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Biomedical subjects

M Brooks

Publications and source records attributed to M Brooks.

At least 55 records · Page 3Linked to original sources
PubMed1991

Bleeding disorder (von Willebrand disease) in a quarter horse.

Bleeding diathesis in a Quarter Horse filly was caused by von Willebrand disease. Hemorrhage occurred mainly from mucosal surfaces and after trauma. Quantitative and qualitative measurements of plasma von Willebrand factor (vWF) documented a specific deficiency of vWF high molecular weight multimers, and concurrently greater than expected deficiency of vWF activity relative to vWF concentration. These findings are characteristic of type-II von Willebrand disease in human beings. Application of vWF assays used in human and small animal medicine now permits evaluation of vWF and diagnosis of von Willebrand disease in horses with bleeding disorders.

Animals↗
PubMed1991

Cystourethrometric findings in patients with detubularized right colonic segment for bladder replacement.

Urodynamic evaluation was performed in 13 men 4 to 18 months after cystoprostatectomy and bladder replacement using a detubularized right colonic segment. All patients are continent by day and only 3 are incontinent during the night to a degree that necessitates use of a condom catheter. Two patients awaken every 2 to 3 hours to void and the remainder have nocturia comparable to normal men of their age. The residual volume was 0 to 70 ml. The urethral closure pressure was normal, and in 3 patients studied preoperatively and postoperatively no significant change was observed other than shortening of the profile length. Maximal flow rates were normal although the pattern was intermittent. In 2 patients no cystoplasty contractions were recorded and in all but 2 patients the amplitude of the contractions was less than 40 cm. water. Simultaneous bladder and urethral pressure recordings during bladder filling demonstrated no change in urethral pressure in 10 patients. Although creation of a reservoir with a low pressure and careful preservation of the infraprostatic urethra are important for continence in these patients, we believe that the absence of normal sacral route reflexes after cystoprostatectomy is an important contributing cause to nocturnal incontinence.

Colon↗
PubMed1991

A sensitive immunoassay for von Willebrand factor.

We have developed an ELISA specific for canine von Willebrand factor antigen (vWF:Ag) that also strongly reacts with the VWF:Ag of humans and many other vertebrates. This assay was designed to avoid the use of immunoreagents of human origin, however, commercially available antibodies to human vWF:Ag may also be used. von Willebrand factor (vWF) was quantitated using a modified double-sandwich ELISA with polyclonal antibodies specific for canine vWF:Ag. The assay was as sensitive for measuring canine vWF:Ag as previously published immuno-radiometric assays and the most sensitive ELISA for human vWF:Ag. Employing commercially available antibodies to human vWF:Ag in the same double-sandwich configuration, the lower limit of detection for human vWF:Ag was 4.8 x 10(-6) units/ml, lower by a factor of ten than previously reported ELISAs. In addition, a wide range of vWF:Ag levels can be determined with just a single plasma dilution. The assay readily distinguishes type III von Willebrand disease from other types of von Willebrand disease having very low levels of vWF. This vWF ELISA can be used to evaluate large numbers of plasma samples simultaneously and is therefore well-suited for large-scale screening programs.

Animals↗
PubMed1991

Electrosurgical thin loop conization by selective double excision.

Thin loop electrosurgical conization of the cervix was performed in 30 women, using a selective double excision (SDE) technique in order to conserve cervical tissue. The entire excisional cone was completed within 4 minutes, and blood loss was estimated at 5 ml or less. All cervices healed in patterns identical to CO 2 laser conizations. Critical tissue margins were easily identified by the pathologist. Compared to simple loop excisional cones, SDE saved greater than 2 cm3 of cervical stroma.

Cervix Uteri↗
PubMed1991

Superfecundation identified by HLA, protein, and VNTR DNA polymorphisms.

Parentage analysis has revealed a high probability that a man accused of paternity is the biological father of a male child. The child in this study, however, was the twin of a female child who could not have been fathered by the accused man. The mother of the children subsequently accused a second, unrelated man, who was excluded from paternity of the boy, but was very probably the biological father of the girl.

Adult↗
PubMed1991

Imaging of the orthopaedic patient: implications for primary care.

Pain in the skeleton is the foundation on which this article is based. Patients with musculoskeletal pain are frequently seen in primary care. There are many diagnostic imaging studies available to aid the practitioner in formulating and confirming a working diagnosis. This article offers specific guidelines for ordering imaging studies for common orthopaedic problems. The authors take into consideration costs and reliability of tests with each recommendation. The trend in many cases is to order magnetic resonance imaging scans rather than traditional radiographs. The indications for the commonly requested studies are reviewed.

Bone Diseases↗
PubMed1990

Cuticular lipid differences between the malaria vector and non-vector forms of the Anopheles maculatus complex.

Two chromosomal forms (E and F) of the Anopheles maculatus Theobald complex were distinguished by gas-liquid chromatographic (GC) analysis of cuticular lipids in association with a multivariate principal component analysis. The GC chromatogram obtained from n-hexane extracts of individual specimens showed no consistent qualitative differences in normalized peak areas between forms. Of the seventeen consistent peaks, five were found to be quantitatively different between forms at a high (99.5-99.95%) level of statistical confidence. Relative ratios of these five quantitatively different GC peaks were used as criteria to distinguish single specimens as either form E or form F. Chemical structures of the five GC peaks were assigned by both electron impact and chemical ionization gas chromatography/mass spectrometry analysis. The first three peaks, which were always doublets, were partially resolved saturated and mono-unsaturated free fatty acids; the other two peaks were n-alkanes. Principal component analysis substantiated that the vector form E has very similar cuticular lipid profiles and is well separated from the non-vector form F.

Animals↗
PubMed1990

Evaluation of the efficacy and cost effectiveness of health education methods to increase medication adherence among adults with asthma.

We randomized 135 adult asthma patients to a control group, and 132 patients to an experimental group which received a special health education intervention. Four adherence measures were documented at baseline and 12-month follow-up: correct inhaler use, inhaler adherence, medication adherence, and total adherence rating. Costs to routinely deliver the intervention were $32.03/patient. Experimental group patients exhibited a significantly higher level of improvement in adherence (44 percent) than control group patients (2 percent).

Adolescent↗
PubMed1989

DNA primase isolated from the yeast DNA primase-DNA polymerase complex. Immunoaffinity purification and analysis of RNA primer synthesis.

We have utilized immunoaffinity chromatography as a means of efficiently isolating a stable yeast DNA primase from the DNA primase-DNA polymerase complex, allowing identification of the polypeptides associated with this DNA primase activity and comparison of its enzymatic properties with those of the larger protein complex. A mouse monoclonal antibody specifically recognizing the DNA polymerase subunit was used to purify the complex. Stable DNA primase was subsequently separated from the complex in high yield. The highly purified protein fraction which bound to the DNA polymerase antibody column consisted of polypeptides with apparent molecular masses of 180, 86, 70, 58, 49, and 47 kDa. DNA primase activity eluted with a fraction containing only the 58-, 49-, and 47-kDa polypeptides. Partial chemical cleavage analysis of these three proteins demonstrated that the 49- and 47-kDa polypeptides are structurally related while the 58-kDa protein is unrelated to the other two. A DNA primase inhibitory monoclonal antibody was able to inhibit the activity of the purified DNA primase as well as the activity of the enzyme in the larger complex. In immunoprecipitation experiments, all three polypeptides were found in the immune complex. Thus, these three polypeptides are sufficient for DNA primase activity. In reactions using ribonucleotide substrates and natural as well as synthetic DNA templates, the purified DNA primase exhibited the same precise synthesis of unit length oligomers as did the larger protein complex and was able to extend these RNA oligomers by one additional unit length. An examination of the effects of deoxynucleotides on these DNA primase-catalyzed reactions revealed that the yeast DNA primase is an RNA-polymerizing enzyme and lacks significant DNA-polymerizing activity under the conditions tested.

Adenosine Triphosphate↗
PubMed1989

Adult nesidioblastosis. An unusual cause of fasting hypoglycemia.

Laidlaw coined the term nesidioblastosis in 1938 to characterize the neodifferentiation of the islet cells of Langerhans from pancreatic duct epithelium. It is well recognized in the pediatric population as a frequent cause of persistent neonatal hypoglycemia. However, its occurrence in adults is presumed to be rare and, therefore, it is not appreciated as a cause of hyperinsulinism. Three women, aged 29, 42, and 63, with adult onset hyperinsulinism secondary to nesidioblastosis are reported. All three patients required near-total pancreatectomy. The preoperative findings were consistent with hyperinsulinemic hypoglycemia as with insulinomas. Results of pancreatic imaging studies were normal in two patients and one patient had a pancreatic examination by computerized tomography and magnetic resonance imaging, with false-positive results. Two of the three patients had previously undergone a 50 per cent distal pancreatectomy in which the resected specimens were interpreted as normal in one patient and consistent with nesidioblastosis in the second. Both patients subsequently developed recurrent symptomatic hyperinsulinemic hypoglycemia that persisted despite dosage adjustments in diazoxide therapy. The oldest patient underwent a 95 per cent pancreatectomy at the initial surgical exploration because an insulinoma could not be identified. The other patients underwent a completion 95 per cent pancreatectomy. In both, histochemical examination of each specimen disclosed nesidioblastosis, characterized by clusters of islet cells interspersed throughout the exocrine tissue.

Adult↗
PubMed1988

Pheochromocytoma multisystem crisis. A surgical emergency.

Three of 27 patients treated for pheochromocytoma between 1974 and 1987 presented with pheochromocytoma multisystem crisis (PMC). This unusual presentation consists of multiple organ system failure, temperature often greater than 40 degrees C, encephalopathy, and hypertension and/or hypotension. Although urgent medical therapy achieved blood pressure control in all three patients, the other manifestations of PMC progressed rapidly in spite of alpha and even beta blockade. The first patient died during attempts to localize a septic focus. The other two patients underwent urgent adrenalectomy and had postoperative improvement in their multiple organ system failure. All three tumors were large and produced markedly elevated levels of epinephrine. In conclusion (1) PMC is an unusual presentation of pheochromocytoma; (2) its manifestations include multiple organ system failure, high fever, encephalopathy, and vascular lability; (3) it may result from increased epinephrine secretion; and (4) successful treatment of PMC demands prompt diagnosis, vigorous medical preparation, and emergency tumor removal if the patient's condition continues to deteriorate.

Adrenal Gland Neoplasms↗
PubMed1988

Pheochromocytoma crisis.

Of 26 patients with pheochromocytoma treated between 1974 and 1986, two presented with pheochromocytoma crisis. This unusual presentation consists of hyper- and/or hypotension, high fevers (greater than 40 degrees C), encephalopathy, and multiple organ system failure. Both patients had large tumors associated with markedly elevated levels of epinephrine. Although hypertension was adequately controlled in both patients with phenoxybenzamine, phentolamine (1 patient) and nitroprusside, both patients deteriorated rapidly. The first patient expired during attempts to identify a source of sepsis. None was found at autopsy. The second patient underwent urgent adrenalectomy which reversed the multiple organ system failure and resulted in patient survival. We conclude from review of these patients and three others in the literature that (a) crisis is an unusual presentation of pheochromocytoma; (b) its manifestations include vascular lability, high fever, encephalopathy and multiple organ system failure; (c) it may be the result of increased epinephrine secretion; (d) successful treatment of pheochromocytoma crisis demands prompt diagnosis, vigorous medical therapy and emergent tumor removal if the patient continues to deteriorate.

Adrenal Gland Neoplasms↗
PubMed1988

Insulinoma and abdominal tuberculosis.

A patient is described in whom active abdominal tuberculosis was discovered during an exploratory laparotomy for a suspected insulinoma.

Adenoma, Islet Cell↗
PubMed1986

Modulation of fluoropyrimidine metabolism by chlorpromazine.

Chlorpromazine is a potent inhibitor of calmodulin and can alter the accumulation, metabolism, and incorporation into RNA of several fluoropyrimidine drugs. Using S-180 murine sarcoma cells, the accumulation of the base Fluorouracil and its metabolism to ribonucleotides is enhanced by chlorpromazine treatment, as measured by HPLC. In contrast, the accumulation and metabolism of the nucleoside Fluorouridine was suppressed by chlorpromazine. Cytotoxicity studies revealed that non-toxic concentrations of chlorpromazine were synergistic with Fluorouracil, but were antagonistic with Fluorouridine. These findings suggest that modulation by chlorpromazine of specific nucleoside kinase involved in Fluorouracil metabolism can result in increased therapeutic utility.

Animals↗