[Why does blood have a pH-value of 7.4? The theory of acid-base management]

Aim of the present paper is to discuss the physiologic principles of the acid-base status, in particular those of the pH value. The alpha-stat theory of acid-base management interprets the normal value of arterial pH, usually thought of as being 7.40, as a value derived from the intracellular pH, which is close to neutrality. This appears to have offered an evolutionary advantage, since most of the intermediates in biosynthetic pathways are ionized at neutrality resulting in a decreased rate of penetration across biological membranes of these compounds thus producing a benefit for the economy of a cell. Finally, we present the clinical implications of both the alpha-stat and the pH-stat strategy of acid-base management.

Antibiotics for preventing meningococcal infections

BACKGROUND

Meningococcal disease is a contagious bacterial disease caused by Neisseria meningitidis (N. meningitidis). The highest documented risk of disease is for household contacts during the first seven days of a case being detected. Prophylaxis is considered for those in close contact with people with a meningococcal infection and in populations with known high carriage rates as carriers are at increased risk of disease and may pose a risk of infection to others.

OBJECTIVES

To study the effectiveness of different prophylactic treatment regimens in: (1) preventing secondary cases of meningococcal disease after contact with a case; (2) preventing cases of meningococcal disease in populations with a high rate of N. meningitidis carriers; (3) eradicating N. meningitidis from the pharynx in healthy carriers of N. meningitidis;This review also addresses the issues of adverse affects and development of drug resistance.

SEARCH STRATEGY

Electronic searches on The Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library Issue 2, 2004), MEDLINE (January 1966 to July 2004), EMBASE (1980 to September 2004), LILACS (1982 to July 2004), and searches of references of all identified studies.

SELECTION CRITERIA

Randomised or quasi-randomised clinical trials addressing the effectiveness of different antibiotic treatments for (a) prophylaxis of/against meningococcal disease; (b) eradication of N. meningitidis.

DATA COLLECTION AND ANALYSIS

Two reviewers independently appraised the quality of each trial and extracted data from the included trials. Dichotomous data were analysed by calculating the relative risk (RR) and 95% confidence interval for each trial.

MAIN RESULTS

There were no cases of meningococcal disease during follow up in any of the trials, thus effectiveness regarding prevention of future disease cannot be directly assessed. Ciprofloxacin (relative risk (RR) 0.04; 95% CI 0.01 to 0.12), rifampin (RR 0.17; 95% CI 0.12 0.24), minocycline (RR = 0.30; 95% CI 0.19 to 0.45) and ampicillin (RR 0.41; 95% CI 0.25 0.66) proved effective at eradicating N. meningitidis one week after treatment, compared with placebo. However, after one to two weeks only rifampin (RR 0.20; 95% CI 0.14 to 0.29) and ciprofloxacin (RR 0.03; 95% CI 0.00 to 0.42) still proved effective. No trials evaluated ceftriaxone against placebo. Ceftriaxone was more effective than rifampin, after one to two weeks of follow up (RR 5.93; 95% CI 1.22 to 28.68). Rifampin continued to be effective compared to placebo until up to four weeks of post treatment follow up but resistant isolates were seen following prophylactic treatment.

AUTHORS' CONCLUSIONS

Given the fact that the use of rifampin in an outbreak setting might lead to the circulation of isolates resistant to rifampin, use of ciprofloxacin or ceftriaxone should be considered.Placebo-controlled trials do not seem ethical as prophylactic treatment has been proven to reduce the risk of disease among household contacts. More trials comparing the effectiveness of ceftriaxone, ciprofloxacin and rifampin for eradicating N. meningitidis could provide important insights.

Granulomes annulaires disséminés et immunodépression iatrogène

BACKGROUND

Granuloma have already been described in the context of immunosuppression. We report six cases of widespread granuloma annulare occurring in patients with drug-induced immunosuppression.

CASE REPORTS

There were four women and two men, with mean age of 61 years (35-76). Three patients were treated with chemotherapy for breast (2 cases) and liver cancer. One woman was given chemotherapy for Hodgkin's disease. One had undergone liver transplantation and was given cyclosporine, another was treated with systemic steroids for polyarthritis. All had generalized non-photoexposed granuloma annulare, composed of multiple erythematous papules, sometimes with annular pattern. The lesions were localized on the trunk, legs and arms. Histopathology revealed granuloma annulare in each patient.

DISCUSSION

These six cases suggest a relationship between drug-induced immunodeficiency and generalized granuloma annulare. The immune dysregulation induced by the drugs may have been responsible for the formation of granuloma annulare.

Fractures of the calcaneum

We have assessed the long-term results after operative and non-operative treatment of undisplaced and displaced calcaneal fractures.

At a mean of 6.5 years, we reviewed 70 patients with a calcaneal fracture who were divided into four groups: group 1, 18 patients with undisplaced fractures and a normal Böhler’s angle (BA) who had been treated non-operatively; group 2, 23 with intra-articular fractures and a BA < 10° who had been treated non-operatively; group 3, 13 with intra-articular fractures and a BA > 10° who had been treated surgically; and group 4, 16 with intra-articular fractures and a BA < 10° who had been treated surgically.

The results were assessed by a clinical score considering pain, return to work, return to physical activity, change in shoe-wear and the requirement for subtalar arthrodesis.

Patients with undisplaced calcaneal fractures had a good outcome. Those with displaced fractures treated surgically who presented at follow-up with a BA > 10° had a satisfactory functional outcome and those with displaced fractures who had non-operative treatment had a poor outcome. The poorest outcome was consistently seen in patients who were treated operatively without restoration of BA. Open reduction and internal fixation of intra-articular calcaneal fractures can only be expected to benefit those patients in whom nearly anatomical reconstruction is obtained.

Oral versus intravenous antibiotic treatment for febrile neutropenia in cancer patients

BACKGROUND

Fever occurring in a neutropenic patient remains a common life-threatening complication of cancer chemotherapy. The common practice is to admit the patient to hospital and treat empirically with intravenous broad-spectrum antibiotics. Oral therapy could be an alternative approach for selected patients.

OBJECTIVES

To compare the efficacy of oral antibiotics versus intravenous (IV) antibiotic therapy in febrile neutropenic cancer patients.

SEARCH STRATEGY

We searched the Cochrane Cancer Network Register of trials (November 2002), the Cochrane Library (issue 2, 2002), MEDLINE (1966 to 2002), EMBASE (January 1980 to 2002) and LILACS (1982 to 2002). We searched several databases for ongoing trials. We checked the conference proceedings of the Interscience Conference of Antimicrobial Agents and Chemotherapy (ICAAC) 1995 to 2002 and all references of included studies and major reviews were scanned.

SELECTION CRITERIA

Randomised controlled trials comparing oral antibiotic/s to intravenous antibiotic/s for the treatment of neutropenic cancer patients with fever. The comparison between the two could be started initially (initial oral), or following an initial course of intravenous antibiotic treatment (sequential).

DATA COLLECTION AND ANALYSIS

Two reviewers independently assessed trial eligibility, methodological quality and extracted data. Data concerning mortality, treatment failures and adverse events were extracted from included studies assuming an "intention-to-treat" basis for the outcome measures whenever possible. Relative risks (RR) with 95% confidence intervals (CI) for dichotomous data were estimated.

MAIN RESULTS

Fifteen trials (median mortality 0, range 0 to 8.8%) were included in the analyses. The mortality rate was similar comparing oral to intravenous antibiotic treatment (RR 0.91, 95% CI 0.51 to 1.62, 7 trials, 1223 patients). Treatment failure rates were also similar (RR 0.94, 95% CI 0.84 to 1.05, all trials). No significant heterogeneity was shown for all comparisons but adverse events. This effect was stable in a wide range of patients. Quinolones alone or combined with another antibiotics were used with comparable results. Adverse reactions, mostly gastrointestinal were more common with oral antibiotics.

REVIEWERS' CONCLUSIONS

Based on the present data, oral treatment is an acceptable alternative to intravenous antibiotic treatment in febrile neutropenic cancer patients (excluding patients with acute leukaemia) who are haemodynamically stable, without organ failure, not having pneumonia, infection of a central line or a severe soft-tissue infection. The wide confidence interval for mortality allows the present use of oral treatment in groups of patients with an expected low risk for mortality, and further research should be aimed at clarifying the definition of low risk patients.

A survey of autologous blood transfusion practices in Germany

This survey was designed to evaluate the use of autologous blood transfusion techniques in Germany in 2000 and to identify how the use of these techniques has changed over the past 5 years. Questionnaires were mailed to the chief anaesthesiologists of 400 randomly selected German hospitals with > or =25 surgical beds. Information was sought about the current and past use of preoperative autologous blood donation (PABD), acute preoperative haemodilution and peri-operative blood salvage. Data were requested for the calendar year 2000. Three hundred and forty-three (86%) completed questionnaires were returned. PABD, haemodilution and peri-operative blood salvage were used by 85, 54 and 67% of respondents, respectively. Thirty-seven per cent of PABD users reported that PABD use declined, 28% reported that it increased and 34% reported that it remained unchanged over the past 5 years. The proportions of those reporting declining vs. increasing use of PABD did not differ significantly (P = 0.09). Sixty per cent of users of haemodilution reported that its use declined, 10% reported that it increased and 29% reported that it remained unchanged over the past 5 years. Sixteen per cent of hospitals that were equipped with cell-washing devices reported that the use of these devices declined, 47% reported that it increased and 37% reported that it remained unchanged over the past 5 years. The results indicate that autologous blood transfusion techniques were widely used in Germany in 2000, with PABD being the most common technique. The use of PABD did not change significantly, the use of haemodilution declined markedly and the use of peri-operative cell salvage increased markedly during the past 5 years before the survey.

Arrhythmien aus dem rechten Ventrikel

Right ventricular arrhythmias predominantly occur in young patients with rare cardiac diseases. Underlying cardiac conditions include idiopathic right ventricular outflow-tract tachycardia (RVOT-VT), arrhythmogenic right ventricular cardiomyopathy (ARVC), Brugada syndrome, and postoperative congenital heart disease (i.e. tetralogy of Fallot). According to the underlying cardiac disease, there are significant differences in the diagnostic and therapeutic management and prognosis which is mainly determined by life-threatening ventricular arrhythmia recurrences and sudden cardiac death. To provide optimal treatment for affected patients, a detailed diagnostic evaluation and risk stratification is mandatory. Tailored treatment strategies aim at the suppression or effective termination of recurrent ventricular tachyarrhythmias and prevention of sudden death by antiarrhythmic drug therapy, catheter ablation, and the implantation of cardioverter-defibrillators. This review summarizes the current knowledge on pathogenesis, diagnosis, treatment and prognosis of those conditions that are associated with arrhythmias originating from the right ventricle.

Preeclampsia is associated with loss of neuronal nitric oxide synthase expression in vascular smooth muscle cells of the human umbilical cord

AIMS

Umbilical blood vessels are not innervated and regulation of blood flow to the placenta must depend on structural changes and the effect of vasoactive factors. Failure to achieve these adaptations may result in reduced fetoplacental perfusion. The purpose of this study was to determine whether neuronal nitric oxide synthase (nNOS) is expressed in human vascular smooth muscle cells (VSMCs) of the fetoplacental circulation. nNOS has been described as a non-endothelial NOS counterregulating vasoconstriction only in the VSMCs of animal models. Therefore, we investigated nNOS expression in the fetoplacental unit from preeclamptic and healthy pregnancies.

METHODS AND RESULTS

We investigated nNOS regulation by immunohistochemistry, Western blotting and reverse transcriptase-polymerase chain reaction analysis. nNOS activity was determined by measuring the conversion of L-3H-arginine to L-3H-citrulline. nNOS expression was revealed only in VSMCs of the human umbilical veins, but not in umbilical arteries. A more direct assessment of nNOS activity showed that a small, but consistent amount of nNOS is present in the denuded media of the umbilical vein. In VSMCs of the umbilical veins during preeclampsia a total loss of nNOS protein expression and a significant decrease in mRNA expression were seen.

CONCLUSIONS

Loss of nNOS expression is associated with preeclampsia. It may alter the regulation of blood flow in the fetal and maternal placental vasculature in preeclampsia. However, the impact of NO produced by nNOS on the vascular tone of umbilical veins remains to be elucidated.

Accidental tenfold overdose of propofol in a 6-month old infant undergoing elective craniosynostosis repair

We report a 6-month-old male infant undergoing elective craniosynostosis repair who accidentally received a tenfold dose of propofol over a 4-h operative period. Myocardial dysfunction was observed after nearly 3 h of infusion; this could not solely be explained by the propofol overdose.

[Trevira: a new polyester implant for the treatment of incisional hernia. Results of an experimental study]

OBJECTIVE

The synthetic implant meshes in clinical use for the treatment of abdominal hernias are generally made of polyester in France and of polypropylene in Germany. Serving as an implant material for the replacement of the cruciate ligament, the Trevira is another polymer of polyester in clinical use with excellent results. This animal trial was performed to ascertain whether it offers any advantages over polypropylene for abdominal incisional hernia repair.

MATERIAL AND METHODS

[corrected] In 12 pigs 10 x 10 cm of the abdominal wall preserving the peritoneum was resected and subsequently implanted a 15 x 15 cm synthetic mesh of polyethylene terephthalate (Trevira) in half of them and of polypropylene (Prolene) in the other half using a sublay technique. After two and six month the implant size was measured and the extend of the foreign body reaction determined by the microscopically presence of foreign body giant cells.

RESULTS

No significant differences concerning the implant size were shown between the two groups at any of the time periods. The acute inflammatory reaction observed was significantly higher at the polypropylene than at the polyethylene terephthalate implant (number of giant cells after 2 month: Prolene 2.2 +/-0.4, Trevira: 0.8 +/-0.2, after six month: Prolene: 4.6 +/-1.3, Trevira: 1.1 +/-0.5). In contrast to the polyethylene terephthalate all polypropylene samples showed calcification areas after six month.

CONCLUSION

In this animal trial Trevira mesh showed a high biocompatibility with a low foreign body reaction. It appears to be a promising new implant for the treatment of hernia.

[Possibilities of computer-assisted navitation in knee para-articular osteotomies]

Osteotomies in the knee region for incipient osteoarthritis in active patients have become increasingly popular in recent years. A computer-guided navigation system should help increase the surgeon's accuracy and lower the risk of intraoperative complications for this technically demanding type of surgery. Furthermore, computer navigation might be a powerful research and educational tool. The technical principles and the clinical implications of this system for knee osteotomies are described in the following article.

Flint mining in prehistory recorded by in situ-produced cosmogenic 10Be

The development of mining to acquire the best raw materials for producing stone tools represents a breakthrough in human technological and intellectual development. We present a new approach to studying the history of flint mining, using in situ-produced cosmogenic 10Be concentrations. We show that the raw material used to manufacture flint artifacts approximately 300,000 years old from Qesem Cave (Israel) was most likely surface-collected or obtained from shallow quarries, whereas artifacts of the same period from Tabun Cave (Israel) were made of flint originating from layers 2 or more meters deep, possibly mined or quarried by humans.

Epidemiology and clinical features of vivax malaria imported to Europe: sentinel surveillance data from TropNetEurop

BACKGROUND

Plasmodium vivax is the second most common species among malaria patients diagnosed in Europe, but epidemiological and clinical data on imported P. vivax malaria are limited. The TropNetEurop surveillance network has monitored the importation of vivax malaria into Europe since 1999.

OBJECTIVES

To present epidemiological and clinical data on imported P. vivax malaria collected at European level.

MATERIAL AND METHODS

Data of primary cases of P. vivax malaria reported between January 1999 and September 2003 were analysed, focusing on disease frequency, patient characteristics, place of infection, course of disease, treatment and differences between network-member countries.

RESULTS

Within the surveillance period 4,801 cases of imported malaria were reported. 618 (12.9%) were attributed to P. vivax. European travellers and immigrants were the largest patient groups, but their proportion varied among the reporting countries. The main regions of infection in descending order were the Indian subcontinent, Indonesia, South America and Western and Eastern Africa, as a group accounting for more than 60% of the cases. Regular use of malaria chemoprophylaxis was reported by 118 patients. With 86 (inter-quartile range 41-158) versus 31 days (inter-quartile range 4-133) the median symptom onset was significantly delayed in patients with chemoprophylaxis (p < 0.0001). Common complaints were fever, headache, fatigue, and musculo-skeletal symptoms. All patients survived and severe clinical complications were rare. Hospitalization was provided for 60% and primaquine treatment administered to 83.8% of the patients, but frequencies varied strongly among reporting countries.

CONCLUSIONS

TropNetEurop data can contribute to the harmonization of European treatment policies.

Leucémie aleucémique non T non B CD4+ CD56+ (2 cas)

INTRODUCTION

Non T non B CD4+ CD56+ leukemia is often revealed by cutaneous lesions. We report 2 patients with this disorder who had characteristic anatomoclinical findings.

CASE REPORTS

An 81 year-old female and a 75 year-old man presented with erythematous macules which increased in number and progressed to infiltrated plaques and nodules. The lesions became ecchymotic, but the patients remained in good general condition and blood count as well as bone marrow examination were unremarkable. A cutaneous biopsy revealed a lymphomatous mononuclear cell infiltrate. The cells expressed CD4 and CD56, but not CD3. The cutaneous lesions preceded for 10 and 9 months respectively the appearance of overt leukemia and medullar involvement. At this stage, the patients deceased rapidly from their leukemia.

DISCUSSION

This is an original anatomoclinical syndrome. The histopathologist must pay attention to the unusual CD4+ and CD3- immunophenotype and search for CD56 expression. The malignant cell responsible for this type of leukemia is now individualized and corresponds to a type II dendritic cell precursor.

Prospects for cleaning ash in the acidic effluent from bioleaching of sulfidic concentrates

Leaching of ashes in sulfuric acid (pH 1.0, liquid-to-solid (L/S) ratio 10:1, 25 degrees C) has been characterized with respect to the neutralizing capacity and the dissolution of dominant ions and trace elements. The conditions mimic the oxidation stage of a biohydrometallurgical process for base metal production from sulfidic mineral concentrates. Direct acid leaching of ash, integrated with this metallurgical process, offers a feasible route to the sustainable handling of metal-rich ashes. The treated ash will be deposited together with the inert mineral residue. Cd, Co, Cu, Ni and Zn are effectively leached and can be recovered utilizing existing hydrometallurgical technology, but the recovery of other readily dissolved metals, notably Mn, U and V, requires that additional steps are implemented. We make two recommendations for industrial processes. The first is to replace limestone with ash from biofuels, except peat, for pH control in biohydrometallurgical processing. This requires a modest increase of fresh alkali compared with limestone. The second is to implement sulfuric acid leaching of fly ash from the combustion of solid waste and other metal-rich fuels (used wood, tires), thereby avoiding costly ash-deposits. There is a significant economic incentive for these changes, since no costly ash-deposits and less limestone will be needed.

Determination of the 8B neutrino spectrum

We have measured the total energy of the alpha particles following the beta decay of 8B by implanting 8B into a planar silicon surface barrier detector. Calibration was performed using alpha particles following the beta decay of 20Na, similarly implanted. The alpha spectrum is used to infer the 8B neutrino spectrum which is an important input in the interpretation of experiments that detect energetic neutrinos from the Sun. The alpha spectrum reported here is in disagreement with the previous best measurement which used two detectors in coincidence.

The concomitant occurrence of multiple epidermal cysts, osteomas and thyroid gland nodules is not diagnostic for Gardner syndrome in the absence of intestinal polyposis: a clinical and genetic report

Gardner syndrome, a phenotypic variant of familial adenomatous polyposis, is characterized by the classical clinical triad of skin and soft tissue tumours, osteomas and intestinal polyposis, but disease patterns with pairs of these findings have also been reported. Different mutations in the adenomatous polyposis coli (APC) gene have been shown to be associated with Gardner syndrome disease phenotypes. A 36-year-old patient presented with multiple epidermal cysts on the face, left ear lobe and neck, and the possible diagnosis of Gardner syndrome was based on the additional findings of two classical osteomas in the left radius and ulna and a cold non-malignant nodule of the thyroid gland. Intestinal polyposis was lacking at the time of examination. Major deletions but not microdeletions were excluded by a cytogenetic analysis with 650 chromosomal bands per haploid set. Systematic sequencing of the entire coding region of the APC gene (> 8500 bp) of the patient and five healthy controls was also performed. As a results, new APC gene polymorphisms were identified in exons 13 [A545A (A/G)] and 15 [G1678G (A/G), S1756S (G/T), P1960P (A/G)]. We also detected D1822V (A/T) which has recently been reported to be potentially related to colorectal carcinoma, and genotyped 194 randomly chosen healthy individuals from the Glasgow area for this as well as for the above variants in exons 13 and 15. Interestingly, of the 194 controls, 112 carried the DD (57.7%), 71 the DV (36.6%), and the remaining 11 (5.7%), including our patient, the VV genotype. It is therefore unlikely that APC D1822V serves as an important marker for colorectal carcinoma. In conclusion, we failed to identify obvious germline candidate mutations in > 8500 bp of the coding region of the APC gene in a patient with multiple epidermal cysts, osteomas and a thyroid gland nodule; major chromosomal deletions were excluded. Therefore, we assume that only the presence of intestinal polyposis is a marker for Gardner syndrome.