Teaching breast ultrasound skills including core-needle biopsies on a phantom enhances undergraduate student's knowledge and learning satisfaction.

PURPOSE: To investigate whether a training program on breast ultrasound skills including core-needle biopsies to undergraduate students can improve medical knowledge and learning satisfaction. METHODS: Medical students attending mandatory classes at the Medical School of the University of Saarland received a supplemental theoretical and hands-on training program on ultrasound (US) breast screening and on US-guided core-needle biopsy using an agar-agar phantom. Experienced breast specialists and ultrasound examiners served as trainers applying Peyton's 4-step training approach. The students' theoretical knowledge and hands-on skills were tested before and after the training program, using a multiple-choice questionnaire (MCQ), the Objective Structured Clinical Examination (OSCE) and a student curriculum evaluation. RESULTS: The MCQ results showed a significant increase of the student's theoretical knowledge (50.2-75.2%, p < 0.001). After the course, the OSCE showed a mean total of 17.3/20 points (86.5%), confirming the practical implementation of the new skills. The student curriculum evaluation in general was very positive. A total of 16/20 questions were rated between 1.2 and 1.7 (very good) and 3 questions were rated as 2.1 (good). CONCLUSION: Undergraduate student's medical education can be enhanced by teaching breast US skills.

Potential of testosterone buciclate for male contraception: endocrine differences between responders and nonresponders.

Suppression of serum LH and FSH, by testosterone (T) alone or in combination with other agents, has proved to be the most promising approach to male contraception. T enanthate, the only androgen preparation tested in male contraceptive efficacy trials so far, must be injected every week due to its short terminal elimination half-life of 4.5 days and leads to supraphysiological T serum levels. A new T ester synthesized under WHO and NIH auspices, testosterone buciclate (TB), showed a favorable pharmacokinetic profile, with a terminal half-life of 29.5 days when tested in hypogonadal men. Here we describe the results of the first clinical trial with TB for male contraception. After two control examinations, normal healthy male volunteers were given a single im injection of 600 mg TB (group I; n = 4) and 1200 mg TB (group II; n = 8) on day 0. Follow-up examinations were performed every 2 weeks up to week 32. In both groups mean serum T levels remained in the normal physiological range throughout the study course. Serum levels of dihydrotestosterone (DHT) showed a dose- and time-dependent increase, with serum levels slightly above the normal range in group II for several weeks and a maximal concentration of 3.8 +/- 0.5 nmol/L (mean +/- SE) in week 6. No suppression of spermatogenesis to oligozoospermia was observed in group I. However, in group II, spermatogenesis was suppressed to azoospermia in three of eight volunteers in week 10 that persisted up to weeks 14, 20, and 22, respectively. In these three men, LH and FSH were suppressed by TB injections to the respective assay detection limits, whereas in the other five subjects, mean serum levels were only decreased to values near the lower normal limit for LH and FSH, respectively. In addition, throughout the study course, a significant difference in serum sex hormone-binding globulin was detected between the responders (mean values, 21.2-26.4 nmol/L) and nonresponders (mean values, 36.2-46.3 nmol/L). Serum levels of LH as well as total and free T at baseline and after TB injection were lower in the responders than in the nonresponders. Both subgroups showed similar increases in serum LH and FSH after GnRH stimulation. In a newly introduced GnRH antagonist suppression test, serum LH and T were decreased to significantly lower levels in the responders. These results indicate a different hormonal equilibrium and probably different susceptibility to feedback regulation of the responders compared to the nonresponders.(ABSTRACT TRUNCATED AT 400 WORDS)

PIP: Testosterone alone and the combination of gestagens and gonadotropin-releasing hormone antagonists with testosterone represent the most feasible potential agents for hormonal male contraception. The World Health Organization's Special Program of Research, Development, and Research Training in Human Reproduction has initiated a testosterone ester synthesis program and identified testosterone buciclate (TB) as the most promising approach to suppression of luteinizing hormone (LH) and follicle-stimulating hormone (FSH). This paper presents the results of the first clinical trial of TB. 12 men were given a single intramuscular injection of 600 mg (group I) or 1200 mg (group II) of TB and followed every 2 weeks for up to 32 weeks. Mean serum testosterone levels in both groups remained in the normal physiological range throughout the study period. Serum levels of dihydrotestosterone showed a time- and dose-dependent increase in group II. Although no suppression of spermatogenesis was observed in the 4 men in group I, azoospermia occurred in 3 of the 8 volunteers in group II beginning at week 10 and persisting to weeks 14, 20, and 22, respectively. In the remaining 5 men in group II, mean serum LH and FSH values were depressed to values near the lower limit of normal. Serum sex hormone-binding globulin and free testosterone were lower in responders than non-responders to TB. The range of responses recorded in group II suggests that men have a different hormonal equilibrium or different set-point for regulation of gonadotropin secretion and, thus, susceptibility to exogenous hormonal steroids.

Evaluation of right ventricular performance with a right ventricular ejection fraction thermodilution catheter and MRI in patients with pulmonary hypertension.

STUDY OBJECTIVES: We sought to compare catheter studies using a right ventricular ejection fraction (REF) catheter together with echocardiography and MRI in patients with pulmonary hypertension. PATIENTS AND METHODS: We compared hemodynamic findings, echocardiography, and MRI studies in 16 patients with pulmonary hypertension. Six healthy volunteers served as control subjects for the MRI studies. RESULTS: MRI imaging provided accurate assessment of cardiac output in all but two patients. As compared with MRI, the REF catheter constantly underestimated the REF and overestimated right ventricular volumes in patients with pulmonary hypertension. REF, end-systolic and end-diastolic right ventricular volumes, and right ventricular muscle mass, as determined by MRI, were almost identical in patients with preserved cardiac function and those with low-output failure. The only factor that was different in both groups was the severity of tricuspid regurgitation. CONCLUSION: Right ventricular dimensions and muscle mass do not differ in patients with pulmonary hypertension who have low cardiac output and those who do not. According to our results, the major determinant of cardiac output in these patients appears to be the severity of tricuspid regurgitation. The REF catheter provides invalid data on right ventricular dimensions in patients with pulmonary hypertension.

[Performance of different CT angiography imaging modalities in detecting renal artery stenoses]. / Leistungsfähigkeit verschiedener Darstellungsmodalitäten der CT-Angiographie beim Nachweis von Nierenarterienstenosen.

PURPOSE: Purpose of the study was to compare the sensitivity and specificity of various display modalities in the detection of renal artery stenosis. In particular, the difference between hard-copy reading and interactive analysis at the workstation was assessed. MATERIALS AND METHODS: Selected patients (n = 31) with expected suboptimal conditions for CT angiography due to long-standing hypertension and compromised renal function were included. Six radiologists evaluated independently a total of 77 renal arteries with 49 renal artery stenoses proven by angiography. Image analysis included: mode A: interactive display, analysis of multiplanar reformats and axial sections at the workstation, mode B: visualization of MIPs in the coronal and axial planes as hard copies only, mode C: visualization of MIPs and axial sections as hard copies only. RESULTS: The following sensitivities and specificities were found for internal readers and (readers from outside institutions): mode A: 94.8%, 87.9%, mode B: 97.7% (95.1%), 80.3% (75.4%); mode C: 97.0% (95.3%), 78.8% (76.6%). The differences were statistically not significant (p > 0.05). CONCLUSIONS: Standardized hard copies of MIPs plus axial CT provide sufficient accuracy to detect renal artery stenosis compared to interactive imaging even in this highly selected group of patients.

[Incarcerated Spieghel-Hernie mimicking an acute exacerbation of Crohn's disease]. / "Akute Exazerbation des Morbus Crohn" erweist sich sonographisch als inkarzerierte Spieghel-Hernie.

We report on a 25-year-old woman with long-standing Crohn's disease. Upon admittance to the emergency department, the patient complained of abdominal pain with increasing intensity over the last few days. Clinical examination revealed an abdominal mass in the right lower quadrant, and blood tests showed elevated markers of inflammation. Surprisingly, abdominal ultrasound did not show the suspected complication of Crohn's disease, but rather an incarcerated abdominal wall hernia, which turned out to be a spigelian hernia upon surgical repair. This case stresses the importance of abdominal ultrasound to rule out other diagnoses in patients with chronic inflammatory bowel disease in the emergency setting before starting a potentially dangerous treatment with high-dose steroids.

[Surgical treatment of osseous metastases of the pelvis]. / Operative Behandlung von Metastasen des knöchernen Beckens.

Metastases are the most frequent malignant tumors of the skeleton. Breast cancer is the most frequent primary tumor with osseous metastases followed by renal cell carcinomas, bronchial carcinomas, and thyroid tumors. The predominant localization of bone metastases is the spine, followed by the pelvis, femur, ribs, skull, sternum, and humerus. The overall incidence of bone metastases has increased due to improved diagnosis, prolonged survival by adjuvant therapy, and improved follow-up. Osseous metastases of the pelvis are usually diagnosed only late in the course of the disease because of their considerable delayed onset of clinical symptoms. Therefore, treatment is usually focused on a palliative approach to reduce pain and to improve the quality of life. We introduce three patients with bronchial, renal cell, and cholangiocellular carcinoma in an incurable tumor stage with osseous metastases in the pelvis. The metastatic osteolyses caused pain and symptoms of instability. Despite high doses of opiate analgesics, the patients were neither free of pain nor could they be mobilized. The palliative treatment included preoperative tumor embolization followed by tumor resection and implantation of a hip prosthesis. The preoperative embolization reduced intraoperative bleeding and made tumor resection, osteosynthesis, and implantation of the hip prosthesis possible. Mobilization with moderate pain could be achieved in these three patients for the rest of their lives.

[Concepts for optimizing stent graft treatment of abdominal aortic aneurysms based on results of animal experiments]. / Konzepte zur Optimierung der Stentgraftversorgung von Bauchaortenaneurysmen auf der Basis tierexperimenteller Ergebnisse.

PURPOSE: In the endoluminal therapy of abdominal aortic aneurysms, a short proximal aneurysm neck, endoleaks and the large size and stiffness of the introducer systems are responsible for many of the complications and sub-optimal outcomes. The purposes of the present review article is to to suggest strategies to minimize these complications based on the results of experimental studies in animals. MATERIAL AND METHODS: After implanting various types of stents across the renal artery origins, the functional and morphological changes in the kidneys and renal vessels were studied by various authors. In order to prevent progressive widening of the proximal aneurysmal neck and graft dislocation, Sonesson et al. performed a laparoscopic banding around the proximal neck in pigs. To study the effects of endoleaks, Marty, Schurink and Pitton carried out pressure measurements in experimental aneurysms with and without endoleaks. Sakaguchi und Pavcnik developed the "Twin-tube endografts" (TTEG) and the "Bifurcated drum occluder endografts" (BDOEG) and tested them in dogs. RESULTS: Up to 3 months after suprarenal stent placement, Chavan et al. detected no significant fall in the mean inulin clearance in sheep (140 +/- 46 ml/min before, 137 +/- 58 ml/min after). Nasim et al. and Malina et al. reported similar observations with respect to renal function. Suprarenal fixation may result in isolated thrombotic occlusions of the renal arteries and microinfarcts in the kidneys. Mean aortic diameters at the level of banding were significantly smaller in the animals with aortic banding as opposed to those in the control group without banding (8 mm vs 11 mm, p = 0.004). The banding caused a secure proximal fixation of the stent-graft. Persistent endoleaks resulted in significantly higher intraaneurysmal pressures. Although the TTEG and the BDOEG stent-grafts required smaller sheaths, occlusions were observed in 8% (TTEG) and 60% (BDOEG) of the graft limbs. DISCUSSION: Supra-renal fixation of the stent-graft does not significantly affect renal function. Depending partly on the stent-graft-Design, isolated microinfarcts in the kidneys or thrombotic occlusions of the renal arteries may occur. A laparoscopic banding of the aorta at the proximal neck after graft implantation could prevent widening of the proximal neck and graft dislocation with the passage of time. To reduce the incidence of endoleaks, embolization of large branches, particularly those arising from aneurysms without mural thrombus is advisable. Due to the relatively high rate of occlusion of the graft limbs, the TTEG and the BDOEG stent-graft designs still require refinement. A rational application of the results of these animal experimental studies in clinical practice could markedly improve the long-term results of endoluminal stent grafting of abdominal aortic aneurysms.

Activation of pro-astacin. Immunological and model peptide studies on the processing of immature astacin, a zinc-endopeptidase from the crayfish Astacus astacus.

To contribute knowledge of the processing and activation of invertebrate proteolytic enzymes, we studied the metalloprotease astacin, a digestive enzyme from the freshwater crayfish Astacus astacus (decapod crustacean). It is the prototype of the protein family of astacins, members of which occur in organisms from bacteria to man and are involved in a variety of physiological reactions. According to its genomic structure, astacin is produced as a zymogen [Geier, G., Jacob, E., Stöcker, W. & Zwilling, R. (1997) Arch. Biochem. Biophys. 337, 300-307]. To localize and follow the processing of pro-astacin in different parts of the digestive tract, we synthesized two peptides covering the pro part of pro-astacin and raised antibodies against them. In addition, antiserum against the whole active astacin was produced. Using immunohistochemical investigation, we detected pro-astacin in the F cells of the hepatopancreas and all the way into the tubular lumen and the collecting ducts of this gland. Immunoblot assays revealed only active astacin, and never pro-astacin, present in the cardiac stomach. We conclude from these studies that astacin is secreted into the lumen of the hepatopancreatic tubules in its pro form and is activated on its way to the stomach. To investigate which of the two endopeptidases found in the digestive tract of crayfish, astacin or trypsin, is responsible for cleaving the propeptide from pro-astacin, we synthesized different peptides that mimick the activation site. MS analysis of the cleavage products of astacin and trypsin showed that astacin is capable of catalyzing its own activation. Any contribution of trypsin would require the successive action of an aminopeptidase. Substituting glycine for arginine at position -1 of the activation site does not prevent astacin activity. As most members of the astacin protein family have basic amino-acid residues in this position, in these cases also astacin-specific cleavage would be possible.