Filtration of fentanyl is not the cause of the elevation of arterial blood pressure associated with post-bypass ultrafiltration in children

Modified ultrafiltration after cardiopulmonary bypass in children has been shown to be associated with an increase in arterial blood pressure. As part of a series of studies to investigate the possible causes of this blood pressure elevation, the hypothesis that if filtration was removing a significant amount of fentanyl, then the increase in blood pressure might be due to pain was proposed. Ten children, aged between 0.5 and 9.3 years (median 3.8 years), weighing 5.9 to 25..5 kg (median 15.7 kg), underwent corrective cardiac surgery (incorporating modified ultrafiltration). A standard anesthetic protocol was followed, with up to 78 μg/kg of fentanyl given prebypass for analgesia. After completion of cardiopulmonary bypass, modified ultrafiltration was commenced at 100 mL/min until a hematocrit of 35% was reached. Samples were taken of arterial blood (prefiltration, 3, 10, and 20 minutes postfiltration), the venous reservoir blood (prefiltration) and the filtrate (5 and 10 minutes into filtration). Hemodynamic data were recorded both prefiltration and postfiltration. The hemodynamic data showed the expected rise in both systemic arterial pressure and cardiac index after ultrafiltration. The plasma fentanyl concentrations did not significantly change after ultrafiltration: 1.59 to 12.39 ng/mL (median 6.27 ng/mL) prefiltration and 2.05 to 15.59 ng/mL (6.29 ng/mL) at 3 minutes, 2.22 to 12.64 ng/mL (6.87 ng/mL) at 10 minutes, and 1.83 to 11.52 ng/mL (5.85 ng/mL) at 20 minutes postfiltration. The concentration of fentanyl in the venous reservoir, 2.06 to 11.64 ng/mL (7.04 ng/mL), was not significantly different from the plasma levels. The level of fentanyl in the filtrate was significantly less than the plasma levels, 0.243 to 1.87 ng/mL (0.894 ng/mL) at 5 minutes and 0.385 to 1.688 ng / mL (0.952 ng / mL) at 10 minutes into filtration; (P < 0.02 by the Wilcoxon signed-rank method). The data show that the plasma fentanyl concentration was not significantly reduced by modified ultrafiltration. The fentanyl levels found prefiltration were maintained postfiltration, and the observed changes in systemic arterial pressure were not due to an acute fall in the plasma concentration of analgesic drug.     

Laparoscopic partial fundoplication vs laparoscopic Nissen-Rosetti fundoplication

Background: Since 1992, all patients at our institution who have met standard accepted criteria for surgical intervention for complicated gastroesophageal reflux disease have been entered into a prospective sequential clinical study to evaluate outcomes of the laparoscopic approach to the Nissen-Rosetti procedure and a modified Toupet procedure. Methods: A standardized workup with upper GI series, esophagography, and endoscopy was used in all patients. Manometry, pH testing, and other special tests were used selectively. A measuring technique was used to determine wrap size without the use of dilators. The short gastric vessels were left intact in all patients. A cosurgeon approach was used, with technical factors described herein. Results: Some 226 of 231 cases were completed laparoscopically (98%)—125 patients in the Nissen-Rosetti group and 101 in the partial fundoplication group. There were no clinical failures in either group. The partial fundoplication group performed better than the Nissen-Rosetti group in all categories of comparison. Return to normal eating habits was much earlier in the partial wrap group (p < 0.0001). Postop distal esophageal sphincter pressures in the two groups were equal at 15 mmHg. Eight patients suffered significant dysphagia requiring endoscopy and dilatation, all in the Nissen-Rosetti group (p < 0.01). Minor complications occurred in 12% of the total group. There was a total surgical revision rate of 3%. There were no gastric or esophageal perforations. Average operative time was 30 min. Average hospital stay was 1.4 days. Hospital charges for the laparoscopic approach averaged $6,000 dollars compared to $12,000 for the open approach. Conclusion: Laparoscopic partial fundoplication is as effective as laparoscopic Nissen-Rosetti fundoplication, with a higher satisfaction rate and fewer side effects. Measuring for wrap and hiatus size eliminates the need for and risk of using stiff dilators. By utilizing cosurgeons and currently available technology, cost, operative time, hospital time, and complications can be reduced to a finite minimum. Received: 12 December 1995/Accepted: 12 August 1996     

Nutrition and immune function

Despite provision of adequate calories and nitrogen, patients receiving current nutrition support formulations often have suppression of immune function. Certain nutrients may act pharmacologically on the immune system. The choice of nutrients appropriate for a given disease state must take into consideration the nutritional status of the subject, presence of infection, injury or hypermetabolism, and the specific immune defect. Nutritional therapy specific for certain disease states is complex and in its infancy but may hold promise for improved patient outcome. Randomized prospective trials to evaluate efficacy are mandatory. Continued research into individual nutrients to elucidate mechanisms of immunomodulation must follow. In the meantime, broad application of products shown to be effective for a specific indication is inappropriate.     

Aortic reconstruction in kidney transplant recipients

Renal transplantation has increased the longevity of patients with uremia. An increasing number undergo aortic reconstruction, which exposes the transplanted kidney to ischemic injury. To evaluate the risk for renal failure, loss of the transplant, and methods of renal protection, we reviewed our experience. Clinical data were reviewed for 10 consecutive patients (7 men, 3 women; mean age 52.7 years [range 32 to 75 years]) with a transplanted kidney who underwent aortic reconstruction between 1977 and 1994 at our institution. Mean interval between renal transplantation and aortic reconstruction was 5.9 years (range 1 month to 12.7 years). Seven patients required emergency repair because of dissection (2 patients), aneurysm rupture (4 patients), or symptomatic aneurysm (1 patient); three underwent elective repair. Reasons for reconstruction included aortic dissection (2 patients), aneurysm of the descending thoracic (2 patients), thoracoabdominal (1 patient), or abdominal aorta (3 patients), and aortoiliac occlusive disease (2 patients). Patients with thoracic or thoracoabdominal reconstructions underwent repair with atriofemoral, aortofemoral, or femorofemoral shunt placement or bypass. Of the five abdominal aortic reconstructions, the kidney was protected with aortofemoral shunt placement in one patient and cold renal perfusion in three. In two of them, topical cooling of the kidney also was used. One patient with acute aortic dissection died at 39 days as a result of respiratory failure. Loss of the recently transplanted kidney was caused by acute rejection. One patient had a transient increase in serum creatinine concentration. Eight had no worsening of renal function, and none of the nine survivors lost the transplanted kidney. We conclude that aortic reconstruction can be safely performed in kidney transplant recipients. Patients in whom thoracic or thoracoabdominal aortic reconstruction was required were protected with an atriofemoral or aortofemoral bypass or shunt. Patients undergoing abdominal aortic reconstruction did well when cold renal perfusion with or without local cooling of the transplant was used for renal protection. Transplanted kidneys appeared to tolerate ischemic injury similarly to native kidneys.Presented at the Twentieth Annual Meeting of the Peripheral Vascular Surgery Society, New Orleans, La., June 10, 1995.     

Relative carriage rates of nuclear dehydrogenating clostridia in two populations of different colorectal cancer risk

Carriage of nuclear dehydrogenating clostridia has been associated with colon cancer and implicated in its aetiology. This study has compared the carriage of these organisms in a British population at high risk for the development of colon cancer with a low risk Nigerian population. Clostridia were found in all of the stools from both populations. Nuclear dehydrogenating clostridia were only found in the stools of the British subjects (32%). These results support the suggestion that the carriage rate of nuclear dehydrogenating clostridia in a population is related to the risk of colon cancer.     

The common heat shock protein receptor CD91 is up-regulated on monocytes of advanced melanoma slow progressors

Despite advances in our understanding of tumour immunology there is no therapy of proven survival benefit for advanced melanoma. Nevertheless, disease progression is slow in a small proportion of patients with metastatic melanoma, suggesting a contribution to outcome from host factors. Recent data have indicated the importance of the heat shock protein receptor CD91 in immune responses to, and progression of, infectious disease. Here we investigate the relationship between CD91 expression and outcome in malignancy. Rare melanoma patients were recruited with advanced disease that was progressing unusually slowly. CD91 expression on their monocytes was compared with control patients with more typical rapidly advancing metastatic disease. Th1 and Th2 cytokines, as well as innate and adaptive immune subsets, were also measured in the two groups. A significant increase in median CD91 expression levels was observed in slow progressors (P = 0.006). There were no differences in other immune subset markers or inflammatory cytokines. The ability of CD91 to internalize and cross-present tumour antigens through the major histocompatibility complex class I pathway may maintain CD8-positive cytotoxic T cell responses and contribute to slow progression of advanced melanoma.     

Development of hatching blastocysts from immature human oocytes following in-vitro maturation and fertilization using a co-culture system

Recently, in-vitro maturation (IVM) of immature human oocytes recovered from non-stimulated follicles has been applied in the treatment of infertility. However, in previous reports, very few embryos cultured in conventional medium have reached the expanded blastocyst stage following in-vitro maturation and fertilization (IVM/IVF). The objective of this study was to investigate whether the developmental competence of human embryos following IVM/IVF could be enhanced by the use of a human ampullary cell co-culture system. Immature human oocytes were aspirated from small follicles at Caesarean section and then cultured in medium containing human menopausal gonadotrophin for 36 to 48 h, followed by insemination. Zygotes were randomly cultured either in conventional culture medium alone or in the co-culture system. Of 48 embryos cultured in conventional medium alone, all arrested at the 2-16- cell stage on day 3 after insemination. Of 46 embryos cultured in the co-culture system, 26 embryos (56.5%) arrested at the 2-16-cell stage. Six embryos (13%) developed to the morula stage. Fourteen embryos (30.4%) developed to expanded blastocysts and two blastocysts were hatching on day 7 after insemination. We conclude that co-culture significantly enhances the development of blastocysts in embryos resulting from IVM/IVF.      

Analysis of association fiber system in piriform cortex with intracellular recording and staining techniques

The piriform cortex of the opossum has been studied with intracellular recording and staining techniques. The experiments were designed to investigate the association fiber system, but the results have also revealed new properties of the afferent fiber system from the olfactory bulb and the inhibitory systems within the piriform cortex. Following shock stimulation of the lateral olfactory tract (LOT), the response of pyramidal cells consists of an initial excitatory postsynaptic potential (EPSP) followed by a long-lasting inhibitory postsynaptic potential (IPSP). The LOT-evoked EPSP consists of two components: an initial monosynaptic followed by a disynaptic component. The monosynaptic EPSP can be isolated by the use of conditioning LOT shocks to block the IPSP and disynaptic EPSP. The disynaptic EPSP can be demonstrated by cutting LOT fibers at the surface of the cortex to eliminate the monosynaptic EPSP and by the use of bicuculline to block the IPSP. The latency of the IPSP is sufficiently brief so that the disynaptic EPSP is blocked at presumed intrasomatic recording sites unless these experimental manipulations are carried out. In all histologically verified pyramidal cells in both layers II and III in which the appropriate tests were carried out, both mono- and disynaptic EPSP components were present. It was concluded on the basis of anatomical considerations, however, that a small number of pyramidal cells would be expected to receive only a disynaptic EPSP. Evidence that the LOT-evoked disynaptic EPSP is mediated, at least in part, by association axons was provided by direct stimulation of these fibers in layer III and by demonstrating that the EPSP is present distal to cuts that sever LOT axons. Direct stimulation of association axons in layer III evokes both a monosynaptic EPSP and a disynaptic IPSP in pyramidal cells at similar latencies. This IPSP is indistinguishable in properties from that evoked by LOT stimulation. Indirect evidence indicates that it is mediated via both feedforward and feedback mechanisms. In most neurons the association fiber-evoked EPSP is masked by the IPSP in response to single deep shocks but can be demonstrated by blocking the IPSP with a preceding LOT shock or by application of bicuculline. Intracellular injection of horseradish peroxidase (HRP) revealed that pyramidal cell axons give rise to an extensive system of local collaterals with a large number of synaptic terminal-like swellings in layer III. It is postulated that these collaterals synapse on both pyramidal and nonpyramidal cells.(ABSTRACT TRUNCATED AT 400 WORDS)     

Cutaneous Scedosporium apiospermum infection in an immunocompromised patient

Scedosporium apiospermum infection occurred in the left forearm of a patient who was taking oral prednisolone for pulmonary fibrosis. The infection appeared to follow a scratch from a blackcurrant bush. This is the first reported case in the United Kingdom of a cutaneous infection from Scedosporium apiospermum in an immunocompromised patient.     

Detection of chromosomes and estimation of aneuploidy in human spermatozoa using fluorescence in-situ hybridization

The development and application of fluorescence in-situ hybridization (FISH) has opened the way for comprehensive studies on numerical chromosome abnormalities in human spermatozoa. FISH can be rapidly applied to large numbers of spermatozoa and thus overcomes the major limitation of karyotyping spermatozoa after penetration of zona-free hamster oocytes. The simultaneous hybridization of two or more chromosome-specific probes to spermatozoa and subsequent detection of the bound probes using different fluorescent detection systems enables two or more chromosomes to be localized simultaneously in the same spermatozoon and provides a technique for undertaking reasonable estimates of aneuploidy. The most commonly used probes are those which bind to the centromeric region of specific chromosomes. Most studies to date have concentrated on estimating aneuploidy in spermatozoa from normospermic men, although reports are beginning to appear on aneuploidy in spermatozoa from subfertile and infertile men. Multi- probe FISH studies have generally reported disomy (hyperhaploidy) estimates of 0.05-0.2% per chromosome. There is preliminary evidence that some chromosomes such as X, Y and 21 are predisposed towards higher rates of non-disjunction during spermatogenesis. There are also suggestions of inter-donor variability in aneuploidy frequencies for specific chromosomes, although this requires confirmation in larger studies. While FISH is clearly a powerful technique that has many applications in reproductive medicine, it must also be realized that it does have limitations and the technology itself is still evolving and has yet to be fully validated on spermatozoa.