Humoral immune response to autologous blood transfusion in hip surgery: whole blood versus packed red cells and plasma

BACKGROUND AND OBJECTIVES

The immune response to the transfused autologous buffy coat content in whole blood has, to date, not been studied in detail.

SUBJECTS AND METHODS

Patients undergoing hip arthroplasty were studied according to whether they received autologous whole blood (WB) (n = 30), autologous fresh-frozen plasma and buffy coat-poor red cells (RC) (n = 40), or no transfusion (NT) (n = 27). Plasma levels of tumour necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6) and complement SC5b-9 were analysed by enzyme-linked immunosorbent assay (ELISA) 7 days after surgery.

RESULTS

There were no significant between-group differences regarding the time course of TNF-alpha, IL-6 and complement SC5b-9 plasma level changes, the infection rate, or the length of hospital stay.

CONCLUSION

In comparison to the impact of surgery on cytokine and complement levels, the transfusion of autologous buffy coat is not relevant.

[Coronary reoperation: a 16 years retrospective analysis]

BACKGROUND

Coronary artery bypass grafting (CABG) reoperation is being performed with increasing frequency.

AIM

To assess the early and long term results of coronary reoperations in our institution and to identify prognostic factors.

PATIENTS AND METHODS

214 patients subjected to coronary reoperations between 1983 and 1999 were retrospectively studied.

RESULTS

Mean age was 64.2 years (range 42-79 years), 202 (94.4%) were male and 12 (5.6%) female. The mean interval between the operations was 125.7 months (range 6-252 months). 10 (4.6%) were emergency surgeries. Overall operative mortality was 5.6% (11 deaths) and in 5 patients (3.4%) a perioperative myocardial infarction was noted. Univariate analysis identified moderate or severe left ventricular failure (p = 0.048) as predictor of increased operative mortality, meanwhile age over 75 years (p = 0.02) and moderate or severe left ventricular failure (p = 0.01) were identified as predictors of increased in hospital mortality in the multivariate analysis. Follow up of in hospital survivors (mean interval 65 months, range 4 to 190 months) documented a 5 years survival rate of 82.9%, a 10 years survival rate of 73.1% and a 15 years survival rate of 53.4%. Moderate or severe left ventricular failure (p < 0.0001) and emergency surgeries (p = 0.007) were identified as factors influencing the late survival in the stepwise logistical regression analysis. Multivariate analysis identified left ventricular failure (p = 0.01) and peripheral vascular disease (p = 0.01) as predictors of decreased late survival.

CONCLUSIONS

Coronary reoperation has a low mortality in patients with a normal ventricular function and also has an excellent overall and disease free survival in the first 10 years of follow up. Left ventricular function is an independent risk factor increasing in hospital and late mortality.

Prevention of construction falls by organizational intervention

OBJECTIVES

Determine if a university based (third party) intervention can improve construction contractor organizational performance to increase use of fall prevention practices and technologies.

SETTING

Falls are the leading cause of worker injury and death in the construction industry. Equipment and practices that can prevent falls are often not used appropriately in the dynamic construction work environment.

METHODS

A contractual partnership between a university and construction contractors created management systems to ensure use of fall protection measures. Audits by university faculty provided accountability for implementing the fall prevention system. Evaluation was conducted by quasiexperimental methodology comparing changes in audit score from baseline to fifth quarter from baseline for intervention and control contractors.

RESULTS

Audit scores improvement was greater for intervention than for control contractor group.

CONCLUSION

A third party intervention can improve contractor fall prevention performance.

Microtubule disassembly increases endothelial cell barrier dysfunction: role of MLC phosphorylation

Endothelial cell (EC) barrier regulation is critically dependent on cytoskeletal components (microfilaments and microtubules). Because several edemagenic agents induce actomyosin-driven EC contraction tightly linked to myosin light chain (MLC) phosphorylation and microfilament reorganization, we examined the role of microtubule components in bovine EC barrier regulation. Nocodazole or vinblastine, inhibitors of microtubule polymerization, significantly decreased transendothelial electrical resistance in a dose-dependent manner, whereas pretreatment with the microtubule stabilizer paclitaxel significantly attenuated this effect. Decreases in transendothelial electrical resistance induced by microtubule disruption correlated with increases in lung permeability in isolated ferret lung preparations as well as with increases in EC stress fiber content and MLC phosphorylation. The increases in MLC phosphorylation were attributed to decreases in myosin-specific phosphatase activity without significant increases in MLC kinase activity and were attenuated by paclitaxel or by several strategies (C3 exotoxin, toxin B, Rho kinase inhibition) to inhibit Rho GTPase. Together, these results suggest that microtubule disruption initiates specific signaling pathways that cross talk with microfilament networks, resulting in Rho-mediated EC contractility and barrier dysfunction.

Physical and physiological plasticity of hematopoietic stem cells

Stem cells from a variety of tissues have recently been shown to be capable of differentiating into cells characteristic of a separate tissue, apparently in response to microenvironmental signals. This is hierarchical plasticity. We have shown that both human and murine neurosphere cells with potential for differentiating into neurons, oligodendrocytes, and astrocytes can produce hematopoietic stem cells when engrafted into fetal sheep or murine day 3.5 blastocysts, respectively. We have also demonstrated an alternative form of stem cell plasticity: functional plasticity at different points in cell cycle transit and at different phases of a circadian rhythm. We have shown that long-term engraftment varies reversibly as primitive murine stem cells (lineage-negative rhodamine(low) Hoechst(low)) transit the cell cycle under stimulation by interleukin-3 (IL-3), IL-6, IL-11, and steel factor, with engraftment being defective in late S/early G2. Engraftment also varies markedly with circadian time. Presumptive mechanisms for these phenotypic shifts include alteration in adhesion protein expression with consequent changes in marrow homing. Most recently, we have also demonstrated that stem cell differentiation varies markedly with cell cycle transit. There are other features of the hematopoietic stem cell which suggest that it is a highly plastic cell with the ability to rapidly change its membrane phenotype, while exhibiting extraordinary directed motility. These data suggest that cell cycle and circadian plasticity should be considered additional major features of the hematopoietic stem cell phenotype.

Black female patients with type 2 diabetes mellitus: knowledge, attitudes and physical activity

The aim of this study was to obtain baseline data from female Type 2 Diabetes Mellitus (Type 2 DM) patients on their general health status, demographics, their knowledge of and attitudes towards diabetes and exercise, as well as their present physical activity levels.The sample of convenience consisted of 93 patients between the ages of 36 and 70 years, who were attending the Mamelodi Hospital Diabetic Outpatient Clinic.Demographic, clinical, diabetes knowledge, diabetes attitude and physical activity data were captured. Data were summarized with descriptive statistics. Pearson product-moment correlation was employed to assess relationships and Cronbach’s alpha measured reliability.It was found that the sample had a low educational level. (84% schooling up to St 7) Several risk factors for the control of diabetes were identified in the sample. (Class I obesity, HbAI c-levels acceptable to compromised, 75% on treatment for hypertension) They had low scores on knowledge of diabetes ( mean,SD =4.72,2.05 out of 15) and low levels of physical activity. (mean, SD—2.85,2.09) Patients agreed with the attitude in the scale that the health care professionals require skills to educate and counsel diabetic patients, as well as bring about behavioral changes in the patients.( r=0.62) They also agreed that diabetes has a substantial psychosocial impact on their lives. (r=0.41) The highest correlation between to sub-scales was between the need for special training of health care professionals who care for diabetic patients and the psychosocial impact of the disease. (r=0.41) Patients should be educated about the basic physiology of diabetes, insulin action and causes of hypoglycaemia. They should also be motivated to increase physical activity on a continuous basis.Culturally sensitive research is needed to identify health beliefs, motivation for the control of diabetes and environmental and personal barriers to exercise and physical activity in this population.

HIV infection in general surgical patients at the Ga-Rankuwa/MEDUNSA complex South Africa

OBJECTIVE

To assess the possible impact of HIV infection on the management of general surgical patients at the Ga-Rankuwa Hospital.

DESIGN

A prospective study.

SETTING

Ga-Rankuwa Hospital/Medical University of Southern Africa (MEDUNSA) Academic Complex, Pretoria, South Africa.

SUBJECTS

Nine hundred and forty one patients admitted to general surgical wards.

MAIN OUTCOME MEASURES

HIV infection and CD4 counts.

RESULTS

Nine hundred and forty one patients admitted to general surgical wards from January 1966 to December 1997 were tested for HIV infection. Twelve per cent tested positive. HIV positive patients were significantly younger [33 +/- 10 versus 41 +/- 7 (men +/- SD) years, Chi-square = 51, p < 0.0001]. There was no correlation of HIV positivity to the patient's sex (p = 0.7). In forty three HIV positive patients treated surgically, mortality was attributed to HIV/AIDS in only one patient with a CD4 count of 47/ul who died following laparotomy for peritonitis. CD4 counts done during follow up in thirty one HIV positive patients revealed a count of < 500/ul in eleven patients.

CONCLUSION

It is predicted that an increasing number of patients with HIV/AIDS will be admitted to general surgery wards of the Ga-Rankuwa Hospital. Surgeons are advised to take universal precautions to prevent HIV infection.

The novel transcription factor e(y)2 interacts with TAF(II)40 and potentiates transcription activation on chromatin templates

Weak hypomorph mutations in the enhancer of yellow genes, e(y)1 and e(y)2, of Drosophila melanogaster were discovered during the search for genes involved in the organization of interaction between enhancers and promoters. Previously, the e(y)1 gene was cloned and found to encode TAF(II)40 protein. Here we cloned the e(y)2 gene and demonstrated that it encoded a new ubiquitous evolutionarily conserved transcription factor. The e(y)2 gene is located at 10C3 (36.67) region and is expressed at all stages of Drosophila development. It encodes a 101-amino-acid protein, e(y)2. Vertebrates, insects, protozoa, and plants have proteins which demonstrate a high degree of homology to e(y)2. The e(y)2 protein is localized exclusively to the nuclei and is associated with numerous sites along the entire length of the salivary gland polytene chromosomes. Both genetic and biochemical experiments demonstrate an interaction between e(y)2 and TAF(II)40, while immunoprecipitation studies demonstrate that the major complex, including both proteins, appears to be distinct from TFIID. Furthermore, we provide genetic evidence suggesting that the carboxy terminus of dTAF(II)40 is important for mediating this interaction. Finally, using an in vitro transcription system, we demonstrate that recombinant e(y)2 is able to enhance transactivation by GAL4-VP16 on chromatin but not on naked DNA templates, suggesting that this novel protein is involved in the regulation of transcription.

[Germline mutations of the ret proto-oncogene in Chilean patients with hereditary and sporadic medullary thyroid carcinoma]

BACKGROUND

Medullary thyroid carcinoma (MTC) may occur either as a sporadic or familial disease. Multiple endocrine neoplasia (MEN) type 2, inherited as an autosomal dominant disease, is characterized by MTC only (FMTC) or coexistence of MTC with other endocrine neoplasia (NEM 2A, 2B). Germline mutations of the RET proto-oncogene (cRet) are found in the inherited forms and in some apparently sporadic MTC cases.

AIM

To study RET mutations in 8 families with MEN 2.

MATERIAL AND METHODS

RET mutations were screened in peripheral blood DNA from 18 patients and 87 high risk carriers belonging to 8 MEN 2 families and 52 sporadic MTC. Exons 10, 11, 13, 14, 15 and 16 of the c-Ret were amplified by polymerase chain reaction (PCR) and examined by direct sequencing of PCR products and/or restriction enzyme analysis.

RESULTS

Five MEN 2A and one FMTC families with a germline mutation at codon 634, one MEN 2A and one FMTC family carrying a mutation at codon 620 were identified. Mutations were found in 23 out of 87 high risk carriers. In addition, we detected a S891A (exon 15) germline mutation in a sporadic MTC patient and in one out of her three sons and V804M (exon 14) in another sporadic MTC case and in one out of his six relatives, indicating in both cases the presence of a sporadic misclassified familial disease.

CONCLUSIONS

These results underscore the importance of routine application of c-Ret testing in all cases of MTC either familial or sporadic.

Detection of differential gene expression in biofilm-forming versus planktonic populations of Staphylococcus aureus using micro-representational-difference analysis

Microbial proliferation and biofilm formation on biologic or inert substrates are characteristics of invasive Staphylococcus aureus infections and is associated with phenotypic alterations such as reduced antimicrobial susceptibility. To identify genes which are typically expressed in biofilms, a micro-representational-difference analysis (micro-RDA) was adapted for gram-positive bacteria and used with cDNA derived from populations of S. aureus DSM 20231 growing in a biofilm or plankonically. In comparison to previously described cDNA RDA protocols, micro-RDA has the advantages that only minimal quantities of total RNA are needed and, most importantly, that total RNA can be used since the large amount of rRNA in total RNA does not interfere with the micro-RDA procedure. Using a series of spiked controls with various amounts of MS2 RNA in a background of total RNA from S. aureus, the equivalent of five copies of MS2 per cell were detectable after three rounds of subtractive enrichment. Five genes were identified as being differentially expressed in biofilm versus planktonic cultures. These genes revealed homology to a threonyl-tRNA synthetase, a phosphoglycerate mutase, a triosephosphate isomerase, an alcohol dehydrogenase I, and a ClpC ATPase. Differential levels of expression were subsequently confirmed by standard Northern blotting. In conclusion, micro-RDA is a sensitive and specific method to detect transcripts differentially expressed as a function of different S. aureus growth conditions.

Estimation of conduit taper for the hydraulic resistance model of West et al

The model of West, Brown and Enquist (1999) showed that total hydraulic resistance in trees can be independent of path length, provided that vascular conduits taper sufficiently. The original model defined the coefficient of taper, a bar, in terms of conduit radius and segment number, but segments can be difficult to distinguish in old stems. Adhering strictly to the definitions and assumptions of West et al., we derived several equations for the estimation of a bar based on measurements of tracheary radius and flow path length. However, an additional parameter, b, was introduced to permit different models of variation in the length of segments along the flow path besides the volume-filling model of West et al., including a fixed-length model and intermediate versions. One of the new equations was fitted to previously published data for two tree species to illustrate the estimation of conduit taper from path-length relations, which proved quite sensitive to variation in b. Sampling protocols for improving such analyses are suggested.

Stem cell engraftment strategies

The donor stem cell phenotype and host microenvironment determine the outcome of a stem cell transplant. In a series of transplant studies in syngeneic male to female or congenic Ly5.1/Ly5.2 models in which hosts have received no or minimal irradiation (100 cGy), evidence overwhelmingly supports the concept that syngeneic engraftment is determined by stem cell competition. These approaches can be extended to H-2 mismatched allogeneic mouse combination when antigen pre-exposure and CD40-CD40 ligand antibody blockage are employed. A human trial in patients with resistant neoplasia infusing pheresed blood with 10(8) CD3 cells/kg showed that tumor responses and complete chimerism occur with very low levels of CD34+ cells/kg and that the extent of previous treatment is a critical factor in determining chimerism. A major feature of transplants is the phenotype of the donor stem cell. This phenotype shows dramatic reversible plasticity involving differentiation, adhesion protein expression, and engraftment with cytokine-induced cell-cycle transit. Homing is probably also plastic. Marked fluctuations in engraftment capacity are also seen at different points in marrow circadian rhythm.

[Treatment of advanced heart failure by heart transplantation]

BACKGROUND

Heart transplantation currently provides the most effective treatment for advanced heart failure. However, medical therapy for this condition has also improved, heart donors are scarce and the cost of the procedure is high. Therefore the indications and management of these patients need reevaluation.

AIM

To analyze the results of 24 patients submitted to heart transplantation for end-stage heart failure needing repeated hospitalizations and i.v. inotropes for compensation.

PATIENTS AND METHODS

The group was comprised by 21 men and 3 women with a mean age of 36.8 years, mean left ventricular ejection fraction 19 +/- 4.5%, mean systolic pulmonary artery pressure 48 +/- 13 mmHg (24-70) and mean pulmonary vascular resistance 2.6 Wood Units (1-5). Fourteen patients (58%) had a previous median sternotomy. Immunosuppression did not include induction therapy and steroids were discontinued early.

RESULTS

Operative mortality was 4% at 30 days. Actuarial survival at one year was 90% and at 5 years 72%. Freedom from rejection at one year was 76% and at 5 years 50%. Freedom from infection was 70% at one year and 56.5% at five years. All patients with more than 3 months of follow-up were in functional class I.

CONCLUSIONS

These results justify the proposed modifications for transplantation protocols.

Modeling of olive oil degradation and oleic acid inhibition during chemostat and batch cultivation of Bacillus thermoleovorans IHI-91

Olive oil degradation by the thermophilic lipolytic strain Bacillus thermoleovorans IHI-91 in chemostat and batch culture was modeled to obtain a general understanding of the underlying principles and limitations of the process and to quantify its stoichiometry. Chemostat experiments with olive oil as the sole carbon source were successfully described using the Monod chemostat model extended by terms for maintenance requirements and wall growth. Maintenance requirements and biomass yield coefficients were in the range reported for mesophiles. For a chemostat experiment at D = 0.3 h(-1) the model was validated up to an olive oil feed concentration of about 3.0 g L(-1) above which an inhibitory effect occurred. Further analysis showed that the liberated oleic acid is the main cause for this inhibition. Using steady-state oleic acid concentrations measured in chemostat experiments with olive oil as substrate it was possible to derive a kinetic expression for oleic acid utilization, showing that a concentration of 430 mg L(-1) leads to a complete growth inhibition. Oleic acid accumulation observed during batch fermentations can be predicted using a model involving growth-associated lipase production and olive oil hydrolysis. Simulations confirmed that this accumulation is the cause for the sudden growth cessation occurring in batch fermentations with higher olive oil start concentrations. Further, an oscillatory behavior, as observed in some chemostat experiments, can also be predicted using the latter model. This work clearly demonstrates that thermophilic lipid degradation by Bacillus thermoleovorans IHI-91 is limited by long-chain fatty acid beta-oxidation rather than oil hydrolysis.

Isolation and characterization of lipid-degrading Bacillus thermoleovorans IHI-91 from an icelandic hot spring

An efficient lipid-degrading thermophilic aerobic bacterium was isolated from an icelandic hot spring and classified as Bacillus thermoleovorans IHI-91. The aerobic bacterium grows optimally at 65 degrees C and pH 6.0 and secretes a high level of lipase (300 Ul(-1)). The newly isolated strain utilizes several lipids such as palmitic acid, stearic acid, lanolin, olive oil, sunflower seed oil, soya oil, and fish oil as sole carbon and energy source without an additional supply of growth factors. The degradation of about 93% of triolein, which is present in olive oil, was observed after only 7h of fermentation at a maximal growth rate of 1.0 h(-1). During growth at optimal conditions on yeast extract, the doubling time was only 15 min. Based on 16S rDNA studies, DNA-DNA hybridization and morphological and physiological properties, the isolate IHI-91 was identified as Bacillus thermoleovorans IHI-91 sp. nov. Because of its production of high concentrations of thermoactive lipases and esterases and the capability of degrading a wide range of lipids at high temperatures, the isolated strain is an ideal candidate for application in various biotechnological processes such as wastewater treatment.

Comparison of heat and cold stress to assess thermoregulatory dysfunction in hypothyroid rats

How borderline impairment of thyroid function can affect thermoregulation is an important issue because of the antithyroidal properties of a many environmental toxicants. This study compared the efficacy of heat and cold stress to identify thermoregulatory deficits in rats subjected to borderline and overt hypothyroidism via subchronic exposure to propylthiouracil (PTU). After 3 wk of exposure to PTU in the drinking water (0, 2.5, 5, 10, and 25 mg/l), rats were subjected to a heat stress challenge (34 degrees C for 2.5 h). After one more week of PTU treatment, the same rats were subjected to a cold stress challenge (7 degrees C for 2.5 h). Core temperature (T(c)) was monitored by radiotelemetry. Baseline T(c) during the light phase was reduced by treatment with 25 mg/l PTU. The rate of rise and overall increase in T(c) during heat stress was attenuated by PTU doses of 10 and 25 mg/l. Cold stress resulted in a 1.0 degrees C increase in T(c) regardless of PTU treatment. The rate of rise in T(c) during the cold stress challenge was similar in all PTU treatment groups. There was a dose-related decrease in serum thyroxine (T(4)) at PTU doses >/=5 mg/l. Serum triiodothyronine (T(3)) was reduced at PTU doses of 5 and 25 mg/l. Serum thyroid-stimulating hormone (TSH) was marginally elevated by PTU treatment. Overall, heat stress was more effective than cold stress for detecting a thermoregulatory deficit in borderline (i.e., 10 mg/l PTU) and overtly hypothyroid rats (i.e., 25 mg/l PTU). A significant thermoregulatory deficit is manifested with a 78% decrease in serum T(4). A thermoregulatory deficit is more correlated with a reduction in serum T(4) compared with T(3). Serum levels of TSH are unrelated to thermoregulatory response to heat and cold stress.