Acetabular salvage in revision total hip arthroplasty using the bipolar prosthesis

From June 1978 to December 1987, 106 revision total hip arthroplasties (THA) for acetabular salvage were performed using a bipolar device. Bone grafting was necessary in most of the patients. Five patients were unavailable for follow-up examination, leaving 96 patients (101 hips), who were followed for an average of two years 11 months (range, two months to 8.5 years). Excellent or good results were obtained in 43 patients; fair results were achieved in 20 patients. Of the nine patients with poor results, five demonstrated roentgenographic evidence of subluxation, and four showed no roentgenographic changes that could explain their persistent pain. Twenty-nine of these bipolar revisions failed and required reoperation. Fourteen of these failures were revised using fixed, cementless devices in conjunction with bone grafting. Ten patients developed deep-wound infection. Nine were treated successfully; the tenth patient died of overwhelming sepsis, her case complicated by multiple infected joint arthroplasties. While the results of revision THA in the present series are not as satisfactory as those reported by others who used fixed cemented or fixed cementless acetabular components, they are superior to the results obtained with excisional arthroplasty, the only alternative in many of these cases.     

Bromocriptine self-administration and bromocriptine-reinstatement of cocaine-trained and heroin-trained lever pressing in rats

Rats were trained to lever press for intravenous cocaine (1.0 mg/kg/injection) and then switched to bromocriptine (0.3, 1.0, or 3.0 mg/kg/injection) on a FR-1 reinforcement schedule. Bromocriptine sustained responding at all three doses; hourly drug intake increased linearly with log-dose. In a second experiment, animals were trained to respond for cocaine (1.0 mg/kg/injection) or heroin (0.1 mg/kg/injection) reinforcement; drug was available for the first 2 h of each daily session; saline was substituted for cocaine or heroin for 5 subsequent hours. One hour into each saline substitution session, an intravenous injection of saline or bromocriptine (0.0, 0.5, 1.0, or 2.0 mg/kg) was given. Bromocriptine reinstated both cocaine-trained and herointrained lever pressing; under these conditions, the drug was most effective in the heroin-trained animals. Reinforcing doses of clonidine (0.0625 and 0.125 mg/kg), methohexital, and nicotine (0.05 and 0.1 mg/kg), and a sub-intoxicating dose of ethanol (2 g/kg) failed to reinstate cocaine-trained responding. These data indicate that bromocriptine has cocaine-like and heroin-like stimulus and reinforcing effects.     

Trends in burn admissions in Scotland during 1970–1992

This retrospective study involved analysis of the data of the inpatients discharged with a diagnosis of burns, from various hospitals in Scotland, during the period 1970–1992. There were 51350 such inpatients all over Scotland, with an average annual rate of 2233 cases. Overall burn incidence in actual numbers was 43.7 per cent in < 15 year olds, 41.2 per cent in 15–64 year olds and 15.1 per cent in ≥ 65 year olds. Burn rates per 100 000 population were highest in < 15 year olds and lowest in 16–64 year olds.

The pattern of burn admissions has changed. Since 1987 the highest numbers of burn inpatients were the 16–64 year olds, followed by children, then the elderly. There has been a gradual but sustained fall in burns admissions in all age categories. The downward trend was statistically significant (t = 8.48, 21 d.f., P < 0.001). Though the population of the elderly (≥ 65 year olds) increased by about 13 per cent, the burn admissions and all deaths due to burns did not reveal an upward trend. The population of the old (81 + year olds) increased by 60 per cent during the same period. The incidence of burns was above average when > 80 year olds were considered separately, approaching the levels found in children. However the rate and incidence of burns in the 65–80 year olds resembled that of the younger age group (16–64 year olds).

The total number of deaths due to burns and/or smoke inhalation has declined in all age groups and the decline has been statistically significant (chi-squared = 19.62, 1 d.f., P < 0.001). Maximum number of deaths occurred in ≥ 65 year olds (44 per cent), followed closely by 16–64 year olds (43.5 per cent), and 12.5 per cent of deaths in adolescents and children. The decline was due to improved management of burns and a decrease in the number of patients having large body surface area burns.     

Ectopic Pregnancy in Lower Segment Uterine Scar

Summary: A case of ectopic pregnancy in a lower uterine segment scar following previous Caesarean section is reported. A significant scar defect may result in deep implantation within the myometrium with the risk of persistent pain and bleeding followed inevitably by uterine rupture. In this report we discuss a number of management options. Except in the special situation of superficial implantation in a shallow scar defect where there is ultrasound evidence of continuity of the gestational sac with the uterine cavity we would strongly advise termination of the pregnancy.     

Evaluation of loose bodies in the elbow with MR imaging

The evaluation of loose bodies in the elbow is usually done by means of clinical examination, radiography, and postarthrographic computed tomography (CT). The authors review their experience with magnetic resonance (MR) imaging in place of postarthrographic CT for the evaluation of loose bodies in the elbow. The prospective interpretation of MR studies of the elbow in 20 patients was compared with arthroscopic findings. All elbows were imaged in multiple planes with thin sections, surface coils, and combinations of T1, T2, and proton-density weighting. The sensitivity for showing loose bodies with MR imaging was 100%, and the specificity was 67%. Because this was a nonblinded study, the results are biased and caution must be used when extrapolating these results to the general population. In this limited experience, MR imaging has reliably shown loose bodies in the elbow, and in the authors' institutions has replaced postarthrographic CT for that purpose.     

Isoflurane Anesthesia Attenuates Endothelium-dependent Pulmonary Vasorelaxation by Inhibiting the Synergistic Interaction between Nitric Oxide and Prostacyclin

Background: Endothelium-derived nitric oxide causes vasodilation in part by increasing the dilator activity of other endothelium-derived mediators, including prostacyclin and a K sup +ATP channel-dependent hyperpolarizing factor. Although previous studies have proposed that isoflurane (ISO) depresses endothelium-dependent vasorelaxation by inhibiting endothelium-derived nitric oxide activity, the effects of ISO on the interactions among endothelium-derived dilators have not been characterized. The aim of this study was to determine the mechanisms underlying the inhibitory effect of ISO on endothelium-dependent relaxation in canine pulmonary arteries. Specifically, the goal was to assess the effects of ISO on the individual actions and on the synergistic interactions of these endothelium-derived mediators.

Methods: Canine pulmonary arterial rings were suspended for isometric tension recording. The effects of 1 minimum alveolar concentration ISO (0.4 mM) on vasorelaxation responses to bradykinin, A23187, acetylcholine, cromakalim, and SIN-1 were assessed in phenylephrine-precontracted rings with and without pretreatment with a nitric oxide synthase inhibitor (N sup omega -nitro-L-arginine methyl ester; L-NAME), a cyclooxygenase inhibitor (indomethacin), or a K sup +ATP, channel inhibitor (glybenclamide).

Results: Isofluane attenuated pulmonary vasorelaxation induced by bradykinin, A23187, and cromakalim but had no effect on relaxation induced by acetylcholine or SIN-1. Neither the nitric oxide-mediated nor the prostacyclin-mediated components of relaxation induced by bradykinin and A23187 were altered by ISO. However, ISO abolished the K sup +ATP -mediated component of relaxation and the K sup +ATP -dependent synergistic interaction between nitric oxide and prostacyclin.     

Lasers in surgery.

In January 1991 the winter meeting of the Surgical Research Society was held at St. Bartholomew's Hospital and the Institute of Education, London. During the meeting a symposium was held entitled 'Shedding light on lasers'. Speakers addressed the general principles of lasers, laser-tissue interactions and the applications of lasers in gastro-enterology and in vascular disease. This was followed by an open discussion of the current indications, complications and outcome, together with future possible applications for lasers in medicine.     

Experimental evaluation of free-tissue transfer to promote healing of infected wounds in dogs

An experimental model was designed to evaluate the course of healing and the changes in bacterial concentrations of infected forelimb wounds with devascularized bone in dogs. Infected leg wounds were allowed to heal by secondary intention or were covered with a full-thickness or split-thickness skin graft, an epigastric skin/fat flap, or a gracilis musculocutaneous flap. All skin grafts failed. Gracilis muscle flaps were superior to epigastric skin/fat flaps in decreasing soft-tissue bacterial concentrations. Quantitative bone cultures, however, were positive at reexploration 6 weeks later in 33% of all legs covered with a flap. X-ray films were successful in predicting the presence or absence of bone infection in 70% of all legs. Postmortem arteriograms of legs covered with muscle flaps showed neovascularity to bone. This study suggests muscle flap coverage of wounds debrided of contaminated, necrotic, or infected bone and soft tissue to be an excellent method of providing well-vascularized soft tissue promoting healing and resolution of infection.     

Molecular cytogenetic characterization of Thinopyrum and wheat--Thinopyrum translocated chromosomes in a wheat--Thinopyrum amphiploid

The wheat--Thinopyrum amphiploid 'Agrotriticum # 3425' (AT 3425), which is highly resistant to Cephalosporium stripe, was identified to carry seven pairs of Thinopyrum chromosomes, three pairs of wheat--Thinopyrum translocated chromosomes and 18 pairs of wheat chromosomes. Fluorescence genomic in situ hybridization (FGISH), C-banding, sequential C-banding and FGISH, and denaturing polyacrylamide gel electrophoresis (SDS-PAGE) were used to characterize and identify the chromosomes. The Thinopyrum chromosomes in AT 3425 were designated as T1 through T7 based on their C-banding patterns. The FGISH and C-banding patterns of mitotic chromosomes in AT 3425 and meiotic chromosomes in the hybrid between AT 3425 and wheat cultivar 'Chinese Spring' (CS) revealed that wheat chromosomes 1D, 2B and 3D were involved in the three wheat-Thinopyrum chromosome translocations designated as (W-T)1, (W-T)2, and (W-T)3 respectively. The analysis of high-molecular-weight glutenin subunits in single seeds of AT 3425 confirmed the involvement of wheat chromosome 1D in the translocation (W-T)1. The designations 1DSuu.1DL-1TL, 2BSuu.2BL-2TL and 3DSuu.3DL-3TL were suggested for the wheat--Thinopyrum translocated chromosomes (W-T)1, (W-T)2 and (W-T)3 in AT 3425 respectively.