB1 expression. The increase in both ROX1 and ANB1 RNAs aerobically in this mutant suggests that the repressor is nonfunctional in the mutant.

Coordinate occupancy of AP-1 sites in the vitamin D-responsive and CCAAT box elements by Fos-Jun in the osteocalcin gene: model for phenotype suppression of transcription

Osteocalcin, a bone-specific protein and marker of the mature osteoblast, is expressed only in nonproliferating osteoblasts in a mineralizing extracellular matrix, while type I collagen is expressed in proliferating cells. The nuclear proteins encoded by the c-fos and c-jun protooncogenes are expressed during the proliferation period of osteoblast phenotype development. We present evidence that AP-1 (HeLa cell-activating protein 1) sites residing within two promoter elements of the osteocalcin gene bind the Fos-Jun protein complex: the osteocalcin box (OC box; nucleotides -99 to -76), which contains a CCAAT motif as a central element and influences tissue-specific basal levels of osteocalcin gene transcription, and the vitamin D-responsive element (VDRE; nucleotides -462 to -440), which mediates enhancement of osteocalcin gene transcription. Gel electrophoretic mobility-shift analysis demonstrated high AP-1 binding activity in proliferating osteoblasts and dramatic changes in this activity after the down-regulation of proliferation and the initiation of extracellular-matrix mineralization in primary cultures of normal diploid osteoblasts. Methylation interference analysis established at single nucleotide resolution that purified recombinant Fos and Jun proteins bind in a sequence-specific manner to the AP-1 sites within the VDRE and OC box. Similarly, an AP-1 motif within a putative VDRE of the alkaline phosphatase gene, which is also expressed after the completion of proliferation, binds the Fos-Jun complex. These results support a model in which coordinate occupancy of the AP-1 sites in the VDRE and OC box in proliferating osteoblasts may suppress both basal level and vitamin D-enhanced osteocalcin gene transcription as well as transcription of other genes associated with osteoblast differentiation--a phenomenon we describe as phenotype suppression. This model is further supported by binding of the Fos-Jun complex at an AP-1 site in the type alpha I collagen promoter that is contiguous with, but not overlapping, the VDRE. Such a sequence organization in the collagen VDRE motif is compatible with vitamin D modulation of collagen but not with osteocalcin and alkaline phosphatase expression in proliferating osteoblasts.

Molecular characterization of immune inhibitor A, a secreted virulence protease from Bacillus thuringiensis

The gene for the secreted neutral metalloprotease, immune inhibitor A (InA), from Bacillus thuringiensis var. alesti has been cloned and sequenced. The deduced amino acid sequence has been confirmed by partial amino acid sequencing. The central part of the amino acid sequence showed similarity to the active site in thermolysin. Southern and Western blots show that InA-related sequences are common among other B. thuringiensis subspecies. In Western blots, 17 out of 25 tested species gave a positive signal. Culture filtrates from subspecies expressing InA were toxic when injected in Trichoplusia ni larvae, whereas filtrate from a strain negative in Western blot had no effect when injected. The LD50 dose of purified InA protein injected in T. ni larvae was 12.5 +/- 2.5 ng per mg of larval body weight.

Does single-amino-acid replacement work in favor of or against improvement of the thermostability of immobilized enzyme?

Thermostabilities of kanamycin nucleotidyltransferase and of its mutants that became thermostable, in the free state, because of single-amino-acid replacements were studied after immobilization of the enzymes on cyanogen bromide-activated Sephadex G-200 particles. Lys in place of Gln at position 102 decreased the thermostability of the immobilized enzyme, whereas replacement with other amino acids enhanced it.

Clinical effects of rheum and captopril on preventing progression of chronic renal failure

A clinical trial, to evaluate the effects of a Chinese herbal drug, Rheum E and angiotensin converting enzyme inhibitor, Captopril on chronic renal failure (CRF), was conducted. Thirty cases with initial serum creatinine (Scr) levels of 344.8 +/- 114.0 mumol/L were allocated randomly to 3 groups: Rheum E treated group, Captopril treated group and Rheum E + Captopril group. A control group of 12 cases were on dietary therapy alone. During the 6-22 months of treatment, all the patients were kept on low-protein (0.6g/kg/d), and low-phosphorus (10mg/kg/d) diet. The results showed that the progression rate of renal failure, calculated by regression analysis of 1/Scr vs time, was found to be retarded after treatment with the increased regression coefficient (b value). Scr levels and blood urea nitrogen were kept stable or fell slightly. Albumin rose during the follow-up period (P less than 0.05) in the treated patients, being more marked in both Rheum E and Rheum E + Captopril groups. Uremic symptoms of nausea, anorexia improved in most of the treated patients. It is concluded that long-term low-dose Rheum E taken orally is beneficial to CRF. Its effect is better than that of Captopril. The regime of Rheum E and Captopril is a preferable choice in the long-term treatment for preventing progression of CRF.

[Changes of the microcirculating blood volume in the reproductive axis during estrous cycle of the rats]

The microcirculating blood volume of the hypothalamic-pituitary-ovarian axis in the female rats was measured using radiobiomicrosphere method during the estrous cycle. The blood flow volume of the hypothalamus and the pituitary was not significantly different between each phase of the estrous cycle. The ovarian blood flow volume was the highest in metestrus and the lowest in estrus. The difference between them was significant (P less than 0.02). The uterine blood flow volume was the highest in metestrus and remained at higher level in diestrus and then changed to the lowest in estrus. The values in metestrus and diestrus were significantly higher than that in estrus (P less than 0.01, P less than 0.05, respectively). The blood flow volume of the oviduct in proestrus was significantly lower than that in estrus (P less than 0.05). The above results suggest that the cyclic changes of the blood volume of the ovary, uterus and oviduct are closely related to their functional state and the hormonal changes.

[Prevalence study on dementia and Alzheimer disease]

An epidemiological survey on dementia and Alzheimer disease (AD) was carried out in a community of 5055 persons over the age of 55 at Jingan district of Shanghai. Diagnoses were made according to the diagnostic criteria of dementia of DSM-III-R and of AD of NINCDS-ADRDA. It was found that dementia is not uncommon in the aged, and AD was the leading category of dementia. The age and sex adjusted prevalence rate of dementia was 2.57% in those over 55, 3.46% in those over 60, and 4.61% in those over 65, and that of AD was 1.50%, 2.05% and 2.90% respectively. Beside age, the other risk factors were female sex, bereavement of spouse, low education and unfavorable socio-economic status.

[Preparation on monoclonal antibodies against laminin receptors and their inhibitory effects on attachment and spreading of tumor cells]

Monoclonal antibodies against laminin receptors (LN) isolated from a highly metastatic human giant cell carcinoma of lung (PG) were prepared by routine hybridoma technique. Two positive clones secreted monoclonal antibodies against laminin receptors, one of which was named McB1. McB1 was bound more efficiently to LN-R of cultured PG tumor cells immunohistochemically. McB1 could markedly inhibit the attachment and spreading of S-180 mouse ascitic tumor cells and PG tumor cells on laminin substrate. Monoclonal antibody against LN-R is definitely useful in studying the interaction between tumor cells and extracellular matrix and the molecular mechanisms of invasion and metastases of tumor cells.

[Detection of sorbitol content in crystalline lens of normal rats and rats with diabetic cataract by 1H-NMR]

The pulse Fourier NMR was employed to measure the artificial diabetic cataract lens at various stages of its formation, and the lenses of the normal rats. Data obtained by using this method show that all the peaks that of water concentrate in the range of delta less than 4 ppm. The peak value at delta = 3.20 ppm is on a marked increase during the formation of cataract which is caused by the phosphate metabolites, such as GPC, ATP, ... etc, in cataract lens. With the development of the disease, the peak width at delta = 3.73 ppm becomes greater and greater, which shows that the activity of sorbitol dehydrogenase has decreased. This leads to a high concentration of the sorbitol in the cataract lens. Consequently, the osmosis pressure in the cataract lens is increased, and excessive water might dip into the crystalline lens to keep the balance of the osmosis pressure. And this might result in the hydration of the fiber cell of the crystalline lens, which might cause a swelling or blisters. These results are in favour of the prolongation of the relaxation time of cataractous lens reported in our other papers, and also support those gained by biochemical studies issued in the medical literature.

[Study on the variation of relaxation time in diabetic cataractous lenses of rats by using NMRA]

Nuclear magnetic resonance analysis (NMRA) was used to measure the relaxation time T1 and T2 of the protons in the different-stage-diseased lenses of rats with diabetic cataract caused by the streptozotocin, and the results were put in comparison with those obtained from the control group, showing that after one month of medication the values of T1 and T2 in the cataractous lenses are greater than those gained from the control group. The variation, as time goes on, becomes greater and greater. T1 and T2 indicate the speed of the free induction decay (FID) signals, and the variation of the FID signals are in direct proportion to that of the proton content of the samples. This shows that an increase in T1 and T2 indicates an increase in the water content in the diseased lenses, and the changes in ratio of "bound" water to free water. Such changes may be explained that the space for "bound" water is occupied by some other macromolecules, causing the alteration of the macromolecular structure, and consequently the aggregation of protein and the degeneration or dehydration or dehydration of the membrane occur, which may give rise to another scattering centre. So the scattering of the lens increases and its transparency decreases. This result is in agreement with some reports in the medical literature. As T1 and T2 are quite different in the normal and pathological tissues, and the protons are the most extensive nucleus in all biological tissues, NMR is a very important method to determine the proton relaxation time in the biological tissue and to judge if it is normal or not.(ABSTRACT TRUNCATED AT 250 WORDS)

Budd-Chiari syndrome. Surgical treatment of 45 cases

Fourty-five patients with Budd-Chiari syndrome were treated surgically from December 1985 to May 1988. The procedures consisted of cavoatrial shunt, mesoatrial shunt, transcardiac membranotomy, splenopneumopexy, portal vein-systemic vein shunt and re-opened umbilical vein-right auricle shunt, etc. Two of the patients died postoperatively. Others showed improvement after follow-up for 3-24 months. Recurrent hemorrhage from varices did not occur after operation in all patients. The diagnosis, surgical indications, and various methods of surgery for Budd-Chiari syndrome were discussed.

[Clinical study of 30 cases of affective disorder with mental retardation]

Thirty cases of affective disorder with mental retardation (MR) were reported. The prevalence of affective disorder, clinic characteristics and cause of misdiagnosis in these patients were discussed. Authors found that the criteria of affective disorder set by Chinese Medical Association (1984) can be used in the patients with mild or moderate MR. Typical elated mood and flight of idea were rare. The major symptoms of these patients include hyperactivity or hypoactivity, hyperplasia or bradylogia, and increase or decrease of instinctive behavior. The atypical symptoms in manic-depressive psychoses are more common in these cases. In the most of these patients, the good result has been found.

Factor IX Chongqing: a new mutation in the calcium-binding domain of factor IX resulting in severe hemophilia B

A Chinese patient with sporadic, severe hemophilia B was found to have a low level of total factor IX antigen (3.5 U/dl), but less apparent antigen in an assay using a calcium-dependent antibody fraction (1.1 U/dl). This suggested a defect in the factor IX Gla domain coded mainly by exon 2 of the factor IX gene. Exon 2 was therefore amplified and sequenced. An A to T substitution was found at nucleotide 6455 of the patient's factor IX gene. This transversion changes the codon for Glu 27 in normal factor IX to a codon for Val. Since Glu 27 becomes an essential Gla residue, the defect should result in altered calcium-binding or calcium-dependent conformation of the patient's factor IX. The introduction of a hydrophobic side chain also appears to affect the hemophilic protein's stability. In leukocyte DNA from the patient's mother, the nucleotide sequence of exon 2 was entirely normal. Thus, barring somatic mosaicism within her germ cells, the new mutation occurred in oogenesis of her ovary.

The myelin-deficient rat mutant: partial recovery of oligodendrocyte maturation in vitro

The morphological and immunocytochemical identification and characterization of the myelin-forming cell, the oligodendrocyte, have defined a model system for developmental studies. The myelin-deficient (md) rat mutant lacks myelin in the central nervous system and fails to express the normal developmental increase in oligodendroglial and myelin markers, apparently as a consequence of a point mutation in the proteolipid protein gene. In the present work, we compared the developmental pattern of primary glial cultures derived from newborn md rat brains to those derived from wild-type animals. Brain cell suspensions were prepared from each rat pup and cultured separately. We found by immunocytochemical and enzymatic analyses for the various markers that the developmental cascade of oligodendroglial marker expression is delayed, oligodendrocytes failing to mature compared to normal cultures. However, a partial recovery of marker expression was observed in md-derived cultures as compared to development previously reported in the intact md animals. We suggest that the partial recovery of the sequential expression of oligodendroglial markers may be due to a supportive environment provided to the oligodendrocyte progenitor cell (1) by tissue culture conditions or (2) by the absence of the blood-brain barrier in contrast to its presence in the intact animal.

Plasma Observations Near Neptune: Initial Results from Voyager 2

The plasma science experiment on Voyager 2 made observations of the plasma environment in Neptune's magnetosphere and in the surrounding solar wind. Because of the large tilt of the magnetic dipole and fortuitous timing, Voyager entered Neptune's magnetosphere through the cusp region, the first cusp observations at an outer planet. Thus the transition from the magnetosheath to the magnetosphere observed by Voyager 2 was not sharp but rather appeared as a gradual decrease in plasma density and temperature. The maximum plasma density observed in the magnetosphere is inferred to be 1.4 per cubic centimeter (the exact value depends on the composition), the smallest observed by Voyager in any magnetosphere. The plasma has at least two components; light ions (mass, 1 to 5) and heavy ions (mass, 10 to 40), but more precise species identification is not yet available. Most of the plasma is concentrated in a plasma sheet or plasma torus and near closest approach to the planet. A likely source of the heavy ions is Triton's atmosphere or ionosphere, whereas the light ions probably escape from Neptune. The large tilt of Neptune's magnetic dipole produces a dynamic magnetosphere that changes configuration every 16 hours as the planet rotates.

[A study on the promotion of adhesion properties of adhesives to metals treated by positive oxidation]

The adhesion to three alloys: Durabond, GH30 and soft Co-Cr, by PE adhesive was investigated. The surfaces of metals were treated by polishing, sand-blasting, positive-oxidation and complex processing in order to test the tensile bond strengths between metals and PE adhesive; to study the effects of the surface treatment of metals on adhesive properties; and to compare the tensile strength with that from the control experiment with EB composite resin and Panavia-EX resin under the same conditions. The results showed the mean tensile bond strengths between PE adhesive and Durabond, GH30 and soft Co-Cr alloys after the treatment of sandblasting and positive oxidation were 214.65 +/- 51.68 kg/cm2, 372.88 +/- 21.88 kg/cm2 and 349.21 +/- 48.32 kg/cm2 respectively, displaying better adhesive properties and stability of resistance to water.

[Comparison of effect in the change of respiration by stimulating three trigeminal subnucleus]

Experiments were performed on 31 rabbits. After recovery from surgical anesthesia the change of respiration were observed in various experimental conditions, under which original nucleus of trigemini (ONT), terminal nucleus of trigemini (TNT), spinal tractus nucleus of trigemini (SNT) were respectively stimulated by an electrical current (EC) or monosodium glutamate (MSG) or lidocaine (LID). Because SNT had a longitudinal long shape, three different sections of SNT were selected as stimulating points respectively, namely rostral point (A2.33 mm), middle point (AP0 mm) and caudal point P1.9 mm). Phrenic nerve discharge and its integrated curve, PCO2 and blood pressure were recorded by a RM-6000 polygraph. The results indicated that the stimulations of EC and MSG to SNT and TNT enhanced respiratory activity obviously. Stimulation of EC and MSG to ONT caused much less enhancement of respiration. Microinjection of LID to TNT and ONT decreased respiratory activity, but microinjection of LID to SNT increased. The present experiment concluded that stimulation of SNT and TNT could cause significant change in respiration.

[Observation on enhanced adhesion to dentin by amino acid]

An amino acid was adopted to pretreat the surface of dentin. The bond strength between GP adhesive and dentin mediated by the amino acid was enhanced after the pretreatment. Furthermore, the longer the stored time of extracted tooth was, the better the effect of adhesion was. This pretreatment will benefit the adhesive restoration for dead tooth or low activity tooth clinically.

[Contribution of EEG to the diagnosis of epilepsy in Shanghai]

The electroencephalographs (EEGs) of 9963 patients examined for some form of neurological disorder were studied. The male:female ratio was 129:1 and the age range of 11-40 years accounted for 67.12% of those studied. Of 3914 clinically confirmed epileptic patients, 68.37% had an abnormal EEG characterized by major general or focal discharges. 50.56% of 3814 suspected epileptic patients exhibited high levels of abnormal discharge and 452 non-epileptic patients also exhibited abnormalities. Such discharges also occurred in 671 patients suspected of other neurological disorders.

Three point mutations in the factor IX genes of five hemophilia B patients. Identification strategy using localization by altered epitopes in their hemophilic proteins

In five patients with hemophilia B and detectable Factor IX antigen, altered reactivity to a specific polyclonal antibody fraction or monoclonal anti-Factor IX antibodies was noted. Amplification of selected portions of their Factor IX genes by polymerase chain reaction allowed rapid identification of a single base transition in each of the five families tested. In a patient with severe hemophilia and an altered calcium binding domain, a G to A transition in exon II changed the codon for Glu-27 to Lys (Factor IXSeattle 3). Patients from two families with mild hemophilia with decreased reactivity to a MAb that binds to a site within the sequence coded for by exon IV had a G to A transition changing the codon for Gly-60 to Ser (Factor IXDurham). Two unrelated patients with moderately severe hemophilia lacked reactivity to another murine monoclonal anti-Factor IX which binds to an epitope in the amino-terminal half of the heavy chain of Factor IXa. In these patients, exon VIII contained a G to A transition changing Arg-248 to Gln (Factor IXSeattle 4).

[A study of the quality of Fujian native Magnolia officinalis Rehd. et Wils. var. biloba Rehd. et Wils]

This study reports on the connexion of the content of the efficacious constituents, magnolol and honokiol of Magnolia officinalis var. biloba with age, diameter of the trunk and various parts of the tree, thus presenting a basis for its collection, quality control and clinical applications.

[The relationships between thymus, other immune organs and various diseases in children (analysis of 621 cases)]

Thymuses, spleens, lymph nodes, tonsils and appendices from 621 autopsy cases were reviewed. The degree of atrophy of these organs might be classified into 3 grades. The main diagnoses of these cases involved more than 130 different diseases, which could be divided into 9 groups: infection, benign tumor, malignant tumor, deformity, amniotic fluid aspiration, fungal infection, autoimmune disease and hemorrhage, etc. Cases of infection with a course less than 5 days showed mild atrophy of the thymus and those cases with a longer course might show moderate or severe degree of atrophy. Cases of benign tumor showed no relationship between the degree of atrophy and the course of the disease. Nevertheless, in cases of malignant neoplasms even there was a history of short course, showed severe atrophy of the thymus. Only mild atrophy was obtained in those patients with deformity, amniotic fluid aspiration and hemorrhage, while severe atrophy was seen in those cases with fungal infection and autoimmune disease. In 81% of the cases, the degree of thymus atrophy was in accordance with those of the other immune organs.

The factor IX BamHI polymorphism: T-to-G transversion at the nucleotide sequence -561. The BamHI/MSPI haplotypes in blacks and Caucasians

The polymerase chain reaction (PCR) method was used to amplify a 356-bp DNA segment containing the suspected BamHI polymorphic site of the factor IX gene. Following the enzyme digestions and gel electrophoresis, polymorphic genotypes (-,+ and +/- types) were observed. The gene frequencies for the rare (+) allele are about 36% in blacks and 2% in Caucasians. The 356-bp DNA was further purified and sequenced. The sequencing gels revealed a single nucleotide substitution (T to G) at position -561 of the gene in blacks and Caucasians. The T-to-G transversion generated a new BamHI site (GGATCC,+type) from a nonenzymatic site, (TGATCC,-type).

The effect of copper IUD on microcirculation of blood flow in rabbit uterus

A survey of the rabbit's normal microcirculation of blood flow volume in the endometrium and myometrium with or without a copper intrauterine device (IUD) was made. It was found through statistical analyses that the IUD stimulated the endometrium so that microcirculation of blood flow volume in the endometrium increased significantly, but it did not change the microcirculation of blood flow volume in the myometrium and in the opposite uterus.

Several nodulins of soybean share structural domains but differ in their subcellular locations

Four soybean cDNA nodule-specific clones encoding nodulin-23, -26b, -27 and -44 were observed to cross-hybridize under low stringency conditions. Nucleotide sequence analysis revealed that the cDNAs contain three distinct domains: two domains with 70 to 95% homology separated by a third domain unique to each cDNA. Despite a number of nucleotide insertions and deletions, the protein sequences are conserved in the two domains which correlate with the homologous nucleotide domains. The amino terminal domain of each nodulin contains putative signal sequences for membrane translocation, although only two (nodulin-23 and -44) meet all the criteria for a functional signal. Immuno-precipitation of hybrid-release translation products of the four cDNAs revealed that nodulin-23 is associated with the peribacteroid membrane while nodulin-27 is in the cytoplasmic fraction of the nodule. These four nodulins are members of a diverse family with conserved structural features and the genes encoding them appear to have recently evolved from a common ancestor.

Studies on the phenomenon of latent propagated sensation along the channels. II. Investigation on the lines of LPSC on the twelve main channels

Applying an electric impulse at the Jing points and then tapping on the skin surface along the lines perpendicular to the channels, latent PSC of 12 channels was examined respectively on 200 patients at an acupuncture clinic. Of the cases examined, 68.5% were found to have positive latent PSC. No prominent difference was found among the 12 main channels. In patients with higher sensitivity of latent PSC and in those with marked PSC as well, the traces of latent PSC can be located simply by tapping (i.e. without electric impulsation at the Jing points), and the width of the sensitive lines is about 0.5 cm. Furthermore, in cases with marked PSC, the latent sensation lines were always found to be a continuation of the marked ones. These facts indicate that the latent PSC is a common meridian phenomenon in a large number of individuals.