Longitudinal Measurements of FGF23, Sarcopenia, Frailty and Fracture in Older Community Dwelling Women

BACKGROUND

FGF23 has been associated with frailty and functional performance in older individuals, but the association to sarcopenia is unknown.

OBJECTIVES

To investigate the association between FGF23, frailty, sarcopenia and fractures in older community dwelling women.

DESIGN

Prospective longitudinal cohort study.

SETTING

Malmö, Sweden.

PARTICIPANTS

995 75-year-old women, followed prospectively for ten years, with re-investigations after five (n=667) and ten (n=324) years.

MEASUREMENTS

C-terminal levels of FGF23 were measured and a frailty index of 'deficits in health' created. Sarcopenia was defined by low muscle mass and strength and "probable sarcopenia" by low muscle mass only. Incident fractures were continuously registered for 10-years. Based on tertiles of FGF23, odds ratio for frailty, sarcopenia and probable sarcopenia was investigated using logistic regression models adjusted for: eGFR, PTH, calcium, vitamin D and phosphate. Fracture-free survival during 10-year follow-up was depicted using Kaplan Meier curves.

RESULTS

While fracture-free survival did not differ between tertiles, women in the highest tertile of FGF23 had lower muscle strength and gait speed, and higher proportion with impaired mobility at baseline. At age 75, these women had higher odds of also being frail (ORadj 1.6 (95% CI 1.1-2.4)) and suffering from probable sarcopenia (ORadj 1.8 (95% CI 1.1-3.1)), but not sarcopenia. At follow-up the association between FGF23 and probable sarcopenia was not evident. While the association with frailty was attenuated at age 80 after adjustment (ORadj 1.6 (95% CI 1.0-2.5)), women in the highest tertile had higher odds of being frail at age 85 (ORadj 3.4 (95% CI 1.7-6.6)).

CONCLUSIONS

FGF23 may be a promising clinical marker for muscle strength, functional performance, and frailty in older women, but not for future fragility fractures. Whether FGF23 is also associated with sarcopenia requires further investigation.

In community-dwelling women frailty is associated with imminent risk of osteoporotic fractures

Frailty reflects an accelerated health decline. Frailty is a consequence of fracture and contributes to fracture. Greater frailty was associated with higher fracture risk. Frail women were at immediate risk (within 24 months) of a hip or major fracture. Fracture prevention could be improved by considering frailty status.

INTRODUCTION

Frailty encompasses the functional decline in multiple systems, particularly the musculoskeletal system. Frailty can be a consequence of and contribute to fracture, leading to a cycle of further fractures and greater frailty. This study investigates this association, specifically time frames for risk, associated fracture types, and how grade of frailty affects risk.

METHODS

The study is performed in the OPRA cohort of 1044, 75-year-old women. A frailty index was created at baseline and 5 and 10 years. Women were categorized as frail or nonfrail and in quartiles (Q1 least frail; Q4 most frail). Fracture risk was assessed over short (1 and 2 years) and long terms (5 and 10 years). Fracture risk was defined for any fracture, major osteoporotic fractures (MOFs), and hip and vertebral fracture, using models including bone mineral density (BMD) and death as a competing risk.

RESULTS

For women aged 75, frailty was associated with higher risk of fracture within 2 years (Hip SHR_adj. 3.16 (1.34-7.47)) and MOF (2 years SHR_adj. 1.88 (1.12-3.16)). The increased risk continued for up to 5 years (Hip SHR_adj. 2.02 (1.07-3.82)); (MOF SHR_adj. 1.43 (0.99-2.05)). Grade of frailty was associated with increased 10-year probability of fracture (p = 0.03). Frailty predicted fracture independently of BMD. For women aged 80, frailty was similarly associated with fracture.

CONCLUSION

Frail elderly women are at immediate risk of fracture, regardless of bone density and continue to be at risk over subsequent years compared to identically aged nonfrail women. Incorporating regular frailty assessment into fracture management could improve identification of women at high fracture risk.

Kidney function and its association to imminent, short- and long-term fracture risk-a longitudinal study in older women

Reduced kidney function is associated with an increased fracture risk, although the relationship between an age-related decline and fractures needs further investigation. We followed kidney function and fracture risk for 10 years. A mild-moderate decline in kidney function was associated with fracture, but not in advanced age.

INTRODUCTION

With age, kidney function declines. Though well known that chronic kidney disease is associated with increased fracture risk, the extent to which the typical age-related decline contributes is unclear. In the OPRA cohort, a longitudinal study of older non-selected women, we investigated the association between kidney function and fracture.

METHODS

Cystatin C-based kidney function estimates were available at age 75 (n = 981) and 80 (n = 685). Women were categorized by kidney function: normal (CKD stages 1 and 2), mild-moderate (3a), poor (3b-5), and imminent, short- and long-term fracture risk investigated. BMD measurements and kidney function for risk prediction were also evaluated; women were categorized by both reduced kidney function (stages 3-5) and osteoporosis status.

RESULTS

In the short term, 2-3 years, mild-moderate kidney dysfunction was associated with the highest risk increase: osteoporotic fractures (2 years HRadj 2.21, 95% CI 1.27-3.87) and also up to 5 years (between 75 and 80 years) (HRadj 1.51, 1.04-2.18). Hip fracture risk was similarly increased. This association was not observed from age 80 nor for women with poorest kidney function. Reduced kidney function was associated with higher risk even without osteoporosis (osteoporotic fracture; HRadj 1.66, 1.08-2.54); risk increased by having both osteoporosis and reduced function (HRadj 2.53, 1.52-4.23).

CONCLUSION

Older women with mild-moderate reduction of kidney function are at increased risk of fractures, but not those with the worst function. Our findings furthermore confirm the value of osteoporosis assessment and it is possible that in this age group, age-related decline of kidney function has limited contribution compared with BMD.

Reduced kidney function is associated with BMD, bone loss and markers of mineral homeostasis in older women: a 10-year longitudinal study

Kidney function decreases with age; however, the long-term influence on bone density (BMD) in older women already at risk of osteoporosis is unknown. We followed kidney function and bone loss for 10 years. Declining kidney function was adversely associated with bone loss and mineral homeostasis in old women, though it attenuated with advanced aging.

INTRODUCTION

Existing studies do not fully address the relationship between kidney function and bone metabolism with advanced aging in Caucasian women. This study describes the association between kidney function, BMD, bone loss and bone metabolism in older women and provides a review of the available literature for context.

METHODS

We studied participants from the OPRA cohort with follow-up after 5 and 10 years. Using plasma cystatin C (cysC), estimated glomerular function rate (eGFR) was evaluated at age 75 (n = 981), 80 (n = 685) and 85 (n = 365). Women were stratified into "normal" function (CKD stages 1-2), "intermediate" (stage 3a) and "poor" (stages 3b-5), and outcome measures-BMD, bone loss and markers of mineral homeostasis-were compared.

RESULTS

Femoral neck (FN) BMD positively associated with kidney function at 75 years old ([Formula: see text] = 0.001, p = 0.028) and 80 years old ([Formula: see text] = 0.001, p = 0.001), although with small effect size. Prevalence of osteoporosis (FN T-score ≤ - 2.5) did not differ with kidney function. Measured at age 75, women with poor kidney function had higher annual percentage bone loss over 5 years compared to those with normal function (2.3%, 95% CI 1.8-2.8 versus 1.3%, 95% CI 1.1-1.5, p = 0.007), although not when measured from age 80 or 85. Additionally, markers of mineral homeostasis (PTH, phosphate, vitamin D, calcium), CRP and osteocalcin differed by kidney function.

CONCLUSIONS

In old women, kidney function is associated with BMD, bone loss and altered mineral homeostasis; probably, a relationship attenuated in the very elderly.

Vertical Field MR Imaging of Upper Thorax and Spine in Small Children

To improve image quality in a vertical field MR imaging unit, operating at low field strength (0.3 T), we have designed a half-elliptical coil for use in the upper thoracic region of small children. Our intention was also to shorten the examination time, which until now has been long, because several scans with different coils have been necessary to cover the thoracic region. The experimental coil is designed so that a child's shoulders fit into the central region. The coil consists of 2 serially connected cable-loops, mounted on a foam rubber vest. The coil performance was tested in a phantom and improvements relative to standard coils were demonstrated in in vivo studies. The results indicate that by using the half-elliptical coil, the signal-to-noise (S/N) ratio can be improved by a factor of 2 to 3 in the thoracic region of a child.

C-reactive protein, bone loss, fracture, and mortality in elderly women: a longitudinal study in the OPRA cohort

SUMMARY

This longitudinal study investigates the association between C-reactive protein (CRP), osteoporosis, fractures, and mortality in 1044 elderly women. CRP was not an indicator for low bone mineral density (BMD), bone loss, or fracture in elderly women; however, women with elevated CRP levels over a prolonged period lost more bone over the 10-year follow-up, although fracture risk was not increased.

INTRODUCTION

Inflammation may contribute to the pathophysiology underlying impaired bone metabolism. This study investigates the association between CRP, BMD, bone loss, fracture risk, and mortality in women aged 75 and above.

METHODS

This longitudinal study is based on 1044 women, all age 75 at inclusion, reassessed at ages 80 and 85, with a mean follow-up time of 11.6 years (maximum 16.9 years).

RESULTS

Women in the lowest CRP quartile (mean 0.63 mg/L) had lower BMD compared to those in the highest CRP quartile (mean 5.74 mg/L) at total hip (TH) (0.809 vs. 0.871 g/cm2, p<0.001) and femoral neck (FN) (0.737 vs. 0.778 g/cm2, p=0.007). A single measurement of CRP was not associated with bone loss; however, women with persistently elevated CRP, i.e., ≥3 mg/L at ages 75 and 80 had significantly higher bone loss compared to women with CRP<3 mg/L (TH -0.125 vs. -0.085 g/cm2, p=0.018 and FN -0.127 vs. -0.078 g/cm2, p=0.005) during 10 years of follow-up. Women in the highest CRP quartile had a lower risk of osteoporotic fractures (hazard ratios (HR) 0.76 (95% confidence intervals (CI) 0.52-0.98)) compared to those in the lowest, even after adjusting for weight and BMD. Mortality risk was only increased among women with the highest CRP levels.

CONCLUSION

CRP was not an indicator for low BMD, bone loss, or fracture in elderly women in this study. Persistently elevated CRP however seemed to be detrimental to bone health and may be associated with a higher rate of bone loss. Only the highest CRP levels were associated with mortality.

Influence of thawing method on motility, plasma membrane integrity and morphology of frozen-thawed stallion spermatozoa

Different thawing methods are used for stallion semen, however, it is unclear which method is the optimal one. To determine if the thawing temperature has an effect on semen quality, we compared 2 thawing temperatures, 75 degrees C and 37 degrees C. The following parameters were used to measure sperm quality: sperm motility, sperm viability, plasma membrane integrity and sperm morphology. Twenty-three ejaculates from 10 Dutch Warmblood stallions were thawed either at 37 degrees C for 30 sec or at 75 degrees C for 7 sec. Sperm motility was evaluated by a Hamilton Thorn Motility Analyser. Plasma membrane integrity and sperm viability were evaluated by using a live/dead fluorescein stain containing a calcein AM probe and ethidium homodimer-1 probe. The eosinaniline blue staining method was used to evaluate the percentage of live and dead cells, as well as sperm morphology. There was no significant difference (P = 0.84) between sperm motility after thawing at 37 degrees C and 75 degrees C. There was also no significant difference (P = 0.053) between the percentage of live spermatozoa using the calcein AM/ethidium homodimer stain after thawing at 37 degrees C and 75 degrees C. There was, however, a significant difference (P = 0.032) between the percentage of live spermatozoa using the eosin-aniline blue stain after thawing at 37 degrees C compared with that at 75 degrees C. In conclusion, our laboratory results indicated that stud farms using frozen semen should thaw the straws at 37 degrees C instead of 75 degrees C. The lower temperature is easier to work with, as thawing at the higher temperature requires special equipment and has to be timed very carefully to avoid damage to the spermatozoa.

Calibration of a radioactive ink-based stack phantom and its applications in nuclear medicine

This paper describes a stack phantom useful for imaging complex activity distributions. It is based on images printed with radioactive ink using a commercial ink-jet printer. The application for the phantom is in the evaluation of planar and SPECT scintillation camera images and for validation of Monte Carlo simulated images. The accuracy in generating the activity distributions on paper sheets is especially important. Here we describe the calibration procedure for the ink-jet printer. The goal of the printer calibration is to find the relationship between the digital image count (voxel grey level) and its corresponding activity on the paper sheets (radioactivity). The relationship between the voxel grey level and the radioactivity on the paper sheets (measured by scanning technique and well counter) was found to be logarithmic, and a 3rd degree polynomial was found to fit the relationship. The distribution of radioactivity in the ink cartridge was investigated by pinhole SPECT. The distribution of (99m)Tc solution was found to be homogeneous in the ink solution. Experimental studies were done directly on Monte Carlo simulated heart images from the NCAT phantom. The result showed that the simulated images are similar to the images measured using the ink-jet technique. This stack phantom could be a promising solution with an advantage that the exact geometry generated in Monte Carlo could be imitated in the phantom. The phantom is a very flexible device and clearly much more versatile than conventional phantoms which have a fixed geometry and spatial limitation.

Immunization against gnRH in mature mares: antibody titres, ovarian function, hormonal levels and oestrous behaviour

The aim of the present study was to investigate the effect of active immunization against GnRH in mature Standardbred mares (three experimental and one control mare) on antibody titres, ovarian function, hormonal levels and oestrous behaviour. The mares were individually teased with a stallion once each day. During the first part of the experiment (period I: late April until November), blood was sampled every third day during the first 3 months, thereafter once per week. In the second part of the experiment (period II: December until August), sampling was carried out every second week. Progesterone, oestradiol-17beta and LH were analysed. Rectal gynaecological examination was made with the same intervals as the blood samplings and included palpation of the genital organs and ultrasonography. The experimental mares were immunized against GnRH with a GnRH-BSA conjugate. Equimune (Vetrepharm, Bracetown, Business Park, Clonee, Co. Meath, Republic of Ireland) was used as adjuvant. The mares were immunized on four occasions (20-30 day intervals) and GnRH antibody titre was determined. All immunized mares produced antibodies against GnRH but the maximum titres as well as the duration of a greater than 10% binding capacity varied between the mares (1 : 1600 to 1 : 50 000; 5 to 12 months, respectively). After the first injection, all mares showed one oestrus and ovulated at the regular time. In two of the mares, the immunization resulted in ovarian atrophy. Their hormone levels of progesterone, oestradiol- 17beta and progesterone decreased to basal levels and the cyclical hormone pattern was interrupted from approximately 30 days onwards. They continued to show oestrous signs but with irregular durations and intervals. The third mare showed ovarian suppression only for short periods and not in both ovaries at the same time; the hormone levels were basal for only about 20 days (days 50-70) and the mare ovulated on day 75 after start of immunization. The other mares ovulated after 13.5 and 15 months, respectively. It is concluded that the effect of immunization against GnRH in mature mares was individual concerning antibody titre response and the suppression of ovarian activity and hormone levels. Mares with totally inactive ovaries continued to show oestrous signs but with irregular intervals and durations.

Effect of GnRH immunisation on hormonal levels, sexual behaviour, semen quality and testicular morphology in mature stallions

The aim of this study was to investigate the effect of gonadotrophin-releasing hormone (GnRH) immunisation on mature stallions that had been used for breeding. Four Standardbred stallions were used in the study: 3 experimental animals and 1 control animal. Semen was collected regularly, i.e. twice/week, during the 4 months prior to the experimental period. The stallions were immunised against GnRH with a GnRH-BSA conjugate. Equimune was used as the adjuvant. The stallions were immunised on 5 occasions, 4 at 2 week intervals, and the fifth 4 weeks after the fourth. Blood samples were taken once a week for analysis of GnRH antibody titre and every third week for testosterone and oestrone sulphate analyses. Semen was collected once a week, and libido and sexual behaviour were observed. Ejaculate volume, sperm concentration, total number of sperm in the ejaculate, sperm motility and sperm morphology were evaluated. Testicular size was measured once a week. At the end of the study, the stallions were castrated, and a histological examination of the testes performed. All immunised stallions produced antibodies against GnRH, and plasma testosterone concentration decreased. However, the effect of immunisation varied between stallions. In 2 of the stallions, high levels of antibodies were found, while in the third, the level was moderate. Four weeks after the first immunisation, a decrease in libido was observed. Two months after the first immunisation, marked changes in semen quality were observed in the 2 stallions with high antibody titres. Fourteen weeks after the first immunisation, the total number of sperm/ejaculate had decreased from >8.6 x 10(9) to <2.7 x 10(9), sperm motility from >59 to <10% and the frequency of morphological normal spermatozoa had decreased from >60 to <14%. The dominating abnormalities were abnormal head shapes, proximal cytoplasmic droplets and detached heads. In the third stallion, only slight changes in semen quality were found. No changes were observed in the control stallion. Decreases in testicular size were noted in all of the experimental stallions. Pronounced histological alterations in the testes were observed in 2 of the stallions. It is concluded that the vaccine was effective in stimulating production of GnRH antibodies and in suppressing testicular function and androgen secretion. However, there was an individual variation in the responses among the stallions and, further, libido was not totally suppressed.

Aerobic bacterial flora of semen and stallion reproductive tract and its relation to fertility under field conditions

This study was initiated in order to investigate the bacterial flora of the stallion genital tract by taking consecutive samples from normal stallions in regular use. The objective was to determine whether any growth of potential pathogens, particularly P. aeruginosa and K. pneumoniae, in fresh semen and urethra was associated with the presence of inflammatory cells in the semen and whether bacterial growth had any effect on sperm morphology and pregnancy results. Sixteen stallions, only used for A.I., housed at 3 different commercial stud farms, were used. A wide variety of microorganisms was found in almost all samples from fresh semen (total 115 samples). P. aeruginosa was isolated from 46/115 (40%) of the samples and from 12 of the 16 stallions. K. pneumoniae was isolated from the semen of one stallion. Samples taken from the distal urethra after ejaculation contained fewer microorganisms than samples from fresh semen. No bacteria were found in 51% of the extended semen samples. Most of the stallions had an acceptable sperm morphology, and very few of the ejaculates contained inflammatory cells. Pregnancy results among the stallions varied, but were acceptable for most of them. There was no correlation between the frequency of samples testing positive for P. aeruginosa in raw semen and pregnancy results.

Effectiveness of two systems for transporting equine semen

The storage and transport of cooled, liquid semen is an effective way of facilitating the use of desirable stallions for breeding mares located on distant farms. The Equitainer System is the most widely used transport container and it has been shown that it is possible to ship semen in this container and obtain good conception rates. However, the cost of Equitainers is high, and stud-farms that ship large quantities of semen have tended to rely on cheaper alternatives, even though little documentation exists concerning their reliability, especially under extreme temperature conditions. Two different containers for transporting equine semen (the Equitainer and a styrofoam box) were compared in their effectiveness at maintaining semen quality (i.e. sperm motility and plasma membrane integrity) during 24 h of storage. The transport containers were stored at 2 different environmental temperatures, i.e., room temperature (20 degrees C) and 37 degrees C. Thirty-seven ejaculates from 10 Standardbred stallions (3 to 6 samples per stallion) were examined. Sperm function and plasma membrane integrity were assessed using a Mika Motion Analyzer and a fluorescein stain (Calcein AM/Ethidium homodimer) in fresh diluted semen that had been stored for 24 h at room temperature (20 degrees C). Another 18 ejaculates from 5 stallions were examined using methods described above, but the transport boxes were kept at a high environmental temperature (37 degrees C). After storage at room temperature, there was no significant difference in total sperm motility and frequency of spermatozoa with an intact plasma membrane between the 2 types of transport boxes. A significant difference was seen in linear sperm motility, with the Equitainer being the better container. However, a significant difference was also seen in average path velocity, with the styrofoam box being the better container. After storage at 37 degrees C, the Equitaner maintained semen quality better. A significant difference was seen in total sperm motility, average path velocity, lateral head displacement and frequency of spermatozoa with an intact plasma membrane between the 2 types of transport boxes. Although, both transport containers were satisfactory when used under normal conditions. The Equitainer seemed superior under more extreme temperatures and during longer transport periods (> 24 to 30 h).

Effect of insemination dose on pregnancy rate in mares

Different insemination doses have been used for artificial insemination(AI) in horses. Since the insemination dose can affect the pregnancy rate, it is important to ensure that an adequate dose be used regardless of the type of inseminationprotocol used. The aim of this study was to find out if it is possible to decrease the insemination dose from 500 x 10(6) progressively motile spermatozoa to 300 x 10(6) progressively motile spermatozoa and still maintain an acceptable pregnancy rate when using extended fresh semen. Thirteen stallions of known fertility and a well-defined group of 64 mares were used in the study. The mares were randomly assigned to 1 of 2 insemination groups. Examination for pregnancy was performed by ultrasonography per rectum approximately 16 d after the last insemination. When using an insemination dose of 300 x 10(6) progressively motile spermatozoa the pregnancy rate per cycle was 75%. With an insemination dose of 500 x 10(6) progressively motile spermatozoa the pregnancy rate per cycle was 64%. There was no significant difference in the pregnancy rate between the 2 insemination doses (P = 0.341). We conclude that when using fresh extended semen it is unlikely that an insemination dose of 300 x 10(6) progressively motile spermatozoa would yield a lower pregnancy rate than a dose of 500 x 10(6) progressively motile spermatozoa if stallions with good quality semen are selected.

Aerobic bacterial flora of semen and stallion reproductive tract and its relation to fertility under field conditions

This study was initiated in order to investigate the bacterial flora of the stallion genital tract by taking consecutive samples from normal stallions in regular use. The objective was to determine whether any growth of potential pathogens, particularly P. aeruginosa and K. pneumoniae, in fresh semen and urethra was associated with the presence of inflammatory cells in the semen and whether bacterial growth had any effect on sperm morphology and pregnancy results. Sixteen stallions, only used for A.I., housed at 3 different commercial stud farms, were used. A wide variety of microorganisms was found in almost all samples from fresh semen (total 115 samples). P. aeruginosa was isolated from 46/115 (40%) of the samples and from 12 of the 16 stallions. K. pneumoniae was isolated from the semen of one stallion. Samples taken from the distal urethra after ejaculation contained fewer microorganisms than samples from fresh semen. No bacteria were found in 51% of the extended semen samples. Most of the stallions had an acceptable sperm morphology, and very few of the ejaculates contained inflammatory cells. Pregnancy results among the stallions varied, but were acceptable for most of them. There was no correlation between the frequency of samples testing positive for P. aeruginosa in raw semen and pregnancy results.

Assessing the quality of raw semen: A review

An analysis of semen characteristics can provide a reasonable basis upon which to develop a strategy for maximizing the fertility of a stallion. However, the repeatability of semen characteristics between ejaculates within stallions is low to moderate. Factors such as season, collection technique, frequency of collection and disturbances in spermatogenesis contribute to this variation. Fertility can, however, be influenced by a host of other factors besides semen characteristics, including management, semen handling procedures and the number of mares being bred. Parameters usually included in a conventional evaluation of raw semen quality are volume, sperm concentration, total number of spermatozoa in the ejaculate, percentages of motile spermatozoa, sperm morphology, seminal pH, longevity of sperm motility and bacteriological status. Although, these evaluations provide a lot of information, their correlations with fertility are somewhat conflicting. However, it seems likely that the prediction of male fertility could be improved if additional parameters based on the functional characteristics of spermatozoa were to be used. Several functional tests have been investigated, such as the use of fluorescent stains as a marker for cell membrane integrity, sperm-oocyte binding tests and the hypoosmotic swelling test. In this study, emphasis is placed on sperm motility and sperm morphology, but in addition, some functional tests are also discussed.

Attainment of spermatogenesis in Swedish cross-bred boars

Twenty peripubertal Swedish cross-bred boars were used to study the testicular differentiation and the maturation of spermatozoa (epididymal) between 100 and 180 days of age. In all animals the sex cords were small and solid at 100 days of age. Spermatogenesis started at approximately 115 days of age and was completed, i.e. the cellular organization of the seminiferous tubules indicated a sexually mature testis with normal spermatogenesis, at 180 days of age. By 125 days of age only a few spermatozoa were found in the cauda epididymidis Furthermore, a high frequency of sperm morphological alterations were seen. The sperm concentration in the cauda increased with increasing age, and simultaneously the frequency of abnormal spermatozoa decreased. However, not all boars had a 'mature' semen picture in the cauda epididymis at 180 days of age.

Prostaglandin F2 alpha metabolite levels following an embryo transfer procedure in the mare

Hormonal, chemical, and mechanical stimuli can activate the arachidonic acid cascade and result in formation of prostaglandins and related substances. These compounds can have a profound role in the initiation of the inflammatory process (Higgins & Lees 1984). Prostaglandin (PG) F_2α is the key hormone in reproductive physiology with well-known effects on reproductive performance e.g. luteolysis and abortion. An activation of the arachidonic acid cascade, caused by mechanical manipulation during an embryo transfer procedure, might be one explanation for early embryonic loss.

Vertical field MR imaging of upper thorax and spine in small children. Evaluation of a new surface coil

To improve image quality in a vertical field MR imaging unit, operating at low field strength (0.3 T), we have designed a half-elliptical coil for use in the upper thoracic region of small children. Our intention was also to shorten the examination time, which until now has been long, because several scans with different coils have been necessary to cover the thoracic region. The experimental coil is designed so that a child's shoulders fit into the central region. The coil consists of 2 serially connected cable-loops, mounted on a foam rubber vest. The coil performance was tested in a phantom and improvements relative to standard coils were demonstrated in in vivo studies. The results indicate that by using the half-elliptical coil, the signal-to-noise (S/N) ratio can be improved by a factor of 2 to 3 in the thoracic region of a child.

Comparison between retrospective gating and ECG triggering in magnetic resonance velocity mapping

ECG-triggered cinematographic studies of the cardiovascular system are hampered by several technical restrictions such as the inability to image end-diastole, ghosting, varying signal intensity, and phase contributions from eddy currents. Retrospective gating may solve these problems, but involves signal manipulation such as interpolating raw data from a time window. In this study, the performance of the two gating strategies was compared in quantitative MR velocity mapping on the abdominal aorta in eight healthy volunteers and on a pulsatile flow phantom. The results were compared to a one-dimensional velocity mapping technique and Doppler ultrasound. Finally, the consequence of decreasing the time window in the raw data interpolation used for retrospective gating was also examined. With retrospective gating, a low-pass filtering was seen, causing significantly prolonged duration and decreased amplitude of flow pulses. However, by reducing the time window retrospectively gated flow measurements were in good agreement with those that are ECG triggered. When fulfilling the demand of a narrow time window for interpolation, retrospective gating offers several advantages in MR velocity mapping.

Effects on testosterone, LH and cortisol concentrations, and on testicular ultrasonographic appearance of induced testicular degeneration in bulls

It is well known that heat stress has a detrimental effect on testicular functions. In addition to the alteration of semen quality and testicular damage, reproductive hormone secretion can be altered. The objective of this study was to describe changes in plasma concentrations of testosterone, LH and cortisol, as well as in testicular ultrasonographic appearance after induced testicular degeneration. Four Swedish Red and White bulls, aged 3 years, were used. They were fed according to Swedish standards. The scrotum was covered with an insulation device during 96 h. Semen was collected weekly 3 times before and up to 4 months after insulation. Testicular ultrasonography and clinical genital examination were performed with the same intervals. Heparinized blood samples were taken from the jugular vein at 2 h interval during 24 h every 2 weeks during the study. Blood samples were tested for the content of testosterone, LH and cortisol. Data were analysed, using one way analysis of variance of seminal data, clinical examination data as well as 24 h hormonal output data as percentage of mean individual pretreatment values. The use of a 5 MHz B-mode ultrasound unit did not contribute with an objective estimation of the degree of testicular degeneration. In 3 of the bulls testosterone levels had a tendency to decrease and LH to increase during the time of severe degeneration, whereas an opposite trend was seen during the regenerative phase, changes becoming significant 15 weeks after scrotal insulation. Variation between animals was big. Cortisol levels had a decreasing trend, changes being significant only in individual bulls at 10 and 15 weeks after scrotal insulation.(ABSTRACT TRUNCATED AT 250 WORDS)

Ultrasonography as a diagnostic tool in a stallion with seminal vesiculitis: A case report

A 14-years old warm-blood trotter with a chronic genital infection was examined by B-mode ultrasonography. The purpose was to evaluate ultrasonography as a diagnostic tool in genital tract infections.

Improved receiver coil for upper thoracic spine imaging in a vertical magnetic field

To improve image quality in the upper thoracic spine, an anatomically shaped copper wire loop coil, made to fit over the patient's shoulders, was constructed. The coil was permanently mounted on a foam-rubber vest to facilitate attachment to the patient. Phantom and in vivo studies of the performance of the coil in healthy volunteers showed as much as a two times greater signal-to-noise ratio relative to that of standard coils for the upper thoracic spine. In a patient with lesions in the upper thoracic cord, the coil gave better image quality in the region of interest than did the standard coils. The coil has been integrated into the authors' routine imaging equipment and has been the coil of choice for imaging of the upper thoracic spine on their 0.3-T vertical field system.

Effects on testosterone, LH and cortisol concentrations, and on testicular ultrasonographic appearance of induced testicular degeneration in bulls

It is well known that heat stress has a detrimental effect on testicular functions. In addition to the alteration of semen quality and testicular damage, reproductive hormone secretion can be altered. The objective of this study was to describe changes in plasma concentrations of testosterone, LH and cortisol, as well as in testicular ultrasonographic appearance after induced testicular degeneration. Four Swedish Red and White bulls, aged 3 years, were used. They were fed according to Swedish standards. The scrotum was covered with an insulation device during 96 h. Semen was collected weekly 3 times before and up to 4 months after insulation. Testicular ultrasonography and clinical genital examination were performed with the same intervals. Heparinized blood samples were taken from the jugular vein at 2 h interval during 24 h every 2 weeks during the study. Blood samples were tested for the content of testosterone, LH and cortisol. Data were analysed, using one way analysis of variance of seminal data, clinical examination data as well as 24 h hormonal output data as percentage of mean individual pretreatment values. The use of a 5 MHz B-mode ultrasound unit did not contribute with an objective estimation of the degree of testicular degeneration. In 3 of the bulls testosterone levels had a tendency to decrease and LH to increase during the time of severe degeneration, whereas an opposite trend was seen during the regenerative phase, changes becoming significant 15 weeks after scrotal insulation. Variation between animals was big. Cortisol levels had a decreasing trend, changes being significant only in individual bulls at 10 and 15 weeks after scrotal insulation.(ABSTRACT TRUNCATED AT 250 WORDS)

Experimentally induced testicular alterations in boars: hormonal changes in mature and peripubertal boars

Eleven sexually mature boars and 10 peripubertal boars were used to study the effects of elevated testicular temperature on plasma hormonal levels. The scrotum of the boars was covered with a textile-aluminium foil insulation device for 100 h. Insulation of the scrotum in the peripubertal boars took place at an age of 100 days. Blood samples were drawn 3 times daily for 12 days in the mature boars, starting 3 days before scrotal insulation. In the peripubertal boars, blood sampling was performed once a day for 11 days, starting the first day of scrotal insulation. During scrotal insulation, the plasma levels of testosterone, oestradiol-17 beta and oestrone sulphate decreased continuously in the mature boars. After removal of the scrotal insulation device there was a continuously increase, back to normal levels of oestradiol-17 beta and oestrone sulphate. The plasma levels of testosterone showed an immediate rise of brief duration after removal of the device in 5 of the boars, while in the other 6 boars the rise in testosterone levels came 4 days after removal and lasted for 3 days. In the peripubertal boars, there were no significant differences in the hormone levels between the experimental and control animals during and after scrotal insulation. However, the decrease in testosterone concentration over time, during scrotal insulation, was significant within the experimental group.

Experimentally induced testicular alterations in boars: sperm morphology changes in mature and peripubertal boars

Seven mature boars and 8 peripubertal boars were used to study the effects of elevated testicular temperature. The scrotum of the boars was covered by a textile-aluminium foil insulation device for 100 hours. Insulation of the scrotum in the peripubertal boars took place at an age of 100 days. Pronounced changes in sperm characteristics, e.g. decreased sperm motility and high numbers of proximal cytoplasmic droplets, abnormal sperm head shapes and abnormal acrosomes, were seen during week 3 to 5 after scrotal insulation in the mature boars. An "immature" semen picture, i.e. low sperm motility, low total sperm count and high numbers of proximal cytoplasmic droplets and abnormal sperm head shapes, was seen in the first ejaculates in the peripubertal experimental boars. The semen picture was normal in the control boars. A maturation of the semen picture over time was seen in the experimental boars. However, remaining abnormalities in the sperm morphology together with the testicular histology indicate lasting pathological changes in the testes.

Experimentally induced testicular alterations in boars: histological and ultrastructural findings

Nine mature boars (8 experimental and one control) were used to study the effects of elevated testicular temperature. The scrotum was covered by a textile-aluminium foil insulation for 100 hours. The boars were divided into 4 groups and were slaughtered at the end of scrotal insulation (group I), 10 days (group II), 20 days (group III) and 40 days (group IV) after scrotal insulation. In groups I and II changes were seen among primary spermatocytes and spermatids, although the changes in group II were more severe. In group III the changes were restricted to the spermatids and in group IV most of the tubules were normal. The epididymal spermatozoa showed slight changes in group I, severe changes in groups II and III and were normal in group IV. The results indicated that spermatogonia were not affected, whereas primary spermatocytes seemed to be the most susceptible germ cell type. Scrotal insulation produced restricted damage that was reversible when the insulation was removed and turned out to be a suitable method to study regeneration processes in the testis of boars.

Semen quality and fertility after heat stress in boars

Sperm morphology and the fertilizing capacity of ejaculated spermatozoa were examined in 6 Swedish Landrace boars before and after heat stress. The boars were exposed to 35° C during 100 h in a climatic room. Fertility was measured by insemination of gilts before and at various times after heat stress. Each gilt (n = 44) was inseminated with a total of 5×109 spermatozoa diluted to 10O ml with EDTA-glucose diluent and fertilization was assessed by examining recovered ova 2 days after insemination.

Changes in semen quality varied among the boars from a very weak response in 2 boars to pronounced semen alterations occurring 2–6 weeks after heat stress in the other boars. A close relationship was found between seminal changes and fertilization rates, all ejaculates which had high fertilization rates being of the same quality as the pre-exposure ejaculates. The ejaculates that had poor fertility were characterized by lowered sperm motility and increased numbers of spermatozoa with abnormal heads, proximal cytoplasmic droplets and nuclear pouch formations.

Synchronization of oestrus in gilts with a progestin [Oxolven (Sa 45.249)]

The efficiency of a synthetic progestin, Oxolven, as a synchronising agent for mature gilts was investigated. Using capsules is not a suitable form of administration when group-feeding is practised. Another form of administration is proposed for large scale use in the pig production.

FITC-Dextrans as tracers for macromolecular movements in the nervous system. A freeze-drying method for dextrans of various molecular sizes injected into normal animals

A freeze-drying method has been developed by which fluorescein thiocarbamoyl dextrans (FITC-dextrans) can be localized in thin sections from nervous tissue and muscles. Labelled dextrans with molecular weights of 3,000, 20,000, 70,000 and 150,000 were injected intravenously (i.v.) into golden hamsters and samples from brain, trigeminal ganglia and sciatic nerves were examined 30 min or 4 h later. For comparison experiments were also carried out in mice and some other tracers were tested as well. The dextrans did not pass out of blood vessels in cerebral cortex and white matter. The blood vessels in the trigeminus ganglion were permeable to all of the tested compounds, i.e. even the FITC-dextran with mol.wt. 150,000. Little, if any, i.v. injected dextran could be detected in the endoneurium of sciatic nerve fascicles. Even very high concentrations of dextrans (mol.wt. 3,000 and 150,000) injected around the sciatic nerves did not penetrate the perineurium of the sciatic nerve. As compared with other tracers dextrans have the advantage that they can be obtained in a wide range of molecular sizes. With the proposed technique presented at the end of this article they can be used for studies on vascular permeability in deep tissue like brain, ganglia and peripheral nerve. The use of these tracers will probably be particularly advantageous in investigations concerning the etiology of edematous conditions.

Uptake and retrograde axonal transport of various exogenous macromolecules in normal and crushed hypoglossal nerves

Macromolecular tracers were injected into the tongue or around a crush in mouse hypoglossal nerves. At various times thereafter, the tracers were histochemically localized on the basis of peroxidase activity. The distribution of reaction product was then examined using light microscopy in order to study the influence of molecular charge and size on uptake and retrograde axonal transport from the periphery or from the crushed axon. Of various proteins with peroxidase activity, horseradish peroxidase and cytochrome-c showed the greatest penetration into axons proximal to the crush. Following injection into the tongue, intra-axonal cytochrome-c was detectable in some of the peripheral branches but not any of the other proteins. Retrograde transport to the nerve cell bodies was demonstrated for horseradish peroxidase and cytochrome-c, both from the tongue and from the axonal crush but not for microperoxidase, myoglobin, hemoglobin, lactoperoxidase and catalase. The number of neuronal cell bodies having detectable reaction product was higher for peroxidase-injected than for cytochrome-c-injected animals. Ferritin and iron-dextran (Imferon) also accumulated in hypoglossal neurons, but this could be detected only after repeated injections into the tongue. Uptake and retrograde transport from the tongue or from the crush occurred both for anionic and for cationic horseradish peroxidase. This is interpreted as evidence against absolute specificity in the uptake and transport of macromolecules on the basis of electrical charge.

A sensitive method for histochemical demonstration of horseradish peroxidase in neurons following retrograde axonal transport

A study was made on the effects of various fixatives and some other histochemical parameters used in the procedure for demonstrating labeled neurons following retrograde axonal transport of horseradish peroxidase (HRP). The enzyme was injected into the tongue of adult mice and the results were obtained by counting labeled hypoglossal neurons following certain variations in the procedure. Paraformaldehyde in the fixative should be avoided since it reduces the number of labeled neurons as compared to glutaraldehyde in a concentration of 1.5-2.5% Fixation for about 4 h is recommended followed by a wash in 5% sucrose buffer overnight. Variables in the histochemical procedure were systematically studied in order to determine optimal pH, buffer type, buffer concentration and substrate concentration. The effect of using a "preincubation" in buffer containing only diaminobenzidine tetrahydrochloride (DAB) was also examined. These results were used to develop a modified histochemical procedure which produced a substantial increase in the number of detectable HRP-labeled neurons as compared to equivalent sections that were reacted in the incubation medium described by Graham and Karnovsky. The modified histochemical procedure involves incubation (no preincubation with DAB only) of sections in the dark for 30 min in a solution consisting of 10 ml cacodylate buffer (pH 5.1;0.1 M), 20 mg DAB and 0.1 ml of 1% hydrogen peroxide. The Kodak Wratten no. 46 filter is recommended for light-microscopical identification of labeled neurons since it is closely matched to the absorption spectrum of the DAB reaction product and consequently greatly increases the contrast of HRP-labeled neurons.