Isolation of Virus Capable of Lysing the Brown Tide Microalga, Aureococcus anophagefferens.

Viruses have been hypothesized to control blooms of Aureococcus anophagefferens gen. et sp. nov. (Chrysophyceae), a marine phytoplankton that since 1985 has caused devastating summer blooms called "brown tide." By means of ultrafiltration methods, viruses specific to this alga were isolated from both the Great South Bay and Peconic Bay systems of Long Island, New York, during the summer bloom period of 1992. Cell lysis of healthy algal cultures was demonstrated, as well as continuing reinfection with serial transfers of cultures. Electron microscope surveys yielded images of phage-like virus particles with tails that could attach to A. anophagefferens cells within minutes of exposure. The isolation and cultivation of this virus highlights the need for further study of viral infection of eukaryotic algae and the potential for a better understanding of algal bloom control by viral infection.

Diuretic-associated hypomagnesemia in the elderly.

Serum magnesium concentration was measured in 320 consecutive elderly patients (mean age, 81 years) receiving diuretic therapy at the time of hospital admission. When compared with serum concentrations of 250 elderly patients who were not taking diuretics at the time of hospital admission, only the group taking thiazide diuretics had a significantly reduced mean serum level. The 24-hour urine sampling from representative subgroups demonstrated impaired magnesium-conserving ability in hypomagnesemic subjects receiving loop and thiazide diuretic therapy. Patients taking therapy that included a potassium-sparing diuretic had no significant evidence of reduced magnesium-conserving ability. Dietary assessments of the study population revealed suboptimal magnesium intake in the diet.

Prevention of neocarzinostatin-induced cell death and morphologic change in SK-N-SH human neuroblastoma cells by continuous exposure to nerve growth factor.

Neocarzinostatin is an antineoplastic agent that induces differentiated morphology in human (SK-N-SH) neuroblastoma cells in culture. We have compared this morphological differentiation with that induced by the endogenous differentiation inducer, nerve growth factor (NGF), and have explored the effects of exposure to NGF upon the morphological changes induced by neocarzinostatin in SK-N-SH cells. Both NGF and neocarzinostatin induced process outgrowth in these cells. The processes formed in the presence of NGF however, were shorter and thinner than those induced by neocarzinostatin. Furthermore, only neocarzinostatin induced enlargement of the somata of the cells, and caused cell death in a concentration-dependent fraction of the culture. These distinguishing features of treated cells allowed us to determine whether or not NGF exposure altered responsiveness of the cells to neocarzinostatin. NGF (100-1000 ng/mL) protected SK-N-SH cells from the morphological and cytocidal effects of neocarzinostatin (1-hr exposure, 0.017 to 0.033 micrograms/mL). Protection from neocarzinostatin required that NGF be continuously present for a period beginning 24 hr prior to neocarzinostatin exposure and continuing for the duration of the experiment, implying that the protection afforded by NGF has a latency necessitating pretreatment, and is reversible. These results suggest that neocarzinostatin is taken up by the cells and can exert its effects once NGF is removed, even after neocarzinostatin is washed out of the medium. The signal transduction cascade triggered by NGF receptor binding may prevent the action of neocarzinostatin or the expression of the cellular changes induced in SK-N-SH cells by neocarzinostatin.

Moderately severe anaphylactoid reaction to pentastarch (200/0.5) in a patient with acute severe asthma.

The use of synthetic colloids for resuscitation and volume replacement is common in the intensive care unit. Although adverse reactions have been reported to colloid solutions, the incidence of severe reactions to the starch derivatives is low. We report a case of an anaphylactoid reaction to pentastarch (200/0.5) in a young asthmatic who received it as a fluid challenge in the intensive care unit. The pathogenesis and implications of such a reaction in an asthmatic are discussed.

Eradication of endotracheal tube biofilm by nebulised gentamicin.

OBJECTIVE: To compare the efficacy of gentamicin, nebulised via the endotracheal tube (ET), with that of parenteral cefotaxime or parenteral cefuroxime in preventing the formation of ET biofilm. SETTING: General intensive care units in two university teaching hospitals. DESIGN: The microbiology of ET biofilm from 36 ICU patients eligible to receive antibiotic prophylaxis was examined. Peak and trough tracheal concentrations of gentamicin, cefotaxime or cefuroxime were measured in each patient group, on the 2nd day of intubation. PATIENTS: Twelve patients received gentamicin (80 mg) nebulised in 4 ml normal saline every 8 h, 12 cefotaxime (1 g, 12 hourly) and 12 cefuroxime (750 mg, 8 hourly). Prophylaxis was continued for the duration of intubation. MEASUREMENTS AND RESULTS: Samples of tracheal secretions were taken on the 2nd day of ventilation for determination of antibiotic concentrations. Following extubation, ETs were examined for the presence of biofilm. Pathogens considered to be common aetiological agents for VAP included Staphylococcus aureus, enterococci, Enterobacteriaceae and pseudomonads. While microbial biofilm was found on all ETs from the cephalosporin group, microbial biofilm of these micro-organisms was found on 7 of the 12 ET tubes from patients receiving cefotaxime [ S. aureus (4), pseudomonads (1), Enterobacteriaceae (1), enterococcus (1)] and 8 of the 12 ET tubes from patients receiving cefuroxime [Enterobacteriaceae (6), P. aeruginosa (1) and enterococcus (1)]. While microbial biofilm was observed on five ETs from patients receiving nebulised gentamicin, none of these were from pathogens for ventilator-associated pneumonia (VAP). Tracheal concentrations of both cephalosporins were lower than those needed to inhibit the growth of pathogens recovered from ET tube biofilm. The median (and range) concentrations for cefotaxime were 0.90 (<0.23-1.31) mg/l and 0.28 (<0.23-0.58) mg/l for 2 h post-dose and trough samples, respectively. Two hours post-dose concentrations of cefuroxime (median and range) were 0.40 (0.34-0.83) mg/l, with trough concentrations of 0.35 (<0.22-0.47) mg/l. Tracheal concentrations (median and range) of gentamicin measured 1 h post-nebulisation were 790 (352-->1250) mg/l and then, before the next dose, were 436 (250-1000) mg/l. CONCLUSION: Nebulised gentamicin attained high concentrations in the ET lumen and was more effective in preventing the formation of biofilm than either parenterally administered cephalosporin and therefore may be effective in preventing this complication of mechanical ventilation.

Implications of endotracheal tube biofilm for ventilator-associated pneumonia.

OBJECTIVE: To determine the relationship between, and antibiotic resistance of, endotracheal tube (ET) biofilm and pulmonary pathogens in ventilator-associated pneumonia (VAP). SETTING: General intensive care units in two university teaching hospitals. DESIGN: The microbiology of ET biofilm and tracheal samples from patients with and without VAP were compared. For individual patients, matching pairs of pathogens were confirmed as identical and characterised for antibiotic susceptibility. PATIENTS: 40 intensive care unit patients - 20 with VAP, 20 without VAP as control. The duration of intubation (median and range) was 6.5 days (3-17) and 5 days (2-10), respectively. MEASUREMENTS AND RESULTS: Samples of tracheal secretions were taken during ventilation for bacteriological culture. Following extubation, ETs were examined for the presence of biofilm. Isolates of high pathogenic potential included Staphylococcus aureus, enterococci, Enterobacteriaceae, pseudomonads and Candida spp. Where the same microorganism was found on tracheal and ET samples by phenotyping, these were confirmed as identical by genotyping and characterised for antibiotic susceptibility in both the free floating and biofilm forms. Seventy per cent of patients with VAP had identical pathogens isolated from both ET biofilm and tracheal secretions. No pairing of pathogens was observed in control patients (p < 0.005). Susceptibility data for these pairs show that the ET acts as a reservoir for infecting microorganisms which exhibit significantly greater antibiotic resistance than their tracheal counterparts. CONCLUSION: This investigation provides further evidence for the role of ET biofilm in VAP. The difficulty in eradicating an established microbial biofilm using antibiotics implies that increased attention must be directed towards modification of the ET to prevent or substantially reduce biofilm formation.

Comparison of single-dose ceftizoxime with multidose cefoxitin chemoprophylaxis for patients undergoing hysterectomy.

A single dose of ceftizoxime was comparable to three perioperative doses of cefoxitin as adjunctive antibiotic chemoprophylaxis against infectious morbidity in women undergoing elective abdominal (60% of patients) or vaginal (40% of patients) hysterectomy. In a double-blind, randomized, prospective, controlled trial, patients were randomized to receive either a single 1-gm dose of ceftizoxime, a newer, broadly active cephalosporin, or three 2-gm doses of cefoxitin intravenously. Twenty-nine women treated with ceftizoxime and 33 women treated with cefoxitin were evaluated. Patient groups were similar for age, other demographic factors, indications for surgery, surgical procedures performed, and selected microbiologic findings. Postoperative infectious morbidity requiring antibiotic treatment was similar among women who received ceftizoxime (27.6%) and those receiving cefoxitin (33%) (P = 0.6). Women receiving ceftizoxime also required a similar number of days of hospitalization (ceftizoxime, 4.7 +/- 1.7 days; cefoxitin, 5.6 +/- 4.5 days; P = 0.3). Both study drugs appeared to be safe and well tolerated. Single-dose ceftizoxime appears to be as efficacious as and more cost-effective than multidose cefoxitin when used as adjunctive chemoprophylaxis in patients at risk for postoperative infection after hysterectomy.

Evaluation of long-term efficacy and safety of transdermal fentanyl in the treatment of chronic noncancer pain.

The objective of this international, multicenter, open-label trial was to assess the efficacy and safety of up to 12 months of therapy with transdermal therapeutic system (TTS) fentanyl in patients (n = 532) with chronic noncancer pain. The trial was completed by 301 (57%) of the patients. The main outcome measures were pain control assessment, global treatment satisfaction, patient preference for TTS fentanyl, and quality of life. The mean dose of transdermal fentanyl (TDF) increased from 48 to 90 microg/h during a period of 12 months. During treatment, on average 67% of patients within the efficacy analysis group (n = 524) reported very good, good, or moderate pain control. Global satisfaction (very good or good) was also stable at 42%. The majority (86%) of patients reported a preference for TDF over their previous treatment (P < .001, binomial test). Short Form 36 quality-of-life scores improved from baseline for bodily pain. The most frequent treatment-related adverse events were nausea (31%), constipation (19%), and somnolence (18%). With regard to opioid-specific adverse events (respiratory depression [< 1%], adrenal insufficiency [< 1%], drug abuse/dependence [1%], and opioid withdrawal syndrome [3%]), these were extremely rare and, with the exception of opioid withdrawal syndrome, none was considered definitively related to the treatment. Long-term treatment with TDF provided a stable degree of pain control in the majority of patients with moderate to severe chronic noncancer pain. It was preferred by the majority of patients compared with their previous opioid medication. Overall, long-term treatment with TDF was generally well tolerated, particularly in view of the low incidence of potentially serious side effects such as drug abuse/dependence and respiratory depression. However, at present, it is important that patients receiving TDF should still be subject to careful assessment and monitoring.

Intraoperative bupivacaine diminishes pain after lumbar discectomy. A randomised double-blind study.

A randomised double-blind study was carried out on 60 patients undergoing elective lumbar discectomy. Patients in the study group (n = 30) received an injection of 10 ml of 0.5% bupivacaine into the wound; the control group (n = 30) received none. Postoperative pain was measured by a visual analogue pain scale and by the amount of morphine administered by a patient-controlled analgesia system. Patients in the study group had lower pain scores, used less morphine, waited longer until their first demand for analgesia and reported their postoperative pain to be less severe.

Transdermal fentanyl in patients with chronic, nonmalignant pain: a case study series.

Four cases of patients with chronic, nonmalignant pain who received transdermal fentanyl are presented. These indicate that some patients may benefit from such treatment but also serve to emphasize the importance of careful patient selection and assessment.

Midazolam sedation for outpatient fibreoptic endoscopy: evaluation of alfentanil supplementation.

Alfentanil, a short-acting opioid, was used as an adjuvant to midazolam for sedation of 30 outpatients undergoing upper gastrointestinal endoscopy. The operating conditions and recovery times were compared with those of a similar group of 30 patients sedated with midazolam only. The use of alfentanil resulted in improved operating conditions and a more rapid recovery. Patient acceptance was high.

Continuous spinal anaesthesia for caesarean section in the morbidly obese.

The use of a continuous spinal anaesthetic technique for the caesarean delivery of three morbidly obese patients is described and the advantages discussed.

The effect of patient position and obesity on the spread of epidural analgesia.

The aim of this study is to assess the effect of patient positioning and obesity on the height of block achieved during routine labor epidural analgesia. Forty patients weighing <80 kg were allocated to a control group and a further 40 weighing >100 kg to a study group. Half the patients in each group received an epidural injection in the lateral position, the remainder were in the sitting position. After insertion of an epidural catheter and injection of 12 ml of 0.25% bupivacaine plain the patients remained in position for a further 5 min. The height of block achieved, as assessed by loss of cold sensation, showed no difference between any of the groups. The results indicate that, for routine labor epidural analgesia, using 12 ml of 0.25% plain bupivacaine, neither patient positioning nor obesity affects the height of block achieved.

Postoperative analgesia following total hip replacement: a comparison of intrathecal morphine and diamorphine.

Sixty patients undergoing elective total hip replacement under spinal anaesthesia were randomly assigned to receive either intrathecal (IT) diamorphine 0.75 mg (n = 30) or IT morphine 1.0 mg (n = 30). Postoperative pain scores, analgesic requirements and side effects were assessed by a blinded observer. Postoperative pain scores were broadly similar and satisfactory for both groups but the amount of additional IV morphine required to achieve this was significantly reduced in the morphine compared with the diamorphine group (P < 0.05). Twelve of the morphine group required no postoperative analgesics compared with four in the diamorphine group (P < 0.02). There were no differences between the groups in the incidence of side effects such as emesis and pruritus. No significant postoperative respiratory depression was noted. In the doses used intrathecal morphine provided superior postoperative analgesia to that of intrathecal diamorphine.

Postoperative gastric emptying in outpatient anesthesia: the effect of opioid supplementation.

Acetaminophen (paracetamol) 20 mg/kg was administered orally to 45 gynecological outpatients who had received either alfentanil 5 micrograms/kg, fentanyl 1 microgram/kg, or no analgesic supplement immediately prior to the induction of general anesthesia. Postoperative gastric emptying, assessed by acetaminophen absorption, was significantly inhibited in those given alfentanil. This inhibition is unlikely to be of great clinical importance and was much less than that found in previous studies using longer-acting opioids such as morphine.

Use of auditory evoked responses as a measure of recovery from benzodiazepine sedation.

The amplitude of the P300 component of auditory evoked responses was found to be depressed by benzodiazepine sedation and was subsequently used to monitor the recovery of volunteers sedated with midazolam. The amplitude of the evoked responses was found to be highly correlated with blood midazolam levels but to be no more sensitive than standard psychomotor testing in assessing recovery from sedation.

A comparison of the effect of intramuscular diclofenac, ketorolac or piroxicam on postoperative pain following laparoscopy.

Sixty patients presenting for in-patient gynaecological laparoscopic surgery were randomly allocated to receive either diclofenac 75 mg (n = 20), ketorolac 30 mg (n = 20) or piroxicam 20 mg (n = 20) as an intra-muscular injection immediately after induction of anaesthesia. Postoperative visual analogue scores over the first 24 hours, using a 10 cm scale, ranged from 3.2-0.5 in the diclofenac group, 2.7-0.85 in the ketorolac group and 2.8-0.5 in the piroxicam group. The scores did not differ significantly between the three groups (p > 0.05). Mean time (SD) to first analgesia was 27(94) minutes in the piroxicam group, 16 (30) minutes in the diclofenac group and 62 (120) minutes in the piroxicam group. Six out of twenty patients in the diclofenac group required further analgesia compared to nine out of twenty in the other two drug groups. This difference was not significant. There were no reports of increased bleeding, bronchoconstriction, bleeding from the upper gastrointestinal tract, renal impairment or pain from the intra-muscular injection site in any of the groups. The administration of a non-steroidal anti-inflammatory drug to patients presenting for laparoscopic surgery reduces postoperative pain. There were no obvious differences between the agents used.

Health assessment and its relationship to nursing practice in New Zealand.

Health assessment has been an integral component of nursing education in Australia for over a decade. New Zealand has only recently embarked down this path and might benefit from the Australian experience. This article will discuss health assessment in the context of three issues currently topical in nursing in New Zealand. The issues are annual registration based on evidence of competence to practice, a review of undergraduate curricula, and the development of nurse practitioner/advanced nurse practitioner roles. The meaning of the concept 'health assessment' is also clarified in order to provide consistency as new initiatives in nursing are currently being developed.