Genetic identification of the main opportunistic Mucorales by PCR-restriction fragment length polymorphism

Mucormycosis is a rare and opportunistic infection caused by fungi belonging to the order Mucorales. Recent reports have demonstrated an increasing incidence of mucormycosis, which is frequently lethal, especially in patients suffering from severe underlying conditions such as immunodeficiency. In addition, even though conventional mycology and histopathology assays allow for the identification of Mucorales, they often fail in offering a species-specific diagnosis. Due to the lack of other laboratory tests, a precise identification of these molds is thus notoriously difficult. In this study we aimed to develop a molecular biology tool to identify the main Mucorales involved in human pathology. A PCR strategy selectively amplifies genomic DNA from molds belonging to the genera Absidia, Mucor, Rhizopus, and Rhizomucor, excluding human DNA and DNA from other filamentous fungi and yeasts. A subsequent digestion step identified the Mucorales at genus and species level. This technique was validated using both fungal cultures and retrospective analyses of clinical samples. By enabling a rapid and precise identification of Mucorales strains in infected patients, this PCR-restriction fragment length polymorphism-based method should help clinicians to decide on the appropriate treatment, consequently decreasing the mortality of mucormycosis.

[Bacterial spectra and antibiotics in odontogenic infections. Renaissance of the penicillins?]

BACKGROUND

The role played by odontogenic infection in dental, oral, and maxillofacial surgery is not to be underestimated even at the present time. An extensive, standardized, prospective study was performed with the intention of verifying the bacterial spectrum of odontogenic infections to evaluate antibiotic sensitivity.

MATERIAL AND METHODS

Bacterial spectra and resistograms of 65 patients with an odontogenic infection were analyzed in a prospective study under standardized conditions for specimen collection and transport.

RESULTS

A total of 226 bacterial strains were analyzed. The ratio between anaerobes and aerobes was approximately 2:1. The most frequent aerobes were members of the genera Streptococcus (46 isolates), Staphylococcus (10 isolates), and Neisseria (9 isolates), respectively. The anaerobic gram-positive spectrum was dominated by members of the genera Eubacterium (19 isolates), Peptostreptococcus (16 isolates), and Actinomyces (12 isolates). The most frequently isolated gram-negative anaerobes were Prevotella (46 isolates), and Fusobacterium (21 isolates). The overall resistance to antibiotics was very low: only 7.3% of all bacteria were resistant to penicillin G/V, and 8.8% showed resistance to ampicillin. The resistance rates to other beta-lactam antibiotics were 4.4% to piperacillin and 0.6% to imipenem, respectively. Penicillin G presented the highest antimicrobial activity among aerobes: only 4.5% of anaerobic strains were resistant of penicillin G. The other resistance rates of anaerobic bacteria to antibiotics were as follows: ampicillin 24%, doxycycline 34%, erythromycin 18%, and clindamycin 9.3%. Penicillin G was also highly antimicrobially active to anaerobes. The resistance rates were: penicillin G 8.1%, ampicillin 2.6%, doxycycline 9.2%, erythromycin 10.2%, and clindamycin 1.4%, respectively.

Eagle-Syndrom

A 47-year-old patient suffered from right-sided facial pain in the chin and lower cheek, hyperpathia, and difficulties in swallowing. The diagnosis of Eagle's syndrome was based on digital palpation of the bilaterally elongated styloid process and radiography. Eagle's syndrome should be considered in patients with difficulty swallowing, masticatory pain, globus sensation, and neuropathic pharyngeal or facial pain. If conservative therapy fails, selected patients may benefit from surgical excision of elongated styloid processes if pain relief by local anesthesia is proven.

Die ossäre Metastase im Oberkiefer als Erstmanifestation eines Nierenzellkarzinoms

BACKGROUND

Bone metastases in the upper jaw are relatively rare but not unusual in oral and maxillofacial surgery. In many cases finding the primary tumour is difficult because of its occult location.

CASE REPORT

We describe a 53-year-old female patient who suffered from a tumor in the oral cavity. The first histological and clinical diagnosis revealed a granuloma pyogenicum. Because of the delayed healing process another biopsy became necessary showing a metastasis of an unknown primary tumor. Diagnostic procedures detected an adenocarcinoma of the left kidney with pelvic metastases. Appropriate surgical intervention and chemotherapy were subsequently initiated.

CONCLUSION

The present case report demonstrates how difficult it can be to provide the right pathological diagnosis in biopsy material even regarding obvious malignancy. Therefore thorough diagnostic efforts are indispensable to facilitate the causal treatment of an unknown primary tumor.

Computergestützte Kaukraftanalyse bei Patienten mit Unterkieferkontinuitätsresektionen

BACKGROUND

Surgical treatment of tumors of the oral cavity often requires a segmental resection of the mandible. This always implies a considerable loss in function and aesthetics. The aim of the present study was to measure the chewing force obtained by patients after mandibular resection.

PATIENTS AND METHODS

In a group of 20 patients (twelve males, eight females, average age 59 years), chewing force were registered by means of a computerized measurement device. In 16 patients, the defect was bridged by a reconstruction plate, in three with an iliac bone graft stabilized by miniplates, and in one patient with only two miniplates.

RESULTS

The maximum value in the molar region was 186 N und the minimum was 28 N. The average bite force in the molar region reached 81.1 N (+/-46.1) with 42.9 N (+/-35.7) in the front region. The highest value was registered in a patient with an iliac bone graft without soft tissue defect. The lowest was found in patients with bony chin defects.

CONCLUSION

Based on these results, a reduction of 76% in the molar region and 59% in the incisor region was observed. These values might be helpful in providing a more realistic definition of the functional loadings found in patients after mandibular resection, which in turn may help in the development of new reconstruction devices.

Weichteilinfektionen in der Mund-, Kiefer- und Plastischen Gesichtschirurgie

BACKGROUND

Soft tissue infections in the maxillofacial region are mainly caused by Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli but also by members of the genera Enterococcus, Klebsiella, and Enterobacter, respectively.

METHODS

In a prospective study 96 patients with severe maxillofacial non-odontogenic postoperative soft tissue infections were analyzed with regard to the bacterial spectrum and resistance patterns against antibiotics. The dominating bacteria were Streptococci (25% of the isolates) and Staphylococci (24% of the isolates). In addition, members of Enterobacteriaceae were isolated in approximately 10% of the cases. The most frequent anaerobes found were as follows: Peptostreptococcus, Eubacterium, Prevotella and Fusobacterium.

RESULTS

The resistance rates against antibiotics found were: penicillin G 36%, ampicillin 42%, and doxycycline 36%. In addition, the resistance rate against erythromycin and clindamycin was 26% and 7%, respectively. No resistant strains were detected against vancomycin and teicoplanin. All anaerobes showed a low antimicrobial resistance as previously described for odontogenic infections.

CONCLUSION

In summary, soft tissue infections in the maxillofacial region present a different spectrum of bacteria in contrast to the well-investigated odontogenic infections. Antibiotic administration should be, whenever possible, performed after differentiation of involved strains and resistogram. The most promising antibiotics are imipenem, meropenem, and ciprofloxacin as well as cefotiam. Modern fluoroquinolones will be the antibiotics of the future.

Measurement of oxygen partial pressure in the mandibular bone using a polarographic fine needle probe

In this study, the oxygen partial pressure in the cancellous bone substance of the mandible was measured for the first time with a polarographic fine needle probe. This has so far only been established in soft tissue. The aim was to prove and to test the feasibility in principle of this method of measurement in order to ascertain the normal values for the O2 partial pressure in healthy bone. These values were afterwards compared with the results of measurements in areas of different pathological bone conditions in order to assess the clinical suitability of the method for "mapping" during mandibular resection. Measurements of oxygen partial pressure were made in a total of 42 patients (16 women, 26 men). Of these, 12 patients with clinically normal bones served as a control group. Seventeen patients had osteoradionecrosis following radiation treatment, and 13 patients presented with chronic osteomyelitis of the mandible. All measurements were carried out with a polarographic fine needle probe applied to the cancellous bone substance. The statistical analysis included a comparison of the mean values of the oxygen partial pressures measured. No statistical correlation between oxygen partial pressure and pH and hemoglobin values could be detected. The average oxygen partial pressure in the healthy mandibular bone was 71.4 mmHg. In non-healthy bone, the value fell to an average of 30.6 mmHg (osteoradionecrosis 32.3 mmHg, chronic osteomyelitis of the mandibular bone 28.4 mmHg). Statistically, the differences in the group values ascertained were highly significant (P < 0.005). The data found show that this method can be successfully used to detect poorly perfused bone. The values are reproducible and reflect the clinical situation. In the long term, the method appears to be a suitable diagnostic tool for assessing the oxygen supply in bone in studying various clinical problems related to bone surgery.

[Intraoperative adverse events in minor oral surgery. Risk analysis]

AIM OF THE STUDY

The aim of this prospective study was to evaluate oral surgical procedures performed as day surgery under local anesthesia. We examined patients' general condition, and besides checking for intraoperative complications we analyzed postoperative bleeding in patients with hemostatic disorders.

PATIENTS

The patient population consisted of 1540 patients (797 female, 743 male), who underwent a total of 2055 minor oral surgical procedures over a 5-year period (1998-2002). Before the treatment started a data file was made for each patient, which contained information on his or her past medical history, concomitant medication, why the operation was indicated, premedication, anesthetic and surgical techniques applied, and postoperative treatment.

RESULTS

Systemic pathologies influencing surgical decisions were found in 316 patients (20.5%), affecting 676 interventions (32.9%). In 109 patients (5.3% of the 2055) altered hemostasis was found. The surgical procedures recorded were: (operative) tooth extraction (n=394), interventions for surgical conservation of teeth (n=272), treatment for cysts (n=140), surgical revisions (n=46) and preprosthetic surgery (n=19). Passing complications, mostly systemic in nature, occurred during 27 sessions of local anesthesia (1.3%). There were 87 adverse events intraoperatively (4,2%), most of which were confined to the surgical field; specifically 15% of these complications took the form of hemorrhage. We observed no significant correlation between the occurrence of intraoperative complications and patients' gender, predisposing systemic pathologies including bleeding disorders, or age. Postoperative hemorrhage was observed significantly more frequently in patients with impaired hemostasis and required admission to hospital for inpatient treatment in 2 cases.

CONCLUSION

According to our investigation, oral surgery can be performed in patients with compromised general condition with as few intraoperative complications as in patients with no general medical problems. However, in individual cases specific risk factors can be present and oral surgery may be temporarily contraindicated, at least as day surgery.

[Mortality prognostic factors of cardiogenic shock complicating an acute myocardial infarction and treated by percutaneous coronary intervention]

OBJECTIVE

To determine the in-hospital prognosis and late outcome of cardiogenic shock complicating acute myocardial infarction treated by early (< 24 hours) percutaneous coronary intervention (PCI).

METHODS

Retrospective monocentric study of a consecutive cohort of patients undergoing early PCI (< 24 heures) for cardiogenic shock complicating acute myocardial infarction from 1994 to 2004.

RESULTS

The cohort included 175 patients (mean age = 65 +/- 14 years, 68% male). A successful PCI was obtained in 69% of patients. The in-hospital mortality was 43%. Independent risk factors associated with an increased mortality were: absence of TIMI three flow (P < 0.0001), absence of smoking (P < 0.009) and the need for mechanical ventilation (P < 0.002). Nor stent use or anti GP IIb/IIa infusions were predictors of a better outcome. At hospital discharge, mean left ventricular ejection fraction (LVEF) was 38 +/- 12%. Kaplan-Meier estimate of survival was 63% for in-hospital survivors (maximum follow-up = 9 years). Independent predictors of an impaired long-term outcome were: a LVEF < 0.3 (P < 0.028) and 3-vessel disease on coronary angiography (P < 0.004).

CONCLUSION

In-hospital mortality of patients suffering cardiogenic shock complicating acute myocardial infarction and treated by PCI remains high despite PCI improvement. The long-term survival appears, however, to be better than that of patients with coronary artery disease and low LVEF.

[Stress tests of reconstruction plates for bridging mandibular angle defects]

AIM

The aim of the present study was to evaluate the mechanical stress in reconstruction plates used for bridging mandibular angle defects and in the screw-plate-bone interface with the finite element method. Additionally, the influence of reconstruction plate geometry, screw configuration, and screw diameter upon the mechanical stress distribution was determined. Suggestions for design improvements of the plate were derived from the results.

MATERIAL AND METHODS

Based on the geometrical data of a human mandible, an angle defect bridged by a titanium reconstruction plate was generated and exposed to chewing force. The reconstruction plate was securely fixed by M 2.7 titanium screws. A variation of plate design, screw configuration, and screw diameter was carried out. The mechanical stress was calculated following the von Mises stress hypothesis.

RESULTS

Using the standard plate the mechanical stress in all components exceeded by far the ultimate tensile strength. Possible clinical consequences could be a fatigue fracture of the plate, loosening of the screw, and irreversible damage of the bone leading to infection. Increasing the screw diameter by 50% would lead to a decrease of the mechanical stress by far more than 50%. An increase of the interface area between bone and plate and a triangular screw configuration diminishes the mechanical stress further, which may consequently allow a reduction of plate thickness with better adaptation to the actual jaw geometry.

CONCLUSION

As a preliminary result the reconstruction plate could be thinned out in areas subject to less mechanical load.

Comparison of the bond strength of selected adhesive dental systems to cortical bone under in vitro conditions

The study was performed to compare the tensile bond strength attained between composite and bone and between bone and bone using two different adhesive systems (Clearfil New Bond and Histoacryl) in vitro. Sixty porcine bone specimens with a total thickness of 4.0 mm (+/- 0.5 mm) and a cortical layer of 1.5 mm (+/- 0.2 mm) were obtained under standardised conditions. Ten specimens each were assigned to four experimental groups: group A: Clearfil New Bond (bone-composite); group B: Clearfil New Bond (bone-bone); group C: Histoacryl (bone-composite); group D: Histoacryl (bone-bone). The tensile bond strength of the adhesive agents mentioned above was measured 15 min after application and also after light-curing of the composite filling material (Tetric Ceram, colour A2; groups A and C) using a universal testing machine. The tensile bond strength measured was as follows: group A 8.00 MPa (+/- 1.36 MPa), group B 6.39 MPa (+/- 2.05 MPa), group C 5.22 MPa (+/- 1.96 MPa), and group D 1.95 MPa (+/- 0.49 MPa). Tensile bond strength was significantly increased in group A compared to groups C and D (P < 0.05, Tukey's test). The values in group D were significantly reduced compared to all other groups (P < 0.05, Tukey's test). Despite the limitations of an in vitro investigation, it can be concluded that adhesive systems might be a useful alternative in bone bonding. The use of dentin adhesives seemed to produce higher bond strength to bone than that attained with the cyanoacrylate adhesive.

Stimulus complexity enhances auditory discrimination in patients with extremely severe brain injuries

There is controversy as to what extent the processing of spectrally rich sounds in the human auditory cortex is related to the processing of singular frequencies. An informative index of the function of the auditory cortex, particularly important in neurological patients, is the mismatch negativity (MMN), a component of auditory event-related potentials. In the present study the MMN was recorded in 79 patients with extremely severe diffuse brain injuries, most of them in persistent vegetative state or minimal consciousness state. Both sinusoidal ('pure') and complex musical tones were used. Different statistical approaches converged in that musical tones elicited an MMN significantly more frequently, and of a larger amplitude, than simple sine tones. This implies that using simple stimuli in clinical populations may lead to a severe underestimation of the functional state of a patient's auditory system. The findings are also in line with behavioral and physiological data indicating independent processing of complex sounds in the auditory cortex.

Temporomandibuläre Funktionsbefunde nach Dysgnathieoperationen im Vergleich zu einer bevölkerungsrepräsentativen Studie

AIM

The temporomandibular function of patients after orthognathic surgery was evaluated with the Helkimo index (D 0-III) and compared with a normal population.

PATIENTS AND METHODS

Temporomandibular disorders (TMD) were evaluated with the Helkimo index (D 0-III) in a group of patients (n=105, F=69, M=36) after osteotomies. The average follow-up time was 47 months (9-141 months). The osteotomies performed were as follows: 58 bilateral sagittal split osteotomies, 12 Le Fort I osteotomies, 22 bimaxillary osteotomies, and 13 segment-osteotomies. A control group (n=202, F=114, M=88, age 20-39 years) was examined in an epidemiological study. The statistical analysis was performed using Windows software SPSS 10.0.

RESULT

In 82.8% of the patients no symptoms or mild dysfunction were found. The comparison between the patient group (31.4%) and the control group (31.7%) revealed a similar frequency. The most frequent dysfunction was a reduced mobility of the mandible, which determined the statistical significance (p<0,05) between the patients and the control group for the dysfunction group D II and D III. The chi-square test could not detect any difference between sex and the kind of osteotomy with regard to dysfunction.