International trade standards for commodities and products derived from animals: the need for a system that integrates food safety and animal disease risk management.

A case is made for greater emphasis to be placed on value chain management as an alternative to geographically based disease risk mitigation for trade in commodities and products derived from animals. The geographic approach is dependent upon achievement of freedom in countries or zones from infectious agents that cause so-called transboundary animal diseases, while value chain-based risk management depends upon mitigation of animal disease hazards potentially associated with specific commodities or products irrespective of the locality of production. This commodity-specific approach is founded on the same principles upon which international food safety standards are based, viz. hazard analysis critical control points (HACCP). Broader acceptance of a value chain approach enables animal disease risk management to be combined with food safety management by the integration of commodity-based trade and HACCP methodologies and thereby facilitates 'farm to fork' quality assurance. The latter is increasingly recognized as indispensable to food safety assurance and is therefore a pre-condition to safe trade. The biological principles upon which HACCP and commodity-based trade are based are essentially identical, potentially simplifying sanitary control in contrast to current separate international sanitary standards for food safety and animal disease risks that are difficult to reconcile. A value chain approach would not only enable more effective integration of food safety and animal disease risk management of foodstuffs derived from animals but would also ameliorate adverse environmental and associated socio-economic consequences of current sanitary standards based on the geographic distribution of animal infections. This is especially the case where vast veterinary cordon fencing systems are relied upon to separate livestock and wildlife as is the case in much of southern Africa. A value chain approach would thus be particularly beneficial to under-developed regions of the world such as southern Africa specifically and sub-Saharan Africa more generally where it would reduce incompatibility between attempts to expand and commercialize livestock production and the need to conserve the subcontinent's unparalleled wildlife and wilderness resources.

Balancing livestock production and wildlife conservation in and around southern Africa's transfrontier conservation areas.

Biodiversity conservation, of which the transfrontier conservation area movement is an integral part, and more effective livestock production/trade are pivotal to future rural development in southern Africa. For that reason, it is imperative to effectively ameliorate the obstacles that have impeded progress towards the coexistence of these two sectors for more than half a century. Transboundary animal diseases, foot and mouth disease in particular, have been and continue to be the most important of these obstacles. Fortunately, new developments in international sanitary standards applicable to trade in commodities and products derived from animals are beginning to make a solution possible. However, while progress in principle has been achieved, practical implementation remains problematic for technical reasons, exacerbated by inconsistent attitudes towards acceptance of non-traditional international trade standards. This paper describes the background to this situation, progress that has been achieved in the recent past and remaining difficulties that need to be overcome to advance towards achievement of balanced rural development in southern Africa.

Cadmium, copper, iron, and zinc concentrations in kidneys of grey wolves, Canis lupus, from Alaska, Idaho, Montana (USA) and the Northwest Territories (Canada).

Cadmium, copper, iron, and zinc levels were measured in the kidneys of 115 grey wolves (Canis lupus) from Idaho, Montana and Alaska (United States), and from the Northwest Territories (Canada). No significant differences in the levels of iron or copper were observed between locations, but wolf kidneys from more northern locations had significantly higher cadmium levels (Alaska > Northwest Territories > Montana ≈ Idaho), and wolves from Alaska showed significantly higher zinc than other locations. Additionally, female wolves in Alaska had higher iron levels than males, and adult wolves in Montana had higher copper levels than subadults.

Semen cryopreservation in the Indian rhinoceros (Rhinoceros unicornis).

The objective was to identify an extender and cryoprotectant combination for Indian rhinoceros (Rhinoceros unicornis) sperm that yielded high post-thaw sperm quality. Male Indian rhinoceroses (n=6; 7.5-34 yr old) were anesthetized and subjected to a regimented electroejaculation procedure (75-100 mAmps; 4-10 volts; 7-150 stimuli; total of 10 electroejaculation procedures). High quality semen fractions from each ejaculate were divided into four aliquots and a 2 x 2 factorial design used to compare the effect of two sperm extenders (standard equine [EQ] and skim milk-egg-yolk-sugar [SMEY]), and two cryoprotectants (glycerol and dimethylsulfoxide [DMSO]). Cyropreserved samples were thawed and assessed for motility, viability and acrosome integrity over time. Electroejaculate fractions processed for cryopreservation had high sperm concentration (516 x 10(6)/mL) and motility (79%). Post-thaw sperm characteristics were higher (P<0.05) when semen was cryopreserved in EQ versus SMEY. Post-thaw motility of sperm cyropreserved in EQ averaged 50-55% compared to 22-37% in SMEY, with no significant differences in sperm characteristics of samples cyropreserved in glycerol and DMSO. In conclusion, sperm collected from Indian rhinoceroses via electroejaculation were cryopreserved using EQ extender with either glycerol or DMSO; post-thaw quality was adequate for use in assisted reproductive procedures.

Single vs weekly courses of antenatal corticosteroids for women at risk of preterm delivery: A randomized controlled trial.

CONTEXT: The practice of administering weekly courses of antenatal corticosteroids to pregnant women at risk of preterm delivery is widespread, but no randomized trial has established the efficacy or safety of this practice. OBJECTIVES: To evaluate the efficacy of weekly administration of antenatal corticosteroids compared with a single course in reducing the incidence of neonatal morbidity and to evaluate potential complications of weekly treatment. DESIGN AND SETTING: Randomized, double-blind, placebo-controlled intention-to-treat trial conducted in 13 academic centers in the United States from February 1996 through April 2000. PARTICIPANTS: A total of 502 pregnant women between 24 and 32 completed weeks' gestation who were at high risk of preterm delivery. INTERVENTION: All patients received a complete single course of antenatal corticosteroids (either betamethasone, 12 mg intramuscularly repeated once in 24 hours for 2 doses, or dexamethasone, 6 mg intramuscularly repeated every 12 hours for 4 doses). Participants who had not delivered 1 week after receipt of the single course were randomly assigned to receive either betamethasone, 12 mg intramuscularly repeated once in 24 hours for 2 doses every week until 34 weeks' gestation or delivery, whichever came first (n = 256), or a similarly administered placebo (n = 246). MAIN OUTCOME MEASURE: Composite neonatal morbidity (including severe respiratory distress syndrome, bronchopulmonary dysplasia, severe intraventricular hemorrhage, periventricular leukomalacia, proven sepsis, necrotizing enterocolitis, or perinatal death). RESULTS: Composite morbidity occurred in 22.5% of the weekly-course group vs 28.0% of the single-course group (unadjusted relative risk, 0.80; 95% confidence interval, 0.59-1.10). Neither group assignment nor the number of treatment courses was associated with a reduction in composite morbidity. CONCLUSIONS: Weekly courses of antenatal corticosteroids did not reduce composite neonatal morbidity compared with a single course of treatment. Weekly courses of antenatal corticosteroids should not be routinely prescribed for women at risk of preterm delivery.

Species-specific sperm-egg interaction affects the utility of a heterologous bovine in vitro fertilization system for evaluating antelope sperm.

The purpose of this study was to evaluate cryopreserved fringe-eared (FE) oryx (Oryx gazella callotis) sperm function using a heterologous in vitro fertilization (IVF) system previously developed to study scimitar-horned (SH) oryx (Oryx dammah) spermatozoa. Semen was collected by electroejaculation from FE oryx (n = 2) and SH oryx (n = 2), evaluated immediately postcollection, and cryopreserved. Thawed spermatozoa were evaluated for motility, forward progression, and acrosomal status immediately post-thaw, after Percoll-separation, and 1, 2, 3, and 8 h after culture in IVF medium. In vitro-matured cow oocytes (n = 924) were inseminated with either domestic bull, FE, or SH oryx spermatozoa and after an 8-h coincubation period, half the oocytes were fixed and examined for sperm penetration, polyspermy, and male pronuclear formation. The remaining oocytes were placed into in vitro culture and evaluated for cleavage after 48 h. Overall, there were no between-species differences in sperm motility and acrosome integrity. However, an effect of time (P < 0.05) and a species-by-time interaction (P < 0.05) were detected for both parameters. Penetration, male pronuclear formation, and embryo cleavage were high (>90%, >85%, and >70%, respectively) for oocytes inseminated with domestic bull and SH oryx spermatozoa and did not differ (P > 0.05) between species. In contrast, very few oocytes (2.8%, 4 of 141) inseminated with FE oryx sperm were penetrated. Cleavage was rare (8.0%, 16 of 200) in oocytes inseminated with FE oryx spermatozoa and did not differ (P > 0.05) from that in parthenogenetic controls (4.2%, 3 of 72). Furthermore, FE oryx spermatozoa were incapable of penetrating zona-free cow oocytes. These results indicate that species-specific differences in gamete interaction may exist even between very closely related nondomestic bovids.

Melting corneal ulcer management in a greater one-horned rhinoceros (Rhinoceros unicornis).

Acute unilateral keratomalacia, probably secondary to trauma, occurred in a greater one-horned rhinoceros (Rhinoceros unicornis) transferred between zoologic facilities. Following 2 days of medical treatment, a 360 degrees conjunctival surgical graft was performed. Staphylococcus and yeast were isolated from a perioperative culture of the affected eye and were treated with antimicrobials. There was rapid healing and minimal midcorneal scar formation with peripheral corneal clarity.

Comparing ovulation synchronization protocols for artificial insemination in the scimitar-horned oryx (Oryx dammah).

Ovarian response and pregnancy success in scimitar-horned oryx (n=28) were compared, following treatment with two synchronization protocols and fixed-time artificial insemination (AI) with frozen-thawed semen. Each oryx received two injections of 500 microg of prostaglandin-F(2alpha) analogue (PGF(2alpha)-only) 11 days apart, and half received PGF(2alpha) in combination with an intravaginal progesterone-releasing device (CIDR11+PGF(2alpha)). Semen was collected by electroejaculation from anaesthetised adult oryx and cryopreserved. Anaesthetised females were transcervically inseminated 56.0+/-1.1 h (+/-S.E.M.) after PGF(2alpha) injection and/or device withdrawal using 28.0+/-1.5x10(6) motile thawed sperm. Ovarian endocrine response was monitored in 20 females by analysing faecal oestrogen and progesterone metabolites. Periovulatory oestrogen peaks were detected in 19/20 (95%) females after synchronization. There were no between-treatment differences in oestrogen concentrations or peak characteristics (P0.05). Luteal development after synchronization was delayed in half the progesterone treated (CIDR11+PGF(2alpha)) females, and faecal progestin excretion profiles indicated that the ovulatory follicle associated with synchronization either failed to ovulate or to fully lutenise. Pregnancy was diagnosed by ultrasonography and/or rectal palpation and was monitored by faecal progestin excretion. More (P=0. 013) pregnancies resulted from the PGF(2alpha)-only treatment (37.5%, 5/14) than from the CIDR11+PGF(2alpha) treatment (0/14), and four healthy scimitar-horned oryx calves were born, three after gestation intervals of 247 days and one after 249 days.

Fetal anatomy revealed with fast MR sequences.

Although all the imaging studies in this pictorial essay were done for maternal rather than fetal indications, fetal anatomy was well visualized. However, when scans are undertaken for fetal indications, fetal motion in between scout views and imaging sequences may make specific image planes difficult to obtain. Of the different techniques described in this review, we preferred the HASTE technique and use it almost exclusively for scanning pregnant patients. The T2-weighting is ideal for delineating fetal organs. Also, the HASTE technique allows images to be obtained in 430 msec, limiting artifacts arising from maternal and fetal motion. MR imaging should play a more important role in evaluating equivocal sonographic cases as fast scanning techniques are more widely used. Obstetric MR imaging no longer will be limited by fetal motion artifacts. When complex anatomy requires definition in a complicated pregnant patient, MR imaging should be considered as a useful adjunct to sonography.

Improved outcomes for very low birth weight infants associated with the use of combined maternal corticosteroids and tocolytics.

OBJECTIVE: To determine the effects of maternal antenatal treatment with tocolytics, corticosteroids and the use of combined tocolytics and corticosteroids on the morbidity and mortality of very low birth weight infants. STUDY DESIGN: This retrospective study was conducted on all infants born in Tennessee in 1989 and 1990 who weighed < 1,500 g at birth and had no serious malformations. Registered nurses traveled to the delivery hospitals of all study subjects and abstracted information using a structured data collection form. Mortality was ascertained through the computerized linkage of birth and death certificates. Multiple logistic regression analysis was used to control for covariates. RESULTS: As compared to infants whose mothers received no treatment, infants whose mothers received both corticosteroids and tocolysis had a reduced risk of infant (odds ratio 0.38, 95% confidence interval 0.25-0.58) and neonatal mortality (OR 0.32, CI 0.19-0.51) as well as a reduced risk of seizures (OR 0.46, CI 0.23-0.93). Restricting the analysis of infants at 24-28 weeks' gestation and < 1,000 g at birth revealed similar findings regarding mortality. CONCLUSION: The use of combined corticosteroids with tocolytics was associated with better neonatal outcomes than the use of corticosteroids alone, tocolytics alone or no treatment.

Dynamics of the fetal adrenal, cholesterol, and apolipoprotein B responses to antenatal betamethasone therapy.

OBJECTIVE: Prior studies suggest that fetal plasma cholesterol is regulated in part by the rate of uptake and utilization of low-density lipoprotein cholesterol by the fetal adrenals for use in steroid biosynthesis. Direct evidence for this phenomenon and the kinetics of this process is, however, virtually impossible to obtain in a controlled experiment in the developing human. In the current study we sought to take advantage of the anticipated transient inhibition of the hypothalamic-pituitary-adrenal axis that occurs after antenatal therapy with glucocorticosteroids, to evaluate the temporal relationship between fetal adrenal steroids and plasma lipoprotein cholesterol levels in umbilical cord blood at delivery. STUDY DESIGN: Umbilical cord serum was obtained at delivery from 136 infants (30.5 +/- 2.7 weeks' gestation) who previously had been treated in utero with betamethasone, 12 mg per 12 or 24 hours for one or two doses and from 308 preterm infants (30.5 +/- 2.1 weeks) who had not been exposed to such therapy. We quantified the concentrations of dehydroepiandrosterone sulfate and cortisol as representative fetal adrenal steroids and also measured the total cholesterol and apolipoprotein B; the relationship between the steroids and lipids as a function of the interval between initial treatment and delivery was analyzed. RESULTS: Umbilical cord levels of dehydroepiandrosterone sulfate and cortisol were significantly reduced within the first 24 hours after initial treatment and remained significantly lower than in control infants through 4 days after initial treatment. In contrast, serum levels of cholesterol were significantly increased 3 to 4 days after treatment but fell on day 5. Serum levels of apolipoprotein B generally followed the same pattern as cholesterol. Cholesterol levels also were higher than normal in infants delivered >1 week after initial betamethasone treatment. CONCLUSIONS: The results of this study are consistent with the view that the plasma cholesterol pool in the fetus is regulated, at least in part, by the rate of uptake of low-density lipoprotein cholesterol and utilization by the fetal adrenals as substrate for steroidogenesis. Betamethasone also may influence cholesterol and lipoprotein synthesis in the fetus.

The effect of manual removal of the placenta on post-cesarean endometritis.

OBJECTIVE: To determine if intraoperative glove change and placental delivery method affect the post-cesarean endometritis rate. METHODS: After informed consent, women who required cesarean were randomly assigned to one of four study groups: 1) no glove change plus manual placental extraction, 2) no glove change plus spontaneous placental delivery, 3) glove change plus manual extraction, and 4) glove change plus spontaneous delivery. Bilateral glove change by both primary and assistant surgeons occurred immediately after delivery of the newborn and before delivery of the placenta. External uterine massage and traction on the umbilical cord were performed to assist spontaneous delivery of the placenta. A first-generation cephalosporin was routinely administered after umbilical cord clamping for prophylaxis of post-cesarean endometritis. RESULTS: Of 760 women entered into the study, we included 643 who did not have intrapartum chorioamnionitis or cesarean hysterectomy. The four groups were comparable with respect to selected maternal and intrapartum characteristics, including maternal and gestational age, parity, presence of labor, and the presence and duration of membrane rupture. The postoperative endometritis rate was significantly higher in women whose placentas were extracted manually (31 versus 22%, P = .01). Operator glove change did not alter the incidence of endometritis (relative risk 1.0, 95% confidence interval 0.79-1.3). CONCLUSION: Manual extraction of the placenta is associated with a significantly greater risk of post-cesarean endometritis than that observed with assisted spontaneous placental delivery. Intraoperative glove change does not decrease post-cesarean endometritis.

Does magnesium sulfate affect the length of labor induction in women with pregnancy-associated hypertension?

OBJECTIVE: Our purpose was to determine whether seizure prophylaxis with magnesium sulfate prolongs induction of labor in women with pregnancy-associated hypertension. STUDY DESIGN: Women with a singleton pregnancy in vertex presentation between 32 and 42 weeks' gestation who required induction of labor for either preeclampsia, preeclampsia superimposed on chronic hypertension, or transient hypertension were randomized to receive either magnesium sulfate or phenytoin (Dilantin) for seizure prophylaxis. Women with rupture of the membranes, spontaneous contractions resulting in cervical change, or an initial cervical examination showing > 2 cm dilatation and 50% effacement were excluded. RESULTS: Fifty-four women were randomized to receive either magnesium sulfate (n = 28) or phenytoin (n = 26). The two groups were similar for selected maternal antepartum, intrapartum, and postpartum characteristics that have been associated with a prolongation or failure of labor induction. The two groups were also similar for the interval from the start of induction to (1) the first examination > or = 5 cm cervical dilatation and (2) delivery and in the frequency of women requiring cesarean delivery. CONCLUSION: Compared with phenytoin, magnesium sulfate seizure prophylaxis in women with pregnancy-associated hypertension does not prolong the induction of labor nor does it result in an increase in cesarean deliveries.

The relation between magnesium sulfate therapy and fetal heart rate variability.

OBJECTIVE: To determine the relation between magnesium sulfate therapy and fetal heart rate (FHR) variability. METHODS: Twelve women diagnosed with preeclampsia who were to receive magnesium sulfate for seizure prophylaxis were recruited. Exclusion criteria included delivery anticipated within 2 hours, gestational age less than 28 weeks, abnormal fetal testing, fetal growth retardation, and use of illicit drugs or medications. Six grams of magnesium sulfate in 100 mL 0.9% saline was administered intravenously over 20 minutes, followed by a continuous infusion of 2 g/hour. A cardiotocogram analysis computer system was used to analyze various elements of the FHR pattern before, during, immediately after, and 60 minutes following magnesium sulfate loading. For each time interval, the basal heart rate, number of accelerations and decelerations, number of minutes of high and low variability, mean minute range variation, and the short-term (3.75-second interval) variability were measured. RESULTS: There was a statistically significant decrease in short-term variability 60 minutes after initiation of therapy (6.7 +/- 2.0 versus 9.8 +/- 3.3 milliseconds; P = .003). Long- and medium-term variability did not change significantly after magnesium sulfate was administered. CONCLUSION: Although magnesium sulfate therapy was associated with an objectively measured, statistically significant decrease in short-term variability, the decrease was not clinically significant; furthermore, it was not associated with a decrease in long-term variability or in the number of accelerations measured.

The predictive value of umbilical artery Doppler studies for preeclampsia or fetal growth retardation in a preeclampsia prevention trial.

OBJECTIVE: To determine the clinical utility of longitudinal Doppler umbilical artery systolic-diastolic ratios (S/D) to predict the occurrence of either preeclampsia or fetal growth retardation (FGR) in a low-risk population. METHODS: Healthy nulliparas with singleton gestations were enrolled in a double-blind trial of low-dose (60 mg) aspirin for preeclampsia prevention. Treatment was initiated at 24 weeks and continued until delivery. Continuous-wave Doppler studies were scheduled before assignment to treatment and at 27-31, 32-36, and 37-42 weeks. Preeclampsia was defined as a persistent diastolic blood pressure of at least 90 mmHg with proteinuria, and FGR was defined as birth weight below the tenth percentile. Doppler values were considered abnormal if they exceeded the 90th percentile for the gestational age range in the study population. Summary predictive values were computed for the abnormal S/D at each gestational age interval. To assess the potential effect of the administration of low-dose aspirin, logistic regression was used to model the relation between the Doppler indices, aspirin use, and these abnormal pregnancy outcomes. RESULTS: A total of 1665 Doppler examinations were performed on 565 women. Forty-four fetuses developed FGR and 21 women were diagnosed with preeclampsia. The positive predictive values of an abnormal S/D for the subsequent development of FGR were 13-17% across the gestational age ranges studied, and the positive predictive values for preeclampsia were 0-5%. Aspirin treatment did not affect the relation between the Doppler indices and these outcomes in the logistic regression model. CONCLUSION: Elevated umbilical artery S/D is not a clinically useful predictor of either FGR or preeclampsia in a low-risk population.

Osteosarcoma of the larynx.

A case of laryngeal osteosarcoma in a 75-year-old man is described. The osteosarcoma probably arose by dedifferentiation of a chondrosarcoma of the cricoid cartilage. Laryngeal osteosarcoma is rare: the literature is reviewed and management discussed.

Morphometric analysis, ploidy and response to chemotherapy in squamous carcinomas of the head and neck.

The histopathology of 54 squamous carcinomas of the head and neck was evaluated by qualitative grading and morphometry in order to identify those features which predicted a good response to cisplatinum chemotherapy. The histopathology of 66 cases was correlated with tumour ploidy, determined by flow cytometry of paraffin-embedded material, since a separate study has shown that aneuploid carcinomas respond better to chemotherapy. The degree of differentiation was a poor predictor of ploidy, although diploid carcinomas did show more keratin and less nuclear pleomorphism than aneuploid carcinomas. The prominence of nucleoli in tumour cells and the surface area to volume (s/v) ratio of the tumour islands were the variables most strongly correlated with ploidy, with diploid carcinomas having prominent nucleoli and a low s/v ratio. A good response to chemotherapy was related partly to the architecture of the carcinoma (pushing border and low s/v ratio), and partly to the tumour cells (well differentiated) and the percentage of necrotic tumour. A lack of inflammatory reaction or desmoplasia was associated with a poor response. The results indicate that both subjective and objective histopathological criteria may be used to predict ploidy and the response to cisplatinum chemotherapy of squamous carcinoma of the head and neck. A combination of s/v ratio and the percentage of necrotic tumour can be used to identify a group of patients with a relatively good survival.

Pericardial constriction caused by primary mesothelioma.

Primary pericardial mesothelioma is an extremely rare tumour. This case illustrates the typical late presentation with symptoms and signs of constrictive pericarditis. An unusual feature was complete encasement of the heart by tumour. No satisfactory treatment is available.