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Biomedical subjects

J Hedley-Whyte

Publications and source records attributed to J Hedley-Whyte.

At least 55 records · Page 3Linked to original sources
PubMed1975

Cellular distribution and clearance of aerosolized dipalmitoyl lecithin.

Wistar-Lewis rats were anesthetized anc connected to a 3-MHz nebulizer which aerosolized 250 muCi l-alpha-1-palmitoyl-2palmitoyl-[9-10-3H]phosphatidylcholine ([3H]DPL) for 3 min. Appleton frozen-section autoradiographs showed greater than 4 times background radioactivity in approximately 30% of alveoli at 1 min and 2 h after aerosol. As tritium content in the lung decreased, it increased in liver, spleen, kidney, blood, and urine. Percentage of radioactivity from [3H]phosphatidylcholine in the liver declined with time, while [3H]phosphatidylethanolamine doubled between 2 and 12 h. One minute postaerosol 2,500 +/- 500 (SE) type I cells/mm3 lung and 2,500 +/- 750 type II cells/mm3 lung had greater than 20 times background radioactivity; 2 h later only 950 +/- 250 type I cells/-m3 lung still had levels of radioactivity greater than 20 times background while 3,150 +/- 600 type II cells/mm3 lumg now had this level of 3HIDPL. Corresponding numbers of alveolar macrophages were 450 +/- 250 1 min postaerosol and 1,100 +/- 200 after 2 h. Aerosolized DPL as a synthetic surfactant is hampered by significantly faster clearance from the alveolar surface as compared with normal in vivo DPL.

Aerosols↗
PubMed1975

Continuous positive-pressure ventilation and choledochoduodenal flow resistance.

Resistance to flow through the choledochoduodenal junction was measured during constant perfusion (0.8 ml saline/min). In eight dogs, intermittent positive-pressure ventilation (IPPV) and continuous positive-pressure ventilation (CPPV) were compared. Pressure in the common bile duct was always higher during JPPV than IPPV. With the first application of CPPV the rate of intravenous fluid was adjusted to maintain constant Hct. Mean hepatic venous pressure (Phv) increased from 6.6 to 11.5 cmH2O (P less than 0.001). Mean pressure in the common bile duct increased (P less than 0.001) from 11.6 to 14.1 cmH2O. The average increase in resistance was 21%. Changes reversed with return to IPPV. During the second application of CPPV, intravenous fluid was increased to maintain constant arterial pressure. Phv increased to 12.8 cmH2O and pressure in the common bile duct increased to 15.0 cmH2O (30% increase). In four additional dogs, choledochoduodenal resistance during continuous CPPV was reduced by intravenous vasopressin, intravenous norepinephrine and intraducta phenylephrine. CPPV increases resistance to flow through the choledochoduodenal junction, probably by vascular engorgement.

Animals↗
PubMed1975

Prevention of gram-negative bacillary pneumonia using polymyxin aerosol as prophylaxis. II. Effect on the incidence of pneumonia in seriously ill patients.

All 744 patients admitted to a Respiratory-Surgical Intensive Care Unit (RSICU) were included in a prospective study of the effects of a polymyxin (2.5 mg/kg body wt/day in six divided doses) or a placebo aerosol sprayed into the posterior pharynx and tracheal tube (if present), during 11 alternating 2-mo treatment cycles. The incidence of upper airway colonization in the RSICU with Pseudomonas aeruginosa was 1.6% during the polymyxin treatment cycles (total 374 patients) and 9.7% during the placebo cycles (370 patients) (X2 equals 23.2, P less than 0.01). 3 patients in the RSICU acquired Pseudomonas pneumonia, as defined by independent "blinded" assessors, during the polymyxin cycles while 17 acquired a Pseudomonas pneumonia during the placebo cycles (X2 equals 10.2, P less than 0.01). The overall mortality was similar in both placebo and polymyxin-treated groups (12.2 vs. 12.0%). Systemic antibiotic usage was similar in the different cycles; 49% of patients in the placebo and 53% in the polymyxin-treated groups received systemic antibiotics while in the RSICU.

Aerosols↗
PubMed1975

Uptake into brain proteins of 35S-methionine during morphine tolerance.

Effect of morphine sulfate on protein synthesis in rat brain was evaluated in tolerant and nontolerant rats. Male Wistar-Lewis rats were randomly distributed to control, tolerant and nontolerant groups. The rats were made tolerant by giving morphine sulfate (25 mg/kg b.i.d.) for either 42 or 84 days. An aqueous solution of 35S-methionine (0.5 muc/g b.w.t.) was administered i.v. Rats from each group were then sacrificed at 20 minutes, 1 hour and 2 hours after 35S-methionine. The 35S-activity in trichloroacetic acid-precipitated proteins and supernatant fractions from cortex, hypothalamus, putamen, corpus callosum, thalamus, cerebellum, kidney and liver was determined. In addition the amounts of label in lipid, saline-soluble and insoluble proteins of whole brain for tolerant and control rats were determined. The 35S-activity in brain proteins of non-tolerant rats did not differ from those of controls. The six brain areas in tolerant rats 1 and 2 hours after injection of 35S-methionine showed a 15 percent, then 30 percent increase in radioactivity (disintegrations per minute per milligram of protein). Proteins from putamen and corpus callosum had w/w 60 percent of the 35S-activity found in hypothalamus and cortex. There was no difference in 35S-activity in kidney and liver between control and tolerant rats. The radioactivity of the brain lipids was 2 percent of that found in proteins in both tolerant and control groups. Protein synthesis in morphine tolerant rat brain is significantly (P smaller than .01) increased as judged by incorporation of 35S-methionine.

Animals↗
PubMed1973

Prevention of gram-negative bacillary pneumonia using aerosol polymyxin as prophylaxis. I. Effect on the colonization pattern of the upper respiratory tract of seriously ill patients.

A prospective study used polymyxin B by aerosol to reduce colonization of the upper respiratory tract with nosocomial gram-negative bacilli. 58 high-risk patients from the Respiratory-Surgical Intensive Care Unit entered the trial. 33 were randomly selected to receive 2.5 mg/kg/day of polymyxin B by hand atomizer into the pharynx, and tracheal tube if present. 17 of 25 control patients became colonized with gram-negative bacilli as compared with 7 of 33 polymyxin-treated patients (p < 0.01). Control patients became colonized with a total of 33 gram-negative bacilli: 3 were Pseudomonas aeruginosa, 21 were species of Enterobacteriaceae. The polymyxin-treated patients became colonized with a total of 11 gram-negative bacilli: no P. aeruginosa and only 3 species of Enterobacteriaceae were recovered. Colonization increased with duration in Respiratory-Surgical Intensive Care Unit and with time of required controlled ventilation. Polymyxin most effectively prevented the increase in colonization in treated patients who stayed in the Respiratory-Surgical Intensive Care Unit for longer than 1 wk and who required controlled ventilation for at least 72 h.

Adult↗