PubMed Health⌕ Search

Biomedical subjects

M McCulloch

Publications and source records attributed to M McCulloch.

At least 19 recordsLinked to original sources
PubMed2006

Liver transplantation at Red Cross War Memorial Children's Hospital.

UNLABELLED: The liver transplant programme for infants and children at Red Cross War Memorial Children's Hospital is the only established paediatric service in sub-Saharan Africa. Referrals for liver transplant assessment come from most provinces within South Africa as well as neighbouring countries. PATIENTS AND METHODS: Since 1987, 81 children (range 6 months-14 years) have had 84 liver transplants with biliary atresia being the most frequent diagnosis. The indications for transplantation include biliary atresia (48), metabolic (7), fulminant hepatic failure (10), redo transplants (3) and other (16). Four combined liver/kidney transplants have been performed. Fifty-three were reduced-size transplants with donor/recipient weight ratios ranging from 2:1 to 11:1 and 32 children weighed less than 10 kg. RESULTS: Sixty patients (74%) survived 3 months-14 years post-transplant. Overall cumulative 1- and 5-year patient survival figures are 79% and 70% respectively. However, with the introduction of prophylactic intravenous ganciclovir and the exclusion of hepatitis B virus (HBV) IgG core Ab-positive donors, the 1-year patient survival is 90% and the projected 5-year paediatric survival is > 80%. Early (< 1 month) post-liver-transplant mortality was low. Causes include primary malfunction (1), inferior vena cava thrombosis (1), bleeding oesophageal ulcer (1), sepsis (1) and cerebral oedema (1). Late morbidity and mortality was mainly due to infections: de novo hepatitis B (5 patients, 2 deaths), Epstein-Barr virus (EBV)- related post-transplantation lymphoproliferative disease (12 patients, 7 deaths) and cytomegalovirus (CMV) disease (10 patients, 5 deaths). Tuberculosis (TB) treatment in 3 patients was complicated by chronic rejection (1) and TB-drug-induced subfulminant liver failure (1). CONCLUSION: Despite limited resources, a successful paediatric programme has been established with good patient and graft survival figures and excellent quality of life. Shortage of donors because of infection with HBV and human immunodeficiency virus (HIV) leads to significant waiting-list mortality and infrequent transplantation.

Adolescent↗
PubMed2005

Liver transplantation for children: Red Cross Children's Hospital experience.

BACKGROUND: The liver transplant program for infants and children at the Red Cross Children's Memorial Hospital is the only established pediatric service in sub-Saharan Africa. Since 1985, 250 infants and children have been assessed and 155 accepted for transplantation. METHODS: Since 1987, 76 children (range 6 months to 14 years) have had 79 liver transplants, with biliary atresia being the most frequent diagnosis. The indications for transplantation include biliary atresia (n = 44), metabolic (n = 7), fulminant hepatic failure (n = 10), redo transplants (n = 3), and other (n = 15). Three combined liver/kidney transplants have been performed. Forty-nine were reduced-size transplants with donor: recipient weight ratios ranging from 2:1 to 11:1, and 29 children weighed < 10 kg. RESULTS: Fifty-six (74%) patients survived 3 months to 12 years posttransplant. Cumulative 1- and 5-year patient survival data are 79% and 70%, respectively. However, with the introduction of prophylactic intravenous gancyclovir and the exclusion of hepatitis B virus (HBV) IgG core Ab-positive donors, the projected 5-year pediatric survival has been >80%. Early (<1 month) post-liver-transplant mortality was low, but included: primary malfunction (n = 1); inferior vena cava thrombosis (n = 1); bleeding esophageal ulcer (n = 1); and sepsis (n = 1). Late morbidity and mortality was mainly due to infections: de novo hepatitis B (5 patients, 2 deaths); Epstein-Barr virus (EBV)-related posttransplantation lymphoproliferative disease (12 patients, 7 deaths); and cytomegalovirus disease (10 patients, 5 deaths). Tuberculosis (TB) treatment in three patients was complicated by chronic rejection (n = 1) and TB drug-induced subfulminant liver failure (n = 1). CONCLUSIONS: Despite limited resources, a successful pediatric program has been established with good patient and graft survival figures and excellent quality of life. Shortage of donors due to HBV and human immunodeficiency virus (HIV) leads to significant waiting list mortality and infrequent transplantation.

Adolescent↗
PubMed2004

Liver transplantation for children--the Red Cross Children's Hospital experience.

UNLABELLED: Liver transplantation for infants and children has been available in South Africa at a single centre, the only established service in Sub-Saharan Africa, for more than a decade. Current concerns have shifted from an initial target of early post-transplant survival to quality of life in the long-term. MATERIALS AND METHODS: Since 1985, 225 infants and children have been assessed, with 146 accepted for transplantation. Sixty-nine have had 71 orthotopic liver transplants (OLTx). Biliary atresia was the most frequent diagnosis (54%) followed by acute liver failure (ALF) (15%). Waiting list mortality has remained high (23%), particularly for the ALF group (50%). Forty-three were reduced size transplants with donor: recipient weight ratios ranging from 2:1 to 11:1. Twenty-seven were <10 kg. RESULTS: Fifty (74%) survive 1 month-12 years post-transplant. Actuarial survival after 1996 since HBV core antibody positive donor livers were refused and prophylactic IV ganciclovir used has been >82%. Early post-OLTx mortality was low (5%), one primary non-function, one IVC thrombosis, one PV thrombosis, but late morbidity and mortality (20%) was mainly due to viral infection: de novo hepatitis B (five patients, three deaths), EBV-related post-transplantation lymphoproliferative disease (PTLPD) (eight patients, six deaths) and CMV disease (11 patients, five deaths). Tuberculosis prophylaxis, required in six cases, resulted in major morbidity in two and mortality in one. Poor compliance played a significant role in seven deaths. Hypertension requiring medication along with some compromise of renal function has been present in all but two patients. However, all those of school-going age (25) attend school normally and remain in good health and only three of the survivors have abnormal liver function tests. CONCLUSIONS: Successful liver transplantation is possible in a developing country with limited resources. Scarcity of virus-free donors (HBV and HIV) leading to waiting list mortality and infrequent re-transplantation along with long-term consequences of immunosuppression (infection, lymphoma and renal toxicity) remain problems. Intense education of the caregiver and close follow-up, particularly of those living at long distances has partly addressed the compliance problem.

Actuarial Analysis↗
PubMed2003

Fast, real-time spectrometer based on a pulsed quantum-cascade laser.

We describe a mid-infrared spectrometer that is based on the combination of a multiple-pass absorption cell and a submicrosecond pulsed quantum-cascade laser. The spectrometer is capable of both making sensitive measurements and providing a real-time display of the spectral fingerprint of molecular vapors. For a cell with a path length of 9.6 m, dilution measurements made of the nu9 band transitions of 1,1-difluoroethylene indicate a sensitivity of 500 parts in 10(9), corresponding to a fractional absorbance of 4 x 10(-4).

Journal Article↗
PubMed2001

Real-time three-dimensional dobutamine stress echocardiography in assessment stress echocardiography in assessment of ischemia: comparison with two-dimensional dobutamine stress echocardiography.

OBJECTIVES: This study was designed to test the feasibility and efficacy of using real-time three-dimensional echocardiography (RT-3D) to detect ischemia during dobutamine-induced stress (DSE) and compares the results with conventional two-dimensional echocardiography (2D). BACKGROUND: Real-time three-dimensional echocardiography, a novel imaging technique, offers rapid acquisition with multiple simultaneous views of the left ventricle (LV). These features make it attractive for application during stress. METHODS: Of 279 consecutive patients screened for image quality by 2D, 253 patients with adequate images underwent RT-3D and 2D within 30 s of each other at baseline and at peak DSE. RESULTS: Real-time three-dimensional echocardiography and 2D showed good concordance in detection of abnormal LV wall motion at baseline (84%: Kappa = 0.59) and at peak DSE (88.9%: Kappa = 0.72). Left ventricular wall motion scores were similar at baseline and peak DSE using both techniques. Interobserver agreements for detection of ischemia at peak DSE were superior for RT-3D, 92.7% compared with 84.6% for 2D (p < 0.05). Mean scanning time at peak stress by RT-3D in 50 randomly selected patients was shorter, 27.4 +/- 10.7 s compared with 62.4 +/- 20.1 s by 2D (p < 0.0001). In 90 patients with coronary angiograms, RT-3D had a sensitivity of 87.9% in the detection of coronary artery disease (CAD) compared with 79.3% by 2D. CONCLUSIONS: Real-time three-dimensional dobutamine stress echocardiography is feasible and sensitive in the detection of CAD. The procedure offers shorter scanning time, superior interobserver agreements and unique new views of the LV.

Coronary Disease↗
PubMed2001

Real-time 3-dimensional echocardiography imaging for right ventricular endomyocardial biopsy: a comparison with fluoroscopy.

Real-time 3-dimensional (RT3D) echocardiography has the potential to precisely identify the position of an object in 3-dimensional space. Therefore, we hypothesized that RT3D echocardiography could rapidly facilitate accurate placement of a bioptome within the right ventricle and may offer advantages over a fluoroscopically guided approach. During 63 routine right ventricular biopsy procedures (total of 315 biopsy attempts) in 33 cardiac allograft recipients, the bioptome was initially guided against the intraventricular septum with the use of biplane fluoroscopy. Bioptome position was then evaluated by RT3D echocardiography by using the Volumetrics Model 1 with the transducer placed at the apex. Multiple long-axis and short-axis planes were simultaneously visualized and customized to identify the tip of the bioptome. Bioptome placement was prospectively classified as septal, free wall/septal junction, or free wall. Of the 36 patients studied, 33 (91%) had adequate RT3D images. Of 315 bioptome placements visualized by RT3D echocardiography after fluoroscopic placement, bioptome position against the septum was confirmed in 113 (36%), against the septal/free wall (anterior or posterior) junction in 140 (44%), against the free wall in 60 (19%), and in the coronary sinus in 2 (1%). RT3D echocardiography is readily feasible for use in the majority of transplant patients undergoing right ventricular endomyocardial biopsy. Visualization of the bioptome in multiple simultaneous planes allows accurate localization of the biopsy site. The potential for improved localization of the bioptome tip in the right ventricle may have important clinical implications for augmenting the efficacy of this procedure.

Adult↗
PubMed2000

Doctors' attitudes to the care of children with HIV in South Africa.

A descriptive survey was conducted on the attitudes of medical staff to caring for HIV-infected children, in three teaching hospitals in Cape Town, South Africa. The study was designed to determine whether the knowledge of a patient's HIV-positive status affects the doctor's attitude and management, to determine doctors' perceived competence with regard to the management of paediatric AIDS and to identify their major concerns in the management of paediatric patients with HIV infection. The response rate was 86%, including 89% of consultants, 81% of registrars and 87% of medical officers employed at the hospitals during the period July/August 1996. The study has highlighted that doctors working in a situation where the epidemic has only recently emerged perceive themselves as being inadequate with regard to managing HIV infection in children. There are indications that doctors may be influenced by the HIV-positive status of children when making decisions regarding their medical management. One of the major concerns with regard to the management of patients with HIV, expressed by doctors in the study, was the lack of management protocols and policy guidelines.

Acquired Immunodeficiency Syndrome↗
PubMed2000

Ten years of liver transplantation at Groote Schuur Hospital.

INTRODUCTION: Liver transplantation has evolved from an experimental procedure to being the treatment of choice for many patients with end-stage liver disease, and is performed on a routine basis in most major centres throughout the world. However, certain situations peculiar to developing countries have a major impact on liver transplant programmes in these countries. We present the results of the liver transplant programme in Cape Town. PATIENTS AND METHODS: All patients undergoing orthotopic liver transplantation at Groote Schuur Hospital and Red Cross War Memorial Children's Hospital were included in this report. Standard surgical techniques were used for procuring the donor liver, the recipient hepatectomy and the subsequent implantation of the liver. All patients received standardised peri-operative management; in particular, the immunosuppressive protocol consisted of cyclosporin, steroids and azathioprine. Since October 1988, 83 patients have undergone 89 orthotopic liver transplants. There were 44 adults and 39 children, the age range being from 6 months to 56 years. The commonest indications for hepatic transplantation in adults included cryptogenic cirrhosis, auto-immune hepatitis and primary sclerosing cholangitis. In children biliary atresia was the commonest cause of liver failure. RESULTS: Of the 81 patients transplanted, 50 are alive and well with follow-up ranging from 2 months to 9.5 years. The cumulative graft survival rate was 72% at 1 year and 61% at 5 years. Six patients have undergone re-transplantation and 4 patients have had combined liver/kidney transplants. De novo hepatitis due to hepatitis B virus (HBV) has occurred in 8 patients following transplantation. Subsequent investigation has shown that 5 of the donors of these livers were hepatitis B core antibody (HBcAb)-positive, while information on the remaining 3 was not available. Tuberculosis (TB) has been a significant problem in 4 patients, with 2 deaths precipitated by anti-TB drug-induced hepatitis. Post-transplant lymphoproliferative disorder was also responsible for significant postoperative morbidity. CONCLUSION: Orthotopic liver transplantation has been established at Groote Schuur Hospital as the treatment of choice for selected patients with chronic end-stage liver disease. However, hepatitis B and TB appear to present a problem. The particularly high prevalence of HBV carrier status in our donor population may necessitate the use of living donors in the future.

Adolescent↗
PubMed2000

Liver transplantation in children--the Red Cross War Memorial Children's Hospital experience.

Liver transplantation for infants and children has been available in South Africa for more than a decade. Current concerns have shifted from an initial target of early post-transplant survival to quality of life in the long term. Since 1985, 175 infants and children have been assessed, with 104 accepted for transplantation. Fifty have had orthotopic liver transplants (OLTx), 48 (3 retransplants) in Cape Town and 2 abroad. Biliary atresia was the most frequent diagnosis (52%) followed by acute liver failure (ALF) (16%). Waiting list mortality has remained high (15%), particularly for the ALF group (50%). Thirty-four patients survive 1 month--14 years post-transplant. Early post OLTx mortality was low (7%) but late morbidity and mortality (23%) were mainly due to viral infection: de novo hepatitis B (5 patients, 2 deaths), EBV-related post-transplantation lymphoproliferative disease (PTLPD) (6 patients, 4 deaths) and CMV disease (9 patients, 4 deaths). Tuberculosis prophylaxis, required in 6 cases, resulted in major morbidity in 1. Hypertension requiring medication along with some compromise of renal function has been present in all but 2 patients. However, all those of school-going age (20) attend school normally and remain in good health and only 3 of the survivors have abnormal liver function tests. Successful liver transplantation is possible in a developing country with limited resources. Scarcity of virus-free donors (HBV and HIV) leading to waiting list mortality and infrequent retransplantation along with long-term consequences of immunosuppression (infection, lymphoma and renal toxicity) remain problems.

Child↗
PubMed1999

Australia's oldest human remains: age of the Lake Mungo 3 skeleton.

We have carried out a comprehensive ESR and U-series dating study on the Lake Mungo 3 (LM3) human skeleton. The isotopic Th/U and Pa/U ratios indicate that some minor uranium mobilization may have occurred in the past. Taking such effects into account, the best age estimate for the human skeleton is obtained through the combination of U-series and ESR analyses yielding 62,000+/-6000 years. This age is in close agreement with OSL age estimates on the sediment into which the skeleton was buried of 61,000+/-2000 years. Furthermore, we obtained a U-series age of 81,000+/-21,000 years for the calcitic matrix that was precipitated on the bones after burial. All age results are considerably older than the previously assumed age of LM3 and demonstrate the necessity for directly dating hominid remains. We conclude that the Lake Mungo 3 burial documents the earliest known human presence on the Australian continent. The age implies that people who were skeletally within the range of the present Australian indigenous population colonized the continent during or before oxygen isotope stage 4 (57,000-71,000 years).

Animals↗
PubMed1998

Axonal swellings and degeneration in mice lacking the major proteolipid of myelin.

Glial cells produce myelin and contribute to axonal morphology in the nervous system. Two myelin membrane proteolipids, PLP and DM20, were shown to be essential for the integrity of myelinated axons. In the absence of PLP-DM20, mice assembled compact myelin sheaths but subsequently developed widespread axonal swellings and degeneration, associated predominantly with small-caliber nerve fibers. Similar swellings were absent in dysmyelinated shiverer mice, which lack myelin basic protein (MBP), but recurred in MBP*PLP double mutants. Thus, fiber degeneration, which was probably secondary to impaired axonal transport, could indicate that myelinated axons require local oligodendroglial support.

Animals↗
PubMed1997

ESR analysis of teeth from the palaeoanthropological site of Zhoukoudian, China.

An ESR dating study on teeth collected from layers 3, 6/7 and 10 at Locality 1, Zhoukoudian provides results that are in general agreement with an earlier multi-dating study and confirm an age range of 300-550 ka for the Homo erectus remains in the Peking Man Cave. Uncertainties due to U-uptake and the external gamma dose rates do not allow very precise age estimates for the respective layers.

Animals↗
PubMed1995

Post traumatic stress disorder: turning the tide without opening the floodgates.

The development of the legal concept of nervous shock represents a compromise between the need to compensate those suffering psychiatric damage and the need to protect a defendant from unlimited liability. The criteria which have developed to achieve this balance are arbitrary ones, which take little account of psychological or physiological knowledge about post traumatic stress disorder. It is suggested that recent developments in scientific understanding of this condition could usefully inform the legal process, and that some aspects of the dilemma could be avoided.

Humans↗
PubMed1985

Propofol ('Diprivan') for induction and maintenance of anaesthesia.

The use of propofol for the induction and maintenance of anaesthesia was investigated. Induction with propofol was straightforward, with only a small drop in blood pressure. Pain on injection was the only noteworthy complication, particularly when propofol was injected via a small vein in the dorsum of the hand. A rapid infusion of 9.0 mg/kg/h for 30 min and then 4.5 mg/kg/h supplemented with fentanyl maintained anaesthesia without problem. The duration of action of atracurium was unaffected by the infusion of propofol, but the duration of action of vecuronium appeared to be prolonged. Three investigations of propofol, dissolved in soya bean oil, were carried out.

Anesthesia, Intravenous↗
PubMed1981

The relationship of glucose utilization and morphological change in the visual system in hexacarbon neuropathy.

A reduction in local glucose utilization occurs in the superficial layer of the superior colliculus of rats following exposure to 0.5% 2,5-hexanedione in drinking water for 3 weeks. Axonal pathology, with increased neurofilaments and swelling, is seen at about 5 weeks in the distal portions of the optic pathways to the superior colliculus. These lesions in the optic system occur earlier and are more marked than those in the peripheral nerves and dorsal columns. The results suggest that the functional abnormality, as implied by the decreased glucose utilization, precedes the morphological changes in hexacarbon neuropathy.

Animals↗