703 Is the Grass Always Greener on the Other Side? – How Do Breast Cancer Patients Feel About Moving to a ‘Green Hub’?

Aim

Between January and September 2020 our base hospital recorded zero COVID-19 incidence in breast surgery patients, in 30 days post-op, with stringent admission protocols including 14 days self-isolation, PCR testing, ‘green’ wards and designated ‘green’ theatres. However, as the UK entered its third lockdown in January 6th2021 the decision was made to move breast cancer surgery off-site to a ‘green hub’ 43 miles away. The aim of this study was to assess the impact this had on patients.

Method

Patients who had surgery moved off-site were requested to anonymously complete a questionnaire which was either posted or handed to them at follow-up. The questionnaire contained 11 Multiple Choice questions and a comments section.

Results

16 of 19 patients (84.21%) responded to the questionnaire. 16 of 16 (100%) understood the reason for the move. 2 (12.5%) stated that it increased anxiety/stress levels while 3 (18.75%) reported the opposite, and the remainder were neutral. 14 (87.5%) said the move made them feel safer, 1 (6.25%) did not feel safer, with the remaining 1 (6.25%) unsure. 15 (93.75%) felt they received enough information at base and 16 (100%) received sufficient discharge information at the ‘green hub’. All 16 (100%) were satisfied with the move off-site but only 15 (93.75%) supported the decision.

Conclusions

The responses indicate that the decision to move breast surgery off-site was supported and well understood. And while for a minority of patients this increased pre-operative anxiety/stress levels, it did make the majority feel safer.

Remission of T2DM by digital twin technology with reduction of cardiovascular risk: interim results of randomised controlled clinical trial

Funding Acknowledgements

Type of funding sources: Private company. Main funding source(s): TWIN HEALTH INC

Background

 Twin Precision Treatment (TPT) is a novel intervention designed to improve glycemia and reverse T2D using a Whole-Body Digital Twin (WBDT) platform powered by Artificial Intelligence and the Internet of Things. Technology enabled precision nutrition, a combination of macro, micro and biota nutrients, along with Continuous Glucose Monitoring (CGM) have been demonstrated to be a key for reversal of diabetes. WBDT platform captures 174 health markers and 3000 daily data points through a panel of blood tests and connected devices that measure weight, physical activity, sleep and BP. CGM is used initially and then the algorithm predicts personalized glucose responses from multiple inputs. Nutritional, physical activity and sleep counseling is through an app or phone to provide individualized meal plans that balance 87 macro, micro and probiotic nutrients to reduce glucotoxicity and lipotoxicity. Program physicians titrate medications and monitor metabolic outcomes. 

Purpose

 To assess the initial change, in glycemic, extra glycemic, cardiovascular parameters for patients who completed 3 months longitudinal follow up.

Methods

 We performed an interim analysis [n = 173, 139 TWIN Intervention arm (T), 34 Control group (C)] of ongoing randomized controlled trial of TPT across India

Results

 The mean age (years) in the T was 43.04 (±8.6, 95% CI 41.57 to 44.52) which was significantly less as compared to the C 51.4 (±9.6, 95% CI 48.3 to 54.5); p < 0.0001. The mean duration of diabetes (years) in the T was 3.5 (±2.6) which was comparable to the C 4.3 (±2.6); p = 0.12 ns. In the T there were 113 male (84.3%) and 21 female (15.6%) as compared to C, 15 male (38.4%) and 24 female (61.5%); p < 0.0001. The difference of change for HbA1c (%), small dense LDL-C sdLDL (mg/dL), TG/HDL Ratio, HOMA 2IR (%), Visceral Adiposity Index (VAI), Systolic BP (mmHg), BMI (kg/m2), Framingham Risk Score (%), in T when compared to C, were significant. The mean reduction HbA1c, sdLDL, HOMA 2IR, VAI, SBP, BMI, FRS in T was -3.2 % (8.8 to 5.6), -14.1 mg/dL, (52.6 to 38.5), -0.9 % (1.9 to 1), -2.3 (4.6 to 2.3), -10.3mmHg (128.4 to 118.1), -2.9 kg/m2 (27.1 to 24.2), -7.9% (16 to 8.1), respectively. (figure) At baseline in T, mean daily intake of medication was 1.7 which reduced significantly (p < 0.0001) to 0.05. 96 patients in T were able to stop anti-diabetic medications

Discussion

 The initial results are an early indicator for the translation of the scientific rationale for the technological intervention, through digital twin technology, powered by Internet of Things and Artificial Intelligence, as a modality to enable reversal of diabetes. TPT appears to have potential to mitigate the cardiovascular risk as assessed by Framingham Risk Score and modulate the non glycemic parameters, including BMI and SBP. However, larger, long-term studies would yield precise insights for the durability of the significant change that has been observed in this study Abstract Figure. Comparison for the Change in the Glycemi

Histological Examination of Tissue Obtained in Early Pregnancy Loss

Background It is a routine practice to send histological sample after surgical evacuation of early pregnancy loss. Objective This study was carried out to see the justification of regular histological study by carrying out the histological study of early pregnancy loss and to find the prevalence of gestational trophoblastic disease in early pregnancy loss. Method It was a descriptive prospective study, conducted in Nepal medical college teaching hospital from February to October 2020 in Obstetrics and Gynaecology department. Clinical data such as age, parity, gestational age and diagnosis were collected of 130 patient of early pregnancy loss. Then histological study were sent after surgical evacuation. Result Among the age group, 21-30 age group was maximum. (64.61%), more than half of the patient was primigravida (53.07%) and most of the cases were between 6 to 9 weeks of gestation. Incomplete abortions were maximum (43.07%), missed abortions 38.46%, blighted abortions 16.15%, enevitable abortions 1.53% and septic abortion was 0.76%. Among histological finding, 72.30% were product of conception, 15.38% of the cases had no product of conception, decidual tissue only in 6.92%, partial mole in one case (0.76%), complete mole in one case (0.76%) and hydrophic changes in one case (0.76%). The total cases of Gestational trophoblastic diseases (GTD) were 3(2.30%). Conclusion In our study we found 2.3% of cases of GTD, which was quite high in compare to Western word. So it is a good practice to do histological study of all cases of EPL in our country to detect GTD, determining cause for recurrent pregnancy loss and detecting unexpected fetal pathology.

Use of a chalazion clamp for intraoral biopsies: a technical note

Oral biopsies are common diagnostic and therapeutic procedures in oral and maxillofacial surgical (OMFS) outpatient departments. The chalazion clamp is similar to a pair of forceps. One extension has a flat, solid, oval plate, the other, a ring-like structure that is used to clamp and retract soft tissues. We highlight the benefits of using this simple, widely-available tool during oral biopsies. We find that the clamp increases effectiveness and efficiency for the clinician and assistant. We recommend its use in daily OMFS practice.

High power single-mode delivery of mid-infrared sources through chalcogenide fiber

Mechanically robust and low loss single-mode arsenic sulfide fibers are used to deliver high power mid-infrared sources. Anti-reflection coatings were deposited on the fiber facets, enabling 90% transmission through 20 cm length fibers. 10.3 W was transmitted through an anti-reflection coated fiber at 2053 nm, and uncoated fibers sustained 12 MW/cm² intensities on the facet without failure. A Cr:ZnSe laser transmitted >1 W at 2520 nm, and a Fe:ZnSe laser transmitted 0.5 W at 4102 nm. These results indicate that by improving the anti-reflection coatings and using a high beam quality mid-infrared source, chalcogenide fibers can reliably deliver ≥10 W in a single mode, potentially out to 6.5 µm.

Mode-selective amplification in a large mode area Yb-doped fiber using a photonic lantern

We demonstrate selective spatial mode amplification in a few mode, double-clad Yb-doped large mode area (LMA) fiber, utilizing an all-fiber photonic lantern. Amplification to multi-watt output power is achieved while preserving high spatial mode selectivity. We observe gain values of over 12 dB for all modes: LP₀₁, LP_11a, and LP_11b, when amplified individually. Additionally, we investigate the simultaneous amplification of LP₀₁+LP_11a and LP_11a+LP_11b, and the resultant mode competition. The proposed architecture allows for the reconfigurable excitation of spatial modes in the LMA fiber amplifiers, and represents a promising method that could enable dynamic spatial mode control in high power fiber lasers.

Outcome of Twin Deliveries at a Tertiary Care Centre of Eastern Nepal

BACKGROUND

Twins, compared to singletons, have higher perinatal mortality and morbidity. The aim of this study was to describe the twinning rate, epidemiological variables and hospital outcome of twin deliveries and to find out ways of better management of twins in our part.

METHODS

A retrospective evaluation of the outcome of 92 twin pregnancies during one year study period (1st January 2014 to 31st December 2014) was conducted at BPKIHS. Twins delivered within the institution were included but cases less than 28 weeks gestation were excluded. Maternal and neonatal data were retrieved and analysed.

RESULTS

The twinning rate was 9.2/1000 (92/10,031). The mean birth weight was 1636.30 ±339.21 grams and mean gestational age 34.31±2.67 weeks(28 - 40 weeks). One hundred eighty-two babies (98.9%) were low birth weight (LBW) while 32.1% were small for gestational age (SGA). There was mild, moderate and severe growth discordance in 63 (68.5%)22 (23.9%)and 7 (7.6%) respectively. Three (3.26%) of 92 pairs had twin-to-twin transfusion syndrome. The hospital mortality rate was 10.87% (20/184) and 69 (37.5%) babies had complications. The clinical causes of death were hyaline membrane disease in 7 (3.3%), severe birth asphyxia in 5 (2.7%), congenital malformations in 3(1.6%) and sepsis in 3 (1.6%) babies.

CONCLUSIONS

Twin deliveries are common in this hospital and have poor hospital outcome with more complications and mortality. Hence there is a need for further studies with long term follow-ups to plan for better management of twins in our part.

Geographic predictors of primary multidrug-resistant tuberculosis cases in an endemic area of Lima, Peru

SETTING

Peru reports among the highest multidrug-resistant tuberculosis (MDR-TB) rates in the Americas, with a growing proportion in previously untreated tuberculosis (TB) cases. The identification of clusters of primary MDR-TB compared with drug-susceptible TB (DS-TB) could help prioritize interventions.

OBJECTIVE

To examine the clustering of primary MDR-TB case residences and their proximity to high-risk locations in San Juan de Lurigancho District, Lima, Peru.

DESIGN

Enrolled primary MDR-TB and primary DS-TB cases were interviewed and their primary residence was recorded using handheld Global Positioning System devices. Kuldorff's spatial scan statistic was used for cluster detection (SaTScan(TM), v. 9.1.1). Identified clusters were visualized in Quantum Geographic Information Systems software (v1.8.0). The following cluster centers were tested: a health centre with the highest TB and MDR-TB rates (Clinic X), a hospital and two prisons. Using regression analyses, we examined predictors of primary MDR-TB cases.

RESULTS

A statistically significant cluster of primary MDR-TB cases was identified within a 2.29 km radius around Clinic X. Proximity to Clinic X remained a significant predictor of primary MDR-TB in adjusted regression analyses.

CONCLUSION

We identified a hotspot of primary MDR-TB cases around Clinic X in a TB-endemic area. Causes of this clustering require investigation; targeted interventions for this high-risk area should be considered.

Rhabdomyolysis Due to Severe Hypophosphatemia in Diabetic Ketoacidosis

Rhabdomyolysis is a syndrome characterized by injury to skeletal muscle fibers with disruption and release of toxic metabolites into circulation. It is characterized by triad of muscle weakness, myalgia and dark urine and is associated with increased creatine kinase and lactate dehydrogenase. A severely malnourished 10 year old girl with severe diabetic ketoacidosis as hemr initial presentation of type 1 diabetes mellitus developed rhabdomyolysis (CK- 12,000 U/L) with non-oliguric renal failure during her initial course of hospital stay. The possible cause of her RM was attributed to severe hypophosphatemia (minimum serum phosphate, 0.8 mg/dL). Management of diabetic ketoacidosis phosphate supplementation and urinary alkalinization with diuresis improved her clinical course. She was discharged on Day 9 with Insulin. We recommend frequent monitoring of serum phosphate during early period of DKA, particularly in malnourished children, and its normalization in case of severe hypophosphatemia.

Donor surfactant protein D (SP-D) polymorphisms are associated with lung transplant outcome

Chronic lung allograft dysfunction (CLAD) is the major factor limiting long-term success of lung transplantation. Polymorphisms of surfactant protein D (SP-D), an important molecule within lung innate immunity, have been associated with various lung diseases. We investigated the association between donor lung SP-D polymorphisms and posttransplant CLAD and survival in 191 lung transplant recipients consecutively transplanted. Recipients were prospectively followed with routine pulmonary function tests. Donor DNA was assayed by pyrosequencing for SP-D polymorphisms of two single-nucleotide variations altering amino acids in the mature protein N-terminal domain codon 11 (Met(11) Thr), and in codon 160 (Ala(160) Thr) of the C-terminal domain. CLAD was diagnosed in 88/191 patients, and 60/191 patients have died. Recipients of allografts that expressed the homozygous Met(11) Met variant of aa11 had significantly greater freedom from CLAD development and better survival compared to those with the homozygous Thr(11) Th variant of aa11. No significant association was noted for SP-D variants of aa160. Lung allografts with the SP-D polymorphic variant Thr(11) Th of aa11 are associated with development of CLAD and reduced survival. The observed genetic differences of the donor lung, potentially with their effects on innate immunity, may influence the clinical outcomes after lung transplantation.

Characterizing viral subtypes to assess patterns of HIV transmission

We characterized HIV-1 subtypes among 204 persons newly diagnosed with HIV in Ontario from 2003 to 2005 using samples from the Canadian HIV Strain and Drug Resistance Surveillance Program. We examined HIV-1 subtype by demographic characteristics and exposure category, and determined independent predictors of infection with a non-B HIV subtype using multivariate logistic regression. The distribution of HIV subtypes was: B 77.0%, C 10.3%, AG 4.9%, A 2.5%, AE 2.5% and others 3.0%. Overall, 23.0% were non-B, greater in women than in men (62.8% versus 12.4%, P < 0.0001) and persons under 35 years (31.1% versus 18.5% in those ≥35, P = 0.04). Non-B subtype was predominant (78.9%) among persons from HIV-endemic regions and considerable (28.6%) among other persons infected heterosexually. In multivariate modelling adjusted for gender, non-B subtype was significantly associated with birth in an HIV-endemic region (adjusted odds ratio [aOR] 59.2, P < 0.0001) and heterosexual exposure (aOR 6.3, P = 0.02). Additionally, compared with men who had sex with men, non-B subtype was greater among heterosexual women (aOR 17.8, P < 0.001) and women who injected drugs (injection drug use, aOR 13.4, P = 0.01). We found a non-negligible proportion of non-B subtypes among women infected heterosexually not from HIV-endemic countries, providing interesting insights into HIV transmission patterns.

Dopamine agonist therapy in early Parkinson's disease

BACKGROUND

Dopamine agonists are being used increasingly as first line treatment for Parkinson's disease, but there remains uncertainty about their clinical and cost-effectiveness relative to levodopa.

OBJECTIVES

This meta-analysis aims to quantify more reliably the benefits and risks of dopamine agonists compared to placebo or levodopa in early Parkinson's disease.

SEARCH STRATEGY

We searched CENTRAL (The Cochrane Library), MEDLINE, EMBASE, PubMed, LILACS and Web of Science, plus major journals in the field, abstract books, conference proceedings and reference lists of retrieved publications.

SELECTION CRITERIA

Randomised trials comparing an orally administered dopamine agonist (with or without levodopa) versus placebo or levodopa or both placebo and levodopa in participants with early Parkinson's disease.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted data on clinician-rated disability, motor complications, other side-effects, treatment concordance, levodopa dose and mortality.

MAIN RESULTS

Twenty-nine eligible trials, involving 5247 participants, were identified. Participants randomised to a dopamine agonist were less likely to develop dyskinesia (odds ratio (OR) 0.51, 95% confidence interval (CI) 0.43 to 0.59; P < 0.00001), dystonia (OR 0.64, 95% CI 0.51 to 0.81; P = 0.0002) and motor fluctuations (OR 0.75, 95% CI 0.63 to 0.90; P = 0.002) than levodopa-treated participants. However, various 'non-motor' side-effects, including oedema (OR 3.68, 95% CI 2.62 to 5.18; P < 0.00001), somnolence (OR 1.49, 95% CI 1.12 to 2.00; P = 0.007), constipation (OR 1.59, 95% CI 1.11 to 2.28; P = 0.01), dizziness (OR 1.45, 95% CI 1.09 to 1.92; P = 0.01), hallucinations (OR 1.69, 95% CI 1.13 to 2.52; P = 0.01) and nausea (OR 1.32, 95% CI 1.05 to 1.66; P = 0.02) were all increased in agonist-treated participants (compared with levodopa-treated participants). Agonist-treated participants were also significantly more likely to discontinue treatment due to adverse events (OR 2.49, 95% CI 2.08 to 2.98; P < 0.00001). Finally symptomatic control of Parkinson's disease was better with levodopa than with agonists, but data were reported too inconsistently and incompletely to meta-analyse.

AUTHORS' CONCLUSIONS

This meta-analysis confirms that motor complications are reduced with dopamine agonists compared to levodopa, but also establishes that other important side-effects are increased and symptom control is poorer with agonists. Larger, long-term comparative trials assessing patient-rated quality of life are needed to assess more reliably the balance of benefits and risks of dopamine agonists compared to levodopa.

Dopamine agonist therapy in early Parkinson's disease

BACKGROUND

Dopamine agonists are being used increasingly as first line treatment for Parkinson's disease, but there remains uncertainty about their clinical and cost-effectiveness relative to levodopa.

OBJECTIVES

This meta-analysis aims to quantify more reliably the benefits and risks of dopamine agonists compared to placebo or levodopa in early Parkinson's disease.

SEARCH STRATEGY

We searched CENTRAL (The Cochrane Library), MEDLINE, EMBASE, PubMed, LILACS and Web of Science, plus major journals in the field, abstract books, conference proceedings and reference lists of retrieved publications.

SELECTION CRITERIA

Randomised trials comparing an orally administered dopamine agonist (with or without levodopa) versus placebo or levodopa or both placebo and levodopa in participants with early Parkinson's disease.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted data on clinician-rated disability, motor complications, other side-effects, treatment concordance, levodopa dose and mortality.

MAIN RESULTS

Twenty-nine eligible trials, involving 5247 participants, were identified. Participants randomised to a dopamine agonist were less likely to develop dyskinesia (odds ratio (OR) 0.51, 95% confidence interval (CI) 0.43 to 0.59; P < 0.00001), dystonia (OR 0.64, 95% CI 0.51 to 0.81; P = 0.0002) and motor fluctuations (OR 0.75, 95% CI 0.63 to 0.90; P = 0.002) than levodopa-treated participants. However, various 'non-motor' side-effects, including oedema (OR 3.68, 95% CI 2.62 to 5.18; P < 0.00001), somnolence (OR 1.49, 95% CI 1.12 to 2.00; P = 0.007), constipation (OR 1.59, 95% CI 1.11 to 2.28; P = 0.01), dizziness (OR 1.45, 95% CI 1.09 to 1.92; P = 0.01), hallucinations (OR 1.69, 95% CI 1.13 to 2.52; P = 0.01) and nausea (OR 1.32, 95% CI 1.05 to 1.66; P = 0.02) were all increased in agonist-treated participants (compared with levodopa-treated participants). Agonist-treated participants were also significantly more likely to discontinue treatment due to adverse events (OR 2.49, 95% CI 2.08 to 2.98; P < 0.00001). Finally symptomatic control of Parkinson's disease was better with levodopa than with agonists, but data were reported too inconsistently and incompletely to meta-analyse.

AUTHORS' CONCLUSIONS

This meta-analysis confirms that motor complications are reduced with dopamine agonists compared to levodopa, but also establishes that other important side-effects are increased and symptom control is poorer with agonists. Larger, long-term comparative trials assessing patient-rated quality of life are needed to assess more reliably the balance of benefits and risks of dopamine agonists compared to levodopa.

Marie Stopes Society, Pakistan: 1000 cases of quinacrine sterilization (QS)

OBJECTIVES

To evaluate the safety, efficacy and acceptability of QS in Karachi, Pakistan.

METHODS

1000 women who had chosen sterilization during the 4-year period 1994 to 1997 inclusive were offered QS at both stationary clinics and in a mobile van at 23 sites in the outskirts of Karachi. The protocol involved transcervical insertion to the uterine fundus of 252 mg quinacrine in 7 pellets and 55 mg of ibuprofen in 3 pellets through an IUD inserter, during the proliferative phase of the menstrual cycle. Two doses were administered one month apart. A temporary method of contraception was provided for 3 cycles, usually DMPA. Follow-up was scheduled: monthly for 3 months, quarterly for 1 year and then every 6 months for 4 years.

RESULTS

The crude pregnancy rate after 4 years was 2.0%. Minor complications and complaints were reported by 59% of the patients. There was one ectopic pregnancy and no major complications.

CONCLUSIONS

QS was found to be safe and effective and has become the most popular method of sterilization in our area of Pakistan.

Long acting beta-agonists versus theophylline for maintenance treatment of asthma

BACKGROUND

Theophylline and long acting beta-2 agonists are bronchodilators used for the management of persistent asthma symptoms, especially nocturnal asthma. They represent different classes of drug with differing side-effect profiles.

OBJECTIVES

To assess the comparative efficacy, safety and side-effects of long-acting beta-2 agonists and theophylline in the maintenance treatment of asthma.

SEARCH STRATEGY

Randomised, controlled trials (RCTs) were identified using the Cochrane Airways Group register. The register was searched using the following terms: asthma and theophylline and long acting beta-agonist or formoterol or foradile or eformoterol or salmeterol or bambuterol or bitolterol. Date of last search was April 2003. Titles and abstracts were then screened to identify potentially relevant studies. The bibliography of each RCT was searched for additional RCTs. Authors of identified RCTs were contacted for other relevant published and unpublished studies.

SELECTION CRITERIA

All included studies were RCTs involving adults and children with clinical evidence of asthma. These studies must have compared oral sustained release and/or dose adjusted theophylline with an inhaled long-acting beta-2 agonist.

DATA COLLECTION AND ANALYSIS

Potentially relevant trials, identified by screening titles and/or abstracts, were obtained. Two reviewers independently assessed full text versions of these trials to decide whether the trial should be included in the review, and assessed its methodological quality. Where there was disagreement between reviewers, this was resolved by consensus, or reference to a third party. Data were extracted by two independent reviewers. Inter-rater reliability was assessed by simple agreement. Study authors were contacted to clarify randomisation methods, provide missing data, verify the data extracted and identify unpublished studies. Relevant pharmaceutical manufacturers were also contacted.

MAIN RESULTS

Six trials originally met the inclusion criteria. Five used salmeterol and one, bitolterol. In an updated version of the review, six more trials were included. Four trials used salmeterol and two used formoterol. They were of varying quality. Salmeterol improved FEV1 significantly more than theophylline in five studies and salmeterol use was associated with significantly more symptom free nights in all the studies comparing these agents. Formoterol, used in two studies was reported to be as effective as theophylline. Bitolterol, used in only one study, was reported to be less effective than theophylline. Subjects taking salmeterol experienced fewer adverse events than those using theophylline (Parallel studies: Relative Risk 0.44; 95% CI: 0.30 to 0.63), Risk Difference -0.11 (95%CI: -0.16 to -0.07), NNT 9 (6, 14). Significant reductions were reported for central nervous system adverse events (Relative Risk 0.50; 95%Confidence Intervals 0.29, 0.86), Risk Difference -0.07(95% CI -0.12, -0.02), NNT 14(8, 50) and gastrointestinal adverse events (Relative Risk 0.30; 95%Confidence Intervals 0.17, 0.55), Risk Difference -0.11(-0.16, -0.06), NNT 9(6, 16).

REVIEWER'S CONCLUSIONS

Long-acting beta-2 agonists are at least as effective than theophylline in reducing asthma symptoms including night waking and improving lung function. Fewer adverse events occurred in subjects using long-acting beta-2 agonists(salmeterol and formoterol) as compared to theophylline.

Comparison of analytical methods for quantitation of isolated porcine hepatocyte yields

As cell-based therapies receive approval for clinical evaluation and use, the development of reliable methods to quantify cell number and control the dose of therapy delivered is becoming increasingly important. An example is the determination of the number and volume of primary porcine hepatocytes used in an extracorporeal treatment for patients with liver disease. Conventional cell counting using optical microscopy was compared against two alternate methods to quantify isolated porcine hepatocytes: (1) automated cell counting using a commercially available particle characterization instrument, and (2) quantitation by cell mass. Methods were compared based on accuracy, precision, specificity, linear range, and ruggedness. The automated method delivered substantially improved accuracy, precision, and ruggedness when compared to the conventional optical method. It also provided valuable information about the size distribution of cell preparations, which often contained clumps of cells, and showed that processing steps such as cryopreservation can alter the size characteristics of a cell population. The automated method was also faster, and was well suited to use in a commercial manufacturing process. The mass-based method was simple and inexpensive, but suffered from nonlinearity at low cell concentrations. Automated cell quantitation using a commercially available particle characterization instrument proved to be the preferred method for obtaining accurate and consistent porcine hepatocyte counts in a timely manner.