Probability of appendicitis before and after observation

STUDY OBJECTIVE: To examine patients with abdominal pain for changes in probability of appendicitis during observation. STUDY DESIGN: Retrospective cohort study. SETTING: University-affiliated community hospital. METHODS: 252 patients with abdominal pain who were examined underwent short-term (10.4 hours) observation (95% confidence interval [CI], 8.7, 12.1) before the decision to operate during a one-year period. Alvarado's scoring system and a probability-of-diagnosis nomogram were used to assign scores and estimate probability of appendicitis. MEASUREMENTS AND RESULTS: In the study group, mean score of patients with appendicitis increased after observation from 6.8 (95% CI, 6.2, 7.4) to 7.8 (95% CI, 7.3, 8.3), corresponding to a change in probability of appendicitis from 50% to 65%. Mean score of patients without appendicitis decreased from 3.8 (95% CI, 3.5, 4.1) to 1.6 (95% CI, 1.58, 1.62), corresponding to a change in probability from 35% to 22%. The difference between mean scores for patients with and without appendicitis increased from 2.6 (95% CI, 2.0, 3.2) to 6.2 (95% CI, 6.15, 6.25) during observation. The study group initially had intermediate probability of appendicitis (score, 4.35; 95% CI, 4.04, 4.66) compared with high probability for patients who went directly to surgery after their initial evaluation (63 patients; score, 7.59; 95% CI, 7.05, 8.73) and low probability for patients with abdominal pain who were sent home after their initial evaluation without observation or surgery (2,097 patients; score, 1.87; 95% CI, 1.48, 2.26). CONCLUSION: In this group of patients with intermediate initial probability of appendicitis, observation improved the ability to distinguish patients with from those without appendicitis.     

Inhibition of human subgingival plaque protease activity by chlorhexidine.

Subgingival plaque samples from three discrete sites in each of eight patients with adult chronic periodontitis were used to determine the ability of 0.001, 0.01, 0.1 and 1.0 mM chlorhexidine to inhibit bacterial proteolytic activity. This activity was measured by monitoring the increase in relative fluorescence (excitation and emission wavelengths of 495 and 525 nm, respectively) accompanying the degradation of fluorescein isothiocyanate (FITC)-labelled bovine serum albumin or FITC-labelled transferrin. Chlorhexidine at concentrations of as low as 0.01 mM inhibited the proteolytic degradation of both substrates by more than 50%. As the growth of dental plaque bacteria is dependent upon the liberation of nutrients (amino acids, peptides and carbohydrates) from host-derived macromolecules, similar effects in vivo might explain the ability of chlorhexidine to inhibit plaque formation at subminimal inhibitory concentrations.     

Development of dental plaque on the incisor teeth of monkeys (Macaca fascicularis).

Bacterial plaque which had accumulated for 0.5, 1, 2, 4, 7, 14 and 28 days was cultured from the labial surface of one of the central incisor teeth in 15 monkeys (Macaca fascicularis). Each sampling area was defined by a metal well contained within a custom-made removable acrylic block. The number (log10) of the total colony forming units (c.f.u.) increased significantly from 3.40 to 6.02 between 0.5 and 28 days. Similarly the number of streptococci increased from 2.80 to 4.79 during the same period, although when expressed as a percentage of the total c.f.u., the proportions decreased from 34.9 per cent at 1 day to 6.9 per cent at 7 days and then remained at that level. The number of micro-aerophilic actinomyces increased throughout the period of plaque accumulation and comprised 15.3 per cent of the total c.f.u. at 28 days. Neisseriae were infrequently isolated from 0.5- and 1-day-old plaque and were not recovered at more than 1 per cent of the total c.f.u. during any period of plaque accumulation. The fastest doubling time (median) of the total c.f.u. was 1.9 h (range 1.3-18.5 h). The rapid development of dental plaque after tooth cleaning emphasizes the importance of regular and meticulous oral hygiene to control the accumulation of potentially periodontopathic and cariogenic bacteria.     

Prevalence of atopy and range of bronchial response to methacholine in 7 and 11 year old schoolchildren.

A sample of 397 from 2503 children aged 7 and 11 years, who took part in an earlier questionnaire study of respiratory symptoms in Southampton, was chosen for methacholine bronchial provocation and allergen skin testing. Results were obtained from 330 (84%). A good level of repeatability was achieved for bronchial provocation testing giving a 95% confidence interval equivalent to 1.74 doubling concentrations. The main problem encountered with methacholine was its bitter taste in high concentrations. The proportion of children, in whom the dose of methacholine which produced a fall of 20% in the forced expiratory volume in one second (PD20 methacholine) was less than or equal to 6.4 mumol, fell from 29.1% at 7 years to 16.5% at 11 years. The prevalence of atopy increased from 26% at 7 years to 31.6% at 11 years. A highly significant association was found between bronchial responsiveness to methacholine and atopy, which was independent of symptoms or age group.     

Ureaplasma in lung. 2. Association with bronchopulmonary dysplasia in premature newborns

Infants with Ureaplasma urealyticum in the lower respiratory tract are at risk for chronic lung disease (CLD) or bronchopulmonary dysplasia (BPD) but causality has been difficult to prove. The goal of this study was to identify ureaplasma in human neonatal lung tissue using the in situ hybridization (ISH) procedure described in Part 1 (Exp. Mol. Pathol., in press) of this report. By correlating their presence with the histopathologic findings, it may be possible to provide further evidence of the pathogenicity of ureaplasmas and their association with BPD. Lung autopsy tissue from seven infants with positive cultures and seven infants with negative cultures for ureaplasma were included in the study. All culture-positive infants were positive for ureaplasma on ISH and all had histopathologic evidence of BPD. Two of the seven infants with negative cultures were positive for ureaplasma with ISH. Of interest, these two infants were also found to have BPD at autopsy. The other five infants with negative cultures were also negative for ureaplasma on ISH and had no evidence of BPD. This study correlates the presence of U. urealyticum by ISH with the finding of BPD on histopathologic evaluation and provides evidence that it has a role in the development of CLD.     

Cloning and sequence analysis of the glucoamylase gene of Neurospora crassa

A 1.0-kb DNA fragment, corresponding to an internal region of the Neurospora crassa glucoamylase gene, gla-1, was generated from genomic DNA by the polymerase chain reaction, using oligonucleotide primers which had been deduced from the known N-terminal amino-acid sequence or from consensus regions within the aligned amino-acid sequences of other fungal glucoamylases. The fragment was used to screen an N. crassa genomic DNA library. One clone contained the gene together with flanking regions and its sequence was determined. The gene was found to code for a preproprotein of 626 amino acids, 35 of which constitute a signal and propeptide region. The protein and the gene are compared with corresponding sequences in other fungi.     

Monocytoid B cell lymphoma.

The clinical, light microscopic, ultrastructural, immunocytochemical and cytogenetic features of a case of monocytoid B cell lymphoma were investigated. The tumour initially affected the cervical and supraclavicular nodes, but 33 months later affected the left parotid salivary gland. The patient had subclinical Sjögren''s syndrome. The neoplastic cells showed characteristic morphological features and had peri- and interfollicular distribution in the node. Immunocytochemically the tumour cells were L26, 4KB5, MB2, CD19, CD20, CD22 and IgM/kappa positive. Prominent plasmablastic plasmacytoid differentiation was present in the recurrent tumour, suggesting an origin from post-follicular B cells. The lymphoma cells showed unusual cytogenetic abnormalities.