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Biomedical subjects

R Kohl

Publications and source records attributed to R Kohl.

11 recordsLinked to original sources
PubMed2006

Polyethylene glycol (molecular weight 400 DA) vehicle improves gene expression of adenovirus mediated gene therapy.

PURPOSE: A significant limitation of adenoviral mediated suicide gene therapy is poor gene distribution in vivo. The choice of vehicle has been demonstrated to affect the level of adenoviral delivered gene transduction. We examined the hypotheses that 1) adenovirus suspended in PEG400 improves gene expression in the naïve canine prostate model, 2) improved transgene expression with PEG400 results in improved tumor control and 3) vehicle affects the initial adenoviral spread from a single intratumor injection. MATERIALS AND METHODS: The magnitude and volume of gene expression were measured 24 hours following intraprostatic injection of adenovirus suspended in PEG400 (12.5% weight per volume) or saline as vehicle. Tumor growth delay was measured in mice bearing human tumor xenografts following the injection of adenovirus in PEG400 and saline. The initial spread of adenovirus was measured by confocal microscopy following a single injection of fluorescently labeled adenoviral particles in human tumor xenografts using each vehicle. RESULTS: Adenovirus suspended in PEG400 provided an average of twice the level of gene expression in the canine prostate and significantly better tumor control relative to saline in preclinical tumor models (p = 0.046 and 0.036, respectively). The initial spread of adenovirus with PEG400 was superior to that of adenovirus in saline and the latter was largely limited to the needle tract. CONCLUSIONS: Adenoviral gene therapy vectors suspended in PEG400 results in improved tumor control because of greater initial adenoviral spread, and the increased volume and magnitude of gene expression in vivo.

Adenoviridae↗
PubMed1995

Long-term efficacy of fluid ability interventions with older adults.

Three-year follow-up data were gathered from 108 elderly persons to investigate the long-term efficacy of fluid ability (Gf) interventions with the aged. Results suggested that the effects of reminding older persons to use previously acquired training strategies facilitated 3-year Letter Series performance, particularly so for stress inoculation participants. No reminder effects were observed for Letter Sets scores. While 3-year declines in Letter Sets performance were observed for all persons, losses in Letter Sets performance were minimized to a greater extent for stress inoculation group participants than for those in both the induction training and control conditions. These data collectively underscore the interaction between qualitatively different types of Gf interventions and the ongoing use of previously acquired training strategies as factors in the maintenance of Gf training effects in older persons.

Aged↗
PubMed1993

Salivary total protein and experimental Coriolis sickness.

Symptomatic reporting has been used in quantifying the severity of motion sickness including Coriolis sickness. This study was designed to objectively examine if the dynamic changes of salivary protein concentration relate to the severity of Coriolis sickness. Healthy adults with normal vestibular function underwent a modified Coriolis Sickness Susceptibility Index (CSSI) test, utilizing a staircase profile. Salivary samples were obtained prior to stimulation, 15, 30, and 45 min following stimulus onset, and/or upon reaching "nausea-II" endpoint. Total protein concentration tended to rise over the initial 30 min of stimulation, and then level off or decline. A statistically significant difference was found between the pre-stimulation and 30 min samples. Although some variability existed among the subjects, the general pattern of changes along the time course was similar. An inverse correlation approaching statistical significance was found between control (non-stimulus) total protein levels, and minutes of Coriolis stimulation required to reach the "nausea-II" endpoint. Thus, baseline salivary total protein levels can be of use in predicting susceptibility of Coriolis sickness and other forms of motion sickness.

Adult↗
PubMed1992

The use of epidural anesthesia and analgesia in aortic surgery.

During a 3-year period, sixty-four consecutive patients, who had elective aortic reconstruction were investigated to determine whether epidural anesthesia and analgesia, combined with light general anesthesia, would lower the rate of perioperative complications in this high-risk group of patients. The epidural group comprised 32 consecutive patients who had surgery during the 20-month period from July 1986 to December 1987. These patients were compared with the previous 32 patients who had aortic reconstruction at Huntington Memorial Hospital (Pasadena, CA) using conventional general anesthetic techniques. Cardiovascular and respiratory morbidity, length of hospital stay, length of intensive care unit stay, and duration of endotracheal intubation were compared. There was no statistically significant difference in cardiovascular morbidity, length of hospital stay, or intensive care unit stay between the two groups. There was however, a striking decrease in respiratory complications and length of intubation in the epidural anesthesia group (P less than 0.005). The authors conclude that epidural anesthesia and analgesia, combined with a light general anesthetic may confer benefits over conventional general anesthesia in patients undergoing aortic surgery.

Analgesia, Epidural↗
PubMed1992

Arterial emboli of venous origin.

In a small but significant group of patients with documented systemic emboli, a source is never determined. It is in this group of patients that an arterial embolus of venous origin should be considered. During the past 20 years, we identified four patients who fulfilled the diagnostic criteria for an arterial embolus of venous origin. In each, the diagnosis was made during life. In addition, we reviewed the 40 additional patient reports in the literature that appeared to meet the criteria for the diagnosis of venous origin arterial emboli. Noninvasive methods were useful in determining the presence of thrombus in the venous system, and right to left shunting across an intracardiac defect. We conclude that treatment with heparin is the mainstay of therapy, and that caval interruption should be used only on a selective basis.

Adult↗
PubMed1990

Coagulopathy after snake bite by Bothrops neuwiedi: case report and results of in vitro experiments.

Coagulation studies were performed in a patient who had been bitten by a snake of the species Bothrops neuwiedi. The patient presented with hemorrhagic necrosis at the envenomization site and considerable bleeding from venous puncture sites. He developed a severe defibrination syndrome with a clottable fibrinogen level of approximately 0.1 g/l. Fibrinogen was not measurable by clotting time assay. Fibrin degradation products were greatly elevated. Treatment with antivenom caused an anaphylactic reaction within ten minutes and serum sickness after three days. In vitro experiments revealed that B. neuwiedi venom directly activates Factors II and X, but does not activate Factor XIII. In vivo consumption of Factor XIII after B. neuwiedi envenomization is ascribed to the action of Factor IIa. At low venom concentrations clotting is initiated by activation of prothrombin by the venom either directly or via Factor X activation. Treatment with heparin might be beneficial in coagulopathy secondary to snake bite by reducing circulating active thrombin. The venom contains thrombin-like proteases which cause slow clotting of fibrinogen, and plasmin-like components causing further proteolysis of fibrinogen and fibrin. Antivenom has no effect on the proteolytic action of the snake venom. The in vivo effects of antivenom are presumably caused by acceleration of the elimination of venom components from the circulation. Intravenous administration of antivenom caused normalization of blood coagulation parameters within 48 h.

Adult↗
PubMed1979

X;15 translocation in a retarded girl: X inactivation pattern and attempt to localise the hexosaminidase A and other loci.

Cytogenetic studies on a retarded girl showed a complex S;15 translocation, karyotype 45,X,-15,+t(X15). The translocation X chromosome was non-randomly partially inactivated, the inactivation being mainly confined to the X segment and in some cells only to the X long arm. Gene marker studies failed to show anomalous segregation of the hexosaminidase A gene or any other gene markers tested.

Abnormalities, Multiple↗
PubMed1977

The influence of alpha-receptors on lordosis in the female rat.

The alpha-adrenergic agonist clonidine suppressed lordotic responding in spayed female rats brought into heat by estrogen and progesterone. The suppression was blocked by the alpha-antagonist yohimbine, but not by phenoxybenzamine or pimozide. The suppression was blocked by the alpha-antagonist yohimbine, but not by phenoxybenzamine or pimozide. Phenoxybenzamine itself had no suppressive effect on lordosis, though yohimbine did under some conditions. These results argue against an important facilitatory influence of norepinephrine on lordosis in the rat. Further, in comparison with the quite different findings recently reported from the guinea pig, they offer support for the presence of two different kinds of alpha-adrenergic receptors in the brain with different physiological functions.

Animals↗