Nuclear lamin A-associated proteins are required for centromere assembly

Many Lamin A-associated proteins (LAAP's) that are key constituents of the nuclear envelope (NE), assemble at the "core" domains of chromosomes during NE reformation and mitotic exit. However, the identity and function of the chromosomal core domains remain ill-defined. Here, we show that a distinct section of the core domain overlaps with the centromeres/kinetochores of chromosomes during mitotic telophase. The core domain can thus be demarcated into a kinetochore proximal core (KPC) on one side of the segregated chromosomes and the kinetochore distal core (KDC) on the opposite side, close to the central spindle. We next tested if centromere assembly is connected to NE re-formation. We find that centromere assembly is markedly perturbed after inhibiting the function of LMNA and the core-localized LAAPs, BANF1 and Emerin. We also find that the LAAPs exhibit multiple biochemical interactions with the centromere and inner kinetochore proteins. Consistent with this, normal mitotic progression and chromosome segregation was severely impeded after inhibiting LAAP function. Intriguingly, the inhibition of centromere function also interferes with the assembly of LAAP components at the core domain, suggesting a mutual dependence of LAAP and centromeres for their assembly at the core domains. Finally, we find that the localization of key proteins involved in the centromeric loading of CENP-A, including the Mis18 complex and HJURP were markedly affected in LAAP-inhibited cells. Our evidence points to a model where LAAP assembly at the core domain serves a key function in loading new copies of centromeric proteins during or immediately after mitotic exit.

Varieties of secrets and secret varieties: the case of biotechnology

This article examines several trends that have combined to veil the new field of biotechnology in secrecy: the transformation of biotechnology from an essentially academic field characterized by strong norms of openness to a field with extensive corporate connections that have reached even to research in leading universities; the establishment of intellectual property rights for life-forms initiated by the landmark Supreme Court decision, Diamond v. Chakrabarty; and the limiting of public access to information about the genetically altered organisms whose use in agriculture, industry, and medicine falls under government controls. The article also examines the effects of the U.S. biotechnology industry's demand for secrecy on the negotiations for a protocol to the 1972 Biological Weapons Convention, particularly the turn from requirements for transparency to protection of opacity with respect to biotechnology and other biological processes, equipment, and production.

A comparison of a hospital outpatients department and general practice in remote Queensland

A survey of all ambulant patients attending the hospital outpatients' department and the private general practice in a remote town in Queensland sought information on patients' reasons for attending. Patients handed the completed questionnaires to their practitioner, who indicated the type of visit and the focus of the encounter. There was little difference between the facilities in terms of patient demographics, except that males accounted for a higher proportion of encounters at the Outpatients' Department (OPD), mainly as emergency encounters. Excluding emergency encounters, patients appeared to perceive the facilities as alternative practices. The practitioners' reports suggested some differences in practice and/or experience between the two facilities, which were in line with commonly held perceptions about OPD and private general practice. The data suggest that the similarities between the two facilities may outweigh the differences. Moreover, the differences between rural hospital practice and rural general practice should be seen as providing the opportunity for more rounded training, rather than mutually exclusive forms of practice.

Videoconferencing: practical advice on implementation

Videoconferencing provides a useful tool for improving information flow, with clinical, educational and administrative uses being particularly relevant to rural and remote Australia. This paper describes the range of possible uses for computer-based videoconferencing and describes the authors' experience in delivering rural medical education in North Queensland via videoconference. Principles that ensure successful videoconferencing are outlined and are applicable to a variety of formats and uses. They include the need to keep it simple, the importance of thorough preparation, and ensuring that education drives technology, rather than the converse.

Reflex muscle contraction in anterior shoulder instability

Reduced proprioception may contribute to recurrent anterior shoulder instability. Twelve patients with unilateral shoulder instability were investigated for evidence of deficient proprioception with an activated pneumatic cylinder and surface electromyography electrodes; the contralateral normal shoulder was used as a control. The latency between onset of movement and the detection of muscle contraction was used as an index of proprioception. No significant difference in muscle contraction latency was detected between the stable and unstable shoulders, suggesting that there was no significant defect in muscular reflex activity. This study does not support the use proprioception-enhancing physiotherapy in the treatment of posttraumatic anterior shoulder instability.

Air versus carbon dioxide insufflation in double contrast barium enemas: the role of active gaseous drainage

Air has been traditionally used as the negative contrast agent in double contrast barium enema (DCBE) examinations, but causes abdominal pain in the 24 h following the procedure. The frequency of post-procedural pain is less when carbon dioxide (CO2) is used as the negative contrast agent. We evaluated patients following DCBE examinations (using either air or CO2) by means of a questionnaire, to determine whether active drainage of gas altered the post-procedural pain. There was no difference in the pain experienced in the groups receiving CO2 with either active or passive drainage, or in the group receiving air with active drainage. Compared with the other groups there was a significantly higher incidence and severity of pain in the group receiving air and passive drainage. We conclude that active drainage of air following a DCBE examination is as effective as using CO2 in reducing post-procedural pain and swelling.

Day case arthroscopy under local anaesthesia

A prospective study of the effectiveness of local anaesthesia in arthroscopy of the knee was performed in 212 consecutive patients. Arthroscopic surgery was undertaken successfully in 121 cases (57%), including meniscectomy and drilling of osteochondral defects. Dynamic evaluation of the patellofemoral joint articulation was possible and demonstration of pathological abnormalities was felt to be beneficial by some patients. The method described is safe, reliable, confers good postoperative analgesia and enables physiotherapy to begin immediately. Conversion to general anaesthesia was necessary in one case due to pain localised to a stiff and osteoarthritic hip. Intra-articular haemorrhage was found to be a problem in one case with synovitis. Only ten patients complained of moderate pain, none had severe pain. Local anaesthesia is contraindicated in cases with ipsilateral osteoarthritis of the hip or with significant synovitis of the knee. This technique is particularly suited to day case surgery.

Rupture of the ulnar collateral ligament of the thumb in a 5-year-old girl

Injuries to the metacarpophalangeal joint of the thumb are rare in children and usually involve avulsion of the bone or cartilage. We describe a tear of the ulnar collateral ligament of the thumb with minimal symptoms in a 5-year-old girl.

Competitive inhibition of human skin collagenase by N-benzyloxycarbonyl-L-prolyl-L-alanyl-3-amino-2-oxopropyl-L-leucyl-L- alanylglycine ethyl ester

A 'ketomethylene' peptide, N-benzyloxycarbonyl-L-prolyl-L-alanyl-3-amino- 2-oxopropyl-L-leucyl-L-alanylglycine ethyl ester, was synthesized and shown to be a fairly potent competitive inhibitor of human skin collagenase.

Severe ocular injuries from orthodontic headgear

Dislocation of extraoral orthodontic tractional devices (headgear) resulted in penetrating ocular injuries in three eyes of two patients. An endophthalmitis caused by mixed flora developed in each injured eye. Despite medical and surgical therapy, only one eye retained useful vision two years following injury. All wearers of headgear and their families should be educated in the proper use of these devices and about the potential for severe facial injuries. Penetrating ocular injuries initially may be relatively asymptomatic. Thus, even persons with seemingly minor injuries from such devices should seek immediate and thorough ophthalmic evaluation. In eyes with penetrating injuries, culture of intraocular fluids should be performed at the time of initial repair. Because the penetrating device is heavily contaminated with oral flora, broad-spectrum antibiotics should be administered by intravenous, subconjunctival, and intravitreal injection. Such injuries, although rare, may have a grave prognosis.

Results of anterior segment surgery with vitrectomy instruments

We used closed-eye endosurgery to treat 58 patients with anterior segment problems. These included nonsenile cataract, residual lens material, pupillary membranes, vitreocorneal touch, aphakic pupillary block glaucoma, intraocular lens complications, epithelial ingrowth, and total hyphema. Thirty-five eyes showed an increase in visual acuity of more than two Snellen lines, 13 eyes demonstrated no change, and ten eyes lost more than two lines. Complications included endophthalmitis, retinal detachment, retinal tears, increased intraocular pressure, postoperative hemorrhage, and bullous keratopathy.