Predictors of persistent airway stenosis in patients with endobronchial tuberculosis

SETTING

The university and municipal hospitals in Seoul, Korea.

OBJECTIVE

To evaluate the predictors of persistent airway stenosis following anti-tuberculosis chemotherapy in patients with endobronchial tuberculosis (TB).

DESIGN

Diagnosis of TB was confirmed by microbiology or histopathology. Bronchoscopic examinations revealed that patients had endobronchial lesions compatible with endobronchial TB. Study subjects had at least one follow-up bronchoscopy to evaluate their treatment response. Treatment response was determined by changes in the degree or extent of airway stenosis between the first and last bronchoscopic examinations.

RESULTS

Sixty-seven subjects were recruited retrospectively from Seoul National University Hospital and Seoul National University Boramae Hospital. Persistent bronchostenosis occurred in 41.8% of the patients. In multivariate regression analysis, age >45 years (OR 3.65), pure or combined fibrostenotic subtype (OR 5.54) and duration from onset of chief complaint to the initiation of anti-tuberculosis chemotherapy >90 days (OR 5.98) were identified as independent predictors of persistent airway stenosis. Oral corticosteroids (prednisolone equivalent >or=30 mg/d) did not reduce the frequency of persistent airway stenosis.

CONCLUSION

Early diagnosis and early administration of anti-tuberculosis chemotherapy before involvement of the deeper airways is important to prevent the development of unwanted sequelae of bronchostenosis.

Treatment outcomes of 70 cases of early esophageal carcinoma: 12 years of experience

Early esophageal cancer (EEC) has an excellent prognosis compared to advanced esophageal cancer. Nowadays, endoscopic mucosal resection (EMR) may offer another alternative to cure early cancers of the gastrointestinal tract. We aimed to evaluate the clinical outcomes of EEC in Korea after curative treatments; EMR or surgery. We retrospectively reviewed the medical records of patients diagnosed as EEC from January 1994 to August 2005 at Yonsei University Medical Center, Seoul, Korea. Among 888 patients diagnosed with esophageal cancer, 70 (7.9%) were included as EEC. Among them, 10 patients (14.3%) were treated by EMR, and 50 (71.4%) by operation. The treatment outcomes of EEC in relation to various clinicopathologic factors along with survival rates were analyzed. There were 18 cases (30%) of mucosal lesions and 42 cases (70%) of submucosal lesions. Overall 5-year survival rate was 84.3%. When comparing treatment outcomes between EMR-treated and operated groups, there were no significant differences in complete remission (80%vs. 84%), recurrence (20%vs. 16%) and 5-year survival rate (100%vs. 78.3%). EEC is a potentially curable entity with a good clinical prognosis. EMR can be considered as another treatment arm for EEC, along with surgical resection.

Emergency department experience of primary diffusion weighted magnetic resonance imaging for the patient with lacunar syndrome

BACKGROUND

The purpose of this study was to evaluate the usefulness of a particular magnetic resonance imaging technique known as primary diffusion weighted imaging (DWI) for patients with lacunar syndrome in the emergency department (ED).

METHODS

Patients with one of five classic lacunar syndromes underwent DWI as primary imaging modality. The DWI findings were classified into groups: (a) having a lesion with high signal intensity, (b) having a lesion with mixed signal intensity, and (c) unremarkable. The final clinical diagnoses were extracted from the patients' medical records, and used as a reference standard.

RESULTS

Of 151 DWI images, 120 (79%) were interpreted as high signal lesions, 21 (14%) as mixed signal lesions, and 10 (7%) as unremarkable. All patients with high signal lesions or unremarkable findings were diagnosed with ischaemic stroke. The patients with mixed signal lesions were diagnosed with haemorrhagic stroke with an exception of one ischaemic stroke.

CONCLUSION

Primary DWI is a feasible and useful neuroimaging tool for patients with lacunar syndrome in the ED.

Long term results from percutaneous radiofrequency neurotomy on posterior primary ramus in patients with chronic low back pain

PURPOSE

We report on our experience of percutaneous radiofrequency neurotomy (PRN) on the posterior primary ramus (PPR) with at least two years follow-up.

METHODS

228 patients underwent PRN on the PPR for refractory low back pain. 128 patients met the inclusion criteria of facetal originated pain (group II), while 100 patients did not (group I). Radiofrequency (RF) procedures were applied in the usual manner. Pain relief was assessed at 1 week, 1 month, 6 months and 2 years using visual analog scale (VAS).

FINDINGS

Positive responders were 56% at 1 week, 46% at 1 month, 18% at 6 months, and 13% at 2 years after PRN in group I, and 78.9% at 1 week, 75.4% at 1 month, 62.5% at 6 months, and 54.7% at 2 years in group II. Prominent local tenderness, percussion tenderness, pain on getting up, extension and transitional movement, radiating pain on buttock and/or posterior thigh, and good immediate response were found to be significantly related to good outcome.

CONCLUSION

PRN on the PPR has long-term beneficial effects. Long-term good results can be achieved after proper selection of patients with facet joint related low back pain.

Determinants of diagnostic bronchial washing in peripheral lung cancers

OBJECTIVE

To establish clinical determinants affecting the diagnostic yield of bronchial washing.

SETTING

We performed bronchial washing in 241 consecutive patients with bronchoscopically invisible lung tumours. Of these, 150 patients known to have lung cancer were enrolled for the final analysis.

DESIGN

A multi-centre study.

RESULTS

Bronchial washing provided a diagnosis of lung cancer in 30 of the 150 patients (20%). Tumour size > or = 3 cm (P = 0.005), the location of the tumour within 8 cm of the carina (P = 0.003), and exposed type bronchus sign of tumour (P < 0.001) were factors affecting diagnostic bronchial washing for bronchoscopically invisible lung cancers. However, multivariate logistic regression revealed that exposed type bronchus sign was the sole determinant (OR 19.22, 95% CI 4.23-87.46, P < 0.001).

CONCLUSION

Bronchial washing is a useful procedure for the diagnosis of bronchoscopically invisible lung cancers. As the tumour-bronchus relationship is the most important determinant of a diagnostic yield, the routine use of bronchial washing should be considered for tumours with exposed type bronchus sign.

A new and simple transection knife for study of neurodegeneration and neuroregeneration in animal model

BACKGROUND

The purpose of this study was to design and make a simple, inexpensive brain knife that could produce consistent results following transection in animal model.

MATERIALS AND METHODS

After testing various materials including commercially available products, microelectrode recording needles as used in deep brain stimulation (DBS) surgery were selected as ideal candidates. They were modified to serve as type of wire-knife for the purposes of study. For this study, the major pathway for dopaminergic neuron from substantia nigra to striatum was selected for transection. A total of 40 Sprague-Dawley rats were assigned to 8 groups; normal, 1-4, 6, 8, and 10 weeks post-transection. Degree of cell death was determined and surviving neurons were counted by means of fluorescent microscopic examination, immunohistochemistry involving tyrosine hydroxylase (TH)-immunoreactive staining, and mapping to verify complete transection.

RESULTS

Compared to control, percentage of remaining neurons in each group was 61.3, 36.8, 29.9, 5.1, 5.9, 7.0%, respectively. Completeness of lesion was correlated with the absence of TH-immunoreactivity in the striatum.

CONCLUSION

Our model seems to provide complete cell death in early period after transection with consistent results. Thus, this type of brain knife can be very handy, without any extra cost, in any research model involving transection of fiber bundle for studies on neurodegeneration and neuroregeneration.

Lack of association between COPD and transforming growth factor-beta1 (TGFB1) genetic polymorphisms in Koreans

OBJECTIVE

Many genetic variations have been suggested as genetic risk factors for the development of chronic obstructive pulmonary disease (COPD), including single nucleotide polymorphisms in the transforming growth factor-beta1 (TGFB1) gene. We attempted to elucidate the association between TGFB1 genetic polymorphisms and COPD among Koreans.

DESIGN

The genotypes of 102 male patients with COPD and 159 volunteers with similar distributions of age, sex and smoking intensity, as well as normal pulmonary function, were determined for three previously associated TGFB1 single nucleotide polymorphisms (SNPs), -10807G/A (rs2241712) and -509T/C (rs1800469), located in or near the promoter, and 29T/C (rs1982073), located in exon 1 of the TGFB1 gene.

RESULTS

No significant associations between COPD and the three TGFB1 SNPs could be identified. In addition, the haplotypes composed of three TGFB1 SNPs were not associated with the presence of COPD.

CONCLUSION

These results differ from previous reports involving Caucasians, and might reflect racial differences in the pathogenesis of COPD.

beta-lapachone induces growth inhibition and apoptosis in bladder cancer cells by modulation of Bcl-2 family and activation of caspases

AIM

To study in vitro the molecular mechanism of apoptosis caused by beta-lapachone, a quinone obtained from the bark of the lapacho tree (Tabebuia avellanedae).

MATERIALS AND METHODS

The study was carried out on human bladder carcinoma T24 cell line. Determination of cell viability was done using trypan blue exclusion method, apoptosis quantitative estimation - by DAPI staining and agarose gel electrophoresis for DNA fragmentation. Flow cytometry analysis, RT-PCR and Western blot analysis, colorimetric assay of caspase activity were applied as well.

RESULTS

It was found that in micromolar range of concentrations beta-lapachone inhibited the viability of T24 cells by inducing apoptosis, which could be proved by formation of apoptotic bodies and DNA fragmentation. Treatment of T24 cells with beta-lapachone resulted in a down-regulation of Bcl-2 expression and up-regulation of Bax expression. beta-lapachone-induced apoptosis was also associated with activation of caspase-3 and caspase-9, inhibition of IAP expression, and degradation of poly (ADP-ribose) polymerase, phospholipase C-gamma1 and beta-catenin proteins. At the same time Fas and FasL levels were inhibited upon treatment with beta-lapachone in a concentration-dependent manner.

CONCLUSION

beta-lapachone-induced apoptosis in T24 cells is mediated, at least in part, by the mitochondrial-signaling pathway.

Right heart dysfunction in post-tuberculosis emphysema

SETTING

University-affiliated general hospital.

OBJECTIVE

To evaluate the pump performance of right heart before and after exercise in post-tuberculosis emphysema.

DESIGN

In patients with post-tuberculosis or primary emphysema (similar lung volumes), body plethysmography, arterial blood gas analysis and echocardiography were performed at rest and after exercise. Right heart pump performance was evaluated with the ejection fraction.

RESULTS

At rest, in post-tuberculosis emphysema, diffusing capacity (mean +/- SE 72.7 +/- 3.9 vs. 91.0 +/- 7.1% of reference) and right ventricular ejection fraction (57.5 + 1.4 vs. 61.3 +/- 1.2%) were lower and PaCO2 (42.7 +/- 1.1 vs. 38.6 +/- 0.7 mmHg) was higher, while lung compliance, airway resistance, PaO2, and alveolar-arterial oxygen difference were not different. After exercise, PaO2 (65.6 +/- 2.8 vs. 80.5 +/- 3.5 mmHg) and right ventricular ejection fraction (51.2 +/- 2.4 vs. 59.6 +/- 1.7%) were lower and PaCO2 (47.0 +/- 1.5 vs. 40.9 +/- 1.5 mmHg) was higher in post-tuberculosis emphysema, whereas alveolar-arterial oxygen difference was not different. PaCO2 and alveolar-arterial oxygen difference increased, and PaO2 and right ventricular ejection fraction decreased in post-tuberculosis emphysema, while they did not significantly change in primary emphysema.

CONCLUSION

In post-tuberculosis emphysema, the impairment of gas exchange was more serious. Global assessment should be focused on right heart dysfunction which might be more affected than in primary emphysema.

Ocular haemodynamic responses to induced hypercapnia and hyperoxia in glaucoma

AIM

To determine the ocular haemodynamic response to gas perturbations in glaucoma.

METHODS

Intraocular pressure (IOP), systemic systolic and diastolic blood pressure (SBP and DBP), and retrobulbar blood flow velocities, measured by colour Doppler imaging (CDI), were recorded at two visits. CDI was used to measure peak systolic and end diastolic velocities (PSV and EDV) and resistance index (RI) in the ophthalmic artery (OA), central retinal artery (CRA), and short posterior ciliary arteries (SPCAs). At the first visit, measurements were taken at baseline (B1: breathing room air) and during isoxic hypercapnia (end tidal PCO(2) increased 15% above baseline) in 16 normal subjects and 12 patients with glaucoma. On another day, measurements were repeated at a second baseline (B2) and during hyperoxia (100% oxygen breathing) for 15 normal subjects and 13 glaucoma patients. Baseline systemic data were compared using paired t tests; REANOVA was performed to compare group differences at baseline and to determine the vessel response to each condition. Fisher's LSD was used for post hoc comparison.

RESULTS

Baseline OA PSV was lower for the glaucoma than for the normal group (p = 0.047); the groups were otherwise similar at baseline. IOP demonstrated no response to hypercapnia, but reduced during hyperoxia for both the normal subjects (p<0.0001) and glaucoma patients (p = 0.04). During hypercapnia, SBP increased in normal subjects (p = 0.03) and glaucoma patients (p = 0.01); DBP increased in normal subjects (p = 0.021). There was a corresponding increase in ocular perfusion pressure (OPP) for normal subjects (p = 0.01) and glaucoma subjects (p = 0.028), and as a result OPP was included as a covariate in the REANCOVA model. Hypercapnia resulted in increased PSV in the CRA of normal subjects (p = 0.035) and increased PSV and EDV in the SPCAs of glaucoma patients (p = 0.041 and p = 0.030 respectively). Hyperoxia resulted in reduced PSV and EDV in the ophthalmic arteries of normal subjects only (p = 0.001 and 0.031 respectively).

CONCLUSIONS

These findings suggest the presence of relative vasoconstriction in glaucoma patients, which is at least partially reversed by hypercapnia.

Induction of apoptosis by carboplatin and hyperthermia alone or combined in WERI human retinoblastoma cells

This paper investigated the induction of apoptosis and perturbation of cell cycle progression caused by carboplatin (CPt) and hyperthermia alone or combined in WERI human retinoblastoma cells in vitro. An incubation of the cells with 25 or 50 microm of CPt at 37 degrees C caused apoptosis, which progressively increased during the 24-72 h treatment. Hyperthermia at 42.5 degrees C for 1 h induced apoptosis, which became significant from 24 h after the heating. Heating the cells in the presence of CPt and subsequent incubation with CPt was far more effective than treating the cells with hyperthermia or CPt treatment alone in inducing apoptosis in the WERI cells, indicating that the combination of these two modalities is potentially useful for the treatment of retinoblastoma. It appeared that the apoptosis in WERI cells caused by hyperthermia and CPt occurs during G1 phase. An interesting observation was that caspase 9 activation preceded the release of cytochrome C from mitochondria during apoptosis in WERI cells, contrary to the general notion that caspase 9 is activated by cytochrome C.

Blood flow per unit retinal nerve fibre tissue volume is lower in the human inferior retina

AIM

To determine if perfusion per unit tissue volume of retinal nerve fibre layer and optic nerve head in the inferior sector is lower than in the superior sector.

METHODS

Heidelberg retinal tomogram (HRT) for topographic measurement of optic nerve head and retinal nerve fibre layer and Heidelberg retinal flowmeter (HRF) for retinal blood flow were performed on 19 normal healthy subjects. Measurements from the superior and inferior sectors were compared. The perfusion/nerve fibre ratio (PNR); the blood flow per unit retinal nerve fibre tissue volume, was calculated in each sector with a formula; HRF flow measurements divided by HRT measurements.

RESULTS

Retinal nerve fibre layer thickness in the inferior retina was significantly higher than in the superior retina (p<0.05). There were, however, no differences in retinal blood flow between the superior and inferior retinal sectors. The PNR in the inferior sector were significantly lower than in the superior sector (p=0.047 for HRF mean flow/rim volume and p = 0.0282 for HRF 75th percentile flow/rim volume).

CONCLUSIONS

The inferior sector of retinal nerve fibre layer and optic nerve head may have lower blood flow per unit nerve tissue volume compared to the superior sector. This result suggests that the inferior sector is more vulnerable to elevated intraocular pressure (IOP) and ischaemic insults in glaucomatous optic neuropathy.

Anesthetic management of a patient with relapsing polychondritis--a case report

Relapsing polychondritis is a rare multisystem disorder of uncertain etiology. It is characterized by recurrent and progressive destruction of both elastic and hyaline cartilages as well as connective tissue. Respiratory tract involvement is associated with high mortality and morbidity. General anesthesia may be required in these patients for tracheostomy, bronchoscopy, nasal reconstruction, aortic valve replacement, and recent tracheobronchial stenting which they usually sustain. Tracheostomy was once the most likely surgical procedure in relapsing polychondritis. However, this procedure is only effective in patients with upper subglottic involvement. In cases of extensive tracheobronchial involvement, tracheostomy is ineffective because the distant tracheal collapse below the tracheostomy is still unresolved. We would like to report a case of relapsing polychondritis with tracheobronchial involvement, who underwent an emergent tracheostomy. Tracheostomy with continuous positive airway pressure (CPAP) effectively improved her airway collapse. Herein, we also discuss the anesthetic management after review of the current literature.

Diagnosis of progressive compression of the aortic true lumen with intraoperative transesophageal echocardiography during repair of dissection of thoracic aorta--a case report

We report an incident of progressive compression of the true lumen of aorta which happened immediately after cardiopulmonary bypass (CPB) and was diagnosed with intraoperative transesophageal echocardiography (TEE) in a patient undergoing an emergent repair of type A aortic dissection under femoral perfusion. During the CPB period, intraoperative TEE revealed gradual expansion of the false lumen which nearly obstructed the true lumen of the dissected aorta. The possible mechanism was related with distension of the false lumen by a dominant flow from retrograde femoral perfusion of CPB. With the application of intraoperative TEE, we could easily detect the hemodynamic changes of thoracic aorta and find the real causes so as to solve the perfusion abnormalities.

A quinolone alkaloid with antioxidant activity from the aleurone layer of anthocyanin-pigmented rice

The aleurone layer of Oryza sativa cv. Heugjinmi yielded a new quinolone alkaloid, 4-carbomethoxy-6-hydroxy-2-quinolone (1), showing moderate antioxidative activity in a 1,1-diphenyl-2-picrylhydrazyl free-radical scavenging assay. Physical and spectroscopic evidence has determined the structure of the compound.

Molecular authentication of Panax ginseng species by RAPD analysis and PCR-RFLP

In order to develop convenient and reproducible methods for the identification of ginseng drugs at a DNA level, randomly amplified polymorphic DNA (RAPD) and PCR-restriction fragment length polymorphism (PCR-RFLP) analyses were applied within Panax species. To authenticate Panax ginseng among ginseng populations, RAPD analysis was carried out using a 20 mer-random primer. The similarity coefficients among the DNA of ginseng plants analyzed were low, ranging from 0.197 to 0.491. In addition, by using PCR-RFLP analysis, very different fingerprints were obtained within Korean ginseng plants. These results suggest that these methods are able to authenticate the concerned Panax species. Broader application of this approach to authenticate other morphologically similar medicinal materials is rationalized.

Accumulation of intraventricular fat in an intracranial epidermoid tumor: case report

OBJECTIVE AND IMPORTANCE

A fat component within the ventricles or subarachnoid space in fat-containing tumors such as an epidermoid or a dermoid has been observed in rare instances. However, there have been no reports regarding an increase in the size of such a fat component. We describe the case of an epidermoid tumor with intraventricular fat that showed an increase in size and amount.

CLINICAL PRESENTATION

A 26-year-old woman was admitted with headache and diplopia. Computed tomography and magnetic resonance imaging of the brain revealed a fat-containing suprasellar tumor and widespread fat globules in adjacent sulci and cisterns and within the frontal horn of the lateral ventricle.

INTERVENTION

The patient underwent a pterional craniotomy. Removal of the suprasellar tumor was nearly total. Histopathological examination revealed an epidermoid tumor. Sequential magnetic resonance imaging throughout the ensuing 65-month period revealed no evidence of tumor recurrence; however, the intraventricular fat remained and increased in size. The patient underwent surgery via the transcallosal approach at 69 months after the initial operation, and the presence of free-floating oily fat globules was confirmed.

CONCLUSION

In the case of a fat-containing tumor with free fat in the cerebrospinal fluid spaces, careful serial examination is necessary, with particular attention to the possibility of changes in size.

Hemodynamic responses of thiopental and propofol in different-aged patients during endotracheal intubation

BACKGROUND

Thiopental and propofol are 2 popularly used anesthetic induction agents that have different pharmacological and pharmacokinetic actions. It is not clear how the hemodynamic responses differ in different-aged patients using these 2 drugs for anesthetic induction. The aim of this study was to investigate the hemodynamic responses to propofol and thiopental of different-aged patients during endotracheal intubation.

METHODS

Sixty patients, 20 to 83 years old, were included in this study. Patients were randomly divided into 6 groups according to age and different inductive anesthetics. Non-invasive blood pressure (NIBP) monitoring was performed every minute before anesthesia, during anesthetic induction with 5 mg.kg-1 thiopental or 2 mg.kg-1 propofol intravenously, and after intubation.

RESULTS

Propofol induction produced a smaller mean arterial pressure increase immediately after intubation than did thiopental induction in adult and elderly groups (101.0 +/- 18.5 and 104.0 +/- 21.1 mmHg in the propofol groups vs. 138.3 +/- 17.1 and 138.9 +/- 16.1 mmHg in the thiopental groups at 1 minute after intubation, p < 0.001 and p = 0.001, respectively). Differences in heart rate between propofol and thiopental groups were found in young and adult groups (85.1 +/- 9.2 and 81.7 +/- 10.9 in the propofol groups vs. 94.5 +/- 9.9 and 95.0 +/- 14.0 beats per minute in the thiopental groups at 1 minute after intubation, p = 0.041 and p = 0.029, respectively).

CONCLUSION

Propofol induction produced more stable hemodynamics after intubation in adult and elderly patients than did thiopental induction. Therefore, it is safer to use propofol for induction and intubation in adult and elderly patients.

Hepatopulmonary syndrome in poorly compensated postnecrotic liver cirrhosis by hepatitis B virus in Korea

BACKGROUND

Hepatopulmonary syndrome (HPS) refers to the association of hypoxemia, intrapulmonary shunting and chronic liver disease. But there is no clear data about the prevalence of HPS in postnecrotic liver cirrhosis by hepatitis B virus (HBV), the most common cause of liver disease in Korea. The aim of this study was to investigate the prevalence of HPS in poorly compensated postnecrotic liver cirrhosis by HBV, and the correlation of the hepatopulmonary syndrome with clinical aspects of postnecrotic liver cirrhosis by HBV.

METHODS

Thirty-five patients underwent pulmonary function test, arterial blood gas analysis and contrast-enhanced echocardiography. All patients were diagnosed as HBV-induced Child class C liver cirrhosis and had no evidence of intrinsic cardiopulmonary disease.

RESULTS

Intrapulmonary shunt was detected in 6/35 (17.1%) by contrast-enhanced echocardiography. Two of six patients with intrahepatic shunts had significant hypoxemia (PaO2 < 70 mmHg) and four showed increased alveolar-arterial oxygen gradient over 20 mmHg. Only cyanosis could reliably distinguish between shunt positive and negative patients.

CONCLUSIONS

The prevalence of intrapulmonary shunt in poorly compensated postnecrotic liver cirrhosis by HBV was 17.1% and the frequency of hepatopulmonary syndrome was relatively low (5.7%). 'Subclinical' hepatopulmonary syndrome (echocardiographically positive intrapulmonary shunt but without profound hypoxemia) exists in 11.4% of cases with poorly compensated postnecrotic liver cirrhosis by HBV. Cyanosis is the only reliable clinical indicator of HPS of HBV-induced poorly compensated liver cirrhosis. Further studies are required to determine if the prevalence and clinical manifestations of HPS varies with etiology or with geographical and racial differences.

Ocular blood flow measurements and their importance in glaucoma and age-related macular degeneration

This survey of methods for assessing ocular hemodynamics in glaucoma and age-related macular degeneration is not complete, but it does cover those likely to be encountered in the literature. A fundamental problem in getting to grips with the ocular blood flow literature is the difficulty in comparing the results of similar studies employing different assessment techniques. As evident from the discussion above, each technique evaluates a portion of the ocular circulation in a distinct way. Some of the methods overlap with regard to the tissues that can be used for examination, while others are directed at entirely different parts of the ocular vasculature. Despite these difficulties, hemodynamic studies of glaucoma and AMD are likely to grow in importance. On the basis of accumulating epidemiological and clinical evidence, it is becoming apparent that intraocular pressure is not the sole etiological factor in glaucoma, and retinal pigment epithelium senescence is not the sole etiological factor in AMD. Circumstantial evidence of vascular involvement in glaucoma and AMD has now been bolstered by experimental evidence. If the current pace of refinement of newly established technologies for evaluating ocular blood flow is maintained, they will soon be ready for deployment in the clinic. The only problem is the availability of expensive instruments and trained personnel. The ultimate beneficiaries of work in this area will not be researchers, but patients.

Effect of brimonidine tartrate on ocular hemodynamics in healthy volunteers

While alpha2-adrenergic agonists, such as brimonidine tartrate, significantly reduce the intraocular pressure (IOP), the presence of vasoconstrictor postsynaptic alpha2 receptors on vascular smooth muscle raise the possibility that brimonidine could potentially compromise ocular blood flow. Consequently, the ocular hemodynamic effects of brimonidine were studied in normal subjects. Twelve healthy volunteers were included in this prospective, double-masked, placebo controlled, crossover-designed clinical trial. They received either brimonidine tartrate 0.2% or placebo b.i.d. for 2 weeks. Goldmann tonometry and color Doppler imaging (CDI) were performed at baseline, at 2 hr, 1 week, and 2 weeks after the treatment. Fundus angiography using a scanning laser ophthalmoscope was performed at baseline and 2 weeks after treatment to determine retinal arteriovenous passage time. Brimonidine lowered IOP at 2 hr, 1 week, and 2 weeks (p = 0.058, p = 0.031, and p = 0.022, respectively). Brimonidine did not affect the retrobulbar arterial velocities measured by CDI, nor retinal arteriovenous passage time. In conclusion, two-week treatment with brimonidine reduces IOP and does not reduce the bulk retinal or retrobulbar arterial perfusion in young healthy volunteers.

Distal anterior cerebral artery aneurysms: clinical features and surgical outcome

Aneurysms of the distal anterior cerebral artery (DACA) are rare and their surgical treatments present some unique difficulties from a technical standpoint. In this report, we presented our experiences of cases with DACA aneurysms, and analyzed the clinical features and prognostic factors affecting the final outcomes. Among 770 cases of intracranial aneurysms operated from 1990 to 1998, 19 cases of DACA aneurysms (2.5%) were studied retrospectively. The characteristic findings were female preponderance (M:F = 1:2.8), common multiple aneurysms (57.9%), and frequent intracerebral hemorrhage (ICH) on initial brain CT scan (42.1%). All patients were operated via interhemispheric approach. Intraoperative aneurysmal rupture was developed only in 3 cases (15.8%), and had no relationship with the final outcome Fifteen out of 19 patients (78.9%) showed favorable outcome with a mortality rate of 5.3%. The follow-up data suggest that the initial ICH on brain CT scan portend a poor prognosis.

New neuroretinal rim blood flow evaluation method combining Heidelberg retina flowmetry and tomography

AIM

Accurate Heidelberg retina flowmeter (HRF) measurements require correct manual setting of the HRF photodetector sensitivity. The neuroretinal rim produces a weak signal relative to the peripapillary retina. A newly developed HRF alignment and sensitivity protocol, capable of accurate rim measurement, was investigated.

METHODS

18 eyes of nine healthy volunteers were examined by HRF. Three images of each eye were taken using three different imaging methods. Method 1: a conventional image (optic nerve head centred image with photodetector sensitivity optimised for the strong signal from the peripapillary retina); method 2: the setting of method 1 with photodetector sensitivity optimised for the weak signal from the rim; and method 3: the setting of method 2 with the temporal rim margin tangent to the lateral image border to remove the overpowering signal from the temporal peripapillary retina. The neuroretinal rim was defined by the Heidelberg retina tomograph (HRT). Blood flow and reflectivity values (DC component) in the rim area were compared for the three methods using pointwise analysis. Coefficients of variation of repeated measurements in 12 subjects have been calculated for method 3.

RESULTS

The neuroretinal rim area measured by method 1 had a significantly lower brightness compared with method 2 and 3 (p=0.0002 and p=0.0002, respectively). Method 2 provided proper sensitivity for the weak signals of the rim area based on rim tissue DC values; however, this sensitivity setting was too high for the strong signal from the peripapillary retina. Method 3 avoided the strong peripapillary signal with the proper signal from the rim and provided significantly higher flow values of the rim area at 75 and 90 percentile pixels (p=0.0065 and p=0.0038 respectively) compared with method 2. Interobserver repeatability ranged from 16.85% to 21.96% for the different parameters.

CONCLUSIONS

Method 3 provides an accurate and reproducible flow measurement of the neuroretinal rim area through proper sensitivity for the weak rim signal, alignment, and removal of the strong temporal signal from the image. This new method is recommended to improve accuracy of blood flow measurement in the neuroretinal rim.