Pollinator adaptation and the evolution of floral nectar sugar composition

A long-standing debate concerns whether nectar sugar composition evolves as an adaptation to pollinator dietary requirements or whether it is 'phylogenetically constrained'. Here, we use a modelling approach to evaluate the hypothesis that nectar sucrose proportion (NSP) is an adaptation to pollinators. We analyse ~ 2100 species of asterids, spanning several plant families and pollinator groups (PGs), and show that the hypothesis of adaptation cannot be rejected: NSP evolves towards two optimal values, high NSP for specialist-pollinated and low NSP for generalist-pollinated plants. However, the inferred adaptive process is weak, suggesting that adaptation to PG only provides a partial explanation for how nectar evolves. Additional factors are therefore needed to fully explain nectar evolution, and we suggest that future studies might incorporate floral shape and size and the abiotic environment into the analytical framework. Further, we show that NSP and PG evolution are correlated - in a manner dictated by pollinator behaviour. This contrasts with the view that a plant necessarily has to adapt its nectar composition to ensure pollination but rather suggests that pollinators adapt their foraging behaviour or dietary requirements to the nectar sugar composition presented by the plants. Finally, we document unexpectedly sucrose-poor nectar in some specialized nectarivorous bird-pollinated plants from the Old World, which might represent an overlooked form of pollinator deception. Thus, our broad study provides several new insights into how nectar evolves and we conclude by discussing why maintaining the conceptual dichotomy between adaptation and constraint might be unhelpful for advancing this field.

Characterization of Nanoscale Particles Produced by Laser Vaporization / Condensation in a Diffusion Cloud Chamber

Nanoscale metal oxide particles have been synthesized by using a novel method which combines laser vaporization of metal targets with controlled condensation in a diffusion cloud chamber. The following oxides have been synthesized: ZnO, SiO2, Fe2O3, Bi2O3, PdO, NiO, AgO, TeO, Sb2O3, TiO2, ZrO2, A12O3, CuO, In203, SnO2, V2O5 and MgO. With this method, the size of the particles can be conveniently controlled by careful control of the degree of supersaturation which is accomplished by adjusting the temperature gradient, total pressure, and partial pressure of the metal vapor generated by laser vaporization in a diffusion cloud chamber. The microscale structures of the SiO2 and A1203 particles exhibit interesting web-like matrices with a significant volume of vacancies. These materials may have special applications in catalysis and as reinforcing agents for liquid polymers.

Secondary sexual characters and sperm traits in coho salmon Oncorhynchus kisutch

A study was undertaken to examine secondary sexual characters (spawning colouration and overall body size) in relation to sperm metrics in one alternative reproductive tactic of coho salmon Oncorhynchus kisutch: large hooknose males that spawn in dominance-based hierarchies. Males with less intense red spawning colouration had higher sperm velocities than males with darker red spawning colouration. There was no relationship between male body size and sperm metrics. These results suggest that within an alternative reproductive tactic, variation in sperm competition intensity may select for a trade-off between investment in sexual colouration and sperm quality.

Criticaly of pH for accurate fluorometric measurements of dipyridamole levels in biological fluids

Extended release dipyridamole (DIP) is widely used in clinical practice as an Aggrenox formulation, which is proven to improve outcomes for secondary stroke prevention in patients after acute vascular events. However, presently established fluorometry techniques are not suitable for trace amount determinations, because of the variable background fluorescence. The authors sought to determine whether biological fluid pH is important for the serial measures of DIP levels in the animal experiments and in patients treated with Aggrenox after ischemic stroke. Post-stroke patient (n = 34) and mice (n = 25) samples were tested to determine DIP levels by established techniques with FluoroMax 3 spectrofluorometer. Both the absorption and emission spectra of DIP were affected by modifications in pH. Fluorescence of DIP was found to be maximal at a wavelength of 490 nm (excitation 420 nm) and the spectral pattern was independent of pH. The intensity of fluorescence, however, was drastically lower at low pH (at pH 2.6, fluorescence was 4% of intensity at pH 9.8). Background plasma fluorescence, however, was completely unaffected by changes in pH. Using these fluorometric characteristics, a regression model that facilitates the efficient and sensitive determination of DIP concentration in biological fluids was formulated. Exploiting pH-dependent characteristics of DIP versus serum fluorescence patterns permits a convenient mathematical model to determine DIP concentration. This relatively inexpensive and time-efficient procedure can quantify drug levels in human/animal plasma/serum, thereby directly determining the level of patient adherence to the prescribed drug regimen, be it in the context of clinical trials or compliance with the animal protocol.

Standards and guidelines for performing central dual X-ray densitometry from the Canadian panel of International Society for Clinical Densitometry

The International Society for Clinical Densitometry (ISCD) is a multidisciplinary nonprofit global organization formed to ensure excellence in densitometry imaging, interpretation, and application. The Canadian panel of the ISCD represents ISCD in Canada and oversees Canadian bone densitometry certification programs. The standards of care from the Canadian panel of the ISCD have been developed in order to establish the minimum level of acceptable performance for the practice of bone densitometry in Canada. A variety of techniques are available for skeletal assessment of bone mineral density, which vary in accuracy, precision, and clinical utility as well as availability. This article focuses on central dual X-ray absorptiometry in adults and does not address densitometry in the pediatric population. Other technologies will be addressed in a subsequent article.

The Arabidopsis Information Resource (TAIR): a comprehensive database and web-based information retrieval, analysis, and visualization system for a model plant

Arabidopsis thaliana, a small annual plant belonging to the mustard family, is the subject of study by an estimated 7000 researchers around the world. In addition to the large body of genetic, physiological and biochemical data gathered for this plant, it will be the first higher plant genome to be completely sequenced, with completion expected at the end of the year 2000. The sequencing effort has been coordinated by an international collaboration, the Arabidopsis Genome Initiative (AGI). The rationale for intensive investigation of Arabidopsis is that it is an excellent model for higher plants. In order to maximize use of the knowledge gained about this plant, there is a need for a comprehensive database and information retrieval and analysis system that will provide user-friendly access to Arabidopsis information. This paper describes the initial steps we have taken toward realizing these goals in a project called The Arabidopsis Information Resource (TAIR) (www.arabidopsis.org).

Bedside monitoring of cerebral blood flow in patients with acute hemispheric stroke

OBJECTIVE

To test the practicability of a new double indicator dilution method for bedside monitoring of cerebral blood flow (CBF) and to assess the clinical value of CBF monitoring as a prognostic tool for outcome and in therapy of elevated intracranial pressure (ICP) in patients with acute hemispheric stroke.

DESIGN

Prospective study. Clinical evaluation of a new method.

SETTING

Neurological intensive care unit of a university hospital.

PATIENTS

Ten patients with acute complete middle cerebral artery territory- or hemispheric infarctions.

INTERVENTIONS

Two combined fiberoptic thermistor catheters were placed in the right jugular bulb and in the thoracic aorta. Central venous injections of ice-cold indocyanine green dye were performed. CBF was estimated by calculating the mean transit times of the cold bolus and dye.

MEASUREMENTS AND MAIN RESULTS

A total of 104 reproducible CBF measurements were obtained. No complications associated with the method were observed. Twelve pairs of measurements were performed within 30 mins with unchanged clinical conditions. The standard deviation of repeated measurements was 2.7 mL/100 g/min; the interrater reliability was between 0.95 and 0.99. The median CBF in patients who died (n = 4) was lower (27 mL/100g/min) than in those who survived (n = 6) (45 mL/100g/ min). Patients who died more frequently had low CBF values of <30 mL/100g/min (22 of 38; 58%) than patients who survived (10 of 54; 19%). A total of 37 CBF measurements were done during ICP elevation of >20 mm Hg. In patients who survived, ICP elevations were only associated with low CBF values in 5 of 26 events; whereas in patients who died, ICP elevations were associated with low CBF values in 8 of 11 events.

CONCLUSIONS

The new double indicator dilution technique may be suitable for serial bedside CBF measurement. It is easy to perform and can be rapidly repeated in the ICU environment. Validation of the method by comparison with standard methods is needed. The preliminary data indicate that bedside monitoring of CBF may give prognostic information for outcome and may guide therapy of elevated ICP in patients with malignant hemispheric infarction.

Endovascular treatment of a grade IV transverse sinus dural arteriovenous fistula by sinus recanalization, angioplasty, and stent placement: technical case report

OBJECTIVE AND IMPORTANCE

The frequent association of dural arteriovenous fistulae (DAVFs) and dural sinus thrombosis may render the treatment of these complex lesions difficult. We report a case of DAVF eradicated by recanalization of the chronically thrombosed transverse sinus (TS) and sigmoid sinus followed by balloon angioplasty and stent deployment at the site of the fistula.

CLINICAL PRESENTATION

A 52-year-old man presented with a Type IV DAVF of the left TS with widespread white matter changes secondary to venous hypertension. Arterial feeders arose from the left internal carotid, external carotid, and vertebral arteries. The distal segment of the left TS, the left sigmoid sinus, and the proximal segment of the right TS were occluded. Reverse flow was observed in the deep venous system and in the superior sagittal sinus.

INTERVENTION

Endovascular access was gained through the left internal jugular vein. Mechanical recanalization of the thrombosed left TS and sigmoid sinus was followed by balloon angioplasty and placement of six overlapping stents extending from the TS to the proximal internal jugular vein. Angiograms performed after surgery showed resaturation of antegrade venous drainage as well as complete eradication of the fistulous connections. The patient was discharged with an improving clinical

CONCLUSION

Recanalization of a chronically occluded dural venous sinus through a jugular approach is feasible. In addition to eradicating cerebral venous hypertension by reestablishing antegrade venous drainage, balloon angioplasty and stent deployment at the DAVF site produced complete closure of the fistula. This may prove to be a new therapeutic strategy for management of DAVF.

The Canadian SCORE questionnaire: optimizing the use of technology for low bone density assessment. Simple Calculated Osteoporosis Risk Estimate

The Simple Calculated Osteoporosis Risk Estimation (SCORE) questionnaire is a tool to assist physicians to identify women who might require bone densitometry. The purpose of this study was to develop a Canadian SCORE and to assess validity and reliability. Twenty sites enrolled 307 postmenopausal women ages 50-70 yr. SCORE results were compared to hip and lumbar spine bone density assessed by dual X-ray absorptiometry. Sensitivity and specificity of a range of SCORE cut-points were assessed in a receiver operating characteristics analysis to determine the optimal cut-point for SCORE. With low bone density defined as a T-score < or = -2.0, a SCORE cut-point of 6 in women ages 50-59 yr displayed a sensitivity of 0. 96, 95% confidence interval (CI) (0.89, 1.00), a specificity of 0.51, 95% CI (0.43, 0.58). In women ages 60-70 yr, a SCORE cut-point of 8 displayed a sensitivity of 0.90, 95% CI (0.80, 0.97) and a specificity of 0.20, 95% CI (0.11, 0.29). The test-retest reliability (intraclass correlation coefficient) was 0.95. SCORE performed better in women in their fifties than women in ther sixties. Older women require higher SCORE cut-points. The use of SCORE as an initial measure for identifying those at risk for osteoporosis may reduce costs by limiting unnecessary tests.

[Fibrinolysis of intraventricular hematoma with rt-PA]

Intraventricular administration of recombinant tissue plasminogen activator (rt-PA) is an experimental therapy to hasten the lysis of intraventricular hemorrhages. We report nine patients (7 male, 2 female, mean age 64a) with intracerebral hematoma with ventricular extension who were treated with intraventricular infusion of rt-PA (2-32 mg, mean dose 17 mg). In two patients, clinically significant bleeding complications were associated with the fibrinolytic therapy. In one of these patients, fibrinolytic therapy was stopped. Other complications could not be observed. In eight of all nine patients, a rapid and extensive reduction of the amount of intraventricular blood occurred. A persistent shunt became necessary in two patients. We conclude, that intraventricular fibrinolysis probably leads to a faster clearance of intraventricular blood. Despite of fibrinolytic treatment, a permanent shunt becomes necessary in some cases. Intraventricular fibrinolysis is a potentially hazardous therapy with the risks of bleeding complications and infection.

Intermittent etidronate therapy to prevent corticosteroid-induced osteoporosis

BACKGROUND AND METHODS

Osteoporosis is a recognized complication of corticosteroid therapy. Whether it can be prevented is not known. We conducted a 12-month, randomized, placebo-controlled study of intermittent etidronate (400 mg per day for 14 days) followed by calcium (500 mg per day for 76 days), given for four cycles, in 141 men and women (age, 19 to 87 years) who had recently begun high-dose corticosteroid therapy. The primary outcome measure was the difference in the change in the bone density of the lumbar spine between the groups from base line to week 52. Secondary measures included changes in the bone density of the femoral neck, trochanter, and radius and the rate of new vertebral fractures.

RESULTS

The mean (+/-SE) bone density of the lumbar spine and trochanter in the etidronate group increased 0.61 +/- 0.54 and 1.46 +/- 0.67 percent, respectively, as compared with decreases of 3.23 +/- 0.60 and 2.74 +/- 0.66 percent, respectively, in the placebo group. The mean differences between the groups after one year were 3.72 +/- 0.88 percentage points for the lumbar spine (P = 0.02) and 4.14 +/- 0.94 percentage points for the trochanter (P = 0.02). The changes in the femoral neck and the radius were not significantly different between the groups. There was an 85 percent reduction in the proportion of postmenopausal woman with new vertebral fractures in the etidronate group as compared with the placebo group (1 of 31 patients vs. 7 of 32 patients, P = 0.05), and the etidronate-treated postmenopausal women also had significantly fewer vertebral fractures per patient (P = 0.04).

CONCLUSIONS

Intermittent etidronate therapy prevents the loss of vertebral and trochanteric bone in corticosteroid-treated patients.

Regression of advanced refractory ovarian cancer treated with iodine-131-labeled anti-CEA monoclonal antibody

Advanced chemotherapy-resistant ovarian cancer has a poor prognosis, thus requiring new therapeutic modalities. A complete clinical remission, using two cycles of 131I-labeled murine MN-14 anti-CEA monoclonal antibody (MAb), given intravenously, is reported in a patient with advanced ovarian cancer refractory to paclitaxel (Taxol) therapy. The patient first received radioimmunotherapy with approximately 74 mCi 131I-MN-14 IgG, followed 4 mo later by a similar dose of radiolabeled MAb. A partial remission was seen by CT 1 mo after the first radioimmunotherapy, and a further objective response was documented after the second radioimmunotherapy. CT scans performed 6 and 11 mo after the second radioimmunotherapy showed stable and minimal residual changes. However, a whole-body PET scan with [18F]fluorodeoxyglucose (FDG-PET) was negative in these regions. The CA-125 also decreased to only 13 U/ml, compared to the baseline value of 7700 U/ml. Based on CT, FDG-PET, serum CA-125 and physical exam, the patient was in complete clinical remission for 8 mo when the CA-125 levels rose. CT also showed a new suspicious lesion, presumably a peritoneal implant. No toxicity was seen after the first injection, and only Grade 1 thrombocytopenia and Grade 2 leukopenia developed after the second injection, both reversing within 6 wk. This is a report of a complete clinical remission with radiolabeled anti-CEA antibodies in a patient with chemotherapy-refractive metastatic ovarian cancer.

Radioimmunotherapy of medullary thyroid cancer with iodine-131-labeled anti-CEA antibodies

This study evaluates the pharmacokinetics, dosimetry, toxicity and therapeutic potential of radiolabeled NP-4 and MN-14 anti-CEA antibodies in medullary thyroid cancer (MTC).

METHODS

Eighteen patients with advanced MTC entered exploratory clinical studies with therapeutic doses of 131I-labeled NP-4 and MN-14 murine monoclonal antibodies (MAbs) reactive with carcinoembryonic antigen (CEA). Doses administered ranged from 46 mCi for 131I-MN-14 lgG to 195 mCi for 131I-MN-14 F(ab)2 in patients negative for human anti-mouse antibodies (HAMA).

RESULTS

The radioconjugate blood half-life (T1/2) for the whole lgG was 42.5+/-5.0 hr compared to 18.8+/- 4.1 hr for the bivalent fragments. Tumor doses of 17.5+/-11.0 and 11.4+/-6.3 cGy/mCi were estimated for 131I-MN-14 lgG and F(ab)2, respectively. Tumor/red marrow dose ratios exceeded 3:1 for most lesions. Red marrow doses of up to 350 cGy generally could be delivered with < grade 4 toxicity. Seven of 14 evaluable patients showed evidence of anti-tumor effects lasting up to 26 months, based on physical exam, tumor markers or computed tomography.

CONCLUSION

This study demonstrates that anti-CEA MAbs may be suitable for radioimmunotherapy of metastatic or recurrent MTC.

Improved detection of medullary thyroid cancer with radiolabeled antibodies to carcinoembryonic antigen

PURPOSE

This investigation was undertaken to assess the targeting of established and occult medullary thyroid cancer (MTC) with radiolabeled monoclonal antibodies (MAbs) reactive with carcinoembryonic antigen (CEA).

PATIENTS AND METHODS

Twenty-six assessable patients with known (n = 17) or occult (n = 9) MTC were studied with radiolabeled anti-CEA MAbs. Scintigraphic images were collected to determine targeting of tumor lesions.

RESULTS

The targeting results of technetium 99m (99mTc)-,iodine 123 (123I)-, and iodine 131 (131I)-labeled anti-CEA antibodies (all directed against the same epitope of CEA) indicated that all these reagents were capable of detecting established and occult MTC. The sensitivity for detection of known sites of disease ranged from 76% to 100% for the various anti-CEA MAbs used, when compared with computed tomography (CT), magnetic resonance imaging (MRI), bone scan, or other imaging modalities. Moreover, the antibody scan was positive in seven of nine patients with occult disease (patients with negative conventional imaging studies, but who had elevated calcitonin and/or CEA levels). Three of seven patients underwent surgery and the disease was confirmed by histopathology in all three.

CONCLUSION

Anti-CEA MAbs are excellent agents for imaging recurrent, residual, or metastatic MTC. The high lesion sensitivity in patients with known lesions, combined with the ability to detect disease, may make these agents ideal for staging patients, monitoring disease pretherapy or posttherapy, and especially for evaluating patients with recurrent or persistent hypercalcitonemia or CEA elevations after primary surgery. Analogous to radioiodine in the evaluation of patients with differentiated thyroid cancer, radiolabeled anti-CEA MAbs may achieve a similar role in diagnosing and monitoring patients with MTC.

Targeting and initial radioimmunotherapy of medullary thyroid carcinoma with 131I-labeled monoclonal antibodies to carcinoembryonic antigen

The targeting potential of 131I-labeled NP-4 and MN-14 anti-CEA (carcinoembryonic antigen) monoclonal antibodies (MAbs) was assessed in 19 patients with metastatic medullary thyroid cancer (MTC). Seventeen of these patients also entered pilot radioimmunotherapy studies with nonmyeloablative doses of 131I-anti-CEA MAbs. Tumor targeting was possible in all 19 patients, with an overall lesion sensitivity of 91%. Tumor dosimetry with 131I-MN-14 IgG or F(ab)2 was very favorable, with tumor doses of 14.3 +/- 8.3 cGy/mCi and tumor:red marrow dose ratios exceeding 3:1 for most lesions. Limited antitumor effects lasting up to 26+ months, based on physical exam, tumor markers, computed tomography, or a followup MAb scan, were seen in 5 of 11 assessable patients given relatively low doses of 131I-labeled anti-CEA MAbs. We conclude that anti-CEA MAbs are excellent agents for targeting metastatic MTC. The high tumor uptake of the 131I-anti-CEA antibodies and evidence of tumor response in some patients suggest that radioimmunotherapy with radioiodinated anti-CEA MAbs may be an effective treatment for MTC, particularly when the maximum tolerated dose is given alone or in combination with autologous red marrow or peripheral stem cell support.

Induction of nitric oxide synthase in demyelinating regions of multiple sclerosis brains

The amount of messenger RNA encoding human inducible nitric oxide synthase and the presence and distribution of NADPH diaphorase were determined in tissue sections from multiple sclerosis (MS) and control brains. Levels of human nitric oxide synthase messenger RNA were markedly elevated in MS brains when compared to normal control brains. NADPH diaphorase activity, a histochemical stain reflecting nitric oxide synthase catalytic activity, was detected in reactive astrocytes in active demyelinating MS lesions and at the edge of chronic active demyelinating lesions. Control brains did not contain NADPH diaphorase-positive astrocytes. These results implicate the free radical nitric oxide in the pathogenesis of demyelinating MS lesions.

Acquired von Willebrand's syndrome in association with a lupus-like anticoagulant corrected by intravenous immunoglobulin

We are reporting on a 47-year-old man who presented with a prolongation of the activated partial thromboplastin time (APTT) prior to orthopedic surgery. An evaluation suggested an inhibitor when his plasma prolonged a normal control APTT upon 50:50 solution of patients with normal plasma. The platelet-neutralizing procedure (PNP), anticardiolipin antibody, and antinuclear antibody (ANA) were positive. Further studies revealed decreased von Willebrand factor ristocetin cofactor (vWF:RCoF), von Willebrand factor antigen (vWF:Ag), an inhibitor to vWF, and absent high-molecular-weight vWF multimeters. Assays of FVIII:C, FIX, and FXI were nonparallel to the standard curve. Intravenous immunoglobulin (IVIG) corrected the APTT, multimeric pattern, and FVIII:C by the 7th day postinfusion. This case demonstrates the efficacy of IVIG for acquired von Willebrand's syndrome (vWS) and also represents a unique combination of a lupus-like anticoagulant and acquired vWS in a patient without the full serological requirement for systemic lupus erythematosus (SLE). Whether patients with acquired vWS and lupus inhibitors are more or less susceptible to either a thrombotic complication or hemorrhage is not established. Prospective studies for the incidence of lupus inhibitor/antiphospholipid syndromes and vWF deficiencies are needed to assess this question.

Extracorporeal shock wave lithotripsy induces the release of prostaglandins which increase ureteric peristalsis

The aim of this study was to identify the changes in secretion of prostaglandins into the urinary tract as a result of treatment by extracorporeal shock wave lithotripsy (ESWL) and to determine their effects on ureteric motility. Sixteen patients with renal or upper ureteric calculi were studied. A peripheral blood and urine sample was collected immediately before and after ESWL, with further samples taken 24 h later. The following variables were assessed by radioimmunoassay:prostaglandin E2 (PGE2), prostaglandin F1 alpha (PGF1 alpha), and thromboxane B2 (TXB2). An in vitro canine study was then designed to study the activity of TXB2, PGF1 alpha and PGE2 on an isolated intact canine ureter model. Significant elevations of TXB2 were found immediately after ESWL in both serum and urine, which fell almost to pre-treatment levels by 24 h. PGF1 alpha levels showed significant elevations at 24 h but no immediate increase as seen with TXB2. In contrast, PGE2 levels were unchanged in the urine but significantly decreased in the serum. In vitro studies showed that both TXB2 and PGF1 alpha repeatedly produced an increased frequency of ureteric contraction. ESWL results in the release of prostaglandins from the urinary tract which are shown to cause increased ureteric peristalsis.

Intensive management of severe head injury

Intensive management of patients with severe head injury offers the best hope of minimizing death and functional disability in a young, working population. Secondary neurologic insult can be decreased by cardiorespiratory support and ICP control from the outset. Rapid neurologic assessment, airway management, and support of circulation are the basis of emergency management for head injury. Patients with severe head injury require intensive care management for two major reasons: management of ICP and management of organ system dysfunction. Care should not be withheld because of initially grim (and inaccurate) prognostic assessment. Newer techniques for assessing the adequacy of cerebral circulation may allow refinement of management strategies in the future.

Symptom status and quality of life following prostatectomy

When prostatectomy is proposed as treatment for the symptoms of prostatism, the decision to operate should depend on how patients evaluate their symptoms and on objective information about the outcomes. We undertook a health interview study to determine the probabilities for symptom relief, improvement in the quality of life, and complications following surgery and to evaluate patient concern about the symptoms of prostatism. The operation was effective in reducing symptoms: 93% of severely and 79% of moderately symptomatic patients experienced improvement; however, a statistically significant improvement in indices of quality of life occurred only among patients with acute retention or severe symptoms prior to surgery. Short-term complications of varying severity occurred in 24% of patients; in addition, 4% reported persistent incontinence and 5%, impotence. Patients with similar symptoms reported considerable difference in the degree to which they were bothered by their symptoms. The result emphasizes the importance of patient participation in the decision to undergo prostatectomy.

Factors indicative of outcome in a comparative trial of acyclovir and vidarabine for biopsy-proven herpes simplex encephalitis

A total of 208 patients underwent brain biopsy for presumptive herpes simplex encephalitis and were randomized to receive either vidarabine, vira-A, at 15 mg/kg/day, or acyclovir, at 30 mg/kg/day for ten days. 69 patients (33%) had biopsy-proven disease; 37 received vira-A and 32 acyclovir. With the exception of age, patient populations were balanced for demographic characteristics. Overall survival for acyclovir recipients was 72% compared with 46% for vira-A-treated patients 18 months after therapy (p = 0.008). After adjustment for differences of age between treatment populations by multivariant regression analyses, acyclovir treatment remained superior to vidarabine therapy (p = 0.041). Mortality varied according to the level of consciousness at the onset of therapy. For lethargic, semicomatose and comatose patients, mortality was 42%, 46%, and 67%, respectively, for the vira-A-treated patients and 0%, 25% and 25%, respectively, for acyclovir-treated patients. Six months post-therapy morbidity assessments revealed five (14%) vira-A versus 12 (38%) acyclovir recipients who had returned to normal function, while eight (22%) and three (9%), respectively, had moderate debility. Outcome differences were significant (p = 0.02; Wilcoxon, 2-sample test) using an adapted scoring system. Age and Glasgow coma scale greater than 10 predicted the best outcome following acyclovir treatment. Disoriented patients who flex and respond by eye to pain had no mortality and 50% returned to normal. These data indicate that acyclovir is the treatment of choice for biopsy-proven herpes simplex encephalitis.

Vidarabine versus acyclovir therapy in herpes simplex encephalitis

We randomly assigned 208 patients who underwent brain biopsy for presumptive herpes simplex encephalitis to receive either vidarabine (15 mg per kilogram of body weight per day) or acyclovir (30 mg per kilogram per day) for 10 days. Sixty-nine patients (33 percent) had biopsy-proved disease; 37 received vidarabine, and 32 acyclovir. The mortality in the vidarabine recipients was 54 percent, as compared with 28 percent in the acyclovir recipients (P = 0.008). Six-month mortality varied according to the Glasgow coma score at the onset of therapy. For scores of greater than 10, 7 to 10, and less than or equal to 6, mortality was 42, 46, and 67 percent in the patients treated with vidarabine, as compared with 0, 25, and 25 percent in those treated with acyclovir. A six-month morbidity assessment using an adapted scoring system revealed that 5 of 37 patients receiving vidarabine (14 percent) as compared with 12 of 32 receiving acyclovir (38 percent) were functioning normally (P = 0.021). Eight vidarabine-treated patients (22 percent) and three acyclovir-treated patients (9 percent) had moderate debility. Patients under 30 years of age and with a Glasgow coma score above 10 had the best outcome with acyclovir treatment. We conclude that acyclovir is currently the treatment of choice for biopsy-proved herpes simplex encephalitis.

Neurologic intensive care unit monitoring

Monitoring modalities unique to the neurologic intensive care unit include intracranial pressure monitors and neuroelectrophysiologic monitors. Each modality fullfills criteria for accuracy, responsivity during clinical change, and stability over time for trend analysis. Intracranial pressure monitoring may be accomplished by any of three approaches--ventricular catheter, subarachnoid bolt, or epidural pressure transducer. Intracranial pressure control has proved beneficial in at least three different illnesses--acute closed head injury, acute noncommunicating hydrocephalus, and Reye's syndrome. Other illnesses, such as cerebral hemorrhage, near drowning, meningitis, encephalitis, and cerebral mass lesions, are often associated with ICP elevations. Neuroelectrophysiologic monitoring encompassing electroencephalography (EEG), signal-processed EEG, and evoked potentials has proved to be most beneficial to the intensive care setting. Evoked potentials are most useful for monitoring patients in drug-induced coma or muscle paralysis in whom a clinical neurologic examination is unreliable. Focal neurologic deficits, incipient brainstem ischemia, and possibly brain death can be deduced from multimodality-evoked potentials (brainstem auditory and somatosensory). Evoked potential apparatus can be used to record sequential stimuli and trend changes. Signal-processed EEG apparatus (compressed spectral array and cerebral function monitor) are used to assess global or regional EEG activity for longer periods of time. Interpretation of signal-processed EEG recording requires some experience with this technique, but it is much easier to interpret than a standard 16-lead EEG. These monitors are useful in evaluating some forms of abnormal EEG activity and in monitoring gross changes in global or regional electrical activity. Currently available technology offers dynamic insight into the management of acute neurologic illnesses. The technology in evoked potential and signal processed EEG monitoring will eventually reduce the size and complexity of the instrumentation, making its application routine. Intracranial pressure monitoring is already routine in many intensive care units, although its use is occasionally sporadic. We believe that application of appropriate neurologic monitors improves therapy and outcome in neurologically injured and ill patients.