Synthetic interpolated DSA for radiation exposure reduction via gamma variate contrast flow modeling: a retrospective cohort study

BACKGROUND

Digital subtraction angiography (DSA) yields high cumulative radiation dosages (RD) delivered to patients. We present a temporal interpolation of low frame rate angiograms as a method to reduce cumulative RDs.

METHODS

Patients undergoing interventional evaluation and treatment of cerebrovascular vasospasm following subarachnoid hemorrhage were retrospectively identified. DSAs containing pre- and post-intervention runs capturing the full arterial, capillary, and venous phases with at least 16 frames each were selected. Frame rate reduction (FRR) of the original DSAs was performed to 50%, 66%, and 75% of the original frame rate. Missing frames were regenerated by sampling a gamma variate model (GVM) fit to the contrast response curves to the reduced data. A formal reader study was performed to assess the diagnostic accuracy of the "synthetic" studies (sDSA) compared to the original DSA.

RESULTS

Thirty-eight studies met inclusion criteria (average RD 1,361.9 mGy). Seven were excluded for differing views, magnifications, or motion. GVMs fit to 50%, 66%, and 75% FRR studies demonstrated average voxel errors of 2.0 ± 2.5% (mean ± standard deviation), 6.5 ± 1.5%, and 27 ± 2%, respectively for anteroposterior projections, 2.0 ± 2.2%, 15.0 ± 3.1%, and 14.8 ± 13.0% for lateral projections, respectively. Reconstructions took 0.51 s/study. Reader studies demonstrated an average rating of 12.8 (95% CI 12.3-13.3) for 75% FRR, 12.7 (12.2-13.2) for 66% FRR and 12.0 (11.5-12.5) for 50% FRR using Subjective Image Grading Scale. Kendall's coefficient of concordance resulted in W = 0.506.

CONCLUSION

FRR by 75% combined with GVM reconstruction does not compromise diagnostic quality for the assessment of cerebral vasculature.

RELEVANCE STATEMENT

Using this novel algorithm, it is possible to reduce the frame rate of DSA by as much as 75%, with a proportional reduction in radiation exposure, without degrading imaging quality.

KEY POINTS

• DSA delivers some of the highest doses of radiation to patients. • Frame rate reduction (FRR) was combined with bolus tracking to interpolate intermediate frames. • This technique provided a 75% FRR with preservation of diagnostic utility as graded by a formal reader study for cerebral angiography performed for the evaluation of cerebral vasospasm. • This approach can be applied to other types of angiography studies.

Does the clopidogrel CYP2C19 genotype assay predict postprocedure stenosis in cerebral aneurysms treated with a flow diverter?

OBJECTIVE

Flow diverters have emerged as a popular modality for treating cerebral aneurysms but require dual antiplatelet therapy (DAPT) after placement. Clopidogrel is a common choice but is a prodrug that some patients may not convert into an active metabolite. The CYP2C19 genotype assay is used to predict activation speed; however, limited data exist showcasing whether this genotype accurately predicts postprocedure complications after flow diversion treatment of cerebral aneurysms. Therefore, the authors sought to characterize whether CYP2C19 genotype correlated with the development of postprocedure intimal hyperplasia (stenosis) after flow diverter placement.

METHODS

Medical records were reviewed for patients who underwent flow diverter treatment of cerebral aneurysm at a single academic institution between January 1, 2012, and May 31, 2020. Patient demographics and comorbidities were reviewed alongside CYP2C19 genotype assay, DAPT regimen, and postprocedure angiogram data. Stenosis was defined based on review of angiogram data by two independent physicians.

RESULTS

In this review of 120 unique cerebral aneurysms, 102 received DAPT with clopidogrel and 18 received DAPT with an alternative agent. Stenosis was present on 3-month follow-up angiogram for 35/102 (34.3%) aneurysms receiving DAPT with clopidogrel and in 11/18 (61.1%) aneurysms receiving an alternative DAPT regimen (p = 0.031). The CYP2C19 genotype did not correlate with postprocedure stenosis (p = 0.35).

CONCLUSIONS

Clopidogrel was a significantly more effective DAPT agent for preventing stenosis when compared to nonclopidogrel DAPT regimens. The clopidogrel CYP2C19 genotype did not predict postprocedure stenosis in this cohort of 120 cerebral aneurysms treated with a flow diverter.

Case report: Transvenous coil embolization of a high-grade Galenic dural arteriovenous fistula

Introduction

Galenic dural arteriovenous fistulas (dAVFs) are a rare form of dAVF and rarely described in the literature. Their distinct location requires different surgical approaches than dAVFs occurring at the nearby sites of the straight sinus and torcular Herophili, and their high risk of hemorrhage makes these dAVFs very challenging to approach surgically. In this report, we present a unique case of Galenic dAVF.

Case description

The patient is a 54-year-old female who presented with a 2-year history of progressive headaches, cognitive decline, and papilledema. A cerebral angiogram demonstrated a complex dAVF to the vein of Galen (VoG). She underwent transarterial embolization with Onyx-18 which resulted in minimal reduction in arterial venous shunting. She subsequently underwent a successful transvenous coil embolization resulting in complete occlusion of dAVF. The patient's postoperative course was complicated by interventricular hemorrhage; however, she had a remarkable clinical recovery with resolution of headaches and improvement in cognitive function. A follow-up angiogram completed 6  months post-embolization demonstrated very mild residual shunting.

Conclusion

In the unique case presented here, we demonstrate the efficacy of transvenous embolization via an occluded straight sinus as an alternative therapeutic option to eliminate cortical venous reflux.

Cerebral venous sinus thrombosis with an acute subdural hematoma treated with endovascular intervention: A case report

We report two cases of endovascular intervention for management of cerebral venous sinus thrombosis complicated by an acute intracranial hemorrhage during treatment with therapeutic anticoagulation. The first patient developed an acute subdural hematoma with progressive enlargement and was subsequently managed with venous sinus thrombectomy. The second patient developed an intraparenchymal and subdural hematoma and was treated with middle meningeal embolization. Anticoagulation is the primary treatment for cerebral venous sinus thrombosis but also contraindicated in an acute intracranial hemorrhage. In these cases, after endovascular intervention both patients resumed therapeutic anticoagulation without further hematoma expansion or additional invasive interventions. Both patients made an excellent neurological recovery and returned to their baseline functional independent status. Given the need for anticoagulation, endovascular intervention in the form of thrombectomy or middle meningeal artery embolization may be a viable adjuvant to anticoagulation in select patients.

Cumulative Radiation Exposure in Aneurysmal Subarachnoid Hemorrhage: A Single-Institution Analysis

OBJECTIVE

Diagnosis and management of aneurysmal subarachnoid hemorrhage (aSAH) depend heavily on imaging modalities that repeatedly expose patients to ionizing radiation. There is limited literature on cumulative radiation exposure in this patient population, which is a problem compounded by wide variation among institutions. The present study quantifies the cumulative cranial exposure to ionizing radiation resulting from diagnostic medical imaging and medical procedures during initial hospitalization for ruptured aSAH at a single academic institution and estimates the risk of future adverse events related to radiation injury.

METHODS

We performed a retrospective observational study of adults who presented to our institution during a nearly 3-year period with acute-onset aSAH, which was confirmed with diagnostic imaging, and had the aneurysm treated with either surgical clip ligation or endovascular embolization.

RESULTS

A total of 131 patients met the inclusion criteria. Eighty-eight patients (67%) were treated with endovascular embolization and 43 (32%) were treated with clip ligation. We found the average radiation dose to the head during the incident hospitalization for aSAH to be 4.40 Gy (95% confidence interval, 3.91-4.89). Angiography and interventional radiology procedures accounted for most of this exposure.

CONCLUSIONS

Most patients were exposed to levels of ionizing radiation that put them at considerable risk of deterministic radiation injury. Providers should be aware of the potential consequences of acute and long-term radiation exposure in this patient population, so they can monitor and counsel individuals accordingly and take steps to safely limit radiation exposure during aSAH management.

Neuraxial and general anesthesia for outpatient total joint arthroplasty result in similarly low rates of major perioperative complications: a multicentered cohort study

Background

Neuraxial anesthesia when compared with general anesthesia has shown to improve outcomes following lower extremity total joint arthroplasty. It is unclear whether these benefits are present in outpatient surgery given the selection of healthier patients.

Objective

To compare the effects of neuraxial versus general anesthesia on outcomes following ambulatory hip and knee arthroplasty.

Methods

Multicentered retrospective cohort study in ambulatory hip or knee arthroplasty patients between January 2017 and December 2019. Primary endpoint examined 30-day major postoperative complications (mortality, myocardial infarction, deep venous thromboembolism, pulmonary embolism, stroke, and acute renal failure).

Results

Of 11 523 eligible patients identified, 10 003 received neuraxial anesthesia, while 1520 received general anesthesia. 30-day major complications did not differ between neuraxial anesthesia and general anesthesia groups (1.8% vs 2.3%; aOR=0.85, CI: 0.56 to 1.27, p=0.39). There was no difference in 30-day minor complications (surgical site infection, pneumonia, urinary tract infection; 3.3% vs 4.1%; aOR=0.83, CI: 0.62 to 1.14, p=0.23). The neuraxial group demonstrated reduced pain and analgesia requirements and had less postoperative nausea and vomiting (PONV). Median recovery room length of stay was shorter by 52 min in the general anesthesia group, but these patients were more likely to fail same day discharge (33% vs 23.4%; p<0.01).

Conclusion

Anesthesia type was not associated with an increased risk for complications. However, neuraxial anesthesia improved outcomes that predict readiness for discharge: patients had less pain, required less opioids, and had a lower incidence of PONV, thus improving the rate of same day discharge.

Trial registration number

NCT04203732.

Bilateral Decompressive Hemicraniectomy for Diffuse Cerebral Edema and Medically Refractory Elevated Intracranial Pressure in Aneurysmal Subarachnoid Hemorrhage: A Case Series

Decompressive hemicraniectomy (DCHC) may be indicated in the setting of subarachnoid hemorrhage (SAH) complicated by persistent elevated intracranial pressure (ICP) that is refractory to medical interventions. Outcomes can be variable as indications for surgery can include focal hematomas, infarctions, and regional or diffuse edema. Bilateral DCHC for medically refractory elevated ICP in the setting of SAH is not well described in the literature, and the viability of this option in terms of patient outcomes is unclear. We describe the cases of four patients with medically refractory ICP secondary to diffuse cerebral edema who underwent bilateral DCHC in the setting of SAH. This is a retrospective case review of four patients with aneurysmal SAH who underwent bilateral DCHC for management of diffuse global edema resulting in medically refractory ICP. We describe two patients who made impressive recoveries after bilateral DCHC and two patients who required significant continued care needs despite ICP control in all patients. Bilateral DCHC is a viable option for control of refractory elevated ICP in SAH patients who develop diffuse cerebral edema. Bilateral DCHC in this setting can be considered after exhaustion of other therapeutic options.

Facial segmental haemangioma with PHACE Syndrome successfully treated with oral propranolol

PHACE syndrome describes the association of large segmental haemangioma with extracutaneous features (posterior fossa anomalies, arterial, cardiac, eye and endocrine anomalies). We report a case of segmental facial infantile haemangioma with PHACE syndrome treated successfully with oral propranolol without neurological sequelae.

Improved analgesia and reduced post-operative nausea and vomiting after implementation of an enhanced recovery after surgery (ERAS) pathway for total mastectomy

Background

Enhanced Recovery After Surgery (ERAS) pathways have been shown in multiple surgical disciplines to improve outcomes, including reduced opioid consumption, length of stay, and post-operative nausea and vomiting (PONV). However, very few studies describe the application of ERAS to breast surgery and even fewer describe ERAS for outpatient surgery. We describe the implementation and efficacy of an Enhanced Recovery After Surgery (ERAS) pathway for total skin-sparing mastectomy with immediate reconstruction in an outpatient setting.

Methods

We implemented an evidence-based, multimodal ERAS pathway for all patients undergoing total skin-sparing mastectomy surgery with immediate reconstruction at a single 23-h stay surgery center. Highlights of the ERAS pathway included: preoperative acetaminophen, gabapentin, and scopolamine; regional anesthesia for the breast (Pectoral blocks type 1 and 2 or paravertebral block); and intraoperative dexamethasone and ondansetron. This retrospective study included all American Society of Anesthesiology (ASA) Class 1–3 patients undergoing total skin-sparing mastectomy surgery with immediate reconstruction between July 2013 and April 2016. We compared 96 patients who were in the ERAS pathway (ERAS group) to a retrospective cohort of 276 patients (Pre group). The primary outcome was total perioperative opioid consumption. Secondary outcomes were highest postoperative pain scores, incidence of PONV, and length of stay.

Results

Patients in the ERAS group had significantly lower total perioperative opioid consumption compared to the Pre group (mean (SD): 111.4 mg (46.0) vs. 163.8 mg (73.2) oral morphine equivalents, p < 0.001). Patients in the ERAS group also had a lower incidence of PONV (28% vs. 50%, p < 0.001). Patients in the ERAS group reported less pain in the recovery room, with a two-point decrease in highest pain score (median [interquartile range (IQR)]: 4 [2,6] in ERAS group vs. 6 [4,7] in Pre group, p < 0.001). There was no clinically significant difference in length of stay (median [IQR]: 1144 min [992, 1259] in ERAS group vs. 1188 [1058, 1344] in Pre group, p = 0.006).

Conclusion

Implementation of an ERAS pathway for total skin-sparing mastectomy with reconstruction that incorporates regional anesthesia is feasible in a 23-h-stay hospital. Patients in the ERAS pathway had improved post-operative analgesia and reduced post-operative nausea and vomiting.

Electronic supplementary material

The online version of this article (10.1186/s12871-018-0505-9) contains supplementary material, which is available to authorized users.

Pleural infection in a New Zealand centre: high incidence in Pacific people and RAPID score as a prognostic tool

BACKGROUND

Whilst there is an increase in incidence of pleural infection worldwide, there is a paucity of New Zealand data.

AIMS

This study looked at the epidemiology of pleural infection in a single New Zealand institution and evaluated the RAPID score as a prognostic tool.

METHODS

A retrospective review was performed on patients with pleural infection over a 3-year period. Pleural infection was defined as having clinical evidence of infection and fulfilling one of the following: (i) positive pleural fluid Gram stain or culture, (ii) frank pus, (iii) pH <7.2 or (iv) radiological evidence of complex effusion.

RESULTS

There were 108 patients; 76% were male, and mean age was 54 years. Two thirds of patients came from the most deprived areas. The dominant ethnic group was Pacific people (42%), which was twice as high as the Pacific population in the area (19%), P < 0.0001. After adjusting for deprivation, Pacific people were still over-represented, P = 0.0002. There were 14 deaths (13%), and these were associated with increasing age (P = 0.001) and urea (P = 0.007) but not ethnicity or socioeconomic deprivation. The RAPID score found that those in the high-risk (P = 0.026) and moderate-risk (P = 0.036) groups had significantly higher mortality compared with the low-risk group.

CONCLUSION

The over-representation of Pacific people with pleural infection is not fully explained by socioeconomic deprivation, highlighting other factors at play, such as genetic susceptibility. The RAPID score was of clinical utility in predicting mortality in our population.

Primary imatinib resistance in chronic myeloid leukemia patients in a developing country: BCR-ABL kinase domain mutations or BCR-ABL independent mechanisms?

Clinical resistance to imatinib (IM) in chronic myeloid leukemia (CML) carries adverse consequences. We investigated 22 CML patients who developed IM-resistance for BCR-ABL kinase domain (KD) mutations. The median follow-up for this study was 101.9 months (range: 22.2 to 176.5 months) and the estimated mean overall survival was 150.87 months (95% CI: 130.0 to 171.0). Five out of 22 patients tested positive for BCR-ABL KD mutations: 2 had T315I, 2 had E255K and 1 had V289F mutations. Of the remaining 17 patients who did not harbor BCR-ABL KD mutations, 11 patients received nilotinib while the rest continued on IM. All 17 achieved haematological remission but only 5 patients achieved complete cytogenetic remission, 4 of whom did so after switching to nilotinib. Our study shows that most of our IM-resistant patients do not test positive for BCR-ABL KD mutations by available testing methods and the role of second generation tyrosine kinase inhibitors remains undetermined. A critical analysis of the BCR-ABL KD mutations and the underlying mechanisms/ pathways of BCR-ABL independent IM-resistance along with potential treatments in the horizon will be discussed.

Factors Affecting the Obliteration Rate of Intracranial Aneurysms Treated with a Single Pipeline Embolization Device

OBJECTIVE

To evaluate the clinical and angiographic outcomes of intracranial aneurysm treatment using a single Pipeline embolization device (PED), and to evaluate the factors affecting aneurysm obliteration rate.

METHODS

The demographic characteristics and anatomic features of 58 aneurysms in 47 patients treated with a single PED were reviewed retrospectively. All aneurysms treated with a PED at a single center and with follow-up angiograms for at least 6 months were included in this study.

RESULTS

The overall rate of complete and near-complete occlusion was 84% (49 of 58) after a mean follow-up period of 18.3 months. The rate of complete aneurysm obliteration was lower in aneurysms with an arterial branch arising from the aneurysm neck compared with aneurysms without an arterial branch (13% [1 of 8] vs. 68% [34 of 50]; P = 0.0075). The overall rate of complete and near-complete aneurysm occlusion was 90% (45 of 50) in aneurysms without an arterial branch arising from its neck. There were no statistically significant associations between obliteration rate and aneurysm neck width, size, or type, or history of previous coil embolization.

CONCLUSIONS

Our data suggest that a single PED is sufficient to induce complete or near-complete obliteration of most aneurysms. The presence of a branching artery arising from the aneurysm neck is highly predictive of incomplete occlusion after treatment with a single PED.

A case of chronic myeloid leukaemia in blast transformation with leukemic ascites

Chronic Myeloid Leukaemia (CML) is a disease characterised by a distinctive marker that is the Philadelphia Chromosome and an ability to transform into blast phase, which confers a poor prognosis. The median survival was reported to be between three to six months in correlation to blast phase. Extramedullary involvement with CML to sites such as pleural, meningeal and bones have been reported. We report a case of 41-year-old man who was diagnosed with CML in blast phase and presented with ascites. Ultrasound of abdomen showed coarse echotexture of liver suggestive leukaemic infiltration to the liver. The liver profile was severely deranged and associated with coagulopathy. Flow cytometry analysis of the peritoneal fluid revealed presence of myeloblasts consistent with CML in blast crisis with leukaemic ascites. Bone marrow biopsy also confirmed disease transformation. He received standard induction chemotherapy for acute myeloid leukaemia with dose modifications based on liver enzymes performance. Our case highlights an unusual presentation of CML in blast crisis with leukaemic ascites and the challenges in managing cytotoxic treatments due to the liver infiltration.

Fatal quinine-induced thrombocytopenia from pulmonary haemorrhage

Severe drug-induced thrombocytopenia is a well known but rare complication of quinine. This paper presents a discussion on quinine-induced thrombocytopenia based on a patient who developed fatal thrombocytopenia and pulmonary haemorrhage.

NK/T cell lymphoma associated with peripheral eosinophilia

NK/T cell lymphoma, nasal type is an aggressive and uncommon malignancy. Disease that occurs outside of the aerodigestive tract exhibits an even more aggressive clinical behaviour and does not respond as well to conventional therapy compared to its nasal counterpart. We report such a case of NK/T cell lymphoma, nasal type, that presented as an anterior chest wall mass, arising from the left pectoralis muscle. An interesting feature we wish to highlight is the associated eosinophilia that corresponded to disease activity, exhibiting fluctuations with surgical resection and chemotherapy. To the best of our knowledge this is the third reported case of NK/T cell lymphoma that is associated with peripheral eosinophilia. Our case highlights the role of certain NK cell subsets that play a major role in eosinophilic activation in NK/T lymphomas and calls for more research into further classification of this disease by virtue of its NK cell subsets.

Root canal treatment and special needs patients

AIM

To identify current trends of root canal treatment for patients with special needs.

METHODOLOGY

A postal questionnaire was sent to General Dentists in Victoria, Australia and Endodontists and Special Needs Dentists across Australia to determine the extent of root canal treatment performed on special needs patients.

RESULTS

Over a four-month period, 1120 questionnaires were distributed with an overall response rate of 63.9% (n = 716). Response rates were 63.2% (n = 655), 68.5% (n = 50) and 100.0% (n = 11) amongst General Dentists, Endodontists and Special Needs Dentists, respectively. Endodontists (95.7%) and Special Needs Dentists (100.0%) performed significantly more root canal treatment on adult patients with special needs compared with 51.2% of General Dentists, (P < 0.001 and P = 0.001 respectively; Fisher's exact test). The most common reasons for not undertaking root canal treatment included limited cooperation, poor oral hygiene and uncontrolled movement. Amongst General Dentists, 75.7% opted for extraction in preference to root canal treatment. Significantly, more specialist practitioners performed root canal treatment utilizing conscious sedation (P < 0.001) and general anaesthesia (P = 0.003). Most specialist practitioners (69.1%) had undertaken single-visit root canal treatment on special needs patients compared with only 29.7% of General Dentists (P < 0.001).

CONCLUSIONS

Root canal treatment in special needs patients was more likely to be carried out by specialist dental practitioners who were more likely to utilize a pharmacological approach for behaviour guidance and to perform single-visit root canal treatment compared with General Dentists. A multidisciplinary approach for special needs patients who require root canal treatment provides an opportunity for these patients to retain their dentition.

Economic evaluation of ezetimibe combined with simvastatin for the treatment of primary hypercholesterolaemia

OBJECTIVE

This study aims to assess the cost-effectiveness of ezetimibe plus simvastatin (E/S) versus atorvastatin or simvastatin monotherapy as second-line treatment of primary hypercholesterolaemia from the Dutch healthcare perspective.

METHODS

The evaluation used a Markov model and patient data from the Dutch EASEGO study in which patients failing to reach goal low-density lipoprotein cholesterol levels on atorvastatin 10 mg or simvastatin 20 mg had their dose doubled or switched to ezetimibe 10 mg plus generic simvastatin 20 mg (E10/S20). The second scenario, based on Dutch guidelines, switched patients from simvastatin 40 mg to atorvastatin 40 mg, or ezetimibe 10 mg was added to simvastatin 40 mg (E10/S40). The key effectiveness input measure was change in total cholesterol/high-density lipoprotein ratio obtained from the EASEGO study. In conformity with published studies linking reduced lipid levels to reduced risk of cardiovascular events, the present model assumed that a lipid decrease with ezetimibe may be a signal for reduced risk of cardiovascular events. Model parameters were derived from published literature. Sensitivity analyses were performed for the key parameters.

RESULTS

In the EASEGO scenario, incremental cost-effectiveness ratio for E10/S20 was <euro>3497/quality-adjusted life-years (QALY) vs atorvastatin 20 mg and <euro>26,417/QALY vs simvastatin 40 mg. In the Dutch guidelines scenario, E10/S40 was dominant (more effective and cost-saving) vs atorvastatin 40 mg. Varying model inputs had limited impact on the cost-effectiveness of E/S.

CONCLUSIONS

The analysis showed the cost-effectiveness of E/S versus atorvastatin 20 mg or simvastatin 40 mg (EASEGO scenario) at a threshold of <euro>30,000/QALY and vs atorvastatin 40 mg was dominant (Dutch guidelines). Thus, E/S seems a valuable cost-effective second-line treatment option for patients not attaining lipid treatment goals.

Can we predict sputum eosinophilia from clinical assessment in patients referred to an adult asthma clinic?

BACKGROUND

There is overwhelming evidence that asthma guidelines aimed at reducing airway inflammation are superior to those based on clinical symptoms alone. This involves targeting eosinophilic inflammation with inhaled corticosteroids.

AIM

Because induced sputum is not readily available, our study set out to investigate whether the collective or singular use of routine asthma investigations can predict sputum eosinophilia.

METHODS

Eighty patients underwent skin prick testing, blood tests (IgE, full blood count), spirometry, exhaled fraction nitric oxide (FeNO), PD15 to hypertonic saline, and induced sputum testing at first assessment. A predictive model for sputum eosinophilia (defined as ≥3% eosinophils) was sought using routinely available tests.

RESULTS

Fifty-four subjects underwent both induced sputum and FeNO testing. Seventeen (30%) revealed eosinophilic inflammation, nine (16%) neutrophilic, four (7%) mixed granulocytic and 26 (46%) paucigranulocytic. Positive predictors for sputum eosinophilia included low forced expiratory volume in 1 s (FEV(1))% predicted, raised serum eosinophil, positive smoking history, Polynesian ethnicity and negative asthma family history. There was a non-statistically significant trend for FeNO predicting sputum eosinophilia. The best combination of predictors was low FEV(1)% predicted, raised serum eosinophil, positive smoking history and negative family history of asthma.

CONCLUSION

This study demonstrates that the serum eosinophil count and FEV(1) combined with aspects of a clinical history may provide a simple and practical alternative to assessment of airway (sputum) eosinophilia in the clinical setting. A full blood count can be performed at a substantially lesser cost and with greater accessibility than induced sputum. We feel the time has come for the clinical utility of the serum eosinophil count to be revisited.

Do our guardians need guarding? An examination of the Australian system of self-regulation of alcohol advertising

In this study the Australian system of self-regulation of alcoholic beverage advertising was examined. Sixteen advertisements, eight print and eight television advertisements, were subjected to public scrutiny. Respondents rated advertisements using a self-completion questionnaire based directly on the Australian Alcoholic Beverage Advertising Code. Responses were collated and where a majority of respondents had endorsed items that constituted a breach of the cose, a complaint, ostensibly from a member of the general public, was made to the Advertising Standards Council. All sixteen advertisements were regarded by the public as containing aspects which breached the code. However, the Advertising Standards Council rejected all but one of the sixteen complaints, often directly contradicting the opinions of our respondents. The social policy implications of these results are considered. It is contended that the system of self-regulation of alcohol advertising does not serve the public interest.

Relationship between common functional polymorphisms of the p22phox gene (-930A > G and +242C > T) and nephropathy as a result of Type 2 diabetes in a Chinese population

OBJECTIVE

Genetic determinants are important in diabetic nephropathy (DN). Oxidative stress has also emerged as an important pathogenic factor in DN and vascular NADH oxidase is a major source of reactive oxygen species (ROS). Previous small studies reported a strong but contradictory association between functional genetic variation of p22(phox), an important subcomponent of NADH oxidase, and DN. We investigated the association between two common functional single nucleotide polymorphisms (SNPs) (-930 A > G and +242 C > T) and DN in a much larger group of Chinese patients with Type 2 diabetes mellitus (T2DM).

RESEARCH DESIGN AND METHODS

Case-control study of Chinese subjects with long-standing T2DM (> 10 years). Cases (n = 306) were subjects with a spot urinary albumin : creatinine ratio (ACR) of > 113 mg/mmol or elevated serum creatinine. Control subjects (n = 306) had ACR < 3.3 mg/mmol and normal serum creatinine. Genotyping was carried out by standard PCR and restriction fragment length polymorphism analysis.

RESULTS

Gender distribution, age, duration of diabetes and HbA(1c) were similar in cases and control subjects. Distribution of genotypes in the control subjects for both SNPs was consistent with the Hardy-Weinberg equilibrium. Distribution of genotypes did not differ significantly between cases and control subjects for both polymorphisms-+2424C > T: cases CC 84.6%, CT 15.0%, TT 0.4% and control subjects CC 87.6%, CT 11.8%, TT 0.6% (P = 0.45); -930 A > G: cases AA 40.5%, AG 41.8%, GG 17.7% and control subjects AA 38.2%, AG 49.0%, GG 12.8% (P = 0.12). Distribution of alleles was also similar-+2424 C > T: cases C 92.2%, T 7.8% and control subjects C 93.5%, T 6.5% (P = 0.66); -930 A > G cases A 61.4%, G 38.6% and control subjects A 62.7%, G 37.3% (P = 0.38). We estimated that our study has approximately 80% power to detect a relative risk of 1.65 (for +242 C > T) and 1.35 (for -930 A > G) conferred by the minor allele, respectively.

CONCLUSIONS

In contrast with previous small studies, our data suggest that these SNPs do not confer significantly increased susceptibility to DN secondary to T2DM in Chinese subjects.

Association of renal function and delta-aminolevulinic acid dehydratase polymorphism among Vietnamese and Singapore workers exposed to inorganic lead

OBJECTIVES

To investigate the effect of delta-aminolevulinic acid dehydratase (ALAD) polymorphisms on the association between blood lead and renal function among Vietnamese and Singaporean workers who were exposed to low to medium levels of inorganic lead, and to study the distribution of ALAD polymorphism among Vietnamese, Chinese, Malays and Indians.

METHODS

A total of 459 male and female workers were studied. Blood and urine were collected for each worker in order to determine ALAD genotype, blood lead, and urinary delta-aminolevulinic acid (ALAU). Renal function tests included urine albumin (Ualb), urine beta2 microglobulin (Ubeta2m), urinary alpha1 microglobulin (Ualpha1m), N-acetyl-glucosaminidas (NAG), and urine retinol blinding protein (RBP). A multiple regression model with interaction term was applied to fit the entire data and to explore the modifying effect of ALAD polymorphism on the relation of blood lead to each renal function parameter.

RESULTS

ALAD1-1 was the predominant genotype for all the ethnic groups while ALAD2-2 was the rarest. The frequency of ALAD2 allele was higher among Malays (8.8%) and Indians (10.6%) compared to the Chinese (5.0%) and Vietnamese (4.3%). The geometric mean of blood lead for all workers was 19.0 microg/dl. The models for Ubeta2m, Ualpha1m, and NAG showed that the ALAD1-2/2-2 group had higher beta coefficients than the ALAD1-1 group. Corresponding to 10 microg/dl blood lead, ALAD1-1 homozygotes had an increment of 1.288 microg/g Cr, 1.175 mg/g Cr, and 1.995 U/g Cr for Ubeta2m, Ualpha1m, and NAG, respectively. ALAD1-2/2-2 subjects had higher increments of 3.802 microg/g Cr, 2.138 mg/g Cr, and 3.89 U/g Cr for Ubeta2m, Ualpha1m, and NAG, respectively.

CONCLUSION

The frequency of the ALAD2 allele is as low in Vietnamese workers as in Chinese. Workers with the ALAD2 allele appeared more susceptible to the effects of lead (especially at higher levels) on renal function.

Changes in cerebral hemodynamics and cerebral oxygenation during surgical evacuation for hypertensive intracerebral putaminal hemorrhage

OBJECTIVES

The aim of this study was to evaluate the changes in cerebral hemodynamics, tissue oxygenation and blood flow before and after surgery for spontaneous intracerebral hematomas.

METHODS

Eleven patients who underwent surgical decompression of spontaneous putaminal hematoma were studied. Intracranial pressure (ICP), cerebral perfusion pressure (CPP), brain tissue oxygen (PtiO2), and carbon dioxide tensions (PtiCO2), brain pH and regional cerebral blood flow (rCBF) were recorded prior to removing the bone flap and then on skin closure on completion of the operation.

RESULTS

Following surgical decompression, mean ICP decreased significantly (P < 0.05); mean CPP, PtiO2, brain pH and rCBF improved although the changes were not significant.

CONCLUSION

Surgical decompression for spontaneous intracerebral hematomas leads to significant reductions in ICP. This is accompanied by improvements in CPP, PtiO2 and rCBF in the penumbra.

Alpha-synuclein haplotypes implicated in risk of Parkinson's disease

The authors examined four- and six-loci haplotype constructs (from five single nucleotide polymorphisms and three microsatellite regions) of the alpha-synuclein gene in patients with Parkinson's disease (PD) and controls in an ethnic Chinese population. Logistic regression analysis demonstrated an association of NACP-Rep1 (p = 0.002) and L478 (p < 0.0001) with risk of PD after correction for the effects of age, sex, and the other polymorphic loci. Specific four-loci and six-loci haplotypes were significantly associated with an increased or decreased risk of PD.

Spermine reduces infarction and neurological deficit following a rat model of middle cerebral artery occlusion: a magnetic resonance imaging study

The role of nitric oxide (NO) in post-ischemic cerebral infarction has been extensively examined, but few studies have investigated its role on the neurological deficit. In the present study, we investigated the effect of spermine on the temporal evolution of infarct volume, NO production and neurological deficit using magnetic resonance imaging in a model of permanent focal cerebral ischemia in rats. Spermine given at 10 mg/kg 2 h after ischemia reduced the infarct volume by 40% and abolished brain NO production and improved the neurological score 24 h, 48 h and 72 h after ischemia. Spermine also reduced the neurological deficit as evaluated by rotamex, grip strength and neurological severity score tests.

Academic achievement, close up work parameters, and myopia in Singapore military conscripts

AIM

To determine the relation of refractive error to environmental factors, including close up work, in Singapore military conscripts.

METHODS

A cross sectional study was conducted on 429 Singapore military conscripts. Non-cycloplegic refraction and A-scan biometry were performed in both eyes. A detailed questionnaire was administered by in-person interview to obtain information about current and past near work activity, extra tuition lessons, educational experiences, and family demographics.

RESULTS

Myopia associated with the conscript having been educated in the (gifted, special, or express) educational streams (adjusted odds ratio (OR) = 3.8, 95% confidence interval CI 2.0-7.3), and having completed pre-university education (OR=4.1, 95% CI 1.9-8.8). The reported close up work activity at age 7 years did correlate with age of onset of myopia (p<0.001). In parallel, supplemental tuition lessons in primary school has (OR=2.6, 95% CI 1.4-4.9) associated with conscript myopia. Parental myopia was positively associated with myopia (p<0.001), but this relation disappeared when adjusted for environmental factors. Current (p=0.83) and past close up work activity at age 7 years (p=0.13) did not correlate with myopia.

CONCLUSION

Educational level and educational stream positively related to myopia. A relation was observed with reported close up work activity in early childhood and with tuition classes during elementary school, but not with current close up work activity. These results underscore the strong influence of environment in myopia pathogenesis but a role for close up work activity remains indeterminate.

Myopia: gene-environment interaction

INTRODUCTION

Myopia has reached epidemic proportions in Japan, Hong Kong, Taiwan and Singapore. This review summarises the evidence for environmental and genetic factors as well as gene-environment interaction for myopia for both epidemiologic studies as well as animal models.

METHODS

A literature review was conducted after a Medline search on articles on the genetic or environmental aetiology of myopia in animal or epidemiologic studies. Articles on the methodology of gene-environment studies were also reviewed. All articles reviewed were articles published in peer-reviewed journals.

RESULTS

Cross-sectional studies have found a positive association between myopia and near work activity such as reading and writing. Likewise, laboratory research has shown that environmental factors such as visual deprivation may lead to the development of myopia in animals. While linkage studies in humans are currently being conducted to identify possible markers for myopia in the human genome, several neurotransmitters, modulators and growth factors that influence refractive development have already been identified in animal models that may help identify candidate genes. Epidemiologic studies have also evaluated the combined effects of hereditary factors, environmental factors and gene-environment interaction on myopia development.

CONCLUSIONS

Both genes and environmental factors may be related to myopia. There are no conclusive studies at present, however, that identify the nature and extent of possible gene-environment interaction. Further linkage analysis, affected sib-pair studies, and family-based association studies may better identify the nature of gene-environment interaction.

Cauda equina syndrome after spinal anaesthesia in a patient with severe vascular disease

PURPOSE

Spinal anaesthesia is selected for many lower extremity surgical procedures each year in the United States with a high degree of safety and efficacy. Even when adverse neurological outcomes have occurred, anatomical abnormality or coagulopathy have been implicated in the majority of cases. Epinephrine is used in high concentrations in many of these anaesthetics to increase the duration and intensity of the block. Although epinephrine is known to decrease spinal cord blood flow, its use in normal patients has not caused complications. We report a case where spinal anaesthesia with bupivacaine and epinephrine resulted in anterior spinal artery compromise and the development of a cauda equina syndrome postoperatively.

CLINICAL FEATURES

A 57-yr-old man with severe coronary artery and peripheral vascular disease was scheduled for incision and drain of an abscess of the left thigh. He received an atraumatic dural puncture and injection of 12.5 mg bupivacaine with 0.2 ml 1:1000 epinephrine. During onset, he experienced a severe, painful sensation of the thighs which resolved with development of the block. Postoperatively, he was noted to have exacerbation of proximal muscle weakness and decreased perineal sensation and rectal tone. Subsequent EMG studies demonstrated proximal neuron loss consistent with cauda equina syndrome, presumed to be related to insufficiency of the anterior spinal artery.

CONCLUSION

Routine use of epinephrine in spinal anaesthesia for patients with multi-organ vascular disease should be considered carefully because of the possibility of vascular insufficiency of the spinal cord which would be exaggerated by the vasoconstrictive effect of epinephrine.

An unusual cause of acute chest pain during epidural anesthesia

BACKGROUND AND OBJECTIVES

Selective sympathetic denervation during epidural anesthesia results in a small, active gut. These changes can also result in selective activity in one segment of the gut that is absent in other segments.

CASE REPORT

A 61-year-old male was scheduled for bilateral total knee replacement during epidural anesthesia. Following onset of the epidural block, he experienced severe left-sided chest pain. Surgery was canceled. A portable chest radiograph revealed a widened mediastinum, and he underwent angiography to rule out a dissecting thoracic aortic aneurysm. The left subclavian artery could not be visualized, and an MRI was obtained, which was normal. After his return to the intensive care unit, he had a large bowel movement and his chest pain resolved.

CONCLUSION

Selective activity of the gastrointestinal tract during the onset of epidural anesthesia created a visceral pain, which effectively simulated pain with a cardiovascular origin.

TGF-beta1 in colonic neoplasia: a genetic molecular and immunohistochemical study

Transforming growth factor-beta proteins are key regulators of cellular growth and differentiation. To understand the role of TGF-beta in colonic tumour progression, 47 paraffin embedded samples from colonic tumours (13 adenomas, and 34 adenocarcinomas) were studied. Gene mutations in the region coding for the active protein were studied by PCR SSCP analysis of exons 5, 6, and 7. TGF-beta1 mRNA expression and localization were studied by NISH using cDNA probes generated by RT-PCR. Protein distribution was investigated by immunohistochemistry using antibodies against both intracellular and extracellular forms. Three mutations were found: one in exon 5 (Dukes C) and two in exon 7 (Dukes C and A). TGF-beta1 mRNA was observed in 9 (69%) of 13 adenomas and in 30 (88%) of 34 adenocarcinomas. Levels of TGF-beta1 mRNA and proteins were higher in colorectal carcinomas than in colorectal adenomas. Tubular adenomas associated with dysplasia showed greater expression of TGF-beta1 than adenomas without dysplasia and than non-neoplastic colonic mucosa. In dysplasia and cancer, epithelial neoplastic cells and stromal cells were positive for TGF-beta1. In normal tissue endothelial cells and granulocytes sporadically showed immunoreactivity for TGF-beta1, whereas epithelial cells were all negative. The three mutations in TGF-beta1 exons 5, 6 and 7 found in colorectal adenocarcinomas suggest that TGF-beta1 mutation may play a role in colorectal carcinogenesis and that the presence of the mutant form contributes to the transformed state. Our two other findings, the loss of staining gradient in normal colonic mucosa and the higher levels of TGF-beta1 mRNA and proteins in colorectal carcinomas than in colorectal adenomas, indicate that the de-regulation of TGF-beta1 expression may occur as an early event in colorectal carcinogenesis. Although TGF-beta1 expression is generally a reflection of cellular differentiation, tumour grade is not associated with TGF-beta1 mRNA expression. Beside being present in the epithelial cells of the colonic tumours, TGF-beta1 mRNA also occurred in the stroma: its localization in the macrophages adjacent to tumour strongly suggests that TGF-beta1 could be secreted by macrophages. This hypothesis should lead to new therapeutic strategies for colorectal carcinoma.

Molecular genetic analysis of TGF-beta1 in ovarian neoplasia

Malignant ovarian tumours have been associated with a loss of autocrine growth inhibition by transforming growth factor-beta. This study aimed to detect abnormalities in the gene structure, expression and localization of TGF-beta1, in paraffin-embedded samples from 31 ovarian neoplasias (21 malignant, 5 borderline and 5 benign). Gene mutations in the region coding for the active protein were detected by PCR-SSCP analysis of exons 5, 6 and 7. mRNA expression and localization was studied by nonisotopic in situ hybridization (NISH) using cDNA probes generated by the reverse transcriptase polymerase chain reaction (RT-PCR), and immunohistochemistry, using antibodies against both intracellular and extracellular (matrix-associated) forms of TGF-beta1. Four mutations were found: one in exon 6 (serous adenocarcinoma), one in exon 7 (Mullerian tumor), and two in exons 5 and 6 from a serous cystoadenoma. TGF-beta1 mRNA was expressed in 87% and proteins in 90% of ovarian tumours. Most tumours expressing large amounts of TGF-beta1 mRNA, also contained a large number of protein binding sites. In malignant tumors, TGF beta1 was more strongly expressed in high-grade ovarian carcinomas with a cystic-papillary pattern than in tumours with a solid growth pattern. Normal ovarian tissue (follicles, granulosa cells) adjacent to tumor showed weak epithelial labeling and staining. Gene mutation did not correlate with histological type of tumor, mRNA or protein expression. TGF-beta1 mutation and abnormalities in its expression seem to occur in benign and malignant ovarian tumors, and could be involved in their pathogenesis. TGF beta1 gene mutations may act in multistage ovarian neoplasia, by reducing epithelial cell responsiveness to TGF-beta1 negative growth control.

Molecular genetic analysis of TGF beta1 in breast cancer

Conflicting data suggest that TGF-beta1 can either inhibit or promote the progression of breast cancer. To determine the biological role of TGF beta1 in mammary carcinoma, in this study we examined the gene structure, expression and localization of TGF-beta1 using paraffin-embedded samples from 32 (27 IDC, 1 ILC, 1 DCIS, 1 ADH) breast lesions. Gene mutations in the region coding for the active protein were investigated by PCR-SSCP of exons 5, 6, and 7. mRNA -TGF-beta1 expression and distribution was examined by NISH using cDNA probes generated by RT-PCR and immunohistochemistry. We detected two mutations in exon 6 TGF-beta1 from IDC; and TGF beta1 mRNA and proteins in 28 (87%) of the tumors. Invasive breast carcinomas had more intense TGF-beta1 activity than CIS and than normal tissue adjacent to tumor. TGF beta1 mRNA and proteins were higher at the edge of the tumor than in the center and were also higher in less differentiated breast neoplasms. TGF-beta1 mRNA transcription and protein levels did not correlate either with TGF-beta1 exon 6 mutation or type and grade of differentiation of breast tumors. These observations suggest that TGF beta1 mutations in breast neoplasms might cause loss or inactivation of the growth inhibitory effects of TGF-beta1. They also support the proposed role of TGF-beta1 in the pathogenesis of breast cancer.

Increased expression of the cyclin D1 gene in Barrett's esophagus

Previous studies have found a 3-10-fold amplification and overexpression of the cyclin D1 gene in about 32% of human esophageal squamous cell carcinoma. The purpose of this study was to evaluate the prevalence of increased expression of the cyclin D1 protein in Barrett's esophagus. Using 69 formalin-fixed and paraffin-embedded human esophageal specimens, which had been removed endoscopically or obtained at surgery during 1993 and 1994, all immunohistochemical analyses were performed using an avidin-biotin complex immunoperoxidase technique. Increased nuclear expression of the cyclin D1 protein was noted in 32 of 69 samples (46%; 44% of the samples from males and 50% of the samples from females). Positive nuclear staining for the cyclin D1 protein in Barrett's disease with intestinal metaplasia was found in 38% of the male cases and 25% of the female cases, whereas in gastric metaplasia it was positive in 33% of men and 48% of women. Nuclear accumulation of the cyclin D1 protein was also found in both dysplastic and nondysplastic lesions, and it was not associated with sex, age, or cigarette or alcohol consumption. Samples from patients taking proton pump inhibitors tended to be less frequently positive (32%) for cyclin D1 nuclear staining when compared to patients taking H2 antagonists (45%) or antacids (55%). These studies suggest that increased expression of cyclin D1 is an early event in the tumorigenic process of esophageal adenocarcinomas and that the increased expression of this gene might predispose the epithelium to malignant transformation.

Simultaneous double-isotope autoradiographic measurement of local cerebral glucose metabolic rate and acid-base status in rat brain

We developed a double-isotope autoradiographic method for the simultaneous measurement of the local cerebral metabolic rate for glucose (1CMRG) and index of regional acid-base status (rABI) in single brain slices using [2-14C]deoxy-D-glucose (DG) and 5,5-dimethyl-[2-14C]oxazolidine-2,4,dione (DMO). After iv isotope administration, paper chromatography separates plasma DMO from DG activity using a methanol-methylene chloride solvent system. Initial tissue autoradiograms depict regional DMO plus DG and DG metabolite distribution. After 14 days in a well-ventilated hood, 97.5 +/- 0.5% of all DMO is lost from tissue sections by sublimation, and a second autoradiogram depicts DG plus DG metabolite distribution. Retention of brain lipids does not alter beta-particle self-absorption, avoiding problems associated with isotope extraction with solvents. Autoradiograms are digitized and converted to isotope-content images. The second autoradiogram is used for 1CMRG computation. After subtracting the second regional isotope-content value from the first, the DMO content is obtained and used to compute rABI. Application of this method to normal animals yields expected values for 1CMRG and rABI. This method is amenable to whole-slice digitization and creation of functional images of 1CMRG and ABI followed by pixel-by-pixel correlations of the two variables, making this a potentially valuable tool for the investigation of the relationships between glucose metabolism and brain acid-base balance.