The effect of medium selection on adipose-derived stem cell expansion and differentiation: implications for application in regenerative medicine.

The use of adipose-derived stem cells is wide-spread in both basic biology and regenerative medicine, due to the abundance of adipose tissue and the multipotent differentiation potential of the cells. However, the methods used to isolate and culture cells vary greatly between different research groups. Identification of medium formulations which provide rapid cell expansion while maintaining cell phenotype would have clear advantages. We compared growth and differentiation potential along the adipogenic lineage in human ADSCs in nine different media. We further assessed induced and spontaneous differentiation along the adipogenic, chondrogenic and osteogenic lineage in three different media. There was significant variation in the rate of growth between different media. All media supported ADSC phenotype and adipogenic differentiation, although there was variation between the different media. Differentiation along the adipogenic, chondrogenic and osteogenic lineages in the three media was confirmed, with some upregulation of specific genes observed when cells were left to spontaneously differentiate. Our study shows a direct comparison of human ADSCs grown in different media, both reported in the literature and commercially available. It indicates that rapid proliferation occurs most often in media which contain 10 % foetal bovine serum and that differentiation along different lineages can be induced but also occurs spontaneously once cells become confluent. These data provide a tool for other researchers to facilitate the choice of medium formulation most appropriate for different applications.

A randomized comparison of the MCRI On-X and CarboMedics Top Hat bileaflet mechanical replacement aortic valves: early postoperative hemodynamic function and clinical events.

OBJECTIVE: This study compared hemodynamic function and clinical events in consecutive patients randomly assigned to receive a wholly supra-annular replacement valve or a valve with an intra-annular component. METHODS: Fifty-two patients with an average age of 62 years (range 40-74 years) were sized for both a CarboMedics Top Hat valve (CarboMedics Inc, Austin, Tex) and an MCRI On-X valve (Medical Carbon Research Institute, LLC, Austin, Tex) before random assignment to receive either valve type. Echocardiographic and clinical assessments were performed in the immediate postoperative period and at 1 year. RESULTS: The mean effective orifice areas were 1.41 +/- 0.42 cm2 for the Top Hat and 2.17 +/- 0.78 cm2 for the On-X (P < .0001). The mean pressure differences were 12.2 +/- 4.4 mm Hg and 6.9 +/- 3.6 mm Hg, respectively (P < .0001). New York Heart Association functional class was better with the On-X than the Top Hat valves, but there were no differences in clinical events, regression of left ventricular mass, or measures of hemolysis. CONCLUSION: The partially intra-annular MCRI On-X valve was hemodynamically superior to the wholly supra-annular CarboMedics Top Hat valve. However, there were no differences in early clinical outcomes between the two valve types.

Significant reduction of endemic MRSA acquisition and infection in cardiothoracic patients by means of an enhanced targeted infection control programme.

Due to increasing methicillin-resistant Staphylococcus aureus (MRSA) infection in cardiothoracic patients at St Thomas' Hospital, an enhanced infection control programme was introduced in September 2000. It was based on UK national guidelines on the control of MRSA and targeted additional identified risk factors for surgical site infection (SSI). It included recognition of the problem by senior staff and their taking responsibility for it; intensive support, education and advice from the infection control team; improved ward and theatre hygiene; pre-admission, admission and weekly MRSA screening; isolation and clearance treatment; nursing care pathways for MRSA colonized patients; and teicoplanin plus gentamicin surgical prophylaxis. The effectiveness of the programme was assessed by retrospective analysis of computerized patient data for the 16 months before and after the introduction of the programme. There was no significant change in the number of operations or the proportion of patients admitted with MRSA, although nine patients were cleared of carriage before admission. However, there were significant falls in the proportion of patients acquiring MRSA on the ward [38/1036 to 14/921, P=0.003, RR 2.4 (95%CI 1.32-4.42)] and in the rate of bloodstream MRSA infections [12/1075 to 2/956, P=0.014, RR 5.34 (95%CI 1.20-23.78)]. Sternal and leg wound infections both halved (from 28/1075 to 13/956 and 16/1075 to 7/956, respectively) but this did not reach statistical significance. These results demonstrate that an enhanced, targeted infection control programme based on the UK national guidelines, SSI prevention guidelines and local risk assessment can reduce the incidence of nosocomial MRSA acquisition and invasive infection in cardiothoracic patients in the face of continuing endemic risk.

Hospital mortality and long-term survival after pulmonary resection in the elderly.

We have studied the hospital mortality and long-term survival in two groups of patients: those between 50 and 69 years of age (group 1, n = 136) and those older than 70 years of age (group 2, n = 43). The two groups were similar in terms of the distribution of histological type and postsurgical staging. The patients were treated by either lobectomy or pneumonectomy; the lobectomy rate was similar in both groups: 61% and 51% (not significant). Hospital mortality for group 1 was 4.4% and for group 2, 6.9%. Mortality was higher in both groups after pneumonectomy compared with lobectomy, but this was not significant (group 1, 6.2% versus 1.9%; group 2, 9.1% versus 4.7%). Hospital mortality after pulmonary resection was greater in the elderly, but this was not significant (lobectomy: 1.9% [group 1] versus 4.7% [group 2]; pneumonectomy: 6.2% [group 1] versus 9.1% [group 2]. The overall long-term survival at 2 and 4 years was 62.3% and 50.0% for group 1 and 72.5% and 66.6% for group 2. We suggest that the operative risk in the elderly is not prohibitive and the long-term results are acceptable. Patients should not be denied operation on the basis of age alone.

HIV-1 infection and cardiothoracic surgery: the difference in attitudes between consultants and junior surgeons in the United Kingdom.

A postal survey was carried out inviting the opinions of consultant and trainee cardiothoracic surgeons on the subject of operating upon patients who are either HIV-1 antibody positive or suffer from full-blown AIDS. The questionnaire contained both cardiac and thoracic clinical situations, all of which under normal circumstances would be managed surgically with low operative mortality and long median survival. The overall response rate was 72.4%. A significantly greater number of consultants replied compared to juniors, 80% and 51.6%, respectively (P less than 0.001). In both groups, surgeons were more likely to operate upon a patient who was HIV-1 antibody positive than one who had AIDS. There were no significant differences in the replies of consultants and juniors to the clinical scenarios presented. However, a greater number of juniors admitted to modifying their surgical practice in the light of the increasing incidence of HIV-1 infection (P less than 0.001). Routine preoperative HIV antibody testing was advocated by 77.8% of consultants and 75% of juniors and this rose to 95.1% and 97%, respectively, if patients were in the traditionally high risk groups. Four consultants admitted that they were already performing routine preoperative HIV antibody screening. This survey emphasized the real concern amongst cardiothoracic surgeons, irrespective of their grade, about HIV-1 infection and the need for both education and clear policy guidelines to deal with this difficult issue.

Performance data and the mortuary register.

OBJECTIVE: To compare departmental records of deaths after cardiac surgery with the hospital's information system. DESIGN: Matched pairs comparisons: (i) historic record compared with current record from another source; (ii) contemporary records from different sources; and (iii) timed records from different sources. SETTING: Regional cardiothoracic units at St George's and St. Thomas's Hospitals. SUBJECTS: 2664 cardiac surgical operations at St George's between January 1992 and June 1994, 215 deaths in the cardiac surgery database at St Thomas's between April 1993 and March 1997, 120 in-hospital deaths received by the mortuary at St George's during June 1999. MAIN OUTCOME MEASURES: The difference in the number of in-hospital deaths from departmental, hospital, and mortuary sources. RESULTS: Four of 2664 operations (0.15%) had been incorrectly coded as leaving hospital alive. Fewer than 80% of the actual number of deaths after cardiac surgery at St Thomas's had been recorded on either the departmental database or the hospital administration system. For 9% of deaths received in the mortuary, it took more than 6 working days for the hospital record to be updated, and at the time of reporting 1 case had not been updated after 14 working days: the date of death was inaccurate in 4/113 (3.5%) of cases. CONCLUSIONS: The mortuary staff can contribute to improving the accuracy of body counts. Death rates and performance data should not be published without statistical peer review.

Is antibiotic prophylaxis ever necessary before transoesophageal echocardiography?

Evidence strongly suggests that antibiotic prophylaxis should not be used routinely for transoesophageal echocardiography for any indication.

Rupture of the tracheobronchial tree.

Eleven cases of tracheobronchial rupture are described. Nine were the result of external non-penetrating trauma and all but three had other serious injuries. The remaining two were caused by endobronchial intubation. Of the cases caused by external injury, respiratory tract injury was confined to the cervical trachea in three. Two required tracheostomy and repair and the third was managed conservatively; all made satisfactory recoveries. Intrathoracic rupture was recognised on or soon after admission in three cases. One patient died of uncontrollable pulmonary haemorrhage before he could be operated on; immediate repair gave good long term results in the other two. In three cases rupture of the main bronchus was not recognised until complete obstruction developed three, five, and 12 weeks after the accidents. The strictures were resected and the lung re-expanded. Robertshaw endobronchial tubes ruptured the left main bronchus in two patients undergoing oesophageal surgery. Uneventful recovery followed immediate repair. The difficulty of confirming rupture of a major airway is discussed and the importance of conserving the lung when the diagnosis has been missed is emphasised.

Herniation of the heart into the right pleura following blunt chest trauma--an unusual presentation.

A 21-year-old male patient had sustained a blunt chest and abdominal trauma during a traffic accident. All the major injuries were on the left side. On the second day, a massive shift of the mediastinum to the right was noted. Further investigations raised the suspicion of herniation of the heart into the right pleural cavity. However, the patient's hemodynamic stability did not fit into the picture. Echocardiography and CT scan helped reinforce our suspicion. Herniation was confirmed at the operation, which was performed through median sternotomy. The patient recovered well without complications.

Effect of acute cigarette smoking on gastric secretion.

The effects of smoking one cigarette on a plateau of submaximal gastric secretion induced by histamine acid phosphate (16 nmol kg-1 h-1 (0.005 mg kg-1 h-1)) were measured in eight normal volunteers and in eight duodenal ulcer subjects. The rate of secretion in both groups fell by 25% without any statistically significant change in pyloric loss or duodenogastric reflux. It is concluded that smoking reduces gastric secretion. The possibility that relative antral hypoacidity induced by regular smoking produces an increase in parietal cell mass via a feedback mechanism mediated by gastrin is discussed: such a mechanism would explain the previously reported positive correlation between maximal gastric secretion of acid and the total dose of cigarettes.

Intracellular filaments in human cancer cells: a histological study.

The distribution of intracellular filamentous systems in human breast and colonic cancers has been demonstrated by means of the tannic acid-phosphomolybdic acid-milling dye staining technique. Plasma membrane-associated staining is prominent in breast carcinomas and is strongest in anaplastic tumours. Strong staining is also noted in the cells at the margins of the tumours where the malignant cells are invading the surrounding tissues. In colonic carcinomas, filaments are mainly restricted to the terminal web region of the cells but dedifferentiation is accompanied by the development of circumferential staining of the cell membrane. The results are discussed in relation to immunohistochemical and electron microscopic studies of contractile proteins in non-muscle cells.

Emergency endovascular stent grafting of a traumatic thoracic aortic dissection.

An endovascular stent graft was successfully used in the management of a patient with multiple injuries, who sustained an acute type B dissection of the thoracic aorta. We discuss the multidisciplinary approach taken, the contra-indications of conventional surgery, and the radiological imaging employed. We conclude that stent grafts can be safely deployed without morbidity or mortality in a multiply injured patient.

Attitudes of cardiothoracic surgeons in the UK to human immunodeficiency virus.

A survey was carried out into attitudes of cardiothoracic surgeons in the UK to human immunodeficiency virus type 1 (HIV-1) infection associated with clinical situations that would normally have been managed surgically with low operative mortality rates and long median survival times. The survey response rate was 72.4 per cent. In patients with acute valvular insufficiency or with continuing angina despite maximal medical therapy (unstable angina) who were HIV-1 antibody positive, 75.8 and 80.8 per cent, respectively, of surgeons would operate. If the patient had end-stage infection, acquired immune deficiency syndrome (AIDS), 29.7 per cent and 34.7 per cent, respectively, would consider surgical intervention. When asked to perform simple procedures such as open lung biopsy or pleurectomy on a patient with AIDS, more than half of surgeons would operate (52.2 and 65.6 per cent respectively). In patients with operable carcinoma of the lung and asymptomatic HIV-1 infection 52.3 per cent would operate. This fell to 15.0 per cent if the patient had a diagnosis of AIDS. The majority of surgeons (77.2 per cent) felt patients should have an HIV-1 antibody test before operation and this rose to 95.6 per cent if patients were in a high-risk group; 60.2 per cent of surgeons had changed their surgical practice to reduce the risks of blood-borne infection.