Body mass index, sexual difficulties and sexual satisfaction among people in regular heterosexual relationships: a population-based study.

BACKGROUND/AIMS: The aims of this study were to clarify the relationship between body mass index (BMI) and sexual difficulties and to investigate if BMI influenced sexual satisfaction, over and above the effects of sexual difficulties. METHODS: Cross-sectional analyses of a nationally representative computer-assisted telephone interview. Eight thousand, six hundred and fifty-six respondents were recruited by random digit dialling in 2004-2005. Only those in a sexually active, heterosexual relationship were included in the current analyses. RESULTS: After adjustments for demographic factors, both overweight and obese male and female participants were more likely to report worrying during sex about whether their body was unattractive. Among women, associations were also found between higher BMI and lack of interest in sex. No other significant associations between BMI and sexual difficulties were evident. There was an association between BMI and extreme physical pleasure for women but not men over and above the effects of sexual difficulties, with obese women being more likely than normal weight women to report extreme physical pleasure. No associations were found for either men or women between BMI and whether or not they reported extreme emotional or sexual satisfaction with their relationship. CONCLUSIONS: With the exception of body image difficulties, there is little association between BMI and self-reported sexual difficulties. Furthermore, extreme sexual and emotional satisfaction appeared to be associated with the presence or absence of sexual difficulties and not overly influenced by BMI. Overall, clinicians and patients should be aware that being overweight is not necessarily detrimental to sexual functioning.

Renal prothrombin mRNA is significantly decreased in a hyperoxaluric rat model of nephrolithiasis.

Although urinary prothrombin fragment 1 (UPTF1) possesses several hallmarks expected of a regulatory protein in urolithiasis, its precise role remains unknown. To determine the relationship between renal prothrombin (PT), the parent molecule of UPTF1, and lithogenesis, this study quantified and compared levels of renal PT mRNA in healthy rats (n = 10) and rats rendered lithogenic (n = 10) by ingestion of 0.75% ethylene glycol for 8 weeks. Studies included morphological and histological examination of the kidneys with scanning electron microscopy of the urinary filtrates of control and experimental animals. Haematuria and calcium oxalate (CaOx) crystals occurred in the urine of all experimental rats, but not in those of controls. Histological examination showed birefringent nephroliths and associated damage in kidneys of lithogenic rats, which were not seen in the control group. The amounts of total RNA extracted from both groups of rats were similar, but the median ratio of PT to beta-actin transcript of 11.14 x 10(-4) (10.65 x 10(-4) +/- 2.24 x 10(-4)) in the control rats was significantly (p < or = 0.001) reduced to 6.47 x 10(-4) (6.57 x 10(-4) +/- 2.72 x 10(-4)) in the lithogenic group. These results demonstrate that renal PT mRNA is reduced by approximately 42% in lithogenic rats and confirm the existence of a direct association between renal PT synthesis and calculogenesis. Attempts to compare renal PT and urinary levels of PTF1 were unsuccessful because of interference from hepatic PT circulating in the blood, haematuria, and the presence of urinary CaOx crystals. This is the first report of a significant reduction in the renal expression of a urinary protein well documented to inhibit CaOx crystal growth and aggregation in undiluted human urine in vitro.

Immunogenicity, safety, and memory of different schedules of Neisseria meningitidis A/C-diphtheria toxoid conjugate vaccine in infants in Niger.

We studied one to four doses of meningococcal polysaccharides A and C conjugated to diphtheria toxoid (Men D) versus A/C polysaccharide (Men PS) vaccine in 618 infants in Niger. Men PS at 24 months permitted evaluating memory. Two Men D doses (at 3 and 9 months) induced higher serum bactericidal activity (SBA) than other regimens. SBA titers after Men PS at 24 months were higher in those given Men D in infancy versus Men PS. While responses were lower for serogroup C, hyporesponsiveness was not evident. Men D was well-tolerated. A single Men D dose in infancy appeared to induce memory.

Karyotypes found in the population declared at increased risk of Down syndrome following maternal serum screening.

Of the 65 328 pregnancies of South Australian mothers screened by the South Australian Maternal Serum Antenatal Screening (SAMSAS) Programme between 1 January 1991 and 31 December 1997, 3431 (5.25%) were declared at increased risk of fetal Down syndrome. Fetal or neonatal karyotype was determined in 2737/3431 (79.8%) of these pregnancies, including 16 with early fetal loss. Interrogation of the database of the South Australian Neonatal Screening Service showed 643 live-born infants whose phenotype was not subsequently questioned among the 694 pregnancies whose karyotype was not determined. Of the remaining 51/3431 pregnancies, 19 ended in early fetal loss without karyotyping and no newborn screening or other records could be found for 32 cases. The 129 instances of abnormal karyotype found were Down syndrome (84), trisomy 18 (four), trisomy 13 (three), triploidy (two), female sex chromosome aneuploidy (six) and male sex chromosome aneuploidy (five), inherited balanced rearrangements (19), mosaic or de novo balanced abnormalities (four) and unbalanced karyotypes (two). In the pregnancies declared at increased risk of fetal Down syndrome, only the karyotype for Down syndrome occurred with a frequency greater than that expected for the general, pregnant population.

Methods for measuring crystallization in urolithiasis research: why, how and when?

Whereas crystalluria does not distinguish between kidney stone formers and healthy people and thus can be considered a physiologic event, kidney stone formation is a pathologic incident and reflects a specific form of biomineralization. Both single urinary crystals as well as whole kidney stones form under exquisite control of organic macromolecules. Simple crystal formation in the urinary tract is distinguished from stone formation in the kidney by the process of particle retention. The latter occurs either because nucleated crystals strongly aggregate to particles too large to pass freely through the tubules ('free particle' theory), or because crystals become abnormally adherent to tubular cell surfaces ('fixed particle' theory). Since it is impossible to mimic all the processes involved in stone formation in vitro, it is highly important to carefully chose a specific crystallization process for in vitro studies, and to select the most appropriate experimental conditions for measuring the chosen process as reliably as possible. This overview aims at critically reviewing the principles of currently available assay systems for studying crystallization processes involved in stone formation. Consensus is reached by the experts that no in vitro system really mimics what happens in renal stone formation, but that carefully designed in vitro studies will always play an important part in urolithiasis research. For such studies, it is highly important to exactly control the appropriate experimental conditions that are relevant to a specific crystallization process under investigation. Practical guidelines for researchers working with crystallization systems are provided, and it is concluded that international efforts should be made to standardize the terminology, to agree on a set of basic experimental parameters (temperature, pH, artificial urine composition), and to adopt simple tests or conditions are reference points for quality and comparative control.

A comparative study of the adsorption of amino acids on to calcium minerals found in renal calculi.

To assess the binding of individual amino acids to the principal calcium minerals found in human kidney stones, the adsorption of 20 amino acids on to calcium oxalate monohydrate, CaHPO4*2H2O, Ca3(PO4)2 and Ca5(PO4)3OH crystals was determined over the physiological urinary pH range (pH 5-8) in aqueous solutions. All amino acids adsorbed most strongly at pH 5, and this decreased in all cases as the pH was increased. The amino acids which adsorbed most strongly were aspartic acid, glutamic acid and gamma-carboxyglutamic acid, with the last displaying the strongest affinity. All amino acids bound more avidly to calcium oxalate monohydrate than to any of the phosphate minerals. Adsorption on to CaHPO4*2H2O was generally higher than for Ca3(PO4)2 and Ca5(PO4)3OH, for which all amino acids, with the exception of gamma-carboxyglutamic acid, had only a weak affinity. The binding affinity of these acids is thought to be due to their zwitterions being able to adopt conformations in which two carboxyl groups, and possibly the amino group, can interact with the mineral surface without further rotation. The strong binding affinity of di-and tri-carboxylic acids for calcium stone minerals indicates that proteins rich in these amino acids are more likely to play a functional role in stone pathogenesis than those possessing only a few such residues. These findings, as well as the preferential adsorption of the amino acids for calcium oxalate monohydrate rather than calcium phosphate minerals, have ramifications for research aimed at discovering the true role of proteins in stone formation and for potential application in the design of synthetic peptides for use in stone therapy.

Intracrystalline proteins and the hidden ultrastructure of calcium oxalate urinary crystals: implications for kidney stone formation.

The external appearance of urinary calcium oxalate (CaOx) crystals suggests that they are solid, homogeneous structures, despite their known association with proteins. Our aim was to determine whether proteins comprising the organic matrix of CaOx crystals are superficial or intracrystalline in order to clarify the role of urinary proteins in the formation of kidney stones. CaOx crystals were precipitated from centrifuged and filtered, or ultrafiltered, healthy human urine. They were then treated with dilute NaOH to remove bound proteins, partially demineralized with EDTA, or fractured and subjected to limited proteolysis before examination by low-resolution scanning electron microscopy or field emission scanning electron microscopy. Crystals precipitated from centrifuged and filtered urine had a complex interior network of protein distributed throughout the mineral phase, which appeared to comprise closely packed subcrystalline particles stacked in an orderly array among an amorphous organic matrix. This ultrastructure was not evident in crystals deposited in the absence of macromolecules, which were completely solid. This is the first direct evidence that crystals generated from cell-free systems contain significant amounts of protein distributed throughout a complex internal cribriform ultrastructure. Combined with mineral erosion in the acidic lysosomal environment, proteins inside CaOx crystals would render them susceptible to attack by urinary and intracellular renal proteases and facilitate their further dissolution or disruption into small particles and ions for removal by exocytosis. The findings also have broader ramifications for industry and the materials sciences, as well as the development and resorption of crystals in biomineralization systems throughout nature.

Simple, sensitive and accurate method for the quantification of prothrombin mRNA by using competitive PCR.

A method for the quantification of prothrombin (PT) mRNA species in hepatic tissues of rats was developed with the use of competitive PCR. To validate the quantification approach, sequential dilutions of total RNA from one of the samples were reverse transcribed. Their equivalent volumes were amplified together with a known amount of non-homologous competitor cDNA with identical nucleotide primers. The disparate sizes of target and competitor permitted the easy identification and quantification of bands in samples after densitometric analysis of ethidium bromide-stained agarose gels. Ratios of intensities of target and competitor bands were plotted against the initial amounts of total RNA species used, giving a linear relationship. The slope of this line was virtually identical with that obtained when the sample RNA was replaced with recombinant target cDNA, indicating that recombinant cDNA behaved in PCR identically with that made by reverse transcription and permitting the estimation of transcripts in reverse transcription reactions by using the recombinant counterpart of each as a standard. To avoid variation in the final results, the amount of competitor used in the assay was calculated separately from the equivalence point of the reverse-transcribed total RNA of one of the tissue samples; PCR was performed only for the minimum number of cycles required to detect products. A standard curve was made in each PCR run by amplifying differing amounts of recombinant cDNA species of PT or beta-actin together with a constant amount of its competitor. The numbers of transcripts in the tissues were then determined directly by PCR incorporating the same amount of respective competitor (as used in the standard curve) and comparing the ratios of products with the standard curve. Application of this method revealed that the median ratio of PT message to beta-actin message in hepatic tissues of 10 normal rats was 0.37, with a mean+/-S.D. of 0.37+/-0.07 (range 0.27-0.47). Although the method was developed for the quantification of PT transcripts in liver, it can easily be used for non-hepatic tissues as well. The technique is simple, quick and sensitive and requires only a very small amount of substrate.

Effects of inter-alpha-inhibitor and several of its derivatives on calcium oxalate crystallization in vitro.

The bikunin peptide chain of the protease inhibitor inter-alpha-inhibitor (IalphaI) has been reported to be an inhibitor of calcium oxalate (CaOx) crystallization, and hence has been proposed as having a role in CaOx kidney stone formation. However, further experimental evidence is required to assess if fragments of IalphaI other than bikunin may play a role in the regulation of crystallization events in stone formation. The aim of the present study was to assess the effects of IalphaI and several of its derivatives on CaOx crystallization in a seeded inorganic system and to compare these effects with those of a known inhibitor of crystallization, prothrombin. IalphaI was purified from a preparation of human plasma and fragmented by alkaline hydrolysis, and two of its peptide chains, bikunin and heavy chain 1 (H1), were purified further by HPLC. Their purity was confirmed by SDS/PAGE. Using Coulter counter and [(14)C]oxalate analysis and scanning electron microscopy, IalphaI, its H1 chain and bikunin from urine and from plasma were shown to be relatively weak inhibitors of CaOx crystallization in vitro at expected physiological concentrations. It was concluded that members of the IalphaI family may not be as important in kidney stone formation as has been generally proposed, although further studies are required before a possible role for IalphaI and its fragments in stone formation can be unambiguously discounted.

Safety and immunogenicity of three doses of a Neisseria meningitidis A + C diphtheria conjugate vaccine in infants from Niger.

BACKGROUND: High rates of endemic disease and recurrent epidemics of serogroup A and C meningococcal meningitis continue to occur in sub-Saharan Africa. A meningococcal A + C polysaccharide diphtheria-toxoid-conjugated vaccine may address this issue. METHODS: In Niger three doses of a bivalent meningococcal A + C diphtheria-toxoid-conjugated vaccine (MenD), containing 1, 4 or 16 microg of each polysaccharide per dose, administered at 6, 10 and 14 weeks of age, were compared with Haemophilus influenzae type b-tetanus toxoid-conjugated (PRP-T) vaccine given with the same schedule or with a meningococcal A + C polysaccharide vaccine (MenPS) given at 10 and 14 weeks of age. One blood sample was taken at the time of enrollment (6 weeks of age) and another was taken 4 weeks after the primary series. RESULTS: All doses of MenD were well-tolerated. After the primary series a higher proportion of infants had detectable serum bactericidal activity against serogroup A for each dose of MenD (from 94% to 100%) than for MenPS (31%) or H. influenzae type b-tetanus toxoid-conjugated vaccine (18.9%); P < or = 0.05. Significant differences were also observed for serogroup C MenD 4 microg or MenD 16 microg (100%) vs. MenPS (69.7%) or Haemophilus influenzae type b-tetanus toxoid-conjugated vaccine (24.3%); P < or = 0.05. When MenPS vaccine was given to 11-month-old children, the immune response measured by both enzyme-linked immunosorbent assay and serum bactericidal assay was greater in those previously immunized with MenD than in those immunized with MenPS vaccine. CONCLUSION: MenD was safe among infants in Niger, and immunization led to significantly greater functional antibody activity than with MenPS. The 4-microg dose of MenD for both the A and C serogroups has been selected for further studies.

The hole truth: intracrystalline proteins and calcium oxalate kidney stones.

The ultimate aim of our research is to understand the role of macromolecules in the formation of human kidney stones, particularly their interactions with calcium oxalate (CaOx) crystals. The invariable association of stones with proteins raises the possibility that proteins play a role in their formation, similar to the role of proteins in healthy biomineralization. Do these proteins induce mineralization? Are they merely a response to the disease process? Or are they protective molecules that were overwhelmed by mineral supersaturation? A protein of particular interest is fragment 1 (F1) of prothrombin. We have shown that mRNA for prothrombin is present in the kidney. Because the F1 fragment of prothrombin present in urine is slightly different from that found in the blood, we refer to this protein as "urinary prothrombin fragment 1" (UPTF1). Available evidence suggests that the kidney manufactures the protein for protection against stone disease and that the protein has a directive role in stone formation. We now have evidence that proteins are interred within CaOx crystals precipitated from human urine, where it is distributed in continuous channels. These proteins could facilitate crystal deconstruction and removal after attachment to the renal epithelium and endocytosis. We suspect that the formation of CaOx crystals in the urine is a normal process designed to permit harmless disposal of an excess of calcium, oxalate, or both. The incorporation of proteins provides a second line of defense against stone formation by enabling the destruction and removal of retained crystals. Understanding the basic molecular strategies by which plants produce protein-containing CaOx crystals may provide insight into human CaOx stone formation.

The impact of maternal serum screening on the birth prevalence of Down's syndrome and the use of amniocentesis and chorionic villus sampling in South Australia.

OBJECTIVES: To describe the impact of maternal serum screening on the birth prevalence of Down's syndrome and on the use of amniocentesis and chorionic villus sampling in South Australia. DESIGN: A descriptive population-based study. SETTING: South Australia (population 1.48 million persons; approximately 20,000 births per year). PARTICIPANTS: Women who had births or terminations of pregnancy with Down's syndrome in 1982-1996, women who had maternal serum screening in 1991-1996, amniocentesis or chorionic villus sampling in 1986-1996. METHODS: Analysis of data from multiple sources on maternal serum screening, amniocentesis and chorionic villus sampling, births and terminations of pregnancy. MAIN OUTCOME MEASURES: Total prevalence and birth prevalence of Down's syndrome each year in 1982-1996; proportion of pregnant women using maternal serum screening in 1991-1996, and proportion using amniocentesis and chorionic villus sampling by indication in 1986-1996, by age group. RESULTS: Use of maternal serum screening for Down's syndrome increased from 17% when introduced in 1991 to 76% of women who gave birth in 1996. Between 1982 and 1986 and 1996, terminations of pregnancy for fetal Down's syndrome increased from 7.1 % to 75% and the birth prevalence of Down's syndrome fell by 60% from 1.05 to 0.42 per 1,000 births, against the background of an increase in total prevalence due to increasing maternal age. The use of amniocentesis increased from 5.8% in 1991 to 10.1% in 1996 mainly due to the increase among women younger than 35 years with maternal serum screening as the main reason. The increasing chorionic villus sampling rate among younger women stabilised at 0.4%, while the rate among older women decreased from 11.0% to 7.4%. CONCLUSIONS: The introduction of maternal serum screening in South Australia has resulted in increased use of any prenatal testing for Down's syndrome from about 7% (mainly older women having amniocentesis or chorionic villus sampling) to 84% of women (about 8% having direct amniocentesis or chorionic villus sampling and 76% having maternal serum screening first). This has resulted in a significant fall in the birth prevalence of Down's syndrome. maternal serum screening was the first indication of Down's syndrome for about half the terminations of pregnancy for Down's syndrome in 1993-1996, including three quarters of those in younger women.

The prothrombin gene is expressed in the rat kidney: Implications for urolithiasis research.

There is considerable interest in determining the role of prothrombin fragments, especially urinary prothrombin fragment 1 (UPTF1), in the pathogenesis of calcium oxalate (CaOx) urinary calculi. This fragment is present in abundance in the matrix of CaOx crystals generated in human urine in vitro and has also been detected in human urinary stones containing calcium. More recently, prothrombin gene expression has been reported in the human kidney. However, studies examining the renal biosynthesis of prothrombin or perhaps only its fragments during experimental lithogenesis, and in consequence, the role of UPTF1 in stone formation, cannot be carried out in humans. The aim of this investigation therefore was to determine whether prothrombin gene expression is present in the rat kidney. Total RNA was isolated from the kidneys and livers of 12 rats. Using reverse transcriptase PCR, mRNAs corresponding to the thrombin and fragment 1 + 2 (F1+2) regions of prothrombin were analysed by agarose gel electrophoresis. The expression of glyceraldehyde 3-phosphate dehydrogenase was also examined to determine whether the quality of the tissue mRNAs was adequate for analyses. The amplified products were identified by sequence analysis. All kidneys displayed evidence of expression of the thrombin and F1+2 domains of the prothrombin gene. Furthermore, the sequences of these PCR-derived products from kidney were identical to those from liver. This suggests that the prothrombins secreted by these two organs are identical. The fact that prothrombin biosynthesis occurs in both the human and rat kidney presents an opportunity for using established rat models of stone disease to evaluate the influence of lithogenic conditions on prothrombin gene expression, and the potential role of UPTF1 in vivo.

Prothrombin gene expression in rat kidneys provides an opportunity to examine its role in urinary stone pathogenesis.

Urinary form of prothrombin (PT) fragment 1 is the most abundant protein in calcium oxalate crystals generated in human urine. The protein has also been detected in human calcium-containing stones. In its purified form, the protein inhibits calcium oxalate crystal growth and, more importantly, aggregation in aqueous inorganic solutions and undiluted human urine. Recently, PT gene expression has been reported in human kidneys. However, access to human renal tissue for studies is limited, and it is not possible to easily manipulate PT biosynthesis in human subjects. The aim of this investigation, therefore, was to determine whether PT gene expression is present in rat kidneys. Samples of total RNA were isolated from the kidneys and livers (positive controls) of 12 male hooded Wistar rats. Using reverse transcription-PCR, mRNA corresponding to the thrombin and F1+2 regions of PT was analyzed by agarose gel electrophoresis. The expression of the "housekeeping" gene glyceraldehyde-3-phosphate dehydrogenase was also examined, to determine the availability of amplifiable substrate in each specimen. The amplified products were also sequenced, to determine their identities. All rat kidneys displayed evidence of expression of the thrombin and F1+2 domains of the PT gene. This similarity between human and rat kidneys allows the possibility of using established rat models of stone disease to evaluate therapeutic strategies to reduce stone formation.

Inhibition of calcium oxalate crystal growth and aggregation by prothrombin and its fragments in vitro: relationship between protein structure and inhibitory activity.

During blood coagulation, prothrombin (PT) is ultimately degraded to three fragments, thrombin, fragment 1 (F1) and fragment 2 (F2), which, collectively, contain all of the structural features of PT. One of these fragments, F1, is excreted in human urine and is the principal protein occluded into calcium oxalate (CaOx) crystals precipitated from it. This urinary form of F1, which we have named urinary prothrombin fragment 1 is present in calcium stones and is a potent inhibitor of CaOx crystallization in urine in vitro. The aim of this study was to determine whether PT itself and its other activation products, namely, thrombin, F1 and F2 also inhibit CaOx crystallization, by comparing their effects in a seeded, inorganic crystallization system. A secondary objective was to assess the relationship between the structures of the proteins and their inhibitory activities. PT was isolated from a human blood concentrate rich in vitamin K-dependent proteins. Following initial cleavage by thrombin, the resulting fragments, F1 and F2, were purified by a combination of reversed phase HPLC and low pressure column chromatography. The purity of the proteins was confirmed by SDS/PAGE and their individual effects on CaOx crystallization were determined at the same concentration (16.13 nM) in a seeded, metastable solution of CaOx using a Coulter Counter. [14C]Oxalate was used to assess deposition of CaOx and crystals were visualized using scanning electron microscopy. The Coulter Counter data revealed that the proteins reduced the size of precipitated crystals in the order F1 > PT > F2 > thrombin. These findings were confirmed by scanning electron microscopy which showed that the reduction in particle size resulted from a decrease in the degree of crystal aggregation. [14C]Oxalate analysis demonstrated that all proteins inhibited mineral deposition, in the order F1 (44%) > PT (27.4%) > thrombin (10.2%) > F2 (6.5%). It was concluded that the gamma-carboxyglutamic acid domain of PT and F1, which is absent from thrombin and F2, is the region of the molecules which determines their potent inhibitory effects. The superior potency of F1, in comparison with PT, probably results from the molecule's greater charge to mass ratio.

The effect of warfarin therapy on the charge properties of urinary prothrombin fragment 1 and crystallization of calcium oxalate in undiluted human urine.

Urinary prothrombin fragment 1 (UPTF1) is the principal protein in calcium oxalate (CaOx) crystals precipitated from human urine and is a potent inhibitor of CaOx crystallization, a property that should depend, at least in part, upon the extent of gamma-carboxylation of the 10 glutamic residues in its N-terminal region. Warfarin therapy limits full gamma-carboxylation of vitamin K-dependent proteins, including UPTF1. The aims of this study were to determine the effect of warfarin therapy on UPTF1, its occlusion into CaOx urinary crystals, and its influence on the crystallization of CaOx in undiluted human urine. In the first part of the study, urines were collected from six men prior to cardiac surgery and after stabilization on long-term warfarin treatment. Proteins in the urines and in the matrix of CaOx crystals precipitated from them were analyzed by two-dimensional SDS-PAGE and Western blotting. In urine, at least two charge variants of UPTF1 with low isoelectric point (pI) values were detected before and during warfarin therapy, but additional higher pI forms of the protein were also seen during anticoagulation. Nonetheless, the majority of UPTF1 was present in the more fully gamma-carboxylated state. CaOx crystals precipitated from the same urine samples contained only low pI forms of UPTF1. The effect of warfarin treatment on CaOx crystallization in urine was tested by collecting two consecutive 24-h urine samples from 16 men prior to cardiac surgery and during subsequent warfarin treatment. CaOx crystallization was induced in each sample by the addition of sodium oxalate. The size and volume of the particles deposited were determined using a Coulter counter, and the crystals were examined by scanning electron microscopy (SEM). There were no significant differences between the urinary metastable limits before or during warfarin treatment or in the total volume of crystals precipitated. A slight increase in the mean diameter of the crystalline particles precipitated from the urines during anticoagulant therapy was not significant. SEM showed little evidence of changes in overall particle size, although individual crystals of CaOx tended to be larger during warfarin treatment. It was concluded from these studies that the binding of UPTF1 to CaOx crystal surfaces is related to the degree of gamma-carboxylation of its Gla domain, which would also influence the protein's inhibitory effects on CaOx crystallization. However, during warfarin therapy the majority of UPTF1 exists in a highly charged state, indicating that it is completely, or almost completely, gamma-carboxylated, which would explain the lack of any difference between CaOx crystallization parameters in the urine of subjects before and during warfarin administration. We conclude that physiologically significant reductions in the inhibitory potency of UPTF1 would be likely to occur only as a result of proscription of gamma-carboxylation more extensive than that induced by warfarin.

Rectal cancer: the Basingstoke experience of total mesorectal excision, 1978-1997.

OBJECTIVE: To examine the role of total mesorectal excision in the management of rectal cancer. DESIGN: A prospective consecutive case series. SETTING: A district hospital and referral center in Basingstoke, England. PATIENTS: Five hundred nineteen surgical patients with adenocarcinoma of the rectum treated for cure or palliation. INTERVENTIONS: Anterior resections (n = 465) with low stapled anastomoses (407 total mesorectal excisions), abdominoperineal resections (n = 37), Hartmann resections (n = 10), local excisions (n = 4), and laparotomy only (n = 3). Preoperative radiotherapy was used in 49 patients (7 with abdominoperineal resections, 38 with anterior resections, 3 with Hartmann resections, and 1 with laparotomy). MAIN OUTCOME MEASURES: Local recurrence and cancer-specific survival. RESULTS: Cancer-specific survival of all surgically treated patients was 68% at 5 years and 66% at 10 years. The local recurrence rate was 6% (95% confidence interval, 2%-10%) at 5 years and 8% (95% confidence interval, 2%-14%) at 10 years. In 405 "curative" resections, the local recurrence rate was 3% (95% confidence interval, 0%-5%) at 5 years and 4% (95% confidence interval, 0%-8%) at 10 years. Disease-free survival in this group was 80% at 5 years and 78% at 10 years. An analysis of histopathological risk factors for recurrence indicates only the Dukes stage, extramural vascular invasion, and tumor differentiation as variables in these results. CONCLUSIONS: Rectal cancer can be cured by surgical therapy alone in 2 of 3 patients undergoing surgical excision in all stages and in 4 of 5 patients having curative resections. In future clinical trials of adjuvant chemotherapy and radiotherapy, strategies should incorporate total mesorectal excision as the surgical procedure of choice.

Inter-alpha-inhibitor in calcium stones.

1. A broad spectrum of proteins has been detected within calcium stones. A newcomer to the field of urolithiasis is the blood protein inter-alpha-inhibitor. Inter-alpha-inhibitor comprises three protein chains linked by chondroitin sulphate: two heavy chains, H1 (65 kDa) and H2 (70 kDa) and a light chain (approx. 30 kDa) most commonly known as bikunin. The physiological function of the two heavy chains is unknown; nor has their presence been reported in urine. However, bikunin has been implicated in various renal diseases, including urolithiasis. 2. This study was undertaken to determine which chains of inter-alpha-inhibitor are actually present in calcium kidney stones. Organic extracts were obtained from 10 calcium stones and analysed by SDS/PAGE and Western blotting. The H1 and H2 chains of inter-alpha-inhibitor were detected in 9 of the 10 stones, but only one stone contained a protein with a molecular mass close to that of bikunin (30-35 kDa). 3. These results demonstrate for the first time that H1 and H2 are present in stones and show that the bikunin chain of inter-alpha-inhibitor may not be the only part of the molecule implicated in stone formation.

Inhibition of growth and aggregation of calcium oxalate crystals in vitro--a comparison of four human proteins.

The aim of this study was to compare directly, in the absence of interfering contaminants, the inhibitory effects of Tamm-Horsfall glycoprotein (THG), human serum albumin (HSA), alpha1-microglobulin and prothrombin fragment 1 (PTF1) on calcium oxalate crystallization. These proteins have been detected in urinary calculi, and with the exception of THG in calcium oxalate crystals generated from undiluted human urine. THG was isolated from the urine of healthy men, while PTF1 was purified from Prothrombinex-HT, a human blood concentrate; HSA and alpha1-microglobulin were obtained from commercial sources. The effects of these proteins were determined, separately, at the same final concentration (32 nM) on calcium oxalate crystallization in a seeded, inorganic reaction system, using Coulter Counter and [14C]oxalate analysis. Analysis of [14C]oxalate data showed that THG, HSA and alpha1-microglobulin had no measurable effect on deposition of calcium oxalate. However, PTF1 significantly inhibited mineral deposition by 19.6%. The average size of the particles precipitated was reduced from the control value of 8.6 microm to 7.3, 5.9, 5.6 and 4.0 microm in the presence of alpha1-microglobulin, HSA, THG and PTF1 respectively. These findings were confirmed by scanning electron microscopy, which also revealed that the smaller particles deposited in the presence of the proteins resulted from reduced crystal aggregation rather than a decrease in the size of the individual crystals. It was concluded that, on a molar basis, PTF1 is a more potent inhibitor of calcium oxalate crystal aggregation than THG, HSA and alpha1-microglobulin. Moreover, unlike those proteins it significantly inhibits the deposition of calcium oxalate. These findings have implications for the putative role of urinary proteins in the formation of calcium oxalate stones.