[A prospective study of position selection combined with autologous blood intrathoracic infusion in the treatment of postoperative persistent air leakage with an unexpanded lung]

We prospectively studied 17 patients with spontaneous pneumothorax or giant emphysematous bulla at Rizhao Hospital of Traditional Chinese Medicine from October 2020 to March 2022. All patients underwent thoracoscopic interventional therapy, had experienced continued air leakage for 3 days with closed thoracic drainage postoperatively, had an unexpanded lung on CT, and/or failed to intervention with position selection combined with intra-pleural thrombin injection(referred to as "position plus1.0"). They were all treated with position selection combined with autologous blood (100 ml) and thrombin (5 000 U) intra-pleural injection(referred to as "position plus 2.0").The success rate of the "position plus 2.0" intervention was 16/17, and the recurrence rate was 3/17. There were four cases of fever, four cases of pleural effusion, one case of empyema, and no other adverse reactions. This study has shown that the "position plus 2.0" intervention is safe, effective, and simple for patient with persistent air leakage failed to intervention with"position plus 1.0" after thoracoscopic treatment of pulmonary and pleural diseases related to bulla.

[Effectiveness and safety of medical glue assisted argon plasma coagulation union giant emphysematous bulla volume reduction via thoracoscope on the treatment of spontaneous pneumothorax with subpleural bullae]

Objective: To evaluate the effectiveness and safety of a new treatment protocol that combined "medical glue assisted argon plasma coagulation"(hereinafter called "APC plus") and "giant emphysematous bulla volume reduction"(hereinafter called "one thoracoscope plus one needle") via medical thoracoscopy on the spontaneous pneumothorax patients whose chest high resolution CT (HRCT) showed multiple subpleural bullae (SPB) and at least one SPB≥4 cm in diameter. Methods: A retrospective analysis was performed on the clinical data of 46 cases of spontaneous pneumothorax with multiple SPB(at least one SPB≥4 cm in diameter), 42 males and 4 females, aged from 31 to 79 (68.5±10.3) years,from June 2018 to December 2021 in Rizhao Hospital of Traditional Chinese Medicine. The time of air leakage discontinuance, the disappearance rate and reduction degree of target subpleural blebs one week after operation, the degree of reduction and the incidence of postoperative complications were observed. Two-year follow-up after operation was carried out to assess the recurrence rate and its short- and long-term complications. Results: Among the 46 patients, SPB disappeared or nearly disappeared in 39 cases (84.78%), decreased in number or reduced in volume in 5 cases (10.87%), and remained unchanged in 2 cases (4.35%) after the intervention of "APC Plus"; 40 patients stopped leaking within 1 week and 6 cases stopped leaking over a week. Eleven patients finished the 3-year follow-up, 13 finished 2-year follow-up and 6 finished 1-year follow-up, with only 1 relapse. No serious complications occurred in all these 46 patients. Conclusion: "APC plus" combining with "one thoracoscope plus one needle" is safe and effective in the treatment of pneumothorax patients with multiple subpleural bullae of varying sizes.

[Effect of closed extension tube on preventing airway leakage during artificial airway clearance]

Objective: To explore the role of closed extension tube in preventing airway leakage during artificial airway clearance. Methods: The test lung was connected with a ventilator for mechanical ventilation. The pressure parameters were set as 16/5, 20/6, 24/7, 28/8, 32/9 and 36/10 cmH₂O(1 cmH₂O=0.098 kPa), respectively. The circuit was connected with an open extension tube or a closed extension tube. The ventilator was set with different pressure parameters to observe the changes of airway pressure and tidal volume during airway clearance. Results: (1) The pressure parameters were set as 16/5, 20/6, 24/7, 28/8, 32/9 and 36/10 cmH₂O, and the airway pressures (in cmH₂O) of circuit connected with open extension tube were (15.94±0.27)/(4.81±0.04), (20.09±0.23)/(6.05±0.16), (23.89±0.41)/(6.94±0.06), (27.90±0.22)/(7.71±0.18), (31.92±0.13)/(8.74±0.12)and(35.65±0.31)/(9.72±0.07), respectively.Under the same ventilator pressure parameters, the airway pressures (in cmH₂O) of circuit connected with close extension tube were (16.36±0.06)/(4.85±0.04), (20.54±0.26)/(6.44±0.12), (24.36±0.24)/(7.01±0.33), (28.69±0.25)/(8.07±0.08), (32.97±0.33)/(8.93±0.09), (37.34±0.29)/(9.75±0.08), respectively. The airway pressure of circuit connected with open extension tube was lower than that connected with closed extension tube(P<0.05);with the increase of the pressure setting of the ventilator, the difference of the airway pressure between the two extended tubes gradually increased. When the maximum inspiratory pressure of the ventilator was set 36 cmH₂O, the difference reached 1.69 cmH₂O. (2) The airway pressures (in cmH₂O) dropped from (15.94±0.27)/(4.81±0.04), (20.09±0.23)/(6.05±0.16), (23.89±0.41)/(6.94±0.06), (27.90±0.22)/(7.71±0.18), (31.92±0.13)/(8.74±0.12), (35.65±0.31)/(9.72±0.07) to (13.42±0.4)/(3.15±0.14), (16.81±0.6)/(4.30±0.14), (20.22±0.5)/(5.48±0.45), (23.73±1.4)/(6.25±0.22), (24.78±0.7)/(7.13±0.21), (20.83±0.4)/(6.61±0.19)when the suction port of the open extension tube was opened (P<0.05);and the tidal volume (in L) also decreased from 0.328±0.004, 0.580±0.012, 0.621±0.003, 0.626±0.003, 0.615±0.003, 0.603±0.002 to 0.272±0.008, 0.416±0.051, 0.487±0.047, 0.396±0.116, 0.507±0.022, 0.508±0.079, respectively (P<0.05). The decrease of airway pressure and tidal volume gradually increased with the increase of ventilator setting pressure. When the ventilator setting parameter was 36/10 cmH₂O, the decrease of airway inspiratory pressure was (14.82±0.51) cmH₂O and the maximum reduction of tidal volume was (0.164±0.021)L. (3)The airway pressure (in cmH₂O) was increased to(15.70±0.23)/(4.80±0.33), (19.01±0.81)/(5.71±0.34), (22.27±0.62)/(6.85±0.44), (25.35±2.09)/(7.94±0.16), (28.38±0.46)/(8.96±0.23), (33.34±0.71)/(9.71±0.25) when the suction tube was inserted from the suction port of the open extension tube in the open state, and the tidal volume (in L) was increased to 0.340±0.016, 0.563±0.020, 0.571±0.030, 0.556±0.026, 0.514±0.021, 0.512±0.031 as well.The airway pressure and tidal volume of the ventilation circuit were higher than those in the open state, but still lower than those in the closed state. Compared with the closed state of the suction port, the maximum pressure drop and tidal volume decrease were (3.53±0.46) cmH₂O and (0.101±0.011) L, respectively. (4) The pressure of the ventilator was set between 16/5 cmH₂O to 36/10 cmH₂O. The airway pressure (in cmH₂O) was decreased from (16.26±0.04)/(4.85±0.04), (20.74±0.15)/(6.42±0.11), (25.09±0.31)/(7.10±0.13), (29.38±0.24)/(8.17±0.09), (33.80±0.16)/(9.02±0.17), (37.89±0.19)/(9.83±0.07) to(16.36±0.06)/(4.85±0.04), (20.54±0.26)/(6.44±0.12), (24.36±0.24)/(7.01±0.33), (28.69±0.25)/(8.07±0.08), (32.97±0.33)/(8.93±0.09), (37.34±0.29)/(9.75±0.08), respectively during the insertion of the suction tube from the suction port of the closed extension tube, and the tidal volume (in L) was decreased from0.361±0.005, 0.592±0.003, 0.631±0.001, 0.642±0.007, 0.633±0.007, 0.626±0.08 to 0.335±0.005, 0.588±0.008, 0.631±0.002, 0.638±0.004, 0.628±0.004, 0.618±0.005.The maximum pressure change of the ventilation circuit was (0.83±0.27) cm H₂O and the maximum tidal volume change was (0.008±0.006)L. The changes of airway pressure and tidal volume were significantly lower than those of ventilation circuit connected with open extension tube under the same pressure parameters. Conclusion: The connection of closed extension tube in mechanical ventilation circuit can reduce the airway leakage during artificial airway clearance, which is worthy of clinical recommendation.

[Non-pharmacological prevention and treatment of delirium in the intensive care unit]

Delirium is an acute brain dysfunction that is a common and difficult-to-eliminate problem in the ICU. It is an important factor leading to prolonged hospital stay, increased treatment costs, and long-term cognitive impairment. Nonetheless, compared with the treatment of respiratory failure and its primary disease, the prevention and treatment measurements of delirium have not received enough attention, and its management strategies are still controversial. Evidence-based medicine currently does not support pharmacological approaches to preventing or treating delirium. Instead, it adopts a combination of multiple nonpharmacological methods to manage delirium in ICU patients through standardized evaluation and monitoring under the guidance of doctors and the cooperation of patients and their families.

[Correlation between aspiration and long-term survival of inpatients with chronic obstructive pulmonary disease]

Objective: To retrospectively analyze the high risk factors of death in patients with chronic obstructive pulmonary disease (COPD) and to explore the influence of aspiration on the long-term survival rate of COPD patients. Methods: A retrospective analysis of clinical data of inpatients, who were admitted to the First Affiliated Hospital of Guangzhou Medical University from April 2012 to December 2013 due to COPD exacerbations and had radionuclide aspiration test, was conducted. Meanwhile, we phoned the patients' family members, whose phone numbers were recorded in the electronic patient record system, to follow up the patients' survival status, and learn the causes of death from their death records if patients died during follow-up period. Inquired the resident administration patients belonging to according to their original address to get patient's current contact information if changed. Besides, if family members of patients failed to provide death record, we should look up information concerned from the medical records room of the hospital where they died. Results: The follow-up for the last patient was performed on February 20, 2017.The time span of this study is 58 months, starting from the radionuclide aspiration test for the first patient and ending with the follow-up for the last patient. 16 of the 53 patients(16/53, 30.2%)were tested positive whose average age was slightly higher than patients without aspiration (76.0±6.8 vs 70.9±9.9), but there was no significant difference between them(P=0.064). The aspiration rates among patients over and under the age of seventy were 14/35 and 2/18 respectively, and there was a significant difference between them(P = 0.03). Compared to the aspiration-negative patients, the aspiration-positive patients had higher incidence rate of pneumonia in COPD exacerbations (11/16 vs 9/37, χ²= 9.383, P = 0.002).The major cause of death in the patients with and without aspiration were respectively severe pneumonia and pulmonary encephalopathy(P<0.05 in both cases).Among COPD patients who took radionuclide aspiration test, the median survival time of the patients with and without aspiration were about 3 and 5 years respectively. The high-risk factors influencing long-term survival of the COPD patients with aspiration included ICU-involved medical history and accompanying pneumonia. Conclusions: The incidence rate of aspiration is relatively high in COPD patients over 70 years old. Compared to COPD patients without aspiration, COPD patients with aspiration have higher incidence rate of pneumonia and shorter median survival time. ICU-involved medical history and severe pneumonia are the two high-risk factors influencing long-term survival of COPD patients with aspiration.To improve the survival time of COPD patients with aspiration, we need to attach importance to the prevention and treatment of aspiration.

Simple practical system for directly measuring magnetocaloric effects under large magnetic fields

Direct measurements of the adiabatic temperature change (ΔT_ad) in Gd and Mn_1.15Fe_0.8P_0.5Si_0.5C_0.05 are made using a homemade adiabatic magnetocalorimeter at 260-360 K and 0-7 T. The system uses a servo motor to drive the samples into and out of the magnetic field under a vacuum environment provided by the Physical Property Measurement System (PPMS). The peak values of ΔT_ad for Gd and Mn_1.15Fe_0.8P_0.5Si_0.5C_0.05 at 7 T are 8.71 K and 6.41 K at ambient temperatures of 303 K and 317 K, respectively. Based on the theory model, it is found that ΔT_ad of Gd depends on the 2/3 exponential function of magnetic field H (ΔT_ad ∝ H^2/3), whereas the Mn_1.15Fe_0.8P_0.5Si_0.5C_0.05 compound follows the power law of ΔT_ad ∝ H^0.66-1.04 due to the first order magnetic transitions. Furthermore, using the constructed experimental instrument, the adiabatic temperature change in different magnetic materials, including materials with first/second order magnetic transition and blocks, flakes, or powders, can be directly measured under large magnetic fields and wide temperature spans.

[Impact of HIV and Mycobacterium tuberculosis co-infection on related mortality]

Objective: To understand the impact of HIV and Mycobacterium tuberculosis (MTB) co-infectious (HIV/MTB) on related mortality in Guangxi Zhuang Autonomous Region, provide evidence for the development of a better HIV/MTB co-infection control and prevention program. Methods: A multiple cross-systems check (MCSC) approach was used to confirm the HIV/MTB co-infection individuals on data related to treatment, follow-up, epidemiological comprehensive and Tuberculosis (TB) special report system. Social demography characteristics, incidence of TB among HIV positive individuals, HIV incidence among MTB infection persons etc., were described. We compared the mortalities and related risks between HIV/MTB co-infection and mono HIV positive individuals as well as between the HIV/MTB co-infection and mono MTB infection persons, using both the Chi Square test and the Cox's proportional hazard regression model (Cox). Results: Reported data showed that the incidence of MTB co-infection in the HIV cohort was 17.72% (2 533/14 293), while HIV incidence in the TB patients was 5.57% (2 351/42 205), respectively. The mortality of HIV/MTB co-infection in the HIV/AIDS cohort was 15.16% (384/2 533) within one-year of observation and was significantly higher than the mortality (13.63%,1 603/11 760) of mono HIV positive individuals (P<0.000 1). The percentage of the HIV/AIDS death cases was 19.33% (384/1 987) who registered and died in the 2011 calendar year were caused by MTB co-infection. Among all the HIV/MTB co-infection patients who had been identified from the HIV cohort, 60.05% (1 521/2 533) had initiated ART, 15.48% (392/2 533) had been cured for TB and 27.48% (696/2 533) had been under complete TB regimen. Among the confirmed HIV/MTB cases from the TB cohort, the cure rate of TB was 19.70% (463/2 351) and the percentage of completed TB regimen was 37.26% (876/2 351). The percentage of the individuals whose CD(4)(+) T lymphocyte cells count appeared less than 200 cell/μl was 64.13% (785/1 224), upon the HIV diagnoses were made. Compared with individuals who were under mono HIV infection, the mortality risk on HIV/MTB co-infection was 1.17 times higher during the five-year observation period, then the patients with only mono MTB infection and the mortality risk in patients with HIV/MTB co-infection was 25.68 times higher under the 12-month observation period. Conclusions: Both the incidence and mortality of HIV/MTB appeared high in Guangxi, with mortality and the risk of mortality in the HIV/MTB co-infection group significantly higher than that in both the HIV mono infection and the MTB mono infections groups. Both the rate of antiretroviral treatment coverage and the cure rate of TB treatment should be increased in no time as well as the capability of early TB case-finding among people living with HIV.

[Effect of connecting airbag in different filling state at the front end of piezometric tube in noninvasive ventilation circuit on man-machine synchronization]

Objective: To investigate the effect of connecting airbag in different filling state at the front end of piezometric tube in the noninvasive ventilation circuit on pressure transmission and human-machine synchronization. Method: In test 1, the airbag was connected to a piezometric tube which was placed in a closed container, the filling state of the airbag was regulated, and the pressure inside the container was changed to observe the corresponding pressure change in the piezometric tube. In test 2, the airbag in different filling state was connected at the front end of piezometric tube in noninvasive ventilation circuit. Twelve subjects were connected to the ventilator such that dynamic changes in the pressure inside the mask (Pmask) and piezometric tube (Ptube) could be measured. Data with normal distribution was analyzed by t test, while data with abnormal distribution was analyzed by K-W test. Results: In test 1, the pressure inside the container changed between 0 and 50 cmH(2)O(1 cmH(2)O=0.098 kPa), when the big airbag was filled at 1/5, 2/5, 3/5, 4/5, the medium-sized airbag was filled at 3/5, 4/5, 5/5, and the small airbag was filled at 4/5, the pressure inside the piezometric tube changed synchronously with the pressure inside the container with no statistically significant difference(P>0.05). In a state of no filling in the small airbag and the medium-sized airbag, and filled at 1/5 in the small airbag, the pressure inside the piezometric tube no longer changed with the pressure in the container when the pressure reached a certain level .When the small airbag was filled at 1/5, 2/5, 3/5, 5/5, the medium-sized airbag at 1/5, 2/5, and the big airbag at 5/5, and all the airbags were in the state of no filling , the difference in the pressure between the piezometric tube and the container was statistically significant. In test 2, respiratory ventilation parameters were set on 10/4 cmH(2)O-30/14 cmH(2)O , and the connecting airbag at the front end of piezometric tube in noninvasive ventilation circuit. The platform pressure in the mask was slightly higher than that in the piezometer tube, and the baseline pressure in the mask was slightly lower than that of the piezometer tube. When the big airbag was filled at 1/5, 2/5, 3/5, 4/5 and medium-sized airbag at 2/5, 3/5, 4/5, the pressure difference between Pmask and Ptube was less than 0.5 cmH(2)O, which was acceptable clinically. When the big airbag was filled at 1/5, 2/5, 3/5 and the medium-sized airbag at 2/5, 3/5, there was no significant difference in trigger work before and after connecting the airbag at the front end of the piezometric tube(P>0.05). Conclusion: Connecting the airbag at the front end of the piezometric tube could avoid the forming of condensate in piezometric tube. The airbag showed good properties of pressure conductivity under ideal size and filling state.

[The influence of condensate in the piezometric tube on patient ventilator interaction during noninvasive positive pressure ventilation]

OBJECTIVE

To study the effects of condensate in the piezometric tube on patient ventilator interaction during noninvasive positive pressure ventilation.

METHODS

Eleven healthy adults volunteered to receive noninvasive positive pressure ventilation. Different capacity of physiological saline was injected gradually into the piezometric tube until the volunteers could not trigger the ventilator or the total volume of the water reached 1.5 ml. The dynamic changes of the pressure of mask(Pmask), piezometric tube near mask (Ppro), piezometric tube near breathing machine(Pdis), and the flow were observed.

RESULTS

With increasing volume of saline injected, the trigger time TItri(Pmask) increased from 0.09(0.07-0.11) to 0.31(0.22-0.39)s, the trigger pressure TPtri(Pmask) increased from 0.26(0.15-0.33) to 2.29(1.76-3.09)cmH2O, and the pressure-time product PTP (Pmask) increased from 0.02(0.01-0.03) to 0.55(0.41-0.68) cmH2O·s. Ineffective triggering rate increased from 0 up to 9 times/min, and spurious triggering rate increased from 0 up to 33 times/min. The plateau pressure of Pmask and Ppro exceeded the preset parameters, increased significantly as compared with 0 ml, from (9.74±0.34)to (15.79±3.10) cmH2O and from(9.80±0.31) to(15.44±3.47) cmH2O. The change of plateau pressure of Pdis was not significant [from (9.85±0.29)to (12.58±2.64)cmH2O]. The baseline pressure of Pmask, Ppro and Pdis changed from (3.67±0.36) to (8.40±3.22) cmH2O, from (3.71±0.32) to (8.13±3.55) cmH2O and from( 3.77±0.32) to (5.36±1.25) cmH2O, respectively. The pressure fluctuation of platform of Pmask increased significantly compare with 0 ml, from 0.60(0.48-0.71) to 7.94(7.11-8.63)cmH2O. The frequency of fluctuation of platform increased as many as 7 times during a single respiratory period. The time when the pressure of the Pdis began to change was delayed to Pmask and Ppro, 0.11(0.08-0.12)s compared with 0 ml.

CONCLUSION

Condensate in the piezometric tube during noninvasive positive pressure ventilation could influence patient-ventilator synchrony. To improve patient ventilator interaction in noninvasive positive pressure ventilation, condensate in the piezometric tube should be avoided.

Characteristics and clinical significance of lymph node metastases near the recurrent laryngeal nerve from thoracic esophageal carcinoma

This study aimed to evaluate the characteristics of lymph node (LN) metastases from thoracic esophageal carcinoma near the recurrent laryngeal nerve and the influence of these metastases on patient prognosis and to determine the reasonable regional LN dissection range. The clinical data from 120 patients who underwent resection for thoracic esophageal carcinoma were analyzed retrospectively. LN metastases near the recurrent laryngeal nerve were detected in 34.2% of the cases, and the metastasis rates in the left and right LNs near the recurrent laryngeal nerve were 20.8 and 15.8%, respectively. The primary tumor site (metastasis rates for esophageal cancer in the upper thoracic segment vs chest or lower thoracic segment: 60.0 vs 40.3 or 15.8%, respectively; P < 0.01), tumor differentiation (poorly differentiated vs well differentiated or differentiated: 56.0 vs 22.0 or 35.6%, respectively; P < 0.05), and tumor invasion depth (T3 and T4 vs T1 and T2: 42.9 and 50.0% vs 8.33 and 14.3%, respectively; P < 0.01) were factors that significantly influenced LN metastasis near the recurrent laryngeal nerve LN metastases near the recurrent laryngeal nerve were associated with cervical LN metastasis. The 3-year survival rate of patients with LN metastasis near the recurrent laryngeal nerve was much lower than that of patients with other LN metastases (29.3 vs 58.2%; P < 0.05). In thoracic esophageal carcinoma cases, LNs near the recurrent laryngeal nerve should be resected. This could improve the patient prognosis and reduce the incidence of postoperative local recurrence.

Unsupervised segmentation of multiparameter MRI in experimental cerebral ischemia with comparison to T2, diffusion, and ADC MRI parameters and histopathological validation

This study presents histological validation of an objective (unsupervised) computer segmentation algorithm, the iterative self-organizing data analysis technique (ISODATA), for analysis of multiparameter magnetic resonance imaging (MRI) data in experimental focal cerebral ischemia. T2-, T1-, and diffusion (DWI) weighted coronal images were acquired from 4 to 168 hours after stroke on separate groups of animals. Animals were killed immediately after MRI for histological analysis. MR images were coregistered/warped to histology. MRI lesion areas were defined using DWI, apparent diffusion coefficient (ADC) maps, T2-weighted images, and ISODATA. The last techniques clearly discriminated between ischemia-altered and morphologically intact tissue. ISODATA areas were congruent and significantly correlated (r = 0.99, P < 0.05) with histologically defined lesions. In contrast, DWI, ADC, and T2 lesion areas showed no significant correlation with histologically evaluated lesions until subacute time points. These data indicate that multiparameter ISODATA methodology can accurately detect and identify ischemic cell damage early and late after ischemia, with ISODATA outperforming ADC, DWI, and T2-weighted images in identification of ischemic lesions from 4 to 168 hours after stroke.

Intracellular calcium stores in isolated tracheal smooth muscle cells

We investigated the effects of acetylcholine (ACh) and histamine on intracellular calcium concentration ([Ca2+]i) and contraction of freshly isolated guinea pig tracheal smooth muscle cells. Previous electrophysiological studies revealed that agonists elicit cation and Cl- currents, but a role for Ca2+ in mediating these effects remains unresolved. Here we characterize agonist-induced changes of [Ca2+]i, using fura 2, and examine the contribution of the sarcoplasmic reticulum (SR) to regulation of [Ca2+]i. We provide evidence that the rise of [Ca2+]i and the contraction elicited by ACh or histamine are largely due to release of Ca2+ from stores. Agonists elicited Ca2+ transients in Ca(2+)-free solution with 0.5 mM ethylene glycol-bis (beta-aminoethyl ether)-N, N, N',N'-tetraacetic acid (EGTA), whereas prolonged exposure to Ca(2+)-free solution diminished the rise of [Ca2+]i. In addition, blockade of SR Ca(2+)-adenosinetriphosphatase (ATPase) by cyclopiazonic acid (CPA) or thapsigargin caused elevation of [Ca2+]i and reduction of ACh-evoked increase of [Ca2+]i. In many cells, [Ca2+]i fell below baseline (undershoot) after ACh or caffeine. CPA abolished this undershoot and reduced the rate of recovery of [Ca2+]i to basal levels. Furthermore, oscillations of [Ca2+]i were elicited in the presence or absence of extracellular Ca2+, and these too were reversibly abolished by CPA. Our results provide evidence that Ca2+ stores play a significant role in agonist-mediated increase of [Ca2+]i in tracheal muscle and that the SR contributes to the restoration of basal Ca2+ levels.

Platelet-activating factor induces pseudopod formation in calcitonin-treated rabbit osteoclasts

We demonstrated previously that platelet-activating factor (PAF), a potent inflammatory mediator, acts on osteoclasts to elevate cytosolic [Ca2+] and stimulate resorption. However, it is not clear whether the effects of PAF on resorptive activity are direct or indirect. In the present study, we investigated the effects of PAF on osteoclast motility. Osteoclasts were isolated from the long bones of neonatal rabbits, and cell motility and morphology were monitored using time-lapse video microscopy. Calcitonin, a hormone known to induce retraction of pseudopods and inhibit resorptive activity, was used to render osteoclasts quiescent. Within 10 minutes of calcitonin treatment (100 ng/ml, final), pronounced retraction of pseudopods was observed in 68 of 112 cells tested. When PAF (200 nM, final) was added 10 minutes after calcitonin treatment, pseudopods were evident 1 h later in 15 of 37 calcitonin-responsive cells tested. In contrast, pseudopods were evident in only 4 of 31 calcitonin-responsive cells treated with control solutions (PAF-vehicle or S-PAF, the biologically inactive stereoisomer of PAF). Pseudopod formation was quantified by measuring the planar area of pseudopods with a computer-based video analysis system. When assessed 60 minutes following PAF treatment, the pseudopod area was significantly greater in PAF-treated cells than in control cells. In some calcitonin-treated osteoclasts, PAF induced pseudopod formation when applied focally using an extracellular micropipette, consistent with a direct action of PAF. We conclude that PAF directly induces pseudopod formation in calcitonin-inhibited osteoclasts, a morphologic response indicative of osteoclast activation.

[A clinical study on adoptive immunotherapy of bone metastatic neoplasm with tumor infiltrating lymphocytes]

In order to establish a more efficient and less toxic approach than lymphokine activated killer (LAK) cell in adoptive immunotherapy (AIT), tumor infiltrating lymphocytes (TILs) were isolated from operation and biopsy samples of 10 patients with bone metastatic tumor during 1990 approximately 1992. TILs activated and expanded in vitro were adoptively transferred to patients with bone metastatic lesions. Complete response in 1, partial response in 2, minor response in 3 and nonresponse in 4 patients with TILs immunotherapy were observed. The effective rate was 30%, P > 0.01. The results of this preliminary study indicate that adoptive immunotherapy with large number of TILs is an encouraging approach in the treatment of advanced neoplasm with bone metastasis.

Unstable fracture of thoracolumbar spine treated with pedicle screw plating. A report of 90 cases

Ninety cases of unstable fracture of thoracolumbar spine treated with a modified Roy-Camille type of pedicle screw plating are reported. They were followed up for an average of 2 years and 5 months. Comparing the pre- and postoperative X-ray films for the angles of kyphosis, degrees of compression of anterior vertebral height and degrees of displacement, the results were quite satisfactory. A complete reduction was obtained in 74% of the unstable fractures at the levels between the T11 and L3 vertebrae. This kind of internal fixation has been proved to be strong and safe allowing for early mobilization with few complications. The operative technique is described and the causes of complication are analyzed.

Platelet-activating factor stimulates resorption by rabbit osteoclasts in vitro

We have shown previously that platelet-activating factor (PAF), a potent inflammatory mediator, acts directly on isolated rat osteoclasts to elevate cytosolic free Ca2+ concentration ([Ca2+]i). The purpose of this study was to examine the effects of PAF on osteoclast function. Osteoclasts were isolated from the long bones of neonatal rabbits and studied in three ways. [Ca2+]i of fura-2-loaded osteoclasts was monitored by microspectrofluorimetry. In 9 out of 16 cells tested, PAF (10-100 nM) caused elevation of [Ca2+]i that peaked then returned to baseline. In contrast, the biologically inactive precursor and metabolite of PAF, lyso-PAF, was without effect. Using time-lapse videomicroscopy, we found that PAF elicited retraction of peripheral pseudopods. Although calcitonin induced sustained retraction and immobility, the response to PAF was transient and, within 30 min, pseudopods reformed. To assess effects of PAF on resorptive activity, osteoclasts were cultured on dentin slices for 48 h in the presence of vehicle, PAF (200 nM), or calcitonin (100 ng/ml). PAF increased the area of individual resorption pits (from control values of 1,660 +/- 110 to 2,240 +/- 200 microns2, P < 0.05) and the total planar area resorbed per unit area of substrate (from 7.6 +/- 1.6 to 14.5 +/- 3.1 x 10(4) microns2/cm2, P < 0.025). As expected, calcitonin significantly decreased resorptive activity. These data indicate that PAF activates osteoclastic resorption. PAF may play a role in mediating the resorption of bone and mineralized cartilage in inflammatory diseases such as rheumatoid arthritis and periodontitis.

Pulsed Doppler technique in evaluation of pulmonary hypertension

A pulsed Doppler technique combined with cross sectional echocardiography was used to examine the flow velocity pattern in the pulmonary artery (PA) in 17 patients with PA hypertension documented by cardiac catheterization and in 16 healthy subjects as control. In healthy subjects the blood flow pattern in systole showed a round shape, in PA hypertension group it was either narrow triangular or intermediate. There was a significant correlation between the corrected acceleration time and mean PA pressure, the coefficient being -0.78. An improved correlation (r = -0.82) was found between acceleration time and natural log of mean PA pressure. Using PA acceleration time of 100 ms or less as a criteria resulted in a 76.5% sensitivity and a 100% specificity for detection of PA hypertension. This technique made the noninvasive estimation of pulmonary hypertension possible.

[Experimental study of hemodynamic changes following obliteration of the vertebral artery and surgical treatment]

This experiment on dogs was to compare the hemodynamic changes following ligation of the carotid artery on one side and the first segment of vertebral artery on both sides, with that after restoration of the cut-off circulation through anastomosing the previously ligated carotid and vertebral arteries. The hemodynamic changes after obliteration and following restoration of circulation, both in vessels and cerebellum, were monitored by ways of regional clearance of hydrogen, Doppler velocimetory of blood flow, angiography of vertebral artery and blood gas analysis. The difference of results in each paired sample was statistically very significant. These models worked with success in 20 out of 24 dogs, a rate of 83%. Following re-establishment of circulation by means of vascular anastomosis, blood flow and blood supply to the ischemic cerebellum increased to normal or nearly normal. It suggests that this kind of surgical procedure may be of value in clinical treatment.

[Experimental study on the application of calcium phosphate bioceramics in repairing periodontal osseous defects]

Two kinds of Tricalcium phosphate Ceramic (TPC) powder and one kind of Calcium pyrophosphate Ceramic (CPC) powder, all prepared by the research group, were used in the animal study. The tissue response to these ceramic and biocompatibility of the ceramic were evaluated histopathologically. First, eighteen male mongrel dogs were divided randomly into six groups, and then, both in mandible and maxilla eight 2-wall osseous defects were created bilaterally in each dog. At each side of jaw, one defect remained empty while the other three defects were implanted with TPC and CPC. The dogs were sacrificed at 2, 4, 8, 16, 24 and 32 weeks after implantation for histologic observation.