Online process control for directional solidification by ultrasonic pulse echo technique

A method of controlling the actual growth velocity during directional solidification based on ultrasound has been developed. For this purpose a pulse echo technique is used to measure the actual solidification rate online. This quantity is used to control the furnace velocity. Solidification experiments with metallic alloys and constant furnace velocity often result in non-steady actual solidification rates. Experiments carried out with online process control demonstrate that a really steady-state solidification with a constant solidification rate is achieved.

Soil-to-grain transfer of fallout 137Cs for 28 winter wheat cultivars as observed in field experiments

In order to find wheat cultivars with a minimum soil-to-grain transfer of fallout (137)Cs, 28 winter wheat cultivars were investigated at 3 different sites with different soil types in Bavaria, Germany. Each cultivar was grown on an area of 10 m(2) and harvested in August 1999. The soil-to-grain concentration ratios (C(r)) of (137)Cs varied by a factor of up to 3 from cultivar to cultivar at a given site and from site-to-site for a given cultivar. The mean C(r) values at the three sites, 4.2 x 10(-4), 4.9 x 10(-4) and 7.5 x 10(-4), differed significantly. The fact that no cultivar showed similar C(r) values at the three sites indicates a strong influence of the soil on C(r). The cultivars Flair, Kornett and Previa showed a minor uptake of (137)Cs compared with the mean of all cultivars at each site. Unlike (137)Cs, the (40)K concentrations in the wheat grains varied only within a small range (122-190 Bq kg(-1)) at each site, which is due to the potassium regulation by the plants. For both radionuclides, the differences between the root uptake characteristics of the cultivars may not only be explained by an inter-cultivar variability due to genetic differences between the cultivars, but also by an intra-cultivar variability due to different soil conditions.

[Clinical usefulness and perspectives of sentinel node biopsy in the management of breast cancer]

INTRODUCTION

In view of its predictive potential, axillary nodal status plays a particularly important role in breast cancer. The concept of sentinel node biopsy (SNB) revealed an accurate method with low postoperative morbidity for staging the axilla in patients with lymph node-negative breast cancer. The aim of this study was to show that SNB alone must have a place in routine clinical work and is reliable after preoperative chemotherapy (PC) and also in patients with multicentric tumors (MC).

PATIENTS AND METHOD

Between April 1997 and March 2002, a total of 300 SNBs were performed in patients with uni- or bilateral breast cancer. Of them, 45 who had completed PC and 13 with multicentric lesions underwent SNB followed by axillary dissection. The sentinel nodes (SN) were labelled with a blue dye and radioactive colloids. Median follow-up was 33.6 months (range 8.2-67.0) (StAw 1.4).

RESULTS

The detection rate in the learning phase was 81.8% and later 93.5%, independently of the size of the primary tumor. Overall accuracy and negative predictive value of the first 55 patients, after PC and in those with MC came to 97.8% and 96.7%, 97.6%, 95.8% and 100%, respectively. Through focused pathologic examination, staging was improved in 11.3% of patients. A year after the procedure, one patient developed recurrence. Morbidity after SNB alone was significantly lower than after axillary dissection.

CONCLUSION

Our experience shows SNB to be reliable and accurate for axillary staging in breast cancer patients. Morbidity after SNB alone was low. Conclusive data on the local recurrence rate are not yet available. Under certain conditions, SNB appears to have future clinical potential, even in patients with PC and MC, which must be confirmed in further multicentric studies. In the meantime, this method has attained definite value in the surgical therapy of breast cancer patients.

Expression of beta hCG and alpha CG mRNA and hCG hormone in human decidual tissue in patients during tubal pregnancy

We recently showed that endometrial tissue produces hCG during the secretory phase of the menstrual cycle. Based on these findings, we hypothesized that the decidua should also be able to secrete hCG. We examined the decidualized endometrium of patients with extrauterine pregnancies. Decidual specimens were obtained for mRNA extraction and paraffin embedding from 24 patients that were between weeks 6-11 of tubal pregnancy. Tissues were evaluated and classified into one of three groups based on the endometrial differentiation that took place prior to conception: (A) high secretory transformation, (B) diminished transformation with restricted decidualization and (C) inferior endometrial proliferation. Decidual gland hCG secretion was demonstrated immunohistochemically and by Western blotting. Serum hCG levels were higher (P < 0.0001) in patients from group A than group C. mRNA expression of both the beta subunit (beta-hCG) and alpha subunit (alpha-CG) was determined by RT-PCR. Furthermore, the specificity of beta-hCG amplification was confirmed by restriction enzymes. beta-LH amplification was not found. Moreover, the degree of endometrial transformation and the level of decidualization was found to correlate with hCG hormone staining and beta-hCG mRNA expression. hCG protein in the decidua was present in the glands of the compact layer and in the spongy layer, and was more pronounced in previously transformed high secretory endometrium than in inferior endometrium. In conclusion, this study provides the first evidence that hCG is produced in the decidua of patients during extrauterine pregnancies and might play a possible paracrine role.

Shoulder-arm morbidity following axillary dissection and sentinel node only biopsy for breast cancer

AIMS

The purpose of this study was to examine the outcome of shoulder-arm morbidity in patients with breast cancer after various axillary staging procedures. We used a new specific summation score to compare conventional axillary node dissection (AD) and sentinel node only biopsy for postoperative shoulder-arm morbidity.

METHODS

Eighty-five patients undergoing conventional AD and 66 patients undergoing sentinel node biopsy were evaluated both subjectively (questionnaire) and objectively (clinical examination) for reduced muscle strength, limited range of motion, lymphedema and pain, dysesthesias and loss of sensitivity. The symptoms elicited were rated by their severity with a single summation score describing all symptoms reported.

RESULTS

Subjective evaluation of patients undergoing breast conserving surgery showed a highly significant difference in favor of SNB only (P< or =0.002). On clinical examination the outcome of patients with SNB only was also significantly or highly significantly better (difference in arm volume:P =0.007; difference in arm muscle strength: P=0.016; loss of sensitivity: P<0.001). Of a total score of 100 (=no symptoms), the mean for AD patients was 80.2 vs 92.8 for SNB patients (P=0.001). In patients undergoing total mastectomy the difference was only significant for pain sensations and total scores.

CONCLUSIONS

SNB appears to reduce morbidity. Summation scores are a suitable and practicable tool for describing the symptoms associated with axillary surgery.

[Rapid induction of withdrawal with opiate antagonists under anesthesia: an alternative to treatment of opiate dependence?]

Rapid induction of withdrawal by opiate antagonists under anesthesia is an opiate detoxification technique. This technique is useful to reduce intensity and duration of withdrawal. Therefore, this technique represents an alternative strategy in the treatment of opiate addicted patients. This paper attempts to present a brief history of this technique, and a critical review of related issues.

Is sentinel lymph node biopsy reliable and indicated after preoperative chemotherapy in patients with breast carcinoma?

BACKGROUND

Many studies support the concept and accuracy of sentinel lymph node biopsy (SNB) for staging patients with breast carcinoma, which can be performed with low morbidity in lymph node negative patients. Preoperative chemotherapy (PC) plays an important role in the treatment of patients with operable breast carcinoma and is another approach with which to reduce radical surgery in patients with more advanced disease. It is of interest whether the sentinel lymph node accurately represents the axillary status after PC and, thus, whether the sentinel node concept can be applied to both groups.

METHODS

Thirty-three patients underwent SNB after chemotherapy and prior to axillary lymph node dissection.

RESULTS

The average greatest tumor dimension before chemotherapy (33 mm +/- 2 mm) was significantly larger (P = 0.000) than after therapy (20 mm +/- 3 mm). Histopathologic complete remission was seen in only three patients. One or two sentinel lymph nodes (average, 1.7 lymph nodes) were identified with certainty in 29 of 33 procedures and accurately predicted axillary lymph node status in all of these patients. Breast-conserving surgery was possible in 21 patients (64%), and axillary lymph nodes were involved in 22 patients (67%).

CONCLUSIONS

Even after patients undergo PC, SNB seems to be a reliable method for accurate staging of the axilla in those more advanced breast carcinoma. Thus, axillary dissection may be avoided in certain patients. Lymph node involvement seems to be likely in women with suspicious axillary findings before chemotherapy who have no visible sentinel lymph nodes on preoperative lymphosintigraphy and in patients without recurrent tumors. Further investigation of the SNB concept in this patient group should be evaluated in larger studies.

Pyrimidine-2,4,6-Triones: a new effective and selective class of matrix metalloproteinase inhibitors

Matrix metalloproteinases (MMPs) are a family of zinc endopeptidases that have been implicated in various disease processes. Different classes of MMP inhibitors, including hydroxamic acids, phosphinic acids and thiols, have been previously described. Most of these mimic peptides and most likely bind in a similar way to the corresponding peptide substrates. Here we describe pyrimidine-triones as a completely new class of metalloprotease inhibitors. While the pyrimidine-trione template is used as the zinc-chelating moiety, the substituents have been optimized to yield inhibitors comparable in their inhibition efficiency of matrix metalloproteinases to hydroxamic acid derivatives such as batimastat. However, they are much more specific for a small subgroup of MMPs, namely the gelatinases (MMP-2 and MMP-9).