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Biomedical subjects

D Griffin

Publications and source records attributed to D Griffin.

At least 73 records · Page 4Linked to original sources

Biologic response (antiviral) to recombinant human interferon alpha 2a as a function of dose and route of administration in healthy volunteers.

The kinetics of the antiviral effect of intramuscular and intravenous injections of recombinant human interferon alpha 2a were investigated in healthy volunteers. Cohorts of eight to 11 subjects received single intramuscular injections of either 0.3 X 10(6), 3 X 10(6), or 18 X 10(6) U or an intravenous infusion of 18 X 10(6) U over 30 minutes. Serial samples of peripheral blood mononuclear cells were analyzed for antiviral effects including both (2'-5') oligoadenylate synthetase activity and resistance to vesicular stomatitis virus infection in vitro. A dose-response relationship was established between recombinant human interferon alpha 2a dose and both vesicular stomatitis virus resistance and (2'-5') oligoadenylate synthetase activity. At the 0.3 X 10(6) U dose an antiviral effect occurred without clinical side effects. The presence of clinical side effects is not necessary for an antiviral effect.

2',5'-Oligoadenylate Synthetase↗

Correlation of angiographic abnormalities with disease manifestations and disease severity in polyarteritis nodosa.

We evaluated angiograms of 26 patients with polyarteritis nodosa (PAN) as well as the associated clinical and laboratory features. All patients had visceral angiograms and either biopsy or angiographic proof of PAN. Severe disease was defined as central nervous system PAN, renal failure requiring dialysis, gangrene of fingers or toes, cardiomyopathy, bowel infarction, hepatic failure, or hepatic infarction. The presence of aneurysms was associated with severe hypertension, hepatitis B surface antigenemia and clinically severe disease. Angiography may therefore identify a subset of patients with more severe involvement and may be of value in management decisions.

Adolescent↗

The differential prenatal diagnosis of cystic hygromata and encephalocele by ultrasound examination.

The difficulty in distinguishing an encephalocele from a cystic hygroma has recently been highlighted by five patients referred to our unit with an incorrect diagnosis of cystic hygroma. A review of the literature revealed four other cases of misdiagnosis. Based on review of 46 patients with one or other diagnosis, we have attempted to establish guidelines to aid diagnosis. We have always been able to identify the bony defect in the fetal vault in cases of encephaloceles. The pattern of the septa is usually characteristic in cystic hygroma.

Diagnosis, Differential↗

Positive and electron capture negative ion methane chemical ionization mass spectrometry of pyrrolizidine alkaloids.

Pulsed positive and negative ion methane chemical ionization mass spectrometry of pyrrolizidine alkaloids is reported. Positive ion spectra are characterized by a high relative abundance of [MH]+ ions while the negative ion spectra exhibit ion peaks due to dissociative electron capture. Fragmentation in both positive and negative ion spectra primarily occurs at the ester groups with the positive charge residing with the pyrrolizidine ring system while the negative charge in contrast tends to reside with the necic acid moiety. Esterification at C-9 v. C-7 can be distinguished for non-cyclic esters of retronecine in the positive ion spectra.

Chemical Phenomena↗

Doppler blood flow waveforms in the descending thoracic aorta of the human fetus.

A linear-array pulsed Doppler duplex has been used to study third-trimester Doppler flow velocity waveforms (FVW) in the descending thoracic aorta of 98 normal and 20 severely growth-retarded fetuses. Waveforms have been normalized (frequency index profile; FIP) to remove the effect of the angle of insonation and so allow comparison at different gestational ages and with complicated pregnancies. There is an increase in end-diastolic velocities with advancing gestational age indicating a reduction in placental resistance. The growth-retarded fetuses showed a significant reduction in end-diastolic velocities and an increase in the pulsatility index (normal PI: mean 1.83, SD 0.22; growth-retarded PI: mean 2.78, SD 0.60). This reduction of diastolic blood flow may indicate reduced placental vascularity and predict impending fetal hypoxia.

Aorta, Thoracic↗

Monoclonal antibodies that distinguish between subspecies of human interferon-alpha and that detect interferon oligomers.

Monoclonal antibodies to human interferons (HuIFN) of the alpha-class have been prepared by screening against 125I-labeled IFN in a rapid liquid-phase radioimmunoassay. All of the six antibodies produced react with HuIFN-alpha 2 and with some components of HuIFN-alpha N (Namalwa); three of the antibodies also bind HuIFN-alpha 1, and these either do not bind or bind very weakly the 25K component of Namalwa. Reaction of the antibodies with IFN components blotted onto nitrocellulose after separation on reducing gels suggests that two of the antibodies are against conformational determinants, whereas the epitopes recognized by the other antibodies are not destroyed by reduction or SDS treatment; these antibodies can be used to detect the presence of oligomers in IFN preparations. From the reaction of the antibodies with different alpha-IFN in immunoblots, in an antiviral assay, and in an ELISA, it was concluded that at least five different epitopes are recognized by the six antibodies, only one of which is non-neutralizing.

Animals↗

Biosynthesis of abscissic acid.

The fungus Cercospora rosicola has been studied as a model system for abscissic acid biosynthesis. 1'-dDeoxyabscissic acid and 4'-hydroxy-a-ionylidene acetic acid have been identified as endogenous compounds in this fungus. The results of feeding these and other putative intermediates suggest that abscissic acid biosynthesis proceeds via the successive oxidations of a 3-methyl-5-(2',6',6'-trimethylcyclohex-2'-en-1'-yl)-2,4-pentadienyl intermediate. Preliminary results suggest that a similar pathway may operate in plants.

Abscisic Acid↗

Wheat pasture poisoning. II. Tissue composition of cattle grazing cereal forages and related to tetany.

Thirty-two aged Hereford and Angus cows (avg 10.2 yr old) grazed mixed cereal (wheat and rye) pastures from December 6, 1979 to April 23, 1980 (138 d). On d 104 (March 19), five cows developed tetany. On the day of tetany, the mean plasma Ca of the cows with tetany was 4.1 mg/dl. Cows with tetany had plasma Mg concentrations of 1.7 mg/dl on the day of tetany, but 15 d before tetany and 6 d post-tetany, levels were lower (1.2 mg/dl). Cows with tetany had large increases in plasma parathyroid hormone (PHT) as well as vitamin 1, 25 dihydroxy D3 [1,25(OH)2D], plasma glucose, lactic acid and beta-hydroxybutyric acid. Plasma K of these cows followed a similar trend as plant K, except it was not as pronounced. Plasma inorganic P of these same cows was exceedingly low, less than 3 mg/dl several times, although the forage P did not indicate a P deficiency. Levels of plasma hydroxyproline in these cows indicated that bone resorption may have been low during most of the grazing season, even though levels of plasma hydroxyproline were initially high and high subsequent to tetany. High levels of plasma glucose and lactic acid were associated with the time of tetany. Apparently, cows developed inappetence around the time of tetany, as suggested by the high levels of plasma beta-hydroxybutyric acid. Cows with wheat pasture poisoning appeared to respond to the severe hypocalcemia with large increases in plasma 1,25(OH)2D. Plasma 1,25(OH)2D changes were similar to plasma hydroxyproline changes (and possible bone resorption rates) and seemed inversely proportional to plasma Ca and directly proportional to plasma PTH concentrations. Generally, cerebrospinal fluid (CSF) composition was not affected as much as plasma composition, except for the low levels of CSF Ca. These data indicate that a metabolic deficiency of Ca (hypocalcemia) was the cause of tetany.

3-Hydroxybutyric Acid↗

Self-healing reticulohistiocytosis: a clinical, histologic, and ultrastructural study of the fourth case in the literature.

A case of self-healing reticulohistiocytosis is reported. Our case differed from those previously reported in that tumors developed 17 days after birth (instead of at birth) and all tumors disappeared rapidly within three weeks (instead of two to three and one-half months). Hematologic abnormalities such as absolute neutropenia, marked lymphocytosis with many atypical cells, and atypical monocytes in bone marrow in association with this disease have not previously been reported. The patient had palpable liver which persisted with absolute neutropenia for about a month. The diagnosis of self-healing reticulohistiocytosis was confirmed by characteristic histology and by the demonstration of Langerhans' cells with typical granules in the tumor cells.

Bone Marrow↗

Obstructive apneas during sleep in patients with seasonal allergic rhinitis.

The possible role of high nasal airway resistance in the pathogenesis of obstructive sleep apnea has been examined in 7 patients with seasonal (ragweed) allergic rhinitis, a naturally occurring model of reversible nasal obstruction. Measurements of nasal resistance and overnight polysomnographic studies were performed during the ragweed season when the patients complained of nasal obstruction; and 6 to 8 wk later when the symptoms had subsided (control study). During the symptomatic phase, mean (+/- SE) nasal resistance was 4.9 +/- 0.8 cm H2O/L/s, and the patients experienced 1.7 +/- 0.3 obstructive apneas per hour of sleep. In contrast, at the time of the control study, nasal resistance had decreased to 2.5 +/- 0.3 cm H2O/L/s (p less than 0.01); and the rate of obstructive apneas had decreased to 0.7 +/- 0.4 per hour of sleep (p less than 0.005). The duration of these apneas had also decreased from 15.5 +/- 0.8 s to 6.1 +/- 2.9 s (p less than 0.01). Apneas were rarely associated with significant O2 desaturation and were fewer in number than typically seen in a clinically significant sleep apnea syndrome. In male patients there was a direct relationship (r = 0.9) between the change in nasal resistance from symptomatic to control studies and the corresponding change in frequency of obstructive sleep apneas. Coincident with these respiratory changes at the time of the control study was an increase in the amount of slow-wave sleep (p = 0.05) and a small reduction in the frequency of arousals during sleep (p = NS). We conclude that in patients with allergic rhinitis, obstructive sleep apneas are longer and more frequent during a period of symptomatic nasal obstruction than when symptoms are absent. The results support the concept that a high nasal resistance may be a contributing factor in the pathogenesis of obstructive sleep apneas in general.

Adult↗

Antifertility effects of immunization of female baboons with C-terminal peptides of the beta-subunit of human chorionic gonadotropin.

Fifteen adult female baboons were immunized with a conjugate of tetanus toxoid coupled with a synthetic carboxy-terminal peptide of the beta-subunit of human chorionic gonadotropin and another 15 were immunized with tetanus toxoid. Freund's complete adjuvant was used in all immunizations. All females were placed with males of proven fertility during the third menstrual cycle after the primary immunization and those not sustaining pregnancy were mated in two additional consecutive cycles. Four pregnancies occurred following 42 matings in the conjugate-immunized group and 15 pregnancies resulted from 21 matings in the tetanus toxoid-immunized animals. Low levels of antibodies reactive to baboon chorionic gonadotropin were found in the pregnant animals in the conjugate-immunized group.

Animals↗

Anthelmintic efficacy of low-dose phenothiazine against strains of sheep nematodes susceptible or resistant to thiabendazole, levamisole and morantel tartrate: effect on patent infections.

The anthelmintic efficacy of low-dose phenothiazine therapy, administered as a 1:40 phenothiazine: molasses mixture, was tested against patent infections of strains of Haemonchus contortus, Trichostrongylus colubriformis and Ostertagia spp susceptible or resistant to thiabendazole (an other benzimidazoles), levamisole and morantel tartrate. Phenothiazine reduced faecal egg output for both susceptible and resistant strains of all three nematodes. In daily doses of 0.25 g per sheep per day and above it completely inhibited larval production in susceptible strains. Against resistant strains, there was a reduced efficiency with 82.3 per cent inhibition of egg hatch at the 0.25 g per sheep per day level. Phenothiazine treatment had no significant effect on worm numbers for either susceptible or resistant worms. It is suggested that benzimidazole-resistant strains may be cross-resistant to phenothiazine.

Animals↗

Anthelmintic efficacy of low-dose phenothiazine against strains of sheep nematodes susceptible or resistant to thiabendazole, levamisole and morantel tartrate: efficiency against sequentially administered infections.

Low-dose daily phenothiazine therapy, administered as a 1:40 phenothiazine:molasses mixture, was tested against sequential infections of strains of Haemonchus contortus. Trichostrongylus colubriformis and Ostertagia spp susceptible or resistant to thiabendazole, levamisole and morantel tartrate. Phenothiazine at a dose rate of 0.5 g per sheep per day significantly reduced the numbers of worm eggs per gram of faeces in both susceptible and resistant strains by an average of 48 per cent and 60 per cent respectively. Phenothiazine completely inhibited larval production in susceptible strains. With resistant worms, larval production was depressed by up to 85.7 per cent. Treatment with phenothiazine : molasses mixture reduced the numbers of worms which became established in resistant Ostertagia spp and susceptible T colubriformis but had no effect on the establishment of susceptible H contortus and Ostertagia spp or resistant H contortus and T colubriformis.

Administration, Oral↗