Accumulation, stability, and localization of a major chloroplast heat-shock protein

Diverse higher plant species synthesize low molecular weight (LMW) heat shock proteins (HSPs) which localize to chloroplasts. These proteins are homologous to LMW HSPs found in the cytoplasm of all eukaryotes, a class of HSPs whose molecular mode of action is not understood. To obtain basic information concerning the role of chloroplast HSPs, we examined the accumulation, stability, tissue specificity, and intra-chloroplast localization of HSP21, the major LMW chloroplast HSP in pea. Intact pea plants were subjected to heat stress conditions which would be encountered in the natural environment and HSP21 mRNA and protein levels were measured in leaves and roots. HSP21 was not detected in leaves or roots before stress, but the mature, 21-kD protein accumulated in direct proportion to temperature and HSP21 mRNA levels in both tissues. All of the HSP21 in leaves was localized to chloroplasts; there was no evidence for its transport into other organelles. In chloroplast fractionation experiments, greater than 80% of HSP21 was recovered in the soluble chloroplast protein fraction. The half-life of HSP21 at control temperatures was 52 +/- 12 h, suggesting the protein's function is critical during recovery as well as during stress. We hypothesize that HSP21 functions in a catalytic fashion in both photosynthetic and nonphotosynthetic plastids.

A protein homologous to the Torpedo postsynaptic 58K protein is present at the myotendinous junction

The 58K protein is a peripheral membrane protein enriched in the acetylcholine receptor (AChR)-rich postsynaptic membrane of Torpedo electric organ. Because of its coexistence with AChRs in the postsynaptic membrane in both electrocytes and skeletal muscle, it is thought to be involved in the formation and maintenance of AChR clusters. Using an mAb against the 58K protein of Torpedo electric organ, we have identified a single protein band in SDS-PAGE analysis of Xenopus myotomal muscle with an apparent molecular mass of 48 kD. With this antibody, the distribution of this protein was examined in the myotomal muscle fibers with immunofluorescence techniques. We found that the 48K protein is concentrated at the myotendinous junctions (MTJs) of these muscle fibers. The MTJ is also enriched in talin and vinculin. By double labeling muscle fibers with antibodies against talin and the 48K protein, these two proteins were found to colocalize at the membrane invaginations of the MTJ. In cultured myotomal muscle cells, the 48K protein and talin are also colocalized at sites of membrane-myofibril interaction. The 48K protein is, however, not found at focal adhesion sites in nonmuscle cells, which are enriched in talin. These data suggest that the 48K protein is specifically involved in the interaction of myofibrillar actin filaments with the plasma membrane at the MTJ. In addition to the MTJ localization, 48K protein is also present at AChR clusters both in vivo and in vitro. Thus, this protein is shared by both the MTJ and the neuromuscular junction.

Effects of human pancreatic lipase-colipase and carboxyl ester lipase on eicosapentaenoic and arachidonic acid ester bonds of triacylglycerols rich in fish oil fatty acids

Fish oil chylomicrons, obtained from mesenteric duct chyle of rats fed [3H]20:5 and [14C]20:4 or [3H]20:5 and [14C]18:2 in a fish oil emulsion, were incubated with human pancreatic lipase-colipase, human carboxyl ester lipase (CEL) and human duodenal contents. With duodenal contents, the triacylglycerols labelled with [3H]20:5 and [14C]20:4 were rapidly converted to free fatty acids (FFA) and monoacylglycerols. Also during incubation with lipase-colipase the [3H]- and [14C]triacylglycerols disappeared completely and at equal rates, but in this case much [3H]20:5 and [14C]20:4 accumulated in diacylglycerols. When CEL was also added, the rate of disappearance of [3H]- and [14C]triacylglycerols increased and the radioactivity of diacylglycerols decreased markedly. During incubation of chylomicrons labelled with [3H]20:5 and [14C]18:2 with lipase-colipase, the rates of hydrolysis of [3H]- and [14C]triacylglycerols were similar, but more [3H]20:5 than [14C]18:2 accumulated in diacylglycerols. The accumulation of [3H]diacylglycerol was reduced by adding CEL. Also when fatty acids were analyzed by gas chromatography, 20:5 was enriched in remaining triacylglycerol and in diacylglycerol after incubation with lipase-colipase alone. The data thus indicate that both lipase-colipase and CEL participate in the hydrolysis of 20:5 and 20:4 ester bonds of dietary triacylglycerol.

[Bioelectric potentials of bone in experimental fracture healing]

A specific electric potential gradient exists on the surface of long bone and the electric gradient changes after fracture. The electric potentials at the fracture site were measured and it was shown to change most actively during the early healing phase, and thereafter reached the normal level gradually. When soft tissue was damaged, certain potential changes occurred. But this change was different from that in the fracture site, indicating that the tissue has "biological window" effect of electrization.

[Electron microscopic observation of the effects of Rhodiola kirilowii (Regel.) Maxim. in preventing damage of the rat viscera by a hypoxic high altitude environment]

This paper has shown that the pathologic damages done to rat's viscera due to hypoxic environment of altitude can be reduced significantly by oral administrations of Shengmaiyin, Danshen-Chuanxiong mixture and Rhodiola kirilowii. Shengmaiyin that maintains interior substances in the plate layer bodies proves more effective than Danshen-Chuanxiong mixture, while the latter excels in preventing capillary contraction, thus improving blood circulation. Rhodiola kirilowii has the effects of both Shengmaiyin and Danshen-Chuanxiong mixtures.

[Measurement and clinical application of MEFV and PEFV curves in young children]

Previous studies of children's ventilatory functions revealed that a history of pediatric respiratory illness could cause an adult airway to be highly susceptible to the adverse effects of a variety of bronchial stimulants and infectious agents and easy to develop obstructive airway diseases in adult life. Ten indexes of ventilatory function were measured with MEFV and PEFV curves in 333 normal young children aged between 3 and 6, and 15 sick children of bronchopneumonitis in the same age range. Multiple regression equations of different indexes of normal children were set up. The measured values of various indexes of the sick children were much lower than the correspondent predicted values calculated from multiple regression equations, especially VT, VmaxFRC and VmaxFRC/FRC (P less than 0.05). The results suggest that the measurement of PEFV is a convenient and sensitive method to test children's ventilatory function.

The tal gene undergoes chromosome translocation in T cell leukemia and potentially encodes a helix-loop-helix protein

We have analyzed t(1;14)(p32;q11) chromosome translocations from two patients with T cell acute lymphocytic leukemia. The chromosome 1 breakpoints of these patients lie within a kilobasepair of each other, and thus define a genetic locus (designated tal) involved in T cell oncogenesis. Moreover, we have identified sequences within tal that potentially encode an amphipathic helix-loop-helix motif, a DNA-binding domain found in a variety of proteins that control cell growth and differentiation. The homology domain of tal is especially related to that of lyl-1, a gene on chromosome 19 that has also been implicated in T cell oncogenesis. Hence, tal and lyl-1 encode a distinct family of helix-loop-helix proteins involved in the malignant development of lymphocytes.

[Mitochondrial encephalomyopathy. Report of a case]

A typical case of mitochondrial encephalomyopathy with lactic acidemia and stroke-like episodes (MELAS) was reported. The main clinical manifestations consisted of short stature, psychomotor deterioration, sensorineural deafness, and hemiparesis. The laboratory findings disclosed abnormal lactic acid tolerance abnormal EEG, VEP, AEP, SEP, and MCV. The CT scan showed multiple intracerebral infarcts, basal ganglia calcifications, and cerebral atrophy. A muscle biopsy was performed. The frozen sections with modified gomori trichrome stain revealed ragged-red-fiber which reacted strongly positive in NADH-TR stain. The electron microscopy revealed subsarcolemmal aggregation of mitochondria of various sizes with paracrystalline inclusions, abnormally arranged cristae, and osmiophilic dense-bodies in their matrices.

Normal brain tissue response to photodynamic therapy: histology, vascular permeability and specific gravity

The response of photodynamic therapy on normal brain was investigated in 140 Fisher rats. The rats were injected i.p. with Photofrin II (12.5 mg/kg) and 48 h later the dural area over the frontal cortex was photoactivated with red light (630 +/- 1 nm) from an argon dye laser. Treatment was performed with optical energy densities of 140 and 70 J/cm2. Histopathology, vascular permeability and specific gravity measurements were conducted on different populations of rats at 4 h, 24 h, 72 h and 1 week after photodynamic therapy (PDT). Histopathology revealed similar gross and microscopic pathology associated with light energies of 70 and 140 J/cm2 after all time points. A large cerebral infarct approximately the size of the brain surface area treated, evolved 24 h following treatment. Evans blue extravasation indicated a small area of vascular permeability evident as early as 4 h following PDT treatment at both energy levels, with increasing permeability evident at later time points. Specific gravity measurements taken on a representative area of the lesion indicated a significant (P less than 0.01) amount of edema present at 24 h post treatment with a gradual reduction approaching control values over the time period of 1 week. The data indicate a significant amount of damage to normal brain from low PDT treatment doses.

Quantitative benedict test using bicinchoninic acid

Cupric ion (Cu2+), in complex form, functions as a selective oxidizing agent for a variety of compounds in the qualitative Benedict test. Cupric ion is reduced to cuprous ion (Cu+) in the reaction. We found that the cuprous ion formed in this type of redox reaction could be detected and quantified using 2,2'-bicinchoninic acid. This reagent produced an intense purple complex with cuprous ion. The color development in this modified Benedict test was dependent on pH, temperature, and time. The reaction is insensitive to ethanol and sodium dodecyl sulfate. This improved method of the Benedict test has enhanced sensitivity and makes the quantitation of compounds possible. This method should be useful for studies of Benedict-positive compounds which are available only in small amounts.

Hydrolysis of triacylglycerol arachidonic and linoleic acid ester bonds by human pancreatic lipase and carboxyl ester lipase

The hydrolysis of polyenoic fatty acid ester bonds with pure human colipase-dependent lipase, with carboxyl ester lipase (CEL) and with these enzymes in combination was studied, using [3H]arachidonic- and [14C]linoleic acid-labelled rat chylomicrons as a model substrate. During the hydrolysis with colipase-dependent lipase, the amount of 3H appearing in 1,2-X-diacylglycerol (DG) markedly exceeded that of 14C. When CEL was added in addition this [3H]DG was efficiently hydrolyzed. CEL alone hydrolyzed the triacylglycerol (TG) at a low rate. The hydrolysis pattern with human duodenal content was similar to that seen with colipase-dependent lipase and CEL in combination. Increasing the concentration of taurodeoxycholate (TDC) and taurocholate (TC) or of TDC alone stimulated the hydrolysis of [3H]- and [14C]TG, but increased the accumulation of labelled DG that could act as substrate for CEL. It is suggested that very-long-chain polyenoic fatty acids of DG formed during the action of the colipase-dependent lipase on TG containing these fatty acids may be a physiological substrate for CEL.

Molecular cloning and expression of Bacillus thuringiensis subsp. galleriae insecticidal crystal protein genes in Escherichia coli

The location of the toxin gene of B. thuringiensis subsp. galleriae (H5ab) on the Mr-130Md plasmid is determined by molecular cloning. Double digestion fragments (BamHI and SalI) and PstI restriction fragments as well, from the 130 Md plasmid, of B. thuringiensis subsp. galleriae, are ligated with the cloning vector pAT 153 respectively and transformed into E. coli strain HB 101. Out of 208 transformants, three colonies (FG2, FG9, FG19) give positive hybridization reaction using the HD-1 delta-endotoxin gene as a probe. They are presumed to contain the delta-endotoxin gene of B. thuringiensis subsp. galleriae. Western blot assays indicate that Mr-130 kDal and 68 kDal, crystal proteins produced by clone FG2 react with anticrystal protein antibody. The protein extracts of clone FG2 are lethal to Ostrinia furnacalis (Guenee). This is the first report with regard to the cloning and expression of the B. thuringiensis subsp. galleriae (H5ab) delta-endotoxin gene.

Experimental studies on the prevention and treatment of chickenpox and herpes zoster with measles vaccine

In 151 chickenpox patients treated with live attenuated measles vaccine, the cure rate was 100%. In 145 cases of herpes zoster, the effective rate was 100% (completely cured in 91.7% and improved in 8.3%). In the treated group, the time needed for the subsidence of fever and skin rash and the duration of the disease were markedly shorter than those in the control group (P less than 0.01). It is particularly effective for alleviating pain, preventing and relieving postherpetic neuralgia in patients with zoster. The application of measles vaccine to the patients in the chickenpox incubation period might prevent the development of the disease, and decrease the incidence and death rate of varicella zoster virus infection in highly susceptible patients. The mechanism of its anti-viral action and production of interferon in the body is discussed.

The major low-molecular-weight heat shock protein in chloroplasts shows antigenic conservation among diverse higher plant species

Several plant species are known to synthesize low-molecular-weight nucleus-encoded heat shock proteins (HSPs) which localize to chloroplasts. DNA sequence analysis of chloroplast HSP cDNAs from pea (Pisum sativum) and soybean (Glycine max) has shown that the carboxyl-terminal halves of these proteins are homologous to low-molecular-weight HSPs from a wide range of eucaryotes (E. Vierling, R. T. Nagao, A. E. DeRocher, and L. M. Harris, EMBO J. 7:575-581, 1988). We used a pea cDNA to construct fusion proteins containing either the carboxyl-terminal heat shock domain or the amino-terminal domain of the chloroplast HSP. The fusion proteins were overexpressed in Escherichia coli and used to produce choloroplast HSP-specific polyclonal antibodies. The carboxyl-terminal antibodies recognized chloroplast HSP precursor proteins from pea and from three divergent plant species, Arabidopsis thaliana, petunia (Petunia hybrida), and maize (Zea mays). The amino-terminal antibodies recognized effectively only the pea precursor. When intact plants of each species were subjected to a heat stress regime mimicking field growth conditions, significant levels of the mature forms of the chloroplast HSPs accumulated in pea, A. thaliana, and maize. The levels of accumulated HSPs remained unchanged for 12 h following the stress treatment. We conclude that the synthesis of chloroplast-localized HSPs is an important component of the stree response in all higher plants and that chloroplast HSPs from dicotyledonous and monocotyledonous plants have a conserved carboxyl-terminal domain.

[Determination of Se Zn Cu concentrations in serum of middle school teachers in Beijing City]

The concentrations of serum selenium, zinc and copper were measured in 187 teachers (representative group of population) from six middle schools in Beijing city. The means, standard deviations, normal ranges were found out. The result was compared with that in the recent literature. Since serum selenium concentrations were found close to the lower limit of the normal range, it is suggested that to increase adequately the daily intake of dietary selenium will be beneficial for safeguarding one's health against the related diseases.

[Surgical treatment of aneurysm of the membranous ventricular septum: report of 27 cases]

Twenty-seven patients aged 4 to 26 years with aneurysm of the membranous ventricular septum were operated on in Shanghai Chest Hospital, from August 1985 to April 1987. Of the patients, 22 were diagnosed by left ventriculography, and were found to be associated with other cardiac defects such as VSD, ASD. All the patients had an uneventful early postoperative course and excellent late results. It is emphasized that a thorough recognition of the lesion and complete repair of the malformation are important in the avoidance of residual shunt and recurrent defects.

Characterization of Inositol Phosphates in Carrot (Daucus carota L.) Cells

We have shown previously that inositol-1,4,5-trisphosphate (IP(3)) stimulates an efflux of (45)Ca(2+) from fusogenic carrot protoplasts (M Rincón, WF Boss [1987] Plant Physiol 83: 395-398). In light of these results, we suggested that IP(3) might serve as a second messenger for the mobilization of intracellular Ca(2+) in higher plant cells. To determine whether or not IP(3) and other inositol phosphates were present in the carrot cells, the cells were labeled with myo-[2-(3)H]inositol for 18 hours and extracted with ice-cold 10% trichloroacetic acid. The inositol metabolites were separated by anion exchange chromatography and by paper electrophoresis. We found that [(3)H]inositol metabolites coeluted with inositol bisphosphate (IP(2)) and IP(3) when separated by anion exchange chromatography. However, we could not detect IP(2) or IP(3) when the inositol metabolites were analyzed by paper electrophoresis even though the polyphosphoinositides, which are the source of IP(2) and IP(3), were present in these cells. Thus, [(3)H] inositol metabolites other than IP(2) and IP(3) had coeluted on the anion exchange columns. The data indicate that either IP(3) is rapidly metabolized or that it is not present at a detectable level in the carrot cells.

Alterations in intermediate filament proteins in rat kidney proximal tubule epithelial cells

Changes in the intermediate filament composition of rat kidney proximal tubule cells in culture have been investigated. The data suggest that differentiated tubular epithelial cells do not express vimentin, but vimentin expression is induced when the cells begin to proliferate in culture. The cultured cells are positive for both cytokeratins and vimentin by immunofluorescence microscopy. The data support the concept that the intermediate filament composition of proximal tubule epithelial cells can be altered during proliferation induced by nephrotoxic chemicals or by neoplastic transformation.

Localization of calcitonin gene-related peptide (CGRP) at a neuronal nicotinic synapse

The localization of calcitonin gene-related peptide (CGRP) in the parasympathetic cardiac ganglion of the frog was investigated with an immunofluorescence method. By doubly staining the whole ganglion with antibodies against a synaptic-vesicle antigen and anti-CGRP antibodies, we found that all of the boutons at the nicotinic synapses on the postganglionic neurons contained immunoreactivity against this peptide. In contrast, neither the muscarinic nor the adrenergic terminals of the postganglionic fibers on the cardiac muscle contained CGRP immunoreactivity. This suggests that CGRP is involved in the functions of the neuronal nicotinic synapses.