In sickness and in health.

This final instalment in the literary series deals with the relationship between general and oral health and methods of maintaining good oral hygiene.

Toothache tales: Part 1.

This selection of literary extracts deals with the subject of toothache from the point of view of the sufferer. Circumstances, effects and remedies, orthodox and otherwise, are described.

Toothache tales: Part 2.

The second part of the selection of literary excerpts on toothache deals with extraction as the ultimate curse. In common with killing a cat, there are many ways to do it.

Atrazine effects on in vitro maturation and in vitro fertilization in the bovine oocyte.

The effect of low levels of atrazine (2-chloro-4-ethylamino-6-isopropylamino-s-triazine) on in vitro oocyte maturation, in vitro capacitation of sperm, or in vitro fertilization of bovine oocytes and on the quality of blastocyst formation was studied. Bovine oocytes collected from abattoir ovaries were matured, fertilized, and developed to the blastocyst stage in vitro. Embryos that reached a morula or blastocyst stage were stained with Hoechst 33258 stain to determine the number of blastomeres per embryo. Three bulls whose fertilization rates were proven consistent among straws were used for this study. Atrazine was tested at concentrations of 0.01, 0.1, 1, and 10 microM in either the maturation medium, sperm capacitation medium, or the fertilization medium. Because atrazine was dissolved in ethanol, an ethanol control was used to determine any possible effects of ethanol on the in vitro process. The addition of atrazine to both the maturation and fertilization media did not result in any significant difference in fertilization rates between the controls and the treatments. In the capacitation medium, a significant difference between the controls and the atrazine levels of 0.1, 1, and 10 microM was noted for one bull. Atrazine did not affect the number of blastomeres per embryo. There was not a significant difference (p>0.05) in the number of blastomeres per embryo between the controls and the different levels of atrazine in each medium. This study indicates that low levels of atrazine do not have an effect on in vitro fertilization rates or the number of blastomeres per embryo produced in vitro.

By their teeth shall ye know them.

These extracts from the literary archive focus on the role of teeth as a facial feature. Their contribution to favourable and unfavourable facial appearance by their presence or absence, their use as a guide to character and as a means of identification are illustrated.

Seminal plasma and IVF potential. Biochemical constituents of seminal plasma of males from in vitro fertilization couples.

PURPOSE: Many components of seminal plasma play a role in sperm motility by serving as energy sources. Human seminal plasma contains over 30 proteins, including forward motility proteins, antifertility proteins, and coagulation/liquefaction proteins. This study was designed to determine any correlation between motility or fertilization rates and concentrations of fructose, lactic acid, citric acid, carnitine, and protein in human seminal plasma. METHODS: Fertilization rates were determined by in vitro methods. Fructose, lactic acid, citric acid, and carnitine concentrations were ascertained using high performance liquid chromatography. Protein concentration was determined by Bradford assay. RESULTS: Protein concentrations were significantly different as a function of sperm motility levels. Other constituents of human seminal plasma showed an overall correlation, though not significant. No constituent exhibited significant differences as a function of fertility levels. CONCLUSIONS: Protein concentration was significantly lower for samples with high motility. No significant differences between fertility levels and constituents measured were found.

Characterizing the reproductive physiology of the male southern black howler monkey, Alouatta caraya.

Limited reproductive data are available for any species of howler monkey, including those listed as threatened (Alouatta pigra) and endangered (A. palliata) by the Convention on International Trade in Endangered Species Status (CITES) report. The Southern black howler monkey (A. caraya) is being considered as a model species to develop assisted reproductive technology (ART) for vulnerable howler species. Specific objectives of this study were to evaluate the effect of 1) time of year on ejaculate quality and testosterone concentration, 2) age of male on ejaculate quality, and 3) seminal plasma on sperm longevity in vitro. Three adult (4.5 to 5 years) and 3 subadult (1.5 to 2.5 years) males were evaluated for a 1.5-year period. Semen samples were obtained by electroejaculation, and testosterone levels were monitored by fecal steroid metabolite radioimmunoassay. Males produced coagulum-free ejaculates throughout the year. Likewise, most (4/6) males exhibited constant testosterone levels (3.66 +/- 0.45 ng/g) during the year. Testosterone levels for the remaining 2 males, housed as a bachelor troop, were elevated (43 ng/g) during the months of May and June. Seminal characteristics were similar (P > .05) between age groups. Average semen volume was higher during the summer months (P < .05). Sperm concentrations were highly variable through the year and ranged from 7.0 x 10(6) sperm/mL to 583.0 x 10(6) sperm/mL. Percentages of motile sperm (73% +/- 2.3%) and forward progressive sperm motility (3.3 +/- 0.1), however, were consistent (P > .05) throughout the year. The average pH (8.9 +/- 0.1) and osmolality (356.7 +/- 26.1 mmol/kg) of raw semen also did not vary (P > .05) throughout the year. Ejaculates from subadult males, however, contained more (P < .05) morphologically abnormal spermatozoa than adult ejaculates. In addition, in vitro sperm longevity was poor (<2 hours) for subadult male samples, regardless of the presence or absence of seminal plasma (P > .05). For adult males, seminal plasma was detrimental to sperm longevity; however, spermatozoa survived more than 5 hours in vitro when seminal plasma was removed. Although subadult males produce semen, these ejaculates would not be ideal for further characterization of seminal traits or development of ART for other howler monkey species.

As others see us.

Another installment from the literary archives focuses on the public image of dentists and dentistry. The feedback is not exactly flattering.

The influence of husbandry schedules on the number of embryos collected from superovulated mice.

We undertook this study to assess the effect of urine and fecal contamination in the cages of male mice on embryo production in females placed in these cages for breeding. Each superovulated female was placed with a stud male in a cage that was cleaned at 1, 24, or 168 h prior to breeding. Approximately 41 h after mating, embryos were flushed from the oviducts, and we determined the number of embryos and their developmental stages for each treatment group. The number of two-cell embryos collected did not differ significantly when cages were cleaned 1 or 24 h prior to mating the mice. However, significantly (p < 0.05) fewer embryos were recovered when cages were changed 168 h before the animals were mated.

Linear and angular changes in dento-facial dimensions in the third decade.

The object of the study was to examine changes in dento-facial dimensions and relationships during the third decade of life, and consisted of a prospective cephalometric study. The data used consisted of 90 degree left lateral cephalometric radiographs of 21 males and 26 females at ages 18 years (T1) and 21 years (T2), and for 15 of the males and 22 of the females at 28 years (T3). Various dimensions representative of dento-facial morphology were measured and the changes in dimensions over time were calculated and tested for significance with the one sample t-test. In general, skeletal and dental relationships remained relatively stable. Face height and jaw length dimensions increased by small amounts.

Cardiopulmonary resuscitation training for family members of patients on cardiac rehabilitation programmes in Scotland.

Existing cardiopulmonary resuscitation (CPR) training programmes have failed to reach those most likely to witness a cardiac arrest, such as families of cardiac patients. In 1993, the Scottish Health Service Advisory Committee suggested that CPR training could be offered as part of cardiac rehabilitation programmes. A survey was carried out to identify the current extent and nature of such training and factors influencing its provision. Questionnaires were mailed to all the 45 Scottish cardiac rehabilitation programmes on the British Heart Foundation's register. A 93% response rate was achieved. Only 37% of programmes provided information to families about attending a CPR course and 37% actually provided CPR training The numbers trained by these programmes were very small. Hospital programmes were significantly more likely than community programmes to provide CPR training (chi2 = 6.65, P < 0.01) as were those which included an exercise component (chi2 = 7.63, P < 0.01). Reasons for not providing training ranged from lack of resources and lack of staff training, to not having considered it. CPR training is provided as part of cardiac rehabilitation programmes to a limited extent. Ways of recruiting and increasing the number of family members of cardiac patients who are trained in CPR need to be found.

A review of changes in lower arch alignment from seven to fifty years.

Changes in alignment in the untreated lower arch were studied at various developmental stages: 7 to 10 years, 10 to 12 years, 12 to 15 years, 13 to 18 years, 18 to 21 years, 21 to 28 years, and 18 to 50 years. On average, crowding decreased between 7 and 12 years and increased thereafter. The maximum increase occurred in the teenage years between 13 and 18, little or no change occurred in the third decade, and small increases occurred later in life. The possible cause of these changes is discussed in relation to the deterioration in alignment reported in orthodontically treated patients after retention.

The layman's view of orthodontics: a literary review.

It is probably true to say that the masticatory apparatus attracts proportionally greater attention than any other part of the body. Evidence that this is so is provided, not only by the degree of specialisation within the dental profession, but by the frequency with which references to teeth and dentistry crop up in literature. Generations of biographers, novelists, poets, playwrights and essayists have written about their dental experiences and included the dentition in describing the facial appearance of characters, factual and fictional. The literary extracts in this article, culled from an extensive collection, refer to orthodontics. They provide a fascinating insight into the patient's perspective on that speciality and make entertaining reading.

Lower arch crowding in the third decade.

Lower arch crowding and dimensions were measured on study models of 46 untreated subjects, 20 male and 26 female, at age 18 years (T1), 21 years (T2), and 28 years (T3), and the changes during the observation periods calculated. Only very small changes, few of them detectable clinically, were found. The findings are discussed in relation to the changes reported in untreated subjects in other age groups and in orthodontically-treated subjects after retention.

Tumor cell heterogeneity: impact on mechanisms of therapeutic drug resistance.

PURPOSE: The aim of these studies was to determine whether chemotherapy-resistant tumor cell sublines derived from a single starting cell population with identical treatment protocols, have the same mechanism of resistance. METHODS AND MATERIALS: Twelve cyclophosphamide-resistant sublines were derived from KHT-iv murine sarcoma cells by repeated exposures to 2, 4, or 8 microg/ml doses of 4-hydroperoxycyclophosphamide (4-OOHCP). To investigate possible mechanisms of resistance, glutathione (GSH) levels, glutathione S-transferase (GST) activity, and aldehyde dehydrogenase (ALDH) activity were determined. In addition, studies with the GSH depletor buthionine sulfoximine (BSO) and the ALDH inhibitor diethylamino-benzaldehyde (DEAB) were undertaken. RESULTS: Resistant factors to 4-OOHCP, assessed at 10% clonogenic cell survival, ranged from 1.5-7.0 for the various cell lines. Crossresistance to melphalan and adriamycin also were commonly observed. Increased GSH levels, GST activity and ALDH activity were detected in the sublines but not all exhibited the same pattern of biochemical alterations. The response to GSH and ALDH inhibitors also varied among the sublines; the resistance being reversible in some cell lines but not others. CONCLUSION: The present results indicate that when resistant sublines are derived simultaneously from the same starting cell population, the observed mechanisms of resistance may not be the same in each of the variants. These findings support the hypothesis that preexisting cellular heterogeneity may affect mechanisms of acquired resistance.

Late lower arch crowding in relation to soft tissue maturation.

Changes in lower arch space condition and incisor inclinations were measured in relation to changes in the cross-sectional area and separation of the lips in habitual posture in 23 boys and 23 girls between the ages of 12.5 and 15.5 years. Correlation analysis revealed no direct relationship between the increase in lower arch crowding and the changes in lip size and position. In girls, the increase in lower arch crowding was associated to some extent with retroclination of the upper incisors and an increase in the interincisal angle. A very tenuous relationship was found between changes in the upper lip size and position and changes in incisor angulation.