Norditerpenoid alkaloids from the roots of Aconitum leave Royle

From the roots of Aconitum leave Royle growing wild in Northern Pakistan, Swat district, three new alkaloids, 8-methyllycaconitine (1), 14-demethyllycaconitine (2), N-deethyllycaconitine-N-aldehyde (3) have been isolated along with four known compounds, lappaconitine (4), lycaconitine (5), lapaconidine (6) and lycoctonine (7).

Absorption, distribution, metabolism and excretion of daily oral doses of [14C]methyl parathion in hens

Adult hens were given oral daily doses of 2 mg (2 microC(i))/kg/day (14% of oral LD(50) in male rats) of [14C]methyl parathion (O,O-dimethyl O-4-nitrophenyl phosphorothioate) for 10 consecutive days. Five treated hens were sacrificed at 1, 2, 4, 8, 12, 24, and 48 h after the last dose. Methyl parathion was absorbed from the gastrointestinal tract and distributed rapidly. Maximum radioactivity was detected in tissues within 8 h of dosing, (ng methyl parathion equivalent/g fresh tissue or ml plasma): Plasma (189.2), liver (94.7), kidney (146.2), brain (61.4), gastrointestinal tissues (106.7). Methyl parathion was detected in the plasma, kidney and liver, while methyl parathion metabolite p-nitrophenol was detected in the liver and in the kidney. Elimination of methyl parathion from plasma was monophasic with a terminal half-life of 17.5 h, corresponding to an elimination rate constant of 0.039 ng/hr. Most of the absorbed radioactivity was excreted in the combined fecal-urine excreta (98%). Analysis of the metabolites in the excreta revealed that non-conjugated metabolites accounted for 13% of the total excretion. Conjugated metabolites accounted for 87% of the total excretion; of that, 6% as p-nitrophenyl-glucoronide conjugate, 7% as p-nitrophenyl-sulfate conjugate, 23% as bound hot sulfuric acid hydrolyzable residues, and 51% as water soluble metabolites. The presence of majority of radioactivity in the excreta as conjugated metabolites indicates that determining only unbound p-nitrophenol as a biological marker for methyl parathion exposure underestimates total fecal-urine excretion of p-nitrophenol. The slow elimination rate of methyl parathion is significant, since hens are more comparable to humans with respect to their cytochrome P450 activities.

Candida lusitaniae catheter-related sepsis

OBJECTIVE

To present a case describing Candida lusitaniae candidemia in an immunocompetent patient successfully treated with fluconazole antifungal therapy. Time-kill studies of the C. lusitaniae isolate using amphotericin B, and an extensive review of the literature are also presented.

CASE SUMMARY

A 52-year-old immunocompetent Latin-American woman was admitted to the special care unit with severe sepsis. Her recent medical history included an exploratory laparotomy for gallstone pancreatitis, requiring cholecystectomy, segmental sigmoid colectomy, drainage of peritoneal abscesses, and a colostomy. In addition, the patient required a central venous catheter (CVC) placement for prolonged broad-spectrum antibiotic therapy and total parenteral nutrition therapy. Yeast was isolated from the abdominal abscess and blood cultures obtained on day 1, and from the catheter tip on day 5. The woman received initial empiric antifungal therapy with fluconazole, which was later changed to amphotericin B. After the yeast was identified as C. lusitaniae on day 8, this was changed to fluconazole for the duration of therapy. C. lusitaniae was not present in blood cultures taken two weeks after the CVC was removed, and the cultures remained negative thereafter. After a prolonged hospitalization, the patient was discharged home.

DISCUSSION

Disseminated infections with C. lusitaniae usually occur in immunocompromised patients, although isolated reports of C. lusitaniae infections in immunocompetent patients have been described. Therapeutic challenges of C. lusitaniae treatment include its primary resistance to amphotericin B and species misidentification. Isolates recovered from our patient were submitted for fungus time--kill studies that suggested unique susceptibility patterns to amphotericin B, indicating a trend toward resistance.

CONCLUSIONS

Based on variable susceptibility patterns of C. lusitaniae to amphotercin B and flucytosine, fluconazole is an appropriate choice as first-line therapy for C. lusitaniae candidemia.

The etiologic role of the osteo-meatal complex in the pathogenesis of sinusitis: a retrospective study of clinical, CT and endoscopic findings in 143 patients

The etiological role of the osteo-meatal complex (OMC) in the pathogenesis of sinus disease is a debatable issue. The charts of 143 patients who underwent endoscopic sinus surgery at the American University of Beirut Medical Center between 1992 and 1995 were reviewed. Clinical symptoms included facial pain, nasal obstruction, headache, and postnasal drip. CT scan and endoscopic findings were reviewed. The presence of OMC disease radiologically was correlated with all the clinical, nasal endoscopic and other radiologic findings (disease in the rest of paranasal sinuses, or presence of concha bullosa). Its etiological role in patients with sinusitis is discussed.

RESULTS

No endoscopic findings could be statistically correlated with the OMC disease. Facial pain and postnasal drip were the only clinical symptoms that statistically correlated with the OMC disease (p-value = 0.009 and 0.008, respectively). The OMC disease correlated with the radiological evidence of sinusitis in any of the sinuses.

Pneumocystis carinii pneumonia in pregnancy

OBJECTIVE

To report five new cases of Pneumocystis carinii pneumonia (PCP) and to review and analyze the existing reports on the subject.

METHOD

Five new cases of PCP during pregnancy are described. The cases, case series, and related articles on the subject in the English language were identified through a comprehensive MEDLINE search and reviewed.

RESULTS

More than 80% of women with AIDS are of reproductive age, and PCP is the most common cause of AIDS-related death in pregnant women in the United States. Among 22 reviewed cases, the mortality rate was 50% (11 of 22 patients), which is higher than that usually reported for HIV-infected individuals with PCP. Respiratory failure developed in 13 patients (59%), and mechanical ventilation was therefore required, and the survival rate in patients requiring mechanical ventilation was 31%. Maternal and fetal outcomes were better in cases of PCP during the third trimester of the pregnancy. A variety of treatment regimens were used, including sulfamethoxazole-trimethoprim (SXT) alone or in combination with pentamidine, steroids, and eflornithine. The survival rate in patients treated with SXT alone was 71% (5 of 7 patients) and for those treated with SXT and steroids was 60% (3 of 5 patients), with an overall survival rate in both groups of 66.6% (8 of 12 patients).

CONCLUSION

PCP has a more aggressive course during pregnancy, with increased morbidity and mortality. Maternal and fetal outcomes remain dismal. Treatment with SXT, compared to other therapies, may result in an improved outcome. Withholding appropriate PCP prophylaxis may adversely affect maternal and fetal outcomes.

Effects of methylenedioxymethamphetamine on noradrenaline-evoked contractions of rat right ventricle and small mesenteric artery

We have compared the effects of methylenedioxymethamphetamine (MDMA) and cocaine on contractions to noradrenaline in 1 Hz paced rat right ventricular strips, and in rat small mesenteric artery and aorta. Noradrenaline increased the force of contraction of 1 Hz paced ventricular strips with a pD(2) (-log EC(50)) of 5.64+/-0.07. Both cocaine (10 microM) and MDMA (10 microM) significantly increased the potency of noradrenaline to 6.31+/-0.11 and 6.42+/-0.13, respectively. However, in the presence of cocaine (10 microM) which increased the potency of noradrenaline to 6.78+/-0.15, MDMA (10 microM) no longer increased the potency of noradrenaline (pD(2) of 6.78+/-0.32). Likewise, following chemical sympathectomy, MDMA failed to increase the potency of noradrenaline. The potency of the agonist isoprenaline, which is not a substrate for the noradrenaline transporter, was not increased by either cocaine or MDMA. In rat small mesenteric artery, but not aorta, MDMA and cocaine significantly increased the potency of noradrenaline, but in the presence of cocaine, MDMA had no further effect. Hence, MDMA shares with cocaine an ability to potentiate the actions of noradrenaline, an action in the case of MDMA which may involve competitive blockade of the noradrenaline transporter, rather than simply displacement of noradrenaline. Since cocaine is linked to an increased incidence of myocardial infarction, these results may have implications in terms of cardiac morbidity of MDMA.

Citrus pectin: characterization and inhibitory effect on fibroblast growth factor-receptor interaction

This study was undertaken to characterize the pectin from four citrus species and to determine their in vitro inhibitory activities on the binding of fibroblast growth factor (FGF) to the FGF receptor (FGFR). Pectin from various parts of lemon, grapefruit, tangerine, and orange were isolated and characterized. Tangerine had the highest pectin content among the four citrus species. Segment membrane contained as much as or more pectin than flavedo/albedo. Anhydrogalacturonic content was highest in pectin from segment membrane of tangerine and flavedo/albedo of grapefruit. Lemon pectin contained the highest methoxyl content (MC), and grapefruit contained the largest proportion of lower molecular weight (<10000 Da) pectin. Tangerine contained the highest neutral sugar in both flavedo/albedo and segment membrane. The interdependency of heparin on factor-receptor interaction provides a means for identifying new antagonists of growth factor activity and thus for treatment of various diseases. These results showed that pectin significantly inhibited the binding of FGF-1 to FGFR1 in the presence of 0.1 microg/mL heparin. The pectin from the segment membrane of lemon was the most potent inhibitor. The inhibition activity was significantly correlated with sugar content, MC, and size of pectin. Kinetic studies revealed a competitive nature of pectin inhibition with the heparin, a crucial component of the FGF signal transduction process. The observation that the heparin-dependent biological activity of FGF signal transduction is antagonized by citrus pectin should be further investigated for the use of these pectins as anti-growth factor agents for potential health benefits.

Epidemic dengue transmission in southern Sumatra, Indonesia

An outbreak of dengue fever (DF), dengue haemorrhagic fever (DHF), and dengue shock syndrome (DSS) in the city of Palembang, south Sumatra, Indonesia was investigated to (i) validate epidemic occurrence, (ii) confirm dengue virus aetiology and associated serotype(s), (iii) provide a demonstrable measure of community impact, and (iv) identify causative relationship (if any) with climatic El Niño Southern Oscillation (ENSO) influences. Trend analysis based on a 6-year retrospective review of hospital records demonstrates a 3-fold increase in clinical cases for the outbreak period (January-April 1998), relative to historical records. In the 2 hospitals surveyed, the monthly mean number of outbreak-related dengue cases over 4 months was 833 (range 650-995 cases/month); the mean monthly value for the previous 72 months was 107 (range 14-779 cases/month). An apparent trend in epidemic transmission was observed, evolving from a 5-year cyclic phenomenon to an annual occurrence, often indistinguishable from one year to the next. The proportional distribution of clinical outbreak cases into DF, DHF and DSS diagnostic categories was 24%, 66%, and 10%, respectively. The population aged 10-19 years accounted for the largest (35%) proportion of hospitalized DHF cases, followed by children aged 5-9 years (25%) and children aged 4 years (16%). Serum samples obtained during acute illness from 221 hospitalized patients were examined using serology, RT-PCR, and virus isolation in cell culture: 59% of samples had laboratory evidence of a dengue infection. All 4 dengue virus serotypes (DEN 1-4) were identified in epidemic circulation, with DEN 3 predominating (43%). DEN 1 was the principal serotype associated with less severe dengue illness, suggesting that virulence may be, in part, a function of infecting serotype. The climatic influence of ENSO on rainfall and temperature in the months leading up to and during the outbreak was dramatic, and is likely to contribute to favourable outbreak conditions.

Late prosthetic valve endocarditis caused by Staphylococcus hemolyticus

We describe a case of late PVE in a 78-year-old man that was caused by Stapylococcus hemolyticus and occurred 5 years after aortic valve replacement. This is the first reported case of PVE due to this organism.

Intrahepatic stones: the UKM experience

Intrahepatic stones remain a major source of morbidity and mortality. With improving techniques in hepatobiliary surgery, the management and the outcome of intrahepatic calculi is reviewed. Forty-nine cases referred from all over Malaysia between January 1993 to June 1996 were analyzed retrospectively. There were thirty-two females and seventeen males. The median age was 46 years. Biliary diseases encountered in association with intrahepatic calculi included benign strictures (n = 14), ascariasis (n = 3), cholangiocarcinoma (n = 1), Caroli's disease (n = 1), and thalassaemia, (n = 1), fifty-six percent of stones were located in both the intrahepatic ducts while 34% were found in the left intrahepatic duct. Thirty-one patients underwent common bile duct exploration either alone or in combination with liver resection or bilioenteric anastomosis. Despite the various combinations of surgical and non-surgical intervention 28 (57.1%) patients had residual stones. Despite the availability of newer techniques in hepatobiliary surgery, residual stones were common, resulting in higher treatment costs.

Predictive value of repeat renal biopsies in children with nephrotic syndrome

In children who exhibit a frequently relapsing course of minimal change disease (MCD), treatment is often difficult and frustrating to the physician and the family since the goal of a sustained remission remains elusive. The progression of the disease is often unpredictable from its clinical presentation since the lesion of MCD may evolve into a more severe form, such as mesangial IgM nephropathy or focal segmental glomerulosclerosis (FSGS), without alteration in signs and symptoms. Alkylating agents such as cyclophosphamide, or immunosuppressives such as cyclosporine can induce a more sustained remission, but are fraught with inherent toxicity, which makes difficult the decision to use these drugs in patients with MCD. Over a 10-year period we studied 49 patients who had more than one renal biopsy. Repeat biopsies were performed either to delineate the morphological lesion prior to change in therapy, or to confirm suspected drug toxicity, which would necessitate discontinuation of therapy. A total of 83 repeat biopsies were performed in these 49 patients. Of the 49 patients, 25 had MCD, and in 21 of these the lesion evolved into either IgM nephropathy (n = 7) or FSGS (n = 14). Of patients with IgM nephropathy (n = 12), 50% evolved into FSGS. The clinical diagnosis made prior to the repeat biopsy did not confirm with the histological diagnosis in 43% of cases, and a change in therapy or cessation of therapy was carried out in 43 of 83 repeat biopsy instances. Since the complications were mild and the ability of clinical findings to accurately predict the histological lesion limited, we conclude that repeat renal biopsies are a useful tool to fashion optimal therapy in children with frequently relapsing nephrotic syndrome.

Trauma in the elderly: a new epidemic?

Australia's population is ageing. Statistics predict that by the year 2021, 17.8% of our population will be over the age of 65 years. These statistics are reflected in most Western nations. The elderly represent an increasing proportion of emergency department patients. They are generally more acute on presentation, they get admitted more frequently, and account for an increasing proportion of admissions to intensive care units. The elderly trauma patient will increasingly consume more resources than patients from any other age group. There are significant differences in physiology and response to trauma between the elderly patient and the young. Airway compromises, a decrease in lung compliance, a change in cardiovascular haemostasis and the prevalence of pre-existing disease all contribute to increase morbidity and mortality in a patient with an already limited physiological reserve. Many studies demonstrate an increased mortality in hospitalized elderly trauma patients. For those who die from traumatic insult, death is mainly due to multiorgan system failure. The long-term functional outcome of the elderly trauma patient has been investigated by a number of authors. One study showed that only 8% of survivors returned to independent living 1 year post-polytrauma. Another more encouraging study showed that 89% of survivors of blunt multiple trauma after 38 months were independent and living at home. Ethical issues have been raised regarding the appropriateness of care for the severely injured elderly patient given today's ever-shrinking hospital finances and bed shortages. Today's environment is very challenging as frequently, the clinician is forced to make an economic decision on who will take the last critical care bed, which is a far from optimal situation.

Radical resection for naso-lacrimal duct tumour

Naso-lacrimal duct tumours are uncommon and present with epiphora and swelling. Since the naso-lacrimal duct is embedded in bone for the majority of its anatomical length, the late presentation of proptosis is due to orbital extension of the tumour. Radical surgical treatment is necessary to establish clear margins and facilitate reconstruction.

Characteristics of acute pancreatitis in University Kebangsaan Malaysia

We analyzed the characteristics of patients presenting with acute pancreatitis to our unit. A total of 71 patients were admitted to the Surgical Department at University Kebangsaan Malaysia (UKM) over a period of seven years, between January 1990 to December 1996 with acute pancreatitis. There was a fourfold increase in incidence of acute pancreatitis in our hospital from January 1990 to December 1996. The commonest identifiable aetiology was gallstones followed by alcohol. There were two deaths. We conclude that acute pancreatitis is increasingly being diagnosed in our local population. This may be due to either greater awareness or changes in lifestyle of the population.

Conjugated polysaccharide vaccines

The joining of polysaccharide antigens to various proteins can result in increased immunogenicity of vaccines composed of such antigens. This article discusses conjugated polysaccharide vaccines for Haemophilus influenzae, Streptococcus pneumoniae, and Neisseria meningitis. Increased availability and use of such vaccines may result in the ability to give more effective vaccines earlier in life, further reducing the incidence of diseases caused by these organisms.

Glutathione S-transferase of goat lens: evidence for expression of only class mu isoenzymes

PURPOSE

It has been suggested that glutathione S-transferases (GSTs) of the mammalian ocular lens detoxify various toxicants and cataractogens; therefore, it provides protection against cataractogenesis. In this study the GST isoenzymes of goat lens have been purified and characterized.

METHODS

The goat lens homogenate was subjected to affinity chromatography over GSH-linked epoxy activated Sepharose 6B. The isoenzymes of the GST were separated by chromatofocusing on a Mono-P column using FPLC.

RESULTS

Two GST isoenzymes, GST 7.2 and GST 6.6, were purified to apparent homogeneity from goat lens. GST 7.2 appeared to be a heterodimer of Mr. 26,500 and Mr. 25,000 subunits, the GST 6.6 showed a homodimeric subunit structure of Mr. 25,000. Western blotting and the N-terminal region amino acid sequence analysis indicated that both isoenzymes of goat lens belong to the mu-class GST.

CONCLUSION

Although they share varying degrees of structural correlation, the two isoenzymes of goat lens seem to be the products of two distinct genes. The isoenzyme expression pattern of GST in goat lens is similar to bovine lens, which also contains two isoenzymes belonging only to GST mu.

The paucity of minimal change disease in adolescents with primary nephrotic syndrome

Data are sparse regarding the histological lesions associated with the primary nephrotic syndrome in adolescents. To our knowledge there are only two published articles that have specifically addressed the histopathological lesions that typify idiopathic nephrotic syndrome in the adolescent population. We reviewed our experience from the last 14 years of children between the ages of 12 and 18 years who were referred to our center for the evaluation of the nephrotic syndrome. A total of 29 adolescents met the inclusion criteria for this review. All patients were biopsied prior to the initiation of treatment. The sex ratio consisted of 52% males and 48% females and the racial breakdown was largely African-American, with 83% black adolescents, 7% Hispanic, and 10% Caucasian patients. Minimal change nephrotic syndrome (MCNS), the predominant lesion of children at an early age, was noted in only 20% of patients. The majority of patients (55.2%) had focal segmental glomerulosclerosis (FSGS); 7% had IgM nephropathy and 3.5% had diffuse mesangial hypercellularity. Only 7% of biopsied adolescents had membranoproliferative glomerulonephritis. Our results indicate that the most common lesion in this predominantly African-American patient population is FSGS, with only a small number showing MCNS. Thus, in our experience derived from a racially mixed population, adolescents with the nephrotic syndrome are less likely to have MCNS than younger children.

Effective postponement of diabetic nephropathy with enalapril in normotensive type 2 diabetic patients with microalbuminuria

OBJECTIVE

This study determines the long-term efficacy of the ACE inhibitor, enalapril, in reducing the progression of microalbuminuria to clinical albuminuria in normotensive patients with type 2 diabetes.

RESEARCH DESIGN AND METHODS

There were 103 normotensive type 2 diabetic patients with persistent albumin excretion rate (AER) 20-200 micrograms/min and normal renal function followed for 5 years in a prospective randomized single-blind placebo-controlled trial. AER, blood pressure, fasting plasma glucose, and HbA1 were measured very 3-4 months and glomerular filtration rate (GFR), renal plasma flow (RPF), and urinary urea every 12 months.

RESULTS

In the patients treated with enalapril, AER decreased from 55 +/- 33 to 20 +/- 59 micrograms/min (geometric mean +/- SD), whereas in the placebo group, AER increased from 53 +/- 31 to 85 +/- 90 micrograms/min after 5 years. Within 5 years, 7.7% (4/52) of enalapril-treated subjects and 23.5% (12/51) of placebo-treated subjects progressed to clinical albuminuria defined as AER > 200 micrograms/min and at least 34% above baseline (risk reduction = 66.7%, P < 0.001). AER increased at an annual rate of 12.3% (95% CI 9.8-14.9) in the placebo group, while it declined by 16.7% (95% CI -18.3 to -15.2) in the enalapril group (P < 0.001). In addition, 8 of the 12 placebo-treated patients had evidence of coronary artery disease. The rest of the parameters remained practically unchanged in the two groups.

CONCLUSIONS

After 5 years of therapy with enalapril, compared with placebo, normotensive subjects with type 2 diabetes experienced significantly less progression of microalbuminuria to clinical albuminuria, reduced AER, and preserved GFR.

Preferential overexpression of a class MU glutathione S-transferase subunit in mouse liver by myristicin

The present studies were undertaken to elucidate the mechanism of induction of glutathione S-transferase (GST) in mouse liver by myristicin, an active constituent of parsley leaf. A/J albino mice, given 5 to 50 mg doses of myristicin, showed 4- to 14-fold increase in liver GST specific activity over the control. GST purified from equal amounts of control and myristicin-treated livers indicated a marked increase in the GST activity. A relatively higher increase in GST activity towards 2,4-dichloronitrobenzene and a profound increase in the levels of GST mu on Western blot analysis of the myristicin-treated mouse liver suggest a preferential induction of GST mu. Results of the study also indicate that out of the two mu class GST subunits (Mr. 26,500 and Mr. 25,000) expressed in liver only one (Mr. 26,500) is significantly elevated. Myristicin treatment caused a slight change in the GST pi levels while the levels of GST alpha showed a modest increase. These results suggest that myristicin could be an effective chemopreventive agent, particularly for carcinogens that are detoxified by the mu class GST.

Lupus nephritis in children: a longitudinal study of prognostic factors and therapy

There are only a few studies in the pediatric literature that have analyzed risk factors for renal failure in childhood lupus nephritis. This study reviewed the outcome of 56 children (4 to 18 yr of age) with lupus nephritis seen at the authors' institution over a 27-yr period (1965 to 1992), in relation to risk factors and therapy. All children underwent percutaneous renal biopsy before the institution of therapy. From 1965 to 1987, treatment for Class III and IV lupus nephritis consisted of high-dose pulse methylprednisolone, 500 mg daily for 10 days, followed by oral prednisone. From 1987 to 1992, IV cyclophosphamide was given monthly for 6 months and then every 3 months for a period of 3 yr for patients with Class III and Class IV disease. Of 56 children, 42% had Class IV and 21% had Class III histology at onset. The mean follow-up period was 4 yr and ranged from 0.5 to 20.3 yr. Life-table analysis showed that the cumulative proportion of patients surviving was 82.8% at 5 yr and 67.7% at 10 yr. Renal survival was 44.4% at 5 yr and 29% at 10 yr, after the initial diagnosis of lupus nephritis was made. Age at diagnosis, race, sex, initial serum creatinine level, and the presence of proteinuria, hypertension, and DNA antibody titers were reviewed with respect to disease progression, as was the histological class at diagnosis. The effect of the different therapies was also examined. Univariate analysis revealed a significant association of progression to ESRD with an elevated serum creatinine level (P = 0.021), decreased C3 complement (P = 0.024), hypertension (P = 0.053), and histological classification of Class IV lupus nephritis (P = 0.031). Multivariate analysis demonstrated that progression to ESRD was independently associated with an initial Class IV histology (relative risk, 1.78; P < 0.003), hypertension at presentation (relative risk, 1.67; P < 0.003), and a low C3 complement level in conjuction with a high creatinine level (relative risk, 1.52; P < 0.028). Among children with lupus nephritis, those with Class IV disease, hypertension, high creatinine levels, and low C3 complement levels at the time of diagnosis are at increased risk for ESRD. Initial histological classification of lupus nephritis was the most reliable prognostic factor for disease progression. This study was unable to detect a difference in outcome for the two treatment groups.

Lingual thyroid: tongue-splitting incision for transoral excision

Two patients presenting to the Central Military Hospital of Beirut with symptomatic lingual thyroid are reported. I131 thyroid scanning revealed the lingual thyroid to be the only functional thyroid tissue present in each patient. Subsequent CT scanning demonstrated the large size of these ectopic thyroids causing significant mechanical obstruction. These were excised transorally using a posterior midline tongue-splitting incision and reimplanted in the rectus abdominis muscles. Details of this modified tongue-splitting surgical approach are described. A brief review of the literature concerning lingual thyroid and its surgical treatment is also presented as well as three patients operated on for lingual thyroid at the American University of Beirut Medical Centre between 1975 and 1994 using an external neck incision.

Aggressive, long-term cyclosporine therapy for steroid-resistant focal segmental glomerulosclerosis

Short-term cyclosporine (CsA) has been shown to reduce the proteinuria in refractory nephrotic syndrome, but the effect on disease progression has not been evaluated. This study was undertaken to evaluate whether maintenance CsA therapy in steroid-resistant focal segmental glomerulosclerosis (FSGS) will prevent progression to ESRD. Twenty-one black and Hispanic children (mean age, 8.4 +/- 4.5 yr) with biopsy-proven, steroid/cyclophosphamide-resistant FSGS were treated with CsA (initiated at 6 mg/kg per day and titrated to the serum cholesterol level to achieve a response). The mean CsA dose was 7 (4 to 20) mg/kg per day, the duration of CsA therapy was 27.5 (3 to 97) months, and the duration of follow-up was 8.5 +/- 4.7 yr. At the end of CsA therapy, the mean (+/- SE) proteinuria fell from 6.2 +/- 0.2 to 2.0 +/- 0.1 g/24 h (P < 0.001), the mean albumin rose from 1.95 +/- 0.04 to 3.41 +/- 0.04 g/dL (P < 0.001), the mean cholesterol decreased from 472 +/- 12.7 to 257 +/- 5.3 mg/dL (P < 0.005), and the mean creatinine rose from 0.79 +/- 0.02 to 1.16 +/- 0.03 mg/dL (P < 0.005). Seven children continue to receive maintenance CsA therapy, and 14 patients have had CsA stopped: 6 for an increase in serum creatinine and/or continued proteinuria, 5 for sustained remission, 2 for noncompliance, and 1 for pregnancy. Five (24%) of the 21 patients progressed to ESRD.(ABSTRACT TRUNCATED AT 250 WORDS)

In vitro sensitivity of medically significant Fusarium species to various antimycotics

Sixteen isolates belonging to Fusarium chlamydosporum (n = 4), Fusarium equiseti (n = 1), Fusarium moniliforme (n = 2), Fusarium oxysporum (n = 3), Fusarium proliferatum (n = 1), and Fusarium solani (n = 5) were tested against amphotericin B, 5-fluorocytosine, fluconazole, itraconazole, ketoconazole, JAI-amphotericin B (water-soluble compound), hamycin and amphotericin B combined with 5-fluorocytosine, using antibiotic medium M3, high-resolution broth (pH 7.1), Sabouraud's dextrose, and yeast-nitrogen broth media (1 ml/tube). The minimal inhibitory and minimal fungicidal concentrations of 5-fluorocytosine and fluconazole for all species were > 100 micrograms/ml. All Fusarium isolates, except F. equiseti (3.125 micrograms), gave minimal inhibitory concentrations of 12.5-100 micrograms/ml for hamycin. The values for amphotericin B, itraconazole, ketoconazole, JAI-amphotericin B, and amphotericin B combined with 5-fluorocytosine were 1.56-100, 0.78-50, 3.125-100,50-100, and 1.56 to > 100 micrograms/ml, respectively. Although a wide range of minimal inhibitory concentrations was recorded for most of the isolates studied, it appears that some--F. solani, F. oxysporum, F. chlamydosporum, F. equiseti, and F. moliniforme--were more susceptible to amphotericin B, itraconazole, ketoconazole, hamycin, and amphotericin B in the presence of 5-fluorocytosine. All isolates showed resistance to 5-fluorocytosine and fluconazole. The minimal fungicidal concentrations were either the same or several times higher than the minimal inhibitory concentrations.

Beware the anomalous portal vein

Portal vein thrombosis is an unusual potential complication of liver resection. In our case it was due to ligation of the right branch of the portal vein during right hepatectomy in a patient without portal vein bifurcation. Hepatic angiography can delineate this abnormality and influence the choice of surgical management.

Interactions of glutathione S-transferase-pi with ethacrynic acid and its glutathione conjugate

Ethacrynic acid, a diuretic drug known to be an inhibitor of glutathione S-transferases (GSTs), has been shown to enhance the cytotoxicity of the alkylating agent class of chemotherapeutic drugs in cultured cancer cells resistant to alkylating agents. This action of ethacrynic acid is presumably mediated by inhibition of GSTs which are implicated in detoxification of alkylating agents. In addition to being an inhibitor of GSTs, ethacrynic acid also interacts with GSTs as a substrate for conjugation with GSH to yield an ethacrynic acid-GSH conjugate. This conjugate is formed both enzymatically and non-enzymatically and itself is a GST inhibitor. Since ethacrynic acid-GSH conjugate is itself likely to be able to mediate reversal of alkylating agents through GST inhibition, we have synthesized and purified the ethacrynic acid-GSH conjugate, studied the kinetics of inhibition of human lung pi-class GST by ethacrynic acid and the conjugate, and compared the kinetics of the enzymatic and non-enzymatic formation of the conjugate using an HPLC method. Results of our studies showed that the ethacrynic acid-GSH conjugate was a more potent inhibitor of human lung GST-pi than ethacrynic acid (Ki = 1.5 vs. 11.5 microM, respectively) and that their mechanisms for GST inhibition were distinct (competitive and non-competitive, respectively). Comparison of enzymatic and non-enzymatic rates of conjugate formation in vitro indicated that GST-pi catalyzed a rapid conjugation of ethacrynic acid with GSH at a concentration of ethacrynic acid an order of magnitude above that required to nearly completely inhibit GST catalyzed conjugation of 1-chloro-2,4-dinitrobenzene. However, because of the rapid non-enzymatic reaction, and the inhibition of GST-pi with the accumulation of the conjugate in the reaction mixture, the overall quantity of the conjugate formed after 150 min was nearly identical in the presence or absence of GST-pi. Results of these studies suggest that inhibition of GSTs by ethacrynic acid-GSH conjugate may be the main mechanism through which ethacrynic acid reverses alkylating agent resistance.

Glutathione S-transferases of human skin: qualitative and quantitative differences in men and women

Glutathione S-transferase (GST) isozymes of male and female leg skin have been characterized. GST activities and protein have been quantified in a number of male and female skin samples and the results indicate that as compared to the male skin, female skin contains a higher amount of GST activity as well as protein. Both male and female leg skin contain three GST isozymes with pI values 9.9, 9.1 and 4.8. In accordance with previous findings the major isozyme, pI 4.8 belongs to the pi-class, whereas the two minor forms pI 9.1 and 9.9 belong to the alpha-class. Each of the three isozymes is more abundant in female skin. Surprisingly, the specific activities and Kcat values of the female skin GSTs, particularly of the pi-class isozyme were found to be significantly higher as compared to those of male skin isozyme. Studies into the kinetics of inhibition by hematin also indicated differences in male and female skin GSTs. Whereas we confirm the presence of an alpha-class GST, pI 9.9, in human skin with an apparently higher subunit M(r) value as compared to other human alpha-class GSTs, contrary to the previous report (Del Boccio et al. (1987) Biochem. J. 244, 21-25), the results of the present studies show that the N-terminus of this alpha-class GST is blocked.

Comparative studies on the effect of butylated hydroxyanisole on glutathione and glutathione S-transferases in the tissues of male and female CD-1 mice

1. Male CD-1 mice had about 1.6-fold higher glutathione (GSH), 2-fold higher glutathione S-transferase (GST) activity and 2.8-fold higher GST protein in their livers as compared to the female mice. 2. When mice were fed a diet containing 0.75% BHA for 2 weeks, a 1.8-fold increase was observed in GSH levels of female mice liver as opposed to only 1.2-fold increase in male mice. BHA caused 10-fold increase in GST activity and protein in livers of female mice as compared to only about 3-4-fold increase in livers of males. Differential induction of GSH and GST in males and females was also observed in other tissue besides liver but was not as remarkable. 3. Sex-related differences were also observed in the induction of the alpha- and mu- and pi-classes of GSTs by BHA; most noticeable being GST pi, which was induced to about 10-fold in female liver as opposed to only 3.4-fold in male liver.

Characterization of two novel subunits of the alpha-class glutathione S-transferases of human liver

More than 85% of the complete amino-acid sequence of the alpha-class glutathione S-transferase omega (GST omega) of human liver, described for the first time in this communication, show that GST omega is a heterodimer of two closely related novel alpha-class GST subunits. The sequences of these subunits, omega 1 and omega 2, have over 97% homology between them and are also highly homologous to the two alpha-class subunits characterized previously. Characterization of these two novel alpha-class subunits described in this report would explain the molecular basis for high degree of heterogeneity observed among the alpha-class human GSTs.

Reversed-phase chromatographic method for specific determination of glutathione in cultured malignant cells

A chromatographic method for the specific determination of glutathione in malignant cell lines is described. The method is based on the ability of glutathione-S-transferase to specifically and quantitatively conjugate glutathione to 1-chloro-2,4-dinitrobenzene and chromatographic quantitation of the resultant conjugate, dinitrophenyl-S-glutathione, by reversed-phase liquid chromatography. The assay can be performed on 20,000 g supernatants of cell homogenates without acid extraction. 2-Mercaptoethanol, a sulfhydryl compound often used as a thiol-protective agent to preserve enzymatic activities of a number of enzymes, did not interfere with glutathione determination by this method. The dinitrophenyl-S-glutathione isolated from either standard glutathione samples or from cell homogenates was shown to be identical to authentic dinitrophenyl-S-glutathione using mass spectrometry. Recovery of glutathione in standard samples by the current method was identical to that determined using 5,5'-dithiobis(2-nitrobenzoic acid). Exogenous glutathione added to supernatants of cell homogenate in the presence or absence of 2-mercaptoethanol was also completely recovered.

Glutathione S-transferases of human lung: characterization and evaluation of the protective role of the alpha-class isozymes against lipid peroxidation

Glutathione S-transferase (GST) isozymes of human lung have been purified, characterized, quantitated, and, based on their structural and immunological profiles, identified with their respective classes. The tau-, mu-, and alpha-class GSTs represented 94, 3, and 3% activities of total human lung GSTs toward CDNB, respectively, and 60, 10, and 30% of total GST protein, respectively. Both the mu- and the alpha-class GSTs of human lung exhibited heterogeneity. The two mu-class GSTs of human lung had pI values of 6.5 and 6.25 and were differentially expressed in humans. Significant differences were seen between the kinetic properties of these two isozymes and also between the lung and liver mu-class GSTs. The alpha-class GST isozymes of lung resolved into three peaks during isoelectric focusing corresponding to pI values of 9.2, 8.95, and 8.8. All three alpha-class GSTs isozymes had blocked N-termini and were immunologically similar to human liver alpha-class GSTs. Peptide fingerprints generated by SV-8 protease digestion and CNBr cleavage indicated minor structural differences between the liver and the lung alpha-class GSTs. The three alpha-class GSTs of lung expressed glutathione peroxidase activities toward the hydroperoxides of phosphatidylcholine, phosphatidylethanolamine, and phosphatidylglycerol, with Km values in the range of 22 to 87 microM and Vmax values in the range of 67-120 mol/mol/min, indicating the involvement of the alpha-class GSTs in the protection mechanisms against peroxidation. All three classes of lung GSTs expressed activities toward leukotriene A4 methyl ester and epoxy stearic acid but the mu-class GSTs had relatively higher activities toward these substrates.

Evaluation of therapies in the treatment of Helicobacter pylori associated non-ulcer dyspepsia

This randomised double blind placebo controlled study evaluated the effectiveness of colloidal bismuth subcitrate (CBS), ampicillin and their combination in the treatment of Helicobacter Pylori in non-ulcer dyspepsia (NUD) and assessed if elimination of this organism is associated with improvement of gastritis and the symptoms. Forty-eight NUD patients with H. pylori and histologic gastritis were randomly allocated to one of the three regimens for 28 days. Symptoms were assessed before and after treatment. Forty-three patients completed the trial. Repeat endoscopy within 48 hours of completing treatment showed suppression of H. pylori in 6 of 7 patients (85.7%) on combined therapy and one of 8 patients (12.5%) on CBS therapy (p = 0.0205). There was no suppression of the bacteria in patients treated with ampicillin. Repeat endoscopy performed 2 weeks after completing treatment showed suppression of H. pylori in 3 of 7 patients (42.9%) on combined therapy and none in the other two groups. Patients on combined therapy who had suppression of H. pylori, 48 hours or 2 weeks after completing treatment were noted to have historical improvement of their gastritis (p = 0.0001 and p = 0.05 respectively). This was also associated with improvement of symptoms in these patients.

Gender related differences in the expression and characteristics of glutathione S-transferases of human colon

In the present study, the expression of glutathione S-transferase (GST) isozymes was compared in human male and female colon tissues. GST isozymes were purified and quantified in five male and five female colon tissue samples. Noticeable differences were observed in the isoelectric focusing profiles (IEF) of the GSTs, from male and female colon tissues. Both male and female colon tissues had three common GST peaks with pI values of 9.2, 6.7 and 4.8. An additional GST peak with a pI value of 6.2 found in all females was not found in males. Based on kinetic, immunological and structural properties, these isozymes were classified into alpha (pI 9.2), mu (pI 6.7 and 6.2) and pi (pI 4.8) classes. Activity of the alpha-class GST in male colon was approx. 2-fold higher than the corresponding isozyme in female colon. The pi-class GST 4.8 was the most predominant GST in both the sexes and its activity with CDNB as substrate was more abundant (about 1.6-fold) in female colon as compared to that in male colon. Significant differences were seen in substrate specificities between male and female colon GST 4.8. Sex related differences were also observed in the inhibition kinetics of GST pi from male and female colon in the presence of hematin. In addition, GST pi isolated from female colon was more thermostable as compared to the corresponding male isozyme. The thermostability of purified GST pi isozyme from males or females was not affected by incubation of the enzyme with either estrogen, testosterone or progesterone.

Glutathione S-transferases of mouse liver: sex-related differences in the expression of various isozymes

Sex-related differences in the expression of glutathione S-transferase (GST) isozymes of mouse liver have been described. There were no apparent qualitative differences in the isoelectric focusing profiles of the GST isozymes from male and female mouse liver. Both male and female mice have at least four GST isozymes in their liver with pI values of 9.8, 8.7, 6.4 and 5.7. Kinetic, immunological, and structural properties including the N-terminal region amino acid sequences of these isozymes have been determined and they have been classified into alpha, mu, and pi classes. The most cationic isozyme (pI 9.8) belongs to the alpha class and is comparatively more abundant in female liver. The isozyme having pI 8.7 belongs to the pi class and is more abundant in male liver. The mu class GST pI 6.4 as well as the isozyme having pI 5.7 which corresponded to the a class isozyme GST 8-8 of rat liver were more abundant (about 1.5-fold) in male mouse liver as compared to the female. Interestingly, present studies reveal sex-related differences in the heat stabilities of the alpha and pi class GSTs of mouse liver. The alpha class GST pI (9.8) isolated from female mouse liver was more thermostable as compared to the corresponding enzyme from male mouse liver. On the contrary, the pi class GST (pI 8.7) from male mouse was more thermostable as compared to the corresponding enzyme from the female mouse.

t-butylated hydroxytoluene enhances intracellular levels of glutathione and related enzymes of rat lens in vitro organ culture

Studies were undertaken to investigate the effect of t-butylated hydroxytoluene (BHT) on reduced glutathione (GSH) levels and related enzymes in rat ocular tissues. GSH levels were significantly enhanced when 1 microM BHT was included in the medium of rat lens cultures. BHT had a dose-dependent effect on GSH levels of lenses in cultures. Inclusion of 10 microM BHT in the culture medium resulted in a twofold increase in GSH levels of the lens within 24 hr. Increased gamma-glutamylcysteine synthetase activity concomitant with the increased amount of [35S]methionine incorporation in GSH strongly suggested that BHT caused enhanced levels of GSH in lenses by increasing de novo biosynthesis. A significant increase was also observed in glutathione S-transferase (GST) levels of lenses in culture containing BHT in the medium. Present studies also demonstrated that rat lens expresses only the mu and pi class GST isoenzymes and both these classes of isoenzymes were elevated by BHT. Oral administration of BHT to rats also resulted in enhanced in vivo levels of GSH in lens, retina and cornea. In addition, a significant in vivo increase in the levels of GST, GSH-peroxidase, GSH-reductase, gamma-glutamylcysteine synthetase, and glucose 6-phosphate dehydrogenase was observed in the lens, retina, and cornea of BHT-fed rats.

Purification and characterization of glutathione S-transferases from rat pancreas

Glutathione S-transferases (GSTs) of rat pancreas have been characterized and their interrelationship with fatty acid ethyl ester synthase (FAEES) has been studied. Seven GST isozymes with pI values of 9.2, 8.15, 7.8, 7.0, 6.3, 5.9 and 5.4 have been isolated and designated as rat pancreas GST suffixed by their pI values. Structural, immunological and kinetic properties of these isozymes indicated that GST 9.2 belonged to the alpha class, GST 7.8, 7.0, 6.3 and 5.9 belonged to the mu class, whereas GST 8.15 and 5.4 belong to pi class. The N-terminal sequences and pI values of the mu class isozymes suggested that rat GST subunits 3, 4 and 6 may be expressed in pancreas. N-Terminal sequences of both the pi class isozymes, GST 8.15 and 5.4, were similar to that of GST-P, but there were significant differences in the substrate specificities of these two enzymes. Results of peptide finger print studies also indicated minor structural differences between these two isozymes. None of the GST isozymes of rat pancreas expressed FAEES activity. Rat pancreas had a significant amount of FAEES activity, but it segregated independently during the purification of GST indicating that these two activities are expressed by different proteins and are not related as suggested previously.

Characterization of a novel glutathione S-transferase isoenzyme from mouse lung and liver having structural similarity to rat glutathione S-transferase 8-8

In mouse lung, glutathione S-transferase (GST, EC 2.5.1.18) isoenzymes belonging to the three major known classes, Alpha, Mu and Pi, have been previously characterized, along with an isoenzyme (pI 5.7) that could not be identified with the Alpha, Mu or Pi classes of GSTs. In the present studies we have demonstrated that this isoenzyme is also expressed in liver. Its structural, kinetic, and immunological properties have been determined and compared with those of the three classes of GSTs. GST 5.7 has a subunit molecular mass of 23 kDa, which is intermediate between that of the previously characterized Alpha (25 kDa) and Pi (22.5 kDa) class GST subunits of mouse lung. Comparison of peptide maps of GST 5.7 with those representative of Alpha, Mu and Pi class GST isoenzymes of mouse lung showed that it had a distinct peptide fragmentation pattern. Kinetic and immunological properties of GST 5.7 were also distinct from other mouse GST isoenzymes belonging to the Alpha, Mu or Pi classes. N-Terminal amino-acid-sequence analysis of a 6 kDa fragment generated by CNBr digestion of mouse lung GST 5.7 revealed a 15-residue sequence that was distinct from sequences of known Alpha, Mu and Pi class mouse GSTs. The sequence, however, matched with the sequence of rat GST 8-8 between amino acid residues 106 and 120 with a 73% identity. The 6 kDa and 12 kDa fragments generated by CNBr digestion of mouse liver GST 5.7 also gave sequences which matched with those of rat GST 8-8 between positions 106 and 120 and 167 and 186, with a high degree of identity. These studies suggest that mouse GST 5.7 structurally corresponds to rat GST 8-8 and belongs to the Alpha class.