Search PubMed⌕ Search

Biomedical subjects

M Thoma

Publications and source records attributed to M Thoma.

At least 37 records · Page 2Linked to original sources
PubMed1992

A model for penicillin production with and without temperature shift after the growth phase.

A strain of Penicillium chrysogenum producing about 8 milligrams/l of penicillin V, was cultivated in a 10-1 bioreactor. Under carbon (C)-limitation during the production phase a glucose/ammonium sulphate mixture was fed using microprocessor control. When the temperature was shifted from 25 degrees C to 30 degrees C at the end of the active growth phase, the specific penicillin production rate was increased by 30%, while the yield remained constant. Maximal productivity without sporulation was obtained when the net growth rate of the active (respiring and producing) biomass, estimated by measuring the respiration rate under defined conditions, was equal to or higher than 0.004 h-1. A model was developed for penicillin fermentation during C-limitation possessing the following properties: (1) the model is based on ordinary differential equations; (2) the influence of different nutrients is considered; (3) the model recognizes two cell types (active and inactive); (4) the model describes the influence of a temperature shift at the end of the vigorous growth phase.

Fermentation↗
PubMed1991

Protection of immunosuppressed mice against infection with Pseudomonas aeruginosa by recombinant P. aeruginosa lipoprotein I and lipoprotein I-specific monoclonal antibodies.

Outer membrane protein I (OprI) is one of the major proteins of the outer membrane of Pseudomonas aeruginosa. The protective effect of OprI vaccination and that of three OprI-specific monoclonal antibodies (MAbs) against infection with P. aeruginosa were tested in immunosuppressed mice. The combination of Oprl and MAb 2A1 protected the mice against a challenge with a 96-fold 50% lethal dose. The binding site of MAb 2A1 was mapped, resulting in the identification of a protective epitope (amino acids 7 to 20).

Animals↗
PubMed1989

[Neonatal pleuropulmonary staphylococcal infection with multiple abscesses of the liver].

We report the case of a neonate who developed septicemia due to a methicillin-susceptible Staphylococcus aureus strain at six days of age. At eight days of age, physical evaluation revealed a tense, tender abdomen and further enlargement of the liver, and abdominal ultrasonography demonstrated multiple liver abscesses. On the following day, pleuropulmonary lesions developed and required mechanical ventilation. Recovery was achieved using parenteral vancomycin and fosfomycin for 15 days followed by oral pristinamycin for ten days. This case is unusual in that the infection was acquired by the digestive route probably as a result of lymphangitis of the breast in the mother, and multiple liver abscesses were associated with the pleuropulmonary localization. It provides further evidence of the value of ultrasonography for the diagnosis and monitoring of liver abscesses, including multiple abscesses.

Female↗
PubMed1983

[Echographic aspects of biliary lithiasis and its complications].

Ultrasonic appearances of various types of gallbladder stones are described and findings on ultrasonic imaging of the main complications of biliary lithiasis analyzed. New possibilities for examination of the principal biliary pathway are being opened up by progress in improving resolution of the ultrasonoscope and by advances in knowledge of ultrasonic anatomy of the biliary tracts.

Biliary Fistula↗
PubMed1976

[Biological availability of potassium from a sustained release preparation].

The bioavailability of potassium from a sustained-release KC1 preparation has been compared in 10 healthy volunteers with that of a non-sustained-release KC1 coated tablet by means of urinary elimination data. From the 40 mEq KC1 additionally administered, 35.2 mEq (88%) and 35.5 mEq (88.8%) respectively were eliminated by the kidneys. On the evidence of this elimination data the sustained-release potassium preparation showed the same bioavailability as the non-sustained-release KC1 tablets. The retard form was excellently tolerated.

Biological Availability↗
PubMedDate not supplied

Predictability of the size of laser-induced lesions in T1-Weighted MR images obtained during interstitial laser-induced thermotherapy of benign prostatic hyperplasia.

The purpose of this study was to predict diameters of lesions induced by laser-induced thermotherapy (LITT) of benign prostatic hyperplasia (BPH) from MRI signal/tissue temperature correlations during on-line monitoring with a temperature-sensitive fast low-angle shot (FLASH) sequence. Twenty LITT procedures with Nd:YAG (1,064 nm) and diode (830 nm) lasers were monitored on line with a T1-weighted FLASH sequence at 1.5 Tesla. Interstitial prostate temperature (T) was measured on line in 10 LITT procedures and laser energy deposition in 12. Slopes of linear regression curves for signal intensity (SI) over T were applied to determine SI at 60 degrees C to estimate diameters of intraprostatic LITT lesions. Diameters of unperfused LITT lesion cores in contrast-enhanced T1-weighted images served as gold standards. Linear regression curves with an average slope of -.54% SI/degrees C were obtained in 17 LITT procedures. Correlation coefficients were r = .92-.95 for SI/T and SI/energy deposition. Baseline variation of SI at body temperature was +/-3.9%, corresponding to +/-7 degrees C. Prediction of size (13 lesions) from on-line FLASH imaging was correct in 10 of 13, whereas 3 lesions were overestimated. Prediction of LITT lesion diameters from on-line MRI monitoring is possible with a temperature-sensitive FLASH sequence in the prostate. Accuracy may suffice to assign target regions of interest to tissue locations to be protected from coagulation.

Aged↗
PubMedDate not supplied

[Early results of a prospective study in patients with computer-assisted femur shaft preparation in total hip endoprosthesis implantation (Robodoc system)--indications, outcome, complications].

AIM: Indications, results, advantages and disadvantages of the computer-guided femoral preparation in total hip arthroplasty (Robodoc) in our patients are recorded and represented. METHOD: 41 patients who underwent a computer-guided femoral preparation in total hip arthroplasty (Robodoc) were examined after 1 year on average in a prospective study. The evaluation was made using the Harris Hip Score. The advantages and disadvantages of the Robodoc-assisted surgery are described. RESULTS: More than 80% of the patients had a good or very good result (> 80 points of Harris Hip Score) 3 month after surgery; after 6 months in 20 of 21 patients a score of more than 85 pts. was calculated. The following complications were noticed: thrombotic embolism (2) with one lethal embolism included, fracture of the greater trochanter using the straight stem (3), aseptic drainage due to hematoma (2). 12 patients noticed a postoperative pain at the distal marking pin location (condylus femoris medialis) for an average of 3 months. CONCLUSION: Generally, Robodoc-assisted surgery may be performed in all uncemented total hip arthroplasties. The individual indication should be checked because of the increased effort of surgery, the advantages and disadvantages, and the non-proven better long-term results in comparison to the regular technique. It seems that the Robodoc system provides advantages in post-traumatic arthritis and deformities of the proximal femur (varus and valgus neck) on account of the computer-aided preoperative planning and correct operative realization.

Adult↗
PubMedDate not supplied

Left paraduodenal hernia: a case report.

Congenital internal hernias often remain unrecognized since they are infrequent and produce nonspecific abdominal symptoms. Abdominal imaging during a symptomatic episode leads to the diagnosis. Surgical treatment is essential regarding the risks of incarceration. We report a case of left paraduodenal hernia misdiagnosed for over thirty years despite extensive imaging and surgical exploration.

Abdominal Pain↗
PubMedDate not supplied

Domain formation in monolayers.

For phospholipids at the air/water interface we demonstrate that molecular chirality in some, but not in all, cases influences the domain shapes. In other cases chirality in the head group region can cause a chiral structure considering the tail arrangement. This indicates head group ordering. Minute changes of the molecular structure may change domain morphology from circular to dendritic. This can be related to slight changes of the lattice structure. In case of a dendritic domain the chains are more tilted, the deviation from hexagonal symmetry is more pronounced, and hence the lattice anisotropy is larger. This can be understood also in view of recent simulations considering diffusion-limited aggregation models. In experiments at the oil/water interface we show that the electrostatic repulsion between domains is reduced by exchanging air against oil. Also line tension is reduced which can be understood by means of simple molecular models. The oil may penetrate into domains of the ordered phase if it is aliphatic and exhibits the same chain length as the lipid. In other cases it is excluded from the ordered monolayer regions. Taking aliphatic dioles as the most simple models we show that head group chirality is expressed in domain shapes, and partly also in lattice structure.

Biophysical Phenomena↗
PubMedDate not supplied

The influence of obesity on the disease-free survival in primary breast cancer.

Hyper-estrogenism is more common in obese than in non-obese women. Consequently obesity has been shown to increase the risk of hormone department tumors. Some investigators have claimed that obesity at the time of primary treatment may be an independent prognostic factor for breast cancer, but this issue is still controversial. Therefore, we conducted a retrospective analysis to assess the influence of obesity at the time of primary treatment on disease-free survival (DFS). Obesity was defined as an excess of more than 25% of ideal weight according to Broca's index ([Height (cm) -100])-10%). The Cox-model was used for multivariate analysis. Mean follow-up was 61 (range 6-126) months. 295 (62.3%) patients were classified as of normal weight and 178 (37.6%) as obese. Mean excess of ideal weight was 8.9 kilograms (kg) in premenopausal and 13.9 kg in postmenopausal patients (non-parametric t-test p < 0.00001). Patients with tumor size < 20mm, 20-50mm and > 50mm had a means excess of the real weight of 10.6kg, 12.5kg and 16.1kg, respectively (non-parametric t-test p < 0.0001). Percentual excess of real weight compared to ideal weight was 22.4 [+/-21.2] kg in patients without recurrence and 21.5 [+/-21.9] in patients with recurrent disease (nonparametric t-test p = 0.7256). Univariate analysis revealed no significant association between obesity and the DFS. Multivariate analysis identified axillary lymph node involvement as the only statistically significant prognostic factor for disease-free survival (RR 1.55; 95%-confidence interval 1.02-2.36; p:0.0368). Because of the high correlations and node-status, tumor size and histological grading, the other factors failed to be prognostically relevant in this analysis. Obesity was not found to influence DFS of patients with primary breast cancer and is therefore unlikely to constitute an independent prognostic factor. It may, however, contribute to delayed diagnosis, since a significant proportion of obese patients were diagnosed with local advanced disease.

Breast Neoplasms↗