Air pollution is associated with the risk of neurodegenerative disorders: a prominent role of PM10

Background

Studies revealed an implication of air pollution in neurodegenerative disorders, although this link remains unclear. Here, we investigated this testing multiple pollutants simultaneously.

Methods

In the Moli-sani cohort (N = 24,325; ≥35 years; 51.9% women, baseline 2005-2010), we estimated yearly levels of exposure to nitrogen oxides (NOX, NO, NO2), ozone (O3), particulate matter (PM10) and BTX hydrocarbons (benzene, toluene and xylene) in 2006-2018, applying residence geo-localization of participants and Kriging interpolation algorithm to land measurements of air pollutants. We performed a principal component analysis and tested association of the resulting principal components (PCs) with the incident risk of Parkinson (PD) and Alzheimer disease (AD), through multivariable Cox PH regressions adjusted for age, sex and education level completed.

Results

Over 24,308 subjects with pollution data available (51.9% women, 55.8(12.0) years), we extracted three PCs explaining ≥5% of pollution exposure variance: PC1 (38.2%, tagging PM10 exposure), PC2 (19.5%, O3/CO/SO2), PC3 (8.5%, NOx/BTX hydrocarbons). Over a mean follow-up of 10.9(2.1) years, we observed statistically significant associations of PC1 with an increased risk of PD (HR[CI] = 1.04[1.02-1.05]; 405 incident cases) and AD (1.06[1.04-1.08]; 218 cases). These associations were confirmed when we analyzed PM10 levels averaged over follow-up time, in models further adjusted for professional exposures like working class, compartment and toxic compounds and lifestyles like smoking and drinking habits, physical activity and adherence to Mediterranean diet (PD: 1.27 [1.19-1.37]; AD: 1.22[1.16-1.28] per 1 μg/m3 increase of PM10).

Conclusions

This evidence supports an influence of air pollution - especially PM10 - on increased neurodegenerative risk in the Italian population, independent on concurring risk factors. This suggests reducing PM10 pollution as a potential strategy to reduce neurodegenerative risk.

Key messages

• PM10 levels are associated with increased Parkinson and Alzheimer disease risk.

• This suggests to act on air pollution to reduce neurodegenerative risk in the general population.

Risk of nasopharyngeal cancer in productive sectors and formaldehyde exposure in bakeries industry

Background

The International Agency for Research on Cancer evaluated formaldehyde (F) as carcinogenic for human in association with Nasopharyngeal Cancer (NPC). Occupational exposure to F occurs in many industrial sectors also in those non-traditional. For example in Tuscany F was detected in a bakery where a NPC case had ever worked.

Methods

In this study a) A case control approach (OCCAM) was used for monitoring occupational risks based on current information sources. Three Italian Regional Operating Centres, collected NPC cases from cancer registries and/or hospital discharge records. Controls were randomly sampled from the regional health service population data. Occupational histories were available through record linkage with the social security pension database (INPS). Study results were reported by industrial sectors, area and gender. b) A specific study on F exposure was conducted in bakeries and pastry industry carrying out measurements to determine the concentration of F in specific tasks and positions.

Results

717 cases linked with INPS database. Increased ORs for several industrial sectors such as iron and steel, wood and plastic were observed. In two regions also health and veterinary services and hairdressers were at increased risk, but based on few cases of exposed workers. In the non traditional sector of bakeries and pastry industries, where workplaces were monitored, high levels of F in personal air samplings were found, in particular in processes that involve a strong leavening.

Conclusions

Many productive sectors, in which F exposure could occurred, were observed to be at higher risk. The measurements performed in the non traditional sector monitored, confirmed the F exposure in some phases of the work process. With this study we contributed to increased knowledge on the risk of NPC within the monitoring system of occupational risks, and to deepen exposure to F in a non traditional productive sector such as bakeries and pastry industries.

Key messages

The epidemiological method used (OCCAM) in this study provides further information on the role of occupational exposure in the development of nasopharyngeal cancer. The measurements performed in the bakeries and pastry industries provide new additional information on the exposure to formaldehyde in some work process phases of a non-traditional productive sector.

Comprehensive genomic analysis of the dromedary T cell receptor gamma (TRG) locus and identification of a functional TRGC5 cassette

The emergent availability in public databases of more complete genome assemblies allows us to improve genomic data obtained by classical molecular cloning. The main goal of this study was to refine the genomic map of the dromedary TRG locus by integrating our previous genomic data with the analysis of recent genomic assemblies. We identified an additional TRGC cassette, defined as a V-J-C recombination unit, located at the 5' of the locus and made up of five TRGV genes followed by three TRGJ genes and one TRGC gene. Hence, the complete dromedary TRG locus spans about 105 Kb and consists of three in tandem TRGC cassettes delimited by AMPH and STARD3NL genes at the 5' and 3' end, respectively. An expression assay carried out on peripheral blood showed the functional competency for the dromedary TRGC5 cassette and confirmed the presence of the somatic hypermutation mechanism able to enlarge the repertoire diversity of the dromedary γδ T cells.

Missense mutations in exon 2 of the MED12 gene are involved in IGF-2 overexpression in uterine leiomyoma

Uterine leiomyoma (UL), the most common benign tumour found in females, is associated with many recurrent genetic aberrations, such as translocations, interstitial deletions and specific germline mutations. Among these, mutations affecting exon 2 of the mediator complex subunit 12 (MED12) gene are commonly detected in the majority of ULs. Mutational analysis of the MED12 gene, performed on 36 UL samples, revealed that 12 leiomyomas (33.4%) exhibited heterozygous missense mutations in codon 44 of exon 2 of the MED12 gene, four leiomyomas (11.1%) showed internal in-frame deletions, and two leiomyomas (5.5%) exhibited deletions involving intron 1-exon 2 junction, which caused a predicted loss of the splice acceptor. No mutations were detected in uterine myometrium (UM) and pseudocapsule (PC) samples, including those from women with a MED12 mutation in UL. These data showed that the PC is a healthy tissue that surrounds the UL to maintain UM integrity. Analysis of insulin-like growth factor 2 (IGF-2) and collagen type IV alpha 2 (COL4A2) mRNA expression levels in the same set of ULs revealed that only those with MED12 missense mutations expressed significantly higher levels of IGF-2 mRNA. In contrast, MED12 gene status does not appear to affect mRNA expression levels of the COL4A2 gene. On the basis of this finding, we suggest that the MED12 status stratifies the ULs into two mutually exclusive pathways of leiomyoma genesis, one with IGF-2 overexpression and the other with no IGF-2 activation. The occurrence of IGF-2 overexpression could be therapeutically targeted for the non-surgical treatment of leiomyomas.

Gene expression analysis reveals an angiogenic profile in uterine leiomyoma pseudocapsule

The pseudocapsule (PC) of the uterine leiomyoma (UL) is an anatomic entity that surrounds the myoma separating it from the myometrium (UM). Although a number of microarray experiments have identified differences in gene expression profile in the UL when compared with the UM, there is a lack of systematic studies on the PC. In this study, quantitative RT-PCR analysis was performed on 18 matched PC, UL and UM specimens and results showed that the PC displays a specific gene expression profile. The low expression level of insulin-like growth factor (IGF-2), a fibroid specific marker, that we found in the PC and the UM when compared with the UL, clearly indicates that the PC is in structural continuity with the UM. However, the significant increase in endoglin expression level in PC with respect to the UL and UM indicates that an active neoangiogenesis is present in PC. Conversely, other angiogenic factors such as von Willebrand factor (vWF) and vascular endothelial growth factor A (VEGF-A) seem to have little influence on the PC angiogenesis. Because the endoglin is preferentially expressed in proliferating endothelial cells, whereas the vWF and VEGF-A are preferentially expressed in preexisting endothelial cells, our idea is that the angiogenic activity in the PC is linked to wound healing. The angiogenic activity is also sustained by intermediate expression level of cystein-rich angiogenesis inducer 61, connective tissue growth factor and collagen 4α2 genes all involved in the neoangiogenesis, that we detected in the PC. Taken together our data demonstrate that the specific expression pattern observed in the PC could be the response of the uterine wall's smooth cells to the tension imposed by the tumor. As a consequence, a neovascular structure is generated involving regenerative processes. For these reasons, we suggest that the laparoscopic intracapsular myomectomy (LIM), a new surgical technique that preserves the PC during the UL removal, should always be preferred, to favor a faster and proper uterine healing.

[The contribution of surveillance systems of occupational diseases and mesothelioma in environmental health studies]

National surveillance systems of occupational diseases may contribute to evaluate the work-related component of diseases investigated in SENTIERI Project. For a description of SENTIERI, refer to the 2010 Supplement of Epidemiology & Prevention devoted to SENTIERI Project. The National Workers Compensation Authority (INAIL) archives all occupational diseases claims (more than 230 000 in the period 2000-2007) and is in charge of their compensation. The Italian National Mesothelioma Register (ReNaM) and the Sinonasal Cancer Register (ReNaTuNS) record high occupational etiological fraction neoplasms (i.e. mesothelioma and sinonasal cancers). The former has identified more than 10 000 mesothelioma cases until now, and covers almost the whole country; the latter is active only in three Italian regions, Piemonte, Lombardia and Toscana. The monitoring of cancer sites at lower occupational etiological fraction is based on a record-linkage procedure between population-based cancer registries and employment history data, available at the Italian National Institute for Social Security (INPS). Finally, the informative system Mal.Prof collects and classifies all the diseases possibly related to the work environment reported by the Prevention Services of the Local Health Units.

[Italian national register of low etiological fraction occupational cancer pursuant to art. 244 of legislative decree n. 81/2008]

Legislative decree No. 81/2008 in the article n. 244 states that ISPESL, now INAIL, realizes a register of occupational cancers with low etiological fraction by means of a data collection method based exclusively on voluntary reports by GPs, healthcare and social security agencies (ReNaLOC) and a surveillance cancer monitoring system (OCCAM) based on linkage of routinely available data (cancer registries, hospital discharge records, Italian Social Security archives). ReNaLOC has produced a partial picture of the situation, it includes 1.584 cases as of June 2011. With OCCAM many situations of known risks were identified and others are worthy to be deepen.

Occurrence of nonceliac gluten sensitivity in patients with allergic disease

BACKGROUND

The aim of this study was to determine the occurrence of gluten sensitivity (GS) in a group of allergic patients and to assess the efficacy of a gluten-free diet (GFD) on the improvement of the symptomatology in those who were diagnosed with GS.

METHODS

262 unrelated allergic patients with gastrointestinal symptoms of obscure origin were tested for GS condition by biopsy. All patients were also genotyped for the typical celiac DQ2 and DQ8 molecules and investigated for several hematological parameters such as antigliadin and antiendomysial antibodies. Patients displaying mucosal lesions were invited to follow a GFD.

RESULTS

Seventy-seven of the 262 allergic patients were positive to mucosal lesions, but negative to the antiAGA, antiEMA and to DQ2 and DQ8 molecules. We found, instead, a prevalence of the DQA1*05 allele, whereas anemia of inflammatory origin represented the predominant complaint in our subjects. The positive patients, who, after the GS diagnosis, followed a GFD, exhibited control of symptoms as well as stabilization of the hematological parameters even if allergic manifestations were not abated.

CONCLUSIONS

A nonceliac gluten-sensitive enteropathy (NCGSE) commonly occurs in allergic patients. Based on the high prevalence of NCGSE in allergy, it is recommended that biopsy should be part of the routine investigation of allergic disease to offer the benefits of treatment with a GFD to the patients.

Organization, structure and evolution of 41kb of genomic DNA spanning the D-J-C region of the sheep TRB locus

A genomic region of 41,045 bp encompassing the 3'-end of the sheep T cell receptor beta chain was sequenced. Extensive molecular analysis has revealed that this region retains a unique structural feature for the presence of a third D-J-C cluster, never detected in any other mammalian species examined so far. A total of 3 TRBD, 18 TRBJ and 3 substantially identical TRBC genes were identified in about 28kb. At 13kb, downstream from the last TRBC gene, in an inverted transcriptional orientation, lies a TRBV gene. Sequence comparison and phylogenetic analyses have demonstrated that the extra D-J-C cluster originated from an unequal crossing over between the two ancestral TRBC genes. Interspersed repeats spanning 22.2% of the sequence, contribute to the wider size of the sheep TRB locus with respect to the other mammalian counterparts, without modifying the general genomic architecture. The nucleotide and predicted amino acid sequences from peripheral T cells cDNA clones indicated that the genes from cluster 3 are fully implicated in the beta chain recombination machinery. Closer inspections of the transcripts have also shown that inter-cluster rearrangements and splice variants, involving the additional cluster, increase the functional diversity of the sheep beta chain repertoire.

Genomic organization of the sheep TRG1@ locus and comparative analyses of Bovidae and human variable genes

gammadelta T cells commonly account for 0.5%-5% of human (gammadelta low species) circulating T cells, whereas they are very common in chickens, and they may account for >70% of peripheral cells in ruminants (gammadelta high species). We have previously reported the ovine TRG2@ locus structure, the first complete physical map of any ruminant animal TCR locus. Here we determined the TRG1@ locus organization in sheep, reported all variable (V) gamma gene segments in their germline configuration and included human and cattle sequences in a three species comparison. The TRG1@ locus spans about 140 kb and consists of three clusters named TRG5, TRG3, and TRG1 according to the constant (C) genes. The predicted tertiary structure of cattle and sheep V proteins showed a remarkably high degree of conservation between the experimentally determined human Vgamma9 and the proteins belonging to TRG5 Vgamma subgroup. However systematic comparison of primary and tertiary structure highligthed that in Bovidae the overall conformation of the gammadelta TCR, is more similar to the Fab fragment of an antibody than any TCR heterodimer. Phylogenetic analysis showed that the evolution of cattle and sheep V genes is related to the rearrangement process of V segments with the relevant C, and consequentely to the appartenence of the V genes to a given cluster. The TRG cluster evolution in cattle and sheep pointed out the existence of a TRG5 ancient cluster and the occurrence of duplications of its minimal structural scheme of one V, two joining (J), and one C.

Artiodactyl emergence is accompanied by the birth of an extensive pool of diverse germline TRDV1 genes

Molecular cloning of cDNA from gamma/delta T cells has shown that in sheep, the variable domain of the delta chain is chiefly determined by the expression of the TRDV1 subgroup, apparently composed of a large number of genes. There are three other TRDV subgroups, but these include only one gene each. To evaluate the extent and the complexity of the genomic TRDV repertoire, we screened a sheep liver genomic library from a single individual of the Altamurana breed and sheep fibroblast genomic DNA from a single individual of the Gentile di Puglia breed. We identified a total of 22 TRDV1 genes and the TRDV4 gene. A sequence comparison between germline and the rearranged genes indicates that, in sheep, the TRDV repertoire is generated by the VDJ rearrangement of at least 40 distinct TRDV1 genes. All germline TRDV1 genes present a high degree of similarity in their coding as well as in 5' and 3' flanking regions. However, a systematic analysis of the translation products reveals that these genes present a broadly different and specific repertoire in the complementarity-determining regions or recognition loops, allowing us to organize the TRDV genes into sets. We assume that selection processes operating at the level of ligand recognition have shaped the sheep TRDV germline repertoire. A phylogenetic study based on a sequence analysis of the TRDV genes from different mammalian species shows that the diversification level of these genes is higher in artiodactyl species compared to humans and mice.

Evolution of TRG clusters in cattle and sheep genomes as drawn from the structural analysis of the ovine TRG2@ locus

The availability of genomic clones representative of the T-cell receptor constant gamma (TRGC) ovine genes enabled us to demonstrate, by fluorescent in situ hybridization (FISH) on cattle and sheep metaphases, the presence of two T-cell receptor gamma (TRG1@ and TRG2@) paralogous loci separated by at least five chromosomal bands on chromosome 4. Only TRG1@ is included within a region of homology with human TRG locus on chromosome 7, thus TRG2@ locus appears to be peculiar to ruminants. The structure of the entire TRG2@ locus, the first complete physical map of any ruminant animal TCR gamma locus, is reported here. The TRG2@ spans about 90 kb and consists of three clusters that we named TRG6, TRG2, and TRG4, according to the constant genes name. Phylogenetic analysis has highlighted the correlation between the grouping pattern of cattle and sheep variable gamma (TRGV) genes and the relevant TRGC; variable (V), joining (J), and constant (C) rearrange to be found together in mature transcripts. The simultaneous results on the TRG2@ locus molecular organization in sheep and on the phylogenetic analysis of cattle and sheep V expressed sequences indicate that at least six TRG clusters distributed in the two loci are present in these ruminant animals. The inferred evolution of TRG clusters in cattle and sheep genomes is consistent with a scenario where a minimal ancient cluster, containing the basic structural scheme of one V, one J, and one C gene, has undergone a process of duplication and intrachromosomal transposition.

Exon-intron organization of TRGC genes in sheep

A series of genomic clones derived from a sheep library were used to determine the germline configuration and the exon-intron organization of TRGC2, TRGC3, and TRGC4 genes. Based on the outcomes of molecular analysis, we compared and aligned the genomic sequences with the known complete cDNA sequences of sheep and deduced the exon-intron organization of TRGC genes in this ruminant animal, EX1, corresponding to the disulfide-linked constant domain, and EX3, corresponding to the transmembrane and cytoplasmatic domains, are similar in length in all genes. Conversely, the hinge-encoding EX2A, EX2B, and EX2C exons differ in number and length between genes, and EX2A contains the TTKPP motif irrespective of whether it occurs in single or triplicate form. The molecular data also indicate that at least one additional gene is present in sheep. Phylogenetic analysis grouped the ruminant TRGC genes in two clusters that could have emerged from two ancestral forms that underwent a series of duplications giving rise to the new sequences that were selected and then fixed in the ruminant lineages. A correlation between the cluster distribution in the phylogenetic tree of TRGC genes and their expression during fetal development is discussed.

Genomic organization of sheep TRDJ segments and their expression in the delta-chain repertoire in thymus

cDNA sequences obtained from polymerase chain reaction products of reverse-transcribed RNA from sheep thymus showed the presence of a large number of members of the TRDV1 gene family. Some are TRDV1 genes also found in peripheral blood lymphocytes, while four genes had not been described so far. The cDNA sequences also showed extensive junctional diversity and a preferential usage of the three TRDJ elements. We characterized the genomic organization of the sheep TRDJ locus and detected a correlation between the nonrandom usage of TRDJ elements during development and their chromosomal order.

The GLT-1 and GLAST glutamate transporters are expressed on morphologically distinct astrocytes and regulated by neuronal activity in primary hippocampal cocultures

The GLT-1 and GLAST astroglial transporters are the glutamate transporters mainly involved in maintaining physiological extracellular glutamate concentrations. Defects in neurotransmitter glutamate transport may represent an important component of glutamate-induced neurodegenerative disorders (such as amyotrophic lateral sclerosis) and CNS insults (ischemia and epilepsy). We characterized the protein expression of GLT-1 and GLAST in primary astrocyte-neuron cocultures derived from rat hippocampal tissues during neuron differentiation/maturation. GLT-1 and GLAST are expressed by morphologically distinct glial fibrillary acidic protein-positive astrocytes, and their expression correlates with the status of neuron differentiation/maturation and activity. Up-regulation of the transporters paralleled the content of the synaptophysin synaptic vesicle marker p38, and down-regulation was a consequence of glutamate-induced neuronal death or the reduction of synaptic activity. Finally, soluble factors in neuronal-conditioned media prevented the down-regulation of the GLT-1 and GLAST proteins. Although other mechanisms may participate in regulating GLT-1 and GLAST in the CNS, our data indicate that soluble factors dependent on neuronal activity play a major regulating role in hippocampal cocultures.

Mammalian LIN-7 PDZ proteins associate with beta-catenin at the cell-cell junctions of epithelia and neurons

The heterotrimeric PDZ complex containing LIN-2, LIN-7 and LIN-10 is known to be involved in the organization of epithelial and neuronal junctions in Caenorhabditis elegans and mammals. We report here that mammalian LIN-7 PDZ proteins form a complex with cadherin and beta-catenin in epithelia and neurons. The association of LIN-7 with cadherin and beta-catenin is Ca(2+) dependent and is mediated by the direct binding of LIN-7 to the C-terminal PDZ target sequence of beta-catenin, as demonstrated by means of co-immunoprecipitation experiments and in vitro binding assays with the recombinant glutathione S-transferase:LIN-7A. The presence of beta-catenin at the junction is required in order to relocate LIN-7 from the cytosol to cadherin-mediated adhesions, thus indicating that LIN-7 junctional recruitment is beta-catenin dependent and that one functional role of the binding is to localize LIN-7. Moreover, when LIN-7 is present at the beta-catenin-containing junctions, it determines the accumulation of binding partners, thus suggesting the mechanism by which beta-catenin mediates the organization of the junctional domain.

Effects of fetuin on zona pellucida hardening and fertilizability of equine oocytes matured in vitro

In vitro fertilization (IVF) has had poor success in the horse, a situation related to low rates of sperm penetration through the zona pellucida (ZP). Zona pellucida hardening (ZPH) is seen in mouse and rat oocytes cultured in serum-free medium. The hardened ZP is refractory to sperm penetration. Fetuin, a component of fetal calf serum, inhibits ZPH and allows normal fertilization rates in oocytes cultured in the absence of serum. We evaluated whether fetuin is present in horse serum and follicular fluid (FF) and whether fetuin could inhibit ZPH in equine oocytes matured in vitro, thus increasing sperm penetration during IVF. The presence of fetuin in equine serum and FF was confirmed by immunoblotting. Oocytes submitted to in vitro maturation (IVM) in medium containing fetuin were used for ZPH assay or IVF. Intracytoplasmic sperm injection (ICSI) was carried out as a control procedure. The presence of fetuin during IVM did not affect the rate of maturation to metaphase II. Maturation of oocytes in the presence of fetuin reduced ZPH in a dose-dependent manner. After both IVF and ICSI, there was no significant difference in oocyte fertilization between fetuin-treated and untreated oocytes. The fertilization rate was significantly higher after ICSI than after IVF, both in fetuin-treated and in untreated oocytes. In conclusion, fetuin reduced ZPH in equine oocytes but did not improve sperm penetration during IVF. This implies that, in the horse, "spontaneous" ZPH is unlikely to be the major factor responsible for inhibiting sperm penetration in vitro.

Assignment of the TCRA/TCRD locus to sheep chromosome bands 7q1.4-->q2.2 by fluorescence in situ hybridization

Two genomic clones for the TCRA/TCRD locus have been isolated and characterized in sheep. The first clone corresponds to a new sheep Valpha element, the other to the entire Cdelta gene. Chromosomal mapping by fluorescence in situ hybridization (FISH) of Valpha and Cdelta clones localized the TCRA/TCRD locus on sheep chromosome region 7q14-->q22. This is the first physical assignment for genomic clones on sheep chromosome 7 by FISH. Moreover, the present data put the ovine 7q14-->q22 and the human 14q11.2 regions in the same syntenic group.

The mitochondrial permeability transition

This review summarizes recent work on the regulation of the permeability transition pore, a cyclosporin A-sensitive mitochondrial channel that may play a role in intracellular calcium homeostasis and in a variety of forms of cell death. The basic bioenergetics aspects of pore modulation are discussed, with some emphasis on the links between oxidative stress and pore dysregulation as a potential cause of mitochondrial dysfunction that may be relevant to cell injury.

The S-adenosyl-L-homocysteine hydrolase of Drosophila melanogaster: identification, deduced amino acid sequence and cytological localization of the structural gene

S-adenosyl-L-homocysteine hydrolase (AdoHcyase, EC 3.3.1.1) catalyzes the hydrolysis of S-adeno-syl-L-homocysteine to adenosine and homocysteine and thus plays a crucial role in normal cellular metabolism. We have isolated the cDNA for Drosophila melanogaster AdoHcyase by screening a Drosophila ovarian expression library. The 1584-nucleotide cDNA encodes a protein of 431 amino acids, showing 80.5% identity with human AdoHcyase. Southern analysis of genomic DNA and in situ hybridization to salivary gland chromosomes indicate that a single gene encodes the D. melanogaster AdoHcyase. The gene resides in region 13C1-2 on the X chromosome. Transcript analysis shows a single AdoHcyase mRNA present in unfertilized eggs, and, at a more or less constant level of expression, in all developmental stages tested, ranging from early embryos to adults. The deduced amino acid sequence was compared to a putative AdoHcyase-like protein encoded by a cDNA mapping to the 89E region of the second chromosome and showing much lower similarity to known AdoHcyases. We discuss the hypothesis that a sequence that originated by duplication of an ancestral AdoHcyase gene has, in the course of evolution, been recruited to supply a different function.

Kinetic analysis of the mitochondrial permeability transition

The permeability transition process in rat liver mitochondria was studied by following the swelling consequent to external solute equilibration through the membrane pore. The kinetics of the transition was analyzed according to a model based on the assumptions that the transition rate follows a first-order process and that the solute diffusion rate strongly depends on the pore conformation. Three kinetic parameters, easily calculated from absorbance measurements during mitochondrial swelling, were used to determine whether changes of the swelling rate are due to changes of (i) the transition rate, (ii) the amount of permeabilized mitochondria, (iii) the mean pore dimension, or (iv) the number of pores per mitochondrion. The model was tested for transitions induced either by phenylarsine oxide (PhAsO) or by Ca2+ and Pi. Under both conditions, only a definite fraction of mitochondria was permeabilized, and the transition always followed a first-order reaction, indicating that mitochondria behaved as a homogeneous population. However, the equilibration of external solutes was rapid only in a fraction of permeabilized mitochondria and slow in the remaining fraction, due to restricted solute diffusion through narrower pores. With 0.2 mM PhAsO as the inducer, the fraction of permeabilized mitochondria was about 0.8. Sucrose diffusion was rapid only in 15% of this fraction (half-time less than 1 s) and restricted in the remaining 85% (half-time of about 60 s). Increasing PhAsO concentrations increased the number of pores per mitochondrion and the rate constant of the permeability transition, but not the mean pore diameter and the fraction of permeabilized mitochondria. With 0.28 microM free [Ca2+] and 1 mM Pi as the inducers, the fraction of permeabilized mitochondria was about 0.43. Sucrose diffusion was rapid in 60% of this fraction and restricted in the remaining 40% (half-time of about 9 s). The permeabilization process started above a threshold- free [Ca2+] of 0.15 microM, and the rate constant and the fraction of permeabilized mitochondria reached a maximum at about 0.2 microM, while both parameters were inhibited at higher free [Ca2+].

Factors affecting the H+/e- stoichiometry in mitochondrial cytochrome c oxidase: influence of the rate of electron flow and transmembrane delta pH

A study is presented of the factors affecting the H+/e- stoichiometry of the proton pump of mitochondrial cytochrome c oxidase, isolated and reconstituted in phospholipid vesicles (COV). Under level flow conditions, i.e., in the absence of a transmembrane delta muH+, the H+/e- ratio, obtained from spectrophotometric measurements of the initial rates of electron flow and H+ release specifically elicited by cytochrome c, varied from around 0 to 1, depending on the actual rate of electron flow through the oxidase. At steady state the H+/e- ratio for the oxidase was specifically depressed by the transmembrane delta pH. The study of the H+/e- ratio of the pump was complemented by an analysis of the redox pattern of cytochrome c, CuA, and heme a. From both sets of results and recent structural data from other groups, it is concluded that the dependence of the H+/e- ratio on the rate of electron flow through the oxidase and transmembrane delta pH is associated with the possible occurrence of two electron transfer pathways in cytochrome c oxidase, a coupled one (cyt c-->CuA-->heme a-->heme a3-CuB) and a decoupled one (cyt c-->CuA-->heme a3-CuB). The contributions of the two pathways, differently affected by kinetics and thermodynamic factors, will determine the actual H+/e- ratio of the pump. A possible role of heme a in the proton pump and the physiological implication of the variable H+/e- ratio in the oxidase are discussed.

The Ste locus, a component of the parasitic cry-Ste system of Drosophila melanogaster, encodes a protein that forms crystals in primary spermatocytes and mimics properties of the beta subunit of casein kinase 2

Males of Drosophila melanogaster lacking the Y chromosome-linked crystal locus show multiple meiotic alterations including chromosome disorganization and prominent crystal formation in primary spermatocytes. These alterations are due to the derepression of the X chromosome-linked Stellate sequences. To understand how the derepression of the Stellate elements gives rise to these abnormalities, we have expressed the protein encoded by the Stellate sequences in bacteria and produced an antibody against the fusion protein. Immunostaining of crystal- testes has clearly shown that the Stellate protein is a major component of the crystals. Moreover, in vitro experiments have shown that this protein can interact with the catalytic alpha subunit of casein kinase 2 enzyme, altering its activity.

Interaction systems between heterochromatin and euchromatin in Drosophila melanogaster

The constitutive heterochromatin is still one of the major unsolved problems in genetics. In Drosophila melanogaster three genetic systems involving specific interactions between heterochromatic and euchromatic genetic elements are known: the Segregation Distortion, the crystal-Stellate and the abo-ABO systems. The genetic and molecular analysis of each system will allow the identification of all the components and the elucidation of the mechanisms underlying their interactions. The results of this analysis should provide insights into the biological significance of heterochromatin and into the evolutionary forces that result in the maintainance and stability of this enigmatic genetic material.

Physiological effectors modify voltage sensing by the cyclosporin A-sensitive permeability transition pore of mitochondria

This paper reports an investigation on the modulation of the mitochondrial permeability transition pore (MTP) by the membrane potential. Energized rat liver mitochondria loaded with a small Ca2+ pulse in sucrose medium supplemented with phosphate favor a high MTP "closed" probability because of the high membrane potential and therefore maintain a low permeability to sucrose. Upon depolarization by the addition of fully uncoupling concentrations of carbonyl cyanide p-trifluoromethoxyphenylhydrazone (FCCP) mitochondria favor a high MTP "open" probability and rapidly undergo a process of osmotic swelling following sucrose diffusion toward the matrix. A titration with FCCP reveals that discrete subpopulations of mitochondria with different gating potentials for MTP opening may exist, since increasing concentrations of FCCP increase the fraction of mitochondria undergoing osmotic swelling. We show that physiological effectors (Ca2+, Mg2+, ADP, palmitate) modify pore opening in a mitochondrial population by shifting the fraction of mitochondria with a functionally open pore at any given membrane potential. Many inducers and inhibitors may therefore affect the pore directly through an effect on the MTP voltage sensing rather than indirectly through an effect on the membrane potential. Thus, many effectors may induce pore opening by shifting the MTP gating potential to higher levels, whereas many inhibitors may induce pore closure by shifting the MTP gating potential to lower levels.

[Biomechanical-clinical interpretation of firearm wounds. General problems. VIII. Propedeutic ABC of terminal ballistics]

The Authors, consistent with their aim to compare and contrast the two protagonists of bullet wounds, namely the bullet and its soft human target, delineating their respective profiles, strengths and weaknesses, feel obliged to dwell at some length on the most frequently pathogenetic regulation firearms. Up until the early twentieth century bullet wounds could be generically classified among the forms of open traumatism, but with the advent of high-speed bullets they have come to take on a unique profile of their own, setting against the old permanent cavity due to mechanical insult a new type of transitory ghost, the definition of which as a cavity would merely be an oversimplification in theoretical terms. Can we really attribute this somewhat privileged dimension to bullet wounds today or must we relegate them once again to the sphere of mechanical traumatisms, albeit with a new inflammatory key to their interpretation, making the most in this sense of the contribution provided by the speed of the bullet? The literature is abundant, but uncertain; we intend to attempt an answer to this tricky question in the following pages, devoted more properly to terminal ballistics. Undoubtedly, the new speeds have had a substantial impact on the wounds inflicted upon the soft target, but the streamlining of the jacket has modified and even offset the results, giving rise to the unexpectedly humanitarian bullet, later subject to reappraisal in military quarters as tactically more efficient, because it obliges the enemy to employ greater resources for recovering, assisting and healing the wounded. We can safely claim that ballistic science in the field of light or portable firearms is experiencing a contradiction between the speed of the bullet and the streamlining of the jacket which makes this speed possible, but which undermines the efficacy of the often unconfessable results. Short-barrelled firearms, which on account of their defensive role, the alibi of their problematic access to speed, and their characteristic use as "last-chance" weapons, are less subject to international constraints and enjoy an extensive civilian market with specific claims to stopping power, thus become the true witnesses to a reality no different to the one Dum-Dum interpreted: the field of modern regulation firearms is shrouded in similar doubts, strengthened by the increasingly short barrels of the weapons, remedies and temptations, with, in addition, the increasingly precarious nature of the human element behind the firearm.(ABSTRACT TRUNCATED AT 400 WORDS)

[Biomechanical-clinical interpretation of firearm wounds. General problems. IX. Propedeutic ABC of terminal ballistics]

In this chapter, the leading role is played by the mechanical-thermal-ballistic device, issued as a long-barrelled regulation firearm to modern armies. The most accurate description of this type of firearm and its present and possible future development seeks to be in line with the objective comparison between the biological matter and the mechanical material, which constitutes the essential basis for any optimal nosological, aetiological, or pathogenetic classification of bullet wounds. We should not forget that the advent of the M 16 A 1 has aroused great technical interest, particularly--though not only--as regards the hydroshock aspect, and that the technological developments in future can hardly fail to increasingly confirm the singular nature of bullet wounds, which refuse to be encompassed merely within the somewhat limited sphere of their strictly local effects, but carry a broader significance in a critical context open to further verification in the future. There can be no denying that this unique nature of modern bullet wounds makes them ideal candidates bearing witness to a new interpretation of traumatism, which at present is only in its infancy.

[Biomechanical and clinical interpretation of firearm wounds. General problems. VII. Propedeutic ABC of terminal ballistics]

The parallelism breaks down, and the bullet, which is now the subject, speeds towards the object, the body, its target. The ideal vantage point for capturing the moment of impact is the nose. We set up our station here, imaging that were are a kind of TV camera recording with cold objectivity, in slow motion, instant by instant, the marks and the impact made by the hard body on its soft target.

[Terminal ballistics. 2. (The skin)]

It goes without saying that, at first glance, it is the velocity with which the fired bullet pierces the solid target and perhaps even penetrates it that bears witness to the efficiency of a firearm. Prior to the advent of ceramic and composite materials, iron and its clone, steel, provided the most satisfactory and most coveted evidence as a test material in both the positive and negative senses. It the biological field, wood and deal in particular were for decades the only witnesses, alongside tests in cadavers, which, despite obvious reservations, provided us with a wealth of data, much of which is still regarded today as among the mainstays of forensic didactics. Prominent among these, in terms of clinical importance, in that they mark the start of the bullet wound, are the velocity and energy thresholds per presentation area. The bullet, after overcoming the barrier of the skin, continues on its course through the soft tissues, and there leaves its most authentic and singular mark as a bullet wound.

[Biomechanical-clinical interpretation of firearm wounds. General problems. XI. Propedeutic ABC of terminal ballistics]

The pathogenetic potentiality of firearms differs in relation to whether we are dealing with rifled long-barrelled weapons, handguns, or smooth-bore long-barrelled guns. Up until a few years ago, the tissue-damaging effect, at least in the modern warfare context, of short-barrelled or smooth-bore long-barrelled firearms, was thoroughly negligible; today, however, their impact, as causes of wounds and death, is steadily increasing, and for the first time small bullets designed for low-cost military training are also coming to play a primary role on the battlefield. At the same time short-gun bullets are appearing which, which in the name of "stopping power" seem to contradict the very definition of a handgun. The smooth-bore long-barrelled gun, in turn, is casting off the anti-humanitarian image of the trench gun to play the more suggestive ordinance role of the grenadiercumhunter.

[Biomechanical-clinical interpretation of firearm wounds. General problems. X. Propedeutic ABC of terminal ballistics]

Any discussion of firearms which failed to take due account of the complex interaction between the weapon and its user would be missing the point. This interaction takes on a major role, particularly in the case of military ordinance weapons; their "optimal" use demands the maximum control of this interaction, which is of the utmost importance for the tactical role of the soldier-weapon system. The use of the latest long-barrelled ordinance firearms is more acceptable precisely because of their smaller calibre (which also means reduced interaction with the user). Today the traditional primacy of the long-barrelled weapon (now getting progressively shorter) is threatened by the short-barrelled gun cartridge, which we have seen used on an extensively scale in recent militia warfare. Paradoxically, it is precisely this cartridge, whose main shortcoming is its low propellant content (and thus reduced kinetic energy) which is expected to provide the kind of killing performance capable of snuffing out even "the dead man's last five seconds".

[Propedeutic to general problems of the hypothesis of a new "open" interpretation of firearm wounds of soft tissues]

On the basis of a review of the literature and their own personal knowledge and experience, the authors define the state of the art regarding a point of considerable importance, namely the leaky gut hypothesis. Taking gunshot wounds in soft tissues as their starting point, they believe that such lesions are among the most suitable for illustrating the chain of events which translates an entirely local pathology--admittedly serious--into a systemic pathology carrying a very severe prognosis, if the physician is unable to interrupt this clinical course.

[Biomechanical and clinical interpretation of firearm wounds. General problems. VI. Propedeutic ABC of terminal ballistics]

Any lengthy and properly structured propedeutic ABC of terminal ballistics must necessarily embrace a comparison between the two main protagonists of gunshot wounds. It is almost a specular, yet distorted image of the ritual act consumed by the larger mammals, not proud of their mutual aggression, but the conformation between mechanics and biology, or between kilogram-metres and life. The two types of physical entity brought together through the unique agency of a new language--both biological and mechanical, but necessarily halting and inadequate--stand out like two parallel lines opposite one another, displaying their respective profiles and most intimate structures. One can take this as far as the biological paradox of the clash between the dimension of power and the chance quality of life.

[Biomechanical and clinical interpretation of firearm wounds. General problems. V. The propaedeutic ABC of terminal ballistics]

Modern portable firearms, whether for military or civilian use, present substantially different features as instruments for striking, wounding and killing compared to those used in the past on account both of their intrinsic characteristics as thermo-chemico-ballistic machines, guaranteeing extra, more easily achievable performance and of the characteristics of the bullets used. The factors responsible for this difference, which consists essentially in an unprecedented wounding capability, are, in the military field, the enormous amount of research which only now is beginning to yield a bare minimum of concrete results in terms of futuristic forms and devastating performance, amongst other things because it is easier to achieve, and, in the "civilian" field, the maniacal search for an unlikely definitive wound, based on the unusual nature of the cartridge and on sophisticated training.

pH-dependent lipid packing, membrane permeability and fusion in phosphatidylcholine vesicles

We have studied the rate of membrane fusion, the lipid dynamics and order and the membrane permeability of phosphatidylcholine vesicles as a function of pH. Acidification induced very different effects depending on the state of the bilayer. In liquid-crystalline bilayers, acidification decreased the rate of membrane fusion, the acyl chain motion and disorder and the rate of K+ release, whereas in solid bilayers acidification increased the rate of membrane fusion, the lipid acyl chain disorder and the rate of K+ release. These pH-dependent modifications are interpreted in terms of conformational and/or packing changes of the phosphatidylcholine head group in the membrane. In solid bilayers, these changes are not easily accommodated by the rigid structure, and the resulting stress leads to an unstable bilayer.

Cancer family syndrome: cytogenetic investigations, in vitro tetraploidy, and biomarker studies in a large family

Fifty-five members of a family with the cancer family syndrome (CFS) were investigated for the following potential biomarkers for cancer proneness: (1) cytogenetics of peripheral blood lymphocytes and skin fibroblasts; (2) in vitro tetraploidy of dermal fibroblast monolayer cultures; (3) quantitative serum immunoglobulin determinations; (4) study of genetic linkage with respect to eight blood group markers including Kidd. Biological specimens were obtained from 14 patients affected with cancer, 21 subjects at risk, and 20 healthy subjects. None of the markers tested in this family, in order to identify a biomarker for the status of CFS gene carrier, was found to be useful. Our search for linkage to other biological markers (DNA RFLPs and NK cells) is in progress.

[The clinical biomechanical interpretation of gunshot wounds. The general problems (IV). The propedeutic ABCs of the terminal ballistics]

If we want to enunciate the damaging potential of a bullet fired from a gun we have to express ourselves right from the outset in terms of destructive work, that is to say not only destruction of the structures the bullet passes through, but also, above all, destruction of the homeostatic condition. In modern terms, this is particularly true of the abdomen, which, in perspective, above and beyond any direct involvement, is a candidate for an interesting role. As regards the translation of this destructive force in mathematical language, formulae are proposed in kilogram-meters, feet per second and Joules. A basic factor in external ballistics, quite apart from the actual forces involved, is the trajectory in space, the hyperbola, though we should also reflect on the problem of resistance, which has such a considerable effect on the behaviour of the "ideal" bullet in the atmosphere (the smallest calibre for a given mass, with the attempt to rid itself of its forced subordination to the calibre of the barrel). This leads us on to the subsequent concept of the "ballistic coefficient" and, in itself definitively established the basic assumptions of terminal ballistics.

[Reinterpretation of the hepatic abscess, a new dimension in abdominal digestive surgery]

Pyogenic abscess of the liver is viewed here as a surgical disease, which appears to raise doubts as to its actual identity. Though located in a given abdominal organ, such abscesses find it hard to recognize this as their exclusive setting and attempt to shrug off these traditional confines. They aspire, rightly or wrongly perhaps, to symbolize a splanchnic context, though, in actual fact, the latter--at least for contingent, doctrinal reasons--is confined to the bipolar liver-bowel system. This context presents its candidacy as playing a leading role in a disease of such importance as to be regarded almost as the "Caudine Forks" of the very process of "surgical" dying. Liver abscess and multiorganic or multisystemic organ failure (MOF or MSOF) might thus be viewed as the two opposite poles (taxonomically definable) of a single clinical condition, which fans out over a broad area and for the most part is only barely known to us. Though is characterized by its abdominal location, it would be all too simple to define the condition as abdominal. In this case, in fact, the abdomen speaks an unusual language, not the habitual, traditional, "spatial" language of location, but the as yet uncertainly articulated "biological" or, why not, even "biosurgical" language of mediation. Is this then a turning point in the pathological field? No, if by that we mean a new concept of the problem. In effect, the concept dates back several centuries and, moreover, darries a heavy burden of responsibility, such as, for instance, having induced the Nobel Prize-winner Elie Metcknicoff (Metcknicoff E., The prolongation of life. London, Heinemann, 1907) to come up with theories appropriated and implemented surgically by Sir William Arbutnot Lane, gaining him nothing but sad notoriety (Gordon R., Great Medical Disasters, Hutchinson, London-Melbourne, 1983). "Concept" is a euphenism, and a more appropriate term might be simply "intuition". The real innovation lies in reviving this old intuition, reinterpreting it now, in fact, as a "concept". The code for this modern interpretation has barely been sketched out in its essentials, but is daily going from strength to strength.(ABSTRACT TRUNCATED AT 400 WORDS)

Depressed level of natural killer cells in cancer family syndrome

Individuals from kindred with cancer family syndrome (CFS) have an increased genetic risk for the development of adenocarcinoma of the colon as well as of several other organs. Previous studies have suggested that this high occurrence of adenocarcinoma in this as in other hereditary neoplastic syndromes may be correlated to an underlying abnormality in immunological tumor surveillance. In attempt to define a marker that might identify individuals within CFS kindred at risk of developing cancer, we determined natural killer (NK) cell number and NK cell function in affected and healthy members of a CFS family. We studied 13 cancer-affected patients, 20 unaffected but "at-risk" subjects, 20 healthy subjects and 26 normal individuals matched to the patients with colon cancer on the basis of sex and age. We determined the number of NK cells and their function concurrently, using a monoclonal antibody and a 51Cr-release assay with K562 as target cells. We found that the number of NK cells was significantly (P = 0.00004) reduced in cancer patients as compared with healthy subjects and normal controls. Of the 20 at-risk individuals 9 had levels lower than the norm, while 11 showed normal-values. Consequently, the mean percentage of NK cells of this group does not differ either from that of normal subjects or from that of cancer patients. Mean NK cell function was lower in cancer patients than in healthy members of the CFS family but the differences were not statistically significant. Therefore, the mean NK cell function per single cell, expressed as a ratio between cytotoxicity (LU) and the number of NK1-positive cells, resulted paradoxically in an increase when compared with that of normal subjects. The possible mechanisms for this dichotomy were examined.

Interaction of the fluorescent probe N-(lissamine Rhodamine B sulfonyl)dipalmitoylphosphatidylethanolamine with phosphatidylcholine bilayers

The surface density of the fluorescent probe N-(lissamine Rhodamine B sulfonyl)dipalmitoylphosphatidylcholine is the same in the two lipid leaflets of phosphatidylcholine bilayers containing the probe. In the liquid-crystalline state, the probe molecules aggregate above a threshold amount, approximately 0.2 mol/mol phospholipids. Above this threshold value, the surface density of the free probe molecules is constant, and all probe molecules added are incorporated in the aggregated form. The aggregation of the probe increases by approximately 20% when the medium pH is lowered to 4. In the gel state, the probe aggregation is higher than that in the liquid-crystalline state, and the free probe molecules distribute unevenly in the bilayer surface. Even though the results obtained in our model system cannot be directly extrapolated to all model systems, we point out that care is to be taken in the use of the probe. In fact, only in membranes in the liquid-crystalline state in which the amount of probe molecules to phospholipid molecules is lower than 1:7 the fluorescence response of the probe is independent of the pH changes and of the molecular aggregation.

Lipid miscibility and size increase of vesicles composed of two phosphatidylcholines

The size increase of small unilamellar vesicles composed of binary mixtures either of saturated fatty acid phosphatidylcholines with different chain lengths or of saturated and unsaturated phosphatidylcholines was found to depend on the miscibility properties of the lipid components. No size increase was detected in vesicles formed by two miscible phosphatidylcholines. In vesicles composed of two lipids which are partially immiscible in the gel state, a size increase was observed at temperatures which mainly overlapped the range of temperatures of the lipid phase transition. The rate of size increase of vesicles composed of two lipids which are immiscible in the gel state was faster than that of vesicles composed of two partially immiscible phosphatidylcholines, and the process occurred not only at the temperature ranges of the lipid phase transition, but also when both lipids were in the gel state. The vesicle size increase process occurred without the mixing of the internal content of the vesicles. A model is proposed in which the presence of 'fractures' between membrane regions of different fluidity and/or lipid composition controls the rate of this process.

Gramicidin induced aggregation and size increase of phosphatidylcholine vesicles

To investigate the role of membrane proteins in the fusion process, linear hydrophobic polypeptide gramicidin was used as fusogenic agent in small unilamellar vesicles (SUV) constituted of saturated lecithins. It was found that gramicidin, externally added to a suspension of vesicles, induces a reversible vesicles aggregation. When incorporated into the bilayer, gramicidin induces increase in vesicle size. The vesicle size increase was monitored by column chromatography and transmission electron microscopy. The process of vesicle size increase occurs only when the lipid membrane is in the gel state. A maximum is observed in the kinetics at a temperature of approx. 25 degrees C lower than the phase transition temperature of lipids. Higher rates of vesicle size increase are obtained as the lipid chain length increases. The process is accompanied by a release of internal vesicle content and by membrane lipid mixing.

Free H-Y antigen induces in vitro testicular differentiation of human XX embryonic indifferent gonads

In accordance with the anchorage site hypothesis, Daudi beta 2-microglobulin (-) HLA (-) human male Burkitt lymphoma cells are incapable of stably maintaining H-Y antigen on their plasma membrane; instead, they excrete it into the culture medium. The proposed testis-organizing function of Daudi H-Y antigen in solution, previously demonstrated in bovine ovarian embryonic cells, has been tested for the first time in human undifferentiated gonads. Cultured in the presence of Daudi excreted H-Y antigen, gonads obtained from early human embryos of 46, XX chromosomal constitution underwent precocious and complete testicular differentiation.

Phospholipid miscibility in ternary mixtures

The gel to liquid-crystalline phase transition of aqueous dispersions of phospholipid mixtures was investigated by means of the repartition of the spin label 2,2,6,6-tetramethylpiperidine-I-oxyl between aqueous space and lipid hydrocarbon region. The dimyristoylphosphatidylcholine (DMPC)/dibehenoylphosphatidylcholine (DBPC) and dipalmitoylphosphatidylcholine (DPPC)/DBPC phase diagrams indicate gel phase immiscibility, whereas the distearoylphosphatidylcholine (DSPC)/DBPC phase diagram indicates non-ideal gel phase miscibility at low DBPC molar fractions. Aqueous dispersions of DMPC/DPPC/DBPC ternary mixtures show two distinct phase transitions, the first associated with the melting of a DMPC/DPPC phase and the second with the melting of a DBPC phase. Aqueous dispersions of DMPC/DSPC/DBPC ternary mixtures show to phase transitions at low DSPC molar fractions; the first is probably associated with the melting of a DMPC/DSPC phase, and the second with the melting of a DBPC/DSPC phase. At high DSPC molar fractions, only one phase transition is observed; this suggests that all the lipids are mixed in gel state membranes.