Photolithographic nanoseeding method for selective synthesis of metal-catalysed nanostructures.

In this work we present a general method for the selective synthesis by photolithography of localised nanostructures in planar geometries. The methodology relies on the previous concept of photo-patternable metallic nanoparticle (NP)/polymer nanocomposites, which can provide a range of NP sizes, polydispersity and densities. First, a photoresist containing metallic ions is patterned by photolithography. Silver NPs are synthesised in situ after the exposure and development of the patterned thin film via the thermal-induced reduction of ions embedded in its structure. Gentle plasma ashing is used to selectively remove the polymer, which leaves NPs on the patterned areas. These NPs are used as seeds for subsequent processes. In order to demonstrate the flexibility of the method, its use to selectively produce localised nanostructures through different processes is shown here. Following a top-down approach, high aspect-ratio silicon nanograss has been produced by reactive ion etching and masking by the NPs. In a bottom-up approach, 280 nm copper clusters have been selectively grown in arrays. This method can be easily extrapolated to other metals and it provides a quick way to selectively generate hierarchical nanostructures in large planar areas that can be used for different applications, such as the fabrication of nanostructured sensor arrays.

Student-led microfluidics lab practicals: Improving engagement and learning outcomes.

Microfluidics has shown rapid growth in both research and development and offers significant commercialisation potential for biomedical and diagnostic applications in particular. However, there is a lack of awareness of microfluidics outside the field of study, and few dedicated educational programmes are available. While many topics incorporate microfluidics teaching, reported initiatives in the literature have not yet taken a problem based learning (PBL) approach to the delivery of practical sessions. The educational approaches already reported typically focus upon production and testing of pre-determined device designs for specific applications, using a "recipe" style of lab teaching. Here, we report on a newly designed lab section of a microfluidic teaching component utilising problem based learning (PBL) to involve the students in all aspects of design, manufacture, and performance characterisation of microfluidic solutions. Details of the lab design and development are given enabling others to replicate the lab structure described here or use it as a basis for the design of similar PBL microfluidics teaching labs. A key focus of the work has been the evaluation of the student experience, and the results of a survey indicate a high degree of student satisfaction and skills development due to the PBL approach.

Successful immunotherapy of HCMV disease using virus-specific T cells expanded from an allogeneic stem cell transplant recipient.

Opportunistic infection remains the principal cause of mortality in allogeneic stem cell transplant recipients with active extensive chronic graft-versus-host disease. Human cytomegalovirus (HCMV) represents an important cause of disease in this setting and the toxicity of protracted and recurrent antiviral treatment together with eventual drug resistance represents a significant limitation to therapy. Although the expansion and adoptive transfer of HCMV-specific T cells from the healthy original donor can be an effective strategy to control viral replication, this is not possible when donors are seronegative or are subsequently inaccessible. Here we demonstrate for the first time, the successful expansion of HCMV-specific T cells from a seropositive transplant recipient of a seronegative graft with active HCMV disease and the long-term reconstitution of protective antiviral immunity following their adoptive transfer back into the patient.

The COBE Spectra cell separator is more effective than the Haemonetics MCS-3P cell separator for peripheral blood progenitor cell harvest after mobilization with cyclophosphamide and filgrastim.

BACKGROUND: Peripheral blood is rapidly replacing bone marrow as a source of hematopoietic progenitor cells for autologous transplantation. The advantages of peripheral blood progenitor cell transplantation are enhanced by the ability to collect sufficient progenitor cells to ensure rapid neutrophil and platelet recovery in a single procedure on some cell separators. STUDY DESIGN AND METHODS: A prospective randomized study was undertaken to compare peripheral blood progenitor cell yields from two cell separators (MCS-3P, Haemonetics and Spectra, COBE). Fifteen consecutive patients were mobilized with cyclophosphamide 2 g per m2 (Day 0) and filgrastim 10 micrograms per kg (Days 1-11). Consecutive collections (Day 10, Day 11) were performed with each machine once: patients were randomly assigned to either machine for the initial collection. RESULTS: Collection time was longer on the MCS-3P (p = 0.001), and the volume processed was greater with the Spectra (p < 0.0001). Despite similar nucleated cell yield (p = 0.62), the yield of CD34+ cells (p = 0.001) and colony-forming units-granulocytic-monocytic (p = 0.0001) was significantly higher with the Spectra. The yield of nucleated cells per unit of blood volume processed was higher for the MCS-3P (p = 0.0007), while the CD34+ cell yield (p = 1) and colony-forming units-granulocytic-monocytic yield (p = 1) per unit of blood volume processed were similar for the two machines. The collection of CD34+ cells at levels > 2 x 10(6) per kg (p = 0.063), 5 x 10(6) per kg (p = 0.031), and colony-forming units-granulocytic-monocytic > 1 x 10(5) per kg (p = 0.25) after a single collection was superior for the Spectra. CONCLUSION: The yield of progenitor cells after collection on the Spectra was superior to that achieved with the MCS-3P, because of the larger volume of blood processed per procedure. This would permit more patients to undergo only one collection.

The clinical usefulness of breast milk sodium in the assessment of lactogenesis.

OBJECTIVE: A study was undertaken to assess the value of breast milk sodium concentration (BM [Na+]) during early lactogenesis in predicting nursing outcome. METHODS: Samples of breast milk from 130 nursing mothers were obtained between the 3rd and 8th postpartum day for analysis of BM [Na+]. Approximately half the mothers were referred for nursing problems, although no problems were anticipated in the other primiparous mothers. A BM [Na+] of < or = 16 mmol/L was considered normal. For women with normal BM [Na+], follow-up was scheduled at 1 month, whereas those with high [Na+] were evaluated more frequently with repeated [Na+] determinations. RESULTS: Of the 65 women with normal BM [Na+] (excluding five mothers who had experienced breast surgery), 95.4% were exclusively and successfully breast-feeding at 1 month without intervention. Of 60 women with high BM [Na+], all of whom received intervention, 55% were ultimately successful. In general, those who failed tended to have higher initial [Na+] determinations; additionally, the longer the [Na+] remained elevated, the lower the success rate. Infant weight gain was greater if the initial BM [Na+] was normal. Infants of mothers with normal BM [Na+] gained an average of 994 g above birth weight by 1 month in contrast to the average weight gain of 818 g in infants of mothers with initially elevated [Na+]. CONCLUSION: This study suggests that a normal drop in [Na+] is highly predictive of successful lactation, although a prolonged elevation of [Na+] signifies impaired lactogenesis with a high risk of failure. The clinical usefulness and limitations of this determination are discussed.

Ineffective suckling: a possible consequence of obstructive positioning.

Failure to thrive in breastfed babies frequently is attributed to inadequate lactation. In some cases, the origin of inadequate lactation may be ineffective suckling that obstructs milk flow. To support this conclusion, an infant who presented with failure to thrive was studied at the breast with magnetic resonance imaging.

The Sda antigen in the human kidney and colon.

The range of concentration of the Sda blood group antigen has been determined in the human adult kidney and colon. No Sda antigen was found in 2% of kidneys. Immunofluorescent studies of the kidney showed that Sda is present in the distal convoluted tubules and collecting ducts and occurs in the same location as Tamm-Horsfall protein. No Sda antigen was detected in about 2% of colons. In an additional 6%, no antigen was detected in saline extracts but was present in an insoluble form. In the colon, Sda is sited on the brush borders of the epithelial cells and in the goblet cells. No Tamm-Horsfall protein was identified in the colon.

Monoclonal antibody EBM/11: high cellular specificity for human macrophages.

A monoclonal antibody, EBM/11, was raised against isolated human lung macrophages. Immunohistochemically this antibody reacted with freshly isolated lung macrophages and blood monocytes, mononuclear cells (presumptive macrophages) in sections of lung, skin, stomach, small and large bowel, pancreas, spleen, tonsil, placenta, liver, gall bladder, heart, thyroid, pituitary, brain, and peritubular and mesangial cell in kidney. Microglial cells and osteoclasts also labelled with EBM/11. The antibody reacted with cytoplasmic structures rather than with cell membranes. The epitope recognised by EBM/11 was present on four polypeptides (of 120, 70, 64 and 22 kilodaltons). It did not react with any other cell type in the tissues screened except the epithelium of renal proximal tubules. This antibody may be useful in identifying and elucidating the function of macrophages in pathological processes.

Human renin: a new class of inhibitors.

A new class of human renin inhibitor is described, containing a novel analogue of the peptide bond. High inhibitory potency was observed for octapeptide-length substrate analogues but inhibition progressively weakened as the molecule was shortened from the amino terminal end.

Occurrence and significance of Mallory bodies in morbidly obese patients. An immunohistochemical study.

Liver biopsies from 61 consecutive patients with morbid obesity (less than 60% overweight) and from 48 patients with alcoholic liver disease were examined for the presence of Mallory bodies. For the detection both routine haematoxylin and eosin stained sections and sections exposed to an immunohistochemical technique were employed. The latter uses an antiserum which recognizes antigenic determinants in Mallory bodies. Using haematoxylin and eosin staining. Mallory bodies were not detected in any of the biopsies from the obese patients, but found to be present in 63% of the patients with alcoholic liver disease. Using the immunohistochemical technique, Mallory bodies were found in the liver of 2 obese patients (3%) and in 36 patients with alcoholic liver disease (75%). None of the Mallory body positive obese patients showed signs of diabetes mellitus, cholestasis or hypocholesterolemia, but both patients admitted previous excessive alcohol consumption. It is concluded that the immunohistochemical detection of Mallory bodies is more sensitive than routine staining. Further, Mallory bodies are rare findings in livers of obese patients and may be related to excessive alcohol consumption.

Postendoscopy barium enema examinations.

A study was designed to evaluate whether sigmoidoscopy performed on the same day as barium enema examination interferes with quality or interpretation of the barium study. The study included 295 patients who had either single- or double-contrast barium enema examinations subsequent to sigmoidoscopy performed either on a prior day or the same day. Luminal air, spasm, colonic fluid, and mucosal coating were assessed, as was the resultant diagnostic quality of each barium examination. The results suggest that rigid or fiberoptic sigmoidoscopy can be performed the same day as single- or double-contrast barium enema examinations without adversely affecting the quality or interpretation of the barium study.

Immune complex nephritis in alcoholic cirrhosis: detection of Mallory body antigen in complexes by means of monoclonal antibodies to Mallory bodies.

A Mallory body (alcoholic hyaline) antigen (JMB2) which is also present in intermediate filaments of epithelial origin was demonstrated immunohistochemically in renal glomeruli of three out of eleven patients with alcoholic liver damage. In two of these patients, both of whom had alcoholic cirrhosis with Mallory bodies, it was associated with mesangial deposits of IgA and C3. JMB2 was not found in glomeruli of normal controls, nor in a series of cases of glomerulonephritis in non-alcoholic patients. It is concluded that JMB2 is present in immune complexes in renal glomeruli of patients with renal disease consequent on alcoholic liver disease.

Immunohistochemical analysis of HLA (A, B, C) antigens in liver disease using a monoclonal antibody.

The distribution of HLA class I antigens was studied in 42 liver biopsies and eight necropsies by an immunoperoxidase technique employing a monoclonal antibody which reacts with the heavy chains of class I (A, B, C) HLA antigens. In normal liver HLA class I antigens could not be detected on hepatocyte cell membranes or cytoplasm; these antigens were present on the cell membrane of bile duct epithelium, on sinusoidal lining cells, fibroblasts, and blood vessel endothelium. However, in all patients with acute alcoholic hepatitis, most cases of primary biliary cirrhosis and some cases of chronic active hepatitis HLA class I antigens were detectable focally or diffusely on the cell membrane of hepatocytes; in two cases of acute viral hepatitis (non-A, non-B) HLA class I antigens were present in granular form in the cytoplasm of all hepatocytes. These findings may be relevant to the prolonged survival of liver allografts in man and other species and in the pathogenesis of some liver diseases.

Distribution of HLA class 1 antigens in normal human tissue and in mammary cancer.

With a monoclonal antibody which reacts with all HLA class 1 antigens it was found that these antigens are not uniformly distributed in all nucleated cells. Rather HLA class 1 antigens are restricted in their distribution to lymphoid cells, endothelial cells of small vessels, and certain epithelia including mammary duct cells. These antigens were not detected on hepatocytes, specialised cells of the central nervous system, or on the tumour cells of 8 out of 17 human mammary cancers. Given the hypothesis that T cells only respond to foreign antigens on cells which share a common major histocompatibility antigen, these results imply that the T cell responses to viral infections of hepatocytes--for example, hepatitis B virus and the CNS--for example, subacute sclerosing encephalitis, are mediated through an antigen system other than HLA class 1. The absence of HLA class 1 antigen on many mammary cancer cells may be of prognostic significance if T cell modulation of tumour growth is mediated through this class of antigens.

Mallory bodies in alcoholic and non-alcoholic liver disease contain a common antigenic determinant.

An immunohistochemical technique is described for the detection of Mallory bodies (MBs) in paraffin sections of liver tissue. This is based on proteolytic digestion of sections before exposure to an antiserum which recognises a unique antigenic determinant in MBs. With the use of this procedure it has been shown in alcoholic liver disease, primary biliary cirrhosis. Indian childhood cirrhosis, Wilson's disease, diabetes mellitus, and hepatocellular cancer that the MBs found in these disorders contain this unique antigenic determinant. It is postulated, therefore, that the mechanism of formation of MBs is similar in liver diseases of diverse aetiology. In addition, it has been demonstrated that the immunohistochemical procedure is more sensitive than routine staining; MBs were detected in five out of 12 fatty livers by immunohistochemical and only in one by H and E staining. As MBs in fatty livers were not associated with polymorph filtration or fibrogenesis it is argued that MB formation is not an absolute prerequisite for the progression of acute to chronic liver disease.