[Polymerase chain reaction applied for detection of Toxoplasma gondii in lymph nodes]

In order to investigate the morbidity of toxoplasmic lymphadenitis, polymerase chain reaction (PCR) was used to detect DNA of Toxoplasma gondii within lymph nodes in 3 groups of 120 patients with different diseases. After extracting the DNA of each sample, PCR was employed to amplify toxoplasma DNA. The results showed that the amplification product of 210 bp was confirmed in 7 patients: 3 cases of Hodgkin's disease (HD), 2 cases of non-Hodgkin's lymphoma (NHL) and 2 cases of chronic lymphadenitis (CL). Each PCR product was then subjected to Southern blot hybridization. Besides the 7 cases proved by PCR, 1 case of CL was found positive. The positive percentages of HD, NHL and CL were 9.38% (3/32), 4.88% (2/41), and 6.38% (3/47), respectively. The total positive rate was 6.67% (8/120).

Genetic disruption of host nitric oxide synthase II gene impairs melanoma-induced angiogenesis and suppresses pleural effusion

Our previous study showed that genetic disruption of nitric oxide (NO) synthase II (NOS II) expression inhibits the metastatic ability of non-immunogenic B16 melanoma cells in syngeneic mice. In the present study, the mechanisms for this metastasis suppression were determined. B16-BL6 and B16-F10 murine melanoma cells were injected i.v. into syngeneic wild-type (NOS II(+/+)) and NOS II-null (NOS II(-/-)) C57BL/6 mice. Both melanoma cells produced less and smaller experimental pulmonary metastases in NOS II(-/-) mice than in NOS II(+/+) mice. Moreover, less metastatic pleural effusion was observed in NOS II(-/-) mice than in NOS II(+/+) mice. Immunohistochemical analyses indicated that absence of NOS II expression was correlated with decreased vascular endothelial growth factor expression and tumor-associated vascular formation. After activation with lipopolysaccharide and IFN-gamma, neither melanoma cell line produced detectable levels of NO. Our data demonstrate that tumor-induced expression of host NOS II enhances melanoma metastasis and pleural effusion, at least in part, through regulation of vascular formation and vascular permeability.

Ethnic comparisons of disease severity in children hospitalized with pneumonia in New Zealand

OBJECTIVE

To determine if there are ethnic differences in disease severity in children hospitalized with pneumonia in New Zealand.

METHODOLOGY

A population based audit of children hospitalized in Auckland with pneumonia over 12 months from 1 November 1994 to 31 October 1995. The study population was children aged from 0 to 14 years with a discharge diagnosis of pneumonia. The sample was stratified by ethnicity and included 151 Pacific, 85 Mäori and 151 European children. Measurements were made of demographics and prehospital care; vital signs and therapy received in the emergency department and inpatient wards and laboratory investigations performed. Comparisons between the three ethnic groups were adjusted for age, weight, gender, socio-economic status and relationship with primary care.

RESULTS

A larger proportion of Pacific (15%) and Mäori (22%) children than European children (8%) had a respiratory rate elevated for > or = 2 days, odds ratio (OR) (95% CI): Pacific versus European 2.7 (1.1, 6.8), Mäori versus European 4.3 (1.7, 11.6). A larger proportion of Pacific (15%) and Mäori (15%) children than European children (< 1%) had a heart rate elevated for > or = 2 days, OR Pacific versus European 17.2 (3.2, 320), Mäori versus European 26.1 (4.4, 508). Compared with European children, a larger proportion of Pacific and Mäori children received intravenous fluids and antibiotics. A larger proportion of Pacific (29%) and Mäori (27%) children than European children (11%) received oxygen for > = 2 days, OR Pacific versus European 3.2 (1.6, 6.6), Mäori versus Europeans 2.6 (1.2, 6.2).

CONCLUSIONS

Based on the comparisons of vital signs and intensity of therapy, Pacific and Mäori children hospitalized with pneumonia have more severe pneumonia than European children.

A prospective evaluation of surgeon performed sonography as a screening test in blunt abdominal trauma

INTRODUCTION

Sonography has found a role in the evaluation of patients with abdominal injury. However, the accuracy of sonography as performed by non-radiologists remains controversial. This study aims to determine the accuracy of focused abdominal sonography for trauma when performed by surgeons.

MATERIALS AND METHOD

Over a 1-year period, 48 patients with abdominal injury were initially evaluated for free intraperitoneal fluid by sonography. These tests were performed by 2 surgeons who had received instructions and performed a minimum of 30 examinations. Sonographic findings were then compared with other diagnostic modalities including computed tomography (CT) scan, diagnostic peritoneal lavage and exploratory laparotomy.

RESULTS

The sensitivity, specificity, positive predictive value, negative predictive value and accuracy for sonography were found to be 0.86, 0.92, 0.89, 0.90 and 0.89, respectively. Although not specifically sought for, 2 cases of solid organ injury and 1 haemothorax, which were missed in initial examinations and X-rays, were detected on sonography.

CONCLUSION

In conclusion, our initial experience suggests that local surgeons can perform a focused sonographic examination for trauma with acceptable accuracy. Although sonography lacks the sensitivity of diagnostic peritoneal lavage and the accuracy of CT scan, the diagnostic algorithm for abdominal trauma should include sonography as a screening test.

Microbiological profile of a shipboard environment and the flora on contact lenses of seamen

PURPOSE

The purpose of this study was to culture and identify the spectrum of organisms (and their sensitivities) that contaminate the extended wear contact lenses of seamen in their working environment. A secondary aim was to identify the most appropriate first-line antibiotic regimen to be used on seamen who sustain contact lens-related corneal keratitis on board ship.

METHODS

Twenty pairs of contact lenses of 20 seamen in one group and 24 pairs in another group wearing contact lenses were collected at the end of 1 week of extended wear. Groups one and two differed only in the way lenses were stored prior to culturing. All contact lenses were then brought to the microbiological lab within 24 hours for culture and sensitivity testing.

RESULTS

The most common contaminants on the contact lenses in this study were Staphylococcus epidermidis and Staphylococcus aureus, organisms resident on the normal eyelids. Enterobacterand Pseudomonas species, present in a shipboard environment, were also identified as contaminants on the contact lenses. The organisms cultured from the contact lenses correlated well with those of normal lid flora as well as from the ship environment and are probably derived from these sources. Storage in saline-containing preservatives yielded significantly less positive bacterial cultures from the contact lenses in our study. All bacterial isolates were sensitive to ciprofloxacin whereas several bacteria resistant to cefazolin and gentamicin were identified.

CONCLUSION

The most common contaminants on the contact lenses in this study were Staphylococcus epidermidis and Staphylococcus aureus, organisms resident on the normal eyelids. Enterobacter and Pseudomonas species, which are normally present in a shipboard environment, were also identified as contaminants on the contact lenses. Ciprofloxacin is effective against all organisms identified as contaminants on the contact lenses in this study. Of all the antibiotics tested, it is probably the most suitable agent against contact lensrelated keratitis under such shipboard circumstances and is thus recommended in these situations.

Renal toxicity of the carcinogen delta-aminolevulinic acid: antioxidant effects of melatonin

An increased incidence of cancer in patients suffering from acute intermittent porphyria (AIP) is thought to be related to delta-aminolevulinic acid (ALA) accumulation. Chronic treatment with ALA augmented 8-oxo-7,8-dihydro-2'-deoxyguanosine levels, decreased microsomal and mitochondrial membrane fluidity and increased lipid peroxidation in blood serum. Co-treatment with melatonin completely counteracted the effects of ALA. Melatonin effectively protects DNA and microsomal and mitochondrial membranes in rat kidney from oxidative damage due to ALA. Because of its low toxicity and anticarcinogenic properties, melatonin could be tested as an agent to reduce oxidative damage in patients with AIP.

The carboxamide feG(NH2) inhibits endotoxin perturbation of intestinal motility

The submandibular gland rat-1 (SMR1) salivary gland prohormone contains several peptides, submandibular gland peptide-T (SGP-T) and the tripeptide, FEG, which possess anti-inflammatory activities. The D-isomeric form of FEG, feG, also is a potent anti-inflammatory peptide. In this study, we compared the inhibitory activity of feG and its carboxamide derivative, feG(NH2), on the perturbations of intestinal motility induced by intravenous lipopolysaccharide. feG(NH2) was 20-30 times more potent than feG in reducing the motility disturbances induced by lipopolysaccharide. feG may undergo square-amidation to yield a hormone that strongly down-regulates intestinal responsiveness to endotoxin.

Melatonin reduces phenylhydrazine-induced oxidative damage to cellular membranes: evidence for the involvement of iron

Phenylhydrazine and iron overload result in augmented oxidative damage and an increased likelihood of cancer. Melatonin is a well known antioxidant and free radical scavenger. The aim of this study was to determine whether melatonin would protect against phenylhydrazine-induced oxidative damage to cellular membranes and to evaluate the possible role of iron in this process. Changes in lipid peroxidation and microsomal membrane fluidity were estimated after the treatment of rats with phenylhydrazine (15 mg/kg body weight, daily, 7 days) alone and melatonin or ascorbic acid (15 mg/kg body weight, two times daily, 8 days), or their combination. Additionally, lipid peroxidation was measured in liver homogenates from untreated and melatonin or ascorbic acid-treated rats in vivo and exposed to iron in vitro. Melatonin, but not ascorbic acid, reduced phenylhydrazine-induced lipid peroxidation in vivo in spleen (3.16+/-0.06 vs. 3.83+/-0.12 nmol/mg protein, P<0.05) and plasma (7. 73+/-0.52 vs. 9.96+/-0.71 nmol/ml, P<0.05) and attenuated the decrease in hepatic microsomal membrane fluidity (1/polarization, 3. 068+/-0.007 vs. 3.027+/-0.008, P<0.05). In vitro exposure to iron significantly enhanced the lipid peroxidation in liver homogenates from untreated (3.34+/-0.75 vs. 1.25+/-0.28, P<0.05) or ascorbic acid-treated rats (2.72+/-0.39 vs. 0.88+/-0.06, P<0.05) but not from melatonin-treated rats (1.49+/-0.55 vs. 0.68+/-0.20, NS). It is concluded that free radical mechanisms are involved in the toxicity of phenylhydrazine and that the antioxidant melatonin, but not ascorbic acid, reduces the toxic affects of phenylhydrazine in vivo and of iron in vitro in cell membranes. Therefore, melatonin co-treatment in conditions of iron overload may prove beneficial.

[Lymphocyte subset and its apoptosis in chronic hepatitis C]

OBJECTIVE

To explore the autoimmune pathogenesis induced by hepatitis C virus.

METHODS

Serum anti-GOR and peripheral blood lymphocyte subset and its apoptosis rate after activated by Pokeweed mitogen (pwm) in vitro were measured by enzyme-linked immunosorbent assay and flow cytometry, respectively. Eighteen individuals with chronic hepatitis C and 16 healthy controls were observed.

RESULTS

The positive rates of serum anti-GOR (66.7%) and ANA (44.4%) were significantly higher in chronic hepatitis C than normal controls (chi(2)=26.86, chi(2)=9.30, P<0.005). The apoptosis percentage of PBMCs and CD3(+)T cell was elevated in individuals with chronic hepatitis C when compared with normal controls (t=2.44, P<0.05). However, the apoptosis percentage of CD4(+)T and CD19(+)B cells in PBMCs was significantly decreased in patients with anti-GOR positive compared to anti-GOR negative (t=3.17, P<0.01; t=2.294, P<0.05). Similarly, the percentage of CD4(+)CD8(+) T cells in anti-GOR positive patients was increased and CD3(+)/CD4(+) was decreased (t=2. 18, P<0.05) compared to anti-GOR negative (t=2.44, P<0.05; t=2.18, P<0.05).

CONCLUSION

autoimmune response exists in chronic hepatitis C patients. There is an imbalance of lymphocyte subset and its apoptosis, which may be one of the important reasons for the mechanism of autoimmune pathogenesis of chronic hepatitis C.

[Investigation of hepatitis B virus infection in blood donors]

To investigate the status of HBV-M and HBV DNA in blood donors, 583 serum samples were detected by ELISA technique and polymerase chain reaction. The results were that hepatitis B virus marker(HBV-M) positive rate was 55.9%(326/583), HBV DNA 9.78%(57/583). The data indicate that there is high incidence of HBV infection in blood donors. The donors should be strictly tested for HBV in the future.

Outdoor work and the risk of pterygia: a case-control study

AIM

To investigate the relationship between outdoor work and pterygium formation in a hospital-based case-control study in Singapore.

METHOD

Sixty-one patients with pterygium (49 males, mean age 54.2 years) and 125 controls (41 males, mean age 50.2 years), excluding patients with cataract and age-related macular degeneration presenting at outpatient clinics of the Singapore National Eye Centre were interviewed face-to-face with a standard questionnaire. Demographic data and information on outdoor work and eye protection, were collected.

RESULTS

Thirty-eight subjects (20.4%) were outdoor workers and 148 (79.6%) were indoor workers. Outdoor workers were more likely to be male smokers and alcohol drinkers with lower family income and higher sunlight exposure than indoor workers. The crude odds ratio for pterygium in outdoor workers was 7.0 (95% confidence interval 3.2, 15.3). The adjusted odds ratio was 4.2 (95% confidence interval 1.7, 10.1).

CONCLUSION

There is a statistically significant association between outdoor work and pterygium formation, which may be related to the higher exposure to sunlight and dust in outdoor workers. Efforts may be made to educate outdoor workers to wear proper equipment to protect their eyes against excessive sunlight.

Risk factors for the development of pterygium in Singapore: a hospital-based case-control study

PURPOSE

A hospital-based case-control study, designed to evaluate the risk factors for the development of pterygium in Singapore.

METHODS

Sixty-one cases and 125 controls were interviewed at the Singapore National Eye Centre. Information on present and past (5 and 10 years ago) exposure to sunlight on weekdays and weekends, sociodemographic data, behavior lifestyle and family history of eye disease was collected.

RESULTS

Patients with pterygia were mostly males, smoked and drank alcohol more often, had lower combined family incomes and were more likely to have a family history of eye disease. The adjusted odds ratios for the development of pterygia were 1.27 (95 percent confidence interval 1.06 to 1.54) and 1.31 (95 percent confidence interval 1.09 to 1.57) for participants who had spent more time in the sun five and ten years ago respectively.

CONCLUSIONS

Pterygium is an important public health problem in Singapore and its development is related to the amount of sunlight exposure.

[Four-year follow-up and molecular epidemiologic investigation of intrafamilial transmission of HCV infection]

OBJECTIVE

To study the intrafamilial transmission of HCV infection.

METHODS

Four-year follow-up and molecular epidemiologic investigation of HCV infection in a village was carried out. The diversity of HCV core region was analysed by reverse transcription nested polymerase chain reaction, Okamoto genotyping method, and single strand conformation polymorphism analysis (SSCP).

RESULTS

The incidence of positivity of anti-HCV and -HCVRNA raised from 21.30% (75/352) to 43.18% (152/352). There were 42 families with two or more members serological positive for anti-HCV and/or -HCVRNA. There were a 3.46-fold increase of intrafamilial propagation of HCV infection in the past 4 years. HCV genotyping by Okamoto method showed that 90.67% (136/150) belonged to Type 1b/II, two cases (1.33%) belong to type 2a/III and three cases (2.00%) were co-infection of both types. Comparison of SSCP patterns revealed that the SSCP of HCV cDNA was identical among members of the same family, but the single strand conformation of HCV cDNA exhibited polymorphism patterns in different families.

CONCLUSION

The results indicate that the cause of marked increase of HCV infection rate in this village in a 4-year period is mainly because of intrafamilial propagation. SSCP is more feasible for molecular epidemiologic investigation of HCV infection than genotyping.

[A study on HBV DNA pre C region A83 mutation in patients with hepatitis B]

Mismatched polymerase chain reaction (MPCR) and restriction fragment length polymorphism assay(RFLP) were performed to detect the HBV DNA pre core A83 mutation in 97 patients with chronic HBV infection in Hunan. HBV DNA pre core A83 mutation were detected in 37 out of 97 patients (37/97,38.1%). It was found that the prevalence of HBV DNA pre core A83 mutation of the patients with severe hepatitis and with CAH(chronic active hepatitis) were significantly higher than those with CPH(chronic persistent hepatitis) and carriers of HBV, and the patients with elevated transaminase (ALT > 70U) or positive HBeAb were significantly higher than those with normal transaminase (ALT < 70U) and with positive HBeAg, respectively. The results suggest that the HBV DNA pre core A83 mutation is associated with active and severe liver tissue in patients with hepatitis B.

[Changes of serum myocardial enzymes in patients with malignant hematologic diseases]

Myocardial enzymes including aspartate aminotransferase (AST), lactate dehydrogenase (LDH), HBD (LDH1 and LDH2), and creatine kinase (CK) and its isoenzyme were monitored in 106 cases of malignant hematologic diseases. The findings were that average values of LDH and HBD increased. There were 82.4% myocardial enzyme levels of 51 patients with leukemia, lymphoma, and myelodysplastic syndrome (MDS) returning to normal or making an obvious reduction after chemotherapy associated with drugs of heart toxicity, while there were increases of the myocardial enzyme levels before chemotherapy. Patients with the increasing of enzyme levels were only 3.9% after chemotherapy. After several courses of chemotherapy, the positive rates of the increasings of CK and CK-MB were higher than that of pretreatment. The results suggest that the injuries of myocardium are possible.

[Genotype distribution of hepatitis C virus in hepatocellular carcinoma tissue in Hunan province]

Genotypes of hepatitis C virus(HCV) were detected by PCR using type-specific primer in 50 patients' hepatocellular carcinoma(HCC) tissue. The results showed that in the 50 HCC specimens, 30(60%) and 3(6%) were infected with the HCV type II and III, 5(10%) and 8(16%) with type II + III and type II + IV, 2(4%) with type II + I + III in combination, respectively. 2 cases were negative for HCV. These data suggest that HCV type II may be a predominant genotype related to hepatocarcinogenesis in Hunan Province, some cases of HCC may result from coinfection of HCV type II and other genotypes, and only few HCC be separately caused by infection of HCV type III.

[A prospective study of posttransfusion hepatitis B virus infection]

OBJECTIVE

To understand the status of HBV posttransfusion infection after blood HBsAg screening of the blood donors.

METHODS

Serum samples of blood recipients and donors were detected for HBV-M and HBV DNA by ELISA technique and polymerase chain reaction respectively.

RESULTS

There were 326 sera positive for HBV-M and 57 for HBV DNA in 583 blood donors' sera. 39 sera were positive for HBV-M and 23 positive for HBV-DNA in 136 sera of blood recipients, the positive seroconversion rates were 28.68% and 16.9% respectively.

CONCLUSIONS

There is high incidence of HBV infection in blood donors though they have been screened for HBsAg. The posttransfusion HBV infections are still occurring, therefore, the blood donors should be strictly tested for HBV-M. If conditions are possible, the HBV DNA had better been screened.

[Ecological effect of CdCl2 on plasmid and role of plasmid in Cd-tolerance of its host]

After treating the plasmid of Escherichia coli HB101 by CdCl2 in vitro or in vivo, the effect of Cd on the structure of plasmid pWH58 DNA was studied through argarose gel electrophesis and restriction fragment length polymorphism analysis. By comparing the growth of E. coli with and without plasmid cultured in the medium with Amp LB and non-anti LB under different concentrations of CdCl2, the effect of Cd on plasmid E. coli of in vivo and the role of plasmid in Cd-tolerance of its host were studied. Cd treatments of E. coli in vitro or in vivo didn't cause an obvious change of the structure of plasmid pWH58 DNA. Plasmid pWh58 could replicate for regeneration and gene express under Cd stress. Plasmid pWH58 of E. coli in vivo lowered Cd-tolerance of its host form 75 mg.L-1 to 50 mg.L-1. Cd-tolerance of E. coli ascended markedly after Cd taming, but had a trend of reversing to original level after restoration, indicating that Cd-tolerance of E. coli could be tamed, but the tamed Cd-tolerance still had no genetic basis.

[Effects of MMP-1 expressing plasmid on rat liver fibrosis]

OBJECTIVE

To observe the effects of MMP-1(Matrix Metalloproteinase-1) expressing plasmid on rat liver fibrosis.

METHODS

We constructed the rat's MMP-1 recombinant plasmid which can be expressed in eucaryotic cells. After encapsulating the MMP-1 recombinant plasmid by lipofectin, we transferred it to the rat's fibrotic liver in vivo intraperitoneally, then observed the effects of the plasmid on the fibrotic liver by RT-PCR, immunohistochemistry and the observation of pathology.

RESULTS

The recombinant plasmid of MMP-1 could increase the degradation of type I and type III collagen in the rat's fibrotic liver according to immunohistochemistry compared with fibrotic modal group(P < 0.01) or compared with colchicine group(P < 0.05). According to the observation of pathology, recombinant plasmid of MMP-1 has some reverse effects on the rat's fibrotic liver compared with fibrotic model group(P < 0.05), but no obvious difference was found between the plasmid and colchicine(P > 0.05).

CONCLUSION

The recombinant plasmid of MMP-1 has some reverse effects on liver fibrosis, but the effects is limited.

High physiological levels of melatonin in the bile of mammals

Bile is an important physiological bodily fluid which functions in the regulation of cholesterol metabolism, promotes the absorption of lipid and fat-soluble vitamins by the gut and serves in the excretion of toxic substances from the liver. Conversely, due to autooxidative processes bile is highly toxic to the hepatocyte and gastrointestinal epithelium. In this investigation, extremely high day time physiological levels of the endogenous antioxidant, melatonin, were measured in the bile of several mammals including rat, guinea pig, rabbit, pig, monkey and humans. Melatonin concentrations in the bile samples ranged from 2,000 to 11,000 pg/ml when measured by radioimmunoassay (RIA). These melatonin levels in bile are 2 to 3 orders of magnitude higher than those in day time serum. The presence of melatonin in bile was confirmed by HPLC with an electrochemical detector. This method, like the RIA, also documented very high levels of melatonin in bile. The presence of high levels of melatonin in bile may be essential to prevent oxidative damage to biliary and small intestinal epithelium induced by bile acids and oxidized cholesterol derivatives.

Augmentation of indices of oxidative damage in life-long melatonin-deficient rats

The chief pineal secretory product, melatonin, is an efficient free radical scavenger and antioxidant. The current study tested whether the life-long reduction of endogenous melatonin levels due to pinealectomy would influence the accumulation of oxidatively damaged products as the animals aged. Rats were either pinealectomized or sham operated when they were 2-months-old. At 25 months of age these animals were killed along with 2-month-old controls. Aging in the pineal-intact animals was associated with increased levels of lipid peroxidation products (malondialdehyde and 4-hydroxyalkenals in the lung, kidney and skin), rises in an oxidatively damaged DNA product (8-hydroxy-deoxyguanosine in liver, kidney and pancreas), and in the levels of protein carbonyls (in the liver). Likewise, advanced age was associated with a significant decrease in membrane fluidity (increased membrane rigidity) of hepatic microsomes in pineal-intact rats. For all of these parameters and in a number of organs, pinealectomy caused further increases in the indices of oxidative damage. Consistent with previous suggestions, the implications of these findings is that aging is associated with the augmented accumulation of oxidatively damaged macromolecules and that these increases are exaggerated when a relative melatonin deficiency is induced by pinealectomy. The findings are consistent with the idea that the accelerated accumulation of oxidatively damaged products after pinealectomy was due to reduction in melatonin since it functions as a free radical scavenger and antioxidant. On the other hand, other pineal secretory products that were reduced as a consequence of pineal removal may have also been responsible for some of the observed changes.

Diagnosis of tuberculous peritonitis

The diagnosis of tuberculous peritonitis may be difficult and elusive. The patient may present with non-specific symptoms of fever, general ill-health or vague abdominal pains. There may be no pulmonary symptoms and the chest X-ray may be normal. The CT scan of the abdomen is sometimes helpful in suggesting the diagnosis. We have found that laparoscopic examination of the abdominal contents and the peritoneum is an effective way to obtain a conclusive diagnosis.

Pterygium: prevalence, demography and risk factors

Pterygium is not just a degenerative disease, but may be a proliferative disorder of the ocular surface. The etiology of pterygia has intrigued researchers for centuries. Several surveys have consistently shown that countries nearer the equator have higher rates of pterygia. A possible reason for this geographic variation is that (ultraviolet) UV B light may be a risk factor for the development of pterygia. UV B radiation may induce cellular changes in the medial limbus of the cornea. Several case-control and cross-sectional studies have attempted to accurately quantify UV light exposure and document its relationship with pterygia. Genetic attributes and other lifestyle behaviors may also contribute to the development of pterygia. However, further research efforts are needed to enable us to better understand the relative contribution of the different risk factors and how each risk factor may be linked to pterygium formation. In addition, the underlying mechanism of the effects of UV radiation needs to be further evaluated. By readdressing these unresolved issues in a newly proposed epidemiological study, new measures might be taken to reduce incidences and improve clinical managements of diseases, in addition to preventing UV exposure by eliminating other contributory factors. Meanwhile, preventive measures such as protection of the eyes by the wearing of sunglasses with UV B protective lenses and brimmed hats outdoors are recommended.

Conjunctival grafting for ocular surface disease

The procedure of transplanting healthy conjunctiva onto eyes with damaged ocular surface epithelium was first described by Thoft in 1977. Today, conjunctival autografting is widely used in pterygium surgery and has been shown to be both safe and effective in reducing pterygium recurrence. Several randomized, controlled, clinical trials have been reported in the literature, and conjunctival autografting is now recognized to have an efficacy equal to that of such adjunct therapies as beta-irradiation and mitomycin C, and yet it is safer than these treatments. Recent modifications of the conjunctival autograft include the conjunctival rotation autograft and the inferior conjunctival transposition flap, both of which have been reported to be associated with low rates of recurrence. With the discovery of the role of limbal stem cells in the maintenance and stability of the corneal surface, recent forms of ocular surface transplantation that have supplanted Thoft's conjunctival transplantation procedure include limbal autograft transplantation and limbal allograft transplantation. In addition, the adjunct use of human amniotic membrane in these ocular surface transplantation procedures has improved success and survival rates in the management of ocular surface disease, which still presents significant challenges to clinicians today.

Analysis of hepatitis G virus (HGV) RNA, antibody to HGV envelope protein, and risk factors for blood donors coinfected with HGV and hepatitis C virus

Serologic, biochemical, and molecular analyses were used to study hepatitis G virus (HGV), antibody to the HGV envelope protein (anti-E2), risk factors, clinical significance, and the impact of HGV on coexistent hepatitis C virus (HCV). Among 329 donors with confirmed HCV infection, 12% were HGV RNA-positive and 44% were anti-E2-positive (total exposure, 56%). HGV RNA and anti-E2 were mutually exclusive except in 9 donors (1.5%); 8 of 9 subsequently lost HGV RNA but anti-E2 persisted. HGV had little impact on alanine aminotransferase, aspartate aminotransferase, or gamma-glutamyl transpeptidase in donors with HGV infection alone or those coinfected with HCV. A multivariate analysis showed that intravenous drug abuse was the leading risk factor for HGV transmission, followed by blood transfusion, snorting cocaine, imprisonment, and a history of sexually transmitted diseases. In summary, HGV and HCV infections were frequently associated and shared common parenteral risk factors; HGV did not appear to cause hepatitis or to worsen the course of coexistent hepatitis C.

Excimer laser photorefractive keratectomy for the correction of myopia

AIM OF STUDY

To ascertain the efficacy, predictability, safety and stability of photorefractive keratectomy (PRK) for the correction of myopia.

METHODS

Nine-hundred and seventy-one eyes of 628 patients had PRK performed for the correction of myopia. The mean pre-operative myopia was -5.7 D +/- 2.21 D (range -1.0 D to -15.25 D). The mean attempted correction was -5.0 D +/- 1.9 D (range -1.0 D to -9.90 D).

RESULTS

Four-hundred and sixty-seven eyes had a follow-up of 6 months or more. Ninety-three percent of low myopic eyes (pre-operative myopia of less than or equal to 6.0 D) and 75% of high myopic eyes (pre-operative myopia of more than 6.0 D) attained an unaided visual acuity of 6/12 or better. Seventy-four percent of low myopic and 50% of high myopic eyes were within 1 D of the intended correction. The mean post-operative refraction at 6 months was 0.60 D +/- 1.46 D. Eight eyes in the high myopia group and 1 eye in the low myope group lost 2 or more lines or best-corrected visual acuity.

CONCLUSION

PRK was safer and produced better results for low myopes.

Changing trends in cataract surgery in Singapore

AIM OF STUDY

To determine the incidence of cataract surgery in Singapore, both island-wide as well as at the Singapore National Eye Centre (SNEC). We also evaluated the changing techniques of cataract surgery performed locally.

METHODS

We analysed all cataract operations performed in Singapore over a 10-year period from 1985 to 1996 using data obtained from Medisave claims. We also analysed data of all cataract operations in SNEC between 1992 and 1996 retrospectively, with emphasis on patient demographics and the changing surgical techniques.

RESULTS

Data from Medisave claims revealed a significant increase in cataract operations from 5,679 in 1986 to 12,177 in 1995. There was a similar increase in SNEC with a rise from 3,714 in 1992 to 7,516 in 1996. This increase was disproportionately greater than the increase in the number of local surgeons over the same period. The incidence of cataract surgery rose from 2.25/1,000 in 1986 to 4.02/1,000 in 1995. Patients older than 60 years accounted for 75% of cases, with a rise in patients older than 80 years from 2.73% in 1992 to 11.43% in 1996. SNEC data showed that the incidence of phacoemulsification rose from 1% in 1992 to 25% in 1996.

CONCLUSION

There is a rising incidence of cataract surgery in Singapore, particularly in the elderly population. There is also a significant change in the pattern of cataract surgery with a sharp rise in the incidence of phacoemulsification over the last 5 years. These findings have an impact on future planning considerations regarding ophthalmic manpower and resources in Singapore.

[Specific cellular and humoral immune responses induced by intramuscular injection of DNA vaccine containing HBV HBsAg gene in mice]

To know the influences on the function of cellular and humoral immunity in mice by DNA vaccine containing HBV HBsAg gene, the DNA vaccine, pcDNA3-HBsAg, in which the HBsAg gene sequences of HBV were inserted into downstream of CMV promoter in pcDNA3, were injected intramuscularly into Balb/C mice. The results were that the serum anti-HBsIgG was detected in all of the pcDNA3-HBsAg immunized mice, but none in control mice; serum levels of Th1 cytokines, interleukine 2, and interferon gamma, were significantly higher in pcDNA3-HBsAg immunized mice than these in controls. It is indicated that the good responses of cellular and humoral immunity can be induced by injection of pcDNA3-HBsAg in Balb/C mice.

[Detection of the level of serum IgG antibody to hepatitis E virus]

The levels of serum IgG antibody to hepatitis E virus (anti-HEV-IgG) was detected in serum specimens from 50 patients with acute sporadic hepatitis E and 20 healthy donors who were positive for anti-HEV-IgG by ELISA titration. The results showed that the level of anti-HEV-IgG in acute hepatitis E patients was significantly higher than that in healthy donors and the average titer is 1:121 and 1:22, respectively (P < 0.01). So acute viral hepatitis E should be diagnozed when the titer of anti-HEV-IgG was over 1:40.

Role of vascular endothelial growth factor on erythropoietin-related endothelial cell proliferation

The vascular actions of recombinant human erythropoietin (rhEPO) are of particular relevance for fully understanding rhEPO effects. This study examines the mechanisms of action of rhEPO on endothelial cells from bovine aorta (BAEC). First, the studies demonstrated that rhEPO acts on BAEC proliferation as a comitogenic growth factor in the presence of fetal calf serum (FCS). The main experimental findings disclosed that an interaction between rhEPO and vascular endothelial growth factor (VEGF) is instrumental for the growth-promoting action of rhEPO, as shown by the blockade (92.8+/-2.2% inhibition, P < 0.01) of the rhEPO-induced BAEC proliferation by a specific anti-VEGF antibody and by the capability of VEGF for substituting FCS in the induction of rhEPO-related BAEC proliferation (increase in BAEC number in the absence of FCS: 20 U/ml rhEPO alone, 0.3+/-2.8%; 5 x 10(-11) M VEGF alone, 52.9+/-3.1%; 20 U/ml rhEPO + 5 X 10(-11) M VEGF, 117.8+/-6.9%, P < 0.01 between the two agents combined with respect to each agent alone). The existence of a positive interaction between rhEPO and VEGF was further demonstrated by observing an increased cytosolic Ca2+ ([Ca2+]i) mobilization response to VEGF (10(-11)M) in BAEC pretreated or not with 20 U/ml rhEPO (delta[Ca2+]i = 704+/-111 versus 246+/-36 nM, respectively, P < 0.01). To further examine the mechanism of the potentiation of VEGF effect by rhEPO, we analyzed the mRNA expression of the VEGF receptors KDR/flk-1 and flt-1. The results disclosed that BAEC pretreatment with rhEPO upregulated the expression of both KDR/flk-1 and flt-1, therefore providing a structural basis for the aforementioned positive interactions between VEGF and rhEPO. Furthermore, inhibition by genistein suggests that tyrosine phosphorylation was involved in the VEGF receptor upregulation. The mechanisms identified in the present study disclose an interaction at the level of mRNA expression and functional effects between a hormone with predominantly hemopoietic effects, namely, erythropoietin, and an angiogenic factor, namely, VEGF. This relationship between rhEPO and VEGF might be of particular importance in neovascularization processes and in patients receiving rhEPO as a treatment.

Hospitalization for pneumonia in children in Auckland, New Zealand

OBJECTIVE

To describe the epidemiology of hospitalizations for pneumonia in children in Auckland, New Zealand.

METHODS

A consecutive sample of children hospitalised with pneumonia at the Starship Childrens Hospital from 1 July 1993 to 30 June 1996. Subjects were Pacific Island, Maori, and European/other children aged 0-14 years resident in north, west and central Auckland who were hospitalized with pneumonia. Comparisons were made of the number of hospitalisations by year, ethnicity, age and season; and of the hospitalisation rates by year, ethnicity and age.

RESULTS

There were 681 children who were hospitalized with pneumonia during 1993-94, 731 during 1994-95 and 630 during 1995-96. The average annual hospitalization rate was 5.0 per 1000 children aged 0-14 years (95% CI 4.8-5.2). The average annual hospitalisation rate for Pacific Island children was 14.0 per 1000 (95% CI 13.0-14.9), for Maori children 6.7 per 1000 (95% CI 6.0-7.4) and for European/other children was 2.7 per 1000 (95% CI 2.6-2.9). Fifty-three per cent of the hospitalised children were less than 2 years of age. A larger percentage of Pacific Island (61%) and Maori (60%) children were aged less than 2 years compared to European/other (42%) children (P < 0.001). There was marked seasonal variability in the number of hospitalizations, with peaks in hospitalizations corresponding to peaks in positive respiratory viral isolates.

CONCLUSIONS

Pneumonia was a consistent cause of hospitalisation for a large number of Auckland children during this 3-year period. Hospitalisation rates and age distribution varied with ethnicity. Hospitalization rates were highest for Pacific Island. intermediate for Maori and lowest for European/other children. Based on these hospitalisation data, pneumonia is a significant cause of morbidity for children in Auckland, New Zealand.

[A clinical observation on the leukopenia treated with shengbaikuai decoction]

OBJECTIVE

To study the effective orally taken medicine in treating the leukopenia.

METHODS

Ninety cases of leukopenia induced by chemotherapy were divided into 3 groups. They were test group treated with Shengbaikuai Decoction (SBK), control group and blank group. Their efficacies were compared with each other, 25 cases with nonchemotherapy were also observed.

RESULTS

WBC count and absolute neutrophil count (ANC) in test group were higher than those of other groups immediately after treatment and 2 weeks later (P < 0.01). The marked effective rate and total effective rate of test group after 2 weeks were 60.0% and 80.0% (P < 0.001) respectively, which were significantly higher than those of other groups. WBC and ANC count after treatment and 3 weeks later were higher than those before treatment in nonchemotherapy group (P < 0.001). The marked effective rate and total effective rate 3 weeks later were 64.0% and 80.0% respectively.

CONCLUSIONS

SBK could increase WBC count rapidly and definitely without apparent side effect.

Effects of angiotensin II on endothelial cell growth: role of AT-1 and AT-2 receptors

Angiotensin II (AngII) is a main mediator in the regulation of vascular tone. Although its effects on vascular smooth muscle cells are well known, data on its role on endothelial biology are still insufficient. The present study examined the effect of endogenous and exogenous AngII on bovine aortic endothelial cells possessing both AT-1 and AT-2 receptors. A DNA synthesis-promoting effect of AT-2 blockade by PD123319 (10(-9) to 10(-7) M) was demonstrated. This effect was transduced through an AT-1-mediated pathway, as shown by using the AT-1 antagonist, losartan. In addition, an AT-1-mediated effect of AngII was demonstrated on bovine aortic endothelial cell proliferation, which occurred despite the absence of AngII-induced Ca2+ transients. In summary, the present study disclosed relevant characteristics of the effect of AngII on endothelial cell growth that have potential pathophysiologic projections, particularly for the use of selective AngII blocking agents.

The role of tyrosine 121 in cofactor binding of 5-aminolevulinate synthase

5-Aminolevulinate synthase (EC 2.3.1.37) is the first enzyme in the heme biosynthesis in nonplant eukaryotes and some prokaryotes. It functions as a homodimer and requires pyridoxal 5'-phosphate as an essential cofactor. Tyr-121 is a conserved residue in all known sequences of 5-aminolevulinate synthases. Further, it corresponds to Tyr-70 of Escherichia coli aspartate aminotransferase, which has been shown to interact with the cofactor and prevent the dissociation of the cofactor from the enzyme. To test whether Tyr-121 is involved in cofactor binding in murine erythroid 5-aminolevulinate synthase, Tyr-121 of murine erythroid 5-aminolevulinate synthase was substituted by Phe and His using site-directed mutagenesis. The Y121F mutant retained 36% of the wild-type activity and the Km value for substrate glycine increased 34-fold, while the activity of the Y121H mutant decreased to 5% of the wild-type activity and the Km value for glycine increased fivefold. The pKa1 values in the pH-activity profiles of the wild-type and mutant enzymes were 6.41, 6.54, and 6.65 for wild-type, Y121F, and Y121H, respectively. The UV-visible and CD spectra of Y121F and Y121H mutants were similar to those of the wild-type with the exception of an absorption maximum shift (420 --> 395 nm) for the Y121F mutant in the visible spectrum region, suggesting that the cofactor binds the Y121F mutant enzyme in a more unrestrained manner. Y121F and Y121H mutant enzymes also exhibited lower affinity than the wild-type for the cofactor, reflected in the Kd values for pyridoxal 5'-phosphate (26.5, 6.75, and 1.78 microM for Y121F, Y121H, and the wild-type, respectively). Further, Y121F and Y121H proved less thermostable than the wild type. Taken together, these findings indicate that Tyr-121 plays a critical role in cofactor binding of murine erythroid 5-aminolevulinate synthase.

Role of nitric oxide-related mechanisms in renal function in ageing rats

BACKGROUND

The impaired renal function and vasodilatation that accompany age need to be re-addressed based upon the new knowledge concerning vascular nitric oxide (NO)-dependent systems. The present study examined the effects of age on the NO-related renal response.

METHODS

The study was performed in euvolaemic, conscious Wistar rats, aged 5 and 18 months. Renal function and haemodynamic measurements with fluorescent microspheres were employed to assess differences between groups.

RESULTS

A first set of experiments showed that ageing rats had a reduced natriuretic and diuretic response to acetylcholine, whereas the response to sodium nitroprusside was preserved. In the same regard, a reduction of the renal functional effects of L-arginine (L-Arg) and L-glycine (L-Gly) was found in the older rats. In the ageing rats, these responses were accompanied by an enhanced effect of the L-Arg competitive analogue, NwNLA, which provoked a marked reduction of renal function. This effect of NwNLA was blocked by the simultaneous administration of a small dose of L-Arg in the ageing but not in the young rats. Systemic haemodynamic studies revealed that in ageing rats, NwNLA reduced renal blood flow and increased renal vascular resistances in a significantly higher proportion than in younger animals. However, flow to other organs, namely, brain, spleen or liver, was affected in a similar manner in both young and old rats. Ultrastructural alterations were found in endothelial cells, which might constitute the anatomical basis for the observed functional derangements.

CONCLUSIONS

The present experiments reveal that ageing is accompanied by significant differences in NO-related responses in the kidney which do not appear to affect blood flow to other organs. The response to L-Arg and L-Arg competitive analogues supports the existence of a marked dependency on NO-related mechanisms in the ageing rats, but not of a decreased baseline activity of the NO-dependent pathways.

Role of arginine 439 in substrate binding of 5-aminolevulinate synthase

5-Aminolevulinate synthase (EC 2.3.1.37) catalyzes the first reaction in the heme biosynthetic pathway in nonplant eukaryotes and some prokaryotes. Homology sequence modeling between 5-aminolevulinate synthase and some other alpha-family pyridoxal 5'-phosphate-dependent enzymes indicated that the residue corresponding to the Arg-439 of murine erythroid 5-aminolevulinate synthase is a conserved residue in this family of pyridoxal 5'-phosphate-dependent enzymes. Further, this conserved arginine residue in several enzymes, e.g., aspartate aminotransferase, for which the three-dimensional structure is known, has been shown to interact with the substrate carboxyl group. To test whether Arg-439 is involved in substrate binding in murine erythroid 5-aminolevulinate synthase, Arg-439 and Arg-433 of murine erythroid 5-aminolevulinate synthase were each replaced by Lys and Leu using site-directed mutagenesis. The R439K mutant retained 77% of the wild-type activity; its K(m) values for both substrates increased 9-13-fold, while the activity of R433K increased 2-fold and the K(m) values for both substrates remained unchanged. R439L had no measurable activity as determined using a standard 5-aminolevulinate synthase enzyme-coupled activity assay. In contrast, the kinetic parameters for R433L were comparable to those of the wild-type. Dissociation constants (Kd) for glycine increased 5-fold for R439K and at least 30-fold for R439L, while Kd values for glycine for both R433K and R433L mutants were similar to those of the wild-type. However, there was not much difference in methylamine binding among the mutants and the wild-type, excepting of a 10-fold increase in K(d)methylamine for R439L. R439K proved much less thermostable than the wild-type enzyme, with the thermotransition temperature, T1/2, determined to be 8.3 degrees C lower than that of the wild-type enzyme. In addition, in vivo complementation analysis demonstrated that in the active site of murine erythroid 5-aminolevulinate synthase, R439 is contributed from the same subunit as K313 (which is involved in the Schiff base linkage of the pyridoxal 5'-phosphate cofactor) and D279 (which interacts electrostatically with the ring nitrogen of the cofactor), while another subunit provides R149. Taken together, these findings suggest that Arg-439 plays an important role in substrate binding of murine erythroid 5-aminolevulinate synthase.

[Study on gene of YRRM in azoospermia]

OBJECTIVE

To detect the abnormal YRRM gene in azoospermia and to explore the pattern of YRRM gene in Chinese men.

METHODS

With the special primer for YRRM, the YRRM gene was analyzed using the PCR method. Extracting the testis total RNA, we performed the RT-PCR. The part of YRRM gene was sequenced.

RESULTS

No amplification band of YRRM gene was noted in 4 of 74 Chinese men with azoospermia (5.4%). The YRRM gene was obviously expressed in the testis of man and showed a 500 bp cDNA fragment. The cDNA and genomic DNA were different because the intron. We found that Chinese people only have YRRM1 pattern of gene, and the sequence of YRRM gene of Chinese men shows that the composition of the nucleotide is same as YRRM1 gene.

CONCLUSION

These cases of abnormal YRRM gene may result in male infertility, YRRM gene and azoospermia is the YRRM1 gene is polymouphase of racial.

[Serum HBV DNA detected by polymerase chain reaction with dUTP/uracil-DNA glycosylase]

The ability of PCR reagent containing dUTP/uracil-DNA glycosylase for controlling carry-over contamination of PCR products was explored. All of 204 sera taken from hepatitis patients were used for HBV DNA detection by PCR with PCR-dUTP/UDG reagent in comparison with that without dUTP/UDG. The results showed that its efficiency of controlling contamination was excellent. At least, contamination of 100 ng PCR products was got rid of. The corresponding rate of HBV DNA detection by PCR-dUTP/UDG in combination with dot hybridization using digoxin-labeled HBV probe was as high as 89.32%, higher than that (81.45%) of PCR without dUTP/UDG plus dot hybridization(P < 0.05). It suggests that PCR-dUTP/UDG method could prevent PCR products from contaminating and increase accuracy and specificity of PCR amplification.

The use of mobile telephones in a district general hospital

Advances in technology have led to the increased availability of mobile telephones, but their use in an NHS hospital has not previously been reported. Junior doctors require easy access to a telephone, but ward telephones are frequently busy and not readily accessible when urgently needed. A one-year retrospective study was carried out on the use of mobile telephones in a small district general hospital.

Submandibular gland peptide-T (SGP-T) inhibits intestinal anaphylaxis

A novel peptide, submandibular gland peptide-T (SGP-T), which reduces allergen-induced hypotension, was examined for effects on intestinal anaphylaxis. Hooded-Lister rats were sensitized to egg albumin and prepared for the measurement of in vivo myoelectric activity of the jejunum. The disruption of migrating myoelectric complexes (MMCs) that occurs upon intraluminal, duodenal challenge with antigen of sensitized rats was inhibited by 75% upon intravenous treatment with 100 micrograms/kg of SGP-T. In addition, SGP-T reduced the number of rats experiencing anaphylactic diarrhea and disrupted MMCs, but the peptide did not alter antigen-provoked release of rat mast cell protease II. The mechanism of action of SGP-T remains to be determined, but it apparently does not act directly on mast cells to exert its antianaphylactic action. These results emphasize that modulation of immediate hypersensitivity reactions is only one of several gastrointestinal activities that are affected by growth factors and peptides released from salivary glands.

Evaluation of commercially available and in-house reverse transcription-PCR assays for detection of hepatitis G virus or GB virus C

Serum samples from 96 Spanish hemodialysis patients, as well as serial dilutions of RNA extracted from a reference strain of hepatitis G virus (HGV), were tested for HGV or GB virus C (GBV-C) RNA. Two different reverse transcription (RT)-PCR-based methods of detection were compared for the ability to detect RNA extracted from the samples: an RT-nested PCR assay with primers derived from the 5' noncoding region (5'NC) or nonstructural region 3 (NS3) sequences and a commercially available RT-PCR assay with primers derived from the 5'NC or NS5A sequences. When RT-nested PCR was performed on 10-fold serial dilutions of RNA from the HGV reference strain, the last positive dilution was 10(-7) to 10(-8). With the commercial RT-PCR assay, the last positive dilution was 10(-6) to 10(-7). When equal amounts of RNA extracted from serum samples from 96 hemodialysis patients were tested for HGV or GBV-C RNA, 25 patients (26%) were positive by the RT-nested PCR. However, only 21 (84%) of these 25 positive patients were positive for HGV or GBV-C by the commercial RT-PCR assay. Analysis of the 5'NC and NS3 sequences amplified by RT-nested PCR demonstrated that all but two positive patients had unique HGV or GBV-C sequences. In summary, RT-nested PCR and a commercially available RT-PCR assay for HGV or GBV-C gave concordant results for 96% of the patients tested.

Hepatitis C in asymptomatic blood donors

Among 248 asymptomatic blood donors positive for antibody to hepatitis C virus (anti-HCV) enrolled in a long-term prospective study, 86% had chronic HCV infection and 14% appeared to have recovered as assessed by serial determinations of serum alanine aminotransferase (ALT) levels and HCV RNA by polymerase chain reaction. Established parenteral risk factors for HCV transmission were identified in 75% of donors. In addition, there was a strong independent association between HCV positivity and cocaine snorting, suggesting that shared snorting devices may be a covert route of parenteral transmission. Ear piercing in males was also significantly associated with transmission. There was no evidence for sexual spread. Although the majority of HCV carriers had both biochemical and histological evidence of chronic viral hepatitis, the extent of liver injury was generally mild. Among a larger population of 280 HCV RNA-positive donors, 17% had repeatedly normal ALT levels, 45% had levels that did not exceed twice, and only 22% had levels that exceeded five times the upper limit of the normal range. Among 81 patients who underwent liver biopsy, only 13% had evidence of severe hepatitis (8%) or cirrhosis (5%), despite a duration of infection that generally exceeded 15 years. No severe histological lesions were observed in blood donors with chronic HCV infection who had repeatedly normal ALT levels. In both donors and blood recipients, the frequency of severe morbidity or mortality related to HCV infection was less than 10% during the first two decades of infection. Further long-term studies are required to see if the progression to severe outcomes continues to accrue at this slow pace or whether it accelerates during subsequent decades.

A comparison of two pertussis epidemics in Auckland

AIM

To determine if the addition of the 6 week dose of pertussis vaccine in 1984 was associated with any change in the hospitalisation rate for children with pertussis and the higher hospitalisation rates for Maori and Pacific Islander children with pertussis.

METHODS

DESIGN

Population based study of pertussis hospitalisations using a retrospective chart review of hospitalisation data for children during the 1991 epidemic, which was compared to previously published data from the 1982 epidemic.

SETTING

Princess Mary and Middlemore hospitals, Auckland.

SUBJECTS

Children aged 0-14 years resident in metropolitan Auckland and hospitalised in Auckland during 1982 or 1991 with pertussis.

MEASUREMENTS

Hospitalisation rates were calculated as number of children with a discharge diagnosis of pertussis per 1000 children aged 0-14 years based on 1981 and 1991 census data. 1982 data were converted to person-years as published report was for an 8 month period. Hospitalisation rates were compared as a relative risk (RR) of hospitalisation in 1991 versus 1982.

RESULTS

There were 84 cases during 8 months in 1982 and 66 cases in 1991. Rates of hospitalisation by ethnic group; in 1982 were 0.24 Other/European (OE), 1.98 Maori (M), 1.37 Pacific Islander (PI); and in 1991 were 0.22 OE, 0.51 M, 0.40 PI. Compared to 1982 the relative risk of hospitalisation in 1991 adjusted for ethnicity was 0.43 (CI 0.33, 0.58, p < 0.0001). Compared to 1982 there was a significant reduction in the hospitalisation rate in 1991 for M (RR = 0.26, CI 0.16, 0.43, p < 0.0001); and PI children (RR = 0.29, CI 0.16, 0.54, p < 0.0001); but not for OE children (RR = 0.91, 95% CI 0.57, 1.46, p = 0.70).

CONCLUSIONS

There was a significant reduction in the rate of hospitalisation for pertussis in 1991 compared to 1982. This reduction in hospitalisation rate was due to a reduction in rates for Maori and Pacific Islander children.

[Determination of metronidazole in gastric juice by high performance liquid chromatography]

Metronidazole (MTZ) is the first chosen drug of anti-anaerobe which was recommended by World Health Organization. In this paper a high performance liquid chromatographic (HPLC) method has been developed to determine the concertration of MTZ in human gastric juice. Gastric juice was obtained by intubation after taking drug, then the sample was precipitated with ethanol to remove proteins, centrifuged, filtered and finally assayed by HPLC. The operating conditions were reversed phase C18 column (4mm x 150mm), CH3OH:KH2PO4 (5mmol/L, pH 4.0) = 10:90 mobile phase with flow rate of 1.5mL/min and detection wavelength at 320nm. The standard working curve was Y = -1.63 + 1.15X, with r = 0.9999, n = 7. The linear range was 2.5-200mg/L. The detection limit was 0.4mg/L. The average recovery was 96.0% and the coefficient of variation was 3.07%. This method can be applied to guide clinical therapy and pharmaceutical research.

Concentrated ascitic fluid reinfusion in cirrhotic patients: a simplified method

A new method for ascites filtration and reinfusion, which uses a single Cuprophan filter and is performed in the dialysis unit, is reported. Thirty-one procedures were performed in 17 patients with cirrhosis and massive ascites. A mean volume of 8.6 L of ascitic fluid was removed; from this volume, 5 L were ultrafiltered and a concentrated ascitic fluid was reinfused (x = 359.8 mL). The whole procedure was completed in a mean time of 248 minutes. No relevant method-related complications were detected. Moreover, no significant changes in blood urea nitrogen (BUN), creatinine, plasma and urinary electrolytes, or platelet count were found, even in the case of repeated procedures (two to nine times). The reinfused fluid contained a mean value of albumin of 4.7 g/dL and significant amounts of globulins and complement. The overall cost of the materials used in the procedure ($49.46) offered competitive advantages with respect to other types of frequently used methods. In conclusion, we present a safe, effective, and time- and cost-saving technique for ascites reinfusion that represents an advantageous alternative to more complicated and expensive methods or to the currently used medical therapy.