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Biomedical subjects

J Butler

Publications and source records attributed to J Butler.

At least 433 records · Page 24Linked to original sources
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Abdominal metastases of infiltrating lobular breast carcinoma: CT and fluoroscopic imaging findings.

Infiltrating lobular carcinoma accounts for only a small fraction of breast carcinomas, with most patients having infiltrating ductal carcinoma. The metastatic patterns of ductal and lobular carcinoma have been shown to be markedly different. Infiltrating lobular carcinoma metastasizes significantly more often to the gastrointestinal tract, pelvic organs, peritoneum/retroperitoneum, and urinary tract than does infiltrating ductal carcinoma. This point has significance for follow-up, the diagnosis of abdominal symptoms, and the therapeutic options for these patients. This article illustrates the broad spectrum of abdominal metastases from lobular breast carcinoma that may be detected with computed tomographic and fluoroscopic examinations, and it describes the role of imaging in the diagnosis of metastatic disease in these patients.

Abdominal Neoplasms↗
PubMedDate not supplied

Non-invasive in vivo characterization of breast tumors using photon migration spectroscopy.

Frequency-domain photon migration (FDPM) is a non-invasive optical technique that utilizes intensity-modulated, near-infrared (NIR) light to quantitatively measure optical properties in thick tissues. Optical properties (absorption, mu(a), and scattering, mu(s)', parameters) derived from FDPM measurements can be used to construct low-resolution (0.5 to 1 cm) functional images of tissue hemoglobin (total, oxy-, and deoxy-forms), oxygen saturation, blood volume fraction, water content, fat content and cellular structure. Unlike conventional NIR transillumination, FDPM enables quantitative analysis of tissue absorption and scattering parameters in a single non-invasive measurement. The unique functional information provided by FDPM makes it well-suited to characterizing tumors in thick tissues. In order to test the sensitivity of FDPM for cancer diagnosis, we have initiated clinical studies to quantitatively determine normal and malignant breast tissue optical and physiological properties in human subjects. Measurements are performed using a non-invasive, multi-wavelength, diode-laser FDPM device optimized for clinical studies. Results show that ductal carcinomas (invasive and in situ) and benign fibroadenomas exhibit 1.25 to 3-fold higher absorption than normal breast tissue. Within this group, absorption is greatest for measurements obtained from sites of invasive cancer. Optical scattering is approximately 20% greater in pre-menopausal versus post-menopausal subjects due to differences in gland/cell proliferation and collagen/fat content. Spatial variations in tissue scattering reveal the loss of differentiation associated with breast disease progression. Overall, the metabolic demands of hormonal stimulation and tumor growth are detectable using photon migration techniques. Measurements provide quantitative optical property values that reflect changes in tissue perfusion, oxygen consumption, and cell/matrix development.

Breast Neoplasms↗
PubMedDate not supplied

Regression pattern in retinopathy of prematurity.

We characterized the regression pattern of retinopathy of prematurity (ROP) for 266 infants examined over a 22-month period. Infants were included in the evaluation with a birth weight of less than or equal to 1500 g. Regression of retinopathy was observed in all but 11 infants, who were treated for threshold ROP. ROP limited to the peripheral retina resolved around term (40 weeks postconceptional age). Posterior ROP and/or stage 3 ROP underwent a protracted course of resolution, often not reaching zone 3 until 42 to 45 weeks after conception. Permanent retinal/vascular sequelae of ROP were observed in 10% of infants with ROP. The most common abnormality was failure to completely vascularize the temporal retinal periphery. Overall, retinal morbidity from ROP was an infrequent occurrence (18 of 266 premature infants--6.8%).

Female↗
PubMedDate not supplied

Phrenic nerve and diaphragm function following open heart surgery: a prospective study with and without topical hypothermia.

In a prospective study, 100 patients undergoing open heart surgery were randomly allocated to receive ice/slush topical hypothermia for myocardial protection (Group I, n = 56) or not (Group II, n = 44). Chest radiographs, diaphragm screening, lung function and phrenic nerve conduction time were assessed pre-operatively and at 1 week and 1 month post-operatively in all patients and subsequently at 3 months, 6 months, 1 year and 2 years in all patients with radiological evidence of diaphragm paralysis. The two groups were similar in terms of age, sex, diabetes and smoking habits. Cardiopulmonary bypass and aortic cross-clamp times were similar in the two groups. Radiological evidence of partial left lower lobe collapse was more frequent in Group I (79 per cent vs. 36 per cent, p < 0.01). Twenty (36 per cent) Group I patients developed unilateral diaphragm paralysis (19 left-sided) compared with none in Group II. Diaphragm paralysis was still present in 19 patients (34 per cent) at 1 month, in five patients (9 per cent) at 1 year and in one patient (2 per cent) at 2 years post-operatively. Phrenic nerve conduction time was recorded in 98 per cent of patients pre-operatively, but was unrecordable on the appropriate side in all 20 patients with diaphragm paralysis 1 week post-operatively. Prolonged phrenic nerve conduction time on the left side was found in a further seven Group I patients 1 week post-operatively. There were no significant differences between the two groups in terms of post-operative arrhythmias, myocardial infarction or mortality.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMedDate not supplied

Platelet responses to cardiopulmonary bypass. Assessment by a shear stress activation technique.

Platelet responses before and during cardiopulmonary bypass were studied using a shear stress activation technique. Whole blood was passed through a 10 microns micro-porous filter and the percentage of platelets retained was determined. Retention in control subjects (n = 20, age 62 +/- 11 years) was 65.2 +/- 15.1%. Patients with ischaemic heart disease (n = 20, age 61 +/- 9 years) had significantly higher retention at 82.6 +/- 13.2%, p less than 0.001. In valvular heart disease (n = 15, age 57 +/- 14 years) the retention rate was 43.5 +/- 15.4%, lower than both controls and ischaemic heart disease patients (p less than 0.001). In vitro haemodilution had no significant effect on platelet retention. High retention rates were maintained in patients undergoing coronary artery surgery. During valve surgery retention increased before aortic cross-clamp removal (83.5 +/- 13.4%) compared with baseline values (p less than 0.001) and remained high 24 hours postoperatively (79.6 +/- 9.4%). Platelet retention also increased within 20 minutes of thoracotomy without cardiopulmonary bypass (n = 10, age 57 +/- 8 years, 79.3 +/- 11.6% versus 61.6 +/- 10.9% baseline, p less than 0.01) and remained high 24 hours postoperatively. Significant differences in platelet responses, assessed by shear stress activation, were demonstrated between healthy controls and patients with ischaemic and valvular heart disease. Surgery, with or without extracorporeal circulation, caused a significant increase in platelet retention.

Aged↗
PubMedDate not supplied

Early extubation after coronary artery bypass surgery: effects on oxygen flux and haemodynamic variables.

The effect of extubation within the first postoperative hour was evaluated in 13 patients (mean +/- SD age 59 +/- 6 years) undergoing elective coronary artery bypass surgery without active systemic hypothermia. The mean cardiopulmonary bypass time was 50 +/- 14 minutes. Postoperative improvements in cardiac index and oxygen uptake (from 2.0 +/- 0.4 l/min/m2 and 144 +/- 26 ml/min postinduction to 2.88 +/- 0.76 l/min/m2 and 229 +/- 104 ml/min, p less than 0.01) were maintained following extubation. Lower postoperative systemic and pulmonary vascular resistances (p less than 0.01) did not change to a significant extent following extubation. Despite a two-fold rise in the intrapulmonary shunt (Qs/Qt) following surgery (18.5 +/- 9.7% vs 9.6 +/- 3.2% before surgery) the immediate post-extubation value was similar (18.8 +/- 8.2%) and all patients were discharged from the cardiac recovery area within 16 hours without complication. Extubation within the first postoperative hour is a safe procedure following elective coronary artery surgery with short bypass times where sustained hypothermia less than 32 degrees C is avoided.

Aged↗