Activation of heat-shock transcription factor in rat heart after heat shock and exercise

Stress-induced transcriptional regulation of the heat-shock proteins (HSP) is mediated by activation and binding of the heat-shock transcription factors (HSF) to the heat-shock element (HSE). Given the similarities between the stressors known to activate the HSF in cultured cells and the physiological stresses known to occur during exercise, HSF activation was examined in the hearts from exercising animals. Sprague-Dawley rats (5 rats/group) were run on a treadmill (24 m/min) for either 0, 20, 40, or 60 min or to exhaustion (102 +/- 7 min). Protein extracts were assessed for HSF activation by mobility-shift gels. Extracts from the hearts of nonrunning rats demonstrated no HSF activation, whereas HSF activation was detected in 80% of the hearts from animals that run for at least 40 min. These results demonstrate that treadmill running is capable of activating the HSF and increasing 70-kDa HSP mRNA in the rat myocardium.

Transgenic canola and soybean seeds with increased lysine

We have increased the lysine content in the seeds of canola and soybean plants by circumventing the normal feedback regulation of two enzymes of the biosynthetic pathway, aspartokinase (AK) and dihydrodipicolinic acid synthase (DHDPS). Lysine-feedback-insensitive bacterial DHDPS and AK enzymes encoded by the Corynebacterium dapA gene and a mutant E. coli lysC gene, respectively, were linked to a chloroplast transit peptide and expressed from a seed-specific promoter in transgenic canola and soybean seeds. Expression of Corynebacterium DHDPS resulted in more than a 100-fold increase in the accumulation of free lysine in the seeds of canola; total seed lysine content approximately doubled. Expression of Corynebacterium DHDPS plus lysine-insensitive E. coli AK in soybean transformants similarly caused several hundred-fold increases in free lysine and increased total sed lysine content by as much as 5-fold. Accumulation of alpha-amino adipic acid (AA) in canola and saccharopine in soybean, which are intermediates in lysine catabolism, was also observed.

Cardiomyoplasty: preservation of the latissimus dorsi muscle

Muscle necrosis has been frequently observed in cardiomyoplasty patients and in experimental animal studies. The purpose of this study was to determine if heat shock could provide protection to skeletal muscle as has been shown in cardiac muscle. A 15-minute heat shock at 42 degrees C resulted in an immediate increase in HSP72 mRNA and was followed within 3 hours by a two-fold increase in HSP72. Surgical dissection of the latissimus dorsi muscle (LDM) followed by an ischemic period resulted in a two-fold increase in HSP72 in control LDM, whereas the already high levels in the heat-shocked LDM increased only slightly with surgery and ischemia. Citrate synthase activity and tissue histology indicated that heat shock did not protect the LDM from the imposed surgical trauma and ischemia insults used in this study.

Heat shock protein (HSP 72) expression in patients undergoing cardiac operations

The major mammalian stress-inducible protein, heat shock protein 72, protects cells from certain stresses and rapidly accumulates in cells after ischemia. Heat shock protein 72 is rapidly synthesized in the myocardium of various species in response to ischemia, but it has not been investigated in human heart. To determine if heat shock protein 72 accumulated in the ischemic myocardium of patients undergoing cardiac operations, we obtained sequential right atrial biopsy specimens from 12 patients undergoing repair at three intervals: before bypass, after reperfusion, and after bypass. Immunoblot analysis for heat shock protein 72 demonstrated a high expression in the human heart compared with other mammalian hearts, p (Binomial) = 0.01. Compared with before bypass, heat shock protein 72 contents after reperfusion and after bypass were 98.2% +/- 8.9%, p (signed-rank) = 0.65, and 87.6% +/- 17.1%, p (signed-rank) = 0.28, respectively. Although heat shock protein 72 concentration was unchanged in hearts after reperfusion and after bypass, the initial prebypass level of heat shock protein 72 was high. The high heat shock protein 72 level detected in human hearts may reflect preoperative disease and drug therapy, or inherently high levels may be usual in the human myocardium. These findings indicate that the myocardium of patients undergoing cardiac operations contains relatively high concentrations of heat shock protein 72, which are not increased during the surgical procedure.

The cuticular localization of integument peptides from particular routing categories

The distribution of integument peptides in relation to chitin and structural features has been studied in the surface epidermis of the caterpillar of Calpodes ethlius by immunoblotting and immunogold labelling using antibodies prepared to peptides isolated from lamellate endocuticle or from hemolymph. The intermoult cuticle consists of an epicuticle, an endocuticle of many chitin containing lamellae, and a chitin containing assembly zone directly above the apical epidermal microvilli and the perimicrovillar space. During the intermoult, the epidermis secretes peptides constitutively, that is, secretory vesicles containing peptides exocytose without accumulating, traverse the perimicrovillar space and form lamellae in the assembly zone. At moulting, the epidermis deposits ecdysial droplets in addition. These interrupt the last few lamellae which later go on to become the perforated ecdysial membrane. The integument is involved with four routing classes of peptide. Secretion is apical into the cuticle (C), basal into the hemolymph (H), bidirectional (BD), or transported to the cuticle across the epidermis from the hemolymph (T). Some peptides change their routing at moulting. There are several patterns of localization. (1) C and BD cuticular peptides occur mainly in chitin containing lamellate cuticle. (2) Some are also present in epicuticle, and are therefore not obligatorily linked to chitin or matrix between chitin fibers. Cuticular peptides that also occur in the hemolymph are glycosylated, whereas most that are only secreted apically into the cuticle are not. All BD but few C peptides carry alpha-D-glucose/alpha-D-mannose. Some C and BD peptides carry N-acetyl glucosamine. (3) C36 extracted from cuticle has most N-acetyl glucosamine and colocalizes with chitin rather than the protein matrix. It is therefore probably the main link between chitin fibers and the matrix. (4) H235 is barely detectable at the apical cell surface during the intermoult but is abundant at moulting around and below the ecdysial droplets. (5) T66 occurs in intermoult lamellate cuticle. At moulting, alone among the peptides examined, it is in ecdysial droplets. Intermoult C and BD peptides are not in ecdysial droplets but continue to be present in the ecdysial membrane, suggesting that constitutive secretion is independent from the exocytosis of transported moult peptides. T66 differs from most hemolymph peptides in that it does not carry N-acetyl glucosamine or alpha-D-glucose/alpha-D-mannose. (6) Weakly reacting BD peptides (and some H peptides barely detectable in cuticle) localize near the apical surface. Their distribution therefore favours apical secretion and retrieval as a mechanism for basal secretion.

Preservation and contrast without osmication or section staining

Conventional treatment of tissues for sectioning and transmission electron microscopy uses aldehyde fixation and osmium tetroxide postfixation. Although the result is aesthetically pleasing, osmication destroys some cell components and reduces the chemical activity of others, such as reaction with antibodies and lectins. We have found that aldehyde fixation followed by uranyl acetate preserves and contrasts most structures and visualizes some that are not easily seen after osmication. Aldehyde/UA treated tissues have enough contrast to be observed without section staining while retaining some of the chemical activity that is lost through osmication. Sections of tissues with good preservation and contrast can be used for immunogold and lectin-gold labelling of at least some molecules.

Shifts in type I fiber proportion in rat hindlimb muscle are accompanied by changes in HSP72 content

Heat-shock protein 72 (HSP72), the inducible isoform of the HSP70 family, is constitutively expressed in rat hindlimb muscles in proportion to the content of type I muscle fibers. To determine whether this relationship was maintained after fiber transformation, male Sprague-Dawley rats were treated with 3,5,3'-triiodo-DL-thyronine (T3) for 40 days or underwent surgical removal of the left gastrocnemius muscle, after which the left plantaris muscle was allowed to hypertrophy for 30 days. Hypertrophied plantaris muscles exhibited an increased number of type I fibers, type I myosin heavy-chain (MHC) protein, and HSP72 content compared with contralateral muscles. Soleus muscles from rats administered T3 exhibited an increased number of type II fibers, citrate synthase activity, and decreased HSP72 content compared with soleus muscles from controls. These results indicate that the relationship between HSP72 content and type I muscle fiber-MHC composition is maintained when muscles undergo fiber transformation and substantiate that HSP72 content in rat skeletal muscle is not directly linked to a muscle's oxidative capacity.

Resection arthrodesis of the knee for tumor: large intercalary allograft and long intramedullary nail technique

Twenty-five patients had a procedure consisting of resection of the distal femur or proximal tibia for aggressive or malignant neoplasms. The resulting bony gap was bridged by allografts averaging 18 cm in length. Fixation was achieved using a long fluted intramedullary nail. The average follow-up time and time to union were 3 years (range, 0.25 to 9 years) and 13 months (range, 6 to 28 months), respectively. Eleven patients had nononcologic complications related to the index surgical procedure, including two patients with allograft nonunion. There were no infections. Three patients had amputations for local recurrence of their tumor. Twenty patients (80%) had no evidence of tumor at the time of follow-up. According to the Evaluation System of the Musculoskeletal Tumor Society, 80% of patients had a satisfactory result. No patient had a nononcologic complication resulting in total failure or amputation. The procedure of resection-arthrodesis of the knee using a large allograft with a long intramedullary nail provides patients with a stable, durable biological reconstruction that allows early weight-bearing, and the procedure carries a low incidence of infection.

The planes of division in twin cell doublets

The fifth stage larval epidermis of Calpodes ethlius (Lepidoptera, Hesperiidae) is a syncytium of doublets where sibling cells remain connected by residual midbodies between mitoses. These twins resemble one another more than their other neighbours in features such as the shape and number of nucleolar particles, the number of actin bundles, the position of condensed chromosomes in female cells and the timing of mitosis. Although the patterns of arrangement of structures may be similar in twinned nuclei they differ in their orientation. We have now found that twins also differ in the orientation of their division planes with respect to the previous plane of division. Similarity of structural pattern but not orientation is most easily explained if nuclei, together with determinants for the plane of division, are free to rotate in the plane of the epithelium.

The timing of division in twin cell doublets

The fifth stage larval epidermis of Calpodes ethlius (Lepidoptera, Hesperiidae) is a syncytium of doublets where sibling cells are twins connected by residual midbodies between divisions. Twin cells resemble one another more than their other neighbours in such features as the shape and number of nucleolar particles, the number of actin bundles and the position of condensed female chromosomes. We have now found that they also resemble one another in the timing of cell division in preparation for pupation. Twins are more likely to divide together than at random. The paired timing of mitosis is presumed to be a result of the twins sharing a common cytoplasm.

Are prosome particles formed by the disintegration of proteasomes?

Quail reticulocyte 19S "prosome" fractions isolated on sucrose density gradients contain two kinds of particles: cylindrical proteasomes and ferritin. When samples of this fraction are prepared for electron microscopy using the one-step stain protocol described in this paper, most of the particles have a rectangular image resembling the proteasome. However, when samples are prepared for electron microscopy using the two-step stain protocol described here, there are few rectangular images. Their place is taken by round particles that resemble the prosome. Thus it appears that the round, raspberry-shaped particles called prosomes and the ring-like proteasome particles may be artifacts of specimen preparation for electron microscopy. We propose that proteasome particles may disintegrate when prepared for electron microscopy by methods such as the two-step stain protocol and that prosome particles represent the component parts of the proteasome. Furthermore, based on the enhancement of proteasome images obtained using the one-step main protocol we propose that, instead of consisting of a stack of four rings, the proteasome is constructed of three components, i.e., a spherical central particle flanked by two flat hexagonal end caps.

The relative positions of condensed chromosomes are maintained between divisions in the epidermis of Calpodes ethlius

The larval epidermis of Calpodes ethlius (Lepidoptera, Hesperiidae) is a syncytium of doublets where sibling cells are twins that remain connected by residual midbodies between mitoses. Twins resemble one another more than their other neighbours in such structural features as the shape and number of nucleolar particles and the number of actin bundles. We have now found that they also resemble one another in the position of the condensed chromosomes that occur in female cells. Female lepidopteran cells contain one or more particles of condensed chromatin, depending on their ploidy. In the epidermis, nuclei with two condensed chromosomes are found in pairs and are separated by the same distances. However, clones of cells with multiple condensed chromosomes are not all alike, suggesting that chromosomes are repositioned at mitosis. Separation distances between chromosomes remain the same between but not through cell divisions, suggesting that determinants for nuclear structure are conserved through interphase and relaxed at mitosis. Although the condensed chromosomes of sibling nuclei resemble one another in their separation, they differ in their orientation, as would be expected if whole nuclei rotate in the plane of the epithelium.

Paired cytoskeletal patterns in an epithelium of siamese twin cells

The epidermis of some insects is a sheet of siamese twin cells which are formed by conserving the midbody between siblings after cell division. We have found that for about 36 h after ecdysis to the 5th stage, the cells of Calpodes caterpillars contain one to five or more actin bundles. The variation in number of bundles occurs in an epithelium that is presumed to be otherwise genetically and developmentally homogeneous. The number of bundles is paired in adjacent cells (P less than 0.005, n = 617). Confocal microscopy shows midbodies between paired but not between unpaired cells. The pairing is reminiscent of the paired nucleolar patterns in these siamese twin cells (Locke, M., H. Leung, Tissue and Cell 17, 573-588 (1985)) or the mirrored patterns of stress fibers in newly divided 3T3 cells (Albrecht-Buehler, G., J. Cell Biol. 72, 595-603 (1977)). The pairing provides further evidence for the operation of transiently heritable factors as determinants for cell pattern.

Inducible isoform of HSP70 is constitutively expressed in a muscle fiber type specific pattern

The most prominent group of stress or heat-shock proteins (HSPs) has an Mr of approximately 70,000 and is collectively referred to as the HSP70 family. The extent of stress inducibility and subcellular location of the various HSP70 isoforms differ, but all appear to be involved with ATP-dependent stabilization or solubilization of proteins. One isoform, termed the inducible isoform of HSP70 (HSP72i), is normally absent in unstressed cells. In a previous study, we detected a protein corresponding in Mr and pI to HSP72i in unstressed rat muscle. Therefore, it was of interest to determine if this expression in unstressed muscle cells is general or confined to specific muscle fiber types. To answer this question we have employed various rat hindlimb muscles that differ in fiber type proportion from predominantly type I (soleus) to predominantly type IIB (white gastrocnemius). Proteins from muscle homogenates were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, blotted to a nylon membrane, probed with a monoclonal antibody for HSP72i, and visualized using an alkaline phosphatase-conjugated secondary antibody. Immunoblot analyses demonstrate the constitutive expression of HSP72i in rat muscles comprised primarily of type I muscle fibers (soleus), but not in muscles comprised primarily of type IIB fibers (white gastrocnemius). In muscles of mixed fiber type, HSP72i content is roughly proportional to the percentage of type I fibers. These results substantiate that unstressed rat muscles express the inducible HSP72 isoform and demonstrate that its constitutive expression is proportional to the type I muscle fiber composition.

The visualization of apoferritin in the secretory pathway of vertebrate liver cells

Electron microscopy has shown that normal mouse liver cells contain abundant cytosolic and lysosomal holoferritin but none in cisternae of the rough endoplasmic reticulum (RER). This does not mean that ferritin is absent from the secretory pathway, since the low contrast of apoferritin and ferritin containing little iron makes it difficult to resolve using standard transmission electron microscopy. We hypothesized that treatment of permeabilized cells and cell fractions with iron should make apoferritin visible by converting it to holoferritin. The iron treatment caused particles resembling the cores of holoferritin to appear in RER and in RER microsomes from mouse liver. We conclude that ferritin occurs in the endoplasmic reticulum and could be secreted, allowing the liver to be a source of serum ferritin.

Golgi complex beads and the transition region

Secretory proteins and membranes move in transfer vesicles from the rough endoplasmic reticulum through the transition region to the outer saccule of the Golgi complex. In both arthropod and vertebrate cells, the GC beads are a characteristic structural component of the transitional region. The beads are particles about half the size of ribosomes arranged equidistantly from one another and the smooth face of the ER. In an active GC, the beads are in rings through which the ER membrane emerges to form transfer vesicles. The beads may be part of the energy-dependent step required for the movement of proteins along eht secretory pathway, since they lose their ring arrangement under conditions that lower cellular ATP. The beads are organizers for Golgi complexes in the sense that they are the first recognizable components of new GCs as they arise from ER. Arthropod GC beads, but not those of vertebrates, can be visualized through their reaction with bismuth in vivo and in fixed tissue. Useful paradigms for traffic between the ER and the GC need to combine structural and biochemical information. Insect fat body, with its readily resolvable bismuth-strained beads and easily fractionated cell components may have particular value for this problem.

The psychosocial-cultural aspects of pregnancy and holistic nursing care

This paper discusses various psychosocial/cultural aspects of pregnancy that may alter the behaviour of the expectant couple. Holistic care plans are more likely to be effective if nurses are cognizant of these influences on the health of the child bearing couple. The quality of life from the moment of conception depends on a vast number of factors not the least being the physical and mental health of the expectant parents. Australian midwives contribute to the quality of maternal and fetal life by providing care throughout the pregnancy. In holistic care the health of the father is also considered therefore the quality of care provided to the growing family in the 1980's is a product of the nurses' knowledge.

Exercising mammals synthesize stress proteins

Spleen cells, peripheral lymphocytes, and soleus muscles were removed from male Sprague-Dawley rats that had been run on a treadmill (24 m/min) for either 20, 40, or 60 min or to exhaustion (86 +/- 41 min) and were labeled in vitro with [35S]methionine at 37 degrees C. Similar tissues from nonrunning control rats were labeled in vitro at either 37 or 43 degrees C (heat shock). Fluorographic analyses of one- and two-dimensional polyacrylamide gel electrophoretic separations of the proteins from cells and tissues of exercised rats demonstrate the new or enhanced synthesis of proteins of approximately 65, 72, 90, and 100 kDa. Although synthesis of these proteins is low or not detectable in tissues from control rats labeled at 37 degrees C, they are prominent products of similar tissues labeled under heat-shock conditions (43 degrees C) and, in fact, correspond in Mr and pI with the so-called heat-shock proteins. These results suggest that exercise is a sufficient stimulus to induce or enhance the synthesis of heat shock and/or stress proteins in mammalian cells and tissues.