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Biomedical subjects

B A Russell

Publications and source records attributed to B A Russell.

18 recordsLinked to original sources
PubMed2005

Studies on doses of methimazole (MMI) and its administration regimen on broiler metabolism.

We designed three experiments to determine both the optimal dose of and time on experiment for methimazole (MMI; 1-methyl-2-mercaptimidazole). Our goals were to determine if chicken growth was related to thyroid hormone levels and if intermediary metabolism changed along with changes in thyroid hormone levels. Initiating MMI at one week of age decreased (P<0.01) plasma thyroid levels and growth in four-week old birds. In contrast, initiating MMI at two and three weeks of age decreased (P<0.05) hormone levels without affecting growth as severely. Although initiating MMI at two weeks of age depressed (P<0.05) plasma thyroid hormones at four weeks, there was little change in vitro lipogenesis at four weeks. Again, initiating MMI at one week of age decreased body weight, plasma thyroid hormones and in vitro lipogenesis at four weeks of age. In addition, this treatment also decreased (P<0.05) malic enzyme activity at this same age period. The second experiment showed that MMI, initiated at 14 days, had no significant effect on 28-day body weight and again decreased both plasma T(3) and T(4) but T(3) replacement increased plasma T(3) in both 14-28-day treatment groups. All body weights were similar at 30 days, however. Lastly, diets containing graded levels of MMI decreased thyroid hormones and body weight (0>0.25>0.5>1 g MMI/kg). In contrast, only the two higher levels (0.5 and 1 g MMI/kg) decreased in vitro lipogenesis. Growth depression, caused by MMI feeding, can occur without changes in lipid metabolism. The length of MMI administration may be as important as dose level in obtaining effects (growth, thyroid hormone depression and inhibition of lipogenesis).

Animals↗
PubMed2005

A study to determine the efficacy of combination LED light therapy (633 nm and 830 nm) in facial skin rejuvenation.

BACKGROUND: The use of visible or near infrared spectral light alone for the purpose of skin rejuvenation has been previously reported. A method of light emitting diode (LED) photo rejuvenation incorporating a combination of these wavelengths and thus compounding their distinct stimulation of cellular components is proposed.Objective. To assess the efficacy and local tolerability of combination light therapy in photo rejuvenation of facial skin. METHODS: Thirty-one subjects with facial rhytids received nine light therapy treatments using the Omnilux LED system. The treatments combined wavelengths of 633 nm and 830 nm with fluences of 126 J/cm(2) and 66 J/cm(2) respectively. Improvements to the skin surface were evaluated at weeks 9 and 12 by profilometry performed on periorbital casts. Additional outcome measures included assessments of clinical photography and patient satisfaction scores. RESULTS: Key profilometry results Sq, Sa, Sp and St showed significant differences at week 12 follow-up; 52% of subjects showed a 25%-50% improvement in photoaging scores by week 12; 81% of subjects reported a significant improvement in periorbital wrinkles on completion of follow-up. CONCLUSION: Omnilux combination red and near infrared LED therapy represents an effective and acceptable method of photo rejuvenation. Further study to optimize the parameters of treatment is required.

Adult↗
PubMed2004

Methimazole, thyroid hormone replacement, and lipogenic enzyme gene expression in broilers.

The purpose of this experiment was to determine the possible relationship between certain indices of lipid metabolism and specific gene expression in chickens fed methimazole to simulate hypothyroidism. Male broiler chickens (Gallus gallus) growing from 7 to 28 days of age were fed diets containing 18% crude protein and either 0 or 1 g methimazole per kilogram of diet. At 28 days, these two groups were further subdivided into groups receiving 18% crude protein diets containing either 0 or 1 mg triiodothyronine (T3) per kilogram. Birds were sampled at 28, 30, and 33 days. Measurements taken included in vitro lipogenesis (IVL), malic enzyme (ME) activity, isocitrate dehydrogenase, aspartate amino transferase, and the expression of the genes for ME, fatty acid synthase (FAS), and acetyl coenzyme carboxylase (ACC). Hypothyroidism decreased IVL and ME at 28 days of age; however, T3 supplementation for 2 days restored both IVL and ME. Paradoxically, continuing T3 replenishment for an additional 3 days decreased IVL but did not decrease ME activity. In contrast, supplemental T3 decreased IVL in euthyroid birds, regardless of the dosing interval, but had no effect on ME activity. Although methimazole decreased ME gene expression, there was only a transitory relationship between enzyme activity and gene expression when plasma T3 was restored with exogenous T3. These data may help to explain some of the apparent reported dichotomies in lipid metabolism elicited by changes in the thyroid state of animals. In addition, most metabolic changes in response to feeding T3 occurred within 2 to 5 days, suggesting that changes in intermediary metabolism preceded morphological changes. In conclusion, the thyroid state of the animal will determine responses to exogenous T3.

Animals↗
PubMed2002

Dietary protein regulates in vitro lipogenesis and lipogenic gene expression in broilers.

The purpose of this experiment was to determine the possible relationship between certain indices of lipid metabolism and specific gene expression in chickens fed graded levels of dietary crude protein. Male, broiler chickens growing from 7 to 28 days of age were fed diets containing 12, 21 or 30% protein ad libitum. In addition, another group of birds was fed on a regimen consisting of a daily change in the dietary protein level (12 or 30%). This latter group was further subdivided such that one-half of the birds received each level of protein on alternating days. Birds were sampled from 28 to 30 days of age. Measurements taken included in vitro lipogenesis, malic enzyme activity the expression of the genes for malic enzyme, fatty acid synthase and acetyl coenzyme carboxylase. In vitro lipogenesis and malic enzyme activity were inversely related to dietary protein levels (12-30%) and to acute changes from 12 to 30%. In contrast, expression of malic enzyme, fatty acid synthase and acetyl CoA carboxylase genes were constant over a dietary protein range of 12-21%, but decreased by feeding a 30% protein diet (acute or chronic feeding). Results of the present study demonstrate a continued role for protein in the regulation of broiler metabolism. It should be pointed out, however, that metabolic regulation at the gene level only occurs when feeding very high levels of dietary protein.

Acetyl-CoA Carboxylase↗
PubMed1998

Effects of varied vocal intensity on ventilation and energy expenditure in women and men.

This study was completed to determine how ventilatory responses change by means of speech reading at three different sound pressure levels (SPL) as compared to quiet breathing prior to each task. The energy required to alter SPL was also studied and compared to energy expenditures during a quiet breathing condition. Twenty-four adults (12 women, 12 men) were studied while reading a standard passage at low, comfortable, and high SPLs for 7 minutes with quiet breathing periods between each task to achieve respiratory steady state and serve as a control to which the reading tasks were compared. The last 2 minutes of exhaled air for all speaking and quiet breathing tasks were collected using a Hans Rudolph mouth breathing face mask. A Sensor Medics Vmax 29 series diagnostic instrument system measured all ventilatory responses and energy expenditures. Volume and timing alterations in ventilation were characterized by measuring tidal volume (V[T]), inspiratory time (T[I]), inspiratory flow rate (V[T]/T[I]), and expiratory time (T[E]). Average ventilation, energy expenditure, and adequacy of ventilation were measured using minute ventilation (V[E]), oxygen consumption (VO2), carbon dioxide production (VCO2), and partial pressure of end-tidal carbon dioxide (end-tidal PET[CO2]). Results indicated volume, timing, ventilation, and energy expenditure values remained closest to quiet breathing values for the comfortable SPL. Volume, ventilation, and energy expenditure were significantly greater for the high SPL and lower for the low SPL, compared to the baseline steady state, indicating that the low SPL causes a ventilatory deficit that was found to be paid back at the end of the speech task during the quiet breathing period. These results demonstrate that an individual's comfortable SPL is the least energy-requiring way to speech breathe. As SPL rises above or below comfortable SPL, speech breathing requires more energy.

Adolescent↗
PubMed1997

Impact of peripherally inserted central catheters on phlebitic complications of peripheral intravenous therapy in spinal cord injury patients.

We investigated the impact of peripherally inserted central catheter (PICC) placement in spinal cord injury patients at high risk for infusion phlebitis. The rate and etiology of phlebitis was investigated in two phases. During Phase I, peripheral IV cannulae and conventional central venous catheters (CVC) were used. During Phase II, patients identified to be at risk for phlebitis received PICCs. The number of peripheral IVs, CVCs and PICCs was tabulated for both phases of the study. Technical, infectious and thrombotic complications were studied prospectively for PICCs and retrospectively for CVCs. We found the rate of phlebitis was 16.5 percent and 2.4 percent for Phases I and II, respectively (p = 0.0002). Three infections occurred in 38 PICCs and one infection was documented in 13 conventional CVCs. The number of peripheral IVs and conventional CVCs was reduced significantly from Phase I to Phase II. No procedural complications, catheter sepsis or clinically apparent venous thrombosis occurred. In conclusion, PICCs reduced the rate of phlebitis thresholds with a low complication rate and reduced the use of peripheral IVs and conventional CVCs.

Catheterization, Central Venous↗
PubMed1994

In vitro regulation of lipogenesis in turkey liver explants.

A mechanical tissue chopper was used to obtain liver explants (35-75 mg) from 2-3-week old turkeys to determine both tissue sensitivity and metabolic effects of adrenergic agonists (isoproterenol, propranolol, norepinephrine and phenoxybenzamine). A previously noted catecholamine induced decrease in in vitro lipogenesis in chicken liver explants was also noted in turkey liver explants. Thus, one set of control points for in vitro regulation is under control of the cAMP system. Preincubation of slices (1 hr) with propranolol blocked the inhibition of lipogenesis caused by alpha and beta-adrenergic agonists (arterenol or isoproterenol) during a subsequent 1-hr incubation. Preincubation of slices with either of these agonists decreased lipogenesis even following an extensive washout. Inhibition could be overcome with propranolol, a beta adrenergic antagonist.

Animals↗
PubMed1993

Antitumor effects of GBS toxin: a polysaccharide exotoxin from group B beta-hemolytic streptococcus.

A group B streptococcus (GBS) isolated from human neonates diagnosed with sepsis and respiratory distress ("early-onset disease") produces a polysaccharide exotoxin (GBS toxin) that, when infused in sheep, causes lung pathophysiology similar to that seen in humans. Histological studies have demonstrated that GBS toxin induces a strong inflammatory response in the lung, with pulmonary sequestration of granulocytes and extensive capillary endothelial damage. The susceptibility of humans to GBS toxin is age-dependent and limited to about 4 days after birth. It is rarely evident thereafter. This suggests that the binding of GBS toxin to the target endothelium occurs via specific components in the developing lung endothelial cells of the newborn that are later lost. We report here that GBS toxin can also bind to developing endothelium associated with neoplasia and induce an inflammatory response. GBS toxin was shown by immunohistochemistry to bind to capillary endothelium of human large-cell carcinomas. In nude mice bearing human tumor xenografts, intravenously administered GBS toxin caused tumor necrosis and hemorrhagic lesions, and substantially inhibited the rate of growth of the tumors. In BALB/c mice bearing Madison lung tumors, GBS toxin induced an inflammatory response resulting in marked changes in tumor morphology, including vasodilation, endothelial and tumor cell necrosis, invasion of lymphocytes and macrophages, and capillary thrombosis. In these tumor models, no evidence of toxicity to the vasculature of other tissues was observed. The reported pathophysiology of GBS in human neonates, the lack of disease in non-neonates colonized with GBS, and these results suggest that GBS toxin may have potential as a well tolerated agent in cancer therapy of some human tumors.

Adenocarcinoma↗
PubMed1990

Uncontrolled nosocomial rotavirus transmission during a community outbreak.

Between Jan. 11 and March 31, 1983, 60 pediatric patients were diagnosed with rotavirus gastroenteritis. Of these cases 24 were community acquired, 29 were nosocomial, and 7 were of undetermined origin. Despite intensive infection control efforts, nosocomial transmission continued as long as patients with community-acquired cases were admitted. The use of disinfectants and germicides that were ineffective against rotavirus may have contributed to the continued nosocomial spread during a community outbreak.

Communicable Disease Control↗
PubMed1989

School-based preventive regimens and oral health knowledge and practices of sixth graders.

The purpose of this study was to examine the oral health knowledge and reported practices of sixth grade students in Wichita, Kansas. A quasi-experimental design was used to test differences between two groups: (1) children who had completed a four-year regimen referred to as the National Preventive Dentistry Demonstration Program (NPDDP), and (2) a control group of children who had not been exposed to any aspect of the NPDDP. Based on incidental learning theory, the research question was whether or not students' knowledge and practices were consistent with the preventive regimes provided at school. The study reported here was not directly connected with the NPDDP. A school nurse-administered questionnaire was obtained from 284 students 16 months after the NPDDP had terminated. Students in all groups reported similar dental health practices; no practical differences were found among groups with regard to knowledge about appropriate fluoride uses and benefits. Students who received sealants were somewhat more knowledgeable about the use and purpose of sealants. Although students in five of the six NPDDP groups had received preventive regimens, these data suggest that they lacked awareness and understanding of the procedures and their value in preventing oral diseases. Generally, students were unable to discriminate among methods appropriate for preventing dental caries and periodontal diseases. Education regarding the purpose and value of preventive regimens should be consistent with, and an integral part of, the delivery of such services.

Analysis of Variance↗
PubMed1989

Longitudinal relationship of asymptomatic hypoglycemia to cognitive function in IDDM.

Early-onset insulin-dependent diabetes mellitus (IDDM) is linked to subsequent learning deficits. To investigate the relationship of learning deficits to metabolic control, 23 children with IDDM (age at testing 71 +/- 21 mo, age at diagnosis 35 +/- 15 mo) diagnosed before 5 yr of age were followed for periods of 6-78 mo. Mean glycosylated hemoglobin (HbA1), episodes of severe hypoglycemia, and frequency of self-monitoring blood glucose (SMBG) measurements less than 2.8 mM (50 mg/dl, asymptomatic hypoglycemia) were recorded every 3 mo. Six subjects entered the study 12.3 +/- 6.7 mo after diagnosis, and only severe hypoglycemia was present before entry. For the remaining 17 subjects, HbA1 and severe and asymptomatic hypoglycemia were present from the time of diagnosis of diabetes. Mean HbA1 level was 10.1 +/- 1.0%, and mean severe hypoglycemic episodes per patient was 2.9, but the frequency was highly skewed; one patient had 37 episodes, and 14 had none. The mean percentage of SMBG readings less than 2.8 mM was 2.4 +/- 2.1. On the revised Stanford-Binet Intelligence Scale there was no correlation between any subscale and severe hypoglycemia. However, the relative frequency of asymptomatic hypoglycemia correlated with scores on the abstract/visual reasoning scale (r = -.39, P = .037). This relationship was primarily accounted for by the relationship of asymptomatic hypoglycemia to performance on the copying subscale (r = -.42, P = .022). Children with frequent asymptomatic hypoglycemic episodes had lower mean copying scores and abstract reasoning scores than those with infrequent episodes.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Glucose Self-Monitoring↗
PubMed1986

Single step purification procedure for the rapid separation of equine leucocytes.

Percoll gradients have been used to separate relatively pure populations of viable equine polymorphonuclear (PMN) and mononuclear (MN) cells. In preliminary studies, a continuous density gradient of 70% Percoll solution was used to separate two distinct leucocyte-rich bands. After measurement of the density of each band on the continuous gradient, discontinuous Percoll gradients, using 60% and 75% Percoll solutions, were used to provide a rapid means of separating PMN and MN cells. The yield of viable cells per ml of blood was 3.0 X 10(6) and 3.2 X 10(6) for MN and PMN cells, respectively. Corresponding values for recovery were 45% and 72%. The purity was 94% for PMNs and 99% for MNs.

Animals↗
PubMed1986

Outbreak of staphylococcal infection in two hospital nurseries traced to a single nasal carrier.

In late January and early February 1983, an outbreak of skin infections (7 of 145 infants) caused by a penicillin/erythromycin resistant strain of Staphylococcus aureus (SA), phage type 3A/3C, occurred in our newborn nursery. A week following the first cluster of infections, another nursery outbreak due to SA with the same antibiogram occurred in a nearby community hospital (11 of 114 infants). Subsequently, a second cluster of infections with the same SA was identified at our nursery. The epidemic strain was carried in the anterior nares of a single nurse who worked at both hospital nurseries on alternate weeks. Investigation revealed that the nurse had an upper respiratory tract infection during each of these outbreaks--simulating "a cloud baby." No further infections have occurred since this nurse was treated and her SA nasal carrier state eliminated.

Cross Infection↗
PubMed1986

Unusual complement activation properties of serum immunoglobulins of the pigeon Columba livia.

Complement-mediated lysis of mouse erythrocytes (MRBC) by whole pigeon antisera was found to occur in the presence of magnesium ions alone. The underlying basis for this observation was demonstrated to be the ability of IgM antibodies to activate the alternative pathway of pigeon complement, whereas IgG activates a calcium-dependent pathway possessing an unusually low lytic capacity. In addition to differing from the alternative pathway by requiring both calcium and magnesium ions, the calcium-dependent pathway exhibited higher activity at low temperature and more rapid kinetics of haemolysis. The presence of early acting C1 in pigeon serum was inferred by the selective depletion of calcium-dependent activity which occurred as a result of incubating serum containing only calcium ions with MRBC sensitized with IgG. Under the same conditions, MRBC sensitized with IgM failed to deplete complement activity, indicating that C1 does not participate in complement activation by this isotype. Interestingly, the calcium-dependent pathway detected in pigeon serum appears to more closely resemble the C1-bypass pathway rather than the classical pathway of mammalian complement.

Animals↗
PubMed1984

Transmission of hepatitis A by transfusion of blood products.

The transmission of hepatitis A by blood products has been thought to occur rarely or not at all. By measuring IgM antibody to hepatitis A virus, we diagnosed a case of hepatitis A transmitted by the transfusion of a unit of fresh frozen plasma. Since the commercial availability of methods for measuring IgM antibody to hepatitis A, four other well-defined cases of hepatitis A transmitted by blood products have been reported in the literature. We detail our case and the natural history and importance of this clinical entity.

Adult↗
PubMed1975

Heroin detoxification. A comparison of propoxyphene and methadone.

Propoxyphene napsylate and methadone hydrochloride were each administered under double-blind conditions to 36 outpatients for 21-day heroin detoxification. The initial dosage was 24 mg/day for methadone hydrochloride and 800 mg/day for propoxyphene napsylate. At these dosages, methadone more effectively suppressed the opiate-withdrawal syndrome, and patients remained in treatment longer in the methadone group (P greater than .05). In regard to heroin abstinence, however, results were not statistically significant in either group, as indicated by the number of patients whose urine was positive for morphine on admission and became negative during treatment, and the number who had morphine-negative urine at the conclusion of 21-day treatment. A one-month follow-up of patients showed that more patients given methadone had entered long-term medical maintenance while more patients given propoxyphene were heroin-abstinent. This study indicates that 21-day heroin detoxification, regardless of chemotherapeutic agent, yields a low rate of heroin abstinence.

Adolescent↗