[Compromising due to additive cerclages : Can surgical treatment of humeral shaft fractures cause damage to the radial nerve?]

BACKGROUND

In many cases the treatment of humeral shaft fractures is challenging and despite the large diversity of available approaches, no standard treatment exists. In addition to conservative treatment, intramedullary nails and plate osteosynthesis are competing methods for healing humeral shaft fractures. Furthermore, cerclage is considered to be an additive treatment for spiral fractures; however, this also increases the risk of radial nerve neuropathy and is said to compromise the perfusion of bone fragments. The goal of this study was to investigate secondary radial nerve neuropathy using additive and limited invasive cerclages for nail osteosynthesis of humeral shaft fractures.

METHODS

In the present study a total of 102 patients with humeral shaft fractures were clinically and neurologically re-examined after having been treated with nail osteosynthesis and additive cerclage via a limited invasive access over the past 5 years. In total 193 cerclages with limited invasive access were inserted during this time period.

RESULTS AND CONCLUSION

Of the patients four (3.9%) showed a secondary radial neuropathy during operative stabilization. Neurophysiological and neurosonographic examinations revealed that this had not been caused by compromising, embedding or severance of the radial nerve due to the cerclage. Two out of these nerve lesions recovered spontaneously within 3 and 6 months, respectively. The other two cases could not be documented over a period of 12 months due to death of the patient. With 3.9% of iatrogenic radial nerve lesions the rate of nerve lesions falls into the lower range of that which has previously been described in the literature for nerve lesions due to operative treatment of humeral shaft fractures (3-12%). We thus conclude that there is no increased risk for iatrogenic injury of the radial nerve using additive and limited invasive cerclage.

Dosimetric characteristics of the novel 2D ionization chamber array OCTAVIUS Detector 1500

PURPOSE

The dosimetric properties of the OCTAVIUS Detector 1500 (OD1500) ionization chamber array (PTW-Freiburg, Freiburg, Germany) have been investigated. A comparative study was carried out with the OCTAVIUS Detector 729 and OCTAVIUS Detector 1000 SRS arrays.

METHODS

The OD1500 array is an air vented ionization chamber array with 1405 detectors in a 27 × 27 cm(2) measurement area arranged in a checkerboard pattern with a chamber-to-chamber distance of 10 mm in each row. A sampling step width of 5 mm can be achieved by merging two measurements shifted by 5 mm, thus fulfilling the Nyquist theorem for intensity modulated dose distributions. The stability, linearity, and dose per pulse dependence were investigated using a Semiflex 31013 chamber (PTW-Freiburg, Freiburg, Germany) as a reference detector. The effective depth of measurement was determined by measuring TPR curves with the array and a Roos chamber type 31004 (PTW-Freiburg, Freiburg, Germany). Comparative output factor measurements were performed with the array, the Semiflex 31010 ionization chamber and the Diode 60012 (both PTW-Freiburg, Freiburg, Germany). The energy dependence of the OD1500 was measured by comparing the array's readings to those of a Semiflex 31010 ionization chamber for varying mean photon energies at the depth of measurement, applying to the Semiflex chamber readings the correction factor kNR for nonreference conditions. The Gaussian lateral dose response function of a single array detector was determined by searching the convolution kernel suitable to convert the slit beam profiles measured with a Diode 60012 into those measured with the array's central chamber. An intensity modulated dose distribution measured with the array was verified by comparing a OD1500 measurement to TPS calculations and film measurements.

RESULTS

The stability and interchamber sensitivity variation of the OD1500 array were within ±0.2% and ±0.58%, respectively. Dose linearity was within 1% over the range from 5 to 1000 MU. The effective point of measurement of the OD1500 for dose measurements in RW3 phantoms was determined to be (8.7 ± 0.2) mm below its front surface. Output factors showed deviations below 1% for field sizes exceeding 4 × 4 cm(2). The dose per pulse dependence was smaller than 0.4% for doses per pulse from 0.2 to 1 mGy. The energy dependence of the array did not exceed ±0.9%. The parameter σ of the Gaussian lateral dose response function was determined as σ6MV = (2.07 ± 0.02) mm for 6 MV and σ15MV = (2.09 ± 0.02) mm for 15 MV. An IMRT verification showed passing rates well above 90% for a local 3 mm/3% criterion.

CONCLUSIONS

The OD1500 array's dosimetric properties showed the applicability of the array for clinical dosimetry with the possibility to increase the spatial sampling frequency and the coverage of a dose distribution with the sensitive areas of ionization chambers by merging two measurements.

Skin tolerance of a new bath oil containing St. John's wort extract

BACKGROUND

Dry and atopic skin requires skin care with lipid-rich emollients and moisturizing bath or shower oils. However, it has been shown recently that some bath oils may even impair the skin barrier.

OBJECTIVE

To investigate the skin-irritating potential of a new bath oil containing a lipophilic St. John's wort (Hypericum perforatum) extract.

METHODS

In this single-center, randomized, double-blind, prospective study, 3 bath oils together with positive and negative controls were applied under occlusion on test areas on the volar forearms of 18 volunteers (visit 1). After 24 h, the tapes were removed, and the test areas were evaluated by a visual score and the instrumental measurement of skin erythema and transepidermal water loss (TEWL) using a Mexameter and a Tewameter (visit 2). The test substances were applied a second time, and the measurements were performed after another 24 h (visit 3).

RESULTS

The positive control, 1% vol/vol sodium lauryl sulfate (SLS), caused a significant increase in skin erythema and TEWL. In contrast, distilled water as a negative control did not influence these parameters. The new bath oil containing St. John's wort extract and 1 of the other 2 commercial products were not different from the water control. The third bath oil displayed a skin-irritating effect similar to SLS.

CONCLUSION

The results of this study confirm the different skin-irritating potential of bath oils and demonstrate good skin tolerance of the new bath oil containing St. John's wort extract.

[Erythema annulare centrifugum Darier. Successful therapy with topical calcitriol and 311 nm-ultraviolet B narrow band phototherapy]

Erythema annulare centrifugum is an acute dermatosis of unclear etiology, which presents with annular erythematous lesions with marginal scale. Therapeutically, systemic and topical glucocorticosteroids are used primarily. We treated a patient with large lesions in the area of the thighs resistant to a therapy with topical glucocorticosteroids, with topical calcitriol in combination with 311 nm ultraviolet B narrow band phototherapy. After four weeks of treatment the skin lesions had cleared nearly completely without any side effects. The combination topical vitamin D3-analogue calcitriol and 311 nm ultraviolet B narrow band phototherapy was effective and can be regarded as a useful alternative to glucocorticosteroids for erythema annulare centrifugum.

Usnea barbata extract prevents ultraviolet-B induced prostaglandin E2 synthesis and COX-2 expression in HaCaT keratinocytes

Usnea barbata and its major constituent usnic acid are potent antimicrobial agents. Here, we have investigated anti-inflammatory properties of an U. barbata extract (UBE) containing 4% usnic acid in an ultraviolet-B (UVB) model with HaCaT keratinocytes. UVB irradiation induced PGE(2) production and COX-2 expression in a time and dose-dependent manner. UBE inhibited PGE(2) production at a half-maximal concentration of 60 microg/ml (2.4 microg/ml usnic acid) that did not affect the UVB-induced upregulation of COX-2, suggesting an effect on enzyme activity rather than on protein expression. The inhibition of PGE(2) production by UBE was not due to cytotoxicity. Besides its known antimicrobial properties, UBE displays specific UVB protective effects that might be useful in the topical treatment of UVB-mediated inflammatory skin conditions.

Continuous renal replacement therapy in patients following traumatic injury

In critically injured patients, the incidence of acute renal failure has been reported to occur in as many as 31% of patients. The use of CRRT modalities for patients following traumatic injuries is becoming more common, albeit slowly, and this therapy may impact upon long-term recovery of renal function and mortality. Historical studies investigating the early use of intermittent dialysis reported significant improvement in survival in patients who were dialyzed earlier and more vigorously than in control subjects. Early trauma patients also showed improved survival following war injuries when dialyzed prophylactically. Although there is a growing acceptance in favor of earlier renal replacement therapy, the published consensus and the practice in many centers has been to dialyze/filter relatively ill rather than relatively healthy patients. The R Adams Cowley Shock Trauma Center (STC) in Baltimore, Maryland, USA, admits over 8,000 trauma patients each year. Within the STC, a program of continuous renal replacement therapy was established in the early 1980's. We review both historical and current literature on the use of renal replacement therapies after traumatic injury, and suggest some future areas of investigation and indications for these modalities.

Infrequent mutation of the tumour-suppressor gene Smad4 in early-stage colorectal cancer

Smad4 is a candidate tumour-suppressor gene identified recently on chromosome 18q21.1. Both alleles are inactivated in nearly one-half of pancreatic carcinomas, but its role in the tumorigenesis of other tumours is still unknown. The aim of this study was to investigate the potential involvement of the Smad4 locus in early-stage colorectal cancers (stages I-III) in tumour samples from a randomised multicentre trial. Of a large collection of DNA samples, 73 with a loss of one allele of the Smad4 gene were analysed for the presence of point mutations in the remaining gene. Patients, from whom biopsies were isolated, were part of a previous randomised multicentre study of the Swiss Group for Clinical Cancer Research on the benefit of adjuvant chemotherapy (SAKK study 40/81). Mutation analysis was restricted to the highly conserved C-terminal domain (exons 8, 9, 10 and 11) of Smad4, using PCR and single-strand conformational variant analysis. Two of the 73 patients (3%) with loss of one allele of Smad4 had a point mutation in the remaining allele. These results indicate that whereas Smad4 point mutations are prevalent in pancreatic carcinoma, they are infrequent in early stages (I-III) of colorectal cancer.

SMAD4 is a predictive marker for 5-fluorouracil-based chemotherapy in patients with colorectal cancer

The gene for the transducer of transforming growth factor-beta/bone morphogenetic protein signalling SMAD4, a potential suppressor of colorectal carcinogenesis, is located at the chromosomal region 18q21. In order to evaluate the clinical relevance of SMAD4 deletion, gene copy alterations were determined by copy dosage using real-time quantitative PCR in 202 colorectal tumour biopsies from a previous randomised study of adjuvant chemotherapy. Patients with normal SMAD4 diploidy turned out to have a three-fold higher benefit of 5-fluorouracil-based adjuvant chemotherapy with a border line significance (overall survival: 3.23, P=0.056; disease-free survival: 2.89, P=0.045). These data are consistent with the previous observation that patients whose cancer had retention of the 18q21 region had a significantly higher benefit from 5-fluorouracil-based therapy. Moreover, these results may provide a refinement at the gene level of the clinical relevance of 18q21 deletion, thereby suggesting SMAD4 as a predictive marker in colorectal cancer. This data also indicate that integrity of this component of the transforming growth factor-beta/bone morphogenetic protein signalling pathway may be a critical factor for benefit of chemotherapy in patients with colorectal cancer.

Combined copy status of 18q21 genes in colorectal cancer shows frequent retention of SMAD7

Deletions of chromosome band 18q21 appear with very high frequency in a variety of carcinomas, especially in colorectal cancer. Potent tumor suppressor genes located in this region encode transforming growth factor beta (TGF-beta) signal transducers SMAD2 and SMAD4, and inactivation of either one leads to impaired TGF-beta-mediated cell growth/apoptosis. Following the assignment of SMAD7 to 18q21, we first refined the SMAD7 gene position within this region by genetically mapping SMAD7 between SMAD2 and SMAD4. Further, to compare the respective frequencies of genetic alterations of these three SMAD genes in colorectal cancer, we undertook a large-scale evaluation of the copy status of each of these genes on DNA samples from colorectal tumor biopsy material. Among a subset of 233 DNA samples for which data were available for all four genes, SMAD4, SMAD2, and the nearby gene DCC showed high deletion rates (66%, 64%, and 59%, respectively), whereas SMAD7 was deleted in only 48% of the tumors. Unexpectedly, we found some gene duplications; SMAD7 appears to be more frequently amplified (10%) than the three other genes (4-7%). Compiled data for SMAD genes in each tumor show that the most common combination (26% of all the tumors) consists of the simultaneous deletions of SMAD2 and SMAD4 associated with normal diploidy or even duplication of SMAD7. Since SMAD7 normally counteracts SMAD2 and SMAD4 in TGF-beta signaling, we hypothesize that the tumor might not benefit from simultaneous SMAD7 inactivation, thereby exerting selective pressure to retain or even to duplicate the SMAD7 gene.

P21 gene expression as an indicator for the activity of adenovirus-p53 gene therapy in non-small cell lung cancer patients

Alterations in the tumor suppressor gene p53 lead to impaired cell cycle control, allowing for the development and growth of tumors. To restore a loss of p53 function, we performed a phase I study of intratumoral gene therapy with adenovirus expressing wild-type p53 in patients with non-small cell lung cancer carrying mutations in the p53 gene. Furthermore, in a phase II study, gene therapy was complemented with simultaneous cisplatin/vinorelbine treatment. Biopsies were obtained from all treated patients before and 24-48 hours after gene therapy to study changes in the expression of p53 target genes. We report here that in most of the cases, the target gene p21 was up-regulated, especially when injection of higher doses of p53-expressing adenovirus was combined with simultaneous chemotherapy, whereas Pig3, previously reported to be highly up-regulated by p53, generally did not show a clear increase. Interestingly, a clear p21 gene response was observed only in tumors showing stabilization or regression. We conclude that p21 appears to be up-regulated after adenovirus-mediated p53 gene transfer and is the most sensitive marker tested for biological response to gene therapy in the small cohort of non-small cell lung cancers that were studied.

bcl-2 expression is reciprocal to p53 and c-myc expression in metastatic human colorectal cancer

Apoptosis (programmed cell death) inhibition may be an important mechanism by which gastrointestinal mucosal cells containing damaged DNA evade normal clearance mechanisms and grow to become invasive tumours. Since bcl-2 is an apoptosis inhibitor, bcl-2 mRNA expression was measured in 21 metastases of colorectal cancer using reverse transcription-polymerase chain reaction analysis. The mean bcl-2 mRNA expression (0.45 U, P < 0.0001) was lower than that of normal mucosal controls (= 1 U). p53 expression was inversely correlated with bcl-2 expression (P = 0.021) in 19 evaluable samples, and in tumours where p53 expression was over twice that of normal colonic mucosal values, bcl-2 mRNA was significantly decreased (mean 0.30, P = 0.0052). c-myc was also inversely correlated with bcl-2 expression (P = 0.025). Decreased bcl-2 expression in metastatic colorectal cancer may be partly due to allelic loss, given the proximity of bcl-2 to the frequently deleted DCC gene on chromosome 18q. However, the inverse correlation to p53/c-myc suggests an active downregulation of bcl-2, possibly following delegation of its apoptosis inhibiting role to other genes.

Five putative drug resistance parameters (MDR1/P-glycoprotein, MDR-associated protein, glutathione-S-transferase, bcl-2 and topoisomerase IIalpha) in 57 newly diagnosed acute myeloid leukaemias. Swiss Group for Clinical Cancer Research (SAKK)

Using a modified quantitative reverse transcriptase (RT) PCR assay in 57 patients with acute myeloid leukaemia (AML) from a Swiss Phase III multicentre study (SAKK 30/85), we measured the m-RNA expression of the genes from the multidrug resistance gene 1 (MDR1), the multidrug resistance associated protein (MRP), glutathione-S-transferase (GST) pi, bcl-2 and topoisomerase (topo) IIalpha. P-glycoprotein (p-gp) was measured by Western blot, and GST activity by functional assays. To analyse progression-free (PFS) and overall survival (OS), parameters were prospectively divided into "low" and "high" groups, according to their median values (exceptions: MDR1 and p-gp). Median follow-up was 60 months.

RESULTS

MDR1- and MRP mRNA levels correlated with each other (r=0.54, Spearman), FABM4/M5 and extramedullary disease. "Low" bcl-2-mRNA predicted longer PFS: 22 months vs. 7 months (median,p=0.02, log rank), and longer OS: 64 months vs. 14 months (p=0.06). "Low" topo IIalpha predicted poorer outcome: median PFS 9 vs. 19 months (p=0.03); median survival 12 months vs. "not reached" (p=0.03). An improved outcome tendency, albeit nonsignificant, was seen in p-gp-negative patients. In a Cox model adjusted for age, performance status, presence of Auer rods, FAB type and clinical response, bcl-2 and topo IIalpha mRNA levels retained their predictive values.

MTS1 expression and prognosis in acute myeloid leukemia

MTS1, a tumor suppressor gene located on chromosome 9p21, has been shown to be altered in a number of human tumor cell lines, primary solid tumors, and leukemias. In this study we found low expression of MTS1 in lymphocytes from seven of nine healthy donors, but in none of eight granulocyte samples from the same controls, suggesting a physiological role of MTS1 in peripheral blood cells capable of proliferation, but not in end-stage differentiated cells. We detected MTS1 mRNA expression in 38 of 57 patients (66%) with acute myelogenous leukemia (AML) treated in a standardized clinical protocol. No deletion of the MTS1 gene was found in any of the AML samples tested. There was no significant association between expression of MTS1 and response to therapy, progression-free, or overall survival. Except for a negative correlation between MTS1 level and leukocyte count at diagnosis (p = 0.03), there was also no association with any of the known prognostic parameters in AML. We conclude that MTS1 shows a significantly higher expression in leukemic than in normal peripheral blood cells, that deletion of MTS1 is not a frequent event in AML, and that its expression is not significantly correlated with outcome of the disease.

Academic health centers in competitive markets

Academic health center (AHC) hospitals and other major teaching hospitals have funded a portion of their academic missions through patient care revenues. Using all-payer state discharge data, this DataWatch presents information on how these institutions are being affected by market changes. Although AHCs are not as successful as other hospitals are in attracting managed care patients, competitive pressures had not eroded AHCs' financial status as of 1994. However, increasing enrollment in managed care and potential changes in both Medicare and Medicaid suggest that pressure on the financing of these institutions' social missions will continue to grow over time.

[Standardization of the Kent Infant Development Scale: implications for primary care pediatricians]

OBJECTIVE

The purpose of this study was the standardization of an infant assessment protocol based on behavioral observations of Spanish parents. The Kent Infant Development (KIDS) scale was translated into Spanish and named "Escala de Desarrollo Infantil de Kent" (EDIK).

PATIENTS AND METHODS

The EDIK normative data were collected from the parents of 662 healthy infants (ages 1 to 15 months) in pediatric clinics. Infants born more than 2 weeks premature or who had serious physical or neurological illness were not included.

RESULTS

EDIK raw scores of Spanish infants were converted to developmental ages by comparing them with the number of behaviors for each age group in the normative sample. We obtained the mean score and standard deviation for the full scale and different domains (cognitive, motor, social, language, and self-help).

CONCLUSIONS

This study shows that EDIK is sensitive to differences in ages and a good instrument that allows one to make a classification between normal infants or those at risk. It should prove useful in developmental pediatric practice.

Topoisomerase II alpha mRNA and tumour cell proliferation in non-Hodgkin's lymphoma

AIMS

To elucidate potential mechanisms of drug resistance, levels of topoisomerase II alpha mRNA, a target for cytostatic drugs, were measured in cryopreserved tumour tissue from 36 patients with non-Hodgkin's lymphoma. To evaluate the potential association between topoisomerase II alpha and cell proliferation, Ki-67 immunostaining was also assessed.

METHODS

The study population comprised 13 patients with low grade and 20 with high grade non-Hodgkin's lymphoma. Three patients had recurrent disease. Topoisomerase II alpha mRNA was quantitated by using reverse transcription polymerase chain reaction (RT-PCR) and the PCR product measured by using HPLC. The MIB-1 monoclonal antibody was used for Ki-67 immunostaining.

RESULTS

Levels of topoisomerase II alpha mRNA correlated strongly with the Ki-67 labelling index and were higher in high grade than in low grade lymphomas. Patients in complete clinical remission of high grade lymphoma had a higher Ki-67 labelling index and tended to have higher topoisomerase II alpha mRNA levels.

CONCLUSIONS

Although topoisomerase II alpha mRNA levels may be indicative of sensitivity to drugs, it is more likely that they reflect the proliferation status of the cell, which in turn involves a large number of additional molecular systems that influence response to treatment.

mRNA expression, measured by quantitative reverse transcriptase polymerase chain reaction, of five putative drug resistance parameters, in normal and leukaemic peripheral blood and bone marrow

Using a quantitative reverse transcriptase PCR assay, the mRNA expression of five putative drug resistance-related genes were assessed in normal peripheral (n = 14) and bone marrow (n = 4) mononuclear cells from healthy donors and patients with acute myeloid leukaemia (n = 11). The mRNA levels of MDR1, the multidrug resistance-associated protein and glutathione-S-transferase pi were equally expressed in both compartments. Bcl-2 mRNA was slightly higher in the leukaemic marrow samples. However, topoisomerase II alpha mRNA levels were found to be much higher in normal and leukaemic marrow cells compared to peripheral blood (p < 0.01), which may, in part, reflect the different proliferation pattern of the mononuclear cells in the two compartments. Such findings could be important for researchers using bulk assays in a mix of samples from peripheral blood or bone marrow to investigate prognostic factors in patients with leukaemia.

Assessment of drug-induced dysregulations among seven resistance-associated genes in human tumour cell lines

Drug-resistance in cell lines and in malignant human tumours is associated with dysregulation of several genes including mdr1, MRP1, GST-pi, bcl-2, DNA topoisomerase II alpha and beta, and thymidine kinase I. mRNA expression was evaluated by quantitative RT-PCR coupled with HPLC in three human tumour cell lines and drug-resistant (DR)-sublines. DR sublines from RPMI-8226 and KB cells specifically overexpressed the mdr1 gene without major changes observed in other putative DR-associated genes. In contrast, the DR-H69 cells exhibited a 34-fold overexpression of the MRP gene accompanied by significant down-regulation of both DNA topoisomerase II alpha and bcl-2 mRNA gene expression, by factors of 43 and 13 respectively. These results demonstrate the concomitant down regulation of topoisomerase II alpha and bcl-2 genes in response to DR. Furthermore, differential patterns of gene dysregulations appear to vary depending upon both the drug used to select resistance and cellular origin.

[A new method for evaluating psychomotor development based on information from parents. The Spanish version of the Kent Infant Development Scale]

OBJECTIVE

The purpose of this dissertation research was to design, standardize and validate the Spanish version of the Kent Infant Development Scale (KIDS).

PATIENTS AND METHODS

This questionnaire is based on information obtained from the parents. It was translated into Spanish and named "Escala de Desarrollo Infantil de Kent" (EDIK). The EDIK normative data were collected from the parents of 662 healthy infants (ages 1 to 15 months) in pediatric clinics in Catalonia (Spain).

RESULTS

Test-retest reliability (r = 0.99; p < 0.001), interjudge reliability (r = 0.98; p < 0.001) and internal consistency (Cronbach alpha = 0.9947) were determined. An "r' of 0.96 was obtained when EDIK scores were compared to their estimated developmental ages obtained from the Denver Developmental Scale. The correlation of the infants' chronological age and their EDIK was 0.96 (p < 0.001).

CONCLUSIONS

The high reliability and validity correlation coefficients demonstrate the sound psychometric properties of the EDIK. It appears to be a useful and acceptable instrument in measuring the developmental status of infants by using the reports of their parents.

Nonradioactive quantification of mdr1 mRNA by polymerase chain reaction amplification coupled with HPLC

We describe a new strategy for quantifying mRNA by using polymerase chain reaction (PCR) coupled with HPLC. PCR-amplified products are directly analyzed with a specific HPLC column and are quantified by standardization against a housekeeping gene, beta-actin. To evaluate the experimental conditions, we examined the multidrug-resistance-associated mdr1 gene expression in two drug-sensitive cell lines (RPMI-8226 and KB-3-1) and in their drug-resistant sublines. This revealed a significant overexpression of the mdr1 gene in chemoresistant sublines that paralleled the degree of in vitro drug resistance and the amounts of mRNA determined by other methods. Results were consistently reproducible, with imprecision (CV) &lt; 25%. The reverse transcription option PCR/HPLC protocol described here is a sensitive, nonradioactive method for quantifying mdr1 mRNA in cell lines or clinical tumor samples, and can be applied to the simultaneous quantification of several mRNA species.

Nonradioactive quantification of mdr1 mRNA by polymerase chain reaction amplification coupled with HPLC

We describe a new strategy for quantifying mRNA by using polymerase chain reaction (PCR) coupled with HPLC. PCR-amplified products are directly analyzed with a specific HPLC column and are quantified by standardization against a housekeeping gene, beta-actin. To evaluate the experimental conditions, we examined the multidrug-resistance-associated mdr1 gene expression in two drug-sensitive cell lines (RPMI-8226 and KB-3-1) and in their drug-resistant sublines. This revealed a significant overexpression of the mdr1 gene in chemoresistant sublines that paralleled the degree of in vitro drug resistance and the amounts of mRNA determined by other methods. Results were consistently reproducible, with imprecision (CV) < 25%. The reverse transcription option PCR/HPLC protocol described here is a sensitive, nonradioactive method for quantifying mdr1 mRNA in cell lines or clinical tumor samples, and can be applied to the simultaneous quantification of several mRNA species.

What every dentist should know about practice purchase

Anyone considering the purchase of a dental practice should heed the 'caveat emptor' maxim since there is a serious risk of dental practice bankruptcy in the present economic environment. To minimise this risk, the purchaser must be equipped with the necessary knowledge and information to ensure purchase terms are sound. This article aims to give guidance on how to assess value and associated risks in the purchase of goodwill and equipment, and sets out the main points to consider in evaluating a practice account prior to acquisition.

Multiple drug resistance gene expression in human renal cell cancer is associated with the histologic subtype

Overexpression of p170 glycoprotein, the product of the multiple drug resistance (mdr) gene, has been associated with resistance to various cytotoxic drugs used in the treatment of human neoplasms. Normal renal epithelial cells express p170 as a function of their secretory capacity. Because renal cell carcinomas (RCC) respond poorly to chemotherapeutic regimens, p170 expression was studied in primary RCC. Such expression was measured in 40 human RCC and normal kidney tissues using immunohistochemical staining with the monoclonal antibody C-219. Staining intensities of the whole tumor and of different areas of the cryostat sections were transformed into digital numbers using an algorithm designed for this purpose. In most tumors, an inhomogeneous staining pattern and a correlation between grade of differentiation and C-219 immunoreactivity was observed. A comparison of the tumors according to their histopathologic subtypes showed clear differences. The means (range) of the staining intensities of the different types of RCC: clear cell carcinoma Grade 1 (n = 3), 2.0 (2.0 to 2.0); clear cell carcinoma Grade 2 (n = 19), 0.8 (0.0 to 2.9); clear cell carcinoma Grade 3 (n = 5), 0.1 (0.0 to 0.2); tubular carcinoma (n = 4), 2.0 (2.0 to 3.0); anaplastic carcinoma (n = 8), 0.05 (0.0 to 0.2); oncocytoma (n = 1), 0.0 (0.0 to 0.0); and normal kidney (n = 40), 0.5 (0.0 to 2.0). The differences between anaplastic, clear cell, and tubular carcinoma were significant (P less than 0.001 by Kruskal-Wallis test). In addition, the difference between the three subgroups of clear cell carcinoma was significant (P less than 0.01). It was concluded that the histopathologic subtypes of RCC correlate with the degree of mdr gene expression, as determined by staining with the C-219 monoclonal antibody.

Folinic acid effect on 5-fluorouracil kinetics in vivo

Synergy of folinic acid and FU has been shown in several experimental systems. In the present study we examined the kinetics of concurrent administration of folinic acid on the kinetics of FU in an in vivo model. Folinic acid significantly increased the amount of FU bound to the TS complex. In the sequential combination of MTX and FU folinic acid had no additional effect. The amount of FU incorporated into RNA was not affected in any of the treatment groups. The results indicate that folinic acid may improve FU cytotoxicity by increased FU binding to TS but has no additional effect on the synergistic sequential MTX-FU combination.

Validity of caregiver information on the developmental status of severely brain-damaged young children

Two studies were conducted to examine the validity of caregiver information on the developmental status of severely brain-damaged young children. First, developmental information on 106 severely brain-damaged young children, obtained from a caregiver-completed behavior inventory--the Kent Infant Development Scale, was compared to that obtained from the Bayley Scales of Infant Development (the Bayley Scales). Developmental age estimates from both tests were highly correlated and similar. Results suggest that it is possible to substitute the Kent Infant Development Scale for the Bayley Scales when measuring the developmental status of severely brain-damaged young children. In a second study examining the differential validity of caregivers' reports, we found that mothers' Kent Infant Development Scales yielded higher developmental age estimates than did teachers' Kent Infant Development Scales.

Social milieu of a residential treatment center for severely or profoundly handicapped young children

Severely or profoundly handicapped young children who lived in a residential treatment center were subjects in a modified time-sampled observation study of social behavior, state, and physical context. The study was conducted for 3 successive years. Although system-level changes in the ecology of the institution over the 3 years did not appear to affect the social-interaction indices, the developmental ages of the children were positively related to social opportunities and social behavior.

Some aspects of the growth of rats

The first quantitatively significant phase of growth for the rats under investigation was finished at body weights of 260 g in females and 410 g in males. During this phase only growth will influence the energy requirements of the rat. The sex-dependent difference in size will be discussed; it is probably caused by the fact that the period of marked cell division activity lasts slightly more than one week longer in male than in female rats.

Grief response of parents after referral of the critically ill newborn to a regional center

Attitudes, feelings, and behavior were studied in 101 mother-father pairs whose critically ill newborn infants survived after referral from the hospital of birth to a regional neonatal intensive-care unit for special care. As measured by an anticipatory-grief score, most parents experienced grief reactions similar to those whose infants do not survive the newborn period. The level of anticipatory grief did not appear to be associated with severity of infant illness as determined by the need for respirator therapy or major surgical procedures. The fathers reported drastic alteration in daily activity while wife and infant were hospitalized in separate facilities, and they assumed a central role in maintaining family stability during the crisis. These data suggest that an organized family-support program could play a prominent part in maintaining family stability during the delivery of newborn intensive care.