MIB-1, p53, bcl-2, and WAF-1 expression in pelvic lymph nodes and primary tumors in early stage cervical carcinomas: correlation with clinical outcome

A complete series of 40 cervical carcinomas with pelvic lymph node metastases were analysed immunohistochemically for prognostic markers. The aims of this study were to examine whether the detection of MIB-1, p53, bcl-2, and WAF-1 could be used as a prognostic marker for tumor recurrence and survival rate. During the period of observation (mean 222, range 72-360 months) 22 (55%) recurrences were encountered and 20 patients died of the disease. There were 35 squamous cell carcinomas (87.5%), 2 adenosquamous carcinomas (5.0%), and 3 pure adenocarcinomas (7.5%). One tumor (2.5%) was well differentiated, 12 tumors (30%) were moderately differentiated, and 27 tumors (67.5%) were poorly differentiated. The primary tumor grade (P=0.037) and radicality of the surgical margins (P=0.021) were significant prognostic factors with regard to tumor recurrence. The site and number of lymph nodes with metastases had no prognostic value. P53, bcl-2, and WAF-1 were not predictive factors for recurrences or the cancer-specific survival rate. The concordant expression of WAF-1 in the primary tumor and in lymph node metastases was lower than for p53 and bcl-2. The proliferative activity (MIB-1) seemed to be lower in tumor cells metastasized to the pelvic lymph nodes than in cells of the primary tumor. Expression of MIB-1 in lymph nodes was predictive of disease-free survival in both univariate and multivariate proportional hazard Cox analyses.

Immunohistochemical expression of p53, bcl-2, and p21(WAF1/CIP1) in early cervical carcinoma: correlation with clinical outcome

The objective of this study was to assess the value of p53, bcl-2, and p21(WAF1/CIP1) immunoreactivity as predictors of pelvic lymph node metastases (LNM), recurrences, and death due to the disease in early stage (FIGO I-II) cervical carcinomas. FIGO stage, type of histopathology, and tumor grade were also evaluated in this series of patients treated by radical hysterectomy (Wertheim-Meigs) between 1965 and 1990. A total of 172 patients were included. A tumor was regarded as positive when more than 30% of the neoplastic cells exhibited immunoreactivity. Positive immunostaining was found in 8.9% for p53, in 43.5% for bcl-2, and in 25.0% for p21(WAF1/CIP1). None of them was able to predict LNM or clinical outcome. Presence of LNM, tumor recurrence, and death from disease were significantly associated with the FIGO stage (P = 0.014, P = 0.009, and P = 0.001, respectively). The 5-year cancer-specific survival rate was 91.6% and the overall survival rate was 90.5%. It was concluded that immunohistochemically detected p53, bcl-2, and p21(WAF1/CIP1) appeared to be of no predictive value with regard to LNM, tumor recurrences, or long-term survival in early cervical carcinomas.

Immunohistochemical expression of p53, bcl-2, and p21WAF1/CIP1 in early cervical carcinoma: Correlation with clinical outcome

Abstract.

Graflund M, Sorbe B, Karlsson M. Immunohistochemical expression of p53, bcl-2, and p21 WAF1/CIP1 in early cervical carcinoma: Correlation with clinical outcome.

The objective of this study was to assess the value of p53, bcl-2, and p21WAF1/CIP1 immunoreactivity as predictors of pelvic lymph node metastases (LNM), recurrences, and death due to the disease in early stage (FIGO I-II) cervical carcinomas. FIGO stage, type of histopathology, and tumor grade were also evaluated in this series of patients treated by radical hysterectomy (Wertheim-Meigs) between 1965 and 1990. A total of 172 patients were included. A tumor was regarded as positive when more than 30% of the neoplastic cells exhibited immunoreactivity. Positive immunostaining was found in 8.9% for p53, in 43.5% for bcl-2, and in 25.0% for p21WAF1/CIP1. None of them was able to predict LNM or clinical outcome. Presence of LNM, tumor recurrence, and death from disease were significantly associated with the FIGO stage (P = 0.014, P = 0.009, and P = 0.001, respectively). The 5-year cancer-specific survival rate was 91.6% and the overall survival rate was 90.5%. It was concluded that immunohistochemically detected p53, bcl-2, and p21WAF1/CIP1 appeared to be of no predictive value with regard to LNM, tumor recurrences, or long-term survival in early cervical carcinomas.

Comparison of calculated, measured and self-assessed intelligibility of speech in noise for hearing-aid users

The Speech Intelligibility Index (SII) was used along with paired-comparison judgements and speech recognition scores to compare the speech intelligibility provided by two hearing-aid frequency responses in two different background noises. The purpose was to validate an SII-based procedure. Test subjects were 26 hearing-aid users representing a wide range of hearing loss configurations. One hearing-aid setting was in close agreement with the NAL-R prescription, whereas the other setting was achieved by reducing the high-frequency gain by about 10 dB compared to NAL-R. There were good overall agreements between results of the three methods. Average speech recognition scores were about 4 percentage points higher for the NAL-R frequency response, which also was subjectively judged as significantly better in terms of speech intelligibility. The SII based procedure was found to be suitable for comparing hearing-aid characteristics within subjects.

The prognostic value of a histologic grading system, DNA profile, and MIB-1 expression in early stages of cervical squamous cell carcinomas

This study evaluated the prognostic importance of a new grading system focusing on the invasive tumor front, DNA profile, and the proliferation marker MIB-1. A complete geographic series of 172 women treated with radical hysterectomy (Wertheim-Meigs) for FIGO stage I-II cervical carcinomas was the target population. The analyses were performed on 141 (82%) squamous cell carcinomas of the complete series. During the period of observation (mean 222 months), 17 recurrences (12.1%) were encountered. Prognostic factors for disease-free survival were lymph node status (P < 0.000001), radical surgical margins (P = 0.00004), and tumor size (P = 0.002). The complete score of the invasive front grading system (IFG), and the individual scores of two variables-pattern of invasion and host response-were all significantly (P = 0.002, P = 0.007, P = 0.0001) associated with pelvic lymph node metastases. Host response was the single most important factor in the IFG system, and it was superior to the complete score in predicting lymph node metastases. The total IFG score was also a significant (P = 0.003) prognostic factor for disease-free survival. DNA ploidy, S-phase fraction, and MIB-1 expression were nonsignificant factors in predicting pelvic lymph node metastases and disease-free survival of the patient. The IFG in the original or modified versions could predict low- and high-risk groups of tumors and therefore be of value in treatment planning for these patients.

The prognostic value of histopathologic grading parameters and microvessel density in patients with early squamous cell carcinoma of the uterine cervix

The purpose of this study was to investigate the prognostic importance of clinical and histopathologic factors, including malignancy grading systems (MGS), partial index (PI), invasive front grading (IFG), and microvessel density. A complete geographic series of 172 early stage (FIGO I-II) cervical carcinomas treated by Wertheim-Meigs surgery during the period 1965-1990 was studied. The patients were followed up for at least 10 years. Significant prognostic factors for disease-free survival were lymph node status (P < 0.0000001), radical surgical margins (P = 0.00003), and tumor size (P = 0.008). In a multivariate Cox analysis it was shown that lymph node status was the single most important prognostic factor with regard to disease-free survival. The total MGS and the PI scores were highly significantly (P = 0.0001) associated with pelvic lymph node metastases and disease-free survival rate in squamous cell carcinomas. The MGS and the PI systems were superior to the IFG system in predicting lymph node metastases. The total IFG score was also a statistically highly significant (P = 0.003) prognostic factor with regard to disease-free survival in both univariate and multivariate analyses. Microvessel density was a nonsignificant prognostic factor. There was a highly significant (P = 0.002) association between vascular space invasion of tumor cells and the presence of lymph node metastases. In conclusion, histopathologic malignancy grading systems provide valuable prognostic information in patients with early stage squamous cell carcinomas of the uterine cervix.

The prognostic value of histopathologic grading parameters and microvessel density in patients with early squamous cell carcinoma of the uterine cervix

Abstract.

Graflund M, Sorbe B, Hussein A, Bryne M, Karlsson M.

The purpose of this study was to investigate the prognostic importance of clinical and histopathologic factors, including malignancy grading systems (MGS), partial index (PI), invasive front grading (IFG), and microvessel density. A complete geographic series of 172 early stage (FIGO I–II) cervical carcinomas treated by Wertheim-Meigs surgery during the period 1965–1990 was studied. The patients were followed up for at least 10 years. Significant prognostic factors for disease-free survival were lymph node status (P < 0.0000001), radical surgical margins (P = 0.00003), and tumor size (P = 0.008). In a multivariate Cox analysis it was shown that lymph node status was the single most important prognostic factor with regard to disease-free survival. The total MGS and the PI scores were highly significantly (P = 0.0001) associated with pelvic lymph node metastases and disease-free survival rate in squamous cell carcinomas. The MGS and the PI systems were superior to the IFG system in predicting lymph node metastases. The total IFG score was also a statistically highly significant (P = 0.003) prognostic factor with regard to disease-free survival in both univariate and multivariate analyses. Microvessel density was a nonsignificant prognostic factor. There was a highly significant (P = 0.002) association between vascular space invasion of tumor cells and the presence of lymph node metastases. In conclusion, histopathologic malignancy grading systems provide valuable prognostic information in patients with early stage squamous cell carcinomas of the uterine cervix.

Prognostic importance of DNA ploidy and p53 in early stages of epithelial ovarian carcinoma

Patients with early stages (FIGO stages IA-IIC) of ovarian cancer continue to experience tumor relapses and they succumb due to their disease after seemingly adequate adjuvant therapy. In a series of 113 patients treated with adjuvant radiotherapy 4-6 weeks after primary surgery, the DNA content and p53 status of the tumors were studied and related to other known prognostic factors (age, FIGO stage, histopathologic type, and tumor grade). The DNA analyses were done by flow cytometry and p53 expression was studied by immunohistochemistry on formalin-fixed and paraffin-embedded tissue. DNA analyses of 103 tumors could be made and the p53 status was determined in 106 cases. Univariate analyses showed that both p53-positivity and aneuploidy of the ovarian tumors were strongly associated with tumor grade. There was also a strong association between p53 expression of the tumors and DNA aneuploidy (DNA index >1.10 and S-phase fraction >11.5%). P53-positivity and tumor grade were the only significant factors for the risk of tumor recurrence. DNA and p53 status alone were not adequate predictive factors to identify clinically relevant subgroups of patients who would benefit from adjuvant postoperative therapy. Tumor grade remains the most important prognostic factor with regard to the risk of tumor recurrence and the cancer-specific survival rate in early stage ovarian carcinoma. Overexpression of p53 also increases the risk of tumor recurrence.

Effect of glycogen loading on skeletal muscle cross-sectional area and T2 relaxation time

This study was performed to investigate if glycogen loading of skeletal muscles, by binding water, would effect the cross-sectional area (CSA) and if an altered water content would alter the transverse relaxation time (T2) measured by magnetic resonance imaging (MRI). Five healthy volunteers participated in a programme with 4 days of extremely carbohydrate-restricted meals followed by 4 days of extremely high carbohydrate intake. The CSA and T2 of thigh and calf muscles were related to the intramuscular glycogen content evaluated at days 4 and 8. An increase in glycogen content from 281 to 634 mmol kg(-1) dry wt increased the CSA of the vastus muscles by 3.5% from 78 +/- 11 to 80 +/- 12 cm2 and the thigh circumference by 2.5% from 146 +/- 20 to 150 23 cm2. Calf circumference increased non-significantly by 4% from 78 +/- 15 to 82 +/- 19 cm2. Mono-exponential T2 decreased in m. tibialis anterior from 27.8 +/- 1.2 to 26.9 +/- 1.7 ms, did not change in m. vastus lateralis 26.5 +/- 1.9 ms/26.6 +/- 1.3 ms or in m. gastrocnemius 29.5 +/- 1.0 ms/29.8 +/- 1.9 ms. Glycogen loading increased the signal intensity mainly at different echo times (TE) 15 and 30 ms. The study shows that increased glycogen filling in the muscles increases muscle CSA and that this can be detected by MRI. The signal intensity increased the most at shorter TEs suggesting a more tight intracellular binding of water in glycogen loaded muscles.

Transfer of continuous-relief diffractive structures into diamond by use of inductively coupled plasma dry etching

The transfer of continuous-relief diffractive structures from resist into diamond by use of direct-write electron-beam lithography followed by dry etching in an inductively coupled plasma is demonstrated. The gases used for the diamond etching are O(2) and Ar. The chemical-vapor-deposited diamond substrate is of optical quality. Our results show that the transfer process generates fairly smooth etched structures. Blazed gratings with periods of 45mum and Fresnel lenses have been manufactured. The blazed gratings have been optically evaluated with a femtosecond laser operating at 400 nm. The diffraction efficiency was 68% in the first order, with a theoretical value of 100%. We intend to investigate the transfer process further and then to fabricate diffractive and refractive elements for use with Nd:YAG high-power lasers.

A hybrid equation for simulation of perfused tissue during thermal treatment

Bio-heat equations (BHEs) are necessary for predicting tissue temperature during thermal treatment. For some applications, however, existing BHEs describe the convective heat transfer by the blood perfusion in an unsatisfactory way. The two most frequently used equations, the BHE of Pennes and the k(eff) equation, use for instance either a heat sink or an increased thermal conductivity in order to account for the blood perfusion. Both these methods introduce modelling inaccuracies when applied to an ordinary tissue continuum with a variety of vessel sizes. In this study, a hybrid equation that includes both an increased thermal conductivity and a heat sink is proposed. The equation relies on the different thermal characteristics associated with small, intermediate and large sized vessels together with the possibilities of modelling these vessels using an effective thermal conductivity in combination with a heat sink. The relative importance of these two terms is accounted for by a coefficient beta. For beta = 0 and beta = 1, the hybrid equation coincides with the BHE of Pennes and the k(eff) equation, respectively. The hybrid equation is used here in order to simulate temperature fields for two tissue models. The temperature field is greatly affected by beta, and the effect is dependent on, e.g. the boundary conditions and the power supply. Since the BHE of Pennes and the k(eff) equation are included in the hybrid equation, this equation can also be useful for evaluation of the included equations. Both these heat transfer modes are included in the proposed equation, which enables implementation in standard thermal simulation programmes.

"Tolerosomes" are produced by intestinal epithelial cells

The development of immunological tolerance to orally fed antigens depends on the sampling, processing and transportation events followed in the intestinal epithelium. We present here a description of a "tolerosome": a supra-molecular, exosome-like structure assembled in and released from the small intestinal epithelial cell. The tolerosome is a approximately 40 nm large vesicular structure that carries MHC class II (MHC II) with bound antigenic peptides sampled from the gut lumen. Tolerosomes isolated from serum shortly after antigen feeding or from an in vitro pulsed intestinal epithelial cell line are fully capable of inducing antigen specific tolerance in naive recipient animals. Purified tolerosomes represent a structure by which fed antigens can be efficiently presented to the immune system. Removal of the tolerosomes from serum by ultracentrifugation or absorption of MHC II results in abrogated tolerance development.

Three dimensional flow in the human left atrium

BACKGROUND

Abnormal flow patterns in the left atrium in atrial fibrillation or mitral stenosis are associated with an increased risk of thrombosis and systemic embolisation; the characteristics of normal atrial flow that avoid stasis have not been well defined.

OBJECTIVES

To present a three dimensional particle trace visualisation of normal left atrial flow in vivo, constructed from flow velocities in three dimensional space.

METHODS

Particle trace visualisation of time resolved three dimensional magnetic resonance imaging velocity measurements was used to provide a display of intracardiac flow without the limitations of angle sensitivity or restriction to imaging planes. Global flow patterns of the left atrium were studied in 11 healthy volunteers.

RESULTS

In all subjects vortical flow was observed in the atrium during systole and diastolic diastasis (mean (SD) duration of systolic vortex, 280 (77) ms; and of diastolic vortex, 256 (118) ms). The volume incorporated and recirculated within the vortices originated predominantly from the left pulmonary veins. Inflow from the right veins passed along the vortex periphery, constrained between the vortex and the atrial wall.

CONCLUSIONS

Global left atrial flow in the normal human heart comprises consistent patterns specific to the phase of the cardiac cycle. Separate paths of left and right pulmonary venous inflow and vortex formation may have beneficial effects in avoiding left atrial stasis in the normal subject in sinus rhythm.

Follow-up of patients treated with oral doxycycline for Lyme neuroborreliosis

The clinical outcome for 69 patients treated with oral doxycycline for Lyme neuroborreliosis was studied retrospectively. The clinical follow-up time was 14 d to 2 y (median 7 months). All patients improved during and after treatment. A complete recovery was seen in 56 patients by 14 d to 9 months (median 6 weeks) after therapy, while 13 patients (19%) still had persistent sequelae 1 y after antibiotic treatment. Six patients were retreated because of new or persistent symptoms, but in no patient was a treatment failure proven. A questionnaire was sent to each patient, asking for time to recovery, sequelae and relapse of symptoms. No patient had experienced relapse of symptoms associated with Lyme neuroborreliosis when answering the questionnaire 2-9 y after treatment. Oral doxycycline seems to be an effective, convenient and inexpensive alternative for the treatment of Lyme neuroborreliosis.

Subtle differences in dissociation rates of interactions between destabilized human carbonic anhydrase II mutants and immobilized benzenesulfonamide inhibitors probed by a surface plasmon resonance biosensor

The development of commercial biosensors based on surface plasmon resonance has made possible careful characterization of biomolecular interactions. Here, a set of destabilized human carbonic anhydrase II (HCA II) mutants was investigated with respect to their interaction kinetics with two different immobilized benzenesulfonamide inhibitors. Point mutations were located distantly from the active site, and the destabilization energies were up to 23 kJ/mol. The dissociation rate of wild-type HCA II, as determined from the binding to the inhibitor with higher affinity, was 0.019 s(-1). For the mutants, dissociation rates were faster (0.022-0.025 s(-1)), and a correlation between faster dissociation and a high degree of destabilization was observed. We interpreted these results in terms of increased dynamics of the tertiary structures of the mutants. This interpretation was supported by entropy determinations, showing that the entropy of the native structure significantly increased upon destabilization of the protein molecule. Our findings demonstrate the applicability of modern biosensor technology in the study of subtle details in molecular interaction mechanisms, such as the long-range effect of point mutations on interaction kinetics.

The pleuromutilin drugs tiamulin and valnemulin bind to the RNA at the peptidyl transferase centre on the ribosome

The pleuromutilin antibiotic derivatives, tiamulin and valnemulin, inhibit protein synthesis by binding to the 50S ribosomal subunit of bacteria. The action and binding site of tiamulin and valnemulin was further characterized on Escherichia coli ribosomes. It was revealed that these drugs are strong inhibitors of peptidyl transferase and interact with domain V of 23S RNA, giving clear chemical footprints at nucleotides A2058-9, U2506 and U2584-5. Most of these nucleotides are highly conserved phylogenetically and functionally important, and all of them are at or near the peptidyl transferase centre and have been associated with binding of several antibiotics. Competitive footprinting shows that tiamulin and valnemulin can bind concurrently with the macrolide erythromycin but compete with the macrolide carbomycin, which is a peptidyl transferase inhibitor. We infer from these and previous results that tiamulin and valnemulin interact with the rRNA in the peptidyl transferase slot on the ribosomes in which they prevent the correct positioning of the CCA-ends of tRNAs for peptide transfer.

The complete set of genes encoding major intrinsic proteins in Arabidopsis provides a framework for a new nomenclature for major intrinsic proteins in plants

Major intrinsic proteins (MIPs) facilitate the passive transport of small polar molecules across membranes. MIPs constitute a very old family of proteins and different forms have been found in all kinds of living organisms, including bacteria, fungi, animals, and plants. In the genomic sequence of Arabidopsis, we have identified 35 different MIP-encoding genes. Based on sequence similarity, these 35 proteins are divided into four different subfamilies: plasma membrane intrinsic proteins, tonoplast intrinsic proteins, NOD26-like intrinsic proteins also called NOD26-like MIPs, and the recently discovered small basic intrinsic proteins. In Arabidopsis, there are 13 plasma membrane intrinsic proteins, 10 tonoplast intrinsic proteins, nine NOD26-like intrinsic proteins, and three small basic intrinsic proteins. The gene structure in general is conserved within each subfamily, although there is a tendency to lose introns. Based on phylogenetic comparisons of maize (Zea mays) and Arabidopsis MIPs (AtMIPs), it is argued that the general intron patterns in the subfamilies were formed before the split of monocotyledons and dicotyledons. Although the gene structure is unique for each subfamily, there is a common pattern in how transmembrane helices are encoded on the exons in three of the subfamilies. The nomenclature for plant MIPs varies widely between different species but also between subfamilies in the same species. Based on the phylogeny of all AtMIPs, a new and more consistent nomenclature is proposed. The complete set of AtMIPs, together with the new nomenclature, will facilitate the isolation, classification, and labeling of plant MIPs from other species.

The complete set of genes encoding major intrinsic proteins in Arabidopsis provides a framework for a new nomenclature for major intrinsic proteins in plants

Major intrinsic proteins (MIPs) facilitate the passive transport of small polar molecules across membranes. MIPs constitute a very old family of proteins and different forms have been found in all kinds of living organisms, including bacteria, fungi, animals, and plants. In the genomic sequence of Arabidopsis, we have identified 35 different MIP-encoding genes. Based on sequence similarity, these 35 proteins are divided into four different subfamilies: plasma membrane intrinsic proteins, tonoplast intrinsic proteins, NOD26-like intrinsic proteins also called NOD26-like MIPs, and the recently discovered small basic intrinsic proteins. In Arabidopsis, there are 13 plasma membrane intrinsic proteins, 10 tonoplast intrinsic proteins, nine NOD26-like intrinsic proteins, and three small basic intrinsic proteins. The gene structure in general is conserved within each subfamily, although there is a tendency to lose introns. Based on phylogenetic comparisons of maize (Zea mays) and Arabidopsis MIPs (AtMIPs), it is argued that the general intron patterns in the subfamilies were formed before the split of monocotyledons and dicotyledons. Although the gene structure is unique for each subfamily, there is a common pattern in how transmembrane helices are encoded on the exons in three of the subfamilies. The nomenclature for plant MIPs varies widely between different species but also between subfamilies in the same species. Based on the phylogeny of all AtMIPs, a new and more consistent nomenclature is proposed. The complete set of AtMIPs, together with the new nomenclature, will facilitate the isolation, classification, and labeling of plant MIPs from other species.

A novel superoxide dismutase with a high isoelectric point in higher plants. expression, regulation, and protein localization

Several isoforms of superoxide dismutase (SOD) with a high isoelectric point (pI) have been identified by isoelectric focusing chromatography in protein extracts from Scots pine (Pinus sylvestris) needles. One of these isoforms, a CuZn-SOD with a pI of about 10 and thus denoted hipI-SOD, has been isolated and purified to apparent homogeneity. A cDNA encoding the hipI-SOD protein was cloned and sequenced. Northern hybridization of mRNA isolated from different organs and tissues showed that hipI-SOD has a markedly different pattern of expression compared with chloroplastic and cytosolic SOD. Furthermore, the transcript levels of hipI-SOD and cytosolic SOD were found to respond differently to mechanical wounding, treatment with oxidized glutathione, paraquat, and ozone. Immunogold electron microscopy localized the hipI-SOD in the plasma membrane of sieve cells and the Golgi apparatus of albuminous cells. Moreover, high protein density was also detected in extracellular spaces such as secondary cell wall thickenings of the xylem and sclerenchyma and in intercellular spaces of parenchyma cells.

Exon-intron organization and chromosomal localization of the mouse monoglyceride lipase gene

Monoglyceride lipase (MGL) functions together with hormone-sensitive lipase to hydrolyze intracellular triglyceride stores of adipocytes and other cells to fatty acids and glycerol. In addition, MGL presumably complements lipoprotein lipase in completing the hydrolysis of monoglycerides resulting from degradation of lipoprotein triglycerides. Cosmid clones containing the mouse MGL gene were isolated from a genomic library using the coding region of the mouse MGL cDNA as probe. Characterization of the clones obtained revealed that the mouse gene contains the coding sequence for MGL on seven exons, including a large terminal exon of approximately 2.6 kb containing the stop codon and the complete 3' untranslated region. Two different 5' leader sequences, diverging 21 bp upstream of the predicted translation initiation codon, were isolated from a mouse adipocyte cDNA library. Western blot analysis of different mouse tissues revealed protein size heterogeneities. The amino acid sequence derived from human MGL cDNA clones showed 84% identity with mouse MGL. The mouse MGL gene was mapped to chromosome 6 in a region with known homology to human chromosome 3q21.

The evidence that exercise during growth or adulthood reduces the risk of fragility fractures is weak

There has never been, and will never be, a randomized double-blind placebo-controlled trial demonstrating that exercise in youth, adulthood or old age reduces fragility or osteoporosis-related fractures in old age. The next level of evidence, a randomized, controlled but unblinded study with fractures as an end-point is feasible but has never been done. The basis for the belief that exercise reduces fractures is derived from lower levels of 'evidence', namely, retrospective and prospective observation cohort studies and case-control studies. These studies are at best hypothesis generating, never hypothesis testing. They are all subject to many systematic biases and should be interpreted with extreme scepticism. Surrogate measures of anti-fracture efficacy are the next level of evidence, such as the demonstration of a reduction in risk factors for falls, a reduction in falls, a reduction in fractures due to falls, an increase in peak bone size and mass, prevention of bone loss in midlife and restoration of bone mass and structure in old age.

Infrared spectra of phthalic acid, the hydrogen phthalate ion, and the phthalate ion in aqueous solution

The infrared spectra of a series of aqueous solutions containing phthalic acid (1,2-benzenedicarboxylic acid) and varying pH were examined using attenuated total reflection Fourier transform infrared spectroscopy and potentiometry. The basis spectra of phthalic acid, the hydrogen phthalate ion, and the phthalate ion were isolated using a factor analysis in which the absorbance of these species varies with pH and total phthalate concentration according to equilibrium and mass balance relations. Assignments of these basis spectra were made by comparison with spectra calculated ab initio. The conditional formation constants of phthalic acid and the hydrogen phthalate ion were determined at 25.0+/-0.1 degrees C in 0.6 M NaCl ionic media using infrared spectroscopy and in 1.5 M NaCl ionic media using both infrared spectroscopy and potentiometry.