Mapping the amide I absorption in single bacteria and mammalian cells with resonant infrared nanospectroscopy.

Infrared (IR) nanospectroscopy performed in conjunction with atomic force microscopy (AFM) is a novel, label-free spectroscopic technique that meets the increasing request for nano-imaging tools with chemical specificity in the field of life sciences. In the novel resonant version of AFM-IR, a mid-IR wavelength-tunable quantum cascade laser illuminates the sample below an AFM tip working in contact mode, and the repetition rate of the mid-IR pulses matches the cantilever mechanical resonance frequency. The AFM-IR signal is the amplitude of the cantilever oscillations driven by the thermal expansion of the sample after absorption of mid-IR radiation. Using purposely nanofabricated polymer samples, here we demonstrate that the AFM-IR signal increases linearly with the sample thickness t for t > 50 nm, as expected from the thermal expansion model of the sample volume below the AFM tip. We then show the capability of the apparatus to derive information on the protein distribution in single cells through mapping of the AFM-IR signal related to the amide-I mid-IR absorption band at 1660 cm(-1). In Escherichia Coli bacteria we see how the topography changes, observed when the cell hosts a protein over-expression plasmid, are correlated with the amide I signal intensity. In human HeLa cells we obtain evidence that the protein distribution in the cytoplasm and in the nucleus is uneven, with a lateral resolution better than 100 nm.

Outcome of pregnancies when fathers are treated with 6-mercaptopurine for inflammatory bowel disease.

OBJECTIVE: The outcomes of pregnancies after maternal use of 6-mercaptopurine (6-MP) for inflammatory bowel disease (IBD) during pregnancy have been reported, but data are lacking for outcomes when the fathers use this drug. METHODS: Subjects were male patients with IBD seen at one center between 1970 and 1997. Patients and their wives were interviewed. Group 1 comprised pregnancies fathered by men who were taking 6-MP. This group was further subdivided into those conceived within 3 months of 6-MP use and those conceived at least 3 months after 6-MP was stopped. Group 2 comprised pregnancies fathered by men with IBD, similar in characteristics to group 1, who had not taken 6-MP before fertilization. Information was collected regarding the fathers, the mothers, and the pregnancies, as well as the health of the children, in a historical cohort study. RESULTS: There were 50 pregnancies in group 1 (13 in 1A and 37 in 1B) and 90 pregnancies in group 2. Four of the 13 pregnancies in group 1A were associated with complications. There were two spontaneous abortions, and two congenital anomalies including a missing thumb in one and acrania with multiple digital and limb abnormalities in the other. Risk of complications was significantly increased when compared with group 1B (p < 0.013) and group 2 (p < 0.002). CONCLUSION: The incidence of pregnancy-related complications was significantly increased when the fathers used 6-MP within 3 months of conception.

Large sessile colonic adenomas: use of argon plasma coagulator to supplement piecemeal snare polypectomy.

BACKGROUND: Residual adenoma is frequently found at the site of endoscopically resected large sessile adenomas on follow-up examination. We evaluated the efficacy of a thermal energy source, the argon plasma coagulator, to destroy visible residual adenoma after piecemeal resection of sessile polyps. METHODS: Seventy-seven piecemeal polypectomies with or without the use of argon plasma coagulator were analyzed retrospectively. All polyps were sessile, 20 mm or greater in size. The results from three groups of patients were compared. The study group was composed of patients who had visible residual adenoma after piecemeal polypectomy and had the base of the polypectomy site treated with the argon plasma coagulator. The first comparison group consisted of patients who underwent standard piecemeal polypectomy in whom the colonoscopist thought that all adenomatous tissue was removed and no further treatment was necessary. The second comparison group included patients in whom visible residual adenoma was left at the base after piecemeal resection of large adenomas. Follow-up colonoscopy was performed approximately 6 months after the initial procedure to check for recurrent/residual adenomatous tissue. RESULTS: The argon plasma coagulator was used after 30 piecemeal polypectomies in an attempt to eradicate visible residual adenomatous tissue; at follow-up, 50% of these cases had complete eradication of adenoma. The group in whom all visible tumor was removed by piecemeal polypectomy alone had an adenoma eradication rate of 54% on follow-up colonoscopy. In the patients in whom visible residual adenoma was left at the site the recurrence rate was 100% on the follow-up examination. Bleeding necessitating endoscopic therapy occurred once (3.3%) in the argon plasma coagulator group; there were four (12.5%) bleeding episodes and one (3.1%) confined retroperitoneal perforation in the complete piecemeal polypectomy group and no complications in the group in which polypectomy was incomplete. CONCLUSIONS: Argon plasma coagulator ablation of residual adenomatous tissue at the polypectomy base is safe and useful. It helps to complete the eradication of large sessile polyps when there is visible evidence of residual polyp.

The influence of inflammatory bowel disease and its treatment on pregnancy and fetal outcome.

The influence of inflammatory bowel disease (IBD) and its therapy upon pregnancy is a frequent consideration before and after conception. We looked at the influence of disease activity and drug therapy during pregnancy on fetal outcome in 147 pregnancies in 124 women. Patients were divided into two groups; 46 (28 ulcerative colitis, 18 Crohn's disease) who received drug treatment during pregnancy, and 101 (42 ulcerative colitis, 59 Crohn's disease) who received no treatment. The frequency of fetal complications was higher than in the general population in the "treated" patients, but was not higher than in patients with IBD who received no drug treatment. Active IBD was present in 43% of the treated patients whose pregnancies resulted in fetal complications. Of patients with Crohn's disease whose pregnancies resulted in fetal complications, active IBD was present in 62.5%. Thus, our experience suggests that patients with IBD who receive therapy during pregnancy are at greater risk of fetal complications than the average population, but that disease activity is more likely to be responsible for this risk than drug treatment. This risk is much more evident in active Crohn's disease than in ulcerative colitis.

Uveitis occurring after colectomy and ileal-rectal sleeve anastomosis for ulcerative colitis.

Uveitis is an extraintestinal complication of ulcerative colitis and Crohn's disease. In most cases, its course parallels that of the underlying bowel disease and improves with its therapy. Occasionally, the two processes are not synchronous. In either case, the uveitis has usually been considered to be dependent on the presence of the colon. This report describes a patient who developed uveitis shortly after colectomy and ileal-rectal sleeve anastomosis for ulcerative colitis, indicating that the continuing presence of the colonic mucosa is not necessary for development of the associated ocular inflammation.

The course of inflammatory bowel disease during pregnancy and postpartum.

To determine whether pregnancy influences the course of inflammatory bowel disease, a survey of 324 patients, 178 with ulcerative colitis and 146 with Crohn's disease was carried out. During pregnancy, 70% of the patients remained unchanged or improved, whereas 30% developed exacerbations. The course of the disease was significantly milder in patients who became pregnant while in remission, as compared to those with moderate to severe disease (P less than 0.001). Postpartum, only 13% of patients, with quiescent to mild disease at term, experienced moderate to severe disease in contrast to 53% of those with active disease (P less than 0.001). We conclude that: 1. The course of inflammatory bowel disease is not adversely affected by concurrent pregnancy or postpartum 2. Exacerbations during or after pregnancy are more frequent in patients with active or uncontrolled disease. 3. Since the risk of relapse during pregnancy and postpartum is significantly lower in patients with inactive disease, treatment designed to induce and maintain remission in the course of pregnancy should minimize such exacerbations.