[All levels miniplate fixation and a modified hybrid fixation method in expansive open-door cervical laminoplasty: a retrospective comparative study]

OBJECTIVE

To retrospectively compare the effect of alternate levels miniplate and anchor fixation with the effect of all levels miniplate fixation in expansive open-door cervical laminoplasty (EOLP).

METHODS

Patients with cervical spondylosis underwent EOLP between July 2015 and June 2016 were included in the study. There were 33 patients in the alternate group (alternate levels miniplate and anchor fixation group) and 34 patients in the miniplate group (all levels miniplate fixation group). Neurological function was evaluated with the Japanese Orthopedic Association (JOA) score and degree of pain was assessed with the visual analogue scale (VAS) score. Basic clinical and surgical data, complication rates and medical costs of the two groups were compared. In addition, radiological examinations were performed pre- and post-operatively and at the final follow-up. Relative imaging data such as anteroposterior diameter (APD), cervical curvature index (CCI) and open angle were collected and compared.

RESULTS

(1) The mean follow-up time was 18.6 months in the alternate group and 18.9 months in the miniplate group. There were no significant differences in operation time, intraoperative blood loss, perioperative complication rates, post-operative hospital stays, VAS scores and neurological recovery rates preoperatively and at the final follow-up between the two groups. (2) Additionally, no obvious differences were observed about CCIs and APDs at the three follow-up time points between the two groups. Post-operative open angles at C4 and C6 in the alternate group were significantly smaller than those in the miniplate group. However, there were no significant differences in C3, C5 and C7 open angles between the two groups post-operatively. Notably, no significant differences were detected about the open angles at all levels between the two groups at the final follow-up. (3) When comparing radiologic data at different time points in each group, CCIs and open angles at each level had no significant differences, but APDs after surgery and at the final follow-up were significantly larger than pre-operative APDs. (4) Total costs in the alternate group were significantly lower than those in the miniplate group.

CONCLUSION

The two surgical methods showed almost the same neurological recovery rates and complication rates. However, use of alternate levels miniplate and anchor fixation in EOLP can reduce medical expenses.

Acute myocardial infarction caused by aortic dissection

Clinical presentation of aortic dissection is similar to that of acute myocardial infarction (AMI). Clinical differential diagnoses from lethal chest pain in emergency department include AMI, aortic dissection, pulmonary embolism, tension pneumothorax, etc. Thrombolytic therapy for recanalization of thrombotic occluded coronary artery in AMI must be considered, but it is absolutely contraindicated for aortic dissection. However, AMI secondary to aortic dissection is a rare condition, which might be caused by compression of the coronary arteries by a hematoma or extension of the dissection into the coronary arterial wall. Surgery is the first choice for AMI secondary to aortic dissection caused by extension of dissection into the coronary arterial wall. We present a case of inferior wall AMI caused by type I aortic dissection with presentation of chest pain and hemiparaplegia of right lower limb.

Calcium oxalate is the main toxic component in clinical presentations of alocasis macrorrhiza (L) Schott and Endl poisonings

Alocasia macrorrhiza (L) Schott and Endl is called Hai Yu, Tien Ho, Shan Yu, Kuan Yin Lien, Tu Chiao lien, Lao Hu Yu and Lang Du in Chinese. Its common English name is Giant Elephant's Ear. The toxic effects of A macrorrhiza arise from sapotoxin and include gastroenteritis and paralysis of the nerve centers. From 1985 to 1993 all individuals who called the Poison Control Center asking for information regarding macrorrhiza were included in this retrospective study. A questionnaire filled out by the Poison Control Center staff collected the demographic data of the victim, the reason for consumption, the prescribed part, clinical symptoms and signs of the victim, and medical outcome of poisonings. Among 27 cases of A macrorrhiza poisoning, the age was 1.5 to 68 y with 12 females and 15 males. One had skin contact and 1 had eye contact. In the 25 cases that consumed the plant leaf or tuber either raw or cooked, the primary symptom was in injected sore throat and the secondary symptom was numbness of the oral cavity. Some patients had salivation, dysphonia, abdominal pain, ulcers of the oral cavity, difficulty in swallowing, thoracodynia, chest tightness and swollen lips. We believe the presence of sapotoxin alone is not sufficient to explain the injected swollen and ulcerative lesions. Calcium oxalate is reported distributed in the entire plant and results in inflammation of the oral cavity and mucous membranes just as our patients had.

[Induction chemotherapy with docetaxel plus cisplatin (TP regimen) followed by concurrent chemoradiotherapy with TP regimen versus cisplatin in treating locally advanced nasopharyngeal carcinoma]

BACKGROUND AND OBJECTIVE

Clinical trials on docetaxel plus cisplatin (DDP) (TP regimen) in treating nasopharyngeal carcinoma (NPC) are still uncertain due to limited samples. This study was to compare the short-term efficacy and toxicity of induction chemotherapy with TP regimen followed by concurrent chemoradiotherapy with TP regimen versus DDP in treating locally advanced NPC.

METHODS

Fifty-seven patients with stage T3-4N2-3M0 NPC diagnosed pathologically from December 2005 to December 2006 were randomized into TP group (30 patients) and DDP group (27 patients). Both groups received TP regimen as induction chemotherapy with docetaxel (70 mg/m(2)) on Day 1 and DDP (80 mg/m(2)) on Day 2, repeating every 21 days for 2 cycles. For concurrent chemotherapy, TP group were administered docetaxel (60 mg/m(2)) on Day 1 and DDP (80 mg/m(2)) on Day 2; DDP group were administered DDP (80 mg/m(2)) on Day 1. Both schedules were repeated every 21 days for 2 cycles. Linear accelerator was used as radioactive source. Irradiation field was designed with CT-simulation and conventional fractions.

RESULTS

The 57 patients received 111 cycles of induction chemotherapy, and 53 of them received 103 cycles of concurrent chemotherapy; four patients ceased induction chemotherapy and three ceased concurrent chemotherapy. All patients completed radiotherapy. The major toxicity of induction chemotherapy was hematologic toxicity; the main toxicities of concurrent chemoradiotherapy were hematologic toxicity and mucositis. The occurrence rates of Grade 3-4 leucopenia and Grade 3-4 neutropenia were significantly higher in TP group than in DDP groups (p <0.05). In concurrent chemoradiotherapy, the application rate of granulocyte colony stimulating factor (G-CSF) was significantly higher in TP group than in DDP group (100% vs. 72.0%, p<0.05). After concurrent chemoradiotherapy, the complete remission (CR) rates of the nasopharynx and regional lymph nodes were 93.3% and 92.9% in TP group, and were 96.3% and 91.3% in DDP group (p>0.05).

CONCLUSIONS

The short-term efficacy of induction chemotherapy with TP regimen followed by concurrent chemoradiotherapy with TP regimen on locally advanced NPC is similar to that of TP regimen followed by concurrent chemoradiotherapy with DDP. The toxicity of the former schedule is severer than that of the latter, but it is tolerable with the use of G-CSF. The long-term efficacy of induction chemotherapy with TP regimen followed by concurrent chemoradiotherapy with TP regimen need to be further studied.

[Application of three questionnaires in screening obstructive sleep apnea in patients with chronic obstructive pulmonary disease]

Objective: To evaluate the clinical value of three questionnaires [Sleep Apnea Clinical Score (SACS), Berlin Questionnaire (BQ), and Epworth Sleepiness Scale (ESS)] in screening obstructive sleep apnea (OSA) in patients with chronic obstructive pulmonary disease (COPD). Methods: A total of 198 patients with COPD were assessed the likelihood of OSA by using the SACS, BQ, ESS, which was confirmed by the overnight polysomnography (PSG). The receiver operating characteristic curve (ROC) and the calculated likelihood ratios were used to compare the values of three scoring systems in predicting OSA in COPD patients. Results: The patients had an average age of (65.5±9.3) years and 92.9% (184 cases) of which were male, 14 cases (7.1%) were female; 27 cases (13.6%) had a high probability of OSA by SACS assessment, 61 cases (30.8%) had a high probability screened by BQ, and 72 (36.4%) had OSA high probability by ESS. The diagnosis of OSA in 75 patients (37.9%) were confirmed by PSG. OSA did not be accurately predicted by ESS screening in patients with COPD, with a ROC curve area under the curve of 0.592 (95% CI: 0.509-0.674, P=0.053). BQ had an area under the ROC curve of 0.706 (95% CI: 0.626-0.779, P<0.001). However, the prediction of SACS was much better, with an area under the ROC curve of 0.810 (95% CI: 0.737-0.871, P<0.001). Conclusion: SACS is superior to BQ and ESS in predicting OSA in this group of patients with COPD.

Haloperidol plasma concentrations in Taiwanese psychiatric patients

Haloperidol and reduced haloperidol are interconverted. The plasma concentrations of these two butyrophenones have been suggested to be important factors in determining the clinical effect of haloperidol treatment. The steady-state plasma concentrations of haloperidol and reduced haloperidol were measured in 322 Taiwanese schizophrenic patients using high performance liquid chromatography. The daily doses of haloperidol varied from 5 to 200 mg (mean +/- SD, 35.3 +/- 34.6 mg). There was a positive correlation between plasma concentrations and doses, following the equation: haloperidol concentration (ng/mL) = 0.88 x dose (mg/day)-1.66. However, the interpatient variation in haloperidol concentrations was up to ten-fold even in patients receiving the same dose (20 mg/day, n = 88). The expected values were about 10% to 50% higher than those reported in Caucasian patients. The plasma reduced haloperidol concentrations were significantly lower than, and correlated with, those of haloperidol in patients with haloperidol levels lower than 25 ng/mL. However, once haloperidol exceeded 25 ng/mL, reduced haloperidol levels rapidly elevated and appeared significantly higher than haloperidol levels. While haloperidol could reach its steady state in about 1 week, reduced haloperidol needed at least 4 weeks to do so. Haloperidol doses of less than 30 mg/day and plasma concentrations lower than 25 ng/mL are recommended for most Chinese patients.

Evidence of genetic heterogeneity of hypertrophic cardiomyopathy in eight Chinese patients

BACKGROUND

The genetic basis causing hypertrophic cardiomyopathy (HCM) was found due to missense mutations in cardiac beta-myosin heavy chain (beta-MHC), cardiac troponin T and alpha-tropomyosin genes in certain affected families. However, most mutations and majority of the affected families were reported to be related to beta-MHC gene. Till now, 20 different missense mutations of beta-MHC gene identified in more than 40 independent families were distributed in exons 8, 9, 13, 14, 15, 16, 19, 20, 21 and 23. Therefore, we chose these 10 exons for screening.

METHODS

Eight probands with HCM and 1 normal control were included for screening. 32P-labeled PCR products of these 10 exons of beta-MHC gene were amplified from genomic DNA obtained from peripheral lymphocytes. PCR-DNA single strand conformation polymorphism (PCR-SSCP) analysis was performed using electrophoresis with polyacrylamide gels with and without 10% glycerol. Large amount copies of these 10 exons were also made from genomic DNA with PCR. Detection of sequencing variation of these exons was determined by the direct sequencing method with dideoxy chain termination method and 35S.

RESULTS

No abnormal extra bands were noted on PCR-SSCP analysis. Sequencing analysis showed no missense mutation in these probands.

CONCLUSIONS

Genetic heterogeneity of HCM is evident in Chinese patients with HCM.

Evaluation of 3D Measuring Methods for Body Surface Damage and Scars

Objective To assess the accuracy and reliability of the two 3D measuring methods, structured-light scanning and single-camera photogrammetry in forensic body surface damage and scar measurement. Methods The measuring results of 86 injuries by the ruler method, structured-light scanning and single-camera photogrammetry were compared and evaluated. The area measuring results of 13 simulated scars by the structured-light scanning, single-camera photogrammetry, Photoshop lasso pixel method and PDF reading software were compared and evaluated. The time consumed was recorded. The known specification information of the stickers was used as the standard value to compare the measuring accuracy of the ruler method, structural-light scanning and single-camera photogrammetry, and to calculate the root mean square error （RMSE）. The consistency evaluation of intraclass correlation coefficient （ICC） for the repeatability of 3 measuring results obtained by different operators and the same operator. Results The differences in results of the two 3D measuring methods and the ruler method had no statistical significance; the differences between measuring results made by the structured-light scanning, single-camera photogrammetry and PDF reading software and that of the Photoshop lasso pixel method had no statistical significance. The post-processing of the single-camera photogrammetry consumed more time than that of other methods. When the long-distance group （10-40 cm） was measured, the results obtained by the ruler method were shorter than the standard value. The RMSE value results were structured-light scanning < single-camera photogrammetry < ruler method. The ICC value intragroup and intergroup were greater than 0.99. Conclusion Both structured-light scanning and single-camera photogrammetry can be applied in recording and measuring forensic body surface damage. The former has better performance in measurement accuracy and stability, while the latter has better color performance but longer post-processing time.

[5-HT(2A) receptor/protein kinase C pathway in mediating long-term facilitation of carotid sinus nerve discharge in chronic intermittent hypoxia rats]

Objective: To explore the role of 5-HT(2A)R/PKC pathway in mediating long-term facilitation (LTF) of carotid sinus nerve (CSN) discharge in chronic intermittent hypoxia (CIH) rats. Methods: With number table, 24 adult SD rats were randomly divided into saline control group (group A, n=6), 5-HT(2A)R antagonist (ketanserin) group (group B, n=6), PKC inhibitor (PKC θ-pseudosubstrate) group (group C, n=6) and combined ketanserin with PKC θ-pseudosubstrate group (group D, n=6). All rats were placed into the animal chambers for CIH treatment, 8 h per day (from 9: 00 to 17: 00) for 4 consecutive weeks. 28 days later, 5 min × 3 times of stimulation with acute intermittent hypoxia (AIH) were given, after that, stable CSN discharge activities were recorded and compared before and after intravenous injection of saline (group A), ketanserin (group B), PKC θ-pseudosubstrate (group C) or ketanserin + PKC θ-pseudosubstrate (group D), respectively. Results: There were no significant difference in the baseline (before AIH stimulation) average peak amplitude of CSN discharge among the four groups (P>0.05). In group A, the amplitude of CSN discharge at 30 min and 60 min after AIH were (5.01 ± 0.53) μV and (4.95 ± 0.34) μV respectively, which were significantly higher than that before AIH (P<0.01). The results implied that the CSN LTF could be induced by AIH in CIH pre-treatment rats. In group B, the amplitude of CSN discharge at 30 min and 60 min after AIH were (3.79 ± 0.42) μV and (3.73 ± 0.46) μV, respectively, which were still significantly higher than that before AIH (P<0.01), showing that carotid sinus nerve LTF couldn't be completely blocked by 5-HT(2A)R antagonist in rats. After injection of PKC θ-pseudosubstrate or ketanserin + PKC θ-pseudosubstrate in group C or D, there were no significant differences in CSN discharge amplitude before and after AIH (P>0.01), suggesting that inhibition of PKC alone or 5-HT(2A)R/PKC pathway could completely block the LTF of CSN. Conclusion: 5-HT(2A)R/PKC pathway was involved in mediating long-term facilitation of carotid sinus nerve discharge in CIH rats.

Induction-concurrent chemoradiotherapy with or without sintilimab in patients with locoregionally advanced nasopharyngeal carcinoma in China (CONTINUUM): a multicentre, open-label, parallel-group, randomised, controlled, phase 3 trial

BACKGROUND

Anti-PD-1 therapy and chemotherapy is a recommended first-line treatment for recurrent or metastatic nasopharyngeal carcinoma, but the role of PD-1 blockade remains unknown in patients with locoregionally advanced nasopharyngeal carcinoma. We assessed the addition of sintilimab, a PD-1 inhibitor, to standard chemoradiotherapy in this patient population.

METHODS

This multicentre, open-label, parallel-group, randomised, controlled, phase 3 trial was conducted at nine hospitals in China. Adults aged 18-65 years with newly diagnosed high-risk non-metastatic stage III-IVa locoregionally advanced nasopharyngeal carcinoma (excluding T3-4N0 and T3N1) were eligible. Patients were randomly assigned (1:1) using blocks of four to receive gemcitabine and cisplatin induction chemotherapy followed by concurrent cisplatin radiotherapy (standard therapy group) or standard therapy with 200 mg sintilimab intravenously once every 3 weeks for 12 cycles (comprising three induction, three concurrent, and six adjuvant cycles to radiotherapy; sintilimab group). The primary endpoint was event-free survival from randomisation to disease recurrence (locoregional or distant) or death from any cause in the intention-to-treat population. Secondary endpoints included adverse events. This trial is registered with ClinicalTrials.gov (NCT03700476) and is now completed; follow-up is ongoing.

FINDINGS

Between Dec 21, 2018, and March 31, 2020, 425 patients were enrolled and randomly assigned to the sintilimab (n=210) or standard therapy groups (n=215). At median follow-up of 41·9 months (IQR 38·0-44·8; 389 alive at primary data cutoff [Feb 28, 2023] and 366 [94%] had at least 36 months of follow-up), event-free survival was higher in the sintilimab group compared with the standard therapy group (36-month rates 86% [95% CI 81-90] vs 76% [70-81]; stratified hazard ratio 0·59 [0·38-0·92]; p=0·019). Grade 3-4 adverse events occurred in 155 (74%) in the sintilimab group versus 140 (65%) in the standard therapy group, with the most common being stomatitis (68 [33%] vs 64 [30%]), leukopenia (54 [26%] vs 48 [22%]), and neutropenia (50 [24%] vs 46 [21%]). Two (1%) patients died in the sintilimab group (both considered to be immune-related) and one (<1%) in the standard therapy group. Grade 3-4 immune-related adverse events occurred in 20 (10%) patients in the sintilimab group.

INTERPRETATION

Addition of sintilimab to chemoradiotherapy improved event-free survival, albeit with higher but manageable adverse events. Longer follow-up is necessary to determine whether this regimen can be considered as the standard of care for patients with high-risk locoregionally advanced nasopharyngeal carcinoma.

FUNDING

National Natural Science Foundation of China, Key-Area Research and Development Program of Guangdong Province, Natural Science Foundation of Guangdong Province, Overseas Expertise Introduction Project for Discipline Innovation, Guangzhou Municipal Health Commission, and Cancer Innovative Research Program of Sun Yat-sen University Cancer Center.

TRANSLATION

For the Chinese translation of the abstract see Supplementary Materials section.

Plasma homovanillic acid in schizophrenics: supportive evidence for the two-subtype hypothesis

Plasma levels of homovanillic acid (pHVA), a major metabolite of dopamine (DA), were measured in a group of 51 schizophrenic inpatients before and during 6 weeks of neuroleptic treatment. Steady-state plasma drug concentrations were monitored in parallel with pHVA. Good responders (n = 22) had higher pretreatment pHVA levels as compared to poor responders (n = 22). Differential pHVA changes during neuroleptic treatment were also found between each group. The two groups did not differ significantly in terms of age, duration of illness, severity of presenting symptoms, neuroleptic, dose, or plasma drug concentration. Two hypothetical subtypes in the group of schizophrenics were proposed.

Snakebite complicated with Vibrio vulnificus infection

Snakebite may be complicated with bacteria infections, most of which are Gram-negative bacillus. Snakebite complicated with Vibrio vulnificus infection has not been reported previously. Vibrio vulnificus infection is characterized by a necrotizing wound infection similar to the local lesion of severe snakebite. In Vibrio infections, aggressive debridement with the administration of strong antibiotics as early as possible is the only effective treatment. We report a 79-y-o man who suffered from snakebite on the right palm with rapid progression of hemorrhagic bulla, necrotizing fasciitis, compartment syndrome, and septic shock. Vibrio vulnificuswas cultured from necrotic tissue after aggressive debridement and fasciotomy. The patient recovered from antibiotic treatment and several courses of reconstruction surgery. Severe bacteria infection, such as caused by Vibrio vulnificus, should be considered in snakebite cases refractory to antivenin dosage.

[Expression and regulation of CD36 mRNA in granulosa cells and its relation with clinical characteristics of polycystic ovary syndrome]

OBJECTIVE

To study the expression of CD36 mRNA in granulosa cells (GCs) of patients with polycystic ovary syndrome (PCOS) and the impact of testosterone, insulin and PPARγ agonist rosiglitazone on GCs.

METHODS

The expression of CD36 mRNA inGCs of patients with PCOS and normal controls were assayed byreal-time PCR.The level of CD36 mRNA after treatment with testosterone, insulin, and rosiglitazone in GCs ofnormal controls were also tested by real-time PCR.

RESULTS

(1) The expression of CD36mRNA in the GCs of PCOS was significantly higher than that of the controls (P<0.05). (2) When testosterone concentration was 1 nmol/L, CD36 mRNA increased in the GCs, but there was no significantdifference compared to the blank control, (P>0.05). When testosterone concentration was 10 nmol/L, the expression of CD36 mRNA in the GCs was higher than that in the blank control with significant difference (P<0.05). When insulin concentration was 10 nmol/L, the expression of CD36 mRNA increased but the difference was not statistically significant (P>0.05). When insulin concentration was 100 nmol/L, the expression of CD36mRNA in the GCswas higher than that in the blank control (P=0.05). When rosiglitazone concentration was 1nmol/L, the expression of PPARγ mRNA in GCs were significantly increased compared with the blank control (P<0.05). The expression of CD36 mRNA atrosiglitazone concentrationof 10 nmol/Lwere significantly increased compared to the concentration of 1 nmol/L (P<0.05).

CONCLUSION

High testosterone and insulin induced the expression of CD36 mRNA.Rosiglitazone increased CD36 mRNA in a dose-related manner in GCs.Increased CD36 mRNA in the GCs of PCOS may be related to the clinical characteristics of PCOS.

[Effects of dynorphin A1-17 on the activities, immunoreactivities and mRNA expression of cNOS and iNOS in rat spinal cord and their mechanisms]

Intrathecal administration(i.t.) of Dynorphin A1-17(Dyn) 1.25-20 nmol produced dose-dependent paralysis of hindlimbs and tail as well as inhibition of tail flick and foot flinch reflexes. The Dyn spinal neurotoxicity and antinociception involve two differential mechanisms: Enhancement of NMDA-Ca(2+)-NOS/NO pathway and c-fos over-expression in the ventral spinal cord for neurotoxicity, and depression of NMDA receptor and NOS activities in the dorsal spinal cord for antinociception. Both brain-derived constitutive NOS (predominant at early stage) and inducible NOS (at later stage) are detrimental, but endothelial constitutive NOS might be beneficial to Dyn spinal neurotoxicity. Dyn exerts a dualistic modulatory effect on [Ca2+]i of the cultured rat single spinal neurons, inducing sustained overload of intracellular free calcium via both NMDA and kappa receptor activation at higher concentrations, and producing significant inhibition of the depolarization-evoked calcium influx only via kappa receptor activation at lower concentrations. Dyn exposure for 1 h produced direct neurotoxicity in the cultured spinal neurons within an optimal range of concentrations.

Clozapine dosages and plasma drug concentrations

Steady-state plasma concentrations of clozapine and its metabolites, desmethylclozapine and clozapine-N-oxide, were measured in 162 Taiwanese patients with refractory schizophrenia. The daily doses of clozapine ranged from 100 to 900 mg, with a mean value of 379.5 +/- 142.2 mg. A dosage of 400 mg/day or lower was used for most patients (n = 131, 81%). Plasma concentrations of clozapine and its two major metabolites were measured using high performance liquid chromatography with ultraviolet detection. The mean plasma clozapine concentration was 566.9 +/- 398.8 ng/mL. The plasma concentrations of desmethylclozapine and clozapine-N-oxide were 46% and 16% of the concentration of the parent drug, respectively. We used an approximate rule that each 100 mg/day dose results in about 150 ng/mL plasma clozapine. This value is about 30% to 50% higher than that reported in Caucasians. The suggested therapeutic plasma clozapine concentration range of 300 to 700 ng/mL can be achieved with a dose range of 200 to 500 mg/day in most Taiwanese patients. Dose-dependent plasma clozapine concentrations were found. The interpatient variation was up to 12-fold in patients receiving the same dose, eg, 400 mg/day (n = 62). In four of these patients, the plasma drug concentrations were very high (1,446 +/- 114 ng/mL). The application of therapeutic drug monitoring in clozapine-treated patients with refractory schizophrenia is important, not only in dose adjustment, prediction of severe side effects such as seizures, and exploration of drug interactions, but also in the effective use of this expensive drug.

Reduced haloperidol/haloperidol ratios after oral haloperidol and decanoate administration in schizophrenics

1. Haloperidol and reduced haloperidol plasma concentrations were measured in thirteen stable schizophrenic patients that received both oral haloperidol and haloperidol decanoate. 2. Significant correlations between reduced haloperidol/haloperidol ratios from oral haloperidol and haloperidol decanoate occurred at week two and week 16, respectively. 3. The formation of RH was consistent during haloperidol decanoate treatment.

Measurements of heart rate variability in patients with unexplained syncope

BACKGROUND

Syncope is a common clinical issue with complex and heterogenous etiologies. Research has shown a large proportion of syncope remained unexplained, even after serial investigations. Head-up tilt test with or without isoproterenol infusion could elicit a recurrence in most patients with unexplained syncope. Therefore, autonomically neural-mediated bradycardia and hypotension have been cited as the mainstays of the mechanism. Since the autonomic function can be reflected by heart rate rariability, this study proposed to determine 24-hour heart rate variability in patients with unexplained syncope.

METHODS

Fifteen patients, 14 males and 1 female, who were defined as showing symptoms of unexplained syncope, were the subjects of this study. Their ages ranged from 38 years to 79 years. Seventeen healthy volunteers matching in age and sex served as the control group. For each patient and volunteer, 24-hour ambulatory electrocardiographic monitoring was done. Heart rate variability was defined as SDNN index, SDNN, SDANN, rMSSD, and pNN50 in time domain measures; and low, high, and total frequency in frequency domain measures.

RESULTS

There was a significantly lower value at low frequency, high frequency, total frequency, rMSSD, and pNN50 in the syncope group than in the control group (p < 0.05). There was no significant difference in SDNN, SDNN index, SDANN and LF/HF ratio between these two groups.

CONCLUSIONS

Patients with unexplained syncope had autonomic withdrawal; this was the case either in both sympathetic and parasympathetic components without changing the sympatho-vagal balance, or in purely parasympathetic component.

Histamine 2 receptor blocker-ranitidine and sinus node dysfunction

BACKGROUND

Histamine 2 (H2) receptors were observed to be present in the sinus node. H2 receptor blockers could attenuate the histamine-induced increase in sinus rate and could thereby worsen sinus node dysfunction. However, the data pertaining to electrophysiological effects of H2 receptor blocker ranitidine on sinus node function are not available as yet, although bradycardia has been occasionally reported along with ranitidine. The present study evaluates the electrophysiological effects of ranitidine on sinus node function, and also determines the safety of administering ranitidine to patients suffering from sinus node dysfunction.

METHODS

Thirty-nine patients with clinical diagnosis of sinus node dysfunction were selected for this study. Electrophysiological effects of intravenous injection of 150 mg ranitidine on sinus node function was evaluated. Tests were performed for 21 patients in the basal state (Group 1) and for 18 patients (Group 2) after autonomic blockade (propranolol 0.2 mg/kg, and atropine 0.04 mg/kg). The sinus cycle length (SCL), sinus node recovery time (SNRT), corrected sinus node recovery time (CSNRT), sinoatrial conduction time (SACT), atrio-His (AH) and His-ventricle (HV) intervals and blood pressure (BP) before and after ranitidine were analyzed.

RESULTS

In Group 1, changes in SCL, SNRT, CSNRT, SACT, AH, HV and BP were not found to be significant. However, in Group 2, wherein the patients received ranitidine after autonomic blockade, it was observed that ranitidine significantly prolonged SCL (905.0 +/- 31.0 to 1000.0 +/- 40.0 msec, p = 0.001), decreased systolic BP (134.7 +/- 4.7 to 124.8 +/- 4.8 mmHg, p < 0.001), and diastolic BP (71.9 +/- 2.0 to 67.9 +/- 1.9 mmHg, p = 0.001), while the changes in SNRT, CSNRT, SACT, AH and HV were not significant.

CONCLUSIONS

A clinical dose of 150 mg ranitidine must be administered by a slow intravenous infusion for at least 5 minutes in case of patients suffering from sinus node dysfunction. Continuous monitoring of BP and heart rate are necessary, especially in cases of autonomic denervation.

Hemolysis, elevated liver enzymes, and low platelet count (HELLP) syndrome with acute cortical blindness

The coincidence of hemolysis, elevated liver enzymes, and low platelet count (HELLP) syndrome and cortical blindness is an uncommon but very dramatic event. We describe a case of HELLP syndrome complicating with acute cortical blindness before delivery. A 27 year-old woman, gravida 1, para 0, with normal medical history, was referred to our emergency department at the 33th week of gestation due to headache, vomiting, and blurred vision. The ophthalmologic examination showed intact pupillary light reflexes and normal ophthalmoscopic findings, but no light perception in either eye. Brain computed tomography showed normal findings. HELLP syndrome and preeclampsia was diagnosed based on the findings of hypertension and proteinuria as well as laboratory data. Prompt delivery was performed in order to achieve good maternal and neonatal outcomes.

[Comparison between PET-CT and MRI in diagnosing nodal metastasis of nasopharyngeal carcinoma]

BACKGROUND & OBJECTIVE

Nodal metastasis pattern of nasopharyngeal carcinoma (NPC) influences treatment planning. This study was to compare the diagnostic value of integrated positron emission tomography-computed tomography (PET-CT) with that of magnetic resonance imaging (MRI) in detecting nodal metastasis of NPC, and explore the regulation of nodal metastasis of NPC.

METHODS

Clinical data of 105 NPC patients, treated in Cancer Center of Sun Yat-sen University from Jun. 2003 to May 2004, were analyzed. All patients underwent PET-CT and MRI. Findings of PET-CT and MRI were evaluated with the results of follow-up. Distribution of metastatic nodes in different nodal groups was assessed.

RESULTS

Among the 105 patients, nodal metastasis patterns shown on PET-CT and MRI were diverse in 35 patients. Thirty cervical nodes were positive on PET-CT, but negative on MRI; 25 of them were later confirmed positive by follow-up. Thirty-seven cervical nodes were negative on PET-CT, but positive on MRI; 21 of them were confirmed negative by follow-up. Based on the results of follow-up, 77 patients (73.3%) had nodal involvement. Level II nodes were the most frequently involved (87.0%). Along the jugular chain, the frequencies of nodal metastases in level III, level IV, supraclavicular fossa, and level VII were 42.9%, 14.3%, 7.8%, and 1.3%, respectively. The frequency of nodal metastases in retropharyngeal nodes was 70.1%. Cervical nodes involvement without retropharyngeal nodes involvement was seen in 23 patients (29.9%).

CONCLUSIONS

The diagnostic accuracy of PET-CT in detecting nodal metastases of NPC is better than that of MRI. The nodal metastases of NPC reveal a decreasing frequency along the jugular chain. Both retropharyngeal and level II nodes are the first-echelon nodes of NPC.

Pericardiocentesis: a 20 patients study

Emergency pericardiocentesis, guided by a two-dimensional echocardiography, was performed on twenty patients with symptomatic pericardial effusion of various types and causes. There were fourteen men and six women. The underlying causes were: primary lung cancer (6 cases), metastatic cardiac tumors (3 cases), tuberculosis (4 cases), complicated interventional procedures with cardiac chamber or vessel perforations (2 cases), dissecting aortic aneurysm (1 case), systemic lupus erythematous (1 case), idiopathic pericarditis (1 case), bacterial pericarditis (1 case), and myxedema heart disease (1 case). Seventeen cases were performed through the left xipho-sternal approach and 3 cases through the apical approach. None of the patients died as a result of these procedures. A two-dimensional echocardiogram is useful in diagnosing cardiac tamponade as well as in guiding pericardiocentesis, and obtaines highly positive results (20/20). The positive rate of pericardial fluid cytology for malignant cells was 89% (8/9), however, pericardial fluid cultures or direct smear for tuberculosis were negative (0/4). In cancer patients, the mean survival time following pericardiocentesis was 4.2 months (range, 1-7.8 months). We concluded that neoplastic involvement of the pericardium is the most frequent cause of symptomatic pericardial effusion. Pericardiocentesis assisted by a two-dimensional echocardiogram is safe and easy. In addition, pericarditis caused by TB is still significant and must be considered in every case in our nation.