Natural rubber from hevea brasiliensis trees (Thailand, RRIM 600 clone) of different age (8, 20, and 35 years) were characterized by size exclusion chromatography coupled with online viscometry according to their distribution of molar mass and branching index at a temperature of 70 degrees C using cyclohexane as solvent. Washing with an aqueous solution of sodium dodecylsulfate and subsequent saponification purified the natural rubber samples. With this procedure physical branching points caused by phospholipids, proteins and hydrophobic terminal units, mainly fatty acids, of the natural rubber (cis-1,4-polyisoprene) molecule, could be removed leading to completely soluble polymer samples. All samples investigated possess a very broad (10 to 50,000 kg/mol) and distinct bimodal molar mass distribution. With increasing age the peak area in the low molar mass region decreases favoring the peak area in the high molar mass region. By plotting the branching index as a function of the both, the molar mass and the age of the trees.
Age Factors ; Chromatography, Gel ; *Hevea ; Molecular Weight ; Online Systems ; Rubber/*analysis ; Viscosity

A rubber tip disconnection of Arrow-Trerotola percutaneous thrombolytic device (PTD) may occur occasionally. We experienced 5 cases of a rubber tip disconnection among 453 mechanical thrombectomy sessions with the use of PTD. We present a report about these five cases and suggest possible causes for the occurrences.
Aged ; Catheter Obstruction/*etiology ; Equipment Failure Analysis/*methods ; Female ; Humans ; Male ; Middle Aged ; Renal Dialysis/*instrumentation ; Rubber ; Thrombectomy/*instrumentation ; Treatment Outcome

OBJECTIVETo explore the damage of respiratory system in the traffic policemen induced by automobile tyre colloidal particle and its allergenicity.

METHODSThe respiratory system symptoms in 445 traffic policemen working outside their offices and 243 controls were investigated and their pulmonary ventilation function index such as FVC, FEV(1.0), MMF and V(50) were determined. The specific IgE antibody of automobile tyre colloidal particle of their serum was determined and the skin-prick test of automobile tyre colloidal particle antigen was performed. Sixty-six traffic policemen working outside their offices and 5 controls with the positive of IgE antibody among them were detected by nasal mucosa provocation test. Sixty-six traffic policemen working outside their offices with the positive of IgE antibody were determined by Terbutaline inhalation test.

RESULTSThe positive rate of respiratory system symptoms of traffic policemen such as cough, stethocatharsis, short breath, nasal obstruction, sneeze and nose running was 38.02%, 27.03%, 20.00%, 23.08%, 27.47%, 32.09% and 34.95% respectively and significantly higher than those of the control with significant difference (P < 0.01) or (P < 0.05). The positive rate of specific IgE antibody of automobile tyre colloidal particle, skin- prick test and nasal mucosa provocation test was 14.51%, 23.73% and 54.55% respectively with significant difference (P < 0.01) and (P < 0.05). The percentage, the actual figure compared with the prediction figure, of the index of pulmonary ventilation function (FVC, FEV(1.0) MMF and V(50)) of traffic policemen were significantly lower than those of the control. Terbutaline inhalation test in 66 positive subjects of specific IgE antibody of automobile tyre colloidal particle was positive in 44 subjects, accounting for 9.67% in all policemen investigated.

CONCLUSIONThe automobile tyre colloidal particle is one of etiological factors that induce pulmonary ventilation function damage and could result in allergic asthma of traffic police.

Adult ; Allergens ; analysis ; Automobiles ; Humans ; Immunoglobulin E ; blood ; Male ; Middle Aged ; Occupational Exposure ; adverse effects ; Police ; Respiratory System ; drug effects ; Rubber ; adverse effects ; Young Adult

One-lung anesthesia can be very helpful to the surgeon during operations on the lung, mediastinum, esophagus, and thoracic aorta The standard method for one-lung anesthesia uses a double-lumen tube (Carlens, Robertshaw, etc). However, these tubes are diffieult to place and may not remain in a correct position. In addition, the lumen of each channel is inevitably too smaU for proper ventilation and suctioning. We have designed a new device for one-lung anesthesia which overcomes these disadvantages. This new device, named SLT (single-lumen tube), was made by amoured wire tube, the proximal end of which was connected to the Rusch rubber tube. So, this tube is larger in diameter, available in various sizes and very economic. We intubated 25 cardiothoracic patients with SLT under the fiberoptic guidance (Group A), and the other 25 cardiothoracic patients were intubated with Bobertshaw double-lumen tube by the direct laryngoscopy (Group B). There were no significant differences in heart rate, blood pressure, PH, PaCO2, PaO2 BE, HCO3, SaO2 and ETCO2 between the two groups compared with induction, one-lung ventilation, and two-lung ventilation values.
Anesthesia ; Aorta, Thoracic ; Blood Gas Analysis* ; Blood Pressure ; Esophagus ; Heart Rate ; Humans ; Hydrogen-Ion Concentration ; Laryngoscopy ; Lung ; Mediastinum ; One-Lung Ventilation* ; Rubber ; Suction ; Ventilation