Experience with microaneurysm formation at the basilar terminus in the rabbit elastase aneurysm model

BACKGROUND AND PURPOSE

Intracranial aneurysms have been induced in mice, rats, rabbits, and primates through carotid artery ligation. We reviewed our experience with RCCA ligation to quantify the rate of aneurysm formation in rabbits.

MATERIALS AND METHODS

In 30 consecutive New Zealand white rabbits, the RCCA was ligated during surgery to create elastase-induced aneurysms. The basilar artery and its bifurcation were harvested at various time points after surgery, including 8 weeks (n = 5), 13 weeks (n = 3), 14 weeks (n = 2), 16 weeks (n = 4), 17 weeks (n = 4), 30 weeks (n = 6), and 33 weeks (n = 6). All specimens were embedded in paraffin and sectioned at 5 microm in a coronal orientation, to show the basilar bifurcation and its branches. All sections were stained with HE. After the sections were evaluated and the photomicrographs were taken, the sections were de-stained and re-stained with VVG staining for elastin.

RESULTS

The IEL was intact and continuous at the BT in all 30 rabbits, as was the medial layer. No bulge-like localized dilation, to suggest microaneurysm or nascent aneurysm formation, was observed at the BT in any subject. There were small (0.08 +/- 0.02 mm in diameter) concave structures along the P1 segments in 5 (16.7%) of 30 rabbits. On adjacent tissue sections, each of these 5 structures was shown to be branch vessels with intact IELs.

CONCLUSIONS

In our rabbit model, unilateral RCCA ligation does not induce microaneurysm formation.

Intrinsic pathway-mediated apoptosis in elastase-induced aneurysms in rabbits

BACKGROUND AND OBJECTIVES

The pathophysiology of saccular aneurysms is complex and multifactorial. The aim of the present study was to understand the mechanism of apoptosis in an elastase-induced aneurysm model in rabbits.

MATERIALS AND METHODS

Elastase-induced saccular aneurysms were created at the origin of the right common carotid artery in 20 rabbits. Aneurysm samples were harvested at 2 and 12 weeks after creation. Expression of apoptosis-associated proteins, including caspases and bcl-2 proteins, were assessed by Western blot analysis (n = 5 at both time points). Terminal deoxynucleotidyltransferase-mediated dUTP nick end-labeling (TUNEL) staining, which indicates the presence of apoptosis, was performed in tissue sections (n = 5 at both time points). The unoperated contralateral common carotid artery was used as a control.

RESULTS

Expression of active caspase-3, the final executioner of apoptosis, and caspase-9, the mediator of the intrinsic mitochondrial pathway, was observed in aneurysms at 2 weeks, whereas the expression of activated caspase-8, the mediator of the extrinsic death receptor pathway, was absent at both time points. Expression of antiapoptotic proteins, Bcl-2 and phospho-Bad, was down-regulated in aneurysms compared with controls at 2 weeks. None of these proteins were differentially expressed at 12 weeks. These results were confirmed by the presence of TUNEL-positive cells in some aneurysms at the early time point.

CONCLUSIONS

In this study of elastase-induced aneurysms in a rabbit model, activation of apoptosis is mediated predominantly by the Bcl-2-mediated intrinsic pathway through the activation of caspase-9.

Evaluation of a clinical scoring scale to direct early appropriate therapy in heparin-induced thrombocytopenia

Background. Heparin-induced thrombocytopenia (HIT) is a serious adverse effect associated with heparin therapy. Current laboratory confirmation for immune mediated HIT often results in false positives and unnecessary treatment, exposing individuals to possible complications. As a result, clinical evaluation has been recommended in conjunction with laboratory testing. We hypothesize that utilization of a clinical scoring scale, the 4T’s, will result in the initial appropriate therapy for suspected HIT.

Methods. This is a retrospective chart review of 108 patients who underwent ELISA testing for HIT at a university hospital. The 4T’s scale was applied, stratifying individuals into low, intermediate, and high-risk categories. Each risk score was compared to the ELISA results to determine if the 4T’s can predict the diagnosis of HIT and result in appropriate management. ELISA optical density scores as well as incidence of adverse events were also compared among risk categories.

Study Results. Individuals with low risk correlate with a negative ELISA compared to intermediate and high-risk individuals (p = 0.01 and p<0.01) and also were significantly more likely to predict institution of appropriate therapy (p<0.01). Median optical density scores were 0.184 (0.046—2.116), 0.226 (0.067—1.887), and 0.476 (0.096—1.309) for low, intermediate, and high 4T scores. Major adverse events include thrombosis and bleeding.

Conclusions. Individuals with low risk were more likely to receive initial, appropriate therapy and were also significantly more likely to have a negative ELISA test result. Individuals with low risk determined by the 4T score therefore may have therapy and serologic testing for HIT withheld.

EEG ALPHA SENSITIZATION IN INDIVIDUALIZED HOMEOPATHIC TREATMENT OF FIBROMYALGIA

Fibromyalgia (FM) patients show evidence of sensitizability in pain pathways and electroencephalographic (EEG) alterations. One proposed mechanism for the claimed effects of homeopathy, a form of complementary medicine used for FM, is time-dependent sensitization (TDS, progressive amplification) of host responses. This study examined possible sensitization-related changes in EEG relative alpha magnitude during a clinical trial of homeopathy in FM. A 4-month randomized, placebo-controlled double-blind trial of daily orally administered individualized homeopathy in physician-confirmed FM, with an additional 2-month optional crossover phase, included three laboratory sessions, at baseline, 3 and 6 months (N = 48, age 49.2 +/- 9.8 years, 94% women). Nineteen leads of EEG relative alpha magnitude at rest and during olfactory administration of treatment and control solutions were evaluated in each session. After 3 months, the active treatment group significantly increased, while the placebo group decreased, in global alpha-1 and alpha-2 during bottle sniffs over sessions. At 6 months, the subset of active patients who stayed on active continued to increase, while the active-switch subgroup reversed direction in alpha magnitude. Groups did not differ in resting alpha. Consistent with the TDS hypothesis, sniff alpha-1 and alpha-2 increases at 6 months versus baseline correlated with total amount of time on active remedy over all subjects (r = 0.45, p = .003), not with dose changes or clinical outcomes in the active group. The findings suggest initiation of TDS in relative EEG alpha magnitude by daily oral administration of active homeopathic medicines versus placebo, with laboratory elicitation by temporolimbic olfactory stimulation or sniffing.

A second-generation, endoluminal, flow-disrupting device for treatment of saccular aneurysms

BACKGROUND AND PURPOSE

We report a preclinical study of a second-generation endoluminal device (Pipeline Embolization Device [PED-2] for aneurysmal occlusion and compare the PED-2 with its first-generation predecessor (PED-1).

MATERIALS AND METHODS

Our Institutional Animal Care and Use Committee approved all studies. The PED-2 is a braided endoluminal, flow-diverting device and was implanted across the necks of 18 elastase-induced aneurysms in New Zealand white rabbits and followed for 1 month (n = 6), 3 months (n = 6), and 6 months (n = 6). A second PED-2 was implanted in the abdominal aorta to cover the origins of the lumbar arteries. Angiographic occlusion rates were documented as complete, near-complete, and incomplete. Parent artery percent diameter stenosis was calculated. Results were compared with a previous publication focused on the PED-1, with use of the same model. We compared ordinal outcomes using Fisher Exact or chi(2) tests. We compared continuous data using analysis of variance.

RESULTS

Occlusion rates (complete and incomplete) for the PED-2 were noted in 17 cases (94%) and 1 (6%), respectively, compared with 9 cases of complete (53%) and 8 (47%) of incomplete occlusion with the PED-1 (P = .0072). No incidents of branch artery occlusion or distal emboli in vessels downstream of the parent artery were observed with the PED-2. Parent artery neointimal hyperplasia was minimal in most cases and was significantly less than in the PED-1.

CONCLUSIONS

The PED-2 is a biocompatible and hemocompatible device that occludes saccular aneurysms while preserving the parent artery and small-branch vessels in our animal model.

Morbidity and mortality associated with creation of elastase-induced saccular aneurysms in a rabbit model

BACKGROUND AND PURPOSE

Elastase-induced aneurysms in rabbits have been proposed as a useful preclinical tool for device development. The object of this study was to report rates of morbidity and mortality associated with the creation and embolization of elastase-induced rabbit aneurysms and to assess the impact of operator experience on these rates.

MATERIALS AND METHODS

Elastase-induced model aneurysms were created in New Zealand white rabbits (n = 700). One neuroradiologist/investigator, naive to the aneurysm-creation procedure at the outset of the experiments, performed all surgeries. All morbidity and deaths related to aneurysm creation (n = 700) and embolization procedures (n = 529) were categorized into acute and chronic deaths. Data were analyzed with single-regression analysis and analysis of variance. To assess the impact of increasing operator experience, we broke the number of animals into 50-animal increments.

RESULTS

There were 121 (17%) deaths among 700 subjects. Among 700 aneurysm-creation procedures, 59 deaths (8.4%) were noted. Among 529 aneurysm-embolization procedures, 43 deaths (8.1%) were noted. Nineteen additional deaths (2.7% of 700 subjects) were unrelated to the procedures. Simple regression-indicated mortality associated with procedures diminished with increasing operator experience (R(2) = 0.38, P = .0180), and that for each 50-rabbit increment mortality was reduced, on average, by 0.6%.

CONCLUSIONS

Mortality rates of approximately 8% are associated with both experimental aneurysm creation and with embolization in the rabbit elastase-induced aneurysm model. Increasing operator experience is inversely correlated with mortality, and the age of the rabbit is positively associated with morbidity.

Effects of a pharmacist-to-dose computerized request on promptness of antimicrobial therapy

OBJECTIVES

To examine the effects of computerized requests for pharmacist-to-dose (PTD), an advanced clinical decision support tool for dosing guidance, on antimicrobial therapy with vancomycin and aminoglycosides, describe PTD request utilization, and identify factors that may prolong this process.

DESIGN

A retrospective review was conducted of patients hospitalized from Jan 2004 to Jun 2006 with suspected pneumonia who received vancomycin, tobramycin, or gentamicin via PTD (study) or routine provider order entry (control).

MEASUREMENTS

The primary endpoint was time to pharmacist completion of PTD request. Secondary data points included medication turn-around times for first doses of vancomycin or aminoglycosides and for first doses of any antibiotic, dose adjustment for renal dysfunction, medication errors, and time of order entry. Multivariate analysis was conducted to identify predictors of total time to pharmacist verification and time to administration of first doses of vancomycin or aminoglycosides.

RESULTS

Median time for pharmacist completion of PTD requests was 29 minutes. Delays were noted in the study group (n = 49) by comparison with the control group (n = 48) for median time to first dose of vancomycin or aminoglycoside (185 vs. 138 min, p = 0.45) and for any antibiotic (134 vs. 118 min, p = 0.42), respectively. Fewer medication errors were reported in the study group (5 vs. 18 errors, p = 0.002). In a multivariate model, PTD was not significantly predictive of time to pharmacy verification or medication turn-around time.

CONCLUSIONS

Pharmacists completed pharmacist-to-dose consultations for dosing guidance of vancomycin and aminoglycosides within a median of 30 minutes. Implementation of a computerized request for clinical pharmacists to provide medication-related clinical decision support increased medication turn-around time of vancomycin and aminoglycosides and reduced medication errors. Consultation of clinical pharmacists by computerized request for initial antibiotic dosing of medications with narrow therapeutic windows is an option for medication-related clinical decision support but providers should be aware that consultation may delay medication turn-around time.

Parvalbumin-positive basket interneurons in monkey and rat prefrontal cortex

Differences in the developmental origin and relative proportions of biochemically distinct classes of cortical neurons have been found between rodents and primates. In addition, species differences in the properties of certain cell types, such as neurogliaform cells, have also been reported. Consequently, in this study we compared the anatomical and physiological properties of parvalbumin (PV)-positive basket interneurons in the prefrontal cortex of macaque monkeys and rats. The somal size, total dendritic length, and horizontal and vertical spans of the axonal arbor were similar in monkeys and rats. Physiologically, PV basket cells could be identified as fast-spiking interneurons in both species, based on their short spike and high-frequency firing without adaptation. However, important interspecies differences in the intrinsic physiological properties were found. In monkeys, basket cells had a higher input resistance and a lower firing threshold, and they generated more spikes at near-threshold current intensities than those in rats. Thus monkey basket cells appeared to be more excitable. In addition, rat basket cells consistently fired the first spike with a substantial delay and generated spike trains interrupted by quiescent periods more often than monkey basket cells. The frequency of miniature excitatory postsynaptic potentials in basket cells was considerably higher in rats than that in monkeys. These differences between rats and monkeys in the electrophysiological properties of PV-positive basket cells may contribute to the differential patterns of neuronal activation observed in rats and monkeys performing working-memory tasks.

Gene expression profiling of experimental saccular aneurysms using deoxyribonucleic acid microarrays

BACKGROUND AND PURPOSE

The molecular characteristics of the pathophysiology of saccular aneurysms remain poorly understood. The purpose of the current study was to investigate the expression of various groups of genes at different stages of aneurysm age in elastase-induced saccular aneurysms in rabbits through the use of deoxyribonucleic acid (DNA) microarrays.

MATERIALS AND METHODS

A microarray consisting of genes related to cell adhesion, apoptosis, cell signaling, growth, inflammation, vascular remodeling, and oxidative stress was constructed by using rabbit nucleotide sequences. Elastase-induced saccular aneurysms were created at the origin of the right common carotid artery (CCA) in 12 rabbits. Two weeks (n=6) and 12 weeks (n=6) after aneurysm creation, ribonucleic acid (RNA) was isolated from the aneurysm and the control unoperated left CCA and was used for microarray experiments. Real-time polymerase chain reaction (RT-PCR) was performed for validation of microarray results.

RESULTS

Of 209 genes, 157 (75%) at 2 weeks and 88 (42%) at 12 weeks demonstrated statistically significant differential expression between aneurysm tissue and the control left CCA tissue (P < .05). Multiple genes implicated in vessel wall remodeling were found to be elevated at 2 weeks and at 12 weeks. Expression of cell adhesion molecules and antioxidant enzymes was down-regulated at 2 weeks but was not significantly different from that of controls at 12 weeks. Most transcription factors, inflammatory genes, and structural genes showed underexpression at both time points. The expression profiles of selected genes were confirmed by RT-PCR.

CONCLUSION

Multiple genes in diverse pathways have been differentially expressed in the rabbit aneurysm model.

The risk of antimalarials in patients with renal failure

We present here a patient with end stage renal failure who received two weeks antimalarial prophylaxis at full dose leading to life threatening toxicity with severe acute megaloblastic anaemia, symptomatic pancytopenia and exfoliative dermatitis. Prompt recognition and treatment can rapidly reverse these fatal effects but more importantly, education of patients before travel is imperative in preventing such events.

The burden of asymptomatic sexually transmitted infections among men in Carletonville, South Africa: implications for syndromic management

OBJECTIVES

To determine the prevalence of sexually transmitted infections (STI) and HIV among men attending an outreach STI/HIV screening service in informal settlements in South Africa over a 3-month period.

METHODS

A mobile clinic van was utilised to offer men: (1) urine screening for gonorrhoea, trichomoniasis, chlamydial and Mycoplasma genitalium infections; (2) serological screening for syphilis and herpes simplex virus type 2 (HSV-2); (3) on-site HIV voluntary counselling and testing. Urethritis pathogens were detected by molecular methods. HIV serostatus was determined using rapid tests. Demographic, sexual behaviour and clinical data were recorded on a nurse-administered questionnaire. Statistical analysis utilised the chi(2) test.

RESULTS

309 men attended the service; 304 (98%) requested serological screening for syphilis and HSV-2, 301 (97%) underwent urine-based screening for urethritis pathogens and 269 (87%) had an HIV test. Over 90% of men were asymptomatic for STI. Gonorrhoea was more prevalent in the symptomatic group (p<0.001); there were no significant differences in the prevalence of other urethritis pathogens between the groups. The total number of infections with each urethritis pathogen was highest in the asymptomatic group with twice as much gonorrhoea, 25 times as much chlamydial infection, six times as much trichomoniasis and nine times as much M genitalium infection compared with the symptomatic group. The overall HIV prevalence among clinic attendees was 29.7%.

CONCLUSIONS

The uptake of both STI and HIV testing was high among men attending the service. The relatively high burden of both STI and HIV among the male clinic attendees has implications for the transmission of HIV.

Long-term but not short-term p38 mitogen-activated protein kinase inhibition improves cardiac function and reduces cardiac remodeling post-myocardial infarction

p38 mitogen-activated protein kinase (p38 MAPK) inhibition exerts beneficial effects on left ventricular (LV) remodeling and dysfunction. p38 MAPK activity is transiently increased soon after myocardial infarction (MI), suggesting brief inhibition may afford the same benefit as long-term inhibition. We examined chronic 12-week p38 MAPK inhibition compared with short-term (7-day) inhibition, and then we discontinued inhibition after MI. Post-MI rats at day 7 received either vehicle, 4-[4-(4-fluorophenyl)-1-(3-phenylpropyl)-5-(4-pyridinyl)-1H-imidazol-2-yl]-3-butyn-1-ol (RWJ67657; RWJ) for 12 weeks (long term; LT-RWJ), RWJ for 1 week and discontinued for 11 weeks (1-week RWJ), or continuous ramipril for 12 weeks. In separate groups of animals, 24 h after MI, vehicle or RWJ was administered for 7 days. Cardiac function was assessed by echocardiography and hemodynamic measurements. Percentage of fractional shortening improved after LT-RWJ and ramipril, but not after 1-week RWJ treatment. Likewise, LV contractility and maximal first derivative of left ventricular pressure (dP/dt(max)) was improved (12.5 and 14.4%) and LV end diastolic pressure (LVEDP) was reduced (49.4 and 54.6%) with both treatments. Functional outcomes were accompanied by regression of interstitial collagen I and alpha-smooth muscle actin expression in LV noninfarct, border, and infarct regions with LT-RWJ and ramipril treatment. Hypertrophy was reduced in noninfarct (18.3 and 12.2%) and border regions (16.3 and 12.0%) with both treatments, respectively. Animals receiving RWJ 24 h after MI for 7 days showed similar improvements in fractional shortening, dP/dt(max), LVEDP, including reduced fibrosis and hypertrophy. In vitro experiments confirmed a dose-dependent reduction in hypertrophy, with RWJ following tumor necrosis factor-alpha stimulation. Continuous but not short-term p38 MAPK blockade attenuates post-MI remodeling, which is associated with functional benefits on the myocardium.

Alterations in GABA-related transcriptome in the dorsolateral prefrontal cortex of subjects with schizophrenia

In subjects with schizophrenia, impairments in working memory are associated with dysfunction of the dorsolateral prefrontal cortex (DLPFC). This dysfunction appears to be due, at least in part, to abnormalities in gamma-aminobutyric acid (GABA)-mediated inhibitory circuitry. To test the hypothesis that altered GABA-mediated circuitry in the DLPFC of subjects with schizophrenia reflects expression changes of genes that encode selective presynaptic and postsynaptic components of GABA neurotransmission, we conducted a systematic expression analysis of GABA-related transcripts in the DLPFC of 14 pairs of schizophrenia and age-, sex- and post-mortem interval-matched control subjects using a customized DNA microarray with enhanced sensitivity and specificity. Subjects with schizophrenia exhibited expression deficits in GABA-related transcripts encoding (1) presynaptic regulators of GABA neurotransmission (67 kDa isoform of glutamic acid decarboxylase (GAD(67)) and GABA transporter 1), (2) neuropeptides (somatostatin (SST), neuropeptide Y (NPY) and cholecystokinin (CCK)) and (3) GABA(A) receptor subunits (alpha1, alpha4, beta3, gamma2 and delta). Real-time qPCR and/or in situ hybridization confirmed the deficits for six representative transcripts tested in the same pairs and in an extended cohort, respectively. In contrast, GAD(67), SST and alpha1 subunit mRNA levels, as assessed by in situ hybridization, were not altered in the DLPFC of monkeys chronically exposed to antipsychotic medications. These findings suggest that schizophrenia is associated with alterations in inhibitory inputs from SST/NPY-containing and CCK-containing subpopulations of GABA neurons and in the signaling via certain GABA(A) receptors that mediate synaptic (phasic) or extrasynaptic (tonic) inhibition. In concert with previous findings, these data suggest that working memory dysfunction in schizophrenia is mediated by altered GABA neurotransmission in certain DLPFC microcircuits.

The detection of urethritis pathogens among patients with the male urethritis syndrome, genital ulcer syndrome and HIV voluntary counselling and testing clients: should South Africa's syndromic management approach be revised?

OBJECTIVES

To determine the prevalence of urethritis pathogens amongst male symptomatic urethritis (MUS) patients, genital ulcer (GUS) patients without urethritis symptoms and men requesting HIV testing at a voluntary counselling and testing (VCT) clinic.

METHODS

A prospective study was conducted in Johannesburg, South Africa. Men from the three groups were screened for urethritis pathogens using molecular tests. Culture for Neisseria gonorrhoeae and, initially, trichomoniasis was performed. Antimicrobial susceptibility testing was undertaken for ciprofloxacin on all gonococcal isolates; ciprofloxacin resistant isolates were screened for ceftriaxone resistance.

RESULTS

664 participants were recruited (438 MUS, 76 GUS and 158 VCT) over 2 years. Gonorrhoea was detected in 62.3% MUS, 15.8% GUS and 3.2% VCT participants. Chlamydial infection was detected in 19.3% MUS, 13.2% GUS and 8.2% VCT participants. Trichomoniasis was detected in 4.9% MUS, 19.7% GUS and 3.8% VCT participants. Mycoplasma genitalium infection was detected in 14.4% MUS, 13.2% GUS and 7.0% VCT participants. Ciprofloxacin resistance increased from 13.0% in the first year to 26.3% in the second year; all resistant isolates were susceptible to ceftriaxone.

CONCLUSIONS

Urethritis pathogens, including Trichomonas vaginalis, should be covered in syndromic management treatment of genital ulcers in the absence of clinical urethritis. Consideration should be given to adding metronidazole to existing MUS treatment. Ciprofloxacin can no longer be relied upon to treat presumptive gonococcal infections in South Africa.

Endovascular treatment of experimental aneurysms with use of fibroblast transfected with replication-deficient adenovirus containing bone morphogenetic protein-13 gene

BACKGROUND AND PURPOSE

Modified coils have failed to improve long-term recanalization of aneurysms. This study examined whether ex vivo transduction of replication-deficient adenovirus containing the bone morphogenetic protein-13 gene (Ad-BMP-13) in fibroblast allografts would improve angiographic results via increased collagen synthesis, compared with fibroblast-coated platinum coils (FBC) and bare platinum coils (PA).

MATERIALS AND METHODS

Aneurysms were embolized with Ad-BMP-13-coated coils (n = 20). Rabbits were sacrificed at 14 days and at 1, 3, and 6 months after implantation. Digital subtraction angiography (DSA) evaluated stability after embolization. Histologic specimens were examined with a qualitative grading system. Masson trichrome evaluated collagen deposition. Findings were compared with previously reported controls for PA and FBC in the same model and time points.

RESULTS

The grading system showed a greater total score (P = .0002) in Ad-BMP-13 (6.8 +/- 1.6) and FBC (6.3 +/- 2.4) compared with PA (4.7 +/- 2.4). A group main effects test showed that aneurysm neck tissue coverage in Ad-BMP-13 (2.5 +/- 1.1) was higher (P = .0007) than both FBC (1.6 +/- 1.4) and PA (0.9 +/- 1.1). Ad-BMP-13 had more (P < .0001) collagen deposition than the FBC and PA. One- and 3-month Ad-BMP-13 collagen depositions increased (P < .05) over the FBC and PA. Finally, Ad-BMP-13 showed radiographic stability in 15 (75%) cases, coil compaction in 4 (20%) cases, and progressive occlusion in 1 (5%) case. There were no differences in angiographic results (P = .6522).

CONCLUSION

The Ad-BMP-13-coated coils can improve neck coverage and dome fibrosis in the rabbit model, even in the absence of observed differences in angiographic outcome.

Rhodococcus equi infection in foals: the science of 'rattles'

Infection with Rhodococcus (Corynebacterium) equi is a well-recognised condition in foals that represents a consistent and serious risk worldwide. The condition manifests itself primarily as one of pulmonary abscessation and bronchitis, hence the terminology of 'rattles' derived from its most obvious clinical sign, frequently terminal when first identified. This review addresses the clinical manifestation, bacteriology and pathogenesis of the condition together with recent developments providing knowledge of the organism in terms of virulence, epidemiology, transmission and immune responses. Enhanced understanding of R. equi virulence mechanisms and biology derived from the recently available genome sequence may facilitate the rational development of a vaccine and the improvement of farm management practices used to control R. equi on stud farms in the future. Reliance on vaccines alone, in the absence of management strategies to control the on-farm challenge is likely to be disappointing.

Drug selection in a patient with a history of hypersensitivity reactions: a practical approach for the orthopedist

Drug allergies are specific to characteristics of the medication's chemical structure.

Antibiotic-resistant gonococci - past, present and future

Gonorrhoea remains one of the commonest STIs from a global perspective and, left untreated or treated inadequately, may result in serious complications such as epididymo-orchitis and pelvic inflammatory disease and their adverse sequelae. Since the introduction of sulphonamides in the 1930s, the gonococcus has shown itself to be a master of adaptability and has acquired a number of chromosomal and plasmid-mediated antibiotic resistance mechanisms. The continual development and spread of in vivo resistant strains has resulted in several key changes in recommended therapy for gonorrhoea over past decades. The recent emergence of quinolone resistance among gonococci isolated in South Africa now threatens to undermine the success of the syndromic management approach to date. Within South Africa, there is now an urgent need to change first-line therapy away from ciprofloxacin to a third-generation cephalosporin. With the lack of new therapeutic agents on the horizon, a future with multi-drug therapy as the main management strategy for antibiotic-resistant gonorrhoea looks inevitable. The importance of condoms in the prevention of gonococcal transmission should not be under-estimated and STI prevention efforts should be increased.

Relationship between aneurysm volume and histologic healing after coil embolization in elastase-induced aneurysms: a retrospective study

BACKGROUND AND PURPOSE

There are, to our knowledge, no histologic data correlating aneurysm volume with histologic healing following coil embolization of aneurysms. We report a retrospective study comparing histologic outcome with aneurysm volume in elastase-induced aneurysms in rabbits.

MATERIALS AND METHODS

Aneurysm volume and histologic healing after coil embolization were retrospectively analyzed in 37 elastase-induced aneurysms in rabbits. Aneurysm dimensions (including neck, width, height, and volume) were measured and calculated. Packing density (PD) was calculated. Angiographic results were evaluated as recurrence, stable, and progressive occlusion. An ordinal grading system was used to evaluate the histologic healing after embolization. Correlations among aneurysm volume, PD, and histologic healing were analyzed by conducting linear regression analysis.

RESULTS

For all the aneurysms in this study, mean aneurysm volume was 80.8 +/- 48.6 mm(3) (from 22 to 192 mm(3)), mean PD was 30.4 +/- 8.3% (from 17% to 49%), and mean histologic score was 6.1 +/- 2.0 (from 0.5 to 9.5), respectively. Correlations between aneurysm volume and PD, aneurysm volume and histologic healing, and aneurysm packing and histologic healing were all significant (P < .01).

CONCLUSION

In this study, aneurysms with smaller volumes and higher PD were associated with the most complete histologic healing. The incomplete healing seen in the larger aneurysms is consistent with the higher incidence of recurrences after endovascular treatment that is seen in large human aneurysms.

An institutional process to improve inpatient glycemic control

Many institutions are evaluating their inpatient patterns of care for patients with diabetes mellitus and hyperglycemia, based upon compelling evidence that strict glycemic control improves outcomes in a variety of hospital settings. In 2005, a multidisciplinary task force was established at the University of Kentucky Chandler Medical Center in Lexington, Kentucky, to guide a process to improve the quality and safety of inpatients with hyperglycemia. This article describes the stepwise process including an examination of our procedures, adoption of standards, and establishment of common protocols and procedures. Successful implementation of the protocols was preceded by extensive educational efforts. Refinement of the protocols based on early experience and feedback from staff has resulted in improvements in glycemic parameters and less reliance on sliding scale insulin regimens.

Bone formation in elastase-induced rabbit aneurysms embolized with platinum coils: report of 2 cases

Histologic findings in 71 elastase-induced rabbit aneurysms embolized with platinum coils were retrospectively reviewed. Mature bone formation was found in 2 aneurysms, one with coils implanted for 3 months and the other with coils implanted for 1 year. We present the histologic findings and offer potential explanations for these observations. These findings may be relevant in understanding mechanisms of aneurysm healing after coil embolization.