Effects of Rapid Increases of Desflurane and Sevoflurane to Concentrations of 1.5 MAC on Systemic Vascular Resistance and Catecholamine Response during Cardiopulmonary Bypass

Background: Airway irritation was hypothesized to trigger the transient cardiovascular stimulation associated with desflurane. The authors administered desflurane during cardiopulmonary bypass (CPB), thus avoiding airway contact, and compared the effects of rapid increases of desflurane to 1.5 MAC on systemic vascular resistance index (SVRI) and catecholamine response to those of 1.5 MAC sevoflurane.

Methods: Forty-eight patients, undergoing elective coronary bypass surgery, were randomly allocated to receive either desflurane or sevoflurane during hypothermic (32-33 [degree sign] Celsius) nonpulsatile CPB at exhaust gas concentrations of 1.5 MAC for 15 min. SVRI was calculated at baseline, 1, 2, 3, 4, 5, 7, 9, 12, and 15 min after starting volatile anesthetics' delivery. Plasma catecholamine concentrations were determined in 12 desflurane-treated patients and 12 sevoflurane-treated patients at baseline, 5, and 15 min.

Results: The time-course of Delta SVRI, (changes in SVRI from baseline), from baseline to 5 min was significantly different between desflurane- and sevoflurane-treated patients, whereas there was no difference from 7 to 15 min. In the desflurane group, SVRI from 1 to 7 min remained unchanged to baseline level, thereafter declining to significantly lower values at 9, 12, and 15 min compared with values from 0 to 5 min, whereas sevoflurane produced an immediate and significant reduction in SVRI. With desflurane, catecholamine concentrations remained unchanged to baseline level at 5 and 15 min; with sevoflurane, they decreased with time.     

Soluble interleukin-2 receptor release defect in vitro in elderly subjects

The evidence from several studies indicates that as individuals age, they may display immune dysfunctions, mostly T cell dysfunctions. Recently, a soluble form of the receptor for interleukin-2 (IL-2) (sIL-2R) has been demonstrated in human sera and in vitro stimulated culture supernatants from human T lymphocytes. In the present paper, we report in vitro sIL-2R production from peripheral blood mononuclear cells in elderly subjects. The results show that no difference exists for unstimulated cultures, whereas after mitogen stimulation the elderly subjects showed the lowest values compared with young ones. These findings suggest that sIL-2R may provide a new tool for the study of T lymphocyte dysfunctions in old age.     

Effects of low-dose propofol administration on central respiratory drive, gas exchanges and respiratory pattern

The effects of sedative-hypnotic doses of propofol on respiratory drive and pattern have not yet been extensively described. Repeated small boluses of propofol (0.6-0.3 mg.kg-1) were administered to ten ASA I patients undergoing carpal tunnel release using regional anaesthesia. Airway pressure, capnography and pneumotachography were continuously recorded. With respect to basal values, no significant variations of respiratory rate, minute volume, tidal volume, inspiratory and expiratory time, total expiratory cycle, Ti/Ttot, TV/Ti, P0.1, EtCO2 and blood gas analysis were observed. Low doses of propofol, to maintain conscious sedation of light sleep, have not been shown to cause respiratory depression.     

gamma-ray spectrometry of soil samples from the Provincia dell'Aquila (Central Italy).

In the Abruzzo Region (Central Italy) there is a lack of measurements of gamma-ray activity in soils and waters. For this reason, we have planned to carry out a systematic measurement of soils in the area of the Provincia dell'Aquila, which covers about one-half of the entire region. In this paper we report the results obtained from 56 soil samples, collected in the northern part of the area of interest (about one-fourth of the total area under study). The results, in terms of content of uranium, thorium and potassium and the activity of caesium are reported, as well as the details on the experimental procedure. The results show a limited content of K and U, with no large variations from site to site, in agreement with the expectations based on the knowledge of the geo-lithological nature of the soil. The amount of Th is also quite limited, with a few exceptions where the Th content is up to five times the average value. Caesium, originated from the fall-out following the Chernobyl accident, is very irregularly distributed owing to the complicated orography of the land. Future plans are also shortly discussed.     

Experimental axonopathy induced by immunization with campylobacter jejuni lipopolysaccharide from a patient with guillain‐barré syndrome

Campylobacter jejuni (C. jejunj) infection is the most common antecedent in the axonal variant of Guillain‐Barré syndrome (GBS). Antibodies against nerve gangliosides found in GBS patients recognize cross‐reactive epitopes in the lipopolysaccharide (LPS) of C. jejuni. This led to the molecular mimicry hypothesis of GBS. We immunized eleven rabbits with a LPS extracted from HS:19 C. jejuni strain isolated from a patient with GBS and complete Freund's adjuvant (CFA)(group I). In a second experiment we immunized seven rabbits with LPS, CFA and keyhole limpet hemocyanin (KLH)(group II). All group I rabbits developed high titers of anti‐LPS, anti‐GM1, anti‐GD1b antibodies and lower titers of anti‐GD1a. One rabbit, 50 days after initial inoculation, showed tremor and weakness. All rabbits of group II developed high titres of antiganglioside antibodies and six animals showed weakness 59–113 days after initial inoculation. Two rabbits died. Pathology showed mild to moderate, tendentially grouped, axonal degeneration in sciatic nerves of four out of five animals. Control rabbits of group I (immunized with CFA only) did not develop antibodies, controls of group II (immunized with CFA + KLH) developed low titers of IgG anti‐GM1. None developed neurological signs or showed axonal degeneration. C. jejuni LPS is a potent B‐cell stimulator capable to induce a strong antiganglioside response in rabbits. However, to induce the neuropathy is crucial to employ KLH, a glycoprotein known to stimulate both humoral and cellular responses. This animal model reproduces the pathogenetic process hypothesized in axonal GBS with antiganglioside antibodies post C. jejuni infection.     

Spinal lipomas in childhood]

Spinal lipomas account for 5% of the tumors of the spinal cord, frequently present already at birth. Most commonly they are associated with forms of dysraphism, but lipomas without bony involvement are considered dysembriogenetic lesions too. Children with lipoma frequently have intact neurological functions, but may become symptomatic later on. Diagnosis is possible also in neurologically intact patients because of skin lesions or subcutaneous masses. Many surgeons suggest early surgery to prevent injury to neural structures from traction due to cord tethering; others prefer to wait for the rise of any symptom before considering surgery. However, neurological recovery after surgery is rarely observed, and, when present, is always partial; the primary goal of surgery is to stop the clinical progression through the detethering of the cord.     

Regional effect of estradiol on rat caudate-putamen dopamine receptors: lateral-medial differences

The effect of a chronic 17 beta-estradiol (10 micrograms, b.i.d.) treatment of 2 weeks to ovariectomized rats was investigated on lateral and medial caudate-putamen dopamine receptors. Dopamine D2 receptors were assayed with [3H]spiperone binding to caudate-putamen homogenates or by autoradiography of forebrain sections. Estradiol treatment leads to a significant increase in the density of lateral caudate-putamen dopamine receptors while for the medial dopamine receptors the increase is non-significant. This effect is observed when plasma levels of 17 beta-estradiol and prolactin are increased. These results indicate that the effect of estradiol on striatal dopamine receptors is heterogeneous and that those in the lateral part are more susceptible to this steroid.