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Biomedical subjects

H W Puffer

Publications and source records attributed to H W Puffer.

At least 19 recordsLinked to original sources
PubMed1984

Oxygen consumption rates of grunion (Leuresthes tenuis) embryos exposed to the petroleum hydrocarbon, benzo[a]pyrene.

Bioconcentration of [14C]benzo[a]pyrene and effects of unlabeled benzo[a]pyrene (BaP) accumulation on the routine oxygen consumption of embryonic grunion (Leuresthes tenuis) were studied. At Day 15, bioconcentration factors over dissolved BaP levels ranged from 249 to 466. Weight-specific respiration rates at Days 14-15 were significantly increased (P less than or equal to 0.05) at a mean BaP body burden of 0.51 ppm wet wt. Oxygen consumption rates of embryos containing 0.70 to 12.80 ppm BaP were not significantly different from control rates. Because in a previous study embryos containing 0.51 ppm BaP exhibited hatching and developmental rates similar to those of controls, their metabolic response to low-level hydrocarbon exposure may be an example of hormesis, an overcompensating metabolic regulation to inhibitory challenges.

Animals↗
PubMed1983

Methods in laboratory investigation. Identification and evaluation of histopathology at microelectrode puncture sites.

Tissue puncture techniques using microelectrodes for various measurements have been criticized for producing undetermined degrees of tissue damage. Therefore, a method permitting routine identification of puncture tracks was developed to determine local microelectrode-induced injury. Rabbits were anesthetized and the femoral arteries surgically exposed. A 3-ml mixture of saline-India ink suspension was introduced through an ear vein. Oxygen-sensitive (pO2) microcathodes were advanced into and through the arterial wall at 10- or 20-micron intervals using a stepping microdrive to 150 to 450 micron and then withdrawn. The arteries were fixed in 10% formalin and gelatin embedded, and serial frozen sections (less than or equal to 15 micron) of the microelectrode puncture area were made. We observed within 5 minutes of microcathode withdrawal a dark, punctate, microscopic discoloration within the arterial wall. Histologically, ink distribution within the arterial wall demonstrated an acute permeability change: puncture depths generally less than 300 micron showed ink-lined microelectrode tracks (generally less than 2 micron wide) in the media, and greater puncture depths showed local hemorrhage and focal laminar accumulation of ink which extended from the track. The immediate adjacent area to microelectrode puncture depths less than 300 micron showed an apparent intact internal elastic lamina and media. Therefore, microelectrode damage has been shown to be primarily limited to microelectrode tissue tracks.

Animals↗
PubMed1983

Correlation of regional disease and in vivo PO2 in rat mammary adenocarcinoma.

A knowledge of the distribution of oxygen tension (PO2) and vascularization in neoplasia has been fundamental to understanding relationships between tumor growth, hypoxia, and therapy. We have combined recessed oxygen microcathode and freeze-substitution techniques to correlate in situ PO2 profiles and morphologic features in 7,12-dimethylbenz(a)anthracene (DMBA) tumors in rats. Overlying connective tissue of transplanted tumor was exposed by a 1-2 mm incision and a cross-stitch pattern demarcated electrode puncture sites for histologic reference. Three buffered salt solutions (BSS) with different PO2 were each allowed to flow through a well over the tumor where electrodes were placed for calibration. Zero electrode oxygen current was recorded from a buffered yeast-agar mixture of zero torr. PO2 was recorded at 5-mu intervals to approximately 1-2 mm. Atmospheric contamination was eliminated by continuous well flow of BSS, 30 torr. Finally, the tumor and surrounding tissues were quick-frozen in vivo with Freon 22 and liquid nitrogen. The tissue block was freeze-substituted and sectioned. PO2 profiles were superimposed onto correspondingly scaled photomicrographs. A viable periphery with a PO2 range of 50-82 torr and a transition to necrotic areas of PO2, 2-13 torr were observed. This transition was characterized by PO2 gradients within distances of 50-300 mu at variable puncture depths. This technique should be useful in further studies of growth, necrosis, and therapy.

Adenocarcinoma↗
PubMed1982

Vasoactive effect of sera from preeclamptic patients.

Investigated was a bioassay method for measurement of vasoactivity in the serum of preeclamptic patients. Intravital microscopy was used to measure the diameter of the principal arteriole and venule in the gastrolienal mesentery of mice before (VD1) and after (VD2) the intravenous injection of sera from preeclamptic primigravid patients and from preeclamptic primigravid patients after treatment with magnesium sulfate (MgSO4). A vasoactive index (VI) was calculated as VD2/VD1. The VIa (vasoactive index for arteriole) of preeclamptic primigravid patients (0.64 +/- 0.39, mean +/- SD) was significantly different (p less than 0.01) from the VIa of normal primigravid patients (0.91 +/- 0.08) and from the VIa of saline controls (0.99 +/- 0.02). Four of the seven preeclamptic primigravid patients had a duration of signs and symptoms dating from the antepartum period (VIa = 0.53 +/-. 0.42), and for three, the diagnosis was made only in the intrapartum period (VIa = 0.77 +/- 0.38). Sera from the MgSO4-treated preeclamptic patients yielded a VIa of 0.91 +/- 0.14, which was not significantly different from that for either the normal primigravid patients or the saline controls. This VIa value was significantly different (p less than 0.01) from the VIa of the untreated preeclamptic patients. These results suggest that here is a vasoactive substance(s) in the sera of preeclamptic patients which may contribute to their arteriolar vasospasm. The magnitude of vasoactivity appears to be related to the duration and severity of preeclampsia but is masked or disappears after treatment of the patient with MgSO4.

Animals↗
PubMed1981

Control of parasitic infestations in killifish (Fundulus parvipinnis).

California killifish (Fundulus parvipinnis) trapped in a Southern California estuary were infested with Gyrodactylus sp, Argulus sp, or Ergasilus sieboldii. They were treated with 0,0-dimethyl 2,2,2-trichloro-1-hydroxyethylphosphonate (DTHP). The effective dosage regimen for Gyrodactylus was 7.50 mg/l for 1 hour on day 1, 3.25 mg/l for 1 hour on day 5, and 0.75 mg/l for 1 hour on day 9; for Argulus, 2.50 mg/l for 1 hour once only; for Ergasilus, 2.50 mg/l for 1 hour once every third day for three treatments. Toxicity testing indicated that repetitive doses of 4.20 mg/l were toxic and that static exposures of more than 1 hour to doses of 7.50 mg/l were lethal to Fundulus.

Animals↗