Kristine Bonnevie,Tine Tammes and Elisabeth Schiemann in Early Genetics: Emerging Chances for a University Career for Women

The beginning of the twentieth century saw the emergence of the discipline of genetics. It is striking how many female scientists were contributing to this new field at the time. At least three female pioneers succeeded in becoming professors: Kristine Bonnevie (Norway), Elisabeth Schiemann (Germany) and the Tine Tammes (The Netherlands). The question is which factors contributed to the success of these women’s careers? At the time women were gaining access to university education it had become quite the norm for universities to be sites for teaching and research. They were still expanding: new laboratories were being built and new disciplines were being established. All three women benefited from the fact that genetics was considered a new field promising in terms of its utility to society; in the case of Tammes and Schiemann in agriculture and in the case of Bonnevie in eugenics. On the other hand, the field of genetics also benefited from the fact that these first female researchers were eager for the chance to work in science and wanted to make active contributions. They all worked and studied in environments which, although different from one another, were positive towards them, at least at the start. Having a patron was generally a prerequisite. Tammes profited from her teacher’s contacts and status. Bonnevie made herself indispensable through her success as a teacher and eventually made her position so strong that she was no longer dependent on a single patron. The case of Schiemann adds something new; it shows the vulnerability of such dependency. Initially, Schiemann’s teacher had to rely on the first generation of university women simply because he was unable to attract ambitious young men to his institute. In those early, uncertain years of the new discipline, male scientists tended to choose other, better established, and more prestigious disciplines. However, when genetics itself had become an established field, it also became more attractive to men. Our case studies also demonstrate that a new field at first relatively open to women closes its doors to them once it becomes established.     

Deciphering the mechanisms of intestinal imino (and amino) acid transport: The redemption of SLC36A1

The absorption of zwitterionic imino and amino acids, and related drugs, is an essential function of the small intestinal epithelium. This review focuses on the physiological roles of transporters recently identified at the molecular level, in particular SLC36A1, by identifying how they relate to the classical epithelial imino and amino acid transporters characterised in mammalian small intestine in the 1960s-1990s. SLC36A1 transports a number of d- and l-imino and amino acids, β- and γ-amino acids and orally-active neuromodulatory and antibacterial agents. SLC36A1 (or PAT1) functions as a proton-coupled imino and amino acid symporter in cooperation with the Na⁺/H⁺ exchanger NHE3 (SLC9A3) to produce the imino acid carrier identified in rat small intestine in the 1960s but subsequently ignored because of confusion with the IMINO transporter. However, it is the sodium/imino and amino acid cotransporter SLC6A20 which corresponds to the betaine carrier (identified in hamster, 1960s) and IMINO transporter (identified in rabbit and guinea pig, 1980s). This review summarises evidence for expression of SLC36A1 and SLC6A20 in human small intestine, highlights the differences in functional characteristics of the imino acid carrier and IMINO transporter, and explains the confusion surrounding these two distinct transport systems.     

Elevated rates of testosterone-related disorders in women with autism spectrum conditions

The androgen theory of autism proposes that autism spectrum conditions (ASC) are in part due to elevated fetal testosterone (FT) levels, which are positively correlated with a number of autistic traits and inversely correlated with social development and empathy. A medical questionnaire was completed by n=54 women with ASC, n=74 mothers of children with ASC, and n=183 mothers of typically developing children to test whether women with ASC have an increased rate of testosterone-related medical conditions, and to see whether mothers of children with ASC show similar abnormalities, as part of the 'broader autism phenotype'. Compared to controls, significantly more women with ASC reported (a) hirsutism, (b) bisexuality or asexuality, (c) irregular menstrual cycle, (d) dysmenorrhea, (e) polycystic ovary syndrome, (f) severe acne, (g) epilepsy, (h) tomboyism, and (i) family history of ovarian, uterine, and prostate cancers, tumors, or growths. Compared to controls, significantly more mothers of ASC children reported (a) severe acne, (b) breast and uterine cancers, tumors, or growths, and (c) family history of ovarian and uterine cancers, tumors, or growths. These results suggest current hormone abnormalities in women with ASC and their mothers. Direct investigations of serum testosterone levels and genetic susceptibility to high testosterone production or sensitivity in women with ASC would illuminate the origin of these conditions. The relationship between FT and current testosterone levels also needs to be clarified. The present results may be relevant to understanding the increased male risk to developing autism.     

Comparison of Habit Reversal and a Behaviorally-Modified Dental Treatment for Temporomandibular Disorders: A Pilot Investigation

This study tested the hypothesis that a habit reversal program emphasizing awareness and reduction of masticatory muscle activity would significantly reduce pain in patients diagnosed with chronic temporomandibular disorder (TMD) and would be a competitive alternative to a behaviorally-modified dental intervention. Eight individuals diagnosed with TMD were randomly assigned to a splint therapy or habit reversal group. Patients in the splint group received an interocclusal appliance (splint) fabricated from acrylic and were instructed to wear the splint day and night up to a maximum of 20 h per day. Patients in the habit reversal group were given a pager and instructed to check tooth position and masticatory muscle tension when paged. Paging occurred approximately once every 2 h during the day, but not at night. Both groups were instructed to avoid tooth contact and relax the masticatory muscles during the 4 weeks of active treatment. Outcome data were collected at 1 month and 1 year post-treatment intervals. Pain decreased significantly for both groups and did not differ between groups. Habit reversal may be as effective as a behaviorally-modified splint therapy for TMD-related pain.     

Regulation of dopamine system responsivity and its adaptive and pathological response to stress

Although, historically, the norepinephrine system has attracted the majority of attention in the study of the stress response, the dopamine system has also been consistently implicated. It has long been established that stress plays a crucial role in the pathogenesis of psychiatric disorders. However, the neurobiological mechanisms that mediate the stress response and its effect in psychiatric diseases are not well understood. The dopamine system can play distinct roles in stress and psychiatric disorders. It is hypothesized that, even though the dopamine (DA) system forms the basis for a number of psychiatric disorders, the pathology is likely to originate in the afferent structures that are inducing dysregulation of the DA system. This review explores the current knowledge of afferent modulation of the stress/DA circuitry, and presents recent data focusing on the effect of stress on the DA system and its relevance to psychiatric disorders.