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Biomedical subjects

P B Terry

Publications and source records attributed to P B Terry.

80 records · Page 5Linked to original sources

False-positive complement-fixation serology in histoplasmosis. A retrospective study.

A review of the records of 79 consecutive patients who had a positive immunodiffusion or complement-fixation test for histoplasmosis showed 28 (35%) with false-positive serologic results in relation to their clinical significance. Twelve patients (15%) had complement-fixation titers of 1:32 or greater, without cultural or histological evidence of active infection. No common clinical or laboratory finding could be correlated with the presence of false-positive tests. The latter finding correlates well with the incidence of false-positive complement-fixation titers (12%) in the normal random patient population.

Adult↗

Collateral ventilation in man.

To determine whether collateral ventilation (defined as the ventilation of alveolar structures through passages or channels that bypass the normal airways) changes with age or emphysema, we compared the mechanics of collateral ventilation in seven young normal subjects, three old normal subjects and five patients with emphysema. In supine normal subjects at the end of a quiet expiration, resistance to airflow was greater through collateral channels than through bronchi and bronchioles. In emphysema, airways resistance could exceed collateral resistance, causing air to flow preferentially through collateral pathways. We conclude that high collateral resistance minimizes collateral airflow in supine normal subjects. When peripheral airways become obstructed or obliterated in emphysema, collateral channels may provide for more even distribution of ventilation.

Adult↗

Carbon dioxide--a major determinant of collateral ventilation.

The effects of local or systemic CO2 and changes in pulmonary vascular pressure and flow on the mechanics of collateral ventilation were studied in anesthetized, paralyzed dogs. The resistance to collateral ventilation (Rcoll) decreased by 36.1% when the air being infused into the obstructed segment was replaced with 10% CO2 while the animal was ventilated with air. When the air used to ventilate the animals was replaced with 10% CO2 while air was infused into the segment, Rcoll decreased by 38.6%. When blood flow into the pulmonary artery was stopped (stop flow), pulmonary artery and left atrial pressure decreased. Rcoll increased following stop flow to 125% of control; however, the fall in pulmonary vascular pressures preceded the change in Rcoll. The increase in Rcoll with stop flow was markedly reduced when 10% CO2 was infused into the segment. We conclude that collateral channels respond both to the local infusion of CO2 and to the CO2 concentration in the surrounding lung and/or blood, and that the state of distention of pulmonary vessels surrounding collateral ventilatory channels is not a primary determinant of Rcoll. In addition we conclude that bronchiolar channels rather than interalveolar pores are the pathways for collateral ventilation.

Animals↗

Collateral ventilation and the middle lobe syndrome.

The mechanics of collateral ventilation in the right middle lobe of 5 young, normal volunteers were studied using a bronchoscopic wedge technique, and the results were compared with those from an upper lobe of the same subjects. At functional residual capacity, the resistance to collateral ventilation in the right middle lobe was 4,042 +/- 559 cm H2O per liter per sec (mean +/- SE), whereas that of the upper lobes was 799 +/- 168 cm H2O per liter per sec. The time constant for collateral ventilation could not be measured in the right middle lobe of any of the subjects because it exceeded their breath-holding times of 6 to 16 sec. The time constant for collateral ventilation in the upper lobes was 4.5 +/- 1.0 sec. We concluded that collateral ventilation in the right middle lobe of young normal subjects is characterized by a high resistance and a long-time constant relative to the upper lobes. This is probably explained by a greater ratio of pleural surface to nonpleural surface in the right middle lobe as compared to the upper lobes. We suggest that ineffective collateral ventilation is a major factor in the pathophysiology of the Middle Lobe Syndrome.

Adult↗

A new controllable suction catheter for blind cannulation of the main stem bronchi.

A new controllable suction catheter is described which was used for blind cannulation of the main stem bronchi. Cannulation of the right main stem bronchus was successful in 24 of 25 attempts (96%). Cannulation of the left main stem bronchus was successful in 22 of 25 attempts (88%). The use of a controllable tip suction catheter increases the rate of successful cannulation of the left main stem bronchus compared to previous reports in the literature.

Bronchi↗

The potential value of CA125 as a tumour marker in small volume, non-evaluable epithelial ovarian cancer.

Seventy four consecutive patients with epithelial ovarian cancer have been followed up longitudinally with serial serum CA125 for up to 48 months. From this database, the CA125 changes in small volume disease have been evaluated. For long term complete responders (n = 12), the mean plateau level of CA125 was 7.2 U/ml (95% confidence interval; 5.6 to 9.2 U/ml). The natural half-life of CA125 at 5.1 days (range 3.8 to 7 days) was calculated from five patients with Stage I and II disease who underwent complete surgical excision. A mean lead time of 99 days (range 14 to 255 days) was demonstrated between marker detection of disease progression and clinically apparent progressive disease in 12 out of 13 patients (92%) who relapsed after chemotherapy induced complete remission. The threshold of tumour volume detection with CA125 is unlikely to be determined by an arbitrary cut-off level. The kinetics of CA125 provide more useful information and the potential to define complete response or indeed cure with CA125 parameters requires further investigation.

Adult↗