Biomedical subjects
D Gross
Publications and source records attributed to D Gross.
New approaches for control of anti-self-reactivity in type 1 diabetes and transplantation of pancreatic islets.
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Suturing--control and conservation.
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Direct visualisation of B1 inhomogeneity by flip angle dependency.
Inhomogeneities in the spatial distribution of the excitatory Radio Frequency (RF) field, are still a dominant source of artifacts and loss of signal to noise ratio in MR imaging experiments. A number of strategies have been proposed to quantify this distribution. However, in this technical note we present a relatively simple MR imaging procedure which can be used to visualise RF inhomogeneities directly either by means of the magnitude or the phase of an image. To visualise the RF field distribution in both the inner and outer volumes of the coil, we have performed experiments in which the entire coil is submerged in a non-conducting fluid. To the best of our knowledge this strategy has not been used previously in order to evaluate coil performance. Finally, we demonstrate that the method is sensitive enough to reveal the effects of the sample properties on the effective RF wavelength of the transmitted field.
The effects of cardiac surgery on early and late pulmonary functions.
BACKGROUND: Impaired pulmonary functions are common in cardiac patients. Early and late effects of cardiac surgery on pulmonary function tests (PFTs) are presented. METHODS: Fifty patients undergoing cardiac surgery (coronary artery bypass grafting [CABG, 74%], valve replacement or valvuloplasty [20%] and combined procedures [6%]) were studied. Anginal and cardiac failure symptoms severity, and smoking history, were evaluated preoperatively. PFTs were studied and compared pre-, and 3 weeks and 3.5 months postoperatively. RESULTS: Pre- and postoperative PFTs were inversely related to severity of preoperative symptoms. Forced vital capacity (FVC) dropped from 98% of predicted preoperatively, to 63% (P < 0.00001) and 75% (P < 0.00001) 3 weeks and 3.5 months postoperatively, respectively. Expiratory volume in the first 1 s of forced expiration (FEV1.0) decreased from 95% to 61% (P < 0.00001) and 70% (P < 0.00001), respectively. Forced expiratory flow at 50% of vital capacity (FEF50) decreased from 85% to 56% (P < 0.00001) and 59% (P < 0.00001). Forced expiratory flow at 75% of vital capacity (FEF75) decreased from 77% to 47% and 47% (P < 0.00001). Peak expiratory flow rate (PEFR) declined from 101% to 66% (P < 0.00001) and 86% (P < 0.003). Maximal voluntary ventilation declined from 103% to 68% (P < 0.00001) and 77% (P < 0.00001). Only FVC (P < 0.0003), FEV1.0 (P < 0.02) and PEFR (P < 0.0001) partially recovered postoperatively. Smoking history did not affect perioperative PFTs. Pre-, but not postoperative FVC, FEV1.0, FEF50 and FEF75 were worse in valve than in CABG patients. CONCLUSIONS: Pulmonary functions deteriorate significantly for at least 3.5 months after cardiac surgery. Preoperative cardiac ischaemic and failure symptoms are inversely related to perioperative PFTs.
Biomechanical evaluation of polylactide absorbable screws used for syndesmosis injury repair.
Simulated syndesmosis injuries were created in 12 fresh-frozen, below-knee cadaver specimens. Six specimens were repaired with a 4.5 mm stainless steel screw, and six were repaired with a 4.5 mm polylactide screw. Three specimens of each group were tested in load to failure by axially loading with 1400 N and externally rotating to 90 degrees. Three specimens in each group underwent fatigue testing by axially loading with 700 N and applying 2.5 N-m of torque for 57,700 cycles. Radiographs and computed tomography scans were evaluated. None of the screws broke or failed. Similar load to failure was noted in polylactide and control groups. Fatigue testing revealed no significant change in stiffness. No significant screw damage was evident on radiographic or computed tomography evaluation. The data suggest that a polylactide screw has sufficient fatigue and failure strength to allow for healing of this injury in a clinical situation.
A pituitary mass and hypopituitarism: improvement after corticosteroid therapy.
Lymphocytic hypophysitis of the anterior pituitary is a rare autoimmune disease, invariably diagnosed either by surgical biopsy of the adenohypophysis or at autopsy. The current report describes the rapid development of hypopituitarism in a 42-year-old nulliparous woman with a large sellar mass, who did not undergo pituitary surgery. Transient regression of the sellar mass and partial improvement of the hypopituitarism was induced by treatment with corticoids. We suggest that the diagnosis of lymphocytic hypophysitis can be established clinically and that conservative treatment with corticoids should be considered prior to surgical intervention.
[Origin and development of autopsy in Württemberg reflected by contemporary sources].
The present study deals with the introduction and the development of coroner's inquest in Württemberg. It could be shown that the contemporary discussion about the incidence of apparent death became an important reason for the establishment of necropsy in 1824. In spite of legal backing the institution of necropsy remained disputed until the end of the Kingdom of Württemberg in 1918. Above all, the differing qualification of the coroners gave rise to criticism. Although the legislator provided a general qualification in surgery, most the coroners did not boast a special expert knowledge. During the time in view, the participation of barber surgeons in necroscopy was decreasing; the percentage of physicians also remained very low. In 1911, only 119 out of 1814 coroners were physicians-on the other side 641 representatives of post-mortem examination worked as small-holders or day-labourers, and another 33 persons even earned their daily living by grave-digging. With regard to this, it is evident that the coroners in Württemberg formed a most heterogeneous group-both in social and in professional respect.
[Reconstruction of the distribution of wound surgeons in the Württemberg kingdom. A contribution to the social history of routine surgeons in the 19th century].
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[Therapeutic thrombocytapheresis--effect on hemorheologic parameters].
Common features of all myeloproliferative diseases (CMPE) are a markedly increased number of platelets and restrictions in the subjective feeling of the patients, comprising symptoms like nausea, headache, sensory deficits and transient paresis. Meanwhile, it has been shown that platelet pheresis (mTD) does not only reduce platelet counts sufficiently but also results in an impressive relief of the subjective complaints. To test the part that rheological mechanisms play hereby, relevant rheological parameters in the blood of 22 CMPE patients and of 8 healthy platelet donors as controls were analyzed before and after treatment with an AS-104 cell separator. Concerning the viscosity of whole blood und the filterability of erythrocytes, there was seen neither a difference between the patients and the controls, nor before and after mTD. As a result of treatment of patients, the moderately raised plasma viscosity was normalized, whereas the aggregation of erythrocytes was significantly lowered. It is concluded that there is an influence of hemorheological conditions on the patient's subjective feeling. These would originate in neurological dysfunctions caused by CMPE-induced restrictions in cortical microcirculation. The erythrocyte aggregation, lowered by mTD, would cause an improvement of microcirculatory fluidity and would, in consequence, abolish the neurological symptoms.
Trends in infectious disease and cancer in HIV infection.
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[Exclusion of wound physicians from health care in Germany 1871/72].
At the beginning of the 1870s, non-academic surgeons were finally banished from officially accepted medical practice in Württemberg - the last German Land in which they had still been recognized. As contemporary reports by barber-surgeons make clear, they had agreed to the elimination of their handiwork - in the hope of winning thereby generous "terms of transition" for the remaining practitioners of their trade. The fact is that in this point, too, barber-surgeons - at least for the most part - had but little success, clearly put them on the losing side in political conflict of professional interests.
Influence of repeated oral doses of ethinyloestradiol on the metabolic disposition of [13C2]-ethinyloestradiol in young women.
OBJECTIVE: To examine the influence of daily oral administration of ethinyloestradiol on the total clearance of 13C-labeled ethinyloestradiol in women. METHODS: 19, healthy, young women received a single IV dose of 0.06 mg 13C-ethinyloestradiol. Subsequently, they were treated with daily oral doses of 0.06 mg ethinyloestradiol for 8 days. On the last day of oral treatment, they received a further IV dose of 0.06 mg 13C-ethinyloestradiol. The pharmacokinetic parameters clearance, area under the serum level-time curve, terminal half-life, steady-state volume of distribution and mean residence time of 13C-ethinyloestradiol in each volunteer were evaluated after both IV doses, and the corresponding pairs of parameters were examined statistically for the significance of intraindividual differences. RESULTS: Following the first (second) intravenous administration, the mean area under the curve was 2.54 (2.67) ng.h.ml-1. The terminal half-life and mean residence time were 9.7 (9.6) h and 10.5 (10.1) h, respectively. The steady-state volume of distribution was 4.3 (3.9) 1.kg-1 and the clearance was 7.0 (6.6) ml.min-1.kg-1. No significant difference was observed in any of these parameters between the first and the second IV doses of 13C-EE2. CONCLUSIONS: Since the clearance in particular remained unchanged after repeated oral administration of ethinyloetradiol, the hypothesis that ethinyloestradiol can inhibit its own metabolism in vivo can be rejected.
[Demise of the wound physician vocation exemplified by the political representative Arnold Schlegel (1850-1924)].
The name of Arnold Schlegel stands for a dazzling and complex personality. After being apprenticed to a barber surgeon in Württemberg, he spent about four decades in Switzerland working as an innkeeper. Yet, Schlegel distinguished himself as one of the leading representatives of the last non-academic surgeons in Württemberg. In contrast to most of his surgical colleagues, most of Schlegel's vocational activities are documented. This study is based on unpublished documents of different archives of Württemberg and Switzerland. The aim of the study is to illuminate the life of Arnold Schlegel and, in view of his policy, to illustrate the trying circumstances of contemporary barber surgery.
[Professional heritage and social origin of the Württemberg barber surgeons of the 19th century].
In nineteenth-century Württemberg, barber surgeons (Wundärzte) were subdivided into various grades. They were increasingly confronted with severe governmental restrictions that both threatened their professional image and weakened their economical prospects. Therefore an archival study has been made on behalf of the social background of surgical examines by means of their father's occupation. As a result it could be shown that more than half the registered fathers were barber surgeons themselves. About 20 percent of the surgical candidates were recruited from the craft, whereas physicians, apothecaries and other professionals could hardly be found. Even pastors, that were supposed to be professionally linked with surgeons, were rarely made reference to. The candidates were classified into two groups, according to different periods of time (1800 to 1829 and 1830 to 1873). As to the social origin of the examinees, no appreciable differences between both periods could be found.