Search PubMed⌕ Search

Biomedical subjects

C Johnson

Publications and source records attributed to C Johnson.

At least 415 records · Page 23Linked to original sources
PubMed1987

'Metrical' factors in the scaling of sentence-initial accent peaks.

Past studies of declination make contradictory claims about the relationship between the length of an utterance and the height of its first accent peak (P1): Some find a large increase in P1 with increased length, others find little or no increase. A possible explanation for this contradiction is that large increases in P1 occur when the first major constituent of the sentence increases from one accented item to more than one, but not as a function of overall length alone. In an experiment, 1 of 2 speakers behaved in the way just outlined; data from the 2nd speaker supported the more general hypothesis that 'metrical' constituent structure is relevant to P1.

Humans↗
PubMed1987

Oligoclonal IgG in tears.

We examined tears from patients with MS and systemic or eye diseases, and normal controls. Tears were isoelectrofocused on agarose gel, silver-stained, and immunofixated for IgG. In the cathodal portion of the gel (pH greater than or equal to 8.3), oligoclonal bands were detected in 14 of 21 (67%) MS tear samples. In most cases, these bands were not present in serum. Only 1 of 26 non-MS subjects showed two faint IgG tear bands, which were strongly present in serum. It appears that oligoclonal IgG bands can be detected in tears as well as in CSF of MS patients.

Adolescent↗
PubMed1987

Reaction of 1-amino- and 1-chlorophthalazine with mammalian molybdenum hydroxylases in vitro.

1-Amino- and 1-chlorophthalazine were tested for possible substrate activity with partially purified rabbit-liver aldehyde oxidase and bovine-milk xanthine oxidase. 1-Chlorophthalazine was a more efficient substrate than the parent compound, phthalazine, with either aldehyde oxidase or xanthine oxidase. The oxidation product of 1-chlorophthalazine was identified as 4-chloro-1-(2H)-phthalazinone on the basis of chromatographic, infra-red and mass-spectral data. 1-Aminophthalazine was oxidized by aldehyde oxidase to 4-amino-1-(2H)-phthalazinone but was a competitive inhibitor of xanthine oxidase. Kinetic studies at different pH values indicated that, in each case, it is the unprotonated form of 1-aminophthalazine that reacts with the molybdenum hydroxylases.

Aldehyde Oxidase↗
PubMed1987

HRE 664, a new parenteral penem. II. Evaluation of the pharmacokinetic behavior and the chemotherapeutic activity in animals.

The pharmacokinetic and chemotherapeutic properties of the new penem antibiotic HRE 664 (Fig. 1) were evaluated in experimental animals. High and sustained blood and serum levels were achieved following parenteral injection in mice, rats, dogs and monkeys. Half-lives ranged from 27 to 40 minutes in the various species tested. The antibiotic was well distributed in the rodents and penetrated well into tissues and body fluids. At 30 minutes after subcutaneous administration to mice (50 mg/kg), concentrations of between 12.4 and 35.9 micrograms/g were measured in the lungs, liver, heart and kidneys, that is 33 approximately 95% of the corresponding level in murine blood (37.7 micrograms/ml). In experimentally induced infections in mice, HRE 664 displayed good chemotherapeutic activity particularly against septicemias caused by methicillin-sensitive and methicillin-resistant Staphylococcus aureus strains and on abscess formation induced by Bacteroides fragilis. Most of the cephalosporins and other beta-lactam antibiotics exhibited low efficacy against these strains of bacteria.

Abscess↗
PubMed1987

Phase II trial of aminothiadiazole in previously treated and untreated patients with advanced colorectal carcinoma: an Illinois Cancer Council Trial.

Eighty-three patients with advanced colorectal carcinoma were entered on a phase II trial of weekly iv aminothiadiazole (125 mg/m2) plus daily oral allopurinol (300 mg). There were five partial responses. Median survival of all patients on study was 36 weeks from entry (48 weeks for those without prior therapy and 34 weeks for those with previous chemotherapy). Toxicity was generally mild and consisted predominantly of stomatitis. In the dose given, aminothiadiazole has limited activity against metastatic colorectal cancer.

Clinical Trials as Topic↗
PubMed1987

Cutaneous microthrombi: a histologic clue to the diagnosis of hypereosinophilic syndrome.

Hypereosinophilic syndrome is a rare systemic disease that frequently has cutaneous lesions. Past reviews of the histopathology of the skin lesions have revealed a nonspecific dermal infiltrate with occasional eosinophils as a constant finding. A case of hypereosinophilic syndrome with cutaneous manifestations, in which the skin biopsy demonstrated multiple cutaneous microthrombi, is reported. The diagnostic and prognostic significance of this finding is discussed.

Diagnosis, Differential↗
PubMed1986

Use of four monoclonal antibodies to detect tumor markers.

A combined panel of monoclonal antibodies to tumor markers was examined in the sera of 454 cancer patients to compare their reactivity. At least one of the four tumor-associated markers (CEA [caranoembryonic antigen], CA 19-9, CA 125, and SLEX [sialylated Lewisx epitope]) was positive with the sera of breast (43%), lung (64%), ovarian (54%), and colorectal (57%) cancer. Each tumor marker's reactivity was distinct in different patients, indicating that different epitopes were being detected. The number of tumor markers that were positive was associated with advancing stages of disease. In advanced stages with distant metastasis, 13% of the patients reacted with all four markers, whereas none of the early-stage patients did. In 14 cases of disease progression, the tumor markers increased with no instance of decrease. Among ten patients with regression, seven showed a decrease in tumor markers and three showed an increase. The authors conclude that the use of four tumor-associated markers expands the number of patients with a positive marker, thereby permitting the monitoring of some patients. Among 60 normals, one showed a weak reactivity with CEA and one with CA 125. Eventually, with more markers, it should be possible to monitor all patients.

Adult↗
PubMed1986

Effects of an ATP site affinity analog on some conformational and enzymatic properties of the canine kidney (Na+ + K+)-ATPase.

We have shown previously that the canine kidney Na+,K+ pump [Na+ + K+)-ATPase) reacts with the ATP affinity analog p-fluorosulfonylbenzoyladenosine (FSBA). At 20 degrees C, we find the time-course of this reaction to be that predicted for a first-order reaction accompanied by competing solvolysis of the reagent. The FSBA-inactivated (Na+ + K+)-ATPase retains the ability to move between the E1 and E2 conformations that predominate in Na+ and K+ medium, respectively. Therefore, FSBA reaction with the enzyme does not interfere significantly with either its alkali metal cation binding or its conformational freedom. The ability of ATP to influence the enzyme's conformation by binding to the high-affinity nucleotide site is decreased, however, in proportion to the degree of inhibition of enzyme activity by FSBA. In addition, the ability of the enzyme to shift from the E1 to the E2 conformation through the (ATP + Na+)-dependent phosphorylation cycle is inhibited by FSBA treatment, as shown by the decreased ability of these substrates to stimulate the K+-dependent p-nitrophenylphosphatase activity. Both of these effects are consistent with specific reaction of FSBA with the ATP binding site of the enzyme. An additional effect of FSBA treatment is that it causes loss of p-nitrophenylphosphatase activity, but to a lesser extent than (Na+ + K+)-ATPase or Na+-ATPase activity. Binding of p-nitrophenylphosphate to the enzyme is apparently unaffected by FSBA treatment, since the Km for p-nitrophenylphosphate is not changed.

4-Nitrophenylphosphatase↗
PubMed1986

Interleukin-1 production and antigen presentation by normal human peritoneal macrophages.

Human peritoneal macrophages from healthy females have been investigated for their capability to produce interleukin-1 (IL-1), their expression of HLA-DR and -DQ, and for their antigen-presenting capacity in concanavalin A, tetanus toxoid (TT), and autologous T-cell proliferative responses. Fifteen out of thirty macrophage populations produced IL-1 but the activity was 1/5 to 1/10 that of peripheral blood mononuclear cells stimulated under similar conditions. High levels of HLA-DR were expressed on all macrophages while lower and more variable levels of DQ were found. All macrophages induced mitogen-dependent T-cell proliferation while the ability to induce a proliferative response to TT was variable, 12/23 tests were positive. In five samples stimulatory capacity of macrophages in the absence of TT was as strong as in the presence of the stimulus, suggesting that in vivo processed immunogen could be responsible for the proliferative response. The surface density of HLA-D-region-determined antigens was not indicative of the macrophages' ability to induce antigen-specific proliferation. IL-1 production, however, correlated with this function. Antigen presentation was not confined exclusively to peritoneal populations consisting of recently immigrant monocyte-like cells, nor were all young macrophages able to present antigen. This may reflect on the diversion of macrophage function by the local environment.

Antigen-Presenting Cells↗
PubMed1986

Rewarming in immersion hypothermia: radio-wave and inhalation therapy.

Anesthetized random source dogs were cooled by ice water immersion (1 degree C) to a stable core temperature of 25 degrees C, and subsequently rewarmed with warm humidified inhalation (43 degrees C, 450 cc of min ventilation/kg), radio wave induction hyperthermia (4-6 W/kg) or both therapies simultaneously. The mean time required for core rewarming to 30 degrees C was 262 +/- 29 min for humidified ventilation, 68.5 +/- 6 min for radio wave therapy (P less than 0.01), and 74.8 +/- 12 for both therapies combined (P less than 0.3 vs. radio wave). There was no tissue damage with these protocols. These data suggest radio wave heating alone is the most rapid non-invasive method for core rewarming in immersion hypothermia.

Animals↗
PubMed1986

Diaphragm use and urinary tract infections: analysis of urodynamic and microbiological factors.

To investigate how diaphragm use predisposes to urinary tract infection we studied 22 women who experienced 1 or more urinary tract infections while using a diaphragm and 21 who used a diaphragm and did not have a urinary tract infection. For women with and without a prior urinary tract infection the mean peak urine flow rate was significantly less with than without a diaphragm. However, the mean decrease in peak urine flow rate with a diaphragm was not significantly greater for women with a prior urinary tract infection. There also was no significant increase in time to peak flow with the diaphragm in place. Women who reported a sensation of obstruction to voiding with a diaphragm demonstrated a significant decrease in peak urine flow rate and this finding was particularly apparent in those with a history of urinary tract infection in whom the peak urine flow rate decreased by an average of 10.0 ml. per second. Current users of a diaphragm with a history of urinary tract infection had heavier growth of coliform organisms from cultures of the vagina and urethra, and significantly more episodes of infection than women without such a history (p equals 0.03 and 0.05, respectively). We conclude that use of a diaphragm can cause urinary obstruction in some women but that the obstruction is of relatively small magnitude and does not correlate with the acquisition of a urinary tract infection. Changes in vaginal flora associated with diaphragm use may be of greater importance.

Adult↗
PubMed1986

Perceptual features from normal-hearing and hearing-impaired children's errors on the NST.

Perceptual features for consonants contained in the nonsense syllable test, were evaluated from normal-hearing and hearing-impaired children's errors. One group consisted of 30 normal-hearing children between 6:0 and 12:8 years of age; the other group consisted of 7 hearing-impaired children between 8:0 and 14:8. The subjects provided verbal responses to list A of the nonsense syllable test which was presented at 25, 35, 45, and 55 dB sensation levels regarding each subject's speech reception threshold. Responses were phonetically transcribed, pooled across sensation levels, converted to confusion matrices, and submitted to Symmetric Individual Differences Scaling. Consonants were analyzed for pre- and inter-vocalic positions. Results revealed that features differed across subject groups and consonant positions. Salient features related to place of articulation, voicing, nasality, sonorancy, and sibilancy.

Adolescent↗