Electrode Positioning for Reliable Telemetry ECG Recordings During Social Stress in Unrestrained Rats

We describe a surgical procedure for optimizing the location of telemetry ECG leads in rats. The new location was aimed at obtaining an accurate representation of ECG features throughout the cardiac cycle by limiting the voltage instability usually observed during intense somatomotor activity and improving the signal-to-noise ratio. The two electrodes (wire loops) were fixed on the dorsal surface of the xiphoid process and in the anterior mediastinum close to the right atrium. The implantation procedure was fast, little invasive, and allowed animals to completely recover from intervention. The performance of the “improved” location (IL, n = 10) with respect to two subcutaneous (SC) positionings (“conventional positioning,” CSP, n = 5; “updated location,” USL, n = 5) was evaluated by comparing ECGs obtained in baseline, stress and recovery conditions and during different behavioral activities (immobility and grooming). The resident-intruder test (emotional/physical challenge) was chosen as experimental stress paradigm. The noise level of ECGs obtained from IL rats was lower than in CSP and USL animals, in all recording conditions. Percentages of correctly recognized beats (CRBs) over the total number of beats (TBs) were significantly higher in IL rats than in CSP and USL animals, both in baseline conditions (99% vs. 11% and 40%) and situations involving high somatomotor activity (stress: 97%, 5% and 16%; recovery: 97%, 7%, and 15%) (p < 0.01). The performance of IL as compared to CSP and USL was also better when percentages during grooming and immobility were considered (grooming: 93% vs. 4% and 23%; immobility: 97%, 6%, and 33%; p < 0.01).     

Duplex-Doppler assessment of cirrhosis in patients with chronic compensated liver disease

Portal venous flow velocity (PFV) was measured with duplex-Doppler equipment in 50 normal subjects and in 117 patients with suspected chronic liver disease who showed no evidence of decompensation such as ascites, hepatic encephalopathy, jaundice or oesophageal bleeding. All the patients underwent percutaneous liver biopsy which demonstrated non-cirrhotic liver disease in 58 cases (CH-patients: steatosis 8, persistent chronic hepatitis 8, active chronic hepatitis 42) and liver cirrhosis in the other 59 cases (LC-patients). The normal subjects and the CH-patients had similar values of max-PFV and mean-PFV (max-PFV 26.7±3.2 and 25.7±3.4 cm/s respectively; mean-PFV 22.9±2.8 and 22.4±3.8 cm/s respectively). The LC-patients’ values (max-PFV 19.3±3.5; mean-PFV 16.9±2.9) were significantly lower than those of the normal subjects (P<0.001) and of the CH-patients (P<0.001). Considering the normal max-PFV to be in the range 20–33.1 cm/s (mean±2 s.d. of the normal subjects, 95% confidence limits), max-PFV was reduced in 0/50 normal subjects, 1/58 CH-patients and 39/59 LC-patients (66.1% sensitivity; 98.2% specificity). In conclusion, the duplex-Doppler measurement of PFV is of great interest in the diagnostic study of patients with suspected chronic compensated liver disease and in the early diagnosis of cirrhosis. A low max-PFV is a reliable pointer to liver cirrhosis, whereas a normal max-PFV indicates a non-cirrhotic liver disease but is less probative. Each centre should standardize normal PFV values in order to establish their own threshold value for diagnosing liver cirrhosis.     

Crystallographic characterization of geometry and conformation of TOAC,a nitroxide spin-labelled Cα,α-disubstituted glycine,in simple derivatives and model peptides *

The molecular and crystal structures of one derivative and two oligopeptides of TOAC, a nitroxide spin-labelled C^αα-disubstituted glycine, have been determined by X-ray diffraction. The derivative is the 5(4H)-oxazolone from Piv-TOAC-OH; the oligopeptides are Z-TOAC-(L-Ala)₂-NHtBu sesquihydrate and p BrBz-TOAC-(L-Ala)₂-TOAC-L-Ala-NHtBu hemihydrate. Incipient and fully developed right-handed 3₁₀-helical conformations are formed by both independent molecules in the asymmetric unit of the terminally blocked tripeptide amide and the terminally blocked pentapeptide amide, respectively. The average geometry and preferred conformation for the piperidine ring of the TOAC residues are also discussed in detail. © Munksgaard 1996.     

Characterization and Properties of an Inhibitor of Factor VIII in the Plasma of Patients with Hemophilia A Following Repeated Transfusions

A circulating anticoagulant, which specifically inhibits Factor VIII (AHF),has been detected in some patients with hemophilia A who had receivedmultiple transfusions. The inhibitor was quantitated by measurement of thedegree of inactivation of Factor VIII. The data presented provide strongevidence for the antibody nature of the Factor VIII inhibitor in hemophilia:(1) All specific inhibitory activity of serum was detected in the G globulinobtained by chromatography of the sera on DEAE cellulose. (2) Fab fragments obtained by digestion of the G globulin with papain, contained 18-22per cent of the specific inhibitory activity, while Fc fragments contained0.4-3 per cent. F(ab')₂ fragments obtained by digestion with pepsin contained 36-61 per cent of the specific inhibitory activity of G globulin. (3)The level of the inhibitor of Factor VIII increased sharply following transfusions of blood and decreased slowly to its preinfusion level. (4) When smallamounts of inhibitor were incubated in vitro with excess Factor VIII, theinhibitor activity was decreased. Infusion of Factor VIII into a patient with alow level of inhibitor decreased the inhibitor activity. (5) Clearance of theisologous inhibitor from the circulation of a normal subject was rapid.

Submitted on December 16, 1966 Accepted on February 9, 1967     

Functional and biophysical analyses of the class XIV Toxoplasma gondii Myosin D

Summary The obligate intracellular parasite Toxoplasma gondii uses gliding motility to migrate across the biological barriers of the host and to invade cells. This unique form of locomotion requires an intact actin cytoskeleton and involves at least one motor protein (TgMyoA) that belongs to the class XIV of the myosin superfamily. TgMyoA is anchored in the inner membrane complex and is essential for the gliding motion, host cell invasion and egress of T. gondii tachyzoites. TgMyoD is the smallest T. gondii myosin and is structurally very closely related to TgMyoA. We show here that TgMyoD exhibits similar transient kinetic properties as the fast single-headed TgMyoA. To determine if TgMyoD also contributes to parasite gliding motility, the TgMyoD gene was disrupted by double homologous recombination. In contrast to TgMyoA, TgMyoD gene is dispensable for tachyzoite propagation and motility. Parasites lacking TgMyoD glide normally and their virulence is not compromised in mice. The fact that TgMyoD is predominantly expressed in bradyzoites explains the absence of a phenotype observed with myodko in tachyzoites and does not exclude a role of this motor in gliding that would be restricted to the cyst forming but nevertheless motile stage of the parasite.Both authors contributed equally to the work.     

STUDY OF THE PARTNERS OF WOMEN WITH HUMAN PAPILLOMAVIRUS INFECTION

Background. Genital human papillomavirus (HPV) infection is one of the most common sexually transmitted diseases, and it has been identified as a significant risk factor for the development of dysplasia and cancer of the uterine cervix. The possible influence of male HPV lesions on female cervix oncogenesis has not been elucidated so far. In the present study we evaluate the male partners of women with clinical or subclinical HPV infection with particular interest in the clinical features of this infection in both partners. Methods. We examined 81 male partners of women affected with human papillomavirus infections. Condylomata acuminata were searched for by visual inspection. Subclinical lesions were searched by 5 power optical magnification lens after application of 5% acetic acid. Results. In men we observed the following percentage of infection: 67% of the partners of women affected with condylomata acuminata, 46% of the partners of women affected with subclinical lesions (acetic acid positive), and 40% of the partners of women with association of HPV and cervical intraepithelial neoplasia. Conclusions. Our data stress that very often the partners of women with HPV subclinical infection, especially when associated with CIN, do not present lesions, and consequently primary prevention may be very difficult.     

LONG-TERM FOLLOW-UP OF''CURED''PROLACTINOMA PATIENTS AFTER SUCCESSFUL ADENOMECTOMY

The long-term follow-up (greater than or equal to 4 years) of clinical, hormonal and radiological aspects in 22 'cured' prolactinoma patients after adenomectomy was studied. Dynamic secretion of PRL and TSH was also evaluated, in order to identify the persistence of any underlying abnormality of hypothalamic pituitary control and to predict relapses. A relapse into hyperprolactinaemia was shown in 36% of patients 5-90 months (mean 46) after surgery. This was accompanied by reappearance of clinical symptoms but not by the radiological demonstration of the adenoma in any patients. A significant PRL rise after domperidone, a dopaminergic antagonist drug, was shown in cured patients after surgery (mean +/- SEM peak, 2977 +/- 645 mU/l) but this was markedly lower than that observed in control subjects (5732 +/- 440 mU/l). In fact, normal PRL increments were shown in only 6/16 (37%) patients. TSH hyper-responsiveness to domperidone normalized in only 46% of patients. Similar PRL responses to those obtained with domperidone were shown when a TRH test was given. A relapse into hyperprolactinaemia was observed in six of ten (60%) non-responders to domperidone and in four of seven (57%) non-responders to TRH, whereas six normal responders to domperidone and TRH had not relapsed at that time. Plasma PRL levels during pregnancy showed increments lower than those observed in normal pregnant women only in domperidone and TRH non-responder patients. These results indicate that a relapse into hyperprolactinaemia and a blunted PRL rise during pregnancy were present only in patients with persistently reduced PRL response to dynamic tests.     

A Modified Transvenous Single Mechanical Dilatation Technique to Remove a Chronically Implanted Active‐Fixation Coronary Sinus Pacing Lead

We described a 77‐year‐old patient, previously implanted with a dual‐chamber pacemaker later upgraded to a cardiac resynchronization therapy‐defibrillator (CRT‐D) device with an active‐fixation coronary sinus pacing lead, who underwent a transvenous mechanical extraction procedure for a device‐related systemic infection. All leads were removed successfully with a transvenous approach. With regard to the coronary sinus (CS) lead (Attain 4195 StarFix, Medtronic Inc., Minneapolis, MN, USA), manual traction was ineffective and extraction required long and challenging mechanical dilatation up to distal CS using either conventional sheaths or modified CS lead delivery. (PACE 2010; 34:e66–e69)