Peri-operative management and analgesic strategy for a patient undergoing quadruple limb amputation

Inadequately managed amputation pain can contribute to postoperative morbidity and mortality. However, amputation pain can be challenging to manage due to its complex nature, with both central and peripheral nociceptive and neuropathic elements. Here, we present the case of a 47-year old man who developed irreversible ischaemic injuries to all four limbs following admission to intensive care with sepsis. He required quadruple amputation and we describe our approach to his peri-operative management including anaesthesia, invasive monitoring and the multi-modal approach to his peri-operative management using a combination of intravenous analgesics, bilateral brachial plexus nerve catheters and a combined spinal and epidural. The patient made a good recovery and was able to return home from a rehabilitation facility 12 months after the operation, able to undertake many tasks himself with the aid of prosthetics.

Contact patterns during the COVID-19 pandemic: findings from British Columbia, Canada

Purpose

Interpersonal interaction between infectious and uninfected individuals facilitates the spread of COVID-19. Physical distancing measures could prevent COVID-19 transmission by reducing the contacts among individuals in the population. In this study, we describe contact rates of residents of British Columbia, Canada to assess the impact of COVID-19 related physical distancing measures in the province.

Methods & Materials

We used data from the BC COVID-19 Population Mixing Patterns survey (BC-Mix) to investigate the contact patterns of residents of British Columbia from September 2020 to July 12, 2021. The BC-Mix is an ongoing repeated online survey with approximately 60,000 participants. Survey respondents provided the number of close contacts made in a single day in response to the question "How many people did you have in-person contact with between 5 am yesterday and 5am today?” In-person contact was defined as “face-to-face two-way conversation with three or more words, or physical skin-to-skin contact such as a handshakes, hugs, kisses and contact sports”. Survey weights were applied in the estimation of overall contact rates and contact rates stratified by age, sex and health region.

Results

A total of 31, 696 respondents were eligible for analysis. Overall average daily contacts decreased by about 28% in response to the physical distancing measures that went into effect on November 19, 2020 (from an average of 6.42 contacts per person prior to this date to 4.62 contacts per person after this date). From September 2020 to February 2021, the average number of daily contacts were higher among female respondents compared to male respondents. However, no notable difference in the average number of daily contact rates was observed between male and female respondents in subsequent weeks. Over the study period, younger age groups (< 55 years) reported higher daily contact overall than older age groups (≥ 55years years). There was also a marked difference in contact rates by health regions over the study period.

Conclusion

Contact patterns in British Columbia varied between September 2020 and July 2021, with a marked decline in average daily contacts noted immediately following the introduction of stricter physical distancing measures in November 2020.

Quantifying Contact Patterns: Development and Characteristics of the British Columbia COVID-19 Population Mixing Patterns Survey

Purpose

Several non-pharmaceutical interventions such as physical distancing, self-isolation, a stay-at-home order, hand washing, and schools and businesses closures were implemented in British Columbia (BC) following the first lab-tested case of COVID-19 on January 26, 2020. These interventions were aimed at minimizing in-person contacts that could potentially lead to new COVID-19 infections. The BC COVID-19 Population Mixing Patterns survey (BC-Mix) was established as a surveillance system to measure behaviour and contact patterns in BC over time to inform the timing of the easing/re-imposition of control measures. We describe the BC-Mix survey design and the demographic characteristics of respondents.

Methods & Materials

The ongoing repeated online survey was launched in September 2020. Participants are recruited through a variety of social media platforms including Instagram, Facebook, YouTube, and community group mailing lists. A follow up survey is sent to participants two to four weeks after completing the first iteration. Survey responses are weighted to BC's population by age, sex, geography, and ethnicity to obtain generalizable estimates. A survey completion rate of at least 33% AND a valid response for the sex questionnaire item AND a valid response for age questionnaire item were required for inclusion in weighting and further analysis. Additional indices such as material and social deprivation index, and residential instability are generated using census and location data.

Results

As of June 14, 2021, over 58,000 residents of BC had participated in the survey of which 31,007 survey responses were eligible for analysis. Of the eligible participants, about 60% provided consent for monthly follow up and about 26% provided their personal health numbers for linkage with other healthcare utilization databases. Approximately 51% were females 39% were 55 years or older, 63% identified as white or not a visible minority and 48% had at least a university degree.

Conclusion

The pandemic response is best informed by surveillance systems capable of timely assessment of behaviour patterns. BC-Mix survey respondents represented a large cohort of British Columbians providing near real-time information on behavioural and contact patterns in BC. Data from the BC-Mix survey continues to inform provincial COVID-19-related control measures.

Near ground horizontal high resolution Cn2 profiling from Shack-Hartmann slopeand scintillation data

Coupled slope and scintillation detection and ranging (CO-SLIDAR) is a very promising technique for the metrology of near ground Cn2 profiles. It exploits both phase and scintillation measurements obtained with a dedicated wavefront sensor and allows profiling on the full line of sight between pupil and sources. This technique is applied to an associated instrument based on a mid-IR Shack-Hartmann wavefront sensor coupled to a 0.35 m telescope, which observes two cooperative sources. This paper presents what we believe is the first comprehensive description of the CO-SLIDAR method in the context of near-ground optical turbulence metrology. It includes the presentation of the physics principles underlying the measurements of our unsupervised Cn2 profile reconstruction strategy together with the error bar estimation on the reconstructed values. The application to data acquired in a heterogeneous rural landscape during an experimental campaign in Lannemezan, France, demonstrates the ability to obtain profiles with a sampling pitch of about 220 m over a 2.7 km line of sight. The retrieved Cn2 profiles are presented and their variability in space and time is discussed.

Positive and Negative Allosteric Modulators of N-Methyl-d-aspartate (NMDA) Receptors: Structure-Activity Relationships and Mechanisms of Action

Excitatory activity in the CNS is predominately mediated by l-glutamate through several families of l-glutamate neurotransmitter receptors. Of these, the N-methyl-d-aspartate receptor (NMDAR) family has many critical roles in CNS function and in various neuropathological and psychiatric conditions. Until recently, the types of compounds available to regulate NMDAR function have been quite limited in terms of mechanism of action, subtype selectivity, and biological effect. However, several new classes of NMDAR agents have now been identified that are positive or negative allosteric modulators (PAMs and NAMs, respectively) with various patterns of NMDAR subtype selectivity. These new agents act at several newly recognized binding sites on the NMDAR complex and offer significantly greater pharmacological control over NMDAR activity than previously available agents. The purpose of this review is to summarize the structure-activity relationships for these new NMDAR modulator drug classes and to describe the current understanding of their mechanisms of action.

The NMDA receptor intracellular C-terminal domains reciprocally interact with allosteric modulators

N-methyl-d-aspartate receptors (NMDARs) have multiple prominent roles in CNS function but their excessive or insufficient activity contributes to neuropathological/psychiatric disorders. Consequently, a variety of positive and negative allosteric modulators (PAMs and NAMs, respectively) have recently been developed. Although these modulators bind to extracellular domains, in the present report we find that the NMDAR's intracellular C-terminal domains (CTDs) significantly influence PAM/NAM activity. GluN2 CTD deletion robustly affected NAM and PAM activity with both enhancing and inhibiting effects that were compound-specific and NMDAR subunit-specific. In three cases, individual PAMs became NAMs at specific GluN2-truncated receptors. In contrast to GluN2, GluN1 CTD removal only reduced PAM activity of UBP684 and CIQ, and did not affect NAM activity. Consistent with these findings, agents altering phosphorylation state or intracellular calcium levels displayed receptor-specific and compound-specific effects on PAM activity. It is possible that the GluN2's M4 domain transmits intracellular modulatory signals from the CTD to the M1/M4 channel gating machinery and that this site is a point of convergence in the direct or indirect actions of several PAMs/NAMs thus rendering them sensitive to CTD status. Thus, allosteric modulators are likely to have a marked and varied sensitivity to post-translational modifications, protein-protein associations, and intracellular ions. The interaction between PAM activity and NMDAR CTDs appears reciprocal. GluN1 CTD-deletion eliminated UBP684, but not pregnenolone sulfate (PS), PAM activity. And, in the absence of agonists, UBP684, but not PS, was able to promote movement of fluorescently-tagged GluN1-CTDs. Thus, it may be possible to pharmacologically target NMDAR metabotropic activity in the absence of channel activation.

Outcomes associated with a thrice-weekly antimicrobial stewardship programme in a 253-bed community hospital

WHAT IS KNOWN AND OBJECTIVES

Antimicrobial stewardship programmes (ASPs) have been shown to decrease antimicrobial resistance, reduce hospital-acquired infections and decrease overall antimicrobial expenditures. At St. Joseph Medical Center in Bellingham, WA, a thrice-weekly ASP was initiated in 2010 with the goals of decreasing carbapenem, fluoroquinolone and vancomycin use and tailoring duration of therapy.

METHODS

Antibiotic use per 1000 patient-days and carbapenem, fluoroquinolone and vancomycin use were evaluated pre- and post-implementation of the ASP. Total antimicrobial expenditures were evaluated for the 3 years prior to ASP implementation and three years following implementation.

RESULTS AND DISCUSSION

Antimicrobial days of therapy per 1000 patient-days declined by 6·4% after implementation of our ASP. There was a 37% reduction in total antimicrobial expenditures after implementation. Carbapenems, vancomycin and levofloxacin use decreased considerably. Ciprofloxacin use increased during the same time period.

WHAT IS NEW AND CONCLUSION

A thrice-weekly, pharmacist-driven ASP can decrease antimicrobial expenditure, shorten duration of therapy and decrease the utilization of carbapenems, vancomycin and levofloxacin.

Adenovirus 36 seropositivity is strongly associated with race and gender, but not obesity, among US military personnel

BACKGROUND

Although several studies have shown a positive association between evidence of anti-adenovirus 36 (Ad-36) antibodies (Ad-36 exposure) and (1) obesity and (2) serum cholesterol in animals, there is limited research demonstrating this association in humans. There is also limited research on transmission, presentation and demographics of Ad-36 infection.

DESIGN

(1) Body mass (body mass index (BMI)), (2) fasting serum cholesterol and triglyceride levels and (3) demographic characteristics were compared between Ad-36 seropositive and seronegative groups. The majority of subjects were matched as cases versus controls on a number of demographic variables.

SUBJECTS

A total of 150 obese and 150 lean active-duty military personnel were studied.

MEASUREMENTS

Subjects completed a questionnaire regarding demographic and behavioral characteristics. Subject serum samples were tested by serum neutralization assay for the presence of anti-Ad-36 antibodies.

RESULTS

In all, 34% of obese and 39% of lean subjects had Ad-36 exposure, an insignificant difference. Serum cholesterol and triglyceride levels were significantly higher among the obese subjects than among the lean, but there were no associations between serum cholesterol and triglyceride levels and Ad-36 exposure. Positive associations were found between Ad-36 exposure and age, race and gender.

CONCLUSION

The study stands in contrast to previous work that has shown a positive relationship between Ad-36 exposure and (1) obesity, and (2) levels of serum cholesterol and triglycerides. In this study there was no association in either case. Unanticipated relationships between Ad-36 exposure and age, race and gender were found, and this is the first time that such a link between Ad-36 exposure and demographics has been found.

A 5-year audit of rhinology procedures carried out in a district general hospital

INTRODUCTION

Although there has been many studies quoting ENT and rhinology complications, there have been none looking at the complication rates of one department with a single specialist rhinologist over a 5-year period.

PATIENTS AND METHODS

Over a 5-year period between 1998 and 2002, the number of operative procedures undertaken in the ENT department in a busy district general hospital was collected in a prospective manner.

RESULTS

A total of 10,768 ENT procedures were undertaken in the department which comprised four consultants and associated junior staff (SpRs/SASs/SHOs); 2507 of these procedures were rhinology cases. There were 39 recorded complications following nasal surgery, giving an overall rhinology complication rate of 1.56%. This included 12 postoperative nose bleeds (0.48%), 5 cases of infection following septal surgery (0.56%), 7 cases of septal perforation (0.75%) and various minor functional endoscopic sinus surgery (FESS) complications (2.17%). These figures are either below or within the quoted literature rates. There were no major complications or deaths recorded following nasal surgery.

CONCLUSIONS

These results compare favourably with those of other studies.

Evaluation of PCR testing of ethanol-fixed nasal swab specimens as an augmented surveillance strategy for influenza virus and adenovirus identification

Viral culture isolation has been widely accepted as the "gold standard" for laboratory confirmation of viral infection; however, it requires ultralow temperature specimen storage. Storage of specimens in ethanol at room temperature could expand our ability to conduct active surveillance and retrospective screenings of viruses with rapid and inexpensive real-time PCR tests, including isolates from remote regions where freezing specimens for culture is not feasible. Molecular methods allow for rapid identification of viral pathogens without the need to maintain viability. We hypothesized that ethanol, while inactivating viruses, can preserve DNA and RNA for PCR-based methods. To evaluate the use of ethanol-stored specimens for augmenting surveillance for detection of influenza viruses A and B and adenoviruses (AdV), paired nasal swab specimens were collected from 384 recruits with febrile respiratory illness at Fort Jackson, S.C., in a 2-year study. One swab was stored at ambient temperature in 100% ethanol for up to 6 months, and the other swab was stored at -70 degrees C in viral medium. For viral detection, frozen specimens were cultured for a variety of respiratory viruses, and ethanol-fixed specimens were tested with TaqMan (TM) probe and LightCycler SYBR green (SG) melting curve assays with at least two different PCR targets for each virus. The sensitivities of the TM and SG assays on specimens stored in ethanol for 1 month were 75% and 58% for influenza A, 89% and 67% for influenza B, and 93 to 98% and 57% for AdV, respectively. Lower specificities of the real-time assays corresponded to the increased detection of PCR-positive but culture-negative specimens. Influenza virus RNA was detected as well or better after 6 months of storage in ethanol.

Identification of larval-stage-specific antigens of Onchocerca volvulus uniquely recognized by putative immune sera from humans and vaccination sera from animal models

Immunity to Onchocerca volvulus is indicated by the existence of putative immune individuals (PI), who do not develop patent infections or clinical symptoms after living in endemic areas for extended periods of time. To gain insight into the nature of the humoral response of PI from Liberia and Ecuador, their sera and those of infected individuals were investigated and compared using western blots. The antigen preparations used were extracts of third- and fourth-stage larvae (L3 and L4, respectively), excretory-secretory proteins (ES-L3) and extracts of third-stage larvae (L3-day2) that had been cultured for 2 days, and extracts of nodular and skin microfilariae. Whereas some antigens were commonly recognized by all individuals, many stage-specific antigens (of 68, 60, 55, 46, 43, 42, 20 and 18 kDa in L3; 100, 88, 80, 50, 48, 45, 40 and 20 kDa in L3-day2; 110, 80 and 72 kDa in ES-L3; 48, 18, 16 and 14 kDa in L4; and 115, 60, 47, 43 and 17 kDa in skin and/or nodular microfilariae) were uniquely recognized by sera from PI. Some of the unique antigens were also recognized by sera from mice and a chimpanzee that were resistant to challenge after immunization with irradiated third-stage larvae. The results support the validity of the assumption that a unique status of immunity develops in certain individuals living in areas where onchocerciasis is endemic.

Onchocerca volvulus: a comparative study of in vitro neutrophil killing of microfilariae and humoral responses in infected and endemic normals

In vitro neutrophil-mediated microfilarial killing, humoral responses to crude adult worm antigens (OVAg) and to four recombinant Onchocerca antigens (GST-OV7, GST-OV103, GST-OV3.6, and MBP-OV16), as well as Western blot analysis to stage-specific Onchocerca proteins were studied in individuals from Bassa County, Liberia, infected with onchocerciasis and in endemic normals, defined as individuals without microfilaridermia. Both groups exhibited high levels of specific serum-dependent killing of microfilariae but could not be differentiated on the basis of these results. However, infected individuals had a significantly higher frequency of antibody response to OVAg (P = 0.0001) except GST-OV103. Based on the pattern of response to the different antigens, 17 categories of specific recognition were observed. Nine of these categories were common to both the infected individuals and the endemic normals, 2 were unique to the infected individuals, and 6 were unique to the endemic normals. Among the endemic normals, we identified a subcategory of individuals who had nondetectable levels of total IgG to OVAg by ELISA and had significantly lower IgG4 responses to OVAg. These same individuals demonstrated evidence of past infection, based on serum antibodies detectable by Western blot analysis to male and female adult worms and skin microfilariae, and had a positive response to two or less of the recombinant antigens. We believe that this subcategory may represent individuals with a unique status of immunity.

Onchocerca volvulus: in vitro cytotoxic effects of human neutrophils and serum on third-stage larvae

The cytotoxic effects of neutrophils co-cultured with infective third-stage larvae (L3) and autologous serum from three groups of individuals: infected (INF), non-patent endemic normals (EN) and non-endemic controls (NEC), were compared using a MTT (3-(4,5 dimethylthiazol-2yl)-2,5 diphenyl tetrazolium bromide) reduction assay as a biochemical parameter of larval viability. The MTT assay permitted the detection of L3 which had suffered varying levels of necrosis. The observations from this study indicate that infected individuals and endemic normals are capable of mounting a specific immune response against the infective L3. This is based on our findings of i) significantly greater numbers of L3 showed necrosis in neutrophil cultures of the INF and EN compared to those from the NEC, ii) a superior ability of cultures from these individuals to inhibit the molting of L3 to fourth-stage larvae, iii) IgG antibodies reactive with the surface of L3, detected by immunofluorescence in the serum of the INF and the EN and iv) recognition of specific antigens in extracts of L3 detected by Western blot analysis. The specific immune response directed against L3 is probably a significant immunological defense mechanism used to limit infection in endemic areas.

The bcl-2 proto-oncogene is overexpressed in systemic lupus erythematosus

Systemic Lupus Erythematosus (SLE) is a disease in which lymphoid hyper-reactivity occurs. Whether this is primary or secondary is not always clear. SLE occurs on a well defined genetic background including genes associated with the major histocompatibility complex (MHC) although family studies demonstrate that other genes must be involved as well. Other potential genes include those involved in intrinsic lymphoid hyper-reactivity, for example by preventing programmed cell death. Such examples exist in murine models of SLE, and in this study we provide evidence that one such controlling protein, bcl-2, is expressed in an increased proportion of both B and T cells in SLE patients. The increased expression was not readily related to disease activity measured by the SIS, nor by routine serological markers. This raises the possibility that the increased expression of bcl-2 seen in lymphoid cells from SLE patients may be of intrinsic genetic origin rather than being secondary to the auto-reactive process. Such increased expression could be expected to interfere with programmed cell death, to produce lymphoid hyper-reactivity and to contribute to the induction and maintenance of this prototypic systemic autoimmune disease.

Identification and characterization of an Onchocerca volvulus cDNA clone encoding a highly immunogenic calponin-like protein

The identification and characterization of a recombinant cDNA clone, designated OV9M, expressing an antigen present in Onchocerca volvulus infective larvae and adult stages is described. Clone OV9M was identified by screening a lambda gt11 cDNA expression library derived from adult O. volvulus mRNA using pooled rabbit antisera raised against the third (L3) and fourth (L4) stage larvae of the parasite. The cDNA clone encodes an open reading frame of 238 amino acids corresponding to a 27-kDa polypeptide. This polypeptide contains a series of five highly conserved repeats of 25 amino acids that are similar to repeats found in calponin, a protein previously only identified in vertebrate smooth muscle. Extension of the 5' end of the cDNA clone revealed two additional repeats extending the sequence to 378 amino acids, encoding a 41.8-kDa protein. Affinity purified antibodies, which bound specifically to the glutathione S-transferase-OV9M fusion polypeptide, recognize a series of antigens in extracts of O.volvulus microfilariae, L3, L4 and adult stages. The apparent molecular weight of the native OV9M protein in the adult is 45 kDa. Similar proteins are present in extracts of other nematodes including Caenorhabditis elegans, and antibodies from other filarial infections are cross reactive with glutathione S-transferase-OV9M fusion polypeptide. Immunoelectron microscopy revealed that the antigen encoded by this clone is present in the longitudinal muscles of the various larval stages and adult worms. Antibodies to the OV9M protein are present in 40-60% of both patently infected and non-patent individuals residing in onchocerciasis endemic areas.

Observations on coronary collateral communications and the control of flow in the coronary circulation of the dog

1. Pressure was measured in the small arterial anastomosing branches of the coronary vascular network. The mean value was 30 mm Hg not significantly different from the mean value of 33 mm Hg for peripheral coronary pressure measured distal to a ligature on the anterior descending branch of the left coronary artery. Evidence was adduced to show that either the anterior descending or the circumflex artery had the capacity to maintain network pressure at levels adequate for tissue perfusion.2. The network has both capacity and compliance. Filling of the network compliance during systole probably accounts for the systolic phase of coronary flow. Flow through the microcirculation is probably entirely diastolic, the combined compliance of the aorta and large vessels together with the network provides the necessary reservoir, the potential energy indicated by diastolic pressure provides the perfusion pressure head.3. Resistance of vessels between the aorta and network cannula (pre-net) was approximately double that of the microcirculation (post-net). The smaller pre-network vessels are of the order 70 mum in diameter. Both pre- and post-network vessels are vaso-active and respond similarly to adrenaline and haemorrhage.

Observations on temperature distribution in the cardiovascular system, thorax and abdomen of monkeys in relation to environment

1. Thermo-electric observations of temperature distribution in the ;core' area of monkeys and baboons are reported.2. Temperature gradients were shown to exist in the inferior vena cava, temperatures rising by a mean value of 0.2 degrees C at the entry of the renal veins and again by a further 0.2 degrees C at the level of the hepatic veins.3. Temperatures in the right atrium were on average 0.1 degrees C lower than in the inferior vena cava due to the return of relatively cooler blood from the superior vena cava.4. Net heat exchanges in the thorax were small. Right atrial and aortic blood temperatures were not significantly different and it was concluded that heat losses in the thorax were balanced by heat production in lungs and heart.5. The mean liver temperature was 0.1 degrees C higher than that of the aortic blood irrespective of the environment.6. The mean temperature recorded from the lumen of the jejunum was 0.2 degrees C warmer than the aorta in the ;warm' environment and 0.4 degrees C hotter than the aorta in the ;cool' environment. In both environments intrajejunal temperature was higher than the liver but the differential was increased by exposure to a ;cool' environment.7. Evidence is adduced to suggest that the gastro-intestinal tract in the body at rest is a major heat producer contributing about double the amount of heat generated by the liver.8. It is suggested that blood flow redistribution in the splanchnic area on exposure of the body to cold is the main cause of the change in aortic-jejunal and jejunal-liver differentials. Metabolic factors have, however, not been excluded.