Acquired resistance to the human hookworm Necator americanus in mice

BALB/c mice were exposed to primary or secondary infection with the hamster-adapted strain of Necator americanus, and the course of infection was monitored through worm recovery and immunological assays. Significantly fewer viable larvae were recovered from the skin site of reinfected mice on day 2 post-infection, and fewer larvae resided in the lungs of challenged mice 3-5 days after infection, suggesting that the skin was involved in resistance to secondary infection. The serum antibody response to L3 antigen was enhanced during secondary infection, peaking on day 9, and the bronchoalveolar leucocyte (BAL) response was more intense at this stage. Thus the secondary BAL response was initiated more promptly than the primary response, peaking on day 13 at twice the intensity of the primary response and five times above the resting level. Differential counts revealed that by far the most significant changes in cell populations were those observed for eosinophils in lavage fluid. At the peak of the response a 925-fold increase over control levels was detected in mice undergoing a challenge infection. Some cellular and serological components of the secondary response were defined in the present work and it was concluded that reinfected mice have the capacity to trap parasites during their passage through the skin and development in the lungs.     

Vasotocin analogues which competitively inhibit vasopressin stimulated uterine activity in healthy women

Summary. Three analogues of posterior pituitary hormones, 1 - deamino - 2 - D - Tyr(OEt) - 4 - Val - 8 - Om - vasotocin(dE - VVT), l-deamino-2-D-Tyr(OEt)-4-Thr-8-Orn-vasotocin(dE-TVT) and 1-deamino-2-D-Tyr(OEt)-oxytocin(dE-OXY) were compared for their inhibitory effects on vasopressin (VP)-induced uterine activity in healthy women. At menstruation, during recording of intrauterine pressure (18 recording sessions in 11 women), intravenous infusion of lysine vasopressin (LVP, 1 ng/min/kg/body weight) induced an increase of the uterine activity and dysmenorrhoea-like symptoms. Intravenous injections of all analogues (10 μg/kg body weight) caused relief of symptoms and inhibition of uterine activity, dE-TVT was the most effective and dE-OXY was least active. With dE-TVT almost complete inhibition of contractions was seen during the first 10 min after injection. The duration of effect was also greatest with that analogue (40–50 min). Only dE-OXY had an agonist effect on spontaneous uterine activity. Pharmacokinetic studies of intravenous dE-TVT (10 ng/kg body weight) showed that the plasma half-life was approximately 16 min and the clearance 30 1/h. The bioavailability of 100 ng/kg given intra-nasally was about 5·5%. Further studies are recommended.     

SACCHARIN DRINKING RATHER THAN OPEN FIELD BEHAVIOUR PREDICTS INITIAL ETHANOL ACCEPTANCE IN WISTAR RATS

This study examined the relationship between saccharin drinking,open field behaviour and ethanol drinking in Wistar rats. Correlationalanalysis revealed that both absolute saccharin drinking andan increase in total fluid intake in the presence of saccharinpositively correlated with the initial acceptance of increasingethanol concentrations in a two-bottle choice situation (2–8%v/v ethanol vs water). This relationship disappeared, however,during further weeks of ethanol drinking when ethanol was availablein a three-bottle choice situation (8% ethanol vs 16% ethanolvs water). In contrast, none of the behavioural parameters measuredin the open field test (forward locomotion, rearings, centralentries, time in central area) correlated with subsequent ethanolconsumption. These results indicate that saccharin dnnking,rather than open field parameters, may predict subsequent ethanolintake during the initial period of exposure to low ethanolconcentrations.     

Adaptive Filtering in Exercise High Resolution ECG as Applied to the Hypertrophic Cardiomyopathy

KEPSKI, R., et al. : Adaptive Filtering in Exercise High Resolution ECG as Applied to the Hypertrophic Cardiomyopathy. The application of adaptive filtering to ECG signals has been investigated for many years. This study shows that the exercise high resolution ECG (HRECG) can also be processed successfully in a similar way. Two groups were included consisting of 20 healthy individuals and 24 patients with hypertrophic cardiomyopathy (HCM) . The HRECG parameters for both groups were similar (  QRSdur: 107 ± 7 vs 114 ± 18 ms NS, LAS: 25 ± 8 vs 22 ± 6 ms NS  ). In the first step, the HRECG signal was acquired at rest to obtain the averaged reference pattern. The next step was associated with peak exercise in which one could calculate short duration averaging (∼ 30 beats) or apply adaptive filtering in which the exercise component (EC) was extracted. Exercise was performed in the supine position on a bicycle ergometer. The load of 50 W was incremented by 50-W steps in 3-minute intervals and the test was ended by fatigue. Signals were recorded in X, Y, and Z bipolar leads with a 20-Hz high pass filter. The short time average QRS duration mostly was abbreviated in normal individuals in contrast to HCM patients in which ventricular activity prolonged with sensitivity, specificity, and negative and positive predictive values: 79%, 65%, 73%, and 72%, respectively. The adaptive recurrent filtration (ARF) after cutoff of the EC at the level of 70 ms (this level is the EC mean value of both groups) showed the following statistics: 63%, 90%, 88%, and 90%. The Student's t-test as applied to the duration of EC allowed a statistically significant difference between normals and HCM patients (  66 ± 4 vs 71 ± 6 ms, P < 0.0052  ) and between HCM patients with and without ventricular tachyarrhythmia and DS (  74 ± 6 vs 69 ± 6 ms, P < 0.046  ).     

Expression of acquired immunity to the hookworm Ancylostoma ceylanicum in hamsters

Four experiments are described in which hamsters, initially exposed to primary infection with Ancylostoma ceylanicum , were given a homologous challenge and components of the secondary response were quantified and compared to relevant control groups. The initial establishment of the L3 larvae was not prevented in immunized hamsters but their growth was slowed and virtually all larvae were lost within a week of challenge, when the majority were still at the L4 stage of development. The loss of worms was associated with an accelerated mucosal mastocytosis and increased systemic antibody. Thus acquired immunity to hookworm larvae in this system acted on L3 and L4 stages, thereby preventing larvae from maturing in immunized animals. In contrast to primary infections, immunized hamsters responding to a challenge infection did not lose weight nor did they experience significant anaemia, because of the lack of adult worms. The secondary immune responses therefore prevented manifestation of hookworm disease among immunized-challenged animals .     

Analysis of Circadian Distribution of Premature Ventricular Contractions in Patients After Heart Transplantation

The aim of our study was to analyze circadian distribution of premature ventricular contractions (PVC) and its coupling interval (CI) in patients after orthotopic heart transplantation (HTx). Forty-two patients (5 females, 37 males) were monitored from 2 weeks to 5 years after HTx; 180 24-hour Holter ECG studies were performed. All recordings were divided into two groups: group I, within 1 month after HTX; and group II, after 1 month. Patients with more than 250 PVC/24 hours were selected for distribution of PVC and CI evaluation. Conclusions : Ventricular arrhythmias occur frequently in patients after heart transplantation. In patients with high Lown scale arrhythmias low occurrence (< 250/24 hours) of PVC was frequently observed (IVa: 81.8%; IVb: 84.7%). Similar patterns of circadian distribution (CD) of PVC and CD of HR in denervated heart after HTx suggest the influence of circulating catecholamines on their occurrence.     

Menadione-Induced Oxidative Stress in Bovine Heart Microvascular Endothelial Cellsa

Objective: Oxidative stress from increased production of reactive oxygen species or decreased efficiency of inhibitory and scavenger systems may contribute to vascular injury. In this study, we developed an in vitro model of vascular injury by menadione-induced oxidative stress in bovine heart microvascular endothelial cells. Methods: Oxidative stress was induced by exposure to menadione. Superoxide, hydrogen peroxide and hydroxyl radical formation was measured by superoxide dismutase-inhibitable cytochrome c reduction, the dichlorofluorescin technique and the salicylate method, respectively. Electron paramagnetic-spin resonance spectroscopy employing 5–5′-dimethyl-1-pyrroline-N-oxide for superoxide trapping was used. Endothelial cell cytotoxicity was assessed by lactate dehydrogenase release. Results: Superoxide and hydroxyl radical were produced in a time- and concentration-dependent fashion. Fluorescence in the presence of dichlorofluorescin confirmed hydrogen peroxide formation. Endothelial cell cytotoxicity became evident after 5 h of menadione treatment at concentrations of 100 μM. 3-Aminobenzamide, a poly(ADP-ribose)polymerase inhibitor, and dimethylthiourea, a hydrogen peroxide and hydroxyl radical scavenger, decreased menadione cytotoxicity, whereas deferoxamine, an inhibitor of hydroxyl radical formation, did not. Conclusions: The results suggest that menadione toxicity is mediated by poly(ADP-ribose)polymerase activation via hydrogen peroxide formation and that menadione-treated bovine heart microvessel endothelial cells provide a suitable in vitro model to study oxidative stress in endothelial cells.     

Late caliceal fistula after kidney transplantation

Caliceal fistula is a rare urological complication that can occur usually shortly after kidney transplantation (KTx). The occlusion of the renal accessory artery with subsequent necrosis of the kidney pole is the most common cause of the fistula development. We report a case of a 57-year-old man with reconstruction of two accessory renal arteries by anastomosis to the side of the main artery during graft placement complicated by late caliceal fistula, managed surgically. Directly after KTx good kidney graft function (serum creatinine concentration 151 micromol/L) was observed. The patient noticed protuberance and pain in the kidney graft area 5 months later. Diagnostic imaging revealed moderate urostasis and liquid collection in the region of the lower graft pole. Administration of a contrast medium through the inserted drain visualized a fistula of a lower renal calyx and ureteric stenosis. Percutaneous drainage was applied with subsequent stop of diuresis through the urethral catheter. During the surgery, the resection of a lower kidney graft pole necrosis was performed, with the closure of caliceal fistula. Simultaneously double pigtail ureteric stent was inserted. After the next two months the pigtail catheter was removed, and neither urostasis in the kidney graft nor liquid collection in the perigraft area were observed. The exceptionality of the case is the late caliceal fistula occurrence. We may only speculate, why it happened 5 months after KTx. The thrombosis of stenosed accessory artery is the most probable cause.     

Hydroxocobalamin. II. Absorption from the Site of Injection and Uptake by the Liver and Calf Muscle in Man

Labeled hydroxocobalamin, administered intramuscularly in man, is absorbed more slowly from the site of injection and deposited in the liver andcalf muscle to a degree equal to or higher than that of cyanocobalamin at anequivalent dose. These findings, together with those reported in Part I ofthis paper, suggest the applicability of hydroxocobalamin as a long-actingvitamin B₁₂ in man. These conclusions, however, require the support to be obtained from long-range observations on patients with vitamin B₁₂ depletion.

Submitted on June 6, 1961 Accepted on August 1, 1961