Efficacy of intentional undersized thoracic endovascular repair for Stanford type B aortic dissection

OBJECTIVES

Thoracic endovascular aneurysm repair (TEVAR) is widely used for the treatment of aortic dissection. Endograft oversizing is a risk factor for stent graft-induced new entry tears and retrograde type A aortic dissection. However, there is no clear consensus on the optimal graft size selection for Stanford type B acute or subacute aortic dissection (TBAD). Herein, we examined the safety and efficacy of TEVAR using an intentionally undersized endograft to treat TBAD.

METHODS

This retrospective chart review study included 82 patients who underwent TEVAR for acute or subacute Stanford TBAD between 2015 and 2022. We measured the true lumen diameter just distal to the subclavian artery and opted for a stent graft of the same diameter. In instances where deformation resulting from false lumen pressure displacement was pronounced, we measured the diameter at the site just proximal to the subclavian artery. Patients' characteristics, procedural, in-hospital, and follow-up data, and aortic remodeling were analyzed. The aortic diameter was analyzed using one-way analysis of variance followed by Dunnett's test. Survival and freedom from re-intervention were estimated using Kaplan-Meier curves.

RESULTS

The follow-up rate was 98.4%. The mean age was 58.3 ± 12.3 years and 76 were men (92.7%). The mean diameters of the stent graft and native proximal landing zone were 30.9 ± 3.2 mm and 30.8 ± 3.0 mm, respectively. The oversize rate of the stent graft in relation to the native proximal aortic diameter was 0.3 ± 4.7%. In-hospital mortality was observed in one patient, retrograde type A aortic dissection in one patient, distal stent graft-induced new entry tear in zero patients, and type 1a endoleak in 22 patients (26.8%). Type 1a endoleaks, characterized by antegrade false lumen blood flow originating from the primary entry, in 12 patients spontaneously disappeared within 1 year of follow-up. According to aortic remodeling, 59 (86.8%) patients achieved complete aortic remodeling at the aortic arch level and 51 (75.0%) at the 8th thoracic vertebral level. The diameters of the aortic arch and descending aorta were significantly reduced compared with the postoperative measurements (P <0.001). Survival rates were 97.5% and 93.6% at 1 and 3 years, respectively. Freedom from re-intervention was 84.7% and 84.7% at 1 and 3 years, respectively.

CONCLUSIONS

Intentionally undersized TEVAR was safe and achieved acceptable aortic remodeling despite a high rate of type 1a endoleaks. A type 1a endoleak was acceptable as it primarily diminished during the mid-term follow-up.

Transcatheter aortic valve replacement in patients with severe aortic stenosis reduced the frequency of intradialytic hypotension

Intradialytic hypotension (IDH) is a common complication during hemodialysis that increases cardiovascular morbidity and mortality. Aortic stenosis (AS) is a cause of IDH. Transcatheter aortic valve replacement (TAVR) has become an established treatment for patients with severe AS. However, whether TAVR reduce the frequency of IDH has not been investigated. This study aims to verify the efficacy of TAVR for reduction of the frequency of IDH. Consecutive hemodialysis patients who underwent TAVR at Sendai Kosei Hospital from February 2021 to November 2021 with available records 1 month before and 3 months after TAVR were included in the study. IDH was defined as a decrease in systolic blood pressure by 20 mmHg or a decrease in the mean blood pressure by 10 mmHg associated with hypotensive symptoms or requiring intervention. Patients with ≥ 3 episodes of IDH in ten hemodialysis sessions comprised the IDH group. Overall, 18/41 (43.9%) patients were classified into the IDH group. In ten hemodialysis sessions, IDH events were observed 2.1, 4.3, and 0.4 times in the overall cohort, IDH group, and non-IDH group, respectively. After TAVR, the incidence of IDH decreased from 43.2 to 10.3% (p < 0.0001) and IDH improved significantly in 15 patients in the IDH group. The result suggested that severe AS was the major cause of IDH in this cohort, and TAVR may be an effective treatment option for reduction of the frequency of IDH in patients with severe AS.

[Transient Left Ventricular Dysfunction after Giant Coronary Aneurysm Resection and Repair of Coronary Arteriovenous Fistula with Coronary Artery Bypass Grafting:Report of a Case]

Coronary artery aneurysm with coronary arteriovenous fistula is a relatively rare clinical setting. We report a surgical case of a 69-year-old male with a giant coronary artery aneurysm, finding coronary arteriovenous fistula on computed tomography (CT). We performed complete aneurysm excision and coronary artery bypass grafting with the left internal thoracic artery to the posterolateral branch. The fistula was located between the giant aneurysm on the circumflex artery and the coronary vein close to the coronary sinus, closed with aneurysm sac. The postoperative CT found no residual aneurysm and fistula. However, the great cardiac vein was thrombosed, and the impeded venous flow by the thrombus seemed to reduce the left ventricular ejection fraction (LVEF). Four months after the operation, the LVEF improved to the preoperative level.

Single Versus Multiple Arterial Revascularization in Patients With Reduced Renal Function: Long-term Outcome Comparisons in 23,406 CABG Patients From Ontario, Canada

OBJECTIVE

To compare the long-term outcomes of MAR versus SAR in patients with renal insufficiency.

SUMMARY OF BACKGROUND DATA

Previous studies have been insufficiently powered to address whether MAR confers long-term benefit over SAR in patients with renal dysfunction who require CABG.

METHODS

We conducted retrospective cohort study in Ontario, Canada of patients who underwent isolated CABG (n = 23,406). The primary outcome was MACE, defined as the composite of stroke, myocardial infarction, and repeat revascularization. We compared patients by matching them on the propensity to have received SAR versus MAR, within groups with preoperative glomerular filtration rate (GFR) ≥60 mL/min/1.73 m2; GFR between 30 and 60; and GFR <30.

RESULTS

In patients with GFR ≥60, the use of MAR versus SAR was associated with a lower rate of MACE [hazard ratio (HR) 0.87 (0.80-0.94)], and a lower rate of long-term mortality [HR 0.87 (0.79-0.97)]. In those with GFR between 30 and 60, MAR was not associated with a difference in MACE [HR 1.04 (0.87-1.26)], and a lower rate of long-term mortality [HR 0.75 (0.65-0.87)] was observed. In those with GFR <30, MAR was not associated with a difference in outcomes.

CONCLUSIONS

MAR versus SAR does not correlate with a difference in MACE amongst patients with GFR between 30 and 60 and better survival raises the possibility of indication bias. Furthermore, MAR did not confer a benefit in those with severely reduced renal function. These data suggest that the potential long-term benefits of using MAR in CABG patients with renal insufficiency may be offset by competing health risks.

Direct Implant of a Transcatheter Aortic Valve Prosthesis for Prosthetic Mitral Valve Endocarditis

We describe the case of a 64-year-old woman presenting with severe prosthetic mitral valve endocarditis 1 year after coronary artery bypass grafting and double valve replacement. Echocardiogram revealed high-pressure gradients through the bioprosthetic MV with a bulky vegetation. As the patient had presented operative difficulties due to severe mitral annular calcification, was in renal failure, and in the absence of any perivalvular involvement, an open-heart surgical catheter-based valve implantation was successfully performed after removal of the infected leaflets, leaving the stent frame and sewing cuff behind. Albeit controversial, this case represents an alternative approach for select high-risk reoperative mitral cases with mitral annular calcification.

Frequency and chaotic analysis of pulsatile motion of blood vessel wall related to aneurysm

BACKGROUND/OBJECTIVE

In this research, using our proposed method, clinical measurements on the pulsatile velocity of blood vessel wall were conducted for cases with aneurysm. Furthermore, detailed analyses of frequency and attracter of trajectories of velocity of blood vessel wall were conducted. On the basis of these analyses, we tried to conduct unified clarification of the change and disturbance of frequency and wave form of pulsatile velocity of blood vessel wall caused by blood vessel diseases such as aneurysm.

RESULTS

In the pulsation motion of blood vessel wall, vasomotion, which is a regular long periodic fluctuation of amplitude of the pulsatile velocity of blood vessel wall, was found to exist. Furthermore, the shift of its frequency into low frequency region was found to correspond well with an increase in I∗, an indicator of progressive degree of visco elasticity of blood vessel wall and it reflects the mechanical deterioration of blood vessel wall. This long periodic fluctuation of amplitude of the pulsatile velocity of blood vessel wall exists in the low frequency region that composes the frequency of the pulsatile velocity of blood vessel wall. On the other hand, wave forms in high frequency region that compose the frequency of pulsatile velocity of blood vessel wall were found to correspond well with each pulsatile velocity wave form of blood vessel wall itself and their disturbances caused by the existence of aneurysm was typically reflected in these wave forms.

CONCLUSION

By dividing frequencies that compose the frequency of the pulsatile velocity of blood vessel wall into low and high frequency regions and conducting analyses at each region, the possibility of accurate selective detection of blood vessel diseases such as mechanical deterioration of blood vessel wall (low frequency region) and morphological change of blood vessel wall that is aneurysm (high frequency region) was indicated.

A novel diagnostic system for Doppler ultrasound of the peripheral arteries to detect the presence of thoracic aortic aneurysm

OBJECTIVE

We aimed to develop a novel ultrasound system and examine its feasibility for noninvasively detecting thoracic aortic aneurysm (TAA) in clinical settings.

METHODS

We developed a novel ultrasound system consisting of a modified console and data analysis algorithm. The exploratory study included 100 patients hospitalized for elective cardiovascular surgery. After admission, the arterial pulse waveform at the left carotid artery was acquired using the novel system. Based on these data, we inferred the presence of TAA based on arterial viscoelasticity and instability, which are reflected into the time-averaged trajectory of deformation of the blood vessel wall caused by disturbance of blood flow. Meanwhile, all patients underwent computed tomography as preoperative screening to confirm the presence of TAA. The sensitivity and specificity of TAA detection using the novel ultrasound system were calculated.

RESULTS

The datasets from 37 patients were not suitable for analysis and were thus discarded. Based on computed tomography findings, 40 patients were categorized into the aneurysm group while 23 were judged not to have and aortic aneurysm. On the other hand, 44 patients were diagnosed as having TAA based on ultrasound findings obtained using the novel system. The overall sensitivity and specificity of the ultrasound system were 0.83 and 0.52, respectively.

CONCLUSION

We successfully developed a novel system for noninvasive, ultrasound-based evaluation of the left carotid artery to detect TAA. Although improvements to the probe and diagnostic algorithm are warranted, this device has potential utility for mass screening to detect asymptomatic TAA as part of community-level healthcare programs.

Differential selective hypothermic intercostal artery perfusion: a new method to probe spinal cord perfusion during thoracoabdominal aortic aneurysm repair

OBJECTIVE

To prevent paraplegia in patients undergoing thoracoabdominal aortic aneurysm repair, the importance of preoperative identification of the Adamkiewicz artery and reconstruction of critical intercostal artery have been advocated. Conversely, significance of collateral network for spinal cord perfusion has been recognized. We invented a new system consisting of a direct monitoring of cerebrospinal fluid temperature (CSFT) and differential selective hypothermic intercostal artery perfusion (D-HIAP).

METHODS

After exposing a critical intercostal artery, a 10-mm prosthetic graft was anastomosed in an end to side fashion. A balloon-tipped catheter was inserted into the graft to perfuse with 15 °C blood. Neighboring intercostal arteries were also perfused in the same fashion. Serial monitoring of CSFT was performed. Between January 2011 and January 2015, D-HIAP was employed in 50 patients with Adamkiewicz artery that located within a reconstructed area.

RESULTS

Significant CSFT drop was recorded after initiation of D-HIAP in 42 (84%) patients. Of those, 34 (68%) patients showed significantly lowered CSFT with D-HIAP into a single critical intercostal artery. Perfusion into plural intercostal arteries was necessary for CSFT drop in 2 cases (4%), and plural intercostal artery perfusion further enhanced CSFT drop that had been modestly achieved by single intercostal artery perfusion in 6 cases (12%). Eight (16%) patients did not exhibit a significant drop in CSFT even when D-HIAP was employed for the critical and neighboring intercostal arteries.

CONCLUSIONS

The detection of a disparity in temperature between the intrathecal space and blood generated by D-HIAP revealed individual variability in CSFT changes, which may imply a complexity in spinal cord perfusion. Intraoperative D-HIAP may help to identify a major blood supply for spinal cord perfusion and underlying collateral network.

Oesophageal mucosal blood flow changes after thoracic endovascular stent graft implantation using a novel sensor probe

OBJECTIVES

Secondary aorto-oesophageal fistula is a rare, lethal complication occurring after thoracic endovascular aneurysmal repair. The cause of secondary aorto-oesophageal fistula is unknown, but a reduction in local oesophageal mucosal blood flow (OMBF) may be a basis for such a devastating sequela. Our study aims to develop a novel blood flow sensor probe to detect changes in OMBF after thoracic stent graft implantation in an experimental swine model.

METHODS

A novel laser Doppler flowmetry sensor probe incorporating an optical fibre sensor within a nasogastric tube was developed using microelectromechanical system technology. OMBF was measured at various levels using this sensor probe, to test its feasibility before and after thoracic endovascular stent graft implantation covering Th4-Th8 vertebral levels in 6 swine.

RESULTS

In the middle oesophagus (Th5-Th7), where the aorta was covered with a stent graft, the measured OMBFs were significantly decreased after thoracic endovascular stent graft implantation than those of baseline (8.6 ± 2.7 vs 18.4 ± 7.9 ml/min/100 g, P < 0.0001), followed by a plateau period for at least 2 h after stent grafting (8.7 ± 3.3 ml/min/100 g, P < 0.0001 vs baseline). OMBFs in the upper (Th1-Th3) and lower (Th9-Th11) oesophagus, where the aorta was not covered with a stent graft, were unaffected by thoracic endovascular stent grafting.

CONCLUSIONS

The novel laser Doppler flowmetry sensor probe was useful to monitor precise changes of OMBF in a swine model, demonstrating a significant reduction in OMBF after thoracic endovascular stent graft implantation.

Predictors of the need for pacemaker implantation after the Cox maze IV procedure for atrial fibrillation

PURPOSE

The Cox maze IV (CMIV) procedure is being used increasingly frequently for surgical ablation of atrial fibrillation (AF). This study aimed to identify the risk factors of the need for postoperative pacemaker implantation (PMI) after CMIV.

METHODS

Preoperative, intraoperative, and postoperative data were retrospectively collected from 67 consecutive patients who underwent CMIV at our institution; 7 (10.4%) required PMI (as a treatment of brady AF or sick sinus syndrome).

RESULTS

Patients who needed PMI tended to have lower preoperative heart rates than those who did not on a 12-lead electrocardiogram (ECG; 68.7 ± 11.6 vs. 79.1 ± 18.5 bpm, p = 0.07) and a 24-h ECG (94,772 ± 9800 vs. 109,854 ± 19,078 beats/day, p = 0.03). A multivariate analysis identified a low amplitude of the fibrillatory wave on preoperative ECG as a risk factor of PMI necessity after CMIV [odds ratio = 14.7; 95% confidence interval (CI) 1.9-324.7; p = 0.007] and internal use of angiotensin-converting enzyme inhibitors or angiotensin receptor blockers (ACEIs/ARBs) as a negative risk factor (odds ratio = 0.16; 95% CI 0.02-0.99; p = 0.049).

CONCLUSIONS

A low amplitude of the fibrillatory wave was identified as a risk factor of PMI necessity, whereas the internal use of ACEIs/ARBs diminished the need for PMI. These factors should be considered before CMIV is performed.

[Surgical Embolectomy for Acute Massive Pulmonary Thromboembolism Requiring Percutaneous Cardiopulmonary Support after Thoracoabdominal Aorta Replacement]

A 48-year-old man was admitted to our hospital and underwent thoracoabdominal aorta replacement. Eight days postoperatively, he developed severe dyspnea and transient drop in blood pressure suddenly following walk rehabilitation. Contrast-enhanced computed tomography showed thrombi in the bilateral main pulmonary artery. Respiratory failure and unstable hemodynamics developed, which required percutaneous cardiopulmonary support (PCPS). Because catheter embolectomy and thrombolytic therapy via pulmonary artery catheter were not effective, surgical thrombectomy was performed. PCPS was successfully removed on the following day. The patient was extubated on postoperative day 10 and discharged without complications on day 46 following rehabilitation. It is important to save a critically ill patient with acute pulmonary embolism requiring PCPS, and surgical treatment should be performed without delay in such patients.

Surgical resection of recurrent extrahepatic hepatocellular carcinoma with tumor thrombus extending into the right atrium under cardiopulmonary bypass: a case report and review of the literature

Background

Recurrent hepatocellular carcinoma accompanied by a right atrial tumor thrombus is rare. No standard treatment modality has been established. Surgical treatment may be the only curative treatment; however, surgery has been considered high risk. We herein describe a patient who underwent resection of a recurrent right atrial tumor thrombus under normothermic cardiopulmonary bypass on a beating heart.

Case presentation

A 60-year-old man underwent a right hepatectomy for hepatocellular carcinoma with diaphragm invasion. During the preoperative cardiac screening, he was diagnosed with an old myocardial infarction with triple-vessel coronary disease. Percutaneous coronary intervention was performed for the left anterior descending artery and left circumflex coronary artery. High-grade stenosis remained in his right coronary artery. Nine months later, computed tomography showed recurrent hepatocellular carcinoma in the diaphragm and a tumor thrombus extending from the suprahepatic inferior vena cava into the right atrium. Surgical resection of the recurrent tumor was performed through a right subcostal incision with xiphoid extension and median sternotomy. The recurrent tumor was incised with the diaphragm and pericardium. Intraoperative ultrasonography revealed that the tumor thrombus was free from right atrium wall invasion and that the right atrium could be clamped just proximal to the tumor thrombus. The right atrium, infrahepatic vena cava, left and middle hepatic veins, and hepatoduodenal ligament were encircled. Cardiopulmonary bypass was performed to prevent ischemic heart disease caused by intraoperative hypotension. Total hepatic vascular exclusion was then performed under normothermic cardiopulmonary bypass on heart beating. The inferior vena cava wall was incised. The tumor thrombus with the diaphragmatic recurrent tumor was resected en bloc. The patient had a favorable clinical course without any complications.

Conclusion

The recurrent hepatocellular carcinoma in the diaphragm and the right atrial tumor thrombus were safely resected using normothermic cardiopulmonary bypass on heart beating.

Surgical removal of calcified amorphous tumor localized to mitral valve leaflet without mitral annular calcification

A cardiac calcified amorphous tumor (CAT) localized to the mitral valve leaflet without mitral annular calcification (MAC) is a rare entity. We report a case of a 69-year-old woman with such a condition, who underwent successful excision of the tumor and mitral valvuloplasty using a glutaraldehyde-treated autologous pericardium. During 38 months of follow-up, no recurrence of a cardiac mass has been recognized. This report addresses questions on the surgical indication for CAT, particularly in cases without MAC, and reviews CATs of the mitral valve.

Contemporary outcome of the surgical management of prosthetic graft infection after a thoracic aortic replacement: is there a room to consider vacuum-assisted wound closure as an alternative?

Objective

Once a replaced prosthetic graft is infected, it is usually necessary to re-replace the thoracic aorta to achieve complete resolution of the infection. It is, however, an exceedingly invasive approach to perform such a repeat surgery on patients in a poor condition. We have managed both re-replacement of an infected prosthetic graft and conservative therapy with vacuum-assisted wound closure (VAC) without re-replacement. These two treatment modalities were retrospectively assessed.

Methods

Retrospective clinical chart review was undertaken on 21 patients with prosthetic graft infection after thoracic aortic replacement between December 1999 and December 2012. Surgical outcomes were evaluated between the two groups: re-replacement group (group R, n = 14) and no-replacement group (group NR, n = 7).

Results

In-hospital survival rates were 64.3 % in group R and 85.7 % in group NR. Mortality in group R included five patients, sepsis in two patients, and intraoperative aortic rupture, heart failure, and cerebral infarction in one. Mortality in group NR included one patient (sepsis). In terms of long-term outcome, one patient in group R and one patient in group NR died of rupture of a residual aortic aneurysm, and one patient in group NR died of renal disease during follow-up (52.8 ± 41.5 months for R and 43.2 ± 28.5 months for NR; mean ± standard deviation).

Conclusions

Re-replacement of an infected prosthetic graft after a thoracic aortic operation still carries a significant risk for mortality. VAC therapy may provide an acceptable option for such a subgroup of patients with this serious condition.

[Fundamental features on percutaneous cardiopulmonary support]

The fundamental features on percutaneous cardiopulmonary support (PCPS) were reviewed. The number of PCPS installation in Japan has been increasing especially in the area of emergency medicine and cardiology. All-in-one package for PCPS system is becoming a mainstream in clinical practice. It is considered to be crucial to understand the details in characteristics and pitfalls on respective products. The results of nation-wide questionnaire indicate that the detailed criteria for PCPS usage in clinical practice appear to be variable among facilities in Japan;therefore, the formulation of guideline and educational system for PCPS installation is required.

Preliminary validation of a new magnetic wireless blood pump

In general, a blood pump must be small, have a simple configuration, and have sufficient hydrodynamic performance. Herein, we introduce new mechanisms for a wireless blood pump that is small and simple and provides wireless and battery-free operation. To achieve wireless and battery-free operation, we implement magnetic torque and force control methods that use two external drivers: an external coil and a permanent magnet with a DC-motor, respectively. Power harvesting can be used to drive an electronic circuit for wireless monitoring (the observation of the pump conditions and temperature) without the use of an internal battery. The power harvesting will be used as a power source to drive other electronic devices, such as various biosensors with their driving circuits. To have both a compact size and sufficient pumping capability, the fully magnetic impeller has five stages and each stage includes four backward-curved blades. The pump has total and inner volumes of 20 and 9.8 cc, respectively, and weighs 52 g. The pump produces a flow rate of approximately 8 L/min at 80 mm Hg and the power generator produces 0.3 W of electrical power at 120 Ω. The pump also produces a minimum flow rate of 1.5 L/min and a pressure of 30 mm Hg for circulation at a maximum distance of 7.5 cm.

[Successful treatment using recombinant thrombomodulin for disseminated intravascular coagulation associated with recurrent prosthetic valve endocarditis]

Prosthetic valve endocarditis(PVE)occasionally evokes sepsis and disseminated intravascular coagulation(DIC). A 46-year-old man developed relapsing active PVE with an annular abscess and suffered from exacerbating sepsis and DIC. Despite the administration of antibiotics, his DIC score increased. Anti-DIC treatment with recombinant thrombomodulin (rTM) was initiated, and his DIC was remarkably resolved. Accordingly, the abscess cavity was closed by using a homograft anterior mitral leaflet, and the aortic root was replaced with the homograft. He is doing well without an evidence of recurrent endocarditis 18 months after the operation. rTM is a new and promising drug for the treatment of DIC with infective endocarditis.

A case of effective cerebrospinal fluid drainage for paraplegia caused by acute aortic dissection

A 65-year-old man with sudden back pain was transferred to our hospital by ambulance, who also complained of sensory and motor disorder of bilateral legs on arrival. The neurological disorder was gradually aggravated and paraplegia below the level of Th10 was manifested. Computed tomography demonstrated DeBakey IIIb acute aortic dissection; therefore, the paraplegia was thought to be due to spinal cord ischemia caused by the acute aortic dissection. Emergent cerebrospinal fluid drainage was performed, and it was very effective for the relief from paraplegia. The hospital course after the drainage was uneventful and he was discharged on the 39th day after the onset of symptoms.

The relationship of genetic aberrations detected by comparative genomic hybridization to DNA ploidy and tumor size in human oral squamous cell carcinomas

We have examined genetic alterations in 11 surgically removed oral squamous cell carcinomas (OSCCs) using comparative genomic hybridization (CGH) and laser scanning cytometry (LSC), which allow quantitative analysis of chromosomal abnormalities. CGH analysis revealed gains and/or losses of DNA sequence copy number in all tumors. Gains in DNA sequence copy number were detected frequently for chromosome arms 3q25-28 (6/11), 5p (6/11) and 8q (5/11), and losses in chromosome arms 18q (4/11), 19q (4/11), 17p (3/11), and 19p (3/11). Amplification of 5p was observed in two tumors. LSC detected DNA aneuploidy with DNA indices ranging from 1.30 to 1.82 in 6 of 11 tumors. The number of chromosomal aberrations was higher in DNA aneuploid tumors than in diploid tumors (8.17 vs 3.60/tumor, P<0.05). Furthermore, the average number of chromosomal aberrations was significantly higher in stage T2 tumors and larger tumors than in stage T1 tumors (7.71 vs 3.25/tumor, P<0.05). Our results suggest that DNA aneuploidy and large tumor size reflect an underlying chromosomal instability.

Identification of genetic aberrations in cell lines from oral squamous cell carcinomas by comparative genomic hybridization

We detected genetic alterations in 14 cell lines established from 14 human oral squamous cell carcinomas (OSCCs) using comparative genomic hybridization (CGH), which allows a comprehensive analysis of chromosomal imbalances and identification of nonrandom genetic aberrations specific to OSCCs. All cell lines showed gains and losses of DNA copy number. DNA losses were detected for chromosomes 18q (10/14) and 4q (9/14) with minimal overlapping regions of 18q12-32 and 4q31-qter, respectively. In contrast, the common sites for increased copy number were chromosomes 5p (12/14), 8q23-ter (11/14), 20p (8/14), 20q (8/14), and 3q25-ter (7/14). These results suggest that losses of 18q12-22 and 4q31-ter and gains of 5p and 8q23-ter play important roles in the development and/or progression of OSCC.

Recognition of a special membrane antigen of squamous cell carcinoma in rats with a monoclonal antibody UB23

This article describes the recognition of a special membrane antigen of the rat squamous cell carcinoma (SCC) by a monoclonal antibody (mAb), UB23, and the characterization of the UB23 antigen expression in the implanted primary and metastatic SCC in rat models. The mAb UB23 was raised against the FF6 tumor, a well-differentiated rat SCC, and it recognized the 120- to 130-kD cell surface antigen in FF6 tumor cells. The UB23 antigen was found in frequently observed small 'basal' cells but not in keratinocytes, and an increased expression was seen in the cells at the interface with peritumoral stroma in both the implanted primary FF6 tumors and metastases. These results indicated that the UB23 antigen is closely related with the cell differentiation and invasion of FF6 cells, and could be useful for analyzing the mechanism of differentiation, invasion and metastasis of SCC in animal models.

Expression of ICAM-1 in implanted primary and metastatic squamous cell carcinomas in rats

FF6 tumor cells are derived from a spontaneous rat squamous cell carcinoma (SCC) which originally arose in the facial skin of a DA rat. In this study, FF6 tumor cells were implanted into rat oral mucosa to establish an ex vivo metastatic model. We analyzed the expression of intercellular cell adhesion molecule-1 (ICAM-1) in the implanted primary and metastatic FF6 tumors by immuno-staining with a monoclonal antibody (mAb) against ICAM-1. The implanted primary FF6 cells showed strong expression of ICAM-1, whereas the tumor cells of metastatic lesions showed weak or negative expression of ICAM-1. By immunostaining with mAb OX6, a number of MHC class II-positive macrophages were detected in tumor mesenchyme and surrounding the metastatic foci. These results suggested that the local immune reaction in the lymph node influenced the expression of ICAM-1 on tumor cells, and that MHC class II-positive macrophages may play a role in transplanted tumor growth and metastases.

Detection and analysis of human papillomavirus 16 and 18 homologous DNA sequences in oral lesions

The prevalence of human papillomavirus (HPV) 16 and 18 was investigated in oral lesions of the population of northeast China including squamous cell carcinomas (SCCs), candida leukoplakias, lichen planuses and papillomas, by southern blot hybridization with polymerase chain reaction (PCR). Amplified HPV16 and 18 E6 DNA was analyzed by cycle sequence. HPV DNA was detected in 14 of 45 SCCs (31.1%). HPV18 E6 DNA and HPV16 E6. DNA were detected in 24.4% and 20.0% of SCCs. respectively. Dual infection of both HPV 16 and HPV 18 was detected in 6 of 45 SCCs (13.3%), but not in other oral lesions. HPV 18 E6 DNA was also detected in 2 of 3 oral candida leukoplakias, but in none of the 5 papillomas. Our study indicated that HPV 18 infection might be more frequent than HPV 16 infection in oral SCCs in northeast Chinese, dual infection of high risk HPV types was restricted in oral SCCs, and that HPV infection might be involved in the pathogenesis of oral candida leukoplakia.

[Hereditary gingival fibromatosis]

Fibromatosis may be defined as diffuse poorly circumscribed overgrowth of the fibrous tissue that infiltrates adjacent normal tissues. They are difficult to eradicate surgically, and recur but not metastasize. Gingival fibromatosis is generally regarded as a disease that leads to an extensively diffuse and remarkable hyperplasia of the maxillo-mandibular gingiva. Occasionally, this lesion covers all teeth. The histogenesis of the fibromatosis remains unexplained. Trauma, endocrine, idiopathic factors and genetic factors have been implicated, but it is uncertain whether any of then play a major role in the development of the disease. Occasional cases with familial history have been reported. The treatment of choice would appear to been block resection of the tumor and surrounding normal structures. Although, this lesion has a high recurrent rate. For this reason, in many of the case reports, that it has been recommended that the follow up period is considerably less than three years.

Electrical burns of lip and mouth in children. Report of 2 cases

2 cases of electrical burns of the oral cavity in young children are reported. Both cases were treated conservatively. 1 of the patients, now that 3 years have passed, has a slight scar with a slight deformity of lower and upper lips. We are planning reconstructive surgery within a short time. There are no functional or developmental disturbances. The main cause of electrical burns in young children is biting or sucking the free end of live extension cords or placing sockets into the mouth. Since most of these injuries are from low-voltage, electric circuits are localized to the surroundings of the mouth. However, the injuries are small or narrow, but reach much deeper than initially appear. Therefore, the scar may be small but the deeper tissue may sustain more extensive damage than expected.

Potassium contracture in the tonic bundle isolated from the enlarged flexor carpi radialis muscle of the frog

The flexor carpi radialis muscle (FCRM) of the frog was divided into phasic and tonic bundles, and the properties of the potassium contracture in the tonic bundle were examined. The potassium contracture was tonic and the contracture induced by K higher than 75 mM consisted of the initial phasic component and of the following sustained component. Both components were abolished by the transverse tubule disruption. The curve relating the peak tension to the log[K]o (activation curve) started at about 15 mM K and reached maximum at about 75 mM K. By reducing [Ca]o, the activation curve shifted downward at higher [K]o, being little affected near the mechanical threshold. The time course of inactivation induced by 20 mM K was slow and monophasic, and was markedly accelerated by reducing [Ca]o. The spontaneous relaxation of the contracture induced by high K was little affected by reducing [ca]o.