The Impact of Intraventricular Hemorrhage and Periventricular Leukomalacia on Mortality and Neurodevelopmental Outcome in Very Preterm and Very Low Birthweight Infants: A Prospective Population-based Cohort Study

OBJECTIVE

To survey the incidence of intraventricular hemorrhage (IVH) and periventricular leukomalacia (PVL) by gestational age and to report the impact on mortality and neurodevelopmental outcome in very preterm/very low birthweight infants.

STUDY DESIGN

This was a population-based cohort study of 1927 very preterm/very low birthweight infants born in 2014-2016 and admitted to Flemish neonatal intensive care units. Infants underwent standard follow-up assessment until 2 years corrected age with the Bayley Scales of Infant and Toddler Development and neurological assessments.

RESULTS

No brain lesion was present in 31% of infants born at <26 weeks of gestation and 75.8% in infants born at 29-32 weeks of gestation. The prevalence of low-grade IVH/PVL (grades I and II) was 16.8% and 12.7%, respectively. Low-grade IVH/PVL was not related significantly to an increased likelihood of mortality, motor delay, or cognitive delay, except for PVL grade II, which was associated with a 4-fold increase in developing cerebral palsy (OR, 4.1; 95% CI, 1.2-14.6). High-grade lesions (III-IV) were present in 22.0% of the infants born at <26 weeks of gestational and 3.1% at 29-32 weeks of gestation, and the odds of death were ≥14.0 (IVH: OR, 14.0; 95% CI, 9.0-21.9; PVL: OR, 14.1; 95% CI, 6.6-29.9). PVL grades III-IV showed an increased odds of 17.2 for motor delay and 12.3 for cerebral palsy, but were not found to be associated significantly with cognitive delay (OR, 2.9; 95% CI, 0.5-17.5; P = .24).

CONCLUSIONS

Both the prevalence and severity of IVH/PVL decreased significantly with advancing gestational age. More than 75% of all infants with low grades of IVH/PVL showed normal motor and cognitive outcome at 2 years corrected age. High-grade PVL/IVH has become less common and is associated with adverse outcomes.

Medium-chain Acyl-CoA dehydrogenase deficiency presenting with neonatal pulmonary haemorrhage

Background

Medium-chain Acyl-CoA dehydrogenase deficiency (MCADD) is the most common inherited disorder of fatty acid beta-oxidation. Signs and symptoms of MCADD typically appear during infancy or early childhood and include vomiting, lethargy, and hypoglycemia. Pulmonary haemorrhage has previously been described in patients with MCADD, but has always been considered a pre-terminal complication caused by heart failure.

Case presentation

We report on a newborn term infant that presented on the second day of life with signs of encephalopathy, followed by hypovolemia and respiratory distress caused by a severe pulmonary haemorrhage. Fluid resuscitation and mechanical ventilation were initiated and the coagulopathy was corrected by the administration of fresh frozen plasma. Echocardiography revealed a normal cardiac function. After 6 days of full intensive care, the patient survived without sequellae. The clinical presentation in absence of signs of infection raised a strong suspicion for a metabolic disorder and genetic testing revealed MCADD due to a homozygous A985G mutation.

Conclusion

The key towards successful management of severe pulmonary haemorrhage in newborns with a coagulopathy and suspicion of an underlying metabolic disorder consists of adequate mechanical ventilation and aggressive use of fresh frozen plasma, while treating the metabolic decompensation and initiating an early diagnostic work-up. MCADD can lead to acute decompensation and present with complications such as pulmonary haemorrhage independent of cardiac function. Hence, in the context of MCADD, pulmonary haemorrhage should not be considered a pre-terminal complication caused by heart failure, and rather than withdrawing care, intensive treatment must be initiated.

Experimental quantification of the feline leukaemia virus in the cat flea (Ctenocephalides felis) and its faeces

Cat fleas (Ctenocephalides felis) were fed via artificial membranes and infected with the feline leukaemia virus (FeLV) from cell cultures. After removing the fleas from the blood source, the quantity of virus in the flea and its faeces was measured over a defined period of time. The virus was detectable in the fleas for up to 30 h at room temperature and up to 115 h at 4 degrees C. In the faeces, the amount of virus decreased much more slowly--after 2 weeks half of the initial amount of virus could still be detected. Thus the faeces might be a source of further infections, e.g. for the flea larvae or the cat itself.

Investigations on the life cycle and morphology of Tunga penetrans in Brazil

In the present study, the life cycle of Tunga penetrans was established in Wistar rats in the laboratory, and the morphology of the resulting developmental stages was studied by means of light and scanning electron microscopy. It was seen that the females enter at a nonfertilized stage through the skin of their hosts. Only there the copulation occurs, while females and males brought together in a Petri dish showed no interest in each other. In any way -- fertilized or not -- the females start about 6 days after penetration and hypertrophy with the ejection of eggs. While fertilized eggs proceed to development, the unfertilized ones remain arrested. The eggs are ovoid and measure about 600 x 320 mum. The larvae hatch from the eggs 1-6 days (mean 3-4) after ejection. Formation of larvae 2 took at least another day, while 4 up to 10 days more were needed until this larva starts pupation (mean 5-7 days). The formation of the adult fleas inside the puparium occurred within 9-15 days (with a maximum hatch at day 12). Adult female fleas having reached the skin of a host start blood sucking within 5 min and prepare to enter the skin. After 24 h, the flea stacked already with two thirds of its body inside the skin. After 40 h, the penetration was completed, and feeding and hypertrophical enlargement started, which was completed on day 6, when eggs became ejected. When studying the morphology of the fleas obtained from different hosts, slight variations were seen, which, however, are not significant for a species separation but may be an indication of the presence of different strains/races or the beginning of such a formation.

Stenting allows weaning and extubation in ventilator- or tracheostomy dependency secondary to benign airway disease

Central airway obstruction can cause severe respiratory insufficiency leading to mechanical ventilation (MV) or artificial airway (AA) dependency. Interventional bronchoscopic procedures have been reported to be of help in weaning patients with malignant airway stenoses from mechanical ventilation, whereas their use in benign disease is only anecdotal. The objectives of this study are to evaluate early, intermediate and long-term outcome of interventional bronchoscopy and stent placement in the treatment of MV/AA dependency due to benign airway obstruction. In a retrospective cohort analysis for the period 1999-2004, we evaluated 15 consecutive ICU patients with documented benign central airway obstruction, who were referred for bronchoscopic management of their condition after multiple failed attempts at weaning from MV or decannulation of the AA. Indications for bronchoscopic treatment were surgery refusal, medical or surgical inoperability, or absence of alternative treatment options. Malacia, post-intubation stenosis and goiter were the main causes of airway obstruction and MV/AA dependency. All patients were treated by means of rigid bronchoscopy, dilatation procedures and stent insertion. All but one patient (93.3%) were successfully and permanently extubated/decanulated immediately after the bronchoscopy. Minor complications occurred in 6 patients (40%) leading to a second intervention. All complications could be managed endoscopically and long-term follow up was uneventful. Interventional bronchoscopy with stent insertion can allow successful withdrawal from MV/AA and can offer longstanding airway patency in selected ventilator- or tracheostomy-dependant individuals with benign airway stenoses,when surgery in not feasable or contra-indicated.

Molecular biological investigations of Brazilian Tunga sp. isolates from man, dogs, cats, pigs and rats

Twenty-four isolates of Tunga were collected from afflicted humans, dogs, cats, pigs and rats in Brazil. To investigate genetic diversity, a hypervariable section of mitochondrial 16S rDNA was amplified using PCR and subsequently sequenced. In order to compare results with another species of the genus Tunga, three isolates of the recently described Tunga trimamillata were also checked. Whereas eleven isolates (five from cats, three from dogs and three from humans) were of identical sequence, thirteen isolates collected from dogs, humans, pigs and rats showed differences in sequence up to 49%, so that the existence of one or more new species of Tunga may be presumed.

Molecular phylogeny of isolates of Ctenocephalides felis and related species based on analysis of ITS1, ITS2 and mitochondrial 16S rDNA sequences and random binding primers

The phylogenetic relationships among 31 different flea isolates representing seven different species were studied by nucleotide sequence comparison of the internal transcribed spacer 1 (ITS1), internal transcribed spacer 2 (ITS2) and/or mitochondrial 16S ribosomal RNA gene (mt16S-rDNA) to examine the patterns of variation. Results show that all regions are useful in discriminating among flea species. In Ctenocephalides felis and Tunga penetrans, some differences in these gene regions occurred among different isolates within the same species. In the latter case, the differences are in the mt16S-rDNA region, with one isolate showing 48% divergence in nucleotide sequence. The taxonomic implications of this result are unclear at present. The gene regions revealed differences between C. felis isolates only after DNA sequencing the PCR products. Further differentiation among C. felis isolates was obtained using four different random binding primers (decamers) and primers for mammalian aldolase to amplify narrow differences in the genome. Using these primers we were able to discriminate between different C. felis isolates and determine that some of the genetic variation coincided with minor differences in response to the control agent imidacloprid. However, overall findings do not support the existence of subspecies of C. felis.

Evidence of horizontal transmission of feline leukemia virus by the cat flea ( Ctenocephalides felis)

The feline leukemia virus (FeLV) is a naturally occurring and widespread retrovirus among domestic cats. The virus is mainly transmitted horizontally through saliva, blood and other body fluids by close contact between cats. Vectors other than cats, e.g. blood-sucking parasites, have not been reported. This study tested the vector potential of the cat flea ( Ctenocephalides felis) for FeLV. In a first feeding, fleas were fed for 24 h with blood from a FeLV-infected cat with persistent viremia. FeLV could be detected in the fleas, as well as in their feces. Fleas were then divided in two populations and fed in a second feeding for 5 h or 24 h with non-infected non-viremic blood. FeLV was again detected in the fleas and their feces. In addition, the two resulting blood samples of the second feeding were subsequently tested for FeLV and both samples were positive for FeLV RNA. The cat flea transmitted the FeLV from one blood sample to another. In a third feeding, the same populations of fleas were fed again with non-infected blood for 5 h or 24 h. This time FeLV was not detected in the fleas, or in the feces or blood samples. Results show that cat fleas are potential vectors for FeLV RNA in vitro and probably also in vivo.

[The armamentarium of the periodontologist]

The aim of this article is to describe the products available to the periodontist for the regeneration of bone and periodontal tissues. According to distinct biological mechanisms responsible for their regenerative potential, these products can be classified upon three groups: bone substitutes, membranes and enamel matrix proteins. The rationale for trying to regenerate the periodontium after the initial non-surgical phase of the periodontal treatment is discussed. The indications of these products according to their biological principles are described as well as their limitations. The safety of the products of allogenic origin is discussed.

In vivo and in vitro effects of imidacloprid on sheep keds (Melophagus ovinus): a light and electron microscopic study

The effects of imidacloprid (Advantage) on sheep keds (Melophagus ovinus Linne 1758) were studied in vivo and in vitro by means of direct observation (monitored on video tape) and by light and electron microscopy. It was found that: 1. Imidacloprid acted rapidly on all motile stages of the sheep keds. Within 3-4 min after exposure they became immobile and their legs and the abdomen started tetanic trembling movements for 15-30 min, leading to death. 2. The compound is apparently taken up by the body, since it also acted on those sheep keds that had been exclusively exposed to imidacloprid-contaminated filter papers. 3. The compound is available and active for more than 1 month in the wool of sheep; even rainfall does not reduce its efficacy. Body contact between treated mother sheep and their lambs protects them from infestation with these ectoparasites. 4. The compound initiates an ultimately lethal destruction of the ganglia, nerve chords and related muscle fibers, as can be seen in electron micrographs.

Bronchoscopic cryotherapy: preliminary experience

Our preliminary experience with the bronchoscopic application of cryotherapy using rapid decompression of liquid nitrous oxide as cooling agent is reported. Seventeen applications through rigid bronchoscopy in twelve patients were performed. A single cryotherapy session was successful in the debulking of obstructive malignant lesions of the central airways in five patients (four non-small cell carcinoma, one renal cell cancer metastasis), and in the treatment of a capillary haemangioma (one patient). Two sessions were successful in the treatment of a metastatic melanoma (one patient) and benign granulation tissue (one patient). Cryotherapy was also successful in the treatment of early bronchial cancer (carcinoma in situ) in four patients, requiring repetitive sessions in two. There were no complications or side-effects. These preliminary findings confirm the safety and efficacy of bronchoscopic cryotherapy in a variety of airway lesions.

Isoflurane, desflurane and sevoflurane for carotid endarterectomy

After carotid endarterectomy under general anaesthesia, the rapid elimination of desflurane and sevoflurane may allow earlier postoperative neurological assessment than after the use of isoflurane. However, desflurane may be associated with tachycardia and hypertension and may therefore increase cardiovascular risk. We investigated haemodynamic and recovery characteristics in patients scheduled for carotid endarterectomy who were anaesthetised with isoflurane, sevoflurane or desflurane. No significant peri-operative differences were noted in cardiac index or ST segment analysis. The times to extubation, movement on command and consciousness were shorter after desflurane and sevoflurane than after isoflurane anaesthesia. Postoperative pain, nausea, vomiting and shivering were similar in the three study groups.

Volume and cellular content of normal pleural fluid in humans examined by pleural lavage

Currently, no reliable data are available on the volume or on the cellular content of pleural fluid in normal humans. In analogy with bronchoalveolar lavage (a technique enabling retrieval of small volumes of epithelial lining fluid from the lung), we developed a pleural lavage (PL) technique consisting of injection and retrieval of 150 ml of saline into the right pleural space, performed during a thoracoscopic sympathicolysis procedure in otherwise healthy subjects suffering from essential hyperhidrosis. With urea used as an endogenous marker of dilution, measured mean right-sided pleural fluid volume was 8.4 +/- 4.3 ml. In a subgroup of subjects, we confirmed that right- and left-sided pleural fluid volumes were similar. Expressed per kilogram of body mass, total pleural fluid volume in normal, nonsmoking humans is 0.26 +/- 0.1 ml/kg. Total cell count in the PL fluid of nonsmoking normal subjects yielded a median of 91 x 10(3) white blood cells (WBC) per milliliter of lavage fluid (interquartile range [IR] = 124 x 10(3) cells/ml). Taking into account a measured dilution factor of 18.86, the total WBC count in the original pleural fluid was 1,716 x 10(3) cells/ml. Differential cell counts yielded a predominance of macrophages (median: 75%; IR: 16%) and lymphocytes (median: 23%; IR: 18%). Mesothelial cells (median: 1%; IR: 2%), neutrophils (median: 0%; IR: 1%), and eosinophils (median: 0%; IR: 0%) were only marginally present. There were no significant differences between males and females or between right- and left-sided pleural fluid in total and differential cell counts. In contrast, in smokers a small but statistically significant increase in pleural fluid neutrophils (median: 1%; IR: 2%; p < 0.015) was observed. In conclusion, PL performed during thoracoscopy for sympathicolysis allowed for the first time determination of the volume and of the total and differential cell contents of the pleural fluid present in normal human pleura.

Use of tranexamic acid for an effective blood conservation strategy after total knee arthroplasty

We have investigated the effect of treatment with tranexamic acid, an inhibitor of fibrinolysis, on blood loss, blood transfusion requirements and blood coagulation in a randomized, double-blind, placebo-controlled study of 42 patients after total knee arthroplasty. Tranexamic acid 15 mg kg-1 (n = 21) or an equivalent volume of normal saline (n = 21) was given 30 min before surgery and subsequently every 8 h for 3 days. Coagulation and fibrinolysis values, blood loss and blood units administered were measured before administration of tranexamic acid, 8 h after the end of surgery and at 24 and 72 h after operation. Coagulation profile was examined (bleeding time, platelet count, prothrombin time (PT), activated partial thromboplastin time (aPTT), plasminogen, beta-thromboglobulin and fibrinogen). Fibrinolysis was evaluated by measurement of concentrations of D-dimer and fibrinogen degradation products (FDP). Total blood loss in the tranexamic acid group was 678 (SD 352) ml compared with 1419 (607) ml in the control group (P < 0.001), and occurred primarily during the first 24 h after surgery. Thirteen patients received 1-5 u. of packed red blood cells in the control group compared with two patients in the tranexamic acid group, who received 3 u. (P < 0.001). Postoperative packed cell volume values were higher in the tranexamic acid group despite fewer blood transfusions. Postoperative concentrations of plasminogen were decreased significantly in the tranexamic acid group (P < 0.001). Platelet count, PT, aPTT, bleeding time, beta-thromboglobulin, fibrinogen and FDP concentrations did not differ between groups, but D-dimer concentrations were increased in the control group. Thromboembolic complications occurred in two patients in the control group compared with none in the tranexamic acid group.

Screw-thread vs Dumon endoprosthesis in the management of tracheal stenosis

STUDY OBJECTIVES

A frequent complication of the widely used Dumon silicone stent is its tendency to migrate when used in tracheal stenosis. We compared the clinical efficacy and complications (including migration) of the Dumon stent with a screw-thread stent, a device with an increased stent-to-wall contact surface and, theoretically, less tendency to migrate.

DESIGN

Retrospective case analysis.

SETTING

Academic hospital.

MATERIALS AND METHODS

Forty-six patients with tracheal stenoses (23 benign and 23 malignant) requiring the placement of 50 stents (29 Dumon and 21 screw-thread) were studied. In 26 patients Dumon stents were used, and in 20 patients screw-thread stents were used. Both patient groups had comparable clinical and stenosis-related characteristics.

RESULTS

Stent insertion and follow-up were uneventful in both the Dumon and the screw-thread insertions, respectively: 62% vs 67% (not significant). There were seven migrations in the Dumon group, compared to only one migration in the screw-thread group, respectively: 24% vs 5%. This difference did not reach statistical significance (p = 0.1). All of the migrations occurred in the benign stenosis group, and none occurred in the malignant-stenosis group, respectively: 8 of 23 vs 0 of 23, p = 0.004. Within the benign-stenosis group, the Dumon stent had a significantly increased risk for migration when compared to the screw-thread stent, respectively: 7 of 13 vs 1 of 11, p = 0.033.

CONCLUSIONS

The screw-thread stent and the Dumon stent are equally effective in the management of tracheal stenosis. There is a general trend toward a decreased migration rate, and a significantly lower risk for migration in patients with benign tracheal stenosis. The (less expensive) screw-thread stent may represent an attractive alternative in the management of tracheal stenosis in general, and may be preferable to the Dumon stent in treating benign tracheal stenosis.

Thoracoscopic T2-T3 sympathicolysis for essential hyperhidrosis in childhood: effects on pulmonary function

Thoracoscopic T2-T3 sympathicolysis (TS) is a minimally invasive treatment for patients suffering from severe, refractory essential hyperhidrosis (EH). TS has previously been shown to be safe and efficacious in children. In order to examine the effects of TS on respiratory function, pulmonary function tests (PFT) were performed prior to and 6 weeks and 6 months after TS in 12 children with EH (3 boys; mean age 12.8+/-2.5 years). Small asymptomatic decreases in forced expiratory volume in one second (FEV1; -2%), forced expiratory flow after expiration of 75% of vital capacity (FEF75; -9.6%), total lung capacity (TLC; -1%), transfer factor for diffusion of carbon monoxide (T(LCO); -7.6%), and transfer coefficient for diffusion of carbon monoxide (K(CO); -1.5%) were observed 6 weeks after TS. These changes are comparable to those observed in adults but did not reach statistical significance in small children. In line with observations in adults, TLC (and T(L,CO)) returned to baseline values 6 months after TS, whereas FEV1, FEF75, and K(CO) remained at their 6-week level. In conclusion, TS causes only small, statistically insignificant, and asymptomatic decreases in pulmonary function in children. TS can, therefore, be considered a safe treatment option in children suffering from severe, refractory EH.

Pharmaco-economic evaluation of a disposable patient-controlled analgesia device and intramuscular analgesia in surgical patients

The present study contrasted the pharmaco-economics and analgesic efficacy of intramuscular (i.m.) opioid treatment with a parenteral disposable patient-controlled analgesia (PCA) system in two groups of 20 female patients (ASA I-II, aged 35-69 years) scheduled for abdominal hysterectomy. The PCA group received a continuous infusion of 1.5 mg h-1 piritramide, a mu-opioid receptor agonist, with incremental doses of 1.5 mg (lock-out interval = 15 min). The i.m. group received 0.3 mg kg-1 piritramide i.m. when requested by the patient with a minimum interval of 5 h. Pain intensity, sedation and the functional recovery of the patients were followed for 72 h post-operatively. The sum of pain intensity differences (SPID) was used as a measure of analgesic efficiency. Equipment and drug costs, and the demand on nursing time were recorded over 3 days post-operatively. The costs of PCA and i.m. therapies per patient were used to calculate the cost-benefit (cost of treatment vs. nursing time) and cost-effectiveness (cost of treatment vs. SPID) analyses. Both treatments initially provided comparable analgesia, but PCA was more efficient after 16 h and significantly reduced nursing time for pain treatment (PCA = 61 +/- 4 min, i.m. = 88 +/- 5 min; P < 0.001). Functional recovery was not different for either treatment. Cost analysis indicated a better cost-benefit ratio for the i.m. treatment (0.35 vs. 1.1 for PCA treatment), but a similar cost-effectiveness for both treatments (PCA = 1.9 Belgian Francs (BEF) unit-1 SPID; i.m. = 1.7 BEF unit-1 SPID).

Purification and functional characterization of an 85-kDa gelsolin from the ascidians Microcosmus sulcatus and Phallusia mammilata

From the pharyngeal baskets of the ascidians Microcosmus sulcatus and Phallusia mammilata we have purified an 85-kDa protein that is characterized as a member of the gelsolin family. These proteins from both species show the same behaviour in functional assays. The ascidian gelsolin binds two actin monomers in a highly cooperative manner. This complex formation is Ca(2+)-dependent, but not completely reversible, as on removal of Ca2+ one actin monomer dissociates leaving a 1:1 complex between gelsolin and G-actin. The properties of F-actin severing and G-actin nucleation depend on the presence of free Ca2+ in a micromolar range, with half maximum activation at about 3 x 10(-6) M. The protein becomes inactivated when Ca2+ concentrations of 0.5 mM are exceeded. Fragmentation of F-actin by the ascidian gelsolin is comparably fast to that of vertebrate gelsolin. A steady state of actin fragmentation is reached within 2-4 s. Promotion of G-actin nucleation is also comparable to that of vertebrate gelsolin. Regarding functional aspects, the ascidian gelsolin is more closely related to vertebrate gelsolin than to an arthropod gelsolin from crayfish tail muscle.

Interventional bronchoscopy: 5-year experience at the Academic Hospital of the Vrije Universiteit Brussel (AZ-VUB)

Our experience with interventional bronchoscopic techniques in a University Hospital is described: in 93 patients during a 5-year period, 149 interventional procedures (i.e., Nd-YAG laser photoresection and/or airway stenting and/or balloon dilatation) have been performed. Laser resection was successful in relieving major symptoms (intractable dyspnea, hemoptysis or retro-obstructive complications) in 35/41 (85%) of malignant indications, and in 18/19 (94%) of benign obstructions. Major complications included one death (1.6%) early in the series, and major nonfatal hemorrhage in three patients (5%), all with malignant disease. In 31/35 (89%) of malignant central airway stenoses treated with stents, respiratory symptoms could be palliated successfully. Mean survival after stenting was 6 +/- 5.3 months. In 20/23 (87%) of benign tracheal stenoses, temporary or permanent stenting allowed for complete restoration of airway patency. The development of inexpensive and simplified insertion techniques for existing stents, and of a new (and even less expensive) type of tracheal stent has enabled the use of airway stenting in all categories of patients. Bronchoscopic balloon dilatation was helpful in the mechanical dilatation of stenoses, and in the unfolding of unopened stents. Finally, a plea for an organised referral system and for active collaboration between interventional bronchoscopy centers is made.

Effects of chlordiazepoxide on opioid-induced antinociception and respiratory depression in restrained rats

This study investigates the influence of possible stress due to housing in Bolman cages on antinociception and on respiratory depression following opioid administration. To evaluate the functional role of this stressor and to modulate it, rats were subcutaneously pretreated with the anxiolytic chlordiazepoxide (CDP; 10 mg/kg) or saline (SAL) before the immobilization in the Bolman cages and before the intravenous administration of small doses of morphine (MOR), sufentanil (SUF), or vehicle (VEH). Antinociception, respiratory impairment and stress were evaluated by means of the tail-flick latency, blood gas analysis, and serum corticosterone (CS), adrenocorticotropic hormone (ACTH), and prolactin (PRL) determinations. The results demonstrated that 10 mg/kg CDP did not alter the antinociceptive effects of low doses of morphine and sufentanil. CDP pretreatment differentially affected the various blood gas parameters. Compared to vehicle pretreatment, there was a larger decrease in PaO2 following MOR and SUF in the CDP-pretreated rats. The effects were most pronounced at the lowest doses of both opioids. A CDP potentiation was also observed for the short-lasting raises in PaCO2 with the lowest concentrations of the opioids. At higher concentrations of the opioids, CDP was without any effect. With regard to the stress hormones, immobilization and an intravenous injection resulted in increases in CS and PRL in both CDP- and VEH-pretreated rats. ACTH did not change in these controls. SUF prevented the CS raises independent of a CDP pretreatment, while ACTH only increased in the SUF plus CDP groups, pointing to a stress-reducing effect of SUF. Also, MOR without CDP prevented the increases in CS, but the opioid intrinsically increased ACTH. These results indicate that restraint in Bolman cages in the present setup, with animals recovering for several hours in these cages after being equipped with an arterial catheter, is stressful but without any significant effect on the opioid-induced antinociception. Pretreatment with an anxiolytic benzodiazepine only minimally affected the outcome of the opioids on respiratory depression and pointed to a stress-reducing effect of low doses of the opioids, especially sufentanil.

Thoracoscopic splanchnicolysis for the relief of chronic pancreatitis pain: experience of a group of pneumologists

Intractable pain is the most invalidating symptom in patients suffering from chronic pancreatitis. Anatomical interruption of the major afferent pain nerves is indicated in severe refractory cases. Among the various techniques and sites of interruption, thoracoscopic splanchnicectomy has emerged as an efficient alternative for the more aggressive open surgical splanchnicectomy, and for the (solely temporarily efficacious) transcutaneous neural blocks, which moreover bear some serious complications. Until now, all reports on thoracoscopic splanchnicectomy were typically surgical, using video-assisted thoracoscopic surgery techniques, double-lumen intubation, and so on. In analogy with thoracoscopic upper dorsal T2-T3 sympathicolysis for essential hyperhidrosis, a simplified thoracoscopic splanchnicolysis technique used in 8 patients suffering from either severe refractory chronic pancreatitis pain (7 patients) or postsurgical epigastric pain is described. Pain control was achieved in 5 of the 7 patients with chronic pancreatitis with a short (20+/-8 min) intervention, short hospitalization (2 days), and simple (single-lumen intubation, no chest drains) procedure. Thus, this simplified thoracoscopic splanchnicolysis technique may represent a valid alternative in the often difficult treatment of refractory chronic pancreatitis pain or other upper abdominal pain.

C-terminally deleted fragments of 40-kDa earthworm actin modulator still show gelsolin activities

C- and N-terminally truncated fragments of earthworm gelsolin were constructed, cloned and expressed in Escherichia coli. G-actin-binding properties of these fragments and their influences on the polymeric state of actin were investigated. A construct lacking a large part of the third segment [E(1-295)] supports actin nucleation similar to the complete protein and shows reduced actin fragmentation property, but is no longer Ca2+-sensitive in its activity. The first and the second segments (E1 and E2) each contain one actin-binding site. In contrast to human gelsolin, E1 in combination with a short N-terminal region of E2 is not sufficient for the F-actin-severing activity of the protein.

Bronchoscopic balloon dilatation in the combined management of postintubation stenosis of the trachea in adults

Bronchoscopic balloon dilatation (BBD) using angioplasty balloon catheters has been employed successfully in the treatment of tracheobronchial stenoses in children and has worked with variable success in adults with bronchial stenosis. In adults with tracheal stenosis, BBD only has been reported anecdotally. In this study, experience with BBD using a valvuloplasty balloon catheter in the combined treatment (with Nd-YAG laser photoresection and stenting) of severe benign postintubation tracheal stenoses in three adults is delineated. BBD was particularly successful in establishing tracheal patency when laser photoresection was contraindicated or was too dangerous; BBD allowed easy insertion of tracheal stents and the "opening" of folded silicone stents. BBD is a simple, inexpensive, safe, and efficient adjunct in the combined treatment of severe postintubation rigid tracheal stenosis in selected adults.

Combined cesarean section and clipping of a ruptured cerebral aneurysm: a case report

We present a case of subarachnoid hemorrhage due to a ruptured cerebral aneurysm of the right internal carotid artery in a patient at 34 weeks of gestation (G2P1). A combined surgical procedure (cesarean section followed by clipping of the aneurysm) was performed with good maternal and fetal outcome. The differential diagnosis, the timing of neurosurgery, and the anesthetic techniques used are discussed.

Scintigraphic visualization of intrathecal liposome biodistribution

BACKGROUND

Liposomes containing local anaesthetics have been administered intrathecally and in the epidural space. Poor attention has been given to the pharmacokinetics of liposomes as drug carriers. Therefore, we observed the biodistribution of liposomes after intrathecal injection in rats by scintigraphic imaging during 24 h.

METHODS

We administered 99mTc-labeled multilamellar (MLV) and small unilamellar vesicles (SUV) of defined size and volume dispersities into the cerebrospinal fluid at the lumbar level. Those vesicles were free of contamination by radiolabeled colloids as visualized by light and electron microscopy and of neurotoxic products from phosphatidylcholine hydrolysis and peroxidation, both during the preparation process and after 24 h incubation in cerebrospinal fluid at 37 degrees C in vitro.

RESULTS

SUV immediately diffused from the lumbar site of injection to the head and were cleared between 1 and 24 h after injection. MLV were cleared more slowly from the spinal space and appeared in the head region 1 h after injection where they accumulated up to 24 h. These differences were explained in terms of vesicle sizes and volumes. SUV with 0.05 micron diameters were rapidly absorbed into the blood through the arachnoid granulations. In contrast, particles larger than the upper size limit of the arachnoid granulations permeability (+/- 8 microns) could accumulate in the head with a slow elimination rate.

CONCLUSION

This difference in clearance from the intrathecal space outlines the importance of defining the size of the liposomes, the distribution of a tracer or a drug inside the liposomal preparation, the chemical stability and the absence of toxic degradation products of liposome formulations before clinical use.

99mTechnetium-stannous oxinate as marker of liposome formulations

Liposomes associated with tin(II) dioxinate were prepared from egg yolk phosphatidylcholine and cholesterol as sterile and pyrogen-free multilamellar or unilamellar vesicles. Complexing of liposomal tin(II) dioxinate with 99mTc attained 98% of the added radioactivity. Thirty percent 99mTc were released during 24-h incubation in biological fluids. The absence of tin colloids seen by electron microscopy and the stability of liposomal phospholipid and tin(II) dioxinate during 72-h incubation at 37 degrees C in plasma and cerebrospinal fluid would allow safe and reliable scintigraphic liposome pharmacokinetic studies.

Total intravenous anesthesia and high-frequency jet ventilation during transthoracic endoscopic sympathectomy for treatment of essential hyperhidrosis palmaris: a new approach

OBJECTIVE

To evaluate the effects of high-frequency jet ventilation (HFJV) applied to both lungs on hemodynamic parameters, oxygenation, and operating conditions during bilateral videothoracoscopic sympathectomy.

DESIGN

A prospective, unblinded study.

SETTING

An ambulatory surgical unit at a university medical center.

PARTICIPANTS

30 patients (11 men, 19 women), ASA status 1.

INTERVENTION

Bilateral videothoracoscopic sympathectomies were performed using total intravenous anesthesia with propofol, alfentanil, and atracurium, and the patients were ventilated with an oxygen-air mixture using HFJV delivered to both lungs with a Hi-Lo Jet tracheal tube (Mallinckrodt).

MEASUREMENTS AND MAIN RESULTS

Mean total anesthesia time was 55 +/- 13 minutes. Hemodynamic parameters remained stable during surgery, although ablation of the sympathetic ganglia induced three incidences of bradycardia (10% of the patients), which were responsive to atropine. Four patients developed oxygen desaturation (Sa O2 < 90%) after the creation of the pneumothorax. Surgical conditions were considered excellent by the surgeons. Concerning postoperative complications, a temporary Horner's syndrome was observed in one patient. Another patient had a mild residual pneumothorax on the first postoperative day that resolved without insertion of a chest tube.

CONCLUSIONS

It was concluded that HFJV applied to both lungs is an easy and safe anesthetic technique that provides excellent surgical conditions and causes a minor incidence of morbidity.

A simplified T2-T3 thoracoscopic sympathicolysis technique for the treatment of essential hyperhidrosis: short-term results in 100 patients

A simplified one-time bilateral thoracoscopic T2-T3 sympathicolysis technique using single-lumen endotracheal intubation with high frequency jet ventilation and electrocautery destruction ("sympathicolysis") of the sympathetic ganglia was applied in 100 consecutive patients with severe essential hyperhidrosis (EH). Providing a pleural space can be created, this technique was proven simple and safe, and short-term clinical results were excellent: palmar hyperhidrosis was cured in 98% of patients, and axillar and plantar improvement was achieved in 62 and 65% of patients, respectively. Side-effects and complications were minor (compensatory hyperhidrosis) or self-limiting (pain). These data confirm the safety and efficacy of thoracoscopic sympathetic interventions for the treatment of EH, and support the evolution toward simplified methodologies.

Biodistribution of liposomes after extradural administration in rodents

We have mapped over 24 h the biodistribution of 99mTc-labelled multilamellar and small unilamellar liposomes in rabbits and rats by scintigraphic imaging after extradural injection. Multilamellar vesicles formed a depot at the site of injection; small unilamellar vesicles spread immediately along the extradural space and entered the systemic compartment 30 min after injection. Well-delineated liver and kidney labellings were seen after 24 h. The use of 3H-cholesterol-labelled small unilamellar vesicles suggested hepatic capture of intact liposomes with sizes averaging 0.05 microns drained unmodified into the systemic circulation through the extradural lymphatics. These results have led to the selection of multilamellar vesicles (0.1-15 microns size range) for clinical trials using liposome-associated local anaesthetics.

A gelsolin-related protein from lobster muscle: cloning, sequence analysis and expression

The tail muscle of the lobster Homarus americanus contains an actin-binding protein with an apparent molecular mass of 105 kDa determined by SDS/PAGE and gelsolin-like properties. We isolated this protein and peptide sequences were obtained after limited proteolysis with chymotrypsin. A tail-muscle-specific cDNA library was constructed in a lambda expression vector and a full-length clone was obtained by screening with a polyclonal anti-(crustacean gelsolin) antibody. The cDNA insert of approx. 3.2 kb length was sequenced. The cDNA contained an open reading frame of 2.265 kb, and the deduced amino acid sequence of 754 residues (83,469 Da) identified the protein as a cytoplasmic member of the gelsolin/villin protein family. Comparison of the lobster gelsolin amino acid sequence with other members of this protein family revealed the characteristic 6-fold repeated segmental structure as well as the three conserved sequence motifs typical of each segment [Way and Weeds (1988) J. Mol. Biol. 203, 1127-1133]. Strong homologies were found with Drosophila gelsolin, human gelsolin, villin core, Dictyostelium severin and Physarum fragmin. In addition, the gelsolin-like protein from lobster muscle revealed motifs that were clearly similar to the actin-bundling region of human villin headpiece although it did not itself contain a distinct headpiece domain. The recombinant lobster gelsolin-like protein, expressed in Escherichia coli as a fusion protein, was purified from inclusion bodies and renatured as a functional protein. There were no significant differences in the biological activity tested between the recombinant and the native protein isolated from lobster muscle.

The complete sequence of a 40-kDa actin-modulating protein from the earthworm Lumbricus terrestris

The complete primary structure of a 40-kDa actin-modulating protein from the earthworm Lumbricus terrestris is presented. A muscle-specific cDNA library of the earthworm was constructed and screened with a specific DNA probe obtained by polymerase chain reaction considering information from peptide sequencing. A full-length clone with a coding region of 1098 bp was isolated. The deduced polypeptide sequence of 366 amino acids (41457 Da) reveals the segmental structure typical of both the 40-kDa and 80-kDa actin-modulating proteins. Prominent similarities to the 80-kDa protein gelsolin especially exist with respect to the first segment and to the C-terminal segment. The comparatively high nucleation efficiency of the earthworm actin modulator is probably determined by its third segment which seems to enable the earthworm actin modulator to bind a second G-actin molecule more tightly than other previously described 40-kDa modulators.

A gelsolin-related actin-severing protein with fully reversible actin-binding properties from the tail muscle of crayfish, Astacus leptodactylus

A Ca(2+)-dependent actin-severing protein was purified from the tail muscle of the crayfish Astacus leptodactylus. The isolation procedure involved extraction at low ionic strength in the presence of EGTA, followed by ammonium sulfate fractionation, ion-exchange chromatography and gel filtration. The purified crayfish actin modulator appeared as a single band with a molecular mass of 105 kDa on SDS/PAGE. The crustacean actin modulator revealed basic functional properties in common with vertebrate gelsolin, like the Ca(2+)-activated severing of F-actin and the nucleation of actin polymerization. However, both proteins differed in major aspects: Ca2+ activation of crayfish actin modulator started at lower threshold concentrations (0.1 microM). The effect of the modulator on shortening the nucleation phase of actin polymerization was significantly weaker at lower modulator/actin ratios. The modulator formed three distinct stoichiometric complexes with G-actin, identified as binary, ternary and quaternary. Binding of G-actin occurred in a low cooperative manner and was completely reversible by EGTA. Despite some properties being similar to those of villin, crayfish actin modulator did not cross-link actin filaments. It is regarded in principle as a gelsolin-type protein, but with characteristic functional deviations from vertebrate gelsolin.

Propofol and methohexitone anaesthesia: effects on the profile of mood state

The influence on mood of anaesthesia by infusion with propofol or methohexitone was evaluated in 80 female patients assessed with the Profile of Mood State preoperatively and at 30 min, 1, 2 and 4 h after anaesthesia. Patients given propofol were more elated and continuously less anxious than those given methohexitone from 1 to 4 h after anaesthesia (54.3, SEM 1.1 vs. 50.7 SEM 1.2). They also felt more agreeable after 2 h (45.4 SEM 1.4 vs. 48.4 SEM 1.2). All patients felt more tired and more confused post-operatively than pre-operatively. Propofol has different and more favourable influences on the post-operative mood state than does methohexitone.

Complete amino acid sequence of the regulatory light chain of obliquely striated muscle myosin from earthworm, Lumbricus terrestris

Amino acid sequence analysis of the regulatory light chain of obliquely striated muscle myosin from earthworm, Lumbricus terrestris, was performed completely. The polypeptide consists of 195 amino acids with a calculated molecular mass of 21943 Da. From the arrangement of amino acid residues, the first EF-hand domain appears to be a specific Ca(2+)-binding site. The unusually long N-terminal region of about 40 amino acids, which is characterized by accumulation of basic amino acids, is similar to that of the myosin A1 catalytic light chain from rabbit skeletal muscle.

A soluble calcium-binding protein (SCBP) present in Drosophila melanogaster and Calliphora erythrocephala muscle cells

1. Soluble calcium binding proteins (SCBP) were isolated from homogenates of whole flies, from the thorax and from muscles of Drosophila melanogaster and Calliphora erythrocephala. 2. Crude preparations were obtained by extraction at low ionic strength, acid and heat treatment. The Drosophila protein was purified by gel filtration, hydrophobic interaction and ion exchange chromatography. In contrast to calmodulin the Drosophila SCBP did not bind to phenyl-Sepharose in a Ca(2+)-dependent way. 3. Both the Drosophila and the Calliphora protein revealed identical properties. 4. The apparent molecular mass of the SCBP is 24 kDa. Separation in urea-PAGE demonstrated the existence of two isoforms. 5. The calcium-binding property was assured by a calcium dependent electrophoretic mobility shift and autoradiography of 45Ca(2+)-incubated Western blots. 6. The proteins are abundant in the thorax and were even detectable in crude extracts of various muscles (leg muscles and the extracoxal depressor). In contrast, in power muscles and in the thoracic ganglion the proteins could not be observed.

Tropomyosin from the striated muscles of carp (Cyprinus carpio) and of icefish (Channichthys rhinoceratus)

Tropomyosin of fast-twitch, slow-twitch and cardiac muscles of carp and icefish has been isolated by hydroxyapatite chromatography. The subunit distribution has been investigated by polyacrylamide gel electrophoresis and by peptide mapping. The purified skeletal muscle tropomyosins all belong to the alpha family and differ from higher vertebrate tropomyosin by the lack of beta subunits. Specific alpha isotypes are however encountered in fast-twitch fibres (alpha w subunit) and slow-twitch or intermediate (pink) fibres (alpha and alpha w subunits). The amino acid compositions and the paracrystals formed by the carp alpha w alpha w and alpha alpha w tropomyosins do not differ markedly from that of rabbit alpha alpha chains. They differ however by their capability to inhibit the ATPase activity of rabbit skeletal muscle acto-HMM system. A beta-like subunit is found in carp cardiac tropomyosin, in the proportion of 25% of the native protein, but not in icefish heart.

Activity of a gelsolin-like actin modulator in rat skeletal muscle under protein catabolic conditions

A gelsolin-like actin-modulating protein was isolated from rat skeletal muscle and characterized with respect to its interaction with actin. The protein, with a molecular mass of approx. 85 kDa, forms a stoichiometric complex with two actin molecules and is activated by micromolar concentrations of Ca2+. It effectively severs actin filaments and promotes nucleation of actin polymerization. The activity of this protein is detectable already in crude extracts by its capability to reduce the steady state viscosity of actin. Actin-modulating activities were determined in muscle extracts of rats kept under protein catabolic conditions, i.e. as generated by corticosterone treatment and starvation. In both cases we found a marked increase of modulator activity. The possibility is discussed that the increased activity of actin modulator indicates a fragmentation of actin filaments prior to the proteolytic degradation of actin.

Properties of tropomyosin from the dual-regulated obliquely striated body wall muscle of the earthworm (Lumbricus terrestris L.)

The obliquely striated body wall muscle of the earthworm Lumbricus terrestris L. possesses a dual actin-linked and myosin-linked regulatory system. Tropomyosin from this muscle has now been purified and its functional properties compared to tropomyosin from vertebrate skeletal muscle. Earthworm tropomyosin has a molecular weight of about 70 000 and is composed of two polypeptide chains of molecular weight of 34 000 and 37 000. Structural and functional similarities to skeletal muscle tropomyosin were demonstrated with respect to the formation and periodicity of paracrystals and nets and the potentiation of skeletal muscle acto-SF1 ATPase activity at low ATP concentration. Likewise, earthworm tropomyosin inhibited skeletal muscle acto-HMM ATPase activity at normal ATP concentrations but to a much greater extent than skeletal muscle tropomyosin; this inhibition was removed by skeletal muscle troponin, in the presence of Ca2+. In a system containing earthworm myosin and skeletal muscle actin, earthworm tropomyosin had no detectable influence on the actin-activated ATPase activity. It is concluded that earthworm tropomyosin plays an active role in the actin-linked troponin-dependent regulatory system and has no measurable effect on the regulation via myosin.