Arm work interferes with normal ventilation

Arm work, by limiting movement of the chest wall and use of the respiratory muscles, may alter breathing pattern and gas exchange sufficiently to interfere with the ability to perform certain tasks. To determine the effects of arm work on breathing pattern during a well-controlled work task, depth of breathing, breathing frequency and end-expiratory lung volume (EELV) were measured at rest and during cycling exercise using an arm and a leg ergometer. Six subjects performed arm work at light, moderate and heavy intensities (30%, 60% and 90% of maximum arm work capacity respectively) and leg work at three intensities where ventilation was matched for that achieved during the arm work. This matching was necessary since the level of ventilation affects the breathing pattern. Subjects breathed on a mouthpiece and tubing that led to automated equipment for the measurement of respiratory variables. Ventilation during arm work was accomplished with a lower depth of breathing, a higher breathing frequency and a decreased EELV compared to leg work. Arm work places increased demands on the ventilatory system, including the muscles of respiration that are also recruited for task performance. The competition for using these muscles for breathing as opposed to a particular work task may result in a compromise in breathing capacity that ultimately may limit the ability to perform tasks requiring sustained heavy use of the arms. These increased demands on the upper body muscles must be considered when evaluating the ability of individuals to perform tasks that involve heavy arm work.     

Hydrophilic interaction liquid chromatography coupled to electrospray mass spectrometry of small polar compounds in food analysis

Reversed-phase liquid chromatography (RPLC) is commonly used to analyze nonvolatile components in food. However, polar low-molecular-weight compounds such as hydrophilic amino acids, di- and tripeptides, and organic acids are often not sufficiently retained and represent a challenge for RPLC. Hydrophilic interaction liquid chromatography in combination with electrospray mass spectrometry (HILIC-ESI-MS) on a carbamoyl-derivatized stationary phase was successfully employed to separate free amino acids and small polar peptides in complex food matrixes such as wheat gluten hydrolysate and Parmesan cheese. Glutamyl dipeptides were separated in a sequence-specific order with peptides with N-terminal glutamic acid residues eluting prior to their reverse sequence analogues. ESI-MSn detection in the positive ionization mode provided the necessary information to unambiguously identify isobaric peptides due to their characteristic fragmentation patterns. The technique also proved useful to separate and identify glycoconjugates between amino acids and reducing sugars (Amadori compounds). The investigation of organic acids present in food used a mobile phase comprising ammonium acetate buffer at pH 7 and mass spectrometric detection in the negative ionization mode.     

Fault-tolerance in balanced sorting networks

Much research has been done on sorting networks but there are very few results concerning their robustness. Our starting point is the balanced sorting network introduced by Dowd et al. and its single-block robust design of Rudolph obtained at the cost of some redundancy and two permuters external to the network. In this article we introduce a new implementation which is more robust than Rudolph's network and needs no redundancy or external permuters. We also consider a class of single-stage designs with redundancy and compare the characteristics of networks discussed.     

Experimental studies on the blood flow through tapered tubes

An investigation of the problem of steady laminar blood flow in small angle, uniformly tapering tubes of circular cross section has been conducted. An approximate pressure flow relationship was obtained by adding an empirical inertial correction to the analytical solution for the pressure drop for the case of slow flow (along radial stream lines) in a tapered tube. The approximate pressure-flow relationship was found to describe data obtained with water for a modified Reynolds Number which ranged from 0 · 2 to 10. This range of modified Reynolds Number corresponds to values encountered in the larger arteries. Pressure-flow data were obtained with tapered tubes of 1° and 2°. Data obtained for blood flow were found to be well described by the approximate relationship and blood viscosities calculated from these relations and the pressure-flow data agreed to 5 per cent with independently determined viscosities.     

Inhibition of endive (Cichorium endivia L.) polyphenoloxidase by a Carica papaya latex preparation

When endive polyphenoloxidase (PPO) was incubated with a crude papaya latex extract, it rapidly lost its activity. Inactivation was ascribed to thermostable nonenzymatic factors of low molecular weight. These factors were partially purified by a two step protocol including gel filtration chromatography on Biogel P2 and ion exchange chromatography using DEAE Sephadex A25. The PPO-inactivation rate was first order, when either inactivating agent or proton concentration was evaluated. Inactivation could be partially reversed by CuSO₄, which suggested that the inactivating factor(s) bound to the copper site of the enzyme. On a more rapid time scale than inactivation, papaya latex extract acted also as a weak noncompetitive PPO inhibitor.     

Actively stabilised diode pumped Tm:YAlO laser

An actively stabilised, continuous-wave, 1.94 /spl mu/m Tm:YAlO laser is presented. Optoelectronic negative feedback stabilisation is utilised to prevent relaxation-oscillation-driven spiking. The amplitude stability of the laser is found to be very robust against cavity perturbation and parasitic radiation back-reflection, making it attractive for practical applications.     

Cladribine (2-CDA) given as subcutaneous bolus injections is active in pretreated Waldenstr?m's macroglobulinaemia. Swiss Group for Clinical Cancer Research (SAKK)

Clinical trials with intravenous cladribine infusions in pretreated patients with Waldenstr?m's macroglobulinaemia have shown a response rate of 40%. Our pharmacokinetic studies revealed that the bioavailability of subcutaneous cladribine is complete but that the concentration-time profile is very different from intravenous administration. We designed this phase II multi-institutional trial to study the activity and toxicity of cladribine given as s.c. bolus injections in patients with symptomatic Waldenstr?m's macroglobulinaemia. Between May 1993 and October 1995, 25 patients were accrued: male/female 18/7, median age 65 years (range 44-85). All except one patient had been pretreated with more than one regimen (median 2, range 0-10). 18 patients had progressed under previous therapy and six were in relapse. All patients received cladribine for a total dose of 0.5 mg/kg per cycle as s.c. bolus injections divided over 5 d at > or = 4 week intervals, for a maximum of six cycles. All 25 patients were evaluable for toxicity and response. A total of 67 cycles were administered (median 3 cycles, range 1-6). Overall response rate including disease stabilization which had been progressive under previous therapy was 68%. 10 patients (40%, 95% CI 21-61%) achieved a partial remission. Seven responders had been progressive under previous therapy. Maximum responses were reached no later than the third cycle. Median time to treatment failure and remission duration were 4.4 (range 0.5-33) and 8 months (5-29), respectively. Four patients (16%) suffered from infections W.H.O. grade > or = 2 (pneumonia grade 2, Staphylococcus septicaemia grade 3, viral encephalitis and pneumonia, both grade 4 with complete resolution). No other severe adverse events were observed. Cladribine given as s.c. 5 d bolus injections was found to be active in pretreated Waldenstr?m's macroglobulinaemia and resulted in durable remissions.     

Phagocyte-induced oxidative stress in patients with haemodialysis treatment and organ transplantation

This study was designed to investigate any seasonal (spring, summer, autumn and winter) changes in haematological parameters in the blood of Tinca tinca measuring the number of red blood cells (RBC), haematocrit, white blood cells, and total plasma proteins. The results show significant changes in RBC and haematocrit in males comparing spring and summer with autumn and winter, whereas in females the RBC remained constant for all 4 seasons but the haematocrit decreased in autumn and winter compared to spring and summer. The white blood cells of male and female animals were significantly lower in spring and winter compared to summer and autumn. In male fish total protein contents significantly decreased in autumn and winter compared to spring and summer, whereas in females protein output significantly decreased in winter compared to the other seasons. The results indicate marked seasonal variation in the blood of male and female Tinca tinca. This variation may play a important protective role for the survival of the animals.