Standards for clinical trials for treating TB

BACKGROUND: The value, speed of completion and robustness of the evidence generated by TB treatment trials could be improved by implementing standards for best practice.METHODS: A global panel of experts participated in a Delphi process, using a 7-point Likert scale to score and revise draft standards until consensus was reached.RESULTS: Eleven standards were defined: Standard 1, high quality data on TB regimens are essential to inform clinical and programmatic management; Standard 2, the research questions addressed by TB trials should be relevant to affected communities, who should be included in all trial stages; Standard 3, trials should make every effort to be as inclusive as possible; Standard 4, the most efficient trial designs should be considered to improve the evidence base as quickly and cost effectively as possible, without compromising quality; Standard 5, trial governance should be in line with accepted good clinical practice; Standard 6, trials should investigate and report strategies that promote optimal engagement in care; Standard 7, where possible, TB trials should include pharmacokinetic and pharmacodynamic components; Standard 8, outcomes should include frequency of disease recurrence and post-treatment sequelae; Standard 9, TB trials should aim to harmonise key outcomes and data structures across studies; Standard 10, TB trials should include biobanking; Standard 11, treatment trials should invest in capacity strengthening of local trial and TB programme staff.CONCLUSION: These standards should improve the efficiency and effectiveness of evidence generation, as well as the translation of research into policy and practice.

Non-Tuberculous Mycobacterial Cervicofacial Lymphadenitis in Children-10-Year Experience in a Tertiary Pediatric Center

BACKGROUND

Lymphadenitis is the most common manifestation of non-tuberculous mycobacteria (NTM) infection in children. We describe the epidemiology and clinical characteristics of NTM lymphadenitis, determine diagnostic yield from tissue sampling, and review management and outcomes.

METHODS

This was a 10-year retrospective review of children aged 0-16 years diagnosed with NTM cervicofacial lymphadenitis who were seen in a pediatric infectious disease clinic in a tertiary public hospital. Data relating to patient demographics, clinical features, surgical and antimicrobial treatment, complications, and outcomes were retrieved from patients' electronic medical records and analyzed.

RESULTS

There were 48 episodes of NTM cervicofacial lymphadenitis in 45 children (17 males and 28 females). Of these episodes, 43.7% manifested as a unilateral single node, mostly parotid (39.6%) and submandibular (29.2%). All patients underwent diagnostic fine-needle aspiration or surgery. Surgical excision more frequently yielded positive histological findings (P = .016). NTM was identified in 22/48 episodes (45.8%) via culture or molecular sequencing. Mycobacterium abscessus was most commonly found (47.8%). Thirty-eight children (79.2%) received antibiotics. Outcomes in 43 episodes revealed full resolution in 69.8%, while 25.6% had de novo disease and 4.6% experienced recurrence at the same site. Overlying skin changes and multiple or bilateral nodal diseases were significantly associated with de novo disease or recurrence (P = .034 and .084, respectively). Complications occurred in 11/70 (15.7%) procedures. Antibiotic-associated adverse effects occurred in 14/38 (36.8%) episodes.

CONCLUSIONS

NTM lymphadenitis remains a challenging condition. More aggressive management with surgical excision and antibiotics is recommended for those with overlying skin changes and extensive nodal disease.

Whole Genome Sequencing Shows Genetic Diversity, as Well as Clonal Complex and Gene Polymorphisms Associated with Fluconazole Non-Susceptible Isolates of Candida tropicalis

Resistance to azoles in Candida tropicalis is increasing and may be mediated by genetic characteristics. Using whole genome sequencing (WGS), we examined the genetic diversity of 82 bloodstream C. tropicalis isolates from two countries and one ATCC strain in a global context. Multilocus sequence typing (MLST) and single nucleotide polymorphism (SNP)-based phylogenies were generated. Minimum inhibitory concentrations (MIC) for antifungal agents were determined using Sensititre YeastOne YO10. Eleven (13.2%) isolates were fluconazole-resistant and 17 (20.5%) were classified as fluconazole-non susceptible (FNS). Together with four Canadian isolates, the genomes of 12 fluconazole-resistant (18 FNS) and 69 fluconazole-susceptible strains were examined for gene mutations associated with drug resistance. Fluconazole-resistant isolates contained a mean of 56 non-synonymous SNPs per isolate in contrast to 36 SNPs in fluconazole-susceptible isolates (interquartile range [IQR] 46−59 vs. 31−48 respectively; p < 0.001). Ten of 18 FNS isolates contained missense ERG11 mutations (amino acid substitutions S154F, Y132F, Y257H). Two echinocandin-non susceptible isolates had homozygous FKS1 mutations (S30P). MLST identified high genetic diversity with 61 diploid sequence types (DSTs), including 53 new DSTs. All four isolates in DST 773 were fluconazole-resistant within clonal complex 2. WGS showed high genetic variation in invasive C. tropicalis; azole resistance was distributed across different lineages but with DST 773 associated with in vitro fluconazole resistance.

Targeted amplification and MinION nanopore sequencing of key azole and echinocandin resistance determinants of clinically relevant Candida spp. from blood culture bottles

The objective of the study was to evaluate the use of targeted multiplex Nanopore MinION amplicon re-sequencing of key Candida spp. from blood culture bottles to identify azole and echinocandin resistance associated SNPs. Targeted PCR amplification of azole (ERG11 and ERG3) and echinocandin (FKS) resistance-associated loci was performed on positive blood culture media. Sequencing was performed using MinION nanopore device with R9.4.1 Flow Cells. Twenty-eight spiked blood cultures (ATCC strains and clinical isolates) and 12 prospectively collected positive blood cultures with candidaemia were included. Isolate species included Candida albicans, Candida glabrata, Candida krusei, Candida parapsilosis, Candida tropicalis and Candida auris. SNPs that were identified on ERG and FKS genes using Snippy tool and CLC Genomic Workbench were correlated with phenotypic testing by broth microdilution (YeastOne™ Sensititre). Illumina whole-genome-sequencing and Sanger-sequencing were also performed as confirmatory testing of the mutations identified from nanopore sequencing data. There was a perfect agreement of the resistance-associated mutations detected by MinION-nanopore-sequencing compared to phenotypic testing for acquired resistance (16 with azole resistance; 3 with echinocandin resistance), and perfect concordance of the nanopore sequence mutations to Illumina and Sanger data. Mutations with no known association with phenotypic drug resistance and novel mutations were also detected.

Author Correction: The higher prevalence of extended spectrum beta-lactamases among Escherichia coli ST131 in Southeast Asia is driven by expansion of a single, locally prevalent subclone

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Association between minimum inhibitory concentration, beta-lactamase genes and mortality for patients treated with piperacillin/tazobactam or meropenem from the MERINO study

INTRODUCTION

This study aims to assess the association of piperacillin/tazobactam and meropenem minimum inhibitory concentration (MIC) and beta-lactam resistance genes with mortality in the MERINO trial.

METHODS

Blood culture isolates from enrolled patients were tested by broth microdilution and whole genome sequencing at a central laboratory. Multivariate logistic regression was performed to account for confounders. Absolute risk increase for 30-day mortality between treatment groups was calculated for the primary analysis (PA) and the microbiologic assessable (MA) populations.

RESULTS

320 isolates from 379 enrolled patients were available with susceptibility to piperacillin/tazobactam 94% and meropenem 100%. The piperacillin/tazobactam non-susceptible breakpoint (MIC > 16 mg/L) best predicted 30-day mortality after accounting for confounders (odds ratio 14.9, 95% CI 2.8 - 87.2). The absolute risk increase for 30-day mortality for patients treated with piperacillin/tazobactam compared with meropenem was 9% (95% CI 3% - 15%) and 8% (95% CI 2% - 15%) for the original PA population and the post-hoc MA populations, which reduced to 5% (95% CI -1% - 10%) after excluding strains with piperacillin/tazobactam MIC values > 16 mg/L. Isolates co-harboring ESBL and OXA-1 genes were associated with elevated piperacillin/tazobactam MICs and the highest risk increase in 30-mortality of 14% (95% CI 2% - 28%).

CONCLUSION

After excluding non-susceptible strains, the 30-day mortality difference was from the MERINO trial was less pronounced for piperacillin/tazobactam. Poor reliability in susceptibility testing performance for piperacillin/tazobactam and the high prevalence of OXA co-harboring ESBLs suggests meropenem remains the preferred choice for definitive treatment of ceftriaxone non-susceptible E. coli and Klebsiella.

Clinical evaluation of serological IgG antibody response on the Abbott Architect for established SARS-CoV-2 infection

OBJECTIVE

This study aimed to evaluate the diagnostic performance of the Abbott Architect SARS-CoV-2 IgG assay in COVID-19 patients.

METHODS

Residual sera from 177 symptomatic SARS-CoV-2-positive patients and 163 non-COVID-19 patients were tested for antibody with the Abbott SARS-CoV-2 IgG assay (Abbott Diagnostics, Chicago, USA). Clinical records for COVID-19 patients were reviewed to determine the time from onset of clinical illness to testing.

RESULTS

Specificity of the assay was 100.0% (95%CI: 97.1-100.0%). The clinical sensitivity of the assay varied depending on time from onset of symptoms, increasing with longer periods from the onset of clinical illness. The clinical sensitivity at ≤6 days was 8.6% (7/81; 95%CI: 3.8-17.5%), at 7-13 days 43.6% (17/39; 95%CI: 28.2-60.2%), at 14-20 days 84.0% (21/25; 95%CI: 63.1-94.7%), and at ≥21 days 84.4% (27/32; 95%CI: 66.5-94.1%). Clinical sensitivity was higher in the ≥14-day group compared to <14 days. There were no differences between the 14-20-day and ≥21-days groups; the combined clinical sensitivity for these groups (≥14 days) was 84.2% (49/57; 71.6-92.1%).

CONCLUSION

The Abbott SARS-CoV-2 IgG test has high specificity. Clinical sensitivity was limited in the early stages of disease but improved from 14 days after the onset of clinical symptoms.

The higher prevalence of extended spectrum beta-lactamases among Escherichia coli ST131 in Southeast Asia is driven by expansion of a single, locally prevalent subclone

The ST131 multilocus sequence type (MLST) of Escherichia coli is a globally successful pathogen whose dissemination is increasing rates of antibiotic resistance. Numerous global surveys have demonstrated the pervasiveness of this clone; in some regions ST131 accounts for up to 30% of all E. coli isolates. However, many regions are underrepresented in these published surveys, including Africa, South America, and Asia. We collected consecutive bloodstream E. coli isolates from three countries in Southeast Asia; ST131 was the most common MLST type. As in other studies, the C2/H30Rx clade accounted for the majority of ST131 strains. Clinical risk factors were similar to other reported studies. However, we found that nearly all of the C2 strains in this study were closely related, forming what we denote the SEA-C2 clone. The SEA-C2 clone is enriched for strains from Asia, particularly Southeast Asia and Singapore. The SEA-C2 clone accounts for all of the excess resistance and virulence of ST131 relative to non-ST131 E. coli. The SEA-C2 strains appear to be locally circulating and dominant in Southeast Asia, despite the intuition that high international connectivity and travel would enable frequent opportunities for other strains to establish themselves.

Prevalence of Healthcare-Associated Infections and Antimicrobial Use Among Adult Inpatients in Singapore Acute-Care Hospitals: Results From the First National Point Prevalence Survey

Background

We conducted a national point prevalence survey (PPS) to determine the prevalence of healthcare-associated infections (HAIs) and antimicrobial use (AMU) in Singapore acute-care hospitals.

Methods

Trained personnel collected HAI, AMU, and baseline hospital- and patient-level data of adult inpatients from 13 private and public acute-care hospitals between July 2015 and February 2016, using the PPS methodology developed by the European Centre for Disease Prevention and Control. Factors independently associated with HAIs were determined using multivariable regression.

Results

Of the 5415 patients surveyed, there were 646 patients (11.9%; 95% confidence interval [CI], 11.1%-12.8%) with 727 distinct HAIs, of which 331 (45.5%) were culture positive. The most common HAIs were unspecified clinical sepsis (25.5%) and pneumonia (24.8%). Staphylococcus aureus (12.9%) and Pseudomonas aeruginosa (11.5%) were the most common pathogens implicated in HAIs. Carbapenem nonsusceptibility rates were highest in Acinetobacter species (71.9%) and P. aeruginosa (23.6%). Male sex, increasing age, surgery during current hospitalization, and presence of central venous or urinary catheters were independently associated with HAIs. A total of 2762 (51.0%; 95% CI, 49.7%-52.3%) patients were on 3611 systemic antimicrobial agents; 462 (12.8%) were prescribed for surgical prophylaxis and 2997 (83.0%) were prescribed for treatment. Amoxicillin/clavulanate was the most frequently prescribed (24.6%) antimicrobial agent.

Conclusions

This survey suggested a high prevalence of HAIs and AMU in Singapore's acute-care hospitals. While further research is necessary to understand the causes and costs of HAIs and AMU in Singapore, repeated PPSs over the next decade will be useful to gauge progress at controlling HAIs and AMU.

A model for decentralised grey wastewater treatment system in Singapore public housing

Global concerns over the sustainable use of natural resources provided the impetus for research into water reclamation from wastewater within the Singapore context. The objective of the research is to study and develop a water infrastructure system as an integral element of architecture and the urbanscape, thereby reducing the need for the large area requirements associated with centralised treatment plants. The decentralised plants were considered so as to break up the large contiguous plot of land otherwise needed, into smaller integrated fragments, which can be incorporated within the housing scheme. This liberated more usable space on the ground plane of the urban housing master plan, enabling water-edge and waterscape relationships within both the private and public domains of varying scale.

Genetic changes in paired atypical and usual ductal hyperplasia of the breast by comparative genomic hybridization

PURPOSE

Breast cancer is thought to develop from noninvasive precursor lesions, although the earliest steps of neoplastic transformation are still undefined. Usual ductal hyperplasia (UDH) is considered to represent a benign proliferation of ductal epithelial cells, whereas atypical ductal hyperplasia (ADH) may represent the first clonal neoplastic expansion of these cells. The aim of this study was to examine genetic alterations in UDH and ADH and to determine the relationship between these lesions in the same breast biopsy.

EXPERIMENTAL DESIGN

Comparative genomic hybridization analysis was used to define copy number alterations in DNA extracted from archival sections of 18 patients. Nine patients showed ADH with adjacent UDH, and nine showed pure UDH. None showed evidence of invasive cancer or ductal carcinoma in situ.

RESULTS

Five of the nine ADH lesions showed chromosome copy number alterations. 16q loss (five cases) and 17p loss (two cases) were the most frequent changes. The associated UDH lesions in these five patients also showed copy number alterations, always a subset of the changes present in the paired ADH. In one other patient, the UDH showed eight chromosomal alterations, whereas the paired ADH showed no changes. Only one of nine cases with pure UDH showed comparative genomic hybridization abnormalities.

CONCLUSIONS

These data support the likelihood that UDH is a precursor of ADH, at least in some cases representing neoplastic growth. The frequencies of 16q and 17p losses suggest that alterations of candidate genes located in these chromosomal regions may play a role early in breast carcinogenesis.

Chromosomal alterations in ductal carcinomas in situ and their in situ recurrences

BACKGROUND

Ductal carcinoma in situ (DCIS) recurs in the same breast following breast-conserving surgery in 5%-25% of patients, with the rate influenced by the presence or absence of involved surgical margins, tumor size and nuclear grade, and whether or not radiation therapy was performed. A recurrent lesion arising soon after excision of an initial DCIS may reflect residual disease, whereas in situ tumors arising after longer periods are sometimes considered to be second independent events. The purpose of this study was to determine the clonal relationship between initial DCIS lesions and their recurrences.

METHODS

Comparative genomic hybridization (CGH) was used to compare chromosomal alterations in 18 initial DCIS lesions (presenting in the absence of invasive disease) and in their subsequent ipsilateral DCIS recurrences (detected from 16 months to 9.3 years later).

RESULTS

Of the 18 tumor pairs, 17 showed a high concordance in their chromosomal alterations (median = 81%; range = 65%-100%), while one case showed no agreement between the paired samples (having two and 20 alterations, respectively). Morphologic characterization of the DCIS pairs showed clear similarities. The mean number of CGH changes was greater in the recurrent tumors than in the initial lesions (10.7 versus 8.8; P =.019). The most common changes in both the initial and the recurrent in situ lesions were gains involving chromosome 17q and losses involving chromosomes 8p and 17p. The degree of concordance was independent of the time interval before recurrence and of the presence of positive surgical margins.

CONCLUSIONS

In this study, DCIS recurrences were clonally related to their primary lesions in most cases. This finding is consistent with treatment paradigms requiring wide surgical margins and/or postoperative radiation therapy.

Tumor angiogenesis as a prognostic assay for invasive ductal breast carcinoma

BACKGROUND

Tumor angiogenesis, as assayed by microvessel density, has been proposed as an independent prognostic marker for clinical outcome in breast cancer patients.

PURPOSE

The present study evaluated the microvessel density assay and assessed its utility, alone and together with the evaluation of other tumor characteristics, in predicting outcome in patients with invasive ductal carcinomas.

METHODS

In a blinded design, cases of invasive ductal carcinoma were selected from a registry containing the records of and tumor specimens from 386 breast cancer patients treated at the Massachusetts General Hospital from 1977 through 1982. After the exclusion of ineligible patients and inadequate specimens, 220 patients were included in the study; their median time of follow-up was 11.5 years. Half of these patients (n = 110) were positive for axillary lymph node metastases. Histologic sections of the tumors were stained immunocytochemically for factor VIII, a coagulation protein expressed by blood vessel endothelium, and for p53 protein. Independently, two analysts counted microvessels in three microscope fields selected from separate vascular regions of the tumor. Variability in microvessel scores between analysts and among different fields of the same tumor was summarized by the coefficient of variation. The kappa statistic tested for agreement between the analysts while correcting for chance agreement. The effects of tumor characteristics on metastasis-free survival and overall survival were tested univariately by the Harrington-Fleming rank test procedure. The effect of multiple factors on survival was tested under a Cox multivariate proportional hazards model.

RESULTS

Microvessel count showed considerable variability between the two analysts and among regions within each tumor, with an overall concordance for tumor classification of 73%. Univariate analysis revealed no association between microvessel count and any other tumor or patient characteristic. Multivariate analysis indicated, for these patients, that nodal status and p53 staining predicted metastasis-free survival and that nodal status, estrogen receptor (ER) status and tumor grade predicted overall survival.

CONCLUSIONS

Microvessel count showed much variation among different regions of each tumor. It did not predict metastasis-free survival or overall survival. Nodal status was the most powerful criterion to stratify these patients with invasive ductal carcinoma of the breast into different survival groups. Only ER status, tumor grade, and p53 staining had additional prognostic utility for these patients after they had been stratified by nodal status.

Effects of short-term culture on benign and malignant human breast epithelium analyzed by image analysis

The ability to culture malignant breast cells is crucial to the success of many scientific studies. However, short-term cultures of breast cancers are composed predominantly of DNA diploid cells, leading to doubt regarding the presence of bonafide cancer cells in these cultures. Morphology by conventional light microscopy is not helpful since cultured benign cells take on features usually associated with malignancy. In this study we examined by image analysis both benign and malignant breast cancer cells before and after culture. Consistent changes in both benign and malignant cells were found following culturing. There also were consistent differences distinguishing the cultures derived from benign and malignant specimens. While the features used were not sufficiently powerful to identify individual cells or cultures as benign or malignant, our results strongly suggest that malignant breast cells do indeed grow in short-term cultures.

Correlation of Pneumocystis carinii cyst density with mortality in patients with acquired immunodeficiency syndrome and pneumocystis pneumonia

Fifteen percent to 20% of patients with the acquired immunodeficiency syndrome and pneumocystis pneumonia do poorly despite early intervention. It is not known what distinguishes those who die, despite early intervention and aggressive therapy, from those who readily respond to therapy. We used image analysis to determine the relative abundance of cysts within aggregates of Pneumocystis carinii found in induced sputa (21 patients) and bronchoalveolar lavage fluid (14 patients) from 35 patients with pneumocystis pneumonia. We calculated a cyst density (number of cysts per area of aggregate) for each aggregate and a mean cyst density for all of the aggregates on the smear. Six patients died within 2 weeks of diagnosis; four of these six patients who had autopsies all had residual P carinii. The mean cyst density for those who died was 9.7 +/- 3.9 (range, 5 to 15 x 10(-3)). The 29 patients who survived beyond 2 weeks had a mean cyst density of 18.4 +/- 8.7 (range, 5 to 35 x 10(-3); P = .01). Mean cyst density was not influenced by the number of aggregates present in the smear, the variation in cyst density among aggregates in a smear, or the episode of pneumocystis pneumonia. Cyst density determinations alone should not be used to predict outcome for individuals with P carinii pneumonia until further study is completed. Nevertheless, the current study suggests that a low cyst density specimen, which may indirectly indicate a greater proportion of trophozoites compared with a high cyst density specimen, may be associated with an unfavorable outcome in acquired immunodeficiency syndrome-associated pneumocystis pneumonia.

Breast cancer incidence in women with abnormal cytology in nipple aspirates of breast fluid

This is a prospective study of breast cancer risk in relation to nipple aspirate fluid cytology in 2,701 volunteer white women from the San Francisco Bay Area first enrolled between 1973 and 1980. The women were not pregnant or lactating and were free of breast cancer within 6 months of entry into the study. The breast cancer status of this cohort was determined between June 1988 and April 1991. Follow-up was complete for 87% (n = 2,343) of the cohort, representing 29,961 person-years and an average of 12.7 years of follow-up. The overall breast cancer incidence was 4.4% (104 of 2,343) and rose with fluid cytology findings as follows: no fluid obtained, 2.6% (9 of 352); unsatisfactory specimen, 4.8% (15 of 315); normal cytology, 4.3% (56 of 1,291); epithelial hyperplasia, 5.5% (18 of 327); and atypical hyperplasia, 10.3% (6 of 58). Relative risks for breast cancer and their 95% confidence intervals were estimated by Cox regression, adjusting for age and year of entry. Compared with the relative risk for women who yielded no fluid, relative risks were: unsatisfactory specimen, relative risk (RR) = 1.4 (95% confidence interval (CI) 0.6-3.3); normal cytology, RR = 1.8 (95% CI 0.9-3.6); epithelial hyperplasia, RR = 2.5 (95% CI 1.1-5.5); and atypical hyperplasia, RR = 4.9 (95% CI 1.7-13.9). These findings were strongest for and were mainly confined to women aged 25-54 years. Women with atypical hyperplasia and a first-degree family history of breast cancer were six times more likely to develop breast cancer than were women with atypical hyperplasia but without a family history of breast cancer (95% CI 1.0-30.2). These findings provide strong support for our hypothesis that hyperplasia and atypical hyperplasia diagnosed in nipple aspirates of breast fluid are associated with an increased risk of breast cancer.

Proliferation of normal breast epithelial cells as shown by in vivo labeling with bromodeoxyuridine

The proliferative activity of normal acinar and ductal breast epithelial cells was studied by in vivo labeling with 5-bromodeoxyuridine (BrdUrd) in 26 cases with concurrent breast carcinoma. The BrdUrd-labeled cells were recognized in histologic sections of paraffin-embedded tissue, using an anti-BrdUrd antibody and an immunoperoxidase reaction. The percentage of BrdUrd-labeled cells showed great variability for both acinar (0% to 2.66%; mean, 0.70%; standard deviation [SD], 0.80%) and ductal cells (0% to 1.99%; mean, 0.51%; SD, 0.57%). The fraction of proliferating epithelial cells declined with the age of the patients and was significantly higher in premenopausal women (1.16% +/- 0.85% for acinar and 0.94% +/- 0.60% for ductal cells) as compared with the postmenopausal women (0.27% +/- 0.46% for acinar and 0.17% +/- 0.22% for ductal cells), P less than 0.01 for acinar and P less than 0.001 for ductal cells, respectively. In some patients, great variability in distribution of proliferating acinar and ductal cells among different lobules and ducts was observed. No difference was found in the number of proliferating acinar and ductal cells situated near or far from their corresponding tumors. No correlation was seen between cell proliferation of normal acinar or ductal cells and cell proliferation of the respective tumors.

Characterization by image cytometry of duct epithelial proliferative disease of the breast

To develop a morphometric model of premalignant breast epithelium, we evaluated 120 lesions classified as nonproliferative disease (n = 20), hyperplasia (n = 20), moderate hyperplasia (n = 20), atypical hyperplasia (n = 20), carcinoma in situ (n = 20), and carcinoma (n = 20) in tissue from surgical biopsy or mastectomy. Atypical hyperplasia, a component of duct epithelial proliferative disease, has frequently been described in breasts with carcinoma. Atypical hyperplasia is generally viewed as premalignant or as a marker of increased risk for breast cancer. Measurements of nuclei in breast lesions were obtained with the Leitz TAS Plus on 4-microns sections stained for DNA with the Azure A Feulgen reaction. Nuclei of duct epithelial lesions had morphometric features that displayed changes from nonproliferative disease to carcinoma. The morphometric data from each lesion were compared among the six disease groups. Means of nuclear area, perimeter, maximum and minimum diameter, and large dark and large light intranuclear areas increased with higher degrees of proliferative abnormality. When the six groups of lesions were compared using the means of the first four nuclear features, atypical hyperplasia was significantly different (P less than 0.05) from carcinoma and non-proliferative lesions, but not from hyperplasia, moderate hyperplasia, or carcinoma in situ. These findings suggest that objective morphometric descriptors for characterizing significant proliferative lesions can be established using image cytometry. The progressive increases also suggest that proliferative breast disease is a continuum that includes premalignant lesions.

Deoxyribonucleic acid cytometry helps identify parathyroid carcinomas

It may be difficult in some patients with parathyroid tumors to distinguish between parathyroid carcinoma and parathyroid adenoma on the basis of clinical and histopathological findings. Patients initially diagnosed as having a parathyroid adenoma have subsequently occasionally developed metastases, and thereby their tumor was proven to be a carcinoma. To determine whether the nuclear DNA content would correlate with the clinical course and pathology of parathyroid tumors DNA cytometry was performed on parathyroid carcinomas (9 patients), histologically atypical adenomas (10 patients), adenomas associated with severe hypercalcemia [serum calcium, greater than or equal to 13.0 mg/dL (greater than or equal to 3.24 mmol/L); 11 patients], typical benign adenomas (11 patients), and incidentally removed normal parathyroid glands (6 patients). Sections were cut from the original paraffin-embedded surgical specimens and stained for nuclear DNA using the azure A Feulgen reaction. Nuclear DNA stain content was measured using an integrating image cytometer, and the results were plotted as histograms. Adjusted optical density (AOD) values were measured (in arbitrary units) to estimate the DNA content of whole nuclei in the specimens. The mean nuclear DNA content in the parathyroid carcinomas [24.6 +/- 2.1 (+/- SE) AOD] was significantly greater than that in the three groups of parathyroid adenomas (P less than 0.005, by unpaired t test) and in the normal parathyroid glands (P less than 0.0005). The mean nuclear DNA content in the atypical adenomas (15.8 +/- 1.6 AOD), profoundly hypercalcemic adenomas (16.8 +/- 1.3 AOD), and typical adenomas (16.0 +/- 1.1. AOD) were similar, and all were significantly greater than that in the normal parathyroid glands (11.5 +/- 0.7 AOD, P less than 0.05). Five distinct DNA histogram patterns were present in the parathyroid specimens from these 47 patients. Four of the 9 parathyroid carcinomas had an aneuploid DNA pattern, an abnormal pattern not found in any of the other groups; 2 of these tumors were originally diagnosed as atypical parathyroid adenomas. Both patients developed recurrent disease, and 1 died from a hepatic metastasis. Therefore, DNA cytometry provides valuable information in differentiating some parathyroid carcinomas from adenomas and diagnosing certain parathyroid carcinomas before the appearance of grossly invasive or metastatic tumor.

Image cytometric classification of premalignant breast disease in fine needle aspirates

Image cytometry for the classification of fine needle aspirate (FNA) biopsies was evaluated in samples from 39 women. Eighteen of them had benign lesions, seven had premalignant lesions, nine had carcinoma in situ, and five had carcinoma. The term, premalignant, here refers to lesions with an increased risk of developing into breast cancer (atypical hyperplasia and, to a lesser extent, moderate or florid hyperplasia). The classifications by cytometry were compared with the microscopic diagnoses of the same FNA samples and of tissue from a subsequent surgical biopsy of the same area. One slide from each breast FNA sample was restained in Azure-A Feulgen. Breast epithelial cells were measured using a texture analysis program on the Leitz TAS-plus. The mean, standard deviation (SD), and interquartile range were calculated for each of 12 nuclear parameters from 200 cells per slide. A discriminant analysis was used to develop a statistical model for classifying individual samples. Six of seven atypical proliferative lesions (atypical hyperplasia and moderate hyperplasia) were identified by image cytometry, but were unrecognized by conventional microscopic examination.

Nuclear DNA analysis of oral hyperplasia and dysplasia using image cytometry

We investigated the value of image analysis in discriminating among oral white lesions with hyperplasia without dysplasia and oral white or white-and-red lesions with moderate or severe dysplasia. Normal oral epithelial tissue was used as a control. Image analysis was applied to 5-micron formalin-fixed sections stained with the azure A-Feulgen reaction for nuclear DNA. For 150-200 cells from each section, 5 nuclear variables were assessed: area, form factor, total stain, average stain and ellipticity. For each variable, 2 measurements were obtained, the mean and the interquartile range, and were used for stepwise discriminant analysis. Using this test, a model of 3 measurements with the most discriminating power was developed. When the jackknife classification test was applied to this model, we could discriminate with 81% accuracy between the 4 groups of tissue studied.

A simulation approach to understanding the masticatory process

An analysis of the reduction of food particle sizes during human mastication is presented in terms of the probability of a particle being broken (selection function) and the distribution of fragment sizes produced when it fails (breakage function). Both selection and breakage functions are defined and a general equation produced. Several feasible behaviours for these two variables that have been suggested in the literature are modelled by computer simulation and the results are compared to published breakdown patterns. The conclusions are that selection and breakage functions probably behave very simply with respect to particle size, and that these behaviours could be deduced from an analysis of food particle size distributions and the rate at which particle sizes are reduced per chew.

Intra ocular lens implantation: a full circle

Four hundred cases of intra ocular lens implantation of the posterior chamber variety were analysed. Operative and post operative complications were minimal. Testing of visual acuity after surgery produced good results. Visual rehabilitation was readily achieved. The development of the various types of intraocular lens implants is traced and their associated problems discussed. It is concluded that the modern posterior chamber lens provides the most effective mode of treatment. Some contra-indications, however, are emphasized.

Chlamydial endocervical infections and cytologic findings in sexually active female adolescents

The association of infection with Chlamydia trachomatis and cytologic changes on Papanicolaou smear was examined in 148 sexually active postmenarchial++ female subjects, aged 13 to 21 years (mean = 17.2) attending a teen clinic. Endocervical samples for micro-organisms (C. trachomatis and Neisseria gonorrhoeae) and a cervical sample for cytologic examination were taken. A detailed evaluation of the cytologic results was made independently of the C. trachomatis status. In 23 (15.5%) subjects tests for isolation of C. trachomatis were positive. Inflammatory changes in epithelial cells, nuclear changes in metaplastic cells, and lymphocytes in the inflammatory exudate were associated with C. trachomatis isolation but suspected "chlamydial inclusions" and cytoplasmic vacuoles in metaplastic cells were not. The results reported here do not support the use of cervical cytologic examination as a definitive diagnostic test for presence of an endocervical chlamydial infection. However, it may be possible to use the cytologic pattern described here to identify a population with a high prevalence of C. trachomatis.

Analytic studies of foam cells from breast cancer precursors

A preliminary study of foam cells from nipple aspirate fluid demonstrated the ability of image analysis to discriminate categories of breast disease. Foam cell images numbering 471 were collected from nipple aspirate samples representing three to six cases of each of the four following disease categories based on breast tissue diagnosis: benign, nonproliferative; hyperplasia; atypical hyperplasia; and cancer. Twenty-two shape and density parameters were measured for each cell image. Using multivariate analysis, eight nuclear and three cytoplasmic parameters showed significant differences (P less than 0.005) when tested among cell populations from the breast disease categories. Linear stepwise discriminant analysis enabled construction of a three-parameter model that was optimal for distinguishing among cell populations from the four categories of breast disease. The means of all twenty-three parameters were then evaluated on a per-patient basis. A second three-parameter model was constructed that distinguished, with 100% accuracy, patients with proliferative disease from those with nonproliferative disease. Grouping disease categories and comparing patients whose diagnosis was benign or hyperplasia versus atypical hyperplasia or malignant, the model placed patients in the correct group 83% of the time.

Nipple aspirate cytology for the study of breast cancer precursors

The association of abnormal nonmalignant cells in nipple aspirate fluid (NAF) and atypical proliferative disease (APD) of breast ducts was examined in the presence and absence of breast cancer in 134 patients. A high frequency of NAF samples with cellular abnormalities (atypical hyperplasia) was found when APD occurred with either breast cancer (70%) or benign breast biopsy specimens (54%). APD was present in 27 malignant cases (80%) and in 39 benign cases (39%). Inasmuch as APD may represent an intermediate step in the malignant transformation of duct epithelium, the cytologic examination of NAF offers a new approach with which to study the spectrum of breast cancer precursors and to assist in identifying women at risk for breast cancer.