Effect of oxygen on lung superoxide dismutase activities in premature baboons with bronchopulmonary dysplasia

We investigated the effects of gestational age and oxygen exposure on superoxide dismutase (SOD) activities in distal fetal lung tissue in primate models of bronchopulmonary dysplasia. During the final third of fetal life, lung coppper-zinc SOD (Cu,ZnSOD) specific activity decreased, whereas lung manganese SOD (MnSOD) specific activity tended to increase. In the premature newborn (140 days, 78% of term gestation), lung total SOD and Cu,ZnSOD specific activities decreased after 6-10 days of ventilation with as needed [pro re nada (PRN)] or 100% oxygen compared with fetal control animals. Neither Cu,ZnSOD mRNA nor protein expression changed after either oxygen exposure at this gestation (140 days) relative to fetal control animals. At this age (6-10 days), lung MnSOD specific activity did not change in oxygen-exposed relative to fetal control animals, even though lung expression of MnSOD mRNA and protein increased after PRN or 100% oxygen exposure. In the very premature 125-day newborn (69% of term), lung Cu,ZnSOD specific activity and protein decreased, whereas Cu,ZnSOD mRNA increased, after 6-10 days of ventilation with PRN oxygen compared with fetal control animals. In fetal lung explants, hyperoxia also decreased expression of SOD activity acutely (16-h exposure, 125 and 140 days gestation). To conclude, expression of SOD activity in the premature primate lung did not increase in response to elevated oxygen tension, apparently due to effects occurring subsequent to the expression of these mRNAs.

Reduced gastric mucosal vascularity in patients with chronic gastritis

OBJECTIVES/DESIGN

Chronic inflammation is increasingly being linked to ischaemia, but the mechanism is poorly understood, and little is known about its effect on local gastric endothelial microvessels. We aimed at studying the number and surface area of gastric mucosal endothelial microstructures in the presence or absence of chronic gastritis.

METHODS

Immunohistochemical assessments were carried out on gastric antral and body biopsies taken from patients with chronic gastritis and others with normal histology. The primary antibody (QB-END/10) was raised against CD34 antigen within the endothelial cell membranes. A computer attached to a microscope was used to count the number and measure the surface area of mucosal endothelial entities.

RESULTS

In patients with Helicobacter pylori gastritis (n = 19), the median number of endothelial microstructures per section was 43 in the antrum and 86 in the gastric body, compared with 205 (P = 0.00004) and 165 (P = 0.002), respectively, in subjects with normal gastric histology (n = 11). The median surface area of the endothelial microstructures was also reduced in patients with gastritis. The normal gastric antrum had more endothelial entities than the normal body (median of 205 vs 165; P = 0.007).

CONCLUSIONS

Within the normal stomach, the antrum is more richly vascularized than the gastric body. However, active chronic gastritis is associated with reduction in both the number and surface area of mucosal endothelial microstructures, with the reduction being more marked in the antrum. This is different from acute inflammation, and is relevant to our understanding of the natural history of mucosal defence, particularly the greater susceptibility of the gastric antrum to ulceration, compared with the gastric body.

Interleukins 4 and 13 upregulate expression of cd44 in human colonic epithelial cell lines

Interleukin 4 (IL-4) inhibits carcinoma cell growth and promotes expression of differentiation-associated products by normal and malignant epithelial cells. The effects of IL-4 and IL-13 on expression of the CD44 transmembrane adhesion receptor were examined in human epithelial cell lines of colonic (HT-29, CaCo-2, DLD-1, T84), breast (MCF-7, ZR75-1) and liver (Hep-G2, PLC/PRF/5) origins as well as mitogen-activated and resting peripheral blood lymphocytes (PBL) and T cell lines (Jurkat, HUT78). Liver and Jurkat cells were negative for CD44. Colonic, breast and HUT78 cells expressed CD44 constitutively and all except DLD-1 and HUT78 also expressed CD44 splice variant (CD44v) epitopes. All cell lines expressed IL-4 receptors, but IL-4 and IL-13 induced upregulation of CD44 only in the colonic cell lines. CD44v was also upregulated, but there was no de novo induction of CD44v in variant-negative cells and no de novo expression of CD44 in the CD44(-) lines. CD44 upregulation in mitogen-activated PBL was not increased by IL-4 and IL-13 and was not inhibited by neutralizing antibodies. Other cytokines tested [interferon gamma (IFN-gamma, tumour necrosis factor alpha (TNF-alpha), transforming growth factor beta1 (TGF-beta1) and IL-6] did not affect CD44 core epitope expression in the cell lines tested.

Downstream elements from the pea albumin 1 gene confer sulfur responsiveness on a reporter gene

The levels of mRNAs for some of the sulfur-rich proteins in seeds are regulated by the level of sulfur supplied to the plants. In peas, there is a mechanism that lowers the level of mRNA for legumin and pea albumin 1 (PA1) when plants are grown under sulfur-deficient conditions. This mechanism acts after transcription initiation. In this study, a gene encoding PA1 was expressed in leaves of transgenic tobacco. Expression of the gene was controlled by the level of sulfur supplied to the plants, mimicking the behaviour of the intact gene in peas. A gene encoding a different high-sulfur protein, ovalbumin, was unresponsive to sulfur status and was used as a reporter gene to test defined regions of the PA1 gene for sulfur responsiveness. These constructs, together with a set of PA1 gene deletions, were tested in transgenic tobacco and yielded the following observations: the PA1 gene was sensitive to sulfur status in the leaf as well as the seed; intron processing of the PA1 transcript was not required for sensitivity to sulfur stress; both the coding region and the 3' flanking regions of the PA1 gene contained sequences which conferred sensitivity to sulfur stress; the sulfur-responsive sequence in the 3' region was contained within a 134-nucleotide segment downstream of the end of the coding sequence. We conclude that there are at least two downstream elements which confer sensitivity to sulfur supply.

Myxoid malignant fibrous histiocytoma mimicking papular mucinosis

Malignant fibrous histiocytoma is the most common type of soft tissue sarcoma in late adulthood. The myxoid variant of malignant fibrous histiocytoma, also known as myxofibrosarcoma, can develop in subcutaneous rather than deep soft tissue, and the true extent of these superficial tumors is often underestimated. Patients with these low-grade myxoid malignant fibrous histiocytomas have an excellent 5-year survival rate, and it is therefore important to recognize them. We present a case with a superficial cutaneous accumulation of mucin that was diagnosed clinically and histologically as papular mucinosis. In retrospect, a subcutaneous presentation of myxofibrosarcoma should have been considered.

Screening for diabetic retinopathy by general practitioners: ophthalmoscopy or retinal photography as 35 mm colour transparencies?

In order to assess the relative ability of general practitioners (GPs) to detect diabetic retinopathy (DR), especially sight-threatening diabetic retinopathy (STDR) by direct ophthalmoscopy or by examining, on a separate occasion, retinal images as 35 mm colour transparencies, a South and Mid Wales primary care-based study was performed in four general practices (six GPs). The participating GPs were provided with standardized training and equipment. Both methods were compared to the 'reference' grade of DR provided by the Diabetic Retinopathy Reading Centre (London), based on the same retinal images. Ophthalmoscopy and retinal photography (Canon CR4 45NM) with mydriasis were all practice based. The clinical assessments were based on a protocol developed for screening for DR in Europe. A total of 996 people with diabetes were identified, representing a prevalence of known diabetes of 2.1%. After exclusions on medical grounds, 897 patients were available for screening, of whom 605 (68%) were photographed. Based on the retinal images, the reference centre identified DR in 43% and STDR in 14.4%. In total, 597 valid comparisons between GPs and the reference centre were obtained; of these, 462 (77%) were high quality photographs which were used in subsequent analysis. The sensitivity for detecting any DR increased from 62.6% (95% CI 55.9-69.4) with ophthalmoscopy to 79.2% (95% CI 73.6-84.9) using retinal photographs, specificity remaining essentially unchanged at 75.0 (95% CI 69.5-80.5) and 73.5% (95% CI 68.0-79.1) with the positive predictive value (PPV) increasing from 67.2 (95% CI 60.4-74.0) to 71.0% (95% CI 65.0-77.0), respectively. The detection of STDR sensitivity increased from 65.7 (95% CI 54.4-77.1) with ophthalmoscopy alone to 87.3% (95% CI 79.4-95.2) based on retinal photographs with specificity falling from 93.8 (95% CI 91.4-96.3) to 84.8% (95% CI 81.2-88.5) and PPV from 65.7 (95% CI 54.4-77.1) to 51.2% (95% CI 42.1-60.3), respectively. We conclude that the use of standardized 35 mm colour transparency retinal photographs for screening by trained GPs in a primary care setting achieves an acceptable detection rate (>87%) for STDR, contrasting with ophthalmoscopy alone (66%), which was below the proposed UK standard of 80%.

Loss of lung mitochondrial aconitase activity due to hyperoxia in bronchopulmonary dysplasia in primates

The premature primate exposed to hyperoxia provides a useful model of bronchopulmonary dysplasia. A critical target in hyperoxic injury is the mitochondrial matrix enzyme aconitase. We hypothesized that this enzyme's activity would decline in the premature baboon lung during exposure to hyperoxia. Total aconitase activity was significantly decreased in the lungs of premature baboons of 140 days gestation with exposure to 100% oxygen for 6-10 days compared with as needed [pro re nada (PRN)] oxygen exposure and fetal controls (P = 0.0001). In activity gels, lungs from 100% oxygen-exposed animals (6-10 days) showed a nearly complete loss of mitochondrial aconitase activity relative to lungs from animals exposed only to PRN oxygen. Decreased lung aconitase activity was not a nonspecific effect of hyperoxia, causing mitochondrial damage or loss, because the activity of the mitochondrial respiratory enzyme cytochrome oxidase was not different in lungs of 100% oxygen-exposed relative to PRN oxygen-exposed newborns. In 125-day-gestation premature primates (age 6-10 days), lung total aconitase activity was correlated with inspired oxygen tension (r = 0.73 for fraction of inspired oxygen > 0.35), whereas, for animals of 140 days gestation, no such correlation was found. Thus the more premature animal's lung was more susceptible to loss of aconitase.

Altered urinary interleukin-8/creatinine ratio in peptic ulcer disease: pathological and diagnostic implications

OBJECTIVES AND METHODS

To assess its clinicopathological and diagnostic significance, interleukin-8 (IL-8) was measured by radioimmunoassay in fasting urine specimens and in gastric mucosal incubates taken from 54 patients with dyspepsia. The presence of Helicobacter pylori, the activity of gastritis, and urine creatinine levels were also assessed.

RESULTS

The median urinary IL-8/creatinine ratio was 0.1 x 10(-6) in patients with current peptic ulcers (n = 13) and 0.2 x 10(-6) in patients with a history of ulcers (n = 8), compared with 0.4 x 10(-6) (p < 0.0001) in patients without ulcers who were infected with H. pylori (n = 20) or not infected (n = 13). The activity of gastritis had a positive correlation with gastric IL-8 (r = 0.5870, p < 0.01) and a negative correlation with urinary IL-8/creatinine ratio (r = -0.6447, p < 0.005). The improvement in the activity of gastritis in 20 patients given anti-H. pylori triple therapy was associated with a significant fall in gastric mucosal IL-8 and a rise in urinary IL-8/creatinine ratio.

CONCLUSIONS

An inverse relationship seems to exist between urinary IL-8 and the activity of gastritis and gastric IL-8. This may represent another concept in the pathogenesis of peptic ulcers and can assist in the noninvasive diagnosis of peptic ulcer disease.

Sending a copy of the letter to the general practitioner also to the parents in a child development centre: does it work?

Following concerns that a considerable extra workload would be involved in sending a copy of the GP outpatient letter to parents following a medical consultation, 100 consecutive letters from the CDC were analysed to see if they could be sent to parents. Changes would have been necessary in 11, of which 6 would need an extra letter to the GP conveying additional specific information. Letters were generally intelligible, but it was recommended that they could be written in a more simple way for parents. Following these recommendations, copies of letters to the GP were sent to parents and the practice reviewed 2 years later. GP letters from 100 consecutive patients who had just visited the Centre were analysed and found to have been sent in 94. Of the remaining six, five were not sent because they contained information specific to the GP. It was felt that this could be rectified fairly easily. An anonymous questionnaire, sent to those receiving a copy of the letter, indicated that it had been very well received. It was felt that this policy was most helpful to the parents and justified a small additional workload.

Insulin-like growth factor-I in Helicobacter pylori gastritis and response to eradication using bismuth based triple therapy

AIMS

To measure insulin-like growth factor-I (IGF-I) concentrations in the presence and absence of Helicobacter pylori infection and in response to eradication of the organism.

METHODS

An enzyme linked immunosorbent assay was used to measure gastric and fasting serum concentrations of IGF-I in 17 patients with and 11 without H pylori infection. Repeat assessments were performed in the infected patients six weeks after they received a two week course of bismuth chelate, metronidazole, and amoxycillin.

RESULTS

IGF-I was detected at very low concentrations in gastric juice and in mucosal incubates. The median serum IGF-I concentration was 88 micrograms/l in the patients infected with H pylori compared with 90 micrograms/l in the non-infected controls; IGF-I concentrations dropped to 77 micrograms/l following eradication therapy (p = 0.014).

CONCLUSION

The similarity in baseline IGF-I concentrations in the presence and absence of H pylori suggests that their subsequent drop after treatment is more likely to be due to the treatment.

Gastric mucosal hepatocyte growth factor in Helicobacter pylori gastritis and peptic ulcer disease

OBJECTIVES

Hepatocyte growth factor (HGF) is increasingly recognized for its role in a variety of hepatic and systemic diseases. Its relationship to gastritis has not been studied. We aimed at measuring gastric mucosal HGF levels in the presence or absence of Helicobacter pylori gastritis, in peptic ulcers, and in response to H. pylori eradication.

METHODS

Fifty one patients were studied. Patients were not entered if they had liver disease, malignancy, or any systemic illness. HGF was measured in gastric antral incubates using an enzyme-linked immunosorbent assay. Assessments were repeated 6 wk after a 2-wk course of anti-H. pylori triple therapy in 12 patients. Code numbers were used for blinding.

RESULTS

The median gastric mucosal HGF level was 36 ng/gm/tissue in patients with H. pylori gastritis (n = 33) compared with 19 ng/gm in 18 negative controls (p = 0.0024), 18 ng/gm after the eradication of H. pylori (p = 0.021), 23 ng/gm in all patients with ulcers (n = 10), and 26 ng/gm/tissue in H. pylori-positive ulcers (n = 7).

CONCLUSIONS

Gastric mucosal HGF levels were elevated in H. pylori gastritis and reduced by its eradication. These results are relevant to our understanding of the increased gastric cell proliferation in patients with H. pylori-related gastritis.

Breaking bad news to patients with cancer

For the patient with cancer, bad news can occur several times between diagnosis and death. Patients expect honesty from professionals. Patients may choose to face up to bad news or actively deny what is happening. Nurses need to be able to deal with the patient's emotional response to bad news.

Chromosomal proteins HMG-14 and HMG-17 are synthesized throughout the S-phase in Burkitt's lymphoma

Here we test whether the targeting of chromosomal proteins HMG-14 and HMG-17 to transcriptionally active regions is due to coincidence of the synthesis of these proteins with the replication and assembly of active chromatin. Cells from the Burkitt's lymphoma line CA46 were synchronized with mimosine. The mRNA levels and the protein synthesis rates of HMG-14/-17 were determined at various stages during the S phase. The expression pattern of HMG-14/-17 was essentially constant throughout this phase of the cell cycle. The half-life for HMG-14/-17 protein corresponded to the doubling time of the cells. These results indicate that HMG-14/-17 are synthesized throughout S-phase and persist through the cell cycle. Targeting of HMGs to active genes is not simply due to the timing of their synthesis during S phase.

Nocturnal enuresis and the use of desmopressin: is it helpful?

We assessed the outcome of the use of an enuretic alarm and desmopressin according to conventional guidelines and investigated the reasons for resistance to desmopressin. Children were given a 4 month course using an enuretic alarm if they had not previously used one; 12 out of 21 were dry (57%) after 4 months and one relapsed 1 month later. Those who had previously failed with an alarm or were considered poorly motivated to use it, were given a 4 month course of intranasal desmopressin. Of these 26 children, 10 (38%) were dry at the end of 4 months but only two (7%) remained dry after this was withdrawn. After the initial treatment with alarm or desmopressin, 27 children were still enuretic and attending the clinic. They were shown how to use the alarm and eight also used the dry bed training technique: 15 had become dry after a further 6 months. Of the 12 children who made no response to intranasal desmopressin, nine were given this medication under supervision in hospital; seven of these children still wet the bed despite producing small amounts of concentrated urine overnight. They also had small measured diurnal bladder capacities. We conclude that if a 4 month course with an enuretic alarm is unsuccessful, rather than using desmopressin, the alarm should be continued with relearning and consideration given to additional use of the dry bed training technique. The major factor causing nocturnal enuresis in children is likely to be a small nocturnal bladder capacity.

Low dose famotidine in the prevention of sleep disturbance caused by heartburn after an evening meal

AIM

To determine whether, in a susceptible population, dosing with 10 mg famotidine 1 h before an evening meal could decrease the interference with sleep caused by heartburn.

METHODS

Patients with a history of frequent heartburn (n = 309) were randomized to receive 10 mg famotidine or placebo 1 h before an evening meal likely to induce symptoms. Patients assessed the efficacy of the treatment in preventing heartburn after the meal, at bedtime and during the night. The number of awakenings due to heartburn and the consumption of antacid tablets taken to alleviate symptoms were also recorded.

RESULTS

Treatment groups were well matched and data from 302 patients were available for analysis. Compared to placebo, famotidine treated patients had: less heartburn after the meal (P < 0.0001 mean global scores), less interference with getting to sleep (P = 0.0156 mean global scores), fewer awakenings (P = 0.0001 difference in mean number) and better control of heartburn during the night (P < 0.0001 mean global scores). They were also almost three times less likely to need antacid treatment than the placebo group during the night (relative odds for no antacid 2.78 (95% CI: 1.29-5.96). Only four patients in each group suffered adverse events.

CONCLUSION

Taking a 10 mg dose of famotidine 1 h before an evening meal appears to be a successful and well tolerated strategy for preventing post-prandial heartburn and avoiding the associated interference with sleep.