Effects of Early Antiretroviral Therapy on the Composition and Diversity of the Fecal Microbiome of SIV-infected Rhesus Macaques (Macaca mulatta)

HIV-infected people develop reproducible disruptions in their gastrointestinal microbiota. Despite the suppression of HIV viremia via long-term antiretroviral therapy (ART), alterations still occur in gut microbial diversity and the commensal microbiota. Mounting evidence suggests these microbial changes lead to the development of gut dysbiosis-persistent inflammation that damages the gut mucosa-and correlate with various immune defects. In this study, we examined how early ART intervention influences microbial diversity in SIV-infected rhesus macaques. Using 16S rRNA sequencing, we defined the fecal microbiome in macaques given daily ART beginning on either 3 or 7 d after SIV infection (dpi) and characterized changes in composition, α diversity, and β diversity from before infection through 112 dpi. The dominant phyla in the fecal samples before infection were Bacteroidetes, Firmicutes, Spirochaetes, and Proteobacteria. After SIV infection and ART, the relative abundance of Firmicutes and Bacteroidetes did not change significantly. Significant reductions in α diversity occurred across time when ART was initiated at 3 dpi but not at 7 dpi. Principal coordinate analysis of samples revealed a divergence in β diversity in both treatment groups after SIV infection, with significant differences depending on the timing of ART administration. These results indicate that although administration of ART at 3 or 7 dpi did not substantially alter fecal microbial composition, the timing of early ART measurably altered phylogenetic diversity.

Blood and Blood Product Conservation: Results of Strategies to Improve Clinical Outcomes in Open Heart Surgery Patients at a Tertiary Hospital Are Maintained 4 Years after Initiation

Blood product usage is an important outcome for patients undergoing cardiac surgery. In 2015, our center made a concerted effort with multiple departments to focus on reducing transfusion rates in surgical patients requiring cardiopulmonary bypass (CPB). Specific changes included an upgrade of the oxygenator in mid-2015 and, in early 2016, implementation of a hemostasis management system (HMS) that used heparin dose-response titration assays for heparin and protamine management. A retrospective chart review demonstrated significant decreases in the quarterly average of patients receiving packed red blood cells (PRBCs) from a baseline of 26.7% to 22.7% following the oxygenator upgrade (p = .021) and from 22.7% to 8.8% following implementation of the HMS (p = .0017). Platelet usage decreased from an average of 50.5% during the baseline and oxygenator upgrade periods to 22.2% following implementation of the HMS (p < .0001). Usage of fresh frozen plasma (FFP) decreased from an average of 28.2% of cases during the baseline and oxygenator upgrade periods to 10.4% during 2016, and cryoprecipitate usage decreased from 38.5% to 15.4%. Heparin usage averaged 56,903 units before implementation of the HMS, decreasing to an average of 43,796 units following HMS implementation (p < .0001). During the same time periods, protamine usage averaged 340.3 mg and 183.2 mg, respectively. Because improvements achieved during quality initiatives may revert back to their pre-intervention state once the assessment period is over, we performed a second retrospective analysis to determine whether the improvements achieved were maintained during the 48 months following the initial study. During 2017-2020, quarterly average usage of blood products was as follows: PRBCs, 11.9%; platelets, 14.7%; FFP, 6.2%; and cryoprecipitate, 11.5%. Quarterly, average use of heparin and protamine were 31,556 ± 2,757 units and 189 ± 113 mg, respectively. These findings indicate that the improvements achieved were not limited to the duration of the initial quality initiative.

Protection of Newborn Macaques by Plant-Derived HIV Broadly Neutralizing Antibodies: a Model for Passive Immunotherapy during Breastfeeding

Preventing human immunodeficiency virus (HIV) infection in newborns by vertical transmission remains an important unmet medical need in resource-poor areas where antiretroviral therapy (ART) is not available and mothers and infants cannot be treated prepartum or during the breastfeeding period. In the present study, the protective efficacy of the potent HIV-neutralizing antibodies PGT121 and VRC07-523, both produced in plants, were assessed in a multiple-SHIV (simian-human immunodeficiency virus)-challenge breastfeeding macaque model. Newborn macaques received either six weekly subcutaneous injections with PGT121 alone or as a cocktail of PGT121-LS plus VRC07-523-LS injected three times every 2 weeks. Viral challenge with SHIVSF162P3 was twice weekly over 5.5 weeks using 11 exposures. Despite the transient presence of plasma viral RNA either immediately after the first challenge or as single-point blips, the antibodies prevented a productive infection in all babies with no sustained plasma viremia, compared to viral loads ranging from 103 to 5 × 108 virions/ml in four untreated controls. No virus was detected in peripheral blood mononuclear cells (PBMCs), and only 3 of 159 tissue samples were weakly positive in the treated babies. Newborn macaques proved to be immunocompetent, producing transient anti-Env antibodies and anti-drug antibody (ADA), which were maintained in the circulation after passive broadly neutralizing antibody clearance. ADA responses were directed to the IgG1 Fc CH2-CH3 domains, which has not been observed to date in adult monkeys passively treated with PGT121 or VRC01. In addition, high levels of VRC07-523 anti-idiotypic antibodies in the circulation of one newborn was concomitant with the rapid elimination of VRC07. Plant-expressed antibodies show promise as passive immunoprophylaxis in a breastfeeding model in newborns. IMPORTANCE Plant-produced human neutralizing antibody prophylaxis is highly effective in preventing infection in newborn monkeys during repeated oral exposure, modeling virus in breastmilk, and offers advantages in cost of production and safety. These findings raise the possibility that anti-Env antibodies may contribute to the control of viral replication in this newborn model and that the observed immune responsiveness may be driven by the long-lived presence of immune complexes.

Blood and Blood Product Conservation: Results of Strategies to Improve Clinical Outcomes in Open Heart Surgery Patients at a Tertiary Hospital

Blood product usage is a quality outcome for patients undergoing cardiac surgery. To address an increase in blood product usage since the discontinuation of aprotinin, blood conservation strategies were initiated at a tertiary hospital in Oakland, CA. Improving transfusion rates for open heart surgery patients requiring Cardiopulmonary bypass (CPB) involved multiple departments in coordination. Specific changes to conserve blood product usage included advanced CPB technology upgrades, and precise individualized heparin dose response titration assay for heparin and protamine management. Retrospective analysis of blood product usage pre-implementation, post-CPB changes and post-Hemostasis Management System (HMS) implementation was done to determine the effectiveness of the blood conservation strategies. Statistically significant decrease in packed red blood cells, fresh frozen plasma, cryoprecipitate, and platelet usage over the stepped implementation of both technologies was observed. New oxygenator and centrifugal pump technologies reduced active circuitry volume and caused less damage to blood cells. Individualizing heparin and protamine dosing to a patient using the HMS led to transfusion reductions as well. Overall trends toward reductions in hospital length of stay and intensive care unit stay, and as a result, blood product cost and total hospitalization cost are positive over the period of implementation of both CPB circuit changes and HMS implementation. Although they are multifactorial in nature, these trends provide positive enforcement to the changes implemented.

Religion

This article argues that religion should be fully integrated into cross-cultural research for four reasons: (a) religion, by itself, occupies a substantial role in people's lives across different cultures; (b) religion has been found to be a strong predictor of important life domains among individuals all over the world; (c) religion has a strong influence on cross-cultural dimensions; and (d) culture also influences and shapes religious beliefs and practices. The authors present a five-dimensional framework of religion and provide recommendations on ways it can be integrated within cross-cultural research.

Beliefs about cybersex and Internet-mediated sex of Latino men who have Internet sex with men: relationships with sexual practices in cybersex and in real life

Cybersex (engaging in sexual self-stimulation while online with another person) and meeting partners for sex are commonly reported among men who have Internet sex with men (MISM). We studied 1,026 Latino MISM in the US and constructed a scale to measure beliefs about cybersex. Respondents were recruited to an online Internet study and compensated for their effort. Factor analysis indicated that there were three dimensions: (1) liking cybersex: perceived anonymity and safety of cybersex; (2) potential for greater IRL interaction in seeking partners on the Internet; and (3) a dimension of negative beliefs about Internet contacts which was not psychometrically stable. Safety referred to physical and HIV-related safety. We formed two scales to describe the first two dimensions. Respondents who were high on the 'liking cybersex: perceived anonymity and safety' scale were more likely than low scorers to use chat-rooms and webcams. They were also more likely than low scorers to have had cybersex and phone sex before meeting. Those who were high on the 'IRL interaction' scale were more likely than low scorers to use e-mail, bulletin boards and paid websites. However, there was significantly less disclosure about HIV status and discussion about safer sex by those higher on the 'IRL interaction scale', and when sex in real life did occur, those higher on the 'IRL interaction' scale were more likely to have receptive oral or anal sex, whereas those high on the 'liking cybersex: perceived anonymity/safety' scale were less likely to have insertive sex or be drunk/high. MISM scoring high on the 'IRL interaction' scale were significantly more likely than low scorers to prefer to meet partners on the Internet. We discuss the implications of the Internet for MSM and for sexual IRL interactions in the Internet age.

Surgical treatment of chondrosarcoma of the sternum

Purpose: We reviewed all tumours of the sternum referred to The London Bone and Soft Tissue Tumour Service between 1956 and 1997 inclusive.

Patients and results: There were eight patients with this pathology, the male to female ratio was 3:1 and their mean age was 53 years. Of these patients, three are alive and disease free, one is alive with recurrence, and four have died, two of the consequences of the disease and two of unrelated causes. Surgery is the principal treatment of these tumours both for excision and subsequent reconstruction.

Discussion: Extended disease-free survival is possible with correct diagnosis, complete excision at the first operation, appropriate skeletal reconstruction, adequate skin cover and appropriate postoperative support and follow-up.

Characteristics of latino men who have sex with men on the internet who complete and drop out of an internet-based sexual behavior survey

To identify biases and threats to validity of Internet survey data collection on HIV-related risk behaviors, we studied 1,546 Latino men who have sex with men on the Internet recruited through banner impressions on a leading national gay Internet site. The study could be completed in English or Spanish. Of those commencing, 33.6% dropped out before completing the 450-field questionnaire. None of the linguistic variables (level of use of Spanish or English) predicted dropout. However, dropouts were more likely to identify as Puerto Rican or Black, to reject the $20 compensation or offer it to a charity, to not have met men for sex on the Internet, to identify as bisexual or heterosexual, and to use Web sites or personal ads for contact and to use the Internet less at home than those who completed the study. Men in seroconcordant monogamous relationships and those who had not met a man for sex on the Internet were also more likely to drop out. These data suggest that there are no linguistic and few demographic and Internet use variables that are associated with dropout. Issues of compensation and respondent characteristics that make it likely that there will be a large number of inapplicable data fields in the questionnaire appear to be significant predictors of dropout. Although there were many data missing, the dropouts did not appear to be at greater HIV-associated risk than the completers. The fact that there appear to be few systematic demographic or Internet use biases in dropouts suggests that the completers do not represent a seriously skewed sample of those Latinos who commence the Internet survey.

Exploring security and privacy issues in hospital information system: an Information Boundary Theory perspective

A small community hospital (67 beds) in Central New York was undergoing a major technological change within the organization, as they move from the use of several legacy information systems to a hospital-wide information system. The focus of the present research is to explore the privacy and security information issues using a framework called Information Boundary Theory [Stanton, 2002]. IBT explains the motivational factors that lead to the revelation or disclosing of information.

Murder misdiagnosed as SIDS: a perpetrator's perspective

AIMS

Child murder misdiagnosed as sudden infant death syndrome (SIDS) is a difficult area to study. We present a perpetrator's descriptions to enrich clinicians' knowledge of possible presenting features of this phenomenon.

METHODS

Interview material was collected as part of a qualitative study of maternal filicide performed from a naturalistic paradigm in order to access the perpetrators' view of events. The woman participant has been convicted for three child murders and two attempted murders which were initially misdiagnosed as SIDS. Interviews were done in the participant's home with her partner present, while she was on leave from prison. Semi-structured interviews were conducted, recorded, transcribed, and analysed for themes. Specific ethical permission was gained to present this case in isolation and the paper was written in consultation with the woman described.

RESULTS

She described initial intense attachment to her first victim and described killing her because she was unable to bear her apnoea attacks and her fear of losing her. She described difficulty grieving for this child and subsequent failure to attach to her next child or feel for the other victims.

CONCLUSIONS

Expressions of intense attachment to an infant and description of intense grief over a death in a way which engages compassion should not deter a paediatrician from considering the possibility of the parent having killed the child.

A nurse's aid to clinical selection of pressure-reducing equipment

The selection of appropriate pressure-relieving equipment for individuals in the community is an important process in the prevention of pressure ulcers. The clinical decision is made by community nurses who are accountable for their actions and who therefore have to have clear rationale for the decisions they make. Risk tools are not a completely reliable or valid method of assessing patients. The current national guidelines (National Institute for Clinical Excellence (NICE), 2001) are not specific in relation to the selection or choice of equipment. This article explores how these decisions are made.

A truly hybrid interventional MR/X-ray system: feasibility demonstration

A system enabling both x-ray fluoroscopy and MRI in a single exam, without requiring patient repositioning, would be a powerful tool for image-guided interventions. We studied the technical issues related to acquisition of x-ray images inside an open MRI system (GE Signa SP). The system includes a flat-panel x-ray detector (GE Medical Systems) placed under the patient bed, a fixed-anode x-ray tube overhead with the anode-cathode axis aligned with the main magnetic field and a high-frequency x-ray generator (Lunar Corp.). New challenges investigated related to: 1) deflection and defocusing of the electron beam of the x-ray tube; 2) proper functioning of the flat panel; 3) effects on B0 field homogeneity; and 4) additional RF noise in the MR images. We have acquired high-quality x-ray and MR images without repositioning the object using our hybrid system, which demonstrates the feasibility of this new configuration. Further work is required to ensure that the highest possible image quality is achieved with both MR and x-ray modalities.

A qualitative study of filicide by mentally ill mothers

OBJECTIVE

To examine descriptions of maternal filicide committed in the context of major mental illness from the frame of reference of a group of perpetrators.

METHOD

Participants were accessed via their treating psychiatrists. A naturalistic paradigm was used. Semi-structured individual interviews were audio-taped and transcribed. Theme analysis of the transcripts was done by repeated reading of transcripts and coding utterances, individually, then jointly by the authors.

RESULTS

Six women were identified, and interviewed. They described intense investment in mothering their child(ren). Descriptions of external stressors were not extreme, but the experience of illness was described as extremely stressful. They described little or no warning or planning. Their descriptions of their children were unremarkable. Motivation was described as altruistic or as an extension of suicide. They described regretting the killings and feeling responsible even though they knew they had been ill at the time.

CONCLUSIONS

The findings underline the difficulty of identification of risk and prevention of maternally ill filicide in the women who described being very caring towards their children, and little or no warning of filicidal urges. They may be better understood in terms of the illness than individual stress or psychodynamics.

Kinematics of the wrist. Evidence for two types of movement

We enrolled 34 normal volunteers to test the hypothesis that there were two types of movement of the wrist. On lateral radiographs two distinct patterns of movement emerged. Some volunteers showed extensive rotation of the lunate with a mean range of dorsiflexion of 65 degrees, while others had a mean range of 50 degrees. The extensive rotators were associated with a greater excursion of the centre of articulation of the wrist. It is suggested that dynamic external fixation of a fracture of the distal radius carries with it the risk of stretching the ligaments or causing volar displacement at the site of the fracture.

Double-blind randomized controlled trial of glutamine-enriched polymeric diet in the treatment of active Crohn's disease

BACKGROUND

Glutamine is traditionally considered a nonessential amino acid but may be conditionally essential in patients with catabolic conditions. Glutamine-supplemented foods in these patients have been shown to prevent deterioration of gut permeability, protect against the development of intestinal mucosal atrophy, and improve nitrogen balance. Animal models of inflammatory bowel disease suggest that glutamine-enriched enteral diets may lead to less severe intestinal damage, less weight loss, improved nitrogen balance, and reduced disease activity. The purpose of the current study was to compare the efficacy of a glutamine-enriched polymeric diet with a standard low-glutamine polymeric diet in the treatment of active Crohn's disease.

METHODS

Eighteen children with active Crohn's disease were randomly assigned to receive a 4-week course of either a standard polymeric diet with a low glutamine content (4% of amino acid composition; group S) or a glutamine-enriched polymeric diet (42% of amino acid composition; Group G). The two diets were isocaloric and isonitrogenous with an identical essential amino acid profile. Remission rates were analysed on an intent-to-treat basis. Changes in clinical and laboratory parameters of disease activity were also compared after 4 weeks of nutritional treatment.

RESULTS

Two of the children, both in group G, were withdrawn from the trial because of nontolerance of the diet. There was no difference between the two groups in proportion of patients achieving remission (intent-to-treat basis): 5 (55.5%) of 9 in group S versus 4 (44.4%) of 9 in group G (p = 0.5). Improvement in mean paediatric Crohn's disease activity index (PCDAI) was significantly more in group S (p = 0.002) but changes in orosomucoid level, platelet count, and weight were not different between the groups.

CONCLUSIONS

The findings suggest that a glutamine-enriched polymeric diet offers no advantage over a standard low-glutamine polymeric diet in the treatment of active Crohn's disease. Rather, it appears to be less effective in improving PCDAI. The reported beneficial effects of glutamine seen in many catabolic states must be viewed with caution when extrapolating to the management of Crohn's disease.

The cost of living: kidney dialysis, rationing and health economics in Britain, 1965-1996

How important is research in shaping policy when a new life-saving medical technology becomes available, but happens to be very expensive? Taking the case of kidney dialysis, this paper argues that the emerging discipline of health economics had little influence relative to national differences in health service organization and cultures of expectation of provision. Paradoxically, the most effective covert rationing was achieved under the British NHS which ostensibly provides free care for all, while the uncentralised market system in the US gave way, on this issue, to almost universal state-subsidised provision. Under the British system, the most cost-effective options for renal care tended to flourish, but some patients were turned away. Physicians have been held responsible for complying with covert rationing: this paper suggests that early gearing towards socially-useful survival filtered back to selection at primary level, possibly continuing long after specialists wished to expand. Public outcry, though muted, reached parliament and caused minor shifts in policy; the main aim of the voluntary pressure campaign, to release more organs for transplant through 'opt-out', remained unrealised in the UK. Yet dialysis was targetted for expansion in the 1980s just at the point when health economists were presenting evidence for its low cost-effectiveness compared with other expensive interventions. According to the main strand of argument in this paper, comparisons with other countries and between regions were most influential in breaking the hold of covert rationing: policy making by embarrassment. However, in the 1990s, there are both theoretical discussions of explicit rationing, and open intiatives afoot to target dialysis for rationing.

Reticulate evolution and the origins of ribosomal internal transcribed spacer diversity in apomictic Meloidogyne

Among root knot nematodes of the genus Meloidogyne, the polyploid obligate mitotic parthenogens M. arenaria, M. javanica, and M. incognita are widespread and common agricultural pests. Although these named forms are distinguishable by closely related mitochondrial DNA (mtDNA) haplotypes, detailed sequence analyses of internal transcribed spacers (ITSs) of nuclear ribosomal genes reveal extremely high diversity, even within individual nematodes. This ITS diversity is broadly structured into two very different groups that are 12%-18% divergent: one with low diversity (< 1.0%) and one with high diversity (6%-7%). In both of these groups, identical sequences can be found within individual nematodes of different mtDNA haplotypes (i.e., among species). Analysis of genetic variance indicates that more than 90% of ITS diversity can be found within an individual nematode, with small but statistically significant (5%-10%; P < 0.05) variance distributed among mtDNA lineages. The evolutionarily distinct parthenogen M. hapla shows a similar pattern of ITS diversity, with two divergent groups of ITSs within each individual. In contrast, two diploid amphimictic species have only one lineage of ITSs with low diversity (< 0.2%). The presence of divergent lineages of rDNA in the apomictic taxa is unlikely to be due to differences among pseudogenes. Instead, we suggest that the diversity of ITSs in M. arenaria, M. javanica, and M. incognita is due to hybrid origins from closely related females (as inferred from mtDNA) and combinations of more diverse paternal lineages.

APOE is linked to Alzheimer's disease in a large pedigree

Although previous association studies have demonstrated that the APOE4 allele is a risk factor for Alzheimer's disease (AD), its value for the prediction of AD in individuals is <100%. The limited predictive value of epsilon4 is also seen in multiply affected families where the epsilon4 allele is not tightly linked to AD. We analyzed a large pedigree multiply affected with AD by lod score linkage analysis at the known loci associated with AD. In this pedigree, the APOE/APOCI gene area was linked to the development of AD, while no linkage was detected to any of the other loci known to be associated with the disease. In this family, then, the inheritance of an epsilon4 allele is highly associated with the early development of the disease (mean age of onset, 62 years), and is a good predictor of disease. However, given the wealth of evidence for association, but not linkage, of APOE4 to AD, we believe this finding suggests that another factor (or factors) interact(s) with APOE to precipitate early disease, and produce positive linkage results. The nature of this factor presently remains unknown.

No association between the intronic presenilin-1 polymorphism and Alzheimer's disease in clinic and population-based samples

Mutations in the Presenilin 1 (PS1) gene on chromosome 14 cause most early-onset familial Alzheimer's disease (AD). An intronic polymorphism in the PS1 gene was recently identified and reported to be associated with late-onset AD [Wragg et al., Lancet 347: 509-512, 1996]. The authors found an excess of homozygotes for the more common allele (allele 1) in AD cases, associated with an approximate doubling of risk. In the present study, we report the PS1 polymorphism distributions in clinic and population-based samples. We were not able to replicate the findings of Wragg et al. [1996]. Our results are consistent with those of other researchers and do not support the conclusion that the PS1 polymorphism is associated with late-onset AD.

The direction of the Whitacre needle aperture affects the extent and duration of isobaric spinal anesthesia

The use of Whitacre spinal needles results in directional flow out of the needle aperture, diverting local anesthetic from the longitudinal axis of the needle. Thus, a change in orientation of the needle aperture would be expected to result in a different local anesthetic distribution in the subarachnoid space. We studied 40 outpatients undergoing elective knee arthroscopy under spinal anesthesia with 60 mg plain lidocaine 2% in a prospective, double-blinded manner. Patients were randomly assigned to either Group I (needle aperture oriented in a cephalad direction throughout intrathecal injection) or Group II (aperture directed caudally). Onset and offset of sensory and motor block were analyzed at frequent intervals. Times to completion of ambulatory milestones, including discharge, were recorded. Group I was characterized by a higher sensory level (T 3.4 +/- 1.3 vs T 6.6 +/- 2.8, P < 0.001). Group I had significantly shorter duration of lumbar sensory anesthesia (149.2 +/- 30.6 min vs 177.8 +/- 23.5 min, P < 0.01) and motor blockade (117.6 +/- 26.1 min vs 150.0 +/- 22.8 min, P < 0.001). Mean time to outpatient discharge was approximately 32 min shorter in Group I. The orientation of the Whitacre needle aperture exerts a major influence on sensory level, as well as the duration of isobaric lidocaine spinal anesthesia.

Evolution of the AT-rich mitochondrial DNA of the root knot nematode, Meloidogyne hapla

Mitochondrial DNA of the root knot nematode Meloidogyne hapla was investigated for intraspecific diversity and divergence from other parthenogenetic root knot nematodes. A 1,900-bp fragment containing COII, tRNAHis, 16S rRNA, ND3 and Cyt b genes has been cloned and sequenced from one individual and an 1,188-bp region within this region was sequenced from four other Australian isolates. M. hapla mtDNA is more than 80% AT-rich, like other Meloidogyne spp. Nucleotide diversity within M. hapla is some 10-fold higher than across three other parthenogenetic species of root-knot nematode (M. arenaria, M. javanica, and M. incognita), implying an earlier origin for M. hapla. Nucleotide divergence between M. hapla and its congener M. javanica is as great as that between Ascaris suum and Caenorhabditis elegans, members of different nematode subclasses, while amino acid sequence difference between Meloidogyne is more than twice as great. This is interpreted as an AT-bias-induced acceleration of the amino acid substitution rate, over and above saturation of nucleotide divergence in the strongly AT-biased DNA, on three lines of evidence: (1) in conserved blocks in 16S rDNA congeneric Meloidogyne have no more differences than between A. suum and C. elegans; (2) the Meloidogyne lineage has more amino acid changes relative to the Ascaris/Caenorhabditis lineage with respect to four of five outgroups, the exceptional outgroup being the only species (Apis) as AT-rich as Meloidogyne; and (3) between the two Meloidogyne there are more first and second but fewer third codon position changes than between the other nematode species. M. hapla is also found to contain a 102-bp tandem repeat of at least 40 copies; a size, arrangement, and position the same as in M. javanica, but sequence comparisons did not demonstrate homology between the two repeats.

Digital pressure during interscalene block is clinically ineffective in preventing anesthetic spread to the cervical plexus

The application of digital pressure above the injection site during interscalene block has been advocated to prevent cephalad spread of local anesthetic. In prior studies, radiographs taken immediately after interscalene injection of radiographic contrast have supported this concept. However, the clinical efficacy of digital pressure has not been previously tested. If digital pressure were effective in inhibiting cephalad spread of local anesthetic, attenuation of both hemidiaphragmatic paresis and the resulting compromise in pulmonary function would be expected. Sensory, motor, and pulmonary effects were prospectively evaluated in 20 patients presenting for elective shoulder surgery. Patients were randomly assigned to receive interscalene block with or without digital pressure. No clinical differences were seen between groups. All 20 patients had ipsilateral hemidiaphragmatic paresis by ultrasonographic evaluation and large mean decreases in forced vital capacity, 31.2% +/- 7.8% (with digital pressure), 33.7% +/- 12.8% (without digital pressure), and forced expiratory volume at one second, 27.9% +/- 9.3% (with digital pressure), 33.7 +/- 12.8% (without digital pressure). Peak sensory level of anesthesia to pinprick was not significantly different between groups, each group having mean levels of C-2 to C-3. Digital pressure was ineffective in limiting the flow of local anesthetic into the cervical plexus. Digital pressure influenced neither the incidence of diaphragmatic paresis nor the resulting large decreases in pulmonary function that result from interscalene block.

Combined spinal-epidural anesthesia for outpatient surgery. Dose-response characteristics of intrathecal isobaric lidocaine using a 27-gauge Whitacre spinal needle

BACKGROUND

Combined spinal-epidural anesthesia (CSE) may offer theoretic advantages for outpatient surgery, because it produces the rapid onset of spinal anesthesia, with the option to extend the blockade with an epidural catheter. In this study, the authors attempted to determine an appropriate initial dose of a short-acting local anesthetic, 2% lidocaine, to administer for outpatient knee arthroscopy using CSE.

METHODS

Data were collected from 90 patients undergoing outpatient knee arthroscopy. Using a double-blinded, prospective study design, patients were randomly assigned to receive CSE with an initial dose of intrathecal 2% lidocaine of 40, 60, or 80 mg. A 27-G 4 11/16-inch Whitacre needle was placed through a 17-G Weiss needle. Onset and regression of sensory anesthesia and motor blockade were measured by a blinded observer at frequent intervals.

RESULTS

All 90 patients had adequate anesthesia. Durations of thoracic and lumbar sensory and lower limb motor blockade were significantly shorter in the 40-mg group compared with the 60- or 80-mg groups (P < 0.0002 Mantel-Cox, Survivorship Analysis). Indices of neural blockade resolved 30-40 min more rapidly in the 40-mg group than in either the 60- or 80-mg group. Times to urinate, site upright in a chair, take oral fluids, and be discharged were all significantly shorter (between 30 and 60 min) in the 40-mg group compared with the 60- and 80-mg groups (P < 0.01). Seven patients required intraoperative epidural supplementation: three in the 40-mg group, three in the 60-mg group, and one in the 80-mg group.

CONCLUSIONS

Combined spinal-epidural anesthesia with a 40-mg initial intrathecal dose of lidocaine provided reliable anesthesia for knee arthroscopy. Duration of spinal anesthesia with lidocaine was dose related.

Planning for physician succession: no longer a luxury

Many physicians are opting for early retirement rather than contend with the increasing loss of control within the changing health care environment. Unfortunately, these retirements are often abrupt--the physician is unaware until it's too late that quick transitions to new successors can yield disastrous financial results. Physicians sometimes overestimate the intrinsic value of their practices. Sometimes they are emotionally unprepared for the change, and bail out at the last minute. In either case, unplanned successions often result in a serious loss of practice value for the physician and a loss of market share for affiliated hospitals and groups. Physicians and administrators must work together to prepare a succession plan allowing adequate time to phase in the new successor. This helps maintain practice value, ensuring there are no unpleasant surprises when the physician retires. In this article, the author also provides a checklist containing succession plan guidelines.

Contradictions in British vaccine policy on hepatitis B

A vaccine for hepatitis B became available in the UK from 1982, but it did not solve the public health dilemmas presented by the disease. In the decade that followed, epidemiologically important groups such as intravenous drug users and gay men were not targetted, while the groups of health workers at the centre of policy concern received little vaccine. This paper draws on models of diffusion, the pattern of the disease, and previous policies on screening, to explain the restricted vaccine policy which was a field for contention through the 1980s and into the 1990s.

What shapes vaccine policy? The case of hepatitis B in the UK

Comparison of hepatitis B vaccine policy with other cases in the past is complicated by the restricted modes of transmission of this disease, which affects relatively few people in the UK. Still, considerations of cost, fear of contamination, divisions of opinion within the medical profession, and regional dispersal of authority are all factors--analysed for other vaccines--which help to explain the limited UK central policy on hepatitis B immunization observed through the 1980s. An important issue, in previous debates on vaccine policies, has been the conflict between public health interests and the rights of individuals to eschew health interventions imposed by the state. It is argued here that this question fed into hepatitis B vaccine policy in an oblique manner, via policy on screening for hepatitis B in the 1970s; minimal screening mainly of selected groups of health workers was favoured, maximizing individual rights. Changes to hepatitis B vaccine policy can be traced, linked with international policy, pharmaceutical company pressure, advances in vaccine technology, and questions of legal liability. The most accurate predictor for vaccine policy appears to have been screening policy. Will this apply to AIDS, which is epidemiologically similar to hepatitis B?

Identification of a receptor-binding region in the core segment of the human anaphylatoxin C5a

In order to identify regions of C5a that contribute to receptor binding and functional activity of the anaphylatoxin, a series of peptides was synthesized in which core segments have been attached to C-terminal segments via native peptidic or disulfide bonds. It has been found that residues Arg40 and Arg46 in the loop-3 region of the core induce a 1000-fold increase in the affinity of the disordered C-terminal segment of C5a. The results obtained from this work lead to the conclusion that the loop-3 region is most likely the core binding site of C5a.

Single versus staged epidural injections of 0.75% bupivacaine: pharmacokinetic and pharmacodynamic effects

Epidural anesthesia may be performed as a single injection or by staged doses. Thirty patients undergoing primary total hip replacement were randomly assigned to have epidural anesthesia using a single injection or a staged technique with 25 mL of 0.75% bupivacaine. Arterial plasma bupivacaine concentrations were significantly higher in the single injection group for the first 15 min but were not significantly different thereafter. Peak bupivacaine concentrations did not differ significantly between groups, but the time to achieve the peak concentration was delayed by staging injections (P = 0.001). Hemodynamic effects were similar between groups. Resolution of thoracic sensory block through T12 and duration of motor block measured by Bromage scale were both significantly longer in the staged injection group (P < 0.01). The method of epidural injection may affect resolution of neural block and the time to reach peak arterial plasma concentration of local anesthetic.

Low, but strongly structured mitochondrial DNA diversity in root knot nematodes (Meloidogyne)

Root-knot nematodes (genus Meloidogyne) have been the subject of recent and numerous studies of genetic variation because of the need to develop molecular diagnostics for the four globally distributed, parthenogenetic species that are significant agricultural pests. Our analysis of Meloidogyne mtDNA improves on previous studies: (i) by examining restriction site polymorphism among a large number of isolates also characterized for standard morphological, host range and allozyme phenotypes; (ii) by using higher resolution electrophoretic techniques; and (iii) by mapping variable restriction sites with reference to the complete nucleotide sequence. This revealed fivefold less sequence divergence (< 0.6%) between variants than estimated in previous restriction fragment length polymorphism (RFLP) studies, but perfect correspondence between mtDNA haplotype and allozyme (esterase) phenotypes. The mtDNA variation, although limited, is strongly structured with as much divergence between two lineages of Meloidogyne arenaria as between either of these and Meloidogyne javanica. The low diversity of mtDNAs suggests that these parthenogenetic lineages arose from distinct but closely related sexual females, a pattern seen in other parthenogenetic complexes. In contrast to the concordance between mtDNA and allozyme markers, there were several discrepancies between the traditional methods of identification. We suggest that further studies of these nematodes should focus on well defined genetic groups, whether or not these coincide with existing taxonomic units.

Current emergency treatment of severe migraine headaches

OBJECTIVE

To compare the efficacy of the combination of meperidine and hydroxyzine IM, versus dihydroergotamine and metoclopramide IV in the treatment of severe migraine headaches.

DESIGN

This was a randomized double-blind, double-dummy study.

SETTING

Established patients, whose headache had failed to respond to their usual abortive agent, were invited to an out-patient headache clinic for the study.

PATIENTS

Twenty-eight patients, diagnosed as suffering from either migraine headache or chronic daily headache, were screened on arrival to exclude life-threatening causes.

INTERVENTION

Group A (14 patients) received dihydroergotamine 1mg and metoclopramide 10mg IV and a placebo injection IM, and Group B (14 patients) received meperidine 75mg and hydroxyzine 75mg IM and a placebo injection IV.

MAIN OUTCOME MEASURES

Patients rated their headaches on a scale of 0-3 prior to treatment and again at 30 and 60 minutes.

RESULTS

Both groups experienced improvement in headache severity. (Group A P = 0.001 and Group B P = 0.003). Improvement in pain scale score was greater for Group A than Group B. (P = 0.006). The number of patients having a mild or no headache in Group A (13/14) was significantly greater than Group B (3/14). (P < 0.001)

CONCLUSIONS

The combination of dihydroergotamine and metoclopramide IV should replace the standard IM narcotic and anti-emetic as the parenteral treatment of choice for severe migraine headache.

Protection of DNA from high LET radiation by two OH radical scavengers, tris (hydroxymethyl) aminomethane and 2-mercaptoethanol

The effect of high linear energy transfer (LET) radiation on DNA in vitro, both in protective and non-protective environments was investigated. Two hydroxyl radical scavengers, tris(hydroxymethyl) aminomethane and 2-mercaptoethanol, were compared for their ability to protect SV40 DNA from radiation damage over a wide LET range. At comparable OH scavenging capacities, significant differences were found between these protective agents, indicating that other, radical scavenger-dependent processes affected the extent to which the DNA was protected. In general, a decrease in single-strand breaks (SSBs) relative to double-strand breaks (DSBs) was observed as LET increased. This effect was more pronounced when a radioprotector was present. Comparison of the relative biological efficiency (RBE) of radiation damage as LET increased showed a peak of DSB production in the mid-LET range. These data agree with measurements made by Christensen et al. (1972). An explanation for this increase in DSB production efficiency has been proposed based on the particle track structure of high-LET radiation.

Clinical experience with patient administered subcutaneous dihydroergotamine mesylate in refractory headaches

This study examines the practicality and efficacy of dihydroergotamine mesylate (DHE) when self-administered subcutaneously in a population of refractory headache patients. Forty-three patients with chronic daily headache or migraine headache without aura, who had been taught self-injection of DHE either through the Raskin Protocol or in an outpatient headache clinic, were contacted by telephone and administered a questionnaire regarding usage and results from DHE injection. Ninety-two percent of patients could successfully administer DHE. Forty-six percent of patients experienced 90% or greater relief of pain and the majority of patients (77%) had greater than 50% relief. Emergency room use was decreased in 83% and 80% preferred DHE to their previous therapy. While side effects were common (79%), only four patients (9%) stopped DHE for this reason. No convincing evidence for the development of rebound headaches due to DHE was found in this sample.