Phosphoregulation on mitochondria: Integration of cell and organelle responses

Mitochondria are highly integrated organelles that are crucial to cell adaptation and mitigating adverse physiology. Recent studies demonstrate that fundamental signal transduction pathways incorporate mitochondrial substrates into their biological programs. Reversible phosphorylation is emerging as a useful mechanism to modulate mitochondrial function in accordance with cellular changes. Critical serine/threonine protein kinases, such as the c-Jun N-terminal kinase (JNK), protein kinase A (PKA), PTEN-induced kinase-1 (PINK1), and AMP-dependent protein kinase (AMPK), readily translocate to the outer mitochondrial membrane (OMM), the interface of mitochondria-cell communication. OMM protein kinases phosphorylate diverse mitochondrial substrates that have discrete effects on organelle dynamics, protein import, respiratory complex activity, antioxidant capacity, and apoptosis. OMM phosphorylation events can be tempered through the actions of local protein phosphatases, such as mitogen-activated protein kinase phosphatase-1 (MKP-1) and protein phosphatase 2A (PP2A), to regulate the extent and duration of signaling. The central mediators of OMM signal transduction are the scaffold proteins because the relative abundance of these accessory proteins determines the magnitude and duration of a signaling event on the mitochondrial surface, which dictates the biological outcome of a local signal transduction pathway. The concentrations of scaffold proteins, such as A-kinase anchoring proteins (AKAPs) and Sab (or SH3 binding protein 5-SH3BP5), have been shown to influence neuronal survival and vulnerability, respectively, in models of Parkinson's disease (PD), highlighting the importance of OMM signaling to health and disease. Despite recent progress, much remains to be discovered concerning the mechanisms of OMM signaling. Nonetheless, enhancing beneficial OMM signaling events and inhibiting detrimental protein-protein interactions on the mitochondrial surface may represent highly selective approaches to restore mitochondrial health and homeostasis and mitigate organelle dysfunction in conditions such as PD.

Products for Alzheimer's self-stimulatory wanderers

The objective of this study was to develop a variety of sensory stimulation products for the behavioral intervention of patients with Alzheimer's type dementia. Many caregivers have relied on physical and chemical restraints as the primary method of patient intervention due to the lack of appropriate dementia management products. This significantly lowers the sufferer's quality of care and life. As the age group most susceptible to Alzheimer's disease (65 and older) is the fastest growing segment of our society, an appropriate care solution must be sought. The specific aim of this study was to develop products that are sensory satisfying for the Alzheimer's patient that exhibits self-stimulatory wandering behavior. Sensory satisfying objects for product development would be determined through structured observations of self-stimulatory wanderers in an institutionalized setting. Variations of product design and mounting would be pursued in order to develop products that are not only safe and effective for patient use, but are easy for the caregiver to implement and maintain. Such products would have widespread commercial application in both the institutional and private care settings such as nursing homes, adult day care facilities, Alzheimer's care facilities, convalescent homes, mental health institutions, and assisted-living facilities.

Pneumococcal pneumonia diagnosis by demonstration of pneumolysin antibodies in precipitated immune complexes: a study in 350 Philippine children with acute lower respiratory infection

In searching for suitable methods for aetiological diagnosis of pneumococcal disease we determined capsular polysaccharide, C-polysaccharide and pneumolysin antibodies bound in immune complexes (IC) in Filipino children. Sera were obtained from 150 healthy infants (all under 12 months old) and from 350 paediatric patients (mean age 18 months) hospitalized with severe pneumonia. The findings in healthy children were not associated with age, sex or pneumococcal carrier status; 3-7% exceeded the cut-off limits for positivity in different antibody assays. By contrast, 97 (51%) of the 190 patients with a complete 3-sample series exceeded the cut-off limit for IC-bound pneumolysin-IgG in at least 1 of the serum samples studied. Positivity rates for IC-bound pneumolysin-IgG in the admission day, in-patient and convalescent sample of the 350 patients were 25%, 25% and 34%. Pneumolysin-IgM, capsular polysaccharide and C-polysaccharide antibodies in the IC were positive in only 4-6% of the patients' samples. IC-bound pneumolysin-IgG antibody assay seem to be a useful method for species-specific diagnosis of pneumococcal infections.

Reliability of parental history of antibiotic use for Filipino children admitted with acute lower respiratory tract infection

Parental history on antibiotic use and the urine antibacterial assay (UABA) result were compared in a study on Filipino children with acute lower respiratory tract infection (ALRI). Among 108 patients in whom urine for the UABA could be collected prior to starting antibiotic treatment in the hospital, 59 (55%) guardians reported preceding antibiotic use, 54% of whom were positive in the UABA. In another 37 (34%), the UABA result was positive, indicating nonreported use of antibiotics. Among 190 patients in whom urine could be collected only after intravenous administration of antibiotic, the UABA demonstrated large inhibition zones after the first dose in most patients but a negative result was seen in 14 cases. The inhibition zone radius was significantly smaller for chloramphenicol than for beta-lactam antibiotics (8.3 mm versus 16.1 mm after one dose; 95% confidence intervals = 7.0-9.7 and 14.9-17.2, respectively). Parental history on antibiotic use gives an underestimate of preceding antibiotic use in children with ALRI in the Philippines. The result partly explains the low yield of blood culture in many studies on ALRI, and stresses the need to develop new diagnostic methods not based on culture for those organisms highly sensitive to antibiotics such as Streptococcus pneumoniae and Haemophilus influenzae.

Coinfection is common in measles-associated pneumonia

BACKGROUND

Measles continues to be a significant health problem in developing countries.

OBJECTIVES

To describe the clinical features of measles-associated pneumonia (MAP) and to identify other pathogens involved.

METHODS

Measles diagnosis was ascertained either by the typical symptom complex or by a sensitive enzyme immunoassay for antibody among children < 5 years of age admitted to the hospital with pneumonia. Other pathogens were identified by blood culture, virus isolation or antigen detection from nasopharyngeal aspirate and antibody determination from serum.

RESULTS

Of 182 MAP cases 162 (89%) had clinically typical measles. Twenty patients had a diagnostic antibody finding with an atypical clinical presentation. Thirteen percent were younger than 9 months of age. The case fatality rate was 17%, with a significantly increased odds ratio (OR) for those with cyanosis [OR 4.6, 95% confidence interval (CI) 1.7 to 13], respiratory rate > or = 60/min (OR 3, 95% CI 1.3 to 7) or fulfilling criteria for very severe pneumonia (OR 5.3, 95% CI 2.3 to 12). Mixed infection was found in 53% of patients. Blood culture was positive in 10 patients, Streptococcus pneumoniae (N = 5) being the most common finding. Adenovirus (19%) and parainfluenza (25%) viruses were the most frequent other viruses. A dense infiltrate was seen significantly more often among measles patients with bacterial coinfection (87.5%) than those with other viruses (36%, P = 0.007) or no evidence of other infection (33%, P = 0.004).

CONCLUSION

In MAP, coinfection with other microbes is common. Cyanosis and a respiratory rate of > or = 60/min predict a greater risk of dying.

Effects of neuroblastoma tumor gangliosides on platelet adhesion to collagen

Gangliosides, sialic acid-containing glycosphingolipids, enhance tumor formation in experimental animals and are associated with tumor progression and metastasis in humans. The mechanism(s) for this activity is (are) unknown. One possibility is enhanced platelet activation, since the interaction of platelets with tumor cells contributes to tumor cell arrest in the vascular compartment. We have previously shown that neuroblastoma tumor gangliosides (NBTG) enhance platelet adenosine triphosphate (ATP) secretion, aggregation, and adhesion. We determined that these NBTG effects are specific for collagen and are mediated through an alpha2 beta1 integrin-dependent mechanism. This report describes the effects of NBTG on a physiologically relevant model of collagen-alpha2 betal interaction. Platelet adhesion to immobilized native collagen fibers similar to those found in the extracellular matrix of blood vessels was determined. Platelet adhesion is enhanced by NBTG in a concentration-dependent manner. Incubation with concentrations of 1 and 10 microM NBTG increased platelet adhesion by 9% and 52%, respectively, compared to less than 1% in controls not incubated with gangliosides (P = 0.001 and P < 0.0001, respectively). In addition to increasing the number of adherent platelets, NBTG promoted more rapid attachment. In NBTG-incubated platelets, platelet adhesion began after a 5-min lag phase and was maximal at 30 min compared to a 20-min lag phase and maximal adhesion at 60 min for control platelets. At 30 min this difference was significant (P = 0.017); however, by 120 min there was no difference between NBTG and controls (P = 0.259). NBTG also induces platelet adhesion at collagen concentrations (0.1 microg) that failed to support adhesion of control platelets. These effects of NBTG require Mg2+ or Mn2+ ions but are not supported by Zn2+ or Ca2+ ions. Furthermore, preincubation of platelets with a blocking antibody (6F1) to the integrin collagen receptor alpha2 beta1 abrogates all of the effects of NBTG. These results indicate that tumor gangliosides enhance platelet adhesion to extracellular matrix collagen and promote rapid stabilization of the collagen-alpha2 beta1 interaction, the initial steps in platelet activation.

Failure mechanisms of anatomic porous replacement I cementless total hip replacement

The APR-I Hip System was designed for metaphyseal bone attachment by proximal patch porous coating and the acetabular component was a hemisphere fixed with screws. The results of 100 consecutive primary total hip arthroplasties performed with the APR-I were studied in patients still alive after an average of 6.7 years. The selection of hips for implantation of this hip system was limited to those patients in whom a satisfactory intraoperative fit could be obtained. This resulted in a distribution of patients such that 75% were younger than age 65 years and only 15% had osteoporotic bone. The revision rate was 16% with a mechanical failure rate of 11%. Seventy percent of hips had progressive loss of fixation. loss of femoral component fixation was correlated with younger patient age, higher patient activity level, metaphyseal fill of less than 90%, and increased polyethylene wear and osteolysis. Eighty-nine percent of hips maintained femoral neck contact with the porous coated collar. The acetabular component was well fixed in 97% of hips. The failure rate of the APR-I stem is unacceptably high and this stem is no longer used by the authors.

Wandering in Alzheimer's dementia patients

The purpose of this research was to describe wandering behaviors of institutionalized patients with Alzheimer's disease in their natural environment. Such descriptive information is necessary before successful product and/or nursing intervention programs can be developed. Videotaped behavioral observations yielded detailed data descriptive of patients with middle and late dementia. These patients have the physical ability to perform various functions, activities, or actions; the individual's mental ability is less supportive of physical ability. The degree of task simplicity required to enable the patient to complete unsupervised tasks depends on the level of dementia. The need for interventions is greatest during unstructured periods of the day.

Tacaribe virus L gene encodes a protein of 2210 amino acid residues

The nucleotide sequence of Tacaribe virus (TV) L gene was obtained from two sets of overlapping cDNA clones constructed by walking along the virus L RNA using two successive synthetic DNA primers. Analysis of the sequence indicated the existence of a unique long open reading frame in the viral complementary strand. The first in-phase AUG codon is in positions 31-33 from the 5' end of the viral complementary L RNA surrounded by a sequence favorable for initiation of protein synthesis. The open reading frame ends at positions 6661-6663. The predicted TV L protein is a 2210 amino acid long polypeptide with an estimated molecular weight of 251,942. Comparison of the amino acid sequence of TV L protein with peptide sequences predicted from L-derived cDNA clones of lymphocytic choriomeningitis virus shows an overall 42% of homology.

Improving perinatal outcome through data management: the design of the small area analysis system

The decentralization of health management requires that appropriate tools be developed for decision support at the local level. The Improved Pregnancy Outcome Data Management System (IPODM) was designed to enable health managers and physicians with little computer experience to access over 500 variables derived from United States Census and California Vital Statistics sources. Using an interactive format one can create datasets describing the sociodemographic composition and perinatal outcome of individuals residing in individual census tracts (or zip codes) and in aggregates of these basic units such as neighborhoods, health catchment areas, or municipal districts. IPODM allows one to analyze this information in terms of tables, plots, maps, and basic statistical procedures using an interactive format. This paper describes the system designed for the State of California and the principles that guided the design.

Assignment of the human and mouse prion protein genes to homologous chromosomes

Purified preparations of scrapie prions contain one major macromolecule, designated prion protein (PrP). Genes encoding PrP are found in normal animals and humans but not within the infectious particles. The PrP gene was assigned to human chromosome 20 and the corresponding mouse chromosome 2 using somatic cell hybrids. In situ hybridization studies mapped the human PrP gene to band 20p12----pter. Our results should lead to studies of genetic loci syntenic with the PrP gene, which may play a role in the pathogenesis of prion diseases or other degenerative neurologic disorders.

Enhancement of mouse natural killer cell activity by type II interferon

It is likely that interferons are key molecules in the physiological regulation of natural killing (NK) activity. This assumption is based on the strong enhancing effect exerted by type I interferon on NK cells. The aim of this study was to examine whether type II interferon, released upon activation of T lymphocytes by a mitogen, had the same enhancing effect. Crude PHA-induced interferon was purified on affinity chromatography columns (Blue Sepharose), and the eluted fractions were tested in parallel for antiviral activity and for in vitro boosting effect on spleen cell natural cytotoxicity. We found that both activities were unseparable. Acid pretreatment of purified type II interferon, as well as addition of anti-type II interferon serum, greatly decreased the enhancement of the spleen cell cytotoxic response. Responder cells to type II interferon are NK cells (surface Ig-negative, Thy-1-negative, devoided of acid Fc receptors) as assessed by classical spleen cell fractionation procedures based on cell surface markers. Comparison between the dose-response curves obtained with type I and type II interferons suggest that both interferon preparations stimulate NK activity in a comparable manner. We could conclude that interferon molecules (type I as well as type II) display a positive immunoregulatory function on NK cells.

Physico-chemical characterization and partial purification of mouse immune interferon

Mouse immune (type T) interferon was produced from suspensions of spleen cells (1 X 10(7) cells/ml) treated with 3 micrograms/ml of phytohaemagglutinin. The crude interferon was chromatographed on four sorbents with varying affinities, namely concanavalin A-Sepharose, Affi-Gel 202, Blue Sepharose CL-6B and Phenyl-Sepharose CL-4B. With each of these the interferon activity was observed to have considerable heterogeneity. By means of affinity chromatography, mouse immune interferon was purified 100 to 200 times with concomitant complete recovery of activity.

Immune interferon induced by phytohemagglutinin in nude mouse spleen cells

Phytohemagglutinin is able to trigger interferon synthesis in spleen cell cultures from nude (nu/nu) mice as effectively as in splenic cell cultures from haired, control (nu/+), thymus-bearing mice. A minor theta-bearing cell population present in the spleen of nude mice appears essential to phytohemagglutinin interferon production, although cooperating cells are also required. The properties of nude mouse phytohemagglutinin interferon are indistinguishable from those displayed by the interferon induced in thymus-bearing mouse spleen cell cultures. Both interferons are unstable at pH 2 and cannot be neutralized by an antiviral interferon serum; hence, their characteristics correspond to those described for type T interferon. As in the case of viral interferon, pretreatment of L cells with nude phytohemagglutinin interferon induced specific enhanced phosphorylation of a 67,000-molecular-weight protein in vitro when cell extracts were incubated with double-stranded RNA and gamma-[32P]ATP.