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Biomedical subjects

P J Rowe

Publications and source records attributed to P J Rowe.

36 records · Page 2Linked to original sources

Correlation of eye color on self-paced and reactive motor performance.

Researchers continue to examine the distinctiveness of motor performance by dark- versus light-eyed individuals. Dark-eyed individuals generally perform better at reactive type tasks (boxing, hitting a ball, defensive positions in football, rotary pursuit), while light-eyed individuals perform better at self-paced tasks (bowling, golf, pitching baseballs). Subjects performed two tasks, rotary pursuit and ball tossing (with light and dark background). Eye color (light or dark) and accuracy of performance were recorded for each subject. No significant difference was found between eye color and performance on the pursuit rotor (reactive activity). A significant difference was found between men's and women's performance in throwing a ball (self-paced activity) at a light-colored background.

Adult↗

Menstrual blood loss and body iron stores in Brazilian women.

Menstrual blood loss (MBL) studies are relevant for developing world women as this could be an important cause of anemia. Whenever a contraceptive method is to be used by such women, consideration should be given to the method which least affects the volume of MBL. In 309 women considered as clinically healthy, MBL, serum ferritin, serum iron and hemoglobin levels were measured: a mean MBL of 23 ml was found. Age, weight, height and previous oral contraceptive use did not affect MBL. Higher parity women may have higher MBL levels but their hematologic indices are not altered. While body iron stores (as judged by serum ferritin levels) are depleted in women who bleed more than 60 ml per cycle, clinical anemia may not be present until their blood loss exceeds 80 ml per menstruation. Brazilian women who lose more than 60 ml of menstrual blood associated with multiple pregnancies without adequate iron supplementation may have a depletion of their body iron stores.

Administration, Oral↗

Consequences of uterine blood loss caused by various intrauterine contraceptive devices in South American women. World Health Organization Special Programme of Research, Development and Research Training in Human Reproduction.

Increased menstrual blood loss (MBL) associated with intrauterine device (IUD) use may precipitate or aggravate iron deficiency anaemia, adversely affecting the health of women particularly those from developing countries. Studies were conducted to define the association of MBL and iron status in South American women; to determine the level of MBL induced by IUD use which would result in iron depletion, the length of time for this depletion to occur and, comparing various IUDS, to determine if any currently tested IUDs are suited to long-term use in South American women. A total of 395 women received one of 5 types of IUDs in Santiago, Chile, and Juiz de Fora, Brazil: Lippes Loop, Multiload-250 and Multiload-375 were used in both centres; in Santiago some subjects received the Copper-7 or ProgestasertR devices and in Juiz de Fora, the TCu 200 and the T-Chloroquin IUDs were also tested. MBL and haemoglobin (HGB) were measured for 3 menstrual cycles before insertion, and following insertion, at one, two, four, six, nine, twelve, eighteen and twenty-four months in the majority of cases. Serum ferritin was measured before insertion and at intervals of six months. Mean values of MBL prior to IUD insertion in both centres varied from 21-30 ml. As with previous publications, the use of the Lippes Loop was associated with the greatest increase in MBL which was sustained throughout the 24 months of observation. Women who had one of the two types of Multiload devices inserted also had increased MBL and reduced ferritin for at least 12 months of use. TCu 200 and Copper-7 IUD users had an initial increase in MBL of 1 to 17 ml in the first six months of observation returning to normal levels beyond six months. Serum ferritin levels were lower for one year and then returned to admission values. ProgestasertR users confirmed previous reports of a reduction of 40-50% in MBL and an increase in serum ferritin. Few significant changes in haemoglobin (HGB) concentrations were found. Serum ferritin levels on admission ranged from 7.1 to 16.4 ng/ml in Santiago and from 15.8 to 23.2 ng/ml in Juiz de Fora. Many women were in a marginal state of iron balance as evidenced by lower serum ferritin values. Changes in serum ferritin were very closely related to those in MBL.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗

Regional and temporal effects of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine on dopamine uptake sites in mouse brain.

When the regional effects of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) on brain dopamine uptake sites in C57 Black mice were studied using [3H]mazindol autoradiography, marked regional differences in effect were seen: the mesolimbic system was less affected than the nigrostriatal tract and within each system the effect was more severe in the terminal fields of the striatum than in the cells of origin. Within the striatum itself there was inhomogeneity of effect, with relative sparing of the dorsomedial aspect compared to the remainder. Complete recovery of [3H]mazindol binding to striatal membranes occurred over 12 months, while dopamine levels recovered more slowly. This supports the concept that MPTP has a highly selective effect within dopaminergic systems and that the initial effect is more pronounced on distal terminals compared to cell bodies. The possibility that recovery of mazindol binding with time may be associated with terminal regrowth needs to be investigated further.

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine↗

The effects of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine on presynaptic dopamine uptake sites in the mouse striatum.

The effects of the specific dopaminergic neurotoxin, 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), were studied on the kinetics of [3H]mazindol binding to striatal membranes of C57 black mice. This radioligand was used to label dopamine uptake sites and when administered in vivo, MPTP caused an irreversible, non-competitive inhibition of mazindol binding, consistent with damage to dopaminergic terminals. This effect was abolished by pretreatment with pargyline, a MAOB inhibitor, suggesting that oxidation of MPTP to the pyridinium moiety, MPP+, is a necessary step for toxicity when mazindol binding is used as an end point. In keeping with these findings, pretreatment of mice with mazindol protected against the dopamine-depleting effects of MPTP in vivo. This data suggests that MPTP exerts its toxic effects via MPP+ which is concentrated intraneuronally via the dopamine uptake system. During this process the neurotoxin irreversibly inactivates the dopamine uptake sites.

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine↗

The effect of doxycycline in infertile couples with male accessory gland infection: a double blind prospective study.

Male accessory gland infection (MAGI, epididymo-prostato-vesiculitis) with abnormal semen quality was rarely the only abnormality in infertile couples since it occurred in no more than 1.6% of 2871 couples evaluated in 7 centres during a 3-year period. Both partners of 33 infertile couples with no other demonstrable abnormality than abnormal semen and MAGI consented to participate in a double blind trial and were treated with either doxycycline, 100 mg/day for 1 month (20 couples) or placebo (13 couples). Follow-up during a total of 175 couple-months included semen analysis and the recording of pregnancy. Pregnancy occurred in 2 of the doxycycline-treated couples (10%) and in 1 of the placebo treated couples (8%), corresponding with conception rates per month of 1.9% and 1.5%, respectively. Sperm motility and, to a lesser extent, morphology showed improvement in both groups. Evidence of infection, namely increased numbers of white blood cells and positive sperm culture, disappeared in both the doxycycline-treated and placebo group. It is concluded that features of MAGI in semen may regress spontaneously and are not influenced by the doxycycline treatment. The concomitant improvement of sperm motility and morphology still does not seem to enhance the probability of conception.

Bacterial Infections↗

Effect of excitotoxin lesions in the medical prefrontal cortex on cortical and subcortical catecholamine turnover in the rat.

Catecholamine turnover in brain areas innervated by dopaminergic neurons was examined 2, 6, and 12 days after bilateral, N-methyl-D-aspartate lesions confined to the rat medial prefrontal cortex. The lesion produced a significant regional increase in the concentration of 3,4-dihydroxyphenylethylamine (DA, dopamine) in both the medial prefrontal cortex and the ventral tegmental area. DA concentrations were increased in the nucleus accumbens on day 6 (128% of control), in the ventral tegmental area on day 2 (130% of control), and in the medial prefrontal cortex on days 2 (145% of control) and 6 (127% of control). The only significant changes in the concentration of 3,4-dihydroxyphenylacetic acid (DOPAC) (197% of control), and in the ratio DOPAC/DA (163% of control) were found in the medial prefrontal cortex on day 6 post-lesion. All parameters had returned to control levels by day 12. DA depletion after the administration of alpha-methyl-p-tyrosine (AMPT) was not significantly different between excitotoxin-lesioned and sham animals on day 6 in all brain regions. Noradrenaline (NA) and 3,4-dihydroxyphenylethyleneglycol concentrations and their ratios, and the depletion of noradrenaline after AMPT were also determined, and the lesion resulted in a significant regional increase in NA in both the nucleus accumbens and the ventral tegmental area. An elevation of NA (147% of control) in the nucleus accumbens was found on day 12. Since the excitotoxin lesion destroys corticofugal efferents from medial prefrontal cortex to the nucleus accumbens, the anterior corpus striatum and the ventral tegmental area, our results provide no evidence for a role of these cortical projections in the regulation of subcortical DA metabolism.(ABSTRACT TRUNCATED AT 250 WORDS)

3,4-Dihydroxyphenylacetic Acid↗

Worldwide patterns of infertility: is Africa different?

The World Health Organisation sponsored a multicentre, collaborative investigation of a standard approach to evaluating infertile couples. The study was conducted between 1979 and 1984 in thirty-three medical centres in twenty-five countries throughout the developed and developing world. Over 5800 couples completed the investigation. African centres had a pattern of infertility different from those in other developing regions or the developed countries. African couples were more likely than those from elsewhere to have secondary infertility or longer duration, a history of sexually transmitted diseases or pregnancy complications, and infertility diagnoses (such as bilateral tubal occlusion or pelvic adhesions) suggestive of previous genital infections.

Adult↗

Termination of very early pregnancy by RU 486--an antiprogestational compound.

RU 486, a new antiprogestational compound, was given to 37 women seeking termination of pregnancy and with amenorrhea of 42 days or less. One patient was found at the second follow-up visit to have an extrauterine pregnancy. The patients received either 25 mg, 50 mg or 100 mg RU 486 twice daily for four days. All patients attended three follow-up visits, one, two and five to six weeks after the start of therapy. The start, duration and amount of bleeding as well as plasma progesterone, beta-hCG and cortisol concentrations were determined for each treatment day and at the follow-up visits. All patients but three started to bleed during treatment. Frequency of complete abortion was 61% (22 out of 36 patients). In only three patients was the pregnancy unaffected by treatment. The clinical efficacy of the treatment was not dose-dependent. Most of the patients experienced only minor side effects in terms of mild uterine pain, nausea and vomiting. However, two patients suffered from heavy bleeding requiring blood transfusion and curettage. In the patients with complete abortion, beta-hCG values decreased significantly but not until the first follow-up visit. The plasma progesterone also decreased. The decrease appeared earlier with the higher daily dose of RU 486. Cortisol concentrations increased during treatment with all 3 dosage regimens but the levels remained within the normal range. It is concluded that treatment with RU 486 may provide a novel therapy for "menstrual regulation" but the efficacy of the treatment needs to be improved to compete with alternatives such as vacuum aspiration.

Abortifacient Agents↗

Effect of prior pregnancy and combined oral contraceptives on baseline menstrual blood loss and bleeding response to intrauterine devices.

No effect of pregnancy was found on baseline menstrual blood loss (MBL) in women within one year of parturition or abortion. The increased bleeding response of women to intrauterine devices (IUDs) was found to be independent of pregnancy status during the year preceding IUD sertion. Women pregnant within a year of insertion had no different MBL than those pregnant more than a year prior to insertion. MBL quantified in subjects within three months of discontinuing combined oral contraceptives (OCs) was significantly lower than in prior non-OC users. Furthermore, MBL was significantly reduced in the former group during the first three menses following IUD insertion. At the sixth and twelfth menses post-insertion, MBL was still lower in prior OC users, but the difference between users and non-users was less and no longer statistically significant.

Contraceptive Devices, Female↗

A comparative study of the effect of the Progestasert TM and Gravigard IUDs on dysmenorrhoea.

Data obtained from questionnaires on the occurrence of dysmenorrhoea in women using IUDs inserted randomly (146 of them Progestasert and 149 Copper 7) are analyzed. In both groups a reduction in the intensity of menstrual cramps was observed over 12 months of use. Although these reductions are significant in each group, they are slightly higher in Progestasert users. However, on comparing the reduction tendencies of both groups, the difference between them is not significant. No significant differences become apparent either when comparing premenstrual and intermenstrual camps. The usefulness of simple questionnaires directed at detecting the nature of pain in currently used family planning forms for IUD users is discussed.

Actuarial Analysis↗