Prevalence, Trend, and Risk Factors for Early Chronic Obstructive Pulmonary Disease: An Analysis of the Nationwide Population-Based Survey from 2010 to 2019 in South Korea

This study aimed to evaluate the prevalence, trends, and risk factors of early chronic obstructive pulmonary disease (COPD) by using a nationally representative sample. The datasets of the Korea National Health and Nutrition Examination Survey 2010-2019 were used, where 80,860 individuals were identified; of these, 9,045 participants aged 40-49 years who underwent spirometry with no missing data were analyzed. Early COPD was defined as forced expiratory volume in 1 s /forced vital capacity ratio < the lower limit of normal (2.5th percentile) in individuals aged <50 years without a history of asthma, inhaler therapy, or persistent respiratory symptoms. The prevalence and trend of early COPD were estimated according to features such as smoking status and pack-years. Joinpoint regression analysis was used to analyze the significant annual change in the trend according to sex, smoking status, and pack-years. A complex sample multivariable-adjusted regression model was used to identify factors affecting early COPD. The estimated population size during 2010-2019 was 82,326,178. Early COPD was present in 4.5% of patients (6.5% of men and 2.3% of women). It was present in 7.7% of current smokers, followed by former and never smokers. Among smokers with ≥ 10 pack-years, early COPD was present in 8.2%, whereas it was present in 2.6% of smokers with < 10 pack-years. Joinpoint regression analyses found a recent decrease in the trend of prevalence in males who were former and current smokers. The multivariable-adjusted logistic regression model showed that being male, lower educational level, smoking status, and pack-years were factors that affected the presence of early COPD. Continued surveillance of this pre-disease condition is required, and further research are warrant.

Thoracic sympathetic ganglion blocks: real-world outcomes in 207 chronic pain patients

BACKGROUND

Thoracic sympathetic ganglion block (TSGB) is a procedure to manage sympathetically maintained upper extremity pain (sympathetically maintained pain). To date, only a few studies have evaluated the clinical effectiveness of TSGB in pain medicine. This study investigated (1) the relationship between technical success of TSGB and pain reduction in patients with chronic upper extremity pain and (2) relevant clinical factors for a positive TSGB outcome.

METHODS

We retrospectively reviewed medical data in 232 patients who received TSGB from 2004 to 2020. Technical success and a positive outcome of TSGB were defined as a temperature increase of ≥1.5°C at 20 min and a pain reduction with ≥2 points on the 11-point Numerical Rating Scale at 2 weeks post-TSGB, respectively. Correlations were assessed using correlation coefficients (R), and multivariable regression model was used to identify factors relevant to TSGB outcomes.

RESULTS

207 patients were ultimately analyzed; among them, 115 (55.5%) patients positively responded to TSGB, and 139 (67.1%) achieved technical success after TSGB. No significant relationship existed between the pain reduction and the temperature increase after TSGB (R=0.013, p=0.855). Comorbid diabetes (OR 4.200) and adjuvant intake (OR 3.451) were positively associated, and psychiatric comorbidity (OR 0.327) and pain duration (OR 0.973) were negatively associated with TSGB outcome.

CONCLUSIONS

We found no significant association between the temperature increase and pain reduction after TSGB. Further studies are warranted to identify significant factors associated with TSGB outcomes in patients with complex regional pain syndrome and neuropathic pain diseases.

Inhibition of Pseudomonas aeruginosa LPS-Induced airway inflammation by RIPK3 in human airway

Although the physiological function of receptor-interacting protein kinase (RIPK) 3 has emerged as a critical mediator of programmed necrosis/necroptosis, the intracellular role it plays as an attenuator in human lungs and human bronchial epithelia remains unclear. Here, we show that the expression of RIPK3 dramatically decreased in the inflamed tissues of human lungs, and moved from the nucleus to the cytoplasm. The overexpression of RIPK3 dramatically increased F-actin formation and decreased the expression of genes for pro-inflammatory cytokines (IL-6 and IL-1β), but not siRNA-RIPK3. Interestingly, whereas RIPK3 was bound to histone 1b without LPS stimulation, the interaction between them was disrupted after 15 min of LPS treatment. Histone methylation could not maintain the binding of RIPK3 and activated movement towards the cytoplasm. In the cytoplasm, overexpressed RIPK3 continuously attenuated pro-inflammatory cytokine gene expression by inhibiting NF-κB activation, preventing the progression of inflammation during Pseudomonas aeruginosa infection. Our data indicated that RIPK3 is critical for the regulation of the LPS-induced inflammatory microenvironment. Therefore, we suggest that RIPK3 is a potential therapeutic candidate for bacterial infection-induced pulmonary inflammation.

A 0.6 Mpc H I structure associated with Stephan's Quintet

Stephan’s Quintet (SQ, co-moving radial distance = 85 ± 6 Mpc, taken from the NASA/IPAC Extragalactic Database (NED)¹) is unique among compact groups of galaxies^2–12. Observations have previously shown that interactions between multiple members, including a high-speed intruder galaxy currently colliding into the intragroup medium, have probably generated tidal debris in the form of multiple gaseous and stellar filaments^6,8,13, the formation of tidal dwarfs^7,14,15 and intragroup-medium starbursts¹⁶, as well as widespread intergalactic shocked gas^5,10,11,17. The details and timing of the interactions and collisions remain poorly understood because of their multiple nature^18,19. Here we report atomic hydrogen (H i) observations in the vicinity of SQ with a smoothed sensitivity of 1σ = 4.2 × 10¹⁶ cm⁻² per channel (velocity bin-width Δv = 20 km s⁻¹; angular resolution = 4′), which are about two orders of magnitude deeper than previous observations^8,13,20,21. The data show a large H i structure (with linear scale of around 0.6 Mpc) encompassing an extended source of size approximately 0.4 Mpc associated with the debris field and a curved diffuse feature of length around 0.5 Mpc attached to the south edge of the extended source. The diffuse feature was probably produced by tidal interactions in early stages of the formation of SQ (>1 Gyr ago), although it is not clear how the low-density H i gas (N_{H i}≲ 10¹⁸ cm⁻²) can survive the ionization by the intergalactic ultraviolet background on such a long time scale. Our observations require a rethinking of properties of gas in outer parts of galaxy groups and demand complex modelling of different phases of the intragroup medium in simulations of group formation.

Atomic hydrogen observations in the vicinity of Stephan’s Quintet are reported, showing a large gaseous structure of around 0.6 Mpc in size in the velocity range of 6,550–6,750 km s⁻¹.

Bispectral index monitoring in spinal anesthesia with sedation can prevent dexmedetomidine related bradycardia: a randomized clinical trial

Background: An unintentional large dose of dexmedetomidine during sedation can lead to increased side effects such as bradycardia and hypotension. We investigated whether the frequency of bradycardia in patients undergoing surgery under spinal anesthesia and sedation with dexmedetomidine was effected if bispectral index (BIS) was used to monitor the sedation. Methodology: Fifty patients between 20 and 60 y of age, who underwent spinal anesthesia, were included in this study. The patients were divided into two groups (control and BIS groups). Patients in the control group were administered a loading dose of 1 μg/kg dexmedetomidine for the first 10 min without BIS monitoring, followed by a maintenance dose of 0.2 μg/kg/h. Patients in the BIS group received a loading dose of 1 μg/kg dexmedetomidine for the first 10 min. The maintenance dose in this group was administered at the discretion of the anesthesiologist to maintain the BIS score between 50 and 70. The baseline heart rate (HR), lowest HR, and the difference between baseline and the lowest HR were calculated. Results: The baseline HR was 74.4 ± 11.0 beats per minute (bpm) and 80.9 ± 16.0 bpm, in the control and BIS groups respectively (p = 0.098). The difference between the baseline and lowest HR in the control and BIS groups was 19.4 ± 7.6 bpm and 25.5 ± 8.8 bpm, respectively (p = 0.011). Low baseline HR was positively correlated with a reduced lowest HR. Conclusions: The frequency of bradycardia during sedation with dexmedetomidine decreased with BIS monitoring. Patients with a low baseline HR were more likely to develop bradycardia during sedation with dexmedetomidine. Therefore, BIS monitoring may be helpful in patients with low baseline HR. Key words: Bispectral index monitor; Dexmedetomidine; heart rate; spinal anesthesia Citation: Kim J, Kim HY, Yun M, Lee J, Kim JD, Kang D. Bispectral index monitoring during sedation with dexmedetomidine in spinal anesthesia prevents bradycardia: a randomized clinical trial. Anaesth. pain intensive care 2021;26(1):14-19 ; DOI: 10.35975/apic.v26i1.1760

The correlation between the STOP-Bang score and oxygen saturation during spinal anesthesia with dexmedetomidine sedation

BACKGROUND

The STOP-Bang questionnaire is a simple screening tool with high sensitivity for the detection of severe obstructive sleep apnea. Predicting airway obstruction would allow the safe management of sedative patients to prevent intraoperative hypoxia. This study was designed to check the correlation between the STOP-Bang score and oxygen saturation (SpO2) during sedation and confirm the availability of the STOP-Bang questionnaire as a preoperative exam for predicting the incidence of hypoxia in sedative patient management.

METHODS

This study included 56 patients who received spinal anesthesia. The pre-anesthesia evaluation was conducted using the STOP-Bang questionnaire. The patients were under spinal anesthesia with an average block level of T10. Dexmedetomidine was infused with a loading dose of 1 μg/kg over 10 min and a maintenance dose of 0.5 μg/kg/h until the end of the procedure. The SpO2 of the patients was recorded every 5 min.

RESULTS

The STOP-Bang score was negatively correlated with the lowest SpO2 (coefficient = -0.774, 95% confidence interval [CI]: -0.855 to -0.649, standard error [SE] = 0.054, P < 0.001). The item of "observed apnea" was the most correlated one with hypoxic events (odds ratio = 6.00, 95% CI: 1.086 to 33.145).

CONCLUSIONS

The STOP-BANG score was significantly correlated with the lowest SpO2 during spinal anesthesia, which enabled the prediction of meaningful hypoxia before it occurred in the sedated patients.

Effects of Alzheimer's disease and Lewy body disease on subcortical atrophy

BACKGROUND AND PURPOSE

Subcortical structures are affected by neurodegeneration in Alzheimer's disease (AD) and Lewy body disease (LBD). Although the co-occurrence of AD and LBD pathologies and their possible interaction have been reported, the effect of AD and LBD on subcortical structures remains unknown. The effects of AD and LBD on subcortical atrophy and their relationship with cognitive dysfunction were investigated.

METHODS

The cross-sectional study recruited 42 patients with pure AD related cognitive impairment (ADCI), 30 patients with pure LBD related cognitive impairment (LBCI), 58 patients with mixed ADCI and LBCI, and 29 normal subjects. A general linear model was used to compare subcortical volume and shape amongst the groups, to investigate the independent and interaction effects of ADCI and LBCI on subcortical shape and volume, and to analyze the relationship between subcortical volume and cognitive dysfunction in each group.

RESULTS

Alzheimer's disease related cognitive impairment and LBCI were independently associated with subcortical atrophies in the hippocampus and amygdala and in the hippocampus and putamen respectively, but their interaction effect was not significant. Compared to the control group, the pure LBCI group exhibited additional local atrophies in the amygdala, caudate and thalamus. Subcortical atrophies correlated differently with cognitive dysfunction according to the underlying causes of cognitive dysfunction.

CONCLUSIONS

The patterns of subcortical atrophies and their correlation with cognitive dysfunction differ according to the underlying AD, LBD or concomitant AD and LBD.

Caspase-dependent cell death-associated release of nucleosome and damage-associated molecular patterns

Apoptosis, which is anti-inflammatory, and necrosis, which is pro-inflammatory, represent the extremes of the cell death spectrum. Cell death is complex and both apoptosis and necrosis can be observed in the same cells or tissues. Here, we introduce a novel combined mode of cellular demise--caspase-dependent regulated necrosis. Most importantly, it is mainly characterized with release of marked amount of oligo- or poly-nucleosomes and their attached damage-associated molecular patterns (DAMPs) and initiated by caspase activation. Caspase-activated DNase has dual roles in nucleosomal release as it can degrade extracellularly released chromatin into poly- or oligo-nucleosomes although it prohibits release of nucleosomes. In addition, osmotically triggered water movement following Cl(-) influx and subsequent Na(+) influx appears to be the major driving force for nucleosomal and DAMPs release. Finally, Ca(2+)-activated cysteine protease, calpain, is an another essential factor in nucleosomal and DAMPs release because of complete reversion to apoptotic morphology from necrotic one and blockade of nucleosomal and DAMPs release by its inhibition.

The controlled growth of single metallic and conducting polymer nanowires via gate-assisted electrochemical deposition

The fabrication of nanowires with well-controlled lengths and diameters is the basis of the application of one-dimensional nanostructures in more sophisticated electronic and biomolecular device systems. A wide variety of materials, including metals and conducting polymers, have been utilized in nanowire arrays as building blocks for chemical or biomolecular sensors. Thus far, the cheapest and most effective way of nanowire synthesis is electrochemical deposition. In this work, we investigate a new method of electrochemical deposition using two-dimensional electric fields instead of the conventional one-directional electric field between working electrodes. Reproducible fabrication of metallic (palladium) and conducting polymer (polypyrrole) single nanowires with diameters down to 30-50 nm is achieved by application of a vertical gate electric field in addition to the lateral one between the two working electrodes. Diameters and lengths of the nanowires can be easily controlled by varying the dimensions of the nanochannels in which the nanowires are grown. A good ohmic contact between the nanowire and gold electrodes is also obtained, indicating the feasibility of electronic devices based on the single nanowires synthesized via this method. In conjunction with experimental findings of nanowire growth mechanism under two-dimensional electric field, molecular dynamic simulations are employed to further understand the deposition process. This improved electrochemical deposition is applicable for controlled and simple fabrication of a wide range of metallic and conducting polymeric nanowires with small diameters.

Analysis of adrenal masses by 18F-FDG positron emission tomography scanning

This study aimed to analyse the characteristics of adrenal masses visible in the computerised tomography (CT) scans which have been also evaluated by 2-[18F]fluoro-2-deoxy-D-glucose positron emission tomography (18F-FDG PET), and to characterise the features of 18F-FDG PET scans associated with various adrenal endocrine tumours, especially benign functional tumours. 18F-FDG PET scans of 105 patients with adrenal masses on the CT scan were analysed. Positive uptakes in the 18F-FDG PET scans were seen in 60 malignant tumours (54 metastasic lesions, six primary adrenal cancers) and seven benign tumours. The positive predictive value of 18F-FDG PET imaging to characterise an adrenal mass as a malignant tumour was 90%; the corresponding negative predictive value to rule out malignancy was also 90%. Benign adrenal tumours were smaller than that of malignant lesions (p<0.05). The mean standardised uptake value max (SUVmax) of the metastatic lesions [8.4+/-6.5 (microCi/g)/microCi/kg] was significantly higher than that of the benign adrenal tumours [2.4+/-1.2 (microCi/g)/microCi/kg, p<0.001]. Examination of only the primary adrenal lesions revealed that all adrenocortical carcinomas, two of three cases of pheochromocytomas, three of five neuroblastomas and two of four cases of primary aldosteronism showed positive 18F-FDG uptake. In conclusion, for patients presenting adrenal masses with a high probability of malignancy, 18F-FDG PET can be used to differentiate malignant from benign adrenal lesions. However, the 18F-FDG PET uptake did not show an always consistent pattern for endocrine tumours, which was probably due to the variability inherent in 18F-FDG uptake. This study suggests that 18F-FDG PET scanning can offer supporting data to localise and characterise adrenal tumours.

The cerebrovascular response to traditional acupuncture after stroke

Acupuncture is useful in treating the nausea and vomiting related to chemotherapy, adult postoperative surgery pain and postoperative dental pain. We obtained single-photon emission computed tomography (SPECT) brain perfusion images of six patients with middle cerebral artery occlusion obtained before and after acupuncture and compared the changes in regional cerebral blood flow (rCBF) to those in normal control. Images were obtained before and after acupuncture at six traditional acupoints (LI 4, 10, 11, 15 and 16 and TE5) in the affected arm. The baseline image was subtracted from the postacupuncture image, to produce a subtraction image displaying only voxels with values >2 SD from the mean and those voxels were coregistered to the baseline SPECT or T2-weighted MRI. Similar images were obtained before and after acupuncture of eight normal volunteers. Statistical parametric mapping with a threshold of P =0.001 and a corrected P of 0.05 was performed for group comparison between postacupuncture and baseline SPECT. Focally increased CBF was seen in all patients especially in the hypoperfused zone surrounding the ischaemic lesion, the ipsilateral or contralateral sensorimotor area, or both. Normal subjects showed increased rCBF mainly in the parahippocampal gyrus, premotor area, frontal and temporal areas bilaterally and ipsilateral globus pallidus. Acupuncture stimulation after stroke patients appears to activate perilesional or use-dependent reorganised sites and might be a way of looking at brain reorganisation.

18F-FDG PET in characterizing adrenal lesions detected on CT or MRI

The purpose of this study was to evaluate the ability of (18)F-FDG PET to characterize adrenal lesions in patients with proven or suspected cancers.

METHODS

A retrospective analysis was performed on 50 adrenal lesions in 41 patients, whose PET scans were done to evaluate the primary or metastatic disease. CT had shown 50 adrenal lesions in 41 patients and MRI had revealed 13 lesions in 10 patients. There were 34 patients with proven malignancy (28 lung cancer, 3 thyroid cancer, 2 colorectal cancer, and 1 lymphoma) and 7 with lung nodules. Of the 50 lesions, 18 were eventually determined to be malignant either by histopathology (n = 7) or by follow-up (n = 11). The remaining 32 lesions were proven or assumed to be benign by histopathology (n = 4) or clinical follow-up (n = 28). Unlike previously published reports, PET was interpreted as positive if the uptake was equal to or greater than that of the liver.

RESULTS

No malignant lesion yielded a negative result on PET. Most lesions (13/18) showed significantly higher FDG uptake than that of the liver. In the remaining 5 lesions (2 metastases from neuroendocrine tumor, 2 early metastases, and 1 necrotic metastasis), FDG uptake was equal to or slightly higher than that of the liver. Of the 32 benign lesions, there were 2 lesions with uptake equal to or slightly higher than that of the liver, 3 with uptake less than the liver but more than the background, and 27 with uptake of the background. MRI identified 3 of the 13 lesions as false-positives but FDG PET correctly identified all 3 as benign. The other 10 adrenal lesions accurately diagnosed by MRI were also characterized by PET. FDG PET for characterization of adrenal lesions showed a sensitivity of 100%, a specificity of 94%, and an accuracy of 96%.

CONCLUSION

FDG PET showed excellent diagnostic performance in differentiating adrenal lesions detected on CT or MRI. Because FDG PET has the additional advantage of evaluating the primary lesions as well as metastases, it could be cost-effective and the modality of choice for the characterization of adrenal lesions, especially in patients with malignancy.

F-18 FDG uptake in a patient with psoriatic arthritis: imaging correlation with patient symptoms

The authors describe a patient with psoriatic arthritis in whom an increased level of F-18 fluorodeoxyglucose (F-18 FDG) uptake was seen in the joints of the hands. The areas of increased activity correlated well with the regions of symptoms reported by the patient. This case illustrates the potential use of F-18 FDG positron emission tomography to quantitatively assess the degree of arthritis activity.

Incidental recognition of left subclavian vein obstruction on renal scintigraphy

In a renal transplant recipient with persistently poor graft function, the flow phase of a renal scan incidentally revealed multiple venous collaterals with focally increased vascular activity near the left lobe of the liver (quadrate lobe). This was initially assumed to represent superior vena cava (SVC) obstruction. A renal biopsy was contemplated to exclude acute rejection because of a nondiagnostic flow phase (loss of a bolus effect). However, because the possibility of venous obstruction at the level of the subclavian and/or brachiocephalic veins (without involving the SVC) also existed, another renal scan was performed, with injection of radiotracer into the contralateral arm. This showed a patent SVC and reasonably preserved renal perfusion consistent with acute tubular necrosis. Subsequently, left subclavian vein obstruction was identified. The graft function improved with conservative management for acute tubular necrosis. These findings illustrate the danger of considering only SVC obstruction when collateral flow patterns and focal hot spots in the liver are present.

A normal variant on Tl-201 and Tc-99m MIBI whole-body imaging: the superior right atrial wall (auricle) and superoanterior right ventricular wall are often seen as mediastinal lesions

PURPOSE

The authors have often observed on Tl-201 and Tc-99m sestamibi (MIBI) scans in patients with thyroid cancer a small focus of increased uptake in the right midparasternal region (focus A) or sometimes in the lower mid chest at the level of the lower sternum (focus B) just inferomedial to focus A. The objective of this study was to assess the frequency of this finding on Tl-201 MIBI studies, to assess the incidence of true pathologic lesions corresponding to these foci, and to identify their nature.

MATERIALS AND METHODS

One hundred ten whole body Tl-201 studies using 4 mCi (148 MBq) and 84 MIBI studies using 20 mCi (740 MBq: first-pass, planar, and SPECT images) were reviewed. The appearance of either focus A or focus B on three orthogonal SPECT images was correlated with an atlas of cross-sectional anatomy and computed tomography. If focus A was seen on the immediate static image (obtained at the end of the first-pass acquisition without moving the patient), this image was coregistered with a selected image from the first-pass study showing the superior vena cava and also with another selected image showing the ascending aorta.

RESULTS

Focus A was seen in 40% of Tl-201 scans and in 49% of MIBI scans, whereas focus B was seen in 20% of Tl-201 scans and 39% of MIBI scans. On correlation of the SPECT images with a cross-sectional anatomy atlas, focus A and focus B invariably corresponded to the superior portion of the right auricle and basal superoanterior right ventricular wall, respectively. These myocardial regions are prominent and sometimes appear as discrete foci because they are considerably thicker than other parts of the right atrial and right ventricular muscle, respectively, and because they are seen partly end-on in the anterior projection.

CONCLUSIONS

The superior portion of the right auricle and basal superoanterior right ventricular myocardium often appear as isolated foci on whole-body Tl-201 and MIBl scans. Neither focus should be interpreted as a metastatic lesion in patients with possible cancer or as an ectopic parathyroid adenoma in patients with hyperparathyroid disease.

F-18 FDG uptake in the large arteries: a new observation

PURPOSE

The cellular components of the atherosclerotic plaque, such as macrophages, exhibits high glucose metabolic activity. The aim of this study was to show the frequency of vascular uptake and possibly to explain the significance of this finding on fluorodeoxyglucose (FDG) positron emission tomographic (PET) scans.

METHODS

We evaluated the presence of FDG vascular uptake in 132 consecutive patients undergoing whole-body PET scans and 5 patients who had only lower extremity scans. The presence of vascular FDG uptake was assessed in the abdominal aorta, iliac, and proximal femoral arteries on the 132 whole-body scans, whereas only the femoral and the popliteal arteries were examined on the leg scans. The patients' ages ranged from 20 to 80 years, and they were divided into three age groups: 35 patients were younger than 40 years (group 1; mean age, 32.4 years), 48 patients were 41 to 60 years (group 2; mean age, 50.3 years), and 54 patients were older than 60 years (group 3; mean age, 70.3 years).

RESULTS

Fifty percent (69 of 137) of the total population showed vascular FDG uptake in at least one vessel. Thirty-four percent (12 of 35) of group 1, 50% (24 of 48) of group 2, and 61% (33 of 54) of group 3 showed vascular wall uptake (P = 0.017 between groups 1 and 3). In addition, the correlation between the mean age of the age groups and the prevalence of FDG vascular uptake is strong (r = 0.99).

CONCLUSIONS

Vascular FDG uptake is present in 50% of the patients examined for this study, with an increased prevalence in older patients. This vascular uptake might be explained by smooth muscle metabolism in the media, subendothelial smooth muscle proliferation from senescence, and the presence of macrophages within the atherosclerotic plaque. The relative contribution of these sources needs further investigation.

Structural basis for the feedback regulation of Escherichia coli pantothenate kinase by coenzyme A

Pantothenate kinase (PanK) is a key regulatory enzyme in the coenzyme A (CoA) biosynthetic pathway and catalyzes the phosphorylation of pantothenic acid to form phosphopantothenate. CoA is a feedback inhibitor of PanK activity by competitive binding to the ATP site. The structures of the Escherichia coli enzyme, in complex with a nonhydrolyzable analogue of ATP, 5'-adenylimido-diphosphate (AMPPNP), or with CoA, were determined at 2.6 and 2.5 A, respectively. Both structures show that two dimers occupy an asymmetric unit; each subunit has a alpha/beta mononucleotide-binding fold with an extensive antiparallel coiled coil formed by two long helices along the dimerization interface. The two ligands, AMPPNP and CoA, associate with PanK in very different ways, but their phosphate binding sites overlap, explaining the kinetic competition between CoA and ATP. Residues Asp(127), His(177), and Arg(243) are proposed to be involved in catalysis, based on modeling of the pentacoordinate transition state. The more potent inhibition by CoA, compared with the CoA thioesters, is explained by a tight interaction of the CoA thiol group with the side chains of aromatic residues, which is predicted to discriminate against the CoA thioesters. The PanK structure provides the framework for a more detailed understanding of the mechanism of catalysis and feedback regulation of PanK.

Structural analysis of glyceraldehyde 3-phosphate dehydrogenase from Escherichia coli: direct evidence of substrate binding and cofactor-induced conformational changes

The crystal structures of gyceraldehyde 3-phosphate dehydrogenase (GAPDH) from Escherichia coli have been determined in three different enzymatic states, NAD(+)-free, NAD(+)-bound, and hemiacetal intermediate. The NAD(+)-free structure reported here has been determined from monoclinic and tetragonal crystal forms. The conformational changes in GAPDH induced by cofactor binding are limited to the residues that bind the adenine moiety of NAD(+). Glyceraldehyde 3-phosphate (GAP), the substrate of GAPDH, binds to the enzyme with its C3 phosphate in a hydrophilic pocket, called the "new P(i)" site, which is different from the originally proposed binding site for inorganic phosphate. This observed location of the C3 phosphate is consistent with the flip-flop model proposed for the enzyme mechanism [Skarzynski, T., Moody, P. C., and Wonacott, A. J. (1987) J. Mol. Biol. 193, 171-187]. Via incorporation of the new P(i) site in this model, it is now proposed that the C3 phosphate of GAP initially binds at the new P(i) site and then flips to the P(s) site before hydride transfer. A superposition of NAD(+)-bound and hemiacetal intermediate structures reveals an interaction between the hydroxyl oxygen at the hemiacetal C1 of GAP and the nicotinamide ring. This finding suggests that the cofactor NAD(+) may stabilize the transition state oxyanion of the hemiacetal intermediate in support of the flip-flop model for GAP binding.

Refinement of the positive predictive value of gallbladder nonvisualization after morphine administration for acute cholecystitis based on the temporal pattern of common bile duct activity

The authors previously reported two major patterns in the time-activity curve of the common hepatic bile duct (BD) after morphine administration in patients with gallbladder nonvisualization. The first pattern consists of a gradual increase in BD activity (of variable duration) occurring during a simultaneous decrease in liver parenchymal activity (BD increase), representing the physiologic effects of morphine administration. The second pattern consists of a continuous decrease in BD activity that parallels the activity in the liver parenchyma (BD decrease), representing lower or no physiologic effects of morphine administration. The authors hypothesize that gallbladder nonvisualization associated with a continuous decrease in BD activity after morphine administration will have a lower positive predictive value (PPV) for acute cholecystitis than gallbladder nonvisualization associated with an increase in BD activity.

METHODS

Thirty-six patients who had morphine-augmented cholescintigraphy were divided into two groups: 19 with BD increase after morphine administration and 17 with BD decrease.

RESULTS

Of the 36 patients, 22 had acute cholecystitis. The positive predictive value (PPV) of gallbladder nonvisualization was 61%. All of the remaining 14 had chronic cholecystitis. Of 19 patients with BD increase, 15 had acute cholecystitis (PPV = 79%), whereas only 7 of 17 patients with BD increase (PPV = 41 %) had acute cholecystitis (P = 0.023 by the one-tailed and 0.038 by the two-tailed Fisher exact tests).

CONCLUSIONS

Gallbladder nonvisualization after morphine administration with the pattern of BD decrease is not as reliable (intermediate probability in this series) for the diagnosis of acute cholecystitis as is nonvisualization of the gallbladder in patients with a pattern of BD increase (high probability).

Development of a thermo-reversible insulin liquid suppository with bioavailability enhancement

The purpose of this work is to develop a thermo-reversible insulin liquid suppository, which undergoes a phase transition to bioadhesive gels at body temperature and enhances the bioavailability of insulin. The effects of insulin and sodium salicylate on the physicochemical properties of a liquid suppository composed of poloxamer P 407, P 188 and polycarbophil were investigated. The pharmacodynamic study and quantitative histological assessment of the rectal mucosa of rats were carried out after the dose of insulin-loaded liquid suppositories with different amounts of sodium salicylate into streptozotocin-treated rats. Only thermo-reversible insulin liquid suppository [insulin/P407/P188/polycarbophil/sodium salicylate (100 (IU/g)/15/20/0.2/10%)] showed the optimal physicochemical properties and good safety in rats. It gave significantly lower plasma glucose levels, AUC(0-->4h) (the area below basal glucose level) and C(nadir) (the plasma glucose levels at the nadir) than did the solid and liquid suppositories without sodium salicylate in rats, indicating that the insulin from liquid suppository with sodium salicylate could be well absorbed in rats due to the absorption enhancing effect of sodium salicylate. It is concluded that thermo-reversible insulin liquid suppository [insulin/P 407/P 188/polycarbophil/sodium salicylate (100 (IU/g)/15/20/0.2/10%)], which was easy to administer without any pain during insertion and remained at the administered sites, could have a potential to be developed as a more convenient, safe and effective rectal delivery system of insulin.

[Radiofrequency treatment of ethmoidal nerve with allergic rhinitis under nasal endoscopy]

OBJECTIVE

To study the effect of radiofrequency treatment of ethmoidal nerve on allergic rhinitis.

METHOD

Eighty-eight cases of allergic rhinitis were treated with ethmoidal nerve radiofrequency under nasal endoscopy.

RESULT

It showed marked effectiveness in 73 cases (83.0%), immprovement in 11 cases (12.5%) and failed in 4 cases (4.5%) in one year follow-up. The overall effective rate was 95.5%.

CONCLUSION

This result indicated that it is a choice for treating allergic rhinitis to apply ethmoidal nerve radiofrequency under nasal endoscopy.

Potent and efficacious thienylamidine-incorporated thrombin inhibitors

Novel thrombin inhibitors incorporating thienylamidine at the P1 position were designed and synthesized. These compounds are potent, trypsin-selective and efficacious in the rat model of venous thrombosis. The proposed P1 binding mode in the thrombin active site was confirmed by X-ray crystallographic analysis.

Structural modification of an orally active thrombin inhibitor, LB30057: replacement of the D-pocket-binding naphthyl moiety

An amidrazonophenylalanine derivative LB30057 (2) was identified as a potent (Ki = 0.38 nM), selective, and orally active thrombin inhibitor. As a continuation of studies into benzamidrazone-based thrombin inhibitors, we have structurally modified compound 2 by replacing the naphthyl group with a variety of hydrophobic moieties. This study led to discovery of several compounds with significantly enhanced potency in thrombin inhibition without sacrificing selectivity against trypsin and oral absorption. The highest activity was obtained with compound 23 (Ki = 0.045 nM).

Discovery of LB30057, a benzamidrazone-based selective oral thrombin inhibitor

Systematic variation of the so-called P-pocket moiety of benzamidrazone-based selective thrombin inhibitors led to the discovery of LB30057. It is potent (Ki = 0.38 nM for human thrombin), selective (Ki = 3290 nM for bovine trypsin), and orally bioavailable (58% oral bioavailability in dogs). LB30057 was efficacious in thrombosis animal models.

gamma-Linolenic acid-containing diet attenuates bleomycin-induced lung fibrosis in hamsters

Although bleomycin (BLM), an antineoplastic drug, is used in the treatment of a variety of tumors, the mechanism(s) that contribute to its induced lung injury and fibrosis are not fully elucidated. Since alterations in the levels of certain fatty acid metabolites have been associated with BLM-induced lung injury, we tested the effects of dietary gamma-linolenic acid (GLA)-containing evening primrose oil on BLM-induced morphological alterations in the hamster lung, the marked elevation of tissue hydroxyproline (a marker for collagen synthesis), and elevated generation of arachidonic acid metabolites (marker of inflammatory mediators). Our data revealed that after 14 d of dietary GLA-containing oil (i) BLM-induced elevation of lung hydroxyproline was suppressed (P < 0.05), (ii) the marked BLM-induced elevation of lung leukotriene B4 (LTB4) (a marker of polymorphanuclear generation of proinflammatory LTB4) was significantly suppressed (P < 0.05). The decrease in LTB4 was accompanied by marked elevations (P < 0.05) of lung prostaglandin E1 (PGE1) and 15-hydroxyeicosatrienoic acid (15-HETrE), both with known antiinflammatory properties. Taken together, data from these studies suggest that dietary GLA-containing oil contributes to tissue elevation of PGE1 and 15-HETrE, which in vivo may attenuate lung inflammation and fibrosis.

Primary and secondary liver/kidney microsomal autoantibody response following infection with hepatitis C virus

Liver/kidney microsomal autoantibody type 1 (LKM-1), which characterizes a subtype of autoimmune hepatitis, is also found in some patients with chronic hepatitis C virus (HCV) infection. Whether HCV and LKM-1 are accidentally or causally related is unknown. This case report describes a child who became infected by HCV after liver transplantation for end-stage liver disease caused by alpha 1-antitrypsin deficiency. LKM-1 was detected by immunofluorescence, anti-microsomal reactivity by Western blotting, anti-HCV and anti-GOR by immunoenzymatic assays, and HCV RNA by polymerase chain reaction. Two weeks after HCV infection, immunoglobulin (Ig) M LKM-1 appeared, followed by IgG1 LKM-1, with titers increasing to 1/2560; antibodies to a 50-kilodalton liver microsomal protein appeared 2 months later. Sera from day 1 posttransplant became positive for HCV RNA. HCV RNA was also detected in a liver biopsy specimen obtained 3 months after surgery. The patient did not produce anti-HCV and anti-GOR antibodies throughout the study and had no histological evidence of hepatitis. The temporal relationship between HCV infection and LKM-1 production suggests that HCV may trigger a primary autoimmune response. The lack of liver damage attributable to autoimmunity or viral infection may be caused by immunosuppression.

Pancreatic exocrine deficiency after partial pancreatectomy in conscious dogs

OBJECTIVE

To describe the secretory responses to physiological stimulation of the exocrine pancreas after partial pancreatectomy in conscious animals.

DESIGN

Controlled study.

MATERIAL

Thirteen mongrel dogs.

INTERVENTIONS

Partial pancreatectomy (n = 4), and creation of gastric and pancreatic (Herrera) fistulas (n = 13). Collections of duodenal juice at 15 minute intervals after an oral meal or during intraduodenal infusion of sodium oleate, and blood samples.

MAIN OUTCOME MEASURES

Protein concentration in duodenal juice and cholecystokinin 33/39 concentrations in plasma one and three months after partial pancreatectomy, and secretion of fluid by the pancreas.

RESULTS

Pancreatic protein output after a meal was significantly reduced at one and three months in dogs after partial pancreatectomy compared with control animals. Protein output in response to an intraduodenal infusion of oleate was also reduced at both time points. In contrast, secretion of fluid after a meal or during infusion of oleate was unchanged by removal of the distal lobe. There was no correlation between the effects of partial pancreatectomy on protein output and plasma concentrations of cholecystokinin 33/39.

CONCLUSION

Pancreatic exocrine deficiency, particularly the reduction in secretion of protein, results directly from the partial pancreatectomy and persists for at least three months after the operation.

Human cerebrospinal fluid protein database: edition 1992

Two-dimensional electrophoresis maps of human cerebrospinal fluid proteins are presented in the form of labeled images. 931 protein spots are identified in spinal fluid from a normal volunteer. Distinct spots that represent variants of the same protein, especially posttranslational modifications, are estimated to reduce the 931 different spots to < 200 different proteins. 248 spots of 29 protein groups have been identified and are indicated on enlargements of specific gel regions. The distribution of protein abundance, mass, charge and shape characteristics of these normal 931 spinal fluid spots are graphically profiled. Analysis of the shape parameter "vertical height: width ratio" reveals that a ratio > 3.5 correlates with glycoproteins, enabling their identification simply by image analysis. Proteins that are not present on the normal map, but appear in spinal fluid in patients with schizophrenia and Creutzfeldt-Jakob disease are illustrated on additional maps.

Effects of gastric inhibitory polypeptide and glucagon on portal venous and hepatic arterial flow in conscious dogs

Gastric inhibitory polypeptide (GIP) has considerable structural homology with glucagon, which is known to increase liver blood flow. We compared the effects of GIP on portal venous and hepatic arterial flow with those of glucagon in conscious dogs. Injection of GIP significantly increased portal venous flow in a dose-related manner (by 7%, 15%, and 46% at doses of 1, 100, and 500 pmol/kg, respectively). The increase in portal venous flow induced by GIP and glucagon was comparable; however, the increase in portal venous flow after GIP injection reached its peak significantly earlier than that after glucagon injection. Hepatic arterial flow decreased after GIP injection (by 17%, 21%, and 35% at doses of 1, 100, and 500 pmol/kg, respectively), whereas it was not altered by glucagon. Thus, GIP causes significant changes in both portal venous and hepatic arterial flow in conscious dogs. Although structurally related, GIP and glucagon may influence liver blood flow through different mechanisms.

Qualitative and quantitative changes in islet cells of autotransplanted pancreas in dogs in relation to glucose metabolism

This study was conducted to clarify the quantitative and qualitative changes in the cells of the islets of Langerhans in the autotransplanted pancreas in dogs and to correlate these changes with alterations of glucose tolerance. The left lobe of a canine pancreas was transplanted into the left iliac fossa. The splenic vessels were anastomosed to the left iliac vessels. The pancreatic duct was left open to the peritoneal cavity. Open biopsies of the autotransplanted pancreas were performed 3, 7, 11, and 14 weeks after transplantation. The islets in the transplanted pancreas were examined ultrastructurally; B-cells, A-cells, and D-cells were identified immunohistochemically and their percentages were determined. Intravenous glucose tolerance tests were performed 3, 5, 7, 11, and 14 weeks after operation, and several indexes (K values and integrated response and increased values for baseline serum and immunoreactive insulin) were calculated. Fibrosis of the transplanted pancreas progressed after transplantation. The percentage of B-cells fell significantly (p < 0.01), whereas that of A- and D-cells did not have significant changes. The ultrastructural study revealed an increase in collagen bundles, degranulation of B-cells, and marked preservation of A-cell granules 3 weeks after transplantation. B-Cells with dark cytoplasm were found 7 weeks after operation. In contrast, clusters of immature B-cells were seen in some sections of the pancreas 14 weeks after autotransplantation. The integrated response in baseline serum was increased significantly (p < 0.01), and the K value was decreased significantly (p < 0.01) 11 weeks after autotransplantation when compared with the initial posttransplant period.(ABSTRACT TRUNCATED AT 250 WORDS)