FTIR of touch imprint cytology: a novel tissue diagnostic technique.

Fourier transform infrared spectroscopic (FTIR) interrogation of biological tissues in real time has largely been a challenging proposition because of the strong absorption of mid-infrared light in water filled tissues. To enable sampling of tissues they must be sectioned and dried, which has time and resource implications. FTIR of touch imprint cytology (TIC) has been proposed to circumvent this problem. TIC is a well known histopathological method of rapidly analysing biological tissues. In this article we demonstrate the ability of FTIR of TIC to provide detailed spectra which can be used to differentiate various tissue pathologies. FTIR spectral profiles of TIC of lymph node and thyroid tissues differ visually when compared with TIC spectra of parathyroid tissue. The lymph node showed strong lipid spectral peaks at 1166cm(-1) and 1380cm(-1) including a very strong carbonyl-ester band at 1748cm(-1), and a strong methylene bending band (scissoring, at 1464cm(-1)). Smaller intensity protein peaks at 1547cm(-1) and 1659cm(-1) were also seen. The thyroid spectra, in addition to evident strong protein peaks at 1547cm(-1) and 1659cm(-1), also demonstrated possible nucleic acid signals at 1079cm(-1) and 1244cm(-1). The C-OH peak at 1037cm(-1) was attributed to carbohydrate signals. Parathyroid adenoma showed a marginal shift to lower wavenumbers with decreased amide I and II peak intensities when compared to hyperplasia. Nucleic acid peak positions at 1079cm(-1) and 1244cm(-1) were of higher intensity in adenomas compared to hyperplastic glands possibly demonstrating an increase in cell proliferation and growth. This study demonstrates the feasibility of cytoimprint FTIR for the intraoperative diagnosis of tissue during surgical neck exploration for the management of hyperparathyroidism. There is potential for the application of the technique in sentinel lymph node biopsy diagnosis and tumour margin evaluation.

Role of Fourier transform infrared spectroscopy (FTIR) in the diagnosis of parathyroid pathology.

BACKGROUND: With the advent of minimally invasive parathyroid surgery (MIPS) accurate pathological diagnosis to differentiate parathyroid adenomas from hyperplasia has become difficult for the pathologist. This is because now single glands are excised, guided by better preoperative localisation scans, while for an accurate pathological diagnosis, at least a two-gland biopsy is required. Ultimately, an accurate pathological diagnosis to establish the aetiology is essential for the management of hyperparathyroidism. To resolve this issue we evaluated the ability of FTIR to accurately differentiate between parathyroid adenoma and hyperplasia using their biochemical signatures. METHODS: Samples of diseased glands were collected intraoperatively from consenting patients over a 1-year period. Sixteen glands were analysed - eight hyperplasias and eight adenomas. Samples were analysed using an infrared spectroscope and reflected the biochemical nature of the sample tissue. Spectra collected were subjected to both empirical and multivariate analytical techniques. RESULTS: Empirical analysis highlighted differences in spectral protein peaks, with possibly additional subtle differences in nucleic acid spectra between the pathologies. A multivariate statistical predictive model demonstrated the sensitivity of FTIR for adenomas to be 93% and hyperplasia 93%, (88% on cross validation testing). CONCLUSIONS: Thus, infrared spectroscopy is potentially an excellent tool to differentiate the two pathologies and could be a useful adjunct to the pathological diagnosis of single glands.

Oestrogen and progesterone receptor assessment in core biopsy specimens of breast carcinoma.

AIMS: To assess the suitability of core biopsy specimens for the immunohistological assessment of oestrogen and progesterone receptors in breast carcinoma. METHODS: Thirty consecutive cases of clinically palpable breast carcinoma, from which both core and excision biopsy specimens were available, were examined. Routinely processed paraffin wax sections were stained using the specific monoclonal antibodies 1D5 (Dako) for oestrogen receptor and NCL-PGR (Novocastra) for progesterone receptor, after an antigen retrieval step using a pressure cooker. Staining results were assessed using the H score system with the results being expressed as negative, weakly positive, moderately positive or strongly positive. RESULTS: Twenty six biopsy specimens contained enough tumour tissue for assessment. Absolute agreement between scoring categories was seen in 19 (73%) cases for oestrogen receptors. However, when all positive categories were added together, agreement between core and excision biopsy specimens increased to 93% (24 cases). Disagreement was seen only in two cases which stained positive in the core biopsy specimens and negative in the excision biopsy specimens. For progesterone receptors, the absolute agreement between all scoring categories was seen only in 11 (42%) cases. When all positive categories were considered together, agreement increased to 69% (18 cases). Five cases were progesterone receptor positive in core but not in excisional biopsy specimens, while three cases were negative in core but positive in excisional biopsy specimens. CONCLUSIONS: The results suggest that core biopsy specimens can be reliably used for oestrogen receptor assessment, but are less reliable for progesterone receptor assessment, probably because of a greater heterogeneity of progesterone receptor staining.

Raman spectral mapping in the assessment of axillary lymph nodes in breast cancer.

This paper is the first reported description of Raman Spectroscopy in the assessment of axillary lymph nodes in breast cancer patients. Raman Spectroscopy is an inelastic scattering spectroscopic technique appropriate for the assessment of unprocessed complex biological tissues. Spectra represent biochemical signatures of the tissue under scrutiny. The described method of Raman spectral mapping produces false-color spectral images of lymph node sections. These can be compared with standard histopathology slides and white light images of nodal tissue. This method has the potential to allow the detailed biochemical assessment of heterogeneous lymph node features, and to contribute towards the development of an optical diagnostic tool for use in a clinical setting.

Rapid flow carbon dioxide laparoscopy disperses cancer cells into the peritoneal cavity but not the port sites in a new rat model.

BACKGROUND: The role of carbon dioxide (CO2) in the pathogenesis of tumor recurrence after laparoscopy remains controversial. Using a new rat model, we studied the effect of different CO2 flow rates on the dispersal of free cancer cells. METHODS: A novel model of desufflation without trocar was developed, and 55 Fischer rats were randomized into three flow groups: group A (rapid, 0.67 l/min; n = 20), group B (slow, 0.44 l/min; n = 20), and group C (gasless, n = 15). We vented CO2 via a portless surgical valve that filtered cells. After the abdominal wall had been suspended to create space, half of the animals in each group (nonrecovery) received 7.5 x 10(6) immunolabeled rat colon cancer cells (RCC2) intraperitoneally, whereas the other half (recovery) received 7.5 x l0(6) viable RCC2 before insufflation or gasless laparoscopy. Nonrecovery animals were killed after 20 l of insufflation. Parietal peritoneal and port-site specimens were examined for RCC2 by fluorescence microscopy (FM) and flow cytometry (FC). The recovery animals were killed at 4 weeks for evidence of wound recurrence. RESULTS: Nine of 10 nonrecovery animals in A had RCC2 on FM or FC, as compared with 2 animals in each of the nonrecovery groups B and C (p = 0.018, Fisher's exact test). Two of the nine animals in group A also had RCC2 in their portless valves. Two recovery (A) animals developed wound recurrence as compared with none in the other groups (p = 0.315). CONCLUSION: In this model, rapid CO2 flow dispersed free cancer cells into the peritoneal cavity, but not into the port sites, thus supporting a role for CO2 in the intraperitoneal dispersal of free cancer cells, but not in wound recurrence.

Raman spectroscopy of parathyroid tissue pathology.

Primary hyperparathyroidism (HPT) in 80% of patients is due to a solitary parathyroid adenoma, while in 20% multigland pathology exists, usually hyperplasia [Scott-Coombes, Surgery, 21(12):309-312, 2003]. Despite recent advances in minimally invasive parathyroidectomy, better preoperative localisation techniques and intraoperative parathyroid hormone (PTH) monitoring, a 4% failure rate [Grant CS, Thompson G, Farley D, Arch Surg, 140:47-479, 2005] persists making accurate differentiation between adenomas and hyperplasia of prime importance. We investigated the ability of Raman spectroscopy to accurately differentiate between parathyroid adenomas and hyperplasia. Raman spectra were measured at defined points on the parathyroid tissue sections using a bench-top microscopy system. Multivariate analysis of the spectra was carried out to construct a diagnostic algorithm correlating spectral results with the histopathological diagnosis. A total of 698 spectra were analysed. Principal-component (PCA)-fed linear discriminant analysis (LDA) used to construct a diagnostic algorithm. Detection sensitivity for parathyroid adenomas was 95% and hyperplasia was 93%. These preliminary results indicate that Raman spectroscopy is potentially an excellent tool to differentiate between parathyroid adenomas and hyperplasia.

Social deprivation amongst short stay psychiatric patients.

Two samples of newly admitted psychiatric patients were examined. Of 558 patients admitted during one year, 76 (13.7 per cent) came in from transitory accommodation or no fixed abode; of 456 patients discharged 131 (28.7 per cent) either changed address during their stay in hospital or left without known accommodation. Of 102 patients in the wards and day hospital on one day, 29 (28.4 per cent) came in from transitory accommodation or no fixed abode, 66 (64.7 per cent) were unemployed, 51 (50 per cent) were living alone. Of the 74 inpatients 30 (40.5 per cent) were homeless and 27 (36.5 per cent) had no visitors. These results indicate that many patients have lost their community supports by the time they reach hospital.

A comparison of referrals to primary-care and hospital out-patient clinics.

All referrals from two general practices to psychiatrists in hospital and primary-care out-patient clinics were examined. Women in all diagnostic groups were preferentially referred to the primary-care clinics, which provided especially for psychotic and chronic illnesses, and at which attendance rates on first and subsequent appointments were substantially higher than at the hospital clinics. The hospital crisis-intervention clinic dealt particularly with acute psychosis and personality disorder. Patients referred to the traditional hospital out-patient service were those with the less common neuroses and personality disorder. These results are reviewed in the context of the criticism that psychiatric clinics in primary care serve only the "worried well".