Adolescent Violence in the Home Among Youth Presenting to an Early Psychosis Service: An Exploration of Contributing Factors

Adolescent violence in the home is a growing public health issue and remains under reported and under-researched. The focus of the present research is to investigate factors that may contribute to adolescent violence in the home, among acohort of young people with co-occurring early psychosis. Data relates to 50 young people (16 females, 33 males, 1 nonbinary) aged from 16-25 who were clients at a youth early psychosis service in Melbourne, Australia. Results from a discriminant function analysis revealed the two major contributing factors to whether someone used violence in the home, were whether a young person had a coexisting neurodevelopmental or intellectual disability and whether they used violence outside the home. The findings provide preliminary evidence that engaging in violence outside the home and the presence of a neurodevelopmental or intellectual disability may make it more likely for young people with early psychosis to use violence in the home.

Alveolar soft part sarcoma metastatic to small bowel mucosa causing polyposis and intussuseption

A report of alveolar soft part sarcoma metastatic to the small bowel is presented. Hematogenous metastases to the small bowel from primary tumors outside the abdominal cavity are uncommon, and most remain asymptomatic and are not discovered until autopsy. However, small bowel metastases can lead to intestinal obstruction, intussuseption or even perforation. While metastases to the small bowel have been described for other tumor types, including melanoma and lung cancer, this is extremely uncommon for sarcoma, especially alveolar soft part sarcoma. We describe a 42-year-old male with a long history of alveolar soft part sarcoma, metastatic to the lung and brain, who developed an intussuseption from metastases to the small bowel.

Methodology of the Cardiovascular Health and Age-Related Maculopathy (CHARM) Study

Age-related macular degeneration (AMD) is responsible for the majority of visual impairment in the Western world. Epidemiological studies examining risk factors for AMD are needed to develop strategies for the prevention of blindness from this condition. A number of potentially modifiable risk factors for AMD have been identified; however, only smoking has been a consistent risk factor across the numerous studies. A growing body of evidence suggests that AMD and cardiovascular disease may have common risk factors. The Cardiovascular Health and Age Related Maculopathy (CHARM) Study was established to examine the risk factors for AMD and its progression, in particular risk factors associated with cardiovascular disease. Examining risk factors for prevalent AMD, cases with AMD were compared with age and gender matched controls with no AMD features. For the assessment of AMD progression, the study examined in 2001 and 2002 those participants with early AMD, or age-related maculopathy (ARM), who had undergone baseline examination between 1992 and 1995 and compared the characteristics of those who had progression of AMD with those who did not. The CHARM study involved both ophthalmic and cardiovascular examinations. Standardised clinical eye examination and grading of the macular stereo photographs were used to determine the AMD status and progression. To examine cardiovascular status, carotid artery ultrasound imaging analysis of systemic arterial compliance, augmentation index and pulse wave velocity were performed. The traditional and novel risk factors for CVD such as levels of glucose, cholesterol, high density lipoprotein cholesterol, low density lipoprotein cholesterol, fibrinogen, C-reactive protein, immunoglobulins A and M, homocysteine, oxidized LDL and the exposure to the Chlamydia Pneumonia infection were determined. DNA was collected for apolipoprotein E genotyping. The present paper outlines the primary aims of the CHARM study, the methodology involved and the recruitment results.

Training and supporting GPs in providing palliative care to a Vietnamese-Australian community

The mooted increasing role for general practitioners to provide palliative care for an aging Australian population has raised the need for improved training and support for GPs to provide 'healthcare for dying people that maximizes quality of life and assists families and carers during and after death'. In order to address this need, the Commonwealth Department of Health and Ageing commissioned a study into the education, training and support needs of GPs in palliative care. This article reports one element of this national study: the needs of GPs who provide palliative care to a Vietnamese-Australian community in Sydney, New South Wales.

A biochanin-enriched isoflavone from red clover lowers LDL cholesterol in men

OBJECTIVE

To determine whether the two major isoflavones in red clover differ in their effect on low-density lipoprotein cholesterol (LDL-C).

DESIGN

A randomised, placebo-controlled, double-blind trial; two parallel groups taking one of the two isoflavones within which treatment and placebo were administered in a crossover design.

SETTING

Free-living volunteers.

SUBJECTS

A total of 46 middle-aged men and 34 postmenopausal women.

INTERVENTION

Two mixtures of red clover isoflavones enriched in either biochanin (n=40) or formononetin (n=40) were compared. Placebo and active treatment (40 mg/day) were administered for 6 weeks each in a crossover design within the two parallel groups.

MAIN OUTCOME MEASURES

Plasma lipids were measured twice at the end of each period.

RESULTS

Baseline LDL-C concentrations did not differ significantly between men (n=46) and women (n=34), nor between those randomised to biochanin or formononetin. Interaction between time and treatments, biochanin, formononetin and corresponding placebos (two-way ANOVA) on LDL-C showed a significant effect of biochanin treatment alone. The biochanin effect was confined to men; median LDL-C was 3.61 (3.05-4.14) mmol/l with biochanin and 3.99 (3.16-4.29) mmol/l with the corresponding placebo (RM ANOVA with Dunnett's adjustment P<0.05). The difference between placebo and biochanin effects on LDL-C was 9.5%. No other lipid was affected and women failed to respond significantly to treatment.

CONCLUSION

Isolated isoflavones from red clover enriched in biochanin (genistein precursor) but not in formononetin (daidzein precursor), lowered LDL-C in men. This may partly explain the previous failure to demonstrate cholesterol-lowering effects with mixed isoflavones studied predominantly in women.

SPONSORSHIP

Novogen Ltd, North Ryde NSW, Australia, provided partial support including provision of tablets and outside monitoring.

Australian doctors and their postgraduate qualifications

BACKGROUND

A key activity for doctors is lifelong learning. This may be as part of professional development, vocational registration, formal postgraduate study, e.g. university diplomas and degrees, or vocational training which leads to fellowship of a professional college. However, there are significant barriers of time and cost that prevent many doctors from participating in lifelong learning.

METHOD

We examined the range of basic and postgraduate qualifications held by a representative sample of 1198 doctors provided by the HIC of Australian doctors.

DISCUSSION

Significant numbers of general practitioners practise without a formal postgraduate qualification in general practice, unlike our specialist colleagues. However, postgraduate studies are undertaken in a variety of other formats and qualifications.

The role of conjugative transposons in the Enterobacteriaceae

Although widely studied in gram-positive Streptococci and in the gram-negative Bacteroides, there is a scarcity of information on the occurrence and nature of conjugative transposon-like elements in the well-studied Enterobacteriaceae. In fact, some of the major reviews on conjugative transposons prior to 1996 failed to mention their occurrence in this group. Recently, their presence has been reported in Salmonella, Vibrio and Proteus species, and in some cases such as the SXT element in Vibrio and the IncJ group element CTnR391, there has been some molecular characterization. The elements thus far examined appear to be larger than the common gram-positive conjugative transposons and to be mosaic in structure, with genes derived from several sources. Recent evidence suggests that in the Enterobacteriaceae the elements may be related to enteric pathogenicity islands. The evolution, distribution and role of these elements in the Enterobacteriaceae is discussed.

Effects of ACE inhibitor therapy on derived central arterial waveforms in hypertension

Large artery properties constitute an important component of left ventricular afterload in hypertension. The present study examined whether such properties were particularly responsive to angiotensin converting enzyme inhibitor therapy. A prospective, randomized, 12-week study in 138 previously treated hypertensive subjects, in 67 of whom usual treatment (UC) was replaced with perindopril (P) therapy. Large artery properties were assessed as central arterial pressure augmentation determined by applanation tonometry of the radial artery and a transfer function. At baseline both augmentation index (AI, %) and pressure (AP, mm Hg) were related to body size, heart rate, and gender. In addition AP was related to age and systolic blood pressure (BP). After 12 weeks of treatment AP decreased significantly in both perindopril and UC groups, whereas AI only decreased significantly (151.7%+/-2.3% to 144.9%+/-2.6%) in those treated with perindopril. Decreases in AP (-4.2+/-0.9 mm Hg v -1.9+/-0.7 mm Hg) and AI (-6.8%+/-2.2% v -2.2%+/-2.5%) from week 0 to week 12 were greater in the perindopril-treated group, but differences between groups failed to reach statistical significance (P = .05 and .09, respectively). The change in AI during the 12-week treatment period was dependent on the initial heart rate (P < .001), systolic BP (P < .05), weight (P < .001), and sex (P < .001), but not on treatment group (P > .5). Al at 12 weeks was negatively correlated with heart rate but regression slopes for the association were virtually identical for perindopril and UC groups. Perindopril treatment produces a greater decrease in AI than continuation with previous therapy, but this can be largely explained by hemodynamic changes rather than direct arterial effects.

The efficacy of direct current stimulation for lumbar intertransverse process fusions in an animal model

STUDY DESIGN

Posterolateral lumbar intertransverse process fusion using a rabbit model with autologous bone graft and direct current stimulation was compared with fusion achieved by using autologous bone graft alone.

OBJECTIVES

To determine the efficacy of direct current electrical stimulation for the posterolateral lumbar intertransverse process fusion technique by using a 20-microA current and the more recently developed 60-microA current delivered by an implantable direct current stimulator.

SUMMARY OF BACKGROUND DATA

Previous studies have demonstrated a positive effect of direct current electrical stimulation on posterior spinal fusion techniques. However, until recently, the environment of an intertransverse fusion was not well simulated. The current research examined the posterolateral lumbar intertransverse process fusion technique with direct current electrical stimulation using a rabbit model. This appears to parallel human fusion techniques more closely and allows for lower cost and technical ease.

METHODS

In this study, 44 adult New Zealand white rabbits underwent an L5-L6 intertransverse process fusion. All the fusions used an autologous bone graft obtained from bilateral posterior iliac crests. A device was implanted in all the rabbits subcutaneously, and they were divided randomly into three groups: a sham or nonfunctioning group, a 20-microA low-current stimulator group, and a 60-microA higher-current stimulator group. Spinal fusion was evaluated radiographically, histologically, and manually as well as by biomechanical testing 5 weeks after surgery.

RESULTS

Radiographic grades, manual palpation, biomechanical strength, and stiffness showed an increasing trend from sham or inactive stimulator groups to low-current and then to high-current stimulator groups. Histologic analysis revealed that the higher-current stimulator showed that, statistically, the healing response of the host tissue to the autograft had increased significantly, as compared with the sham.

CONCLUSIONS

Direct current electrical stimulation is efficacious in improving both the healing rate and strength in this posterolateral lumbar fusion model. In addition, it appears that this effect is enhanced by increasing the stimulation current from 20 microA to 60 microA.

Clear cell sarcoma: the Roswell Park experience

BACKGROUND AND OBJECTIVES

Clear cell sarcoma of the tendons and aponeuroses (CCSTA) is an aggressive, rare soft-tissue tumor with approximately 300 reported cases. Although it appears to be histogenetically related to melanoma, its clinical behavior resembles soft tissue sarcoma with a propensity for lymph node metastases. We report our experience at a tertiary cancer center.

METHODS

Eight cases of CCSTA evaluated at Roswell Park Cancer Institute between 1970 and 1998 were reviewed retrospectively. Patient data analyzed included patient age, gender, anatomic location, size of tumor, development of local, regional and distant recurrence, and patient status at last follow up.

RESULTS

Six of eight patients were alive at 2 years, while three of seven patients were alive at 5 years. Of the patients alive with no evidence of recurrence, two had tumors of less than 2 cm, and the remaining patient had incomplete information regarding tumor size. Five patients recurred within 2 years of definitive surgical management. Four had tumors > 5 cm. All five patients progressed to metastatic disease at a median follow up of 20 months (range 1-108 months) following definitive surgical management and all eventually died of their disease at a median of 3 months (range 0-24 months) from presentation with metastatic disease. Four of five patients with lesions > 5 cm received adjuvant chemotherapy with intent to cure, but all eventually died of disease at 4, 22, 34, and 41 months from initial presentation.

CONCLUSIONS

CCSTA is an aggressive tumor of the soft tissues. Early recognition and management are associated with an excellent long-term prognosis. Tumors greater than 5 cm warrant aggressive surgical management and treatment, and are at high risk of the development of distant disease. Aggressive multiagent chemotherapy appeared to have no impact on outcome. Other adjuvant therapeutic options including immunotherapy should be investigated.

Malignant fibrous histiocytoma: an institutional review

BACKGROUND

A thorough understanding of malignant fibrous histiocytoma (MFH), the most common subtype of soft tissue sarcoma, will lead to improved histologic-specific protocols.

METHODS

126 patients with histologically confirmed MFH were analyzed. The median follow-up was 42 months (range 1-233 months).

RESULTS

Overall survival was 58% at 5 years and 38% at 10 years. Grade significantly influenced prognosis, with 10-year survival of 90%, 60%, and 20% for low, intermediate, and high grade tumors, respectively (p = 0.0007). Distant metastases at initial presentation (p = 0.0002) and size of the primary tumor (p = 0.0007) influenced outcome. Neither anatomic site nor depth of the primary tumor were significant prognostic factors. Positive microscopic margins were associated with a decreased disease-free survival (p = 0.006).

CONCLUSIONS

Tumor grade, size, and distant metastases at initial presentation remain the most important prognostic factors for MFH. Resection with negative microscopic margins decreased the incidence of local recurrence.

Evidence that parenteral testosterone therapy may improve endothelium-dependent and -independent vasodilation in postmenopausal women already receiving estrogen

The gender difference in cardiovascular disease has been partly attributed to higher androgenic hormone levels. Although testosterone in women may not affect lipids, it remains unknown whether it negates favorable estrogenic effects on endothelial function. We have investigated the effects of testosterone implant therapy on arterial reactivity encompassing endothelial-dependent and -independent vasodilation in women using hormone replacement therapy (HRT). B-mode ultrasound measurements of resting brachial artery diameter, following reactive hyperemia [endothelium-dependent flow- mediated dilation (FMD)] and following glyceryl trinitrate (GTN) (endothelium-independent dilation), were recorded in 33 postmenopausal women stabilized on HRT (>6 months), at baseline, and 6 weeks after a testosterone implant (50 mg), with 15 postmenopausal nonusers of HRT serving as controls. In the brachial artery, baseline resting diameter was similar (0.40 +/- 0.01 vs. 0.41 +/- 0.01 cm, P = 0.5). In the treated group, testosterone levels increased (0.99 +/- 0.08 to 4.99 +/- 0.3 nmol/L, P < 0.001), associated with a mean 42% increase in FMD (6.4% +/- 0.7 to 9.1% +/- 1.1, P = 0.03). The control group did not change (8.1% +/- 1.4 to 5.6% +/- 1.0, P = 0.4). ANOVA of repeated measures (P = 0.04) and mean change (P = 0.02) in FMD both demonstrated significantly greater improvement with testosterone compared with controls. GTN induced vasodilation increased with testosterone treatment (14.9% +/- 0.9 to 17.8% +/- 1.2, P = 0.03). Our preliminary data indicate that parenteral testosterone therapy improves both endothelial-dependent (flow-mediated) and endothelium-independent (GTN-mediated) brachial artery vasodilation in postmenopausal women using long-term estrogen therapy. The mechanisms underlying these potentially beneficial cardiovascular effects require further investigation.

Reelin binds alpha3beta1 integrin and inhibits neuronal migration

Mice that are mutant for Reelin or Dab1, or doubly mutant for the VLDL receptor (VLDLR) and ApoE receptor 2 (ApoER2), show disorders of cerebral cortical lamination. How Reelin and its receptors regulate laminar organization of cerebral cortex is unknown. We show that Reelin inhibits migration of cortical neurons and enables detachment of neurons from radial glia. Recombinant and native Reelin associate with alpha3beta1 integrin, which regulates neuron-glia interactions and is required to achieve proper laminar organization. The effect of Reelin on cortical neuronal migration in vitro and in vivo depends on interactions between Reelin and alpha3beta1 integrin. Absence of alpha3beta1 leads to a reduction of Dab1, a signaling protein acting downstream of Reelin. Thus, Reelin may arrest neuronal migration and promote normal cortical lamination by binding alpha3beta1 integrin and modulating integrin-mediated cellular adhesion.

General practitioners' views on patient care research

BACKGROUND

Little research has been undertaken into the factors affecting recruitment by Australian general practitioners of patients for clinical trials. Understanding the differences between recruiters and non-recruiters will assist researchers in better supporting general practitioners involved in such research.

METHOD

A survey of general practitioners involved in recruiting patients for clinical trials for the RACGP Research Program was undertaken.

RESULTS

Recruiters were more likely to be interested in learning more about research, to perceive involvement as worthwhile, to desire a good relationship with Research Program staff and to feel the doctor-patient relationship assists recruitment.

DISCUSSION

Recruiters in general are average general practitioners, male, middle-aged and work in group practices. Most felt some discomfort in recruiting patients, but believed the strong doctor-patient relationship assisted in the process.

CONCLUSION

The Research Program needs to recruit general practitioners interested in research, choose topics of interest, keep recruitment protocols simple and stay in contact.

General practitioners' beliefs, attitudes and reported actions towards chronic fatigue syndrome

OBJECTIVE

To undertake a survey of Australian general practitioners (GPs) to explore their beliefs, attitudes and reported actions with respect to chronic fatigue syndrome (CFS).

METHOD

A random sample of 2090 Australian GPs, stratified by state, was surveyed in May-August 1995.

RESULTS

A 77% response rate was obtained. For the majority of practitioners who pursue a diagnosis of CFS, six symptoms were considered to be of significance: chronic unremitting fatigue for over 6 months; failure to recover energy after rest; reduced exercise tolerance; prostration for several days after exercise; generalised myalgia and poor concentration. Individual counselling was the most frequently used treatment. Thirty-one percent of practitioners reported that they did not believe that CFS is a distinct syndrome. Of these, 70% reported that the most likely cause of chronic fatigue was depression.

CONCLUSION

There is considerable diversity of opinion between practitioners about CFS. The diversity extends from questioning whether the syndrome even exists to different strategies for diagnosis and management.

Volume expansion does not activate neuronal projections from the NTS or depressor VLM to the RVLM

We investigated whether a monosynaptic connection from the nucleus tractus solitarius (NTS) or the depressor ventrolateral medulla (VLM) to the pressor region of the rostral VLM (RVLM) constituted part of the reflex pathway activated by cardiopulmonary baroreceptors. Volume expansion in the conscious rabbit, which elicits renal nerve inhibition predominantly via cardiac mechanoreceptors, was used as the stimulus. The protein Fos was used as a marker of neuronal activation. The retrogradely transported tracer rhodamine-tagged microspheres, previously injected into the pressor region of the RVLM, identified medullary neurons that projected to that region. Volume expansion significantly increased the number of Fos-positive cell nuclei in the NTS and in the depressor VLM. Neurons that projected to the RVLM were found throughout the depressor region of the VLM and in the NTS but were not activated by volume expansion. Thus, although the central reflex pathways activated by volume expansion include the NTS and the depressor region of the VLM, we could not find evidence for a monosynaptic connection between those regions and the RVLM.

Transient peroneal nerve palsies from injuries placed in traction splints

Two patients thought to have distal femur fractures presented to the emergency department (ED) of a level 1 trauma center with traction splints applied to their lower extremities. Both patients had varying degrees of peroneal nerve palsies. Neither patient sustained a fracture, but both had a lateral collateral ligament injury and one an associated anterior cruciate ligament tear. One patient had a sensory and motor block, while the other had loss of sensation on the dorsum of his foot. After removal of the traction splint both regained peroneal nerve function within 6 hours. Although assessment of ligamentous knee injuries are not a priority in the trauma setting, clinicians should be aware of this possible complication in a patient with a lateral soft tissue injury to the knee who is placed in a traction splint that is not indicated for immobilization of this type of injury.

An outbreak of an unusual strain of Serratia marcescens in two Dublin hospitals

We describe a serious outbreak of infection caused by a strain of Serratia marcescens in two Dublin hospitals which occurred over an 11 week period and affected a total of 15 patients. A contaminated bed-pan macerator in the Intensive Care Unit of one hospital was identified as the possible source of infection and spread of the organism probably occurred via hand transmission by hospital personnel and via patient transfer to a second hospital. All isolates of S. marcescens involved in the outbreak had the same antimicrobial susceptibility pattern, with reduced susceptibility to gentamicin, cefotaxime and ciprofloxacin. Epidemiological typing revealed that the strains of S. marcescens isolated in the outbreak were of an uncommon serotype, O21:K14, and using pulsed-field gel electrophoresis, XbaI DNA macrorestriction profiles clustered at 90% similarity. The DNA patterns of the outbreak strain were also highly similar to S. marcescens isolates of the same serotype recovered from a separate Dublin hospital during the same time period as the outbreak described here. In addition, the isolates clustered at 82% similarity with strains of the same serotype from a retrospective collection of S. marcescens isolates from various hospitals in the Dublin area, indicating that these may be genetic variants of the same strain. Although the outbreak was brought under control following implementation of infection control measures, a significant number of similar O:21 isolates of S. marcescens have since been identified in four Dublin hospitals. These results suggest the unique spread of a single strain of S. marcescens in Dublin hospitals.

Choosing a method to answer the question. Quantitative or qualitative--complimentary, not competitive?

One of the defining characteristics of general practice is its heterogeneity. GPs vary widely in their assessment and management of clinical problems. It is therefore likely that this environment will generate numerous questions that require the use of various research approaches. This paper discusses how to choose between these approaches.

Hormonal therapy increases arterial compliance in postmenopausal women

OBJECTIVES

This study investigated the effects of hormonal therapy on large arterial properties.

BACKGROUND

Arterial stiffness is an emerging risk marker for coronary heart disease and is potentially modifiable. Postmenopausal use of hormonal therapy is associated with a lower risk of coronary heart disease.

METHODS

Total systemic arterial compliance (SAC) and pulse wave velocity (PWV) were determined in 26 premenopausal and 52 postmenopausal women, 26 of whom were taking hormonal therapy.

RESULTS

Arterial compliance was greater in the premenopausal group (mean +/- SEM 0.57 +/- 0.04 arbitrary compliance units [ACU]) than in the postmenopausal group not taking hormonal therapy (0.26 +/- 0.02 ACU, p = 0.001). Postmenopausal women taking hormonal therapy had a significantly increased total SAC compared with women not taking hormonal therapy (0.43 +/- 0.02 vs. 0.26 +/- 0.02 ACU, p = 0.001). PWV in the aortofemoral region in the premenopausal women was 6.0 +/- 0.2 vs. 8.9 +/- 0.3 m/s (p < 0.001) in untreated postmenopausal women. However, postmenopausal women taking hormonal therapy had a significantly lower PWV than those not taking hormonal therapy (7.9 +/- 0.2 vs. 8.9 +/- 0.3 m/s, p = 0.01). Eleven postmenopausal women had their hormone replacement therapy withdrawn for 4 weeks, resulting in a significant decrease in SAC and a significant increase in aortofemoral PWV.

CONCLUSIONS

The increased SAC and decreased PWV in women receiving hormonal therapy suggest that such therapy may decrease stiffness of the aorta and large arteries in postmenopausal women, with potential benefit for age-related cardiovascular disorders. The reduction of arterial compliance with age appears to be altered with hormonal therapy.

Effect of continuous venovenous hemofiltration with dialysis on hormone and catecholamine clearance in critically ill patients with acute renal failure

OBJECTIVES

To measure the effect of continuous venovenous hemofiltration with dialysis on cardiovascular stability in the critically ill patients and to assess the extraction of a number of hormones and catecholamines by continuous venovenous hemofiltration with dialysis.

DESIGN

Prospective, clinical study.

SETTING

Intensive care unit of a tertiary medical center.

PATIENTS

Twenty critically ill patients with acute renal failure.

INTERVENTIONS

Timed collections of serum and ultradiafiltrate in patients receiving continuous venovenous hemofiltration with dialysis, with measurements of their catecholamine and hormonal content and calculation of continuous venovenous hemofiltration with dialysis clearances and daily extractions. Correlation of changes in catecholamines with prospectively collected hemodynamic data during the first 24 hrs of continuous venovenous hemofiltration with dialysis therapy.

MEASUREMENTS AND MAIN RESULTS

No significant changes in dopamine, epinephrine, and norepinephrine requirements or plasma concentrations were seen during the first 24 hrs of continuous venovenous hemofiltration with dialysis. Overall daily losses of catecholamines in the ultradiafiltrate were small (dopamine 404 micrograms; epinephrine 32 micrograms; norepinephrine 29 micrograms). Hemodynamic variables remained stable during this period of continuous venovenous hemofiltration with dialysis therapy. All studied hormones were detected in the ultradiafiltrate, but their mean daily extractions were very small (aldosterone 0.37 micrograms; parathyroid hormone 53.4 pmol; cortisol 4.8 mg; T4 and T3 [trace amounts]; thyroid-stimulating hormone 2.6 mU; testosterone [trace amounts]).

CONCLUSIONS

In critically ill patients with acute renal failure, continuous venovenous hemofiltration with dialysis results in minimal losses of catecholamines and is associated with cardiovascular stability. It causes only minor losses of several hormones. These losses are unlikely to be clinically important. Thus, blood purification achieved by continuous venovenous hemofiltration with dialysis does not produce significant catecholamine or hormonal losses and is associated with hemodynamic stability.

Differences in the acute and chronic antihypertensive effects of lisinopril and enalapril assessed by ambulatory blood pressure monitoring

Although lisinopril and enalapril are equipotent angiotensin converting enzyme (ACE) inhibitors lisinopril has been reported to produce greater inhibition of plasma ACE 24 hours after single doses. This study compared the antihypertensive effects of once daily 10mg doses of the drugs using a randomised, double-blind, two period cross-over design with ambulatory blood pressure monitoring. Lisinopril lowered mean 24 hour systolic blood pressure significantly more than enalapril after 4 weeks of treatment (14/7 +/- 2/1mmHg & 9/6 +/- 2/1mmHg, respectively, adjusted SBP difference 4.8mmHg, P < 0.01). This difference was confined to the second 12 hours of the daily dosage interval (adjusted SBP difference 13-24 hours after dosing 9.9mmHg, P < 0.001). The diastolic pressure showed a similar trend but this was not statistically significant. The side effects of each agent were minor. We conclude that chronic, once daily therapy with 10mg of lisinopril reduces systolic blood pressure more effectively than an equal dose of enalapril due to its greater effect in the latter half of the 24 hour dosage interval.

In vivo catecholamine extraction during continuous hemodiafiltration in inotrope-dependent patients

Many critically ill patients require inotropic or vasopressor support to maintain adequate oxygen delivery. Removal of catecholamines by continuous hemodiafiltration (CHD) could alter exogenous catecholamine requirements. The authors have studied hemodynamic state, catecholamine clearances, and catecholamine requirements in 12 critically ill patients (mean APACHE II score, 24.5) receiving CHD. Hemodynamic parameters were assessed before CHD initiation, and at 4 and 24 hours of therapy. Simultaneous determinations of serum and ultradiafiltrate dopamine (D), norepinephrine (NE), and epinephrine (E) concentrations were obtained. There were no significant changes in any of many hemodynamic parameters measured during CHD. Mean catecholamine requirements were not altered by CHD. Plasma catecholamine levels were not significantly affected by CHD (mean values at 0, 4, and 24 hours: D: 10,801, 12,056, and 8,797 pg/ml; NE: 1124, 566, and 926 pg/ml; E: 1,420, 1,383, and 843 pg/ml). Catecholamine clearances from CHD (D:43.7 ml/min; NE: 43.5 ml/min; and E: 46.6 ml/min) resulted in daily excretion of only 379 micrograms D, 32.9 micrograms NE, and 37.2 micrograms E. Clearances of catecholamines by CHD represented a daily loss of less than 0.1% of the administered load. In conclusion, although CHD can remove circulating catecholamines, cumulative daily catecholamine extraction is minimal in pharmacologic terms, and has no impact on hemodynamic status.

Vasoconstriction in the renal vascular bed during exercise: studies in control and heart failure rabbits

1. The effects of graded treadmill exercise on renal blood flow (RBF) were examined in seven rabbits, in which congestive heart failure (CHF) was produced by the administration of doxorubicin, 1 mg/kg, twice weekly for 8 weeks, and in seven controls. A third group of five rabbits underwent doxorubicin treatment with the addition of surgical section of the left renal sympathetic nerve. 2. During submaximal exercise, there was a small reduction in RBF in controls, which was greatly exaggerated in CHF. 3. In both control and heart failure rabbits, there was a precipitous fall in RBF as exercise fatigue developed. 4. Renal sympathectomy ablated these changes in RBF during exercise. 5. It is concluded that in heart failure there is an exaggerated, sympathetically mediated, diversion of blood flow away from the kidney. The onset of exercise fatigue in both normal and heart failure rabbits is accompanied by a marked intensification of this process.

Vasoconstrictor role for vasopressin in conscious, sodium-depleted rats

To define the role of vasopressin as a vasoconstrictor hormone in sodium depletion, systemic hemodynamics and regional blood flow distribution were examined in conscious Sprague-Dawley rats after 6 days of a low-sodium diet. Studies were performed after selective or combined blockade with the vasopressin antagonist [d(CH2)5Tyr(Me)]AVP (AVPA), enalaprilat (CEI), and phentolamine (PHENTOL). Plasma levels of vasopressin were increased significantly after CEI and increased further after PHENTOL and CEI plus PHENTOL. AVPA had no effect on blood pressure, whether given alone or in the presence of PHENTOL, CEI, or CEI plus PHENTOL. Significant falls in peripheral vascular resistance associated with reflex increases in cardiac output were observed when AVPA was given to animals pretreated with either CEI or PHENTOL but not both. AVPA alone produced no significant changes in regional blood flow distribution, but a vasoconstrictor action of vasopressin in the renal vascular bed was revealed after prior treatment with CEI or PHENTOL. Muscle blood flow was also increased in the PHENTOL plus AVPA group compared with the PHENTOL group. No significant additional effects of AVPA were revealed by pretreatment with CEI, PHENTOL, or CEI plus PHENTOL for mesenteric, hepatic, splenic, or cerebral vascular beds. It is suggested that vasopressin acts as a vasoconstrictor hormone in conscious sodium-depleted rats when either the renin-angiotensin system or alpha-adrenergic system is inhibited but not when both systems are blocked. The renal vascular bed is an important site for vasopressin-induced vasoconstriction under these circumstances.

The catecholamine response to acute myocardial infarction: effect of early administration of sotalol

Thirty-five patients with suspected acute myocardial infarction were studied in a randomised controlled trial to determine whether the catecholamine response to myocardial infarction was altered by administration of the beta blocker, sotalol, given within six hours of the onset of chest pain. Myocardial infarction evolved in 30 patients (15 placebo-treated, 15 sotalol-treated) and was associated with markedly increased plasma and urine noradrenaline and adrenaline levels. Intravenously administered sotalol was well tolerated and produced significant acute falls in blood pressure and heart rate. The reduction in heart rate was maintained in the sotalol group with once-daily therapy. Plasma levels of both catecholamines showed slow but very similar falls in the two groups, the decline being evident earlier for adrenaline than for noradrenaline. This was also reflected in the pattern of catecholamine excretion: significant falls in adrenaline but not noradrenaline excretion were seen on day 2 in both groups. Although mean plasma and urinary catecholamine levels tended to be higher in the sotalol group throughout the study, the differences between the sotalol and placebo groups for the changes in plasma or urinary catecholamines with time were not statistically significant. Episodes of ventricular tachycardia occurred in 68% of the patients on day 1 and 27% of patients on day 2. More patients in the sotalol group experienced episodes of ventricular tachycardia (sotalol 89% placebo 54%) but this difference was not statistically significant.(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiovascular, biochemical, and hormonal responses to intravenous sedation with local analgesia versus general anesthesia in patients undergoing oral surgery

The effects of intravenous conscious sedation and general anesthesia on a number of stress variables were compared in healthy patients undergoing oral surgery. In the intravenous sedation group only the levels of plasma growth hormone and prolactin rose significantly. In the general anesthesia group significant rises were seen in heart rate; systolic blood pressure; mean arterial pressure; levels of plasma adrenaline, adrenocorticotropic hormone, cortisol, and prolactin; and levels of blood glucose, all indicative of a stress response. This study demonstrates that oral surgery under intravenous conscious sedation with local analgesia is associated with less patient stress than is oral surgery under general anesthesia.

Role of vasopressin in experimental congestive cardiac failure

The hemodynamic and hormonal changes produced by adriamycin-induced cardiomyopathic congestive heart failure in rabbits were studied. Adriamycin cardiomyopathy in rabbits led to ventricular dilatation, pleural and pericardial effusions, hepatic congestion, and ascites. These pathological changes were associated with the maintenance of a normal blood pressure but a lowered cardiac output and increased total peripheral resistance. Plasma renin activity and plasma norepinephrine were increased twofold in rabbits with congestive cardiac failure. However, plasma vasopressin and osmolality were normal, whereas an increased vascular sensitivity to the infusion of exogenous vasopressin was demonstrated. Despite the normal levels of plasma vasopressin, administration of a specific vascular vasopressin antagonist led to a fall in blood pressure, a significant increase in cardiac output, and a decrease in total peripheral resistance. No such hemodynamic changes occurred on infusing normal rabbits with the vascular vasopressin antagonist, nor did any significant hemodynamic changes occur on injecting vehicle in rabbits with heart failure. These results suggest that in adriamycin-induced cardiomyopathic heart failure in rabbits, there is activation of the renin-angiotensin system and the sympathetic nervous system together with an increased sensitivity to vasopressin. These three hormonal systems help to maintain blood pressure by increasing total peripheral resistance in this experimental model of heart failure.