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Biomedical subjects

M E Baker

Publications and source records attributed to M E Baker.

At least 163 records · Page 9Linked to original sources
PubMed1986

Effect of anatomic variations on deep venous thrombosis of the lower extremity.

Three hundred thirty-seven lower extremities of 256 patients, both symptomatic and asymptomatic, underwent ascending positive contrast venography. Certain anatomic variations were noted to be related to the location and development of deep venous thrombosis (DVT). The thrombus was located entirely in the calf in 44% of asymptomatic limbs and 17% of symptomatic ones (p less than 0.001). There were multiple superficial femoral veins (SFVs) in 31% of the limbs examined, and 40% of those limbs had DVT. This percentage (40%) represented a statistically higher incidence of DVT (p less than 0.001) than those limbs with a single SFV, where the incidence was only 19%. When limbs with multiple SFVs had DVT, only 41% were symptomatic, whereas in those with a single SFV, 72% of the limbs were symptomatic (p less than 0.001). This difference may be the result of internal collaterals due to multiple SFVs. When there were more than five valves in the deep veins between the popliteal fossa and the ischial spine, there was a higher incidence of DVT (35%) as compared to the incidence when there were five or fewer valves (13%) (p less than 0.001).

Humans↗
PubMed1986

CT evaluation of retroperitoneal hemorrhage associated with femoral arteriography.

CT was used to assess retroperitoneal hemorrhagic complications temporally related to femoral artery catheterization in eight patients. In six patients with retroperitoneal hemorrhage caused by an angiographic complication, CT showed a high-density soft-tissue mass originating at the inguinal vessels and extending into the ipsilateral retroperitoneal spaces. In the other two patients, CT not only excluded significant bleeding from the catheterized vessel but determined an alternative diagnosis (hematoma secondary to anticoagulation and pneumatosis intestinalis due to ischemic bowel). CT findings prompted surgery in three patients.

Adolescent↗
PubMed1986

A surprising increase in the affinity of estrogen for rat alpha-fetoprotein after it is treated with N-ethylmaleimide.

Incubation of rat alpha-fetoprotein (AFP) with mM concentrations of N-ethylmaleimide (MalNEt) at 22 degrees, pH7.8 for several hours yields a form of AFP with an equilibrium dissociation constant of 0.1 nM for estrone. This affinity for estrone is about 10 fold higher than that for untreated rat AFP. MalNEt-treated AFP still binds inhibitors and substrates of serine proteases suggesting that the binding of these compounds to AFP does not involve an interaction with a thiol group. MalNEt-treated AFP may be useful for studying the mechanism of estrogen action in vitro and in vivo, estrogen-protein interactions, and the functioning of AFP.

Amniotic Fluid↗
PubMed1986

Diagnostic imaging of abdominal fluid collections and abscesses.

With today's advanced technology, the clinician and radiologist have a number of techniques with which to evaluate the abdomen for fluid collections and/or abscesses. Three points are clear from the plethora of literature concerning this subject: the need to individualize the clinical and imaging approach to each patient suspected of an abnormal fluid collection or abscess, the need to individualize the imaging procedure based upon what is done best at the institution, and the need for percutaneous aspiration of all fluid collections for diagnosis. No single imaging test is totally sensitive or specific for the detection of an infected fluid collection. Overall, CT probably does provide the most accurate means to detect an intra-abdominal abscess. Because of this, and because it is less operator dependent than ultrasound, CT is used most often as the procedure of choice at our institution.

Abdomen↗
PubMed1985

Evidence that progesterone binding uteroglobin is similar to myosin alkali light chain.

Using a computer program designed to detect evolutionary relationships between proteins, I find that exon 2 of rabbit uteroglobin, a progesterone binder, and part of myosin alkali light chain have a comparison score that is 7.2 standard deviations higher than that obtained with a comparison of randomized sequences of these proteins. The probability (p) of getting this score by chance is less than 10(-12). This theoretical finding that these sequences are similar has led to the experimental finding that copper, calcium and the tranquilizer trifluoperazine, a calmodulin binding ligand, affect progesterone binding to uteroglobin.

Amino Acid Sequence↗
PubMed1985

The PDC-109 protein from bovine seminal plasma is similar to the gelatin-binding domain of bovine fibronectin and a kringle domain of human tissue-type plasminogen activator.

PDC-109, a protein of unknown function, is a major component of bovine seminal plasma. Using a computer program designed to detect evolutionary relationships between proteins, I find that the PDC-109 protein is similar to the gelatin-binding domain of bovine fibronectin and part of a kringle domain of human tissue-type plasminogen activator (t-PA). The computer-based comparison of the amino acid sequence of PDC-109 with that of the gelatin-binding domain of fibronectin and part of the second kringle domain of t-PA yields scores that are 15.5 standard deviations and 7.8 standard deviations higher, respectively, than were obtained with a comparison of randomized sequences of these proteins. The probability (p) of getting these scores by chance is less than 10(-50) and 3 X 10(-15), respectively. The similarity between the amino acid sequences of PDC-109 and the gelatin-binding domain in fibronectin and the kringle of t-PA suggests some approaches for identifying the functions of PDC-109. Both t-PA and the gelatin-binding domain of fibronectin have adhesive functions, and the gelatin-binding domain promotes viral transformation of fibroblasts in culture. These functions may be associated with the PDC-109 protein.

Amino Acid Sequence↗
PubMed1985

Human tissue-type plasminogen activator is related to albumin and alpha-fetoprotein.

Using a computer program designed to detect evolutionary relationships between proteins, I find that residues 72-110 of the mature sequence of human tissue-type plasminogen activator (t-PA) and 39 residues at the carboxy terminus of human albumin have a comparison score that is 8.8 standard deviation units higher than that obtained with a comparison of randomized sequences of these proteins. The probability (p) of getting this score by chance is approximately 10(-18), indicating that part of t-PA and albumin are derived from a common ancestor. I also find that alpha-fetoprotein, a relative of albumin is related to t-PA. Part of this region on t-PA has been previously shown to be related to epidermal growth factor. t-PA, albumin, alpha-fetoprotein, and epidermal growth factor have diverse biological activities. The finding that these proteins are related suggests some new approaches for studying their functions.

Amino Acid Sequence↗
PubMed1985

The association of neuroblastoma and myoclonic encephalopathy: an imaging approach.

Myoclonic encephalopathy is a unique clinical syndrome of infants and children that is associated with a neurogenic tumor of ganglion-cell origin in approximately half of cases. A review of the literature as well as our personal experience with two recent infants suggests an imaging approach that includes chest radiography and abdominal computed tomography (CT). Ultrasonography, neck CT, and chest CT myelography may be required in selected patients. An expedient clinical and imaging evaluation of infants and children with opsomyoclonus is important to detect those patients with neurogenic tumors.

Abdominal Neoplasms↗
PubMed1985

Sonography of post-cesarean-section bladder-flap hematoma.

A bladder-flap hematoma is an unusual complication of a lower-uterine transverse cesarean section. As a result of bleeding at the incision site, a hematoma forms between the bladder and lower uterine segment. The clinical, sonographic, and surgical findings in seven patients with this complication are described. In all, sonography showed a solid or complex mass of varying sizes interposed between the posterior bladder wall and the anterior uterine wall. Differentiation of a hematoma from an infected hematoma/abscess can be difficult, but the presence of air in the mass strongly suggests the latter. Sonography can detect this complication easily and accurately, and therefore significantly focus and guide therapy.

Adolescent↗
PubMed1985

Computed tomography of epithelial neoplasms of the anal canal.

Twenty-five patients with squamous-cell or cloacogenic carcinomas of the rectum were evaluated by computed tomography (CT). Seven patients were studied before and 19 after treatment. CT provided excellent definition of tumor extent, including local spread, lymph node involvement, and distant metastases. In one of seven pretherapy studies, CT findings significantly altered patient management. Tumor recurrence was correctly identified in 14 of 19 patients having posttherapy scans, although CT-guided biopsy was required to confirm the presence of malignancy in three cases. Four scans were false positive. Extensive soft-tissue stranding in the ischiorectal fossa and/or perirectal fat associated with a large focal mass occurred in all patients with local tumor recurrence. Stranding was also seen in all patients treated with radiation. CT is an excellent method for preliminary evaluation and follow-up of patients with anal epithelial neoplasms, facilitating rapid and effective management.

Adult↗
PubMed1985

Diethyl pyrocarbonate, a histidine selective reagent, inhibits estrogen binding to receptor protein in rat uterus cytosol.

We find that at pH 6.1 diethyl pyrocarbonate inhibits estrogen binding to its receptor protein in rat uterus. Hydroxylamine partially reverses this inhibition and estrogen partially protects its receptor protein from this inhibition. We suggest that the estrogen receptor protein in rat uterus contains a nucleophilic site that either overlaps or is near the estrogen binding site. Based on the pH of inhibition reaction, the receptor concentration in the experiment, and the partial reversal of the inhibition by hydroxylamine, we suggest that this site contains a histidine residue or possibly an unusually reactive tyrosine residue that is important for estrogen binding.

Animals↗
PubMed1984

Gossypol inhibits estrogen binding to rat alpha-fetoprotein.

We find that gossypol, a male anti-fertility compound, is a reversible competitive inhibitor of estrogen binding to rat alpha-fetoprotein (AFP). The Kd of gossypol for rat AFP is 1.75 microM, which is similar to gossypol's affinity for lactate dehydrogenase isozyme X, the putative site where gossypol exerts its anti-fertility effects. Reacting sodium cyanoborohydride with gossypol reduces its affinity for AFP, showing that intact aldehyde groups on gossypol are important for binding to rat AFP and indicating that gossypol is specifically inter-acting with a nucleophilic site on AFP that influences estrogen binding.

Animals↗
PubMed1984

Amino acid sequence homology between the C3 chain of rat prostatic steroid binding protein and human alpha 2-macroglobulin.

Using a computer program designed to detect evolutionary relationships between proteins, I find that exon 2 of the C3 chain of rat prostatic steroid binding protein has amino acid sequence homology with residues 1058-1119 of the protease inhibitor alpha 2-macroglobulin. This finding suggests interesting approaches for studying the functions of these proteins.

Amino Acid Sequence↗
PubMed1984

Chick oviduct progesterone receptor binding of 15 beta, 17-dihydroxyprogesterone and its analogues.

We have tested derivatives of progesterone obtained by fermentation with Aspergillus giganteus for relative binding affinity for the progesterone receptor of chick oviduct. Our studies show that hydroxyl and oxo substitutents at C-11 and C-15 of progesterone significantly decrease the hormone's affinity for the progesterone receptor. The loss in affinity on introduction of a C-15 hydroxyl in 17-hydroxyprogesterone is restored by acetylation to 15 beta-acetoxy-17 hydroxyprogesterone. The latter compound may have some potential as an in vivo agent.

Animals↗