Increased fine particle deposition in women with asymptomatic nonspecific airway hyperresponsiveness.

Previous studies suggest that lung function tests using monodisperse aerosols can help to identify early stages of lung diseases. We investigated intrapulmonary particle loss and aerosol bolus dispersion-a marker of convective gas transport-in 32 women with asymptomatic nonspecific bronchial hyperresponsiveness (BHR) compared with 60 women without BHR. Deposition of inhaled particles (0.9 micrometer mass median aerodynamic diameter [MMAD]) was calculated from particle losses of inhaled aerosol boluses consisting of di-2-ethylhexyl sebacate droplets. Convective gas mixing was assessed by the aerosol bolus dispersion method. Women with BHR, nonsmokers as well as smokers, showed significantly increased deposition of aerosol particles (nonsmokers: 45.6 +/- 8.8%; smokers: 49.2 +/- 5.4%; mean +/- SD) compared with the control group of female nonsmokers without BHR (38.2 +/- 9.1%; mean +/- SD) (p < 0.01). Aerosol bolus dispersion values showed a trend for higher values in subjects with BHR (nonsmokers: 572 +/- 122 cm3; smokers: 587 +/- 85 cm3) compared with the control group (542 +/- 88 cm3) (p = 0.2). Also, the maximal expiratory flow at 25% vital capacity (MEF25) showed a trend for decreased values in nonsmokers with BHR compared with nonsmokers without BHR (64 +/- 16% of predicted versus 78 +/- 24% of predicted; p = 0.03). These results suggest that deposition of inhaled particles (0.9 micrometer MMAD) administered by the aerosol bolus technique is a sensitive index of peripheral lung injury that is usually not assessable by conventional methods.

Quantification of exercise-induced pulmonary haemorrhage with bronchoalveolar lavage.

Exercise-induced pulmonary haemorrhage (EIPH) causes serious economic losses in the horse racing industry. Endoscopic examination indicates that 40-90% of horses exhibit EIPH following sprint exercise, but the limitations of the endoscope prevent diagnosis in many horses. Bronchoalveolar lavage (BAL) was utilised to detect red blood cells (RBCs) in the terminal airways in 6 horses. Two lavages were performed at weekly intervals prior to exercise, one within 90 min after exercise, and 5 at weekly intervals after exercise. The horses were exercised strenuously at 12.5-14.6 m/s on a treadmill (3 degree incline). Heart rates ranged from 192-207 beats/min, and mean pulmonary arterial pressures (mPAP) ranged from 80-102 mmHg. Neither epistaxis nor endoscopic evidence of EIPH was seen in any of the 6 horses following exercise. However, the number of RBCs in the lavage fluid increased significantly over control values immediately after exercise in all horses but returned to control values by one week after exercise. Haemosiderophages in the BAL fluid did not increase until one week after exercise and remained elevated for 3 weeks after exercise. Twenty per cent of the total population of alveolar macrophages contained haemosiderin. A positive relationship occurred between the number of RBCs in the lavage fluid and mPAP; the amount of haemorrhage increased as the mPAP exceeded 80 to 90 mmHg. The results with BAL used as the diagnostic tool, suggest that all strenuously exercised horses may exhibit EIPH; the amount of haemorrhage appears to be associated with the magnitude of the high pulmonary arterial pressure.

[Lobular carcinoma in situ--what is the best treatment]. / Lobulêre karsinoom in situ--wat is die beste behandeling?

There are at present four different approaches to the management of lobular carcinoma in situ. (i) ipsilateral mastectomy with contralateral biopsy; (ii) ipsilateral segmental excision with block dissection of the axilla; (iii) bilateral mastectomy; and (iv) diagnostic excision biopsy and lifelong follow-up of both breasts with clinical examination and mammography. There are arguments in favour and against all four approaches. Based on the well-established fact that the risk of the patient developing infiltrating lobular carcinoma is equal in both breasts, the most rational approach is excisional diagnostic biopsy of the known lesion and lifelong follow-up of both breasts. Any infiltrating carcinoma will be discovered early with this approach, and the 20-year survival is 95%. If the patient insists that the risk of developing carcinoma must be totally excluded, bilateral mastectomy with breast reconstruction is the only option.

Permeability of cellophane membranes to parotid during dialysis.

Pooled paratoid saliva was dialyzed in cellophane membranes against water for periods of up to 1 week and loss of proteins was monitored by acrylamide gel-electrophoresis. A gradual loss of cationic proteins was observed whereas anionic proteins were not appreciably affected. Loss of the cationic proteins could be greatly reduced by performing dialyses against dilute electrolyte solutions rather than water. These effects were attributed primarily to electrostatic changes associated with the dialysis membranes.

Acrylamide gel electrophoretic studies of extracellular sucrose-metabolizing enzymes of Streptococcus mutans.

This study explored the use of acrylamide gel electrophoretic methods to determine the numbers and types of extracellular sucrose-metabolizing enzymes produced by particular strains of S mutans. Strains HS-6, SL-1, FA-1, and NCTC 10449 were cultured in a chemically defined medium and the extracellular proteins elaborated by the organisms were isolated and subjected to acrylamide gel electrophoresis. Patterns of protein components and sucrose-metabolizing enzymes were then delineated. Three types of sucrose-metabolizing enzymes were observed. One type was involved in the synthesis of polysaccharides that were insolubilized in the gels. Another type was involved in the synthesis of water-soluble polysaccharides. A third type was involved in the splitting of sucrose into reducing sugars without polysaccharide synthesis. Each pattern was distinctive with regard to the numbers, proportions, and types of enzyme components present and their migratory characteristics. From two to at least six components were observed amont the enzyme activity patterns per strain. Extracellular protein patterns showed from 12 to 20 components per strain. Comparative data on growth in the chemically defined medium and Todd-Hewitt broth were also presented. Better growth levels were obtained in all instances with the chemically defined medium over comparable periods of time.

Electrophoretic patterns of parotid fluid proteins from caries-resistant and caries-susceptible individuals.

Parotid saliva samples from caries-resistant and caries-rampant individuals were electrophoresed on polyacrylamide gel slabs. The parotid saliva of the caries-rampant group showed a significantly higher level of anodemigrating proteins, predominantly isoamylases, and a significantly lower level of cathode-migrating proteins than that of the caries-resistant group in both paraffin-stimulated and sour lemon-stimulated salivary flows.

Investigation of possible solvents for extracellular polysaccharides from Streptococcus mutans and Streptococcus sanguis.

The solubilities of extracellular polysaccharide fractions produced by 14 oral streptococcal strains were compared in water, aqueous lithium and guanidine salt solutions, dimethyl sulfoxide (DMSO), and a 9:1 DMSO-water mixture. The best results for solubilizing the fractions were obtained with the DMSO-water mixture procedure, which used the water and DMSO in sequence. By this method all fo the fractions were solubilized.

Receptors: localization and specificity of binding of serotonin in the central nervous system.

Formation of a Schiff base between the ethylamine residue of serotonin and an appropriate carbonyl residue at the receptor site may be among the forces holding serotonin onto the receptor. Reduction of this imine may provide a means of permanently labeling receptors as a preliminary to their isolation.

Antibacterial properties of 3,3',5,5'-tetrachlorotetranitrodiphenylamine.

An analogue of tetramethyldicrylamine, 3,3',5,5'-tetrachlorotetranitrodiphenylamine, was synthesized and tested in vitro for its antibacterial activity.

Preparation and properties of tetramethyl-dipicrylamine.

Tetramethyldipicrylamine has been synthesised. It gives precipitates with ammonium, potassium, rubidium and caesium ions, that vary widely in crystalline form and offer a possibility of qualitative usage in chemical microscopy. The potassium salt is of sufficiently low solubility to be of analytical interest.