Formulation of a cosurfactant-free O/W microemulsion using nonionic surfactant mixtures.

A cosurfactant-free O/W microemulsion composed of oil, a mixture of hydrophilic and hydrophobic surfactants, and water has been developed using food-grade components as a nutrient delivery system. We started our investigation to monitor the phase behavior of this system based on a hydrophilic surfactant (Tween 80). From a phase diagram, the weight ratio of 5.4:33.8:60.8 = oil:surfactant:water was selected as a combination ratio for the O/W microemulsion system. We also investigated the combination effect of different hydrophobic surfactants to Tween 80 on microemulsion formation. Use of hydrophobic surfactants with Tween 80 produced smaller droplets than Tween 80 alone. Rheological studies showed that all microemulsions followed shear-thinning behavior. The turbidity of microemulsions did not change after accelerated stability tests, indicating that this microemulsion system was stable under the given harsh conditions. When docosahexaenoic acid (DHA) oil was applied to this microemulsion system, the particle size and the turbidity were not significantly changed. Dilution with a different aqueous medium, either water or acidic fluid, did not significantly change the microemulsion turbidity. DHA oil incorporated in microemulsion showed higher oxidation stability than free DHA oil.

The effect of Qigong on general and psychosocial health of elderly with chronic physical illnesses: a randomized clinical trial.

OBJECTIVES: Based on the model by Tsang et al. (2002) which summarized the etiological factors and consequences of depression in elderly with chronic physical illnesses, a randomized clinical trial of a special form of Qigong (The Eight Section Brocades) was conducted to assess if it improved the biopsychosocial health of participants. DESIGN: 50 geriatric patients in sub-acute stage of chronic physical illnesses were recruited and randomly assigned into the intervention and control group. The intervention group was given a 12-week period of Qigong practice while the control group was given traditional remedial rehabilitation activities. RESULTS: The intervention group participants expressed improvement in physical health, ADL, psychological health, social relationship, and health in general as reflected by scores of the Perceived Benefit Questionnaire and informal feedback. CONCLUSION: Although results are not significant in the generalization measures, it may be due to small effect size, small sample size, and short intervention period. Although not all of the hypotheses are supported, this report shows that Qigong (the Eight Section Brocades) is promising as an alternative intervention for elderly with chronic physical illness to improve their biopsychosocial health. More systematic evaluation with larger sample size and longer period of intervention is now underway in Hong Kong. Results will be reported once available.

Digital subtraction in gadolinium-enhanced MR imaging of the brain: a method to reduce contrast dosage.

The aim of the study was to investigate the feasibility of using digital subtraction in contrast-enhanced MR imaging of the brain to reduce the MR contrast dosage without jeopardizing patient care. Fifty-two patients with intracranial lesions, either intra-axial or extra-axial, detected by computerized tomography were selected for contrast-enhanced MR imaging with half-dose and full-dose of gadopentetate dimeglumine. The half-dose unsubtracted, full-dose unsubtracted, and half-dose subtracted MR images were visually assessed by counting the number of enhancing brain lesions in the images and quantitatively analyzed by computing their lesion contrast-to-background ratios (CBR). The visual conspicuity of the half-dose subtracted MR images was comparable to that of the full-dose unsubtracted MR images ( p>0.05), whereas the CBR of the half-dose subtracted images was approximately two to three times higher than that of the full-dose unsubtracted images. The half-dose subtracted T1-weighted spin-echo images might be able to replace the conventional standard-dose T1-weighted spin-echo images in MR imaging of the brain.

Primary multifocal leptomeningeal gliomatosis.

A 23-year-old female university student was presented with recent onset of non-specific headache and dizziness. She had no neurological deficit on neurological examination and magnetic resonance imaging of the brain revealed diffuse enhancement in the basal cisterns and cerebral sulci. She was treated as tuberculous meningitis but she did not improve and developed respiratory arrest. Autopsy showed primary multifocal leptomeningeal gliomatosis.

Hypertrophic olivary degeneration following surgical excision of brainstem cavernous hemangioma: a case report.

Hypertrophic olivary degeneration (HOD) is a rare type of neuronal degeneration involving the dento-rubo-olivary pathway. It is distinguished from other types of neuronal degeneration in that hypertrophy, rather than atrophy, takes place in the neurons in the inferior olivary nucleus. Prior to the invention of Magnetic Resonance Imaging (MRI), HOD was difficult to be detected, and a firm diagnosis could only be made at autopsy. We present a case of bilateral HOD following surgical excision of a cavernous hemangioma in the brainstem. The literature and imaging findings of this uncommon condition are reviewed.

Risk factors for development of acute renal failure (ARF) requiring dialysis in patients undergoing cardiac surgery.

Acute renal failure (ARF) is one of the major complications after cardiopulmonary bypass for open heart operations. The present study was undertaken to identify the risk factors for the development of ARF following cardiopulmonary bypass (CPB). Four hundred and forty-seven consecutive patients who underwent open heart procedures from July 1994 to June 1995 were analyzed retrospectively. Their mean age was 55.6 +/- 14.2 (SD) years (range, 18 to 80). Dialysis was instituted whenever a patient exhibited inadequate urine output (<0.5 mL/kg/hr) for 2 to 3 hours despite correction of hemodynamic status and diuretic therapy, especially if fluid overload, hyperkalemia, or metabolic acidosis were also present. Twenty variables were analyzed by univariate analysis; these included nine preoperative variables--age, sex, hypertension, atherosclerosis, diabetes mellitus, left ventricular end-diastolic dimension (LVEDD) >5 cm, preoperative congestive heart failure, renal insufficiency (serum creatinine > or =130 micromol/L on two occasions), and sepsis--10 intraoperative variables--duration of CPB, redo procedures, emergency surgery, use of intraaortic balloon pump (IABP) in operating room, use of gentamicin, use of ceftriaxone, use of sulbactam/ampicillin, requirement of deep hypothermic circulatory arrest, duration of low mean perfusion pressure (mean pressure <50 mmHg for more than 30 minutes), operation on multiple valves--and one postoperative variable--significant hypotension (systolic blood pressure less than 90 mmHg for more than 1 hour). Significant variables or the variables having a trend (p<0.1) to be associated with ARF were included in stepwise multiple logistic regression analyses. Three regression analyses were performed separately. The incidence of ARF requiring dialysis in the study period was 15.0%. Significant risk factors for whole group of patients (regression I) were preoperative renal insufficiency (p<0.0001), postoperative hypotension (p<0.0001), cardiopulmonary bypass time more than 140 min (p<0.005), preoperative congestive heart failure (p<0.01), and history of diabetes mellitus (p<0.01). The risk factors in the valve group of patients (regression II) were preoperative renal insufficiency (p<0.0001) and postoperative hypotension (p<0.05). Risk factors in the CABG patients (regression III) were postoperative hypotension (p=0.0001), CPB time more than 140 min (p<0.05), preoperative renal insufficiency (p<0.05), and age (p<0.05). The authors conclude that preoperative renal insufficiency and postoperative hypotension are the most important independent risk factors for ARF in postcardiac surgical patients. In addition, CPB time greater than 140 minutes and old age are also independent risk factors for ARF in CABG patients. CPB time more than 140 minutes, history of diabetes mellitus, and preoperative congestive heart failure are independent risk factors for development of ARF in our total group of patients. These findings may have important clinical implications in the prevention of ARF in postcardiac surgical patients.

Repair of ruptured sinus of valsalva aneurysm: determinants of long-term survival.

BACKGROUND: Ruptured sinus of Valsalva aneurysm is a rare cardiac anomaly and long-term survival after surgical treatment is not well established. This study was designed to investigate the determinants of long-term survival after repair of ruptured sinus of Valsalva aneurysm. METHODS: From April 1978 to April 1996, 53 patients underwent operation for ruptured sinus of Valsalva aneurysm. The incidence among our cardiac surgical population was 0.56%. Long-term survival was investigated in 46 patients (13 to 65 years) who survived the operation, with 96.2% follow-up completeness (mean+/-standard deviation, 6.5+/-4.9 years; maximum, 17.2 years), by univariate and multivariate analyses. RESULTS: There was no early operative death and no recurrence after the initial repair. Actuarial survival was 83.8%+/-8.4% at 15 years. Reoperation, aneurysm draining into the left ventricle, aortic prosthetic dehiscence, bacterial endocarditis, and aortic cross-clamp time (<70 minutes) were significant factors in long-term survival (p < 0.05). Multivariate analysis revealed that only aortic prosthesis dehiscence was the significant factor influencing late survival (p = 0.0001). CONCLUSIONS: Surgical treatment for ruptured sinus of Valsalva aneurysm is safe and has satisfactory results. Aortic prosthesis dehiscence is the independent determinant for long-term survival. Other factors including bacterial endocarditis, concomitant ventricular septal defect repair, and aortic valve replacement did not independently influence long-term survival.

A survey of the long term outcome of elderly stroke survivors and the needs of their carers.

A survey was conducted to assess the long term outcome of 60 elderly stroke survivors (mean age, 81.7 years). Of these patients, 48% died within one year of discharge and 79% of the mortality occurred in the first six months. Patients discharged to institutions after the initial stroke had a significantly higher risk of death in one year (relative risk=1.47) compared with those who were discharged home. For those who survived for a mean period of 18.6months, 72% (21/29) were institutionalised. This group had significantly worse functional status and mobility compared with those who were living at home. The caring of elderly stroke patients was considered a heavy burden for most carers at home or in institutions and the need for medical and social support was great.

Intraoperative TEE assessment of ventricular septal defect with aortic regurgitation.

BACKGROUND: It is desirable to repair but not replace the aortic valve in patients with ventricular septal defect and acquired aortic regurgitation. Precise definition of the valvar pathology with monitoring of its repair perioperatively would enhance the surgical management of this condition. METHODS: Fourteen consecutive patients (age, 10.6 +/- 6 years; weight 29.7 +/- 5.7 kg) who underwent repair of ventricular septal defect with aortic regurgitation were studied by intraoperative transesophageal echocardiography. The severity of prolapse of each of the individual aortic cusps and its adjacent sinus was assessed and the valvar regurgitation quantified by Doppler-derived regurgitant indices. The echocardiographic and surgical findings were correlated and the preoperative and postoperative echocardiographic data were compared to assess the effectiveness of operation. RESULTS: Eight subarterial and six perimembranous defects were located accurately and their sizes (11.8 +/- 3.0 mm) correlated well (r = 0.80) with the surgical measurements. Transesophageal echocardiography detected prolapse of the aortic valve and its sinus in all 14 patients. The severity of the prolapse was severe in 10, moderate in 4, and mild in 5 leaflets. One the basis of these findings, together with the Doppler-derived mean regurgitant indices, exploration of the valve and valvuloplasty were executed appropriately in 12 of 14 patients. In all 14 patients, transesophageal echocardiography after bypass revealed no further cuspal prolapse and significant reduction of the mean regurgitant index (0.55 +/- 0.23 to 0.17 +/- 0.15, p < 0.0001). Residual ventricular septal defect was detected in 5 patients and the only patient with significant shunting who required reexploration was identified correctly. CONCLUSIONS: Intraoperative transesophageal echocardiography can assess effectively the surgical repair of ventricular septal defect with aortic regurgitation and provide information that directs and alters surgical plans to the benefit of patients.

Surgical resection of pulmonary metastases from nasopharyngeal carcinoma.

BACKGROUND: Nasopharyngeal carcinoma (NPC), unlike other head and neck cancers,is known for its propensity for distant metastases. Chemotherapy remains the mainstay of treatment because of this and the chemosensitivity of the tumour, but long-term control is rare. The surgical management of pulmonary metastases of other extrathoracic malignancies prompted this review of surgical management of patients with NPC. METHODS: Thirteen thoracotomies were performed in 12 patients with pulmonary metastases as the first and only site of relapse of nasopharyngeal carcinoma. Postoperative chemotherapy was given in four patients, radiotherapy to the mediastinum in one patient and both chemotherapy and radiotherapy in two patients. The survival pattern of this group of 12 patients was compared with a historical control group consisting of 65 patients without surgical resection. RESULTS: Lymph node involvement was documented in four patients during operation. Four patients relapsed after surgical resection, two of them were from the group of three patients with lymph node involvement. The site of subsequent relapse was the lung for three patients and the skeletal system for the fourth. The 2 year actuarial survival of the surgically resected group compared favourably with the historical control group (80% and 24.1%, respectively; P=0.0002 by Mantel-Cox text). CONCLUSIONS: Surgical resection of pulmonary metastases from NPC seems to be a promising approach thought the effect of case selection cannot be excluded and further studies are indicated. The importance of exploration and dissection of mediastinal nodes in the surgical management of pulmonary metastases from NPC was demonstrated.

Surgical repair of coarctation of the aorta in neonates: factors affecting early mortality and re-coarctation.

Between October 1979 and January 1993, 85 Chinese neonates in Hong Kong underwent surgical repair for coarctation of the aorta. Their mean (s.e.) age and body weight at operation was 15.6(8.5) days and 3.06(0.56) kg, respectively. Simple coarctation was present in 17 babies, while 36 had additional ventricular septal defect and 31 had associated major complex intracardiac lesions. Subclavian flap aortoplasty was performed in 56 babies, resection with end-to-end anastomosis in 18 and aortoplasty with the use of a GORETEX patch in 11. The overall early mortality rate was 16.5%. To identify risk factors for early operative mortality, various clinical variables, surgical options, associated heart lesions and dimensions of the aortic arch at different sites for each patient were reviewed. Univariate analysis identified statistically significant differences between the survivors and non-survivors for the following factors: preoperative body-weight, arterial pH and base excess, serum urea and creatinine levels. Stepwise logistic regression further distinguished serum creatinine levels and the period of operation as two significant risk factors. Contrary to previous reports, the dimensions of the aortic arch and type of surgery did not affect early operative mortality. Among the 71 hospital survivors followed for 38.2(38) months, residual or recurrent coarctation of the aorta was detected in 12(17%). The different surgical operations were not related to the incidence of late complication. The size of the distal transverse arch, however, was different (P=0.05) in those who did and did not develop aortic sequela. Successful balloon angioplasty was subsequently performed in 11 patients. In an era of echocardiography with prenatal diagnosis and therapeutic catheterization, early recognition of the disease with prompt prostaglandin infusion should prevent collapse of the baby, thus avoiding renal impairment and sever metabolic acidosis. Balloon angioplasty would offer a simple effective treatment of patients who developed aortic re-coarctation.

Wilms' tumor with intracardiac extension: chemotherapy before surgery.

The article describes two Chinese boys ages 2 and 3 years with unilateral Wilms' tumors complicated by intracaval and intracardiac extension. In contrast to the previously recommended treatment with surgery followed by chemotherapy and radiation therapy, the children were managed primarily with combination chemotherapy before definitive operation. Reduction of tumor size on serial imaging was documented, and no viable tumor cells were found when the involved kidney and right atrium were explored. Both patients remained alive without evidence of disease more than 5 years after initial diagnosis. A literature search revealed case reports and retrospective analyses of 70 patients with Wilms' tumors and intracardiac involvement, and a tendency toward preoperative chemotherapy with or without the addition of radiation therapy was observed. The overall outcome of this group of patients parallels the outcome of those without intracardiac extension by histology and stage. Wilms' tumor presenting with extension into the inferior vena cava and right atrium is thus rare and renders the affected child with additional cardiovascular complications and operative risks. As a result of the uncommon occurrence, a consensus on management based on prospective study would be difficult. The present report and the literature are supportive of the use of preoperative chemotherapy in the initial management of advanced Wilms' tumor extending into the right atrium.

Management evolution of pulmonary atresia and intact ventricular septum.

To examine the impact on survival and clinical course of incorporating the morphologic classification of the right ventricle into the evolving management strategy for babies with pulmonary atresia and intact ventricular septum, the surgical results and follow-up status of the first 62 consecutive patients managed in this hospital between 1979 and 1990 were reviewed. Before 1984, all 23 babies from group I underwent primary right ventricular outflow reconstruction irrespective of right ventricular morphology and size. Since 1984, depending on the morphology and size of the right ventricle, 39 babies from group II had either closed transventricular pulmonary valvotomy (n = 31) or a shunt operation (n = 8). There were 10 hospital (43%) and 2 late deaths (total mortality 52%) in our group I patients. Three of the 11 long-term survivors had cyanosis at rest but none had any residual pressure gradient across the pulmonary outflow. Group II had 6 hospital (15%) and 4 late deaths (total mortality = 26%). Of the 29 long-term survivors, 9 had a second-stage right ventricular outflow reconstruction, 8 had balloon valvuloplasty and 2 had successful Fontan operation. At the latest follow-up, 5 children from this group have cyanosis at rest, 1 has a residual gradient (55 mm Hg) across the infundibulum, and 3 have right ventricular dysfunction. The hospital and total mortality for babies in group II was significantly lower than that in group I (p < 0.01). These data suggest that tailoring the treatment to the right ventricular anatomy results in a lower overall mortality although long term postoperative hemodynamic abnormalities are observed in both groups.

Paediatric thymoma: unusual occurrence in two siblings.

Invasive cystic thymoma is reported in two siblings (an 11-year-old girl and a 9-year-old boy) and the radiographic, CT and ultrasonographic features are described. The tumours were removed by thoracotomy. Familial thymic masses are reviewed, and the imaging differential diagnosis of cystic anterior mediastinal mass in a child is discussed.

Modified Fontan procedure for severe Ebstein's malformation with predominant tricuspid stenosis.

Two children, aged 7 and 6 years, had severe Ebstein's malformation of the tricuspid valve and underwent operation because of progressive cyanosis (saturation, 70%). Preoperative angiography demonstrated linear attachment of the distal edges of the displaced anterosuperior and mural leaflets, leaving only a "keyhole" communication between the atrialized and functional portions of the right ventricle. Operation was directed toward completely excising these dysplastic leaflets, which were obstructing the flow of blood. The continuity between the functional right ventricle and pulmonary trunk was left intact. In addition, an atriopulmonary truncal connection was established. Postoperatively, both children were in functional class I with arterial saturation of 95%. Angiography and Doppler echocardiography demonstrated that there was a dominant phase of systolic flow of blood up the pulmonary trunk from the right ventricle, and also diastolic filling of the pulmonary arteries through the atriopulmonary truncal connection. The filling patterns did not change over time for the follow-up period of 4 and 1.5 years, respectively. This modified Fontan procedure appears to be an effective surgical alternative for some patients with severe Ebstein's malformation and predominant tricuspid stenosis.

Balloon valvuloplasty after pulmonary valvotomy for babies with pulmonary atresia and intact ventricular septum.

During a 2 1/2-year period, staged procedures of transventricular closed pulmonary valvotomy followed by balloon valvuloplasty were attempted in 12 babies with pulmonary atresia and an intact ventricular septum. All babies immediately underwent valvotomy when echocardiography revealed a tripartite right ventricle with adequate inflow and outflow dimensions and without sinusoidal-coronary arterial fistulas. After valvotomy, the overall mortality rate was 25% (3/12), but the only surgical death (1/12, 8%) was due to failure to establish continuity between the right ventricular cavity and the pulmonary trunk. The other 2 babies died of neonatal complications after successful valvotomy. Angiocardiography performed 5 to 18 months after valvotomy documented substantial growth of the right ventricular inflow and outflow dimensions in the 9 survivors. Twelve balloon dilation procedures were then performed in 7 babies. All except 1 achieved a significant drop in the right ventricular to left ventricular peak systolic pressure ratio (0.96 +/- 0.40 to 0.56 +/- 0.28; p less than 0.01). Balloon valvuloplasty was not required in 1 baby and failed in the other, who then underwent successful right ventricular outflow tract reconstruction. After these staged procedures, follow-up at 1 month to 20 months (mean follow-up, 14.8 months) revealed resting cyanosis in 3 babies, which was related to severe residual infundibular stenosis (55 mm Hg) in 1 and a subnormal tricuspid valve annulus in 2. The remaining 5 babies (including 1 who required no valvuloplasty) were active and pink (saturation greater than 97%) and had a mean Doppler estimated gradient of 19 mm Hg (range, 8 to 36 mm Hg) across the pulmonary valve.(ABSTRACT TRUNCATED AT 250 WORDS)

An unusual cause of disabling angina following aortic valve replacement.

Severe ostial stenosis of the coronary arteries following aortic valve replacement is a potentially lethal complication. The usual presentations are recent onset of severe angina, ventricular arrhythmias, congestive heart failure, and sudden death. It is generally accepted to arise from injury to the coronary arteries during direct cannulation and continuous perfusion of cardioplegia under high pressure during operation. We report on a patient who developed critical left coronary ostial stenosis after aortic valve replacement. The cause for the stenosis was probably related to the over-sizing and orientation of the prosthesis. The prosthesis was replaced and patch angioplasty of the left coronary ostia performed. The patient was well with normal coronary anatomy three years after surgery.