Molecular "Building Block" and "Side Chain Engineering": Approach to Synthesis of Multifunctional and Soluble Poly(pyrrole phenylene)s

Here, the synthesis of a novel poly(pyrrole phenylene) (PpyP) that is both modular in ways of functionalization and soluble in organic solvents is reported, and therefore solution processable. This is achieved through the functionalization of the side-chain substituents in pyrrole phenylene (PyP) repeating units. ^t Butyl acrylate brushes are first grafted through atom transfer radical polymerization from one type of PyP, followed by oxidative chemical co-polymerization of the grafted PyP with a PyP bearing different side chains-either an azide or a methoxy moiety, resulting in a soluble PpyP where solubility is not dopant-dependent. Successful post-polymerization modification through "click" chemistry and post-polymerization processing via electrospinning are also demonstrated. Additionally, performed computational calculations indicate planarity of the novel polyrrole phenylene monomers and ionisation potentials that favor α-α bond formation during their polymerization.

Modular Synthesis and Biological Investigation of 5-Hydroxymethyl Dibenzyl Butyrolactones and Related Lignans

Dibenzyl butyrolactone lignans are well known for their excellent biological properties, particularly for their notable anti-proliferative activities. Herein we report a novel, efficient, convergent synthesis of dibenzyl butyrolactone lignans utilizing the acyl-Claisen rearrangement to stereoselectively prepare a key intermediate. The reported synthetic route enables the modification of these lignans to give rise to 5-hydroxymethyl derivatives of these lignans. The biological activities of these analogues were assessed, with derivatives showing an excellent cytotoxic profile which resulted in programmed cell death of Jurkat T-leukemia cells with less than 2% of the incubated cells entering a necrotic cell death pathway.

Total Synthesis of (-)-Bicubebin A, B, (+)-Bicubebin C and Structural Reassignment of (-)-cis-Cubebin

The first total synthesis of (-)-bicubebin A, and two previously unreported dilignans, (-)-bicubebin B and (+)-bicubebin C has been achieved through the dimerization of (-)-cubebin, confirming the structure and absolute stereochemistry of (-)-bicubebin A. Analysis of the data for (-)-bicubebin B showed it matched that of reported compound (-)-cis-cubebin. The NMR data of the subsequently synthesized proposed structure of cis-cubebin confirmed that its original proposed structure was incorrect.

Total Synthesis of Ovafolinins A and B: Unique Polycyclic Benzoxepin Lignans through a Cascade Cyclization

Ovafolinins A and B, isolated from Lyonia ovalifolia var. elliptica, are lignans that contain a unique bridged structure containing a penta- and tetracyclic benzoxepin and an aryl tetralin. We report the first total synthesis of these natural products in which an acyl-Claisen rearrangement was initially utilized to construct the lignan backbone with correct relative stereochemistry. Judicious use of a bulky protecting group placed reactive moieties in the correct orientation, thereby resulting in a cascade reaction to form the bridged benzoxepin/aryl tetralin from a linear precursor in a single step. Modification of this route allowed the enantioselective synthesis of (+)-ovafolinins A and B, which confirmed the absolute stereochemistry, and comparison of optical rotation suggests that these compounds are found as scalemic mixtures in nature.

Evaluation of angiographic contrast media and platelet function with impedance aggregometry and the PFA-100TM 'platelet function analyser'

BACKGROUND

Angiographic contrast media are used in balloon angioplasty and may influence thrombotic complications of the procedure. We studied the effect of different media on platelet aggregation in whole blood using impedance aggregometry and the PFA-100 'platelet function analyser' (Dade, USA).

METHODS

Venous blood samples from 18 healthy volunteers were split into four aliquots and mixed with 10% normal saline control, non-ionic medium (iohexol), low-molecular weight ionic medium (ioxaglate) and high-molecular weight ionic medium (diatrizoate). Samples were studied with impedance aggregometry and the PFA-100.

RESULTS

All media caused significant inhibition of aggregation compared with control with both methods (P<0.001). Antiplatelet potency was greatest with diatrizoate, intermediate with ioxaglate and least with iohexol with both methods (P<0.01). Electron microscopy of the PFA-100 membrane demonstrated occlusion of the experimental aperture with platelet thrombus in the control. Inhibition of platelet thrombus was seen with all media, greatest with diatrizoate, intermediate with ioxaglate and least with iohexol.

CONCLUSIONS

The media studied significantly inhibited platelet aggregation in vitro and potency was greater with ionic than non-ionic media. These methods use a combination of shear and chemical agonist with whole blood and may reproduce in vivo arterial conditions better than other techniques.

Thrombophilia in children with cystic fibrosis

In some children with cystic fibrosis (CF), percutaneous long lines occlude sooner than expected (due to thrombophlebitis or thrombosis), and many have a totally implantable venous access device (TIVAD), a recognized complication of which is thrombosis. This complication is more likely if the child has an underlying thrombotic tendency, which may be enhanced in the presence of inflammatory lung disease. There are no reports of an identified association of heritable thrombophilia with CF, although individual cases have been recognized. Our aim was to determine the incidence of thrombophilia in children with CF. In a tertiary pediatric CF center, blood was screened for thrombophilia at annual review, and retested if abnormal. A thrombotic abnormality was found in 41/204 (20%) patients. These included activated protein C resistance (10/204, 5%) with a prevalence similar to that expected, but the following abnormalities had an increased prevalence: antithrombin deficiency (2/204, 1%), protein S deficiency (11/204, 5%), protein C deficiency (8/204, 4%), and lupus anticoagulant (18/204, 9%). There were no differences found in those with thrombophilia for the following parameters: age, gender, genotype, lung function, presence of Pseudomonas aeruginosa, prothrombin time, serum IgE, aspergillus-specific IgE, liver function, and blood inflammatory markers. Fifteen children had TIVADs, 4 of whom had evidence of thrombophilia. In conclusion, a significant proportion of patients had a thrombophilic abnormality. We recommend that thrombophilia screening be performed prior to insertion of a TIVAD, and also in those with a history of venous thrombosis, blocked TIVADs, or recurring problems with long lines.

Prospective double-blind randomized study of the effects of four intravenous fluids on platelet function and hemostasis in elective hip surgery

A prospective randomized double-blind study was performed to determine the effects of three colloids, Haemaccel, Gelofusine and albumin, and also saline on platelet activation, platelet aggregation (induced by adenosine diphosphate (ADP), epinephrine, collagen) platelet agglutination by ristocetin and other hemostatic variables in 55 patients undergoing primary unilateral total hip replacement. The fluids were administered according to normal clinical practice and assessments were made immediately before, at the end, and 2 h after the end of surgery. Surgery was accompanied by thrombin generation (increases in thrombin/antithrombin III complex, prothrombin F1 +2 fragment) platelet activation (betaTG) and compromised coagulation. Generally, the platelet activation appeared to result in platelet desensitization and brought about a persistent reduction in platelet aggregation to ADP and epinephrine, irrespective of the fluid used. Additionally, Haemaccel and Gelofusine inhibited ristocetin-induced platelet agglutination and albumin inhibited collagen-induced platelet aggregation. Gross inhibitory effects of Haemaccel that had been predicted from an earlier in vitro study did not occur. Particular fluids had selective additional effects on the hemostatic system. Albumin infusion served to maintain plasma albumin at normal concentrations postsurgery. The two gelatin preparations, Haemaccel and Gelofusine, maintained plasma viscosity. All three colloids led to a transient increase in activated partial thromboplastin time postsurgery and also a transient fall in the concentration of factor VIII, which were accompanied by a transient increase in bleeding time, but there was no measurable increase in blood loss. Inhibition of platelet aggregation by certain colloids may provide additional protection against the increased thrombotic risk in patients following major surgery.

Study of five cell salvage machines in coronary artery surgery

We evaluated the effectiveness, ease of use and safety of five machines for blood salvage during coronary artery surgery. All were equally effective in concentrating red cells. We measured haemoglobin, packed cell volume, free haemoglobin, white cells, neutrophil elastase, platelets, thrombin-antithrombin complex (TAT), prothrombin activation peptide F1.2, fibrin degradation product (d-dimers), tissue plasminogen activator (tPA) and heparin in wound blood, in washed cell suspensions and in a unit of bank blood prepared for each patient. All machines were equally safe and easy to use and were equally effective in removing heparin and the physiological components measured. There were no adverse effects on patients. Clotting factors are severely depleted both in salvaged blood, even before washing, and in bank blood. Cell savers are a valuable adjunct to coronary artery surgery, but careful monitoring of coagulation is required when the volumes of either bank blood or salvaged blood are large.

Systemic platelet effects of contrast media: implications for cardiologic research and clinical practice

BACKGROUND

Angiographic contrast media cause platelet activation and decrease aggregability in vitro. We have previously shown in vitro a significant antiplatelet effect of contrast media at the concentrations obtained locally in the coronary artery during angioplasty. It is not known, however, whether a systemic effect is present.

METHOD

Thirty patients undergoing diagnostic coronary angiography were prospectively randomized to receive the nonionic medium iohexol, ionic low-molecular-weight medium ioxaglate, or ionic high-molecular-weight medium diatrizoate. Platelet aggregability was measured before and after the investigation with whole blood electrical impedance aggregometry (WBEA) with collagen agonist and the PFA-100 (Dade, Miami, Fla) platelet function analyzer with combined shear, collagen, and adenosine diphosphate as agonists.

RESULTS

With WBEA, with iohexol no difference in impedance change was seen: (medians and ranges) before, 9.8 Omega (4.8-19.2 Omega) versus after, 9.6 Omega (2-19.2 Omega) (P not significant [NS]). With ioxaglate a significant fall was seen: before, 8.6 Omega (6.4-15.2 Omega) versus after, 6.6 Omega (0-12.4 Omega) (P =.004). With diatrizoate a significant and greater fall was seen: before, 10.8 Omega (6.4-17.6 Omega) versus after, 6.6 Omega (0-10.8 Omega) (P =.002). With PFA, no difference in closure time was seen with any medium: iohexol before, 99 seconds (79-142 seconds) versus after, 142 seconds (63-128 seconds) (P NS); ioxaglate before, 120 seconds (75-258 seconds) versus after, 95 seconds (74-258 seconds) (P NS); and diatrizoate before, 114.5 seconds (65-250 seconds) versus after, 100.5 seconds (72-300 seconds) (P NS).

CONCLUSIONS

Ionic but not nonionic contrast media have a systemic antiplatelet effect at diagnostic angiographic doses when measured with WBEA. Such an effect has not been shown before. This may explain the observed improved clinical outcome with ionic contrast media but also might confound platelet studies in coronary angioplasty.

High molecular weight kininogen deficiency: a patient who underwent cardiac surgery

A 66 year old male, referred for cardiac surgery, was found to have high molecular weight kininogen deficiency (activity <1%). Apart from activated partial thromboplastin time (APTT) >300 s, tests of haemostasis were otherwise normal (factors VIII, IX, XI, XII and prekallikrein). No inhibitor of coagulation was found. The activated coagulation time (ACT) was 800 s pre-operatively and >1000 s after heparin. Heparin levels were measured directly by an anti-Xa chromogenic assay, with values of between 2.9 and 3.2 u/ml during cardiopulmonary bypass. Thrombin-antithrombin levels rose from 2.3*g/l before surgery to a peak of 83.5*g/l at the end of cardiopulmonary bypass. Cross linked fibrin d-dimers (XDP) levels rose from 100 ng/ml before operation to 600 ng/ml after protamine administration. The patient had no excess bleeding and no thrombotic complications from surgery. This patient shows that high molecular weight kininogen is not required for thrombin formation or fibrinolysis during cardiac surgery and illustrates the need to measure heparin directly in patients with such contact factor deficiencies.

Diurnal variation in platelet aggregation iwth the PFA-100 platelet function analyser

BACKGROUND

Myocardial infarction is commoner in the morning, and previous small studies suggesting diurnal variation in platelet aggregation have been limited to optical aggregometry with platelet-rich plasma and low shear. This phenomenon was studied using whole blood at high shear rates.

METHOD

Fifteen healthy volunteers were venesected at 0800 hrs supine in bed immediately before rising, at 0830 hrs 30 min after rising, at 1200 hrs and 1700 hrs. Samples underwent the high shear method of PFA-100 using additional chemical agonists of collagen with ADP or collagen with epinephrine. PFA-100 results are reported as closure time of the experimental aperture in seconds, a longer time indicating less platelet aggregation.

RESULTS

With both epinephrine and ADP, a non-significant shortening of closure time was seen on rising. Subsequently, with both agonists the closure time lengthened through the day. With ADP the difference was small (medians 0830 hrs: 85 s, 1700 hrs: 87.5 s) but statistically significant (p = 0.03). With epinephrine it was much more marked (medians 0830 hrs: 114.3 s, 1700 hrs: 140.5 s) and highly significant (p = 0.002).

CONCLUSIONS

These findings demonstrate a diurnal rhythm in platelet function using whole blood at high shear rates. This is likely to be more applicable to the in vivo situation than previously reported optical aggregometry studies.

Tissue factor is rapidly elevated in plasma collected from the pericardial cavity during cardiopulmonary bypass

There is growing evidence that the tissue factor/factor VIIa pathway of coagulation is enhanced during cardiopulmonary bypass. Hitherto, available evidence has suggested that upregulated monocyte bound tissue factor is made available, either in the blood collected from the site of surgery or on circulating cells. However, cellular upregulation is slow, while generation of factor VIIa in blood collected from the pericardial cavity is rapid. We have therefore investigated the possibility of an alternative source of tissue factor, plasma (as opposed to cellular) tissue factor in blood samples taken from the central vein catheter (systemic circulation) and collected from the pericardial cavity during cardiopulmonary bypass. Six patients undergoing first time cardiopulmonary bypass grafting were studied. Tissue factor antigen was found to be rapidly elevated (by 15 min) in the pericardial plasma, approximately 5-fold above systemic levels (p <0.004). Similar elevations were found in markers of coagulation activation, factor VIIa antigen (p = 0.066), prothrombin fragment F(1+2) (p <0.003) and thrombin-antithrombin complex (p <0.03). To explore whether plasma tissue factor was (or had been) functionally active, factor VIIa was measured also with the soluble tissue factor functional assay after removal of heparin. Functional factor VIIa activity fell significantly in the systemic circulation, probably due to the heparin-induced increase (approximately 15-fold) in tissue factor pathway inhibitor (TFPI), but was elevated in pericardial blood compared with that taken from the central line catheter (p <0.006). These results demonstrate that both components of the activation complex for the extrinsic pathway of coagulation are rapidly generated in pericardial blood during bypass.

Two-chain factor VIIa generated in the pericardium during surgery with cardiopulmonary bypass : relationship to increased thrombin generation and heparin concentration

Several recent studies have proposed that coagulation is triggered during cardiopulmonary bypass surgery by extrinsic pathway activation involving factor VIIa generation, but the methodology was indirect. Therefore, 12 patients were studied during routine cardiac and cardiopulmonary bypass surgery. Samples were taken before, during, and after bypass from the perfusate, from the aorta (retrograde cardiac drainage), pericardium, and collected suction fluid originating from the whole operative field. These samples were analyzed by enzyme-linked immunosorbent assay for 2-chain factor VIIa, by prothrombin F1+2 assay, by thrombin-antithrombin (TAT) assay, and for heparin concentration. Factor VIIa, F1+2, and TAT levels in samples from the pericardium were greatly elevated (mean, 0.92 to 1.01, 227 to 334, and 399 to 526 microg/L, respectively; preoperative mean, 0.33, 32.3, and 1.90 microg/L, respectively; P<0. 05 for all), whereas levels in suction fluid were less consistently high. Factor VIIa and both F1+2 and thrombin-antithrombin levels in samples from the aorta, pericardium, and suction fluid were significantly correlated (r=0.57, P<0.001, n=111; and r=0.51, P<0. 001, n=105, respectively), and all were inversely correlated with heparin levels (r>-0.35, P<0.001, n>92). There was no evidence of factor VIIa generation in the circuit during bypass surgery, and both F1+2 and thrombin-antithrombin levels rose only approximately 2-fold, probably because heparin levels were higher than they were in the pericardium (P<0.05). We concluded that appreciable activation of factor VII occurs on the pericardium and that this is associated with increased thrombin generation. Ineffective local heparinization may be partly responsible. These results suggest that pericardium-induced activation of factor VII should be the target of anticoagulant strategies during cardiopulmonary bypass surgery.

EMS systems: foundations for the future

Emergency medical services (EMS) occupy a unique position in the continuum of emergency health care delivery. The role of EMS personnel is expanding beyond their traditional identity as out-of-hospital care providers, to include participation and active leadership in EMS administration, education, and research. With these roles come new challenges, as well as new responsibilities. This paper was developed by the SAEM EMS Task Force and provides a discussion of these new concepts as well as recommendations for the specialty of emergency medicine to foster the continued development of all of the potentials of EMS.

A time-motion study of the emergency medical services turnaround interval

STUDY OBJECTIVE

Because overall EMS system response depends on ambulance availability, we conducted a prospective study of the EMS turnaround interval. This interval represents the time elapsed from ambulance arrival at the hospital until the ambulance reports back in service.

METHODS

An on-site observer, while monitoring EMS radio traffic, recorded the delivery and recovery activities of personnel from a large urban EMS system at a university hospital emergency department. System policy permitted a maximum turnaround interval of 30 minutes. Prospectively defined subintervals were analyzed.

RESULTS

A convenience sample of 122 patient deliveries was collected. Observed and radio-reported times of arrival at the hospital differed by -1'24" to +11'08". In 18.9% of cases, arrival was reported on radio more than 5 minutes after the observed arrival. Time from arrival to removal of the patient from the ambulance averaged 59" (range, 13" to 2'53"), and time from patient removal to emergency department entry averaged 42" (range, 10" to 5'22"). Time from ED entry to placement of the patient on an ED bed averaged 2'11" (range, 33" to 9'35"). Although the mean interval for the verbal report to ED staff was 33" (range, 13" to 2'53"). it was 15" or less in 36% of cases. Writing the ambulance call report took an average of 17'12" (range, 5'20" to 52'11"). The mean time off radio was 29'51" (range, 11'43" to 53'37"), and the mean time the ambulance was actually at the ED was 30'01" (range, 11'25" to 1 degree 17'53"). Observed and radio-reported ambulance departure times differed by -4'31" to +23'32". In 22% of cases, departure times differed by -4'31" to +23'32". In 22% of cases, departure was reported by radio more than 5' after actual departure.

CONCLUSION

In this system, ambulance call report documentation required the greatest subinterval of turnaround interval. The turnaround interval and its subintervals varied widely, and radio contact times correlated poorly with observed times at the ED. Attempts at improvement of overall system response through active management of the turnaround interval may be frustrated by reliance on radio-reported availability.

Legislative and regulatory description of EMS medical direction: a survey of states

OBJECTIVE

To assess regulatory trends in EMS medical direction by examining state EMS legislation and regulations, and legal qualifications for medical direction.

METHODS

A two-page survey was mailed to all 50 state EMS directors, with a repeat mailing to nonresponders and telephone follow-up as needed. Copies of EMS legislation and regulations were requested to assist in the interpretation of answers to survey questions. The questions focused on two physician roles in the oversight of the practice of paramedics; off-line ALS service medical director (ASMD) and on-line medical command (OLMC).

RESULTS

Thirty-nine surveys were returned (78%). Only one state (IL) requires that ASMDs be board-certified in emergency medicine. Thirteen others (33%) permit physicians with primary care specialization or various ACLS/ATLS certifications to serve as ASMDs. Twenty-two states (56%) require only that the ASMD be a physician; three states (8%) have no requirements at all. Eight states (21%) have no requirements for personnel providing OLMC, and another 25 (64%) require only physician licensure. Six states (15%) require various ACLS/ATLS certifications. Several states do not differentiate between the two physician roles. Twenty-four states (62%) provide some type of Good Samaritan protection for medical direction, but in two of these only unpaid medical directors are protected.

CONCLUSIONS

There is tremendous variation in regulatory requirements for physician participation in EMS medical direction activities at the ALS level. Few states have specific training or background requirements for the provision of OLMC, and a requirement for board certification in emergency medicine is the exception, not the rule.

Hazardous materials preparedness in the emergency department

INTRODUCTION

This study was conducted to examine the preparedness of emergency departments (EDs) to safely receive, decontaminate, and treat chemically contaminated patients.

METHODS

The safety officers of all 58 acute-care hospitals in the five-county philadelphia metropolitan region were surveyed by mail, with a repeat mailing to nonresponders followed by telephone contact. The 16 survey questions addressed the ability of EDs to safely decontaminate and treat chemically contaminated patients.

RESULTS

Thirty-eight of 58 hospitals (66%) returned usable surveys. Of these, 24 (63%) have a written plan for decontamination and treatment of chemically contaminated patients in the ED, and 19 (50%) have a hospital-wide disaster plan that includes contingencies for decontamination and treatment of one or more chemically contaminated patients. Thirteen hospitals (34%) conducted a drill of either of these plans in 1994. Twenty (53%) EDs have a specific treatment area for chemically contaminated patients. A stock of supplies for protecting the ED from secondary contamination is maintained by 16 (42%). While 24 (63%) store personal protective equipment, most of these involve only gowns, gloves, and surgical masks; only 13 provide any type of respiratory protection. Nine respondents were certain that patients brought in by local EMS would have been adequately decontaminated in the field, eight stated that they believed or felt decontamination would be adequate, and 12 were concerned that field decontamination might not be adequate. Eighteen hospitals (47%) reported treating one or more chemically contaminated patients in 1994. The authors believe the return rate reflects reluctance to commit hospital policies to paper. This was confirmed during telephone follow-up of nonrespondents when, for example, one safety officer discussed hazardous materials (hazmat) principles for 40 minutes, but refused to complete the survey.

CONCLUSIONS

Hospital hazmat preparedness in this area varies tremendously. A significant proportion of hospitals lack a written plan and equipment to allow the ED to safely and effectively handle the chemically contaminated patient. There is reluctance to discuss this topic.

Urban trauma transport of assaulted patients using nonmedical personnel

OBJECTIVE

To describe one urban trauma transport system to clarify the impact of transport by nonmedical personnel on patient outcome.

METHODS

Retrospective data were assembled over a six-year period through the use of the state trauma registry for an urban county served by seven state-accredited trauma centers. A subset of 4,767 consecutive assaulted patients was analyzed using the TRISS method to estimate survival probability. An unexpected death index (UDI), calculated as the difference between expected (TRISS method) and observed death rates, also was determined. Outcomes for patients transported by fire medics (FMs) vs nonmedical, police personnel (NPs) were compared.

RESULTS

FMs transported 2,108 (44%) and NPs transported 1,356 (29%) of the injured assault victims. The FM-transported patients had a lower expected probability of survival than had the NP-transported patients (p < 0.001). This also was true within the penetrating-injury subgroup (p < 0.001), but not the blunt-injury subgroup. The observed death rate was higher for all the FM-transported patients than it was for the NP-transported patients (15% vs 11%; p < 0.01). The UDIs were not different overall, although the NP-transported patients who had blunt trauma had a significantly lower UDI (p < 0.01).

CONCLUSIONS

NP transport of assaulted patients is generally associated with equivalent outcomes in comparison with FM transport in this urban environment. However, these data also provide evidence of an on-scene implicit triage with more severely injured patients generally transported by FMs.

Patient-initiated refusals of prehospital care: ambulance call report documentation, patient outcome, and on-line medical command

INTRODUCTION

There is a growing interest in cases in which emergency medical services (EMS) providers evaluate a patient, but do not transport the patient to a hospital. A subset of these cases, the patient-initiated refusal (PIR) in which the patient refused care and transport, was studied and evaluated. The objectives of the study were to examine the adequacy of ambulance call report documentation in PIR, to examine the clinical outcome of these patients in one hospital-based, suburban EMS system, and to assess the potential impact of on-line medical command (OLMC) on cases of PIR.

METHODS

The system studied is a hospital-based, transport-capable, advanced life support service in a suburban EMS system, with an annual call volume of 4,200 runs. During the 6-month study period, all ambulance call reports completed by the paramedics and medical command control forms completed by medical command physicians were examined, and cases of PIR collected. Each ambulance call report was examined for adequacy of documentation. Patient outcome was determined from emergency department records and telephone follow-up.

RESULTS

Eighty-five PIRs were documented during the study period. Four cases were excluded because of a missing ambulance call reports and/or medical command control forms, leaving 81 PIRs for analysis. Despite policy requiring OLMC in cases of PIR, OLMC was established in only 23 PIRs (28%). Of these, two (9%) had inadequate ambulance call report documentation. Of the 58 PIR in which OLMC was not established, 25 (43%) had inadequate ambulance call report documentation (p < 0.001, Fisher's exact test). Follow-up was obtained for 54 (67%) PIR. Of these, 37 (68%) did not subsequently see a physician, and all needed no further medical care. Seven (13%) saw their own physicians within a few days of the initial refusal of prehospital care, and had no further problems. Ten patients were seen in an emergency department within a few days. Three (6%) were discharged, and did well. Seven (13%) were admitted to the hospital, with four (7%) admitted to monitored beds, and three (6%) to unmonitored beds. There were no deaths.

CONCLUSIONS

Ambulance call report documentation is better with OLMC than without. Patients who initially refuse care may be ill, and some ultimately will be hospitalized. Further research may elucidate a role for OLMC in preventing refusals by incompetent patients, convincing patients who are competent but appear ill to accept transport, and assisting paramedics with other difficult or unusual circumstances.

Prototype curriculum for a fellowship in emergency medical services

The developments of emergency medicine and emergency medical services (EMS) have occurred simultaneously although at times on parallel paths. The recognition of EMS providers as physician surrogates and emergency care resources as an extension of emergency department care has mandated close physician involvement. This intimate physician involvement in EMS activities is now well accepted. It has, however, pointed out the need for in-depth training of physicians in the subspecialty of EMS.

Transmission of HIV to heterosexual partners of infected men and women

Future heterosexual spread of HIV will in part depend on the efficiency of transmission from men to women and from women to men. We studied seventy-eight female sexual partners of men infected with HIV and 18 male sexual partners of infected women. Participants were interviewed concerning sexual practices, use of contraception and other risk factors for HIV infection. Fifteen out of 78 (19.2%) female partners and one out of eighteen (5.5%) male partners were seropositive for HIV antibody. All couples had practised vaginal intercourse. Seropositive female partners did not differ significantly from seronegative partners with regard to length of relationship, number of acts of vaginal intercourse, other sexual practices, stage of clinical disease in the index case, or numbers of other sexual partners in the last five years. In two women, seroconversion was documented after one act of unprotected sexual intercourse. The majority of infected female partners (eight out of 15) had sexual relationships with men who were asymptomatic and did not practice anal intercourse. Biological factors such as variability in infectivity of the index case and susceptibility of the contact, as well as behavioural variables may be important in determining transmission.

On-line medical command in theory and practice

Paramedics are often required to use on-line medical command (OLMC) when they provide advanced life support. We evaluated the efficacy of OLMC use under this broad patient inclusion rule and limited paramedic discretion. OLMC was associated with an average of an eight-minute longer on-scene time, and an infrequent rate of physician-directed deviation from written treatment protocols (3.7% of all OLMC calls). Of the system's advanced life support patients, 6.1% experienced changes in their prehospital health status, reflected in changes in the patient's level of consciousness. OLMC use was associated with improved health status in 5.5% of patients compared with 3.2% for those treated without OLMC (P = .1). The health status of 1.3% of the patients treated with OLMC deteriorated. This was not significantly different from the 1.1% of patients treated without OLMC whose status deteriorated. We suggest that targeted OLMC use with expanded paramedic discretion may improve the efficacy of OLMC. Further controlled comparative studies of OLMC efficacy under targeted OLMC use versus broad patient inclusion rules are needed.

Heterosexual spread of human immunodeficiency virus in Edinburgh

Heterosexual transmission of human immunodeficiency virus (HIV) was investigated in 123 subjects with no apparent risk factor for infection other than having had heterosexual intercourse with a person who was either infected with HIV or at high risk of being infected with it. Seven subjects were found to be infected with the virus. Risk factors for transmission included being the regular sexual partner of an abuser of intravenous drugs and having a sexual relationship of more than 18 months' duration. Anal intercourse was not a risk factor in the three subjects who admitted to it. There were 41 regular partnerships with abusers of intravenous drugs in which the antibody state and history were fully known for both partners. In these partnerships male to female transmission of the virus occurred in five out of 34 (15%) and female to male in one out of seven. In 30 couples in whom one partner was known to be positive for HIV and an abuser of intravenous drugs four female partners were found to be seropositive at first testing, but there were no new positive results on subsequent serial testing. In six of these 30 couples both partners abused intravenous drugs but the partner who was negative for HIV remained so. Few of the partnerships always practised safe sexual techniques, even after a partner was known to be positive for HIV. Heterosexual transmission of HIV occurred but was incomplete and may be related to the timing of the relationship with the infection.

Human immunodeficiency virus and drug misuse: the Edinburgh experience

During 1985 many drug abusers who lived in Edinburgh were found to be infected with the human immunodeficiency virus (HIV). As a result an alternative counselling and screening clinic for testing for antibodies to HIV was established for use by drug abusers. Four hundred and forty one patients were counselled in the first year, and over 60% were either drug abusers or their sexual contacts. One hundred and fourteen (26%) patients were positive for HIV antibody, and 100 (88%) of these were current or former drug abusers. The HIV seropositivity rate in drug abusers was 52% but was only 7% in their sexual contacts. Services were provided for these people as well as counselling before and after the test. The cost of this counselling service for the first year was 27,000 pounds or 61.22 pounds per patient. The unexpected mobility of 23% of the Edinburgh drug abusers, particularly to other areas of Britain, suggests that similar services need to be set up elsewhere.

Long-term behavioral effects of phenobarbital in suckling rats

Long-term effects of phenobarbital on behavior and learning, persisting after drug withdrawal, have not been defined. To look for such effects on the developing nervous system, we treated albino rat pups with phenobarbital for 30 days and then tested them at intervals starting 10 days after the cessation of drug therapy. Beginning at age 6 days, 12 pups were given Ph subcutaneously, gradually increasing the dose to 30 mg/kg/dose b.i.d. by 11 days and continued until 36 days. Twelve control pups were injected with saline. Serum phenobarbital concentrations at 16 days were 54 to 32 micrograms/ml and at 31 days 36 to 4 micrograms/ml. From 46 to 55 days, all animals were tested in a water T maze. The experimental animals completed the four daily runs faster than controls (P = 0.003), made fewer errors (P = 0.003), and spent less time on error-free runs (P = 0.04). When the same animals were retested in the maze at 129 to 136 days, the trend toward faster times was not significant. There were no differences in brain weights of experimental and control rats at 157 days. Twelve pups treated similarly with phenobarbital at 20 mg/kg/dose b.i.d. spent less time on error-free runs than 12 controls when tested at 48 to 57 days of age (P = 0.05) but no differences were found when 12 similarly treated pups were tested at 79 to 85 days. There were no differences in brain weights of the treated and control rats at 78 days of age. Thus it was shown that phenobarbital administration in suckling rats had an effect on behavior that was present 10 to 20 days after the drug was cleared from their serum.

Expansion of emergency medicine's responsibilities for preclinical education of medical students

Many medical schools have required emergency medicine courses for freshmen medical students, usually through participation in BLS (basic life support) or EMT activities. For several years students at our institution have participated in a required emergency medical technician-ambulance grade (EMT-A) course. While retaining much of the material presented in that original EMT-A course, the course has now been expanded to serve as the medical students' introduction to clinical medicine. This expansion resulted from the belief that emergency medicine provides initial patient contact in the presence of a faculty uniquely suited to introduce the broad domain of clinical medicine to the medical student. Emergency physicians, more than any other specialists, must possess the ability to obtain an incisive history promptly, perform an accurate physical examination, and arrive at an assessment with limited laboratory and radiologic data. Initial access to the clinical education of medical students provides the opportunity to direct their efforts in a prioritized fashion, and thus helps to organize their thought processes for further development as clinicians. Departments of emergency medicine should be willing to accept this incremental responsibility for the introduction of the medical student to the clinical and laboratory assessment of patients.