Time-dose relationships of PMSG and map-intravaginal sponges and its effect on embryonic mortality in Karakul ewe

Different dosage levels of pregnant mare serum gonadotrophin (PMSG) were applied in conjunction with medroxyprogesterone acetate impregnated intravaginal sponges at different times in relation to sponge removal the object of the study was to find the most economical dose level and the correct time of application which would result in the least variability as far as ovarian response and embryonic failure was concerned. The lower dosage levels of PMSG (300 I.U.) injected intramuscularly, two days prior to sponge removal for out of season and on removal for the breeding season treatments, gave the most consistent ovulatory response as well as the lowest incidence of wastage of ova. Losses due to fertilization failure and embryonic death were more or less equally proporttoned within the overall loss of potential ova of 50%and 53,7% recorded respectively for out of season and breeding season treatments

The effect of heterosexual contact on libido and mating dexterity in Karakul rams

No Abstrac

Mitral valve replacement at Tygerberg Hospital: a 5 year follow-up

This study provides 5-year follow-up data of isolated mitral valve replacements with mechanical prosthesis at a large South African tertiary hospital. It also assessed the significance of pre-operative parameters to predict mortality. This is a retrospective study of 187 patients that underwent isolated mitral valve replacement at Tygerberg Hospital from Jan 1998-Dec 2002. Twenty seven patient’s data was incomplete and they were excluded from the study. All patients had rheumatic mitral valve disease and the valve lesions included mitral incompetence, mitral stenosis and mixed mitral valve disease. All patients had a mechanical prosthesis implanted (St Jude medical or Orbis bileaflet valves). The mean follow-up time was 5.41-years. The 30 day mortality was 5.62% and the 5-year survival was 80%. Pre-operative risk factors that significantly increased mortality were pulmonary hypertension and mitral stenosis. Valve-related complications were more common in this series compared to other First World populations but our results compare well with other Third World population groups. Valve thrombosis 4.32% (0.8%/yr), thromboembolism 8.71% (1.61%/yr), anticoagulant related haemorrhage 6.87% (1.27%/yr), prosthetic valve endocarditis 3.08% (0.57%/yr) and re-operation 8.12% (1.5%/yr).Conclusion: Mechanical valve replacement for mitral valve disease that requires valve replacement is still a good treatment option even in third world population groups. In our series, severe pulmonary hypertension, mitral stenosis and reoperation was statistically significantly more common in the “non-survivors” group

A clinical comparison of disposable airway devices

Background: The re-usable Classic laryngeal mask airway (LMA®) is widely used. There are concerns regarding the transmission of pathogens. Disposable airway devices provide a cost-effective alternative. We performed a side by side clinical comparison of these devices applicable to the South African context.Methods: Adult ASA 1-3 patients (30 – 100 kg) presenting for elective peripheral surgery in Tygerberg Academic Hospital were randomised to receive the gold standard Classic LMA®, or one of four disposable devices. They all received a standardised anaesthetic with propofol, fentanyl and isoflurane in 40% O2/N2O. Insertion technique, mask sizes and maximum cuff volumes were per manufacturer’s instructions. The cuff was inflated to achieve an adequate airway seal (no audible leak at an airway pressure of 20cm H2O), or to the maximum recommended volume. Cuff and airway pressures were measured continuously. A protocol was followed for repeated or failed attempts. 115 of the proposed 130 patients were recruited.Categorical data was analysed using Chi squared tests, and one-way ANOVA was performed on parametric data. An alpha level of 0.05 was accepted.Results: The patients were of comparable age, weight, ASA grade and airway grading. There were no statistical differences in the number of times the airway device size had to be changed (p = 0.627), ease of insertion (p = 0.357) or insertion attempts (p = 0.909). Only the Cobra PLA™ was graded as “Grade 4: impossible to establish an airway” in 10% of cases, and the insertion time with this device was prolonged (p = 0.018). The Cobra PLA™ predictably differed from the other groups in cuff volumes (p = 0.001). Cuff pressures were significantly higher in the Ambu™ and LMA Unique™ (p = 0.001).  Maximum airway pressure attainable after 5 minutes was significantly higher in the Ambu™ (p = 0.036). Airway trauma as graded by visible blood on the device was low, and similar between groups (p = 0.237). Secretions were negligible in 67.8% patients and there was no difference in the amount of suctioning required (p = 0.094). Patient comfort was exceptional and comparable, achieving similar visual analogue scores for sore throat (p = 0.742), dysphagia (p = 0.760) and hoarseness(p = 0.258). No complications were noted.Conclusions: We found no difference in routine clinical practice between the Classic LMA®, LMA Unique™, Portex Soft Seal ™, Ambu™ and Cobra PLA™ in terms of ease of insertion, number of attempts, size changes, patient comfort or airway trauma. The Ambu device allowed an airway seal at higher pressures. The Cobra devices had a prolonged average insertion time. The Cobra devices were the only ones found impossible to achieve a satisfactory airway after 3 attempts in 10% of cases, although this did not reach statistical significance

Antiretroviral therapy and anaesthesia

HIV has reached pandemic proportions in Southern Africa. Great emphasis is placed on the prevention and containment of HIV transmission by suppressing virus replication using highly active anti-retroviral therapy (HAART). HAART has proven to be highly effective if taken correctly, and has lead to increased life expectancy. Increasing numbers of HIV-positive patients on antiretroviral (ARV) therapy or HIV-exposed individuals taking prophylaxis present for surgery and critical care management. The anaesthesiologist should be familiar with the anaesthetic implications of HIV as well as the possible drug interactions while on ARV treatment. This article focuses specifically on the anaesthetic implications of the patient on HAART. HAART is HIV treatment with a combination of three or more ARV drugs from five broad classes. The specific HAART regimen in use in South Africa is considered in detail in this article. The pharmacokinetics of the ARV drugs is complex, and subject to interactions at many different sites. Serious drug interactions are possible, including drugs commonly used in anaesthesia. Drug interactions and recommendations are discussed in detail. ARVs are known to cause multiple systemic side effects, including lactic acidosis, Immune Reconstitution Inflammatory Syndrome (IRIS), premature atherosclerosis and increased cardiovascular risk, hyperlipidaemia, insulin resistance, skeletal disorders, hepatotoxicity, lipodystrophy, mitochondrial abnormalities, allergic reactions and pancreatitis. Non-compliance is common, and leads to the rapid development of resistance. The anaesthesiologist may inadvertently exacerbate this in the perioperative period. Recommendations regarding the interruption of treatment and fasting are made. Alternative routes for HAART administration are also explored. The management of the critically ill patient on a HAART regimen is discussed

Geology, geochemistry and Sr–Nd constraints of selected metavolcanic rocks from the eastern boundary of the Saharan Metacraton, southern Sudan : a possible revision of the eastern boundary

Neoproterozoic, Pan-African low-grade metavolcanic rocks and associated mafic and ultramafic rocks of ophiolitic origin have long been identified within the pre-Neoproterozoic Saharan Metacraton (SMC). These low-grade rocks within generally high-grade (upper amphibolite facies) gneiss and schist have not yet been fully investigated, and their geological and geotectonic significance have been recognised only in a very few localities: (1) the Delgo–Atmur ophiolite and low-grade volcano-sedimentary belt, (2) the Rahib ophiolite and low-grade sedimentary fold and thrust belt, both in northern Sudan along the eastern boundary of the Saharan Metacraton and (3) the low-grade volcano-sedimentary rocks in the Central African Republic. Dismembered and low-grade metamorphosed occurrences of mafic extrusive and intrusive and minor ultramafic rocks, grouped as the Arid unit, similar to those of the Arabian Nubian Shield (ANS), are reported here for the first time in the westernmost part of the Nuba Mountains, southeastern Sudan. These occurrences are interpreted to represent part of an ophiolite sequence with a lower cumulate layer composed of layered gabbro and minor cumulate hornblendite and a top layer of thick massive gabbro, pillowed basalt and basaltic andesite. The Arid unit is structurally underlain by basaltic-andesite and andesite and a metasedimentary sequence identified as turbidite and both grouped as the Abutulu unit. All of the rocks are slightly sheared, deformed and metamorphosed under low-grade greenschist facies to epidote amphibolite sub-facies. New geochemical and Sr–Nd isotope data reveal that the low-grade metavolcanic rocks of the westernmost Nuba Mountains represent a Neoproterozoic oceanic arc/backarc assemblage. The massive gabbro and pillowed basalt of the Arid unit show the geochemical characteristics of HFSE-depleted tholeiitic basalt while the co-genetic and more evolved meta-andesite of Abutulu unit show a calc-alkaline signature. Both units display a REE pattern characterized by LILE enrichment indicating formation in an arc/back-arc environment. This arc was active at around 778 ± 90 Ma (Sm– Nd 12 WR isochron) that is similar in age to the arc magmatism in the ANS. The close interval between the TDM Nd model age (average of 10 metavolcanic samples is 814 Ma) and the crystallization age (778 ± 90 Ma) is indicative of little or no involvement of older material. The western Nuba Mountains metavolcanic rocks have eNd values of +5.9 at 778 Ma (average of 12 samples) indicating a depleted mantle source similar to that of the ANS (published range from +6.5 to +8.4). The eNd values of the metavolcanic rocks are different from previously published ages of high-grade basement rocks that occupy the area west of the Kabus suture and east of Abutulu (+2.2 and +3.5 for the Rashad and Abbassyia). It is proposed that the metavolcanic and associated plutonic mafic rocks represent a unique Neoproterozoic entity named the Abutulu terrane that developed in a marginal back-arc basin west of the medium-grade gneiss of the Nuba Mountains. If the Abutulu terrane is included as a part of the ANS, then the eastern boundary of the SMC is adjacent to the western edge of the ANS along the Abutulu suture.http://www.elsevier.com/locate/precamres2017-08-31hb2016Geolog

The BEST study - a prospective study to compare business class versus economy class air travel as a cause of thrombosis

Background. As many as 10% of airline passengers travelling without prophylaxis for long distances may develop a venous thrombosis. There is, however, no evidence that economy class travellers are at increased risk of thrombosis.Objectives. A suitably powered prospective study, based on the incidence of deep-vein thrombosis (DVT) reported in previous studies on long-haul flights, was designed to determine the incidence of positive venous duplex scans and D-dimer elevations in low and intermediate-risk passengers, comparing passengers travelling in business and economy class.Patients/methods. Eight hundred and ninety-nine passengers were recruited (180 travelling business class and 719 travelling economy). D-dimers were measured before and after the flight. A value greater than 500 ng/ml was accepted as abnormal. A thrombophilia screen was conducted which included the factor V Leiden mutation, the prothombin 20210A mutation, protein C and S levels, antithrombin levels, and anticardiolipin antibodies immunoglobulin G (IgG) and immunoglobulin M (IgM). On arrival, lower limb compression ultrasonography of the deep veins was performed. Logistical regression analysis was used to determine the risk factors related to abnormally high D-dimer levels.Results. Only 434 subjects had a full venous duplex scan performed. None had ultrasonic evidence of venous thrombosis. Nine passengers tested at departure had elevated D-dimer levels and these volunteers were excluded from further study. Seventy-four of the 899 passengers had raised D-dimers on arrival. Twenty-two of 180 business class passengers (12%) developed elevated D-dimers compared with 52 of 719 economy class passengers (7%). There was no significant association between elevation of D-dimers and the class flown (odds ratio (OR) 0.61, p = 0.109). The factor V Leiden mutation, factor VIII levels and the use of aspirin were, however, associated with raised D-dimers (OR 3.36, p = 0.024; OR 1.01, p = 0.014; and OR 2.04, p = 0.038, respectively). Five hundred and five passengers were contacted within 6 months and none reported any symptoms of a clinical thrombosis or pulmonary embolus.Conclusion. The incidence of ultrasonically proven DVT is much lower than previously reported. However, more than 10% of all passengers developed raised D-dimers, which were unrelated to the class flown. A rise in D-dimers is associated with an inherent risk of thrombosis and/ or thrombophilia, demonstrates activation of both the coagulation and fibrinolytic systems during long-haul flights, and may indicate the development of small thrombi

A First Search for coincident Gravitational Waves and High Energy Neutrinos using LIGO, Virgo and ANTARES data from 2007

We present the results of the first search for gravitational wave bursts associated with high energy neutrinos. Together, these messengers could reveal new, hidden sources that are not observed by conventional photon astronomy, particularly at high energy. Our search uses neutrinos detected by the underwater neutrino telescope ANTARES in its 5 line configuration during the period January - September 2007, which coincided with the fifth and first science runs of LIGO and Virgo, respectively. The LIGO-Virgo data were analysed for candidate gravitational-wave signals coincident in time and direction with the neutrino events. No significant coincident events were observed. We place limits on the density of joint high energy neutrino - gravitational wave emission events in the local universe, and compare them with densities of merger and core-collapse events.Comment: 19 pages, 8 figures, science summary page at http://www.ligo.org/science/Publication-S5LV_ANTARES/index.php. Public access area to figures, tables at https://dcc.ligo.org/cgi-bin/DocDB/ShowDocument?docid=p120000

Exploring South Africa's southern frontier : a 20-year vision for polar research through the South African National Antarctic Programme

Antarctica, the sub-Antarctic islands and surrounding Southern Ocean are regarded as one of the planet’s last remaining wildernesses, ‘insulated from threat by [their] remoteness and protection under the Antarctic Treaty System’. Antarctica encompasses some of the coldest, windiest and driest habitats on earth. Within the Southern Ocean, sub-Antarctic islands are found between the Sub-Antarctic Front to the north and the Polar Front to the south. Lying in a transition zone between warmer subtropical and cooler Antarctic waters, these islands are important sentinels from which to study climate change. A growing body of evidence now suggests that climatically driven changes in the latitudinal boundaries of these two fronts define the islands’ short- and long-term atmospheric and oceanic circulation patterns. Consequently, sub-Antarctic islands and their associated terrestrial and marine ecosystems offer ideal natural laboratories for studying ecosystem response to change. For example, a recent study indicates that the shift in the geographical position of the oceanic fronts has disrupted inshore marine ecosystems, with a possible impact on top predators. Importantly, biotic responses are variable as indicated by different population trends of these top predators. When studied collectively, these variations in species’ demographic patterns point to complex spatial and temporal changes within the broader sub-Antarctic ecosystem, and invite further examination of the interplay between extrinsic and intrinsic drivers.http://www.sajs.co.zaam2017GeneticsMammal Research InstituteZoology and Entomolog