Low health-related quality of life in adult individuals with multiple limb deficiencies compared with population-based reference values.

BACKGROUND: Knowledge on health-related quality of life (HRQoL) in multiple limb deficiencies (LDs) is limited. OBJECTIVES: To investigate self-reported HRQoL in multiple LDs, assess differences between congenital LD and acquired LD and sex, and to evaluate associations between the types of LDs, demographic variables, and HRQoL. STUDY DESIGN: Cross-sectional cohort study. METHODS: A total of 106 individuals with multiple limb deficiencies treated at the EX-Center were invited by mail to fill out the Short Form-36 survey. RESULTS: Responses from 62 participants, mean age ± SD 49.5 ± 14.2, showed that 43 had congenital LD and 19 had acquired LD. Responders reported reduced HRQoL in all Short Form-36 domains except Role-Emotional, compared with reference values (P < 0.05-<0.001). Individuals with a congenital LD reported worse Bodily Pain than acquired LD (P < 0.05), and women reported lower Physical Function than men (P < 0.05). Sick leave was negatively associated with physical composite score. Living in a rural area was positively associated with Mental Health (P < 0.01), and congenital LD was negatively associated with Vitality (P < 0.05). CONCLUSIONS: Individuals with multiple LDs in Sweden have lower HRQoL compared with reference values. There are significant associations between sick leave and physical function, rural living and mental health, and the type of LD and vitality.

[Extensive pneumatization of the posterior skull]. / Ausgedehnte Pneumatisation des hinteren Schädels.

Hyperpneumatization of the craniocervical bones is a very rare disorder and there are only assumptions as to the cause of this potentially dangerous condition. This article reports the case of a 44-year-old patient with severe pneumatization who became symptomatic after a minor skiing accident without any direct trauma.

Root Rot of Pea and Faba Bean in Southern Sweden Caused by Phytophthora pisi sp. nov.

A root rot disease of pea and faba bean caused by a Phytophthora sp. was observed in fields and field soil samples in southern Sweden. Observations of the disease in pea root rot greenhouse assays were systematically recorded, and incidence and geographic distribution data were compared with the pea root rot caused by Aphanomyces euteiches. Following one successful isolation of the pathogen, isolation procedures and selective media were optimized to retrieve more isolates. Phylogenetic analysis showed that the isolates belong to a novel lineage, closely related to Phytophthora sojae, and proposed here as a new species, P. pisi sp. nov. In a collection of 13 isolates from separate fields, intraspecific variation was detected in both nuclear and mitochondrial loci. Pathogenicity tests on a range of crop plants and wild legumes suggest that the host range of the pathogen is restricted to a group of legumes closely related to pea which, in addition to pea, include the crop species faba bean, lentil, common vetch, and chickpea. Morphology, growth requirements, and pathogenicity traits indicate that the species may be identical to the organism previously described as P. erythroseptica var. pisi. The work characterizes a novel Phytophthora sp. causing root rot of legume crops.

Analysis of genotypic variation in genes associated with virulence in Aggregatibacter actinomycetemcomitans clinical isolates.

BACKGROUND AND OBJECTIVE: Although certain serotypes of Aggregatibacter actinomycetemcomitans are associated more with aggressive periodontitis than are other serotypes, the correlation between distinct lineages and virulence traits in this species is poorly understood. This study aimed to evaluate the polymorphism of genes encoding putative virulence factors of clinical isolates, and to correlate these findings with A. actinomycetemcomitans serotypes, genotypes and periodontal status of the hosts. MATERIAL AND METHODS: Twenty-six clinical isolates from diverse geographic populations with different periodontal conditions were evaluated. Genotyping was performed using pulse-field gel electrophoresis. Polymorphisms in the genes encoding leukotoxin, Aae, ApaH and determinants for serotype-specific O polysaccharide were investigated. RESULTS: The isolates were classified into serotypes a-f, and exhibited three apaH genotypes, five aae alleles and 25 macrorestriction profiles. Two serotype b isolates (7.7%), obtained from Brazilian patients with aggressive periodontitis, were associated with the highly leukotoxic genotype; these isolates showed identical fingerprint patterns and aae and apaH genotypes. Serotype c, obtained from various periodontal conditions, was the most prevalent among Brazilian isolates, and isolates were distributed in two aae alleles, but formed a genetically distinct group based on apaH analysis. Cluster analysis showed a close relationship between fingerprinting genotypes and serotypes/apaH genotypes, but not with aae genotypes. CONCLUSION: Apart from the deletion in the ltx promoter region, no disease-associated markers were identified. Non-JP2-like strains recovered from individuals with periodontal disease exhibited considerable genetic variation regarding aae/apaH genotypes, serotypes and XhoI DNA fingerprints.

Explaining the enigmatic K(M) for oxygen in cytochrome c oxidase: a kinetic model.

We present a mathematical model for the functioning of proton-pumping cytochrome c oxidase, consisting of cyclic conversions between 26 enzyme states. The model is based on the mechanism of oxygen reduction and linked proton translocation postulated by Wikström and Verkhovsky (2007). It enables the calculation of the steady-state turnover rates and enzyme-state populations as functions of the cytochrome c reduction state, oxygen concentration, membrane potential, and pH on either side of the inner mitochondrial membrane. We use the model to explain the enigmatic decrease in oxygen affinity of the enzyme that has been observed in mitochondria when the proton-motive force is increased. The importance of the 26 transitions in the mechanism of cytochrome oxidase for the functional properties of cytochrome oxidase is compared through Metabolic Control Analysis. The control of the K(M) value is distributed mainly between the steps in the mechanism that involve electrogenic proton movements, with both positive and negative contributions. Positive contributions derive from the same steps that control enzyme turnover rate in the model. Limitations and possible further applications of the model are discussed.

Genetic diversity and toxic activity of Aggregatibacter actinomycetemcomitans isolates.

INTRODUCTION: Very little is known of the diversity and expression of virulence factors of serotypes of Aggregatibacter actinomycetemcomitans. Toxic activity on Chinese hamster ovary (CHO) cells and cdt and ltx genotyping were evaluated in A. actinomycetemcomitans serotypes. METHODS: Forty-one A. actinomycetemcomitans isolates were analysed for CHO cell growth inhibition. Genotyping was performed by polymerase chain reactions specific to the ltx promoter region, serotype-specific and cdt region and by sequencing of cdtB. RESULTS: cdtABC was detected in 40 strains. Analysis of the cdtA upstream region revealed 10 cdt genotypes. Toxicity to CHO cells was detected for 92.7% of the isolates; however, no correlation between the toxic activity and the cdt genotype was detected. Serotype c was more prevalent among Brazilian samples (68.0%). Four serotype b isolates from subjects with aggressive periodontitis were associated with high leukotoxin production and exhibited moderate to strong toxic activity in CHO cells, but were classified in different cdt genotypes. High levels of toxicity in CHO cells were not associated with a particular serotype; 57.1% of serotype a isolates presented low toxicity to CHO cells whereas the highly toxic strains belonged to serotypes b and c. Sequencing of cdtB revealed a single nucleotide polymorphism of amino acid 281 but this was not related to the toxic activity in CHO cells. CONCLUSION: Differences in prevalence of the low and highly cytotoxic strains among serotypes reinforce the hypothesis that serotype b and c isolates of A. actinomycetemcomitans are more virulent than serotype a strains.

Alveolar macrophages and CC chemokines are increased in children with cystic fibrosis.

Airway inflammation is an important component of cystic fibrosis (CF) lung disease. We sought to determine whether alveolar macrophages were involved in early CF lung disease. Children with CF (median age 3.1 yrs) participated in a surveillance programme that included annual bronchoalveolar lavage (BAL). Control samples were obtained from non-CF children (median age 3.1 yrs; n = 24) investigated for persistent respiratory symptoms. Pulmonary infection was detected in 31% (16 out of 51) and 38% (nine out of 24) of children from the CF and non-CF groups, respectively. Alveolar macrophages in BAL were increased in CF compared with non-CF in the absence of infection (223x10(3) versus 85x10(3) cells.mL(-1); p = 0.001) and were associated with elevations in the CC chemokines (macrophage inflammatory protein (MIP)-3alpha (chemokine (C-C motif) ligand (CCL)20; 355.8 versus 46.0 pg.mL(-1); p<0.001), monocyte chemotactic protein-1 (CCL2; 263.5 versus 25.3 pg.mL(-1); p<0.001), MIP-1alpha (CCL3; 38.2 versus 4.9 pg.mL(-1); p<0.001) and MIP-1beta (CCL4; 326.6 versus 27.5 pg.mL(-1); p<0.001)). Total cell counts and neutrophil numbers increased in the presence of infection; however, there was no additional effect of CF. Alveolar macrophages and CC chemokines are elevated in the lungs in young children with CF even in the absence of pulmonary infection. Longitudinal studies are required to determine the clinical relevance of these findings.

Mucosal regulatory T cells in airway hyperresponsiveness.

Interest in regulatory T cells (Treg) and their role in immune regulation has grown almost exponentially over the last 10 years, though the notion of a suppressive population of T cells has been in existence since the early 1970s. Recent reports have highlighted the potential role of populations of Treg in control of T-cell-mediated inflammation in tissues, including the lung. In particular, there is now evidence to suggest that Treg form a fundamental part of the regulatory axis operating within the respiratory mucosa and that the number of Treg recruited to the airways may be crucial for the inhibition of airways hyperresponsiveness associated with exacerbations of asthma. A discussion of these concepts is the focus of this chapter.

Microflora in oral ecosystems in subjects with radiation-induced hyposalivation.

AIM: To analyse the microbial flora in specific oral sites in 13 dentate subjects, 6-8 months after completed radiation therapy (RT group) and in 13 matched controls. MATERIAL AND METHODS: The microflora on the tongue, buccal mucosa, vestibulum, supragingival plaque and subgingival region was analysed using duplicate sampling and cultivation technique. A clinical examination was also performed. RESULTS: Candida albicans was found in one or more sites in 54% of the RT subjects and in 15% of the controls. In three RT subjects, C. albicans was found at all four sites analysed. An unexpected finding was that enterococci were found in all RT subjects and in high number in 38%. None of the controls harboured enterococci. In supragingival plaque, Lactobacillus spp. were detected in 92% of the RT subjects and the number and proportion of Lactobacillus spp. were extremely high compared with the controls. Mutans streptococci were detected in high numbers in 31% of the RT subjects, while they were not detected in 23%. CONCLUSION: The microbial results explain why some RT subjects have an increased susceptibility to oral diseases and stress that site-specific microbial analysis is an important diagnostic tool when planning oral health preventive care for RT subjects.

Adhesion and invasion to epithelial cells by fimA genotypes of Porphyromonas gingivalis.

Adhesion to and invasion of epithelial cells by the periodontopathogen Porphyromonas gingivalis is promoted by the major fimbriae, encoded by fimA. The microorganism can be classified in six genotypes, based on fimA sequence, and genotype II strains are more prevalent than others in periodontitis patients. This study aimed to determine the adhesive and invasive abilities on KB cells of different fimA allelic variants of P. gingivalis isolates. Twenty-two isolates and six reference strains representing the six fimA genotypes and non-typeable strains were screened for their adhesion and invasion abilities on KB cells, using standard methods. All strains were able to adhere and, except for one, to invade KB cells. However, these properties were not homogeneous among strains belonging to the same genotype. There was no correlation between adhesion and invasion efficiencies. Isolate KdII 865 (fimA genotype II) was the most invasive and the second most adhesive strain, whereas reference strain ATCC 33277 (fimA I) showed a low adhesion ability but was highly invasive. These data indicated that fimA genotypes of P. gingivalis are not related to the adhesion and invasion abilities on KB cells, suggesting that the increased prevalence and proportion of certain genotypes may be attributed to other characteristics besides FimA variation.

Dental plaque pH and micro-organisms during hyposalivation.

We have previously reported that minor gland and whole saliva flow rates and salivary proteins showed differences in individuals with primary Sjögren's syndrome or head and neck radiation therapy, compared with controls (Eliasson et al., 2005). We now hypothesize that pH and number of acidogenic micro-organisms in dental plaque as well as saliva buffering capacity also differ in these individuals. Plaque pH was measured by the microtouch method up to 60 min after a sucrose rinse. Plaque collected from the same sites was analyzed for counts of total and acidic micro-organisms. Compared with their controls, the irradiated group but not the Sjögren's syndrome group displayed significantly lower plaque pH, increased numbers of lactobacilli and Candida species, as well as reduced buffering capacity. Stepwise regression tests suggested that the buccal minor-salivary-gland secretion rate in the test groups and counts of mutans streptococci in the controls were of significant importance for dental plaque pH.

First Report in Sweden of Downy Mildew on Parsley Caused by Plasmopara petroselini.

During September 2004, downy mildew of parsley caused by a species of Plasmopara was observed in an experimental field of parsley (Petroselinum crispum subsp. crispum L. cv. Gigante d'Italia/Hilmar) in Borgeby in southern Sweden. The summer of 2004 was exceptionally wet and humid. Disease became widespread throughout the field in just a few days. Local growers reported that symptoms consistent with downy mildew had appeared in their parsley fields every year since 2001. Plasmopara, under P. nivea, has been reported on parsley in Europe since the middle of the 19th century (4). In recent years, this disease has caused severe damage to parsley grown in several European countries, e.g., France, Germany, Switzerland, and Belgium (1,3). The first symptoms appeared as faint chlorotic spots on the upper surfaces of the leaves. On the corresponding lower surfaces, mycelium and sporangiophores grew profusely and developed a white mat that in part turned dark gray. Eventually, the leaves and stalks became necrotic and died. The sporangiophores were monopodially branched, 248.4 ± 13.36 µm long (n = 17), each branch ending in 2 to 5 ultimate branchlets tapered toward the tip. The trunk diameter measured 7.0 ± 0.77 µm (n = 9) above the basal part and 6.1 ± 0.81 µm just below the first branch. The sporangia were broadly ellipsoidal to ellipsoidal, hyaline, 22.5 ± 0.73 µm long and 16.6 ± 0.48 µm wide (n µ 40). They were mostly nonpapillate when young, although exit pores 4.8 ± 0.32 µm (n = 10) were visible. Mature sporangia exhibited a dehiscence apparatus and a plug in the exit pore. On the basis of the characteristics above, the pathogen was identified as P. petroselini (= P. nivea pro parte [2]). Independent verification of the identity was done by O. Constantinescu at the Botanical Museum, Uppsala, Sweden. A voucher specimen was deposited at the Herbarium UPS, in Uppsala under the number UPS F-118873. To our knowledge, this is the first report of P. petroselini on parsley in Sweden. References: (1) E. Bèliard and J. Thibault. Phytoma 554:2, 2002. (2) O. Constantinescu. Taxon 54:813, 2005. (3) C. Crepel and S. Inghelbrecht. Plant Dis. 87:1266, 2003. (4) A. de Bary, Ann. Sci. Nat. Bot., Sér. 4, 20:5, 1863.

Minor gland saliva flow rate and proteins in subjects with hyposalivation due to Sjogren's syndrome and radiation therapy.

In this study, the secretion rate and IgA, albumin and lactoferrin concentrations in minor labial and buccal gland saliva were investigated in individuals with hyposalivation due to primary Sjogren's syndrome (pSS; 10 subjects) or head and neck radiation therapy (RT; 10 subjects) and in their matched controls. Whole saliva was similarly examined. The minor gland saliva flow was measured using the Periotron method. IgA, albumin and lactoferrin concentrations were analysed by ELISA techniques. A general finding was that the flow rate and protein concentrations were lower in labial than in buccal gland saliva. In both hyposalivation groups, the labial minor gland saliva secretion rate was lowered compared to their respective controls. The buccal gland saliva flow rate was significantly reduced in the RT group only. IgA and albumin concentrations were not different from the controls in the labial secretions. The concentration of lactoferrin was increased in the RT group. In buccal saliva, the concentrations of all proteins examined but pSS IgA, were increased compared to the controls. Reduced flow rate and increased protein concentrations were seen for whole saliva where the lactoferrin concentration was higher in RT than in pSS subjects. Thus, our findings suggested that minor gland saliva flow rate and protein concentrations are affected in RT and pSS subjects and to highest extent in the former.

Oral bacteria and clinical variables in dependent individuals at a special facility.

The oral health of dependent residents at special facilities has often been reported as being poor, but it is difficult to relate oral health to general health and define the need for oral health care. Microbiological analyses of the oral flora have been suggested as a suitable method for evaluating oral health in this group of patients. A study was performed at a nursing facility where 33 individuals participated. The aim was to describe their oral flora in relation to other health variables and to classify the residents on different risk levels. An oral examination of the residents was made at the facility, together with a 3-day food record and an oral microbiological analysis. The analysis classified the residents in different categories according to both acid-producing bacteria and the flora correlated with a reduction in general health. The categories were based on previous studies conducted at the Department of Microbiology (Faculty of Odontology in Göteborg). The present study revealed that the level for acid-producing bacteria was high in 12 individuals and the micriobial level according to decreased general health was high in seven individuals. A high level of acid-producing bacteria was related to functional impairment, which was in turn related to nutritional problems and help with oral hygiene. The microbial level according to the reduction in general health did not significantly correlate with other variables.

Chemical anoxia delays germ cell apoptosis in the human testis.

An understanding of testicular physiology and pathology requires knowledge of the regulation of cell death. Previous observation of suppression of apoptosis by hypoxia suggested a role for ATP in germ cell death. However, the exact effects of ATP production on germ cell death and of apoptosis on the levels of ATP and other adenine nucleotides (ANs) have remained unclear. We investigated the levels of ANs during human testicular apoptosis (analyzed by HPLC) and the role of chemical anoxia in germ cell death (detected by Southern blot analysis of DNA fragmentation, in situ end labeling of DNA, and electron microscopy). Incubation of seminiferous tubule segments under serum-free conditions induced apoptosis and concomitantly decreased the levels of ANs. Chemical anoxia, induced with potassium cyanide (KCN), an inhibitor of mitochondrial respiration, dropped ATP levels further and suppressed apoptosis at 4 h. After 24 h, many of the testicular cells underwent delayed apoptosis despite ATP depletion. Some cells showed signs of necrosis or toxicity. The addition of 2-deoxyglucose, an antimetabolite of glycolysis, did not alter the results obtained with KCN alone, whereas a toxic concentration of hydrogen peroxide switched apoptosis to necrosis. In most of the testicular cells, mitochondrial respiration appears to play a crucial role in controlling primary cell death cascades. In the human testis, there seem to be secondary apoptotic pathways that do not require functional respiration (or ATP).

Oral microbiota associated with hyposalivation of different origins.

We analysed and compared the oral microbial flora in four groups with hyposalivation caused by radiation therapy (RT), primary Sjögren's syndrome (pSS), medication or unknown factors (Unknown), or neuroleptic treatment (Neuro). A control group with normal salivary secretion was also included. The subjects included were 54 +/- 8 years old and had 25 +/- 4 teeth. We analysed their microflora in rinsing samples using a cultivation technique. A marked increase in Lactobacillus spp. and Candida albicans was characteristic of the RT group. In the pSS group, 85% of subjects had high numbers of mutans streptococci despite good oral hygiene, frequent dental visits and fluoride use. The Unknown group had an oral flora similar to that of the controls. In the Neuro group, with a stimulated secretion rate similar to that of the Unknown group, the numbers of aciduric and acidogenic microorganisms were close to those in the pSS group. The results indicate that changes in the oral microflora associated with hyposalivation are related to the reason for the hyposalivation rather than to the magnitude of the decrease in the salivary secretion rate.

Detection of cytolethal distending toxin activity and cdt genes in Actinobacillus actinomycetemcomitans isolates from geographically diverse populations.

A cytolethal distending toxin (CDT) found in Actinobacillus actinomycetemcomitans inhibits the eukaryotic cell cycle, which may contribute to the pathogenic potential of the bacterium. The presence of the cdtABC genes and CDT activity were examined in 40 clinical isolates of A. actinomycetemcomitans from Brazil, Kenya, Japan and Sweden. Thirty-nine of 40 cell lysates caused distension of Chinese hamster ovary cells. At least one of the cdt genes was detected in all strains examined. The three cdt genes were detected, by PCR, in 34 DNA samples. DNA from one strain from Kenya did not yield amplicons of the cdtA and cdtB genes and did not express toxic activity. Restriction analysis was performed on every amplicon obtained. PCR-RFLP patterns revealed that the three cdt genes were conserved. These data provided evidence that the cdt genes are found and expressed in the majority of the A. actinomycetemcomitans isolates. Although a quantitative difference in cytotoxicity was observed, indicating variation in expression of CDT among strains, no clear relationship between CDT activity and periodontal status was found.

Lactoferrin, amylase and mucin MUC5B and their relation to the oral microflora in hyposalivation of different origins.

There are several reasons for hyposalivation, each affecting the salivary composition in different ways. The aim of this study was to analyze and compare lactoferrin, amylase and mucin MUC5B in stimulated whole saliva collected from subjects with hyposalivation of different origins and to relate the results to the presence of some microbial species associated with oral disorders. Albumin was determined as a marker of serum leakage. The characteristic feature for subjects with radiation-induced hyposalivation was a large increase in lactoferrin, probably due to leakage through inflamed mucosal tissues, while it was a high albumin content for the group with primary Sjögren's syndrome, probably due to disruption of the fragile mucosa. The saliva composition in subjects with hyposalivation of unknown origin or due to medicines was close to that in the healthy controls. All three hyposalivation groups tended to display a decrease in the concentrations of MUC5B and amylase. None of the microbial species analyzed (streptococci, mutans streptococci, Lactobacillus spp., Fusobacterium nucleatum, Prevotella intermedia/Prevotella nigrescens, Candida albicans, Staphylococcus aureus and enterics) correlated with concentration of MUC5B in saliva. The RT group, having the highest concentration of lactoferrin, had the lowest median number of F. nucleatum and was the only group in which median number of P. intermedia/P. nigrescens was zero.

Mathematical modelling of non-stationary fluctuation analysis for studying channel properties of synaptic AMPA receptors.

1. The molecular properties of synaptic alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA) receptors are an important factor determining excitatory synaptic transmission in the brain. Changes in the number (N) or single-channel conductance (gamma) of functional AMPA receptors may underlie synaptic plasticity, such as long-term potentiation (LTP) and long-term depression (LTD). These parameters have been estimated using non-stationary fluctuation analysis (NSFA). 2. The validity of NSFA for studying the channel properties of synaptic AMPA receptors was assessed using a cable model with dendritic spines and a microscopic kinetic description of AMPA receptors. Electrotonic, geometric and kinetic parameters were altered in order to determine their effects on estimates of the underlying gamma. 3. Estimates of gamma were very sensitive to the access resistance of the recording (R(A)) and the mean open time of AMPA channels. Estimates of gamma were less sensitive to the distance between the electrode and the synaptic site, the electrotonic properties of dendritic structures, recording electrode capacitance and background noise. Estimates of gamma were insensitive to changes in spine morphology, synaptic glutamate concentration and the peak open probability (P(o)) of AMPA receptors. 4. The results obtained using the model agree with biological data, obtained from 91 dendritic recordings from rat CA1 pyramidal cells. A correlation analysis showed that R(A) resulted in a slowing of the decay time constant of excitatory postsynaptic currents (EPSCs) by approximately 150 %, from an estimated value of 3.1 ms. R(A) also greatly attenuated the absolute estimate of gamma by approximately 50-70 %. 5. When other parameters remain constant, the model demonstrates that NSFA of dendritic recordings can readily discriminate between changes in gamma vs. changes in N or P(o). Neither background noise nor asynchronous activation of multiple synapses prevented reliable discrimination between changes in gamma and changes in either N or P(o). 6. The model (available online) can be used to predict how changes in the different properties of AMPA receptors may influence synaptic transmission and plasticity.

Deletion of one of two Escherichia coli genes encoding putative Na+/H+ exchangers (ycgO) perturbs cytoplasmic alkali cation balance at low osmolarity.

Two genes in the Escherichia coli genome, b4065 (yjcE) and b1191 (ycgO), are similar to genes encoding eukaryotic Na+/H+ exchangers. Mutants were constructed in which yjcE (GRN11), ycgO (GRF55) or both (GRD22) were inactivated. There was no change in respiration-driven Na+ efflux in any of the mutants when grown in media containing 50-500 mM Na+. The only striking finding was that growth of GRF55 was impaired at low osmolarity. In complex low-salt medium, GRF55 grew at a wild-type rate for three to four generations but then stopped; the growth was partially recovered after a pause, the length of which was dependent on salt concentration. Measurement of cytoplasmic alkali cations showed that an abrupt loss of about one-half of the intracellular K+ preceded the pause. When grown in low-salt medium with only 20 mM added Na+, GRF55 also lost the ability to maintain a sodium concentration gradient. However, this phenomenon appears to be a secondary effect of the ycgO deletion. The double mutant GRD22 has the same properties as GRF55; no additional effect was found. The data indicate that neither ycgO nor yjeE participates in respiration-driven Na+ extrusion. Instead, ycgO is required for growth at low osmolarity. Hence it is concluded that ycgO participates in cell volume regulation, and accordingly it is suggested that ycgO be renamed cvrA.