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Biomedical subjects

B M Brown

Publications and source records attributed to B M Brown.

At least 37 records · Page 2Linked to original sources
PubMed1989

Response of breast carcinoma to endocrine therapy predicted using immunostained pelleted fine needle aspirates.

Fine needle aspirates from 82 patients with breast carcinoma were fixed in methacarn, double embedded in agar or gelatin, and then in paraffin wax. Sequential sections were stained with monoclonal antibodies to the oestrogen receptor-related protein P29 (antibody D5), carcinoembryonic antigen (CEA), epithelial membrane antigen (EMA) and cytokeratin (CAM 5.2). Sixty-one of 82 (74%) aspirates provided sections suitable for immunostaining. Twenty-six (43%) were D5 positive, 23 (38%) CEA positive, 59 (97%) EMA positive, and 54 (89%) CAM 5.2 positive. Twenty-six of these patients were treated with some form of endocrine therapy. Twelve (46%) showed positive staining for D5. Eleven (92%) of the 12 D5-positive patients responded or had static disease, and 8% progressed. Of the 14 D5-negative tumours 43% responded or remained static, and 57% progressed. The difference in response between the D5-positive and the D5-negative tumours was significant (P less than 0.05, Fisher's exact test). There was no correlation between staining for CEA, EMA or cytokeratin and response to endocrine therapy.

Adult↗
PubMed1988

Preoperative evaluation of cervical radiculopathy and myelopathy by surface-coil MR imaging.

During a 2-year period, 256 patients were screened for cervical radiculopathy and myelopathy with surface-coil MR images and plain films. Selected patients had follow-up examinations including CT, myelography, and CT myelography. Thirty-four of these patients underwent cervical spine surgery after MR imaging, which disclosed a total of 50 abnormalities in three major categories: herniated disks, bony canal stenoses, and intradural lesions. MR correctly predicted 88% of all surgically proved lesions compared with 81% for CT myelography, 58% for myelography, and 50% for CT. Missed herniated disks on either MR or CT myelography usually were the result of technically suboptimal studies caused by motion artifacts on MR and beam-hardening artifacts on CT myelography. Small osteophytes adjoining herniated disks sometimes were not predicted on MR, although such osteophytes invariably were seen on plain films and were palpable during standard anterior cervical diskectomy procedures. Herniated disks in the lateral root canals found in two patients appeared to be detected more readily by CT myelography than by MR. All proved lesions were detected by either screening MR images and plain films or by follow-up CT myelograms. MR replaced invasive evaluations by myelography and CT myelography in 32% of preoperative patients. We conclude that MR images, combined with plain films, offer an accurate, noninvasive test for the preoperative evaluation of cervical radiculopathy and myelopathy, while CT myelography is the preferred follow-up examination.

Cervical Vertebrae↗
PubMed1988

Characterization of a phosphodiesterase-immunoreactive polypeptide from rod photoreceptors of developing rd mouse retinas.

In the inherited retinal degeneration of rd mice, cyclic GMP accumulates in affected rod photoreceptors prior to their degeneration. A deficiency in the activity of the visual cell phosphodiesterase apparently results in the accumulation of cyclic GMP. The cyclic GMP phosphodiesterase (PDE) of normal mouse photoreceptors is a heteromeric protein complex of about 170 kDa, consisting of the alpha beta catalytic unit and the gamma inhibitory unit. The isolated complex has low enzyme activity but it can be activated by incubation with histone. Affinity-purified polyclonal antibodies against the PDE complex of bovine rod outer segments were prepared and used to identify in retinas of both normal and rd mice PDE-immunoreactive polypeptides which comigrated on SDS-polyacrylamide gels with the large subunits (88 kDa) of the normal PDE complex. During development of normal retinas, the 88 kDa immunoreactive component of the PDE complex were detected by day 7, with immunoreactivity increasing throughout the second postnatal week. In rd retinas, the 88 kDa immunoreactivity increased after 9 postnatal days, decreased during rod photoreceptor degeneration, and was undetectable in mature rd retinas. Under nondenaturing conditions, the PDE-immunoreactive polypeptide of rd retinas sedimented on sucrose gradients with a sedimentation coefficient of 5.6S and an apparent molecular mass of about 105 kDa; no associated histone-activated PDE activity was detected. These findings show that PDE-immunoreactive polypeptides are synthesized in immature rd photoreceptors and that the PDE-immunoreactive polypeptides fail to form a PDE complex which is comparable to that of normal photoreceptors.

Animals↗
PubMed1987

Etiologic factors in head and neck wound infections.

The use of antibiotic prophylaxis does not prevent all postoperative wound infections. The records of 245 patients undergoing major head and neck surgery were reviewed to determine the cause of wound infection which developed in 17 patients. Patients with Stage IV tumors had an increased infection rate as compared to lesser stages (p less than .01). Reconstruction with a myocutaneous flap was associated with an increased infection rate when compared to primary closure or split-thickness skin graft reconstruction (p less than .001). Probable errors in surgical technique were identified in 10 of 17 infected patients. Neither weight loss, diabetes mellitus, prior radiation therapy, nor prior tracheotomy were found to increase the risk of wound infection (p greater than .05). This study lends insight into factors that may potentiate the development of wound infection despite antibiotic prophylaxis. A strategy to minimize postoperative infection is offered.

Anti-Bacterial Agents↗
PubMed1986

Contrast-enhanced computed tomography scanning of the postoperative spine.

A prospective study of contrast-enhanced computed tomography (CT) scanning was undertaken for 17 levels previously operated upon in the lumbosacral spine in 14 patients. All levels with prior operations were scanned before and after the administration of intravenous contrast medium. A standardized technique for contrast enhancement using high doses of intravenous contrast medium was employed and a specialized technique for measuring enhancement with corrections for scan artifacts was used. Results indicated that measurable contrast enhancement occurred in 16 of 17 postoperative scars up to 12 years after surgery. Enhanced scans provided more accurate delineation of the size and margins of postoperative scarring than precontrast scans. No instances of enhancement of normal disk or recurrent herniated disk were observed. In six instances recurrent herniated disks were predicted on the basis of contrast-enhanced CT scans and subsequently confirmed at reoperation. Contrast-enhanced CT scans meticulously performed appear to permit differentiation between scarring and disk herniation in patients with recurring symptoms after operations for lumbosacral disk disease.

Humans↗
PubMed1985

Assessment of laryngeal function by digital subtraction laryngography.

The evaluation of vocal cord function can be problematic in the presence of oropharyngeal tumors, hypopharyngeal tumors, and supraglottic lesions and in noncompliant adult and pediatric patients. The use of computer image subtraction techniques coupled with digital fluoroscopy has inherent high-quality resolution that can provide an excellent image of vocal cord symmetry and movement. The use of air as the contrast medium provides the ability to measure the extent of vocal cord excursion as well as the extent of piriform sinus lesions. In addition, it is a noninvasive procedure that requires a minimal imaging exposure time, with the result that the patient undergoes minimal radiation exposure.

Air↗
PubMed1985

Computed tomography and chymopapain chemonucleolysis: preliminary findings.

Ten lumbar disk levels in nine patients were examined by computed tomography (CT) before and 6 weeks after chymopapain chemonucleolysis of herniated nucleus pulposus (HNP). Patient selection for chemonucleolysis was partly based on CT scans demonstrating morphologic HNP criteria favoring a successful treatment outcome. Posttreatment CT scans disclosed a measurable HNP size decrease of 1-3 mm at nine of 10 levels studied as well as an increase in HNP attenuation at many levels. CT findings correlated closely with objective clinical parameters used to assess treatment outcomes.

Chymopapain↗
PubMed1984

Light-induced dephosphorylation of a 33K protein in rod outer segments of rat retina.

Phosphorylated proteins may play an important role in regulating the metabolism or function of rod photoreceptors. In mammalian retinas, a photoreceptor protein of 33 000 (33K) molecular weight is phosphorylated in a cyclic nucleotide dependent manner in vitro. Since light initiates the activation of a photoreceptor-specific phosphodiesterase and a rapid reduction in guanosine cyclic 3',5'-phosphate concentration, phosphorylation of the 33K protein may be modulated by light in situ. In order to test this possibility, dark-adapted rat retinas were incubated for 30 min in the dark in phosphate-free Kreb's buffer containing [32P]orthophosphate. Following incubation, rod outer segments were detached by shaking, and the 32P-labeled rod outer segment proteins were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, detected by autoradiography, and quantitated by densitometric scanning. The incorporation of radioactivity (32P) into the 33K protein was higher than into any other rod outer segment protein, and the amount of 32P-labeled 33K protein in the detached rod outer segments remained unchanged during 10 additional min of darkness. The addition of isobutylmethylxanthine to the incubation medium enhanced the incorporation of 32P into 33K protein to about 400% of the original level. Exposure of freshly detached rod outer segments to room light for 90 s decreased the amount of labeled 33K protein to 45% of its original level. The dephosphorylation of labeled 33K protein continued, reaching 12% of the original dark value 10 min after the previously illuminated sample was returned to darkness. Light initiated the phosphorylation of rhodopsin, and rhodopsin phosphorylation continued during the postillumination period of darkness.

1-Methyl-3-isobutylxanthine↗
PubMed1984

Computed tomography of mediastinal abscess secondary to post-traumatic esophageal laceration.

Esophageal laceration resulting in mediastinitis or mediastinal abscess is an uncommon, but clinically significant, complication of chest trauma. Following a normal arch aortogram, CT demonstrated bilateral upper mediastinal air fluid collections in a post-trauma patient with mediastinal widening. Suspected mediastinal abscesses secondary to esophageal laceration were subsequently confirmed by esophagography and at thoracotomy.

Abscess↗
PubMed1984

Epithelial markers in prostatic, bladder, and colorectal cancer: an immunoperoxidase study of epithelial membrane antigen, carcinoembryonic antigen, and prostatic acid phosphatase.

Twenty prostatic adenocarcinomas, 20 transitional cell carcinomas of the bladder, and 20 colorectal adenocarcinomas were stained for epithelial membrane antigen, carcinoembryonic antigen, and prostatic acid phosphatase. Polyclonal affinity purified first and second antibodies and an indirect immunoperoxidase technique were used. All of the colorectal and bladder tumours and 16/20 prostatic tumours were positive for epithelial membrane antigen. All 20 colorectal, 7/20 bladder, and 5/20 prostatic tumours stained for carcinoembryonic antigen. All of the prostatic adenocarcinomas and none of the colorectal or bladder tumours were positive for prostatic acid phosphatase. These markers may be used to discriminate between tumours arising from these sites.

Acid Phosphatase↗
PubMed1983

CT assessment of the adult extrathoracic trachea.

A total of 40 neck computed tomographic (CT) scans in adult patients were retrospectively reviewed and absolute measurements made of the anteroposterior (TRAP) and transverse (TRTR) air spaces at the first tracheal cartilage. For each patient, ratio measurements were calculated of the anteroposterior (TRAP/TC) and transverse (TRTR/TC) tracheal air space relative to the glottic air space at the true cord level. Mean TRAP (2.01 cm) and TRTR (1.84 cm) measurements for normal patients agreed closely with figures reported in prior cadaver preparation studies. The lower normal limit found for absolute tracheal diameter was 1.5 cm (TRAP) and 1.4 cm (TRTR), whereas lower normal limits for relative tracheal to glottic air space diameters were 0.7 (TRAP/TC) and 0.6 (TRTR/TC).

Adult↗
PubMed1983

Digital subtraction laryngography.

Digital subtraction laryngography was used to evaluate laryngeal function in 8 patients: 4 with normal larynxes and 4 with laryngeal disease. Subtracted digital images provided a dynamic display of the extent and symmetry of vocal cord excursions and pyriform sinus inflation, and the vocal cord resting position was also clearly depicted. The technical details of digital subtraction laryngography and its application are described.

Humans↗
PubMed1982

Autophosphorylation of rhodopsin kinase from retinal rod outer segments.

Rhodopsin kinase has been identified as a 68K protein that is more readily extracted from dark-adapted rod outer segments (dark-extract) than from illuminated rod outer segments (light-extract). We observed that a 68K protein is phosphorylated by endogenous protein kinase of dark- or light-extract of bovine rod outer segments and that the amount of incorporated radioactivity (32P) was greater in the dark-than in the light-extract. Phosphorylation of the 68K protein is neither stimulated by cyclic nucleotides nor affected by the light or dark conditions of the phosphorylation reaction. Light-and dark-extracts were centrifuged simultaneously on individual sucrose density gradients revealing that the 68K phosphoprotein cosediments with endogenous rhodopsin kinase activity and that both greater 32P incorporation and higher rhodopsin kinase activity are found in dark-extract as compared to light-extract. These findings suggest strongly that the 68K phosphoprotein and rhodopsin kinase are identical and that rhodopsin kinase undergoes autophosphorylation.

Animals↗
PubMed1982

Gastric wall thickening and extragastric inflammatory processes: a retrospective CT study.

A retrospective CT study was undertaken to evaluate nonneoplastic extragastric lesions associated with gastric wall thickening (GWT). A total of 70 cases was reviewed including 44 with acute pancreatitis, 6 with infected left upper quadrant fluid collections, and 20 with noninfected left upper quadrant fluid collections. Patients with acute pancreatitis and measurable gastric walls disclosed GWT in 67% of cases. All patients with infected left upper quadrant fluid collections (including abscesses and infected splenic hematomas) adjacent to the stomach exhibited GWT on computed tomography (CT). No patients with noninfected perigastric left upper quadrant fluid collections had GWT. Gastric wall thickening has been emphasized as an important feature in CT staging of gastric malignancies and has been noted in intrinsic gastric inflammatory disease. We conclude that extragastric inflammatory processes are commonly identified on CT and can be demonstrated to account for GWT, which appears to be a relatively sensitive and specific sign for distinguishing inflammatory from noninflammatory perigastric lesions.

Abscess↗