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Biomedical subjects

R Gerber

Publications and source records attributed to R Gerber.

At least 19 recordsLinked to original sources
PubMed2006

Confirmed Datura poisoning in a horse most probably due to D. ferox in contaminated tef hay.

Two out of a group of 23 mares exposed to tef hay contaminated with Datura ferox (and possibly D. stramonium) developed colic. The 1st animal was unresponsive to conservative treatment, underwent surgery for severe intestinal atony and had to be euthanased. The 2nd was less seriously affected, responded well to analgesics and made an uneventful recovery. This horse exhibited marked mydriasis on the first 2 days of being poisoned and showed protracted, milder mydriasis for a further 7 days. Scopolamine was chemically confirmed in urine from this horse for 3 days following the colic attack, while atropine could just be detected for 2 days. Scopolamine was also the main tropane alkaloid found in the contaminating plant material, confirming that this had most probably been a case of D. ferox poisoning. Although Datura intoxication of horses from contaminated hay was suspected previously, this is the 1st case where the intoxication could be confirmed by urine analysis for tropane alkaloids. Extraction and detection methods for atropine and scopolamine in urine are described employing enzymatic hydrolysis followed by liquid-liquid extraction and liquid chromatography tandem mass spectrometry (LC/MS/MS).

Animals↗
PubMed2005

Datura contamination of hay as the suspected cause of an extensive outbreak of impaction colic in horses.

Datura poisoning of horses is extensively reviewed. An outbreak of intractable impaction colic affecting 18 of 83 horses was stopped by withdrawing dried tef hay contaminated with young Datura plants. The dried, botanically identified Datura stramonium and D. ferox contained respectively 0.15% mass/mass (m/m) hyoscyamine as well as 0.16% m/m hyoscine (scopolamine) and only hyoscine at a concentration of 0.11% m/m. Immature, unidentifiable plants resembling D. stramonium, contained 0.14% m/m and 0.12% m/m of the 2 respective tropane alkaloids. The outbreak was characterised by protracted and repeated colic attacks due to impaction of the large colon and/or caecum without any other anti-muscarinic signs. Comparative analyses of single specimens of dried seed of the 2 species collected from both fertilised and waste areas revealed that young South African Datura spp. had levels of tropane alkaloids comparable to those in the well-known toxic seed and were, consequently, equally toxic. The inherent danger of tef hay being contaminated with Datura is emphasised. To our knowledge this is the 1st field case of poisoning in horses ascribed to the vegetative parts of Datura spp.

Animals↗
PubMed2004

The use of the standard exercise test to establish the clinical significance of mild echocardiographic changes in a Thoroughbred poor performer.

A 4-year-old Thoroughbred gelding racehorse was referred to the Onderstepoort Veterinary Academic Hospital (OVAH) with a history of post-race distress and collapse. In the absence of any obvious abnormalities in the preceding diagnostic work-up, a standard exercise test was performed to determine an underlying cause for the post-race distress reported. In this particular case oxygen desaturation became evident at speeds as slow as 6 m/s, where PO2 was measured at 82.3 mm Hg. Similarly at a blood pH of 7.28, PCO2 had dropped to 30.0 mm Hg indicating a combined metabolic acidosis and respiratory alkalosis. The cause of the distress was attributed to a severe hypoxia, with an associated hypocapnoea, confirmed on blood gas analyses, where PO2 levels obtained were as low as 56.6 mm Hg with a mean PCO2 level of 25.4 mm Hg during strenuous exercise. Arterial oxygenation returned to normal immediately after cessation of exercise to 106.44 mm Hg, while the hypocapnoeic alkalosis, PCO2 25.67 mm Hg, persisted until the animal's breathing normalized. The results obtained were indicative of a dynamic cardiac insufficiency present during exercise. The combination of an aortic stenosis and a mitral valve insufficiency may have resulted in a condition similar to that described as high-altitude pulmonary oedema, with respiratory changes and compensation as for acute altitude disease. The results obtained were indicative of a dynamic cardiac insufficiency present during exercise and substantiate the fact that an extensive diagnostic regime may be required to establish a cause for poor performance and that the standard exercise test remains an integral part of this work-up.

Animals↗
PubMed2003

[Rare seminoma metastasis to the corpus spongiosum and urethra].

Anaplastic seminomas account for 5-10% of all seminomas. Their metastatic pattern is similar to the classic form of seminoma. We report on an oligophrenic patient with seminoma pT1 who developed a metastasis to the corpus spongiosum and penile urethra, which was successfully treated by local external radiotherapy resulting in long-term tumor remission over a 4-year follow-up period.

Adult↗
PubMed2000

[Prolonged peridural analgesia (PDA) for postoperative pain therapy after major urologic interventions. Experiences with 172 adult patients].

UNLABELLED: The benefits of epidural analgesia are well known, but it is not well understood which types of urologic surgery benefit most from epidural analgesia. In this study, the effects and side effects of prolonged epidural analgesia are prospectively examined and analysed on 172 adult patients in three different operation groups. An epidural infusion of local anaesthetic combined with an opioid and adrenaline was given for a period of 5-7 days. There was no difference between the groups with respect to the effectiveness of the analgesia and patients' perception of the treatment. Mobilization differed, as expected, between the groups, however even after the most major surgery (e. g. cystectomy with bladder substitution), mobilization was impressively unproblematic. Retarded return of regular intestinal function after the transperitoneal operation and partly after lumbotomy compared with the extraperitoneal operation depended on which operation was performed and the amount of analgesia given. The side effects such as sedation, nausea and pruritus were conditional partly on the opiate and partly on the intervention. Up to 11 % showed slight muscular weakness of the lower limbs as a specific side effect of the local anaesthetic. COMPLICATIONS: One patient died of cerebral hypoxia due to an initially undetected subdural catheter placement complicated by severe pre-existent carotid stenosis. In four patients, the epidural analgesia had to be stopped because of catheter migration. There was no clinical evidence of hematoma, abscess or permanent neurological damage. Epidural analgesia works well in terms of analgesia, mobilization and patient satisfaction, bearing in mind the potential side effects and complications. It can be recommended for lumbotomy and long transperitoneal operations however not for extraperitoneal interventions in the lower abdomen such as radical prostatectomy.

Adult↗
PubMed2000

Raised saturated-fat intake worsens vascular function in virgin and pregnant offspring of streptozotocin-diabetic rats.

Adult offspring of severely diabetic pregnant rats are insulin resistant and display cardiovascular dysfunction. When pregnant they develop mild hyperglycaemia. Diets high in saturated fat have been implicated in the development of cardiovascular disease and vascular dysfunction. In the present study we have determined vascular function in small mesenteric arteries from offspring of normal (OC) and diabetic (OD) rats fed standard chow and offspring of diabetic rats fed a diet high in saturated fats (OD-HF) from weaning to adulthood, and throughout their subsequent pregnancies. OD rats displayed an increased sensitivity to noradrenaline (P < 0.05) and impaired sensitivity to the endothelium-dependent vasodilator, acetylcholine. The component of acetylcholine-induced relaxation attributable to endothelium-derived hyperpolarizing factor was reduced in OD-HF rats. Pregnant OD rats also demonstrated impaired maximum relaxation to acetylcholine (pregnant OD rats v. pregnant OC rats P < 0.05). In pregnant OD-HF rats noradrenaline sensitivity was enhanced and endothelium-dependent relaxation further reduced (pregnant OD-HF rats v. pregnant OC rats P < 0.001). The isoprostane, 8-epi-prostaglandin F2alpha, a marker of oxidative stress, was increased in pregnant OD rats (pregnant OD rats v. pregnant OC rats P

Animals↗
PubMed1999

Understanding technology in contemporary surgical nursing: a phenomenographic examination.

The purpose of this paper is to describe the result of phenomenographic research undertaken to identify the qualitatively different ways technology is understood and experienced by contemporary surgical nurses. Twenty surgical nurses were interviewed and conversations were recorded through the use of drawings and audiotape that were analysed using a series of seven analytical steps. There were two major outcomes of the research: eight categories of description were revealed and each one constitutes a conception of the experience and understanding of technology, and an outcome space portraying the logical relations between conceptions was identified. Conceptions revealed demonstrate the importance of technology to the theory, practice, research and education of nurses, and highlight the complexity and significance of technology in contemporary surgical nursing experience.

Attitude of Health Personnel↗
PubMed1999

Growth factor receptors are differentially expressed in cancers of the papilla of vater and pancreas.

OBJECTIVE: To compare growth factor receptor expression in papilla of Vater cancer and pancreatic cancer. SUMMARY BACKGROUND DATA: Cancer of the papilla of Vater has a much better prognosis than pancreatic cancer. Earlier symptoms may result in earlier diagnosis, but different biologic growth behaviors and genetic alterations might also be explanations. PATIENTS AND METHODS: Surgical specimens from papilla of Vater cancers (24 patients) and pancreatic cancers (80 patients), normal papilla of Vater tissues (20 patients), and normal pancreatic tissues (24 patients) were frozen and fixed. The authors compared the expression of the epidermal growth factor receptor (EGFR) and c-erbB2 and c-erbB3 by Northern blot, in situ hybridization, and immunohistochemistry. RESULTS: In papilla of Vater cancer, Northern blots showed comparable EGFR and c-erbB2 mRNA expression but significantly lower c-erbB3 mRNA levels than in normal papilla. In pancreatic cancer, mRNA expression was enhanced compared with normal controls for EGFR (4-fold), c-erbB2 (2.5-fold), and c-erbB3 (5.2-fold). In situ hybridization confirmed this and showed mRNA expression only in cancer cells. EGFR immunohistochemical staining scores were comparable in papilla of Vater cancer (1.17 +/- 0.22) and normal papilla (1.42 +/- 0.25). Staining scores for c-erbB2 (2.72 +/- 0.40 vs. 3.89 +/- 0.37) and c-erbB3 (2.78 +/- 0.35 vs. 3.89 +/- 0.53) were slightly lower than controls in papilla of Vater cancer. In pancreatic cancer, immunostaining scores for EGFR, c-erbB2, and c-erbB3 were significantly higher than controls. CONCLUSION: Members of the EGFR family show similar or lower expression in papilla of Vater cancer than in normal controls. In pancreatic cancer, these receptors are upregulated. This supports the hypothesis that papilla of Vater cancer and pancreatic cancer have biologic differences that may contribute to the different growth of these tumors.

Adult↗
PubMed1999

Phenomenography: a qualitative research approach for exploring understanding in health care.

Phenomenography is a little-known qualitative research approach that has potential for health care research, particularly when people's understanding of their experience is the goal. Phenomenography is explained as a qualitative, nondualistic research approach that identifies and retains the discourse of research participants. This article seeks to present the major assumptions associated with phenomenographic research. An example of the way in which research outcomes are presented is included to emphasize its distinctiveness. It is noted that phenomenography has potential in the area of qualitative health research and will benefit from ongoing development and application.

Data Collection↗
PubMed1999

Maternal food restriction in the second half of pregnancy affects vascular function but not blood pressure of rat female offspring.

Food restriction during pregnancy in rats induces intrauterine growth retardation with consequences persisting into adulthood. In the present study we have investigated the hypothesis that malnutrition in pregnant rats may lead to altered cardiovascular function in adult female offspring. Perinatal growth retardation was induced by a 50% reduction of normal dietary intake in rats during the second half of pregnancy. Systolic and diastolic blood pressure values and heart rate were recorded in conscious female offspring (100 d old) using a femoral artery probe. No significant differences in heart rate, or in systolic and diastolic blood pressures were recorded between control offspring and offspring of nutritionally deprived rats. In order to ascertain whether cardiovascular variables in the offspring were influenced by lactation, subgroups of offspring from food-restricted dams were fostered with lactating dams fed on a normal diet. Blood pressure and heart rate were also found to be normal in these offspring. The rise in blood pressure associated with NO inhibition was similar in all groups. Isolated resistance artery function was assessed in vitro in offspring (100-120 d old) of a second group of semi-starved dams. Small mesenteric arteries from these animals showed reduced endothelium-dependent relaxation (to acetylcholine and bradykinin), but enhanced sensitivity to exogenous NO (sodium nitroprusside). We conclude that food restriction during the second half of pregnancy and/or lactation does not induce hypertension in adult offspring, but may effect subtle changes in vascular function.

Acetylcholine↗
PubMed1998

Multiple machine implementation of enhanced dynamic wedge.

PURPOSE: After acquiring 4 years of experience with Dynamic Wedge, a software-driven one-dimensional (1D) compensation system, we implemented a new software version called Enhanced Dynamic Wedge (EDW). The EDW allows larger (30 cm) and asymmetric field sizes and additional angles for wedged fields. We implemented this software on four similar dual-energy accelerators that also possess upper and lower physical wedge sets. Our goal was to implement EDW with one common wedge factor (WF) table and one set of treatment-planning files. METHODS AND MATERIALS: We measured WFs with an ionization chamber and isodose profiles with both film and a diode array. We used a calculation scheme that requires only entry of the wedge angle and fixed jaw value. Filters for computerized treatment planning were configured for each wedge angle. We also examined to what degree the multileaf collimation (MLC) orientation, which is orthogonal to the EDW direction, was compromised for specific treatment sites. As a comparative test, we examined the dosimetric consistency for the 8 sets of physical wedges on the four machines. Finally, we updated our DW quality assurance program for EDW. RESULTS: The measured EDW WF was common for all four machines to within +/- 1.5% and the calculation scheme held to within 1.5%. The EDW isodoses were consistent among the machines as measured by film and diode array. The treatment-planning filters provided computed isodose profiles that were nearly identical to measured profiles. Regarding MLC orientation, we found that the collimator angle needed for EDW did not compromise isodose distributions, as apparent in measured isodoses and calculated dose-volume histograms. The consistency of the physical wedges did not fare as well. Two of the lower wedge sets had Wfs and profiles different (> 3%) from the other wedge sets. CONCLUSIONS: We have successfully implemented EDW on four machines using only one WF table and one set of treatment-planning filters. The EDW provides for improved treatment techniques for particular sites due to the large field sizes and additional angles available. Daily treatment efficiency has increased because of the remote capability provided by EDW.

Humans↗
PubMed1998

Physician resource utilization in radiation oncology: a model based on management of carcinoma of the prostate.

PURPOSE: To develop a methodology to estimate the comparative cost of physician time in treating patients with localized prostate cancer, using as an example two-dimensional (2D) vs. three-dimensional (3D) conformal irradiation techniques, and to illustrate how current cost-accounting techniques can be used to quantify the cost of physician time and effort of any treatment. METHODS AND MATERIALS: Activity-based costing, a recent innovation in accounting, widely recommended for estimating and managing the costs of specific activities, was used to derive physician resource utilization costs (actual cost of the physician services and related support services consumed). RESULTS: Patients treated with 3D conformal irradiation consume about 50% more physician time than patients receiving 2D conventional radiation therapy. The average professional reimbursement for the 3D conformal irradiation is only about 26% more than for the 2D treatment. Substantial variations in cost are found depending on the total available physician working hours. In an academic institution, a physician working 40 hours a week would have to spend an average of about 60% of available time on clinical services to break even on a 2D treatment process and over 74% of available time on clinical work to break even on a 3D treatment process. The same physician working 50 hours a week would have to spend an average of about 48% of available time on 2D clinical services and about 60% of available time on 3D clinical work to break even. Current Medicare reimbursement for 3D treatment falls short of actual costs, even if physicians work 100% of a 50-hour week. Medicare reimbursement for 2D barely allows the department to break even for 2D treatments. CONCLUSIONS: Costs based on estimates of resource use can be substantially under- or overestimated. A consistent language (method) is needed to obtain and describe the costs of radiation therapy. The methodology described here can help practitioners and researchers more accurately interpret actual cost information. Future use of such cost-estimation methodologies could provide consistent and comparable costs for negotiations with health care providers and help assess different treatment strategies.

Aged↗
PubMed1997

[Treatment of bacterial osteomyelitis using ultrasonic energy waves].

The method and results of uncommon ultrasound treatment in 82 cases of osteomyelitis are presented. The method was supplemented with intraoperative Th 99m isotope diagnostics as well as fluorescence based diagnosis to identify necrotic bone fragments. Ultrasound energy had advantageous effect on soft tissue healing and osteogenesis.

Adolescent↗
PubMed1996

[Percutaneous resection of osteoid osteoma].

Therapeutic management of osteoid osteomas may vary from conservative medical treatment to more aggressive, though effective, surgery. Based on observations in 4 cases in children, we demonstrate the importance of localizing the lesion on the CT-scan before percutaneous resection of the osteoid osteoma involving small bones since this method is the most conservative surgical procedure.

Adolescent↗