Developing High-Performance and Low-Cost Paint Thermoelectric Materials for Low-Midtemperature Applications

Most thermoelectric (TE) materials used to convert heat energy into electrical energy are expensive and, to a certain degree, toxic. Moreover, due to the chemical complexity in the synthesis process, some of the TE materials are not reproducible. Similarly, the scarcity of TE materials hampers their scalability. To address the above issues, this study presents an inexpensive, nontoxic, scalable, and highly reproducible paint-based TE module for the conversion of heat energy to electrical energy. Transport properties with structural analysis indicate that the electrical conductivity of the paint TE material is controlled by the concentration of graphite and sodium silicate, while the Seebeck coefficient is dominated by the ratio of n- and p-type Bi-Sb-Te. The results indicate that the as-developed TE module can withstand an operating temperature of up to 160 °C. At a temperature of 57 °C, the highest power factors of the as-synthesized n- and p-type TE paints are 1.34 and 1.42 μW/(cm K2), respectively. It is also found that the TE module can have a higher output voltage when the cold side of the TE module is allowed to float in the air in comparison to that when it is in contact with the human body. The performance of the paint-based TE module is measured on five parts of the body, namely, the chest, palm, leg, wrist, and neck; the wrist has the highest open-circuit voltage of 1.9 mV, indicating its suitability for wearable applications. Finally, at a temperature gradient of 30 °C, a maximum output power of 6.8 μW is attained.

Safety, regulatory and environmental issues related to breeding and international trade of edible insects in Africa

Insect breeding or farming for food and feed is an emerging enterprise that can address the ever-growing demand for protein and curb high unemployment rates in Africa and beyond. However, for the sector to prosper, its value chain needs to be regulated to ensure sustainability and safety for consumers and the environment. Although a few African countries, such as Kenya, Uganda and Rwanda, have promulgated standards on the use of insects as food and feed, greater efforts are needed in other countries, and relevant policies governing the sector need to be formulated. All over the globe, attention to the regulation of the edible insect sector is increasing, and more investment in the industry is foreseen. Safety issues such as identifying which species should be reared, substrate quality and traceability imposed by importing countries will be critical for expansion of the sector. This paper analyses safety, regulatory and environmental issues related to breeding and international trade of edible insects in Africa and provides case studies and recommendations for sustainable use of insects for food and feed.

The effect of health education intervention through mobile phone on hypertension patients : A systematic review

INTRODUCTION

Hypertension is a silent killer disease that, if not handled properly, will lead to dangerous complications for the patient. Health education through mobile phones can be an intervention used to improve health services and the management of hypertension in the community. This study aims to synthesise research findings on the effect of mobile phone health education interventions on hypertensive patients.

MATERIALS AND METHODS

A systematic review. Search strategy was conducted on international journal databases, namely Scopus, PubMed, ProQuest, Web of Science, and Science Direct with the keywords 'health education', 'mobile phone' and 'hypertension'. Inclusion criteria using PICOS, namely Population: hypertensive patients, Intervention: health education using a mobile phone, Comparation: ordinary health education, Output: knowledge, attitudes, behaviour, Study design: trial method. The publication year 2017-2021.

RESULTS

There were 145 articles found in the search. Articles were identified and screened resulting in five complete articles that met the inclusion criteria. The results of this study found that health education interventions via mobile phones could increase patient knowledge about hypertension; improve self-management; monitor blood pressure; increase adherence to pharmacological treatment, a hypertensive diet, i.e.,low salt intake, vegetable and fruit intake, and physical activity; decrease blood pressure; and improve quality of life. Health education via mobile phones can also provide the latest information quickly to patients about controlling hypertension, antihypertensive drugs, and health services that can be utilised.

CONCLUSION

Health education interventions via mobile phones have a significant positive effect in controlling hypertension in the community, but it is necessary to consider the patient's age, socioeconomic status, literacy conditions, and ability to use mobile phones to receive the health education that will be provided.

Influence of patient-related factors on intraoperative blood loss during double opposing Z-plasty Furlow palatoplasty and buccal fat pad coverage: A prospective study

Background

Surgical procedures including palatoplasty have a risk for complications. The aim of this study was to investigate the intraoperative and early postoperative blood loss using the buccal fat pad (BFP) during cleft lip and/or cleft palate (CL/P) surgery.

Material and Methods

This prospective study included a total of 109 patients with cleft palate (CP) during a three-month period of treatment at Hasanuddin University Dental Hospital (permanent center) and charity trips in rural parts of Eastern Indonesia. All patients were treated with DOZ Furlow technique combined with BFP graft. Before and after surgery, the total amount of intraoperative blood loss was calculated by measuring the weight differences of the gauze swabs that were used to control the surgical bleeding followed by a complete blood count at three days postoperatively.

Results

The difference in the amount of blood loss based on age categories in charity groups was found to be significant (P<0.05). Overall, we found that high body weight and operation time significantly contributed to increased blood loss (P<0.05).

Conclusions

Weight and operative time can contribute to more blood loss during palatoplasty.

Key words:Buccal fat pad, complication, cleft lip, cleft palate, palatoplasty.

Epidemiology, treatment, and recurrence of odontogenic and non-odontogenic cysts in South Sulawesi, Indonesia: A 6-year retrospective study

Background

Diagnosis of jaw cysts is challenging in general dental practice, and most cases are incidentally discovered through routine dental radiography. The aim of this study was to examine the epidemiology and treatment of odontogenic and non-odontogenic cysts to better understand the status of these lesions in populations in South Sulawesi, Indonesia.

Material and Methods

This retrospective study was conducted on patients treated at four different hospitals in Makassar between January 2011 and June 2017. Patients diagnosed as having odontogenic or non-odontogenic cysts were included in the study. Information on variables such as sex, age, histopathological, and anatomical distributions was collected. Statistical analyses were performed using an independent T-test and the Pearson chi-square test (p< 0.05).

Results

A total of 173 samples were collected, of which only 60 were histopathologically analyzed. The patients’ mean age was 30.3 years. The cysts occurred more frequently in women and in the anterior maxilla, followed by the posterior mandible. The radicular cyst was the most prevalent type, followed by the dentigerous cyst. Most cysts were treated with enucleation. Of the patients, 72.8% were followed up, of whom 3.2% had a recurrence and only 19.1% had complaints of clinical symptoms.

Conclusions

Our findings indicate that odontogenic and non-odontogenic cysts widely vary in terms of incidence, with some exhibiting a predilection for specific ages and sites and specific sex. Knowledge of these factors could be useful for both clinicians and pathologists in the diagnosis and choice of the appropriate treatment plan.

Key words:Cyst, epidemiology, odontogenic, non-odontogenic, treatment.

Experimental and Theoretical Investigation of the Effect of Filler Material on the Performance of Flexible and Rigid Thermoelectric Generators

Thermoelectric generators have found many applications where the heat source can be either flat or curved. For a curved heat source, flexible thermoelectric generators are generally used. A filler material with low thermal conductivity can provide additional mechanical support to the thermoelectric module and can reduce convection and radiation losses. Herein, the effect of three different filler materials on the output performance of rigid and flexible thermoelectric generators is investigated. At first, theoretical models are derived and the experimental study validated the models. The experimental study revealed that the flexible thermoelectric modules outperformed the rigid modules; this is due to the reduction of the number of thermal junctions in the flexible modules and due to the differences in the thermal conductivities of the flexible and rigid substrates. Likewise, among TE modules without filler/with air between the TE legs, with polyurethane foam filler material, and with polydimethylsiloxane filler material, air has the lowest thermal conductivity, and therefore, the thermoelectric generator without filler generates higher output power and higher power density than when the other two filler materials are used. For the fixed temperature gradient, the highest power densities for the flexible and rigid thermoelectric generators without filler are 155 and 137.7 μW/cm² for temperature gradients of 10.8 and 10.3 °C, respectively.

In silico structural modeling and analysis of physicochemical properties of curcumin synthase (CURS1, CURS2, and CURS3) proteins of Curcuma longa

Background

Pharmaceutically important curcuminoid synthesis in C. longa is controlled by CURS1, CURS2, and CURS3 genes. The present study detected the physicochemical properties and structural characteristics including the secondary and 3D structure of CURS proteins. The primary, secondary, and tertiary structure of the CURS proteins were modeled and characterized using multiple bioinformatics tools such as ExPasy ProtParam tools, self-optimized prediction method with alignment (SOPMA), PSIPRED, and SWISS-MODEL. The predicted secondary structure of curcumin synthase provided an α-helix and random coil as the major components. The reliability of the modeled structure was confirmed using PROCHECK and QMEAN programs.

Results

The molecular weight of CURS1 is 21093.19 Da, theoretical pI as 4.93, and an aliphatic index of 99.19. Molecular weight of CURS2 and CURS3 proteins are 20266.13 Da and 20629.52 Da, theoretical pI as 5.28 and 4.96, and an aliphatic index of 89.30 and 86.37, respectively. In the predicted secondary structure of CURS proteins, alpha helices and random coils of CURS1, CUR2, and CURS3 were 42.72, 41.38, and 44.74% and 24.87, 31.03, and 17.89, respectively. The extended strands were 16.24, 19.40, and 17.89. QMEAN Z-score is − 0.83, − 0.89, and − 1.09 for CURS1, CURS2, and CURS3, respectively.

Conclusion

Prediction of the 3D model of a protein by in silico analysis is a highly challenging aspect to confirm the NMR or X-ray crystallographic data. This report can contribute to the understanding of the structure, physicochemical properties, structural motifs, and protein-protein interaction of CURS1, CUR2, and CURS3.

A162 THE UTILITY OF FECAL CALPROTECTIN IN PREDICTING SEVERITY OF CLOSTRIDIUM DIFFICILE INFECTION: A SYSTEMATIC REVIEW

Background

Clostridium difficile is an anaerobic, spore-forming, gram-positive bacillus, and a leading cause of infectious diarrhea in hospitalized patients. It is associated with high mortality and morbidity, and places an enormous burden on the healthcare system. Symptoms and severity of CDI vary widely, from illness that resolves with antibiotics, to toxic megacolon, colectomy, and death. The ability to risk-stratify patients to predict severe versus non-severe outcomes at baseline would be clinically useful. The role of fecal calprotectin in predicting severity of CDI has not been well established.

Aims

To perform a systematic review of the literature on the ability of fecal calprotectin to predict disease severity in patients with CDI.

Methods

PubMed, OVID (EMBASE/MedLine) and Cochrane Library databases were searched up until October 2, 2019. Publications of pediatric populations, Inflammatory Bowel diseases, and those only published as abstracts were excluded.

Results

130 non-duplicate citations were screened; after title/abstract screening, and full-text review, 7 articles were included for analysis. Articles were from 2014 onwards, and varied from 29 to 232 patients/samples analyzed; 832 patients in total were analyzed. Three studies were conducted in the USA, two in Europe, one in Israel and in South Korea. Four studies were prospective, and the remaining three were retrospective cohort studies. There was significant heterogeneity between studies with respect to population size, age (when reported), fecal calprotectin assay and cutoff used, method of diagnosis of CDI, and criteria for defining disease severity. There was wide variation in median fecal calprotectin levels between studies. Four studies demonstrated a statistically significant difference of fecal calprotectin according to disease severity, and three did not, of which two of these demonstrated an overall predictive trend with fecal calprotectin.

Conclusions

It is unclear whether fecal calprotectin is predictive of severity of CDI in adult patients without IBD. In the existing literature, there seems to be a statistically significant association or trend towards association in most studies, but due to heterogeneity of methods, assays, cutoffs and populations, the data within these studies cannot be pooled in meta-analysis. Further high-powered, well-designed studies are required to clarify this important clinical question.

Funding Agencies

None

Community perspectives on barriers and challenges to HIV pre-exposure prophylaxis access by men who have sex with men and female sex workers access in Nigeria

Background

Men who have sex with men (MSM), female sex workers (FSW) have critical needs for effective HIV prevention tools. This study identified perspectives of MSM, FSW and policy makers on the needs for, barriers to, and challenges with pre-exposure HIV prophylaxis (PrEP); and the logistics required to support roll-out of PrEP for MSM and FSW in Nigeria.

Methods

Qualitative and quantitative data were collected through a cross-sectional study. The quantitative data were collected through an online survey administered to 519 MSM, FSW and transgender respondents. The qualitative data were collected through 22 focus group discussions with 140 MSM and 80 FSW, and a two-day consultative workshop with 65 participants. Two open-ended questions in the online survey were also a source of qualitative data. Results of the quantitative data were reported descriptively; the qualitative data were inductively examined with a content analytic approach to construct descriptive categories. The findings from the quantitative and qualitative responses were triangulated.

Results

Four hundred and ninety-four (95.2%) online respondents had heard about PrEP through community dialogue (71.3%), and 439 (84.6%) supported its use by MSM and FSW. Fewer than half of the respondents were aware of the clinical care required for PrEP, and misconceptions about PrEP were common. Stated barriers to PrEP uptake were stigma, cost, frequency of HIV counseling and treatment services required, and possible drug-drug interactions. Concerns included possible condom migration, increased risk for sexually transmitted infections and pregnancy for FSW, and poor adherence to medication and hospital schedules. Participants felt that trained peer educators and HIV-test counselors could provide information and refer clients to clinics that provide PrEP. PrEP can be provided through peer-led facilities for MSM and FSW, though its access should be expanded to all persons who are at substantial risk for HIV to prevent negative labeling of PrEP. Public awareness about the use of antiretrovirals for HIV prevention is needed to prevent labeling of PrEP users as being HIV positive.

Conclusion

Although MSM and FSW are interested in the use of PrEP, numerous individual and structural barriers need to be addressed to facilitate access to it in Nigeria.

Biotic priming with Pseudomonas fluorescens induce drought stress tolerance in Abelmoschus esculentus (L.) Moench (Okra)

Drought is a major abiotic stress which negatively affects plant growth and yield. The decrease in rainfall and ensuing drought affect crop production to a larger extent. The present investigation was aimed to evaluate the drought stress mitigation potential of Abelmoschus esculentus (L.) Moench (okra) plants primed with Pseudomonas fluorescens (PF). Okra seeds were primed with 10-7 CFU of PF, germinated and the plants were exposed to drought stress for 7 days, and the recovery potential was assessed after re-watering the plants. Physiological and biochemical parameters were evaluated during stress and recovery. PF treated plants mitigated the effect of drought stress by increasing relative water content (RWC), accumulated metabolites such as sugar, free amino acids and enhanced the activity of non enzymatic antioxidants; phenolics, ascorbate (AsA) and glutathione (GSH) and reactive oxygen species scavenging enzyme like superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX) and guaicol peroxidase (GPX). Drought stress related membrane damage and protein denaturation were also alleviated by PF treatment. During re-watering, PF treated plants regained RWC, total sugar, total amino acid, protein, AsA, GSH, phenolics, SOD, CAT, APX and GPX to appreciable levels. Thus, this study suggests that PF can be used as an agent to effectively mitigate drought stress in okra plants.

Abstract P2-02-05: Comparison of non-breast and ovarian cancer phenotypes of BRCA1/2 mutation carriers across multi-gene panels

Background: BRCA1/2 germline mutations account for the majority of hereditary breast and ovarian cancers. Until 2013, the only way to identify individuals with BRCA mutations was through single gene testing. With multi-gene panel testing (MGPT) including BRCA1/2, BRCA mutations are being identified at an increased rate. To date, the phenotype of BRCA1/2 mutation carriers includes an increased prevalence of breast, ovarian, prostate, and pancreatic cancer, as well as melanoma. The phenotype, however, of mutation carriers identified by panel testing is not well understood.

Methods: All sequential cases submitted to our laboratory for MGPT including BRCA1/2 between June 2013 and June 2015 and BRCA1/2 single gene testing between June 2013 and February 2015 were retrospectively reviewed. Data from 77,345 test request forms were reviewed; probands with a BRCA1 or BRCA2 mutation were selected and analyzed. Probands with no personal history of cancer/not provided (n=528) were excluded.

Results: Of 2,967 BRCA1/2 positive probands, 2,439 (82.2%) had a personal history of cancer, with 2,794 cancers reported. On all tests completed, with the exception of a pancreatic cancer focused panel, breast and/or ovarian cancer were the most commonly observed cancer types (n=2,364, 84.6%). On single gene testing (n=739), prostate (n=16, 2.2%), colorectal (n=8, 1.1%), and pancreatic (n=7, 0.9%) cancers were the other most frequent cancers reported. Across all MGPT cases (n=1,700), additional observed cancers included uterine (n=48, 2.8%), colorectal (n=46, 2.7%), pancreatic (n=37, 2.2%), melanoma (n=29, 1.7%), and thyroid (n=27, 1.6%). For breast cancer-specific gene panel cases (n=934), additional cancers included thyroid (n=12, 1.3%) and uterine cancer (n=10, 1.1%). For gynecologic cancer gene panel cases (n= 482), additional cancers included uterine (n=21, 4.4%), colorectal (n=11, 2.3%), and melanoma (n=11, 2.3%). Cases tested via a pancreatic cancer gene panel (n=25,) had pancreatic cancer (n=17, 68%) reported most frequently, followed by breast (n=6, 24%), colorectal (n=3, 12%), and melanoma (n=3, 12%). For comprehensive cancer gene panel cases (n=254), colorectal (n=28, 11.0%), uterine (n=17, 6.7%), pancreatic (n=14, 5.5%), prostate (n=10, 3.9%), thyroid (n=10, 3.9%), and a variety of rare tumor types (n=15, 5.9%) were among the additional cancers reported.

Discussion: As expected, the majority of cancers reported on almost all tests were breast and/or ovarian cancer. More specifically, the observed cancers for tumor specific cancer panels, matched the relevant cancer type (i.e. pancreatic cancer most commonly reported in those tested via a pancreatic cancer panel). However, on the comprehensive cancer panels, other than breast and ovarian cancer, there appears to be a more even distribution of various cancer types, including rare tumors, in probands who have a BRCA1 or BRCA2 mutation. Further studies should be conducted to examine the phenotypes of BRCA mutation carriers identified via comprehensive cancer panels to determine the association and prevalence of unexpected cancer types with BRCA1/2 mutations. This could have important implications for determining the most appropriate genetic test and management of BRCA mutation carriers.

Citation Format: Jackson M, Yusuf A, Espenschied C, Paudyal T, Profato-Partlow J. Comparison of non-breast and ovarian cancer phenotypes of BRCA1/2 mutation carriers across multi-gene panels [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P2-02-05.

Study on adhesion, proliferation and differentiation of osteoblasts promoted by new absorbable bioactive glass injection in vitro

OBJECTIVE

The objective of this study was to evaluate adhesion, proliferation and differentiation of osteoblasts grown on absorbable bioactive glass-calcium phosphate cement injection (BG-CPC) materials in vitro.

MATERIALS AND METHODS

BG-CPC composite biomaterial samples were prepared in vitro, for culture with MC3T3-E1 rat osteoblasts. Cells were divided into CPC, BG and BG-CPC treated groups. After cultivation for 3d, cells were stained with rhodamine-phalloidin and 4',6-diamidino-2-phenylindole (DAPI) and observed by fluorescence microscopy for osteoblast morphology on the surface of biomaterials. At 24h, 48h and 72h, MTT assay was used to test adhesion and proliferation, and bicinchoninic acid assay (BCA) method was carried out to test ALP activity; ELISA was used to test bone morphogenetic protein (BMP) and TGF-β expression levels at day 3.

RESULTS

Compared with the other two groups, cells in the BG-CPC group had more attachments; the DAPI labelled nuclei were clearer and nuclear shape was more complete and full. Adhesion and proliferation, as well as alkaline phosphatase (ALP) activity of cells for all time points in the BG-CPC group were higher than those in the other two groups and differences were of statistically significant (p<0.05); BMP and TGF-β expression levels were higher than those in the other two groups and the differences were statistically significant (p<0.05).

CONCLUSIONS

In vitro use of new absorbable bioactive glass is able to promote adhesion, proliferation and differentiation of osteoblasts, which may be related to increased BMP and TGF-β expression.

Influence of different host associations on glutamine synthetase activity and ammonium transporter in Santalumalbum L

The present study was aimed at understanding the role of different hosts in ammonium transporter1;2 expressions and glutamine synthetase(GS) activity and their effects on the growth parameters in the sandal. Sandal plant associated with leguminous host expressed better growth parameters. GS activity of leguminous hosts alone and in host associated sandals was analyzed using GS transferase assay. Highest GS activity was expressed in Mimosa pudica-sandal association compared to other leguminous and non-leguminous host associations. The association of N₂ fixing host with sandal enhanced C and N levels in order to maintain the C/N value. The role of ammonium transporters in N nutrition of sandal-host association was elucidated by cloning AMT1;2 from the leaves, haustoria and roots of host associated sandal and quantifying the relative expression by the [Formula: see text] method. SaAMT1;2 was strongly up-regulated in leaves, roots and haustoria of leguminous host associated sandal compared to non-leguminous host associations. The relative increase in SaAMT1;2 expressions and up-regulated GS activity positively affected the growth parameters in sandal when associated with leguminous hosts.

The association of pre-treatment neutrophil to lymphocyte ratio with overall survival in patients with glioblastoma multiforme

Neutrophil-lymphocyte ratio (NLR) is a marker of systemic inflammatory response and its elevation has recently been shown to be a poor prognostic factor in many malignancies including colon, prostate and bladder cancer. The primary aim of this study was to assess the prognostic impact of NLR in a clinically annotated cohort of patients with glioblastoma multiforme (GBM). We hypothesised that elevated NLR would be associated with worse prognosis. Between 2004 and 2009, 137 patients had surgery for GBM and were assessed for consideration of adjuvant therapy at our institution. Of these, 84 patients with an evaluable pre-corticosteroid full blood count result were identified and included in the final analysis. Median overall survival was 9.3 months (range 0.7-82.1). On univariate analysis, age >65 years, gender, ECOG performance status ≥2, frontal tumour, extent of surgical resection, completion of adjuvant chemoradiation protocol and NLR > 4 were significantly correlated with overall survival. Patients with NLR > 4, had a worse median overall survival at 7.5 months versus 11.2 months in patients with NLR ≤ 4 (hazard ratio 1.6, 95 % CI 1.00-2.52, p = 0.048). On multivariate analysis NLR > 4 remained an independent prognostic indicator for poor outcome. These data are an important reminder of the potential relevance of host immunity in GBM. In our cohort, NLR > 4 conferred a worse prognosis independent of other well established prognostic factors. If validated in other cohorts NLR may prove to be a useful addition in predicting prognosis in GBM patients. The demonstration that host immunity plays a role in GBM biology suggests that investigation of emerging therapies which modulate host immune response are warranted in this disease.

A survey of patients' attitudes to upper gastrointestinal endoscopy identifies the value of endoscopist-patient interactive factors

OBJECTIVE

To determine patients' self-reported preferences and expectations for outpatient upper gastrointestinal (UGI) endoscopy, including patients' priorities in obtaining a satisfactory healthcare experience, preprocedure anxiety and its causes, and preferred staff roles.

DESIGN

A composite, dedicated endoscopy questionnaire was used. This included demographic information, validated Likert scale anxiety-related questions and a 15-point ranking scale of aspects of care (1=most important to satisfaction; 15=least important).

SETTING AND PATIENTS

Unselected patients attending for an elective UGI endoscopy at two separate units were surveyed on randomly identified days.

RESULTS

A total of 202 out of 254 patients agreed to participate (79.5%). The values identified as most important to patients included technical skill (2.8) and personal manner of the endoscopist (4.9) and the nurses and support staff (5.8), control of discomfort (5.6) and adequacy of the preprocedure explanation (5.8). The factors considered least important included noise levels (12.5), privacy (10.7) and cleanliness (8.7). Moderate to severe anxiety was recorded in half of the patient cohort, predominantly due to anticipation of pain or the results of the procedure. Most patients preferred the endoscopist to discuss the findings of the endoscopy but expressed no preferences regarding the preprocedure explanation.

CONCLUSION

Patients undergoing UGI endoscopy appear to highly prioritise aspects of care relating to interaction with the endoscopist and the procedure itself. Environmental factors are considered to have much less value. These findings may assist in service redesign around patient-centred care and the development of patient satisfaction surveys in endoscopy.

Plasmodium falciparum: evaluation of a quantitative nucleic acid sequence-based amplification assay to predict the outcome of sulfadoxine-pyrimethamine treatment of uncomplicated malaria

A quantitative nucleic acid sequence-based amplification (QT-NASBA) assay was employed to predict retrospectively the outcome of sulfadoxine-pyrimethamine (SP) treatment of uncomplicated malaria in children aged <6 years in an endemic region. Blood samples were collected at initial diagnosis and during follow-up. Mutation-specific nested PCR methods to analyse DHFR (Arg-59) and DHPS (Glu-540) mutations that are associated with SP drug resistance were applied. Parasite genotyping was performed to distinguish between re-infection and recrudescence. Eighty-six patients were recruited of which 66 were available for follow-up. Nine children were classified as early treatment failure, 13 cases were classified as late clinical failure, 32 as late parasitological failure, and only 12 children had an adequate clinical and parasitological response. DHFR and DHPS mutations conferring SP resistance were abundant in the Plasmodium population. Blood samples obtained 7 days after treatment were used to predict retrospectively the outcome of SP treatment. QT-NASBA was able to give a correct prediction of treatment outcome in 85.7% of the cases. Positive predictive value (PPV) of QT-NASBA case was 95% (95% confidence interval = 88.3-100) and negative predictive value (NPV) was 63% (95% CI = 39.5-86.5). In contrast, microscopy correctly predicted outcome in only 37.5% of the cases. PPV of microscopy was 100% (95% CI = 73.9-100) and the NPV was 25.5% (95% CI = 13.0-38.0). The analysis of a day 7 blood sample with QT-NASBA allows for the prediction of late clinical or parasitological treatment failure in the majority of the cases analysed in the present study.

Effect of PSC 833, a potent inhibitor of P-glycoprotein, on the growth of astrocytoma cells in vitro

Malignant astrocytomas have been found to express P-glycoprotein (Pgp, mdr1 gene product). It was hypothesized that in addition to conferring multidrug resistance, Pgp is intimately associated with the development of astrocytomas. Accordingly, we studied the effect of PSC 833 (PSC, Novartis), a potent inhibitor of Pgp, on the growth of Pgp-expressing astrocytoma cells. The results showed that in all the cell lines tested, PSC (10-60 microM) inhibited the growth as well as induced cell death. Cells exposed to PSC exhibited DNA ladder characteristic of apoptosis. PSC-induced cell death could be reversed by Z-VAD-fmk, a general caspase inhibitor, indicating that PSC-induced cell death was characteristic of caspase-mediated apoptosis. These results suggest a novel therapeutic strategy in the treatment of malignant astrocytomas by inhibitors of Pgp.

Graded balloon atrial septostomy in severe pulmonary hypertension

BACKGROUND

The prognosis of patients with severe primary pulmonary hypertension is poor. The role of balloon atrial septostomy as a palliative procedure in these patients is not well defined. We retrospectively analyzed our data regarding the safety, clinical outcome and survival benefit of graded balloon atrial septostomy in patients with severe pulmonary hypertension.

METHODS AND RESULTS

Eleven patients (7 males), aged 6 to 30 years (mean age 16.2+/-8.9 years), with severe pulmonary artery hypertension (mean pulmonary artery pressure of 76+/-16.9 mmHg) and refractory congestive heart failure and/or recurrent syncope underwent balloon atrial septostomy. Graded balloon dilatation under echocardiographic guidance and arterial oxygen saturation monitoring was done in all the patients. Procedure-related mortality was 18.2%. Significant acute hemodynamic improvement was seen in the survivors (pre-balloon atrial septostomy cardiac index 1.88+/-0.48 L/min/m2; post-balloon atrial septostomy cardiac index 2.18+/-0.37 L/min/m2, p<0.009). Patients were followed up for a mean period of 20.3 months after the procedure (range: 3 months-5 years). There was functional improvement and increased exercise tolerance in all the patients for a mean follow-up period of 14.6 months (NYHA functional class 3.62+/-0.69 to 2+/-0.50). The estimated probability of survival in this cohort at 1 year was only 48%; but 7 of 8 patients (87%) who survived the procedure were alive at 1 year.

CONCLUSION

We conclude that balloon atrial septostomy improves clinical status, hemodynamic variables and possibly also improves survival in selected patients with severe pulmonary artery hypertension. It remains a definite palliative option for refractory primary pulmonary hypertension. However, the procedure-related risks are high in very sick patients and, therefore, balloon atrial septostomy may be advocated early in the course of the disease.

Caffeine metabolism in premature infants

Caffeine has been used frequently in the treatment and prevention of apnea of prematurity. The metabolism of caffeine depends on the activities of the hepatic enzymes that vary from one infant to another. The objective of this study was to determine the influence of postnatal age (PNA), birth weight (BW), study weight (SW), gestational age (GA), postconceptual age (PCA), and gender on the maturation of caffeine metabolism in premature infants. The caffeine base was administered orally as a loading dose of 10 mg/kg, followed by a maintenance dose of 2 mg/kg every 24 hours. The steady-state concentration of caffeine and metabolites was measured in plasma taken on the 5th-day postloading dose. The molar concentration ratios for the N3 (N3-), N7 (N7-), N1 (N1-), and all methyl (Nall-) demethylation processes; clearance (CL); and the percentage of molar concentration of caffeine found in plasma to that of the total caffeine and metabolites (%CAF) were calculated from samples collected from 80 neonatal infants. The 48 male and 32 female premature infants had median (range) BW (g), GA (weeks), SW (g), PCA (weeks), and PNA (days) of 1300 (650-2260), 30 (24-34), 1630 (980-2670), 34 (29-40), and 28 (5-60), respectively. The median (range) of the ratios for the %CAF, CL, and the N3-, N7-, N1-, and Nall- were 86.9 (52.9-99.0), 0.127 (0.046-0.503) ml.kg-1.min-1, 0.032 (0-0.438), 0.070 (0.007-0.471), 0.026 (0-0.283), and 0.0463 (0.003-0.303), respectively. When the patients were stratified into four PNA age groups, each older group showed a consistently higher level of caffeine metabolic activity for the N3-, N7-, and Nall- pathways with a corresponding decrease in the %CAF, whereas no significant differences were seen for the N1-pathway or for CL. No pattern of significant differences between the demethylation process ratios, %CAF, or CL was seen between groups of infants when they were stratified according to BW, SW, PCA, or GA. The female infants were found to have significantly higher rates of caffeine metabolism as shown by %CAF, N1-, N3-, and Nall- processes but not the N7-. Multivariate linear regression analysis by two methods demonstrated that PNA is significantly related to %CAF and Nall-, whereas the female patients had higher levels of metabolic activity for the %CAF and N1- process. The authors conclude that the N7-demethy-lation process is the predominate caffeine metabolic process in premature infants. Furthermore, the maturation of the caffeine metabolism in premature infants with a PNA of less than 60 days increases with postnatal age, regardless of birth weight, gestational age, postconceptual age, and study weight. The female neonatal patients demonstrated a higher rate of caffeine metabolism than the males.

Expedient liquid chromatographic method with fluorescence detection for montelukast sodium in micro-samples of plasma

This study describes an expedient assay for the analysis of the asthma medication, montelukast sodium (Singulair, MK-0476), in human plasma samples. After a simple extraction of the plasma, the drug and internal standard, quinine bisulfate, were measured by HPLC. The chromatographic system consisted of a single pump, a refrigerated autosampler, a C8 4-microm particle size radial compression cartridge at 40 degrees C and a fluorescence detector with the excitation and emission wavelengths set at 350 and 400 nm, respectively. The mobile phase which was delivered at 1.0 ml/min, was prepared by adding 200 ml of 0.025 M sodium acetate, pH adjusted to 4.0 with acetic acid, to 800 ml of acetonitrile, with 50 microl triethylamine. With a run time of only 10 min per sample, this assay had an overall recovery of >97% with a detection limit of 1 ng/ml. The inter- and intra-run relative standard deviations at 0.05, 0.2 and 1.0 microg/ml were all <9.2%, while the analytical recovery at the same concentrations were within 7.7% of the amount added.

Optimization of oral etoposide dosage in elderly patients with non-Hodgkin's lymphoma using the fraction of dose absorbed measured for each patient

This study was undertaken to investigate the pharmacokinetics of etoposide for optimizing its oral dosage in elderly patients with non-Hodgkin's lymphoma (NHL) using the fraction of dose absorbed calculated from the data generated from first oral and intravenous doses in the same patient. Twenty-three NHL patients (ages 61-95 years) entered this study. Each received 50 mg/m2 of etoposide by 1-hour i.v. infusion, which was repeated every 24 hours for 5 days. The second cycle commenced on day 21, with etoposide being administered by mouth at a dose as close to 50 mg/m2 as possible. Serial blood samples were collected and analyzed for etoposide by HPLC. The fraction of dose absorbed (F) was calculated as F = (AUCor/AUCi.v.) (Di.v./Dor), and etoposide was then given orally for the following 20 days at a daily dose equivalent to Dor/F. After 1 week free of etoposide administration, a second cycle of oral etoposide at the adjusted dose was given for 21 days. The mean +/- SD values for t1/2 beta, tmax, Cmax, CLTor, and MRT observed following the first oral dose were 8.98 +/- 4.84 h, 1.39 +/- 0.96 h, 0.083 +/- 0.046 mg.L-1/mg.m-2, 1.89 +/- 1.2 L.h-1/m2, and 10.37 +/- 2.76 h, respectively, and those observed following the first intravenous dose were 8.05 +/- 5.11 h, 1.57 +/- 0.17 h, 0.142 +/- 0.043 mg.L-1/mg.m-2, 1.25 +/- 0.44 L.h-1/m2, and 7.69 +/- 1.53 h, respectively. The mean +/- SD of F was 0.80 +/- 0.34. The data obtained indicate that optimization of etoposide oral dosage using F yielded good clinical results while keeping the morbidity at a level that is similar to that of the i.v. administration.

Simplified high-performance liquid chromatographic method for the determination of gentamicin sulfate in a microsample of plasma: comparison with fluorescence polarization immunoassay

The authors describe a simplified high-performance liquid chromatographic (HPLC) method for the determination of gentamicin sulfate (GEN) in microsamples of plasma using 9-fluorenylmethyl chloroformate (FMOC) as a derivatizing agent and neomycin sulfate as the internal standard (IS). The drug and IS were separated on a 4 microm (particle size), 8 x 100 mm Nova-Pak C18 radial compression cartridge using a mixture of 84.5% acetonitrile and 15.5% water at a flow rate of 2.5 mL/min. The compounds were detected fluorometrically in the effluent at excitation and emission wavelengths of 260 nm and 315 nm, respectively. Sample preparation was performed on 50 microL of plasma using a simple liquid-liquid extraction followed by a room-temperature derivatization procedure. No interference from any endogenous substance or concurrently used drug was observed, and the retention times of the IS and three major components of GEN were 12.4, 19.5, 23.6, and 27.6 min, respectively. The concentration of the GEN in plasma for the range of 0.2-20.0 microg/mL was linearly (r > .997) related to the peak height ratio of the sum of the three major GEN peaks to that of the IS, with CV value at 0.3, 7.5, and 15 microg/mL being <3.61%. A comparison of the results from this assay versus fluorescence polarization immunoassay (TDx) showed a close agreement between the two methods with r = 0.994. This assay is currently being used to monitor GEN and investigate its pharmacokinetics in pediatric patients.

Development of resistance during the early stages of experimental liver carcinogenesis

The present study was designed to determine whether the resistant phenotype is acquired at the initiated cell stage itself or requires further exposure to a promoting regimen to express resistance. Male Fischer 344 rats were initiated with diethylnitrosamine (DENA) (200 mg/kg i.p.) and were subjected to either no further treatment or to the resistant hepatocyte (RH) model of liver tumor promotion. Six weeks later, the resistance of the focal lesions generated in these two groups to the mitoinhibitory effects of 2-acetylaminofluorene (2-AAF) was determined by subjecting the rats to two-thirds partial hepatectomy (PH) in the presence of a mitoinhibitory dose of 2-AAF (5 mg/kg i.p.) given at the time of PH. Labeling index was determined by administering multiple injections of [(3)H]thymidine. All rats were killed 48 h post-PH. While only a small percentage (23%) of the glutathione S-transferase-positive foci generated by DENA in the absence of an exogenous liver tumor promoting regimen were resistant to the mitoinhibitory effects of 2-AAF, a majority (85%) of the foci became resistant to 2-AAF following exposure to the RH model of liver tumor promotion. Further, initiated rats exposed to either 2-AAF or to CCl(4) alone, the two components of the RH model, resulted in 71% of the foci being resistant to the mitoinhibitory effects of 2-AAF. Similar patterns of results were obtained when the resistance of the foci to the mitoinhibitory effects of orotic acid, a liver tumor promoter and an inhibitor of DNA synthesis in normal hepatocytes, was monitored. These results suggest that the majority of initiated hepatocytes are not of resistant phenotype, however, they have acquired a unique ability to express resistance upon exposure to certain agents such as 2-AAF and CCl(4) or to a promoting regimen such as the RH model of liver tumor promotion.

The effect of 1/3 partial hepatectomy on the growth of glutathione S-transferase positive foci

Our previous studies indicated that glutathione S-transferase 7-7 (GST 7-7) positive foci induced after initiation have a lower threshold towards proliferative stimuli compared with surrounding hepatocytes. This observation would predict that persistent growth stimuli of low intensity could be very effective in promoting the emergence of focal lesions. To test this possibility, the present study was designed to determine the effect of 1/3 partial hepatectomy (PH) on the incidence and growth of foci in initiated rat liver. The rationale for using a 1/3 PH was that it is known to induce a proliferative response which is less intense but more prolonged compared with that elicited by 2/3 PH. Male Fischer 344 rats (110-120 g) were initiated with diethylnitrosamine (200 mg/kg, i.p.). Three weeks later 1/3 PH (median lobe), 2/3 PH (median and left lobes) or sham operation (SH) was performed. An additional group of initiated animals had the median lobe and the left lobe of the liver removed sequentially (1/3 + 1/3 PH), 3 weeks apart. All rats were killed 8 weeks after carcinogen administration. The results indicated that the number of GST 7-7 positive foci was similar in all groups; however, the percent area occupied by foci was increased in rats receiving 2/3 PH compared with SH (0.21 +/- 0. 08 versus 0.09 +/- 0.03). Interestingly, 1/3 PH was nearly as effective as 2/3 PH in stimulating the growth of foci (percent area 0.18 +/- 0.06 versus 0.21 +/- 0.08), although the magnitude of the stimulus is only half for the former group compared with the latter; peak labeling index was 19 +/- 6 with 1/3 PH compared with 40 +/- 2 with 2/3 PH. Moreover, the maximum increase in the size of foci (percent area 0.37 +/- 0.12) was achieved when the median and left lobes were removed sequentially, three weeks apart. These results indicate that persistent growth stimuli of low intensity can be very effective in promoting the growth of focal lesions.

First Report of Soybean Dwarf Virus Infecting Lentil and Beet Western Yellows Virus Infecting Lentil and Chickpea Crops in Ethiopia

A survey conducted during November 14-23, 1998, to identify viruses infecting chickpea (Cicer arietinum) and lentil (Lens culinaris) crops in the Shewa province of Ethiopia covered 33 chickpea and 32 lentil fields randomly selected. Identity of the viruses present and virus incidence were determined on the basis of laboratory testing of 100 to 200 randomly collected samples in addition to 15 to 20 symptomatic samples from each field. A total of 5,427 lentil and 3,836 chickpea samples were collected and tested for the presence of 12 different viruses by tissue blot immunoassay (1) at the Plant Pathology Laboratory in Debre Zeit Agriculture Research Center, Ethiopia. All antisera were virus specific, including those for beet western yellows virus (BWYV; ATCC PVAS-647) and soybean dwarf virus (SbDV; ATCC PVAS-650). More than 21% of the samples from 5 chickpea fields were infected; the most common virus was BWYV. Also, at least 21% of the samples from 11 lentil fields were virus positive; the most widespread virus was PSbMV. Highest rates of infection: of lentil in a single field, PSbMV in 58.5% of the samples; in a chickpea field, 41.3% of the samples positive for BWYV. Other viruses such as faba bean necrotic yellows nanovirus (FBNYV) and broad bean wilt fabavirus in chickpea and FBNYV, broad bean stain comovirus, bean yellow mosaic potyvirus, and cucumber mosaic cucumovirus in lentil were detected at very low incidence. Reference: (1) K. M. Makkouk and A. Comeau. Eur. J. Plant Pathol. 100:71, 1994.

Salivary clearance and urinary metabolic pattern of caffeine in healthy children and in pediatric patients with hepatocellular diseases

Measurement of salivary clearance and urinary metabolites of caffeine is an excellent noninvasive tool for assessing liver function, particularly the activity of cytochrome P4501A2 (CYP1A2), N-acetyltransferase (NAT), and xanthine oxidase (XO). This study was undertaken to measure the clearance of caffeine using saliva as a biological fluid and to assess the activities of the above-mentioned enzymes in healthy children and pediatric patients with liver diseases using urinary molar ratios of different caffeine metabolites. The well-established two-sample saliva approach was used to measure the clearance of caffeine in nine pediatric patients with liver diseases (LD) and in nine healthy children. The caffeine metabolites were also measured in the urine of these subjects by high-performance liquid chromatography, and urinary molar ratios of 5-acetylamino-6-formylamino-3-methyluracil (AFMU), 1-methylxanthine (1X), 1-methyluric acid (1U), and 1,7-dimethyluric acid (17U) were employed to estimate the activities of CYP1A2, NAT, and XO. The caffeine salivary clearance and the percentage of the dose excreted in the form of various metabolites were significantly (p < 0.035) smaller in the LD patients than those in healthy children. The urinary molar ratio of [AFMU + 1U + 1X]/17U, which reflects the activity of CYP1A2, was also significantly (p < 0.0005) reduced in these patients. However, there were no significant differences between the two groups in the ratios of AFMU/1X and 1U/1X, which estimate the activities of NAT and XO, respectively. In conclusion, the data obtained suggest that liver disease in pediatric subjects significantly reduces the salivary clearance of caffeine and the activity of cytochrome P4501A2, but it has no impact on the activities of NAT and XO.

Simultaneous high-performance liquid chromatography analysis of azithromycin and two of its metabolites in human tears and plasma

This article describes a high-performance liquid chromatographic (HPLC) method for the measurement of azithromycin (AZI) and two of its metabolites, 9a-N-desmethylazithromycin (ADES) and N-desmethylazithromycin (NDES), in human tears and plasma. The drug, metabolites, and internal standard (n-propylazithromycin [IS]) were detected electrochemically after injection of the extracted sample into the HPLC system. The peak height ratio (AZI, ADES, or NDES to IS) varied linearly, with concentrations in the ranges of 0.1 mg/L to 2.0 mg/L (tears) and 0.01 mg/L to 2.0 mg/L (plasma) of AZI, ADES, and NDES; the correlation coefficient (r) was more than 0.994 mg/L for all of the compounds (n=6). The analysis of tear samples collected at different intervals within 12 hours to 144 hours after a dose of 20 mg/kg of AZI from a trachoma patient yielded concentrations ranging from 1.52 mg/L to 0.34 mg/L for AZI, 0.79 mg/L to 0.27 mg/L for ADES, and 1.99 mg/L to less than 0.20 mg/L for NDES. The concentration of AZI in plasma ranged from 0.15 mg/L to 0.01 mg/L, whereas ADES and NDES were undetectable.

Seismic upgrades of healthcare facilities

Before 1989 seismic upgrading of hospital structures was not a primary consideration among hospital owners. However, after extensive earthquake damage to hospital buildings at Loma Prieta in Northern California in 1989 and then at Northridge in Southern California in 1994, hospital owners, legislators, and design teams become concerned about the need for seismic upgrading of existing facilities. Because the damage hospital structures sustained in the earthquakes was so severe and far-reaching, California has enacted laws that mandate seismic upgrading for existing facilities. Now hospital owners will have to upgrade buildings that do not conform to statewide seismic adequacy laws. By 2030, California expects all of its hospital structures to be sufficiently seismic-resistant. Slowly, regions in the Midwest and on the East Coast are following their example. This article outlines reasons and ways for seismic upgrading of existing facilities.

Transient inhibition by orotic acid does not abolish the in vivo response of rat hepatocytes to a direct mitogen, lead nitrate

BACKGROUND

Orotic acid (OA) is able to inhibit hepatocyte proliferation in vivo induced by 2/3 partial hepatectomy. The present studies were aimed at establishing: (i) whether OA also inhibits hepatocyte proliferation induced by a direct mitogen and, if so (ii) whether the stimulus provided by the mitogen is still expressed following transient inhibition by OA.

METHODS/RESULTS

In the first experiment male Wistar rats were injected with either lead nitrate (100 mumol/kg, i.v.) or saline and 20 h later some animals receiving the mitogen were also implanted with a 400-mg OA tablet (as OA-methyl ester. i.p.). Multiple injections of 3H-thymidine were given to each rat (50 microCi each, 6 h apart, i.p.) until 2 h before killing. All groups were killed 3 days after the initial treatment. Results indicated that OA almost completely inhibited hepatocyte DNA synthesis and labelling induced by lead nitrate (e.g. labelling index was 1.9 +/- 0.5% in the saline-treated group, 44.7 +/- 4.0% in the lead nitrate group and 1.4 +/- 0.3% in the group receiving lead nitrate + OA). Based on the above results, in a second experiment rats were given a similar dose of lead nitrate and a subset of animals was implanted 20 h later with a 400-mg OA tablet, as previously described. Multiple doses of 3H-thymidine were again given to each rat (20 microCi each, 6 h apart) until 2 h before killing. Animals from both groups were killed at 3, 6 or 8 days after lead nitrate. Results indicated that, while at day 3 lead nitrate-induced DNA synthesis was effectively inhibited by OA, at day 6 the proliferative response was resumed in the group receiving OA. Cumulative labelling index over 6 days was 30.3 +/- 1.4 in rats given the mitogen alone and 52.1 +/- 2.2 in the group exposed to lead nitrate + OA.

CONCLUSIONS

These data indicate that: (i) OA is also able to inhibit hepatocyte proliferation induced by a direct mitogen such as lead nitrate; this, in turn, suggests that its inhibitory effect is not unique to the stimulus elicited by partial hepatectomy. (ii) The proliferative response triggered by the mitogen is not abolished by the transient (3-4 days) inhibitory phase imposed by OA. Possible mechanisms underlying these effects are considered in the discussion.

Expedient liquid chromatographic assay for paclitaxel in plasma after its administration to cancer patients

A rapid and expedient liquid chromatographic method for the analysis of paclitaxel in plasma is described. Paclitaxel and the internal standard (IS, N-nitrosodiphenylamine) were separated on a 10-microns particle, 8 mm x 10 cm C18 cartridge in conjunction with a radial compression system preceded by Guard Pak with a C18 insert. The mobile phase was a mixture of 1 mM sodium phosphate buffer (pH 5) and acetonitrile (55.5:45.5 per volume), and the flow rate was 4.5 ml/min. The compounds were extracted from plasma with ethyl acetate and were detected in the effluent spectrophotometrically at 227 nm. The recovery of paclitaxel from plasma at concentrations equivalent to 50, 400, and 800 micrograms/L paclitaxel in plasma was 79.1, 75.2, and 74.3%, respectively, and the retention times of the drug and IS under these conditions were 5.26 and 6.45 min, respectively. The relationship between the concentration and peak height ratio (drug/IS) was linear (r = 0.9938-0.9998) in the range of 10-1,600 micrograms/L, and no interference in the assay was observed. The intrarun coefficient of variations (CV) at 50, 250, and 800 micrograms/L were 4.9, 5.4, and 4.1%, respectively, and the deviations from theoretical accuracy at these concentrations were 1.2, 0.5, and 5.4%, respectively. We are currently using this assay to investigate the pharmacokinetics of paclitaxel in cancer patients treated with this agent in a combined chemotherapy.

The enhancing effect of fasting/refeeding on the growth of nodules selectable by the resistant hepatocyte model in rat liver

Caloric restriction causes a generalized decrease in growth rate and has been shown to delay the development of both spontaneous and induced neoplasia. In contrast to chronic food restriction, the extreme condition of fasting/refeeding is associated with an overall increase in cell turnover in several organs, including liver, compared with regular feeding. The present study was therefore designed to investigate the effect of complete food withdrawal followed by refeeding on the growth of hepatocyte nodules in initiated rat liver. Male Fischer 344 rats were given a single dose of diethylnitrosamine (DEN, 200 mg/kg i.p.) and then, starting 1 wk later, they were exposed to one or three cycles of fasting (3 days) followed by refeeding (11 days). The control group was fed continuously. Seven weeks after DEN administration all rats were subjected to the resistant hepatocyte model (2-acetylaminofluorene coupled with CCl4) and 2 weeks later 2/3 partial hepatectomy (PH) was performed. All animals were killed 2 weeks after surgery. At PH rats given one cycle of fasting/refeeding had significantly larger glutathione S-transferase 7-7-positive hepatic lesions compared with controls (mean area 0.73 +/- 0.04 versus 0.50 +/- 0.05 mm2, P < 0.025; mean percent area 25.6 +/- 3.2 versus 12.4 +/- 0.9, P < 0.005), while no significant change was observed in their number. The observed differences were more pronounced with three cycles of fasting/refeeding. A similar pattern of results was obtained at the time of killing. It is concluded that fasting/refeeding can exert a positive effect on the growth of rat hepatocyte foci and nodules, in contrast to the general inhibitory effect on carcinogenesis caused by food restriction.