Inositol Pyrophosphates Modulate S Phase Progression after Pheromone-induced Arrest in Saccharomyces cerevisiae

Several studies have demonstrated the activation of phosphoinositide-specific phospholipase C (Plc) in nuclei of mammalian cells during synchronous progression through the cell cycle, but the downstream targets of Plc-generated inositol 1,4,5-trisphosphate are poorly described. Phospholipid signaling in the budding yeast Saccharomyces cerevisiae shares similarities with endonuclear phospholipid signaling in mammals, and many recent studies point to a role for inositol phosphates, including InsP₅, InsP₆, and inositol pyrophosphates, in mediating the action of Plc. In this study, we investigated the changes in inositol phosphate levels in α-factor-treated S. cerevisiae, which allows cells to progress synchronously through the cell cycle after release from a G₁ block. We found an increase in the activity of Plc1 early after release from the block with a concomitant increase in the levels of InsP₇ and InsP₈. Treatment of cells with the Plc inhibitor {"type":"entrez-nucleotide","attrs":{"text":"U73122","term_id":"4098075","term_text":"U73122"}}U73122 prevented increases in inositol phosphate levels and blocked progression of cells through S phase after pheromone arrest. The enzymatic activity of Kcs1 in vitro and HPLC analysis of [³H]inositol-labeled kcs1Δ cells confirmed that Kcs1 is the principal kinase responsible for generation of pyrophosphates in synchronously progressing cells. Analysis of plc1Δ, kcs1Δ, and ddp1Δ yeast mutants further confirmed the role that a Plc1- and Kcs1-mediated increase in pyrophosphates may have in progression through S phase. Our data provide genetic, metabolic, and biochemical evidence that synthesis of inositol pyrophosphates through activation of Plc1 and Kcs1 plays an important role in the signaling response required for cell cycle progression after mating pheromone arrest.     

Prevalence and level of Listeria monocytogenes and other Listeria sp. in ready-to-eat minimally processed and refrigerated vegetables

Minimally processed and refrigerated vegetables can be contaminated with Listeria species bacteria including Listeria monocytogenes due to extensive handling during processing or by cross contamination from the processing environment. The objective of this study was to examine the microbiological quality of ready-to-eat minimally processed and refrigerated vegetables from supermarkets in Osijek, Croatia. 100 samples of ready-to-eat vegetables collected from different supermarkets in Osijek, Croatia, were analyzed for presence of Listeria species and Listeria monocytogenes. The collected samples were cut iceberg lettuces (24 samples), other leafy vegetables (11 samples), delicatessen salads (23 samples), cabbage salads (19 samples), salads from mixed (17 samples) and root vegetables (6 samples). Listeria species was found in 20 samples (20 %) and Listeria monocytogenes was detected in only 1 sample (1 %) of cut red cabbage (less than 100 CFU/g). According to Croatian and EU microbiological criteria these results are satisfactory. However, the presence of Listeria species and Listeria monocytogenes indicates poor hygiene quality. The study showed that these products are often improperly labeled, since 24 % of analyzed samples lacked information about shelf life, and 60 % of samples lacked information about storage conditions. With regard to these facts, cold chain abruption with extended use after expiration date is a probable scenario. Therefore, the microbiological risk for consumers of ready-to-eat minimally processed and refrigerated vegetables is not completely eliminated.     

Skin histology and its role in heat dissipation in three pinniped species

ABSTRACT: BACKGROUND: Pinnipeds have a thick blubber layer and may have difficulty maintaining their body temperature during hot weather when on land. The skin is the main thermoregulatory conduit which emits excessive body heat. Methods: Thorough evaluation of the skin histology in three pinniped species; the California sea lion-Zalophus californianus, the Pacific harbor seal-Phoca vitulina richardsi, and the Northern elephant seal-Mirounga angustirostris, was conducted to identify the presence, location and distribution of skin structures which contribute to thermoregulation. These structures included hair, adipose tissue, sweat glands, vasculature, and arteriovenous anastomoses (AVA). Thermal imaging was performed on live animals of the same species to correlate histological findings with thermal emission of the skin. Results: The presence and distribution of skin structures directly relates to emissivity of the skin in all three species. Emissivity of skin in phocids (Pacific harbor and Northern elephant seals) follows a different pattern than skin in otariids (California sea lions). The flipper skin in phocids tends to be the most emissive region during hot weather and least emissive during cold weather. On the contrary in otariids, skin of the entire body has a tendency to be emissive during both hot and cold weather. Conclusion: Heat dissipation of the skin directly relates to the presence and distribution of skin structures in all three species. Different skin thermal dissipation patterns were observed in phocid versus otariid seals. Observed thermal patterns can be used for proper understanding of optimum thermal needs of seals housed in research facilities, rescue centers and zoo exhibits.     

Light-activated deoxyguanosine: photochemical regulation of peroxidase activity

Photochemical activation of a deoxyribozyme with peroxidase activity was achieved by the synthesis and incorporation of a caged deoxyguanosine.     

Prevalence of mood dysfunction in epilepsy patients in Croatia

Fifty consecutive and consenting epilepsy patients from the Zagreb Epilepsy Center were examined for the presence of depressive symptoms using the Beck Depression Inventory (BDI). This questionnaire has been previously validated for use in the Croatian population. Mean age of the patients was 30.8 +/- 13.5 years, 60.4% were females. Majority of them were employed (72.9%) and single (62.5%), and 35.4% had a university degree. Most of them had complex partial seizures (n=40, 80%), and 6 (12%) were diagnosed with idiopathic generalized epilepsy. Assessment with the BDI showed that 33.3% of patients had recent depressive symptoms: 6.3% had mild depressive symptoms, 8.4% moderate and 18.6% severe depressive symptoms. Three patients (6.4%) attempted suicide in the past, two of them had current suicidal ideation, and all of them were severely depressed. This is the first and preliminary study assessing mood dysfunction in epilepsy patients in Croatia. Increased prevalence of depression in epilepsy patients suggests specific approach and need for early treatment.     

Murine cytomegalovirus m38.5 protein inhibits Bax-mediated cell death

Many viruses encode proteins that inhibit the induction of programmed cell death at the mitochondrial checkpoint. Murine cytomegalovirus (MCMV) encodes the m38.5 protein, which localizes to mitochondria and protects human HeLa cells and fibroblasts from apoptosis triggered by proteasome inhibitors but not from Fas-induced apoptosis. However, the ability of this protein to suppress the apoptosis of murine cells and its role during MCMV infection have not been investigated previously. Here we show that m38.5 is expressed at early time points during MCMV infection. Cells infected with MCMVs lacking m38.5 showed increased sensitivity to cell death induced by staurosporine, MG132, or the viral infection itself compared to the sensitivity of cells infected with wild-type MCMV. This defect was eliminated when an m38.5 or Bcl-X(L) gene was inserted into the genome of a deletion mutant. Using fibroblasts deficient in the proapoptotic Bcl-2 family proteins Bak and/or Bax, we further demonstrated that m38.5 protected from Bax- but not Bak-mediated apoptosis and interacted with Bax in infected cells. These results consolidate the role of m38.5 as a viral mitochondrion-localized inhibitor of apoptosis and its functional similarity to the human cytomegalovirus UL37x1 gene product. Although the m38.5 gene is not homologous to the UL37x1 gene at the sequence level, m38.5 is conserved among rodent cytomegaloviruses. Moreover, the fact that MCMV-infected cells are protected from both Bak- and Bax-mediated cell death suggests that MCMV possesses an additional, as-yet-unidentified mechanism to block Bak-mediated apoptosis.     

Reasons for extraction of permanent teeth in urban and rural populations of Croatia

The survey aimed to determine the reasons for extraction of permanent teeth by general dental practitioners in urban and rural population of the Senj region, Adriatic coast, Croatia. During a two-year period (1998-9), a total of 2006 teeth were extracted in both regions, in patients aged 15+. The causes were defined as follows: (1) decay or root without a crown (radix relicta), (2) periodontal disease, (3) endodontic or periapical diseases and (4) other reasons--orthodontics/prosthodontics and dental trauma. The statistical Chi-square-test was used to determine the significant difference between the populations and the sexes. Dental caries was the most frequent cause for extraction (over 50%), followed by endodontic and periapical diseases (23%) as the result of untreated caries and at the end periodontal disease (21%). Urban population more often lose teeth due to periodontal disease (22.75%) than rural (18.93%, p < 0.05). Similarly, this is more frequent in the urban male population (25.61%) than the female urban population (20%, p < 0.05). In rural areas, people more often lost teeth as a result of endodontic and periapical disease (25.85%) than in the urban locations (19.07%, p < 0.01) and this is more frequent in women from rural areas (28.37%) than the rural men (22.44%, p < 0.05). Periodontal disease was not the main cause of tooth loss in either the rural or the urban population. Dental caries and its sequel remain the most important challenge for the dental service. It also reveals the inadequacy of dental services. Education of both the population and the general dental practitioners must be conducted in order to improve oral hygiene and to insist on conservative rather than extraction therapy.     

Klatskin tumor--results of surgical therapy

Between January 1st 1990 and December 31st 1999, 24 patients affected by Klatskin tumor underwent operation in our department of surgery. According to Bismuth's classification, there were 0 (0%) type I, 5 (21%) type II, 6 (25%) type IIIa, 4 (17%) type IIIb and 9 (37%) type IV tumors. Five patients (21%) were treated by curative resection (group I) while in 14 patients (58%) palliative surgical procedure was performed (group II). In 5 cases (21%) the extension of malignancy did not allowed any procedure (group III). Curative resection for malignant tumors of the hepatic duct bifurcation included wide tumor excision and bile duct resection at the liver hilum (with wedge hepatic resection in one patient) and creation of biliary-enteric anastomosis. Palliative surgical procedure included stent insertion. Jaundice was completely relieved in all patients undergoing resection, since 3 patients (21%) after stenting hadn't satisfactory biliary drainage. There was 1 (20%) perioperative death in the group 1, while in group 2, 5 patients (36%) died postoperatively. In this series, the mean postoperative survival of all patients was 16 months. The mean postoperative survival of patients undergoing localized tumor resection with curative intent was 38 months, in contrast to 10 months for those undergoing operative stent insertion. in addition, only 1 patient from group III, in whom only exploratory surgery were performed survived 7 months, while other 4 patients died in the hospital. This retrospective review suggests that aggressive surgical treatment could improve survival and quality of life in patients suffering from Klatskin tumor.     

Dental evidence of exhumed human remains from the 1991 war in Croatia

The aim of this paper is to present the post mortem dental evidence and dental health of the victims exhumed throughout the territories of Croatia that was temporarily occupied during the war. A total number of 62,432 teeth out of 1,253 human bodies exhumed from 5 different counties were analyzed. The majority of victims inhabited those areas before 1991. Post mortem dental characteristics were analyzed according to the American Board of Forensic Odontology and WHO methodology. The results show the highest level of the dental health before 1991 in the Vukovarsko-Srijemska County. The decayed (D), missing (M), filling (F), teeth (T), DMFT of that County was at the lowest level i.e. at 5.2. In all of the other counties, it was always between 6 and 12. The material most frequently used for the dental fillings was amalgam. Its highest frequency level was recorded in the County 4 (8%) and lowest in the County 1 (1.5%), p<0.001. The most frequent prosthodontic appliances were acrylic dentures. Their frequency was lowest in the County 5 (1.3%) and highest in the County 3 (11.6%), p<0.001. Determination of sex and dental age showed that victims were mostly men (79%) of middle and elderly age (89%). Teeth were useful also for monitoring of the quality of exhumations--taking into consideration number of empty dental sockets. The highest number of empty dental sockets was recorded in the County 3 (40.4%) and lowest in the County 1 (13.5%), p<0.001. Even after many years in the soil, teeth proved to be the most preserved human organs and valuable indicators of identity as well as of the way of life before death.