Sarcoidosis in a Hong Kong Chinese woman

Sarcoidosis is rare in the Chinese population and most patients with sarcoidosis present with asymptomatic mediastinal lymphadenopathy. We report on a 31-year-old woman who presented with bilateral hilar lymphadenopathy and pulmonary infiltration that spontaneously resolved without treatment, and we present a review of the literature on sarcoidosis among the Hong Kong Chinese population.

One-week use of ranitidine bismuth citrate, amoxycillin and clarithromycin for the treatment of Helicobacter pylori-related duodenal ulcer

BACKGROUND

Proton pump inhibitors have been widely used in combination with amoxycillin, clarithromycin or metronidazole for the treatment of Helicobacter pylori infection.

AIM

To study the effects of 1-week ranitidine bismuth citrate (RBC)-based triple therapy in the treatment of H. pylori-related duodenal ulcers.

METHOD

Patients with duodenal ulcers and H. pylori infection were prospectively randomized to receive either RBC with amoxycillin and clarithromycin for 1 week (RAC), or omeprazole with amoxycillin and clarithromycin for 1 week (OAC). No additional ulcer healing drug was used after the 1-week medication. Patients were assessed for H. pylori eradication, ulcer healing and side-effects after receiving the therapies.

RESULTS

One hundred consecutive patients were recruited to this study, with 50 patients randomized to each treatment group. In the intention-to-treat analysis, duodenal ulcers were completely healed in 45 (90%) patients in the RAC group and 43 (89.6%) in the OAC group (P = 1.0). H. pylori eradication was confirmed in 47 (94%) in the RAC group and 42 (87.5%) in the OAC group (P = 0.31). There was no significant difference in the severity of side-effects experienced by the two treatment groups.

CONCLUSION

One-week RBC-based triple therapy is an effective treatment for H. pylori-related duodenal ulcers. The therapeutic effects are comparable to a 1-week course of proton pump inhibitor-based triple therapy.

Nonmalignant hyperthermia on induction of anesthesia in a pediatric patient undergoing bidirectional Glenn procedure

We report a case of severe hyperthermia in a 6-month-old boy with a single ventricle, dextrocardia, asplenia, and transposition of the great arteries, during induction of anesthesia on three separate occasions. To our knowledge, this is the first case reported of repeated intraoperative hyperthermia not related to malignant hyperthermia, infection, neuroendocrine tumor, or iatrogenic causes (e.g., anticholinergic blockade or warming devices). The severe hyperthermia may be secondary to the medications given before and during induction and/or the stress of the induction. Among the induction medications given during the three episodes, fentanyl is the most likely contributing drug. Human data indicate that opioids increase the sweating threshold and decrease the vasoconstriction and shivering thresholds. The medications could cause a widening in the thermoregulation interthreshold and the stress could induce nonshivering thermogenesis.

Ulcer recurrence after gastric surgery: is Helicobacter pylori the culprit?

OBJECTIVES

Helicobacter pylori is the most important cause of recurrent peptic ulcer disease. However, its role in ulcer recurrence after peptic ulcer surgery is unclear. We aimed at studying the prevalence and distribution of H. pylori in patients who had undergone peptic ulcer surgery, and any association between H. pylori infection and ulcer recurrence in these patients.

METHODS

Patients with previous vagotomy or partial gastrectomy presenting with dyspepsia or ulcer bleeding were recruited. Ulcer recurrence was documented by endoscopy. Biopsy specimens were taken from the gastric remnant and gastroenteric anastomosis in patients with previous partial gastrectomy, or from the antrum and corpus in vagotomized patients. H. pylori infection was detected by either a positive rapid urease test or the presence of the bacteria on histology.

RESULTS

Ninety-three patients were studied; 73 patients (78%) had partial gastrectomy and 20 (22%) had vagotomy with drainage. H. pylori infection was documented in 36 patients (49%) in the gastrectomy group and in 13 (65%) in the vagotomy group. Thirty-six patients in the gastrectomy group had recurrent ulcers and 15 (42%) of them had H. pylori infection. Twelve patients in the vagotomy group had recurrent ulcers and eight (67%) of them were H. pylori positive. The prevalence of H. pylori infection did not differ between patients with or without ulcer recurrence.

CONCLUSION

H. pylori infection cannot account for ulcer recurrence after peptic ulcer surgery.

Diagnosis of Helicobacter pylori infection after gastric surgery for peptic ulcer: is the rapid urease test useful?

BACKGROUND

The usefulness of the rapid urease test (RUT) in diagnosing Helicobacter pylori infection after peptic ulcer surgery is unknown.

METHODS

Patients who had undergone peptic ulcer surgery were offered endoscopic examination if they presented with dyspepsia or gastrointestinal bleeding. Biopsy specimens were taken for RUT and histology from the corpus and the stoma in patients who had undergone partial gastrectomy or from the corpus and the antrum in patients who had undergone vagotomy. Histologic examination using haematoxylin and eosin stain and Warthin-Starry stain were used as the gold standard.

RESULTS

Ninety patients were studied (69 had partial gastrectomy and 21 had vagotomy). Forty-three patients (32 in the partial gastrectomy group and 11 in the vagotomy group) were positive for H. pylori by histology. The respective sensitivity of RUT was 59% (stoma) and 75% (corpus) in the partial gastrectomy group (P = 0.36) and 55% (antrum) and 73% (corpus) in the vagotomy group (P = 0.51).

CONCLUSIONS

RUT is not sensitive for detecting H. pylori after acid reduction surgery.

Cytopathic effects of the major surface protein and the chymotrypsinlike protease of Treponema denticola

Prominent antigens of Treponema denticola have been suggested to be mediators of the cytopathic effects typically seen in periodontal disease. In the present study of the T. denticola major surface protein (Msp) and the surface-expressed chymotrypsinlike protease complex (CTLP), we characterized the ability of these proteins to adhere to and lyse epithelial cells. Msp and CTLP were closely associated in spirochete outer membranes. Purified Msp, both native and recombinant, and CTLP bound to glutaraldehyde-fixed periodontal ligament epithelial cells. Adherence of Msp was partially blocked by specific antibodies. Adherence of CTLP was partially blocked by serine protease inhibitors and was further inhibited by specific antibodies. Both native Msp and CTLP were cytotoxic toward periodontal ligament epithelial cells, and their cytotoxicity was inhibited by the same treatments that inhibited adherence. Msp, but not CTLP, lysed erythrocytes. Msp complex (partially purified outer membranes free of protease activity) was cytotoxic toward a variety of different cell types. Pore-forming activities of recombinant Msp in black lipid model membrane assays and in HeLa cell membranes were similar to those reported for the native protein, supporting the hypothesis that Msp cytotoxicity was due to its pore-forming activity.

Subgingival microbiota of shallow periodontal pockets in individuals after head and neck irradiation

This study aimed at investigating the subgingival plaque microorganisms of shallow pockets (< or = 5 mm) in subjects who previously received irradiation in the head and neck region for treatment of nasopharyngeal carcinoma. Direct microscopy and anaerobic culture were used. Subgingival paper point samples were taken from 6 tooth-sites (one/sextant) per subject for direct microscopy (n = 108). Another set of paper points was taken from the deepest of the previously selected sites (one per subject) with: group A) no bleeding on probing to the sulcus depth (n = 9) and group B) bleeding on probing to the sulcus depth (n = 6) for microscopic and anaerobic culture study. Under the microscope, the microflora was found to be a complex mixture comprising gram-positive and gram-negative cocci, rods and filaments, fusiforms, curved rods and spirochetes. Low level of fungi were observed and mycelia were occasionally detected. There was no significant variation in the plaque bacterial morphotypes observable according to sites of isolation and no significant difference between group A and group B in morphotypes of the different microflora. The predominant cultivable microflora comprised several species of facultative and obligate anaerobic bacteria: Gemella, Peptostreptococcus, Staphylococcus, Stomatococcus, Streptococcus, Actinomyces, Eubacterium, Lactobacillus, Propionibacterium, Neisseria, Veillonella, Bacteroides, Campylobacter, Capnocytophaga, Fusobacterium, Kingella, Porphyromonas and Prevotella species. There was no difference between the two groups except the significantly higher proportion of Kingella dentrificans isolated from group B sites. However, colonization of the gingival sulcus in these individuals by microbes that are normal flora of: skin (Peptostreptococcus prevotii and Propionibacterium granulosum) and gut (Eubacterium aerofaciens, Fusobacterium mortiferum and Fusobacterium varium) was detected. These findings appear to suggest that the major components of the subgingival microflora of shallow sites in previously head- and neck-irradiated individuals are similar to that of gingivitis sites in the normal population although they may contain bacterial or fungal species uncommon in normal subjects.

One-week antibiotics versus maintenance acid suppression therapy for Helicobacter pylori-associated peptic ulcer bleeding

Bleeding peptic ulcer is the most important cause of upper gastrointestinal bleeding. Our aim was to compare the effect of anti-Helicobacter therapy with maintenance treatment of H2-receptor antagonist in the prevention of relapses of ulcer and bleeding. Patients with bleeding duodenal or gastric ulcers and H. pylori infection were randomized to receive either a one-week course of triple therapy with bismuth subcitrate, metronidazole, and tetracycline plus ranitidine or a six-week course of ranitidine 300 mg/day. After the ulcers healed, the antibiotic-treated patients were not given any medication, whereas the ranitidine-treated patients continued to receive a maintenance dose of 150 mg/day. One hundred twenty-six patients were randomized to receive anti-Helicobacter therapy and 124 patients to receive long-term ranitidine. H. pylori eradication was achieved in 98.2% in those who received triple therapy and 6.1% in those who received ranitidine (P < 0.0001). At the six-week follow-up, ulcer healing was documented in 88.2% in those who received triple therapy and 86.1% in those who received ranitidine (P = 0.639). Recurrent ulcer developed in nine of the ranitidine-treated patients and three of them presented with recurrent upper gastrointestinal bleeding. One patient in the antibiotic group developed recurrent ulcer without rebleeding (P = 0.01). It is concluded that eradication of H. pylori is sufficient for the prevention of recurrent bleeding ulcers.

Does smoking predispose to peptic ulcer relapse after eradication of Helicobacter pylori?

OBJECTIVES

To investigate whether smoking would increase ulcer recurrence after eradication of Helicobacter pylori (H. pylori) without maintenance acid-suppression therapy.

METHODS

A total of 287 patients, 256 patients with duodenal ulcers and 31 patients with gastric ulcers, were followed-up for up to 18 months after ulcer healing and successful eradication of H. pylori. There were 83 smokers (defined as smoking > or = 10 cigarettes/day) and 204 patients who never smoked or stopped smoking after the diagnosis of peptic ulcer disease. None were taking nonsteroidal anti-inflammatory drugs or receiving maintenance acid suppression therapy. Endoscopy was repeated either at the end of the follow-up period or when ulcer symptoms recurred.

RESULTS

Of the 83 smokers, 3 (3.6%) had ulcer recurrence, which included two duodenal ulcers and one gastric ulcer. Of the 204 nonsmokers, 4 (2.0%) had ulcer relapse, and all being recurrent duodenal ulcers. Four smokers (4.8%) and nine nonsmokers (4.4%) had recurrence of H. pylori infection after 10-18 months. There was no significant difference in ulcer relapse or recurrence of H. pylori infection between smokers and nonsmokers.

CONCLUSIONS

Cigarette smoking did not increase the recurrence of peptic ulcers after eradication of H. pylori.

Conservation of msp, the gene encoding the major outer membrane protein of oral Treponema spp

The major surface protein (Msp) of Treponema denticola has been implicated as a mediator of the interaction between the spirochete and the gingival epithelium in periodontal diseases. Previous studies showed that the Msp of T. denticola ATCC 35405 had porin activity, depolarized epithelial cell membranes, bound to extracellular matrix components of epithelial cells, and formed a regular hexagonal surface array in the treponemal outer membrane. The gene encoding Msp in ATCC 35405 was recently cloned, sequenced, and expressed in Escherichia coli (J. C. Fenno, K.-H. Müller, and B. C. McBride, J. Bacteriol. 178:2489-2496, 1996). In the present study, we identified genes encoding Msp-like proteins in several oral spirochetes. A prominent heat-modifiable Msp-like protein having an apparent molecular mass of between 43 and 64 kDa was present in all oral spirochete strains tested. Antibodies raised against the ATCC 35405 Msp reacted strongly with the Msp proteins of T. denticola ATCC 35404 and T. vincentii, reacted very weakly with the Msp protein of T. denticola ATCC 33520, and did not react with T. denticola OTK, T. socranskii, and T. pectinovorum. The msp loci of the T. denticola strains and T. vincentii were identified in analyses using PCR with oligonucleotide primers derived from the DNA sequence flanking msp in ATCC 35405. Southern blot analysis showed at least three groups of related msp DNA sequences. Comparison of DNA sequences of the 5' and 3' ends of the msp genes showed high sequence homology in the flanking regions and signal peptide coding regions, while the homologies between regions encoding the mature peptide were as low as 50%. The entire msp DNA sequences of T. denticola ATCC 33520 and OTK were determined, and the deduced Msp amino acid sequences were compared to the sequence of the previously reported Msp of ATCC 35405. The results show that the msp locus is conserved in oral treponemes but that there are significant differences between the mature Msp peptides of different strains. Further studies of the antigenic domains, functional domains, and physical structures of Msp proteins, based on these results, will enhance understanding of the role of Msp in the cytopathology associated with oral spirochetes.

The major surface protein complex of Treponema denticola depolarizes and induces ion channels in HeLa cell membranes

The oral spirochete Treponema denticola is closely associated with periodontal diseases in humans. The 53-kDa major surface protein (Msp) located in the outer membrane of T. denticola serovar a (ATCC 35405) has both pore-forming activity and adhesin activity. We have used standard patch clamp recording methods to study the effects of a partially purified outer membrane complex containing Msp on HeLa cells. The Msp complex was free of the chymotrypsin-like proteinase also found in the outer membrane of T. denticola. Msp bound to several HeLa cell proteins, including a 65-kDa surface protein and a 96-kDa cytoplasmic protein. The Msp complex depolarized and increased the conductance of the HeLa cell membrane in a manner which was not strongly selective for Na+, K+, Ca2+, and Cl- ions. Cell-attached patches of HeLa cell membrane exposed to Msp complex exhibited short-lived channels with a slope conductance of 0.4 nS in physiologically normal saline. These studies show that Msp binds both a putative epithelial cell surface receptor and cytoplasmic proteins and that the Msp complex can form large conductance ion channels in the cytoplasmic membrane of epithelial cells. These properties may contribute to the cytopathic effects of T. denticola on host epithelial cells.

Cytopathic effects of Treponema denticola chymotrypsin-like proteinase on migrating and stratified epithelial cells

The effects of Treponema denticola and its outer membrane-bound chymotrypsin-like proteinase on periodontal ligament epithelial cell cultures at different stages of maturity were studied. In sparse cultures with migrating epithelial cells, large intracellular vacuoles were formed rapidly following exposure to live T. denticola. Treponemes showing structural damage were seen occasionally inside membrane-bound vesicles. Intensive membrane blebbing occurred in infected cells and continued for up to 48 h before the cell died. Blebbing could also be induced by a purified chymotrypsin-like proteinase of T. denticola. Cortical actin and alpha-actinin of the bacterium-treated cells showed disorganization, and pericellular fibronectin was degraded by both whole T. denticola and the isolated proteinase. Epithelial cells with well-formed lateral cell contacts appeared to be more resistant to the effects of T. denticola than migrating isolated cells. In multilayer epithelial cultures, adhesion of T. denticola and membrane blebbing were observed infrequently. There was no evidence of invasion of T. denticola into epithelial multilayers. However, immunogold electron microscopy showed rapid transport of T. denticola chymotrypsin-like proteinase into newly formed large intracellular vacuoles within the epithelial layers. These vacuoles were lined by membranes studded with ribosomes. T. denticola-treated epithelial multilayers had loose cell contacts, collapsed intercellular spaces, and increased permeability. Through its capacity to cause these unique cytopathic effects, the chymotrypsin-like proteinase of T. denticola has the potential to contribute to the initiation of periodontal disease.

The syndrome of lethal catatonia

Lethal catatonia (LC) is a life-threatening neuropsychiatric syndrome associated with a host of psychiatric, neurologic and medical conditions. The clinical picture is characterised by fragmented psychotic symptoms, catatonic phenomena particularly alternating stupor and agitation, altered consciousness, hyperthermia and other autonomic disturbances. A case of LC in a 19-year-old Chinese woman showing a dramatic response to lorazepam and bromocriptine is described and a brief overview of the contemporary literature is provided.

Excimer laser photorefractive keratectomy for myopia: six-month follow-up

In this study, 108 eyes of 62 patients had photorefractive keratectomy (PRK) with a 193 nm excimer laser to correct myopia. The eyes were assigned to one of three groups: low, moderate, or high myopia. Six months after PRK, 88.9% of eyes in the low myopia group, 90.0% in the moderate myopia group, and 23.8% in the high myopia group achieved an uncorrected visual acuity of 20/40 or better. In the low myopia group, 88.9% were within +/- 1 diopter (D) of attempted correction, as were 70.0% in the moderate group and 18.8% in the high myopia group. There were no significant complications. We conclude that excimer laser PRK appears to be a safe and relatively accurate procedure to correct low to moderate myopia but not high myopia because of regression over time.

Microbiology of the pericoronal pouch in mandibular third molar pericoronitis

The microorganisms associated with mandibular third molar pericoronitis were investigated using direct microscopy and anaerobic culture method. The pericoronal pouch was sampled with paper points in A) 8 patients without mandibular third molar pericoronitis and B) 6 patients with mandibular third molar pericoronitis. Under the microscope, the microflora was found to be a complex mixture comprising gram-positive and gram-negative cocci, rods and filaments (including fusiform and curved rods), motile rods and spirochetes. Significantly higher proportions of motile, gram-negative rods were found in group B than in group A. The predominant cultivable microflora of 9 samples: A (4) and B (5) comprised several species of facultative and obligate anaerobic bacteria, namely Peptostreptococcus, Streptococcus, Actinomyces, Eubacterium, Propionibacterium, Veillonella, Porphyromonas, Prevotella, Bacteriodes, Fusobacterium, Campylobacter, Staphylococcus, Stomatococcus, Lactobacillus, Neisseria, Capnocytophaga, Haemophilus, Selenomonas and Centipeda species. The microflora in pericoronitis appeared similar to that of diseased periodontal pockets.

Pore-forming properties of the major 53-kilodalton surface antigen from the outer sheath of Treponema denticola

A 53-kDa protein from the outer sheath of the oral spirochete Treponema denticola was purified to homogeneity and shown to reconstitute channels in black lipid bilayer model membranes. The channel had a single-channel conductance of 1.8 nS in 0.1 M KCl, making this the largest porin channel observed to date (estimated diameter, 3.4 nm). Electron micrographs of 53-kDa-protein-containing outer sheaths of T. denticola showed a regular hexagonal array of darker staining pits.

Characterization, cloning, and binding properties of the major 53-kilodalton Treponema denticola surface antigen

Treponema denticola surface proteins were studied for their biochemical and biological characteristics. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis of detergent extracts of whole cells revealed a major protein of 53 kDa and a number of minor proteins. Antiserum raised against whole cells of T. denticola ATCC 35405 reacted with the 53-kDa protein and a 72-kDa protein but not with the other proteins. Immunoelectron microscopy with anti-53-kDa-protein antibodies showed that the 53-kDa protein is located on the surface of the cell. SDS-PAGE analysis of unheated samples indicated that the 53-kDa protein is the major component of oligomers with molecular masses ranging from 130 to 300 kDa. Western blot (immunoblot) analysis showed that the high-molecular-mass oligomers reacted with whole-cell antiserum and anti-53-kDa-protein antibody. The aggregates dissociated into their subunits after heating to 70 degrees C. Isoelectric focusing followed by SDS-PAGE indicated that the 53-kDa protein was separated into several forms with apparent pI values ranging from 8.0 to 5.5. The oligomeric forms were highly resistant to proteolysis by trypsin and proteinase K, whereas the monomeric proteins were readily digested. A clone expressing a 53-kDa antigen in Escherichia coli was isolated from a lambda ZAP II DNA library of T. denticola ATCC 35405. The recombinant protein had exactly the same molecular mass as the major 53-kDa T. denticola surface protein and reacted with antisera raised against this protein. The role of T. denticola ATCC 35405 surface proteins in attachment to laminin, fibronectin, gelatin, fibrinogen, and bovine serum albumin (BSA) was studied by a modified Western blot binding assay. Fibronectin, laminin, and fibrinogen attached to the 53-kDa surface protein of T. denticola as well as to a 72-kDa protein, whereas no attachment to gelatin or BSA was observed. Attachment could be inhibited by pretreating the blots with fibrinogen but not with gelatin or BSA. Our results suggest that the 53-kDa major surface protein of T. denticola may play a role in the attachment to host proteins and may thus be an important virulence determinant of this species.

Development of an automated human sperm quality system

A computer-automated system, including hardware and software components, is developed for objective assessment of human sperm density and other characteristics, including morphological abnormalities and motility. The hardware component essentially consists of an IBM AT, a relatively low-cost image processing board and other inexpensive commercially available instruments. On the other hand, the software component is developed through the incorporation of image analysis, pattern recognition and modelling techniques with the knowledge of human reproduction from the available literature. The whole system is expected to produce a practical and cost-effective means for the routine assessment of human semen quality.

Determination of vitamin U and its degradation products by high- performance liquid chromatography with fluorescence detection

A high-performance liquid chromatographic method has been developed for the determination of vitamin U in tablets and capsules. Threonine was employed as the internal standard through the assay. The o-phthalaldehyde derivatives were prepared and then chromatographed isocratically on a reversed-phase C18 column. The optimum reaction time for both vitamin U and threonine at pH 10.5 is 5 min. Vitamin U and its major degradation product in the dosage forms, viz., methionine sulphoxide, were separated and quantified with a relative standard deviation of about 1%, using a fluorescence detector with excitation and emission wavelengths at 340 and 450 nm respectively. A linear relationship has been established between the peak area ratio of vitamin U/threonine and the concentration of vitamin U over the range of 2.5-50 micrograms/ml.

Failure to prostaglandin A1 to modify renal diatrizoate uptake in experimental acute renal failure

Acute renal failure (ARF) was induced in rats by intramuscular injection of glycerol. Forty-eight hours later prostaglandin A1 (PGA1) in a dose of 1, 5 or 25 microgram/kg bodyweight or phosphate buffer was infused intravenously over 15 min into these animals and controls. After 14 min, 125I-labeled diatrizoate was injected intravenously in a dose of 15 mg/kg bodyweight. Uptake and distribution of diatrizoate were measured one minute later in whole kidneys or kidney slices to provide indices of glomerular filtration. Diatrizoate concentrations were also measured in liver, plasma and washed red cells. Plasma volume was estimated with 125I-labeled albumin. PGA1 produced a dose-related increase in plasma diatrizoate concentration in ARF which was not accounted for by changes in uptake by the kidney, liver or red cells or by changes in plasma volume. It exceeded the relatively small increase in diatrizoate uptake which occurred in the kidney. Intrarenal distribution of diatrizoate did not change. These observations in the kidney suggest that intravenous PGA1 does not improve glomerular filtration in this model of established ARF.

Effect of rotation on radiographic dimensions of the humerus and femur

Ten humeri and ten femora were radiographed in nine positions of longitudinal rotation. In each position total, medullary and cortical widths of the diaphyses (TW, MW, CW) were measured to assess the effect of rotation on these dimensions. The results were expressed as differences from the values in the neutral position (delta TW, delta MW, delta CW). In the humerus, medial rotation produced greater changes than lateral rotation. Though rotation in either direction increased CW, the systematic error due to medial rotation to only 5 degrees (approximately +0.0058 cm per degree) was more than double that due to lateral rotation. In the femur, lateral rotation had the greater effect, producing a marked decrease in CW (approximately -0.0072 cm per degree). Medial rotation produced only a slight increase in CW. The ratios CW/TW ("cortical index") and CA/TA ("area ratio") were calculated and expressed as differences from the values in the neutral position (delta CW/TW, delta CA/TA). Rotation affected these variables much less than the linear dimensions. Furthermore, through the variance of delta TW, delta MW and delta CA/TA increased only slightly or not at all. These results suggest that if radiographic morphometry is to be applied to the humerus and femur, these ratios rather than transverse dimensions should be used. Sequential changes in CW may be totally obscured by small rotational errors.