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Biomedical subjects

H A Jones

Publications and source records attributed to H A Jones.

At least 55 records · Page 3Linked to original sources
PubMed1982

Glassy cell carcinoma of the cervix: report of three cases.

Glassy cell carcinoma is a poorly differentiated adenosquamous carcinoma of the cervix, hallmarked by aggressive behavior, occurrence in association with pregnancy, and a poor patient survival rate. Three of these very rare cervical, primary malignancies are reported. At the time of this writing, only one patient has survived.

Adenocarcinoma↗
PubMed1978

Bedside rebreathing technique for measuring carbon-monoxide uptake by the lung.

The uptake of carbon monoxide can be measured at the bedside by a rebreathing technique using an anaesthetic bag. A good correlation was found between this method and the standard single-breath measurement in normal subjects and in patients with interstitial lung disease. The rebreathing technique was as sensitive as the single-breath method in detecting lung haemorrhage in a patient with Goodpasture's syndrome, and was able to monitor its resolution as quickly.

Adult↗
PubMed1978

Uneven perfusion and ventilation within lung regions studied with nitrogen-13.

The clearance of nitrogen-13 (13N) from the upper, mid and lower zones was measured with a gamma camera during spontaneous breathing in 10 seated subjects. The clearance was monitored after (a) an intravenous injection of 13N dissolved in saline and (b) equilibration with 13N gas in closed circuit. Subjects breathed air first, and then a 30 or 11% oxygen mixture. For any region, the time for 90% elimination (T90) was related to the volume expired by the whole lung during that time (VE90). For the mid and lower zones, the clearance was faster (VE90 smaller) after intravenous 13N than after equilibration with 13N gas. This difference persisted when 30% or 11% oxygen was inspired. For the lung overall, the physiological dead space for a mean tidal volume of 884 ml was 277 ml for intravenous 13N clearance, and 384 ml for 13N clearance after equilibration. The conclusions drawn for this study are (1) ventilation in relation to volume is uneven within lung regions (2) intraregional perfusion in relation to volume is also uneven (3) at a local level the well-ventilated units are better perfused (4) these inhomogeneities are not affected by raising or lowering the inspired oxygen concentration.

Adult↗
PubMed1977

Effect of 30% oxygen on local matching of perfusion and ventilation in chronic airways obstruction.

1. Sixteen patients with chronic bronchitis and airways obstruction were given radioactive nitrogen (13N) by intravenous injection and by inhalation, while breathing air and after 10-20 min breathing 30% oxygen. The clearance of 13N from four zones of each patient's whole lung field was monitored. 2. The 13N clearance of each region in these patients with chronic bronchitis was much slower than in normal subjects. Oxygen breathing produced a significant delay in the clearance of intravenously administered 13N in 23 zones in 10 patients but no systematic change in clearance after inhaled 13N. 3. With inhalation of 30% oxygen there was no no significant change in the mean minute ventilation, tidal volume or arterial PCO2. 4. The results suggest that local hypoxic vasoconstriction is present in some patients on breathing air and that this is relieved by 30% oxygen, resulting in a diversion of local blood flow from well-ventilated to more poorly ventilated areas. The fall in VA/Q on 30% oxygen is insufficient to increase arterial PCO2.

Airway Obstruction↗
PubMed1977

Relationship between intrapulmonary airway diameter and smooth muscle tone in excised lungs.

1. Intrapulmonary bronchi in excised dog lungs were outlined with tantalum dust and stereoscopic radiographs taken during deflation and inflation of the lung after rinsing with solutions of saline, histamine, isoprenaline or EDTA. Dimensions of airways were calculated from measurements of the stereoscopic X-ray images. 2. After treatment with EDTA to minimize bronchial smooth muscle activity, airway diameters increased at all transpulmonary pressures (Ptp) and lung volumes relative to their diameter after treatment with histamine; airway hysteresis in relation to Ptp decreased. 3. At low lung volumes, the per cent increase from histamine to EDTA for airways of different sizes was the same (24-30%) but at high volumes (30 cm H2O distending pressure) the dilatation induced by EDTA was 30% for airways less than 3.0 mm diameter and 13% for those greater than 5.0 mm diameter. 4. Even at high lung volumes, intrapulmonary airways are free to constrict or dilate in spite of the stiffness of the supporting parenchyma.

Animals↗
PubMed1976

Detection of intrapulmonary hemorrhage with carbon monoxide uptake. Application in goodpasture's syndrome.

We devised a noninvasive measure of pulmonary hemorrhage of value in the management of Goodpasture's syndrome. We reasoned that alveolar uptake of inhaled carbon monoxide during breath holding would increase in the presence of extravascular blood, but clearance of its radioisotope (C15O) from a lung field would be delayed. Thus, the ratio of uptake to clearance would indicate lung hemorrhage. In 15 controls and six patients with renal failure without hemorrhage, this ratio ranged from 0.73 to 1.5. In eight patients with Goodpasture's syndrome the ratio ranged from 1.5 to 16.5, returning to normal between episodes of bleeding. Measurements of carbon monoxide uptake alone in 10 patients with Goodpasture's syndrome were at times well above that predicted for their hemoglobin level, whereas in renal failure with acute pulmonary edema increased carbon monoxide uptake was rarely found. Thus, monitoring of the single-breath carbon monoxide uptake alone can detect episodes of lung hemorrhage.

Adolescent↗
PubMed1976

Local regulation of pulmonary blood flow and ventilation-perfusion ratios in the coatimundi.

Small catheters (ca. 3 mm diam at tip) were wedged in subsegmental bronchi in anesthetized coatimundi (Nasua nasua) during spontaneous breathing. Mixed expired gases of a group of lobules were sampled continuously without contamination from neighboring units, and local tidal volume, frequency, carbon dioxide production, and oxygen consumption were measured, as well as mixed venous PO2 and PCO2. Local ventilation-perfusion ratio, alveolar PO2, PCO2, and blood flow were calculated. There was a 22% reduction (range 15-38) in local perfusion (as percent of flow at PAO2 100 mmHg) per 10 mmHg fall in local alveolar oxygen tension over the PAO2 range 150-36 mmHg. Local hypercapnia had little effect on local flow. Local tidal volume (ca. 1% of total tidal volume) was unaffected by changes in alveolar gas tensions. The contribution of vasoconstriction or vasodilatation, as a negative feedback system, to the stability of local PAO2 was greatest close to the physiologic range (65-85 mmHg) falloderate efficiency.

Animals↗
PubMed1976

Distribution of extravascular fluid volumes in isolated perfused lungs measured with H215O.

The distributions per unit volume of extravascular water (EVLW), blood volume, and blood flow were measured in isolated perfused vertical dog lungs. A steady-state tracer technique was employed using oxygen-15, carbon-11, and nitrogen-13 isotopes and external scintillation counting of the 511-KeV annihilation radiation common to all three radionuclides. EVLW, and blood volume and flow increased from apex to base in all preparations, but the gradient of increasing flow exceeded that for blood and EVLW volumes. The regional distributions of EVLW and blood volume were almost identical. With increasing edema, lower-zone EVLW increased slightly relative to that in the upper zone. There was no change in the distribution of blood volume or flow until gross edema (100% wt gain) occurred when lower zone values were reduced. In four lungs the distribution of EVLW was compared with wet-to-dry ratios from lung biopsies taken immediately afterwards. Whereas the isotopically measured EVLW increased from apex to base, the wet-to-dry weight ratios remained essentially uniform. We concluded that isotopic methods measure only an "exchangeable" water pool whose volume is dependent on regional blood flow and capillary recruitment. Second, the isolated perfused lung can accommodate up to 60% wt gain without much change in the regional distribution of EVLW, volume, or flow.

Animals↗
PubMed1975

Bronchial hysteresis in excised lungs.

1. Intrapulmonary bronchi in excised dog lungs were outlined with tantalum dust and stereoscopic radiographs taken during deflation and inflation of the lung with air, saline, Ringer or EDTA solutions. Dimensions of airways as a percentage of their values at full inflation were calculated from measurements of the stereoscopic X-ray images. 2. The mean deflation-inflation diameter difference at a transpulmonary pressure of 5 cm H2O was 20% in the air-filled lung, 9% in the saline filled preparation and 2% after filling with EDTA in saline. 3. These results show that the intrapulmonary bronchi have an intrinsic hysteresis separate from the hysteresis imposed on them by the expansion of the surrounding parenchyma. This intrinsic hysteresis is mainly due to the tone of the smooth muscle in the bronchial wall.

Animals↗