The presence of antibiotic resistance genes in coastal soil and sediment samples from the eastern seaboard of the USA.

Infections from antibiotic resistant microorganisms are considered to be one of the greatest global public health challenges that result in huge annual economic losses. While genes that impart resistance to antibiotics (AbR) existed long before the discovery and use of antibiotics, anthropogenic uses of antibiotics in agriculture, domesticated animals, and humans are known to influence the prevalence of these genes in pathogenic microorganisms. It is critical to understand the role that natural and anthropogenic processes have on the occurrence and distribution of antibiotic resistance in microbial populations to minimize health risks associated with exposures. As part of this research, 15 antibiotic resistance genes were analyzed in coastal sediments and soils along the eastern seaboard of the USA using presence/absence quantitative and digital polymerase chain reaction assays. Samples (53 soil and 192 sediment samples including 54 replicates) were collected from a variety of coastal settings where human and wildlife exposure is likely. At least one of the antibiotic resistance genes was detected in 76.4% of the samples. Samples that contained at least five or more antibiotic resistance genes (5.7%) where typically hydrologically down gradient of watersheds influenced by combined sewer outfalls (CSO). The most frequently detected antibiotic resistance target genes were found in 33.2%, 34.4%, and 42.2% of samples (target genes blaSHV, tetO, and aadA2, respectively). These data provide unique insight into potential exposure of AbR genes over a large geographical region of the eastern seaboard of the USA.

Extracorporeal shock wave lithotripsy of parotid stones. Results of a prospective clinical trial.

The extracorporeal shock wave treatment of parotid stones is a rather new therapy. Its usefulness was determined in a prospective study. Seventy-six patients (36 female, 40 male, 2 to 80 years of age) with symptomatic, sonographically detectable solitary sialoliths of the parotid gland were treated with an extracorporeal piezoelectric shock wave therapy after unsuccessful conservative therapy (sialagogues, gland massage, bougienage of the secretory duct). At most, 3 treatments per patient were performed. Altogether, 38 of the 76 patients (50%) were free of stones and no longer suffered from complaints after completion of shock wave treatment and a mean follow-up period of 48 months (range 6 to 71 months). During the follow-up period, in no case could renewed stone formation be observed. Residual stone fragments were detectable in 20 patients (26%), but did not cause further symptoms. Thirteen patients (17%) with residual stone fragments stated a significant improvement of their complaints after therapy. Five patients (7%) did not observe any changes of their pretherapeutic complaints and underwent parotidectomy. The therapeutic success was not influenced by stone size or by stone localization within the gland. During the follow-up period, no side effects of the therapy were identified. With stones of the parotid gland, extracorporeal shock wave lithotripsy is -- after one has used conservative therapies (sialagogues, gland massage) -- the treatment of choice, avoiding in the majority of cases a parotidectomy with its operative risks (paresis of the facial nerve, Frey's syndrome).

[Color Doppler ultrasound studies of benign and malignant lymph nodes]. / Farbdopplersonographische Untersuchungen von benignen und malignen Halslymphknoten.

Color-coded duplex sonography is being increasingly used in the head and neck as another method for diagnosis of such disorders as stenosis of arteries or veins or hemangiomas. A possible additional advantage of testing is the ability to differentiate benign from malignant tumors. Since the underlying cause of a suspicious lesion is most important for treatment strategies, we investigated histologically-proven benign and malignant cervical lymph nodes for determining the value of color-coded duplex sonography. In the present study, 135 patients (45 women and 90 men; ages 30-63 years) with palpable cervical lymph nodes were examined with both ultrasound and color-coded duplex sonography. Afterwards, lymph nodes were removed by open biopsies or neck dissections. The histological results were then compared to perfusion velocities and pulsation indices from the color-coded duplex sonography. However, no significant differences were found between the benign and malignant nodes. When comparing perfusion and color, each group was seen to be non-homogeneous and no typical distribution of vascularization was demonstrable. Findings showed that color-coded duplex sonography is currently not an accurate indicator of lymph node pathology.

[Current status of minimally invasive treatment methods in sialolithiasis]. / Aktueller Stand minimal-invasiver Behandlungsverfahren bei der Sialolithiasis.

Newly available minimally invasive methods have changed established treatment of human sialolithiasis during the past several years. After basic in vitro and in vivo investigations, two systems of shockwave treatment proved to be useful for clinical application: extracorporeal shockwave lithotripsy (piezoelectric system) and intracorporeal laser lithotripsy (using a rhodamine-6G dye laser). Following our clinical experiences with these methods a differential scheme for managing sialolithiasis is recommended depending on localization of the calculi and their maximal diameters. Submandibular stones are best treated by extra-corporeal lithotripsy if the stone is located in intraglandular parts or in the gland hilum. Stones of the hilum can also be treated by laser lithotripsy. In the distal parts and near the duct orifice, papillotomy and stone extraction should be tried independent of the stone size. If the stone is located in the intraglandular parts of the duct system or in the hilum and its diameter is over 12 mm, submandibulectomy is necessary. Calculi of the parotid gland should only be treated by extracorporeal lithotripsy, regardless of size and location.

[Pneumatic intracorporeal lithotripsy of salivary calculi. In vitro and animal experiment studies]. / Pneumatische intra-korporale Lithotripsie von Speichelsteinen. In-vitro- und tierexperimentelle Untersuchungen.

BACKGROUND: The effort to use minimally invasive strategies in the treatment of human sialolithiasis in principle seems to allow the clinical application of pneumatic lithotripsy because of the small diameters of the probes involved. While this kind of therapy is already used successfully in urology, we investigated the method during in vitro and animal experiments. MATERIALS AND METHODS: The treatment of stones and tissue utilized the pneumatic lithotripter "Lithoclast". This system works with ballistic energy and is similar to a biologic "pneumatic hammer". Thirty salivary calculi were treated with pneumatic lithotripsy. Four submandibular salivary glands and their ducts were removed intraoperatively and were exposed to the pneumatic probes. Moreover, in two cases a salivary concretion was also implanted prior to pneumatic lithotripsy. In two rabbits the ducts of the parotid glands were ligated for 2 weeks. On the basis of the in vitro experiments, concretions were placed in two of the four salivary ducts. Following this, the pneumatic probes were inserted along the ducts and lithotripsy was completed. RESULTS: All of the 30 salivary calculi were reduced to sizes smaller than 1.5 mm in diameter. No macroscopic or microscopic damage was detectable while the probe was in a duct. However, in both cases with implanted calculi retropulsion of fragments occurred consequent perforation of the ducts. After application of ballistic pulses along the duct, small periductal hematoma without any perforation were detected macroscopically. Microscopically, only small bleeding was observed along the submucosa and partial loss of epithelium was found. In contrast, the pulse application to the implanted concretions lead to destruction of the calculi with perforation of the ducts as well as hemorrhage in the surrounding tissue. CONCLUSIONS: The method of pneumatic lithotripsy used in the present study resulted in sufficient destruction of salivary calculi. In vitro and in vivo lithotripsy of duct implanted calculi led to perforation of the salivary duct in all cases. Because of these results, the clinical use of this technique to treat human sialolithiasis appears to be not justified.

[Color Doppler ultrasound studies of parotid tumors]. / Farbdopplersonographische Untersuchungen von Parotistumoren.

BACKGROUND: Color-coded duplex sonography is being increasingly used in the head and neck as another method of diagnosis of, for example, stenosis of arteries or veins or of hemangioma. Moreover, it is of greatest interest in having the ability to differentiate benign from malignant tumors. Since the underlying type of tumor is directly responsible for the (operative) treatment recommended we have investigated histologically proven benign and malignant parotid tumors. PATIENTS: Thirty-six patients (20 women, 16 men, ages 32-66 years) with parotid tumors of unknown histology were examined by means of ultrasound and color-coded duplex sonography. Afterwards, tumors were treated by complete parotidectomy. Histological results were compared postoperatively to the data from the color-coded duplex sonography. MATERIALS AND METHODS: Ultrasound B sonography. All patients were examined with a "Sonoline SI-450" (Siemens), using a 7.5 MHz transducer. Color-coded sonography. The color-coded duplex sonograph used was the Quantum 2000 (Siemens). All investigations were carried out with a 7.5 MHz transducer. Criteria of color-coded duplex sonography. Criteria of the investigation were the qualitative range of color distribution as an indication of vascularization and measurement of perfusion velocity--as far as possible--with mean pulsatility indices. The mean pulsatility index represented peripheral resistance and was proportional to it. All data were collected from three areas in the center of the tumor and tumor margins, respectively. Tumors selected were 17 histologically proven pleomorphic adenomas, 15 adenolymphomas and 4 adenoid cystic carcinomas. RESULTS. In comparing perfusion velocity and mean pulsatility indices, no significant difference was detected between pleomorphic adenomas and adenolymphomas. A loss of perfusion and color was seen in both tumor types, although it occurred more often in the adenolymphomas. These cystic areas in most cases had already been clearly detected with normal B-scan sonography. In two of the four malignancies there were no obvious differences to the benign tumors. In the other two cases of malignancy a pronounced vasularization was detected and, therefore, an extended distribution of color. This finding together with decreased perfusion velocity and low mean pulsatility indices indicated low peripheral resistance. CONCLUSIONS: At this point it is not possible routinely to utilize color-coded duplex sonography as an accurate indicator of underlying pathology of parotid neoplasms. A differentiation among different types of benign tumors is not possible using the technique, nor can malignancies be recognized definitively by this method.

[Imaging superficial skin tumors of the ENT area. High frequency ultrasound in comparison with computerized tomography and magnetic resonance tomography]. / Darstellung oberflächlicher Hauttumoren im HNO-Bereich. Hochfrequenzultraschall im Vergleich mit Computertomographie und Kernspintomographie.

In order to improve the preoperative diagnosis of superficial skin tumors in the head and neck, 32 patients with 42 basal cell carcinomas, squamous cell carcinomas and malignant melanomas were investigated using different imaging techniques. All patients were examined preoperatively with high-frequency ultrasound (HFU), computed tomography (CT) and magnetic resonance imaging (MRI). New high-frequency ultrasonic scanners (15- and 20-MHz) having an axial resolution of 50-90 microns permit visualization of dermal and cartilaginous structures with an anatomical accuracy to a range of 15 mm in tissue. Exact measurement of the skin tumors and their relation to adjacent structures was feasible. Histologically different tumors could be discriminated by their echo-structure in 80% of the cases. CT and MRI provided additional information when the tumor extension perpendicular to the skin exceeded 15 mm. If tumor extension was less than 15 mm, CT and MRI were inferior to high-frequency ultrasound in the diagnosis of superficial skin tumors and did not provide any additional information. The experience reported has shown that high-frequency ultrasound is a valuable tool for preoperative evaluation of superficial skin tumors in terms of tumor extension and possible invasion of functionally and esthetically important adjacent structures. This knowledge can support preoperative planning of possible resections as well as reconstruction and may help to obtain an appropriate informed consent.

[Electrohydraulic intracorporeal lithotripsy of salivary calculi. In vitro and animal experiment studies]. / Die elektrohydraulisch-intrakorporale Lithotripsie von Speichelsteinen. In vitro- und tierexperimentelle Untersuchungen.

BACKGROUND: Extracorporeal lithotripsy is now used routinely for the treatment of salivary duct stones. The question arose whether electrohydraulic intracorporeal lithotripsy, which is applied in urology and gastroenterology, might also be useful in the treatment of this disease. Before its possible clinical application the influence of electrohydraulic intracorporeal shock waves on salivary stones in vitro and any influence on the tissue in the head and neck region (in vivo) had to be investigated. MATERIALS AND METHODS: In vitro experiments. Fifty-eight salivary stones and 11 extirpated human submandibular glands were treated by three different electrohydraulic devices. Animal experiments. Electrohydraulic shock waves were applied to the dilated Stensen's duct and other tissues (muscle, parotid gland, facial nerve) of six rabbits. RESULTS: Of 58 salivary stones, 53 (91%) were fragmented, 39 (67%) with a remaining size of less than 1.5 mm and 14 (24%) more than 1.5 mm. In 5 cases (9%) no effects were seen at all. Fragmentation occurred independent of the mineralogical components of the stone and independent of the different lithotriptors used. The smaller the probe diameter and the larger the stone, the more shock waves were needed to achieve fragmentation. With the smaller probes the stones could not be fragmented completely. In human submandibular glands, extensive tissue lesions could be evidenced macroscopically and histologically after application of electrohydraulic shock waves in vitro. Application of electrohydraulic shock waves to the dilated parotid gland duct of rabbits led to perforations of the duct after 1-5 single pulses. Lesions of nerves and blood vessels could also be observed within the duct environment. This occurred with all of the different electrohydraulic devices, probe diameters and intensities used. In our opinion the damage produced is probably the result of both the direct effect of the plasma as well as the resultant stress wave. CONCLUSION: In view of the severe damage caused to different tissues, use of the described method for the treatment of stones in the narrow human salivary ducts should be greatly restricted.

[Minimally invasive treatment of sialolithiasis using extracorporeal shock waves]. / Minimal-invasive Behandlung der Sialolithiasis mittels extrakorporaler Stosswellen.

BACKGROUND: In the past, management of sialolithiasis required surgical extirpation of the afflicted gland, in case the concrements could not be removed by dilatation or dissection of the glandular duct. The aim of the present study was to investigate the safety and efficiency of extracorporeal shockwave lithotripsy of salivary gland stones in men. PATIENTS AND METHODS: 51 patients with symptomatic solitary salivary stones which could not be removed by conservative measures received extracorporeal piezoelectric shockwave treatment. The concrements had a median diameter of 8 (4-18) mm and were located in the submandibular gland (69%) and in the parotid gland (31%). A total number of 72 shockwave treatments (maximum 3 treatments per patient) were performed under continuous sonographic monitoring. RESULTS: In 45 patients (88%) complete fragmentation of the concrements was achieved. Piezoelectric shockwave therapy was tolerated without any need for anesthesia, nor administration of sedatives or analgesics. The only untoward effects resulting from therapy were individual localized petechial hemorrhages after 10 out of 72 treatments (13%) and transient swelling of the gland immediately after shockwave application (2/72, (3%)). Twenty weeks after initial treatment 90% of the patients (46/51) were free of discomfort, and 53% of the patients (27/51) were stone free. The stone clearance rates of patients exhibiting concrements of the parotid gland (81%) were significantly higher than those of patients with stones of the submandibular gland (40%, p < 0.01). Auxiliary measures such as dilatation or dissection of the salivary duct were required only in patients suffering from concrements of the submandibular gland (20%). No long-term damage to the treated salivary gland nor to adjacent tissue structures were noted during the median follow-up period of 9 (1-24) months. CONCLUSION: Extracorporeal piezoelectric shockwave therapy promises to become a safe, comfortable and effective minimal-invasive, non-surgical treatment of salivary stones.

[Tissue reactions with administration of piezoelectric shock waves in lithotripsy of salivary calculi]. / Gewebereaktionen unter Applikation von piezoelektrischen Stosswellen zur Lithotripsie von Speichelsteinen.

Before clinical application of an extracorporeal piezoelectric lithotripter to treat sialolithiasis, tissue reaction during shockwave application was examined in vitro and in experiments with animals. Application of shockwaves to human tissue in vitro showed neither macroscopic nor microscopic effects. In animal experiments, the acute experiment (16 rabbits, Chinchilla-Bastard) revealed minor bleeding in the parenchyma of the parotid gland, while the chronic experiment (14 rabbits, Chinichilla-Bastard) revealed no morphologic tissue damage to the parotid region of the rabbit, as a result of piezoelectric shockwaves. However, when the eye was placed in the shockwave focal area and the shockwaves were transmitted via the fissura orbitalis to the endocranium, brain damage could be detected morphologically. In conclusion, the authors feel that the clinical application of extracorporeal piezoelectric fragmentation of salivary stones is justified, provided that a reliable positioning of the patient and exact sonographic location of the concrement are possible.