Comparison of bone remodelling around short stem and conventional straight stem in total hip replacement: a prospective randomized radiographic and dual-energy X-ray absorptiometric study.

OBJECTIVE: The aim of study was to evaluate periprosthetic bone mineral density (BMD) changes of proximal femur, osseointegration and clinical outcomes after implantation of short-stemmed and conventional straight-stemmed prostheses. METHODS: This prospective, randomized study included 50 patients with unilateral total hip replacement. The patients were randomized into 2 cohorts: patients with a cementless short stem Metha (n=25) and patients with a cementless conventional straight stem Bicontact evaluated as the control (n=25). Periprosthetic BMD changes were measured using a DEXA performed at one-week, 3-monts, 6-months and 1-year follow up. Clinical evaluation with Harris hip score (HHS) and radiographic assessment were performed through a 1 year follow up. RESULTS: Compared to 1-week postoperative assessment, there were differences in BMD changes between the groups at the final follow-up in all ROIs, with statistical significances in ROI 1, 2, 3, 6 and 7. The loss of periprosthetic BMD in all ROIs around straight stems at each time-point was observed. There was a tendency towards a regain of BMD in all ROIs at 1-year follow-up compared to the 3-months postoperative assessment with the short stems. Less pronounced bone loss was observed around the short stems that the straight stems in ROI 1 (‒2.9 % % vs ‒16.2 %), 5 (‒4.7 % vs ‒8.9 %) and 7 (‒8.6 % vs ‒20 %). The periprosthetic BMD exceeded baseline values in the short stem cohort in ROI 2 (+4.4 % vs ‒5 %), 3 (+5.6 % vs ‒2.5 %) and 6 (+4.3 % vs ‒10 %). All stems had a radiographically stable fixation. Stress shielding-related bone resorption was markedly lower in the short stem cohort. The HHS score was comparable between the two cohorts. CONCLUSION: The implant-specific stress shielding altered the proximal loading condition for both stems; however, the results of this study suggest a more physiological strain distribution with the short stems versus the straight stems (Tab. 3, Fig. 3, Ref. 25).

Antimicrobial effect of 4-hydroxybenzoic acid ester with glycerol.

WHAT IS KNOWN AND OBJECTIVES: Parabens have been commonly used as preservatives in pharmaceutical and cosmetics industries for almost 50 years. These compounds are thermostable, pH-stable and inexpensive and have a wide antimicrobial effect. The antimicrobial activity of parabens in emulsion system is limited by their poor solubility in water phase, which is increasing with the length of their alkyl chain. The aim of this work was preparation of 1-O-(4-hydroxybenzoyl)-glycerol, more hydrophilic and naturally occurring analogue of parabens, and comparison of its antimicrobial activity with commercially used parabens (4-hydroxybenzoic acid, methylparaben, ethylparaben, propylparaben). METHODS: 1-O-(4-Hydroxybenzoyl)-glycerol was obtained by the transesterification reaction of methyl paraben with glycerol. Purity was confirmed by determination of melting point and by GC/MSD. Antimicrobial activity of 1-O-(4-hydroxybenzoyl)-glycerol and commercially used parabens was determined by spectrophotometrical monitoring of microbial growth in media containing the testing substances, using spectrophotometers PowerWave XS and Cary 50 Conc. RESULTS AND DISCUSSION: 1-O-(4-Hydroxybenzoyl)-glycerol was prepared with purity >99%. This compound showed antimicrobial activity against all tested microorganisms (Staphylococcus aureus, Escherichia coli, Saccharomyces cerevisiae and Fusarium culmorum). In comparison with other tested substances, 1-O-(4-hydroxybenzoyl)-glycerol showed less inhibitory activity at the highest concentration of 20 mmol/L, with the maximum inhibitory activity ca. 70%. On the other hand, antimicrobial activity of 1-O-(4-hydroxybenzoyl)-glycerol at the lower concentrations (2·5 mmol/L, 1·25 mmol/L) was the same or, in some cases, even higher (S. aureus) in comparison with commercially used parabens. WHAT IS NEW AND CONCLUSION: A novel hydrophilic analogue of parabens was synthetized and tested for its antimicrobial activity against selected microorganisms in model system. This study confirms antimicrobial potential of 1-O-(4-hydroxybenzoyl)-glycerol, which is comparable with other commercially used parabens. Unlike commercial parabens, it is possible to expect more significant antimicrobial activity of 1-O-(4-hydroxybenzoyl)-glycerol in real emulsion systems due to the increased solubility of this substance in water phase and also the lower skin irritation.

[Our experience with the metha short hip stem]. / Nase skúsenosti s krátkym femorálnym driekom Metha.

PURPOSE OF THE STUDY: The aim of the study was to evaluate the clinical and radiographic results of total hip arthroplasty (THA) with the Metha short hip stem and their comparison with the outcomes of THA using a conventional cementless stem. MATERIAL AND METHODS: A total of 30 Metha stems and 30 standard Biocontact stems implanted in the period from 2007 to 2012 were evaluated. The Metha patient group comprised 22 women and six men, with the mean age of 58.9 ± SD 8.7 years (43-75), mean height of 164.2 ± 6.3 cm (156-178), mean body mass of 68.2 ± 12 (48-91) and mean BMI of 25 ± 3.9 (19-32). The Biocontact group included 19 women and 11 men, with the mean age of 63.6 ± 10.8 years (45-77), mean height of 166.6 ± 6.6 cm (152-175), mean body mass of 77.6 ± 13.1 (46-104) and mean BMI of 27.6 ± 4.3 (20-37). The evaluation was based on plain X-ray findings and clinical status assessed using the Harris hip score and 10-point visual analogue scale (VAS) for pain before surgery and at final follow-up. RESULTS: In the Metha group the mean pre- and post-operative Harris hip scores were 41.7 ± 9.9 (28-57) and 94.4 ± 5.1 (82-100), respectively. In the Biocontact group the values were 41.5 ± 11.9 (32-64) and 89.3 ± 11.2 (57-100), respectively. The mean VAS for low back and thigh pain improved from the pre-operative value of 7.41 ± 2.1 (4-9) to 0.56 ± 1.0 (0-3) in the Metha group and from 7.29 ± 2.2 (4-9) to 1.64 ± 1.8 (0-5) in the Biocontact group. The post-operative results in both rating systems were significantly better (p<0.05) in the Metha than the Biocontact group patients. All stems showed radiographic evidence of good osteointegration. Stem subsidence and calcar atrophy were recorded in one patient of the Metha group. In the Biocontact group stem subsidence was found in two patients and signs of stress shielding in 14 patients. DISCUSSION: Short hip stems have been introduced in THA implantation with the aim to restore physiological biomechanics as much as possible and to ensure good long-term functioning of the joint replacement as well as to save the proximal femoral bone tissue for potential THA re-implantation. Our results of short hip stem implantation presented in this study are compared with the results of relevant recently published literature. CONCLUSIONS: Short hip stems show adequate osteointegration without need for diaphyseal fixation and allow for more natural weightbearing distribution in the proximal femur. The short- and mid-term clinical results are better than with the use of conventional cementless stems. They can be recommended as an optimal choice for use in younger patients with good bone quality who are expected to require THA re-implantation.

Recent advances in computational predictions of NMR parameters for the structure elucidation of carbohydrates: methods and limitations.

All living systems are comprised of four fundamental classes of macromolecules--nucleic acids, proteins, lipids, and carbohydrates (glycans). Glycans play a unique role of joining three principal hierarchical levels of the living world: (1) the molecular level (pathogenic agents and vaccine recognition by the immune system, metabolic pathways involving saccharides that provide cells with energy, and energy accumulation via photosynthesis); (2) the nanoscale level (cell membrane mechanics, structural support of biomolecules, and the glycosylation of macromolecules); (3) the microscale and macroscale levels (polymeric materials, such as cellulose, starch, glycogen, and biomass). NMR spectroscopy is the most powerful research approach for getting insight into the solution structure and function of carbohydrates at all hierarchical levels, from monosaccharides to oligo- and polysaccharides. Recent progress in computational procedures has opened up novel opportunities to reveal the structural information available in the NMR spectra of saccharides and to advance our understanding of the corresponding biochemical processes. The ability to predict the molecular geometry and NMR parameters is crucial for the elucidation of carbohydrate structures. In the present paper, we review the major NMR spectrum simulation techniques with regard to chemical shifts, coupling constants, relaxation rates and nuclear Overhauser effect prediction applied to the three levels of glycomics. Outstanding development in the related fields of genomics and proteomics has clearly shown that it is the advancement of research tools (automated spectrum analysis, structure elucidation, synthesis, sequencing and amplification) that drives the large challenges in modern science. Combining NMR spectroscopy and the computational analysis of structural information encoded in the NMR spectra reveals a way to the automated elucidation of the structure of carbohydrates.

[Right colon cancer--clinicopathological findings]. / Cancerul colonului drept--particularitati anatomo-clinice.

BACKGROUND: The right colon cancer (RCC) has some particularities from point of view of epidemiology, clinical aspects, therapy and prognosis. MATERIAL AND METHODS: We retrospectively analyzed the patients operated in the First Surgical Unit Iasi during 2004 until 2009, for right colon cancer. The patients' data from the medical files were digitally encoded and included into a MS Access database, and statistically analyzed. RESULTS: 219 cases were included into the analysis, which represents 24.17% from all the patients with colorectal cancer. The median age was 66 years old. A palpable mass into the right abdominal quadrant was founded in 41.5% and anemia in 65.3%. Abdominal ultrasound exam has been performed in all the patients, with 71.3% sensitivity for primary tumor positive diagnosis. Resectability was 89.5% but without multivisceral resections. The intraoperative complication rate was 6.8%; postoperative morbidity was 19.4% with an incidence of anastomotic leak of 1.38%. The postoperative mortality rate was 2.77%. The mean overall survival was 40.13 +/- 1.93 months (median: 49.26). The prognosis factors for the survival rate were: histologic type of the tumor, stage and tumor grading, vascular and perineural invasion. The presence of metastasis in more than 3 lymphnodes as well as resection of fewer than 11 lymphnodes were found as negative prognosis factors for the survival rate. CONCLUSIONS: RCC has an increasing incidence and it is associated especially with elderly patients. The RCC resectability is about 90% with acceptable rates of morbidity and mortality. Perineural and vascular invasion as well as rate of positive lymphnodes and count of resected lymphnodes are prognosis factor for overall survival rate.

[The porcelain gallbladder-laparoscopic approach]. / Vezicula de portelan--abord laparoscopic.

A long time porcelain gallbladder was considered a relative contraindication to laparoscopic cholecystectomy, because of a high incidence of gallbladder cancer. From 12,000 patients underwent cholecystectomy in First Surgical Clinic of Iasi, 5 (0.04%) patients had porcelain gallbladder. All patients underwent ultrasound examen. Patients with porcelain gallbladder were classified as Type I to II according to preoperative ultrasound findings: three cases with porcelain gallbladder type I and two cases with porcelain gallbladder type II (in one case we found associated gallbladder carcinoma). We describe a three cases with porcelain gallbladder type I (complete calcification of gallbladder wall) treated by laparoscopic approach. Laparoscopic cholecystectomy was difficult because of adhesions and problems with grasping the thick gallbladder wall, but the postoperative course was uneventful. The histopathologic result of the specimen established the diagnosis of porcelain gallbladder type I and no cancer in the calcified wall of the gallbladder. We conclude based on cases presented and the literature review, although there is a high conversion rate, that patients with a type I porcelain gallbladder should be considered for laparoscopic cholecystectomy using a preoperative selection based on the ultrasound findings.

Acute appendicitis--open or minimally-invasive approach?

BACKGROUND: Although laparoscopy has become the standard approach in other procedures, this technique is not generally accepted for acute appendicitis. AIM: To evaluate the results after minimally invasive appendectomies. METHODS: All medical records of patients operated for acute appendicitis during the last year were retrospectively reviewed. We considered only patients with diagnosis of acute appendicitis confirmed by histopathology. We designed two groups: operated by open approach (OA) and operated by minimally-invasive approach (MIA). The two groups were compared for differenced in homogeneity and main end results: morbidity, mortality, hospital stay. RESULTS: The men/women ratio was 112/88 (1.27), with a mean age of 31.83 +/- 1.06 years. There were more women in the MIA and more men in the OA group, p = 0.001. The Alvarado score was significant lower in MIA group (5.69 +/- 0.24 versus 6.57 +/- 0.23, p = 0.009). Comorbidities were noted in 51% from the patients, most of them in MIA group: 58.8%; N = 60, p = 0.016. Mean operation time was similar in both groups: 36.96 +/- 1.48 in OA versus 37.03 +/- 1.39 minutes in MIA. The postoperative mortality rate was 0.5%. The postoperative morbidity rate was 12%. Even though the number of cases with postoperative complications were double in OA group (16 cases versus 8 cases in MIA group) it did not reach statistical significance, p = 0.073. Histopathological examinations revealed early acute appendicitis in 45.5% cases (N = 91), suppurative appendicitis in 46.5% (N = 93) and gangrenous appendicitis in 8% (N = 16); early acute appendicitis was more frequent in MIA group and suppurative appendicitis in OA group: p = 0.017. The hospital stay was similar in both groups: 4.34 +/- 0.39 in OA versus 3.58 +/- 0.25 days in MIA group; p = 0.103. CONCLUSIONS: MIA is a safe procedure and can be performed even in the patients with comorbidities. We didn't find any statistical significant difference from point of view of postoperative morbidity; however more postoperative complications were find in OA vs MIA group. The postoperative hospital stay was similar in both groups.

Probability current and antiresonances of particle tunneling through biased heterostructures.

A flow of independent particles, traveling across a biased heterostructure, is shown to produce an essentially constant probability current density in the gate. Based on this observation, a phenomenological boundary condition was proposed for evaluating the eigenfunctions of the Hamiltonian and for the computing the gate probability current density in a three-layer metal-oxide-semiconductor (MOS) heterostructure. Sharp antiresonances are obtained in the probability current, which are interpreted as quasi-bound states in the heterostructure. Results show that the antiresonant states should contribute the least to the gate current as the particles are strongly localized behind the interfacial barrier. The main contribution to the gate current of the MOS structure should come from the states between the antiresonances which are always supplied with particles from the bulk.

Photoluminescence of silicon nanocrystals embedded in silicon oxide.

The bonding structure and the optical properties of silicon-rich silicon oxide films which were prepared using plasma-enhanced chemical vapor deposition (PECVD) with thermal oxidation were studied in detail. The composition and bonding structures were explored using X-ray photoelectron spectroscopy (XPS). The luminescent properties were studied using Raman spectroscopy and photoluminescence (PL) measurements. Results show that high-temperature (approximately 1000 degrees C) annealing of as-deposited Si-rich silicon oxide gives rise to phase separation and formation of crystalline Si phases in the oxide films. Upon high temperature annealing, the PL (550-900 nm) intensity was significantly reduced in stoichiometric oxide or in low Si-content (prepared with [N2O]/[SiH4] gas flow ratio > 2.5) films whereas an opposite trend was found in higher Si-rich samples. Particularly, for the red band (650 nm) and the infrared band (750 nm), the PL intensity was significantly enhanced by annealing slightly Si-rich samples ([N2O] / [SiH4] = 2.5) at 1100 degrees C. This observation was explained by the formation of Si nanocrystallites via phase separation reaction and the removal of defect-related absorption centers during annealing.

Training on a virtual reality simulator--is it really possible a correct evaluation of the surgeons' experience?

UNLABELLED: Laparoscopic simulators provide a safe and efficient means of acquiring surgical skills. It is well known that virtual reality training improves the performance of young surgeons. Most of the virtual reality simulators have construct validity and can differentiate between novice and expert surgeons. However, for some training modules and trainees categories the possibility to distinguish the real surgeon's experience is still discussed. METHODS: A total of 14 young surgeons were evaluated during a 5 days postgraduate laparoscopic course using a LapSim Basic Skills, v. 3.0 simulator and a Virtual Laparoscopic Interface (VLI) hardware. The best performances of the surgeons were included in a MS Access database and statistical analyzed. RESULTS: There were 6 males and 8 women with a mean age of 30.21 +/- 1.01 years old (range 26-38). Nine surgeons (64.28%) were young residents without any laparoscopic surgical experience (group I), and the other 5, had some laparoscopic surgical experience (10 to 30 laparoscopic procedures) (group II). During the instrument navigation task we found that both hands performances were significant better in group II--the navigation time was 12.43 +/- 1.31 vs 19.01 +/- 1.40 seconds for the left hand--p = 0.006 and 13.57 +/- 1.47 vs 22.18 +/- 3.16 seconds for the right hand--p = 0.032); the right instrument angular path degree was also shorter for experienced surgeons (153.17 +/- 16.72 vs 230.88 +/- 22.6 - p = 0.017). The same data were noted for the lifting and grasping module. However, the suturing module tasks revealed contradictory results: the group I residents recorded better performances then the group II surgeons: total time--677.06 +/- 111.48 vs 1122.65 +/- 166.62 seconds; p = 0.043; right instrument path (m)--15.62 +/- 2.47 vs 25.73 +/- 3.13; p = 0.028; right instrument angular path (degree)--3940.43 +/- 572.54 vs 6595.5597 +/- 753.26; p = 0.017. CONCLUSIONS: Laparoscopic simulators are useful to evaluate the surgeons' experience; the parameters of the instrument navigation and lifting and grasping modules, which require a higher degree of eye-hand coordination, were better for residents with previous surgical experience and revealed a good transfer of training (TOT). The suturing module is less influenced by surgeons' experience. This result is probably explained by a lack of TOT.

Structure of the O-polysaccharide of Providencia alcalifaciens O8 containing (2S,4R)-2,4-dihydroxypentanoic acid, a new non-sugar component of bacterial glycans.

A glycerol teichoic acid-like O-polysaccharide was obtained by mild acid degradation of the lipopolysaccharide of Providencia alcalifaciens O8 and studied by chemical methods and NMR spectroscopy, including 2D ROESY, {(1)H,(13)C} HSQC, and HMQC-TOCSY experiments. It was found that the compound contains a new component of bacterial lipopolysaccharides: ether-linked (2S,4R)-2,4-dihydroxypentanoic acid (Dhpa), which was identified by NMR spectroscopy. The following structure of the repeating unit of the polysaccharide was established: [structure: see text]

The binary phase behavior of 1,3-dimyristoyl-2-stearoyl-sn-glycerol and 1,2-dimyristoyl-3-stearoyl-sn-glycerol.

The binary phase behavior of pure 1,3-dimyristoyl-2-stearoyl-sn-glycerol (MSM) and 1,2-dimyristoyl-3-stearoyl-sn-glycerol (MMS) was investigated in terms of polymorphism, melting and crystallization behavior, SFC, hardness and microstructure. Samples were crystallized at cooling rates of 3.0 and 0.1 degrees C/min. The asymmetric TAG demonstrated lower melting and crystallization points at both cooling rates. All samples crystallized in the beta' polymorph when cooled at 0.1 degrees C/min and in the alpha polymorph when cooled at 3.0 degrees C/min. The experimentally determined kinetic phase diagram of MSM-MMS was monotectic for both cooling rates. This data was well described by a thermodynamic model using the Bragg-Williams approximation for non-ideality of mixing and suggested that in both the solid and liquid states, like pair interactions (MSM-MSM and MMS-MMS) were favored over MSM-MMS interaction. A strong tendency to phase separation in the solid phase was also observed. For both cooling rates, the fit of the SFC (%)-time curves to a modified form of the Avrami model indicated that crystallization occurred in two distinct kinetic steps. Depressions seen in SFC did not correspond to depressions in hardness or melting temperatures.

[Struma ovarii]. / Struma ovarii.

UNLABELLED: Struma ovarii is a rare tumor in its pure form, but its true incidence is hard to estimate because of all the variation in the diagnostic criteria due to the fact that some authors reported it as within a teratoma and others only in its pure form. In general, it is an asymptomatic tumor, "benign-like" in most of the cases, and the diagnostic is based only on the histopathological findings. MATERIAL AND METHOD: This is a retrospective study of all ovarian tumors treated in our departments over a period of 11 years, from January 1, 1995 to January 1, 2006. RESULTS: All medical records of 644 patients were reviewed, of which 502 patients (77.96%) with unilateral tumors and 142 (22.04%) with bilateral involvement. 879 tumors were removed: 88.39% benign and 11.61% malignant. Struma ovarii was demonstrated in 2 patients. The only complaint in these 2 patients diagnosed and treated in our clinics was pain in the lower abdomen. The clinical examination and ultrasound suggested ovarian tumors, but the diagnosis was made on the histopathological findings. Following surgical treatment (classic or laparoscopic) the postoperative course was excellent, confirming that this approach is the only practical solution.

[Abdominal tuberculosis--a surgical reality]. / Tuberculoza abdominala--o realitate chirurgicala.

Abdominal tuberculosis is a rare disease, with non-specific findings. Peritoneal tuberculosis is a frequent cause of low gradient ascites. The records of 22 patients (Il males, 11 females, mean age 41,17 years, and range 17-74 years) diagnosed with abdominal tuberculosis (TBC) in First Surgical Clinic, "St. Spiridon" University Hospital Iasi between 1995 and 2006 were analyzed retrospectively and the literature was reviewed. From these 22 patients diagnosed with abdominal tuberculosis, there were: peritoneal TBC in 16 cases, intestinal TBC in 5 cases, mesenteric lymph nodes TBC in 1 case. The patients with intestinal TBC, were presented with complications, 2 perforations with peritonitis, 1 intestinal obstruction, and 2 as ileo-cecal "tumors" solved by right colectomy, 4 enterectomy (3 entero-enterostomies and 1 ileo-colic anastomosis). The patients with peritoneal TBC were diagnosed by laparoscopy and peritoneal biopsy in 13 cases, and by laparotomy in 3 cases. In peritoneal tuberculosis ascites was present in 15 cases. Other common findings were weight loss (12 cases), weakness (5 cases), abdominal pain (15 cases), anorexia (5 cases) and night sweat (2 cases). Only two patients had chest radiography suggestive of a new TBC lesion. In those patients with peritoneal tuberculosis, subjected to operation, the findings were multiple diffuse involvements of the visceral and parietal peritoneum, white "miliary nodules" or plaques, enlarged lymph nodes, ascites, "violin string" fibrinous strands, and omental thickening. Biopsy specimens showed granulomas, while ascitic fluid showed numerous lymphocytes. Post operatory evolution and management were applied by the TBC Medical System and the patients were treated 6 months by tuberculostatics, with favorable evolution. Abdominal tuberculosis should be considered for diagnosis, in patients with non-specific symptoms of abdominal pain, fever, loss of appetite, abdominal distension and even symptoms of acute abdomen. Laparoscopy is the best approach for peritoneal tuberculosis, and emergency surgery is necessary for acute complication like obstruction and peritonitis. Specific antituberculosis drugs are indicated in postoperative period.

New structure for the O-polysaccharide of Providencia alcalifaciens O27 and revised structure for the O-polysaccharide of Providencia stuartii O43.

The O-polysaccharide was obtained by mild acid degradation of the lipopolysaccharide from Providencia alcalifaciens O27 and studied by sugar and methylation analyses along with (1)H and (13)C NMR spectroscopy, including 2D (1)H,(1)H COSY, TOCSY, ROESY, H-detected (1)H,(13)C HSQC, and HMBC experiments. It was found that the polysaccharide is built up of linear partially O-acetylated tetrasaccharide repeating units and has the following structure: [structure: see text] where Qui4NFo stands for 4-formamido-4,6-dideoxyglucose (4-formamido-4-deoxyquinovose). The O-polysaccharide structure of Providencia stuartii O43 established earlier was revised with respect to the configuration of the constituent 4-amino-4,6-dideoxyhexose (from Rha4N to Qui4N).

Structure of the O-polysaccharide and serological cross-reactivity of the lipopolysaccharide of Providencia alcalifaciens O32 containing N-acetylisomuramic acid.

The O-polysaccharide was obtained by mild acid degradation of the lipopolysaccharide of Providencia alcalifaciens O32 and studied by sugar and methylation analyses, solvolysis with triflic acid, 1H and 13C NMR spectroscopy, including two-dimensional 1H,1H COSY, TOCSY, ROESY, H-detected 1H,13C HSQC and HMBC experiments. It was found that the polysaccharide has a branched tetrasaccharide repeating unit containing 2-acetamido-3-O-[(S)-1-carboxyethyl]-2-deoxy-D-glucose (D-GlcNAc3Slac, N-acetylisomuramic acid) with the following structure: [ STRUCTURE: SEE TEXT]. Serological studies with O-antisera showed antigenic relationships between P. alcalifaciens O32 and O29 as well as several other Providencia and Proteus strains sharing putative epitopes on the O-polysaccharides.

Structures and serology of the O-antigens of Proteus strains classified into serogroup O17 and former serogroup O35.

INTRODUCTION: Bacteria of the genus Proteus are facultative pathogens which commonly cause urinary tract infections. Based on the serological specificity of the O-chain polysaccharide of the lipopolysaccharide (O-polysaccharide, O-antigen), strains of P. mirabilis and P. vulgaris have been classified into 60 serogroups. Studies on the chemical structure and serological specificity of the O-antigens aim at the elucidation of the molecular basis and improvement of the serological classification of these bacteria. MATERIALS AND METHODS: The O-polysaccharide was prepared by acetic acid degradation of the lipopolysaccharide isolated from dried bacterial mass of each strain by hot phenol/water extraction. (1)H- and (13)C-NMR spectroscopy was used for structural studies. Serological studies were performed with rabbit O-antisera using enzyme immunosorbent assay, passive hemolysis test, and the inhibition of reactions in these assays as well DOC-PAGE and Western blot. RESULTS: Four Proteus strains belonging to serogroups O17 and O35 were found to possess similar O-polysaccharide structures, in particular having the same carbohydrate backbone built up of tetrasaccharide repeating units. However, they differ in the presence or absence of additional substituents, such as phosphoethanolamine in P. mirabilis O17 and glucose in P. penneri O17, as well as in the pattern and degree of O-acetylation of various monosaccharide residues. Serological studies also showed close relationships between the O-antigens studied. CONCLUSIONS: Based on these data it is proposed to reclassify strain P. mirabilis PrK 61/57, formerly representing the O35 serogroup, into the serogroup O17 in the Kauffman-Perch classification system of Proteus.

Structure of the O-polysaccharide from the lipopolysaccharide of Providencia alcalifaciens O29.

The O-polysaccharide was obtained by a mild acid degradation of the lipopolysaccharide of Providencia alcalifaciens O29. Structural studies were performed using sugar and methylation analyses along with 1H and 13C NMR spectroscopy, including two-dimensional 1H, 1H COSY, TOCSY, ROESY, H-detected 1H, 13C HSQC and HMBC experiments. On the basis of the data obtained, the following structure of the branched tetrasaccharide repeating unit of the O-polysaccharide was established: [structure: see text].

[Gastric stromal tumor. Case report]. / Tumora gastrica stromala. Prezentare de caz.

UNLABELLED: Gastrointestinal stromal tumors (GIST) are the most common mesenchymal tumors of the gastro intestinal tract and express the c-kit proto-oncogene protein (CD-117). We report herein a case of a 58 years old male with upper abdominal pain and anaemia. Preoperative endoscopic and barium meal exams showed a submucosal tumor in the gastric fornix. Endoscopic biopsy revealed spindle-shaped cells with elongated nuclei specific of GIST. We performed a stapled resection of the gastric fornix associated with Hiss angle reconstruction. Postoperative histologic exam revealed the same spindle-shape cells characteristic of GIST with 2-5 mitosis/50HPF. Almost all of the cells showed immunoreactivity for c-kit, CD-34 and a Ki-67 labeling index of 30%. Postoperative course was non eventful and after 3 month the patient has no recurrence. CONCLUSIONS: GIST are rare gastric tumors and are usually associated with bleeding and abdominal pain. The preoperative diagnosis is usually established by endoscopy with biopsy or endoscopic ultrasonography fine needle aspiration and barium meal exam. Only immunoreactivity is able to differentiate GIST from other mesenchymal tumors. Surgical resection is a safe and effective treatment. The chemotherapy with tyrosine kinases competitive inhibitors (e.g. imatinib mesylate) is also recommended.

The O-polysaccharide from the lipopolysaccharide of Providencia stuartii O44 contains L-quinovose, a 6-deoxy sugar rarely occurring in bacterial polysaccharides.

The O-polysaccharide (O-antigen) of Providencia stuartii O44:H4 (strain 3768/51) was obtained by mild acid degradation of the lipopolysaccharide and studied by sugar and methylation analyses along with (1)H and (13)C NMR spectroscopy, including 2D (1)H,(1)H COSY, TOCSY, ROESY, and H-detected (1)H,(13)C HSQC, and HMQC-TOCSY experiments. The O-polysaccharide was found to have a branched hexasaccharide repeating unit of the following structure: [Formula: see text].