[Deprescribing: an essential part of rational pharmacotherapy]

Deprescribing is a planned, systematic process supervised by a healthcare professional. It is considered to be a fundamental part of good prescribing. Deprescribing can be defined as the complete withdrawal of medications as well as dose reduction. The patient's health status, life expectancy, values, preferences and the therapeutic goals should be given serious consideration while planning the deprescribing process. The main objective of deprescribing may vary but reaching the patients' goals and improving their quality of life remain constant priorities. In our article, based on the international literature, we review potential deprescribing targets such as the characteristics of high-risk patients, medications that should prompt a therapy review and the ideal settings for deprescribing. We also cover the steps, risks and benefits of the process, and discuss the existing specific guidelines and algorithms. We provide information on the enablers and barriers of deprescribing among both patients and healthcare professionals, and discuss international initiatives as well as the future of deprescribing. Orv Hetil. 2023; 164(24): 931-941.

Impact of the COVID-19 Pandemic on Ambulatory Care Antibiotic Use in Hungary: A Population-Based Observational Study

The COVID-19 pandemic and related restrictions have potentially impacted the use of antibiotics. We aimed to analyze the use of systemic antibiotics (J01) in ambulatory care in Hungary during two pandemic years, to compare it with pre-COVID levels (January 2015-December 2019), and to describe trends based on monthly utilization. Our main findings were that during the studied COVID-19 pandemic period, compared to the pre-COVID level, an impressive 23.22% decrease in the use of systemic antibiotics was detected in ambulatory care. A significant reduction was shown in the use of several antibacterial subgroups, such as beta-lactam antibacterials, penicillins (J01C, -26.3%), and quinolones (J01M, -36.5%). The trends of antibiotic use moved in parallel with the introduction or revoking of restriction measures with a nadir in May 2020, which corresponded to a 55.46% decrease in use compared to the previous (pre-COVID) year's monthly means. In general, the systemic antibiotic use (J01) was lower compared to the pre-COVID periods' monthly means in almost every studied pandemic month, except for three months from September to November in 2021. The seasonal variation of antibiotic use also diminished. Active agent level analysis revealed an excessive use of azithromycin, even after evidence of ineffectiveness for COVID-19 emerged.

Trends in Opioid Utilisation in Hungary, 2006-2020: A Nationwide Retrospective Study with Multiple Metrics

BACKGROUND

Opioid use is well-documented in several countries: some countries struggle with overuse while others have almost no access to opioids. For Europe, limited data are available. This study analysed Hungarian opioid utilisation in ambulatory care between 2006 and 2020.

METHODS

We obtained national drug utilization data on reimbursed opioid analgesics (ATC code: N02A) from a national health insurance database for a 15-year period. We investigated utilisation trends, using three volume-based metrics (defined daily dose per 1000 inhabitants per day (DID), oral morphine equivalent per 1000 inhabitants per day, packages dispensed per 1000 inhabitants per year). We stratified data based on administration routes, analgesic potency and reimbursement categories.

RESULTS

Total opioid utilisation increased during the study period according to all three metrics (74% in DID) and reached 5.31 DID by 2020. Upward trends were driven by an increase both in weak and strong opioid use (79% vs. 53%). The most commonly used opioids were fentanyl (in the strong category; 0.76 DID in 2020) and tramadol (in the weak category; 2.62 DID in 2020). Overall, tramadol was also the most commonly used opioid throughout the study period. Oral administration of opioid medications was dominant. Based on reimbursement categories, musculoskeletal pain was becoming a more frequent indication for opioid use (1552% increase in DID), while opioid use for cancer pain declined significantly during the study period (-33% in DID).

CONCLUSIONS

Our low utilisation numbers might indicate underuse of opioid analgesia, especially for cancer pain.

Az antibiotikum ambuláns alkalmazásának jellemzői és tendenciái Magyarországon (2010–2019)

Összefoglaló. Bevezetés: Az antibiotikumok észszerű alkalmazása kulcsfontosságú a hatékonyságuk megőrzésében és a néhol kritikus méreteket öltő antibiotikumrezisztencia visszaszorításában. Célkitűzés: A hazai ambuláns antibiotikumfelhasználás jellemzőinek, trendjeinek bemutatása. Módszer: A 2010 és 2019 közötti időszakra vonatkozó, dobozszámban kifejezett ambuláns szisztémás antibiotikumfelhasználási adatokat – a WHO 2019. évi indexe alapján – „defined daily dose” (DDD – napi átlagdózis) egységbe konvertáltuk. Standardizált technikai egységünk a DDD/1000 fő/nap volt (DID). Az antibiotikumfelhasználás értékelésére nemzetközileg elfogadott minőségi indikátorokat alkalmaztunk. Eredmények: Az antibiotikumfelhasználás mértéke kismértékű ingadozást mutatott (min.: 12,9 DID, max.: 14,7 DID), viszont a szezonális ingadozás a teljes megfigyelt időszakban jelentős mértékű volt. A széles versus szűk spektrumú béta-laktámok és makrolidek felhasználási hányadosa évről évre tovább emelkedett (2010: 13,3 vs. 2019: 71,6), a fluorokinolonok alkalmazási aránya továbbra is meghatározó (2010: 14,3%, 2019: 14,5%). A vizsgált 12 minőségi indikátor közül a tanulmány nyitó évében 4, a tanulmány záró évében 6 indikátor esetében a legkedvezőtlenebbül teljesítő európai országok közé tartoztunk. Megbeszélés: A hazai antibiotikumalkalmazás mértéke európai mérce szerint nem magas, de csökkentésére látszik lehetőség; mintázata szuboptimális, és az évek során kedvezőtlen irányba változott. Következtetés: A kapott antibiotikumfelhasználási adatok s azok értelmezése alapján rendkívül sürgető morális kötelesség a szakmai és hatósági intervenciókra épülő hazai antibiotikumstratégia és -akcióterv mielőbbi kidolgozása, implementálása. Orv Hetil. 2022; 163(4): 140–149.

Summary. Introduction: Prudent antibiotic use is an important tool to preserve their effectiveness as well as reverse and confine antibiotic resistance. Objective: To evaluate the trends and characteristics of Hungarian outpatient antibiotic use. Methods: Crude, package level antibiotic sales data for the period 2010–2019 were converted into DDD (defined daily dose) and were standardized for 1000 inhabitants and per year (ATC-DDD index, version 2019). Internationally validated drug-specific quality indicators were used to evaluate antibiotic use. Results: The scale of antibiotic use was stagnating with minimal fluctuation (min.: 12.9 DID, max.: 14.7 DID), and with high intra-year seasonality index. The ratio of the consumption of broad to narrow spectrum beta-lactams and macrolides increased gradually from year to year (2010: 13.3 vs. 2019: 71.6) and the relative consumption of fluoroquinolones is still remarkable (2010: 14.3%, 2019: 14.5%). Out of the twelve surveyed drug-specific quality indicators in the first and last year of analysis, we were ranked among the weakest European countries in the case of four and six indicators, respectively. Discussion: The scale of Hungarian outpatient antibiotic use is not high, in European comperison, but has some reserve capacity for reduction. The pattern of Hungarian antibiotic use is suboptimal and had further decreased quality through the years. Conclusion: Based on the recorded data of antibiotic use and their interpretation, the development of national antibiotic strategy (including both professional and authority interventions) is a pressing moral obligation. Orv Hetil. 2021; 163(4): 140–149.

Factors Facilitating and Hindering Development of a Medication Use Review Service in Eastern Europe and Iran-Cross-Sectional Exploratory Study

Polypharmacy is a common issue in patients with chronic diseases. Eastern-European countries and Iran are exploring possibilities for implementing the Medication Use Review (MUR) as a measure for optimizing medication use and ensuring medication safety in polypharmacy patients. The aim of this study was to gain insights into the development of the community pharmacy sector and map facilitators and barriers of MUR in Eastern Europe and Iran. The representatives of the framework countries received a questionnaire on community pharmacy sector indicators, current and future developments of pharmacies, and factors encouraging and hindering MUR. To answer the questionnaire, all representatives performed document analysis, literature review, and qualitative interviews with key stakeholders. The socio-ecological model was used for inductive thematic analysis of the identified factors. Current community pharmacist competencies in framework countries were more related to traditional pharmacy services. Main facilitators of MUR were increase in polypharmacy and pharmaceutical waste, and access to patients’ electronic list of medications by pharmacists. Main barriers included the service being unfamiliar, lack of funding and private consultation areas. Pharmacists in the framework countries are well-placed to provide MUR, however, the service needs more introduction and barriers mostly on organizational and public policy levels must be addressed.

Use of Proton Pump Inhibitors in Hungary: Mixed-Method Study to Reveal Scale and Characteristics

Background

Due to their efficacy and tolerability, utilization of proton pump inhibitors (PPI) has significantly increased worldwide. Parallel to the clinical benefits, potential long-term side effects have been observed, which, along with increasing medical expenses and potential drug interactions, justifies the analysis of the trends of utilization.

Objective

The aim of the present study was to show the level, pattern, and characteristics of PPI use.

Methods

We assessed the nationwide use of proton pump inhibitors in ambulatory care based on aggregated utilization data from the National Health Insurance database. The annual PPI utilization was expressed as the number of packages and as number of DDDs per 1,000 inhabitants and per year. For 2018, we estimated PPI exposure as the number of packages and as the number of DDDs per user per year. The annual reimbursement costs of proton pump inhibitors were also calculated. Moreover, three patient-level surveys were carried out in non-gastroenterological inpatient hospital departments to reveal characteristics of proton pump inhibitor use, namely dose, duration, and indication.

Results

The PPI utilisation increased from 5867.8 thousand to 7124.9 thousand packages and from 41.9 to 50.4 DDD per 1,000 inhabitants and per day between 2014 and 2018. Nationwide data showed that 14% of the adult population was exposed to proton pump inhibitors in 2018, while among hospitalized patients, the prevalence of proton pump inhibitor use was between 44.5% and 54.1%. Pantoprazole was the most frequently used active ingredient, both in the nationwide data and in the patient-level surveys. In the patient-level survey in majority of patients (71.5%-80.0%) proton pump inhibitors were prescribed for prophylaxis. Many inpatients (29.4%-36.9%) used 80 mg pantoprazole per day. The average number of PPI packages per user was 6.5 in 2018 in the nationwide data. The duration of PPI therapy was typically between 1 and 5 years in the patient-level surveys and nearly 20% of the inpatients had been taking proton pump inhibitors for more than 5 years.

Conclusions

Our data suggests that Hungarian patients receive proton pump inhibitors in high doses and for a long time. Use of proton pump inhibitors beyond their recommended indications was also found.

Vitex agnus-castus in premenstrual syndrome: A meta-analysis of double-blind randomised controlled trials

Although chasteberry (Vitex agnus-castus, VAC) has been studied in several clinical trials and available as medicine for the alleviation of premenstrual syndrome (PMS) symptoms, the efficacy of properly characterised preparations has not been assessed in meta-analyses. The aim of our work was to evaluate the efficacy of VAC in PMS. The meta-analysis was performed following the PRISMA guidelines using the PICOS format, taking into account the CONSORT recommendations. PubMed, Embase, the Cochrane Central Register of Controlled Trials and Web of Science were searched for studies on VAC. The analysis assessed the efficacy of properly characterised products VAC compared to a placebo for the alleviation of PMS symptoms in terms of responder rate, considering the decrease of Total Symptom Score or PMS Diary score. The random effects model was used to calculate summary relative risk (RR) and 95% confidence interval (CI). Only those randomised, double-blind, placebo-controlled trials were included that fulfilled the criteria of the CONSORT recommendations aiming at the proper characterization of herbal products. Out of the 21 clinical trials, three studies (520 females) fulfilled the inclusion criteria, comparing the efficacy of special extracts Ze 440 and BNO 1095 to a placebo for the treatment of PMS. VAC preparations were confirmed to be effective in the reduction of PMS symptoms: women taking VAC were 2.57 (95% CI 1.52-4.35) times more likely to experience a remission in their symptoms compared to those taking the placebo. Although several clinical trials have been carried out with VAC, the majority of the studies cannot be used as evidence for efficacy due to incomplete reporting, especially concerning the description of the used medication. More trials following the CONSORT recommendations are needed to assess the efficacy of VAC extracts.

Ginger (Zingiber officinale): An alternative for the prevention of postoperative nausea and vomiting. A meta-analysis

BACKGROUND

Postoperative nausea and vomiting (PONV) is a distressing outcome related to surgeries. Traditionally, ginger has been used in the treatment of nausea and vomiting for thousands of years. Recently, several randomized, placebo-controlled clinical trials (RCTs) have been conducted to evaluate the efficacy of ginger in PONV.

PURPOSE

To systematically evaluate the efficacy of ginger on postoperative nausea and vomiting (PONV) compared to placebo, based on RCTs.

STUDY DESIGN

The meta-analysis was reported following the PRISMA guidelines using the PICO format, and it was registered with the PROSPERO register.

METHODS

PubMed, Embase, the Cochrane Central Register of Controlled Trials and Web of Science were searched for relevant studies. Human, placebo-controlled clinical studies of patients undergoing any types of surgery, receiving pharmacological doses of ginger per os were included. Only clinical trials with explicit description of the ginger preparation used were analysed. No language or publication year restrictions was applied.

RESULTS

Ten randomized trials including a total of 918 patients were pooled for the statistical analysis. The present meta-analysis supports that ginger has a significant effect on the severity of PONV based on visual analogue scale (VAS) results: in a fixed effects model the pooled standardized mean difference (SMD) was -0.247 (favouring ginger; [LL]: -0.455, [UL]: -0.040, p-value: 0.019). Moreover, our results suggest that ginger reduces the incidence of postoperative nausea and vomiting, as well antiemetic drug demand; however, these effects are not statistically significant compared to placebo, which may be explained by underdosing.

CONCLUSIONS

According to our thorough meta-analysis ginger is safe and well tolerated, and decreases the severity of PONV, and may lower the incidence of postoperative nausea and vomiting, which in turn may reduce antiemetic drug demand, suggesting that ginger may be a useful alternative to antiemetic medications to alleviate PONV.

[Antibiotic use in the Hungarian hospitals in the last two decades (1996-2015)]

INTRODUCTION

Growing bacterial resistance threatens public health, which can be tempered by prudent antibiotic use.

AIM

To quantify systemic antibacterial use in Hungarian hospitals.

METHOD

Consumption data were analysed using the Anatomical-Therapeutic-Chemical - Defined Daily Dose (ATC/DDD) methodology. Data were standardized for patient turnover and also for population to enable international benchmarking.

RESULTS

Hospital antibiotic use was quite constant (22.4 ± 1.5 DDD/100 patient-days), but its composition changed substantially. The use of parenteral products rose gradually (in 1996 26.4% and in 2015 41.6%). The pattern of use was homogenised due to the headway of co-amoxiclav use. A substantial increase of fluoroquinolone (2.3 vs. 4.2 DDD/100 patient-days) and third generation cephalosporin (1.0 vs. 2.9 DDD/100 patient-days) use was detected. In parallel the use of narrow spectra penicillins diminished.

CONCLUSION

Hungarian hospital antibiotic use is low. The causes and the justification of this low use together with the internationally outstanding use of certain antibacterials should be addressed in future studies. Orv. Hetil., 2016, 157(46), 1839-1846.

Regional variation in the management of metastatic gastric cancer in Ontario

BACKGROUND

Geographic variation in cancer care is common when clear clinical management guidelines do not exist. In the present study, we sought to describe health care resource consumption by patients with metastatic gastric cancer (gc) and to investigate the possibility of regional variation.

METHODS

In this population-based cohort study of patients with stage iv gastric adenocarcinoma diagnosed between 1 April 2005 and 31 March 2008, chart review and administrative health care data were linked to study resource utilization outcomes (for example, clinical investigations, treatments) in the province of Ontario. The study took a health care system perspective with a 2-year time frame. Chi-square tests were used to compare proportions of resource utilization, and analysis of variance compared mean per-patient resource consumption between geographic regions.

RESULTS

A cohort of 1433 patients received 4690 endoscopic investigations, 12,033 computed tomography exams, 12,774 radiography exams, and 5059 ultrasonography exams. Nearly all patients were seen by a general practitioner (98%) and a specialist (99%), and were hospitalized (95%) or visited the emergency department (87%). Fewer than half received chemotherapy (43%), gastrectomy (37%), or radiotherapy (28%). The mean number of clinical investigations, physician visits, hospitalizations, and instances of patient accessing the emergency department or receiving radiotherapy or stent placement varied significantly by region.

CONCLUSIONS

Variations in health care resource utilization for metastatic gc patients are observed across the regions of Ontario. Whether those differences reflect differential access to resources, patient preference, or physician preference is not known. The observed variation might reflect a lack of guidelines based on high-quality evidence and could partly be ameliorated with regionalization of gc care to high-volume centres.

[Treatment practice of acute cystitis on the basis of national prescription data]

INTRODUCTION

Urinary tract infections are one of the common diseases in the primary health care.

AIM

To analyse patterns of ambulatory antibiotic use in acute cystitis.

METHOD

Antibiotic use data was based on national-level prescription turnovers. Patterns of antibiotic use were evaluated by prescribing quality indicators. The content of different national guidelines for treatment of acute cystitis and adherence to these guidelines were also evaluated.

RESULTS

For the treatment of acute cystitis quinolones were used predominantly. Norfloxacin (26%) and ciprofloxacin (19%) were prescribed most commonly. The use of internationally recommended agents such as sulphonamides, nitrofurans and fosfomycin shared 15%, 7% and 2%, respectively. The average adherence rate to national guidelines was 66% and certain weak points (e.g. controversial content) of the national guidelines were also identified.

CONCLUSIONS

Antibiotic use in acute cystitis seems to be suboptimal in Hungary. Considering actual local antibiotic resistance patterns, a new national guideline should be worked out for acute cystitis treatment.

[Evaluation of ambulatory antibiotic use in Hungary using drug-specific quality indicators]

INTRODUCTION

Rational use of antibiotics is an important tool in combating antibiotic resistance.

AIM

The aim of the authors was to evaluate the quality of ambulatory antibiotic use in Hungary.

METHOD

Crude antibiotic sales data for the period between 1996 and 2010 were converted into DDD (Defined Daily Dose) per 1000 inhabitants and per year. The recently developed and validated drug-specific quality indicators were used to evaluate antibiotic use.

RESULTS

Beside constant quantity (18.0±1.8 DDD/1000 inhabitants/day), the authors detected major changes in the composition of antibiotic use. Ratios of the consumption of broad to narrow spectrum beta-lactams and macrolides increased eight-fold (1996: 2.2 vs. 2010: 15.8) and consumption of fluoroquinolones tripled. Out of the ten surveyed drug-specific quality indicators, Hungary belonged to the European elite in case of three, while considering the remaining seven, Hungary ranked among the weak or weakest European countries.

CONCLUSION

In quantity Hungary an ambulatory antibiotic use resembles to Scandinavian countries while it mimics antibiotic consumption patterns of southern countries.

Drug-related problems in the elderly

The aging population in developed countries is a growing problem nowadays. The burden on healthcare is particularly high, since the prevalence of the diseases, especially chronic diseases increases with age. Prevalence of polypharmacy is common among elderly patients. While comorbidities require usage of several active agents with evidence based indication, polypharmacy increases the likelihood of interactions and adverse drug reactions, reduces patient compliance, affects quality of life and puts a significant financial burden on the patient and society. In order to reduce drug-related problems among the elderly, different lists of potentially inappropriate drugs and doses were created. One of the earliest known lists is the “Beers criteria”. The use of listed drugs is risky and not recommended for elderly patients. Following foreign examples, a list was compiled and adapted to the Hungarian drug spectrum based on the main concerns and alternative therapeutic suggestions. Orv. Hetil., 2012, 153, 1926–1936.

Variations and determinants of antibiotic consumption in Hungarian adult intensive care units

PURPOSE

The aim of this work was to study the use of systemic antibacterials and its possible determinants in Hungarian intensive care units (ICUs).

METHODS

Hospital pharmacy. departments provided package level dispensing data for their corresponding ICU (2006). Data were converted into defined daily doses (DDDs) and expressed as DDD per 100 patient-days and DDD per 100 admissions. Antibiotics were ranked by volume of DDDs, and the agents responsible for 90% of total use (DU90%) were noted. To explore differences and relationships between antibiotic use and antibiotic policy elements/ICU characteristics, the analysis of variances or the Pearson correlation analysis was performed.

RESULTS

Valid data were obtained for 44 ICUs. Antibiotic use varied widely (from 27.9 to 167.8 DDD per 100 patient-days and from 104.7 to 1784.6 DDD per 100 admissions). In total, 11-34 different antibacterials per ICUs were used, of which, 5-15 were in the DU90% segment. The proportional use of parenteral agents ranged from 46.2 to 98.3%. The mean of overall antibiotic use was highest for penicillins with beta-lactamase inhibitors, followed by quinolones and third-generation cephalosporins. Of the studied factors, only the ICU category (i.e., level of care) showed significant association with total antibacterial use.

CONCLUSIONS

The striking differences in total antibiotic use and the extensive use of the oral agents in some ICUs may indicate room for improvement. As none of the antibiotic policy elements were accompanied by lower antibiotic use in the pooled analysis, it suggests that--beside the ICU category--other unrevealed factors determine antibiotic use.

National trend of antidepressant consumption and its impact on suicide rate in Hungary

PURPOSE

The aim of this study was to analyse the changes in the amount and structure of Hungarian antidepressant consumption at national and regional level, furthermore to investigate the possible relationship between antidepressant sales and trends in suicide rates using regional data.

METHOD

Retrospective analysis of antidepressant sales data was performed on a 12 years period (1993-2004), applying the ATC/DDD methodology developed by WHO. Linear regression model was set up to investigate the trends in antidepressant utilisation. The association between antidepressant consumption and suicide rates was measured by Pearson correlation.

RESULTS

The nationwide utilisation of antidepressants revealed more than five-fold increase in the studied 12 year period. The usage of tricyclic antidepressants (N06AA) decreased to one third of the previous value, while the usage of selective serotonin reuptake inhibitors (N06AB) multiplied by 21. The consumption of 'other antidepressants' (N06AX) was found very low (3.66 DDD/1000 inhabitants/day in 2004). There was not found any significant correlation between increased antidepressant consumption and decreased suicide rates at regional level by our statistical analysis (r (min) = -0.160; r (max) = -0.314).

CONCLUSION

Further investigation is required to identify determinants that have contributed to recent decline in suicide rate in Hungary.

[Hungarian adaptation of a questionnaire for determining depression-specific quality of life]

INTRODUCTION

The Quality of Life in Depression Scale (QLDS) is a widely used outcome measure available in a large number of languages. No measure of quality of life was available for use with depressed patients in Hungary and a decision was taken to adapt the QLDS for this purpose. The adaptation of a questionnaire for use in a new language involves three stages; translation, testing for face and content validity and assessment of the translated measure's psychometric properties.

OBJECTIVES

To adapt the QLDS for use in Hungary and to evaluate its psychometric properties.

METHOD

The dual panel method was used to translate the QLDS into Hungarian. The translation was tested for face and content validity by interviews conducted with depressed patients. Finally, a test-retest postal survey was conducted to determine internal consistency, reproducibility and construct validity.

RESULTS

Interviews conducted with 25 patients indicated that the QLDS was an appropriate measure and that it was well accepted and completed. The postal survey ( n = 50) showed that the measure had good internal consistency (Cronbach's alpha-coefficients were 0.95 at both administrations) and that the test-retest reliability (0.89) indicated good reproducibility with limited random measurement error. Correlations of QLDS scores with those for the Nottingham Health Profile sections were as expected, providing evidence of convergent and divergent validity.

CONCLUSION

Given the acceptability of the Hungarian version of QLDS to depressed patients and the excellent psychometric properties of the adapted questionnaire it is concluded that the adaptation was successful. The measure is suitable for use in clinical practice and studies involving depressed patients in Hungary.

Reasons for polypharmacy among psychiatric patients

INTRODUCTION

Increasing attention has recently been focused on polypharmacy, which is often referred to as an indicator of irrational drug consumption. Although polypharmacy is an important risk factor for problems arising from drug therapies, certain health concerns and conditions or patient-specific factors may justify the need for polypharmacy. In recent years there no data have been published regarding polypharmacy in Hungary.

OBJECTIVE

The authors examined the frequency of polypharmacy among psychiatric patients. The study also looked at the extent to which comorbidity and demographic characteristics (age, gender) were responsible for the multiple drug use.

METHODS

An inpatient database of the year 2001 at the psychiatric department was analysed. Based on the standard definition of polypharmacy the authors enrolled into the polypharmacy group those patients who were on more than five drugs as part of chronic and simultaneous therapy. The data were analysed with the SPSS 9.0 statistics program package.

RESULTS

Among the psychiatric patients included in the study (N = 984) the frequency of polypharmacy was 33.6%. Significant correlation was found between the investigated factors (age, gender, comorbidity) and polypharmacy. On the basis of OR-values, comorbidity was the strongest inducer of polypharmacy.

CONCLUSION

Polypharmacy cannot be fundamentally regarded as unnecessary drug use. Numerous facts prove that in certain diseases and conditions adequate polypharmacy is necessary.

The use of micro-organisms for L-ascorbic acid production: current status and future perspectives

L-Ascorbic acid (L-AA) has been industrially produced for around 60 years in a primarily chemical process utilising D-glucose (D-glc) as starting material. Current world production is estimated at approximately 80,000 tonnes per annum with a worldwide market in excess of U.S. $600 million. We present a brief overview of research geared to exploiting micro-organisms for the industrial production of vitamin C, with emphasis on recent approaches using genetically engineered bacterial strains. We also discuss the potential for direct production of L-AA exploiting novel biochemical pathways with particular reference to yeast fermentations. The potential advantages of these novel approaches over current chemical and biotechnological processes are outlined.

The unique features of starch metabolism in red algae

Red algae (Rhodophyceae) are photosynthetic eukaryotes that accumulate starch granules outside of their plastids. The starch granules from red algae (floridean starch) show structural similarities with higher plant starch granules but lack amylose. Recent studies have indicated that the extra-plastidic starch synthesis in red algae proceeds via a UDP glucose-selective alpha-glucan synthase, in analogy with the cytosolic pathway of glycogen synthesis in other eukaryotes. On the other hand, plastidic starch synthesis in green cells occurs selectively via ADP glucose in analogy with the pathway of glycogen synthesis in prokaryotes from which plastids have evolved. Given the emerging consensus of a monophyletic origin of plastids, it would appear that the capacity for starch synthesis selectively evolved from the alpha-glucan synthesizing machinery of the host ancestor and its endosymbiont in red algae and green algae, respectively. This implies the evolution of fundamentally different functional relationships between the different subcellular compartments with regard to photosynthetic carbon metabolism in these organisms. It is suggested that the biochemical and molecular elucidation of floridean starch synthesis may offer new insights into the metabolic strategies of photosynthetic eukaryotes.

Copy-DNA cloning and characterisation of a potato alpha-glucosidase: expression in Escherichia coli and effects of down-regulation in transgenic potato

Polymerase chain reaction-based methodology was used to obtain a cDNA clone (MAL2) from potato (Solanum tuberosum L.) with the sequence characteristics of an alpha-glucosidase. Phylogenetic analysis of the deduced polypeptide encoded by this cDNA demonstrated that the most similar sequences were alpha-glucosidases and alpha-xylosidases of plant origin. The MAL2 cDNA was expressed in Escherichia coli and the recombinant MAL2 protein was affinity-purified. MAL2 catalysed the hydrolysis of a range of maltooligomers and p-nitrophenyl-alpha-D-glucopyranoside with a pH optimum of 5.5-5.7. The substrate with the lowest Km value was maltotetraose (3.7 mM). The MAL2 expression product did not catalyse the hydrolysis of xyloglucan oligosaccharides, p-nitrophenyl-alpha-D-xylopyranoside or gelatinised potato starch. MAL2 was down-regulated in transgenic potato plants using an antisense approach. In several independent transgenic antisense lines, MAL2 expression was severely down-regulated. Despite this, no decrease in total extractable alpha-glucosidase and alpha-xylosidase activity could be detected in tissues from the transgenic plants. In glasshouse trials, no visible phenotype, change in tuber yield or carbohydrate content was associated with MAL2 down-regulation. The implications of these results are discussed.

Postoperative infections following total knee replacement: an epidemiological study

From January 1991 to June 1997 217 patients undergoing monolateral or bilateral total knee replacement (TKR) were consecutively enrolled in a prospective study on the incidence of postoperative infections and related risk factors. Regional antimicrobial prophylaxis (teicoplanin 400 mg) was used in 263 (95%) prostheses implanted; in the remaining 14 implants (5%) perioperative antibiotic prophylaxis (teicoplanin 800 mg) was administered as usual by systemic route. None of the patients experienced local or systemic adverse effects. Over the 2-year follow-up period, 8 (2.9%) primary site infectious complications were recorded, i.e. 4 superficial infections, which were cured without involvement of the prostheses, and 4 deep infections, which required prosthesis removal. Six infections occurred in patients who had undergone previous surgery of the same knee joint, and 2 in patients undergoing primary TKR (p= 0.0005); diabetic patients had infections (13%) more frequently than non-diabetic patients (1.9%, p=0.01). Staphylococci were the leading organisms isolated from infections; however 3 strains of Escherichia coli were isolated from patients who had undergone a previous prosthesis implantation at the same knee joint. Regional administration of teicoplanin appears to be a safe and valuable prophylactic technique; however, in patients at risk of infection a prophylactic regimen which is also active against gram-negative bacteria should probably be considered.

Combined MR-relaxation and MR-cryoporometry in the study of bone microstructure

MR-Relaxation (MRR) of 1H nuclei and MR-Cryoporometry (MRC) are combined to assess their feasibility and their potential in the study of bone microstructure. In principle, both techniques are able to give information on the structure of the pore space confining the fluids. Cow femur samples were carefully cored and cleaned in order to remove the natural fluids inside. For MRR analysis quasi-continuous distributions of T(1) and T(2) were obtained on samples fully saturated with water. Cyclohexane was used as a saturating fluid for MRC analysis. All T(1) and T(2) quasi-continuous distributions of water confined in bone samples are more than three decades wide, showing sufficient details to differentiate the samples. Pore size distributions obtained by MRC also differentiate the samples showing different characteristics of the pore space structure in the range of the highest sensitivity of the method (typically 3 to 100 nm, mesopore range). In particular, in samples where MRR shows a large fraction of signal with relaxation times below 10(2) ms, MRC indicates a large fraction of pore volume with pore sizes in the mesopore range.

Tuberization in potato involves a switch from apoplastic to symplastic phloem unloading

Phloem unloading was studied in potato plants in real time during the early stages of tuberization using carboxyfluorescein (CF) as a phloem-mobile tracer, and the unloading pattern was compared with autoradiography of tubers that had transported (14)C assimilates. In stolons undergoing extension growth, apoplastic phloem unloading predominated. However, during the first visible signs of tuberization, a transition occurred from apoplastic to symplastic transport, and both CF and (14)C assimilates subsequently followed identical patterns of phloem unloading. It is suggested that the switch to symplastic sucrose unloading may be responsible for the upregulation of several genes involved in sucrose metabolism. A detailed analysis of sugar levels and (14)C sugar partitioning in tuberizing stolons revealed a distinct difference between the apical region of the tuber and the subapical region. Analysis of invertase activity in nontuberizing and tuberizing stolons revealed a marked decline in soluble invertase in the subapical region of swelling stolons, consistent with the switch from apoplastic to symplastic unloading. However, cell wall-bound invertase activity remained high in the apical 1 to 2 mm of tuberizing stolons. Histochemical analysis of potato lines transformed with the promoter of an apoplastic invertase gene (invGE) linked to a reporter gene also revealed discrete gene expression in the apical bud region. Evidence is presented that the apical and lateral tuber buds function as isolated domains with respect to sucrose unloading and metabolism.

Tuberization in potato involves a switch from apoplastic to symplastic phloem unloading

Phloem unloading was studied in potato plants in real time during the early stages of tuberization using carboxyfluorescein (CF) as a phloem-mobile tracer, and the unloading pattern was compared with autoradiography of tubers that had transported (14)C assimilates. In stolons undergoing extension growth, apoplastic phloem unloading predominated. However, during the first visible signs of tuberization, a transition occurred from apoplastic to symplastic transport, and both CF and (14)C assimilates subsequently followed identical patterns of phloem unloading. It is suggested that the switch to symplastic sucrose unloading may be responsible for the upregulation of several genes involved in sucrose metabolism. A detailed analysis of sugar levels and (14)C sugar partitioning in tuberizing stolons revealed a distinct difference between the apical region of the tuber and the subapical region. Analysis of invertase activity in nontuberizing and tuberizing stolons revealed a marked decline in soluble invertase in the subapical region of swelling stolons, consistent with the switch from apoplastic to symplastic unloading. However, cell wall-bound invertase activity remained high in the apical 1 to 2 mm of tuberizing stolons. Histochemical analysis of potato lines transformed with the promoter of an apoplastic invertase gene (invGE) linked to a reporter gene also revealed discrete gene expression in the apical bud region. Evidence is presented that the apical and lateral tuber buds function as isolated domains with respect to sucrose unloading and metabolism.

Rupture of the quadriceps tendon after arthroscopic lateral meniscectomy: A postoperative complication?

We report a case of complete quadriceps tendon rupture that occurred a few days after arthroscopic lateral meniscectomy. Complications following arthroscopy are rare; there have been many reports of quadriceps tendon rupture in the literature, but none by this kind of mechanism.

Biosynthesis of L-ascorbic acid (vitamin C) by Saccharomyces cerevisiae

Saccharomyces cerevisiae cells incubated with D-glucose (D-Glc), D-galactose or D-mannose (D-Man) synthesised D-erythroascorbic acid (D-EAA) but not L-ascorbic acid (L-AA). Accumulation of D-EAA was observed in cells incubated with D-arabinose (D-Ara) whilst accumulation of L-AA occurred in cells incubated with L-galactose (L-Gal), L-galactono-1,4-lactone and L-gulono-1,4-lactone. When S. cerevisiae cells were incubated with D-[U-(14)C]Glc, D-[U-(14)C]Man or L-[1-(14)C]Gal, incorporation of radioactivity into L-AA was observed only with L-[1-(14)C]Gal. Pre-incubation of yeast cells with D-Ara substantially reduced the incorporation of L-[1-(14)C]Gal into L-AA. Our results indicate that, under appropriate conditions, yeast cells can synthesise L-AA via the pathway naturally used for D-EAA biosynthesis.

An unusual epidemic of Staphylococcus-negative infections involving anterior cruciate ligament reconstruction with salvage of the graft and function

We performed a retrospective study of 13 patients who had postoperative clinical and laboratory signs of infection after autogenous bone-patellar tendon-bone (BPTB) anterior cruciate ligament (ACL) reconstructions. From January 1991 to November 1996 we experienced only 2 infected knees in 1,300 reconstructions, but between December 1996 and February 1997 10 patients in 70 ACL reconstructions developed a postoperative suspected infection. We found the origin of contamination (coagulase-negative Staphylococcus) in the supposedly sterile inflow cannula. When we changed this device, we had only 1 infection in the next 400 reconstructions. The diagnosis in these cases was derived from clinical signs and laboratory results, but only 2 of 11 samples of aspirated synovial fluid tested positive for Staphylococcus. The mean interval between the surgery and the onset of signs of infection and the start of antibiotic therapy was 7.7 days. All the patients had antibiotic association at the highest level. Six knees underwent arthroscopic debridement when the clinical signs indicated resistence to antibiotics. The normal postoperative rehabilitation program was modified but was not discontinued. Although recovery time was longer, overall results were similar to uncomplicated reconstructions. On the basis of our experience, we believe that when there is a notable increase in infection rates, a thorough search for contamination is indicated. Our source of infection was material that was thought to be sterile. Ultimately, early diagnosis and treatment is of critical importance to obtain good results. Even suspicion of infective postoperative complication should be sufficient cause to search for responsible microorganisms and begin antibiotic therapy. Arthroscopic debridement should be proposed to patients with resistence to antibiotics.

Regional prophylaxis with teicoplanin in monolateral or bilateral total knee replacement: an open study

From January 1991 to June 1997, patients undergoing primary elective monolateral or bilateral total knee replacement (TKR) were consecutively enrolled in a prospective, open clinical study on the efficacy and safety of regional prophylaxis with teicoplanin (TEC). Those scheduled for monolateral TKR (115 patients) received 400 mg of TEC in 100 ml of saline as a 5-min infusion into a foot vein of the leg to be operated on immediately after the tourniquet was inflated to 400 mm Hg (ca. 50 kPa). For patients undergoing bilateral surgery (45 patients), regional administration of TEC was also repeated for the second knee operation. Follow-up ranged from a minimum of 2 years to 8 years. None of the patients experienced local or systemic adverse effects following regional administration of TEC. In the immediate postoperative and 2-year follow-up periods, only one superficial infection of the primary site attributable to intraoperative contamination (prophylaxis failure) out of the 205 prostheses implanted was observed. Deep infections involving the prosthesis did not occur. Infectious complications at distant sites were observed in nine cases (urinary tract infection due to Escherichia coli in eight cases, and Salmonella enteritidis gastroenteritis in one case) in the immediate postoperative period; they all were rapidly cured after antibiotic treatment. A delayed prosthetic infection, related to hematogenous spread of the etiological agent and therefore not considered a prophylactic failure, was observed in a patient who had undergone TKR 5 years before. Regional administration of TEC in monolateral and bilateral TKR appears to be a safe and valuable prophylactic technique.

How useful is docusate in patients at risk for constipation? A systematic review of the evidence in the chronically ill

The effectiveness of docusate for constipation has not been studied in the terminally ill. Controversy also exists concerning its effectiveness in the chronically ill. Because chronically ill patients and terminally ill patients have several risk factors for constipation in common, we undertook a systematic review of prospective controlled trials of oral docusate in the chronically ill to clarify the utility of this drug in populations with advanced disease. The data sources were Medline 1966-April 1997, CINAHL 1982-April 1997, Current Contents August 1996-April 1997, Cochrane Library, a hand search of Index Medicus 1940-1966, three palliative care journals, references in relevant articles and texts, and direct contact with experts. Prospective controlled trials evaluating oral docusate in humans with chronic illness and identifiable risk factors for, or preexisting, constipation were selected. Only materials abstracted in English or French were considered. Information was collected by two independent reviewers and included patient demographic data, study design, dose of docusate, outcomes of stool consistency, stool frequency, need for other laxatives, and assessment of methodologic and reporting quality. Of nine identified studies, four were eligible. These incorporated three different designs and sample sizes that ranged from 15 to 74. Quality assessment scores were low (range 0.46-0.52 with a perfect score being 1.0). Three studies were flawed in blinding of treatment allocation and the use of co-interventions. All studies showed a small trend toward increased stool frequency on docusate. Because of significant clinical heterogeneity in the identified studies, pooled data analysis was not feasible. At present, the use of docusate for constipation in palliative care is based on inadequate experimental evidence. Randomized controlled trials with chronically ill patients and patients with advanced disease are needed to determine its role in prevention and treatment of constipation.

Purification and characterisation of a novel starch synthase selective for uridine 5'-diphosphate glucose from the red alga Gracilaria tenuistipitata

Red algae (Rhodophyceae) are photosynthetic eukaryotes that accumulate starch granules in the cytosol. Starch synthase activity in crude extracts of Gracilaria tenuistipitata Chang et Xia was almost 9-fold higher with UDP[U-14C]glucose than with ADP[U-14C]glucose. The activity with UDP[U-14C]glucose was sensitive to proteolytic and oxidative inhibition during extraction whilst the activity with ADP[U-14C]glucose appeared unaffected. This indicates the presence of separate starch synthases with different substrate specificities in G. tenuistipitata. The UDPglucose: starch synthase was purified and characterised. The enzyme appears to be a homotetramer with a native M(r) of 580 kDa and displays kinetic properties similar to other alpha-glucan synthases such as stimulation by citrate, product (UDP) inhibition and broad primer specificity. We propose that this enzyme is involved in cytosolic starch synthesis in red algae and thus is the first starch synthase described that utilises UDPglucose in vivo. The biochemical implications of the different compartmentalisation of starch synthesis in red algae and green algae/plants are also discussed.

Structure of aspartate-beta-semialdehyde dehydrogenase from Escherichia coli, a key enzyme in the aspartate family of amino acid biosynthesis

Aspartate beta-semialdehyde dehydrogenase (ASADH) lies at the first branch point in an essential aspartic biosynthetic pathway found in bacteria, fungi and the higher plants. Mutations in the asd gene encoding for ASADH that produce an inactive enzyme are lethal, which suggests that ASADH may be an effective target for antibacterial, herbicidal and fungicidal agents. We have solved the crystal structure of the Escherichia coli enzyme to 2.5 A resolution using single isomorphous replacement and 3-fold non-crystallographic symmetry. Each monomer has an N-terminal nucleotide-binding domain and a dimerisation domain. The presence of an essential cysteine locates the active site in a cleft between the two domains. The functional dimer has the appearance of a butterfly, with the NADP-binding domains forming the wings and the dimerisation domain forming the body.A histidine residue is identified as a likely acid/base catalyst in the enzymic reaction. Other amino acids implicated in the enzymic activity by mutagenesis are found in the active site region and define the substrate binding pocket.

Intra-articular ACL reconstruction in the over-40-year-old patient

We compared two groups of patients who had undergone anterior cruciate ligament (ACL) reconstruction. The groups were similar in regard to sex distribution, index injury, absence of meniscal or chondral lesions, surgical technique, and postoperative rehabilitation programs, but different in age. In the study group the mean age was 42.6 years, while in the control group the mean age was 20 years. The clinical results were assessed at a mean of 29 months after surgery using the Lysholm score, International Knee Documentation Committee form, Tegner activity level, and the KT-1000 arthrometer test. No significant differences were reported. Standard X-ray studies showed no variation between the two groups in the postoperative period. Intra-articular ACL reconstruction using a bone-patellar tendon-bone graft can be recommended in selected patients over 40 years of age as an alternative to conservative treatment.

Role of MR imaging in the management of "skier's thumb" injuries

"Skier's thumb" is an acute rupture of the ulnar collateral ligament (UCL) of the metacarpophalangeal (MCP) joint of the thumb. As the method of choice in evaluating soft tissue injuries, MR imaging is useful in evaluating UCL injuries. This article reviews current concepts regarding the rupture of the UCL, including a study of 34 UCL injuries in which MR imaging was used as the main diagnostic tool. When correlated with surgical findings, MR imaging resulted in identifying UCL tears with 96% sensitivity and 95% specificity.

Three cases of patella fracture in 1,320 anterior cruciate ligament reconstructions with bone-patellar tendon-bone autograft

Between September 1992 and December 1996 we reviewed three transverse displaced fractures of the patella occuring in 1,320 ACL reconstructions using bone-patellar tendon-bone autograft. All the patients suffered local injury to the donor knee between 8 and 12 weeks postoperatively. Immediate rigid fixation using single or double anterior tension band allowed early mobilization and full weight bearing. Between 6 and 9 months after fracture, the screws and the wire were removed and the grafts tested. Results of the pivot shift and Lachman test under anesthesia were negative and arthroscopic visualisation showed the graft to be intact. Postoperative assessment included the Lysholm and Tegner scales, the International Knee Documentation Committee Evaluation form (IKDC), KT-1000 arthrometer, and isokinetic dynamometer strength testing. No significant differences in the final outcome were noted between reconstructions complicated by patellar fracture and normal ACL reconstructions.

Sedation for intractable distress in the dying--a survey of experts

Terminal sedation is a phrase that has appeared in the palliative care literature in the last few years. There has not been a clear definition proposed for this term, nor has there been any agreement on the frequency with which the technique is used. A postal survey of 61 selected palliative care experts (59 physicians, two nurses) was carried out to examine their response to a proposed definition for 'terminal sedation', to estimate the frequency of this practice and the reasons for its use, to identify the drugs and dosages used, to determine the outcome, and to explore the decision-making process. Opinions on physician-assisted suicide and voluntary euthanasia were also sought. Eighty-seven per cent of the experts responded from eight countries, although predominantly from Canada and the United Kingdom. Forty per cent agreed unequivocally with the proposed definition, while 4% disagreed completely. Eighty-nine per cent agreed that 'terminal sedation' is sometimes necessary and 77% reported using it in the last 12 months--over half of these for up to four patients. Reasons for using this method included various physical and psychological symptoms. The most common drugs used were midazolam and methotrimeprazine. Decision making usually involved the patient or family, and varied with respect to the ease with which the decision was made. The use of sedation was perceived to be successful in 90 out of 100 patients recalled. Ninety per cent of respondents did not support legalization of euthanasia. In conclusion, sedating agents are used by palliative care experts as tools for the management of symptoms. The term 'terminal sedation' should be abandoned and replaced with the phrase 'sedation for intractable distress in the dying'. Further research into the management of intractable symptoms and suffering is warranted.

Prospects for advancing the understanding of complex biochemical systems

The application of mathematical theories to understanding the behaviour of complex biochemical systems is reviewed. Key aspects of behaviour are identified as the flux through particular pathways in a steady state, the nature and stability of dynamical states, and the thermodynamic properties of systems. The first of these is dealt primarily in theories of metabolic control, and metabolic control analysis (MCA) is an important example. The valid application of this theory is limited to steady-state systems, and the cases where the essential features of control can be derived from calibration experiments which perturb the state of the system by a sufficiently small amount from its operating point. In practice, time-dependent systems exist, it is not always possible to know a priori whether applied perturbations are sufficiently small, and important features of control may lie farther from the operating point than the application of the theory permits. The nature and stability of dynamical and thermodynamical states is beyond the scope of MCA. To understand the significance of these limitations fully, and to address the dynamical and thermodynamical properties, more complete theories are required. Non-linear systems theory offers the possibility of studying important questions regarding control of steady and dynamical states. It can also link to thermodynamic properties of the system including the energetic efficiency of particular pathways. However, its application requires a more detailed characterisation of the system under study. This extra detail may be an essential feature of the study of non-equilibrium states in general, and non-ideal pathways in particular. Progress requires considerably more widespread integration of theoretical and experimental approaches than currently exists.

IFN gamma and TNF alpha cause an increased release of C3 by murine macrophages

Macrophages from mice bearing Lewis lung carcinoma release higher amounts of C3 molecules than macrophages from healthy mice. The C3 pro-releasing activity operating in vivo was suspected to be due to an immunological network. Indeed, the supernatants of splenocytes from tumor bearing mice, but not from normal mice, induced in vitro an increased release of C3 molecules by macrophages. Recombinant IFN gamma and TNF alpha were strong inducers of C3 release, while IL-2 acted poorly. The C3 pro-releasing activity of splenocyte supernatants was largely prevented by their pretreatment with specific mAb anti IFN gamma or anti TNF alpha, but not completely prevented by the simultaneous neutralization of the two cytokines. Taken together, these results show that murine macrophages increase the release of C3 molecules upon treatment with IFN gamma or TNF alpha and that these cytokines released in vivo by splenocytes from tumor bearing mice may account, together with a yet unknown factor, for a humoral network causing the increased release of C3 by peritoneal macrophages.

Regional and systemic prophylaxis with teicoplanin in monolateral and bilateral total knee replacement procedures: study of pharmacokinetics and tissue penetration

Twenty-four patients undergoing monolateral or bilateral total knee replacement (TKR) procedures were randomized to receive teicoplanin (T) either systemically or regionally. Subjects scheduled for systemic prophylaxis and undergoing monolateral (six patients) or bilateral (five patients) TKR received a single 800-mg dose of T in 100 ml of saline as a 5-min infusion into a forearm vein 2.5 h before surgery. For regional prophylaxis, patients undergoing monolateral surgery (eight subjects) received 400 mg of T in 100 ml of saline as a 5-min infusion into a foot vein of the leg to be operated on immediately after the tourniquet was inflated. For the five patients scheduled for bilateral operation and regional prophylaxis, the administration of T was also repeated for the second knee operation. The tourniquet, as the standard TKR surgical technique, was inflated to 400 mm Hg (c. 50 kPa) in all 24 patients immediately before the beginning of surgery and kept in place for the duration of the operation. Samples of serum, bone, skin, synovia, and subcutaneous tissue were collected at timed intervals during surgery. They were microbiologically assayed for T by using Bacillus subtilis as the test organism. Overall, the mean T concentrations obtained with regional route prophylaxis were found to be 2 to 10 times higher than those achieved following systemic prophylaxis. Moreover, peak levels in different tissues after regional prophylaxis were significantly higher (P < 0.05). None of the patients experienced adverse effects due to regional or systemic T administration; no prosthetic or wound infections were observed in the follow-up period (from 12 to 26 months).

Fluoride-Induced Inhibition of Starch Biosynthesis in Developing Potato, Solanum tuberosum L., Tubers Is Associated with Pyrophosphate Accumulation

Pretreatment of discs excised from developing tubers of potato (Solanum tuberosum L.) with 10 millimolar sodium fluoride induced a transient increase in 3-phosphoglycerate content. This was followed by increases in triose-phosphate, fructose 1,6-bisphosphate and hexose-phosphate (glucose 6-phosphate + fructose 6-phosphate + glucose 1-phosphate). The effect of fluoride is attributed to an inhibition of glycolysis and a stimulation of triose-phosphate recycling (the latter confirmed by the pattern of (13)C-labeling [NMR] in sucrose when tissue was supplied with [2-(13)C]glucose). Fluoride inhibited the incorporation of [U-(14)C] glucose, [U-(14)C]sucrose, [U-(14)C]glucose 1-phosphate, and [U-(14)C] glycerol into starch. The incorporation of [U-(14)C]ADPglucose was unaffected. Inhibition of starch biosynthesis was accompanied by an almost proportional increase in the incorporation of (14)C into sucrose. The inhibition of starch synthesis was accompanied by a 10-fold increase in tissue pyrophosphate (PPi) content. Although the subcellular localization of PPi was not determined, a hypothesis is presented that argues that the PPi accumulates in the amyloplast due to inhibition of alkaline inorganic pyrophosphatase by fluoride ions.