Synthesis of novel modified dipeptide inhibitors of human collagenase: beta-mercapto carboxylic acid derivatives

The synthesis of a series of thiol-containing, modified dipeptide inhibitors (8) of human collagenase, which incorporate various carboxylic acid derivatives at the presumed P1 position, beta to the thiol group, is described. The compounds were evaluated, in vitro, for their ability to inhibit the degradation of rat skin type 1 collagen by purified human lung fibroblast collagenase, and structure-activity relationship studies are described. Optimum potency (IC50 values in the nanomolar range) was achieved by incorporating methyl (compounds 43a, 56a, and 57ab) or benzyl esters (44a) at the P1 position. Small amides were also accommodated (e.g. primary amide 47a), but in general, increasing the size of the P1 amide substituent lowered potency. PheNHMe, TrpNHMe, and Tyr(Me)NHMe substituents were found to be approximately equipotent P2'-residues. The results of testing all four diastereoisomers 56a-d of the compound with (S)-TrpNHMe at the P2' position indicated that the S,S,S diastereoisomer 56a possessed highest potency (IC50 2.5 nM) and that the second most potent diastereoisomer was 56d (IC50 12 nM) with the R,R,S configuration. It appeared that the orientation of the P1' and the thiol-bearing centers to each other is a more critical influence on potency than any absolute stereochemical requirements. It is suggested that the high potency of the beta-mercapto carboxylic acid derivatives may be a consequence of bidentate coordination of the thiol and carbonyl groups to the active-site zinc ion in the collagenase enzyme.

Morphology, Oviposition, and Embryogenesis in an Australian Population of Acrobeloides nanus

A population of Acrobeloides nanus in Australia is described and illustrated, based on light and scanning electron microscopy. Embryogenesis from egg laying to hatching is followed over a wide range of temperatures. At 15 C, hatching occurs in about 125 hours and at 35 and 37.5 C after about 40 hours. At 40 C, egg development ceases early in cleavage. The capacity of A. nanus to develop over such a range of temperatures, and its anhydrobiotic capabilities, are discussed in relation to its survival and wide distribution in Australia.

The facilitation and evocation of seizures. A questionnaire study of awareness and control

The finding that seizures can be precipitated in some epileptic patients by stimuli which originate from outside the central nervous system is not new. The influence of psychological changes on seizure frequency has, however, been much more difficult to determine. Patients who become aware of such associations may gain some control over their seizures. One hundred randomly selected out-patients with epilepsy were asked about their awareness of such associations and whether, as a consequence, they believed they had any control of their seizures. Ninety-two reported associations between seizures and facilitators or precipitants. The group who had made associations between independent states or stimuli and their seizures were more likely to have poorly controlled seizures and to be taking more anticonvulsants. Many had used this knowledge to control their seizures.

Workshops for consultants on the teaching of clinical communication skills

A group of senior medical school staff concerned about the short-lived effects of communication training formed the Medical Interview Teaching Association. They felt that communication training needed to be reinforced throughout the curriculum and that this would need active involvement by large numbers of consultants. To achieve this they planned a series of workshops. Seventeen consultants and eight other senior staff agreed to participate in the pilot workshop. This was a 3 1/2-day residential workshop. The structure was adapted from a 'faculty development' model used successfully in the USA. Participants worked mostly in small groups helped by experienced facilitators. The teaching style was learner centred and therefore the details of the problem-based agenda and the choice of working methods were largely determined by the participants themselves. There were also some conventional lectures and demonstrations. Evaluation was by postal questionnaire 2 weeks later. This requested both qualitative comments and Likert scale ratings about every aspect of process and outcome. Most responses were strongly positive. Participants felt they made good progress in developing new skills and new curriculum ideas. They also felt more motivated and self-aware as teachers. The learner-centred approach and the diversity of learning activities were seen as very useful. The unstructured approach to self-awareness training was felt to be less useful. It is concluded that such workshops could well lead to more effective communication training and may also have wider implications for medical education.

Psychiatric education improves internists' knowledge: a three-year randomized, controlled evaluation

Trainees were randomized into four groups: (1) control; (2) consult; (3) liaison; or (4) consult-plus-liaison to evaluate the psychiatric knowledge gained after two different training programs for primary care residents. Consult was a 1-month rotation on the Psychiatry Consultation Service. Liaison consisted of 31-hour workshops over 1 year. Consult-plus-Liaison refers to both training programs, experienced in consecutive years. An oral examination was administered before and after training. The analysis of variance and tests of simple effects revealed significant training effects for both groups. The effect size of training was greater for residents exposed to both programs, compared with either one alone. The two different training programs were both effective in improving the psychiatric knowledge of primary care residents and exposure to both programs proved superior to either one alone.

Perceptions of psychological problems in general practice: a comparison of general practitioners and psychiatrists

All general practitioners and psychiatrists working in a single health district were sent a questionnaire on their perceptions of the prevalence of psychological problems among patients consulting in general practice. One hundred and twenty-one GPs (75%) and 10 (83%) psychiatrists responded. GPs and psychiatrists agreed that up to 20% of consulting patients were likely to be clinically depressed; they also agreed on the most appropriate management, although GPs tended to be more conservative than psychiatrists would advise on making use of hospital services. GPs, however, believed non-specific psychological problems to be significantly less common than did psychiatrists. This expectation may help explain the reported failure of GPs to diagnose all psychological problems identified by formal psychiatric instruments.

The facilitation and evocation of seizures

Despite the fact that environmental factors have been demonstrated to be important in the genesis of seizures in people with epilepsy, such factors have received scant attention in the education of clinicians or in the provision of services for managing patients with epilepsy. This paper reviews the history of, and literature about, reflex epilepsy, with particular reference to seizures which occur in response to psychological states or stimuli, and discusses the possible implications for management, and the rationale for the use of psychological interventions which may complement drug treatments in the management of epilepsy.

TAN-1, the human homolog of the Drosophila notch gene, is broken by chromosomal translocations in T lymphoblastic neoplasms

Previously we described joining of DNA in the beta T cell receptor gene to DNA of an uncharacterized locus in a t(7;9)(q34;q34.3) chromosomal translocation from a case of human T lymphoblastic leukemia (T-ALL). We now show that the locus on chromosome 9 contains a gene highly homologous to the Drosophila gene Notch. Transcripts of the human gene, for which we propose the name TAN-1, and its murine counterpart are present in many normal human fetal and adult mouse tissues, but are most abundant in lymphoid tissues. In t(7;9)(q34;q34.3) translocations from three cases of T-ALL, the breakpoints occur within 100 bp of an intron in TAN-1, resulting in truncation of TAN-1 transcripts. These observations suggest that TAN-1 may be important for normal lymphocyte function and that alteration of TAN-1 may play a role in the pathogenesis of some T cell neoplasms.

Modified deoxyoligonucleotides stable to exonuclease degradation in serum

Unmodified deoxyoligonucleotides are rapidly degraded in serum-containing medium. Utilizing internally labelled deoxyoligonucleotides the deoxyribonuclease profile for fetal calf serum and human serum was determined. It was found that the predominate nuclease activity in both systems was 3' exonuclease. Deoxyoligonucleotides are protected from exonuclease degradation in sera and cell media by simple terminal modifications that maintain high binding activity for the complementary DNA sequence.