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Biomedical subjects

R R Rogers

Publications and source records attributed to R R Rogers.

At least 37 records · Page 2Linked to original sources
PubMed1989

Gain in weight and length during early infancy.

Although rate of growth is generally recognized as a valuable indicator of health status, few reference data are available for gain in weight or length during the period of most growth in infancy. We have therefore summarized our data concerning gains in length and weight of 203 breast-fed males, 216 breast-fed females, 380 formula-fed males, and 340 formula-fed females. Seven sets of measurements (at ages 8, 14, 28, 42, 56, 84 and 112 days) were made with each infant. The 5th, 10th, 25th, 50th, 75th, 90th and 95th centile values together with the means and standard deviations are presented for selected age intervals on a feeding-specific (i.e. breast-fed or formula-fed) and sex-specific basis. We believe that these data will be useful as a reference for interpreting results of infant studies.

Aging↗
PubMed1989

Iron absorption from infant foods.

To determine the bioavailability of iron from iron-fortified infant foods, we have determined erythrocyte incorporation of the stable isotope, 58Fe, after feeding the following foods extrinsically labeled with 58Fe: 1) rice cereal with apples and bananas ("cereal-fruit product"), 2) Mead Johnson Enriched Baby Food (MJEBF), a vitamin, mineral, and protein-enriched rice cereal, 3) vegetables and beef ("vegetable-beef product"), 4) grape-juice, and 5) MJEBF. Foods 1-4 were fortified with ferrous sulfate, and food 5 was fortified with ferrous fumarate. Blood was obtained at ages 140, 168, and 196 d of age, and the test meal was fed under standardized conditions at 154 d of age. Erythrocyte incorporation of the 58Fe label was determined from the increase in the mass isotope ratio, 58Fe/57Fe, from the baseline value (at 140 d of age) to the follow-up values. The mass isotope ratio was determined by inductively coupled mass spectrometry. Geometric mean total iron incorporation into erythrocytes from the test meal of MJEBF fortified with ferrous sulfate (food 2) was 0.05 mg, and from the vegetable-beef product test meal (food 3) was 0.08 mg. The low value for MJEBF is presumably explained by the low level of iron fortification. The low value for the vegetable-beef product may reflect the presence of inhibitors of iron absorption. Geometric mean erythrocyte incorporations of iron from the test meals with foods 1, 4 and 5 were 0.15, 0.14, and 0.18 mg, respectively. These erythrocyte incorporation values are 20 to 26% of the estimated 0.7 mg requirement for absorbed iron, and therefore seem nutritionally important.

Biological Availability↗
PubMed1989

Beyond morality: the need for psychodynamic understanding and treatment of responses to the AIDS crisis.

The purpose of this paper is to identify a broad range of issues that both impact, and are impacted by, psychiatric intervention in AIDS and AIDS-related cases, with a special concern towards emphasizing the need for application of a psychodynamic perspective, in the understanding and treatment of pathological responses to the AIDS crisis. As a cornerstone of the psychiatric model, psychodynamic evaluation and treatment can provide a breadth of focus and depth of understanding crucial to a resolution of some of the deeper psychosocial aspects involved in the reaction to and spread of the AIDS virus. A case example is used to illustrate psychodynamic factors which precluded the patient's ability to choose monogamy, and which contributed to the "transmission" of a cyclic pattern of psychodynamic pathology.

Acquired Immunodeficiency Syndrome↗
PubMed1988

Immunologic effects of perinatal exposure of rats to dioctyltin dichloride.

Studies were conducted to determine the period of immune system development that was most sensitive to perturbation by the known immunotoxicant di-n-octyltin dichloride (DOTC). Fischer 344 rats were exposed prenatally, both pre- and postnatally, or postnatally to DOTC by oral gavage of pregnant and/or lactating females. At various ages, ranging from 3 to 16 wk of age, offspring were examined for a number of immune functions. These included body and lymphoid organ weights; lymphoproliferative responses to B- and T-cell mitogens; natural killer cell activity; and primary antibody response to sheep erythrocytes. Prenatal (10-20 of gestation), pre- and postnatal (d 11-20 of gestation and 2-11 d of age), or postnatal (2-13 d of age) oral dosing of dams with 20-50 mg/kg DOTC resulted in no consistent alteration in immune function in offspring. However, direct oral dosing of rat pups to 5-15 mg/kg DOTC, beginning at 3 d of age and then 3 times per week up to 24 d of age for a total of 10 doses, resulted in significant suppression of the lymphoproliferative response of splenocytes to a T-cell mitogen in 10-wk-old rats (i.e., 7 wk after the last exposure to DOTC). Lymphoproliferative responses returned to control levels by 12 wk of age. In comparison young adult (8 wk old) rats dosed with 10 or 20 mg/kg DOTC under an identical dosing schedule (i.e., 3 times per week for a total of 10 doses) showed no suppression in the mitogen response of splenocytes 4 wk after the last exposure to DOTC. These results suggest that direct dosing of pups during early postnatal life may be the most effective means of inducing immunosuppression with DOTC during immune system development. The results also provide evidence for the greater sensitivity of the developing immune system compared with the fully developed immune system for a known immunotoxicant.

Administration, Oral↗
PubMed1988

Electrophysiological observations during QRS alternans in a patient with incessant tachycardia.

Electrophysiological observations during preoperative and intraoperative study of a 46-year-old patient with incessant ventricular tachycardia and QRS alternans demonstrated a potential mechanism for this electrocardiographic finding. During QRS alternans, conduction delay (or block) was recorded from the site of origin of the tachycardia, high on the anterior septum to the His bundle: After procainamide infusion, the tachycardias slowed and, concurrent with the disappearance of QRS alternans, conduction from the site of tachycardia origin to the His bundle could no longer be demonstrated.

Electrocardiography↗
PubMed1988

Use of the stable isotope, 58Fe, for determining availability of nonheme iron in meals.

Because of reluctance to use radioisotopes for studies of iron absorption in children, we have explored the feasibility of using the least abundant stable isotope of iron, 58Fe (natural abundance, 0.322 weight %) in a study of nonheme iron absorption. With a balanced cross-over design, each of 16 school-age children was fed a standardized lunch on 3 consecutive days and, 28 days later, an alternate standardized lunch on 3 consecutive days. The lunch included either a beef patty or a beef-soy patty. The mass isotope ratio, 58Fe/57Fe (MIR58/57), was measured in blood by inductively coupled plasma mass spectroscopy before and 14 days after (i.e. study day 15) consuming the three lunches. The MIR58/57 on study day 15 was used as a baseline value for lunches fed on study days 29, 30, and 31. Incorporation of 58Fe into erythrocytes was greater from the lunch with beef patty than from the lunch with beef-soy patty (geometric mean values 2.02 and 1.05% of the dose, p less than 0.03). Based on the similarity of our results with those obtained in adults with radioisotopes, we conclude that 58Fe is a satisfactory tag for studies of nonheme iron absorption from meals.

Child↗
PubMed1988

Erythrocyte incorporation of ingested 58-iron by infants.

The least abundant stable isotope of iron, 58Fe (natural abundance 0.322 weight %), was administered orally to infants to explore the feasibility of using a stable rather than a radioisotope in studies of iron absorption. The dose of 58Fe was given between feedings at age 126 days. The mass isotope ratio, 58Fe/57Fe, was determined in blood by inductively coupled plasma mass spectroscopy and at ages 140, 168, and 196 days. The percentage of the 58Fe dose entering the circulation (3.2 to 16.0%) was inversely correlated with serum ferritin concentration (r = -0.867, p less than 0.01). For individual infants the SD of the percentage of administered dose of iron appearing in the circulation ranged from 0.22 to 1.28. We conclude that the method is likely to be suitable for within-subject comparisons of iron availability from foods. Because of the large between-subject variation, we are pessimistic for this age group about the usefulness of study designs based on group comparisons.

Absorption↗
PubMed1988

Enhancement of natural killer cell activity and interferon production by manganese in young mice.

The effect that MnCl2 has on murine splenic natural killer (NK) cell activity was investigated in infant (10 days old), pre-weanling (18 days old) and weanling (24 days old) C57BL/6J mice. A single intraperitoneal injection of 10, 20 or 40 micrograms MnCl2/g body weight caused a significant enhancement in NK activity, as determined by the in vitro 51Cr release assay. Comparable enhancement of NK activity was observed for age-matched mice injected intraperitoneally with polyinosinic polycytidylic acid (Poly I:C). Both MnCl2 and Poly I:C caused elevations in serum interferon levels. Time-course studies revealed that interferon levels returned to normal within 48 hours following injection with either MnCl2 or Poly I:C; however enhanced NK activity persisted for up to 48 hours in Poly I:C-injected mice and 72 hours in MnCl2-injected mice. The administration of rabbit anti-asialo GMl to MnCl2-injected mice completely abrogated the enhanced NK activity. In addition, the injection of rabbit anti-mouse interferon alpha, beta but not gamma completely abrogated the enhanced NK activity. In addition, the injection of rabbit anti-mouse interferon alpha, beta but not gamma completely abrogated the enhancement of NK activity by MnCl2 and to a lesser extent the enhancement of NK activity by Poly I:C. These results indicate that despite low levels of NK activity in pre-weanling mice, MnCl2 is capable of enhancing this activity by 8-9 fold. Furthermore, Mn-enhanced NK activity in these young mice appears to be mediated by the production of interferon alpha, beta.

Animals↗
PubMed1987

Alteration of immune function in mice following carcinogen exposure.

Treatment of mice with the direct-acting alkylating agent methyl methanesulfonate produced marked suppression of the humoral response to sheep erythrocytes and suppression of T cell responses to foreign antigens. These effects occurred without loss of spleen, thymus or body weight and in the absence of peripheral blood, splenic or bone marrow cytotoxicity. In comparison, exposure to urethan decreased spleen weights, number and viability of spleen cells, and numbers of circulating lymphocytes. Significant suppression of T cell mitogen responsiveness was observed at all dose levels of urethan. Thymus weights, proliferative responses to the B cell mitogen lipopolysaccharide and delayed hypersensitivity responses were decreased at the highest urethan dose. Cyclophosphamide treatment significantly depressed thymic weight, lymphoproliferative responses of T and B cells, antibody production and delayed hypersensitivity responses. These results suggest differential sensitivity in components of the host defense system to weak carcinogens.

Animals↗
PubMed1987

Selective immunotoxic effects in mice treated with the adenosine deaminase inhibitor 2'-deoxycoformycin.

Mice were administered the adenosine deaminase inhibitor 2'-deoxycoformycin by daily intraperitoneal injection for five days and evaluated 24 h, 72 h and 6 days after the final dose. Spleen weight was decreased in treated mice for up to 6 days after treatment whereas body weight was significantly affected only at 24 h in mice administered 4 micrograms 2'-deoxycoformycin/g of body weight. The number and relative percentage of circulating lymphocytes were decreased 24 and 72 h after the last injection. Lymphoproliferative responses to T cell mitogens were suppressed for at least 72 h post-treatment whereas the mixed lymphocyte response was normal at 24 h but was depressed at 72 h post-treatment. Conversely, natural killer cell activity was greater in treated mice than in controls for the entire observation period. Data from cell surface marker analysis provided indirect evidence that natural killer effector cells lack sensitivity to 2'-deoxycoformycin. The antibody responses of mice treated with 2 or 4 micrograms 2'-deoxycoformycin/g over four days prior to or after immunization with sheep erythrocytes were suppressed or enhanced, respectively, compared to controls. These results indicate selective effects of 2'-deoxycoformycin on immune function and suggest that subpopulations of lymphocytes differ in the degree of sensitivity to 2'-deoxycoformycin.

Adenosine Deaminase Inhibitors↗
PubMed1987

The effects of nickel on immune function in the rat.

The immunotoxic potential of NiCl2 was evaluated in Fischer 344 rats following a single intramuscular injection at doses ranging from 10 to 20 mg/kg. Twenty-four hours following treatment, selected cellular and humoral immune function parameters were examined. Significant (P less than 0.05) decreases in body weights were observed in rats injected with 15 and 20 mg/kg NiCl2 as were decreases in spleen weights of rats receiving 20 mg/kg. The lymphoproliferative responses of splenocytes to the T cell mitogens concanavalin A (Con A), phytohemagglutinin (PHA), the T and B cell mitogen pokeweed mitogen (PWM) and the B cell mitogen Salmonella typhimurium mitogen (STM) were not significantly different from controls. No significant differences were observed between control and Ni-treated rats in the primary antibody response to sheep red blood cells (SRBC). On the other hand, natural killer (NK) cell activity was significantly (P less than 0.05) suppressed in rats injected with 10, 15, or 20 mg/kg NiCl2. NK cell suppression was observed in both male and female rats and for both allogeneic W/Fu-G1 target cells as well as xenogeneic YAC-1 target cells. Ni-induced suppression of NK activity was transient, with levels returning to control values within three days following treatment. Ni-induced suppression of NK activity was also manifested by an increase in mortality of rats injected with MADB106 tumor cells. These results extend to a second species our earlier findings that Ni suppresses NK activity.

Animals↗
PubMed1987

Bioavailability of dietary urea nitrogen in the infant.

Because the human body has no enzymes capable of hydrolyzing urea, nitrogen from this source becomes bioavailable only by release of ammonia from urea by bacterial hydrolysis in the intestines, with subsequent absorption and utilization of ammonia. To explore extent to which urea ingested in milk becomes bioavailable, we fed di-15N-urea (both nitrogen atoms in the form of the stable isotope 15N) and determined urinary excretion of di-15N-urea (excreted without having become bioavailable) and mono-15N-urea (urea containing only one atom of 15N and therefore reflecting excretion of absorbed ammonia). The largest percentage of the ingested di-15N-urea was excreted promptly in the urine still in the form of di-15N-urea. We conclude that most of the urea ingested by a normal infant is not bioavailable.

Animals↗
PubMed1987

Effects of manganese, calcium, magnesium, and zinc on nickel-induced suppression of murine natural killer cell activity.

The effects that divalent metals have on nickel-induced suppression of natural killer (NK) cell activity were studied in mice. Male CBA/J mice were given a single intramuscular injection of metal salt on a body weight basis. The metal doses used were the following: nickel chloride, 4.5-36 micrograms/g; manganese chloride, 20-80 micrograms/g. Twenty-four hours after metal injection, splenic NK cell activity was assessed using a 51Cr-release assay. Ni significantly (p less than 0.01) suppressed NK activity, while Mn significantly (p less than 0.01) enhanced NK activity. No alteration in NK activity was observed in mice injected with Mg, Ca, or Zn. Since these divalent metals have been shown to have antagonistic effects on Ni-induced carcinogenicity and toxicity, they were used in combination with Ni to determine if such antagonisms exist for NK cell activity. The injection of Ni and Mn in combination at a single site resulted in the enhancement of NK activity, although this enhancement was at a level below that observed following the injection of Mn alone. Injection of Mg, Zn, or Ca in combination with Ni did not affect NK activity compared to saline controls. In contrast, the injection of Ni in one thigh followed immediately by Mn, Mg, Ca, or Zn into the other thigh resulted in significant suppression of NK activity for all metals compared with saline controls. An interesting finding was that the injection of Ni followed immediately by Mn into the opposite thigh resulted in even greater reductions in NK activity than Ni alone. Suppression of NK activity by Ni and Mn injected at separate sites was not seen when Mn injection preceded Ni injection by 1 h. These data indicate that both the divalent metal and the timing of its injection relative to Ni injection are critical for altering Ni-induced suppression of NK cell activity.

Animals↗
PubMed1987

Immune function in mice exposed to the adenosine deaminase inhibitor 2'-deoxycoformycin during immune system development.

Pregnant mice were administered 2'-deoxycoformycin (2dCF), a potent inhibitor of adenosine deaminase activity, by intraperitoneal injection on day 7 or 15 of gestation or from day 8-12 or 14-18 of gestation. A total dose of 0.5 or 2.0 micrograms 2dCF/g of maternal body weight was given to the dams. In a separate study, pups born to nontreated dams were given 5 intraperitoneal injections totaling 0.5, 2.0 or 4.0 micrograms 2dCF/g beginning at 4 weeks of age. Administered doses of 2dCF were at levels known to profoundly suppress adenosine deaminase levels in adult mice. Pups born to dams injected with 2dCF from day 14-18 all died within 48 h of birth whereas other injection schedules had no effect on birth rate or survival of pups. In utero 2dCF exposure had little effect on immune function in offspring. On the other hand, body, spleen and thymus weight, and splenic cellularity were decreased in weanling mice 24 h after the last injection of 4 micrograms/g 2dCF. Proliferative responses of splenocytes to T cell mitogens and alloantigens were likewise suppressed at both 2.0 and 4.0 micrograms/g 2dCF. Suppression of proliferative responses in treated weanling mice were no longer apparent at 7 weeks of age although splenic cellularity and weight remained lower than control values. These results are similar to those we have reported for 8 week old mice given similar doses of 2dCF, with the exception of elevated levels of NK cell activity in older 2dCF-treated mice and suggest that there may be age-related differences in the sensitivity of certain cell populations to the effects of 2dCF.

Adenosine Deaminase Inhibitors↗
PubMed1987

Variables related to pro-choice attitudes among undergraduates.

Pro-choice attitudes among undergraduates were assessed to determine the extent of anti-abortion sentiments during President Reagan's first term in office, which was marked by his support of the anti-abortion issue as well as by increased media coverage of the right-to-life movement. Self-administered questionnaires were completed by 840 participants enrolled in introductory psychology classes at a university in central Texas during the week prior to the presidential election of 1984. Students were asked if they would approve or disapprove of abortion under four different circumstances. Results indicated that the majority of both males and females were in favor of allowing abortion under all four conditions.

Abortion, Legal↗
PubMed1986

Inflatable and noninflatable penile prostheses: comparative follow-up evaluation.

This evaluation was conducted with 63 men who were organically impotent and subsequently received either an inflatable penile prosthesis (n = 43), a noninflatable penile prosthesis (n = 14), or both in succession (n = 6). The patient groups were compared for sexual satisfaction, sexual activity, mental status, complications, satisfaction with prosthesis, and relationship changes. The methods of evaluation were the Derogatis Sexual Functioning Inventory and two unstandardized questionnaires. Significant differences were found between the two patient groups: inflatable prosthesis recipients report being more sexually satisfied, more satisfied with their implant, experiencing less psychiatric distress, having a more rapid postsurgical recovery, more sexually active, and experiencing more positive changes in relationships with their partners than do recipients of a noninflatable prosthesis. The data suggest that the inflatable prosthesis may be a more favorable choice for most individuals than noninflatable devices.

Adaptation, Psychological↗