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Biomedical subjects

M Hamm

Publications and source records attributed to M Hamm.

At least 19 recordsLinked to original sources
PubMed2002

Changes in the cell wall network during the thermal dehydration of alfalfa stems.

The effects of heat treatments used to dry alfalfa stems were investigated. Heating at 70 or 100 degrees C caused no major change in the cell wall composition, but xylanase had lower activity on the cell wall of heated material and the amount of xylose released varied with the temperature used. Chemical fractionation of cell wall carbohydrates showed that the main changes occurring during stem dehydration concerned pectic polymers and probably hemicelluloses. There was less material soluble in ammonium oxalate from alfalfa heated at 100 degrees C than from fresh alfalfa. The results suggest that heat processing causes some changes in the cell wall network. Environmental scanning electron microscopy was used to examine fully hydrated tissues at high resolution. There was cell distortion without disruption of cell walls as water was lost.

Carbohydrates↗
PubMed2001

[A young man with adynamia, subepicardial ischemia and sleep apnea].

HISTORY AND CLINICAL FINDINGS: A 44-year-old manager presented himself for the assessment of nocturnal apnoea. He reported increasing lack of drive and nightly angina pectoris. INVESTIGATIONS: Polysomnography indicated obstructive apnoea and hypopnoea with a respiratory disturbance index of 29.1, while the ECG showed T wave inversion in all leads. There was severe hypothyroidism with atrophic thyroid tissue. DIAGNOSIS, TREATMENT AND COURSE: The patient had an obstructive sleep apnoea syndrome (OSAS), hypothyroidism with myxoedema, hypopnoea and myocardial ischaemia. He was treated with negative peak airway pressure (nCPAP) ventilation, administration of L-thyroxine and initiation of anti-anginal medication, which relieved his symptoms. The severe hypothyroidism was thought to be the most important cause of his respiratory disorder and angina. CONCLUSION: This case illustrates the connection between hypothyroidism and OSAS. Hypothyroidism must be excluded in patients with OSAS, regardless of the patient's age.

Adult↗
PubMed2001

[Unenhanced spiral computerized tomography in acute diagnosis of flank pain. Examination in contraindications for contrast medium administration].

The diagnostic value of unenhanced helical computed tomography was investigated in a prospective study. In 53 patients (aged 35 to 82 years) with acute flank pain tomography was performed in addition to abdominal plain film and ultrasound examination. All 53 patients had a contraindication for intravenous administration of contrast medium. Ureteral calculi were either confirmed or excluded by retrograde ureteropyelography in 44 cases, in 9 patients by asservation of calculi and clinical follow-up. Helical computed tomography was able to precisely identify all of the 34 ureteral calculi, whereas abdominal plain films led to 6 false positive and 17 false negative findings. In 1 patient with retroperitoneal lymphoma (diagnosed by CT) false positive findings occurred. Unenhanced helical computed tomography reaches a distinctively increased diagnostic value (sensitivity 100%, specificity 95%, accuracy 97%) in the evaluation of acute flank pain as compared to conventional radiologic imaging and ultrasound. This non-invasive procedure is to be considered method of choice for patients with contraindications for the application of radiopaque material.

Acute Disease↗
PubMed2001

[Long-term treatment of primary pulmonary hypertension with inhaled iloprost].

BACKGROUND: Continuous intravenous infusion of prostacyclin is an effective treatment for primary pulmonary hypertension. This approach, however, requires the insertion of a permanent central venous catheter with the potential risk of serious complications. Recently, administration of aerosolized iloprost, a stable prostacyclin analogue, has been introduced as an alternative therapy for severe pulmonary hypertension. METHODS: We evaluated the effects of treatment with aerosolized iloprost over a one-year period on exercise capacity and hemodynamic variables in patients with primary pulmonary hypertension. RESULTS: Twenty-four patients with primary pulmonary hypertension received aerosolized iloprost at a cumulative daily dose of 100 to 150 micrograms for at least one year. The mean (+/- SD) walking distance in the 6-min-walk test increased from 278 +/- 96 meters at base line to 363 +/- 135 meters after 12 months (P < 0.0001). During the same period, the mean pulmonary artery pressure declined from 59 +/- 10 mmHg to 52 +/- 15 mmHg (P = 0.006), the cardiac output increased from 3.8 +/- 1.4 l/min to 4.4 +/- 1.3 l/min (P = 0.02), and the pulmonary vascular resistance declined from 1.205 +/- 467 dynes.s.cm-5 to 925 +/- 469 dynes.s.cm-5 (P = 0.0003). Treatment was generally well tolerated and except for mild coughing, minor headache and jaw pain in some patients, no side effects occurred. CONCLUSIONS: Long-term treatment with aerosolized iloprost is safe and has sustained effects on exercise capacity and pulmonary hemodynamics in patients with primary pulmonary hypertension.

Administration, Inhalation↗
PubMed2001

Biochemical course after radical retropubic prostatectomy: preliminary results.

OBJECTIVE: To investigate prognostic factors in localized and lymphatically spread prostate cancer. METHODS: The biochemical course after radical retropubic prostatectomy in 306 patients was subject to a retrospective analysis. RESULTS: Prostate-specific antigen (PSA), Gleason score (prostatectomy specimen) and pathological stage proved to be prognostically relevant (p < 0.0001). PSA, Gleason score and tumor stage also were to be considered as (independent) prognostic factors by means of a multivariate analysis (p < 0.001), whereas perineural invasion (prostatectomy specimen) and preoperative bone marrow findings (CK 2) had no impact on the course of the disease. After a median follow-up of 1,307 days (3.6 years), a biochemical relapse occurred in 41.8%. CONCLUSION: High preoperative PSA values and the resulting high portion of advanced tumor stages are a possible basis for the high biochemical relapse rate in our collective. The learning curves of several surgeons and the previously more restrictive pelvic lymphadenectomy (surgical understaging) may also be considered causes.

Aged↗
PubMed2001

Unenhanced helical computed tomography in the evaluation of acute flank pain.

OBJECTIVE: The diagnostic value of unenhanced helical computed tomography (CT) for the evaluation of acute flank pain is investigated in a prospective study. PATIENTS AND METHODS: In 125 patients aged 18-86 years, we performed unenhanced helical CT in addition to abdominal plain film, abdominal ultrasound and urinalysis as a diagnostic measure for acute flank pain. Ureteral calculi were confirmed or, respectively, excluded by retrograde ureteropyelography in 80 cases. In the other cases, diagnosis was verified by clinical course and/or stone asservation. RESULTS: In 91 of 125 patients the flank pain was caused by a ureteral calculus. In 67 of 91 patients with urolithiasis, stones could be collected for analysis. Helical CT was able to precisely identify 90 ureteral calculi. Abdominal plain films led to 8 false-positive and 48 false-negative findings. Thus, sensitivity of plain radiography, ultrasound and urinalysis was 47, 11 and 84% with a specificity 76, 97 and 32%, respectively. CONCLUSIONS: Unenhanced helical CT reaches a distinctively increased diagnostic value (sensitivity 99%, specificity 97%) in the evaluation of acute flank pain as compared to plain radiography, ultrasound and urinalysis.

Acute Disease↗
PubMed2001

Radioisotope guided pelvic lymph node dissection for prostate cancer.

PURPOSE: The localization of lymph node metastases in prostate cancer varies enormously. Due to high morbidity complete pelvic lymphadenectomy is often decreased to modified staging lymphadenectomy, resulting in loss of sensitivity for detecting micrometastases. Based on the promising results of intraoperative gamma probe application for identifying sentinel lymph nodes in malignant melanoma, breast and penis cancer, we identified sentinel lymph nodes in prostate cancer using a comparable technique. MATERIALS AND METHODS: In 117 patients 99mtechnetium nanocolloid was transrectally injected directly into the prostate under ultrasound guidance 1 day before pelvic lymphadenectomy. Thereafter dynamic lymphoscintigraphy was done. Initially lymph nodes identified as sentinel lymph nodes by the gamma probe were removed and subsequently modified pelvic lymphadenectomy was performed. RESULTS: Lymphatic metastasis was detected in 28 cases. An average of 4 sentinel lymph nodes were identified per patient in 25 of 27 patients with micrometastasis, of which those in 24 contained micrometastasis for 96% sensitivity. In contrast, sensitivity of modified pelvic lymphadenectomy was 81.5%. In 16 patients only sentinel lymph nodes were positive. An average of 21.8 lymph nodes (range 10 to 51) was dissected per patient at pelvic lymphadenectomy. Lymph node metastasis was noted in 6 of the 46 patients with a prostate specific antigen between 4 and 10 ng./ml. and in 8 of the 64 with a stage pT2 tumor. CONCLUSIONS: Our study shows individual variability of lymphatic drainage of the prostate and limited sensitivity for detecting positive lymph nodes when the pelvic dissection area is limited. Furthermore, our experience implies that the identification of sentinel lymph nodes is feasible, not only in breast cancer and malignant melanoma, but also in prostate cancer using a comparable technique.

Aged↗
PubMed2000

Long-term treatment of primary pulmonary hypertension with aerosolized iloprost, a prostacyclin analogue.

BACKGROUND: Continuous intravenous infusion of epoprostenol (prostacyclin) is an effective treatment for primary pulmonary hypertension. This approach requires the insertion of a permanent central venous catheter, with the associated risk of serious complications. Recently, aerosolized iloprost, a stable prostacyclin analogue, has been introduced as an alternative therapy for severe pulmonary hypertension. METHODS: We evaluated the effects of aerosolized iloprost on exercise capacity and hemodynamic variables over a one-year period in patients with primary pulmonary hypertension. RESULTS: Twenty-four patients with primary pulmonary hypertension received aerosolized iloprost at a daily dose of 100 or 150 microg for at least one year. The mean (+/-SD) distance covered in the six-minute walk test increased from 278+/-96 m at base line to 363+/-135 m after 12 months (P<0.001). During the same period, the mean pulmonary arterial pressure before the inhalation of iloprost declined from 59+/-10 mm Hg to 52+/-15 mm Hg (P=0.006), cardiac output increased from 3.8+/-1.4 liters per minute to 4.4+/-1.3 liters per minute (P=0.02), and pulmonary vascular resistance declined from 1205+/-467 dyn x sec x cm(-5) to 925+/-469 dyn x sec x cm(-5) (P<0.001). The treatment was generally well tolerated, except for mild coughing, minor headache, and jaw pain in some patients. CONCLUSIONS: Long-term treatment with aerosolized iloprost is safe and has sustained effects on exercise capacity and pulmonary hemodynamics in patients with primary pulmonary hypertension.

Administration, Inhalation↗
PubMed2000

First experience with gamma probe guided sentinel lymph node surgery in penile cancer.

Because of the curative approach, the detection of lymph node metastases in squamous cell carcinoma (SCC) of the penis is of significant clinical relevance. Sentinel lymph node (SLN) identification by means of lymphangiography has been proven to be insufficiently safe. However, the high morbidity of inguinal lymphadenectomy and the considerable individual variability regarding the location of lymph node metastases justify the necessity of a technique that enables the identification of SLNs. Since 1998, SLNs have been intraoperatively identified and selectively dissected, after peritumoral injection of technetium-99m nanocolloid and using lymphoscintigraphy, in three patients (one with malignant melanoma and two with SCC). At least one SLN could be detected in each patient. The maximum surgical time was 30 min. There were no severe complications. Lymph node metastases did not occur in any patient. Upon a mean follow-up of 10 months, all patients are currently free of tumor. Owing to the long-term results of sentinel lymphadenectomy in malignant melanoma of other locations and our preliminary results with respect to penile carcinoma. we consider the current method appropriate as the only primary operation for lymph node staging in early stages and, in combination with modified inguinal lymphadenectomy, in locally advanced stages.

Aged↗
PubMed1999

[Malignant mesothelioma of the tunica vaginalis testis].

A case of malignant mesothelioma of the tunica vaginalis testis is reported in a 77-year-old male patient. There was no history of asbestos exposure. Recurrent right hydrocele with a papillar inguinal mass was the main clinical feature. An inguinal radical orchiectomy with en bloc resection of the surrounding tissue was performed. The therapeutic options for this rare, but aggressive neoplasm are discussed. Because of the disappointing results of antineoplastic chemotherapy or radiation therapy, the importance of initial radical surgical treatment with complete excision is emphasized.

Aged↗
PubMed1999

[Therapy of extrinsic ureteral obstruction by 2 parallel double-J ureteral stents].

We present our experiences with the approach of placing 2 parallel ureteral Double-J stents simultaneously in extrinsically obstructed ureters. In all 5 reported patients therapy with single ureteral stents had failed despite correct stent position. With the increased stiffness of 2 parallel ureteral silicon 7F Double-J stents ureteral kinking and luminal compression could be reduced leading to sufficient reduction of hydronephrosis. This approach with potential space between the stents preserves urinary flow through as well as around the stents which is considered to be the most important mechanism in stented ureters. In cases of extrinsic ureteral obstruction with failure of a single stent the simultaneous use of 2 parallel Double-J ureteral stents should be taken into account as a technically easy therapeutic option. It may obviate percutaneous nephrostomy tube placement or more invasive therapy.

Adolescent↗
PubMed1999

Determination of cardiac output by the Fick method, thermodilution, and acetylene rebreathing in pulmonary hypertension.

Assessment of cardiac output is an important part of the management of patients with pulmonary hypertension. The accuracy of the thermodilution technique in patients with low cardiac output or severe tricuspid regurgitation has been questioned. To address this issue, we simultaneously compared 105 cardiac output measurements by the Fick method and thermodilution in 35 patients with pulmonary hypertension. Moreover, we evaluated the acetylene rebreathing technique, a noninvasive method of determining cardiac output. The mean difference +/- 95% limit of agreement between thermodilution and the Fick method was +0.01 +/- 1.1 L/min. The mean difference +/- 95% limit of agreement between acetylene rebreathing and the Fick method was -0.23 +/- 1.14 L/min. Neither the mean agreement nor the 95% limits of agreement of both thermodilution and acetylene rebreathing with the Fick method were affected by the presence of low cardiac output or severe tricuspid regurgitation. We conclude that thermodilution and acetylene rebreathing are useful tools for assessing cardiac output in patients with pulmonary hypertension, even in the presence of low cardiac output or severe tricuspid regurgitation.

Acetylene↗
PubMed1999

["Since when have you had mucoviscidosis?" Comment on as yet rarely recognized disease entity in internal medicine].

In Germany, many adult patients with cystic fibrosis are still treated by pediatricians. There are still not enough specialists for internal medicine (and particularly pulmonologists) with sufficient knowledge about cystic fibrosis for the treatment of estimated 2000 adult CF-patients. The knowledge about the three basic principles of cystic fibrosis therapy--regular high-dose antibiotics, high-energy and high-fat nutritional support and specific physiotherapy--has to be transferred to adult medicine in order to assure competent care for this "new" group of patients. Cystic fibrosis is also becoming more and more and more important in the field of intensive care medicine and transplantation. Specific diagnostic procedures are important in adult respiratory medicine in order to confirm or exclude late manifestations of the disease. Understanding of the genetic basis of cystic fibrosis and the correlations between genotype and phenotype is beginning to emerge.

Adult↗
PubMed1999

[Lung transplantation in Hanover: an interim balance-sheet after ten years].

BACKGROUND: We reviewed our experience with various forms of lung transplantation (heart-lung [HLTx], bilateral lung [BLTx] and single lung [SLTx]) from December 1987 to September 1998 at Hannover University. PATIENTS: In 258 patients 282 procedures (46 HLTx, 142 BLTx and 94 SLTx) were performed. Major indications were pulmonary fibrosis (n = 73), obstructive lung disease (n = 55), cystic fibrosis (n = 48), primary pulmonary hypertension (PPHT, n = 36), secondary pulmonary hypertension (n = 30) and retransplantation (n = 24). RESULTS: The 1-, 3- and 5-year survival rates in all 258 recipients were 77%, 70% and 63% respectively. Significantly better 1-year survival was noted in patients with cystic fibrosis (90%), pulmonary fibrosis (81%), obstructive lung disease (71%) and secondary pulmonary hypertension (83%) when compared to patients with primary pulmonary hypertension (58%). There was no significant difference in actuarial 1-year survival rates between the different procedures (HLTx 78%, BLTx 77%, SLTx 77%). Bronchiolitis obliterans syndrome (BOS) proved to be the major obstacle for long term survival. Actuarial freedom from BOS was 80% at 1 year and only 45% at 5 years. Various treatment strategies including augmentation of immunosuppression could only temporarily halt the deterioration of lung function in the majority of patients with BOS. CONCLUSIONS: Lung transplantation provides a true therapeutic option for patients with endstage lung disease. However, improved long term outlook will depend on a better understanding and treatment of bronchiolitis obliterans.

Adolescent↗