Mechanobiology of the relocation of proteins in advecting cells: in vitro experiments, multi-physics modeling, and simulations

Cell motility-a cellular behavior of paramount relevance in embryonic development, immunological response, metastasis, or angiogenesis-demands a mechanical deformation of the cell membrane and influences the surface motion of molecules and their biochemical interactions. In this work, we develop a fully coupled multi-physics model able to capture and predict the protein flow on endothelial advecting plasma membranes. The model has been validated against co-designed in vitro experiments. The complete picture of the receptor dynamics has been understood, and limiting factors have been identified together with the laws that regulate receptor polarization. This computational approach might be insightful in the prediction of endothelial cell behavior in different tumoral environments, circumventing the time-consuming and expensive empirical characterization of each tumor.

Mucinous Carcinoma of Sweat Glands

Three cases of primary cutaneous mucinous carcinoma of sweat gland origin are presented. Patients were a 47-year-old man and 2 females aged 70 and 71 years. The clinical and pathologic features of the described tumors were similar to those reported in the literature, except for 2 of the involved sites (abdominal skin and vulva), not previously described.

Leptin level lowers in proportion to the amount of aerobic work after four weeks of training in obesity

Leptin values are higher in obesity. Physical exercise reduces fat mass (FM) and decreases leptin levels. Intensity of physical training seems to play a role in reducing circulating leptin. In 16 obese subjects (8 men and 8 women, age 38.6±3.9 years, BMI 35.9±1.8 kg/m(2)), leptin was sampled before and after 4 weeks of controlled training. Eight subjects (4 men and 4 women) performed an aerobic training schedule (Group A), the remainders an aerobic training program with a bout of work beyond the anaerobic threshold (AT) (Group B). Training determined a reduction in leptin levels in both groups, which was significant in Group A (12.2 vs. 27.8 μg/l, p<0.05), even when related to the change in FM (0.372 vs. 0.762 μg/l/kg, p<0.05). FM decreased significantly in Group B when compared to Group A (-7.4 vs. -2.6 kg, respectively, p<0.001). While in Group A the slight loss of FM was aggregated to a significant decrease in leptin levels, the opposite occurred in Group B. In Group A, leptin lowering was proportional to the amount of total work performed (p<0.001, R(2)=0.89). In obesity, a reduction is observed in leptin levels after short-term training, which is seemingly dissociated from concomitant decrease of FM. Aerobic training alone appears to be linked to a greater leptin reduction, which is well correlated with the amount of work performed.

Acute post-exercise oxygen uptake, hormone and plasma metabolite response in obese men

This study aimed to compare oxygen uptake (  VO2), hormone and plasma metabolite responses during the 30 min after submaximal incremental exercise (Incr) performed at the same relative/absolute exercise intensity and duration in lean (L) and obese (O) men. Eight L and 8 O men (BMI: 22.9 ± 0.4; 37.2 ± 1.8 kg · m(-2)) completed Incr and were then seated for 30 min.   VO2 was monitored during the first 10 min and from the 25-30(th) minutes of recovery. Blood samples were drawn for the determination of hormone (catecholamines, insulin) and plasma metabolite (NEFA, glycerol) concentrations. Excess post-exercise oxygen consumption (EPOC) magnitude during the first 10 min was similar in O and in L (3.5 ± 0.4; 3.4 ± 0.3 liters, respectively, p=0.86). When normalized to percent change (  VO2END=100%), %   VO2END during recovery was significantly higher from 90-120 s in O than in L (p ≤ 0.04). There were no significant differences in catecholamines (p ≥ 0.24), whereas insulin was significantly higher in O than in L during recovery (p=0.01). The time-course of glycerol was similar from 10-30 min of recovery (-42% for L; -41% for O, p=0.85), whereas significantly different patterns of NEFA were found from 10-30 min of recovery between groups (-18% for L; +8% for O, p=0.03). Despite similar EPOC, a difference in   VO2 modulation between groups was observed, likely due to faster initial rates of   VO2 decline in L than in O. The different patterns of NEFA between groups may suggest a lower NEFA reesterification during recovery in O, which was not involved in the rapid EPOC component.

Mass loads of dissolved and particulate mercury and other trace elements in the Mt. Amiata mining district, Southern Tuscany (Italy)

Total dissolved and particulate mercury (Hg), arsenic (As), and antimony (Sb) mass loads were estimated in different seasons (March and September 2011 and March 2012) in the Paglia River basin (PRB) (central Italy). The Paglia River drains the Mt. Amiata Hg district, one of the largest Hg-rich regions worldwide. Quantification of Hg, As, and Sb mass loads in this watershed allowed (1) identification of the contamination sources, (2) evaluation of the effects of Hg on the environment, and (3) determination of processes affecting Hg transport. The dominant source of Hg in the Paglia River is runoff from Hg mines in the Mt. Amiata region. The maximum Hg mass load was found to be related to runoff from the inactive Abbadia San Salvatore Mine (ASSM), and up to 30 g day(-1) of Hg, dominantly in the particulate form, was transported both in high and low flow conditions in 2011. In addition, enrichment factors (EFs) calculated for suspended particulate matter (SPM) were similar in different seasons indicating that water discharge controls the quantities of Hg transported in the PRB, and considerable Hg was transported in all seasons studied. Overall, as much as 11 kg of Hg are discharged annually in the PRB and this Hg is transported downstream to the Tiber River, and eventually to the Mediterranean Sea. Similar to Hg, maximum mass loads for As and Sb were found in March 2011, when as much as 190 g day(-1) each of As and Sb were measured from sites downstream from the ASSM. Therefore, the Paglia River represents a significant source of Hg, Sb, and As to the Mediterranean Sea.

Rationale for hospital-based rehabilitation in obesity with comorbidities

Severely obese patients affected by two or more chronic conditions which could mutually influence their outcome and disability can be defined as "complex" patients. The presence of multiple comorbidities often represents an obstacle for being admitted to clinical settings for the treatment of metabolic diseases. On the other hand, clinical Units with optimal standards for the treatment of pathological conditions in normal-weight patients are often structurally and technologically inadequate for the care of patients with extreme obesity. The aims of this review paper were to review the intrinsic (anthropometrics, body composition) and extrinsic (comorbidities) determinants of disability in obese patients and to provide an up-to-date definition of hospital-based multidisciplinary rehabilitation programs for severely obese patients with comorbidities. Rehabilitation of such patients require a here-and-now multidimensional, comprehensive approach, where the intensity of rehabilitative treatments depends on the disability level and severity of comorbidities and consists of the simultaneous provision of physiotherapy, diet and nutritional support, psychological counselling, adapted physical activity, specific nursing in hospitals with appropriate organizational and structural competences.

[Labour epidural analgesia for a parturient with a factor XI deficiency: an ill-considered challenge or a reasonable risk?]

The authors report the performance of a labour epidural analgesia in a 26-year-old parturient presenting a moderate factor XI (FXI) deficiency. If haemostasis disorders usually contraindicate an epidural analgesia (with a risk of epidural haematoma), a moderate FXI deficiency is not an absolute contraindication to perform such an epidural analgesia. Desmopressin, sometimes used in surgery to reduce the bleeding, was administered to withdraw the catheter in better haemostasis conditions. No neurological signs were observed.

QT prolongation in anaesthetized guinea-pigs: an experimental approach for preliminary screening of torsadogenicity of drugs and drug candidates

Many non-cardiovascular drugs can prolong the QT interval of the electrocardiogram (ECG); this is an accessory property not necessary for their pharmacological action and generally linked to the block of the potassium HERG channels and delayed cardiac repolarization. The QT prolongation can lead to a dangerous tachyarrhythmia, called torsade de pointes, and potentially to fatal ventricular fibrillation. The experimental approaches, aimed at an early identification of this undesidered property, often require sophisticated and expensive equipment or the use of superior animal species (dog, primates) that cannot be employed easily for ethical and/or economic reasons. This work aimed to study drug-induced QT prolongation in anaesthetized guinea-pigs and to evaluate the reliability of such an experimental approach to obtain a satisfying predictive parameter of the torsadogenicity of drugs in humans. Seven drugs that were torsadogenic in humans (astemizole, cisapride, haloperidol, quinidine, sotalol, terfenadine and thioridazine) and two that were non-torsadogenic (chlorprotixene and diazepam) were administered i.v. to guinea-pigs under pentobarbital anaesthesia. The ECGs were recorded by four electrodes inserted in the subcutaneous layer of the limbs. Both RR and QT intervals were measured in Leads II and III and then the correct QT values were calculated by Bazett and Fridericia algorithms (QTcB and QTcF, respectively). All the drugs, with the exception of chlorprotixene and diazepam, produced a dose-dependent prolongation of the QT and RR intervals and a significant increase of QTcB and QTcF values. It can be concluded that this method represents a rapid and low-cost procedure to evaluate the cardiac safety pro fi le in the preliminary screening of a high number of drugs or drug candidates.

Neonatal respiratory morbidity risk and mode of delivery at term: influence of timing of elective caesarean delivery

AIM

To establish whether the timing of delivery between 37 + 0 and 41 + 6 wk gestation influences neonatal respiratory outcome in elective caesarean delivery, following uncomplicated pregnancy, thus providing information that can be used to aid planning of elective delivery at term.

METHODS

All pregnant women who were delivered by elective caesarean delivery at term during a 3-y period were identified from a perinatal database and compared retrospectively with pregnant women matched for week of gestation, who were vaginally delivered. Maternal characteristics, neonatal outcome, incidence of respiratory distress syndrome (RDS) and transient tachypnea of the newborn (TTN) were analysed. During this time, 1284 elective caesarean section deliveries occurred at or after 37 + 0 wk of gestation.

RESULTS

Neonatal respiratory morbidity risk (odds ratio, OR), including RDS and TTN, was significantly higher in the infant group delivered by elective caesarean delivery compared with vaginal delivery (OR 2.6; 95% CI: 1.35-5.9; p < 0.01). While TTN risk in caesarean delivery was not increased (OR 1.19; 95% CI: 0.58-2.4; p > 0.05), the RDS risk was significantly increased (OR 5.85; 95% CI: 2.27-32.4; p < 0.01). This RDS risk is greatly increased in weeks 37 + 0 to 38 + 6 (OR 12.9; 95% CI: 3.57-35.53; p < 0.01). After 39 + 0 wk, there was no significant difference in RDS risk.

CONCLUSIONS

Infants born by elective caesarean delivery at term are at increased risk for developing respiratory disorders compared with those born by vaginal delivery. A significant reduction in neonatal RDS would be obtained if elective caesarean delivery were performed after 39 + 0 gestational weeks of pregnancy.

[Sentinel lymph nodes in cutaneous melanoma: the experience in the Florence area]

In the period 1997-2001, 466 sentinel lymph nodes from 342 lymphatic basins in 322 melanoma patients were examined at the Health Unit of Florence. The lymphatic mapping was performed through pre-operative lymphoscintigraphy using technetium-labelled nano-colloid, intradermal injections of vital blue dye and intra-operative gamma-probe. The examined patients were 182 females and 140 males. Sentinel lymph node was one in 65.2% of cases; two sentinel lymph nodes were detected in 27% of cases and more than 2 sentinel nodes were detected in 7.8% of cases. Melanoma metastases in one or more sentinel lymph nodes were found in 61/322 patients (18.9%). Lymphatic basins resulted to be involved by melanoma metastases were 64/342 (18.7%); sentinel lymph nodes containing metastatic melanoma deposits were 73/466 (15.6%). No metastasis was found in patients with melanoma thickness < or = 1 mm. One or more positive sentinel lymph nodes were found in 7.5% of patients with melanoma thickness > 1.00 and < or = 1.50 mm, in 27.7% of patients with melanoma > 1.50 and < or = 3.00 mm, in 38.2% of patients with melanoma > 3.00 and < or = 4.00, and in 60.7% of patients with melanoma > 4.00 mm. Frozen section analysis of sentinel lymph nodes, performed in 59/61 patients with nodal metastases, detected nodal involvement in 21 patients (35.6%). Metastases were identified by routine hematoxylin-eosin staining in 57/64 positive lymphatic basins; in 7 cases (11%) metastases were detected by immunohistochemical stainings (S100 and HMB-45). A nodal nevus was found in 3/466 sentinel lymph nodes (0.6%). Our data are analyzed and compared to previously data of the literature. The value of frozen section analysis and the major problems in the diagnosis of melanoma micrometastases in sentinel lymph nodes are discussed. The importance of the sentinel node biopsy for the detection of occult metastases and for the correct staging of melanoma patients are stressed, according to the new TNM melanoma classification.

Microsatellite analysis in cutaneous malignant melanoma

The status and relevance of repetitive nucleotide sequences or microsatellite alterations in sporadic cutaneous melanoma has not been fully clarified. In this study we evaluated the presence of microsatellite alterations in a series of sporadic primary and metastatic melanomas in order to discover which genetic events may have a pathogenetic role in the development of this disease. Tumour samples were obtained from 21 patients with sporadic cutaneous melanoma, and from eight corresponding positive sentinel lymph nodes and one corresponding in-transit metastasis. In each specimen, selected neoplastic cells were procured by laser-assisted microdissection. Polymerase chain reaction-based microsatellite analysis was performed using a panel of 11 microsatellite markers, located at chromosome 2p, 4q, 9p, 16q, 17p and 21q. Overall, we found microsatellite alterations in five (23.8%) melanomas. Of these, one case showed alteration at marker D2S2182 and one at marker D17S261, whereas in another case alterations at three loci, D2S2182, D2S2291 and D9S171, were found. The fourth patient demonstrated an alteration at locus D9S171 both in the primary tumour and in the histologically positive sentinel lymph node. The fifth case was characterized by alterations at D2S2182 and at D17S250, whereas the corresponding in-transit metastasis showed the same alterations as the primary tumour and an additional alteration at IFN alpha. In conclusion, our study confirms previous observations that cutaneous melanomas demonstrate microsatellite alterations, although such instability occurs at a lower frequency than specific mismatch repair defects. Genetic analysis of metastatic lesions revealed that the same microsatellite alterations as in the primary tumour are seen, but additional genetic changes may develop during disease progression.

Molecular epidemiology of an outbreak of Serratia marcescens in a neonatal intensive care unit

OBJECTIVE

To investigate and control a biphasic outbreak of Serratia marcescens in a neonatal intensive care unit (NICU).

DESIGN

Epidemiological and laboratory investigation of the outbreak.

SETTING

The NICU of the 1,470-bed teaching hospital of the University "Federico II," Naples, Italy.

PATIENTS

The outbreak involved 56 cases of colonization by S marcescens over a 15-month period, with two epidemic peaks of 6 and 3 months, respectively. Fourteen (25%) of the 56 colonized infants developed clinical infections, 50% of which were major (sepsis, meningitis, or pneumonia).

METHODS

Epidemiological and microbiological investigations, analysis of macrorestriction pattern of genomic DNA through pulsed-field gel electrophoresis (PFGE) of clinical and environmental isolates, and institution of infection control measures.

RESULTS

Analysis of macrorestriction patterns of genomic DNA by PFGE demonstrated that the vast majority of S marcescens isolates, including three environmental strains isolated from two handwashing disinfectants and the hands of a nurse, were of the same clonal type. The successful control of the outbreak was achieved through cohorting of noncolonized infants, isolation of S marcescens-infected and -colonized infants, and an intense educational program that emphasized the need for adherence to glove use and handwashing policies. The NICU remained open to new admissions.

CONCLUSIONS

Outbreaks caused by S marcescens are very difficult to eradicate. An infection control program that includes molecular typing of microorganisms and the proper dissemination among staff members of the typing results is likely to be very effective in reducing NICU-acquired infections and in controlling outbreaks caused by S marcescens, as well as other multiresistant bacteria.

Carcinomas of sweat glands: report of 60 cases

CONTEXT

Several aspects of sweat gland carcinomas (incidence, classification, diagnosis, and behavior) have not been definitively clarified and need to be studied further.

OBJECTIVE

The clinicopathologic findings of a large series of sweat gland carcinomas, collected during a period of 15 years, are presented.

METHODS

Sixty sweat gland carcinomas (41 porocarcinomas, 3 syringomatous carcinomas, 8 ductal carcinomas, 5 adenoid cystic carcinomas, and 3 mucinous carcinomas) were analyzed histologically and immunohistochemically.

RESULTS

Porocarcinomas were composed of eosinophilic and clear atypical cells arranged in solid-cystic lobular masses. These tumors were divided into 2 subgroups: horizontal porocarcinomas, showing a prominent intraepidermal component, and nodular porocarcinomas, which demonstrated predominant nodular growth. Syringomatous carcinomas presented keratinizing and nonkeratinizing cysts, dilated tubules (sometimes with a "tadpole" appearance), small neoplastic ducts, solid islands, and cellular cords. Ductal carcinomas were characterized by a prominent formation of tubules, solid islands, and cellular cords. Adenoid cystic carcinomas presented a characteristic pattern, showing basaloid monomorphous cells with moderately atypical nuclei, arranged in cribriform or solid islands and in tubular structures. Mucinous carcinomas were composed of moderately atypical cells with eosinophilic vacuolated cytoplasm, forming solid and cystic islands floating in large mucin pools. Immunohistochemically, cytokeratin was found in neoplastic cells in all cases, carcinoembryonic antigen was detected in 73% of cases, and actin-positive (myoepithelial) cells were not found.

CONCLUSIONS

Although numerous studies have been published in recent years, the histologic features, histogenesis, and classification of sweat gland carcinomas still remain controversial and need to be clarified by further studies.

[Growth and choices in orthopedic or orthodontic therapy]

Although the clinical aspects of the skeletal Class II can be numerous, in most cases an insufficient sagittal development of the mandible can be identified. Besides the functional disorder caused by the sagittal skeletal problem, the aesthetic appearance is damaged. To provide an efficient orthodontic or orthopedic treatment, the practitioner must consider this aesthetic prejudice, while correcting the functional disorder. One of the main goal when correcting skeletal Class II relationships is to improve the sagittal development of the mandibular growth. The sagittal impact is greater for the horizontal growth and will improve the aesthetic appearance. In addition, the treatment will be easier, shorter and therefore less traumatic because of the spontaneously natural self correction. Finally, the correction will be more stable because the functions such as breathing and swallowing will be easily rehabilitated. To obtain convenient aesthetic and functional corrections of skeletal Class II relationships, four essential rules must be taken care of: finding the best therapeutic choice, choosing the best moment to start treatment, initiating an efficient unlocking, providing an overall treatment.

Androgen receptor expression in prostate carcinoma cells suppresses alpha6beta4 integrin-mediated invasive phenotype

Prostate cancer cells may lose androgen-sensitivity after androgen ablation therapy, becoming highly invasive and metastatic. The biological mechanisms responsible for higher tumurogenicity of androgen-independent prostate carcinomas are not entirely known. We demonstrate that androgen receptor regulation of adhesion and invasion of prostate cancer cells through modulation of alpha6beta4 integrin expression may be one of the molecular mechanisms responsible of this phenomenon. We found that protein and gene expressions of alpha6 and beta4 subunits were strongly reduced in the androgen-sensitive cell line LNCaP respect to the androgen-independent PC3 and that transfection of PC3 cells with a full-length androgen receptor expression vector resulted in a decreased expression of alpha6beta4 integrin, reduced adhesion on laminin, and suppressed Matrigel invasion. Growth in soft agar was also suppressed in androgen receptor-positive PC3 clones. Treatment of androgen receptor positive clones with the synthetic androgen R1881 further reduced alpha6 and beta4 messenger RNA expression as well as adhesion on laminin and Matrigel invasion. Our results indicate that androgens regulate cell-extracellular matrix adhesion and invasion by modulation of integrin expression and function, thus keeping a low invasive phenotype of prostate cancer cells.

Oxygen uptake and cardiac performance in obese and normal subjects during exercise

Work capacity and cardiopulmonary performance were studied in a group of 11 young obese subjects (BMI 39.9 kg/m2) and a group of 10 young normal subjects (BMI 22 kg/m2). First of all they underwent an incremental cycle ergometer test up to exhaustion. Subsequently, every subject of the two groups performed a constant work rate test at different work loads to estimate cardiac output (Q) below anaerobic threshold (AT) by a 20-second CO2 rebreathing method. Obese subjects had a significantly lower AT (79 vs. 109 W). The ratio between oxygen uptake and heart rate (VO2/HR) (O2 pulse) was higher in the obese group; nevertheless, this variable became significantly lower if we took into consideration the ratio between O2 pulse and kilogram fat-free body mass or kilogram body weight. Both these observations suggest that their reduced work tolerance is linked with a reduced oxygen supply to the muscles in activity. Q increased in similar ways in obese and normal subjects at the preset work rates. The ratio Q/body surface (cardiac index; CI) that we considered in order to try to minimize the differences in body sizes between the two groups, increased less in response to increasing work rates in our obese subjects than in normal subjects. As a whole, these data appear to be in line with a relatively less efficient cardiac performance during progressive work rates in obese subjects.

Augmentation ileocystoplasty in a case of eosinophilic cystitis

Eosinophilic cystitis (EC) is a rare form of bladder inflammation characterized by massive eosinophilic infiltration of the bladder wall. The most frequent signs and symptoms are pollakiuria, urgency, macroscopic haematuria and hypogastric pain: the involvement of the ureters may cause hydronephrosis and renal failure. Eosinophilia and eosinophiluria are present in 35% and in 50% of the cases respectively. EC may evolve towards sclerosis up to the anatomoclinical picture of small retracted bladder, which requires to be differentiated from tubercular cystitis, interstitial cystitis and cancer. Imaging techniques are not definitely diagnostic. Diagnosis can be reached only by biopsy with the microscopic demonstration of eosinofilic infiltration of the whole bladder wall in the early and acute stages, while fibrosis with poor cellularity predominates in the chronic stages. Etiology is unknown and the hypothesis of an allergic origin is unproved even though remissions or recoveries induced by steroidal therapy have been reported. Surgical therapy of EC, as in our observation, is absolutely required to correct urgency and incontinence and to prevent renal failure when the urinary upper tract has been primarily or secondarily involved.

[Assessment of various new predictive parameters of the outcome of mechanical ventilation weaning]

OBJECTIVE

To evaluate new indexes predicting weaning outcome from mechanical ventilation.

EXPERIMENTAL DESIGN

Prospective study with two main end-points: a comparison of weaning indexes between successful and unsuccessful groups and an evaluation of their predicting value.

ENVIRONMENT

Surgical-Medical Intensive Care Unit.

PATIENTS

Patients ventilated for more than 72 hours and subjected to a weaning trial until spontaneous ventilation.

MEASUREMENTS

Traditional weaning parameters [respiratory rate (fsb), expiratory minute volume (Vesb), Maximal Inspiratory Pressure (MIP)] along with the new indexes [fsb/Vtsb) (rate to tidal volume ratio), CROP index (Compliance Rate Oxygenation Pressure), P0.1/MIP, IEQ (Inspiratory Effort Quotient), WI (Weaning Index)] were measured before discontinuation of ventilation support.

RESULTS

A statistically significant difference was observed between successful and unsuccessful groups for the following parameters: fsb, MIP, fsb/.Vtsb, CROP, Po.1/MIP and WI while no differences were observed for Vesb and IEQ. The sensitivity and specificity for the new indexes were respectively: fsb/Vtsb: 0.65 and 0.58; CROP: 0.70 and 0.63; P0.1/MIP: 0.85 and 0.36; WI: 0.69 and 0.47.

CONCLUSION

A statistically significant difference between successful and unsuccessful groups was observed for some but not all new indexes; the diagnostic accuracy of the new indexes were no better than additional parameters.

Metabolic aspects and sympathetic effects in the obese subject undergoing exercise testing

An impaired plasma Epinephrine (E) and Norepinephrine (NE) response has been described in obese patients during physical exercise. Serum potassium level is influenced either by physical exercise or by the adrenergic system. We studied 12 young obese patients and 12 young controls, all without any cardio-respiratory disorders, who underwent a cycloergometric test with steps of 20 watts every four minutes until exhaustion. During the test we recorded serum potassium levels, E and NE, insulin, glucose and RQ to confirm or not the observation of the reduced adrenergic response in obese patients. During exercise, although both groups reached a not significantly different mean peak value of maximal activity, E and NE increased, more in the controls than in the obese subjects (at peak of exercise 221 +/- 44.1 vs 71 +/- 21.5 pg/ml respectively for E; 2035 +/- 164.8 vs 1141 +/- 313.7 pg/ml respectively for NE). RQ was constantly lower in the obese patients than in the normals both during and after the stress. In both groups potassium increased significantly, but the obese patients had a significantly lower increment at peak of activity when compared to the controls (delta K+: 0.52 +/- 0.11 vs 1.007 +/- 0.17 meq/l respectively, p < 0.05). Insulin and glucose had a behaviour in line with literature in both groups. The behaviour of potassium could be an index of a higher effect of beta-adrenergic system in obese patients than in normals despite the different increases of catecholamines in the two groups. This hypothesis may agree with the preferential metabolic use of fatty acids in our obese patients as indicated by RQ values.

[Pneumonia in severe head injury. A prospective study]

Impairment of the state of consciousness is an important contributing factor in the onset of respiratory tract infections; in this study the data were collected prospectively to investigate the incidence and clinical implications of pneumonia in a population of head injured patients. The study was conducted on all patients treated at our centre throughout 1990. The incidence of pneumonia in the head injured was 10.8% versus 7.3% in the rest of the patients. Mortality in the group with pneumonia was not significantly different from the group without pneumonia. The average time of onset was on the fifth day from admission. The lung injury score (LIS) on the sixth day, the time on artificial ventilation and the length of stay in intensive care were significantly greater in those with pneumonia (1.18, 14.6 days and 21.9 days versus 0.8, 4.2 days and 12.9 days respectively). Staphylococcus was the single most frequently isolated germ. Our study concludes that pneumonia represents a relatively frequent and early complication in patients with head injury, and it is associated with prolonged artificial ventilation and longer staying in ICU.

Breathing pattern during and after maximal exercise testing in young untrained subjects and in obese patients

More rapid and more shallow breathing (RSB) than usual, manifested by a lower tidal volume and greater breathing frequency at a given level of ventilation, may be caused by inspiratory muscle fatigue and pulmonary congestion. It has been observed during recovery in young trained adults after very high exercise levels and in middle-aged patients with cardiac disease, after their maximal work load. We studied the breathing pattern during and after exercise testing up to the maximal work capacity in a group of normal untrained, young people and in a group of young obese subjects. RSB was present in normal subjects after a work load which required a maximal O2 consumption near the theoretical value (93% in our cases) and was not present in obese patients probably because neither inspiratory muscle fatigue, nor pulmonary congestion occurs in these subjects. Maximal heart rate at peak of exercise was significantly higher in normal subjects and a direct correlation between delta Vt and maximal heart rate was found in all normal subjects. This is compatible with the hypothesis that RSB is mainly due to an initial interstitial pulmonary edema, as supposed by other authors.

Creatine kinase and creatine kinase-MB isoenzyme during and after exercise testing in normal and obese young people

We report creatine kinase (CK) and CK-MB values during a cycloergometric test up to maximal work capacity in 10 normal subjects aged 20 to 39 years (mean body mass index, 22 kg/m2) and 11 obese patients aged 17 to 42 years (mean body mass index, 41 kg/m2), all without any cardiorespiratory diseases. Total CK was significantly higher in obese patients. The CK-MB was not significantly different between the two groups, except at the first recovery when it was increased in obese patients and decreased in normal subjects. These results could be due to more important total stress of the total musculature, especially cardiac, and especially cardiac musculature in obese patients during a physical effort. Considering the mean values of total CK of our obese patients, it may be possible that they have myocardial damage at percentages of CK-MB less than those of lean subjects generally accepted at more than 4 percent. Moreover, in obese heart patients myocardial distress during exercise testing may be present despite heart rate at peak exercise beneath the theoretic maximal.

Catecholamine-stimulated potassium transport in erythrocytes from normal and obese subjects

The beta adrenergic-modulated Na+/K+ ATPase pump rate of red blood cells was measured in vitro in 18 non diabetic obese patients. After challenge of erythrocytes with beta adrenergic selective agonist Salbutamol, the decrement of the K+ concentration in the suspending medium was assumed to be related to the Na+/K+ ATPase pump rate or to the number of beta 2 receptors. The mean K+ uptake was markedly increased in the erythrocytes of obese patients (1.58 mEq/l SD 0.18) if compared with 38 normal subjects (1.30 mEq/l SD 0.11) and with a population of 30 atopic patients that we have previously reported to have a reduced red cells beta 2 receptor activity (1.09 mEq/L SD 0.11). These results are not consistent with the hypothesis that a reduction in the Na+/K+ ATPase pump rate (at least in red blood cells) may be responsible for decreased metabolic rates leading to obesity. Since the autonomic nervous system is involved in the regulation of the cardiovascular system, it is conceivable that an increased Na+ ATPase pump rate (or supersensitivity) may be responsible of the increased incidence of hypertension, congestive heart failure and unexplained sudden death associated with obesity in some patients.

Work capacity and cardiopulmonary adaptation of the obese subject during exercise testing

Twelve obese patients (six male subjects) aged 17 to 42 years with a mean body mass index (BMI) of 40 kg/m2 and 12 normal subjects (six male subjects) aged 19 to 39 years with a mean BMI of 22 kg/m2 underwent a cycloergometric test until exhaustion to assess work capacity and cardiopulmonary adaptations of the two groups. Minute ventilation, expiratory gas concentrations, and heart rate, together with anaerobic threshold (AT) were determined in each subject during the test. The same subjects were then submitted to normocapnic hyperpnea at rest to assess the oxygen cost of breathing. We found that in the obese patients, the maximal sustainable work rate was not different from that of controls (120 vs 136 W) while AT was significantly lower (78 vs 110 W). Nevertheless, there was no difference in maximum VO2 and in VO2 at AT levels (expressed in milliliters per minute) indicating that cardiac, pulmonary, vascular, and muscle performance did not differ from obese to normal subjects. Greater muscular effort was needed by obese patients when moving their heavier legs and less when doing external work with a decreased gross mechanical efficiency and an identical net mechanical efficiency between the two groups.

[Survival of 213 patients who recovered in resuscitation from cardiac arrest]

213 patients who received in-hospital cardiopulmonary resuscitation (CPR) were studied over a period of five years (1985-89) to determine hospital and long-term survival. The following factors were evaluated in determining outcome: age, ECG on admission, clinical history, year, month, hour of admission. A 5-year survival table was complied for all discharged from hospital. The results showed that age, clinical history, month and hour of admission were not influencing factors; asystole as opposed to ventricular fibrillation was however associated with significantly higher in-hospital mortality (p less than 0.005). Hospital survival was 14.6% with an ascendant range from 1986 to 1989 (p less than 0.05); all the patients were discharged mentally unimpaired with over 50% surviving 1.5 years after discharge and 33% 5 years after. The study shows that the highest cause of cardiac arrest is ischaemic cardiopathy in male patients with an average age of 60 years. Total neurological recovery after CPR was confirmed to be a determinant predictor factor of survival.

Relationship between body mass and tolerance to physical stress in obese patients

Eleven obese patients, 5 males; age: 17-42; body mass index (BMI): 40; % of ideal weight: 187%, and 10 normal subjects (5 males; age: 19-39; BMI: 22; % of ideal weight: 103%), both groups without heart and respiratory disorders, underwent a cycloergometric test with subsequent 20-watt increases every 4 min until exhaustion. During the test, ventilation/minute, expiratory gas concentration and heart rate were measured, and the anaerobic threshold (AT) was determined in each subject. The obese patients showed a significantly lower AT than normal subjects (p less than 0.01); showing values which decreased with the increase in the grade of obesity expressed in BMI or in percent of their ideal weight. Moreover, in the obese patients, the O2 consumption (VO2) had significantly increased compared to that of normal subjects at no resistance and at all work levels. The negative correlation between the AT value and the BMI in obese patients can attribute their increase in VO2 during stress to (1) the inertial overloading caused by obesity especially considering the adipose tissue of their legs, or (2) to their level of 'fitness' being lower than that of normal subjects.

[Control of the side effects of ketamine: chlordemethyldiazepam vs diazepam in pre-anesthesia]

The pre-operative circulatory and psychotomimetic side-effects are studied in one hundred patients undergoing elective plastic-reconstructive surgery and anesthetized by ketamine 5-8 mg/kg i.m. Fifty patients were premedicated by atropine 0.01 mg/kg + CDDz 0.0285 mg/kg i.m. (group C), fifty by atropine 0.01 mg/kg + Dz 0.14 mg/kg i.m. (group D). All patients breathed spontaneously. Statistical analysis was performed with X 2 test. Not statistical difference was observed for the circulatory side-effects, whereas the frequency of emergence phenomena fell significantly from 31% to 14% (p less than 0.05) with CDDZ in greater than 16 years old patients. These finding seem confirm that CDDZ is more effective than DZ in reducing the psychotomimetic side-effects of ketamine, though it may be recommended a its wider experiment in this connection.

Involvement of Ca2+-dependent pathways in the inhibition of human natural killer (NK) cell activity by cortisol

The role of Ca2+ as a second messenger of the glucocorticoid inhibition of human natural killer (NK) cell activity was evaluated using Ca2+ entry blockers (verapamil and its desmethoxy derivatives LU46973 and LU47093), calmodulin antagonists (pimozide and two naphthalensulfonamide derivatives, W-7 and W-13), the Ca2+ channel agonist BAY K 8644 and the calcium ionophore A23187. Peripheral blood mononuclear (PBM) cell preparations were incubated for 20 h with 1 x 10(-6) M cortisol and these agents in various combinations (concentration range: 1 x 10(-9) -1 x 10(-5) M) and then assayed in a direct 4-h cytolytic assay using 51Cr-labeled K 562 target cells. Exposure to cortisol led to a significant reduction of NK cell activity (about 50% vs. spontaneous activity). Ca2+ entry blockers and calmodulin antagonists were per se minimally effective, but significantly enhanced cortisol-dependent inhibition of NK cell activity. Raising extracellular Ca2+ by CaCl2 or intracellular Ca2+ by the calcium channel agonist BAY K 8644 or the ionophore A23187 resulted in an appreciable reduction of these effects. Similar results were obtained when these substances were added to monocyte-depleted or NK cell-enriched suspensions exposed to cortisol. Our data are consistent with the view that extra- and intracellular Ca2+ plays a role in the control of human NK cell activity. It is also conceivable that both calcium flux into the cell and the calcium calmodulin system are involved in the cortisol-induced inhibition of natural cytotoxicity.

Studies on the mechanism of cortisol inhibition of human natural killer cell activity: effects of calcium entry blockers and calmodulin antagonists

The role of Ca2+ in mediating the inhibition by glucocorticoids of human natural killer (NK) activity was investigated using Ca2+ entry blockers (verapamil and its desmethoxy-derivatives LU46973 and LU47093) and calmodulin antagonists (pimozide and two naphthalenesulfopamide derivatives, W-7 and W-13). Peripheral blood mononuclear (PBM) cell preparations were incubated for 20 h with 1 x 10(-6) M cortisol and these agents in various combinations (concentration range: 1 x 10(-7) - 1 x 10(-5) M) and then assayed in a direct 4-h cytolytic assay using 51Cr-labeled K 562 target cells. Exposure to cortisol led to a significant reduction of NK cell activity (about 50% with respect to the spontaneous activity). Ca2+ entry blockers displayed per se a dose-dependent depressive effect on cytotoxicity and gave significant enhancement of cortisol-dependent inhibition. Calmodulin antagonists were per se minimally effective but clearly amplified the cortisol-mediated inhibition. Raising extracellular Ca2+ by CaCl2 or intracellular Ca2+ by the ionophore A23187 yelded an appreciable reduction of these effects. Our data are compatible with the view that extracellular and intracellular Ca2+ play a role in the control of human NK cell activity. Moreover, it is conceivable that the mechanisms involved in glucocorticoid inhibition of NK cell activity involve Ca2+-dependent pathways.

Inhibition by cortisol of human natural killer (NK) cell activity

The effects of cortisol on the natural killer (NK) activity of human peripheral blood mononuclear (PBM) cells were studied in vitro using a direct 4-h 51Cr-release assay and K 562 cell line as a target. Preincubation for 20 h of PBM cells drawn from healthy donors with 1 X 10(-8) to 1 X 10(-5) M cortisol resulted in a significant decrease of NK cell activity. The magnitude of the suppression was directly related to the steroid concentration and inversely related to the number of effector cells. Cortisol was able to minimize the enhancement of NK cytotoxicity obtainable in the presence of immune interferon (IFN-gamma). A significantly higher suppression was achieved after sequential exposure of PBM cells to cortisol and equimolar levels of prostaglandin E2 (PgE2). The concomitant incubation with theophylline and isobutyl-methylxanthine failed to enhance the cortisol-induced suppression, whereas PgE2-dependent inhibition significantly increased after exposure of PBM cells to methyl-xanthines. The inhibitory effect of cortisol was partially or totally prevented by the concomitant incubation with equimolar amounts of 11-deoxycortisol and RU 486 but not of progesterone. Treatment of NK effectors with a monoclonal anti-human corticosteroid-binding globulin (CBG) antibody produced an enhancement of the spontaneous NK activity and a partial suppression of cortisol-mediated effects. Our results suggest that endogenous glucocorticoids play a role in the regulation of NK cell-mediated cytotoxicity. Since the effect of cortisol was additive to that of PgE2 and was not changed by phosphodiesterase inhibitors, it is conceivable that the hormone acts at a level different from the adenylate cyclase-phosphodiesterase system. Data obtained with the use of antiglucocorticoids and the anti-CBG antibody are compatible with a role both of high-affinity glucocorticoid receptors and of CBG in mediating cortisol action on the human NK cell activity.