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Biomedical subjects

R Hofmann

Publications and source records attributed to R Hofmann.

At least 19 recordsLinked to original sources
PubMed1995

Aortic valve replacement: is the stentless xenograft an alternative to the homograft? Early results of a randomized study.

From November 1992 to October 1993 we randomized 101 patients over 60 years of age undergoing elective aortic valve replacement, with or without concomitant coronary artery bypass grafting, to receive either a cryopreserved aortic or pulmonary homograft (n = 38) or a stentless porcine aortic valve xenograft (Edwards Prima 2500) (n = 63). The majority of all valves (92%) were inserted freehand in the subcoronary position. Six homografts (16%) were implanted as a free-root replacement and two xenografts (3%) were used as a mini root. There were four in-hospital deaths (4%), three in the homograft group and one in the xenograft group (homograft, 7.9% versus xenograft, 1.6%; p = not significant). Forty-one patients were followed at 3- to 6-month intervals for 9 +/- 2 months (3 to 14 months) and valve pathology was assessed routinely by means of color flow Doppler echocardiography. Two patients in the homograft group developed new aortic insufficiency grade II; all others remained with trivial or no valve incompetence. The mean gradient remained unchanged to immediate postoperative measurements (homograft, 5 +/- 1 mm Hg versus xenograft, 11 +/- 4 mm Hg; p < 0.001). Despite a slightly higher transvalvular gradient, xenografts achieved excellent initial results when compared to homografts. Ease of implantation and freedom from thromboembolism indicate that xenografts can be an acceptable alternative to homografts, particularly in older patients with small aortic annuli. Long-term studies assessing the durability of the xenograft are necessary for final evaluation.

Aged↗
PubMed1995

Negotiating ureteral stenoses and kinks with a hydrophilic wire.

Negotiating a tortuous or obstructed ureter with a wire can be time-consuming and sometimes tiring. The principle of using a slippery floppy wire and then replacing it with a stiff wire through a 5-french open-ended ureteral catheter yields a high success rate. The ureteral catheter can be used for a radiocontrast study and allows access for a 0.035 'coaxial wire', which can be used as a guide wire for a single or double J stent.

Humans↗
PubMed1995

Internally concealed cocaine: analytical and diagnostic aspects.

Thirty persons arrested at Frankfurt airport for smuggling internally concealed cocaine in 1993/1994 were investigated. An X-ray examination (in all 30 cases), immunochemical examination of urine (in 27 cases) and of saliva (in 20 cases) was performed in parallel. An X-ray examination gave positive results in all examined persons. EMIT cocaine metabolite assay (cut off 300 ng benzoylecgonine (BE)/mL) was positive in eight urine samples. After reducing the cut off to 150 ng BE/mL urine, eleven samples were classified as positive. The results were confirmed by means of chromatographic determinations. These findings showed limited role of immunological examination of urine as a screening test in suspected smuggling of internally concealed drugs. All saliva samples showed negative immunochemical results. The number of concealed containers ranged from 44 to 135 per person. The amount of cocaine hydrochloride found in particular cases ranged from 242 to 1050 g net weight, divided into containers weighing from 5.7 to 13.8 g. Drug packages were obviously machine-made. The packages smuggled by a particular person were uniform. However, a distinct interpersonal variability in drug packages was observed, in regard to the number of protective layers (4-7), size, weight, and cocaine purity. This may be helpful for the identification of production site. The leaching of cocaine from selected containers was investigated in a stirring bath and was independent of the conditions applied.

Adult↗
PubMed1994

Detection of aneuploid cells in acute lymphoblastic leukemia with flow cytometry before and after therapy.

We have evaluated the proliferative activity and DNA content of immunophenotyped hematopoietic cells applying flow cytometry. After indirect immunofluorescence the cell membrane was permeabilized for propidium iodide staining of DNA. Compared with single parameter detection of DNA content this method has more certainty in the determination of aneuploidies in lymphatic leukemia cells. Immunophenotyped residual normal hematopoietic cells were used as an internal standard. If this method was tested for evaluation of therapeutic effects after chemotherapy greater sensitivity in detection of minimal residual disease was observed than when using microscopic evaluation or single parameter DNA analysis in cases of aneuploid lymphoblastic leukemias.

Aneuploidy↗
PubMed1992

Scatter factor is a glycoprotein but glycosylation is not required for its activity.

Scatter factor (SF) is a protein produced by fibroblasts, smooth muscle cells, and human placenta which scatter cohesive epithelial cell colonies and increases cellular motility. SF bound to concanavalin A and other lectins with high affinity. SF could also be stained with a glycoprotein specific stain. Incubation of producer cells (N-ras-transformed 3T3), with tunicamycin homolog A1 did not have any significant effect on the secretory activity of SF. The treatment of SF with N- and O-glycanases as well as endoglycosidase H had no effect on its activity. However, treatment of target (Madin Darby canine kidney) cells with tunicamycin A1, abolished the scattering response. These studies suggest that scatter factor is a glycoprotein, but glycosylation is not required for its secretion or activity by the producer cells; however, glycosylation of proteins in the target cells is required for SF action.

3T3 Cells↗
PubMed1992

Endoscopic and open stone surgery in morbidly obese patients.

Management of urinary stone disease in the morbidly obese patient can be troublesome and problematic. We present 4 recent female patients with an average weight of 442 pounds and an average height of 5 feet 2 inches. The patients underwent a total of 8 open surgical or endoscopic procedures for partial or complete staghorn calculi. Complications encountered included inability to reach the stones with rigid or flexible ureteroscopes, inadvertent incision above the 10th rib for pyelolithotomy, intraoperative rhabdomyolysis during a flank incision, consecutive temporary renal failure and wound infection. We discuss the limitations of extracorporeal shock wave lithotripsy, retrograde endoscopic manipulation, percutaneous antegrade surgery and open surgical approaches. Such patients continue to represent diagnostic challenges and high risk therapeutic options.

Adult↗
PubMed1992

Renal artery embolism: clinical features and therapeutic options.

Renal artery embolism is an infrequent but important cause of renal loss. However, due to its rarity and nonspecific presentation diagnosis is often delayed and occasionally missed. Furthermore, proper therapeutic intervention is not well established and aggressive surgical management is often ill-advised. We review the literature and present 3 cases seen recently at our institution. Selective intra-arterial infusion of thrombolytic agents appears to be the most favorable treatment. The duration of occlusion does not necessarily correlate with the return of renal function, and the degree of collateral renal blood flow can be important.

Adult↗
PubMed1992

Ureteroscopy without routine balloon dilation: an outcome assessment.

A retrospective analysis of 156 rigid ureteroscopic stone procedures in 145 patients revealed successful manipulation in 90%. The stone-free rate after adjunctive procedures was 95%. Access was achieved without balloon dilation in all but 18 patients. There were 24 perforations, occurring in 31% of proximal, 8% of mid ureteral and 8% of distal stone manipulations. Of the evaluable patients 63% underwent radiographic assessment for stricture disease, 75% at 6 months or more after the procedure. The stricture rate was 3.5% in all patients and 5.9% in patients with perforations. Of 37 patients evaluated for vesicoureteral reflux only 1 had reflux. Questionnaire followup was obtained for 74% of the patients (mean followup 2.6 years) and 32% felt normal within 3 days. Postoperative symptoms included flank pain (13%), renal colic (12%), pelvic discomfort (30%) and Double-J stent related complaints (49%). Of the patients 15% have reported recurrent stones. Ureteroscopy is effective and well tolerated, and it has minimal long-term complications.

Catheterization↗
PubMed1992

Pyonephrosis: diagnosis and treatment.

A series of 23 confirmed cases of pyonephrosis initially treated by percutaneous nephrostomy drainage were reviewed. Presentation was extremely variable, ranging from sepsis to asymptomatic bacteriuria. Fever, flank pain and leukocytosis were often absent. Ultrasonography was diagnostic in only 3 of 12 patients. In all, 17 patients had associated nephrolithiasis, and 5 patients ultimately required nephrectomy. Renal urine cultures were positive in 16 of 21 instances, with multiple organisms found in 8 of 21, and added bacteriological data not provided by bladder urine cultures in 11 cases. A pre-existing history of urinary tract infection, hypertension and malignancy was common. Percutaneous drainage was a safe, quick and effective diagnostic and therapeutic method.

Adult↗
PubMed1992

Adenosine triphosphate and adenosine diphosphate in human semen: correlation with sperm count and motility.

Adenosine triphosphate (ATP) and adenosine diphosphate (ADP) have been correlated with traditional semen parameters such as forward motility and sperm count. ATP and ADP were determined by a bioluminescence assay using the luciferin-luciferase reaction. Short boiling of the ejaculate was performed to inactivate phosphatases (ATPases) in the seminal plasma and the sperm tails. Fresh and deep-frozen semen samples from 45 men with oligozoospermia (n = 22) and normal sperm count (n = 23) were evaluated. Freezing of the sperm for 12 weeks did not effect the ATP or ADP content in the spermatozoa as compared to fresh semen. ATP and ADP concentration was in the range of picomoles/microliter and showed a significant correlation with the number of normal sperm per milliliter and a less marked correlation with the sperm motility. ATP and ADP concentration in the spermatozoa can be measured relatively easy and is reproducible. Unlike the monotonous evaluation of sperm motility by a technician, this biochemical method provides an objective parameter for semen quality. These qualities suggest that this method could be a way to determine the fertilizing potential of semen and to relate this to actual pregnancy rates.

Adenosine Diphosphate↗
PubMed1992

[Initial studies of the possibility of selective ablation of arteriosclerotic vascular changes using laser-induced shock waves].

We studied the effect of laser-induced shock waves in 94 arterial segments from freshly obtained autopsy material. In analogy to the well-established method of shock-wave based lithotripsy, the new principle of our treatment depends on an indirect interaction of the laser energy with the arterial wall via laser-induced mechanical shock waves (angiotripsy). We used a Nd:YAG laser, 1064 nm, 8-20 ns pulse-length to create shock waves that effected smooth craters in arteriosclerotically affected arteries. The histological examination found no thermal damage. Shock waves applied to the healthy and normal arterial wall only resulted in focal intimal ablation and in a minor loosening of the medial structures. The examination of the irrigation solution by means of a laser-guided, high-resolution analysis of the particles revealed that, in 97%, the particles created by our shock wave angiotripsy showed a diameter of less than 5 mm and an area of less than 25 mm2. Based on these first in vitro results, it seems possible to ablate arteriosclerotically affected tissue without significant damage to normal wall segments. Further in vitro and in vivo studies are required to evaluate the clinical implications of this new therapeutic approach.

Angioplasty, Laser↗
PubMed1992

[High-dose-rate brachytherapy of prostatic carcinoma with iridium 192].

In the therapy of localized prostatic cancer the radical prostatectomy shows good results within a five-year interval with no evidence of disease in nearly 90%. An important alternative is the radiotherapy by external beam or interstitial technique with iodine, gold or iridium. We use the high dose rate technique with Ir-192. In this technique five to seven hollow needles are placed in the prostate from perineal punctures under transrectal sonographic control. The three-dimensional brachytherapy planning is done according the actual needle position. A computer program calculates the radiation dose and distribution for each needle by adjustment of time and stops of the Ir-implants. The Ir-192 is temporary loaded twice with 9 Gy supplemented with external beam radiation (18 x 2 Gy). Since 1985 29 patients with localized tumor (T1-T3, N0, M0) have been irradiated. 21/29 had a pelvic lymphadenectomy before. In 85% of the patients were seen no side effects. Only one patient had a serious complication through a recto-vesical fistula. Out of the 21 followed-up patients 16 were in full remission, three had an androgen deprivation because of progression. A local tumor control could be demonstrated by cytology in 70% of the patients. This rational technique seems to be an alternative for patients not eligible for a radical prostatectomy.

Aged↗
PubMed1991

Opitz trigonocephaly syndrome.

We report on a patient with Opitz trigonocephaly syndrome. The girl was the first-born child of consanguineous parents and had trigonocephaly, apparent hypertelorism, upslanted palpebral fissures, strabismus, small nose with broad root, abnormally modeled ears, high palate, short neck with loose skin, polysyndactyly, and prominent clitoris and labia majora. In addition, a complex cardiovascular defect (Eisenmenger disease) was observed. The patient was mentally retarded.

Abnormalities, Multiple↗
PubMed1991

Purification, characterization and mechanism of action of scatter factor from human placenta.

Scatter factor (SF) causes contiguous sheets of epithelium to spread and cells to separate from each other. SF also increases the velocity, area, and reduces the circularity of individual cells. These changes are mediated in part by alterations in protein synthesis, protein phosphorylation, cytoskeletal reorganization, and cell surface components. SF has been purified from the conditioned medium of ras transformed 3T3 cells and human placenta. Sequence information suggests that SF from 3T3 cells is closely related to hepatocyte growth factor. SF is a glycoprotein, but glycosylation is not necessary for its activity. Glycosylation of target cell proteins, however, is required for SF action.

Animals↗
PubMed1991

Immunocytochemical typing of ABO blood groups in vaginal swabs partly contaminated with semen.

ABH typing by immunocytochemical method has been carried out on 163 selected vaginal swabs. 127 cases (78%) were determined correctly, 11 cases (7%) incorrectly and 25 cases (15%) could not be classified. Often, not all of the vaginal cells showed the expected positive staining, which was not counted as a false result. The incorrect results were not dependent on the secretor status, but 37% of the non-secretor cases could not be classified immunocytochemically, as compared with 12% of the secretors. In a second series, 61 vaginal swabs, dried on microscope slides, have been covered with semen from an A1 B secretor. Absorption of heterologous antigens by the vaginal epithelia could be demonstrated only after extremely long incubation with semen and extremely long incubation with the anti-A or anti-B antibodies. From the 163 "native" swabs, 17 gave a positive reaction with the acid phosphatase test, but only one false ABH result. A possible influence of bacteria upon the results is discussed. We believe that in practice, no faults in immunocytochemical ABH typing have to be expected, due to absorption of heterologous antigens.

ABO Blood-Group System↗
PubMed1991

Purulent corporeal cavernositis secondary to papaverine-induced priapism.

Intracavernous autoinjection of vasoactive substances is used to treat erectile dysfunction. Infection of the corpora cavernosa can be a serious life-threatening complication with this treatment modality. Cavernositis is an unusual complication, especially in otherwise healthy men. In diabetic patients with altered blood supply to the penis and a change of cavernous tissue ischemia can lead to a fulminant infection. We report on a 63-year-old diabetic patient who presented with purulent cavernositis a few weeks after beginning intracavernous injection of papaverine. Treatment included bilateral corporotomy, debridement, and placement of intracorporeal irrigation and suction drains. The patient survived this serious infection leaving both corpora cavernosa with severe fibrosis.

Erectile Dysfunction↗