Trends in designing microbial silage quality by biotechnological methods using lactic acid bacteria inoculants: a minireview.

Ensiling is one of the best known method to preserve fodder. The forage before ensiling intended for silages usually contains a low number of lactic acid bacteria (LAB), so it is necessary to apply starter cultures of selected strains. Traditionally, LAB starter cultures were applied to lower the pH by producing lactic acid and to inhibit the growth of undesirable epiphytic microorganisms by competing for nutrients. Nowadays, LAB inoculants have become an effective tool for creating microbial quality of silages by selecting species with extraordinary features. Epiphytic microflora characteristic of plant material used for the production of silages and the sources of undesirable microflora in the ensiling process are discussed. This review focuses on the most frequently studied issues related to the microbial silage quality and the recent trends in increasing the quality by LAB inoculants, with respect to recent directions for selecting types of modern LAB for inoculation. Among them, the main trends described were prevention of the growth of filamentous fungi and detoxification of mycotoxins by LAB inoculants, inhibition of yeast growth by LAB present in preparations and limiting the development of pathogenic bacterial microflora through controlled fermentation with the participation of LAB and the presence of their metabolites.

Genetic variability in hepatitis C virus and its role in antiviral treatment response.

Hepatitis C virus (HCV) is a major health problem worldwide, infecting an estimated 170 million people. The high genetic variability of HCV contributes to the chronicity of hepatitis C. Here, we report results from a large-scale sequence analysis of 67 patients infected with HCV genotype 1, 23 with subtype 1a and 44 with subtype 1b. Two regions of the HCV genome were analysed in samples prior to combined therapy with alpha interferon plus ribavirin, one compressing the hypervariable regions (HVR1, HVR2 and HVR3) of the E2 glycoprotein and another one including the interferon-sensitive determining region (ISDR) and the V3 domain of the NS5A protein. Genetic diversity measures showed a clear tendency to higher genetic variability levels in nonresponder patients to antiviral treatment than in responder patients, although highly disperse values were present within each response group for both subtypes. A more detailed analysis of amino acid composition revealed the presence of several subtype-specific variants in a few positions, but no discriminating positions between responder and nonresponder patients were detected. Our results also revealed that most amino acid positions were highly conserved, especially for subtype 1a. We conclude that the outcome of the antiviral treatment might depend not only on the nature of one or a few independent positions, but more likely on the combination of several positions along the HCV genome. Moreover, the own host's ability to generate an appropriate systemic response, in combination with the action of antivirals, is also likely to be essential for treatment outcome.

Lipofuscin, homocysteine and tissue polypeptide specific antigen in gestational hypertension.

OBJECTIVE: The aim of this study were to assess the levels of lipofuscin (parameter of oxidative stress), homocysteine (as a marker of vascular injury) and tissue specific antigen - TPS - (as a marker of cell proliferation) in relation to arterial pressure of pregnant woman. STUDY DESIGN: Healthy pregnant women (n=18), women with mild 140/90=< RR<160/100 (n=19), and severe 160/100=

The size of selected human skull foramina in relation to skull capacity.

An anatomical study was undertaken in order to investigate whether the sizes of selected human skull foramina with significant venous compartments correlated significantly with skull capacity. A total of 100 macerated human skulls were examined to determine the diameter of the foramina and the skull capacity. Measurements of the surface area of the foramina were made using a computerised digital analysis system. Only the size of the hypoglossal canal and jugular foramen were found to correlate significantly with the capacity of the skull. This correlation, together with the considerable size of the hypoglossal canal, indicated its important role in the venous drainage of the brain. There was considerable centralisation of venous outflow from the brain, with 60% of the area of all venous foramina of the skull occupied by jugular foramina. Asymmetry between the right and left jugular foramina was identified, with an average ratio of 1.6 (ranging between 1 and 3.47). In the case of right-sided domination the correlation between the skull capacity and the size of both jugular foramina was negative (the larger the skull cavity, the less the asymmetry), while in the case of left-sided domination the correlation was positive. Perhaps the left-sided domination is less advantageous for the haemodynamics of blood outflow, as the left brachiocephalic vein is longer and is often compressed by the sternum and aortic arch.

Inhibition of spontaneous induction of lambdoid prophages in Escherichia coli cultures: simple procedures with possible biotechnological applications.

BACKGROUND: Infections of bacterial cultures by bacteriophages are serious problems in biotechnological laboratories. Apart from such infections, prophage induction in the host cells may also be dangerous. Escherichia coli is a commonly used host in biotechnological production, and many laboratory strains of this bacterium harbour lambdoid prophages. These prophages may be induced under certain conditions leading to phage lytic development. This is fatal for further cultivations as relatively low, though still significant, numbers of phages may be overlooked. Thus, subsequent cultures of non-lysogenic strains may be infected and destroyed by such phage. RESULTS: Here we report that slow growth of bacteria decreases deleterious effects of spontaneous lambdoid prophage induction. Moreover, replacement of glucose with glycerol in a medium stimulates lysogenic development of the phage after infection of E. coli cells. A plasmid was constructed overexpressing the phage 434 cI gene, coding for the repressor of phage promoters which are necessary for lytic development. Overproduction of the cI repressor abolished spontaneous induction of the lambda(imm434) prophage. CONCLUSIONS: Simple procedures that alleviate problems with spontaneous induction of lambdoid prophage and subsequent infection of E. coli strains by these phages are described. Low bacterial growth rate, replacement of glucose with glycerol in a medium and overproduction of the cI repressor minimise the risk of prophage induction during cultivation of lysogenic bacteria and subsequent infection of other bacterial strains.

[A case of cancer transformation of planocellular papilloma of the lip into squamous cell carcinoma]. / Przypadek przemiany nowotworowej brodawczaka plaskonablonkowego wargi dolnej w raka plaskonablonkowego kolczystokomórkowego.

Authors presents the case of cancer transformation papilloma planoepithelial of lip into squamous cell carcinoma in 26-years old man. They give attention to necessity of radical remove all changes around the lips. It is especially important because of possibility of cancer transformation in every case of papilloma of lip.

[Giant tonsillolith simulating peritonsillar abscess]. / Olbrzymi kamien migdalka imitujacy ropien okolomigdalkowy.

The authors describe a tonsillolith detected by a 70-year-old man with odynophagy and a history of often tonsillar infections. A diagnosis of peritonsillar abscess was first made. The large concrement was yellowish-gray, measured 41 x 21 x 19 mm, which was one of the largest reported case in the world.

[The case of throat tumor caused by elongated styloid process]. / Przypadek guza gardla w przebiegu zespolu przedluzonego wyrostka rylcowatego.

The authors describe an unusually case of throat tumor and dyspnea in course of Elongated Styloid Process Syndrome. They pay attention to X-ray examination, including CT, in correct diagnosis.

Replication of oriJ-based plasmid DNA during the stringent and relaxed responses of Escherichia coli.

The oriJ-based plasmids contain the origin of DNA replication from the cryptic Rac prophage, present in the chromosomes of most Escherichia coli K-12 strains. The organization of the oriJ replication region resembles that of the bacteriophage lambda, although sequence similarity is small. Here we investigated the regulation of replication of the oriJ-based plasmid in E. coli relA(+) and relA(-) hosts during amino acid starvation and limitation, i.e., during the stringent and relaxed responses. We found that, contrary to plasmids derived from phage lambda, replication of the oriJ-based plasmid proceeds efficiently during both stringent and relaxed responses. On the other hand, density shift experiments and measurement of the stability of a putative replication initiator protein (the lambda O protein homologue) suggest that this replication may be carried out by the heritable replication complex, as previously demonstrated for lambda plasmids. We demonstrate that contrary to bacteriophage lambda p(R) promoter, an analogous promoter from the oriJ region is activated rather than inhibited at increased ppGpp levels. We propose that various responses of these promoters (p(R) and p(R-Rac), which are necessary for transcriptional activation of orilambda and perhaps oriJ, respectively) to ppGpp are responsible for differences in the replication regulation between orilambda- and oriJ-based plasmids during the stringent response.

[An isolated case of laryngeal sarcoidosis]. / Przypadek izolowanej sarkoidozy krtani.

Sarcoidosis is a disease of unknown etiology characterized by non-caseating granulomatous inflammation of various organs, but most frequently involving the lungs of young adults. Sarcoidosis is seldom seen by ear, nose, throat and larynx. The isolated case of sarcoidosis of the larynx is very rare. We present a case of histologically confirmed sarcoidosis of the vocal cord. The clinical aspects, diagnostic problems and therapeutical possibilities of this rare disease are described.

[A case of choanal polyp in a man with aspirin triad and pollinosis]. / Przypadek olbrzymiego polipa choanalnego u chorego z triada aspirynowa i pylkowica.

The authors describe a case of a man with a large choanal polyp descending into the hypopharynx. The man presented additional symptoms of full aspirin intolerance and pollinosis caused with grass pollen antigens. The Caldwell-Luc procedure was performed and the choanal polyp was successfully removed through the mouth. Postoperatively treatment with leukotriene antagonists and with an intranasal steroids with positive clinical effect was begun. However the patient discontinued the therapeutic process causing polyp recurrence within a short time.

Production and purification of SV40 major capsid protein (VP1) in Escherichia coli strains deficient for the GroELS chaperone machine.

Production of the major capsid protein of SV40, VP1, is of great interest for the study on capsid assembly in vitro. Production of soluble His6-VP1 in Escherichia coli strains deficient in the GroELS chaperone machine was substantially higher than in the wild-type strain. The His6-VP1 produced in a groEL mutant strain was readily purified. The protein was able to form higher-order structures as evidenced by analysis of the soluble fraction by gel filtration, by sedimentation in sucrose gradient, and by electron microscopy. We propose the use of groE mutants for the production of the major capsid protein of SV40 and perhaps also other papovaviruses.

[A incidence of cancer in the lateral side of the neck in a 65-year-old woman]. / Przypadek raka w torbieli bocznej szyi u 65-letniej kobiety.

Branchiogenic carcinoma is a rare condition and should not be diagnosed in the absence of the criteria laid down by Dr Hayes Martin. The authors describe a 65 year-old woman with a cystic mass on the side of the neck. The woman was admitted to the hospital for possible branchial cyst. The histopathological analysis showed a carcinoma developed on a branchial cyst. The authors stress the importance of careful and repeated clinical examinations, which exclude the possibility of a primary tumor of other localization.

[Granular cell tumor of the larynx]. / Miesniak ziarnistokomórkowy krtani.

Granular cell tumor is an unusual growth of probably neuroectodermal histogenesis, first reported by Abrikossoff in 1926 with the name of myoblastenmyoma. Authors described a case of a 54 year man with laryngeal seat of granular-cell myoblastoma. In this case Abrikossoff tumor was located in the right vocal chord. The tumor was treated successfully surgically by microlaryngoscopy. The etiology, clinical features and diagnostic difficulties are discussed.

Altered biological properties of cell membranes in Escherichia coli dnaA and seqA mutants.

We present evidence that biological properties of cell membranes are altered in dnaA and seqA mutants of Escherichia coli relative to wild-type bacteria. We found that bacteriophage lambda forms extremely large plaques on the dnaA seqA double mutants. On the single mutants, dnaA and seqA, the plaques are also bigger than those formed on the wild-type host. However, no significant differences in intracellular phage lambda development were observed between wild-type and mutant hosts, indicating that differences in burst size do not account for the observed differences in plaque size. On the other hand, more efficient release of the phage lytic proteins and/or higher sensitivity of the cell membranes to these proteins may result in more efficient cell lysis. We found that the efficiency of adsorption of bacteriophage lambda to the dnaA seqA mutant cells is decreased at 0 degrees C , but not at 30 degrees C, relative to the wild-type strain. A considerable increase in the permeability of membranes of the mutant cells for beta-galactosidase is demonstrated. The dnaA and seqA mutants are more sensitive to ethanol (an organic solvent) than wild-type bacteria, and the seqA strain and the double mutant dnaA seqA are very sensitive to deoxycholate (a detergent). We conclude that lesions in the genes dnaA and seqA result in alterations in cell membranes, such that the permeability and possibly also other properties of the membranes are significantly altered relative to wild-type bacteria.

[A case of hamartoma in the larynx]. / Przypadek guza hamartoma w krtani.

The authors describe a rare case of hamartoma in the larynx of a 31 years old man. The egg sized tumor was situated in the left aryepiglottic fold filling the lower pharyngeal space. The unfortunate location, patient disdain as well as late diagnosis and proper management caused the histologically benign tumor to enlarge and block the laryngeal entrance that endangering life. After initial tracheotomy the tumor was successfully removed through the mouth.

Biochemical and genetic analysis of lambdaW, the newly isolated lambdoid phage.

Otherwise isogenic Escherichia coli CP78 (relA+) and CP79 (relA-) strains are commonly used in studies on the stringent control, the bacterial response to amino acid starvation. We found that these strains are lysogenic for a phage which is spontaneously induced with a low frequency, producing virions able to infect other E. coli strains. Genetic studies, restriction analysis of the phage DNA genome, and electron microscopy revealed that this phage is very similar to, but not identical with, bacteriophage lambda. We called the newly isolated phage lambdaW, and found that most of CP78/CP79 ancestor strains are lysogenic for this phage.

Rapid degradation of polyadenylated oop RNA.

The oop RNA is a short (77 nucleotides (nt)) transcript encoded by bacteriophage lambda which acts as an antisense RNA for lambda cII gene expression. Recently we demonstrated that oop RNA is specifically polyadenylated at its 3' end by poly(A) polymerase I (PAP I), the pcnB gene product. Here we demonstrate that the half life of oop RNA is 3 times longer in the pcnB mutant relative to the pcnB+ host, indicating that polyadenylation of this transcript causes its accelerated degradation. Although it was proposed that polyadenylation of RNAs in bacteria leads to their enhanced degradation, in most cases stabilization of these molecules was observed only when other mutations (pnp, rnb and rne) were present in the pcnB- strain. Therefore it seems that oop RNA may serve as a very useful model in further studies on molecular mechanisms of RNA polyadenylation and degradation in bacteria. Analysis of oop RNA and its degradation product isolated from Escherichia coli cells suggests that both polyadenylated and non-modified oop transcripts can act as antisense RNA.

Polyadenylation of oop RNA in the regulation of bacteriophage lambda development.

We have shown that Escherichia coli pcnB mutants are lysogenized by bacteriophage lambda with lower efficiency as compared to the pcnB+ strains. Our genetic analysis revealed that expression of the lambda cII gene is decreased in the pcnB mutants. However, using various lacZ fusions we demonstrated that neither activities of pL and pR promoters nor transcription termination at tR1 were significantly impaired in the pcnB- host. On the other hand, we found that oop RNA, an antisense RNA for cII expression, is involved in this regulation. Primer protection experiments revealed that oop RNA was polyadenylated and that this polyadenylation was impaired in the pcnB mutant. We found that the oop RNA was more abundant in the pcnB mutant than in the pcnB+ strain. Furthermore, we showed that activity of the pO promoter was not stimulated in the pcnB mutant. Such findings indicated that degradation of oop RNA in the pcnB strain was slower because of inefficient polyadenylation, which could lead to more effective inhibition of cII expression by the antisense oop RNA, resulting in less efficient lysogenization of the host. The oop RNA was found previously to play a role in phage lambda development only under conditions of overproduction of this transcript. Here we demonstrate for the first time, the physiological function of oop RNA in lambda development, confirming that this short transcript plays an important role in the negative regulation of cII gene expression during lambda infection. Moreover, polyadenylation of oop RNA is one of very few known examples of specific RNA polyadenylation by PAP I in prokaryotic cells and its role in gene expression regulation.

Guanosine tetraphosphate (ppGpp)-mediated inhibition of the activity of the bacteriophage lambda pR promoter in Escherichia coli.

It was previously demonstrated that the activity of bacteriophage lambda promoter pR is decreased in wild-type Escherichia coli cells starved for amino acids (during the stringent response). Since pR activity is necessary for the transcriptional activation of ori lambda, this leads to inhibition of the replication of plasmids derived from phage lambda. These results led to the proposal that the pR promoter susceptible to control by the stringent response. However, subsequent studies demonstrated that this promoter is activated by the host dnaA gene product and since the dnaA promoter was reported to be controlled by the stringent response, it is possible that the inhibition of pR activity in amino acid-starved cells is indirect, and results from the impairment of DnaA-mediated transcriptional activation. Here we present evidence that pR is negatively regulated by ppGpp, even when DnaA protein is provided in excess as well as in cells devoid of DnaA function. We have checked that the level of ppGpp is increased during prolonged (up to 4 h) starvation for isoleucine in relA+ cells but not in the relA- mutant. At the same time we observed inhibition of lambda plasmid replication during the stringent, but not relaxed, response, even when DnaA was overproduced. Finally, we found that the activity of a pR-lacZ fusion is inhibited after gratuitously induced overproduction of ppGpp in unstarved cells, irrespective of the status of the dnaA gene product. We conclude that the activity of the pR promoter is inhibited directly by ppGpp.