Inhibitory activities of propolis, nisin, melittin and essential oil compounds on Paenibacillus alvei and Bacillus subtilis

Background

Natural products represent important sources of antimicrobial compounds. Propolis and compounds from essential oils comprise good examples of such substances because of their inhibitory effects on bacterial spores, including bee pathogens.

Methods

Ethanol extracts of propolis (EEP) from Apis mellifera were prepared using different methods: double ultrasonication, double maceration and maceration associated with ultrasonication. Together with the antimicrobial peptides nisin and melittin, and compounds present in the essential oils of clove (Syzygium aromaticum) and cinnamon (Cinnamomum zeylanicum), assays were carried out on one Bacillus subtilis isolate and Paenibacillus alvei (ATCC 6344) against vegetative and sporulated forms, using the resazurin microtiter assay. Synergism with all the antimicrobials in association with tetracycline was verified by the time-kill curve method. Potassium and phosphate efflux, release of proteins and nucleic acids were investigated.

Results

EEPs showed the same MIC, 156.25 µg/mL against B. subtilis and 78.12 µg/mL against P. alvei. The peptides showed better activities against B. subtilis (MIC of 12 µg/mL for melittin and 37.50 µg/mL for nisin). Antimicrobials showed similar inhibitory effects, but cinnamaldehyde (39.06 µg/mL) showed the best action against P. alvei. Melittin and nisin showed the greatest capacity to reduce spores, regarding B. subtilis there was a 100% reduction at 6.25 and 0.78 µg/mL, respectively. Concerning P. alvei, the reduction was 93 and 98% at concentrations of 80 µg/mL of melittin and 15 µg/mL of nisin. EEPs showed the highest effects on the protein release against B. subtilis and P. alvei. Nucleic acid release, phosphate and potassium efflux assays indicated bacterial cell membrane damage. Synergism between antimicrobials and tetracycline was demonstrated against both bacteria.

Conclusion

All antimicrobials tested showed antibacterial activities against vegetative and sporulated forms of P. alvei and B. subtilis, especially nisin and melittin. Synergism with tetracycline and damage on bacterial cell membrane also occurred.

Influence of apitoxin and melittin from Apis mellifera bee on Staphylococcus aureus strains

The antibacterial activities of apitoxin, a venom produced by Apis mellifera bee, and melittin, an antimicrobial peptide from apitoxin, were tested against planktonic and biofilm states of Staphylococcus aureus methicillin-resistant (MRSA), including clinical, and enterotoxin-producing isolates. Also, the synergism of apitoxin and melittin in combination with oxacillin were evaluated as well. The induced morphological changes on S. aureus cells of both products were detected by transmission electronic microscopy (TEM). The minimum inhibitory concentration (MIC) values were 7.2 μg/mL, and 6.7 μg/mL, for apitoxin and melittin, respectively. The minimum bactericidal concentration (MBC) values were 28.7 μg/mL, and 26 μg/mL for apitoxin and melittin, respectively. The time-kill curve assays of apitoxin or melittin with oxacillin exhibited bactericidal synergism against MRSA isolates. TEM images showed cell distortion, cell disintegration with leakage of cytoplasmic content and loss of cytoplasm content. However, apitoxin and melittin did not interfere with staphylococcal enterotoxin production or release. Thus, apitoxin and melittin are potential agents against MRSA that can serve as possible models for new antibacterial drugs.

Schinus molle essential oil as a potential source of bioactive compounds: antifungal and antibacterial properties

AIMS

The study was focused on the evaluation of antimicrobial activity in vitro of the essential oil (EO) of leaves from Schinus molle against bacteria and fungi of clinical importance in the search for the discovery of new active compounds.

METHODS AND RESULTS

The chemical composition of the S. molle EO was determined by gas chromatography/mass spectrometry and its antimicrobial effect was verified by broth microdilution method. The major compounds found were β-pinene (25·23%), epi-α-cadinol (21·29%), α-pinene (18·72%), myrcene (11·54%) and sabinene (5·02%). The EO showed significant antifungal activity against Paracoccidioides brasiliensis (39·06 μg ml^-1 ), weak action against Cryptococcus neoformans (625 μg ml^-1 ) and Trichophyton quinckeanum (625 μg ml^-1 ) and was inactive against Candida sp. In the analysis of the antibacterial action, the micro-organisms tested did not show sensitivity.

CONCLUSIONS

This study showed a promising result of S. molle volatiles against the fungus P. brasiliensis, which causes paracoccidioidomycosis (PCM), a systemic mycosis of great clinical importance in Latin America.

SIGNIFICANCE AND IMPACT OF THE STUDY

The results found here are novel and encourage investigations of the compounds present in this EO, which represents a source of molecules with potential use in the treatment of PCM.

The Veneto Region's Barrett's Oesophagus Registry: aims, methods, preliminary results

BACKGROUND

The natural history of Barrett's Oeosphagus is not completely clarified and Barrett's Oeosphagus Registries are considered useful tools to expand our knowledge on this disease. A Barrett's Oeosphagus Registry has been therefore established in the Veneto Region and neighbouring provinces.

AIMS

The aims of the Registry are to assess the demographical, endoscopical and histological characteristics of Barrett's Oeosphagus patients; the prevalence of non-invasive neoplasia and Barrett's Adenocarcinoma and the timing and incidence of Barrett's Oeosphagus progression to malignancy.

METHODS

An interdisciplinary committee of endoscopists, pathologists and information technology experts was established in 2004 to design a website-based Barrett's Oesophagus Registry for the Veneto Region and neighbouring north-eastern Italian provinces. Protocols for endoscopies and biopsies and standard reports were carefully defined.

RESULTS

In the first 18 months, 397 patients with endoscopically visible and histologically proven Barrett's Oeosphagus were enrolled in the Registry; the median age of these patients was 66 years (male:female=3:1). Most patients (75%) had a Short Segment of Barrett's Oesophagus (<or=3 cm) and only 1 in 4 had a Long Segment of Barrett's Oesophagus (>3 cm). Long Segment of Barrett's Oesophagus patients were 5 years older than the Short Segment of Barrett's Oesophagus patients (p<0.05), suggesting a progression from Short Segment of Barrett's Oesophagus to Long Segment of Barrett's Oesophagus. Though no data are available on the incidence of non-invasive neoplasia or Barrett's Adenocarcinoma (i.e., progression to cancer at least 12 months after enrolment), the prevalence of neoplastic lesions (found within 12 months of enrolment) was 5% for Short Segment of Barrett's Oesophagus and 19% for Long Segment of Barrett's Oesophagus, indicating that a careful multiple-biopsy endoscopic protocol is needed, especially when Long Segment of Barrett's Oesophagus are suspected at endoscopy. The prevalence of Barrett's Adenocarcinoma among patients with non-invasive neoplasia was 1/17 cases of low-grade non-invasive neoplasia and 2/3 cases of high-grade non-invasive neoplasia, indicating that these patients require strict endoscopic and bioptic follow-up.

CONCLUSION

A regional Barrett's Oeosphagus Registry is feasible at a relatively low cost and enables significant data to be collected in a relatively short time. The use of a standardised endoscopic nomenclature and report form, a strict biopsy protocol, a standard report for pathologists improves the quality of endoscopic and histological diagnoses.

Are dyspepsia management guidelines coherent with primary care practice?

BACKGROUND

Spontaneous physician behaviour can affect guideline applicability, implementation strategies and application costs, particularly in relation to widespread pathologies chiefly managed by general practitioners (GPs). Of the array of dyspepsia management guidelines, the closest to general practice, partly owing to proposing committee composition, are the European Society for Primary Care Gastroenterology (ESPCG) guidelines.

METHODS

To evaluate variability in dyspepsia management among GPs in Padua and divergence in spontaneous prescriptive behaviour from the ESPCG dyspepsia guideline, we prospectively studied the behaviour of 39 GPs over a 3-month period of outpatient activity, through questionnaires on each consultation. Test-group representativeness was preliminarily defined in terms of antisecretory drug expenditure.

RESULTS

1790 forms on dyspepsia-related consultations were studied in a population of 51,193 registered patients; 1264 patients with a history of dyspeptic pathology consulted their GP (19% duodenal ulcer (DU), 9% gastric ulcer (GU), 54% gastro-oesophageal reflux disease (GERD), 32% non-ulcer dyspepsia (NUD), 1% cholelithiasis), while 526 patients presented with symptoms of dyspepsia with no previous gastroscopy (EGDS) (42% were aged <45 years), of whom 42% had twice consulted their GP. Empirical management by prescription of symptomatic drugs was the most common procedure in DU (33%), GU (73%) and NUD (74%) relapses. Helicobacter pylori eradication therapy was prescribed in only 2% of patients with a history of organic or functional dyspepsia. 145 patients with uninvestigated dyspepsia were referred for second-level endoscopy and 43 for H. pylori testing. Forty-four percent of endoscopies prescribed for uninvestigated patients did not comply with the ESPCG guideline; full compliance would have determined a 105% rise in endoscopies. Prescriptive variability between GPs was high (based on the Goodman-Kruskal (0.41, P < 0.001) and Cramer tests (V = 0.51, P < 0.005)) and agreement between observed and expected prescriptions according to ESPCG criteria was as low as V = 0.11. On the basis of the most frequently observed behaviours, we developed three options of the ESPCG guideline and compared them to spontaneous prescriptions.

CONCLUSIONS

Highest compliance emerged where the clinical approach for all patients with uninvestigated dyspepsia was symptomatic therapy at first presentation followed by a different attitude at second presentation, setting a higher cut-off age than in the guideline (which in our case proved, on mathematical calculation, to be 55 years).

Myxoid and round cell liposarcoma: a spectrum of myxoid adipocytic neoplasia

Myxoid and round cell liposarcoma accounts for about 30% to 35% of all liposarcomas and, even if still classified by the World Health Organization (WHO) as 2 distinct subtypes, share both clinical and morphologic features. Lesions combining both patterns are frequent and wide agreement exists in considering round cell liposarcoma as the high grade counterpart of myxoid liposarcoma. Furthermore, myxoid and round cell liposarcoma share the same characteristic chromosome change represented most frequently by a reciprocal translocation t(12;16)(q13;p11) that fuses the CHOP gene with the TLS gene. Clinically, myxoid and round cell liposarcoma tend to occur in the limbs with a peak incidence ranging between the third and the fifth decade and exhibit overall a metastatic rate of approximately 30%. A peculiar tendency to metastasize to the soft tissue is observed that should not be interpreted as multicentricity. Microscopically, purely myxoid liposarcoma is composed by a hypocellular spindle cell proliferation set in a myxoid background and associated with a varying number of monovacuolated lipoblasts. The most helpful morphologic clue is represented by the presence of a thin-walled capillary network organized in a plexiform pattern. The most important morphologic variation observed in myxoid liposarcoma is represented by the occurrence of hypercellular areas that may exhibits an undifferentiated round cell morphology. On the basis of the percentage of hypercellularity/round cell formation, a myxoid/round cell liposarcoma (more than 25% hypercellular/round cell areas) and a round cell liposarcoma (more than 75% hypercellular/round cell areas) are somewhat arbitrarily recognized. Both the recognition and the quantification of hypercellular/round cell areas represents a crucial step in the evaluation of this liposarcoma subtype because hypercellularity appears to correlate with the clinical outcome. In consideration of the intrinsic difficulty in establishing accurately the percentage of high grade areas as well as of application of different cut off values, it appears safer to consider any amount of hypercellularity as prognostically relevant. Careful as well as extensive sampling is mandatory to permit detection of the smallest amount of hypercellularity. The differential diagnosis of myxoid liposarcoma includes benign lesions, such as myxoid spindle cell lipoma, intramuscular myxoma and lipoblastoma, and malignant ones such as low grade myxofibrosarcoma, and extraskeletal myxoid chondrosarcoma. In consideration of the great morphologic variability, the application of both immunohistochemistry and genetics has proved helpful in sorting out the more challenging cases.

Well-differentiated liposarcoma (atypical lipomatous tumors)

Well-differentiated (WD) liposarcoma accounts for about 40% to 45% of all liposarcomas therefore representing the larger subgroup of adipocytic malignancies. It tends to occur equally in the retroperitoneum or the limbs followed by the paratesticular area and the mediastinum, with a peak incidence between the fifth and the seventh decades. WD liposarcoma is further subdivided in the adipocytic (lipoma-like), sclerosing, inflammatory, and spindle cell subtypes, of which the first two are by far the commoner. WD adipocytic liposarcoma is composed of a relatively mature adipocytic proliferation, featuring cell size variation as well as at least focal nuclear atypia. A varying number (from many to none) of lipoblasts may be found. Sclerosing WD liposarcoma is characterized microscopically by the presence of scattered distinctive bizarre stromal cells and multivacuolated lipoblasts set in a fibrillary collagenous background. Inflammatory liposarcoma represents a rare variant of WD liposarcoma in which a chronic inflammatory infiltrate predominates to the extent that the differential diagnosis is mainly with nonadipocytic lesions such as inflammatory myofibroblastic tumor, Castleman's disease, and Hodgkin's as well as non-Hodgkin's lymphomas. Spindle cell liposarcoma is the rarest variant and is composed neural-like spindle cell proliferation set in a fibrous and/or myxoid background and associated with an atypical lipomatous component which usually includes lipoblasts. Cytogenetically, WD liposarcoma appears to be relatively homogenous exhibiting characteristic ring as well as giant marker chromosomes containing amplified genetic material derived from the 12q13-15 chromosome region. As WD liposarcomas of any type have no potential for metastasis unless they undergo dedifferentiation, the opportunity to replace the term "WD liposarcoma" with a less frightening denomination has produced a long, sharp debate. WD liposarcoma and atypical lipoma should be considered as synonyms and their use should therefore be determined by the degree of reciprocal comprehension between the surgeon and the pathologist to prevent either inadequate or excessive treatment.

Prevalence of intestinal metaplasia in the distal oesophagus, oesophagogastric junction and gastric cardia in symptomatic patients in north-east Italy: a prospective, descriptive survey. The Italian Ulcer Study Group "GISU"

BACKGROUND

Incidence of adenocarcinoma of distal oesophagus and gastric cardia, probably arising from areas of intestinal metaplasia, has been increasing rapidly.

AIMS

To define prevalence of intestinal metaplasia of distal oesophagus, oesophagogastric junction and gastric cardia and to evaluate potential associated factors, by means of a prospective multicentre study including University and teaching hospitals, and primary and tertiary care centres.

PATIENTS

Each of 24 institutions involved in study enrolled 10 consecutive patients undergoing first-time routine endoscopy for dyspeptic symptoms.

METHODS

Patients answered symptom questionnaires and underwent gastroscopy Three biopsies were taken from distal oesophagus, oesophago-gastric junction and gastric cardia, and were stained with haematoxylin and eosin. Specimens were also evaluated for Helicobacter pylori infection.

RESULTS

A total of 240 patients (124 male, 116 female; median age 56 years, range 20-90) were enrolled in study. Intestinal metaplasia affected distal oesophagus in 5, oesophago-gastric junction in 19 and gastric cardia in 10 patients. Low-grade dysplasia was found at distal oesophagus and/or oesophago-gastric junction of 3/24 patients with intestinal metaplasia vs 2/216 without intestinal metaplasia (p<0.05). A significant association was found between symptoms and presence of intestinal metaplasia, regardless of location, and between Helicobacter pylori infection and intestinal metaplasia at oesophago-gastric junction.

CONCLUSIONS

Intestinal metaplasia of distal oesophagus, oesophagogastric-junction and gastric cardia is found in a significant proportion of symptomatic patients undergoing gastroscopy and is associated with dysplasia in many cases. Although prevalence of dysplasia seems to decrease when specialized columnar epithelium is found in short segment, or even focally in oesophago-gastric junction, these small foci of intestinal metaplastic cells may represent source of most adenocarcinomas of cardia.

Coordinated expression and amplification of the MDM2, CDK4, and HMGI-C genes in atypical lipomatous tumours

Atypical lipomatous tumours (ALTs) represent a distinctive subset of mesenchymal neoplasms featuring mature adipocytic differentiation. Most ALTs are characterized cytogenetically by the presence of supernumerary ring and/or long marker chromosomes derived from the chromosomal region 12q13-15. The 12q13-15 chromosome region contains several genes which may play an important role in human tumorigenesis. A series of ALTs was analysed by investigating the MDM2, CDK4, and HMGI-C genes and their proteins. The study was extended to a series of ordinary lipomas, to determine whether the immunohistochemical investigation of these gene products might play any diagnostic role. Cytogenetic analysis revealed the presence of various cytogenetic aberrations involving the 12q13-15 region in 11/18 (61%) lipomas and of ring chromosomes in all ALTs. Overexpression of mdm2 protein was observed in 6/12 (50%) atypical lipomatous tumours. All lipomas were mdm2-negative. cdk4 overexpression was present in 100% of ALTs. Weak cdk4 immunopositivity was detected in 2/18 (11%) ordinary lipomas in a minority of cells. HMGI-C immunopositivity was observed in 10/12 (83%) ALTs. Positive immunoreactivity was also observed in 8/18 (44%) lipomas. Southern blot analysis revealed amplification of the CDK4 and MDM2 genes in 3/5 ALTs analysed. HMGI-C was amplified in 3/5 cases and was deleted in one case. Mutation analysis of the CDK4 gene did not demonstrate any mutation. These data support the hypothesis that ordinary lipomas may form a molecular genetic and morphological continuum with ALT. At one end of the spectrum are lipomas characterized by 12q13-15 rearrangements and HMGI-C activation and at the other end are ALTs with ring chromosomes, 12q13-15 amplification with overrepresentation of the HMGI-C, CDK4 or MDM2 genes, and aberrant cdk4, mdm2, and HMGI-C protein expression. These findings not only provide insights into the molecular pathogenesis of lipomatous tumours, but also indicate that the immunohistochemical analysis of mdm2 and cdk4 may help to increase diagnostic accuracy.

Synovial sarcoma of the larynx and hypopharynx

Synovial sarcoma represents a mesenchymal malignancy of unknown histogenesis that most often occurs in the lower limbs of young adults. The head and neck region is a relatively rare location, in which the hypopharynx and larynx are, respectively, the most and least often affected anatomic sites. Histologically, synovial sarcomas are classified into monophasic and biphasic variants. Immunohistochemistry plays a major part in the differential diagnosis, enabling the demonstration of epithelial differentiation. Both monophasic and biphasic synovial sarcomas are characterized cytogenetically by the reciprocal translocation t(X;18)(p11.2;q11.2) between chromosomes X and 18. Two cases of synovial sarcoma arising in the larynx and in the hypopharynx and in which cytogenetic analysis detected a diagnostic t(X;18) chromosome aberration are reported here.

Immature teratoma of the pineal gland with isochromosome 12p

An immature teratoma arising in the pineal gland in a 27-year-old male was shown to present an isochromosome 12p as evidenced by cytogenetic and fluorescence in situ hybridization analysis. As i(12p) is characteristic of gonadal germ cell tumors, this case indicates that similar genetic pathways may operate in gonadal and intracranial teratomas.

Atypical electromechanical dissociation in a patient with recurrent pulmonary embolism

A 47-year-old man experienced recurrent pulmonary embolism resistant to aggressive medical and surgical prophylaxis. Although paraneoplastic hypercoagulability was suspected, no endoscopic or radiologic signs of malignancy were detected. Death was the result of electromechanical dissociation, which was attributed to right ventricular outflow obstruction. At autopsy, anaplastic lung carcinoma was found in the left basal segment with superimposed pulmonary infarction. A huge pedunculated thrombus was attached to the left ventricular apex and extended into the ascending aorta, obstructing the left ventricular outflow. To our knowledge, this is the first case of electromechanical dissociation due to left ventricular thrombus in a patient with pulmonary embolism. Radiologic and echocardiographic evaluation of such patients should take into account possible masking of the underlying neoplasm by embolic or hemorrhagic phenomena, or both, and the presence of left-sided cardiac thombi, which may cause catastrophic events.

[Plasmid size determination using 3 methods]

Analysis of bacterial plasmid profiles has been shown to be very important in epidemiological studies, especially those involving outbreaks of nosocomial infections. The molecular weight size of unknown plasmids is determined by comparing their band pattern obtained in agarose gel electrophoresis with those obtained with plasmids that have been used as molecular weight or size standards. In this study, we determined the size of plasmids present in clinical samples of Enterobacter cloacae comparing their electrophoresis mobility with seven plasmids of known size, using three different mathematical methods. For plasmids with molecular weight ranging from 2 kb to 100 kb. The most accurate determinations were obtained by power-function. Analyses using the exponential variables obtained with these plasmids were accurate for two types of plasmids, those with size ranging from 50 kb to 100 kb and those with size ranging from 2 kb to 30 kb. We also observed discrepancies among the methodologies described, including one used by a computer software designed for calculating the size of plasmids DNA.

[Leiomyoma of the female urethra]

Leiomyoma of the urethra is a small, benign and extremely rare tumor of mesenchymal origin. To date, about thirty cases have been reported in the literature. A case of leiomyoma of the urethral meatus that had been incidentally discovered is described. The anatomopathological aspects are presented and the clinical and therapeutic problems are discussed.

[Systemic mastocytosis with portal hypertension and hepatocellular failure]

Systemic mastocytosis is a rare disease of mast cell proliferation with cutaneous and multi-visceral involvement. Portal hypertension and ascites are rare manifestations of systemic mastocytosis. We report a case of systemic mastocytosis presenting with extensive nodular cutaneous lesions and hepatic dysfunction, manifested by portal hypertension (ascites, splenomegaly) and derangement of metabolic function (hyperammonemia, hypoalbuminemia, hypocholesterolemia), a picture resembling that of a common cirrhotic form. The correct diagnosis was established only after tissue sections were appropriately stained for mast cells. On the basis of our and other observations we suggest that systemic mastocytosis be added to the list of infiltrative diseases of the liver with potential evolution to portal hypertension and compromise of biochemical functions.

[Synovial sarcoma of the head and neck: a case report of parapharyngeal region and review of the literature]

Synovial sarcoma is a clinically and morphologically well defined entity that has been described extensively in Literature. It occurs primarily in the para-articular regions, usually in close association with tendon sheaths, bursae and joint capsules. On rare occasions it is also encountered in areas without any apparent relationship to synovial structures, as in the parapharyngeal region or the abdominal wall. It is considered the fourth most common type of sarcoma (7-10%) after malignant fibrous histiocytoma, liposarcoma and rhabdomyosarcoma. There are three histological variants: the classical biphasic, the monophasic fibrous type and the monophasic epithelial type (the biphasic and monophasic fibrous type are equally common). Clinical sign complaints are subtle and at times noted 20 years before diagnosis. The course of the disease is slow and insidious. The most typical presentation is that of a palpable deep-seated swelling or mass associated with pain or tenderness. Patients with synovial sarcoma in the head and neck (10%) tend to have difficulties in swallowing and breathing and not infrequently have alteration or loss of voice. Head and neck synovial sarcoma seem to originate from the paravertebral connective tissue spaces and manifest themselves as solitary retropharyngeal or parapharyngeal masses near the forking of the carotid. Additional cases in this general area have been reported in the soft palate, tongue, maxillofacial region, mandible corner, sternoclavicular region, scapular region and the cervical oesophagus. As in other types of sarcoma, the principal sites of metastases are the lung, but many make their appearance many years after the initial diagnosis.(ABSTRACT TRUNCATED AT 250 WORDS)

["Umbilicate" aspect of some lateral cervical adenomegalies. A possible sign of benign characterization?]

Fifty-one patients were examined by sonography for suspicious cervical adenopathies. In 11 the adenopathies, histologically benign, showed typical "umbilicate" aspect. We present this aspect as a possible benign sign and we advance a pathological interpretation.