High life satisfaction reported among small-scale societies with low incomes

Global polls have shown that people in high-income countries generally report being more satisfied with their lives than people in low-income countries. The persistence of this correlation, and its similarity to correlations between income and life satisfaction within countries, could lead to the impression that high levels of life satisfaction can only be achieved in wealthy societies. However, global polls have typically overlooked small-scale, nonindustrialized societies, which can provide an alternative test of the consistency of this relationship. Here, we present results from a survey of 2,966 members of Indigenous Peoples and local communities among 19 globally distributed sites. We find that high average levels of life satisfaction, comparable to those of wealthy countries, are reported for numerous populations that have very low monetary incomes. Our results are consistent with the notion that human societies can support very satisfying lives for their members without necessarily requiring high degrees of monetary wealth.

Pinning and depinning of the polarization of exciton-polariton condensates at room temperature

A room temperature polariton condensate realized in a microcavity with embedded GaN quantum wells emits linearly polarized light at threshold with the plane of polarization pinned to one of the crystallographic axes. With increasing pumping power, a depinning of the polarization is observed resulting in a progressive decrease of the polarization degree of the emitted light. This depinning is understood in terms of polariton-polariton repulsion competing with the static disorder potential effect. The polarization behavior differs from that of conventional lasers where the polarization degree usually increases as a function of pumping power.

Interplay between galanin and leptin in the hypothalamic control of feeding via corticotropin-releasing hormone and neuropeptide Y

Over long periods, feeding and metabolism are tightly regulated at the central level. The total amount of nutrients ingested is thought to result from a delicate balance between orexigenic and anorexigenic factors expressed and secreted by specialized hypothalamic neuronal populations. We have developed a system of perifused hypothalamic neurons to characterize the relationships existing between the orexigenic peptide galanin and two other physiological modulators of feeding: neuropeptide Y (NPY) and corticotropin-releasing hormone (CRH). We demonstrated that galanin stimulates CRH and NPY secretion from hypothalamic neurons in a dose-dependent manner. Exposure to leptin for 24 h before galanin stimulation decreased NPY secretion by 30%, leaving the responsiveness of CRH neurons intact. These results suggest that CRH and NPY neurons participate to the intrahypothalamic signaling pathway of galanin, an observation that can explain the lower potency of galanin to stimulate food intake in vivo compared with NPY. The differential effects exerted by leptin on CRH and NPY suggest that there exists a subset of NPY neurons that are exquisitely sensitive to marked variations in leptin levels, and that the CRH neurons are less responsive to increases in leptin concentrations.

Association between antifungal prophylaxis and rate of documented bacteremia in febrile neutropenic cancer patients

Published data have suggested a correlation between antifungal prophylaxis and bacteremia in febrile neutropenia. This correlation was investigated among 3002 febrile neutropenic patients enrolled in 4 trials during 1986-1994. Globally, 1322 patients (44%) did not receive antifungal prophylaxis; 835 (28%) received poorly absorbable antifungal agents and 845 (28%) received absorbable antifungal agents. The rates of bacteremia for these groups were 20%, 26%, and 27%, respectively (P=.0001). In a multivariate model without including antifungal prophylaxis, factors associated with bacteremia were: age, duration of hospitalization, duration of neutropenia before enrollment, underlying disease, presence of an intravenous catheter, shock, antibacterial prophylaxis, temperature, and granulocyte count at onset of fever. When antifungal prophylaxis was included, the adjustment quality of the model improved slightly (P=.05), with an odds ratio of 1.19 (95% confidence interval [CI], 0.92-1.55) for patients receiving nonabsorbable and 1.42 (95% CI, 1.07-1.88) for those who were receiving absorbable antifungal agents. Antifungal prophylaxis with absorbable agents might have an impact on the rate of documented bacteremia in febrile neutropenia. This effect should be confirmed prospectively.

Consensus conference definitions for sepsis, septic shock, acute lung injury, and acute respiratory distress syndrome: time for a reevaluation

Definitions for sepsis, septic shock, acute lung injury (ALI), and acute respiratory distress syndrome (ARDS) were developed by consensus conferences with the goal of achieving standardization of terminology and improved homogeneity of patient populations in clinical studies. Although such definitions have been useful in epidemiologic investigations, the criteria specified by the consensus conferences are broad and insufficiently specific to address the problem of heterogeneous mechanisms leading to clinical syndromes. An important challenge is to progress from clinical syndromes, as presently defined, to more specific entities that are delineated by alterations in specific immunologic or biochemical pathways. Such mechanistic definitions will provide more homogeneous groups of patients who can be identified at early stages of their clinical course. This approach encourages focused investigation of pathways leading to organ system dysfunction and death and, also, provides an efficient framework for the development of new therapies useful in critically ill patients.

Meropenem (1.5 g/day) is as effective as imipenem/cilastatin (2 g/day) for the treatment of moderately severe intra-abdominal infections

This multicentre, open-label, randomised trial compared meropenem (0.5 g/8 h) and imipenem/cilastatin (at the commonly used dosage of 0.5 g/6 h) in monotherapy in patients with moderately severe intra-abdominal infections (IAIs). In total, 161 patients were randomised (82 meropenem, 79 imipenem/cilastatin). The mean APACHE II scores in the two groups were 5.8 and 6.4, respectively. At the end of therapy, 65/71 (91.6%) evaluable meropenem recipients were clinically cured or improved, compared to 60/64 (93.8%) imipenem/cilastatin recipients. This difference and that in an intention-to-treat analysis (82.1 vs 86.1%, respectively), were not statistically significant. Both drugs were generally well tolerated. Thus, meropenem 0.5 g/8 h is as clinically effective and well tolerated as imipenem/cilastatin 0.5 g/6 h in moderately severe IAIs.

Empiric therapy of bacterial infections in patients with severe neutropenia

The urgent need to treat presumptive infections in neutropenic patients has meant that initial therapy is empiric based on the pathogens most likely to be responsible for the patient's rise in temperature or other symptoms of infection. The spectrum of causative pathogens has changed over time and reflects the availability and use of antimicrobial agents. Gram-positive organisms predominated in the 1940s and onward until the widespread use of early penicillins and cephalosporins effectively addressed this problem. The upsurge in infections in the 1970s and 1980s caused by Gram-negative organisms, particularly Pseudomonas aeruginosa, Escherichia coli and Klebsiella spp., has been supplanted by a new wave of infections caused by Gram-positive organisms, this time predominantly Staphylococcus aureus, Staphylococcus epidermidis, and the viridans streptococci. The fourth-generation cephalosporins (cefpirome) among other broad-spectrum beta-lactams, by virtue of their enhanced antimicrobial activity against Gram-positive pathogens and greater beta-lactamase stability, are promising candidates for use in the empiric management of febrile episodes in neutropenic patients. Early clinical trial results are promising and should lead the way for further use of these compounds in this indication.

A comparison of outcome from febrile neutropenic episodes in children compared with adults: results from four EORTC studies. International Antimicrobial Therapy Cooperative Group (IATCG) of the European Organization for Research and Treatment of Cancer (EORTC)

The object of this study was to determine whether there were any differences between the 'typical' child with fever and neutropenia and their adult counterpart with regard to infection type and outcome, by analysis of 3080 patients, including 759 children < 18 years of age and 2321 adults. These represented patients randomized in previous trials, between 1986 and 1994, which compared empirical antibiotic regimens for fever in neutropenic patients. There were fewer childhood acute myeloid leukaemia patients than adults but more acute lymphoblastic leukaemia cases and more with solid tumours undergoing intensive myelosuppressive therapy. The children were less likely to be undergoing first induction therapy but the relative incidence of patients receiving relapse schedules or maintenance therapies were not significantly different in the two age groups. Children less frequently had a defined site of infection than adults and where they had a defined site there were more upper respiratory tract but fewer lung infections. There was a similar low incidence of shock at presentation in the two groups but the children's median neutrophil count was lower, and their median duration of granulocytopenia before the trial was shorter. The incidence of bacteraemia was similar, but clinically documented infection was less frequent and fever of unknown origin consequently more common in children. Children developed more streptococcal bacteraemias and fewer staphylococcal bacteraemias than adults (P=0.003) but the relative incidence of various gram-negative species was similar (P=0.57). In general, the children had a better overall success rate and lower mortality than adults. Death from infection was only 1% in children versus 4% in adults (P=0.001), and time to defervescence was shorter in children. In the younger age group, univariate logistic regression models showed high temperature, prolonged neutropenia before the trial and shock as prognostic indicators for the presence of bacteraemia. Solid tumour patients were significantly less likely to have a bacteraemia. Multivariate analysis confirmed the independent prognostic value of these indicators. Using the logistic equation of the selected model, the overall discriminant ability was poor. However, it was possible to identify a small subgroup without shock or high fever and with a short prior duration of neutropenia which carries a particularly low risk of bacteraemia, who could be considered for early discharge, monotherapy and shortened courses of antibodies, in prospective trials.

International Conference for the Development of a Consensus on the Management and Prevention of Severe Candidal Infections

Because of the rapidly increasing incidence of serious candidal infections, a consensus conference of 22 investigators from the United States, Europe, and Japan was held to discuss strategies for the prevention and treatment of deep-organ infections caused by Candida species. Commonly asked questions concerning the management of candidal infections were selected for discussion by the participating investigators. Possible answers to the questions were developed by the investigators, who then voted anonymously for their preferences. In certain instances, unanimity or a strong consensus was the result. In all cases, the full spectrum of responses was recorded and is presented in this report. The forms of candidal infection addressed included candidemia, candiduria, hepatosplenic candidiasis (chronic systemic candidiasis), candidal endophthalmitis, and candidal peritonitis. Prevention and treatment strategies were considered for patients who have undergone surgery, for neutropenic and nonneutropenic patients, and for patients who have undergone bone marrow and solid organ transplantation. The therapeutic roles of amphotericin B (standard and lipid formulations) and the azoles were considered.

Relationship between the prescriber's instructions and compliance with antibiotherapy in outpatients treated for an acute infectious disease

Antibiotics are frequently prescribed in everyday practice for the management of acute microbial infections. The present study was designed to assess the relationship between the prescriber's instructions and the patient's adherence to a prescribed schedule of twice-daily doses of antibiotic for at least 5 days to treat an infectious disease. The trial was conducted by ten practicing physicians on ambulatory patients. Compliance with the antibiotic regimen was evaluated using a microelectronic device, the Medication Event Monitoring System (MEMS). Seventy patients were prescribed an antibiotic in twice-daily doses for 5 to 14 days (mean = 8). Data were available for analysis from 68 of them, aged 18 to 84 years (mean = 44). The "taking compliance" for the whole story group, which corresponded to the ratio of the number of times the bottle was opened and the total number of doses prescribed during the monitoring period, was nearly perfect at 99.6%. However, only 32.6% of the medications was taken within 1 hour before or after the 12-hour interval expected to be optimal for a twice-daily regimen. It therefore seems highly desirable that physicians give more detailed recommendations to their patients regarding the drug regimens they prescribe.

Metabolic base production and mucosal vulnerability during acid inhibition in a mammalian stomach in vitro

Acid inhibition increases gastric mucosal susceptibility to damage by luminal acid. This might be due to reduced metabolic CO2 and bicarbonate whereas, during normal acid, secretion cytoprotective CO2/HCO3- production parallels acid production. Metabolic activity and mucosal damage caused by luminal acid perfusion was determined in an in vitro mouse stomach, with and without acid inhibition, and at 0%, 1%, or 5% serosal CO2 supply. Without acid inhibition there was no mucosal damage at any level of serosal CO2/HCO3- supply. Acid inhibition reduced metabolic CO2 production by 29% (P < 0.004) and resulted in microscopic damage to 55% of the mucosal area and perforation in four of five stomachs (P < 0.05). Although, 1% CO2 supply completely replaced the reduction in metabolic CO2, it did not protect against mucosal damage. Overreplacement by 5% serosal CO2/HCO3- was required to prevent damage. There was no correlation between luminal CO2/HCO3- output and mucosal damage. The protection by endogenous or exogenous CO2/HCO3- appears to act intracellularly rather than by intragastric or intercellular neutralization.

Epidemiology of AIDS dementia complex in Europe. AIDS in Europe Study Group

The aim of the study was to describe the epidemiology of AIDS dementia complex (ADC) in Europe and to assess the possible role of zidovudine therapy in preventing or delaying its occurrence. We used an inception cohort, with data collected retrospectively from patients' clinical records from 52 clinical centers in 17 countries across Europe. The subjects were 6,548 adult people with AIDS consecutively diagnosed from 1979 to 1989. The main outcome measures were codiagnosis of ADC at the time of AIDS diagnosis and ADC-free time after AIDS diagnosis. ADC was reported in 295 patients (4.5%) at the time of AIDS diagnosis and during follow-up in a further 402 of the 5,160 patients (7.8%) who were diagnosed with AIDS based on diseases other than ADC. Whether at the time of AIDS diagnosis or later, the occurrence of ADC was significantly associated with age, transmission category, and CD4+ cell counts. The risk was greater in older patients (14 and 19% greater, at AIDS diagnosis and after, respectively, for a 5-year difference in age), in i.v. drug users than in homosexual and bisexual men (89 and 60% greater, at AIDS diagnosis and after, respectively), and for people with lower CD4+ cell counts (14 and 30% greater for a reduction of 1 on the natural log scale). Risk was almost double for women than for men. A significant reduction, of approximately 40%, was found in the risk of developing ADC after AIDS diagnosis for patients receiving zidovudine therapy, but this effect was present only during the first 18 months of treatment, irrespective of whether treatment began before or after AIDS diagnosis. In conclusion, an increase in the risk of developing ADC either at the time of AIDS diagnosis or thereafter is associated with increasing age, i.v. drug use, and decreased CD4+ cell count. Women tend to have a higher risk of ADC at the time of AIDS diagnosis. Zidovudine therapy appears to have a definite, but time-limited, effect of protecting patients against ADC development after AIDS diagnosis.

Carbon-14-urea breath test as a noninvasive method to monitor Helicobacter felis colonization in mice

We have developed a 14C-urea breath test to follow the course of Helicobacter felis infection in mice. Peak 14CO2 production occurred approximately 8 min after substrate administration. The test values were compared to those from a rapid urease test and correlated with the presence of pathogens by histology. The sensitivity was 99%, specificity 91%, positive predictive value 95% and negative predictive value 99% when the assay was conducted in fasted mice. We conclude that in mice the breath test analysis is a useful noninvasive method for detecting the presence of H. felis or for evaluating therapeutic agents affecting growth or survival of the organism.

An approach to the design and implementation of clinical trials of empirical antibiotic therapy in febrile and neutropenic cancer patients

The results of many clinical trials on empirical therapy in febrile, neutropenic cancer patients cannot be readily transferred to the clinical practice, because the methodology is often flawed and definitions, study endpoints and eligibility criteria differ from trial to trial. This article critically reviews some issues related to the design and implementation of randomised clinical trials of empirical antibiotic therapy in cancer patients. Within the definition of phase III clinical trials, two approaches co-exist, based on the trial's specific aims: the "explanatory" approach and the "pragmatic" approach. The usual "explicit" aim of clinical trials of empirical therapy in febrile, neutropenic patients has been that of comparing the "efficacy" of two regimens. However, this term has been more often used with reference to the antibacterial activity of the regimen under study (explanatory aim) than to indicate the practical benefits it draws to the overall patient population treated for fever and neutropenia (pragmatic aim). These two meanings are often taken as perfectly interchangeable, while, conversely, they are completely distinct (though not independent) treatment effects. Most trials conducted in this patient population in recent years are explanatory trials, though not explicitly so, but their results have been widely applied to clinical practice, as they were pragmatic trials. In an explanatory trial the appropriate endpoint is success or failure (defined by clinical and laboratory data) among those patients affected with the specific infection for which the study drug is being given, while in pragmatic trials survival is probably the more appropriate outcome variable, since they are designed to assess the practical benefits that the overall population of febrile and neutropenic patients can obtain from the new empirical treatment. Unfortunately, survival is not a practical study endpoint for the difficulty in assessing the cause of death in this patient population and, especially, for the need for very large sample sizes, which might render the implementation problematic even for large, multicentre groups. Both types of trials need an intention to treat analysis, but this is especially crucial for pragmatic trials, which should not differentiate those cases in which success was obtained through multiple treatment modifications from those who did not require any treatment change. Obviously, this implies that no conclusion should be drawn about the antibacterial activity of the study drugs and that the number of treatment modifications should be taken into account in the interpretation of the results, especially for quality of life and cost evaluations. Information related to fever and signs of infection, age, underlying disease, neutropenia and concomitant administration of other antibiotics are crucial entry criteria that need to be clearly discussed and defined. Finally, the evaluation of toxicity is problematic in this patient population, due to the existence of a number of toxigenic factors, including the underlying disease, the type of infectious complication, the administration of chemotherapy and radiotherapy and the use of parental nutrition. All these effects tend to overlap, thus impairing the investigator's ability to detect specific drug-related side-effects.

Regulation of murine acid secretion by CO2

To determine whether endogenous metabolic sources alone provide sufficient CO2 for acid secretion in mammals, basal and stimulated acid secretion and metabolic CO2 production were measured concurrently in mouse stomachs, in vitro, without exogenous CO2, and after addition of 5% CO2 serosally. Basal acid secretion was varied by changing luminal pH from 3.2 to 4.0. In the absence of an exogenous supply of CO2 acid secretion was stable under basal conditions and increased during cholinergic stimulation with carbachol. Serosal CO2 supply increased basal and stimulated acid secretion. The increase in basal acid secretion depended on the initial level of acid secretion. At pH 4.0, exogenous CO2 increased acid output (mean +/- SD) by 13% from 112 +/- 11 nmol/min to 126 +/- 8 nmol/min (P < 0.03), whereas at pH 3.6 the increase was 40% (63 +/- 14 to 88 +/- 20 nmol/min, P < 0.04) and 157% at pH 3.2 (21 +/- 13 to 54 +/- 14 nmol/min, P < 0.002). Following cholinergic stimulation a maximal acid output of 321 +/- 38 nmol/min was attained without serosal CO2, whilst addition of 5% CO2 to the serosal solution increased maximal acid secretion by 49% to 479 +/- 96 nmol/min (P < 0.005). Metabolic activity, measured as total gastric CO2 production, was greater as acid secretion rates increased [239 +/- 20 nmol/min at 21 +/- 13 nmol/min (luminal pH 3.2) versus 406 +/- 28 nmol/min at 321 +/- 17 nmol/min (after cholinergic stimulation)]. The data support the concept that basal and sub-maximal acid secretion can be maintained by CO2 available from metabolic sources, but full expression of the acid secretory apparatus requires exogenous CO2.

Oral immunization with Helicobacter pylori urease B subunit as a treatment against Helicobacter infection in mice

BACKGROUND & AIMS

Eradication of Helicobacter pylori infections in humans results in the healing of gastritis and gastric ulcers. This study used a mouse model to test whether oral vaccination can cure Helicobacter infection and gastritis.

METHODS

Mice were infected with Helicobacter felis. Three weeks after infection, the mice were orally immunized with H. pylori urease B subunit. Control mice were simultaneously infected but sham immunized.

RESULTS

Three to 8 weeks after oral immunization of H. felis-infected mice with recombinant H. pylori urease B subunit, the infection cleared and there was no evidence of gastritis. Vaccinated mice remained protected against two consecutive H. felis challenges.

CONCLUSIONS

These results show that the lack of natural immunity against Helicobacter can be overcome by oral immunization and that vaccination offers a novel therapeutic approach to Helicobacter-induced gastritis.

Multicenter quality control study of amikacin assay for monitoring once-daily dosing regimens. International Antimicrobial Therapy Cooperative Group of the European Organization for Research and Treatment of Cancer

During once-daily dosing regimens of aminoglycosides, administration of large single doses results in high peak levels and low 24-h trough levels. However, commercial assays for monitoring aminoglycoside levels are designed to cover the smaller range of serum concentrations usually observed during multiple daily dosing regimens. The study assessed (a) the range of serum concentrations during once-daily dosing of amikacin and (b) the performance of a widely used assay system for measuring concentrations within this range. A total of 42 dosing intervals from eight patients receiving a once-daily regimen of amikacin (20 mg/kg) were monitored. Median (and range) of peak, 8- and 24-h trough levels were 61 (25-89), 5.9 (2.2-19), and 1.3 (< 0.8-6.2) mg/L, respectively. The accuracy of a fluorescence polarization immunoassay for measuring concentrations of amikacin during once-daily dosing regimens was assessed in an international multicenter study. The performance of the assay was excellent for peak and 8-h concentrations; median deviations from the target concentrations were < 5%. The majority of the trough levels (26 of 42) measured in patients during once-daily treatment were within the range of 1-2 mg/L and could also be determined with an accuracy sufficient for clinical monitoring (median deviations 14%).

Monotherapy in serious hospital-acquired infections: a clinical trial of ceftazidime versus imipenem/cilastatin. European Study Group

The clinical and bacteriological efficacy and safety of the antibiotics ceftazidime or imipenem/cilastatin in seriously ill patients with nosocomial infections were compared in a prospective, open, evaluator-blind, multicentre comparative trial. The study was performed in 26 European centres, the majority being intensive care units. Subjects were randomized to receive either ceftazidime 2 g bid or imipenem cilastatin 0.5 g qid given for at least five days after stratification for pneumonia, septicaemia or urinary tract infection (UTI). Three hundred and ninety-three patients with serious nosocomial infections (254 with pneumonia; 91 with septicaemia and 48 UTI were treated between February 1988 and January 1990 and their clinical and bacteriological response to antibiotic treatment assessed. There were no significant differences between ceftazidime and imipenem/cilastatin in clinical efficacy. The failure rates in evaluable patients were 22 and 26% in pneumonia, 23 and 19% in septicaemia and 0 and 5% respectively in those with UTI. Overall there was no significant difference between the two antibiotics for bacteriological response in the three infection strata. However, in patients with pneumonia ceftazidime was significantly more effective than imipenem/cilastatin in clearing patients of Pseudomonas spp.: 3/17 and 11/19 patients respectively had persistent growth of Pseudomonas spp. post-treatment (P = 0.004), and in one ceftazidime failure resistance emerged compared to six imipenem/cilastatin failures in which resistance emerged. Few drug-related adverse events were recorded in either treatment group. Monotherapy with either ceftazidime (2 g bid) or imipenem/cilastatin (0.5 g qid) is safe and effective and could be considered as an alternative to combination therapy for the treatment of serious hospital-acquired infections.

Structure of the genes encoding the rod-core linker polypeptides of Mastigocladus laminosus phycobilisomes and functional aspects of the phycobiliprotein/linker-polypeptide interactions

The 3' portion of the cpc operon in Mastigocladus laminosus encloses the genes 5'-cpcF-cpcG1-cpcG2-cpcG3 3'. The three cpcG genes encode different phycocyanin-associated rod-core linker polypeptides of the phycobilisomes with predicted 279, 247 and 254 amino acids in length. The gene products CpcG show a high similarity at their N-terminal domains (190 amino acids) and an overall identity of 47-53% to one another. Each of the three CpcG polypeptides is highly related to one of the four CpcG gene products of Anabaena sp. PCC 7120 (66-81% identity). It is suggested that these pairs of rod-core linker polypeptides mediate the same specific type of phycocyanin----allophycocyanin interaction in the similar phycobilisomes of M. laminosus and Anabaena sp. PCC 7120. The similarity of the CpcG1, CpcG2 and CpcG3 polypeptides to the single CpcG rod-core linker polypeptide of Synechococcus sp. PCC 7002 (36-41% identity) is lower. The rod-core linker polypeptides are more distantly related to the rod linker polypeptides associated with phycocyanin or phycoerythrin. However, six conserved domains were identified within the N-terminal 190 amino acids of these linker proteins, which bear similar amino acid sequences, including highly conserved basic amino acids. A similar amino acid sequence but with conserved acidic amino acids can be found in the beta subunits of phycocyanin, phycoerythrin and phycoerythrocyanin, which is protruding into the central cavity of the phycobiliprotein hexamers. It is suggested that these domains are sites of phycobiliprotein-hexamer/rod and rod-core linker interactions.

Phycobilisome structure in the cyanobacteria Mastigocladus laminosus and Anabaena sp. PCC 7120

Phycobilisomes of the cyanobacteria Mastigocladus laminosus and Anabaena sp. PCC7120 differ from typical tricylindrical, hemidiscoidal phycobilisomes in three respects. Firstly, size comparisons of the core-membrane linker phycobiliproteins (LCM) in different cyanobacteria by SDS/PAGE reveal an apparent molecular mass of 120 kDa for the LCM of M. laminosus and Anabaena sp. PCC7120. This observation suggests that the polypeptides of these species have four linker-repeat domains. Secondly, phycobilisomes of M. laminosus are shown to contain at least three, but most probably four, different rod-core linker polypeptides (LRC). These LRC, which attach the peripheral rods to the core and thereby make phycocyanin/allophycocyanin contacts, have been identified and characterized by N-terminal amino acid sequence analysis. Additionally, electron microscopy of phycobilisomes isolated from M. laminosus and Anabaena sp. PCC7120 reveals similar structures which differ from those of Calothrix sp. PCC7601 with their typical six, peripheral rods. Based upon protein-analytical results and a reinterpretation of the data of [Isono, T. & Katoh, T. (1987) Arch. Biochem. Biophys. 256, 317-324], we discuss structural implications of recent findings on the established hemidiscoidal model for the phycobilisomes of M. laminosus and Anabaena sp. PCC7120. Up to eight peripheral rods are suggested to radiate from a modified core substructure which contains two additional peripheral allophycocyanin hexamer equivalents that serve as the core-proximal discs for two peripheral rods.

Three C-phycoerythrin-associated linker polypeptides in the phycobilisome of green-light-grown Calothrix sp. PCC 7601 (cyanobacteria)

Microanalyses by SDS-PAGE and microsequencing demonstrate that, under green-light conditions, 3 C-phycoerythrin associated rod-linker polypeptides with different N-terminal amino acid sequences are present in phycobilisomes (PBS) from Calothrix sp. 7601 cells. Two of these polypeptides, corresponding to SDS-PAGE bands at 36 and 37 kDa, could be assigned, respectively, to the cpeC and cpcD genes found on a separate cpeCD-operon in Calothrix sp. 7601 (Federspiel, N.A. and Grossman, A.R. (1990) J. Bacteriol, 172, 4072-4081). The third C-PE rod-linker polypeptide, LR,2PE,33, requires, therefore, a third gene with the suggested locus designation 'cpeE'. A C-PE (alpha beta)6-LR,2PE,33 complex containing this third rod-linker polypeptide could be isolated from phycobilisomes and characterized. PBS from both green- and red-light cells of Calothrix contain a single, unique LRC28 rod-core linker polypeptide which is not altered during chromatic adaptation.

A small multigene family encodes the rod-core linker polypeptides of Anabaena sp. PCC7120 phycobilisomes

The cpc operon of Anabaena sp. PCC7120 is shown to encode ten genes: 5'-cpcB-cpcA-cpcC-cpcD-cpcE-cpcF- cpcG1-cpcG2-cpcG3-cpcG4-3'. The 3' portion of this operon includes four tandemly repeated genes encoding phycocyanin (PC)-associated, rod-core linker polypeptides of the phycobilisomes (PBS). The products of these four genes are most similar at their N termini, and overall are 50-61% identical and 68-76% similar to one another. The four CpcG proteins of Anabaena sp. PCC7120 are 41-47% identical and 62-65% similar to the single CpcG rod-core linker protein in Synechococcus sp. PCC7002. The N-terminal domains of the polypeptides are also more distantly related to the conserved domains of other types of rod-linker polypeptides associated with PC, phycoerythrin, and allophycocyanin (AP). Three of these rod-core linker proteins (CpcG1, CpcG2, and CpcG4) were demonstrated to occur in isolated PBS by N-terminal amino acid sequence analyses. These results indicate that previously proposed models for the PBS of Anabaena sp. are incorrect. It is suggested that the PBS of Anabaena sp. have eight peripheral rods, each of which interacts with the AP of the core via a specific rod-core linker (CpcG) polypeptide.

Prospective randomized evaluation of ciprofloxacin versus piperacillin plus amikacin for empiric antibiotic therapy of febrile granulocytopenic cancer patients with lymphomas and solid tumors. The European Organization for Research on Treatment of Cancer International Antimicrobial Therapy Cooperative Group

Empiric therapy for febrile granulocytopenic patients is mandatory, but whether monotherapy is a safe alternative and whether fluoroquinolones are useful agents for this indication are still controversial issues. The use of monotherapy with intravenous ciprofloxacin (200 to 300 mg every 12 h) was evaluated against combined therapy with piperacillin plus amikacin in febrile granulocytopenic patients with solid tumor or lymphoma. The study was discontinued prematurely because patients treated with ciprofloxacin had a significantly lower overall success rate than patients treated with piperacillin plus amikacin (31 of 48 patients [65%] versus 48 of 53 patients [91%], P = 0.002). Patients with gram-positive coccal bacteremia had a particularly poor outcome: therapy failed for six of eight patients (75%) treated with ciprofloxacin, while therapy failed for none of four patients treated with piperacillin plus amikacin. Death from primary infection during initially randomized protocol therapy occurred in 7 of 48 patients (14.5%) treated with ciprofloxacin and in 3 of 53 (6%) treated with piperacillin plus amikacin. This study does not support the use of this dose of intravenous ciprofloxacin as empiric monotherapy for fever in granulocytopenic patients.

Susceptibility of gram-negative bacteria and Staphylococcus aureus to combinations of ticarcillin and clavulanic acid

Four hundred and fifty-nine blood culture isolates were tested for susceptibility to ticarcillin alone and ticarcillin plus clavulanic acid, a potent beta-lactamase inhibitor. The susceptibilities of the Staphylococcus aureus strains to cloxacillin, methicillin, vancomycin, rifampicin, cefoperazone, ceftriaxone and moxalactam and of the gram-negative strains to Augmentin, azlocillin, mezlocillin, piperacillin, cefoperazone, ceftriaxone, cefotaxime, cefsulodin and tobramycin were also measured. Seventy-one percent of staphylococcal strains were beta-lactamase positive. In the presence of clavulanic acid the ticarcillin spectrum was extended to include beta-lactamase producing Staphylococcus aureus, Serratia marcescens and Klebsiella. All the ticarcillin-resistant Enterobacteriaceae were rendered ticarcillin-sensitive by clavulanic acid. The anti-Pseudomonas activity of ticarcillin plus clavulanic acid differed little from that of azlocillin and piperacillin and was comparable to that of the third generation cephalosporins. The combination of ticarcillin with clavulanic acid should be tested in the treatment of patients with infections caused by ticarcillin-sensitive and ticarcillin-resistant bacteria.

Infection of a lumbar dermoid cyst by an anaerobic peptococcus

A case is reported of a dermoid cyst with a dermal sinus in a young adult, presenting as a subdural empyema due to an anaerobic peptococcus.