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Biomedical subjects

C F Gonzalez

Publications and source records attributed to C F Gonzalez.

At least 37 records · Page 2Linked to original sources
PubMed1986

Intracranial calcification in adults with chronic lead exposure.

Computed tomographic (CT) findings of cerebral and cerebellar calcification are described in three American adults with raised serum lead levels and known exposure to lead for 30 or more years. Calcification patterns were punctiform, curvilinear, speck-like, and diffuse and were found in the subcortical area, basal ganglia, vermis, and cerebellum. Admission serum lead levels ranged from 54 to 72 micrograms/dl (normal, 0-30 micrograms/dl). Nonspecific neurologic manifestations consisted of dementia, diminished visual acuity, peripheral neuropathy, syncope, dizziness, nystagmus, easy fatigue, and back pain. Two patients developed chronic renal disease and hypertension; in both cases, serum parathormone was elevated. Blood, calcium, and phosphorus were normal in all three. No other structural abnormalities were observed with CT. Although the pathophysiologic mechanism of these findings remains poorly understood, it is suggested that chronic lead exposure should be included in the differential diagnosis of unexplained intracranial calcifications in adults.

Brain Diseases↗
PubMed1986

Extracranial vascular angiography.

Noninvasive procedures (ultrasound, CT, and MRI) are increasingly valuable in the diagnosis of diseases of the head and neck. Angiography, however, is still essential in the demonstration of vascular pathology, including the preoperative evaluation of vascular neoplasms. Through angioplasty and embolization techniques, angiography also plays a leading role in the treatment of arteriosclerotic vascular disease, vascular malformations, and vascular neoplasms.

Angiography↗
PubMed1986

Fluorocarbon emulsion as a potential contrast medium in the subarachnoid space and brain tissue. Experiments in cats.

Ventriculosubarachnoid perfusion with oxygenated fluorocarbon emulsion has been used in the treatment of severe cerebral ischemia in cats. The perfusion vehicle is prepared mimicking cerebrospinal fluid in terms of electrolyte content, osmolality, pH, glucose and amino acids. Fluorocarbon emulsion is prepared with the vehicle as the external phase and charged with high partial pressures of oxygen. This fluorocarbon emulsion has been well-tolerated by the central nervous system. In addition to delivering oxygen to the ischemic tissues via the ventriculosubarachnoid space, the fluorocarbon emulsion has an absorption coefficient higher than normal brain and cerebrospinal fluid. This property makes it easily detected on the CT scan. Determination of appearance, attenuation, distribution, and absorption of the fluorocarbon has been performed in cats after direct intraventricular injection of the substances and after perfusion of the emulsion. The results of these experiments stress the possibility of using a fluorocarbon emulsion as a potential contrast medium in the brain and subarachnoid space, particularly after brain anoxia.

Animals↗
PubMed1985

Transfer of Sucrose-Fermenting Ability and Nisin Production Phenotype among Lactic Streptococci.

Transfer of sucrose fermentation ability, nisin production, and nisin resistance from Streptococcus lactis to S. lactis and Streptococcus lactis subsp. diacetylactis occurred between cells immobilized on nitrocellulose filters in the presence of DNase. Transconjugants were able to act as donors to transfer the Suc-Nis phenotype in subsequent mating. No changes in sensitivity to lytic phage c2 were noted in S. lactis transconjugants. However, temperature-independent restriction of lytic phage 18-16 was noted in transconjugants of S. lactis subsp. diacetylactis 18-16. Adsorption studies with phage-resistant transconjugants showed that resistance was not due to lack of adsorption by the lytic phage. Physical evidence for the presence of introduced plasmid DNA was not found in lysates of transconjugants.

Journal Article↗
PubMed1983

Iron-chelating compounds produced by soil pseudomonads: correlation with fungal growth inhibition.

Strains of Pseudomonas putida, Pseudomonas sp., and Pseudomonas aeruginosa were examined for their ability to grow in the presence of the iron chelator, ethylenediamine-di-(o-hydroxyphenylacetic acid). In vitro fungal inhibition assays showed that the isolates varied in their ability to inhibit the growth of representative fungal plant pathogens. Fungal inhibition in vitro was superior to that of previously reported Pseudomonas sp. Studies with Fusarium oxysporum forma sp. lycopersici and a susceptible tomato cultivar demonstrated that Pseudomonas putida PPU3.1 was able to significantly reduce wilt disease.

Journal Article↗
PubMed1983

Plasmid transfer in Pediococcus spp.: intergeneric and intrageneric transfer of pIP501.

Transfer of the broad-host-range resistance plasmid pIP501 from Streptococcus faecalis to Pediococcus pentosaceus and Pediococcus acidilactici occurred between cells immobilized on nitrocellulose filters in the presence of DNase. Expression of the pIP501-linked erythromycin and chloramphenicol resistance determinants was observed in transconjugants. Intrageneric transfer of pIP501 from a P. pentosaceus donor to various pediococcal recipients occurred at frequencies of 10(-4) to 10(-7) transconjugants per input donor cell. Intergeneric transfer of plasmid pIP501 from P. pentosaceus to S. faecalis, Streptococcus sanguis (Challis), and Streptococcus lactis was observed. Similar mating experiments showed no evidence for the transfer of the broad-host-range R-plasmid pAM beta 1 to Pediococcus spp. recipients.

Anti-Bacterial Agents↗
PubMed1982

Malignant lymphoma of the nervous system.

The radiological findings in 22 patients with malignant lymphoma of the nervous system are reviewed in relation to the clinical and histological features. The radiological findings were grouped into four major categories: intracranial, orbital, nasopharyngeal, and spinal. A fifth category, complications, was considered separately. The common neuroradiological manifestations of nervous system lymphoma are reviewed and compared with the recent literature.

Adolescent↗
PubMed1982

Plasmid content of some oral microorganisms isolated from subgingival plaque.

Eighty-five strains of bacterial species selected from the predominant cultivable dental plaque flora of patients with different periodontal pathologies were examined for their plasmid content. Microorganisms studied included: Actinomyces viscosus, A. odontolyticus, Bacteroides asaccharolyticus (B. gingivalis), B. melaninogenicus subspecies intermedius, and subspecies melaninogenicus, Capnocytophaga ochracea (B. ochraceus), and Fusobacterium nucleatum. Three B. melaninogenicus isolates showed plasmids of approximately 2.7-2.9 Mdalton (mega-dalton) molecular size. Restriction enzyme digests of the plasmids demonstrated dissimilar patterns when electrophoresed on agarose gels. In other microorganisms, including the Actinomyces species, plasmids were not observed.

Actinomyces↗
PubMed1979

Bacteriocin, plasmid and pectolytic diversity in Pseudomonas cepacia of clinical and plant origin.

Pseudomonas cepacia strains of plant and clinical origin were compared with the type strains of P. cepacia, P. kingii and P. multivorans. Conventional biochemical tests and antibiotic sensitivity patterns supported the previous proposals of synonymy between P. cepacia, P. kingii and P. multivorans. However, bacteriocin production patterns, onion maceration tests and hydrolysis of low pH pectate agar clearly differentiated strains of clinical and plant origin into two distinct groups; these tests may therefore be helpful in epidemiological studies. In contrast, plant and clinical strains were of equal lethality to mice. Agarose gel electrophoresis indicated the presence of one or more plasmids (molecular weights 9 X 10(6) to 120 X 10(6)) in 15 out of 16 strains of both types examined.

Animals↗
PubMed1978

The CT scan appearance of the brain in the normal elderly population: a correlative study.

Atrophy of the brain as depicted on CT scan was correlated with social and psychological testing in 100 selected volunteers with no known neurologic or psychiatric impairment. The data indicated cognitive impairment based on psychometric test results in those with atrophy, independent of its severity. No organic or biochemical changes could be found that could explain these findings. Repeat examinations at 1-year intervals are planned to evaluate the evolution of these findings.

Aged↗
PubMed1977

Ultrastructure of bacteriophage phi 6: arrangement of the double-stranded RNA and envelope.

Pseudomonas phaseolicola cells synchronously infected with phi 6 were fixed and embedded by several procedures. The diameter of phi 6 measured 75 nm and its nucleocapsid 60 nm. Virus nucleocapsids were icosahedral and surrounded by a double membrane. In planar sections the nucleic acid appeared as a hexagonal ring and in cross section as two angular structures.

Bacteriophages↗
PubMed1975

Computerized transaxial tomography in the evaluation of patients with focal epilepsy.

Computerized transaxial tomography was carried out on 50 consecutive unselected patients referred to a neurologic practice for evaluation of focal epilepsy. Structural abnormalities were defined in 35.3 percent of these studies: porencephalic cysts in six patients, diffuse cerebral atrophy in five, cerebral hemiatrophy in three, focal cortical atrophy in two, neoplasms in two, hydrocephalus in one patient, and cerebeller hypoplasia in one. Computerized transaxial tomography is a useful outpatient procedure for evaluation and follow-up of patients with focal seizure disorders.

Adolescent↗
PubMed1972

Biodegradation of ethylene glycol by a salt-requiring bacterium.

A gram-negative nonmotile rod which was capable of using 1,2-(14)C-ethylene glycol as a sole carbon source for growth was isolated from a brine pond, Great Salt Lake, Utah. The bacterium (ATCC 27042) required at least 0.85% NaCl for growth and, although the chloride ion was replaceable by sulfate ion, the sodium ion was not replaceable by potassium ion. The maximal concentration of salt tolerated for growth was approximately 12%. The bacterium was oxidase-negative when N,N-dimethyl-p-phenylenediamine was used and weakly positive when N,N,N',N'-tetramethyl-p-phenylenediamine was used. It grows on many sugars but does not ferment them, it does not have an exogenous vitamin requirement, and it possesses a guanine plus cytosine ratio of 64.3%. Incorporation of ethylene glycol carbon into cell and respired CO(2) was quantitated by use of radioactive ethylene glycol and a force-aerated fermentor. Glucose suppressed ethylene glycol metabolism. Cells grown on ethylene and propylene glycol respired ethylene glycol in a Warburg respirometer more rapidly than cells grown on glucose. Spectrophotometric evidence was obtained for oxidation of glycolate to glyoxylate by a dialyzed cell extract.

Alcohol Oxidoreductases↗