Correlations between skeletal maturity and dental calcification stages in Korean children

AIM

To evaluate the relationship between dental calcification and skeletal maturity and to identify the tooth with the highest correlation with skeletal maturity index in Korean children.

MATERIALS

For 447 children (205 boys and 242 girls) aged between 5 and 13 years, hand-wrist and lateral cephalometric radiographs were taken to assess skeletal maturity by Fishman's skeletal maturity indicators (SMI) and Baccetti's cervical vertebrae maturation (CVM) stages. Dental panoramic radiographs were taken to assess dental maturity of the permanent mandibular canine, first and second premolar, and second molar using the method devised by Dermirjian.

CONCLUSION

Dental calcification stages determined by panoramic radiographs can be clinically used as useful indices to predict skeletal maturity in Korean children.

Clinical usefulness of ultrasound as an early diagnostic tool for neuroleukemiosis -a case report

Background

Neuroleukemiosis is a rare complication of leukemia. The diagnosis may be delayed owing to non-specific symptoms and the need for special diagnostic modalities.

Case

A 70-year-old man in his sixth year of remission from acute myeloid leukemia was referred to the pain clinic for shooting and radiating pain in the left posterior leg. A lumbar spine magnetic resonance imaging showed mild disc bulging of the L2-3, which was insufficient to explain the patient’s symptoms. With insufficient pain response to lumbar epidural block and piriformis injection, we examined both sciatic nerves using an ultrasound and identified an enlarged hypoechoic mass on the left sciatic nerve at mid-thigh level. After that, we biopsied the mass under general anesthesia, and histology confirmed it to be neuroleukemiosis.

Conclusions

Ultrasound is an inexpensive, non-invasive, simple, and quick diagnostic modality that can be used as a screening tool in the diagnosis of neuroleukemiosis.

Customized surgical guide with a bite block and retraction arm for a deeply impacted odontoma; a technical note

Odontomas can cause impaction of permanent teeth. During the removal of odontomas associated with an impacted tooth, minimally-invasive surgical approaches are necessary. We present a technical note highlighting easy extraction of a deeply impacted odontoma using a patient-specific computer-aided design/computer-aided manufacturing (CAD/CAM) surgical guide. Its use and advantages are described.

Anaphylaxis induced by sugammadex and sugammadex-rocuronium complex -a case report

BACKGROUND

In sugammadex-induced anaphylaxis, sugammadex and/or sugammadex-rocuronium complex have possible allergenic epitope.

CASE

We report a case of sugammadex-induced anaphylaxis during general anesthesia in a 60-year-old male undergoing orthopedic hand surgery, manifesting as profound hypotension and urticaria. The timing of onset was closely associated with sugammadex administration. The patient recovered after extensive therapy including fluid, epinephrine, other vasopressors, steroid, and antihistamine administration. By intradermal skin test which was done at four weeks after anaphylaxis, we confirmed positive reactions to both sugammadex and sugammadex-rocuronium complex.

CONCLUSIONS

This is a rare case of sugammadex-induced anaphylaxis that both sugammadex and sugammadex-rocuronium complex were confirmed as allergenic epitopes.

An easy way to secure catheter in position during marsupialization procedure

Marsupialization is the conservative treatment for cystic lesion in children. This technique requires maintaining the patency between the cyst and oral cavity to allow spontaneous healing of cystic lesion. There have been various fixation methods for securing the patency. However, the previous fixation methods have limitation of being invasive and inability to retain catheter firmly during the treatment. In this technical note, we adopted a novel and easy fixation method to obtain firm stability of catheter without damage to intraoral tissues during marsupialization technique.

Lead fracture of peripheral nerve stimulator for brachial plexopathy -a case report

Peripheral nerve stimulation (PNS) is a useful treatment for chronic pain, but it can cause damage depending on its application site. Here, we describe the case of a 54-year-old man who underwent PNS for brachial plexopathy in 2015. One lead was implanted on the left medial cord to stimulate the medial antebrachial cutaneous nerve, and the other was implanted on the radial nerve to stimulate the posterior antebrachial cutaneous nerve. Both leads were inserted near the shoulder joint but did not cross it. Before PNS, the patient did not move his shoulder and elbow because of severe pain, but the treatment greatly alleviated this pain. Twenty months after the operation, both leads were fractured, and the severe pain returned. Repetitive motion near the joint was closely related to the lead fractures. In conclusion, large joints as the insertion sites of PNS leads should be avoided to prevent lead fractures.

Novel device-based acne treatments: comparison of a 1450-nm diode laser and microneedling radiofrequency on mild-to-moderate acne vulgaris and seborrhoea in Korean patients through a 20-week prospective, randomized, split-face study

BACKGROUND

While device-based acne treatments are widely applied for patients not tolerating conventional medications, related controlled studies have been still limited. Recently, non-ablative 1450-nm diode laser (DL) and fractional microneedling radiofrequency (FMR) have been effectively used for acne, in addition to well-recognized dermal remodelling effects.

OBJECTIVE

To compare the clinical course of acne treatment between DL and FMR.

METHODS

Twenty-five Korean patients with mild-to-moderate facial acne completed treatments with DL and FMR through a 20-week, randomized split-face study. One randomly assigned half side of each patient's face received DL and the other side by FMR. Treatments were scheduled to receive three consecutive sessions at 4-week intervals. Objective assessments including revised Leeds grades, lesion counts, sebum output measurements, and patients' subjective satisfaction were investigated.

RESULTS

Both DL and FMR demonstrated steady improvement of acne and seborrhoea during treatment sessions. While results between two devices were similar during treatment sessions, FMR was superior to DL in the 12-week follow-up. Patients' subjective assessments for seborrhoea improvement were similar between two devices, while those for acne, skin texture, and acne scars were more satisfactory for FMR. For safety profile, no significant difference was observed between two regimens, while mild postinflammatory hyperpigmentation was observed only in DL side.

CONCLUSION

Both DL and FMR demonstrated efficacies for acne and seborrhoea, with reasonable safety profile. FMR was more effective than DL for the long-term maintenance, and subjective assessments for texture and scar improvements. Therefore, a few sessions of these devices would be a viable option for acne treatments.

Clinical Characteristics of Patients with Pseudo-Subarachnoid Haemorrhage who were Successfully Resuscitated from Out-of-Hospital Cardiopulmonary Arrest

Introduction

Pseudo-subarachnoid haemorrhage (PSAH) is a rare neuroradiological finding seen in patients with diffuse cerebral edemas. We investigated clinical characteristics and risk factors for the development of PSAH.

Method

The successfully resuscitated patients in emergency department were classified into two groups: those with pseudo-SAH [PSAH (+)] and those without pseudo-SAH [PSAH (-)]. Clinical variables were analysed.

Results

Pseudo-SAH was found in 31.6% of patients. PSAH was more common in males (p=0.042). The mean age was 39.9±10.3 years in the PSAH (+) group and 54.4±22.0 years in the PSAH (-) group (p=0.038). Outcomes measured by Cerebral Performance Category score were also significantly different between the two groups (p=0.037). Logistic regression analysis found that serum lactate concentration and duration of anoxia were associated with the development of PSAH (with odds ratios and p values of 1.92, p=0.01 and 1.13, p=0.02, respectively).

Conclusions

PSAH itself is a phenomenon that could be seen in post-resuscitation encephalopathy as a consequence of severe anoxic insult.

Combined Spinal Cord Stimulation and Peripheral Nerve Stimulation for Brachial Plexopathy: A Case Report

Brachial plexopathy usually results from an iatrogenic brachial plexus injury and can sometimes cause severe chronic pain and disability. There are a number of possible treatments for this condition, including medication, physical therapy, nerve blocks, and neuromodulation, but they are not always successful. Recently, combined spinal cord stimulation (SCS) and peripheral nerve stimulation (PNS) have been tried for various chronic pain diseases because of their different mechanisms of action.Here, we describe the case of a 54-year-old man who was diagnosed with brachial plexopathy 8 years ago. He underwent video-assisted thoracoscopic surgery to remove a superior mediastinal mass. However, his brachial plexus was damaged during the surgery. Although he had received various treatments, the pain did not improve. For the management of intractable severe pain, he underwent SCS 2 years ago, which initially reduced his pain from numeric rating scale (NRS) 10/10 to NRS 4 - 5/10, but the pain then gradually increased, reaching NRS 8/10, 6 months ago. At that time, he was refractory to other treatments, and we therefore applied PNS in combination with SCS. The PNS electrode was positioned on the radial nerve under ultrasound guidance. After combined PNS and SCS, his background pain disappeared, although a breakthrough pain (NRS 3 - 4/10) was caused intermittently by light touch. Furthermore, the patient's need for analgesics decreased, and he was satisfied with the outcome of this combined treatment. We concluded that combined SCS and PNS is a very useful treatment modality, which can stimulate the target nerve both directly and indirectly, and hence, relieve pain from brachial plexopathy.

Efficacy of combination therapy with probiotics and mosapride in patients with IBS without diarrhea: a randomized, double-blind, placebo-controlled, multicenter, phase II trial

BACKGROUND

Probiotics can be beneficial in irritable bowel syndrome (IBS). Mosapride citrate, a selective 5-HT4 receptor agonist, stimulates gastrointestinal motility. We investigated the efficacy of combination therapy with probiotics and mosapride for non-diarrheal-type IBS.

METHODS

Two hundred and eighty-five IBS patients were randomly assigned to either a combination of probiotics (Bacillus subtilis and Streptococcus faecium) and mosapride at one of four different doses or a placebo for 4 weeks. The primary outcome was the proportion of patients experiencing adequate relief (AR) of global IBS symptoms at week 4. The secondary outcomes included subject's global assessment (SGA) of IBS symptom relief, individual symptoms, stool parameters, and IBS-quality of life.

KEY RESULTS

The proportion of AR at week 4 was significantly higher in all treatment groups compared to the placebo group (53.7% in group 1, 55.0% in group 2, 55.2% in group 3, 53.6% in group 4 [the highest dose], and 35.1% in placebo group, respectively, p < 0.05). The proportion of patients reporting 'completely or considerably relieved' in the SGA was higher in the treatment groups than in the placebo group. The abdominal pain/discomfort score in the treatment group 4 was more prominently improved compared with that of the placebo group. In patients with constipation-predominant IBS, the improvements in stool frequency and consistency were significantly higher in the treatment groups 4 and 1, respectively, than those in the placebo group.

CONCLUSIONS & INFERENCES

Combination therapy with probiotics and mosapride is effective for relief of symptoms in patients with non-diarrheal-type IBS. The study has been registered in the US National Library of Medicine (http://www.clinicaltrials.gov, NCT01505777).

Efficacy of ramosetron in the treatment of male patients with irritable bowel syndrome with diarrhea: a multicenter, randomized clinical trial, compared with mebeverine

BACKGROUND

The 5-HT(3) receptor antagonists are known to be effective for the treatment of diarrhea-predominant irritable bowel syndrome (IBS), but not widely used yet. The aim of this study was to compare the efficacy and safety of ramosetron, a 5-HT(3) receptor antagonist, and mebeverine in male patients with IBS with diarrhea (IBS-D).

METHODS

This study was performed in a multicenter, randomized, open-label design. Data of 343 male patients with IBS-D who were randomized to either a 4-week treatment of ramosetron 5μg once daily or a 4-week treatment of mebeverine 135 mg three times daily were analyzed by the intent-to-treat analysis. The primary efficacy parameter was the proportion of patients with adequate relief of IBS symptoms at the last week of treatment. The secondary endpoints were changes in each symptom score and the safety profiles.

KEY RESULTS

The responder rates for global IBS symptoms, abdominal pain/discomfort and abnormal bowel habits in the ramosetron and mebeverine groups significantly increased during the treatment period. The severity scores of abdominal pain/discomfort and urgency, the stool form score, and the stool frequency in both treatment arms were significantly reduced, compared with the baselines. There were no significant differences in the responder rates (37%vs 38% on ITT analysis) and adverse event profiles between the ramosetron and mebeverine groups. Neither severe constipation nor ischemic colitis was reported by ramosetron-treated patients.

CONCLUSIONS & INFERENCES

Ramosetron 5μg once daily is as effective as mebeverine three times daily in male patients with IBS-D.

Recombinant human arginase inhibits proliferation of human hepatocellular carcinoma by inducing cell cycle arrest

Human hepatocellular carcinoma (HCC) has an elevated requirement for arginine in vitro, and pegylated recombinant human arginase I (rhArg-PEG), an arginine-depleting enzyme, can inhibit the growth of arginine-dependent tumors. While supplementation of the culture medium with ornithine failed to rescue Hep3B cells from growth inhibition induced by rhArg-PEG, citrulline successfully restored cell growth. The data support the roles previously proposed for ornithine transcarbamylase (OTC) in the arginine auxotrophy and rhArg-PEG sensitivity of HCC cells. Expression profiling of argininosuccinate synthetase (ASS), argininosuccinate lyase (ASL) and OTC in 40 HCC tumor biopsy specimens predicted that 16 of the patients would be rhArg-sensitive, compared with 5 who would be sensitive to arginine deiminase (ADI), another arginine-depleting enzyme with anti-tumor activity. Furthermore, rhArg-PEG-mediated deprivation of arginine from the culture medium of different HCC cell lines produced cell cycle arrests at the G(2)/M or S phase, possibly mediated by transcriptional modulation of cyclins and/or cyclin dependent kinases (CDKs). Based on these results, together with further validation of the in vivo efficacy of rhArg-PEG against HCC, we propose that the application of rhArg-PEG alone or in combination with existing chemotherapeutic drugs may represent a specific and effective therapeutic strategy against HCC.

CK2 mediates phosphorylation and ubiquitin-mediated degradation of the PML tumor suppressor

The PML tumor suppressor controls growth suppression, induction of apoptosis, and cellular senescence. PML loss occurs frequently in hematopoietic and solid tumors. PML loss often correlates with tumor progression. Casein kinase 2 (CK2) is a stress-activated serine/threonine protein kinase that is oncogenic and frequently overexpressed in human tumor of multiple histological origins. In addition, CK2 overexpression due to gene amplification has been reported to be an adverse prognostic factor in non-small cell lung cancer. At the 5th International Conference on Protein Kinase CK2 in Padova, Italy, we reviewed our recent findings that PML undergoes ubiquitin/proteasome-mediated degradation in immortalized and tumor derived cell lines. PML degradation depends on direct CK2 phosphorylation of PML Ser517. PML mutants that are resistant to CK2 phosphorylation display increased tumor suppressive functions in assays measuring apoptosis, replicative senescence, and in xenograft models. More significantly, CK2 pharmacological inhibition enhances PML tumor suppressive property. These data identify a key post-translational mechanism that controls PML protein levels in cancer cells and suggest that CK2 inhibitors may be beneficial anti-cancer drugs.

Bond length and the electron density at the bond critical point: XX, ZZ, and CZ bonds (X = Li-F, Z = Na-Cl)

The aim was to investigate the relationship between the bond length and the electron density at the bond critical point in homonuclear X--X and Z--Z and heteronuclear C--Z bonds (X = Li-F, Z = Na-Cl). The d,rho(c) pairs were obtained from 472 target bonds in DFT-optimized (B3LYP/6-311+G(d,p)) small molecular species. These species were selected arbitrarily but with a view to maximize the range widths WR for each atom combination. It was found that (i) with one clear exception, the d(A - A) means (A = X or Z) correlate linearly with the bond lengths d(A(2)) of the respective diatomic molecules; (ii) the d(A - A) means correlate parabolically with n, the formal number of valence electrons in the atoms of the bond; and (iii) with increasing sample size N the ratio WR(rho(c))/WR(d) appears to converge toward a representation f [WR(rho(c))/WR(d)](N-->infinity) characteristic of A. Detailed analysis of the d,rho(c) relationship has shown that by and large simple power regression accounts best for the DFT data. The regression coefficients of d = arho(c) (-b) and rho(c) = alphad(-beta) (b, beta > 0) vary with n in a seemingly irregular manner but one that is consistent with simple chemical notions. The d(A(2)) can be approximated in terms of multilinear MO electron occupancies.

The rate of iron corrosion for different organic carbon sources during biofilm formation

The effects of total organic carbon and biofilm on microbial corrosion were quantified using serum bottles in a 2 x 2 factorial design. Both organic carbon and biofilm bacteria had a significant effect on the iron corrosion rate, irrespective of the levels of the other variable (p = 0.05). There was no evidence of interaction between organic carbon and biofilm bacteria. Within the tested levels, the addition of exogenous organic carbon increased the corrosion rate by an average of 3.838 mg dm(-2) day(-1) (mdd), but the presence of biofilm bacteria decreased the rate by an average of 2.305 mdd. More iron was released from the coupon in response to organic carbon. Powder x-ray diffractometry indicated that the scales deposited on the corroded iron surface consisted primarily of lepidocrocite (gamma-FeOOH), magnetite (Fe3O4) and hematite (alpha-Fe203). Corrosion rates by different organic carbon sources, i.e. acetate, glucose and humic substances, were compared using an annular biofilm reactor. One-way ANOVA suggested that the effect of each carbon source on corrosion was not the same, with the iron corrosion rate highest for glucose, followed by acetate, humic substances and the control. Magnetite was a major constituent of the corrosion products scraped from iron slides. Examination of community-level physiological profile patterns on the biofilms indicated that acetate was a carbon source that could promote the metabolic and functional potentials of biofilm communities.

Characteristics of biofilm community formed in the chlorinated biodegradable organic matter-limited tap water

The aim of this study was to characterize the influence of free chlorine residual on biofilm formation in a chlorinated system in which the biodegradable organic matter (BOM) was limited. The biofilm community was characterized through a community-level physiological profile (CLPP) that was generated using the Biolog GN microplate-based community-level assay. The chlorinated system was run at chlorine residual concentrations of 0.3, 0.5, and 1.0 mg l(-1) with the provision of BOM-limited tap water (0.01 mg l(-1) as assimilable organic carbon and 0.06 mg l(-1) as biodegradable dissolved organic carbon). For comparison, an unchlorinated system was operated in parallel under the same condition. The number of viable heterotrophic bacteria in the biofilm that formed in the chlorinated system over the 3 months of operation averaged 7.2 x 10(3), 4.8 x 10, and 1.6 x 10 CFU cm(-2) for the chlorine residual concentrations of 0.3, 0.5, and 1.0 mg l(-1), respectively. In the unchlorinated system, the average bacterial content was 1.1 x 10(6) CFU cm(-2). Using measures of substrate utilization rate, substrate utilization diversity, and metabolic potential index (MPI), the CLPP patterns demonstrated that the metabolic potentials of the biofilm communities decreased markedly as the chlorine residual levels increased. In particular, the community level of the biofilm that formed in the system with chlorine residual concentration of 1.0 mg l(-1) was the lowest of any biofilm under the tested conditions. The results implied that chlorine residual had a positive biocidal effect on the metabolic potential and/or functional potential of the biofilm community, especially when the BOM level was low. In addition, BOM limitation by itself was not sufficient to control biofilm formation.

Cloning and characterization of a type II integral transmembrane protein gene, Itm2c, that is highly expressed in the mouse brain

An Itm2C cDNA encoding a member of the mouse type II integral transmembrane protein (Itm2) was cloned from a mouse 13.5 days' post-coitum (dpc) embryonic head cDNA library. The nucleotide sequence and protein prediction analyses indicate that the membrane topology of the mouse Itm2c is a type II integral transmembrane protein with the N-terminus being intracellular and C-terminus, which is considered as either an extracellular or a luminal organelle domain. The predicted protein consists of 269 amino acids with a calculated Mr of 30,482 and a theoretical pI of 8.83. A putative N-glycosylation site was identified at amino acid 171, Asn. The single N-glycosylation site is conserved in the three members of the family in both mice and humans. The amino acid sequence of Itm2C is 41 and 49% identical to those of mouse Itm2A and Itm2B, respectively. A single approximately 2.1 kb transcript was detected with different levels in all of the tissues examined by Northern blot analysis. The Itm2c was highly expressed in both adult and postimplantation embryonic brains, although weak or moderate signals were also detected in other adult tissues. Among the tissues examined, RT-PCR analyses in various adult tissue shows that the Itm2c expression is highest in the adult brain. The results from this study suggest that the cloned Itm2c is a member of the Itm2 family that is specifically expressed in adult brains, unlike other members.

Granulocytic sarcoma occurring in the maxillary gingiva demonstrated by magnetic resonance imaging

We report the case of a 43-year-old woman presenting with a painless swelling that had developed over 8 months in the maxillary labial vestibule. An oral examination revealed an exophytic, firm, black-pigmented lesion measuring 3.5 x 1.5 cm that bled on palpation. Periapical radiographs showed a slightly enlarged periodontal ligament space of the left central incisor and bone resorption in the region of the missing lateral incisor. Panoramic and other conventional radiographs showed no obvious lytic area, and a magnetic resonance imaging examination demonstrated a low signal intensity lesion on both the T1-weighted and the T2-weighted images. Therefore, granulocytic sarcoma was suspected. Granulocytic sarcoma of the oral cavity is a rare condition, and its diagnosis is usually difficult. Increased awareness of this entity may minimize misinterpretation of radiographic and clinical findings and can assist suitable treatment planning that is essential to this pathosis.

Intercenter variance in clinical trials of head trauma--experience of the National Acute Brain Injury Study: Hypothermia

OBJECT

In a recently conducted trial of hypothermia in patients with severe brain injury, differences were found in the effects of hypothermia treatment among various centers. This analysis explores the reasons for such differences.

METHODS

The authors reviewed data obtained in 392 patients treated for severe brain injury. Prerandomization variables, critical physiological variables, treatment variables, and accrual methodologies were investigated among various centers. Hypothermia was found to be detrimental in patients older than the age of 45 years, beneficial in patients younger than 45 years of age in whom hypothermia was present on admission, and without effect in those in whom normothermia was documented on admission. Marginally significant differences (p < 0.054) in the intercenter outcomes of hypothermia-treated patients were likely the result of wide differences in the percentage of patients older than 45 years of age and in the percentage of patients in whom hypothermia was present on admission among centers. The trial sensitivity was likely diminished by significant differences in the incidence of mean arterial blood pressure (MABP) less than 70 mm Hg (p < 0.001) and cerebral perfusion pressure (CPP) less than 50 mm Hg (p < 0.05) but not intracranial pressure (ICP) greater than 25 mm Hg (not significant) among patients in the various centers. Hours of vasopressor usage (p < 0.03) and morphine dose (p < 0.001) and the percentage of dehydrated patients varied significantly among centers (p < 0.001). The participation of small centers increased intercenter variance and diminished the quality of data.

CONCLUSIONS

For Phase III clinical trials we recommend: 1) a detailed protocol specifying fluid and MABP, ICP, and CPP management: 2) continuous monitoring of protocol compliance; 3) a run-in period for new centers to test accrual and protocol adherence; and 4) inclusion of only centers in which patients are regularly randomized.

Isolation of neuronal precursors from differentiating P19 embryonal carcinoma cells by neuronal T alpha 1-promoter-driven GFP

The induction of pluripotent P19 embryonal carcinoma (EC) cells with retinoic acid results in their differentiation into cells that resemble neurons, glia, and fibroblasts. To isolate and enrich the developing neurons from heterogeneously differentiating P19 EC cells, we used a recently introduced protocol combining the expression of green fluorescent protein (GFP) driven by a tissue-specific promoter and fluorescence-activated cell sorting. Cells were transfected with the gene for GFP, which is under the control of the neuronal T alpha 1 tubulin promoter. After four days of retinoic acid treatment, GFP was specifically detected in cells undergoing neuronal differentiation. Sorting of fluorescent differentiating P19 EC transfectants yielded populations highly enriched in neuronal precursors and neurons. Immunoreactivity for nestin and neurofilament was observed in 80 and 25% of the sorted cell population, respectively. These results demonstrate that differentiated neuronal precursor cells can be efficiently isolated from differentiating pluripotent embryonic cells in vitro, suggesting that this method can reproducibly provide homogeneous materials for further studies on neurogenesis.

Poly(A) binding protein II in Xenopus laevis is expressed in developing brain and pancreas

We have isolated Xenopus homolog of poly(A) binding protein II (XPABPII) and examined its expression during early embryogenesis and embryonic gut development. XpabpII encodes a nuclear protein of 296 amino acids that contains an alpha-helical coiled-coil domain and a ribonucleoprotein-type RNA binding domain. XpabpII is expressed both maternally and zygotically. In gastrula and neurula embryos, XpabpII is expressed mainly in ectoderm, neural and epidermal. From tailbud through to tadpole stages, the neural tissue specific expression of XpabpII gradually becomes confined to the specific vesicle regions of developing brain, being detected in the eye, olfactory pit, telencephalon and mesencephalon, but being excluded from the diencephalon region. Intriguingly, XpabpII transcripts are observed in differentiating gut endoderm. XpabpII first becomes visible in the anterior part of a stage 35 embryonic gut in which prospective liver, stomach and pancreas are located. During further development, uniform expression in anterior gut gradually becomes restricted to the pancreas rudiment. At the seventh day of development, when the gut has formed a complex coiled structure in which each organ contains clearly differentiated cell type, XpabpII is detectable exclusively in the pancreas. Taken together, we suggest that XpabpII plays a specific role in the polyadenylation process of genes involved in brain and pancreas development.

Dendritic cell-tumor coculturing vaccine can induce antitumor immunity through both NK and CTL interaction

Immunization of dendritic cells (DC) pulsed with tumor antigen can activate tumor-specific cytotoxic T lymphocytes (CTL) that are responsible for protection and regression. We show here that immunization with bone marrow-derived DC cocultured with tumor cells can induce a protective immunity against challenges to viable tumor cells. In this study, we further investigated the mechanism by which the antitumor activity was induced. Immunization of mice with DC cocultured with murine colon carcinoma. CT-26 cells, augmented CTL activity against the tumor cells. Concomitantly, an increase in natural killer (NK) cell activity was also detected in the same mice. When DC were fixed with paraformaldehyde prior to coculturing with tumor cells, most of the CTL and NK cell activity diminished, indicating that DC are involved in the process of presenting the tumor antigen(s) to CTL. NK cell depletion in vivo produced markedly low tumor-specific CTL activity responsible for tumor prevention. In addition, RT-PCR analysis confirmed the high expression of INF-gamma mRNA in splenocytes after vaccination with DC cocultured with tumors, but low expression in splenocytes from NK-depleted mice. Most importantly, the tumor protective effect rendered to DC by the coculturing with CT-26 cells was not observed in NK-depleted mice, which suggests that DC can induce an antitumor immune response by enhancing NK cell-dependent CTL activation. Collectively, our results indicate that NK cells are required during the priming of cytotoxic T-cell response by DC-based tumor vaccine and seem to delineate a mechanism by which DC vaccine can provide the desired immunity.

The role of gastrointestinal endoscopy in long-distance runners with gastrointestinal symptoms

BACKGROUND

Exercise-related gastrointestinal symptoms are not uncommon among athletes. The occurrence of gastrointestinal bleeding has been reported, especially in long-distance runners. We studied gastrointestinal mucosal damage, using gastrointestinal endoscopy, in competitive long-distance runners. Gastrointestinal blood loss and anaemia before and after running were also assessed.

METHODS

Sixteen competitive long-distance runners (all men; age range 16-19 years) participated in the study. All runners completed a symptom questionnaire prior to a 20 km race. Stool occult blood and haematological studies (haemoglobin, haematocrit, serum iron, total iron-binding capacity [TIBC] and ferritin) were performed before and immediately after the race. Gastrointestinal endoscopy was performed to assess macroscopic changes. Colonoscopy was also performed on the patients who had positive stool occult blood before or after the race.

RESULTS

Gastrointestinal symptoms were frequently experienced by the runners. Gastritis (n = 16), oesophagitis (n = 6) and gastric ulcer (n = 1) were found at gastroscopy. Colonoscopy was performed on four patients who had positive stool occult blood. One had multiple erosions at the splenic flexure and one had a rectal polyp. Five runners had anaemia, and all of these had at least one endoscopic lesion (three gastritis, two oesophagitis and one multiple erosion at the splenic flexure). There were significant changes in the following haematological parameters after the race: iron (decreased, P = 0.02), ferritin (decreased, P = 0.001) and TIBC (increased, P = 0.00005).

CONCLUSIONS

Gastrointestinal symptoms and gastrointestinal mucosal damage are prevalent among long-distance runners. Prior to treatment, gastrointestinal endoscopy should be considered in long-distance runners with gastrointestinal symptoms and/or anaemia.

A novel Xenopus acetyltransferase with a dynamic expression in early development

We have isolated a novel acetyltransferase from Xenopus laevis, named Xat-1. Xat-1 cDNA encodes a predicted protein of 846 amino acids that contains tetratricopeptide repeat (TPR) domains mediating protein-protein interactions and a bipartite nuclear localization signal (NLS). Its apparent molecular mass of 98.8 kDa was determined by SDS-PAGE analysis of Xat-1 recombinant protein in vitro translated in rabbit reticulocyte lysate. Xat-1 is homologous to N-terminal acetyltransferase 1 (NAT1), a gene that was originally discovered in yeast. Furthermore, it has many orthologs from human, mouse, Drosophila, C. elegans, and even Arabidopsis, thereby suggesting that these constitute a novel acetyltransferase family whose functions have been not examined. Xat-1 transcripts are expressed at relatively constant levels throughout early embryonic stages. They also exhibit dynamic expression pattern in brain, somites, branchial arches, pronephros, and otic vesicles.

Quantitative analysis of normal major salivary glands using computed tomography

OBJECTIVES

We sought to calculate the size and the computed tomography (CT) number of normal parotid and submandibular glands and to evaluate their relationship with respect to sex, age, and obesity in the Korean population.

STUDY DESIGN

The authors investigated the axial CT images of 42 healthy volunteers. The maximum cross-sectional area (MCSA) was used as an indicator of the size of the gland. Three regions of interest on axial scans were selected to calculate the mean CT number.

RESULTS

There was a significant decrease in the mean MCSA of the submandibular gland and the CT number of both glands with age. The MCSA of the submandibular gland in males was larger than that in females. There was a close correlation between the parotid and the submandibular glands with respect to the CT number, as well as between the left and right glands with respect to the MCSA and the CT number. The body mass index was positively correlated with the MCSA of the parotid gland, whereas the body mass indexes and the CT numbers of both glands were negatively correlated.

CONCLUSIONS

Both age and obesity are closely correlated with the size and the CT number of the major salivary glands. Moreover, the correlation between the CT numbers of the parotid and the submandibular glands may be used for diagnostic purposes.

Comparative radiologic study of bone density and cortical thickness of donor bone used in mandibular reconstruction

OBJECTIVE

The aim of this study was to compare the total cancellous bone density, bone-implant interface density, and cortical thickness of 6 donor bone types commonly used in oral and maxillofacial reconstruction.

METHODS

A total of 120 bones from 20 Korean adults-including iliac bones, fibulas, cranial bones, scapulas, ribs, and clavicles-were selected. The implant recipient site was determined by the shape, contour, and anatomical limitations of the bones. The serial cross-sectional images of each bone were then acquired through computed tomography. Total cancellous bone density, bone-implant interface density around the imaginary implant fixture, and the cortical thickness along both sides of the imaginary fixture on each cross-sectional image were evaluated and compared.

RESULTS

The cancellous bone density of each donor bone type had a statistically significant difference. The cranial bone showed the highest cancellous bone density, followed by the iliac bone, clavicle, scapula, rib, and fibula (P <.05). The bone-implant interface density of the cranial bone, clavicle, fibula, and scapula each belonged to the same Duncan's group, whereas the rib and iliac bone showed lower bone-implant interface density. In average cortical thickness, the scapula and fibula had a thicker cortex surrounding the imaginary implant than the other bones, and the rib had the thinnest cortex.

CONCLUSION

Although more extensive testing is needed to explain the clinical implications of these results, the findings of this study may help clinicians choose the most appropriate donor bone.

Effect of graded running on esophageal motility and gastroesophageal reflux in fed volunteers

The effects of different grades of running on esophageal motility and gastroesophageal reflux in the fed state were evaluated. We studied healthy volunteers (male: 12, age: 27 +/- 5 yr) using ambulatory esophageal manometry, pH catheter and portable digital data recorder. Each exercise was performed 30 min after meal, with 20 min of rest between exercises. Subjects exercised on a treadmill at 40% and 70% maximal heart rate. The number of gastroesophageal reflux episodes, the duration of esophageal acid exposure and percent time pH below 4 were significantly (p < 0.01) increased during exercise at 70% maximal heart rate. The frequency of contraction (contraction/min) (p < 0.05), frequency of repetition (p < 0.01), percent of simultaneous contraction (p < 0.01), percent of above 100 mmHg amplitude (p < 0.05), and frequency of 2-peak contraction (p < 0.01) were significantly increased during exercise at 70% maximal heart rate. However, median amplitude and median duration showed no significant changes between each exercise session. Postprandial running exercises induce gastroesophageal reflux, which correlates with exercise intensity. These effects are mediated by disorganized esophageal motility.

Design and statistical issues in multicenter trials of severe head injury

Multicenter clinical trials are the most powerful agent to evaluate new therapies in medicine, but have failed to impact traumatic brain injury, in which at least 20 such trials have been performed, without a positive result. Such trials need to be carefully planned, with a run-in period to ensure center compliance. Stratification, careful monitoring, adequate sample size, interim analysis and adequate numbers of patients per center are all vital requirements for a useful outcome in such trials.

Quantitative analysis of apical root resorption by means of digital subtraction radiography

OBJECTIVE

This study was performed to assess the diagnostic and quantifying ability of digital subtraction images for simulated apical root resorption, as well as to compare the diagnostic accuracy of conventional intraoral radiographs with digital subtraction images for this condition.

STUDY DESIGN

Digital and intraoral radiographs of 10 sound maxillary central incisors and those with simulated apical root resorption were taken with varying horizontal and vertical angulations of the x-ray beam. Paired t tests were used to compare the lengths of the sound teeth on the images with their actual lengths, and the estimated amount of simulated apical root resorption was compared with the actual amount of tooth loss by means of Emago software. The diagnostic accuracy for detecting lesions was also evaluated on conventional intraoral radiographs and digital subtraction images through receiver operating characteristic (ROC) analysis.

RESULTS

There were no statistically significant differences between the actual lengths and those measured on the reconstructed images of the sound teeth. The calculated amounts of apical root resorption showed no statistically significant differences in comparison with the actual amounts (P >.05). The diagnostic accuracy of the conventional intraoral radiographs in detecting the lesions was low (ROC area = 0.6446).

CONCLUSION

A quantitative analysis of small amounts of apical root resorption can be performed by means of digital subtraction radiography.

Lack of effect of induction of hypothermia after acute brain injury

BACKGROUND

Induction of hypothermia in patients with brain injury was shown to improve outcomes in small clinical studies, but the results were not definitive. To study this issue, we conducted a multicenter trial comparing the effects of hypothermia with those of normothermia in patients with acute brain injury.

METHODS

The study subjects were 392 patients 16 to 65 years of age with coma after sustaining closed head injuries who were randomly assigned to be treated with hypothermia (body temperature, 33 degrees C), which was initiated within 6 hours after injury and maintained for 48 hours by means of surface cooling, or normothermia. All patients otherwise received standard treatment. The primary outcome measure was functional status six months after the injury.

RESULTS

The mean age of the patients and the type and severity of injury in the two treatment groups were similar. The mean (+/-SD) time from injury to randomization was 4.3+/-1.1 hours in the hypothermia group and 4.1+/-1.2 hours in the normothermia group, and the mean time from injury to the achievement of the target temperature of 33 degrees C in the hypothermia group was 8.4+/-3.0 hours. The outcome was poor (defined as severe disability, a vegetative state, or death) in 57 percent of the patients in both groups. Mortality was 28 percent in the hypothermia group and 27 percent in the normothermia group (P=0.79). The patients in the hypothermia group had more hospital days with complications than the patients in the normothermia group. Fewer patients in the hypothermia group had high intracranial pressure than in the normothermia group.

CONCLUSIONS

Treatment with hypothermia, with the body temperature reaching 33 degrees C within eight hours after injury, is not effective in improving outcomes in patients with severe brain injury.

A comparative study of the radiological diagnosis of postoperative maxillary cyst

OBJECTIVES

To compare the diagnostic accuracy for the postoperative maxillary cyst (POMC) of panoramic in combination with Waters' radiography with computed tomography (CT) and of oral and maxillofacial radiologists with non-specialists.

STUDY DESIGN

Nineteen cases of POMC and 19 of postoperative changes were assessed using panoramic in combination with Waters' radiographs and CT by five oral and maxillofacial radiologists and five non-specialists on a five-point scale. The areas under the ROC curves were analysed using the Wilcoxon rank sum test to determine any differences in diagnostic accuracy between the two methods and between the two groups.

RESULTS

The diagnostic accuracy of CT was higher than that of combined panoramic and Waters' radiographs for the oral and maxillofacial radiologists (P < 0.05), but not for the non-specialists (P > 0.05). The diagnostic accuracy of the oral and maxillofacial radiologists for each method was higher than that of the non-specialists group (P < 0.05).

CONCLUSIONS

CT improves the evaluation of POMC. Radiological training and experience leads to more accurate diagnoses.

Optimization of resolution and color reproduction by controlling luminance and contrast levels of a liquid-crystal display monitor

The image quality of a color liquid-crystal display monitor is studied by changing the contrast and the luminance levels. The resolution is assessed with modulation transfer function area (MTFA) that is measured at nine different combinations of the luminance and contrast. At these combinations, we measure the chromaticity coordinates and luminance of red-green-blue channels as a function of the digital-analog convert value. We analyze the relations among MTFA value, constant-channel chromaticity, color gamut, and maximum luminance of a white pattern. From the results, the combination of levels is found that provides both high resolution and good color reproduction.

Identification and developmental expression of par-6 gene in Xenopus laevis

The par genes (partitioning defective) are required to establish polarity in the Caenorhabditis elegans embryo. We have identified the Xenopus homologue of C. elegans PAR-6 (XPAR-6). XPAR-6 is a protein of 377 amino acids with one PDZ domain which is involved in mediating protein-protein interactions. It shares 59% and 58% amino acid identity with the mouse and Drosophila PAR-6, respectively, and 54% overall identity with C. elegans PAR-6. Xpar-6 is expressed both maternally and zygotically. Xpar-6 is first detected in the animal half of the egg, and this pattern of expression persists into the cleavage and blastula stages. At the gastrula stage, the message is detected in animal pole area and in a broad domain of ventral region, but is excluded from dorsal region. With the onset of neurulation, the localized expression of Xpar-6 becomes more obvious, leading to it being enriched in the dorsolateral region along the lateral edges of neural plate and anterior presumptive head region surrounding the anterior border of neural plate. At late tailbud stage, Xpar-6 transcripts show localized expression throughout the head, labeling the branchial arches, eyes, otic vesicles and brain, while more posteriorly Xpar-6 labels the somites, pronephros, tail tip and proctodeum. Therefore, this analysis suggests that Xpar-6 has a regionalized pattern of expression during Xenopus early embryogenesis.

Diagnostic imaging of pigmented villonodular synovitis of the temporomandibular joint associated with condylar expansion

Pigmented villonodular synovitis (PVNS) is a rare lesion of the temporomandibular joint. We report a case which was initially misdiagnosed as a parotid tumor. CT revealed a well-defined mass demonstrating higher attenuation than the adjacent soft tissue with marked expansion of the mandibular condyle. MRI clearly delineated the extent of the lesion which had very low signal intensity on both T1W and T2W sequences due to the effect of hemosiderin. The usefulness of these imaging procedures in diagnosis of PVNS is discussed.

Fractal dimension calculated from two types of region of interest

OBJECTIVES

To compare the effect of using two region of interest (ROI) types on calculating the fractal dimensions of trabecular bone during simulated osteoporosis.

METHODS

Ten 5 mm thick cross-sections from the long bone of a cow were progressively decalcified in 0.1 N Hcl for 5, 10, 20, 30, 60 and 90 min intervals, and radiographed using 0 degrees projection angle in a specially designed device. Two types of ROI (the ruggedness of the boundary and bone profiles) were placed on each digital image. Fractal dimensions and variance in mean pixel intensity were computed from each ROI using the caliper method in ImageFractal (National Institutes of Health, Washington, DC, USA). Correlation analysis quantified the relationship between changes in variance and fractal dimensions of the two types of ROI.

RESULTS

A Strong correlation (r=0.90 approximately 0.98, P</=0.0026) was found between variance in mean pixel intensity and decreasing fractal dimensions calculated from bone profiles. There was no consistency in the ruggedness of the boundary and increasing decalcification.

CONCLUSIONS

The fractal dimensions used to characterize the ruggedness of a boundary of trabecular bone in a two-dimensional ROI are inadequate for the detection of osteoporosis, but those calculated from bone profiles may be a sensitive descriptor of trabecular bone structure.

Effects of galvanic stimulation of the mastoid process on the gastric motility induced by caloric stimulation

The effects of galvanic stimulation to the mastoid portion on the vestibuloautonomic symptoms induced by caloric stimulation, such as nausea, vomiting, and vertigo, were evaluated in this study. Gastric motility was measured by electrogastrography (EGG) in 20 healthy volunteers (11 male and nine female) aged 20-30 (average: 25.4) years. Electrical stimulation of the mastoid process with 1.0-3.0 mA, 1.0 ms, 100 Hz was applied using a bipolar-biaural method during caloric stimulation of the external auditory canal. The dominant frequency and power of EGG were determined using running spectral frequency analysis and the time-course of EGG was evaluated in a pseudo three dimensional graphic. Frequency of EGG was classified into normogastria with 3 cpm, bradygastria with lower than 3 cpm, and tachygastria with higher than 3 cpm. At quiescent period, normogastria was 78.7 +/- 3.7%, bradygastria 5.0 +/- 1.1%, and tachygastria 16.4 +/- 3.7%. Caloric stimulation with warm water in the unilateral ear and cold water in the contralateral ear elicited vestibuloautonomic symptoms, with accompanied decreases in normogastria (57.7 +/-4.6%, P < 0.01) and increases in tachygastria (34.8 +/- 4.8%, P < 0.01). Cathodal stimulation to the mastoid process ipsilateral to cold water irrigation during caloric stimulation restored normal pattern of gastric motility: normogastria in 77.1 + 5.3% and tachygastria in 19.3 +/- 4.7%, and relieved vestibuloautonomic symptoms. Cathodal stimulation to the inhibited vestibular system ameliorates the vestibular symptoms induced by caloric stimulation.

Effects of citicoline combined with thrombolytic therapy in a rat embolic stroke model

BACKGROUND AND PURPOSE

We sought to evaluate the effects of the combination of cytidine-5'-diphosphocholine (citicoline) and thrombolysis on infarct size, clinical outcome, and mortality in a rat embolic stroke model.

METHODS

Eighty-three Sprague-Dawley rats were embolized in the carotid territory with a single fibrin embolus and randomly assigned to the following treatment groups: (1) control (saline), (2) citicoline 250 mg/kg, (3) citicoline 500 mg/kg, (4) recombinant tissue plasminogen activator (rtPA) 5 mg/kg, (5) rtPA 5 mg/kg plus citicoline 250 mg/kg, and (6) rtPA 5 mg/kg plus citicoline 500 mg/kg. rtPA was administered as a continuous intravenous infusion over 45 minutes starting 45 minutes after embolization; citicoline was given intraperitoneally 30 minutes and 24, 48, and 72 hours after embolization. At 96 hours, the brains were fixed and stained by hematoxylin-eosin, and infarct volumes were measured. Neurological scores were determined daily.

RESULTS

The median infarct size, measured as percentage of the affected hemisphere, in the control group was 37% (interquartile range, 26% to 69%) compared with 22% (5% to 52%; P=NS) in group 2, 11% (5% to 34%; P=NS) in group 3, 24% (12% to 31%; P=NS) in group 4, 11% (3% to 22%; P=0.02) in the combined group 5, and 19% (9% to 51%; P=NS) in group 6. The infarct size was significantly reduced in the combined citicoline+rtPA-treated groups to a median of 13% (5% to 30%; P<0.01). Citicoline 500 mg/kg and citicoline combined with rtPA also promoted functional recovery.

CONCLUSIONS

These results demonstrate that the combination of low-dose citicoline and rtPA significantly reduced infarct size in this focal ischemia model.

Interim analyses with delayed observations in clinical trials

The interim analyses based on group sequential procedures are not convenient if the response time relative to the patient accrual rate is long. Since in most trials patients are accrued and randomized continuously, the response data from those already randomized will continue to accumulate when a trial terminates at an interim test. One should analyse all observations received after the trial terminates along with the data that led to the decision to terminate the trial. Although the most likely case is that the combined results are significant, it could happen that the combined results are not significant. We examined the likelihood of such an event. Our study indicated that the O'Brien-Fleming type of group sequential tests with conservative boundaries in the early stages protects from such an unsettling event.

Inflammatory pseudotumor of the liver in patients with recurrent pyogenic cholangitis: CT-histopathologic correlation

PURPOSE

To correlate computed tomographic (CT) features of inflammatory pseudotumors of the liver with histopathologic results in patients with recurrent pyogenic cholangitis.

MATERIALS AND METHODS

CT features of 13 cases of inflammatory hepatic pseudotumor in 10 patients with recurrent pyogenic cholangitis were reviewed. Diagnosis was made by means of surgical resection in all patients. CT scans were analyzed for the appearance of masses and ancillary findings in correlation with the histopathologic findings in each resected specimen.

RESULTS

The masses were 2.0-7.0 cm (mean, 3.5 cm). At nonenhanced CT, the masses appeared as ill-defined, hypoattenuating lesions. At contrast material-enhanced CT, the masses exhibited central hypoattenuating areas with an iso- or hyperattenuating thickened periphery in four cases and a multiseptate appearance with hyperattenuating internal septa and periphery in nine cases. CT-histopathologic correlation showed that the central hypoattenuating area indicated the presence of chronic inflammatory infiltrates with foamy histiocytes, plasmacytes, and lymphocytes, while iso- or hyperattenuating areas in the periphery and internal septa of the mass represented fibroblastic proliferation. All patients had CT features of recurrent pyogenic cholangitis, such as hepatolithiasis, intrahepatic duct stricture and dilatation, common bile duct calculi, pneumobilia, or parenchymal atrophy.

CONCLUSION

Although CT features are not specific, inflammatory pseudotumor should be included in the differential diagnosis in patients with recurrent pyogenic cholangitis and a hepatic mass detected at CT.

Effect of delayed observations on Bayesian decisions for binary data

A Bayesian decision rule for early termination of an experimental study of binary responses is presented. This early termination occurs when the predictive probability of reversing the decision when utilizing the delayed observations is small. The proposed approach utilizes Bayesian inferential tools such as Bayes factors and predictive distributions. A simulation study is conducted to evaluate the performance of the proposed approach. Some guidelines are given to determine when the study should be terminated early and when the investigator should wait for delayed observations before making a conclusion.

Early cerebral blood volume after severe traumatic brain injury in patients with early cerebral ischemia

Recent early cerebral blood flow (CBF) studies on severe head injury have revealed ischemia in a substantial number of patients with a variety of CT diagnoses. However, the underlying derangements causing this early ischemia are unknown, but cerebral blood volume (CBV) measurements might offer some insight into this pathology. Therefore, acute CBF and CBV measurements were performed in 51 adult severely head injured patients within 24 hours after injury. For this purpose the stable Xenon-CT procedure was used for assessment of CBF, and a dynamic CT imaging technique was used for determining CBV. All ischemic patients were found among 35 subjects studied within 4 hours after injury (31%). Based on the occurrence of regional ischemia seven patients with varying anatomical lesions on CT were selected for comparison between CBF and CBV in ischemic and non-ischemic areas. Both CBF (p < 0.02) and CBV (p < 0.02) exhibited significantly lower values in the ischemic zones. Ten patients showing a subdural hematoma (SDH) were studied preceding surgery and seven were ischemic in at least one lobe or brainstem. Ipsilateral CBF was lower than CBF in the contralateral side (p < 0.1). CBV at the ipsilateral side was significantly reduced compared to the contralateral side (p < 0.05). Follow-up studies were performed in three ischemic patients and in one borderline ischemic patient immediately after removal of SDH showing a striking increase in both CBF and CBV. In the remaining 26 subjects follow-up studies were obtained between day 2 and day 8 and all patients showed CBF values within the normal range. These data evidently support the suggestion that compromise of the microvasculature is the cause of early ischemia, rather than vasospasm of the larger conductance vessels. This has implications for acute post-traumatic therapeutical strategies and management of the severely head injured patient and may lead to testing of new drugs that are effective in interfering with processes causing this ischemia.

Factors affecting excitatory amino acid release following severe human head injury

OBJECT

Recent animal studies demonstrate that excitatory amino acids (EAAs) play a major role in neuronal damage after brain trauma and ischemia. However, the role of EAAs in patients who have suffered severe head injury is not understood. Excess quantities of glutamate in the extracellular space may lead to uncontrolled shifts of sodium, potassium, and calcium, disrupting ionic homeostasis, which may lead to severe cell swelling and cell death. The authors evaluated the role of EEAs in human traumatic brain injury.

METHODS

In 80 consecutive severely head injured patients, a microdialysis probe was placed into the gray matter along with a ventriculostomy catheter or an intracranial pressure (ICP) monitor for 4 days. Levels of EAAs and structural amino acids were analyzed using high-performance liquid chromatography. Multifactorial analysis of the amino acid pattern was performed and its correlations with clinical parameters and outcome were tested. The levels of EAAs were increased up to 50 times normal in 30% of the patients and were significantly correlated to levels of structural amino acids both in each patient and across the whole group (p < 0.01). Secondary ischemic brain injury and focal contusions were most strongly associated with high EAA levels (27+/-22 micromol/L). Sustained high ICP and poor outcome were significantly correlated to high levels of EAAs (glutamate > 20 micromol/L; p < 0.01).

CONCLUSIONS

The release of EAAs is closely linked to the release of structural amino acids and may thus reflect nonspecific development of membrane micropores, rather than presynaptic neuronal vesicular exocytosis. The magnitude of EAA release in patients with focal contusions and ischemic events may be sufficient to exacerbate neuronal damage, and these patients may be the best candidates for treatment with glutamate antagonists in the future.

Primary end points in phase III clinical trials of severe head trauma: DRS versus GOS. The American Brain Injury Consortium Study Group

The most commonly used primary end point in phase III clinical trials of severe head trauma is the Glasgow Outcome Scale (GOS), usually dichotomized to favorable (good) and unfavorable (poor) outcomes. The alternative endpoints include the Disability Rating Scale (DRS) with a 31-point scale. The purpose of this study was to compare DRS and GOS using the data collected from two completed clinical trials organized by the American Brain Injury Consortium and two pharmaceutical companies. The two outcome scales were examined and compared in terms of the correlation between the two scales, sensitivity, and p values between the differences between two arms of the trials. There was no indication that the DRS was more sensitive or advantageous relative to the dichotomized or four-category GOS. In addition, the highly significant correlation between the two outcome scales (r = 0.95; p < 0.0001) could not justify the DRS as an end point. The other problems with the DRS include the difficulty of determining the clinically meaningful difference in designing trials. The study suggested that the GOS is a better primary end point than DRS.

Sample size in clinical trials with dichotomous endpoints: use of covariables

In many clinical trials, the primary endpoint is dichotomous. In this article, we examine the possibility of reducing the required sample size by removing variation associated with baseline covariables. Three measures are used to study the size of the reduction. Simulation studies based on a database of head trauma and of stroke patients suggested that a substantial reduction in the sample size can be achieved when the correlation between the endpoint and covariables is strong. A simple ad hoc formula for approximating the required sample size is proposed.

Regional cerebral blood volume after severe head injury in patients with regional cerebral ischemia

OBJECTIVE

Recent early cerebral blood flow (CBF) studies in cases of severe head injury have revealed ischemia in a substantial number of patients with a variety of computed tomographically demonstrated diagnoses. The underlying derangements causing this early ischemia are unknown, but cerebral blood volume (CBV) measurements might offer some insight into this pathological abnormality.

METHODS

For this purpose, stable xenon-enhanced computed tomography was used for assessment of CBF, and a dynamic computed tomographic imaging technique was used for determining CBV. Based on the occurrence of regional ischemia (CBF < 20 ml/100 g/min), seven patients with varying anatomic lesions revealed by computed tomography were identified for comparison between CBF and CBV in ischemic and nonischemic areas.

RESULTS

Both CBF (15+/-4.3 versus 34+/-11 g/min, P < 0.002) and CBV (2.5+/-1.0 versus 4.9+/-1.9 ml/100 g) exhibited significantly lower values in the ischemic zones than in the nonischemic zones (means+/-standard deviations). Among 26 patients with or without ischemia observed during their initial follow-up studies, which were conducted between Days 2 and 8, all patients showed CBF and CBV values within the low-normal range.

CONCLUSION

These data evidently support the suggestion that compromise of the microvasculature is the cause of early ischemia, rather than vasospasm of the larger conductance vessels.

Continuous monitoring of cerebral substrate delivery and clearance: initial experience in 24 patients with severe acute brain injuries

OBJECTIVE

Current neuromonitoring techniques in severe human head injury often fail to detect the causes of clinical deterioration. A sensor is now available for continuous monitoring of brain oxygen tension, carbon dioxide tension, and pH values. In this study, brain tissue oxygen tension was used to differentiate patients at risk for brain ischemia and to predict outcome.

METHODS

The multiparameter sensor was inserted into brain tissue, along with a standard ventriculostomy catheter and a microdialysis probe, in 24 patients. Lactate and glucose were measured by high-pressure liquid chromatography in hourly dialysate samples.

RESULTS

Patients who experienced a good recovery (n = 8) sustained a mean brain partial oxygen pressure of 39 +/- 4 mm Hg, brain partial carbon dioxide pressure (PCO2) of 50 +/- 8 mm Hg, and a brain pH of 7.14 +/- 0.12. Patients with moderate to severe disability (n = 6) sustained a mean brain partial oxygen pressure of 31 +/- 5 mm Hg, brain PCO2 of 47 +/- 2 mm Hg, and a brain pH of 7.11 +/- 0.12. Ten patients who died or remained vegetative sustained a mean brain partial oxygen pressure of 19 +/- 8 mm Hg, a brain PCO2 of 64 +/- 21 mm Hg, and a brain pH of 6.85 +/- 0.41. Mean brain PCO2 levels of 90 to 150 mm Hg were consistently observed after cerebral circulatory arrest or brain death. Dialysate lactate and glucose were less clearly correlated to outcome than brain oxygen tension. Dialysate glucose was extremely low in all patients and zero in most patients who died.

CONCLUSION

Brain oxygen pressure, brain carbon dioxide pressure, and brain pH measurements, as well as a microdialysis probe for glucose and lactate analysis, may optimize the management of comatose neurosurgical patients by allowing a fuller understanding of the dynamic factors affecting brain metabolism.

Interim analyses and early termination of clinical trials

The group sequential tests (GST) are appropriate for performing interim analyses in clinical trials. Various GST are reviewed and compared in this paper in terms of the expected sample size, the maximum sample size, and other practical aspects. Also discussed are the p-values of the significant differences for GST. Common problems and difficulties of using GST in practice are examined. One problem is difficulties associated with the delayed data accumulated after a trial is terminated at an interim test. The GST with O'Brien-Fleming type of boundaries are found to be safe in dealing with delayed observations. Possible approaches for performing futility analyses are illustrated with examples. It is recommended that futility analysis with GST be built into the design of large clinical trials.