Case study: Boomslang envenomation in North-Eastern South Africa

Boomslang (Dispholidus typus) bites are rare in South Africa. This snake's venom is known to be potently haemotoxic, producing a consumptive coagulopathy through the activation of clotting factors II, X, and possibly IX. Monovalent Boomslang antivenom, produced by the South African Vaccine Producers, is highly effective in treating patients who present with haemotoxic envenomation. The majority of health care centres in South Africa do not stock this antivenom due to cost concerns and because envenomation from this snake is so infrequent; this may have lethal consequences for a patient presenting to any such a centre. The usual antivenom dose for effective treatment of a Boomslang bite is two 10 ml vials. We present a case of severe Boomslang envenomation, secondary to a man being bitten on bilateral upper limbs while inside his house, which required three vials of antivenom to treat effectively.

HIV Superinfection Drives De Novo Antibody Responses and Not Neutralization Breadth

Eliciting antibodies that neutralize a broad range of circulating HIV strains (broadly neutralizing antibodies [bnAbs]) represents a key priority for vaccine development. HIV superinfection (re-infection with a second strain following an established infection) has been associated with neutralization breadth, and can provide insights into how the immune system responds to sequential exposure to distinct HIV envelope glycoproteins (Env). Characterizing the neutralizing antibody (nAb) responses in four superinfected women revealed that superinfection does not boost memory nAb responses primed by the first infection or promote nAb responses to epitopes conserved in both infecting viruses. While one superinfected individual developed potent bnAbs, superinfection was likely not the driver as the nAb response did not target an epitope conserved in both viruses. Rather, sequential exposure led to nAbs specific to each Env but did not promote bnAb development. Thus, sequential immunization with heterologous Envs may not be sufficient to focus the immune response onto conserved epitopes.

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HIV superinfection does not efficiently recruit cross-reactive memory B cells

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Superinfection results in antibody responses specific to each infecting strain

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No evidence that superinfection drives the development of bnAbs

Optimising perioperative care for hip and knee arthroplasty in South Africa: a Delphi consensus study

Background

A structured approach to perioperative patient management based on an enhanced recovery pathway protocol facilitates early recovery and reduces morbidity in high income countries. However, in low- and middle-income countries (LMICs), the feasibility of implementing enhanced recovery pathways and its influence on patient outcomes is scarcely investigated. To inform similar practice in LMICs for total hip and knee arthroplasty, it is necessary to identify potential factors for inclusion in such a programme, appropriate for LMICs.

Methods

Applying a Delphi method, 33 stakeholders (13 arthroplasty surgeons, 12 anaesthetists and 8 physiotherapists) from 10 state hospitals representing 4 South African provinces identified and prioritised i) risk factors associated with poor outcomes, ii) perioperative interventions to improve outcomes and iii) patient and clinical outcomes necessary to benchmark practice for patients scheduled for primary elective unilateral total hip and knee arthroplasty.

Results

Thirty of the thirty-three stakeholders completed the 3 months Delphi study. The first round yielded i) 36 suggestions to preoperative risk factors, ii) 14 (preoperative), 18 (intraoperative) and 23 (postoperative) suggestions to best practices for perioperative interventions to improve outcomes and iii) 25 suggestions to important postsurgical outcomes. These items were prioritised by the group in the consecutive rounds and consensus was reached for the top ten priorities for each category.

Conclusion

The consensus derived risk factors, perioperative interventions and important outcomes will inform the development of a structured, perioperative multidisciplinary enhanced patient care protocol for total hip and knee arthroplasty. It is anticipated that this study will provide the construct necessary for developing pragmatic enhanced care pathways aimed at improving patient outcomes after arthroplasty in LMICs.

A study of the pharmacokinetics and thromboxane inhibitory activity of a single intramuscular dose of carprofen as a means to establish its potential use as an analgesic drug in white rhinoceros

The alleviation of pain and prevention of suffering are key aspects of animal welfare. Unfortunately, analgesic drugs are not available for all species. White rhinoceros (Ceratotherium simum), representing one of such species, which survive poaching attempts inflicted with severe facial injuries and gunshot wounds, nonetheless require analgesic support. To improve treatment conditions, this study explored the use of carprofen for the treatment of pain and inflammation in white rhinoceros. The pharmacokinetics of 1 mg/kg intramuscular carprofen was evaluated in six healthy white rhinoceros. The half-life of λ_z and mean residence time was 105.71 ± 15.67 and 155.01 ± 22.46 hr, respectively. The area under the curve and the maximum carprofen concentration were 904.61 ± 110.78 μg ml^-1  hr^-1 and 5.77 ± 0.63 μg/ml, respectively. Plasma TXB₂ inhibition demonstrated anti-inflammatory properties and indicated that carprofen may be effective for a minimum of 48 hr in most animals. With its long half-life further indicating that a single dose could be effective for several days, we suggest that carprofen may be a useful drug for the treatment of white rhinoceros.

Evaluation of disinfection of flexible nasendoscopes using Tristel wipes: a prospective single blind study

INTRODUCTION

The otorhinolaryngology department at Northwick Park Hospital uses the Tristel wipes system for cleaning nasendoscopes in the outpatient clinics. This system uses chlorine dioxide as its only disinfectant. The manufacturer claims the system provides safe sterilisation of nasendoscopes. However, there appear to be no reports in the literature to date that evaluate the efficacy of this system in a clinical setting. The aim of this study was to evaluate the 'in use' efficacy of Tristel wipes in decontaminating nasendoscopes and to identify any significant contamination between cleaning and usage.

METHODS

A total of 31 cleaning episodes were performed. Each cleaning episode included two swabs after cleaning the scopes, one from the tip and the other from the handle. Another two swabs from the same areas were also taken before application to the patient. The microbiology unit evaluated all swabs for bacterial, fungal and mycobacterial growth.

RESULTS

Overall, 123 swabs from 31 cleaning episodes were tested. None of the swabs taken from the tips (n=31) or handles (n=31) after cleaning with Tristel wipes developed any organism growth. Furthermore, none of the swabs taken from the tip of the scopes before using on patients (n=31) developed any growth. Of the 31 swabs taken from the handle before use, 3 developed significant staphylococcal growth.

CONCLUSIONS

In our study, the 'in use' efficacy of Tristel wipes in cleaning the scopes of bacteria, fungi and mycobacteria was 100%. Attention to hand hygiene and the use of gloves should be considered when handling the cleaned scopes to minimise the risk of contamination between cleaning and application to patients.

Defining the human immunodeficiency virus type 1 transmission genetic bottleneck in a region with multiple circulating subtypes and recombinant forms

The Mbeya region of Tanzania has a genetically complex HIV epidemic with multiple subtypes and recombinant forms circulating, together with a high frequency of dual infections with more than one subtype. This study aimed to determine whether this impacted the HIV-1 transmission bottleneck. A total of 210 env sequences from 22 participants were generated from recently infected women from Mbeya using the single genome amplification approach. Participants were infected with subtypes C (n=9), A (n=4), or D (n=1), and recombinants AC (n=4), CD (n=2), AD (n=1), or ACD (n=1). Sixteen participants (73%) were infected with a single variant; five (23%) with multiple variants; and one (4%) was dually infected. Thus the frequency of single variant infections was similar to cohorts located in genetically restricted subtype B or C epidemics, suggesting that multiple circulating subtypes and unique recombinant forms do not have a significant impact on the transmission bottleneck.

How to manage organisational change and create practice teams: experiences of a South African primary care health centre

BACKGROUND

In South Africa, first-contact primary care is delivered by nurses in small clinics and larger community health centres (CHC). CHCs also employ doctors, who often work in isolation from the nurses, with poor differentiation of roles and little effective teamwork or communication. Worcester CHC, a typical public sector CHC in rural South Africa, decided to explore how to create more successful practice teams of doctors and nurses. This paper is based on their experience of both unsuccessful and successful attempts to introduce practice teams and reports on their learning regarding organisational change.

METHODS

An emergent action research study design utilised a co-operative inquiry group. The first nine months of inquiry focused on understanding the initial unsuccessful attempt to create practice teams. This paper reports primarily on the subsequent nine months (four cycles of planning, action, observation and reflection) during which practice teams were re-introduced. The central question was how more effective practice teams of doctors and nurses could be created. The group utilised outcome mapping to assist with planning, monitoring and evaluation. Outcome mapping defined a vision, mission, boundary partners, outcome challenges, progress markers and strategies for the desired changes and supported quantitative monitoring of the process. Qualitative data were derived from the co-operative inquiry group (CIG) meetings and interviews with doctors, nurses, practice teams and patients.

FINDINGS

The CIG engaged effectively with 68% of the planned strategies, and more than 60% of the progress markers were achieved for clinical nurse practitioners, doctors, support staff and managers, but not for patients. Key themes that emerged from the inquiry group's reflection on their experience of the change process dealt with the amount of interaction, type of communication, team resilience, staff satisfaction, leadership style, reflective capacity, experimentation and evolution of new structures.

CONCLUSION

The group's learning supported a view of change that sees the organisation as a living system in which information flow, participation and the development of resilience are key aspects. These themes fit well into an understanding of change based on complexity theory. If managers of the health system wish to enhance organisational change, then their goal may need to shift from optimising health care delivery in a mechanistic model to optimising health care workers in a living system.

Steroids in rhinoplasty: a survey of current UK otolaryngologists' practice

The use of steroids during rhinoplasty to reduce post-operative periorbital oedema and ecchymosis has been advocated. A number of randomized controlled trials have demonstrated the benefit of steroids in rhinoplasty. The aim of this study was to determine current UK practice in the use of steroids during rhinoplasty performed by otolaryngologists.

A postal survey of consultant otolaryngologists in the UK was conducted. We received 203 responses, with 115 consultants performing 12 or more rhinoplasties per year. Only 28 consultants (24 per cent) used steroids routinely in patients undergoing rhinoplasty and of these 11 used a protocol, although this was unpublished. Dexamethasone was the most common steroid used (82 per cent), being administered as a single intravenous dose of 8 mg in the majority of cases (54 per cent). There was no correlation between the use of steroids and the number of rhinoplasties performed by individual consultants.

Despite the evidence supporting the use of steroids to reduce post-operative sequelae following rhinoplasty, only a minority of consultants in the UK appear to use them as part of their practice.

Effects of milnacipran on driving vigilance

BACKGROUND Many psychotropic drugs modify sensory and/or psychomotor functions involved in car driving and as such they can be a causative factor in road accidents. AIM To investigate the effects of the administration of milnacipran, a serotonin and noradrenaline dual-action antidepressant, on the sensory and psychomotor skills implicated in car driving and to determine any possible interactions with the effect of alcohol. METHODS Double-blind, placebo-controlled four-sequence cross-over design with 12 healthy volunteers. Laboratory tests designed to explore motor responses to auditory and visual stimuli and equilibrium on a sensory platform, as well as tests in a real on-road car driving situation, were carried out before the drug administration (control) and at the end of each sequence. RESULTS There was no significant difference in the results of laboratory tests between groups receiving milnacipran compared to placebo. In a real driving situation there were no significant effects of milnacipran. In addition, milnacipran did not accentuate the negative effects of alcohol. CONCLUSIONS Milnacipran, administered at 50 mg b.i.d. to healthy volunteers, does not modify the psychomotor skills required for driving.

Evidence for a role of the JNK cascade in Smad7-mediated apoptosis

Smad proteins are central mediators of the transcriptional effects of transforming growth factor beta (TGF-beta) superfamily that regulate a wide variety of biological processes. Smad7, an inhibitory Smad protein that prevents TGF-beta signaling by interacting with the activated type I TGF-beta receptor, was recently shown to induce sensitization of cells to different forms of cell death. Here we examined the effect of Smad7 on the c-Jun N-terminal kinase (JNK) cascade and investigated the role of this cascade in both the inhibitory and apoptotic functions of Smad7. The transient and stable expression of Smad7 caused a strong and sustained activation of JNK. Expression of a dominant-interfering mutant of mitogen-activated protein kinase kinase 4, which completely abolished Smad7-induced activation of JNK, had no effect on Smad7-mediated inhibition of TGF-beta signaling, indicating that the inhibitory function of Smad7 is independent of the JNK cascade. In contrast, expression of the dominant-interfering mutant of mitogen-activated protein kinase kinase 4 impaired the ability of Smad7 to promote cell death. These experiments reveal a novel link between Smad7 and the JNK cascade, which is essential for potentiation of cell death by this inhibitory Smad.

c-Jun interacts with the corepressor TG-interacting factor (TGIF) to suppress Smad2 transcriptional activity

The Sma and Mad related (Smad) family proteins are critical mediators of the transforming growth factor-beta (TGF-beta) superfamily signaling. After TGF-beta-mediated phosphorylation and association with Smad4, Smad2 moves to the nucleus and activates expression of specific genes through cooperative interactions with DNA-binding proteins, including members of the winged-helix family of transcription factors, forkhead activin signal transducer (FAST)-1 and FAST2. TGF-beta has also been described to activate other signaling pathways, such as the c-Jun N-terminal Kinase (JNK) pathway. Here, we show that activation of JNK cascade blocked the ability of Smad2 to mediate TGF-beta-dependent activation of the FAST proteins. This inhibitory activity is mediated through the transcriptional factor c-Jun, which enhances the association of Smad2 with the nuclear transcriptional corepressor TG-interacting factor (TGIF), thereby interfering with the assembly of Smad2 and the coactivator p300 in response to TGF-beta signaling. Interestingly, c-Jun directly binds to the nuclear transcriptional corepressor TGIF and is required for TGIF-mediated repression of Smad2 transcriptional activity. These studies thus reveal a mechanism for suppression of Smad2 signaling pathway by JNK cascade through transcriptional repression.

Does high-frequency pseudo-random rotational chair testing increase the diagnostic yield of the eng caloric test in detecting bilateral vestibular loss in the dizzy patient?

OBJECTIVES

To assess the incremental diagnostic yield of testing vestibulo-ocular (VOR) gain with high-frequency pseudo-random rotational chair (PsRRC) over testing with bithermal electronystagmography caloric tests in the dizzy patient, particularly in detecting bilateral vestibular loss.

PATIENTS AND METHODS

One hundred ninety-eight patients presenting with dizziness underwent PsRRC and caloric testing. The VOR gain on PsRRC was measured at 0.32 to 5.0 Hz, with gain categorized as normal or decreased. PsRRC results were compared with caloric responses, also categorized as normal, or into graded categories of unilateral or bilateral vestibular loss.

RESULTS

Reduced PsRRC gain was found in 29 (15%) patients, and reduced caloric tests responses in 70 (35%), with 25 (13%) having bilateral loss. Of patients with reduced chair gain, 25 of 29 (86%) demonstrated bilateral caloric loss. PsRRC gain was normal in most patients with unilateral caloric weakness, but was decreased in all patients with bilateral caloric weakness. The probability of a patient with completely normal caloric responses having an abnormal rotation chair in this study group was under 1% (1 of 128).

CONCLUSIONS

PsRRC testing does not offer much additional diagnostic benefit when caloric responses are normal. It is useful in specific conditions, such as unilateral caloric loss for which the patient is not compensating, borderline caloric loss when traditional water caloric tests cannot be used, or for monitoring progressive bilateral vestibular loss.

Effect of laser uvulopalatoplasty on middle ear function

OBJECTIVES

Palatal musculature is known to be responsible for the active opening of the eustachian (auditory) tube. Because laser-assisted uvulopalatoplasty (LAUP) may involve partial division of these muscles, the effect of this procedure on middle ear pressures (MEPs) and middle ear volumes (MEVs) was investigated.

STUDY DESIGN

A controlled interventional trial with one limb receiving treatment and the other none. Preoperative and postoperative measurements were carried out in both groups.

METHODS

A control group of 15 normal volunteers and a study group of 22 patients undergoing LAUP all of whom had normal ears and type A tympanograms before the trial were recruited. Repeat tympanometry was carried out after 3 months in both groups. The results of MEP and MEV were recorded for both groups and analyzed by the Mann-Whitney U test.

RESULTS

A trend toward reduced MEP and MEV was noted in the LAUP group, but did not achieve statistical significance. A study with more patients may achieve significance.

CONCLUSIONS

No significant effects on middle ear pressures or volumes 3 months after LAUP were demonstrated. A much larger study may, however, arrive at a statistically significant result and further work is warranted. Relevant palatal and tubal anatomy is discussed and a brief review of the relevant literature is given.

The effect of surgery upon the quality of life in snoring patients and their partners: a between-subjects case-controlled trial

Snoring is a common complaint in the community. Its psychosocial effect upon the relationship between sleeping partners is not known. This study examines prospectively by detailed tailored questionnaires the differences in the physical, psychological and social aspects in 27 snoring patients and their partners presenting to a snoring clinic and compares them with a control group of 24 patients who had undergone successful Laser-Assisted Uvulopalatoplasty (LAUP) and their partners. All areas examined showed improvement in the non-snoring group, particularly for the patient. Improvement was demonstrated in the non-snoring group's quality of marital state (P < 0.01). Quality of life was improved (P < 0.05). Perceived inadequacies in support were significantly higher in the snoring group (P < 0.05). Evidence of psychiatric disorder apparent in the snoring group was not present in the control group (P < 0.01). This is the first study to demonstrate significant improvement in the quality of life in both patients and their partners, after successful surgery for simple snoring.

Biodistribution and absorbed radiation dose estimates of 99mTc-labeled dimercaptopropionyl human serum albumin

The use of 99mTc-labeled red blood cells (RBC) for the evaluation of left ventricular function using equilibrium-gated blood-pool imaging suffers from several problems and potential risks. In this study, we estimated the absorbed radiation dose of 99mTc-labeled dimercaptopropionyl human serum albumin (DMP-HSA) as a potential alternative to 99mTc-RBC.

METHODS

After the administration of 99mTc-DMP-HSA, whole-body imaging was performed up to 48 h after injection in five volunteers. The heart contents, liver and remainder of the body were used as source organs. Multicompartment modeling of the biodistribution was performed and absorbed radiation dose estimates for 99mTc-DMP-HSA were obtained using the Medical Internal Radiation Dose (MIRD) calculation.

RESULTS

Residence times of 0.62 and 0.43 h were obtained for the heart contents and liver, respectively. Radiation dose estimates yielded an effective dose of 0.0055 mSv/MBq.

CONCLUSION

99MTC-DMP-HSA yielded absorbed radiation doses comparable with those of 99mTc-RBC. Therefore, the radiation properties of 99mTc-DMP-HSA are such that it can be used for clinical diagnostic studies.

Olfactory receptors, Golf alpha and adenylyl cyclase mRNA expressions in the rat heart during ontogenic development

Golf alpha (a G heterotrimeric protein which shares a high homology with Gs alpha) expression was studied in the rat heart before birth and until weaning. Since Golf alpha in the neuro-olfactory epithelium is coupled to olfactory receptors and type III adenylyl cyclase, we looked for the presence of such molecules in the heart. Golf alpha mRNA was detected in the rat heart, highest levels being found in 21-day old fetuses until 3 days post partum. The protein amounts measured by Western blots paralleled the Golf alpha mRNA levels. Immunohistochemical studies revealed the presence of Golf alpha in atrial and ventricular cardiomyocytes. OL1 and latrophilin mRNAs, G protein-coupled olfactory receptors, were expressed at early postnatal stages. Adenylyl cyclase mRNAs for type II, type III, type V and type VI were expressed before birth and until weaning. Elements for an unexpected signaling pathway involving odorant receptors like OL1 and latrophilin, Golf alpha and type III adenylyl cyclase were expressed in rat heart, and appeared developmentally regulated.

Ototoxicity and topical eardrops

Topical aminoglycoside ear drops are theoretically acknowledged to be potentially ototoxic when administered in the presence of a tympanic membrane perforation. Although the development of clinical ototoxicity appears to be rare, nine well-documented and incontrovertible cases (12 ears in total) of iatrogenic topical vestibulotoxicity are presented, representing the largest series in the English language world literature to date. All patients were treated with the topical gentamicin-containing ear drops Garasone, (betamethasone sodium phosphate and gentamicin sulphate) for prolonged periods. Toxicity was found to be primarily vestibular rather than cochlear. Further review of five previously reported cases in addition to the findings from another four patients identified with topical ototoxicity are described. Although compensation occurred in unilateral cases the disability in bilateral cases was typically severe and often resulted in litigation.

The value of sedation nasendoscopy: a comparison between snoring and non-snoring patients

Sedation or sleep nasendoscopy is a widely-used investigation in snorers presenting to otolaryngologists in the UK, despite its non-physiological basis. The presence or absence of snoring and its site of generation were compared between a group of 205 snorers and another of 126 non-snorers. Snoring was produced at nasendoscopy in 45.3% of non-snorers but could not be produced in 18.1% of snorers. There was no significant difference in the site of sound production between the two groups and although the noise produced by the non-snoring group was quieter, this difference was not significant.