An Australian study on the sociocultural context of menopause: directions for contemporary nursing practice

This research project by Berger (1997) investigates the physical, psychological, and sociocultural menopause experiences of a group of seventy women aged 45-70 years from Brisbane, Australia. Thus far the narrative provided for mid-life women shows a preoccupation with medical/biological perspectives that emphasize negative images of menopausal women as estrogen deficient and diseased. This new study is considered to be one of the few more recent attempts that investigates menopausal women within a sociocultural context and explores women's views about menopause as a normal, natural transition part of the ageing process. A qualitative approach (comprising focus groups and interviews) was aimed at women in mid-life who were willing to share their insights of this complex phase, to document individual variations and broad patterns. Findings provided enhanced understanding of many menopause aspects (such as appropriate treatment) that remain controversial. Content analysis uncovered three emerging themes: 1) contrary to popular beliefs menopause usually signified wellness; 2) apart from biological changes, the sociocultural context played a pivotal role in modifying menopause experiences; and 3) women did not feel adequately supported by health professionals. The findings signify that nurses are ideally placed to assist menopausal women in a variety of health care settings.

The human ABCG4 gene is regulated by oxysterols and retinoids in monocyte-derived macrophages

Here we report the induction of gene expression of ABCG4, a member of the ABC transporter subfamily G, from human macrophages by oxysterols and retinoids, agonists of the nuclear receptors LXR and RXR. The cloned ABCG4 transcript has a size of 3.5 kb and contains an open reading frame which encodes a polypeptide of 646 amino acids. Structurally, the putative ABC transporter protein consists of a nucleotide binding fold followed by a cluster of six transmembrane-spanning domains and thus conforms to the group of half-size ABC transporters. Among the human ABC transporter subfamily G members the novel transporter shows highest protein sequence homology and identity to ABCG1 (84 and 72%, respectively). Analysis of the genomic organization demonstrates that the ABCG4 gene is composed of at least 14 exons which extend across a region of 12.6 kb in size on chromosome 11q23.3. Based on its structural features and an LXR/RXR-responsive regulation similar to the cellular lipid export protein ABCA1, we conclude that ABCG4 may be involved in macrophage lipid homeostasis.

Quantification of ultrasound contrast agent response: comparison of continuous wave Doppler and power Doppler to backscattered radiofrequency data

Our goal was to compare two quantification methods of ultrasound contrast agents available in clinical practice [continuous wave Doppler intensity (CWDI) and power Doppler intensity (PWDI)] to the reference technique (radio-frequency analysis) with a simple recirculating flow phantom using a renal dialysis cartridge. Measurements were made at different doses of perflenapent emulsion and BR1. Cineloops of power Doppler images were recorded using a clinically available ultrasound unit (HDI 3000). Simultaneously, integrated backscatter (IBS) was measured by analysis of radiofrequency signals, whereas Doppler signal intensity was measured with a continuous wave Doppler device. A linear relationship was found between CWDI and IBS and between PWDI and IBS when R(2) was calculated for each pair of parameters injection-by-injection. Results are summarized by the average R(2) for all injections between CWDI and IBS (BR1: R(2) = 0.93 +/- 0.05, perflenapent emulsion: R(2) = 0.94 +/- 0.03) and between PWDI and IBS (BR1: R(2) = 0.88 +/- 0.07, perflenapent emulsion: R(2) = 0.79 +/- 0.09). However, for all data obtained from all different injected doses and for both contrast agents, there was considerable variation of CWDI and PWDI values measured for a given value of IBS. In conclusion, for a fixed microbubble population, CWDI and PWDI can be proposed for quantification of USCA. However, their important variations observed at each dose make it difficult to link a single value of PWDI or CWDI or IBS to a single microbubble distribution composition.

Reproducibility of skin characterization with backscattered spectra (12--25 MHz) in healthy subjects

Ultrasonic techniques were developed for quantitative in vivo analysis of skin composition based on measurements of apparent integrated backscatter (IBS) and its frequency dependence (n) between 12.5 and 25 MHz. Parameters were measured at five depths in healthy dermis of the midforearm of 29 volunteers (13 women, 16 men, 20 to 76 years old) on three different days. Reproducibility of measurements was evaluated (standardized coefficients of variation: 7% to 11% for IBS and 9% to 20% for n). Parameter values were significantly influenced by pressure of the ultrasonic probe on the skin, and both room and skin-surface temperatures were correlated to IBS measured in a single subject on 28 days. More precise control of these factors could further improve measurement reproducibility and sensitivity to skin composition. Significant (p < 0.05) differences of parameter values with respect to region of interest depth, age and gender of subjects were discussed in comparison with dermal composition and offer promise that these parameters could be used to characterize skin modifications.

Prolongation of survival of rats injected with hepatoma cells treated by nuclei extracts from mouse and rat embryo cells

Cancer cells express particular genes, part of which are normally active during the embryonic development. On the other hand, young embryos are able to differentiate teratocarcinoma or leukemia cells, likely by producing differentiation factors. In this work, rat and mouse embryo cell nuclei extracts were tested on hepatoma carcinoma cells LFCl2A: they inhibit the cell growth in culture and increase the survival of syngeneic rats injected with hepatoma cells incubated with these extracts. This inhibition is correlated with a decrease of DNA synthesis without toxic effect: It seems to be due to the mixture of tight binding DNA proteins, possibly transcriptional factors.

Neuroendocrine differentiation is a relevant prognostic factor in stage III-IV colorectal cancer

OBJECTIVE

To determine the prognostic relevance of neuroendocrine differentiation in colorectal cancer.

METHODS

The survival of 116 patients with colorectal cancer of stages III (n = 59) and IV (n = 57) was correlated with the extent of neuroendocrine differentiation. Chromogranin A and synaptophysin were used as neuroendocrine markers. Based on the degree of immunoreactivity for these markers, tumours were classified as 0 (no expression of neuroendocrine markers), 1 (< 2% cells staining positive for neuroendocrine markers) and 2 (> 2% cells staining positive for neuroendocrine markers). Patients were followed up for more than 5 years or until death.

RESULTS

Seven of 59 (11.8%) stage III cancers and 13/57 (22.8%) stage IV cancers belonged to group 2. The 96 patients of groups 0 and 1 lived for 48.9 months, whereas the 20 patients of group 2 survived for only 18.6 months (Kaplan-Meier survival curves, P < 0.001). The difference was most striking in stage III disease with 79.4 months' survival for combined groups 0 and 1, and 38.9 months' survival for group 2 (P < 0.01). Using the multivariate Cox regression model, the presence of more than 2% of cells with neuroendocrine differentiation was found to be an independent prognostic parameter for stage III and IV disease. No correlation was observed between neuroendocrine differentiation and tumour location, grade, depth of invasion or stage.

CONCLUSION

Neuroendocrine differentiation is often seen in colorectal cancer. It is an independent prognostic factor in stage III-IV colorectal cancer.

Laser-assisted uvulopalatoplasty for snoring: medium- to long-term subjective and objective analysis

OBJECTIVE

To assess the subjective and objective medium- to long-term results of laser-assisted uvulopalatoplasty for snoring.

DESIGN

A nonrandomized, prospective, before-after trial.

SUBJECTS AND INTERVENTIONS

Fourteen patients underwent laser-assisted uvulopalatoplasty surgery; 2 surgical techniques, which differ with respect to the mode of midline palatal vaporization, were used.

MAIN OUTCOME MEASURES

Subjective analysis included a preoperative and 2 postoperative evaluations of the state of snoring: 4 weeks and 10.1 +/- 7.9 months (mean +/- SD) after completion of last laser treatment. In addition, a score on 5 other sleep-related symptoms was recorded before treatment and after 10.1 +/- 7.9 months; at that time, patients also estimated their overall satisfaction with the procedure. Objective analysis included preoperative nocturnal polysomnographic studies that were repeated postoperatively.

RESULTS

A decline in snoring improvement from 79% (11/14) to 57% (8/14) was recorded; furthermore, state of snoring worsened from 7% (1/14) to 21% (3/14). Likewise, reevaluation of the 5 other sleep-related symptoms at the final follow-up visit uncovered a 57% improvement rate. Overall satisfaction with the procedure was 43%. The results of the postoperative objective studies corresponded to those of the subjective ones and demonstrated significant worsening of respiratory disturbance index in 3 (21%) of the 14 patients, who became mildly apneic. These findings were encountered with both laser techniques.

CONCLUSIONS

The favorable subjective short-term results of laser-assisted uvulopalatoplasty deteriorated with time. In addition, postoperative nocturnal polysomnography showed that the procedure caused mild obstructive sleep apnea in a considerable number of patients who formerly were nonapneic snorers. These findings may be related to velopharyngeal narrowing and progressive palatal fibrosis, caused by the thermal damage inflicted by the laser beam.

Long-term histologic effects of inferior turbinate laser surgery

OBJECTIVE

In this study we sought to define the histologic changes produced by laser treatment of inferior turbinates.

STUDY DESIGN

Eight inferior turbinates with prior laser treatment (mean, 26.8 months) were analyzed by light microscopy after turbinectomy for relief of refractory nasal obstruction. Histologic findings were compared with those of a group of 8 hypertrophic inferior turbinates that had no previous laser surgery.

RESULTS

Laser-treated areas of the inferior turbinates demonstrated a histologically bland appearance, with marked diminution of seromucinous glands and relative preponderance of connective tissue matrix. Prominence of venous sinusoids was also significantly reduced in the laser-treated areas. Surface epithelium including goblet cells was reconstituted over the areas of laser application.

CONCLUSION

Clinical laser surgery of the inferior turbinate produces striking long-term histologic changes.

SIGNIFICANCE

The data suggest a differential response of turbinate histologic components to application of laser energy, with the glandular component being particularly sensitive. Further correlative study is needed to clarify the clinical significance of laser-induced histologic changes in inferior turbinates.

Frontal and Lateral Cephalometry in Patients With Sleep-Disordered Breathing

OBJECTIVES/HYPOTHESIS

The traditional lateral-view cephalometric analysis is limited because it provides only two-dimensional analysis of the three-dimensional craniofacial structure. The objectives were to analyze lateral and frontal cephalometric radiographs in a series of normal patients and those with varying degrees of sleep-disordered breathing and to define the degrees of narrowing or other unfavorable anatomical changes that might differentiate the patients with sleep-disordered breathing from normal subjects.

STUDY DESIGN

A prospective study of 100 adult patients with sleep-disordered breathing and 60 age-matched normal subjects.

METHODS

An analysis of the lateral and frontal cephalometric measurements was performed to assess velopharyngeal anatomical features. A comparison was made between the patients' polysomnographic and cephalometric analyses.

RESULTS

The compromised cephalometric parameters that may be found in patients with sleep-disordered breathing include acute skull-base and bony nasopharynx angles, inferior hyoid position, thickening of the velum, reduced retrovelar posterior air space along with thickening of the velum, thickening of the posterior pharyngeal wall, and narrowing of the velopharyngeal lumen. Worsening of sleep-disordered breathing was generally associated with increased numbers of compromised cephalometric parameters. As body mass index increases, there is reduced velopharyngeal width, the velum thickness is increased, and the posterior pharyngeal wall thickness is increased.

CONCLUSIONS

Sleep-disordered breathing is associated with statistically significant changes in a number of cephalometric measurements. Frontal cephalometric analysis adds further information regarding the anatomical assessment of patients with upper airway obstruction, enhancing the traditional lateral cephalometric view.

Comparison of different cations (Mn2+, Mg2+, Ca2+) on the hydrolytic activity of chloroplast ATPase

The influences of Mn2+, Mg2+, and Ca2+ on the enzymic activity of chloroplast ATPase have been compared, using an HPLC method for the separation of ADP. The dissociation constants of the divalent ion-ATP complexes have been determined by a spectrophotometric method, with the dye antipyrylazo III, and enzymic constants (dissociation constant of the ion-enzyme complexes, Michaelis constants, maximum rates) have been calculated. The comparison between the rates obtained, respectively, with Mn2+ and Ca2+ alone with that given by the mixture of these two ions, allows us to conclude that, as for Mg2+, Mn2+ is also an activator of chloroplast ATPase and that metal-free ATP is the true substrate.

Improved tumor targeting by regional carboplatin application combined with Gelfoam. An experimental study on liver tumor-bearing rabbits

Regional chemotherapy of liver metastases is a promising alternative to systemic chemotherapy. Despite a number of theoretical advantages, extended life expectancy has only been confirmed in two studies. Since tumors have a concentration-dependent response to cytostatics, the primary goal is to increase the cytostatic concentration applied in tumor tissue. The aim of this study on liver tumor-bearing chinchilla rabbits was to show that the regional application of carboplatin leads to an increased concentration in tumor tissue. A further increase in carboplatin concentration by additional regional application of gelatine powder (Gelfoam) was demonstrated in a subsequent test; regional compared to intravenous application increased the carboplatin concentration in the tumor tissue by a factor of 12.1 and coapplication with Gelfoam increased the cytostatic concentration by a factor of 44.3.

Assessment of rat articular cartilage maturation using 50-MHz quantitative ultrasonography

OBJECTIVE

The objective was to assess the relationship between maturation-related structural changes of articular cartilage and variations of acoustic parameters estimated using high frequency ultrasonography.

DESIGN

Patellae taken from 48 immature Wistar male rats and divided into six age groups (from five to 11 weeks old) were explored in vitro using 50-MHz scanning acoustic microscopy, then assessed by histology for the analysis of the cartilage cell distribution and fibrillar collagen organization. The variation of cartilage proteoglycan and collagen content with age was evaluated. Thickness measurements performed on both B-scan images and histologic sections were compared. Ultrasonic radiofrequency signals reflected by the cartilage surface and backscattered from its internal matrix were processed to estimate the integrated reflection coefficient (IRC) and apparent integrated backscatter (AIB).

RESULTS

One-way ANOVA indicated that acoustic parameters and thickness change significantly (P < 0.05) as the animal matures because of age-related changes in cartilage composition and morphology. A moderate correlation was found between IRC and the animal age. The parameter decreased slightly but significantly over time. However, a good correlation was observed between the rat age and the AIB, which decreased significantly over time. The parameter variation was mostly related to the changes in collagen fiber orientation, and/or to a change in cell size, density and organization.

CONCLUSIONS

Current results indicate that acoustic properties of cartilage are affected by maturation-related cartilage changes. This suggests that high frequency ultrasonography may serve as a useful means for the investigation of cartilage matrix structural changes occurring under various clinical circumstances, like those observed during osteoarthritis, and for the evaluation of the efficacy of specific therapeutics.

Evaluation of calcium phosphates and experimental calcium phosphate bone cements using osteogenic cultures

In this study, rat bone marrow cells (RBM) were used to evaluate two biodegradable calcium phosphate bone cements and bioactive calcium phosphate ceramics. The substances investigated were: two novel calcium phosphate cements, Biocement F and Biocement H, tricalcium phosphate (TCP), surface-modified alpha-tricalcium phosphate [TCP (s)] and a rapid resorbable calcium phosphate ceramic consisting of CaKPO(4) (sample code R5). RBM cells were cultured on disc-shaped test substrates for 14 days. The culture medium was changed daily and also examined for calcium, phosphate, and potassium concentrations. Specimens were evaluated using light microscopy, and morphometry of the cell-covered substrate surface, scanning electron microscopy, and energy dispersive X-ray analysis and morphometry of the cell-covered substrate surface. Areas of mineralization were identified by tetracyline labeling. Except for R 5, rat bone-marrow cells attached and grew on all substrate surfaces. Of the different calcium phosphate materials tested, TCP and TCP (s) facilitated osteoblast growth and extracellular matrix elaboration to the highest degree, followed by Biocements H and F. The inhibition of cell growth encountered with R 5 seems to be related to its high phosphate and potassium ion release.

Analysis of the axial transmission technique for the assessment of skeletal status

Ultrasonic wave propagation in human cortical bone has been investigated in vitro using the so-called axial transmission technique. This technique, which relies on velocity measurement of the first arriving signal, has been used in earlier investigations to study bone status during fracture healing or osteoporosis. Two quasi-point-source elements, one transmitter and one receiver (central frequency 0.5 MHz), were used to generate a wide ultrasonic beam, part of which strikes the sample surface at the longitudinal critical angle, and to receive the signals reflected from the sample surface. The analysis of the field reflected from a fluid-solid interface for an incident spherical wave predicts the existence of a lateral wave propagating along the sample surface at a velocity close to the longitudinal velocity, in addition to the ordinary reflected wave and vibration modes. The transducer-sample and the transmitter-receiver distances were chosen such that the lateral wave is the first arriving signal. Validation of the measuring technique was performed on test materials and was followed by experiments on human cortical bones. Experimental results (arrival time and velocity) strongly suggest that the first detected signal corresponds to the lateral wave predicted by theory.

Histopathology of the inferior turbinate with compensatory hypertrophy in patients with deviated nasal septum

OBJECTIVE

To measure the dimensions, composition, and possible structural and/or histopathological changes of the compensatory hypertrophic inferior turbinate in patients with deviated nasal septum.

STUDY DESIGN

A prospective, nonrandomized, and morphometric study.

METHODS

Nineteen patients with deviated nasal septum and compensatory hypertrophy of the inferior turbinate in the contralateral nasal cavity underwent surgery for correction of nasal obstruction. Patients' specimens were compared with those of a control group consisting of 10 inferior turbinates removed at autopsy. Quantitative measurements of the inferior turbinate histological sections were carried out and included the width of the layers and morphometric calculations of the relative proportions of the soft tissue constituents. Also, qualitative study was performed to detect pathological changes.

RESULTS

Of all layers, the inferior turbinate bone underwent a twofold increase in thickness and manifested the most significant expansion (P < or =.001), whereas the contribution of the mucosal layers to the inferior turbinate hypertrophy was modest. The morphometric analysis revealed a larger proportion of venous sinusoids in hypertrophic turbinates, but the difference was small and statistically insignificant. Qualitative assessment disclosed normal mucosal architecture in all inferior turbinates with compensatory hypertrophy. Eleven remained intact, while eight disclosed mild to moderate pathological changes.

CONCLUSIONS

The data gathered in the present study are of importance to the decision-making process regarding turbinate surgery. The significant bone expansion and the relative minor role played by the mucosal hypertrophy would support the decision to excise the inferior turbinate bone at the time of septoplasty.

Acute sinusitis: a histopathological and immunohistochemical study

OBJECTIVE

To provide data on the histopathological and immunohistochemical characteristics of acute sinusitis in humans.

STUDY DESIGN

A nonrandomized, retrospective, controlled, qualitative and quantitative study.

METHODS

Inflamed sinus mucosal tissues were removed during functional endoscopic sinus surgery from 11 patients with acute sinusitis, of whom 6 had complications with extension of inflammation to the orbit (4) or the meninges (2), 3 had recurrent sinusitis, and 2 had acute exacerbation of chronic sinusitis Normal sinus mucosal tissues were retrieved from four patients with various nasal tumors and served as controls All specimens underwent routine histological processing. Representative sections from each region were stained with hematoxylin and eosin, periodic acid-Schiff, and toluidine blue. Immunohistochemical staining for T and B lymphocytes was also applied. A two-phase examination was designed: low-magnification microscopic assessment (x40) to yield the typical pathological features and high-magnification assessment (x400) to count various inflammatory cells.

RESULTS

The lamina propria displayed the most significant changes with edema, extensive infiltration of neutrophils and mononuclear cells, formation of microabscesses, thrombophlebitis, and necrotic foci, whereas the involvement of the epithelial layer in the inflammatory reaction was relatively modest. Immunohistochemistry revealed an increase in the population of T and B lymphocytes. The former were diffusely scattered, whereas the latter also formed distinct clusters: around small venules, adjacent to seromucous glands, and under the epithelium.

CONCLUSIONS

The inflammatory reaction of the lamina propria exceeded that of the epithelial layer. It is assumed that the clusters of B lymphocytes around blood vessels may point to the fact that these cells were recruited from the blood during acute sinusitis.

Frequency dependence of ultrasonic backscattering in cancellous bone: autocorrelation model and experimental results

The goal of this study is to model the frequency dependence of the ultrasonic backscatter coefficient in cancellous bone. A twofold theoretical approach has been adopted: the analytical theoretical model of Faran for spherical and cylindrical elastic scatterers, and the scattering model for weakly scattering medium in which the backscatter coefficient is related to the autocorrelation function of the propagating medium. The ultrasonic backscatter coefficient was measured in 19 bone specimens (human calcaneae) in the frequency range of 0.4-1.2 MHz. The autocorrelation function was computed from the three-dimensional (3D) microarchitecture measured using synchrotron radiation microtomography. Good agreement was found between the frequency dependence of the experimental (f3.38+/-0.31) and autocorrelation modeled (f3.48+/-0.26) backscatter coefficients. The results based on Faran theory (cylindrical Faran model: f2.89+/-0.06 and spherical Faran model: f3.91+/-0.04) show qualitative agreement with experimental data. The good prediction obtained by modeling the backscatter coefficient using the autocorrelation function of the medium opens interesting prospects for the investigation of the influence of bone microarchitecture on ultrasonic scattering.

Computerized ultrasound B-scan characterization of breast nodules

The ability of computerized parameters to discriminate benign from malignant breast nodules from digitized ultrasonic acquisitions has been assessed. The images of 75 lesions, including 19 lesions proved to be malignant at histology and 56 found to be benign, were digitized and characterized by morphometric and texture parameters. The texture parameters, derived from first-order statistics, run-length matrices and co-occurrence matrices, were computed in the entire lesion and in a ring-shape region surrounding the contour of the lesion. The strongest features were found to be issued from the second region. Further investigations confirmed that the discriminant information was contained in the external part of the lesion and, to a lesser extent, in the neighboring tissue. A linear discriminant analysis using three features yielded a sensitivity of 94.7% for a specificity of 80.4% and the "leave-one-out" technique confirmed the results. Comparison with the classifications given by radiologists let us assume that information revealed by texture features is able to help the physician in reducing the number of unnecessary biopsies.

Expression of SIALYL-Le(x) antigen defined by MAb AM-3 is an independent prognostic marker in colorectal carcinoma patients

Expression of mucin-bound sialyl-Le(x) antigen during the progression of colorectal carcinoma and its potential prognostic value were analysed in sections of tumours from 182 patients with a documented follow-up by immunohistochemistry using the monoclonal antibody (MAb) AM-3. Two groups of colonic carcinomas with weak (n = 79) and strong (n = 103) sialyl-Le(x) expression were discerned. The percentage of strongly expressing tumours increased with the progression of the disease (UICC stage I = 10%, stage II = 46%, stage III = 63%, stage IV = 68%, p < 0.0001). Seventy-four percent of patients with carcinomas exhibiting a strong sialyl-Le(x) expression but only 34% of patients with weak sialyl-Le(x) expression died of the disease (p = 0.0026). In multivariate analysis, strong sialyl-Le(x) expression increased the relative risk of cancer-related death 3.8-fold (95% CI = 1.8-7.9, p = 0.00034). The separate analyses of patients in UICC stage II (n = 56), III (n =5 9) and IV (n = 57) revealed that strong sialyl-Le(x) expression was associated with a reduction of the 5-year overall survival rate in UICC stage II (84% vs. 54%, p = 0.0013) and in stage III patients (86% vs. 35%, p = 0.0008) after curative resection but was not relevant in patients with distant metastases. In conclusion, the strong expression of sialyl-Le(x) antigen defined by the MAb AM-3 in colorectal carcinomas is an independent unfavourable prognostic factor after curative resection in stage II and III patients. The predictive power of the sialyl-Le(x) expression may be helpful to define subgroups of patients at high risk for whom preventive adjuvant therapy can be selectively applied before the occurrence of detectable metastases.

In vitro measurement of the frequency-dependent attenuation in cancellous bone between 0.2 and 2 MHz

Our goal was to evaluate the frequency dependence of the ultrasonic attenuation coefficient in cancellous bone. Estimates were obtained in immersion, using a substitution method in the through-transmit mode, by scanning 14 human bone specimens (calcaneus). Measurements were performed with three pairs of focused transducers with a center frequency of 0.5, 1.0, and 2.25 MHz, respectively in order to cover an extended frequency bandwidth (0.2-1.7 MHz). When the experimental attenuation coefficient values were modeled with a nonlinear power fit alpha(f)=alpha0 +alpha(I)f(n), the attenuation coefficient was found to increase as f(1.09+/-0.3) over the measurement bandwidth. However, a substantial variation of the exponent n (0.4-2.2) within specimens and also between specimens was observed. The acoustical parameters were compared to bone mineral density. A highly significant relationship was noted between alpha1 and BMD (r2= 0.75, p< 10(-4)). No correlation was found between n and BMD. Several attenuation mechanisms are discussed as well as the potential impact these results may have in in vivo quantitative measurements.

Natural T-cell response against MHC class I epitopes of epithelial cell adhesion molecule, her-2/neu, and carcinoembryonic antigen in patients with colorectal cancer

The antigens epithelial cell adhesion molecule (Ep-CAM), her-2/neu, and carcinoembryonic antigen (CEA) are potential T-cell targets in antigen-specific vaccination-based cancer therapy. We performed this study to evaluate whether a natural specific T-cell response against these tumor-associated antigens (TAAs) already exists in patients with colorectal carcinoma (CRC). We used the IFN-gamma ELISPOT assay to detect circulating TAA-reactive T cells directly ex vivo in unstimulated peripheral blood mononuclear cells. We analyzed the T-cell response in peripheral blood mononuclear cells of 22 HLA-A2-positive patients with CRC and 8 HLA-A2-positive healthy subjects against 3 HLA A2-restricted peptide epitopes of the TAAs Ep-CAM (GLKAGVIAV), her-2/neu (IISAVVGIL), and CEA (YLSGANLNL). Seven of 22 patients but none of the 8 healthy subjects had T cells specifically secreting IFN-gamma in response to one to three of these antigens (n = 4, Ep-CAM; n = 5, her-2/neu; n = 6, CEA). In three of the seven responding patients, TAA-reactive T cells were further characterized by flow cytometry. In all three patients, the majority of these T cells have a CD3+CD8+IFN-gamma+CD69+CD45RA+ phenotype, resembling activated effector-type T cells. T-cell responses occurred only in patients with metastatic disease (Dukes' stages C and D). The results of this study indicate that natural T-cell responses against TAAs occur in approximately one-half of CRC patients with involvement of lymph nodes or distant metastases, but not in CRC patients with disease confined to the intestinum.

Detection and prognosis of recurrent gastric cancer--is routine follow-up after gastrectomy worthwhile?

BACKGROUND/AIMS

Although routine follow-up after surgery for gastric cancer is recommended its value after gastrectomy has not been evaluated.

METHODOLOGY

All patients who underwent gastrectomy for gastric cancer entering the routine follow-up program between January 1987 and August 1996 were identified. The patients studied were those with either histologically proven recurrence or those in whom recurrence was highly probable from clinical course. Two groups were compared. The first group comprised the patients whose recurrence was detected by routine follow-up prior to the development of clinical signs (asymptomatic group). The second group consisted of the patients who developed clinical symptoms due to a recurrence that was detected subsequently (symptomatic group). The main parameters were the time until recurrence occurred, the pattern of recurrence, treatment and survival.

RESULTS

Out of 184 patients entering the routine follow-up 135 patients had undergone potentially curative gastrectomy. Sixty-seven patients (49.6%) had recurrences. Only 15 (22.3%) belonged to the asymptomatic group and 52 (77.7%) to the symptomatic one. The time until recurrence occurred was not different between the 2 groups (17.1 vs. 18.0 months). Chemotherapy was performed more frequently in the asymptomatic group and survival was longer (8.4 vs. 5.9 months). This difference was due to the time the patients remained asymptomatic (average 43 months). No effect of either early detection or chemotherapy was seen. In the asymptomatic group distant recurrence was common while recurrence in the symptomatic group was more often local but this difference did not reach statistic significance.

CONCLUSIONS

Routine follow-up after gastrectomy for gastric cancer does not contribute to early detection of gastric cancer recurrence. It has no benefit with respect to treatment and survival of patients with recurrent disease and should therefore be reduced to symptomatic and psychological aftercare.

Increased carboplatin concentration in liver tumors through temporary flow retardation with starch microspheres (Spherex) and gelatin powder (Gelfoam): an experimental study in liver tumor-bearing rabbits

Regional chemotherapy of primary and secondary malignant liver tumors is superior to systemic therapy. The regional advantage can be further increased by flow retardation. Absorbable gelatin powder (Gelfoam) and starch microspheres (Spherex) may serve as embolizing agents because of their particle size and embolization time. Carboplatin was for the first time applied as a cytostatic agent in regional chemotherapy. Embolization and flow retardation times were measured. The embolization time of Gelfoam was 27 min, and that of starch microspheres (Spherex), 7 min, on average. Mean flow retardation of Gelfoam was 153 min, and that of starch microspheres (Spherex) 38 min. The concentration differences in systemic and regional chemotherapy were determined in VX-2 liver tumor-bearing rabbits. In regional chemotherapy, the tumor concentration was increased by a factor of 3.6 compared with systemic therapy. Coapplication with an embolizing agent increased the tumor concentration of carboplatin by a factor of 44 to 47. Concentrations of absorbable gelatin powder (Gelfoam) and starch microspheres (Spherex) did not differ significantly.

Models of nursing care: a comparative study of patient satisfaction on two orthopaedic wards in Brisbane

Patient satisfaction measures assist nurses in the evaluation of effectiveness of nursing practice and assist the process of improvement regarding established practice. A comparative study was carried out on 36 patients from a ward using team nursing (Model 1) and 38 patients from a ward using patient allocation (Model 2) in two orthopaedic wards of a 900 bed teaching hospital in Brisbane, Australia. The purpose of the research was to measure if differences in the levels of patient satisfaction were evident. The Patient Satisfaction Survey (Greenhill and Henderson 1997) used in this study encompassed aspects such as patients' feelings and perceptions; nurses' skills, behaviour and attitudes; nurses' communication and education skills; and continuity of care experienced. The results indicated that there were no differences between models of nursing care and levels of patient satisfaction. However, there were significant relationships between patient satisfaction and patients' characteristics such as age, education and health status.

Long-term risk of gastrointestinal tumor recurrence after postoperative treatment with recombinant human growth hormone

BACKGROUND

Recombinant human growth hormone (rhGH) promotes protein synthesis, accelerates wound healing, and maintains immune function in the catabolic state. It has also been claimed that rhGH may promote the activation of residual tumor cells, and therefore, increases the risk of tumor recurrence. This study aimed to investigate whether postoperative administration of rhGH increases the long-term risk of tumor recurrences in patients undergoing major gastrointestinal surgery for malignancy.

METHODS

Patients (n =104) received three different doses of rhGH (0.075 IU/kg, 0.150 IU/kg, and 0.300 IU/kg) during 5 postoperative days in a placebo-controlled trial. Follow-up was performed for 56-70 months after radical tumor resection. Mean survival period and relapse-free survival were compared with the control group.

RESULTS

Complete data were available for 75 patients. Thirty-five percent (n = 20) of all patients treated with rhGH showed tumor recurrences in comparison to 44% (n = 8) of patients given placebo. Mean survival period for rhGH-treated patients was 46 months (median 59 months); in controls, 42 months (median 58 months). The length of relapse-free survival tended to be longer in rhGH-treated patients (2-47 months; median, 21 months) compared with the patients who were given placebo (2-18 months; median, 13 months).

CONCLUSIONS

The results demonstrate no evidence for an increased risk of tumor recurrence after rhGH treatment for a short period of time after removal of a gastrointestinal adenocarcinoma. Therefore, the positive metabolic effects of rhGH application can be used safely in the treatment of the postoperative catabolic state in the patient groups investigated.

Anatomical basis of sleep-related breathing abnormalities in children with nasal obstruction

OBJECTIVE

To define, in a group of children with nasal obstruction, the anatomical differences that differentiate those with quiet, unobstructed nocturnal respiration from those with obstructive sleep-related breathing abnormalities (snoring and obstructive sleep apnea).

DESIGN

Case series.

PATIENTS

Fifty-nine children aged 3 to 13 years (35 boys and 24 girls) with nasal obstruction and without tonsillar hypertrophy, known craniofacial syndromes, or neuromuscular diseases were included in the study.

MAIN OUTCOME MEASURES

Each patient was categorized as to severity of nocturnal obstructive breathing symptoms. Angular and linear cephalometric measurements were used for assessment of craniofacial features. Clinical symptom scores were correlated with the cephalometric measurements.

RESULTS

Significant craniofacial abnormalities were identified in patients prone to obstructive breathing patterns: increased flexure of the cranial base and bony nasopharynx, opening of the gonial angle, shortened mandibular length, dorsocaudal location of the hyoid, reduced posterior airway space, and increased velar thickness.

CONCLUSIONS

A number of anatomical abnormalities may contribute to sleep-related abnormal breathing in otherwise normal children with nasal obstruction. Our results suggest that symptomatic children show some of the same skeletal and soft-tissue configurations that are found in adults with obstructive sleep apnea. While adenoidectomy is generally an effective treatment in children with obstructive sleep-related breathing abnormalities, the underlying craniofacial variances that remain after adenoidectomy may predispose these patients to redevelopment of obstructive breathing abnormalities in adulthood.

[External quality management in inpatient geriatric care--the SIESTA instrument]

Continuous quality improvement in long term care facilities requires systematic cooperation of internal and external quality management. We designed SIESTA to assist skilled nursing care and management in their effort to measure and develop the quality of care in their facility in a rational way.

High-frequency ultrasound characterization of microporous biointegrable polymers in cornea using acoustic parameters

The current work deals with the use of high-frequency quantitative backscatter acoustic microscopy for the evaluation of the biointegration of microporous polymer implants used as support of artificial cornea. A three-dimensional (3-D) 80 MHz ultrasound microscope (25 microns axial resolution at focus) was used for the imaging and characterization of the progressive biointegration of polymers implanted in rabbit cornea. In-vitro and in-vivo studies were performed. Quantitative assessment of the structural changes in the biomaterial was performed using the spectral analysis of the radio frequency signal and the estimation of acoustic parameters in the 10-65 MHz frequency bandwidth. Correlation of in-vitro ultrasound data with histologic findings has shown that attenuation and backscatter coefficients are sensitive to the changes in the polymer pore content with time. Our results obtained in vivo demonstrated that 3-D 80 MHz echography coupled with quantitative characterization provide a unique tool for the non-invasive and objective follow-up of the implant biointegration and should contribute to clinical management of artificial cornea.

Evaluation of error bounds on calcaneal speed of sound caused by surrounding soft tissue

For absorptiometry measurements, soft tissue may have an impact on quantitative ultrasound (QUS) measurements. In the present study, we focused primarily on the quantification of measurement error on speed of sound (SOS) caused by surrounding soft tissue. The relevant soft tissue parameters affecting the inherent SOS inaccuracies are thickness and sound velocity. To meet our goal, SOS measurements were taken at the right heel using a QUS imaging device in 21 healthy subjects. Site-matched measurements of soft tissue thickness (STT) and bone width were performed using magnetic resonance imaging of the heel. Several bone velocities were calculated either by accounting for bone width (SOSBW) only or by taking into account the exact path lengths of all major components traversed by ultrasound &lapr;V(b)). Given that soft tissue composition is difficult to determine in vivo, we chose to estimate lower and upper error bounds on bone velocity (V(b lower) and V(b upper)) by spanning the full range of available values in the literature. The mean BW was 30.7 +/- 2.7 mm and the mean medial and external STTs were 8.8 +/- 1.7 and 8.5 +/- 1.5 mm, respectively. Accounting for true BW only resulted in no significant difference between SOS (1533 +/- 37) and SOSBW (1531 +/- 33). By contrast, accounting for both true BW and surrounding soft tissue resulted in an increase in the calculated bone velocity and statistically significant differences between SOS and V(b upper) (1568 +/- 36) and V(b lower) (1542 +/- 34). Root mean square errors between SOS and the calculated velocities were 0.34, 2. 32, and 0.70% for SOSBW, V(b upper), and V(b lower), respectively. We report here measurement errors caused by soft tissue to be 3 to 20 times higher than the SOS short-term precision (SOS coefficient of variation of 0.1%). Our results suggest that inaccuracies in SOS measurement caused by overlying soft tissue cannot be neglected. Overlying soft tissues may influence outcomes of longitudinal studies, especially if variations in tissue thickness and composition occur during the longitudinal follow-up. A practical way of minimizing the measurement error could be to perform an adequate correction for the overlying soft tissue. However, ideally, this should require knowing both the thickness and sound velocity in soft tissue. One might preferably conduct experimental investigations that directly control soft tissue thickness and composition to resolve this problem.

Multiparametric attenuation and backscatter images for characterization of carotid plaque

The goal of this study was to develop methods for quantitative ultrasound imagery suitable for noninvasive assessment of carotid plaque composition prior to the selection of the technique for revascularization. Using two broadband transducers (5-12 MHz and 12-28 MHz), backscattered radio frequency signals were acquired from entire lengths of 15 carotid endarterectomy specimens. Spectral analysis methods with correction for system response and beam diffraction were applied to radio frequency signals from local volumes of plaque having a 2 mm slice thickness, 1 mm width and axial depth of 480 microm and 240 microm at 10 MHz and 20 MHz, respectively. From these spectra, local values of four ultrasound parameters (integrated backscatter, frequency dependence of backscatter, integrated attenuation and slope of attenuation) were estimated and used to construct quantitative images. To combine information from these different parameter images, a two-step approach was followed. First, in 59 independent quantitative images of highly stenotic plaque, the average parameter values in a central five-by-three pixel region were correlated with plaque composition as assessed by histology to investigate the relationship between parameter values, frequency bandwidth and plaque composition. Discriminant analysis of parameter values vs. plaque composition was made to find a set of predictive equations to classify sets of measurements. Correct classification was obtained for 100% of calcified, 75% of intraplaque hemorrhage and 71% of lipidic plaques of the input data set. Second, each set of pixels from different parameter images was classified using the predictive equations, and a single, local tissue composition image was constructed. Examples of tissue composition images are presented in comparison with corresponding histologic sections. Both agreement and disagreement between image pairs are discussed.

Quantitative ultrasound imaging of the calcaneus: precision and variations during a 120-Day bed rest

This study reports on the precision and variation of quantitative ultrasound (US) parameters [broadband ultrasonic attenuation (BUA) or slope of the frequency-dependent attenuation in dB/MHz and speed of sound (SOS m/second)] after 120 days of continuous bed rest in six normal male volunteers. Quantitative US was measured at the calcaneus using a new US bone imaging scanner. The measurements were carried out on both heels at approximately 2-week intervals. The short-term precision was 0.31% for SOS and 2.8% for BUA. The long-term precision was 0.58% for SOS, 4.7% for BUA. A significant decrease of SOS values of -26 m/second (P < 0.0001) for the right heel and -17 m/second (P < 0.05) for the left heel was found at the group level. In terms of percentage change this represents -1.7% for the right heel and -1.1% for the left heel. These percentage decrements were 3.5-5.5 times that of the short-term precision and 2-3 times that of the long-term precision of the technique. At the individual level, the decrease of SOS was statistically significant (P < 0.05) or marginally significant (P < 0.1) for four out of 6 subjects. For 2 other subjects, similar trends were observed, but without reaching statistical significance. BUA did not change significantly during follow-up. These results are consistent with previous findings on changes of ultrasonic properties from the calcaneus during aging, pregnancy, or therapy, showing that calcaneus SOS is a valuable index of bone loss. These preliminary data suggest that prolonged exposure to simulated weightlessness may lead to a lower SOS, which then could be used for the follow-up of bone demineralization occurring during long-term space flights.

Diagnostics and surgical treatment strategy for rectal cavernous hemangiomas based on three case examples

A 20-year-old man with a congenital vascular malformation extending from the anal canal into the distal sigmoid had had recurrent perianal blood loss as a neonate. A hemangioma was diagnosed for the first time in 1978. The patient received regular and frequent gastroenterological treatment until admission. Decisive for the indication for surgery was the patient's need for blood infusions and shorter bleeding intervals in June 1998. Surgical therapy consisted of deep anterior rectosigmoid resection with coloanal pouch anastomosis. In a second case of a 27-year-old woman a sigmoid hemangioma was diagnosed in conjunction with emergency sigmoid resectioning. Because of recurrent hemorrhages a coloanal pouch was also established here in a second step. The third case involved a 19-year-old woman with a 12-year history of repeated perianal hemorrhages. After sigmoid discontinuity resection we carried out proctectomy with descendostoma creation due to renewed severe intractable perianal bleeding. The histological examination revealed a rectal hemangioma that had caused the repeated perianal hemorrhages. Surgical reconstruction was then achieved by coloanal pouch anastomosis. In view of the good functional and perioperative results, current surgical therapy should aim at preserving continuity and continence by coloanal pouch anastomosis.

Diversity within natural progenies of the grapevine dieback fungus Eutypa lata

The diversity within 16 natural progenies of the grapevine dieback fungus, Eutypa lata, was investigated by sampling single-ascospore isolates mainly in France and using random amplified polymorphic DNA (RAPD) markers, vegetative compatibility (VC), and pathogenicity testing. The combination of RAPD and VC data identified each isolate as a unique genotype within each progeny. Only three RAPD haplotypes did not cluster within the expected groups, i.e. the ascospore families. Within each set of clustering haplotypes, Mendelian 1:1 ratios for absence and presence were observed for RAPD markers, indicating that each progeny was the result of a biparental cross. Only one mycelium was obtained when isolation was performed from the discolored wood sustaining the perithecial stroma. This mycelium was identified as a likely parent of the corresponding progeny by RAPD analysis. The level of diversity measured by the average distance between haplotypes calculated from RAPD data, the percentage of vegetatively compatible pairs and the range of pathogenicity appeared similar between all but one progeny, indicating that crosses occurred within a random-mating population. All the results were consistent with the hypothesis that E. lata is a random-mating species having a high degree of genetic diversity.

Inferior turbinate goblet cell secretion in patients with perennial allergic and nonallergic rhinitis

Perennial rhinitis is clinically associated with a significant increase in nasal mucus secretion. Moreover, it has already been established that the number of goblet cells, in the inferior turbinates of patients with perennial allergic and nonallergic rhinitis, does not differ from that of normal subjects. Thus a question is raised, whether the above-mentioned phenomenon is ascribed exclusively to submucosal glandular activity, or may also be a result of a nonhyperplastic increase of goblet cell functional activity. This study was conducted to assess inferior turbinate goblet cell mucus secretion in a cohort of patients with perennial allergic and nonallergic rhinitis compared with normal controls. A semiquantitative morphometric method was used to examine goblet cell mucus secretion in sections stained with Alcian blue and periodic acid Schiff. Mucus secretion in each section was established in terms of secretory ratio, calculated as the number of secreting goblet cells divided by the number of nonsecreting ones. The mean secretory ratio of patients with perennial allergic (n = 11) and nonallergic rhinitis (n = 23) was 0.89 and 0.57, respectively, compared to controls (n = 10) 0.25. Statistical analysis confirmed that the secretory ratio of patients with perennial allergic rhinitis was significantly higher than that of the control group. No significant difference prevailed between patients with perennial nonallergic rhinitis and controls, as well as between allergic and nonallergic patients. Based on the results of the study, a basal state of nasal goblet cell mucus secretion in nonstimulated healthy people was established. Furthermore, it was concluded that the enhancement in mucus discharge, from the inferior turbinate goblet cells of patients with perennial allergic rhinitis, was attributed to a nonhyperplastic increase of nasal goblet cell functional activity.

Tissue engineering of biphasic joint cartilage transplants

In isolated posttraumatic or idiopathic joint defects the chondral layers and adjacent subchondral spongy bone are usually destructed. For regeneration we suggest the in vitro formation of a cartilage-coated biomaterial carriers (biphases) in order to fill the correspondingjoint defects. In this study Biocoral, a natural coralline material made of calcium carbonate, and calcite, a synthetic calcium carbonate, were used as supports for the cultivation of bovine chondrocytes in a three-dimensional polymer fleece. The cell-polymer-structure was affixed to the biomaterial with a fibrin-cell-solution. The artificial cartilage formed a new matrix and fused with the underlying biomaterial. The results indicate a promising technical approach to anchor tissue engineered cartilage in joint defects.

Fatigue strength of locking screws and prototypes used in small-diameter tibial nails: a biomechanical study

BACKGROUND

One major problem with the use of small-diameter nails in the treatment of tibial fractures is the high rate of fatigue fractures of the locking screws. The objective of this study was to correlate such parameters as diameter of locking screws, influence of notch effect, and material with fatigue strength and fatigue limit.

METHODS

In a biomechanical study, the mechanical properties of 11 different locking screws and screw designs to be used in solid tibial nails were tested under typical fatigue conditions.

RESULTS

The results showed that an increase in the screw's diameter significantly increased the fatigue strength of the tested locking screws and prototypes (p < 0.0005). A 20% increase of diameter improved fatigue strength by 25 to 70%. Absence of thread at the location where the screw contacts the nail's aperture (where the main load is transmitted to the screw and where the screw, therefore, usually tends to break) may double the fatigue strength and fatigue limit by avoiding the negative notch effect of the screw's thread. It was further significant that titanium alloys had a higher fatigue strength compared with stainless steel alloys (p < 0.001). However, the fatigue strength of titanium implants is massively reduced by minimal damage to the surface.

CONCLUSION

Optimizing the core diameter of the locking screws at the aperture of the solid tibial nail by using screws without a continuous thread generates a fatigue strength two to three times higher compared with screws with a continuous thread. Increasing fatigue strength of locking screws might decrease malunion in fractures stabilized by small-diameter nails.

Histopathologic changes of the soft palate after laser-assisted uvulopalatoplasty

OBJECTIVE

To assess late histopathologic changes of the soft palate after laser-assisted uvulopalatoplasty in patients with snoring and mild obstructive sleep apnea.

DESIGN

A nonrandomized, histopathologic controlled study.

SUBJECTS AND INTERVENTIONS

Palatal surgical specimens were removed from 10 patients with snoring and obstructive sleep apnea in whom laser-assisted uvulopalatoplasty was not successful and who subsequently underwent uvulopalatopharyngoplasty. The mean interval between the last laser treatment and uvulopalatopharyngoplasty was 24 months. The patients' specimens were compared with those of a control group consisting of 12 palates and uvulae excised during uvulopalatopharyngoplasty.

RESULTS

After laser-assisted uvulopalatoplasty, all soft palates displayed marked and progressive pathologic changes that increased with every additional treatment and extended far beyond the point of laser beam application. The loose connective tissue present in the lamina propria was replaced by diffuse fibrosis, which also extended to the central layer, on the expanse of seromucous glands and muscle fibers. Other changes included ulceration of the oral epithelium and a patchy inflammatory reaction.

CONCLUSIONS

Extensive thermal-induced changes, involving the 3 layers of the organ, were found. They are compatible with clinical observations reported elsewhere and are probably responsible for the worsening of the obstructive sleep apnea status and the sensation of the pharyngeal dryness that developed months after the laser-assisted uvulopalatoplasty. Although it has immediate benefits, the procedure is still relatively new and all its implications are as yet unknown.

[Non-invasive imaging of atherosclerosis by MRI and ultrasonography]

The concept of the unstable, so-called "high risk" or vulnerable atheromatous plaque has been accepted for several years and its biological, mechanical and cellular features (collagen top, lipid core with macrophages, metalloproteinases...) have been determined. However, the means of investigating these lesions remain limited. A description of their composition has become essential as the prognosis of coronary, aortic and carotid artery disease is no longer evaluated only by morphometric data (degree of stenosis). MRI with T1 or T2 contrast sequences, density of spin, chemical shift, diffusion, magnetisation transfer or spectroscopy provides a non-invasive tool for their study. This method, based on the detection of magnetic atomic nuclei (such as proton H1, carbon 13, sodium 23, potassium 49) enables tissue characterisation by means of the variations in chemical environment and their consequences on the degree of magnetisation of the nuclei studied. High frequency ultrasound could also be used to this end by measuring the coefficients of attenuation and back-scattering. These methods, used clinically and in different animal models, should improve our understanding of the physiopathology, facilitate diagnosis and improve the prognostic accuracy in patients with atherosclerosis.

Ultrasound measurement on the calcaneus: influence of immersion time and rotation of the foot

The aim of this study was to evaluate the influence of immersion time and rotation of the heel around the leg axis on the reproducibility of measurements using an ultrasound bone imaging scanner (UBIS) with a temperature-controlled water bath. Measurements were obtained in 10 men, 11 premenopausal women and 10 postmenopausal women. The right foot of all subjects was scanned 12 times with an interval of 3 min between each scan. The first 10 measurements, performed to study the effect of immersion time, were taken without intermediate repositioning. Measurements 11 and 12 were also taken without removing the foot, but the calcaneus position was varied by an angle of +/-2.5 degrees with respect to the reference position used during the first 10 measurements. Prolonged immersion of the heel led to a decrease in the variations of quantitative ultrasound (QUS) parameters between successive measurements. Following rapid variations with immersion time, the QUS parameters reached a plateau. The effect of immersion time on measurement error remained significant until the first two or three scans for broadband ultrasound attenuation (BUA) and until the sixth or seventh scans for speed of sound (SOS). The variation in BUA was more pronounced (p<0.05) for the group of postmenopausal women (20. 7% change in BUA between the first and tenth scans; p<0.005) than for the group of premenopausal women (6.8% change in BUA between the first and tenth scans; p<0.005). The variations in SOS were similar in the two groups (0.8% variation; p<0.005). The impact of immersion time was smaller for men than for women [2.5%, (p<0.01) and 0.4% (p<0.005) of the change between the first and tenth scans for BUA and SOS respectively]. On the whole, the measurement errors due to rotation of the heel were lower than those caused by immersion time. The variations were significant only in men and premenopausal women. Both immersion time and rotation of the heel may play a role in the precision of QUS and should be carefully standardized, particularly for longitudinal studies. In addition, following these results we have adopted a standardized protocol to derive the technique reproducibility in groups of premenopausal and postmenopausal women. The coefficients of variation were 1.1% for BUA and 0.1% for SOS in premenopausal women, and 1.4% for BUA and 0.13% for SOS in postmenopausal women.

Cooperativity between the enzymatic sites of F1-ATPase revisited by the use of HPLC methods

The fundamental question of the cooperativity between the enzymatic sites of F1-ATPase is examined in the light of new measurements of the enzymatic rate of ATP hydrolysis by CF1, the enzyme isolated from spinach chloroplasts. The experimental data, obtained with a chromatographic method, fit a model that involves two kinds of independent enzymatic sites working with metal-free ATP, with no need of cooperativity between the sites. Binding measurements between ADP or ATP and CF1 by the chromatographic method of Hummel and Dreyer (1962) also support this conclusion. The present data and interpretation are in agreement with those reported recently (Reynafarje and Pedersen, 1996) which show that the first order rate constant of ATP hydrolysis by MF1, the analogous enzyme from mitochondria, is virtually constant under experimental conditions involving either unisite or multisite hydrolysis of ATP. The present data and interpretation are discussed together with those reported previously, in particular with regard to the methods that were used to support the commonly accepted opposite viewpoint.

P-Selectin and platelet clearance

P-selectin is an adhesion receptor for leukocytes expressed by activated platelets and endothelial cells. To assess a possible role of P-selectin in platelet clearance, we adapted an in vivo biotinylation technique in mice. Wild-type and P-selectin-deficient mice were infused with N-hydroxysuccinimido biotin. The survival of biotinylated platelets was followed by flow cytometry after labeling with fluorescent streptavidin. Both wild-type and P-selectin-deficient platelets presented identical life spans of about 4.7 days, suggesting that P-selectin does not play a role in platelet turnover. When biotinylated platelets were isolated, activated with thrombin, and reinjected into mice, the rate of platelet clearance was unchanged. In contrast, storage of platelets at 4 degreesC caused a significant reduction in their life span in vivo but again no significant differences were observed between the two genotypes. The infused thrombin-activated platelets rapidly lost their surface P-selectin in circulation, and this loss was accompanied by the simultaneous appearance of a 100-kD P-selectin fragment in the plasma. This observation suggests that the platelet membrane P-selectin was shed by cleavage. In conclusion, this study shows that P-selectin, despite its binding to leukocytes, does not mediate platelet clearance. However, the generation of a soluble form of P-selectin on platelet activation may have biological implications in modulating leukocyte recruitment or thrombus growth.

Role of P-selectin cytoplasmic domain in granular targeting in vivo and in early inflammatory responses

P-selectin is an adhesion receptor for leukocytes expressed on activated platelets and endothelial cells. The cytoplasmic domain of P-selectin was shown in vitro to contain signals required for both the sorting of this protein into storage granules and its internalization from the plasma membrane. To evaluate in vivo the role of the regulated secretion of P-selectin, we have generated a mouse that expresses P-selectin lacking the cytoplasmic domain (DeltaCT mice). The deletion did not affect the sorting of P-selectin into alpha-granules of platelets but severely compromised the storage of P-selectin in endothelial cells. Unstored P-selectin was proteolytically shed from the plasma membrane, resulting in increased levels of soluble P-selectin in the plasma. The DeltaCT-P-selectin appeared capable of mediating cell adhesion as it supported leukocyte rolling in the mutant mice. However, a secretagogue failed to upregulate leukocyte rolling in the DeltaCT mice, indicating an absence of a releasable storage pool of P-selectin in the endothelium. Furthermore, the neutrophil influx into the inflamed peritoneum was only 30% of the wild-type level 2 h after stimulation. Our results suggest that different sorting mechanisms for P-selectin are used in platelets and endothelial cells and that the storage pool of P-selectin in endothelial cells is functionally important during early stages of inflammation.

Automatic three-dimensional reconstruction and characterization of articular cartilage from high-resolution ultrasound acquisitions

Three-dimensional (3D) high-resolution ultrasonography has proved to be useful for in vitro assessment of cartilage remodeling due to osteoarthritis. The diagnosis is performed by computation of the mean thickness of the cartilage, which reveals hypertrophy or thinning, and by 3D reconstruction of the data, which provides essential information about the size, extent, and localization of the lesion. In both cases, preliminary segmention of the cartilage is necessary. This article proposes an algorithm for automatic segmentation of the cartilage from 3D ultrasonic acquisitions of the rat patella, which includes the detection of the cartilage surface and the cartilage/bone interface. The method was designed on the assumption of regularity and smoothness of the interfaces. The use of a global threshold was sufficient to separate the patella area from the background. The cartilage/bone interface was detected by selection of regions of interest (ROIs) encompassing the interface, followed by the detection of the interface within these ROIs using the graph theory. The method was applied to 162 samples. The detection accuracy was judged to be very good or good in 99% of the cases for the cartilage surface and in 86% of the cases for the cartilage/bone interface. The mean cartilage thickness value in the central part of the patella obtained from the automatic detection method was compared to that obtained manually. The coefficient of correlation between the two measurements was 0.92. These results show that our method is reliable. Thus, fast processing of a large number of acquisitions and a more complete analysis of the cartilage surface become possible.

Bone mineral density in women with cytotoxic-induced ovarian failure

OBJECTIVE

Premature ovarian failure is associated with a reduction in bone mineral density. As survival rates following treatment for haematological malignancies improve, chemotherapy-induced ovarian failure is becoming more common. However, there are few data concerning the impact of this on bone mineral density (BMD). We have therefore measured the BMD in 33 women with ovarian failure following treatment with cytotoxic chemotherapy.

PATIENTS AND DESIGN

We studied 33 women who received combination chemotherapy for Hodgkin's disease (n = 27), non-Hodgkin's lymphoma (n = 4), sarcoma (n = 1) and acute myeloid leukaemia (n = 1). The mean (range) age of the subjects at the time of BMD measurement was 37.5 (24-50) years and the mean (median: range) duration of amenorrhoea was 49 (24: 5-277) months. Eleven women had received hormone replacement therapy (HRT) for a mean (range) duration of 25 (1-62) months. BMD was measured by single photon absorptiometry or single X-ray absorptiometry, and dual energy X-ray absorptiometry at the distal and proximal radius, the femoral neck and the lumbar spine, respectively. BMD was expressed as Z-scores and statistical analysis was performed using the Wilcoxon matched-pairs signed-rank test.

RESULTS

There was no significant reduction in BMD at the hip, spine or a forearm in the cohort as a whole, although there was a trend to reduce bone density at all sites. When patients who had received HRT were excluded from the analysis there were small reductions in mean BMD at all sites, but this was only statistically significant at the proximal forearm (Z-score = -0.65; P = 0.03). Mean BMD of the HRT-treated patients was normal at all sites. Only seven patients (21%) had a BMD Z-score < -2 at any site.

CONCLUSION

It is inappropriate to assume that ovarian failure from different aetiologies has a similar deleterious impact on the skeleton. Untreated premature ovarian failure following cytotoxic chemotherapy results in some reduction in bone mineral density, but this is of a minor degree and is less than that observed in other hypo-oestrogenic states. The reason for this is unclear but studies of residual hormone production in the cytotoxic-damaged ovary may provide an answer.

In vivo results with a new device for ultrasonic monitoring of pig skin cryosurgery: the echographic cryoprobe

One of the main difficulties encountered in cryosurgery is the uncertainty in the extent and depth of the tissue effectively treated during the freezing process. The objective of this study was to evaluate in vivo ultrasonic control of skin cryosurgery using a new echographic cryoprobe. An echographic cryoprobe, developed specifically for dermatology applications, combines a high-frequency (20 MHz) miniature ultrasonic transducer and a N2O-driven closed cryoprobe. Knowledge of the ultrasound velocity of frozen skin is a prerequisite for monitoring the iceball formation kinetics. Therefore, in a first study, we estimated the ultrasound velocity of frozen skin specimens. In a second step, the operation of the echographic cryoprobe was assessed, under in vivo conditions similar to those used in human therapeutics, on normal skin of three female "Large-White" pigs under anesthesia. The mean value of ultrasound velocity of frozen skin obtained by pooling the data from all the skin specimens included in this study was 2865 +/- 170 m per s. The average rates of growth (10(-2) mm per s) of the iceballs were found to be 12.2 +/- 1.0 (pig 1), 9.0 +/- 1.0 (pig 2), and 8.4 +/- 0.9 (pig 3). The echographic cryoprobe had a built-in high-frequency ultrasonic transducer that served two functions. It enabled in vivo real-time monitoring of depth penetration of the iceball and it gave important feedback to the operator or to the console relating to the rate of growth of the iceball. Automatic (i.e., operator-independent) detection of the echo signal from the freezing front and calculation of the depth penetration of the iceball was possible.

[Bone remodeling: evaluation methods]

Bone tissue undergoes continual renewal in order to keep the mechanical competence of the bone matrix. This is performed by two cells: osteoclasts which resorb the calcified matrix and osteoblast which synthetize a new bone matrix. Biochemical markers of bone remodelling allow the evaluation of the activity of each type of bone cells. An unbalance in this process induces modifications of the amount of calcified tissue and of the bone microarchitecture. Several technics based on X-ray and ultrasound allow a non invasive evaluation of these modifications.

In vitro investigation of novel calcium phosphates using osteogenic cultures

A rat bone marrow stromal cell (RBM) culture was used to evaluate novel bioactive calcium phosphate ceramics. Three rapidly resorbable, glassy crystalline materials with the main crystalline phase Ca2KNa(PO4)2 were investigated (sample code GB 1a, GB 14, GB 9). These materials were designed to exhibit a higher degree of biodegradability than tricalcium phosphate. Additionally, a bioactive glass ceramic of low biodegradability was examined (sample code AP 40). RBM cells were cultured on the disc-shaped test substrata for 14 d. The culture medium was changed and calcium and phosphate concentrations of the medium were determined daily. Specimens were evaluated using light microscopy and morphometry of the cell-covered substrate surface, scanning electron microscopy and energy dispersive X-ray analysis. Except for GB 1a, the rat bone marrow cells attached and grew on all substrate surfaces. Of the different calcium phosphate ceramics tested, AP 40 facilitated osteoblast growth and the elaboration of the extracellular matrix to the highest degree followed by GB 9 and GB 14. The inhibition of cell growth encountered with GB 1a seemed to be related to its high phosphate ion release.