Biomedical subjects

L Bernard

Publications and source records attributed to L Bernard.

At least 37 records · Page 2Linked to original sources

PubMed2001

The value of suction drainage fluid culture during aseptic and septic orthopedic surgery: a prospective study of 901 patients.

There are no guidelines on the value of suction drainage fluid culture (SDC), and it is difficult to determine whether the organisms cultured from suction drainage fluid samples are pathogenic or simply contaminants. We performed 2989 cultures of suction drainage fluid samples obtained, during a 1-year period, from 901 patients who underwent aseptic or septic orthopedic surgery (946 operations). The culture results were analyzed to evaluate their ability to detect postoperative infection after aseptic operations or to detect either a persistent or new episode of sepsis in patients known to have infection. For aseptic operations, the sensitivity of SDC was 25%, the specificity was 99%, the positive predictive value was 25%, and the negative predictive value was 99%. For septic operations, the sensitivity of SDC was 81%, the specificity was 96%, the positive predictive value was 87%, and the negative predictive value was 94%. We conclude that, for aseptic orthopedic surgery, SDC is not useful in detecting postoperative infection. However, for septic orthopedic surgery, it is of clinical importance.

Adolescent↗

PubMed2001

Zenker's diverticulum associated with multilevel cervical osteomyelitis.

STUDY DESIGN: A case report of cervical osteomyelitis possibly associated with a Zenker's diverticulum perforation. OBJECTIVES: To present clinical, radiologic, and surgical findings of a cervical osteomyelitis due to a Zenker's diverticulum perforation. SUMMARY OF BACKGROUND DATA: A 56-year-old patient was in an intensive care unit for a severe head injury. He was fed via a nasogastric tube. Four months later he developed a pyogenic cervical vertebral infection. METHODS: Plain films and magnetic resonance imaging showed a diffuse cervical osteomyelitis. Investigation of his dysphagia revealed a Zenker's diverticulum. RESULTS: After administration of antibiotics and surgical treatment of the diverticulum, the cervical infection resolved. Plain films and magnetic resonance imaging showed healing with vertebral fusion. CONCLUSIONS: Cervical osteomyelitis is uncommon. Only one case of direct contamination leading to cervical vertebral osteomyelitis after esophageal perforation has been previously described. Direct contamination of the prevertebral soft tissues by bacteria traveling through the fistula may have occurred. The development of vertebral osteomyelitis in this case is consistent with the hypothesis of direct contamination. Management relies on appropriate antimicrobial therapy and surgical management of the diverticulum. The association of Zenker's diverticulum with vertebral osteomyelitis and discitis is a unique, previously undescribed situation.

Anti-Infective Agents↗

PubMed2001

[Indinavir-ritonavir combination: pharmacologic results and tolerance in patients infected by HIV].

OBJECTIVES: Ritonavir (RTV) is a powerful inhibitor of P450 3A4 cytochorme. When given in combination with indinavir (IDV) it increases the IDV trough concentrations (Cmin) allowing a lower IDV dosage in a twice a day regimen, independently of meals. We report tolerance data and IDV Cmin levels observed in plasma and cerebrospinal fluid (CSF) in a cohort of HIV-infected patients treated with the IDV-RTV combination at different dosages of IDV and RTV. PATIENTS AND METHODS: IDV Cmin was assayed 56 times in 40 patients (few patients had received different dosages of the IDV-RTV combination). Tolerance was recorded. RESULTS: For patients given the IDV-RTV combination at the doses of 800/100 mg b.i.d., 800/200 mg b.i.d. or 400/400 mg b.i.d., the IDV Cmin was 12 times the median IDV IC95. If the Cmin/IC95 ratio was greater than 10 with the 800/100 mg b.i.d. regimen and virological success was achieved, the IDV dosage was reduced to 400 mg b.i.d. For these patients, the 400/100 mg b.i.d. IDV-RTV regimen always gave a Cmin above the IDV IC95. Median Cmin for IDV in CSF was 146 ng/ml (range 71-881 ng/ml), above the IDV IC95. It was possible to control most of the adverse effects by reducing dosage after obtaining the IDV pharmacological levels. Definitive interruption of treatment was required in only 2 cases at mean follow-up of 7.9 months. DISCUSSION: The IDV-RTV combination should be used to improve observance of antiretroviral treatments and reduce the risk of virological failure related to low plasma levels. The IDV-RTV combination at 800/100 mg b.i.d. is a useful protocol when IDV efficacy alone is the goal. The 400/400 mg b.i.d. IDV-RTV regimen is an interesting alternative when efficacy of both inhibitors is the goal. Drug assays should be systematic to adapt individual dosages and limit the risk of adverse effects.

Drug Therapy, Combination↗

PubMed2001

A new approach to determine the genetic diversity of viable and active bacteria in aquatic ecosystems.

BACKGROUND: Discrimination among viable, active, and inactive cells in aquatic ecosystems is of great importance to understand which species participate in microbial processes. In this study, a new approach combining flow cytometry (FCM), cell sorting, and molecular analyses was developed to compare the diversity of viable cells determined by different methods with the diversity of total cells and active cells. METHODS: Total bacteria were determined by SYBR-II staining. Viable bacteria were determined in water samples from different sites by plate count techniques and by the direct viable count (DVC) method. Substrate-responsive cells (i.e., DVC(+) cells) were distinguished from nonresponsive cells (i.e., DVC(-) cells) by FCM and sorted. The genetic diversity of the sorted cell fraction was compared with the diversity of the total microbial community and with that of the culturable cell fraction by denaturing gradient gel electrophoresis (DGGE) of polymerase chain reaction (PCR)-amplified 16S rDNA fragments. The same approach was applied to a seawater sample enriched with nutrients. In this case, actively respiring cells (CTC+) were also enumerated by FCM, sorted, and analyzed by DGGE. RESULTS: The diversity of viable cells varied depending on the methods (traditional culture or DVC) used for viability assessment. Some phylotypes detected in the fraction of viable cells were not detectable at the community level (from total DNA). Similar results were found for actively respiring cells. Inversely, some phylotypes found at the community level were not found in viable and active cell-sorted fractions. It suggests that diversity determined at the community level includes nonactive and nonviable cells. CONCLUSION: This new approach allows investigation of the genetic diversity of viable and active cells in aquatic ecosystems. The diversity determined from sorted cells provides relevant ecological information and uncultured organisms can also be detected. New investigations in the field of microbial ecology such as the identification of species able to maintain cellular activity under environmental changes or in the presence of toxic compounds are now possible.

Bacteria↗

PubMed2001

[Anti-infection prophylaxis after sexual assault. Experience of the Raymond Poincaré-Garches Hospital].

OBJECTIVE: The August 1997 Directive of the Direction of General Health in France extended indications for antiretroviral treatment to risk of HIV exposure by sexual intercourse or syringe sharing. In November 1997, in collaboration with the Hauts-de-Seine MedicoJudiciary center, the Infectious Disease unit of the Raymond Poincaré Garches Hospital established a health care and anti-HIV prophylaxis clinic for victims of sexual assault. We report here the experience in 1998 and 1999. PATIENTS AND METHODS: Between January 1998 and December 1999, 109 victims of sexual assault, 105 women and 4 men, mean age 24.7 +/- 10.6 years attended the clinic. RESULTS: Mean delay from assault to antiretroviral tritherapy (AZT, 3TC, indinavir) was 18.35 +/- 17.39 hours. Mean duration of antiretroviral treatment was 17.4 +/- 11.8 days. HIV screening in perpetrators enabled early interruption of the antiretroviral treatment in 23 cases (21.1%). Sixty-two victims (62%) were still in follow-up at W4/W7. Excellent compliance to tritherapy was observed in these subjects. Clinical intolerance was observed in 46.6% with nausea-vomiting in 91.4% of the cases. Adverse effects led to interruption of indinavir in 5 cases. Initial HIV serology was negative in all cases and no case of HIV seroconversion was observed. Among the 23 known perpetrators, one was HIV-positive with an HIV-RNA at 88,000 copies. Sixty-one victims (55.9%) had been previously vaccinated against the hepatitis B virus; 16 victims were vaccinated after the assault. There were no cases of hepatitis B virus seroconversion. Search for chlamydiae in vaginal secretions was positive in 3 cases and chlamydia serology demonstrated a seroconversion in 1 case. There was no case of syphylitic seroconversion and no case of gonococcal or trichomonas infection. CONCLUSION: The low rate of attendance for follow-up in regards to the gravity of the potential risk of HIV and/or hepatitis B virus transmission and the burden and cost of the antiretroviral treatment highlight the need for better medico-psycho-social support for rape victims. For the victims who attended the clinic, antiretroviral treatment was generally well accepted and well tolerated.

Adolescent↗

PubMed2001

Identification of the gene for oral-facial-digital type I syndrome.

Oral-facial-digital type 1 syndrome (OFD1 [MIM 311200]) is transmitted as an X-linked dominant condition with lethality in males and is characterized by malformations of the face, oral cavity, and digits, and by a highly variable expressivity even within the same family. Malformation of the brain and polycystic kidneys are commonly associated with this disorder. The locus for OFD1 was mapped by linkage analysis to a 12-Mb interval, flanked by markers DXS85 and DXS7105 in the Xp22 region. To identify the gene responsible for this syndrome, we analyzed several transcripts mapping to the region and found mutations in OFD1 (formerly named "Cxorf5/71-7a"), encoding a protein containing coiled-coil alpha-helical domains. Seven patients with OFD1, including three with familial and four with sporadic cases, were analyzed. Analysis of the familial cases revealed a missense mutation, a 19-bp deletion, and a single base-pair deletion leading to a frameshift. In the sporadic cases, we found a missense (de novo), a nonsense, a splice, and a frameshift mutation. RNA in situ studies on mouse embryo tissue sections show that Ofd1 is developmentally regulated and is expressed in all tissues affected in OFD1 syndrome. The involvement of OFD1 in oral-facial-digital type I syndrome demonstrates an important role of this gene in human development.

Abnormalities, Multiple↗

PubMed2001

A prospective comparison of octyl cyanoacrylate tissue adhesive (dermabond) and suture for the closure of excisional wounds in children and adolescents.

BACKGROUND: Recent studies suggest that the use of octyl cyanoacrylate tissue adhesive for closure of both traumatic lacerations and incisional surgical wounds results in a cosmetic outcome comparable to that achieved with conventional sutures. To date, no studies have looked at the use of tissue adhesive for higher-tension wounds, such as those created during cutaneous excisional procedures. OBJECTIVE: To compare the tissue adhesive octyl cyanoacrylate with standard suture for the closure of excisional wounds in children and adolescents. DESIGN: A prospective comparison with blinded assessment of cosmetic outcome. Twenty-eight wounds were closed with monofilament suture and 24 were closed with tissue adhesive. At approximately 2 months, photographs of the incisions were evaluated by 2 dermatologists blinded to the method of skin closure. SUBJECTS: Forty-two consecutive patients undergoing excisional dermatologic procedures at Children's Hospital, San Diego, Calif. These 42 patients had a total of 52 wounds that were evaluated. MAIN OUTCOME MEASURES: The cosmetic appearance of the wounds at 2 months, based on 2 validated wound scales: the Hollander Wound Evaluation Scale and a visual analog scale. RESULTS: There were no differences in early complications between the groups. The suture group scored higher on the visual analog scale (63.3 mm for suture vs 47.8 mm for tissue adhesive), and this difference was statistically significant (P =.02). The suture group also had a higher median score on the Hollander Wound Evaluation Scale, but this difference was not statistically significant (P =.09). CONCLUSION: The cosmetic outcome of cutaneous excisional surgery wounds closed with standard suturing was found to be superior to that of wounds closed with octyl cyanoacrylate.

Adolescent↗

PubMed2001

Cost-Effectiveness of tolterodine for patients with urge incontinence who discontinue initial therapy with oxybutynin: a Canadian perspective.

BACKGROUND: Tolterodine is a novel muscarinic receptor antagonist for the treatment of overactive bladder. OBJECTIVE: The purpose of this study was to examine the cost-effectiveness of tolterodine for patients with urge incontinence (UI) who discontinue initial therapy with oxybutynin in a Canadian setting. METHODS: We compared 2 treatment strategies for the management of adult patients with UI: (1) generic oxybutynin with no further treatment for patients who discontinue and (2) generic oxybutynin with switch to tolterodine (2 mg BID) for patients who discontinue. We developed a 1-year Markov model (4-week cycle length) with transitions between disease states of normal, mild, moderate, and severe. Transition probabilities over 12 weeks were obtained from randomized trial data, and drug discontinuation rates were obtained from Quebec prescription claims data. Outcome measures were time in "normal" health state and quality-adjusted life-years (QALYs) using EuroQol-5D utility scores from a survey of Swedish patients with overactive bladder. Costs to the health care payer and patient out-of-pocket costs (in Canadian dollars) were included. RESULTS: For patients who discontinue oxybutynin, the use of tolterodine is associated with approximately 6 months per year in a normal health or mild disease state, compared with approximately 3 months for those who do not receive further drug therapy after discontinuation. Tolterodine use resulted in an annual additional cost per patient of Can $163. The incremental cost per QALY was Can $9,982 and appeared to be robust to alternative model parameter assumptions. CONCLUSION: Use of tolterodine in patients with UI who discontinue initial therapy with generic oxybutynin lies within currently accepted benchmarks for cost-effectiveness.

Benzhydryl Compounds↗

PubMed2001

Human immunodeficiency virus (HIV) protease inhibitors have no effect on hepatitis C virus (HCV) serum levels of HIV-HCV co-infected patients.

Ten severely immunocompromised HIV-HCV co-infected patients were enrolled in a quantifiable HCV-RNA assay. Serum alanine aminotransferase, HCV-RNA levels and HIV viral loads were determined at baseline, at month three and at month six after initiation of a highly active antiretroviral therapy including an HIV protease inhibitor. HCV genotypes were determined using a line probe assay kit. Our results suggested that this therapy did not result in lower HCV viraemia, whatever the HCV genotypes, and probably had no effect on the outcome of chronic viral hepatitis C. As our patients were severely immunocompromised and their mean increase of CD4 cell counts was less than 50/mm(3), we cannot reach any conclusions about the impact of the improvement of immune status on the HCV-RNA load.

Antiretroviral Therapy, Highly Active↗

PubMed2001

Outpatient parenteral antimicrobial therapy (OPAT) for the treatment of osteomyelitis: evaluation of efficacy, tolerance and cost.

OBJECTIVES: To evaluate the feasibility, efficacy, and cost of outpatient parenteral antimicrobial therapy (OPAT) in the treatment of osteomyelitis. SUBJECTS: 39 patients with an osteomyelitis requiring parenterally administered antibiotics for more than 4 weeks, and able to receive antibiotics at home. METHODS: All patients had a totally implanted catheter. Antibiotics were administered by continuous infusion using a portable elastomeric infusion system, which was changed every day by the patient or by the home-care nurse. Laboratory monitoring and surveillance were performed weekly. Clinical efficacy, adverse effects and quality of life were recorded. RESULTS: The most commonly used antibiotics were vancomycin (51%) and beta-lactam (44%) antibiotics. Thirty patients were available for follow-up for a minimum of 12 months after completion of therapy. Twenty-eight (93%) were considered cured of their infection with a mean of 24 +/- 4 months after completion of antibiotic therapy. Adverse effects among the study patients were rare. The 39 patients in our OPAT programme resulted in a potential saving of US $1 873 885 relative to conventional therapy. CONCLUSION: OPAT is practicable and effective and may be the best alternative treatment for patients suffering from osteomyelitis requiring intravenous therapy.

Adolescent↗

PubMed2001

Bartonella henselae infection mimicking a splenic lymphoma.

We report a Bartonella henselae infection in a 40-y-old patient who presented with fever, weight loss, night sweats, elevated lactate dehydrogenase and multinodular splenomegaly with multiple abdominal lymphadenopathies. Splenic cat-scratch disease is an exceptional diagnosis in adults and can easily be mistaken for a splenic lymphoma, thereby leading to an unnecessary splenectomy.

Adult↗

PubMed2001

Effect of the methodology on peptide amino acid concentrations in blood and plasma of sheep.

Different methodologies for the measurement of peptide amino acid (PAA) in blood and plasma were compared in sheep. Preparation of blood and plasma samples consisted of a deproteinization, either chemical with sulfosalicylic acid (0.04 g for 1 ml of sample) or physical by ultrafiltration (10,000-MW cut-off filters), with or without a subsequent ultrafiltration through a 3,000-MW cut-off filter. Peptide concentrations were determined by quantification of amino acid concentrations before and after acid hydrolysis of samples. Free amino acid concentrations were similar by all the method used (about 2.5 and 2.7 mM, for blood and plasma respectively). Peptide concentrations were higher with chemical deproteinization (10.6 and 4.2 mM, for blood and plasma respectively) than with physical deproteinization (5.7 and 3.3 mM, for blood and plasma respectively). When the deproteinized samples were further treated to remove material of molecular weight above than 3 kDa, peptide concentrations were significantly reduced, which indicates inefficiencies in the ability of the deproteinizing procedures in removing all the proteinaceous materials. Concentration of small PAA (< 3 kDa) in blood was about 1.5-fold that in plasma, mainly due to peptide Gly and Glu derived from the hydrolysis of the erythrocyte glutathione. The choice of a methodology for quantifying circulating peptides is discussed.

Amino Acids↗

PubMed2001

Cloning and functional analysis of SEL1L promoter region, a pancreas-specific gene.

We examined the promoter activity of SEL1L, the human ortholog of the C. elegans gene sel-1, a negative regulator of LIN-12/NOTCH receptor proteins. To understand the relation in SEL1L transcription pattern observed in different epithelial cells, we determined the transcription start site and sequenced the 5' flanking region. Sequence analysis revealed the presence of consensus promoter elements--GC boxes and a CAAT box--but the absence of a TATA motif. Potential binding sites for transcription factors that are involved in tissue-specific gene expression were identified, including: activator protein-2 (AP-2), hepatocyte nuclear factor-3 (HNF3 beta), homeobox Nkx2-5 and GATA-1. Transcription activity of the TATA-less SEL1L promoter was analyzed by transient transfection using luciferase reporter gene constructs. A core basal promoter of 302 bp was sufficient for constitutive promoter activity in all the cell types studied. This genomic fragment contains a CAAT and several GC boxes. The activity of the SEL1L promoter was considerably higher in mouse pancreatic beta cells (beta TC3) than in several human pancreatic neoplastic cell lines; an even greater reduction of its activity was observed in cells of nonpancreatic origin. These results suggest that SEL1L promoter may be a useful tool in gene therapy applications for pancreatic pathologies.

Animals↗

PubMed2001

Microbial community dynamics in Mediterranean nutrient-enriched seawater mesocosms: changes in the genetic diversity of bacterial populations.

A mesocosm experiment was performed to study the influence of nutrients on activity and diversity of bacterial assemblages from the Mediterranean Sea. Changes in the diversity of the predominant bacterial populations were monitored by DGGE fingerprinting of PCR products derived from 16S rRNA encoding genes. Fluctuations in the diversity of the most active populations was inferred by performing the DGGE fingerprinting on the basis of the cellular rRNA after reverse transcription and PCR amplification. DNA-derived DGGE patterns obtained from duplicate control and nutrient-enriched mesocosms showed differences in the development of the bacterial communities between control and nutrient-enriched experimental mesocosms. Multidimensional scaling analysis of the DNA-derived DGGE fingerprints indicated that duplicate treatments were reproducible. DNA- and RNA-derived DGGE fingerprints of bacterial assemblages changed over time, showing that the composition of the bacterial assemblages, as well as the most active bacterial populations changed during different phases of the incubation. Sequences of predominant DGGE bands in RNA-derived patterns were similar to 16S rRNA gene sequences of members of the alpha-, gamma- and delta-Proteobacteria and of the Cytophaga-Flavobacterium-Bacteroides phylum (CFB). Bands corresponding to Ruegeria-like bacteria and members of the CFB became especially dominant during the course of incubation, suggesting that these populations were important contributors to bacterial production and activity in the post-grazing phase of the experiment.

Journal Article↗

PubMed2001

Microbial community dynamics in Mediterranean nutrient-enriched seawater mesocosms: changes in abundances, activity and composition.

Quantitative and qualitative changes in bacterial communities from the Mediterranean Sea were compared in duplicate batch mesocosms with or without addition of inorganic nutrients. Methods including traditional microbial ecology techniques, molecular biology and flow cytometry were combined to determine abundances, production, cell size, activity, culturability and taxonomic diversity of bacterial cells. Addition of nutrients and confinement resulted in an increase of bacterial densities which were rapidly controlled by protozoan grazing. Changes in bacterial activity and morphology were observed during the growth phase of bacteria and under grazing pressure. The proportion of medium-size and culturable cells increased during the growth phase. These cells were preferentially consumed by grazers resulting in a strong limitation of bacterial production. As a consequence of the grazing pressure, large cells were produced and contributed to the remaining bacterial productivity after grazing. Grazing had an effect on the taxonomic composition of bacterial communities by preferentially eliminating gamma-Proteobacteria, alpha-Proteobacteria were preserved. It seems that some species from the genera Ruegeria and Cytophaga may have developed defence strategies to escape predation.

Journal Article↗

PubMed2000

An intervention study on screening for breast cancer among single african-american women aged 65 and older.

PURPOSE: Older single African-American women are the population that is least likely to use screening procedures because of cognition-related, income-related, social-support-related and medical care-related barriers. This study aims to evaluate a breast screening intervention program developed according to socioeconomic, cultural, psychological and behavioral characteristics of older single African-American women.METHODS: Ten public housing complexes were randomly assigned to either intervention or control group. African-American women aged 65 and over were recruited into the study if they were widowed, divorced, separated or never-married in the preceding year, and did not have a history of breast cancer (n = 325). Delivered by lay health educators, the intervention program targeted increasing knowledge on breast health and breast screening, reducing emotional or psychological problems, and increasing support from the significant others of study women. Breast screening-related cognition and behavior were measured at pre-intervention and post-intervention.RESULTS: Comparisons of the pre-intervention and post-intervention measurements showed that while the proportion of women who had a clinical breast examination or mammogram in the preceding year was decreased at the post-intervention in the control group, it was increased in the intervention group. However, the differences did not reach a significant level. No consistent patterns could be found in changes of variables in knowledge, attitudes and beliefs. These results remained similar when potential confounding factors were adjusted using mixed model regression analyses.CONCLUSIONS: These results did not suggest significant effects of an intervention program which used lay health educators to promote breast cancer screening in older single African-American women.

Journal Article↗

PubMed2000

Depression-related variables and breast self-examination in single older african-american women.

PURPOSE: Depression-related symptoms, such as despair and loneliness, may prevent women from using preventive screening for diseases. This study aimed to assess if depression-related variables affect the likelihood of implementation of breast self-examination (BSE) in single African-American women aged 65 and older.METHODS: Subjects for this study included 325 African-American women, aged 65 and older, who were widowed, divorced, separated, or never-married, and lived in ten public housing tenements in Nashville, Tennessee. In-person interviews were conducted to collect information on breast screening behavior, knowledge and attitudes, social networks and activities, medical care use and depression. Depression variables included 19 factors, such as feeling guilty, feeling sad or blue, and feeling worthless.RESULTS: Using logistic regression with adjustment for potential confounders, we found that, compared with women who did not perform BSE, those who performed BSE were less likely to have felt guilty in the preceding year (p < 0.05, odds ratio (OR) = 0.3, confidence interval (CI) = 0.13-0.71). However, the other depression-related variables were not associated with BSE. For example, women who performed BSE and those who did not perform BSE reported feeling sad or blue in equal frequencies (OR = 0.93, CI 0.49-1.7).CONCLUSIONS: In general, this study suggests that there is no overall association between depression-related symptoms and breast self-examination in single African-American women aged 65 and older.

Journal Article↗

PubMed2000

Relationships among Bacterial Cell Size, Productivity, and Genetic Diversity in Aquatic Environments using Cell Sorting and Flow Cytometry.

The study of relationships between cell size and productivity is of key importance in microbial ecology to understand which members of natural aquatic communities are responsible for the overall activity and/or productivity. Flow sorting of microorganisms from different environmental samples was used to analyze the activity of bacterial cells depending on their biovolume. Bacterial cells from five different natural samples taken along the Mediterranean coast including fresh- and seawaters were incubated with tritiated leucine, then stained with SYTO 13 and sorted by flow cytometry according to their average side-angle-scattered (SSC) light. In all samples, a bell-shaped relationship was found between cell biovolume and activity, whereas activity of a given cell-size class varied between samples. In contrast, an inverse relationship was found between biovolumes and abundances. These results suggest that medium-sized cells with highest growth rates are probably submitted to intense grazing. For one sample, bacteria within five different size classes were sorted and the genetic diversity of cells within each sorted size class and that of the whole community were analyzed by the denaturing gradient gel electrophoresis (DGGE) method. The genetic diversity, as determined at the community level was highly represented into the pool of small cells, whereas only few species were present into larger cell subpopulations. The results suggest that only a few genotypes may be dominant within the largest and most productive cells. Furthermore, cell size polymorphism as well as heterogeneous cellular activities were found within some species.

Journal Article↗