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Biomedical subjects

N Campbell

Publications and source records attributed to N Campbell.

At least 37 records · Page 2Linked to original sources

Congenital chylothorax.

The objective of this paper is a retrospective study of all infants treated for congenital chylothorax at the Royal Children's Hospital (RCH), Melbourne, Australia and King Fahad National Guard Hospital (KFNGH), Riyadh, Kingdom of Saudi Arabia. The charts of all infants with congenital chylothorax admitted to RCH over a period of 13 years, June 1982-August 1994, and admissions to KFNGH over a 7-year period, June 1992-August 1998 inclusive, were reviewed including management outcome and complications. There were 19 infants, 13 from RCH and 6 from KFNGH; 11 females and 8 males. Three infants were managed antenatally. Fifteen infants presented immediately after birth. Seven were born with hydrops fetalis, 6 infants had syndromes and 10 infants were born prematurely. Regular infant feeding formula and/or breast milk were used successfully in 12 infants, while in 7 infants medium chain triglycerides (MCT) rich formula was used. Sixteen infants were mechanically ventilated with 75% of them ventilated for < or = 28 days. Fifteen infants received total parenteral nutrition (TPN), and in 80% for < or = 32 days. Hydropic infants had longer duration of mechanical ventilation and hospital stay with mean (range) of 33.9 (3-120) and 115 (23-225) days, respectively, compared with 18 (1-62) and 34.3 (14-88) days for nonhydropic infants. Five infants underwent surgery with failure in four. Sepsis and bronchopulmonary dysplasia were the main complications. The survival rate was 100% regardless of the mode of therapy. The prognosis of Isolated congenital chylothorax in term, and preterm infants is good even in the presence of hydrops. Breast milk and/or regular infant feeding formula should be used initially before proceeding to MCT-rich formula, which may be necessary in some cases. Surgery should be considered if conservative management of congenital chylothorax fails after 4-5 weeks.

Chylothorax↗

Canadian national high blood pressure prevention and control strategy.

Despite major efforts to prevent and control high blood pressure, it is one of the most common and important health problems facing Canadians. To address this issue, Health Canada, in collaboration with the Canadian Coalition for High Blood Pressure Prevention and Control, established an Expert Working Group to prepare a national strategy. The present report outlines a strategy to prevent and control high blood pressure. It is directed at policy makers at the local, provincial, and/or territorial and national levels in both the health and nonhealth sectors. The strategy is based on current research and expertise. A multifaceted, comprehensive approach is proposed because there is no one intervention that will accomplish the goal of improving the health of Canadians through high blood pressure prevention and control. The present report focuses on the general population. It does not address the unique needs of children, pregnant women or aboriginal peoples. Each of these groups needs to be studied in its own right, and, in particular, with the involvement of aboriginal people themselves. An implementation committee has been established to realize this strategy, and the Canadian Hypertension Society is a key stakeholder in this effort. Several initiatives are underway. Strong advocates are necessary to increase public awareness and to support the system changes required for a successful public health approach to reduce the prevalence of hypertension and its complications.

Adult↗

Induction of solid tumor differentiation by the peroxisome proliferator-activated receptor-gamma ligand troglitazone in patients with liposarcoma.

Agonist ligands for the nuclear receptor peroxisome proliferator-activated receptor-gamma have been shown to induce terminal differentiation of normal preadipocytes and human liposarcoma cells in vitro. Because the differentiation status of liposarcoma is predictive of clinical outcomes, modulation of the differentiation status of a tumor may favorably impact clinical behavior. We have conducted a clinical trial for treatment of patients with advanced liposarcoma by using the peroxisome proliferator-activated receptor-gamma ligand troglitazone, in which extensive correlative laboratory studies of tumor differentiation were performed. We report here the results of three patients with intermediate to high-grade liposarcomas in whom troglitazone administration induced histologic and biochemical differentiation in vivo. Biopsies of tumors from each of these patients while on troglitazone demonstrated histologic evidence of extensive lipid accumulation by tumor cells and substantial increases in NMR-detectable tumor triglycerides compared with pretreatment biopsies. In addition, expression of several mRNA transcripts characteristic of differentiation in the adipocyte lineage was induced. There was also a marked reduction in immunohistochemical expression of Ki-67, a marker of cell proliferation. Together, these data indicate that terminal adipocytic differentiation was induced in these malignant tumors by troglitazone. These results indicate that lineage-appropriate differentiation can be induced pharmacologically in a human solid tumor.

Adult↗

Classification of human liposarcoma and lipoma using ex vivo proton NMR spectroscopy.

Prognostication in patients with liposarcoma is a complex and controversial subject based on recognition of lipoblasts, adipocyte nuclear atypia, and qualitative estimations of cellularity and cell size. We show here that for 30 patients with liposarcoma and 5 patients with lipoma, spectral differences on high-resolution, magic angle spinning proton nuclear magnetic resonance (hr-MAS 1H-NMR) spectroscopy relate to known biochemical changes and correlate with adipocyte tissue differentiation, histologic cell type, and cellularity. The NMR-visible level of triglyceride is shown to correlate with liposarcoma differentiation, since the triglyceride level in well-differentiated liposarcoma is 33-fold higher on average than for myxoid/round cell liposarcoma, which in turn is 6-fold higher than the dedifferentiated and/or pleomorphic subtypes. The NMR-visible phosphatidylcholine level serves as an estimate of total tissue cell membrane phospholipid mass and was found to correlate with liposarcoma subtype. Pleomorphic liposarcoma, the most aggressive and metastatic subtype, was found to have a threefold increase in NMR-visible phosphatidylcholine level compared with dedifferentiated liposarcoma. The level of NMR-visible phosphatidylcholine was twofold greater in well-differentiated liposarcoma compared with lipoma and was threefold larger for the hypercellular myxoid/round cell subtype compared with the pure myxoid histology. Thus, NMR-derived parameters of tissue lipid may be used for objective distinction of liposarcoma histologic subtype/grade and lipoma from liposarcoma. These biochemical parameters may ultimately improve prognostication in patients with liposarcoma.

Humans↗

The intestinal epithelial cell: processing and presentation of antigen to the mucosal immune system.

The immunologic tone of the intestinal tract is one of suppressed or highly regulated responses. While there are several components (intrinsic and extrinsic to the gut-associated lymphoid tissue) responsible for this immunologically suppressed tone, the intestinal epithelial call (IEC) has been proposed as a key player in this process. IECs can take up and process antigen but distinct surface molecules and restriction elements allow them to present these antigens to unique regulatory T cells. These include the expression of the class Ib molecule CD1d as well as a novel CD8 ligand, gp180. These molecules come together to activate a subpopulation of CD8+ regulatory cells whose function is to suppress immune responses in an antigen non-specific fashion most likely through cognate interactions. This form of regulation may be unique to the gut-associated lymphoid tissue which is consistent with the unusual demands upon this part of the immune system.

Animals↗

A problem for the idea of voluntary euthanasia.

I question whether, in those cases where physician-assisted suicide is invoked to alleviate unbearable pain and suffering, there can be such a thing as voluntary euthanasia. The problem is that when a patient asks to die under such conditions there is good reason to think that the decision to die is compelled by the pain, and hence not freely chosen. Since the choice to die was not made freely it is inadvisable for physicians to act in accordance with it, for this may be contrary to the patient's genuine wishes. Thus, what were thought to be cases of voluntary euthanasia might actually be instances of involuntary euthanasia.

Decision Making↗

1999 Canadian recommendations for the management of hypertension. Task Force for the Development of the 1999 Canadian Recommendations for the Management of Hypertension.

OBJECTIVE: To provide updated, evidence-based recommendations for health care professionals on the management of hypertension in adults. OPTIONS: For patients with hypertension, there are both lifestyle options and pharmacological therapy options that may control blood pressure. For those patients who are using pharmacological therapy, a range of antihypertensive drugs is available. The choice of a specific antihypertensive drug is dependent upon the severity of the hypertension and the presence of other cardiovascular risk factors and concurrent diseases. OUTCOMES: The health outcomes considered were changes in blood pressure and in morbidity and mortality rates. Because of insufficient evidence, no economic outcomes were considered. EVIDENCE: MEDLINE searches were conducted from the period of the last revision of the Canadian Recommendations for the Management of Hypertension (January 1993 to May 1998). Reference lists were scanned, experts were polled and the personal files of the authors were used to identify other studies. All relevant articles were reviewed, classified according to study design and graded according to levels of evidence. VALUES: A high value was placed on the avoidance of cardiovascular morbidity and premature death caused by untreated hypertension. BENEFITS: Harms and costs: The diagnosis and treatment of hypertension with pharmacological therapy will reduce the blood pressure of patients with sustained hypertension. In certain settings, and for specific drugs, blood pressure lowering has been associated with reduced cardiovascular morbidity and mortality. RECOMMENDATIONS: This document contains detailed recommendations pertaining to all aspects of the diagnosis and pharmacological therapy of hypertensive patients. With respect to diagnosis, the recommendations endorse the greater use of non-office-based measures of blood pressure control (i.e., using home blood pressure and automatic ambulatory blood pressure monitoring equipment) and greater emphasis on the identification of other cardiovascular risk factors, both in the assessment of prognosis in hypertension and in the choice of therapy. On the treatment side, lower targets for blood pressure control are advocated for some subgroups of hypertensive patients, in particular, those with diabetes and renal disease. Implicit in the recommendations for therapy is the principle that for the vast majority of hypertensive patients treated pharmacologically, practitioners should not follow a stepped-care approach. Instead, therapy should be individualized, based on consideration of concurrent diseases, both cardiovascular and noncardiovascular. VALIDATION: All recommendations were graded according to the strength of the evidence and the consensus of all relevant stakeholders. SPONSORS: The Canadian Hypertension Society and the Canadian Coalition for High Blood Pressure Prevention and Control.

Adult↗

Fluctuations in blood lipid levels during furosemide therapy: a randomized, double-blind, placebo-controlled crossover study.

BACKGROUND: Acute decreases in intravascular volume are associated with increases in lipid levels. Furosemide causes acute changes in intravascular volume during prolonged therapy but is thought to have little effect on lipid levels. METHODS: To determine if there are daily acute rises in lipid and lipoprotein levels associated with changes in intravascular volume during long-term furosemide ingestion therapy, we performed a randomized, double-blind, placebo-controlled crossover study in 10 patients. RESULTS: In the 8 hours after furosemide ingestion there were increases in levels of plasma cholesterol (10.1%; P = .001), high-density lipoprotein cholesterol (9.0%; P = .006), and apolipoprotein B (9.8%; P = .003). The increases in levels of triglycerides (11.5%; P = .17) and apolipoprotein A-1 (13.3%; P = .051) were of similar magnitude but more variable and did not achieve statistical significance. There was no substantial change in the total cholesterol-high-density lipoprotein cholesterol ratio (0.6%; 95% CI,-0.74% to 8.6%; P =.88). CONCLUSION: This study indicates that there are acute increases in lipid levels after furosemide ingestion during prolonged therapy, which could affect the interpretation of lipid levels and cardiovascular risk in patients.

Aged↗

Gradient, high-resolution, magic angle spinning 1H nuclear magnetic resonance spectroscopy of intact cells.

The application of new gradient, high-resolution, magic angle spinning (MAS) 1H nuclear magnetic resonance (NMR) spectroscopy to the study of intact undifferentiated and differentiated NIH 3T3 F442A cells demonstrated improved spectral resolution and sensitivity compared with static studies. MAS of cells permits the detection and quantitation of many cellular metabolites that are not clearly resolved in nonspinning measurements and provides an improved visibility of phospholipids. Gradient, MAS enables the use of diffusion weighting for compartment assignment and the determination of mobility for many metabolites which are incompletely resolved using static techniques. The smaller, undifferentiated preadipocytes show no microscopic evidence of cell lysis after 2 h of MAS at 3.5 kHz and 82% of these cells remain viable by trypan blue exclusion. In contrast, 15-19% of the larger, lipid-laden differentiated adipocytes were found to suffer some degree of cell lysis with MAS. This new method is an attractive alternative to either nonspinning perfusion or extraction techniques for NMR studies of cells.

3T3 Cells↗

Aorto-atrial fistula without aneurysm formation in Behçet's disease.

Cardiac disease is known to occur in patients with the multisystemic inflammatory disorder Behçet's disease. An aorto-atrial fistula secondary to Behçet's disease without a sinus of Valsalva aneurysm has not been previously reported. A 30 year old man with a four year history of symptoms and signs consistent with Behçet's disease presented with an aorto-atrial fistula and a large left to right shunt. At operation the defect was repaired with a bovine pericardial patch. There was no evidence of aneurysm formation. The patient made a good recovery and was well at one year follow up.

Adult↗

Factors influencing blood loss in transurethral resection of the prostate (TURP): auditing TURP.

OBJECTIVES: To assess the blood loss accompanying TURP and investigate its association with the resected weight of prostatic tissue, type of anaesthesia, type of presentation, histology, different surgeons and their differing techniques, and thus to reduce the morbidity associated with blood loss and transfusion. PATIENTS AND METHODS: All prostatectomies carried out in a district general hospital were audited prospectively, recording the pre- and post-operative haemoglobin concentration (Hb), blood transfusions and the variables listed above. The audit was repeated a year later. RESULTS: The peri-operative blood loss, as assessed by various indicators, was equivalent to a decrease in Hb of 10-15 g/L (8-11%). The weight of the resected prostatic tissue was the most important measurable factor in determining blood loss. Regional anaesthesia was associated with less blood loss than general anaesthesia. The added use of a suprapubic catheter for irrigation appeared to have a marginal advantage in large resections. The type of presentation, elective or otherwise, and the histological nature of the prostate did not influence blood loss. Smaller transfusions were probably avoidable in patients having smaller resections and a normal pre-operative Hb. On re-auditing, the overall transfusion rate was reduced from 10.8% to 8.2% and from 4.4% to 1% in patients having resections of < 30 g. CONCLUSION: Blood transfusion can be reduced and rationalized. Patients with a normal pre-operative Hb and undergoing resections of < 30 g do not usually require transfusion. Regional anaesthesia is associated with less blood loss but its advantage is overshadowed in practice by the weight of the resected tissue. An audit of this type is repeatable and is useful in raising awareness, objectively assessing differences and advocating and assessing any changes made.

Aged↗

A phase II study of single agent paclitaxel in patients at first relapse following initial chemotherapy for breast cancer.

This study was initiated to evaluate the safety and efficacy of 3-weekly paclitaxel given at 225 mg/m2 over 3 hours without colony stimulating factor support in patients at their first relapse following adjuvant therapy for breast cancer. Thirty patients were entered into the study; all were assessable for response and toxicity. All patients had received adjuvant/neo-adjuvant chemotherapy; 22 patients had had prior hormonal therapy and 26 previous adjuvant radiotherapy. The group was characterized by a short time to first relapse (median 7.5 months (range 2-43)) and widespread disease, with 22 patients having multiple disease sites including: nodes (43%), skin and soft tissue (43%), liver (40%), lung (37%) and bone (50%). A total of 219 cycles of paclitaxel were given, with a median of eight per patient. The major non-haematological toxicities were: grade 3 alopecia (82% cycles), grade 2/3 arthralgia/myalgia (26%), grade 2/3 fatigue (16%) and grade 2/3 peripheral nervous system toxicity (12%). Haematological toxicity was mainly neutropenia of short duration, with grade 4 counts documented in 16% of cycles. Thrombocytopenia was minimal and there were no significant hypersensitivity reactions. The objective response rate was 60% (95% CI 42.5-77.5) with one complete response and 17 partial responses. The median duration of overall response was 30 weeks (range 15-75+ (95% CI 25-33)) with a median survival time for all patients of 42 weeks (range 1-124+). This study demonstrates that paclitaxel 225 mg/m2 is well tolerated as a 3-hour infusion and can be given safely in an outpatient setting without routine use of granulocyte colony stimulating factor. The response rate is encouraging and shows that this regimen is effective in this poor prognosis patient population.

Adult↗

Closed kinetic chain tarsal mechanics of subtalar joint arthroereisis.

The weightbearing biomechanics of the tarsus with and without subtalar joint arthroereisis was investigated in 11 fresh frozen cadaver specimens using a three-dimensional (3-D) radiowave tracking system. Specimens, consisting of the distal half of the tibia and fibula and the intact ankle and foot, were mounted on a nonmetallic loading frame test system that allowed positioning of the foot to simulate midstance position of gait. The tibia was axially loaded to 756 N (one bodyweight) with 15% of the total load diverted through the fibula. Receiving transducers were attached to the talus, navicular, calcaneus, and cuboid bones. Tarsal movements were monitored as the specimen was loaded with and without subtalar joint arthroereisis. Three-dimensional data sets of osseous positions and orientations were collected and analyzed. Significant rotational differences were detected with and without subtalar joint arthroereisis for all four tarsal bones (p < or = 0.05). Tarsal translational position changes were small and not statistically significant.

Arthrodesis↗