Preexpansion of the tensor fasciae latae for free-flap transfer

Preexpansion has become an established technique to prefabricate elective free flap transfers. We report the use of the tensor fasciae latae flap as a donor site in two cases for reconstruction of a burn scar neck contracture and an unstable contralateral below-knee amputation stump, of which other donor sites were ruled out either by the patients' condition or by choice. Implantation and transfer were straightforward and the donor sites of very large flaps were minimized by preexpansion. The preexpanded muscle fasciocutaneous flaps were transplanted with microsurgical anastomoses of the vessels. Apart from a small area of necrosis at the distal tip of the flap developing on the sixth postoperative day, which we excised in a second operation, there were no major complications. The advantages of the combination of preexpansion and free flap transfer as well as the unique anatomical and functional qualities of this musculocutaneous unit are emphasized.     

Diagnosis of renovascular disease by extra- and intrarenal Doppler parameters

It is still a matter of debate as to which parameters should be used for noninvasive diagnosis of renovascular disease by renal Doppler sonography (RDS). The accuracy of RDS in the detection of renal artery stenosis (RAS) was tested in 95 consecutive, moderate to severe hypertensive patients (I-II World Health Organization [WHO] stages). Reno-aortic ratio (RAR) for peak systolic velocity (PSV) was also calculated to assist in the diagnosis of significant (>50%) RAS. Paired receiver-operating characteristic (ROC) analysis was plotted for evaluating the relationship between sensitivity and specificity for each parameter. In a subset of 57 kidneys, the influence of blood pressure and age on intraparenchymal parameters was evaluated. Measurements of maximal peak systolic velocity (PSV) at the site of stenosis, RAR for PSV, and minimum acceleration index in the main renal artery showed high accuracy (areas under the ROC curve 0.97, 0.88, and 0.80, respectively). Among intraparenchymal parameters, early systolic acceleration showed the best area under the ROC curve (0.90), but provided a low positive predictive value (29%) and was significantly influenced by blood pressure (multiple r=0.56; p=0.001). Pulsatility and resistive indices were found to be less powerful as absolute values, and both significantly influenced by blood pressure and age (multiple r=0.60 and 0.50; p=0.001, p=0.02, respectively). However, interindividual variance of intrarenal indices should be minimized by calculation of side difference, although this procedure would become misleading or impossible in patients with bilateral RAS or a single kidney, respectively. These results support the use of extraparenchymal parameters for noninvasive detection of RAS, and emphasize that intrarenal parameters cannot be considered as absolute values.     

Distribution of major and minor alkaloids in tobacco, mainstream and sidestream smoke of popular Indian smoking products

Various Indian smoking products--cigarette, bidi, chutta and a brand of US cigarette--were analysed by gas chromatography-flame ionization detection (GC-FID) for the levels of nicotine and minor tobacco alkaloids in tobacco, mainstream smoke (MS) and sidestream smoke (SS) employing modified smoking standards, namely two puffs/min. The analysis clearly demonstrated relatively higher levels of nicotine and minor tobacco alkaloids in tobacco from bidi (37.7 mg/g) and chutta (34.5 mg/g) when compared with Indian and US cigarettes (14-16 mg/g) studied. Relatively lower levels (SS/MS) of nicotine in SS from bidi and chutta compared with Indian/US cigarettes, suggest that the contribution of nicotine in SS from a single bidi/chutta to environmental tobacco smoke (ETS) is very much less than that of a single Indian/US cigarette. Reduced levels of nicotine in SS of bidi/chutta result in relatively higher deliveries of nicotine in MS as reflected by higher MS/SS values. The observed differences are likely to be due to difference in tobacco processing, burning rate/temperature and design of the smoking product.     

Pharmacokinetics of cyclophosphamide and its metabolites in bone marrow transplantation patients

Classical swine fever virus infection of pigs causes a severe leukopenia and immunosuppression. In the present study, the kinetics of virus infection, and identification of target cells for the virus in peripheral blood were analysed. Virus infection was often not detectable before 5-7 days p.i. A minority of animals yielded detectable infected cells at 3 days p.i., but < 5% PBMC. It was not until 10 days p.i. that this figure increased-to 35-70% PBMC depending on the animal. Detailed analysis of Ficoll-Hypaque-purified PBMC identified the major population to be SWC3+SWC8+CD14+MHCII- granulocytic cells. Microscopic observations determined that these low density granulocytic cells in the PBMC from CSFV infected animals were indeed immature cells. Both the low density granulocytic cells and monocytes were major targets for CSFV infection in the peripheral blood. This is the first demonstration that low density granulocytic cells dominate the blood leukocyte population during CSF, and that such cells are targets for virus infection. The present work also demonstrates that the leukocyte population changes, such as B lymphocyte depletion and the relative dominance of myeloid cells in the blood during CSF, occur before virus infection of the affected cells. Thus, the pathological mechanism therein is not a direct consequence of virus infection.     

Chronic pancreatitis prevalence in liver cirrhosis. Morphological and functional study

In the present study we have examined the ability of the beta-amyloid peptide (A beta(25-35)) to modulate the respiratory burst activity of human monocytes in vitro. Incubation of the cells for 24 h with A beta(25-35) as well as with A beta(1-42) resulted in an enhanced production of reactive oxygen radicals (ROI) in response to phorbol 12-myristate 13-acetate (PMA). Such effect was additively increased by coincubation with interferon-gamma (IFN gamma), and was paralleled by modulation of gene and protein expression of some components of the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase system. Since the effects of A beta(25-35) were also reproduced in primary rat microglia, our findings indicate that A beta(25-35) can potentiate the ability of mononuclear phagocytes to produce ROI, and add further insights into its biological effects.     

Peptide and lipid growth factors decrease cis-diamminedichloroplatinum-induced cell death in human ovarian cancer cells

Growth factors have been demonstrated to regulate the proliferation and viability of a number of cell lineages. Because most drugs used in chemotherapy kill cells through programmed cell death, by the process of apoptosis, we determined whether growth factors, specifically epidermal growth factor (EGF) and lysophosphatidic acid (LPA), which we have demonstrated recently to be a potent growth factor for ovarian cancer cells, would alter the ability of cis-diamminedichloroplatinum (cis-DDP), the most effective chemotherapeutic agent for ovarian cancer, to kill the HEY ovarian cancer cell line. We demonstrate that both EGF and LPA decrease the ability of cis-DDP to kill HEY ovarian cancer cells as assessed by colony-forming cell activity and dye reduction. Morphological changes, DNA release, and electron microscopy suggested that LPA and EGF protect ovarian cancer cells from programmed cell death induced by cis-DDP. Because LPA is present in high levels in ascitic fluid from ovarian cancer patients, and the EGF receptor is expressed by tumor cells from a significant portion of patients where it correlates with prognosis, growth factor modulation of cis-DDP-induced apoptosis may play a role in the poor prognosis associated with ovarian cancer.     

Hypothalamic dopamine D1 receptors are involved in the stimulation of prolactin secretion by high environmental temperature in the female sheep

Recent evidence suggests that dopamine, acting via its D1 receptors, may function as a neurotransmitter in intrahypothalamic pathways involved in the stimulation of prolactin secretion. Functional dopamine D1 receptors are present in the ventromedial hypothalamic nucleus (VMH) and we hypothesized that they might be part of a prolactin-stimulatory pathway activated by stress. We tested this hypothesis in a series of experiments on sheep involving two different forms of stressors, audiovisual (barking dog) and high environmental temperature. We attempted to block the stimulation of prolactin secretion by infusion into the VMH of an antagonist specific for the D1 receptor. Ovariectomised, oestradiol-implanted merino ewes were surgically implanted with bilateral guide tubes directed at the VMH. After a 180 min pretreatment period, the ewes either were or were not exposed to a stressor (30 min of barking dog or 120 min at 35 degrees C, 65% relative humidity). D1 receptor antagonist, SCH23390 or vehicle (0.9% saline) was infused into the VMH (1.7 microliters/h, 120 nmol/h) for 60 min prior to and during the stressor period. Blood was sampled every 15 min via jugular cannulae and the plasma was assayed for prolactin, cortisol and growth hormone (GH). Both stressors significantly increased prolactin concentrations over control levels. SCH23390 infusion significantly attenuated the prolactin response to high environmental temperature, but had no effect on the prolactin response to audiovisual stress. Cortisol concentrations were significantly increased by audiovisual stress only and were not affected by SCH23390. GH concentrations were not changed by either stressor or infusion. Drug infusion alone did not affect the concentration of the hormones. The data suggest that the VMH D1 receptors are involved in a prolactin stimulatory pathway in response to high environmental temperature. The inability of the D1 antagonist to affect the response to the barking dog indicates that this pathway is stress-specific, implying that there is more than one mechanism or pathway involved in the prolactin response to different stressors.     

Functional outcome after myocardial revascularization in ischemic left ventricular failure

BACKGROUND: Myocardial revascularization in patients with left ventricular failure (ejection fraction < 30%) offers survival comparable to heart transplantation. The functional outcome, however, has yet to be determined. In order to assess the clinical results in patients with LVEF < 30% undergoing coronary artery bypass grafts (CABG), 101 consecutive patients operated between 1/91 and 1/97 were reviewed retrospectively. METHODS: The patients were stratified according to presentation: 65 pts had angina (Group 1) and 36 congestive failure (Group 2). Mean age (62 +/- 7 vs 60 +/- 8 yrs), sex (90 vs 88% male), LVEF (0.28 +/- 0.04 vs 0.29 +/- 0.04), prior myocardial infarction (1.2 +/- 0.4 vs 1.2 +/- 0.5 episodes/pt), presence of vital myocardium at scintiscan or low-dose dobutamine echocardiography (92 vs 93%), need for preoperative IABP (3.1 vs 8.3%), aortic cross-clamp (53 +/- 21 vs 60 +/- 21 min) and cardiopulmonary bypass (104 +/- 31 vs 114 +/- 36 min) times were comparable. RESULTS: There was only 1 (1%) perioperative death due to low-output syndrome. Eleven pts (6 vs 5, Group 1 vs Group 2) had postoperative low-output syndrome, requiring IABP in 7 pts (4 vs 3). There were 14 (10 vs 4, Group 1 vs Group 2) deaths during follow-up (29 +/- 19 months, range 2-67), with an overall actuarial survival of 91 +/- 4 vs 100% at 1 yr and 74 +/- 9 vs 78 +/- 10% at 5 yrs in Group 1 vs Group 2, respectively (p = ns). Actuarial symptom-free survival was 89 +/- 4 vs 84 +/- 6% at 1 yr and 49 +/- 9 vs 28 +/- 11% at 5 yrs, respectively (p = 0.05). Despite the high recurrence of congestive failure (22 vs 66% in Group 1 vs Group 2, p = 0.004), improvement in functional class (3.1 +/- 0.8 vs 1.5 +/- 0.7 in Group 1 and 2.7 +/- 0.7 vs 1.8 +/- 0.5 in Group 2) and LVEF (0.28 +/- 0.04 vs 0.38 +/- 0.04 in Group 1 and 0.29 +/- 0.04 vs 0.40 +/- 0.06 in Group 2) was found in both groups at follow-up. CONCLUSIONS: In spite of improving early and late survival after revascularization for ischemic left ventricular failure, patients presenting with congestive failure have an unsatisfactory symptom-free survival. Further studies are necessary to ascertain the relative indications to revascularization or transplantation in this specific patient subgroup.