Increased dietary protein in the second trimester of gestation increases live weight gain and carcass composition in weaner calves to 6 months of age.

Genetically similar nulliparous Polled Hereford heifers from a closed pedigree herd were used to evaluate the effects of dietary protein during the first and second trimester of gestation upon foetal, placental and postnatal growth. Heifers were randomly allocated into two groups at 35 days after artificial insemination (35 days post conception (dpc)) to a single bull and fed high (15.7% CP) or low (5.9% CP) protein in the first trimester (T1). At 90 dpc, half of each nutritional treatment group changed to a high- or low-protein diet for the second trimester until 180 dpc (T2). High protein intake in the second trimester increased birth weight in females (P=0.05), but there was no effect of treatment upon birth weight when taken over both sexes. Biparietal diameter was significantly increased by high protein in the second trimester with the effect being greater in the female (P=0.02), but also significant overall (P=0.05). Placental weight was positively correlated with birth weight, fibroblast volume and relative blood vessel volume (P<0.05). Placental fibroblast density was increased and trophoblast volume decreased in the high-protein first trimester treatment group (P<0.05). There was a trend for placental weight to be increased by high protein in the second trimester (P=0.06). Calves from heifers fed the high-protein treatment in the second trimester weighed significantly more on all occasions preweaning (at 1 month (P=0.0004), 2 months (P=0.006), 3 months (P=0.002), 4 months (P=0.01), 5 months (P=0.03), 6 months (P=0.001)), and grew at a faster rate over the 6-month period. By 6 months of age, the calves from heifers fed high nutrition in the second trimester weighed 33 kg heavier than those fed the low diet in the second trimester. These results suggest that dietary protein in early pregnancy alters the development of the bovine placenta and calf growth to weaning.

Follicle stimulating hormone secretion and dominant follicle growth during treatment of Bos indicus heifers with intra-vaginal progesterone releasing devices, oestradiol benzoate, equine chorionic gonadotrophin and prostaglandin F(2α).

The aim of this study was to investigate the effects on follicle stimulating hormone (FSH) secretion and dominant follicle (DF) growth, of treatment of Bos indicus heifers with different combinations of intra-vaginal progesterone releasing devices (IPRD), oestradiol benzoate (ODB), PGF2α and eCG. Two-year-old Brahman (BN; n=30) and Brahman-cross (BNX; n=34) heifers were randomly allocated to three IPRD-treatments: (i) standard-dose IPRD [CM 1.56g; 1.56g progesterone (P4); n=17]; (ii) half-dose IPRD (CM 0.78g; 0.78g P4; n=15); (iii) half-dose IPRD+300IU eCG at IPRD removal (CM 0.78g+G; n=14); and, (iv) non-IPRD control (2×PGF2α; n=18) 500µg cloprostenol on Days -16 and -2. IPRD-treated heifers received 250µg PGF2α at IPRD insertion (Day -10) and IPRD removal (Day -2) and 1mg ODB on Day -10 and Day -1. Follicular dynamics were monitored daily by trans-rectal ultrasonography from Day -10 to Day 1. Blood samples for determination of P4 were collected daily and samples for FSH determination were collected at 12h intervals from Day -9 to Day -2. A significant surge in concentrations of FSH was observed in the 2×PGF2α treatment 12h prior and 48h after follicular wave emergence, but not in the IPRD-treated heifers. Estimated mean concentrations of total plasma P4 during the 8 days of IPRD insertion was greater (P<0.001) in the CM 1.56g P4 treated heifers compared to the CM 0.78g P4 treated heifers (18.38ng/ml compared with 11.09ng/ml, respectively). A treatment by genotype interaction (P=0.036) was observed in the mean plasma P4 concentration in heifers with no CL during IPRD insertion, whereby BN heifers in the CM 1.56g treatment had greater plasma P4 than the BNX heifers on Days-9, -7, -6, -5, and -4. However, there was no genotype effect in the CM 0.78g±G or the 2×PGF2α treatment. Treatment had no effect on the DF growth from either day of wave emergence (P=0.378) or day of IPRD removal (P=0.780) to ovulation. This study demonstrates that FSH secretion in B. indicus heifers treated with a combination of IPRD's and ODB to synchronise ovulation was suppressed during the period of IPRD insertion but no significant effect on growth of the DF was observed.

Interrelationships of nutrition, metabolic hormones and resumption of ovulation in multiparous suckled beef cows on subtropical pastures.

The effect of nutrition before and after calving on metabolic status and the resumption of ovulation postpartum was examined in multiparous sucked beef cows on subtropical pastures. At 6-7 months of gestation, Droughtmaster cows were randomly assigned on body weight (BW) and stage of gestation to two groups that received either standard subtropical pasture (SP, n = 7, 543 ± 12 kg BW) or improved pasture (IP, n = 7, 564 ± 12 kg BW). The two nutritional treatments were maintained after calving. Starting at 1 week after calving, cows were monitored for BW and body condition score (BCS, biweekly) and for circulating concentrations of insulin, glucose, IGF-1, GH and leptin (weekly). Ovarian follicular status was monitored weekly by trans-rectal ultrasonography. Fecal samples were obtained at 3-week intervals to ascertain percentage crude protein (%CP) and dry matter digestibility (DMD) of pastures. Crude protein and DMD were greater (P < 0.05) for cows on IP during the first 9 weeks after calving after which there were no differences between nutritional treatments. Cows on IP were heavier (P < 0.05) and had a greater (P < 0.01) BCS than cows on SP at 1 week after calving (585 ± 9 kg and 3.7 ± 0.2 BCS and 528 ± 21 kg and 2.3 ± 0.2 BCS, respectively). Cows on SP showed a gradual increase in BW and there were no differences in BW after approximately 7 weeks postpartum whilst BCS remained less for cows on SP. Plasma concentrations of insulin, glucose, IGF-1 and leptin were all greater (P < 0.01) for cows on IP compared with cows on SP, whilst GH did not differ. The diameter of the largest follicle did not differ between cows on IP and SP throughout the postpartum period. However, 7 of 7 cows on IP resumed ovulations between 12 and 15 weeks postpartum whilst only 1 of 7 cows on SP had resumed ovulation during the study. It is concluded from the findings that exposure of cows to IP and SP before and after calving resulted in two groups of cows with different metabolic homeostasis and that the greater circulating concentrations of insulin, glucose, IGF-1 and leptin promoted the earlier resumption of ovulation for cows on IP.

Bovine viral diarrhoea virus in beef heifers in commercial herds in Australia: mob-level seroprevalences and incidences of seroconversion, and vaccine efficacy.

OBJECTIVES: To describe management group (mob)-level seroprevalences and incidences of seroconversion to bovine viral diarrhoea virus (BVDV), and to determine the efficacy of a vaccine against BVDV, in beef heifers in commercial herds in Australia. METHODS: Seroprevalences were assessed in 38 mobs of beef heifers. Of them, 15 mobs that were considered to be at higher risk of BVDV transmission during the upcoming mating period underwent further serological monitoring, and were included in a double-blind controlled trial to assess vaccine efficacy. RESULTS: In 66% of mobs, less than half the heifers were seropositive some months before mating start date. However, in only 2 mobs was the incidence of seroconversion during the mating period greater than 10%, with a very high incidence of seroconversion observed in only 1 mob. The pregnancy proportion in placebo-treated heifers in this mob was acceptable (89%), but a high proportion of placebo-treated heifers (26%) had persistently infected calves. The efficacy of the Pestigard® vaccine in preventing the birth of infected calves was estimated as 80%. CONCLUSIONS: Outbreaks of serious BVDV-related disease are relatively uncommon in mobs of beef heifers, but when they occur, the impact can be large. This highlights the need to approach BVDV control from a risk-assessment perspective, where the likelihood and consequences of widespread BVDV infection in a mob are jointly assessed. Pestigard® vaccination of naïve heifers prior to mating reduces the risk of transplacental infection with BVDV if heifers are exposed to BVDV during early pregnancy.

Animal-level factors affecting ovarian function in Bos indicus heifers treated to synchronize ovulation with intravaginal progesterone-releasing devices and oestradiol benzoate.

The primary objective of this study was to investigate the impact of animal-level factors including energy balance and environmental/management stress, on the ovarian function of Bos indicus heifers treated to synchronize ovulation. Two-year-old Brahman (BN) (n = 30) and BN-cross (n = 34) heifers were randomly allocated to three intravaginal progesterone-releasing device (IPRD) treatment groups: (i) standard-dose IPRD [Cue-Mate(®) (CM) 1.56 g; n = 17]; (ii) half-dose IPRD [0.78 g progesterone (P(4)); CM 0.78 g; n = 15]; (iii) half-dose IPRD + 300 IU equine chorionic gonadotrophin at IPRD removal (CM 0.78 g + G; n = 14); (iv) and a control group, 2× PGF(2α) [500 µg prostaglandin F(2α) (PGF(2α))] on Day -16 and -2 (n = 18). Intravaginal progesterone-releasing device-treated heifers received 250 µg PGF(2α) at IPRD insertion (Day -10) and IPRD removal (Day -2) and 1 mg oestradiol benzoate on Day -10 and -1. Heifers were managed in a small feedlot and fed a defined ration. Ovarian function was evaluated by ultrasonography and plasma P(4) throughout the synchronized and return cycles. Energy balance was evaluated using plasma insulin-like growth factor 1 (IGF-I) and glucose concentrations. The impact of environmental stressors was evaluated using plasma cortisol concentration. Heifers that had normal ovarian function had significantly higher IGF-I concentrations at commencement of the experiment (p = 0.008) and significantly higher plasma glucose concentrations at Day -2 (p = 0.040) and Day 4 (p = 0.043), than heifers with abnormal ovarian function. There was no difference between the mean pre-ovulatory cortisol concentrations of heifers that ovulated or did not ovulate. However, heifers that ovulated had higher cortisol concentrations at Day 4 (p = 0.056) and 6 (p = 0.026) after ovulation than heifers that did not ovulate.

Ovarian responses in Bos indicus heifers treated to synchronise ovulation with intravaginal progesterone releasing devices, oestradiol benzoate, prostaglandin F(2α) and equine chorionic gonadotrophin.

The objectives were: (i) improve understanding of the ovarian responses of Bos indicus heifers treated with different ovulation synchronisation protocols, (ii) compare ovarian responses of B. indicus heifers treated with intravaginal progesterone releasing device (IPRD)+oestradiol benzoate (ODB) versus a conventional prostaglandin F(2α) (PGF(2α)) protocol and (iii) investigate whether reducing the amount of progesterone (P(4)) in the IPRD, and treatment with equine chorionic gonadotrophin (eCG) would increase the proportion of heifers with normal ovarian function during the synchronised and return cycles. Two-year-old Brahman (n=30) and Brahman-cross (n=34) heifers were randomly allocated to three IPRD-treatment groups: (i) standard-dose IPRD (Cue-Mate(®) 1.56g P(4); n=17); (ii) half-dose IPRD (Cue-Mate(®) 0.78g P(4); n=15); (iii) half-dose IPRD+300IU eCG at IPRD removal (n=14), and a non-IPRD control group (iv) 2×PGF(2α) (500µg cloprostenol) on Days -16 and -2 (n=18). IPRD-treated heifers received 250µg cloprostenol at IPRD insertion (Day -10) and IPRD removal (Day -2) and 1mg ODB on Days -10 and -1. Ovarian function was evaluated by ultrasonography and plasma P(4) throughout the synchronised and return cycles. The mean diameter of the dominant follicle observed at 54-56h after IPRD removal, was greater for heifers which ovulated than heifers which did not ovulate (P<0.001; 14.5±1.1 vs. 9.3±0.6mm, respectively). The prevalence of IPRD-treated heifers with ovarian dysfunction (persistent CL, failure to re-ovulate, shortened luteal phase) was 39%. This relatively high prevalence of ovarian dysfunction may explain the commonly reported, lower than expected pregnancy rates to FTAI in B. indicus heifers treated to synchronise ovulation.

The impact of stenting obstructing colorectal tumours in a district general hospital.

INTRODUCTION: The technique of stenting malignant obstructing colorectal lesions is established as an acceptable treatment with a low morbidity and mortality. This paper reviews our experience in stenting malignant colorectal obstruction and compares this group with those who underwent emergency surgery as their primary intervention. METHODS: A retrospectively kept database over four years was reviewed and patients who had undergone either stenting or emergency surgery for a malignant colorectal obstruction were identified. These patients' notes were retrieved and reviewed. RESULTS: During the duration of study, a total of 29 stents were placed in 28 patients, with a mean age of 78 y (range 59-96 years). Patients generally had significant co-existing morbidity, with a median ASA score of 2.5. The timing of stent placement was a mean of 3.4 days (1-9 days) after presentation, including time for relevant investigation and diagnosis. Mean length of hospital stay was 9.8 days (2-36 days). In the emergency operation category, during the period of study, a total of 38 patients had operations for large bowel obstruction, either because the lesion was not suitable for stenting, or the personnel for stenting were not available. These patients ranged in age from 45 to 96 years, with a mean age of 72.4 years. Patients in this group were generally a little fitter than the stented group, with a median ASA grade of 2, and 14/38 patients were ASA1 (the largest group). Despite this Post-operative recovery was slow with these patients, the average length of stay being 16 days (range 8-66 days). CONCLUSIONS: In this study, we report our data on the first four years of stenting malignant bowel obstruction. It is a feasible and acceptable means of treatment, and we have demonstrated comparable morbidity and mortality to that reported in medical literature. The technique may avoid the need for emergency operation with its concomitant risks, lengthy in-patient stay, and high likelihood for a stoma. We would advocate the use of self expanding metal stents where appropriate in the management of large bowel obstruction.

Unidentified retained inferior vena cava myxoma detected by intra-operative trans-oesophageal echocardiography.

We report a unilateral right atrial familial myxoma with a multicentric nature discovered during cardiac surgery. After the patient was weaned off cardiopulmonary bypass, an inferior vena cava myxoma was discovered with intra-operative trans-oesophageal echocardiogram (TOE) which had been missed preoperatively and during surgery.

Does the amount of progesterone in intravaginal implants used to synchronise oestrus affect the reproductive performance of Brahman heifers artificially inseminated at a fixed time.

The study tested the hypothesis that reduced intravaginal implant progesterone (P(4)) concentration to synchronise oestrus would increase pregnancy rates to fixed-time artificial insemination (FTAI) in Bos indicus heifers. Brahman heifers (n = 294; 2 year) were body condition scored (BCS), weighed and scanned for presence of a corpus luteum (CL). Only cyclic heifers were selected and allocated randomly within BCS and 25 kg bodyweight category to one of three P(4) treatment groups. On day 10, heifers received a P(4) implant (CueMate-1-pod, 0.78 g P(4); CueMate-2-pod, 1.56 g P(4); or CIDR-B, 1.9 g P(4)), 2 mg oestradiol benzoate (ODB) intramuscularly (i.m.) and 250 ug cloprostenol i.m.. At day 2, the implant was removed, 250 ug cloprostenol was injected i.m. and tail paint applied. The heifers received 1 mg ODB 24 h later and were FTAI 48-54 h after implant removal (day 0). Ten randomly selected heifers per group were blood sampled and scanned at days 10, 2, 0 and 6 to define the P(4) profiles pre- and post-FTAI. Heifers were heat-detected 18-20 days post-FTAI and oestrous heifers AI'd by the AM/PM rule. Bulls joined the heifers on day 27 post-FTAI. Transrectal ultrasonography estimated conception date on day 72. Statistical analysis examined the effects of treatment, technician, semen, ovarian status, BCS and liveweight, on pregnancy rate (PR) to FTAI. There was no significant difference (p = 0.362) in PR between treatment groups (CueMate 1-pod, 36.4%; CueMate 2-pod, 39.6%: CIDR-B, 28.3%), but PR was higher in those heifers with increased BCS between FTAI and pregnancy diagnosis (p = 0.005). Thirty-three per cent of monitor heifers had plasma P(4) concentrations of <1 ng/ml on day 6 after FTAI; only 20% of these conceived vs 60% of heifers with P(4) ≥ 1 ng/ml. In summary, no significant difference in PR was identified between treatments but good BCS and a rising plane of nutrition were critical to PR of these pure grade Brahman heifers in northern Australia.

Use of vaginal electrical resistance to diagnose oestrus, dioestrus and early pregnancy in synchronized tropically adapted beef heifers.

The primary objective of this study was to determine whether a single measurement of intravaginal electrical resistance (VER), using the commercially available Ovatec probe, can discriminate between dioestrus and oestrus in Bos indicus females, which had been treated to synchronize oestrus. Santa Gertrudis heifers (n = 226) received one of three oestrous synchronization treatments: double PGF(2alpha) 10 days apart, 8-day controlled internal drug release (CIDR) treatment or CIDR pre-synchronization + PGF(2alpha) 10 days after CIDR removal. The heifers were inseminated within 12 h following observed oestrus, or, if not observed, at a fixed time approximately 80 h, following the last synchronization treatment. They were palpated per rectum for signs of pregnancy 9 weeks after artificial insemination (AI). Vaginal electrical resistance measurements were taken at the completion of synchronization treatments (presumed dioestrus), immediately prior to AI (oestrus), and then at 3 and 9 weeks post-AI. Mean VER differed between presumed dioestrus and oestrus (113.7 vs 87.4, p < 0.001). The area under the receiver operating characteristics (ROC) curve was 0.925, indicating that VER was highly discriminatory between dioestrus and oestrus. Vaginal electrical resistance at time of AI was negatively associated with odds of conception when all inseminations were included in the analyses [odds ratio (OR) = 0.97; 95% CI 0.95-1.00; p = 0.018], but not when fixed time AIs were excluded (OR = 1.00; 95% CI 0.97-1.03; p = 0.982). Mean VER readings differed between pregnant and non-pregnant animals at both 3 weeks (120.5 vs 96.7, p < 0.001) and 9 weeks (124.0 vs 100.3, p < 0.001) post-AI. However, 3- and 9-week VER measurements were not highly discriminatory between pregnancy and non-pregnancy (area under ROC curve = 0.791 and 0.736, respectively). Mean VER at time of AI for animals diagnosed in oestrus differed between each of the oestrous synchronization treatments (84.7, 73.6 and 78.9, groups 1-3 respectively, p < 0.001). These findings suggest that measurement of VER may improve accuracy of oestrus diagnoses when selecting cattle for AI following oestrous synchronization programmes involving tropically adapted cattle.

Dietary protein during gestation affects placental development in heifers.

The influence of nutritional protein during the first and second trimesters of pregnancy on placental measures at term and caruncle numbers in the uteri of adult offspring was determined in composite beef heifers. At artificial insemination (AI), heifers were divided by weight and composite genotype into four dietary treatment groups, identified by the level of protein components fed during the first and second trimesters: high/high (HH), high/low (HL), low/high (LH), low/low (LL). Expelled placentas were collected and weighed, and cotyledons were dissected, counted, weighed, and measured. Uteri from mature female offspring were dissected at slaughter and caruncles counted. The number of cotyledons in the expelled placenta was increased by high dietary protein in the second trimester (P=0.02) and varied with genotype (P=0.03). Placental weight was influenced by maternal undernutrition during early gestation dependent on dam genotype (P=0.001). Placental efficiency, as determined by calf weight:placental weight, increased with dam age (P=0.03). Calf birth weight was closely associated with placental weight (P=0.002) and cotyledonary weight (P=0.001) and surface area (P=0.04), but not with the number of cotyledons. Leptin concentrations during early (R=-0.29) and late gestation (R=-0.25) correlated with placental weight, and Insulin-like growth factor binding proteins throughout gestation correlated with the number of cotyledons (R=-0.28 to-0.33). The number of uterine caruncles in the nonpregnant adult offspring did not correlate with the dam's genotype, nutrition treatment, or cotyledon number in the expelled placenta.

Nontypeable Haemophilus influenzae strain 2019 produces a biofilm containing N-acetylneuraminic acid that may mimic sialylated O-linked glycans.

Previous studies suggested that nontypeable Haemophilus influenzae (NTHI) can form biofilms during human and chinchilla middle ear infections. Microscopic analysis of a 5-day biofilm of NTHI strain 2019 grown in a continuous-flow chamber revealed that the biofilm had a diffuse matrix interlaced with multiple water channels. Our studies showed that biofilm production was significantly decreased when a chemically defined medium lacking N-acetylneuraminic acid (sialic acid) was used. Based on these observations, we examined mutations in seven NTHI strain 2019 genes involved in carbohydrate and lipooligosaccharide biosynthesis. NTHI strain 2019 with mutations in the genes encoding CMP-N-acetylneuraminic acid synthetase (siaB), one of the three NTHI sialyltransferases (siaA), and the undecaprenyl-phosphate alpha-N-acetylglucosaminyltransferase homolog (wecA) produced significantly smaller amounts of biofilm. NTHI strain 2019 with mutations in genes encoding phosphoglucomutase (pgm), UDP-galactose-4-epimerase, and two other NTHI sialyltransferases (lic3A and lsgB) produced biofilms that were equivalent to or larger than the biofilms produced by the parent strain. The biofilm formed by the NTHI strain 2019pgm mutant was studied with Maackia amurensis fluorescein isothiocyanate (FITC)-conjugated and Sambucus nigra tetramethyl rhodamine isocyanate (TRITC)-conjugated lectins. S. nigra TRITC-conjugated lectin bound to this biofilm, while M. amurensis FITC-conjugated lectin did not. S. nigra TRITC-conjugated lectin binding was inhibited by incubation with alpha2,6-neuraminyllactose and by pretreatment of the biofilm with Vibrio cholerae neuraminidase. Matrix-assisted laser desorption ionization-time of flight mass spectometry analysis of lipooligosaccharides isolated from a biofilm, the planktonic phase, and plate-grown organisms showed that the levels of most sialylated glycoforms were two- to fourfold greater when the lipooligosaccharide was derived from planktonic or biofilm organisms. Our data indicate that NTHI strain 2019 produces a biofilm containing alpha2,6-linked sialic acid and that the sialic acid content of the lipooligosaccharides increases concomitant with the transition of organisms to a biofilm form.

Relationship between thirty post-thaw spermatozoal characteristics and the field fertility of 11 high-use Australian dairy AI sires.

This study determined the relationship between two measures of field fertility of 11 high-use Australian artificial insemination (AI) dairy bulls and thirty standard laboratory assessments of spermatozoal post-thaw viability. The two measures of field fertility used, conception rates (cCR) and non-return rates (cNRR), were both corrected for all major non-bull variables. Sperm viability assessments were conducted on semen collected within the same season as that used to derive the field fertility estimates. These assessments measured sperm concentration, motility, morphology and membrane integrity at thawing, after 2h incubation and after the swim-up sperm selection procedure. Derivations of these measures and in vitro embryo fertilizing and developmental capacity were also determined. The Genstat Statistical Package [Genstat 5 Release 4.2 Reference Manual, VSN International, Oxford, 2000] was used to conduct an analysis of variance on the viability parameters across semen straws and bulls, and to calculate the strength of correlation between each semen parameter, cNRR and cCR in a correlation matrix. Step forward multiple regression identified the combination of semen parameters that were most highly correlated with cCR and with cNRR. The sperm parameters identified as being most predictive of cCR were the percentage of morphologically normal sperm immediately post-thaw (zeroNorm), the number of morphologically normal sperm after the swim-up procedure (nSuNorm), and the rate of zygote cleavage in vitro (Clv); the predictive equation formed by these parameters accounted for 70% of variance. The predictive equation produced for cNRR contained the variables zeroNorm, the proportion of membrane intact sperm after 2h incubation at 37 degrees C (twoMem) and Clv and accounted for 76.5% of the variation. ZeroNorm was found to be consistent across straws and semen batches within-bull and the sperm parameter with the strongest individual predictive capacity for both cCR (P=0.1) and cNRR (P=0.001). Post-thaw sperm parameters can be used to predict field fertility of Australian dairy sires; the calculated predictive equations are particularly useful for identifying and monitoring bulls of very high and very low potential fertility within a group.

Treatment of primary degenerative arthritis of the elbow by ulnohumeral arthroplasty. A long-term follow-up.

Between 1990 and 1996 we performed 20 consecutive ulnohumeral arthroplasties for primary osteoarthritis of the elbow. The outcome was assessed using the Disabilities of Arm, Shoulder and Hand Score (DASH) and the Mayo Elbow Performance Score (MEPS) at a mean follow-up of 75 months (58 to 132). There were excellent or good results in 17 elbows (85%) using the DASH score and in 13 (65%) with the MEPS (correlation coefficient 0.79). The mean fixed flexion deformity had improved by 10 degrees and the range of flexion by a mean of 20 degrees. In 16 elbows (80%) the benefits of surgery had been maintained, and of 16 patients working at the time of operation, 12 (75%) had returned to the same job. There was no correlation between radiological recurrence of degenerative changes and the amount of fixed flexion deformity, the flexion arc, or the elbow scores.

Renal function, plasma homocysteine and carotid atherosclerosis in elderly people.

Although epidemiological studies suggest that people with minor impairment of renal function are at higher risk of stroke and coronary heart disease, the mechanisms underlying this relation are unclear. One explanation may lie with observations that deterioration in renal function is accompanied by elevations in plasma homocysteine concentrations. There is evidence that moderate hyperhomocysteinemia may play a causal role in atherosclerotic disease. We investigated the relations between renal function, plasma homocysteine and atherosclerosis of the carotid arteries in 128 men and women aged 69-74 years. Renal function was assessed by creatinine clearance and serum creatinine. Duplex ultrasonography was used to quantify the degree of stenosis in the extracranial carotid arteries. Severity of carotid atherosclerosis was greatest in men and women with the poorest renal function, whether measured by creatinine clearance or serum creatinine. After adjustment for plasma homocysteine, pulse pressure and other cardiovascular risk factors, the odds ratio for having carotid stenosis >30% was 4.3 (95% CI 1.4-12.9) in those whose creatinine clearance rate was 55 ml/min or less compared with those whose creatinine clearance rate was >73 ml/min. Even small decrements in renal function were associated with increased risk; people whose creatinine clearance rate was between 56 and 73 ml/min had an odds ratio of 3.8 (95% CI 1.2-11.9). Plasma homocysteine concentrations were significantly higher in people with poorer renal function, but they did not explain the associations we found between carotid atherosclerosis and creatinine clearance or serum creatinine.

Holographic optical elements recorded in silver halide sensitized gelatin emulsions. Part I. Transmission holographic optical elements.

Silver halide sensitized gelatin (SHSG) holograms are similar to holograms recorded in dichromated gelatin (DCG), the main recording material for holographic optical elements (HOE's). The drawback of DCG is its low sensitivity and limited spectral response. Silver halide materials can be processed in such a way that the final hologram will have properties like a DCG hologram. Recently this technique has become more interesting since the introduction of new ultra-high-resolution silver halide emulsions. An optimized processing technique for transmission HOE's recorded in these materials is introduced. Diffraction efficiencies over 90% can be obtained for transmissive diffraction gratings. Understanding the importance of the selective hardening process has made it possible to obtain results similar to conventional DCG processing. The main advantage of the SHSG process is that high-sensitivity recording can be performed with laser wavelengths anywhere within the visible spectrum. This simplifies the manufacturing of high-quality, large-format HOE's.

Writing long holographic diffraction gratings by use of a novel scanning method.

A novel method for writing holographic diffraction gratings is proposed in which the two interfering beams are moved together across the recording medium in such a way that the interference pattern at the medium is unchanged. The phase compensation is discussed both for an idealized setup and for a realistic experimental arrangement.

Mass spectral characterization of lipooligosaccharides from Haemophilus influenzae 2019.

Lipooligosaccharide (LOS) glycoforms from Haemophilus influenzae 2019 were profiled using the high-resolution and accurate mass capabilities of Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometry. Sequence and linkage for two previously unknown LOS glycoforms were subsequently obtained through MSn analyses on FT-ICR and quadrupole ion trap (qIT) instruments. MSn analysis of negative ion precursors confirmed structural details within the lipid moiety, while CID spectra of sodiated precursor ions provided monosaccharide sequence and linkage for the oligosaccharide portion of the molecule. Results obtained in this study indicate that extensive heterogeneity exists within the oligosaccharide moieties in LOS from H. influenzae 2019. More importantly, the data suggest that additional hexose moieties, which are added onto the LOS, are not simple extensions of one particular core structure but rather that structural isomers with different connectivities are present within the heterogeneous mixture.