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Biomedical subjects

A Goetz

Publications and source records attributed to A Goetz.

At least 37 records · Page 2Linked to original sources
PubMed1993

Endoscopically-controlled electrohydraulic intracorporeal shock wave lithotripsy (EISL) of salivary stones.

Twenty-nine patients with salivary stones were treated with the endoscopically-controlled electrohydraulic shock wave lithotripsy (EISL). This new minimally invasive treatment of sialolithiasis is performed under local anesthesia on an outpatient basis with little inconvenience to the patient. For endoscopy, a flexible fibroscope with an additional probe to generate shock waves is placed into the submandibular duct and advanced until the stone is identified. For shock wave-induced stone disintegration, the probe electrode must be placed 1 mm in front of the concrement. The shock waves are generated by a sparkover at the tip of the probe. By means of the endoscopically-controlled shock wave lithotripsy it was possible to achieve complete stone fragmentation in 20 out of 29 patients without serious side effects. In three patients, only partial stone fragmentation could be achieved due to the stone quality. Endoscopically-controlled electrohydraulic intracorporeal shock wave lithotripsy represents a novel minimally invasive therapy for endoscopically accessible salivary gland stones. The advantage in comparison to the endoscopically-controlled laser lithotripsy will be discussed.

Endoscopes↗
PubMed1992

Microbiology, infection control, immunizations, and infectious disease exposure: education and practices in United States nursing schools.

BACKGROUND: Previous data suggest that nursing students in the United States are inadequately protected against hepatitis B. This survey focused on the immunization and education practices, infection control knowledge, and follow-up to infectious disease exposure by U.S. nursing schools. METHODS: To ascertain education requirements, immunization practices, and infectious disease postexposure follow up, a survey was sent to the director or dean of 1164 U.S. nursing schools. RESULTS: Seven hundred sixty-five schools (65.7%) responded to the survey. A microbiology course was required before clinical experience by 49% of schools. Clinical experience in the operating room was given by 16%, 65% of schools offered infectious and communicable disease courses, and 98% offered universal precaution instructions. The hepatitis B vaccine was required by 11%; 2% required yearly influenza vaccination. In a comparison of programs, the diploma schools were more likely to have written policies for infectious disease exposure follow-up and to use appropriate agencies for exposure follow-up (p = 0.0001). CONCLUSIONS: A microbiology course before clinical experience should be encouraged. Immunization policies and infectious disease exposure follow-up are currently inadequate in U.S. associate degree and baccalaureate nursing programs.

Curriculum↗
PubMed1992

Entering first-year residents' experiences and knowledge of infection control of hepatitis B and HIV, at five university-affiliated hospitals.

In 1990, the authors surveyed 149 entering first-year residents at five university-affiliated hospitals concerning the residents' experiences and knowledge of infection control. Sixty residents (40%) had experienced a needlestick injury during medical school, but only 35 of these residents (58%) had reported the mishap. One hundred thirty-nine residents (93%) had received the hepatitis B vaccine. Of those 60 who had experienced a needlestick injury, 57 (95%) had received the vaccine. Of the 149 residents, 111 (74%) reported having received instructions in universal precautions, as advocated by the Centers for Disease Control. There was a trend for residents who had received the vaccine also to have been instructed in universal precautions. Regarding the residents' knowledge of infection control, there was no statistically significant difference between the responses of those who had been instructed in universal precautions and those who had not. The authors conclude that students are at risk for needlestick injuries; however, underreporting is frequent.

Educational Measurement↗
PubMed1991

[Time resolved laser fluorescence microscopy of hematoporphyrin derivative in vivo].

Laser-assisted fluorescence microscopy proved a powerful method for quantitative in vivo measurement of HpD fluorescence. Therefore the aim of the present work was to study the distribution of HpD in tumor vs. adjacent tumor-free tissue of 10 animals over a period of 8 days. We measured additionally the differences in HpD uptake in different tumor subcompartments. In tumor tissue HpD fluorescence showed maximum values 5-9 hours after i.v. application of the drug. The relation tumor-free tissue at that time was about 3-8. The third day of examination showed nearly identical values for both tissues. Between day 5 and day 8 we found an increase of HpD contents in tumor vs. normal tissue in 50% of the examined animals. Comparative measurements in the tumor centre and the tumor edge showed a preferential uptake of HpD in the tumor edge area. Probably the higher retention of HpD in this area is due to the oedema zone surrounding the tumor and to extravasation of HpD.

Animals↗
PubMed1991

[Microcirculatory effects of photodynamic therapy with hematoporphyrin derivative].

Hematoporphyrin derivative photosensitizes selectively malignant tumors following intravenous administration and shows typical fluorescence patterns in the range between 630 nm and 690 nm. Irradiation with laser light (630 nm) causes selective tumor necrosis due to a phototoxic effect. The site of action of this "photodynamic treatment (PDT)" remains obscure. In this study it could be demonstrated that directly after PDT a selective haemorrhage and thrombosis of blood vessels occurs in the tumor tissue. Furthermore, the arterioles of the surrounding normal tissue constrict completely. Venules of normal tissue showed slow thrombosis. Basically, the result of photodynamic treatment was a complete breakdown of tumor tissue microcirculation accompanied by partial damage to the surrounding normal tissue perfusion. This evaluation of the impact of PDT on tumor microcirculation led to the conclusion that a primary site of action of photodynamic therapy may contribute to the selective destruction of tumor microcirculation.

Animals↗
PubMed1990

Epicardial oxygen tensions during changes in arterial PO2 in pigs.

Arterial hypoxemia decreased epicardial tissue PO2, measured by means of a multiwire surface electrode, as well as coronary venous PO2 and myocardial lactate extraction. Left ventricular blood flow increased, O2 delivery, O2 demand and O2 consumption of the left ventricle remained unchanged. Thus, epicardial and coronary venous PO2 indicated decreased capillary and interstitial PO2 rather than cellular hypoxia. A linear relation between mean epicardial PO2 and coronary venous PO2 proves both parameters equally effective in reflecting changes in myocardial tissue oxygenation. However, PO2 distribution curves provide additional information and epicardial PO2 is superior in models with regional changes of myocardial oxygenation.

Animals↗
PubMed1990

[Pancreatic circulation in experimental biliary pancreatitis].

Measurements of pancreatic micro- and macrocirculation were performed to evaluate the pancreatitis-induced changes. Pigs were anesthetized and ventilated mechanically. Hypotension induced side-effects were avoided by adequate volume replacement. After laparatomy, splenectomy and gastroectomy the animals were enterotomized. Systemic hemodynamic parameters were monitored as well as pancreatic blood flow (Q), which was measured electromagnetically, and arterial and portal-venous blood gases. Pancreatic microcirculatory parameters were observed using fluorescence-videomicroscopy after i.v. administration of FITC dextran 150 and FITC labeled autologous erythrocytes. The pigs were randomly assigned to a control (n = 9) and a pancreatitis group (n = 10), the later being induced by the retrograde infusion of sodium-taurocholate. Systemic and pancreatic macrohemodynamic parameters remained constant in both groups, except for avdO2 and O2-consumption (O2-c) decreasing significantly in the pancreatitis group. At baseline 42% of all capillaries were perfused in both groups. In pancreatitis we detected focal areas with persistent stasis and areas which were continuously perfused. In these areas the portion of capillaries perfused by erythrocytes increased significantly to 67%. This was accompanied by an extravasation of FITC dextran. The finding of an unchanged Q beside reduced O2-c and avdO2 during pancreatitis is explained by the changes in pancreatic microcirculation. Focal stasis was observed beside areas showing typical signs of an acute inflammation: increased macromolecular permeability and capillary recruitment, e.g. oedema and hyperaemia.

Acute Disease↗
PubMed1990

Hepatitis B and hepatitis B vaccine requirements in schools of nursing in the United States: a national survey.

To ascertain use of the hepatitis B vaccine and occurrence of hepatitis B infection in nursing students, 1152 U.S. nursing schools were surveyed; 54.3% responded. The vaccine was required by 4.2% and recommended by 7.7%. Baccalaureate programs tended to require the vaccine more than the associate degree or diploma programs (p = 0.062). The occurrence of exposure of nursing students to blood and body fluids in the past 5 years was reported by 89.7%. Students in the diploma program had significantly more exposures (98.6%) than those in the associate degree (92.8%) and baccalaureate programs (82.7%; p less than 0.0005). At least one case of hepatitis B in the past 5 years was reported by 6.8%. Development of positive serologic markers in students after exposure to blood was reported by 7.1%. Seropositivity tended to occur in the Southeast and West (p = 0.035) and in cities with a relatively higher incidence of acquired immunodeficiency syndrome (p = 0.075). Diploma programs were significantly more likely to institute appropriate follow-up for students after exposure to blood of patients who were known or unknown carriers of hepatitis B virus (p less than 0.0001). For students exposed to blood of patients whose hepatitis B status was unknown and patients who were known hepatitis B carriers, 19.2% and 8.9%, respectively, reported they performed no follow-up whatsoever. U.S. nursing students are inadequately protected against hepatitis B. Nursing school administrators and faculty should be educated on the risks of hepatitis B infection and the indications and use of the hepatitis B vaccine.

Body Fluids↗
PubMed1990

Influence of the shock wave application mode on the growth of A-Mel 3 and SSK2 tumors in vivo.

We examined the influence of different shock wave application modes with a Dornier XL1 electrohydraulic lithotripter on the growth of A-Mel 3 and SSK2 tumors implanted under the dorsal skin of hamsters or mice. In a basic protocol, 500 shock waves a day on 4 consecutive days were administered at a discharge rate of 100 waves per minute and focused to the tumor center. This did not affect A-Mel 3 growth. A similar result was obtained with the basic protocol modified to 1000 shock waves a day and a wave application rate of 100 shock waves per second. Growth of A-Mel 3 and SSK2 tumors was significantly delayed, when the basic protocol was used, but the 500 shock waves a day were distributed over four points at the tumor edges and the tumor center. With the same shock wave protocol, lowering the water level over the tumor from 10 cm to 1 cm induced temporary regressions of SSK2 tumors. This was not due to the higher energy applied to the tumor, since twice the number of shock waves (1000 a day instead of 500 a day) was applied at a high water level and did not induce regressions. Four consecutive treatments with intervals between treatments shortened to 3 h and an additional treatment 12 h later at a low water level completely controlled tumor growth in 8 out of 12 SSK2 tumors for more than 150 days. The result showed that addition of a reflected wave from the water surface was most important for the shock wave effect, and suggested that shock wave devices generating similar wave forms should be applied for tumor therapy.

Animals↗
PubMed1990

Photodynamic therapy in head and neck surgery.

The results of a clinical study of photodynamic therapy (PDT) on early stage cancer in head and neck surgery are presented in this report. 30 patients with T1 malignancies of the face and oropharynx have been treated primarily with PDT. After the longest follow up of 14 months two patients revealed recurrence of the disease or residual tumor, two patients have been retreated because of residual dysplastic cells in the control biopsy, and all other patients stay histologically proven free of disease. Hence, PDT appears to be a promising cancer treatment for different histological tumors that penetrate the host tissue definitely less than a laser beam of 630 nm, which is the appropriate wavelength for PDT. Deeper-penetrating malignomas may be accessable for PDT using insertable filters when applying interstitial laser light.

Basal Cell Carcinoma↗
PubMed1990

[Endoscopic controlled laser lithotripsy in the treatment of sialolithiasis].

The article describes the first successful application of endoscopically controlled laserlithotripsy in the ENT field in a patient with recurrent purulent sialadenitis of the left submandibular gland due to sialolithiasis. By means of endoscopically controlled laserinduced lithotripsy of salivary gland stones, it was possible to achieve complete stone fragmentation without harming the glandular duct and the gland.

Adult↗
PubMed1990

Disinfection of water distribution systems for legionella: a review of application procedures and methodologies.

Hospital-acquired legionella pneumonia is emerging as a major problem; potable water distribution systems have been shown to be the primary reservoirs for the legionella organisms. As a result, disinfection measures have been developed to eradicate the organism from the hospital water supply. Each disinfection modality differs in its design and application such that choosing an appropriate cost-effective control measure requires careful analysis and planning. We assess in comparative fashion the disinfection modalities of thermal eradication ("heat-and-flush"), instantaneous steam-heating system, chlorination, ultraviolet light irradiation, ozonation and metal ionization. The theoretical bases, the actual procedure or system, the logistics of implementation, the costs and personnel requirements and the advantages and disadvantages are presented for each modality. Criteria for selection of a method, the use of combinations of methods, parameters for installation, pitfalls in implementation and a plan for subsequent environmental surveillance are discussed in detail.

Cross Infection↗
PubMed1990

An improved closed cranial window technique for investigation of blood-brain barrier function and cerebral vasomotor control in the rat.

A modification of the closed cranial window technique for small laboratory animals is presented. The method facilitates investigation of blood-brain barrier permeability in association with studies of the cerebrovascular response under normal and pathological conditions. Following trephination and preparation of the pia-arachnoid surface, the skull defect is closed again by sealing a cover glass onto a wall of dental cement surrounding the cranial window. The intracranial pressure can then be studied and experimentally manipulated. Care is taken to maintain normal blood-brain barrier function to a small barrier indicator (Na(+)-fluorescein, MW: 376). This is accomplished by opening the skull and dura mater under a column of paraffin oil to avoid exposure of brain tissue to atmospheric pressure. Reactivity of the cerebral surface vessels was assessed during hypercapnia at an arterial PaCO2 of 50.8 +/- 1.1 mm Hg. It was found that small arterioles of 20-50 microns phi had a significantly larger CO2-response than large arterioles of 50-100 microns phi. Pial venules did not respond at all. Superfusion of the cranial window preparation at a rate of 5 ml/h with buffered artificial CSF was tolerated for hours. No alterations of arteriolar or venular diameters nor opening of the blood-brain barrier to Na(+)-fluorescein was observed. These technical modifications enable us to employ a closed cranial window model in small laboratory animals for studies of cerebral microcirculation and blood-brain barrier function under normal as well as under pathological conditions related to brain damage.

Animals↗