Quantifying effectiveness and best practices for bumblebee identification from photographs.

Understanding pollinator networks requires species level data on pollinators. New photographic approaches to identification provide avenues to data collection that reduce impacts on declining bumblebee species, but limited research has addressed their accuracy. Using blind identification of 1418 photographed bees, of which 561 had paired specimens, we assessed identification and agreement across 20 bumblebee species netted in Montana, North Dakota, and South Dakota by people with minimal training. An expert identified 92.4% of bees from photographs, whereas 98.2% of bees were identified from specimens. Photograph identifiability decreased for bees that were wet or matted; bees without clear pictures of the abdomen, side of thorax, or top of thorax; bees photographed with a tablet, and for species with more color morphs. Across paired specimens, the identification matched for 95.1% of bees. When combined with a second opinion of specimens without matching identifications, data suggested a similar misidentification rate (2.7% for photographs and 2.5% specimens). We suggest approaches to maximize accuracy, including development of rulesets for collection of a subset of specimens based on difficulty of identification and to address cryptic variation, and focused training on identification that highlights detection of species of concern and species frequently confused in a study area.

When the answer is a maybe: a retrospective review of indeterminate SARS-CoV-2 results and their associations.

Testing for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) using reverse transcriptase polymerase chain reaction (RT-PCR) may generate indeterminate results (with a cycle threshold ≥30), requiring further investigation to determine the clinical significance. Patient variables which could predict a definitive result ('Detected'/'Not detected') post indeterminate result would aid in optimization of bed management and utilization of limited resources. A retrospective observational study of indeterminate SARS-CoV-2 results in an Irish tertiary hospital from March 2020 to March 2022 was performed to determine whether demographics, comorbidities and immunosuppression were associated with a definitive result upon subsequent investigation. Data was obtained from patient and laboratory records. Analysis of association was explored using Fisher's exact test, and predictability was tested using logistic regression. Of 411 patients with an initial indeterminate test, investigation showed that 299 (72.2%) patients had a subsequent definitive result; 29 were Detected and 270 were Not detected. In the Detected group, a prior diagnosis of COVID-19 was associated with a reduced risk of becoming Detected (crude odds ratio (COR) = 0.10, 95% CI 0.03-0.35). In the Not detected group, vaccinated patients were less likely to have a Not detected result on subsequent testing (adjusted odds ratio (AOR) = 0.57, 95% CI 0.34-0.94). Patients with previous COVID-19 infection were less likely to have a Detected result and vaccinated patients were less likely to have a Not detected result upon investigation of an indeterminate result. This study emphasizes the need for a good clinical and medical history in the management of SARS-CoV-2.

Direct Determination of Fission-Barrier Heights Using Light-Ion Transfer in Inverse Kinematics.

We demonstrate a new technique for obtaining fission data for nuclei away from ß stability. These types of data are pertinent to the astrophysical r process, crucial to a complete understanding of the origin of the heavy elements, and for developing a predictive model of fission. These data are also important considerations for terrestrial applications related to power generation and safeguarding. Experimentally, such data are scarce due to the difficulties in producing the actinide targets of interest. The solenoidal-spectrometer technique, commonly used to study nucleon-transfer reactions in inverse kinematics, has been applied to the case of transfer-induced fission as a means to deduce the fission-barrier height, among other variables. The fission-barrier height of ^{239}U has been determined via the ^{238}U(d,pf) reaction in inverse kinematics, the results of which are consistent with existing neutron-induced fission data indicating the validity of the technique.

Serum vitamin K1 (phylloquinone) is associated with fracture risk and hip strength in post-menopausal osteoporosis: A cross-sectional study.

PURPOSE: Vitamin K may play a potential role in bone metabolism, although further evidence is needed. The mechanisms behind its skeletal effects and optimum intake for maintaining bone health remain poorly defined. To elucidate these two issues, we investigated the association between circulating vitamin K1 (phylloquinone) concentrations with fracture risk, bone mineral density (BMD), hip geometry and plasma dephospho-uncarboxylated-Matrix Gla Protein (dp-ucMGP), an extra-hepatic vitamin K dependent protein (VKDP), in post-menopausal osteoporosis (PMO). METHODS: We studied 374 women aged (mean [SD]) 68.7[12.3] years with PMO. Information including demographics, lifestyle habits and previous fractures was captured through a questionnaire. Serum was analysed for vitamin K1. BMD at the lumbar spine (LS), total hip (TH) and femoral neck (FN) (n = 277) and hip structural analysis (HSA) parameters (n = 263) were derived from DXA scans. VKDPs including undercarboxylated prothrombin (PIVKA-II) and dp-ucMGP were measured in a sub-group (n = 130). RESULTS: Serum vitamin K1 was significantly lower in the group with fractures (prevalent fractures: 0.53 [0.41], no fractures; 0.65 [0.66] µg/L, p = 0.04) and independently associated with fracture risk. The adjusted odds ratio (95% CI) per µg/L increase in vitamin K1 was 0.550 (0.310-0.978, p = 0.042). Among the HSA parameters, serum vitamin K1 was positively associated with cross-sectional area (CSA) (p = 0.02), cross sectional moment of inertia (CSMI) (p = 0.028) and section modulus (Z) (p = 0.02) at the narrow neck (NN) of femur. Dp-ucMGP was detectable in 97 (75%) participants with serum vitamin K1 of 0.26 [0.15] µg/L, whilst PIVKA-II was above the clinical threshold in only 3.8%. CONCLUSIONS: Our data suggest that the positive effect of vitamin K on fracture risk may be related to its effects on bone strength. Higher concentrations of serum vitamin K1 may be required for vitamin K's skeletal effects compared to coagulation. Further prospective or interventional studies are needed for confirmation and should include measures of bone quality.

Use of Lean Six Sigma methodology shows reduction of inpatient waiting time for peripherally inserted central catheter placement.

AIM: The aim of this study was to assess the use of Lean Six Sigma methodology to improve the turnaround time (TAT) for inpatient peripherally inserted central catheter (PICC) placement. MATERIALS AND METHODS: Value stream mapping was used to analyse the workflow process for inpatient PICC placement and to divide it into its component parts. Unnecessary steps were eliminated and variation minimised in the remaining processes. The TAT for PICC line placement was recorded for the 6 months prior to implementation of changes, and subsequently, at the 6-month and 2-year follow-up points. RESULTS: Prior to implementing the changes, the mean TAT for PICC line placement was 3.74±3.28 days (95% confidence interval [CI]=3.3-4.17). Six months after implementation, the mean TAT was 1.89±1.82 days (95% CI=1.72-2.06, p<0.0001). The reduction was sustained such that at 2 years post-implementation the mean TAT was 1.88±1.87 days (95% CI=1.78-1.99, p<0.0001). This was achieved despite a 13.8% increase in overall interventional radiological activity. CONCLUSION: By applying Lean Six Sigma methodology to the complex multifactorial processes involved from ordering a PICC to its final insertion, it was possible to identify areas for improvement and to introduce simple, effective measures that resulted in a significant sustained decrease in the TAT without additional resources.

Icebergs in the Nordic Seas Throughout the Late Pliocene.

The Arctic cryosphere is changing and making a significant contribution to sea level rise. The Late Pliocene had similar CO2 levels to the present and a warming comparable to model predictions for the end of this century. However, the state of the Arctic cryosphere during the Pliocene remains poorly constrained. For the first time we combine outputs from a climate model with a thermodynamic iceberg model to simulate likely source regions for ice-rafted debris (IRD) found in the Nordic Seas from Marine Isotope Stage M2 to the mid-Piacenzian Warm Period and what this implies about the nature of the Arctic cryosphere at this time. We compare the fraction of melt given by the model scenarios with IRD data from four Ocean Drilling Program sites in the Nordic Seas. Sites 911A, 909C, and 907A show a persistent occurrence of IRD that model results suggest is consistent with permanent ice on Svalbard. Our results indicate that icebergs sourced from the east coast of Greenland do not reach the Nordic Seas sites during the warm Late Pliocene but instead travel south into the North Atlantic. In conclusion, we suggest a continuous occurrence of marine-terminating glaciers on Svalbard and on East Greenland (due to the elevation of the East Greenland Mountains during the Late Pliocene). The study has highlighted the usefulness of coupled climate model-iceberg trajectory modeling for understanding ice sheet behavior when proximal geological records for Pliocene ice presence or absence are absent or are inconclusive.

Functional characterization of the transcriptional regulatory elements of three highly expressed constitutive genes in the jewel wasp, Nasonia vitripennis.

The jewel wasp, Nasonia vitripennis Ashmead (Hymenoptera: Pteromalidae), is an easily reared parasitoid that is providing an ever increasingly malleable model for examining the biology and genetics of Hymenoptera. Utilizing genomic and transcriptome resources, 5' upstream transcriptional regulatory sequences (TREs) from three highly expressed genes were identified and cloned. Criteria for TRE selection included the presence of an adjacent gene 5' of the translation initiation site. One gene was methylated whereas the other two were nonmethylated. Each TRE, heat-shock protein 70 (hsp70), activator of 90 kDa hsp ATPase protein 1 (hsp90A), and lipid storage droplet surface-binding protein 1 (lsdp) was linked with enhanced green fluorescent protein (EGFP) coding sequence and cloned into both pDP9e somatic and piggyBac germline transformation vectors. EGFP expression patterns under control of each TRE were compared with patterns of DsRed fluorescence produced from the transformation vector cassette. Functional activity of each TRE was observed in cultured Spodoptera frugiperda 9 (Sf9) cells and Drosophila melanogaster as well as in N. vitripennis embryos demonstrating that all three sequences had functional transcriptional regulatory activity in three different insect orders. Identification and functional characterization of these three TREs will provide critical and necessary resources for further genetic analyses of N. vitripennis, Hymenoptera and other insects.

Towards an understanding of the control of 'crumbly' fruit in red raspberry.

The genetic disorder known as 'crumbly' fruit is becoming a serious problem in the European raspberry industry. The study set out to examine the crumbly phenotype in a red raspberry mapping population under two environments (field and polytunnel) across six seasons in an effort to understand variability of the syndrome and to examine whether genetic factors were important and if so, whether QTL associated with the phenotype could be identified. This highlighted that seasonal, environmental (field or polytunnel) and genetic factors all influence the condition. Two QTL that are important for the genetic control of the condition have been located on linkage groups one and three, and an association with ripening time has been identified.

Air and surface contamination patterns of meticillin-resistant Staphylococcus aureus on eight acute hospital wards.

BACKGROUND: Meticillin-resistant Staphylococcus aureus (MRSA) can be recovered from hospital air and from environmental surfaces. This poses a potential risk of transmission to patients. AIM: To investigate associations between MRSA isolates recovered from air and environmental surfaces with those from patients when undertaking extensive patient and environmental sampling. METHODS: This was a prospective observational study of patients and their environment in eight wards of a 700-bed tertiary care hospital during 2010 and 2011. Sampling of patients, air and surfaces was carried out on all ward bays, with more extended environmental sampling in ward high-dependency bays and at particular times of the day. The genetic relatedness of isolates was determined by DNA microarray profiling and spa typing. FINDINGS: MRSA was recovered from 30/706 (4.3%) patients and from 19/132 (14.4%) air samples. On 9/132 (6.8%) occasions both patient and air samples yielded MRSA. In 32 high-dependency bays, MRSA was recovered from 12/161 (7.4%) patients, 8/32 (25%) air samples, and 21/644 (3.3%) environmental surface samples. On 10/132 (7.6%) occasions, MRSA was isolated from air in the absence of MRSA-positive patients. Patient demographic data combined with spa typing and DNA microarray profiling revealed four likely transmission clusters, where patient and environmental isolates were deemed to be very closely related. CONCLUSION: Air sampling yielded MRSA on frequent occasions, especially in high-dependency bays. Environmental and air sampling combined with patient demographic data, spa typing and DNA microarray profiling indicated the presence of clusters that were not otherwise apparent.

Microbial monitoring of the hospital environment: why and how?

BACKGROUND: The purpose of microbial monitoring of the inanimate environment surrounding a patient can be two-fold; to monitor hygiene standards and also to examine for the presence of specific nosocomial pathogens which may be the source of an outbreak. While both purposes involve routine culture of microorganisms, the methods used for each can differ in order to provide optimal results. The main difference between both purposes is the need for enumeration, site specificity for an aerobic colony count (ACC) for hygiene assessments, and the need to simply detect the presence or absence of multi-resistant nosocomial pathogens for infection control surveillance. AIM: To access current methods used in research studies and during outbreak investigations to detect nosocomial pathogens in the inanimate environment in the clinical setting. METHODS: A Pubmed search of published literature was performed. FINDINGS: Microbial monitoring of the environment can involve the use of swabs, sponges, contact plates and dip slides coupled with a variety of enrichment broths and selective media. The use of molecular methods such as polymerase chain reaction (PCR) can potentially provide a faster turnaround time, resulting in the quicker implementation of infection prevention and control cleaning and disinfection regimens. However, the optimal methods for performing a microbial hygiene evaluation or detecting specific bacterial pathogens are not generally agreed. CONCLUSION: There is a need for agreed standards on the optimal methods, frequency of environmental sampling and acceptable levels of surface contamination within the healthcare system.

Transmission of endemic ST22-MRSA-IV on four acute hospital wards investigated using a combination of spa, dru and pulsed-field gel electrophoresis typing.

The transmission of meticillin-resistant Staphylococcus aureus (MRSA) between individual patients is difficult to track in institutions where MRSA is endemic. We investigated the transmission of MRSA where ST22-MRSA-IV is endemic on four wards using demographic data, patient and environmental screening, and molecular typing of isolates. A total of 939 patients were screened, 636 within 72 h of admission (on admission) and 303 >72 h after admission, and 1,252 environmental samples were obtained. Isolates were typed by spa, dru and pulsed-field gel electrophoresis (PFGE) typing. A composite dendrogram generated from the three sets of typing data was used to divide isolates into 'dendrogram groups' (DGs). Ten percent of patients (92/939) were MRSA-positive; 7 % (44/636) on admission and 16 % (48/303) >72 h after admission (p = 0.0007). MRSA was recovered from 5 % of environmental specimens (65/1,252). Most isolates from patients (97 %, 85/88) and the environment (97 %, 63/65) exhibited the ST22-MRSA-IV genotype. Four DGs (DG1, DG4, DG16 and DG17) accounted for 58 % of ST22-MRSA-IV isolates from patients. Epidemiological evidence suggested cross-transmission among 44/92 patients (48 %) but molecular typing confirmed probable cross-transmission in only 11 instances (13 %, 11/88), with the majority of cross-transmission (64 %; 7/11) occurring on one ward. In the setting of highly clonal endemic MRSA, the combination of local epidemiology, PFGE, spa and dru typing provided valuable insights into MRSA transmission.

An evaluation of the Cortrak Enteral access system in our intensive care.

Appropriate nutrition is considered a cornerstone of Intensive care; however its successful initiation is frequently impeded by decreased gastric emptying secondary to opiates, sepsis, or ileus. The presence of a postpyloric tube will guarantee delivery of calories while reducing the incidence of reflux and aspiration. Enteral nutrition is approximately 100 fold cheaper than parenteral nutrition. A nasojejunal tube may be placed blindly (success 15%), by direct vision with a gastroscope, or under fluoroscopic guidance in the X-ray department. This study examines the use of the Cortrak Enteral access system (CEAS) in placement of nasojejunal tubes, a method facilitated by the use of an electromagnet. A retrospective review was conducted to evaluate the effectiveness of the CEAS for establishing nasojejunal feeding in the Intensive Care Unit (ICU) between January and December 2010. Our results found that the CEAS was successful in positioning a nasojejunal tube in ten out of twelve patients (83% success rate). Successful placement was confirmed by portable abdominal / chest x-ray. Placement took an average of 30 minutes, and prokinetic agents were used to facilitate two placements. The duration of successful enteral nutrition varied from 2 to 15 days post placement. The CEAS is a simple bedside tool for placing postpyloric tubes. While there is a learning curve associated with its use, it may confer significant benefits to individual patients and also to those responsible for ever shrinking budgets.

Operative outcomes for cervical myelopathy and radiculopathy.

Cervical spondylotic myelopathy and radiculopathy are common disorders which can lead to significant clinical morbidity. Conservative management, such as physical therapy, cervical immobilisation, or anti-inflammatory medications, is the preferred and often only required intervention. Surgical intervention is reserved for those patients who have intractable pain or progressive neurological symptoms. The goals of surgical treatment are decompression of the spinal cord and nerve roots and deformity prevention by maintaining or supplementing spinal stability and alleviating pain. Numerous surgical techniques exist to alleviate symptoms, which are achieved through anterior, posterior, or circumferential approaches. Under most circumstances, one approach will produce optimal results. It is important that the surgical plan is tailored to address each individual's unique clinical circumstance. The objective of this paper is to analyse the major surgical treatment options for cervical myelopathy and radiculopathy focusing on outcomes and complications.

Understanding the polarity of ionic liquids.

The polarities of a wide range of ionic liquids have been determined using the Kamlet-Taft empirical polarity scales α, ß and π*, with the dye set Reichardt's Dye, N,N-diethyl-4-nitroaniline and 4-nitroaniline. These have been compared to measurements of these parameters with different dye sets and to different polarity scales. The results emphasise the importance of recognising the role that the nature of the solute plays in determining these scales. It is particularly noted that polarity scales based upon charged solutes can give very different values for the polarity of ionic liquids compared to those based upon neutral probes. Finally, the effects of commonplace impurities in ionic liquids are reported.

Evaluation of different methods to recover meticillin-resistant Staphylococcus aureus from hospital environmental surfaces.

The environment is implicated as a source of healthcare-associated infections (HAIs) and there is a need for evidence-based approaches to environmental sampling to assess cleanliness and improve infection prevention and control. We assessed, in vitro, different approaches to sampling the environment for meticillin-resistant Staphylococcus aureus (MRSA). In a laboratory-based investigation, the recovery of MRSA from two common hospital environments using six different sampling methods was evaluated, with a wild-type strain of MRSA. A 100 cm(2) section of mattress and a laboratory bench surface were contaminated with known inocula of MRSA. Bacteria were recovered by sampling at 30 min after inoculation, using either saline-moistened cotton swabs, neutralising buffer swabs, eSwabs or macrofoam swabs, which were all enriched in tryptone soya broth, or by sampling with direct contact plates or chromogenic 'sweep' plates. The sensitivity (i.e. the minimum number of bacteria inoculated on to a surface which subsequently produced a positive result) of each method was determined for each surface. The most sensitive methods were eSwabs and macrofoam swabs, requiring 6.1 × 10(-1) and 3.9 × 10(-1) MRSA/cm(2), respectively, to produce a positive result from the bench surface. The least sensitive swabbing method was saline-moistened cotton swabs, requiring 1.1 × 10(3) MRSA/cm(2) of mattress. The recovery of bacteria from environmental samples varies with the swabs and methodology used and negative culture results do not exclude a pathogen-free environment. Greater standardisation is required to facilitate the assessment of cleanliness of healthcare environments.

Septic arthritis of the ankle due to Salmonella enteritidis.

Salmonella septic arthritis in healthy, immunocompetent patients is extremely rare. We present the case of a 70-year-old man who presented with a one-day history of painful swelling of his ankle from which was aspirated pus which subsequently grew Salmonella enteritidis. There was no history of trauma or symptoms consistent with Salmonella enterocolitis. Our patient recovered fully after two weeks on intravenous ceftriaxone and six weeks on oral ciprofloxacin. Salmonella is a notifiable disease in the European Union and the United States of America, and is associated with outbreaks as a result of food contamination. The nature of Salmonella arthritis and its appropriate management are outlined.

When are the hands of healthcare workers positive for methicillin-resistant Staphylococcus aureus?

Hand hygiene is a key component in reducing infection. There are few reports on the prevalence of methicillin-resistant Staphylococcus aureus (MRSA) on healthcare workers' (HCWs') hands. The aim of this study was to establish whether HCWs' fingertips were contaminated with MRSA in a clinical hospital setting. The study was conducted in an acute tertiary referral hospital on four MRSA wards that were part of a larger research study on MRSA epidemiology and four other wards not included in the study. The fingertips from all categories of 523 HCWs were sampled on 822 occasions by the imprinting of fingertips on MRSA chromogenic agar plates. The type of hand hygiene agent used, if any, and the immediate prior activity of the HCW were recorded. Overall, 38/822 (5%) fingertips from 523 HCWs were MRSA-positive; 12/194 (6%) after clinical contact, 10/138 (10%) after contact with the patient's environment and 15/346 (4%) after no specific contact. MRSA was recovered on 2/61 (3%) occasions after use of alcohol hand rub, 2/35 (6%) after 4% chlorhexidine detergent, 7/210 (3%) hand washing with soap and water, and 27/493 (5%) when no hand hygiene had been performed. MRSA was recovered from HCWs on seven of the eight wards. MRSA was more frequently present on fingertips on the four non-study wards vs the four MRSA study wards [18/250 (7%), 3/201 (1%), respectively; P

MRSA screening: can one swab be used for both culture and rapid testing? An evaluation of chromogenic culture and subsequent Hain GenoQuick PCR amplification/detection.

The use of a single swab for both MRSA culture and for rapid testing by PCR was evaluated, using the Hain GenoQuick (GQM) methicillin resistant Staphylococcus aureus (MRSA) assay for the rapid detection of MRSA, as a single swab would be the preferred option for routine diagnostic testing. GQM detected current prevalent Irish MRSA strains incorporating all known SSCmec types, including Panton-Valentine leukocidin-positive strains. Using the GQM method, all methicillin-resistant coagulase-negative staphylococci tested were confirmed to be negative, although three of seven gentamicin-resistant methicillin-sensitive Staphylococcus aureus strains tested were identified as MRSA. The theoretical ex-vivo limit of detection of the assay was 704 CFU per GQM assay reaction (1.7 × 10(4) CFU/mL) when MRSA suspensions were used for DNA extraction, or 1.4 × 10(3) CFU/swab (1.4 × 10(4) CFU/mL) using MRSA absorbed onto Copan screening swabs. Swab processing on chromogenic agar prior to PCR resulted in some inhibition of the PCR reaction, increasing the limit of detection of the assay by a factor of four. Based on 540 single swab screening specimens (nasal and groin) processed first for culture assay, then by GQM, the specificity and positive predictive value were both 100%, the negative predictive value was 92%, and the sensitivity was 57%. Culture followed by PCR from a single specimen is not optimal for the rapid detection of MRSA. Further laboratory validation of the GQM assay is required to determine the true diagnostic sensitivity and value of this kit in routine microbiology laboratories, modifying the protocol for single specimens, or using two specimens.

Application of quantitative reverse-transcription PCR (qRT-PCR) for the determination of the total viable count (TVC) on meat samples.

AIM: To apply a quantitative reverse-transcription PCR (qRT-PCR) method to determine the total viable count (TVC) on meat samples. METHODS AND RESULTS: Using two sets of primers to target the ribonuclease-P (RNase P) RNA transcripts of Gram-positive and Gram-negative bacteria, standard curves were generated using the LightCycler 2.0 instrument (Roche Diagnostics). RNA standards were extracted from known cell numbers and subsequently converted to cDNA for the construction of standard curves for quantification of the TVC of beef carcass swabs (n = 60) and beef (n = 30), chicken (n = 50) and pork (n = 49) pieces. A high correlation between the standard plate count method and the qRT-PCR was observed for beef swabs (R(2) = 0·93) and beef pieces (R(2) = 0·82). The correlation coefficient for chicken pieces and pork pieces were R(2) = 0·34 and 0·55, respectively. Using beef pieces (n = 13), an interlaboratory study was conducted and each participating laboratory (n = 3) found a reasonable degree of agreement between the cultural method and the PCR method. CONCLUSIONS: The qRT-PCR assay used in this study can enumerate the total bacteria on beef samples with a high degree of accuracy. SIGNIFICANCE AND IMPACT OF THE STUDY: The qRT-PCR method may have the potential to be applied to various sample types as an alternative rapid method for determining TVCs; however, further validation would be required.

The relationship between gonadotrophins, gonadal hormones and bone mass in men.

OBJECTIVE: Inhibin A and B (Inh A and B), activin A (Act A) as well as FSH may play an important role in bone turnover in perimenopausal women. Data in men are lacking. The aim was to investigate the relationship between circulating concentrations of Inh B and Act A and FSH/LH/testosterone (T) and their contribution to bone mineral density (BMD) in a male population. DESIGN AND SUBJECTS: Cross-sectional case-control study of 156 men, 63 with osteoporosis and 93 controls, aged (mean [SD]) 57.7 [13.7] years. MEASUREMENTS: Areal (aBMD) was measured at the femoral neck, total hip and lumbar spine. Volumetric BMD (vBMD) was calculated at the femoral neck and lumbar spine. Risk factors were assessed including the measurement of LH/FSH/T, Inh B and Act A. RESULTS: After correction for age and body mass index (BMI), associations were found between Inh B and FSH (beta regression coefficient beta = -0.326; P < 0.0001), T (beta = -0.36; P = 0.019) and Act A (beta = -0.4; P = 0.007) and between Inh B and LH (beta = 0.23; P < 0.0001) in all patients. The controls had higher Inh B concentrations compared to the cases (Inh B: controls: 139 [86] pg/ml vs. cases 88 [51] pg/ml; P = 0.005). Act A tended to be lower in the controls (Act A: controls 0.63 [0.24] ng/ml vs. cases 0.75 [0.4] ng/ml; P = 0.056). Univariate regression analyses showed a positive association between Inh B and BMD (P < 0.01) at the lumbar spine and total hip. In contrast a negative association was seen between FSH and BMD at the lumbar spine and femoral neck (P < 0.01). In a partial multivariate regression model that included the gonadal factors only, a positive association was seen between Inh B and BMD at the hip (beta = 0.088; P = 0.04). When all hormones including the gonadotrophins were entered in a full multivariate model, FSH and LH were found to be better predictors of BMD than Inh B or Act A in the controls and cases. CONCLUSIONS: These data suggest that the gonadal peptides and gonadotrophins may play a role in the maintenance of bone mass in men. Future confirmatory longitudinal studies are needed.