Biomedical subjects

S C Hu

Publications and source records attributed to S C Hu.

At least 19 recordsLinked to original sources

PubMed2005

Workplace smoking related absenteeism and productivity costs in Taiwan.

OBJECTIVE: To estimate productivity losses and financial costs to employers caused by cigarette smoking in the Taiwan workplace. METHODS: The human capital approach was used to calculate lost productivity. Assuming the value of lost productivity was equal to the wage/salary rate and basing the calculations on smoking rate in the workforce, average days of absenteeism, average wage/salary rate, and increased risk and absenteeism among smokers obtained from earlier research, costs due to smoker absenteeism were estimated. Financial losses caused by passive smoking, smoking breaks, and occupational injuries were calculated. RESULTS: Using a conservative estimate of excess absenteeism from work, male smokers took off an average of 4.36 sick days and male non-smokers took off an average of 3.30 sick days. Female smokers took off an average of 4.96 sick days and non-smoking females took off an average of 3.75 sick days. Excess absenteeism caused by employee smoking was estimated to cost USD 178 million per annum for males and USD 6 million for females at a total cost of USD 184 million per annum. The time men and women spent taking smoking breaks amounted to nine days per year and six days per year, respectively, resulting in reduced output productivity losses of USD 733 million. Increased sick leave costs due to passive smoking were approximately USD 81 million. Potential costs incurred from occupational injuries among smoking employees were estimated to be USD 34 million. CONCLUSIONS: Financial costs caused by increased absenteeism and reduced productivity from employees who smoke are significant in Taiwan. Based on conservative estimates, total costs attributed to smoking in the workforce were approximately USD 1032 million.

Absenteeism↗

PubMed2002

Clinical comparison of high-dose interferon-alpha2b with or without ribavirin for treatment of interferon-relapsed chronic hepatitis C.

BACKGROUND: Interferon a with ribavirin combination therapy is effective but still unsatisfactory in the treatment of patients with interferon-relapsed chronic hepatitis C. AIMS: To compare, in a randomized, double blind, placebo-controlled study, high-dose interferon-alpha2b with or without ribavirin in the treatment for interferon-relapsers. PATIENTS: A total of 52 patients with interferon-relapsed chronic hepatitis C were randomly assigned to receive 24-week treatment with interferon-alpha2b (6 MU three times per week) combined with either ribavirin (1,000 to 1,200 mg per day) or a matched placebo and then followed for an additional 24 weeks. METHODS: Hepatitis C virus RNA was detected by reverse-transcription polymerase chain reaction. For determining viral concentration, the commercial bDNA Quantiplex hepatitis C virus-RNA 2.0 assay was used. Genotyping was performed by reverse hybridization assay RESULTS: At the end of treatment, no detectable hepatitis C virus RNA levels were observed in 92% (24/26) of patients on interferon alpha2b/ribavirin and 81% (21/26) of patients on interferon alpha2b/placebo. At the end of the follow-up, a higher sustained virological response rate was seen in patients treated with interferon alpha2b/ribavirin than those treated with interferon alpha2b/placebo (69% vs 23%, p < 0.001). Patients with either initially high levels of viral concentration or with genotype 1 responded poorly. Patients who received interferon-alpha2b/ribavirin treatment and in whom no hepatitis C virus RNA was detected at 4th week after treatment had 90% chance to achieve sustained virological response. CONCLUSIONS: High-dose interferon-alpha2b plus ribavirin treatment is highly effective in interferon-relapsed patients.

Adult↗

PubMed2001

Induced sputum derives from the central airways: confirmation using a radiolabeled aerosol bolus delivery technique.

Indirect evidence suggests that induced sputum derives from the surfaces of the bronchial airways. To confirm this experimentally, we employed a radiolabeled aerosol bolus delivery technique that preferentially deposits aerosol in the central airways in humans. We hypothesized that there would be significantly more radioactivity recovered in an induced sputum sample, and greater airways clearance of radiolabeled particles, immediately after a central versus peripheral airways deposition. Ten healthy volunteers underwent radiolabeled aerosol deposition ((99m)Tc sulfur colloid particles) to the central and peripheral airways on separate occasions followed immediately by induced sputum or no sputum (control), while seated in front of a gamma camera. Radioactivity was measured in the selected sputum sample, processed cell pellet, and supernatant fraction. Significantly more radioactivity was present in all portions of the sputum sample after central versus peripheral airways deposition (i.e., selected sample: 15,607 counts +/- 2,985 versus 943 counts +/- 298, p = 0.001). Clearance from the whole lung was significantly greater 40 min after central versus peripheral airways deposition (48 +/- 3% versus 5 +/- 1%, p = 0.0001). Compared with control, induced sputum greatly enhanced clearance after central deposition (48 +/- 3% versus 11 +/- 6%, p = 0.0001), but not after peripheral deposition (5 +/- 1% versus 3 +/- 0.8%). These results provide direct evidence that induced sputum derives from the central airways with little or no contribution from the peripheral airways.

Administration, Inhalation↗

PubMed2000

GB virus-C/hepatitis G virus infection in a hepatitis C virus endemic village: prevalence in residents with low educational attainment and frequent recovery in females.

AIMS/BACKGROUND: GB virus-C/hepatitis G virus (HGV) is a newly identified flavivirus, which may share the same mode of transmission as hepatitis C virus (HCV). The aim of this study was to investigate associated factors of HGV infection and clearance in a HCV endemic village in southern Taiwan. METHODS: Five hundred and ninety-four residents of a village in southern Taiwan were enrolled for hepatitis virus screening. Clinical features were recorded and a questionnaire addressing the possible routes of transmission was filled in by the participating residents. RESULTS: The prevalence of antibody to hepatitis C virus and hepatitis B surface antigen in the 594 residents was 70.7% and 19.5% respectively. Of the 399 residents tested for HGV RNA, GB virus-C/Hepatitis G virus envelop 2 protein (HGV-E2) antibody, and HCV RNA, the prevalence was 13.5%, 25.3%, 53.1% respectively. Multivariate logistic regression analysis showed that low educational attainment was associated with HGV infection, old age and low educational attainment were associated with HCV infection, and female gender was associated with HGV clearance. Alanine aminotransferase (ALT) values were significantly higher for residents with HCV infection alone, HBV infection alone, and co-infection of HCV and HBV than for those without HBV, HCV, and HGV infection. There were no differences in ALT values between subjects with HGV infection alone and those without HBV, HCV, and HGV infections. Residents with co-infection of HGV and HBV, or HGV and HCV had ALT values similar to those with HBV or HCV infection alone. CONCLUSION: HGV infection is common in the HCV endemic village. The transmission of HGV is closely related to low educational attainment. HGV clearance is frequently encountered in females. Co-infection of HGV does not compound hepatocellular inflammation.

Adult↗

PubMed1999

An autoradiographic assessment of epithelial cell proliferation and post-natal maturation of the tracheal epithelium in infant ferrets.

The tracheal epithelium of infant ferrets undergoes rapid postnatal maturation over the first month of life to achieve the pseudostratified columnar configuration characteristic of the large airways of other mammals. We have used in vivo pulsing with tritiated thymidine ((3)HT) to elicit autoradiographic labeling of cells synthesizing nucleic acids in order to characterize more fully the contribution to development of different cell types comprising the nascent epithelial layer during this period of rapid growth. These studies indicate that two distinct populations of epithelial cells possess proliferative potential and contribute to the establishment of the mature adult epithelial layer. These investigations further confirm the mitotic potential of basal cells during a period of rapid postnatal growth and development of the tracheal epithelial layer. These studies also document the contribution to early airway development by non-ciliated cells, which predominate on the luminal border of the ferret trachea at birth. The temporal and histologic patterns of airway epithelial maturation during post-natal life in the ferret as contained in this study exhibit similarities to those which occur with recovery from injury by infection and irritant exposure in mature airways. Thus, the characterization of epithelial cell compartments having proliferative potential may provide insights into the mechanisms whereby normal airway epithelial organization is established and maintained during development as well as the possible recapitulation of these mechanisms during times of epithelial regeneration following injury.

Animals↗

PubMed1999

Elderly use of the ED in an Asian metropolis.

To compare emergency department (ED) use by elderly patients (age 65 yrs or older) with that by younger adult patients (age 15-64 yrs), a prospective consecutive chart review study was conducted from August 1, 1995 through May 31, 1996 in eight designated hospitals in Taipei city (which has 2.6 million residents, 8.4% of whom are 65 yrs or older). Patient age, sex, mode of arrival, living status, triage category, advanced life support (ALS) eligibility, referral, confinement to bed, intensive care unit (ICU) admission, impression, trauma mechanism, and disposition were recorded and compared between the two groups. Of 27,765 adult emergency patients studied during the 10 months, 24% were elderly. The elderly were more likely to be ambulance cases, of high acuity and ALS eligibility, living alone, bed-ridden, and ICU cases (19.4% v 10.5%, 14.8% v 5.5%, 14.7% v 4.3%, 9.7% v 4.1%, 16% v 1.1%, and 4.0 v 1.1%, respectively). The three leading illnesses in the elderly were cerebral vascular accident (6.6%), cancer (5.6%), and cardiovascular disease (5.6%), and the two most common trauma mechanisms were trip (fall from the same level surface) (57.2%) and traffic accident (20.7%). Twenty-seven percent and 22.7% of elderly were disposed to admission and observation, respectively, compared with the 10.9% and 11.4% of the younger patients. Elderly patients have significantly different and more severe presentations to the ED compared with younger adults.

Adolescent↗

PubMed1999

Renal abscess: early diagnosis and treatment.

The purpose of this study was to identify initial clinical characteristics that can lead to early diagnosis of renal abscess in the emergency department and predict poor prognosis. A retrospective review of 88 renal abscess patients, from April 1979 through January 1996, was conducted. Patients were categorized into two groups. In group 1, renal abscess was diagnosed by an emergency physician, whereas in group 2 renal abscess was not diagnosed by an emergency physician. Clinical characteristics included demographic data, predisposing medical problems, duration of illness before diagnosis, time spent in hospital diagnosis, initial signs and symptoms, laboratory tests, and radiology studies that may have been useful in the early diagnostic regimes. Clinical factors were also analyzed for their value in predicting poor prognosis. The mean age of 88 patients with renal abscess was 59.8 years. The most common predisposing disorder was diabetes mellitus, followed by renal calculi and ureteral obstruction. The duration of diagnosis by emergency physicians was shorter for group 1 patients (1.2 +/- .4 v group 2, 2.8 +/- 2.9 days; P < .01) and the blood urea nitrogen level was higher in group 1 (55.7 +/- 42.2 mg/dL, v group 2, 33.5 +/- 33.5 mg/dL; P = .02). In the early diagnosis of renal abscess, emergency physicians should focus on patients who have predisposing disorders, ie, diabetes mellitus, renal stones, immunosuppression, longer duration of symptoms of urinary tract infection, and renal failure, who should promptly be investigated with ultrasound in the emergency department. The cure rate after treatment with routine antibiotics plus percutaneous drainage was 64%. This therapy is recommended for initial treatment. Poor prognosis is associated with elderly patients with lethargy and with elevation of the serum blood urea nitrogen level.

Abscess↗

PubMed1999

Regulation of CBP-mediated transcription by neuronal calcium signaling.

The transcription factor CREB is involved in mediating many of the long-term effects of activity-dependent plasticity at glutamatergic synapses. Here, we show that activation of NMDA receptors and voltage-sensitive calcium channels leads to CREB-mediated transcription in cortical neurons via a mechanism regulated by CREB-binding protein (CBP). Recruitment of CBP to the promoter is not sufficient for transactivation, but calcium influx can induce CBP-mediated transcription via two distinct transactivation domains. CBP-mediated transcription is stimulus strength-dependent and can be induced by activation of CaM kinase II, CaM kinase IV, and protein kinase A, but not by activation of the Ras-MAP kinase pathway. These observations indicate that CBP can function as a calcium-sensitive transcriptional coactivator that may act as a regulatory switch for glutamate-induced CREB-mediated transcription.

Animals↗

PubMed1998

Continuous flumazenil infusion in preventing complications arising from severe benzodiazepine intoxication.

A prospective, randomly controlled study was conducted to test the effect of continuous flumazenil infusion in preventing complications arising from severe benzodiazepine (BZ) intoxication. Patients who were believed to be suffering benzodiazepine intoxication and whose Glasgow Coma Scale (GCS) score was below 10 were enrolled after showing a clear-cut response to flumazenil 0.5 or 1 mg (an improvement by 4 or more on the GCS). The patients were consecutively enrolled and randomized into two groups: a continuous infusion group (CI, n = 50) who were immediately given flumazenil 0.5 mg/h for 5 hours, and a control group (CIN, n = 50). Age, sex, incidence of underlying disease, GCS score at several time points, and complication rate were compared in the two groups. Although the CI group had a higher GCS score at most time points, the complication rate did not significantly differ between the two groups (14 of 36 in the CI group v 12 of 38 in the CIN group, P = .684). A greater incidence of underlying disease and an older age seemed to contribute to the higher complication rates in both groups. Several patients (in both groups) resedated into deeper coma after showing an initial response to flumazenil or after the cessation of flumazenil infusion. For severe BZ intoxication, treatment with flumazenil infusion should still be considered skeptically and should not be recommended as routine management BZ-intoxicated patients with an underlying disease, an older age, and resedation into a deep comatose state after showing an initial response to flumazenil should be treated in an intensive care unit.

Adult↗

PubMed1998

Identification of a signaling pathway involved in calcium regulation of BDNF expression.

A signaling pathway by which calcium influx regulates the expression of the major activity-dependent transcript of BDNF in cortical neurons has been elucidated. Deletion and mutational analysis of the promoter upstream of exon III reveals that transactivation of the BDNF gene involves two elements 5' to the mRNA start site. The first element, located between 72 and 47 bp upstream of the mRNA start site, is a novel calcium response element and is required for calcium-dependent BDNF expression in both embryonic and postnatal cortical neurons. The second element, located between 40 and 30 bp upstream of the mRNA start site, matches the consensus sequence of a cAMP response element (CRE) and is required for transactivation of the promoter in postnatal but not embryonic neurons. The CRE-dependent component of the response appears to be mediated by CREB since it is part of the complex that binds to this CRE, and since dominant negative mutants of CREB attenuate transactivation of the promoter. A constitutively active mutant of CaM kinase IV, but not of CaM kinase II, leads to activation of the promoter in the absence of extracellular stimuli, and partially occludes calcium-dependent transactivation. The effects of CaM kinase IV on the promoter require an intact CRE. These mechanisms, which implicate CaM kinase IV and CREB in the control of BDNF expression, are likely to be centrally involved in activity-dependent plasticity during development.

Animals↗

PubMed1998

Employers' awareness and compliance with occupational health and safety regulations in Taiwan.

An investigation of employers' awareness and compliance with occupational health and safety (OHS) regulations was conducted in a representative group of employers randomly selected from the manufacturing industry in Taiwan. A total of 1,003 employers were interviewed by trained public health personnel. Ten questions related to perceptions of general OHS and five practices on OHS regulations were measured. The results of this study show that the employers were better aware of their responsibility for posting safety warnings, personal protection and providing safety and health equipment. They were less aware of their responsibility in minimizing injuries and accidents in the workplace and in not hiring someone who was found unfit for a certain job from pre-employment physical examination. Less than half of employers knew about regulations of environmental monitoring and even fewer had heard of Material Safety Data Sheets. Level of education and size of the plant were highly associated with employers' awareness of OHS and the awareness was the most significant predictor in the five practices of OHS regulations in this study. Promotion of employers' awareness of OHS in small sized industries in particular, is warranted to enhance better compliance, and a focus for these efforts is identified by this investigation.

Adult↗

PubMed1998

Regional deposition of inhaled particles in human lungs: comparison between men and women.

We measured detailed regional deposition patterns of inhaled particles in healthy adult male (n = 11; 25 +/- 4 yr of age) and female (n = 11; 25 +/- 3 yr of age) subjects by means of a serial bolus aerosol delivery technique for monodisperse fine [particle diameter (Dp) = 1 micron] and coarse aerosols (Dp = 3 and 5 micron). The bolus aerosol (40 ml half-width) was delivered to a specific volumetric depth (Vp) of the lung ranging from 100 to 500 ml with a 50-ml increment, and local deposition fraction (LDF) was assessed for each of the 10 local volumetric regions. In all subjects, the deposition distribution pattern was very uneven with respect to Vp, showing characteristic unimodal curves with respect to particle size and flow rate. However, the unevenness was more pronounced in women. LDF tended to be greater in all regions of the lung in women than in men for Dp = 1 micron. For Dp = 3 and 5 micron, LDF showed a marked enhancement in the shallow region of Vp </= 200 ml in women compared with men (P < 0.05). LDF in women was comparable to or smaller than those of men in deep lung regions of Vp > 200 ml. Total lung deposition was comparable between men and women for fine particles but was consistently greater in women than men for coarse particles regardless of flow rates used: the difference ranged from 9 to 31% and was greater with higher flow rates (P < 0.05). The results indicate that 1) particle deposition characteristics differ between healthy men and women under controlled breathing conditions and 2) deposition in women is greater than that in men.

Administration, Inhalation↗

PubMed1998

Connexin 26 expression in human and ferret airways and lung during development.

Coordinated microscopic and molecular biological studies were used to document gap junction expression during postnatal development in ferret tracheal epithelium and lung and in fetal and adult human airway and lung. Expression of connexin 26 (Cx26) in the ferret airways was limited to the epithelial layer and was observed only during the newborn interval. In contrast, we found Cx26 expressed in the alveolar epithelium of the ferret lung by in situ hybridization, Northern blotting, RT-PCR amplification, and immunocytochemical labeling at all ages examined. This finding was further confirmed by documentation of gap junctional plaques upon ultrastructural examination of freeze-fracture replicas of adult ferret lung tissue. Parallel studies of developing human fetal lung and airway suggested connexin expression in the airways only in the first trimester but, as in the ferret, persistent expression was observed in both fetal and adult lung. These studies suggest that the transient expression of Cx26 is a reliable early indicator of airway epithelial development and differentiation in the airways. In contrast, Cx26 expression persists throughout life in the lung, suggesting that gap junctions serve more perennial intercellular communication functions in the peripheral lung.

Animals↗

PubMed1998

Emergency medical resource use in Taipei city.

BACKGROUND: It is a worldwide trend to serve emergency patients at emergency department (EDs) staffed by board-certified emergency physicians (EPs). The question arises as to how many EPs are cost effective? This cannot be answered until utilization of emergency resources in the community is explored, so that appropriate plans for efficient ED use, staffing and training of EPs can be made. METHODS: A prospective randomized chart-review study was conducted from August 1, 1995, until May 31, 1996, in the EDs of eight large hospitals in Taipei City. These included Chung-Hsin Municipal Hospital (CHH), Chung-Shiaw Municipal Hospital (CSH), Ho-Ping Municipal Hospital (HPH), Jen-Ai Municipal (JAH), Mackay Memorial Hospital (MMH), Tri-Service General Hospital (TSGH), Veterans General Hospital-Taipei (VGH-T) and the Yang-Ming Municipal Hospital (YMH). RESULTS: Of 37,889 cases reviewed, the average daily ED census at each hospital was: VGH-T 198; TSGH 148; MMH 224; HPH 62; YMH 84; CHH 41; JAH 102; and CSH 139. At MMH, pediatric patients comprised 38.8% of emergency patients and the elderly comprised 49% of patients of VGH-T. The average age of patients was 56 years in VGH-T and 40 years in other hospitals. There were 71 (11.1%) pediatric patients and 3,087 (1.8%) adult patients taken to hospital by an emergency medical services (EMS) ambulance. A total of 176 pediatric and 2,230 (8.1%) adult patients belonged to triage categories 1 and 2. VGH-T had a much higher percentage of triage 1 and 2 patients (769, 13%) than the other hospitals. A total of 30.7% of pediatric and 17.4% of adult patients were classified as triage 4 (pseudoemergency). Patients requiring advanced life support, referral cases and patients requiring an intensive care unit (ICU) bed accounted for 1.1%, 0.9% and 0.6% of pediatric patients, and 6.8%, 3.4% and 1.8% of adult patients, respectively. These figures increased to 11.1%, 7.7% and 3.5%, respectively, in VGH-T. Among patients requiring ICU admission, 30% of pediatric and 53% of adult patients were not admitted on presentation to the ED. Of 10,099 children and 27,555 adults who were evaluated for case disposition, 651 (6.5%) and 4,061 (14.7%), respectively, were considered for admission. Among these 542 (83.3%) and 2,894 (71.3%), respectively, were admitted. CONCLUSIONS: VGH-T is a favorable training ground for EPs due to its high volume of adult and elderly, advanced life support eligible, ICU and high acuity patients. MMH is an ideal place for training in pediatric emergency medicine. Utilization of the 119 emergency response system is low. The number of patients with high acuity triage in Taipei City is low. However, Taipei City faces a shortage of acute care beds, especially ICU beds.

Adult↗

PubMed1997

Psoas abscess: making an early diagnosis in the ED.

The variable and nonspecific presentations of psoas abscess, as well as its infrequent incidence in the emergency department (ED), can result in delayed diagnosis or misdiagnosis. Previous reports have not discussed the diagnostic difficulties of psoas abscess from the viewpoint of emergency physicians (EPs), especially in light of the widespread use of ED ultrasonography. This report describes a 1-year experience between November 1993 and October 1994, during which 10 ED patients were diagnosed to have psoas abscess; in 7 cases, diagnoses were established in the ED. Patients' mean age was 64.6 years (range, 46 to 76). Pain was the most frequently encountered symptom (80%), with 5 patients (50%) complaining of flank pain. The triad of fever, flank pain, and limitation of hip movement, which is specific for psoas abscess, was present only in 3 patients (30%). The mean duration of symptoms was 10.6 days (range, 1 to 30 days). The mean time spent to establish the diagnosis was 1.7 days (range, 0 to 7 days). The diagnosis of psoas abscess was established by ultrasound in 6 patients, by computed tomography (CT) in 3 patients, and by surgery in 1 patient. Four patients who presented with either sepsis and nonspecific abdominal/flank pain or sepsis and thigh swelling were diagnosed to have psoas abscess by ultrasound performed by EPs. Only 3 patients were admitted to the ED with an initial diagnosis of psoas abscess. The remaining 7 had the following initial ED diagnoses: 2, fever of unknown origin; 2, septic shock; 1, shock; 1, sepsis; and 1, peritonitis. All but one had manifestations of sepsis. Two patients died of septic shock; these two patients had failed to be drained well. This report also includes a discussion of the role of EPs and ultrasonography in the diagnosis of psoas abscess. With their alertness and their expertise in ultrasonographic techniques, EPs can make an immediate diagnosis and arrange an early drainage procedure. For patients with sepsis of unknown origin, prolonged fever of unknown origin, and some specific manifestations suggestive of psoas abscess, the screening ultrasound should scan not only abdominal solid organs but also peritoneal cavity and retroperitoneal space. In addition, a flow chart is presented for facilitating the diagnosis of psoas abscess in the ED.

Aged↗

PubMed1997

Arterial oxygen desaturation during emergent nonsedated upper gastrointestinal endoscopy in the emergency department.

A prospective study was conducted to see whether emergent esophagogastroduodenoscopy (EGD) in patients with active upper gastrointestinal (GI) bleeding is associated with more oxygen desaturation than nonemergent EGD. Emergent EGD was performed in the study patients with active upper GI bleeding. Nonemergent EGD was performed in the control patients. Determination of oxygen saturation (Sao2) was measured by pulse oximeter. A decrease in Sao2 of > 4% was more frequent in the study patients (26%, 13 of 50) than in controls (6%, 3 of 50) (P < .01). During EGD, mean oxygen saturation decreased significantly in both groups of patients. After EGD, mean oxygen saturation did not recover toward the pre-endoscopy insertion level in the study group (P < .01). A linear association was found that oxygen desaturation = 5.46 + 0.15 (status) -0.06 (baseline oxygen saturation). Emergent EGD for active upper GI bleeding in the emergency department tends to be associated with more frequent significant oxygen desaturation than nonemergent EGD. Continuous oxygen supplementation and oxygen saturation monitoring may be used during emergent nonsedated EGD in the emergency department.

Acute Disease↗

PubMed1997

Direct surgery of carotid cavernous fistulae and dural arteriovenous malformations of the cavernous sinus.

OBJECTIVE: To save the patency of the internal carotid artery (ICA) during the treatment of carotid cavernous fistulae or cavernous sinus dural arteriovenous malformations, direct surgery of the cavernous sinus after failure of endovascular treatment was attempted in this study. METHODS: A total of 78 patients with carotid cavernous fistulae or cavernous sinus dural arteriovenous malformations were treated. Obliteration of the fistulous rent and preservation of the ICA were the therapeutic goals. All patients, except one in whom acute bleeding occurred, received endovascular treatment as the first treatment. In 18 (23.4%) of these 77 patients, it was not possible to obliterate the fistulous rents without sacrificing the ICAs. The 18 patients and the 1 patient with acute bleeding underwent direct surgery to open the cavernous sinus. RESULTS: Various methods, including suturing or clipping the fistulae, sealing the fistulae with fascia and acrylate glue, and packing the cavernous sinus were applied. In each of three complicated cases, the cavernous segment of the ICA was trapped and an intracranial bypass from the petrous segment to the supraclinoid segment was performed. There was nor mortality, and the most common morbidity was transient oculomotor palsy, which occurred in eight patients. Follow-up angiography revealed that the ICAs or bypass grafts were thrombosed in 5 of the 19 patients who had undergone surgery. CONCLUSION: In this series, the overall ICA patency rate of patients who underwent embolization and surgery was 94%, and the obliteration rate of the fistulae was 100%. Direct surgery of the cavernous sinus as a complimentary treatment of embolization can increase the preservation rate of the ICA.

Adolescent↗

PubMed1996

Longitudinal distribution of ozone absorption in the lung: simulation with a single-path model.

A one-dimensional unsteady state diffusion model was used as a basis for simulating the absorption (lambda), breakthrough (V(B)), and dispersion (sigma2) of inhaled ozone boluses as a function of penetration (V(P)) into intact human lungs. The model idealized the respiratory system as a single equivalent tube with cross-sectional and surface areas that varied as a function of longitudinal position. Longitudinal gas transport in the lumen of the equivalent tube occurred by the joint action of bulk flow and a dispersion coefficient, D. Lateral absorption between respired gas and the tube wall was characterized by an overall mass transfer coefficient, K. By inputting published values of anatomic dimensions scaled to a 160-ml conducting airway volume, D values previously reported for inert insoluble gases, and K values equal to gas-phase transfer coefficients determined in physical lung models, a reasonable simulation of the lambda-V(P) distribution measured at a 250 ml/sec respiratory flow was obtained. Simulations of the corresponding V(B)-V(P) and sigma2-V(P) distributions both exhibited the correct shapes but underestimated the actual values. Although the addition of an estimated tissue resistance to K resulted in a poorer simulation of the data, an increase in conducting airway volume from a value of 160 ml estimated by the subjects' CO2 dead space to a value of 200 ml substantially improved the V(B)-V(P) and sigma2-V(P) simulations without sacrificing the quality of the lambda-V(P) simulation. We conclude that the inclusion of a tissue diffusion resistance is not necessary to properly simulate bolus inhalation data during quiet breathing, but a reliable measurement of conducting airway volume is crucial.

Absorption↗