Are clinicians failing to supply adequate information when requesting a histopathological investigation?

AIMS

There is a perception among histopathologists that specimens are often received without adequate clinical details. This is the first study to determine the adequacy of information provided when histopathological investigations are requested.

METHODS

Two thousand sequential requests for histological examination were assessed for adequacy and completeness.

RESULTS

There was no significant difference in the demographic details supplied by physicians and surgeons. Clinical details were inadequate in 6.1% of cases: those from physicians were significantly more often adequate (98.7% v 90.6%) and more often included a diagnosis (74.4% v 38.8%) than those from surgeons. Physicians were more likely to supply their name and contact number but requests frequently lacked details of the sender.

CONCLUSIONS

Specimens are infrequently received with inadequate demographic details, but clinical details and details of the sender are more often lacking. Education of clinical colleagues is required if pathologists are to manage the demand for the service.

Aminolevulinic acid-induced photodynamic therapy: safe and effective ablation of dysplasia in Barrett's esophagus

Photodynamic therapy (PDT) is a treatment in which cell damage is achieved by the action of light on a photosensitizer. The aim of this study was to assess the value of PDT in the treatment of Barrett's esophagus with low-grade dysplasia (LGD). Forty patients with dysplastic Barrett's esophagus were given aminolevulinic acid (ALA) 30 mg/kg orally followed 4 h later by laser endoscopy. Follow-up endoscopy and biopsies were performed at 1, 6 and 12 months. A macroscopic response was seen in 33 out of 40 patients, with a median decrease in columnar epithelial area of 30% (range 0-90%). Post-treatment biopsies showed no dysplasia in 39 out of 40 patients, with LGD remaining in one case. This was maintained at 6 and 12 months. There were no significant side-effects. This study demonstrates that ALA-induced PDT provides safe and effective ablation therapy for Barrett's esophagus and is particularly useful against dysplasia.

The long term ophthalmic morbidity of low birth weight children: a review

Low birth weight infants are at greater risk of ophthalmic morbidity compared to children born at term. There are numerous studies detailing the outcome of low birth weight infants and the purpose of this paper is to discuss and summarize these studies, focusing on the long term effects on visual function and the prevalence of strabismus. The variation in study design will be discussed with regard to the subsequent effect on results. Despite the significant variation between studies, they all report an increase in the prevalence of strabismus and reduced visual acuity. This increase in ophthalmic morbidity is due in part to retinopathy of prematurity (ROP), but not all ophthalmic morbidity can be attributed to ROP.

Maternal nutrition alters the expression of insulin-like growth factors in fetal sheep liver and skeletal muscle

We investigated the influence of maternal dietary restriction between days 28 and 80 of gestation followed by re-feeding to the intake of well-fed ewes up to 140 days of gestation (term is 147 days) in sheep, on expression of mRNA for insulin-like growth factor (IGF)-I, IGF-II and growth hormone receptor (GHR) in fetal liver and skeletal muscle. Singleton bearing ewes either consumed 3.2-3.8 MJ/day of metabolisable energy (ME) (i.e. nutrient restricted - approximately 60% of ME requirements, taking into account requirements for both ewe maintenance and growth of the conceptus) or 8.7-9.9 MJ/day (i.e. well fed - approximately 150% of ME requirements) between days 28 and 80 of gestation. All ewes were then well fed (150% of ME requirements) up to day 140 of gestation and consumed 8-10.9 MJ/day. At days 80 and 140 of gestation, five ewes were sampled from each group and fetal tissues taken. There was no difference in fetal body weight or liver weights between groups at either sampling date, or skeletal muscle (quadriceps) weight at 140 days. IGF-I mRNA abundance was lower in livers of nutrient-restricted fetuses at day 80 of gestation (nutrient restricted 2.35; well fed 3.70 arbitrary units), but was higher than well-fed fetuses at day 140 of gestation, after 60 days of re-feeding (restricted/re-fed 4.27; well fed 2.83;s.e.d. 0.98 arbitrary units, P=0.061 for dietxage interaction). IGF-II mRNA abundance was consistently higher in livers of nutrient-restricted fetuses (80 days: nutrient restricted 7.78; well fed 5.91; 140 days: restricted/re-fed 7.23; well fed 6.01;s.e.d. 1.09 arbitrary units, P=0.061 for diet). Nutrient restriction had no effect on hepatic GHR mRNA abundance, but re-feeding of previously nutrient-restricted fetuses increased GHR mRNA compared with continuously well-fed fetuses (80 days: nutrient restricted 70.6; well fed 75.1; 140 days: restricted/re-fed 115.7; well fed 89.4;s.e.d. 10.13 arbitrary units, P=0.047 for dietxage interaction). In fetal skeletal muscle, IGF-I mRNA abundance was not influenced by maternal nutrition and decreased with gestation age (P<0.01). IGF-II mRNA abundance was higher in skeletal muscle of nutrient-restricted fetuses compared with well-fed fetuses at day 80 of gestation (nutrient restricted 16.72; well fed 10.53 arbitrary units), but was lower than well-fed fetuses after 60 days of re-feeding (restricted/re-fed 7.77; well fed 13.72;s.e.d. 1.98 arbitrary units, P<0.001 for dietxage interaction). There was no effect of maternal nutrition or gestation age on fetal skeletal muscle GHR expression. In conclusion, maternal nutrient restriction in early to mid gestation with re-feeding thereafter results in alterations in hepatic and skeletal muscle expression of IGF-I, IGF-II and/or GHR in the fetus which may subsequently relate to altered organ and tissue function.

Validation of a decision support system for the cytodiagnosis of fine needle aspirates of the breast using a prospectively collected dataset from multiple observers in a working clinical environment

We have used a 692 case dataset, collected retrospectively by a single observer, to develop decision support systems for the cytodiagnosis of fine needle aspirates of breast lesions. In this study, we use a 322 case dataset that was prospectively collected by multiple observers in a working clinical environment to test two predictive systems, using logistic regression and the multilayer perceptron (MLP) type of neural network. Ten observed features and the patient age were used as input features. The systems were developed using a training set and test set from the single observer dataset and then applied to the multiple observer dataset. For the independent test cases from the single observer dataset, with a threshold set for no false positives on the training set, logistic regression produced a sensitivity of 82% (95% confidence interval 73-91) and a predictive value of a positive result (PV +) of 98% (95-99), the values for the MLP were 79% (69-89) and 100%, respectively. However the performance on the prospective multiple observer dataset was much worse, with a sensitivity of 72% (65-80), and PV + of 97% (94-99) for logistic regression and 67% (60-75) and 91% (85-97) for the MLP. These results suggest that there is considerable interobserver variability for the defined features and that this system is unsuitable for further development in the clinical environment unless this problem can be overcome.

Photodynamic therapy for dysplastic Barrett's oesophagus: a prospective, double blind, randomised, placebo controlled trial

BACKGROUND AND AIMS

Photodynamic therapy (PDT) is a treatment in which cell damage is achieved by the action of light on a photosensitizing agent. We have assessed the potential use of PDT in the ablation of Barrett's oesophagus.

METHODS

Thirty six patients with dysplastic Barrett's oesophagus receiving acid suppression medication with omeprazole were randomised to receive oral 5-aminolaevulinic acid (ALA) 30 mg/kg or placebo, followed four hours later by laser endoscopy. Follow up endoscopy was performed at one, six, 12, and 24 months.

RESULTS

Of 18 patients in the ALA group, a response was seen in 16 (median decrease in area in the treated region 30%; range 0-60%). In the placebo group, a decrease in area of 10% was observed in two patients with no change in 16 (median 0%; range 0-10%; treatment v placebo, p<0.001). No dysplasia was seen in the columnar epithelium within the treatment area of any patient in the PDT group. However, in the placebo group, persistent low grade dysplasia was found in 12 patients (p<0.001). There were no short or long term major side effects. The effects of treatment were maintained for up to 24 months.

CONCLUSIONS

This is the first randomised controlled trial of PDT for Barrett's oesophagus. It demonstrates that ALA induced PDT can provide safe and effective ablation of low grade dysplastic epithelium.

What levels of agreement can be expected between histopathologists assigning cases to discrete nominal categories? A study of the diagnosis of hyperplastic and adenomatous colorectal polyps

AIMS

To assess the levels of agreement between histopathologists for a two-class nominal categorization process--the discrimination between hyperplastic and adenomatous colorectal polyps.

METHODS

Fifty hyperplastic and 50 adenomatous polyps received consecutively in the laboratory were categorized by nine histopathologists, and the level of agreement between all observers and the original diagnosis was assessed using kappa statistics.

RESULTS

For the eight observers with 11 months or more experience in histopathology, there was a high level of agreement with kappa statistics ranging from 0.84 to 0.98. This process was performed rapidly with an average of 13 to 22 seconds spent on each case. One observer with only 6-weeks' experience of histopathology had a lower overall level of agreement with kappa statistics ranging from 0.46 to 0.54, but the performance on the later cases was much higher.

CONCLUSIONS

The level of agreement in the distinction between hyperplastic and adenomatous colorectal polyps is high among histopathologists with at least moderate amounts of experience in histopathology. The one virtually naïve observer showed a marked learning response during the study without feedback on case outcome. This suggests that histopathologists are very reliable in assigning cases to distinct nominal categories and that learning of these processes occurs early in a histopathologist's career.

Assessing the conditions for in vivo electrical virtual biopsies in Barrett's oesophagus

It has previously been shown that it is possible to differentiate between squamous and columnar epithelia in rat and resected human tissues using an impedance probe to make in vitro measurements. This probe can be passed down an endoscope allowing measurements to be made in patients. However, the probe emerges parallel to the oesophageal wall, with little room to manoeuvre. The conditions of control required to give reliable readings have been investigated. The importance of pressure applied and the angle of approach to the oesophagus was assessed. Pressures in the range 26.6 Pa to 46.3 kPa and angles in the range 15-90 degrees were considered. In in vitro studies it was observed that it was possible to obtain consistent readings with pressures greater than 2.9 kPa and with angles greater than 15 degrees between the probe and the oesophagus. These conditions can be achieved in vivo, and readings obtained from twelve patients are shown (45 readings on normal squamous, 34 on Barrett's oesophagus and 22 on stomach). At low frequencies (9.6-153.2 kHz), a Mann-Whitney test shows a significant difference (p < 0.001) when comparing the means from squamous and columnar, and also when readings from Barrett's and normal gastric epithelia are compared (p < 0.001).

Proteolysis in human breast cancer

BACKGROUND

The process of proteolysis is important at several stages of the metastatic cascade. A balance between the expression of the genes encoding endogenous proteinases and inhibitors exists and when the production of proteinases exceeds that of inhibitors proteolysis occurs.

AIMS

To determine whether differences in the profile and activity of proteinases and inhibitors exist within breast tumour tissue (n = 51), surrounding background breast tissue (n = 43), normal breast tissue from breast reduction mammoplasty operations (n = 10), and cells of the breast cancer cell line, MCF-7.

METHODS

Proteinase (matrix metalloproteinase 1 (MMP-1), MMP-2, MMP-3, MMP-9, urokinase-type plasminogen activator (uPA), and tissue-type PA (tPA)) and inhibitor (tissue inhibitor of metalloproteinases; TIMP-1 and TIMP-2) expression and proteinase activity were compared using substrate zymography, western blotting, immunohistochemistry, and quenched fluorescent substrate hydrolysis.

RESULTS

The presence of all proteinases and inhibitors was greater in breast tumour tissue when compared with all other types of breast tissue (p < 0.05). The activity of total MMPs as determined by quenched fluorescent substrate hydrolysis was also greater in breast tumours (p < 0.05).

CONCLUSIONS

There is increased proteolysis in human breast tumours when compared with other breast tissues.

Differences in hair follicle dermal papilla volume are due to extracellular matrix volume and cell number: implications for the control of hair follicle size and androgen responses

The size of a hair follicle is thought to be determined by the volume of its dermal papilla. The volume of the dermal papilla depends on the number of cells it contains and on the volume of the extracellular matrix. To establish which of these two variables is related to differences in hair follicle size we performed a stereologic study on 235 hair follicles from different sites, including male facial skin (beard), female facial skin, and scalp. In facial follicles there was a strong correlation between the area of the hair cortex and the volume of the dermal papilla. The area of the hair cortex also correlated with the number of cells in the dermal papilla and with the volume of dermal papilla per cell. In scalp hair follicles, where there was a smaller range of sizes, the correlations between these variables were weaker. In large male facial follicles the mean total dermal papilla volume was almost 40-fold higher than in vellus follicles from female facial skin. This difference was associated with a mean 17-fold greater number of cells in the dermal papilla and a 2.4-fold greater volume associated with each cell. Intermediate results were obtained in scalp follicles. In many regions of the skin hair follicles enlarge in response to androgens during adult life hair. Our results imply that the increase in the volume of the dermal papilla in these follicles is due to an increase in the number of cells, either through proliferation or through the migration of cells from the follicular dermal sheath, and to an increase in the amount of extracellular matrix per cell. As androgens are thought to act primarily on the dermal papilla, these changes may have a direct bearing on the mechanism of androgen-mediated alterations in hair follicle size.

Ablation treatment for Barrett oesophagus: what depth of tissue destruction is needed?

AIM

To establish the depth of Barrett's columnar epithelium and normal squamous oesophageal epithelium, in order to determine the depth of destruction required in ablation treatment for Barrett oesophagus.

METHODS

Histological specimens from 100 cases of Barrett oesophagus and 100 samples of normal squamous oesophageal epithelium were studied. Using a system of multiple measurements until the change in cumulative mean values varied by less than 5%, the overall mean and normal range of depth was calculated for each type of epithelium.

RESULTS

Barrett columnar epithelium is minimally thicker (mean (SEM) 0.50 (0.004) mm; range 0.39 to 0.59 mm) than normal squamous epithelium (0.49 (0.003) mm; 0.42 to 0.58 mm), although this difference is probably too small to be of clinical relevance.

CONCLUSIONS

Although there are numerous clinical reports of various methods of ablation treatment for Barrett oesophagus, little attention has been paid to the depth of tissue destruction required. This is the first study to look specifically at this issue, and it provides information on the necessary depth of epithelial ablation.

A simple method for PCR based analyses of immunohistochemically stained, microdissected, formalin fixed, paraffin wax embedded material

Microdissection was performed on sections cut from formalin fixed, paraffin wax embedded archival material, which had been subjected to conventional immunohistochemistry. Crude DNA extracts, which were obtained from these microdissected samples by a simple microwave step, were then added directly to amplification reactions. Analyses using a range of polymerase chain reaction (PCR) based techniques, including microsatellite repeat polymorphism analysis at the NM23-H1 locus and sequencing of exons 5, 7, and 8 of the p53 gene, were performed successfully. Universal PCR amplification was also carried out on the microdissected material and probes suitable for use in comparative genomic hybridisation (CGH) were obtained in all cases. This technique will enable a range of effective genetic analyses to be carried out on specific subsets of cells that have been characterised previously by immunohistochemistry.

The influence of maternal nutrient restriction in early to mid-pregnancy on placental and fetal development in sheep

Placental weight is a primary factor determining size at birth in many species. In sheep, placental weight peaks at approximately mid-gestation, with structural remodelling occurring over the second half of pregnancy to meet the increasing nutritional demands of the growing fetus. Numerous factors influence placental growth and development in sheep, and many workers (see Kelly, 1992) have investigated the role of maternal nutrition as a regulator of placental and fetal size. We have studied the effects of feeding ewes approximately 50% of their recommended energy requirements during early to mid-pregnancy on fetal and placental indices measured at mid-gestation (i.e. 80 d) and close to term (i.e. 145 d). Maternal nutrient restriction is associated with a reduction in placental weight at 80 d, but an increase in placental weight at 145 d of gestation, compared with ewes fed adequately in early pregnancy. No significant effect on fetal weight was observed at either 80 or 145 d gestation, although differences in body dimensions and the insulin-like growth factor-1 axis were found in lambs from nutrient-restricted ewes delivered close to term. Maternal nutrition during pregnancy plays a pivotal role in the regulation of fetal and placental development in sheep, and therefore has the potential to influence both short- and longer-term health outcomes.

Virtual biopsies in Barrett's esophagus using an impedance probe

Preliminary results of electrical impedance measurements in squamous and columnar epithelia in rat and human tissues are presented. The aim of this work is to show the possibility of differentiating these two types of epithelia in terms of their electrical characteristics. For the measurements, we employed a 1.95-m-long, 3.2-mm-diameter, four-electrode probe designed to be used transendoscopically in the diagnosis of Barrett's esophagus (BE). BE is a condition in which the normal squamous epithelium of the esophagus is replaced by columnar epithelium of the intestinal type. This metaplasia is considered as a premalignant condition that puts patients at a 30-125-fold risk of developing adenocarcinoma of the esophagus. The diagnosis and surveillance of BE involve taking multiple biopsies, an expensive and time-consuming procedure. This study constitutes the first stage in the replacement of tissue biopsy by "virtual biopsies".

Audit of neonatal intensive care transport--closing the loop

To audit the effectiveness of changes in transport arrangements, data on babies ventilated during transfer into a neonatal unit were compared between two periods. During the first period, August 1991-February 1993, an ad hoc transport team operated. Transport practice was changed in 1993 by forming a nine-person nursing transport team, improving training and upgrading monitoring. The second audit period was January 1994-July 1995. The groups were not significantly different for birthweight, gestation or levels of ventilation. Physiological variables were assessed with a "transport score". Improved scores for temperature and pH were achieved on completion of transfer in 1994-95 compared to 1991-93. Stabilizing prior to transfer took longer in the 1994-95 period. No serious deteriorations occurred in transit in the 1994-95 period, three in 1991-93. Audit facilitates identification of problems in transport. Staff, education and equipment changes were associated with improved audited outcomes.

Image analysis of low magnification images of fine needle aspirates of the breast produces useful discrimination between benign and malignant cases

Fine needle aspirates of the breast (FNAB) (n = 362; 204 malignant, 158 benign), prepared by cytocentrifuge methods and stained by the Papanicolaou technique, were analysed using a semi-automated image analysis system at a low magnification which precluded resolution of nuclear detail. The measured parameters were integrated optical density, fractal textural dimension, number of cellular objects (single cells and contiguous groups of cells), distance between cellular objects (mean, s.d., skewness and kurtosis), area of cellular objects (mean, s.d., skewness, kurtosis) and the nearest neighbour statistic. The cases were divided into a 200-case training set and a 162-case test set. Analysis was performed by logistic regression and the multi-layer Perceptron type of artificial neural network. Logistic regression and the neural network produced similar performances with a sensitivity of 82-83%, specificity 85% and a positive predictive value for a malignant result of 85%. A non-parametric analysis of all the predictor variables showed that all except the mean area of cellular objects and the s.d. of this measurement were significant discriminants (P < 0.05), but most were highly interrelated and this was reflected in the selection of only three predictor variables by forward and backward conditional logistic regression. This study shows that much diagnostic information is present in low power views of FNAB, and that image analysis could form the basis of a semi-automated decision-support aid.

Chemical ablation of the gallbladder

BACKGROUND

Chemical ablation of the gallbladder might avoid the need for surgery in elderly, unfit patients. This study examined the efficacy of various chemicals in destroying gallbladder mucosa.

METHODS

Ninety-five per cent ethanol, 3 per cent sodium tetradecyl sulphate (STD), trifluoroacetic acid (TFA) 2 mol/l, tetracycline 50 mg/ml, 30 and 50 per cent phenol, and a mucosal exfoliant solution (compound ethylene diamine tetra-acetic acid) were tested for gallbladder ablation in rabbits. Histology was obtained 8 weeks after exposure to these chemicals.

RESULTS

Thirty per cent phenol, tetracycline, TFA and ethanol when used as single agents were moderately effective in causing complete gallbladder mucosal obliteration, 50 per cent phenol caused a macroscopic burn of the entire gallbladder. The mucosal exfoliant solution and STD on their own did not cause mucosal destruction but had significantly enhanced efficacy when combined with 95 per cent ethanol, allowing reliable mucosal destruction with a 5-min contact duration.

CONCLUSION

Ninety-five per cent ethanol and STD after pretreatment with a mucosal exfoliant solution may be the combination of choice for in situ gallbladder mucosal ablation.

Cytokine and chemokine regulation of proMMP-9 and TIMP-1 production by human peripheral blood lymphocytes

The production and activation of matrix-degrading proteinases such as the matrix metalloproteinases (MMP) by lymphocytes is likely to be an important factor in facilitating lymphocyte trafficking through the endothelial barrier and the extracellular matrix. Leukocyte infiltration into inflammatory sites occurs as a response to members of the chemokine superfamily and other inflammatory mediators. In the present study, highly purified leukocyte subpopulations were cultured with or without chemokines or cytokines, and their ability to express gelatinolytic MMPs and their inhibitors, the tissue inhibitors of metalloproteinase (TIMPs), was analyzed. In the absence of exogenous stimuli, purified CD4+ T lymphocytes produced similar quantities of proMMP-9 and elevated levels of TIMP-1 compared with PBMC, while purified CD8+ and CD3+ populations exhibited less MMP-9 and TIMP-1 activity. In comparison, CD56+ (NK) cells secreted barely detectable levels of proMMP-9 and TIMP-1. The secretion of proMMP-9 by PBMC and purified CD3+, CD4+, and CD8+ lymphocytes was selectively modulated by beta chemokines and proinflammatory cytokines. ProMMP-9 secretion by CD3+ and CD4+, but not by CD8+ T cells was augmented in response to TNF-alpha and IL-1, and down-regulated by IFN-gamma, while macrophage inflammatory protein (MIP)-1alpha, MIP-1beta, and RANTES (regulated upon activation and normally T cell expressed and secreted) (beta chemokines) up-regulated the secretion of proMMP-9 by all of the lymphocyte subsets tested. These results demonstrate that a number of proinflammatory cytokines and chemokines differentially regulate proMMP-9 secretion from purified CD4+ and CD8+ lymphocytes, while for purified CD3+ T cells (consisting of CD4+ and CD8+ cells in approximately a 2:1 ratio), a predominantly CD4+ lymphocyte response profile was demonstrated.

Cytokine and chemokine regulation of proMMP-9 and TIMP-1 production by human peripheral blood lymphocytes

The production and activation of matrix-degrading proteinases such as the matrix metalloproteinases (MMP) by lymphocytes is likely to be an important factor in facilitating lymphocyte trafficking through the endothelial barrier and the extracellular matrix. Leukocyte infiltration into inflammatory sites occurs as a response to members of the chemokine superfamily and other inflammatory mediators. In the present study, highly purified leukocyte subpopulations were cultured with or without chemokines or cytokines, and their ability to express gelatinolytic MMPs and their inhibitors, the tissue inhibitors of metalloproteinase (TIMPs), was analyzed. In the absence of exogenous stimuli, purified CD4+ T lymphocytes produced similar quantities of proMMP-9 and elevated levels of TIMP-1 compared with PBMC, while purified CD8+ and CD3+ populations exhibited less MMP-9 and TIMP-1 activity. In comparison, CD56+ (NK) cells secreted barely detectable levels of proMMP-9 and TIMP-1. The secretion of proMMP-9 by PBMC and purified CD3+, CD4+, and CD8+ lymphocytes was selectively modulated by beta chemokines and proinflammatory cytokines. ProMMP-9 secretion by CD3+ and CD4+, but not by CD8+ T cells was augmented in response to TNF-alpha and IL-1, and down-regulated by IFN-gamma, while macrophage inflammatory protein (MIP)-1alpha, MIP-1beta, and RANTES (regulated upon activation and normally T cell expressed and secreted) (beta chemokines) up-regulated the secretion of proMMP-9 by all of the lymphocyte subsets tested. These results demonstrate that a number of proinflammatory cytokines and chemokines differentially regulate proMMP-9 secretion from purified CD4+ and CD8+ lymphocytes, while for purified CD3+ T cells (consisting of CD4+ and CD8+ cells in approximately a 2:1 ratio), a predominantly CD4+ lymphocyte response profile was demonstrated.

The association between nm23 gene expression and survival in patients with sarcomas

The relationship between the expression of nm23, a putative metastasis-suppressor gene and prognosis was determined for 88 patients with sarcomas. Immunohistochemistry using immunopurified anti-nm23 peptide antibodies was performed and the results of each case graded according to the degree of staining. Univariate and multivariate analyses were carried out to determine the prognostic significance of nm23 staining for sarcoma patients. Expression of nm23 was found to increase in line with metastatic potential in many cases but this did not reach significance for the study as a whole. However, the possibility of nm23 loss occurring in association with metastasis cannot be ruled out in some more aggressive sarcomas, as was demonstrated for six patients with low-scoring, unclassified and synovial sarcomas that had metastasized. The time to metastasis was longer for patients with grade 3 sarcomas (50-75% of tumour cells staining) than similar patients in other staining groups. These results suggest that expression of nm23 genes in sarcomas is variable and has no value as a prognostic indicator for these mesenchymal tumours.

Blood culture is poor method of confirming pneumococcus as cause of childhood pneumonia

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