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Biomedical subjects

C Cobb

Publications and source records attributed to C Cobb.

At least 19 recordsLinked to original sources
PubMed2005

South-East Scotland trabeculectomy survey.

AIM: Assessment of trabeculectomy in South-East Scotland (SESTS) with comparison to National Survey of Trabeculectomy (NST) and outcomes of consultant and trainee surgery. METHOD: A retrospective study of 304 consecutive, primary trabeculectomies, in two Scottish centres (Edinburgh and Dunfermline) with two glaucoma specialists and higher surgical trainees, was performed. The study group had primary open angle glaucoma (65.5%), pseudoexfoliation (6.9%), normal tension glaucoma (7.6%), pigment dispersion syndrome (1.6%), and other complicated glaucoma (18.4%). All patients underwent trabeculectomy by the glaucoma specialist (57.6%) and higher surgical trainee (42.4%) with close scrubbed supervision. RESULTS: Compared to the NST, the waiting time for surgery (<3 months) was significantly less in the SESTS (P<0.001). There was also significantly more use of intraoperative antimetabolites (P<0.01), bleb intervention (P<0.001), and a higher rate of early complications (P<0.025). There was no significant difference in outcome at intraocular pressure (IOP)<2/3 listing IOP (qualified and unqualified) between the SESTS and the NST. Significantly, more patients achieved an unqualified success of IOP<21 mmHg (P<0.01) and an unqualified success of IOP<16 mmHg in the SESTS than the NST (P<0.05). At 1 year post surgery, visual loss of greater than one Snellen line was more common in the NST (P<0.01) as was the use of anti-glaucoma medication (P<0.001). Trainee cases returned to theatre more frequently (P<0.025) and merited more bleb intervention (P<0.01) than consultant cases, but the long-term outcome was similar. CONCLUSION: Our study highlights significant changes in the practice and outcome of trabeculectomy compared to the national survey conducted a decade ago.

Aged↗
PubMed2005

Glaucoma electronic patient record--design, experience and study of high-risk patients.

AIM: To set-up a glaucoma electronic patient record (GEPR) and study referral details to a new glaucoma service, concentrating on high-risk patients. METHOD: A GEPR was designed using the pre-existing hospital information technology (IT) infrastructure. Referral details of all new patients to the glaucoma service were completely electronically entered and analysed. RESULTS: A GEPR was successfully established. A total of 402 referrals were studied. In all, 43% (40) of high-risk clinic patients (IOP>29 mmHg, or C/D ratio >0.8 or moderate to advanced visual field defects) had to wait longer than 8 weeks from GP referral to be seen at the glaucoma service. Of these, nine patients lost more than one line of Snellen's visual acuity attributable to glaucoma. The optometrist failed to document IOP in 17%, fundoscopy in 30%, and visual fields in 45% of all referrals. CONCLUSIONS: A GEPR can be introduced in an NHS setting without disruption of clinical care and ophthalmic training, and facilitates detailed, accurate and rapid audit. Study of high-risk glaucoma referrals showed inadequate optometric referral details and poor prioritisation of urgent cases. This information is being utilised with the cooperation of local optometrists to refine the pattern of glaucoma referrals.

Glaucoma↗
PubMed2002

Effect of a direct-fed fibrolytic enzyme formulation on nutrient intake, partitioning, and excretion in early and late lactation Holstein cows.

The effect of a fibrolytic enzyme formulation on N and P intake, partitioning, and excretion was evaluated in dairy cows in early and late lactation. Twelve lactating Holstein cows (6 early lactation, 6 late lactation) were fed diets with or without the enzyme formulation in a switchback design with three, 4-wk periods. Diets for the early lactation group contained 45% forage, and late lactation diets contained 61% forage. Cows fed diets containing the enzyme formulation gained more weight than those on the control diet; this weight gain with enzyme addition was greater in early lactation cows than in late lactation cows. The main effect of enzyme treatment did not significantly affect apparent digestibility or excretion of N and P, or retention of these nutrients in body tissue. Interactions observed between the effects of group (stage of lactation) and treatment indicated differences in the nature of the milk yield and manure excretion responses to enzyme treatment between early and late lactation cows. These interactions were due to numerical increases in milk yield, feces excretion, and N excretion in early lactation cows fed diets containing the enzyme formulation compared to control, and slight decreases in these measures in late lactation cows with enzyme addition. Cows fed diets containing a direct-fed fibrolytic enzyme formulation had increased body weight gain, but the effect of addition of the enzyme formulation on milk yield and manure nutrient excretion differed for early and late lactation cows.

Animal Nutritional Physiological Phenomena↗
PubMed2000

A case of amelanotic spindle-cell melanoma presenting as metastases to breast and axillary lymph node: diagnosis by FNA cytology.

Metastatic neoplasms to the breast are relatively rare. Spindle-cell lesions of the breast are also uncommon. Here we present a case of fine-needle aspiration (FNA) of an amelanotic, spindle-cell melanoma metastatic to the breast and axillary lymph node. The patient was a 47-yr-old female who presented with a right breast mass, left axillary adenopathy, and a pigmented skin lesion on the back. FNA of the right breast and left axilla showed malignant, nonpigmented spindle cells that were weakly positive for HMB-45 on immunocytochemistry. The skin biopsy showed a pigmented malignant melanoma with epithelioid features, and also weak positivity for HMB-45. Although malignant melanoma is one of the more common tumors to metastasize to the breast, this is the first known case that showed exclusive spindle-cell morphology. History and physical examination were crucial in making the correct FNA diagnosis. The cytologic differential diagnosis of spindle-cell tumors of breast and the discordant morphology between the primary and metastatic melanotic lesions observed in this case are discussed.

Axilla↗
PubMed1996

Medial temporal lobe heterotopia as a cause of increased hippocampal and amygdaloid MRI volumes.

Magnetic resonance imaging (MRI)-based volumetric measurements of the hippocampus and amygdala are useful in detecting hippocampal and amygdaloid sclerosis in patients with temporal lobe epilepsy. In these pathological entities, volumetric MRI analysis shows the epileptogenic structures to be atrophic when compared to the normal, nonepileptogenic side. Described are 2 patients with increased hippocampal and amygdaloid volumes on the side of seizure onset due to medial temporal lobe heteroto pias. Care must be taken in the interpretation of volumetric MRI data to make certain that asymmetries in hippocampal and amygdaloid measurements are due to atrophy and sclerosis of the abnormal side and not to increased tissue such as heterotopic gray matter.

Adult↗
PubMed1996

Myocardial infarction in sickle cell disease.

Gross and microscopic findings consistent with acute (three patients) and healed (four patients) myocardial infarction were found in seven (9.7%) of 72 consecutive hearts from patients with sickle cell disease studied after autopsy between 1950 and 1982. Gross obstructive and atherosclerotic lesions were absent in all seven patients, while microthrombi were present in the arterioles of infarcted tissue in two patients. Pathophysiological mechanisms responsible for the infarction are unclear, but anemia, platelet thrombi, coronary vasospasm, and abnormal rheology related to sickle cells may all be important. Chest pain occurred clinically in six of the seven patients and ECG findings typical of infarction were found in two patients. One patient died suddenly. These findings suggest that ischemic heart disease may be present in a significant number of patients with sickle cell disease and should be considered in all patients who complain of chest pain, whether or not the patient is in crisis.

Adult↗
PubMed1995

Relationships of personality traits and stress to gingival status or soft-tissue oral pathology: an exploratory study.

OBJECTIVES: The purpose of this study was to examine the relationships of personality traits and stress with gingival inflammation and with soft-tissue oral pathology. METHODS: Personality traits of psychoticism (P), extroversion and introversion (E), and neuroticism (N) were measured with Eysenck's personality questionnaire (EPQ). Stress was measured with a modified organizational and individual assessment survey (OIAS) developed by Hendrix. Military recruits from Ft. Leonard Wood, Missouri, were examined for soft-tissue oral pathology and gingival status at weeks one (n = 241) and six (n = 61) of basic combat training (BCT). The EPQ and OIAS were administered to 217 recruits during week six of BCT. A discriminant analysis was used to determine correlations among study variables. RESULTS: Significant correlations (P < .05) were found between personality traits and various measures of tolerance of stress. Little variance was found between groups originally presenting with or without disease. Only physical stress (P < .005) was shown to affect soft-tissue pathology, while gingival inflammation correlated significantly to E scores (P < .02), tolerance to change (P < .02), and anxiety (P < .05). CONCLUSIONS: Data support a possible relationship among certain personality traits, stress variables, and gingival inflammation or soft-tissue pathology in recruits with extreme personality characteristics or perception of high physical stress levels in basic combat training.

Adolescent↗
PubMed1994

Effects of the Nd:YAG laser and combined treatments on in vitro fibroblast attachment to root surfaces.

The purpose of this in vitro study was to evaluate the effects of the Nd:YAG laser either alone or in combination with root planning or air-powder abrasive treatment on fibroblast attachment to non-diseased root surfaces. 28, 4 x 4 mm root specimens and four disc-shaped root specimens 6 mm in diameter were obtained from unerupted 3rd molars. The root segments were randomly assigned to 4 treatment groups: (1) control; (2) laser-only treated; (3) laser treated followed by root planning; (4) laser treated followed by air-powder abrasive treatment. Laser-treated root specimens were exposed for 1 min with the Nd:YAG laser calibrated at an energy setting of 75 mJ at 20 pulses/s using a 320 microns contact fiber. The contact fiber was held parallel to the root segments and the root segments were kept moist with distilled water. Following the prescribed treatments, the root specimens were incubated with fibroblast cultures and then prepared for SEM examination. Results of cell counts of fibroblasts attached to specimens within each treatment group yielded the following means and standard deviations: control groups, 181.64 +/- 44.74; lased only, 78.57 +/- 21.35; lased and root planed 125.35 +/- 26.13; and lased followed by an air-powder abrasive, 177.28 +/- 55.71. Application of ANOVA followed by the Dunn Multiple Comparison test revealed significant differences (p < 0.01) in the number of attached cells between the control and laser-only treated groups; and between the laser-only and laser/air-powder abrasive treated groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Air↗
PubMed1993

Assessment of perfused left ventricular mass in normal, ischemic, and reperfused myocardium by means of single-photon emission computed tomography of technetium-99m isonitrile.

To test the hypothesis that single-photon emission tomography of technetium (Tc) 99m hexakis 2-methoxyisobutyl isonitrile (Tc-MIBI) can accurately measure perfused left ventricular (LV) mass in nonischemic, ischemic, and reperfused myocardium, we acquired Tc-MIBI tomographic images in canines with normally perfused hearts (n = 33) after occlusion of the left anterior descending coronary artery (n = 15), after reperfusion (n = 13), and with subsequent second injection of Tc-MIBI (15 to 18 mCi; n = 12). In all ischemic studies the initial dose of Tc-MIBI (5 to 6 mCi) was injected after coronary artery occlusion but before reflow. Scintigraphic perfused LV mass was calculated from the total voxels demonstrating Tc-MIBI uptake x voxel volume (cm3) x specific gravity of myocardium (1.05 gm/cm3). After being imaged the animals were killed, the left ventricle was weighed, and the risk area was determined by dual perfusion with phthalocyanine blue dye and triphenyltetrazolium chloride (TTC). Perfused LV mass was defined as total LV mass minus the risk area mass. There was good correlation between scintigraphic and morphologic determinations of perfused left ventricular mass in nonischemic hearts (Tc-MIBI left ventricular distribution = 0.84 x left ventricular weight + .20.4, n = 33, r = 0.93, p = 0.0001) and ischemic hearts (Tc-MIBI left ventricular distribution = 0.51 x left ventricular weight + 37.9, n = 15, r = 0.83, p = 0.0001). In animals imaged both before and after reperfusion, scintigraphic determinations of the nonischemic region correlated closely (after-reflow Tc-MIBI distribution = 1.07 x before-reflow Tc-MIBI distribution--8.0, n = 13, r = 0.88, p = 0.0001), indicating that Tc-MIBI does not significantly redistribute into the ischemic zone after reperfusion. After injection of the second dose of Tc-MIBI in acutely reperfused canines, there was good correlation between the distribution mass of Tc-MIBI and the mass of viable myocardium by TTC staining (Tc-MIBI distribution = 0.61 x viable LV mass + 34.2, n = 12, r = 0.77, p = 0.0001). Furthermore, the apparent redistribution of myocardial Tc-MIBI from before and after second injection images correlated with the degree of myocardial salvage by histochemical staining (r = 0.72, p = 0.0082). In conclusion, single-photon emission computed tomography of Tc-MIBI can measure perfused LV mass accurately in both ischemic and nonischemic canine preparations.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1992

An independent application accuracy evaluation of stereotactic frame systems.

The purpose of incorporating stereotactic methodology into neurosurgical procedures is to consistently achieve a high degree of accuracy and precision in localizing intracranial targets. Therefore, the limits of resolution for the therapeutic intervention itself are a function of the accuracy and precision inherent to the particular stereotactic frame system itself. The total clinically relevant error (application accuracy) comprises errors associated with each procedural step, including imaging, target selection, vector calculation and the mechanical errors of stereotactic frames. To evaluate these parameters, a systematic error analysis was carried out in the 4 most commonly used CT-compatible stereotactic devices: the Brown-Roberts-Wells, Cosman-Roberts-Wells, Kelly-Goerss Compass (modified Todd-Wells) and Leksell frames. Over 7,681 independent test measurements were made. The results suggest a potentially significant degree of error in application accuracy of all stereotactic instrumentation which is accentuated by imaging-associated error. These individual error values must be considered with every clinical use of stereotactic frames.

Humans↗
PubMed1992

Aerosol generation by two ultrasonic scalers and one sonic scaler. A comparative study.

The purposes of this study were to compare the amount of aerosols generated from ultrasonic and sonic scalers and to measure the potential depth of respiratory tract penetration. Forty subjects were randomly assigned to receive instrumentation with the magnetostrictive, piezoelectric, or air turbine scaler. The Anderson Air Sampler collected total baseline airborne microbes for 20 minutes prior to treatment and for 20 minutes during instrumentation. This cascade impactor system measures the degree of microbial penetration in a simulated respiratory system. Blood agar plates from the sampler were incubated for 24 hours at 37 degrees C. Colony forming units per cubic foot of air (CFUs/cu. ft.) were enumerated by one blind examiner using a Lab Line Colony Counter. Data for total microbial CFUs/cu.ft. and CFUs/cu.ft. by sampler level were analyzed on the log-transformed data using ANCOVA. Baseline values of airborne bacteria served as the covariate. Results showed no significant difference in mean combined total CFUs/cu.ft. for the magnetostrictive, piezoelectric, or air turbine sonic scalers. The magnetostrictive scaler generated the lowest CFUs/cu.ft. at the deepest level of penetration; however, no significant difference in level of penetration was found among the three scalers.

Aerosols↗
PubMed1991

Ultrasound-guided hepatic cryosurgery in the treatment of metastatic colon carcinoma. Preliminary results.

Cryosurgery, the in situ freezing of cancer, has been proposed in the past as a possible treatment for unresectable hepatic tumors. Its advantage lies in the fact that it is a very focal treatment sacrificing less normal tissue than surgical resection, allowing treatment of multiple lobes. Because cryosurgery does not affect large vessels, tumors in difficult locations, such as adjacent to the inferior vena cava (IVC), can be treated. With the use of intraoperative ultrasound to place the cryoprobes and monitor the freezing process, 18 patients with unresectable metastatic colon carcinoma confined to the liver were treated. Of the 18 patients treated, 4 (22%) are in complete remission as determined by computed tomography (CT) scans and carcinoembryonic antigen (CEA) levels, with a mean follow-up of 28.8 months. Four patients (22%) were not adequately treated at the time of cryosurgery. The number of lesions frozen in each patient ranged from 1 to 12, with a mean of 6 lesions. Fourteen patients had bilobar disease; three patients had previous right lobectomies with recurrences in their remaining left lobes prior to cryosurgery, and one patient had unilobar disease. Mean survival of the 14 cases with recurrence was 21.4 months, with 2 of the 14 still alive. Ultrasound-guided hepatic cryosurgery appears to be an effective treatment for metastatic colon carcinoma to the liver that is unresectable (including patients with bilobar and multiple lesions). These preliminary results indicate that the procedure warrants further study.

Adult↗
PubMed1988

US characteristics of frozen prostate.

Cryosurgery has previously been used successfully to treat prostatic carcinoma. Inability to monitor the freezing led to local complications that limited the use of this modality. In this animal study, monitoring of the freezing process was accomplished with real-time ultrasound. The margin of the frozen tissue appeared as a hyperechoic rim with posterior acoustic shadowing. The thawed cryolesions showed markedly decreased echogenicity compared with normal unfrozen prostate. These characteristic changes should allow safer and more efficacious application of prostatic cryosurgery.

Animals↗
PubMed1988

Fine-needle aspiration cytology in the diagnosis of primary breast cancer.

To evaluate the role of fine-needle aspiration (FNA) cytology in the diagnosis of primary breast cancer, we reviewed our experience over a recent 5-year period at Harbor-UCLA Medical Center. A total of 590 aspirates with subsequent follow-up were documented. One hundred thirty-three primary cancers were histologically proved. Of the 133 cancers, 91 (68%) were diagnosed as malignant by aspiration cytologic examination; another 22 (17%) were reported as suspicious. Of the cancers, 8 (6%) had a benign cytologic diagnosis and 12 (9%) had unsatisfactory smears. No cytologic tests positive for malignancy were found to be benign on histologic examination. With an absolute sensitivity of 75% and a specificity of 100%, we conclude that FNA cytologic examination is highly accurate in the diagnosis of breast cancer. With no false-positive studies, the finding of a clearly malignant cytologic condition obviates the need for biopsy before mastectomy.

Adult↗
PubMed1986

Bile duct carcinoma associated with multiple von Meyenburg complexes in the liver.

A 61-year-old white woman was found to have disseminated abdominal carcinoma at autopsy. The primary site proved to be a bile duct carcinoma arising from ductal epithelium of multiple von Meyenburg complexes of the liver. No other neoplastic lesion was found elsewhere after careful, gross, microscopic examination. This case is thought to represent malignant transformation of the hamartomatous growth, previously reported only exceptionally.

Abdomen↗
PubMed1985

Cholangiography and bile cytopathology in the diagnosis of biliary tract obstruction.

Both percutaneous and endoscopic cholangiography identify strictures, stones, and other causes of biliary obstruction. With a radiologic diagnosis, benign and malignant causes of biliary obstruction can often be differentiated, but cholangiography does not provide a pathologic diagnosis. Therefore, we recommend cytologic examination of bile obtained during cholangiography to provide pathologic evidence of malignant causes of bile duct obstruction. We present the results of the diagnostic work-up of 17 patients with biliary obstruction to demonstrate the value of examining bile for malignant cells in all cases of biliary obstruction requiring cholangiography. If bile is cytopathologically normal, the diagnostic work-up must proceed. Abnormal findings on cytologic examination of bile in this study were confirmed with a tissue diagnosis or at operation (once) for malignant neoplasm in 100% of cases (ie, there were no false-positive results).

Adenoma, Bile Duct↗
PubMed1983

Heterogeneity of serum creatine kinase activity among racial and gender groups of the population.

To develop reference ranges for creatine kinase (CK) appropriate for the patient population served by this hospital, levels of serum CK were measured in 1,537 individuals in our employee population. There was substantial heterogeneity in mean, median, and range of CK levels among the several race/gender subgroups in the population studied. The race/gender subgroups could be placed into three broad groups: a high CK group, composed solely of black men; an intermediate CK group, consisting of nonblack men plus black women; and a low CK group, comprised of nonblack women. Mean CK level of the high CK group was twice that of the intermediate CK group, which, in turn, was twice that of the low CK group. Differences in mean CK values among the subgroups placed into either the intermediate CK group or the low CK group were not significant when tested with analysis of variance. Therefore, practical reference ranges for these groups are as follows: 52-520 U/L for the high CK group; 35-345 U/L for the intermediate CK group; and 25-145 U/L for the low CK group.

Body Height↗