Case of the season. Megaloblastic anemia with subacute combined degeneration (SCD) of the spinal cord.
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OBJECTIVE: To determine ciprofloxacin resistance of corneal isolates of Pseudomonas and to review the clinical response to topical therapy in cases of ciprofloxacin-resistant Pseudomonas keratitis, where medical therapy was begun with 0.3% ciprofloxacin. DESIGN: Retrospective noncomparative case series. PARTICIPANTS: Medical and microbiology records of 141 culture-proven cases of Pseudomonas keratitis, examined between January 1991 and June 1998, were reviewed retrospectively. METHODS: All isolates of the Pseudomonas species from corneal scrapings were tested for their susceptibility to routinely used antibiotics by the Kirby-Bauer disc-diffusion method. The minimum inhibitory concentration of ciprofloxacin was determined by the agar-dilution method for most of the isolates found resistant to ciprofloxacin. Clinical response to initial therapy with 0.3% ciprofloxacin was determined in cases of keratitis caused by ciprofloxacin-resistant Pseudomonas. MAIN OUTCOME MEASURES: Resistance of Pseudomonas isolates to ciprofloxacin and clinical response to initial therapy with 0.3% ciprofloxacin. RESULTS: By use of the in vitro antimicrobial susceptibility test, 22 cases of keratitis caused by ciprofloxacin-resistant Pseudomonas were identified. The minimum inhibitory concentration of ciprofloxacin for these isolates was > or =16 microg/ml (mean = 43 microg/ml). Gentamicin resistance occurred in 63.6% of isolates also, but 90.9% ciprofloxacin-resistant isolates were susceptible to amikacin. Fifteen (76.7%) of 19 patients who initially received ciprofloxacin did not show any clinical improvement even after 3 days of intensive medical therapy. The infiltrate resolved in all 8 cases where the antibiotic therapy was modified on the basis of susceptibility test. Four eyes were subjected to penetrating keratoplasty, and three were eviscerated following failure of treatment with ciprofloxacin. CONCLUSION: True resistance to ciprofloxacin is emerging in ophthalmology even among Pseudomonas isolates; therefore, the empiric treatment of infectious keratitis with ciprofloxacin monotherapy must be critically reviewed at this time.
OBJECTIVE: To examine in vitro susceptibility of bacterial keratitis pathogens to ciprofloxacin. DESIGN: Retrospective review. PARTICIPANTS: The authors examined in vitro susceptibility of 1558 corneal isolates from 1303 patients with culture-proven bacterial keratitis seen at the LV Prasad Eye Institute in Hyderabad, India, during the 6-year period between March 1, 1991, and June 30, 1997. RESULTS: Of 1558 corneal isolates, 478 (30.7%) were not sensitive to ciprofloxacin. Among the isolates, 355 (32.5%) of the 1091 gram-positive cocci were not sensitive to ciprofloxacin, and 2 (10%) of the 20 gram-positive bacilli, 22 (13.3%) of the 165 gram-negative organisms, and 99 (35.1%) of the 282 Actinomycetes and related organisms were not sensitive to ciprofloxacin. Results from chi-square for trends analysis showed a trend of significantly increasing ciprofloxacin insensitivity in bacteria between 1992 and 1997 (P = 0.011). CONCLUSION: This is the first report of significantly increasing ciprofloxacin insensitivity among corneal pathogens. Although the lowered cost and convenience of dispensing a single, commercially available antibiotic such as ciprofloxacin in the initial treatment of bacterial keratitis is desirable, the emergence of ciprofloxacin resistance is a significant finding in this series, and the clinician should proceed with caution in the initial empiric treatment of bacterial keratitis with ciprofloxacin.
OBJECTIVE: To determine the long-term visual acuity after diode laser photocoagulation for threshold retinopathy of prematurity. DESIGN: Retrospective, noncomparative case series. INTERVENTION: Photocoagulation of the peripheral avascular retina with a diode laser indirect ophthalmoscope. MAIN OUTCOME MEASURES: The principal outcome evaluated was best-corrected visual acuity (BCVA). The most recent refractions for these eyes were also collected for analysis. PARTICIPANTS: Thirty-five infants with threshold retinopathy of prematurity treated with laser photocoagulation from 1991 to 1996. RESULTS: After bilateral laser treatment, 14 (56%) of 25 patients who were capable of accurate visual acuity testing had 20/50 or better BCVA in at least 1 eye with 11 (44%) of 25 patients having at least 20/50 BCVA in both eyes. After unilateral treatment, four (40%) of ten had 20/50 or better BCVA in the treated eye while five (50%) of ten laser-treated eyes had a BCVA at least equal to the untreated fellow eye. Compared to eyes with 4 or more diopters (D) of myopia, those with less than 4 D of myopia were 6.4 times more likely to achieve 20/50 or better BCVA (95% confidence interval, 1.7-22.7). The average age at follow-up was 3.7 years. CONCLUSIONS: After laser photocoagulation for threshold retinopathy of prematurity, 29 (48%) of 60 eyes had 20/50 or better visual acuity. Eyes with 4 or more D of myopia were significantly less likely to achieve 20/50 or better visual acuity than eyes with less than 4 D of myopia.
OBJECTIVE: To determine the type and incidence of adverse events seen in the first 13 months of extended wear from a prospective clinical trial involving the use of disposable hydrogels on a 6-night extended wear and replacement schedule. DESIGN: A prospective, noncomparative clinical trial. PARTICIPANTS: Three hundred thirty subjects were enrolled in the study from March 1993 to August 1996 and commenced in extended wear. The subjects were new contact lens users with ages ranging from 16 to 39 years and refractive errors from -1.00 to -6.50-diopter (D) sphere with cylindrical component less than 1.0 D. INTERVENTION: Disposable hydrogel lenses on a 6-night extended wear and replacement schedule. MAIN OUTCOME MEASURES: To determine the incidence of adverse events in the first 13 months of lens wear with the use of disposable hydrogels on an extended wear schedule. In addition, corneal infiltrative events observed with lens wear were classified based on their presenting signs and symptoms. RESULTS: A total of 137 adverse events were seen in 102 subjects in the first 13 months of extended wear. The type of adverse events and the incidence per 100 patients per year of lens wear were as follows: corneal infiltrative events (44.4 events), contact lens papillary conjunctivitis (6.4 events), neovascularization and corneal wrinkling (1.7 events each), corneal striae and superior epithelial arcuate lesions (1.3 events each), and blepharokeratoconjunctivitis (0.4 event). Viral keratoconjunctivitis was also observed (0.8 event). The corneal infiltrative events were further subclassified as follows: contact lens-induced peripheral ulcers (13.6 events), contact lens-induced acute red eyes (12.3 events), infiltrative keratitis (9.7 events), and asymptomatic infiltrative events (8.9 events). There were no events of infectious keratitis. Except for all events of contact lens-induced peripheral ulcers and two isolated events of infiltrative keratitis that resulted in scarring, all of the corneal infiltrative events resolved without sequelae. None of the events caused any loss of best-corrected visual acuity. CONCLUSIONS: Based on the observations from the first 13 months of extended wear in the trial, the majority of the complications associated with extended wear of disposable hydrogels are corneal infiltrative events. No events of microbial keratitis were seen in the first 13 months of extended wear. None of the events were associated with loss in best-corrected visual acuity. Clearly, frequent and regular disposing of lenses does not eliminate adverse effects, and better materials and designs are required for extended wear to be a successful method.
N-Methyl-D-aspartate receptors are present in the nodose ganglion, which contains the cell bodies of vagal afferents, and in the nucleus tractus solitarius, where these afferent fibers terminate. This suggests that N-methyl-D-aspartate receptors are located presynaptically on visceral vagal afferents and/or their target neurons in the nucleus tractus solitarius. To test this hypothesis, we combined anterograde transport of biotinylated dextran amine, following injections into the left nodose ganglion, with electron microscopic immunogold labeling of antipeptide antiserum against the R1 subunit of the N-methyl-D-aspartate receptor in the nucleus tractus solitarius of rat brain. Within the medial nucleus tractus solitarius, the N-methyl-D-aspartate receptor R1 immunoreactivity was seen in dendrites (39% of 639 profiles), axons and axon terminals (41%), and a few neuronal perikarya and glia. Many vagal afferent axons and terminals (40% of 468 profiles) contained N-methyl-D-aspartate receptor R1 immunogold labeling. In addition, 42% of the dendrites contacted by vagal afferent terminals (n = 206) contained N-methyl-D-aspartate receptor R1 immunoreactivity. In axons and dendrites, the gold particles were occasionally seen within asymmetric postsynaptic junctions or at non-synaptic sites on the plasma membrane. More commonly, however, N-methyl-D-aspartate receptor R1 labeling was seen on membranes of vesicular cytoplasmic organelles, suggesting that there is abundant N-methyl-D-aspartate receptor protein available for activity-dependent mobilization to the plasmalemma. Since many vagal afferents are glutamatergic, our results implicate N-methyl-D-aspartate receptors in autoregulation of the presynaptic release and postsynaptic responses to glutamate at the level of the first central synapse in the nucleus tractus solitarius.
OBJECTIVE: Diagnostic technologies are often assessed merely by their accuracy, rather than by their impact on diagnosis and patient management. To this end the authors have undertaken a study to assess the diagnostic and therapeutic impact of magnetic resonance imaging (MRI) and arthrography of the shoulder for patients referred from a rheumatology clinic. METHODS AND PATIENTS: Patients referred from a rheumatology clinic with symptoms warranting imaging of the shoulder were randomised to either MRI or arthrography. Data on the clinician's diagnostic confidence and management were recorded before and after imaging using questionnaires. Patients were followed-up at least 10 months after imaging to see how management plans evolved, and what proportion of patients required further imaging. RESULTS: Fifty three shoulders underwent imaging over a year and entered into the study; 29 randomised to MRI and 24 to arthrography. Both MRI and arthrography had a similar beneficial diagnostic impact in terms of clinical diagnoses (refuted and retained) and new diagnoses established. MRI and arthrography had a similar therapeutic impact, although MRI was associated with a significant shift towards surgical intervention. CONCLUSION: MRI and arthrography a have similar diagnostic and therapeutic impact.
OBJECTIVES: The aim of this study was to evaluate the survival of patients with hypertrophic cardiomyopathy (HCM) after resuscitated ventricular fibrillation or syncopal sustained ventricular tachycardia (VT/VF) when treated with low dose amiodarone or implantable cardioverter defibrillators (ICDs). BACKGROUND: Prospective data on clinical outcome in patients with HCM who survive a cardiac arrest are limited, but studies conducted before the widespread use of amiodarone and/or ICD therapy suggest that over a third die within seven years from sudden cardiac death or progressive heart failure. METHODS: Sixteen HCM patients with a history of VT/VF (nine male, age at VT/VF 19 +/- 8 years [range 10 to 36]) were studied. Syncopal sustained ventricular tachycardia/ventricular fibrillation occurred during or immediately after exertion in eight patients and was the initial presentation in eight. One patient had disabling neurologic deficit after VT/VF. Before VT/VF, two patients had angina, four had syncope and six had a family history of premature sudden cardiac death. After VT/VF all patients were in New York Heart Association class I or II, three had nonsustained VT during ambulatory electrocardiography and 11 had an abnormal exercise blood pressure response. After VT/VF eight patients were treated with low dose amiodarone and six received an ICD. Prophylactic therapy was declined by two patients. RESULTS: Mean follow-up was 6.1 +/- 4.0 years (range 0.5 to 14.5). Cumulative survival (death or ICD discharge) for the entire cohort was 59% at five years (95% confidence interval: 33% to 84%). Thirteen (81%) patients were alive at last follow-up. Two patients died suddenly while taking low dose amiodarone, and one died due to neurologic complications of his initial cardiac arrest. Three patients had one or more appropriate ICD discharges during follow-up; the times to first shock after ICD implantation were 23, 197 and 1,124 days. CONCLUSIONS: This study shows that patients with HCM who survive an episode of VT/VF remain at risk for a recurrent event. Implantable cardioverter defibrillator therapy appears to offer the best potential benefit regarding outcome.
To increase our knowledge of factors leading to Acanthamoeba keratitis in contact lens wearers, we determined the ability of this organism to adhere to corneal epithelial cells (EC) recovered from non-lens wearers (NL) and from subjects using hydrogel contact lenses on a daily (DW) and extended wear (EW) schedule. ECs were incubated with trophozoites of Acanthamoeba and, after 3 h, the median per cent of cells exhibiting adherence was 24, 23 and 23 for NL, DW and EW groups respectively (P=0.552, Kruskal-Wallis Test). There were no differences between the groups for the number of adherent amoebae and a significant majority had only one adherent trophozoite per EC. No difference in adherence was seen with increasing exposure time. Factors other than amoebic adherence to superficial corneal EC are responsible for the increased incidence of Acanthamoeba keratitis in lens wearers.
The two glycosylated N- and C-terminal lobes of buffalo lactoferrin have been produced by limited proteolysis using proteinase K. Lactoferrin is a single chain glycoprotein of molecular mass 80 kDa with two iron-binding sites and two structural lobes connected by a short peptide. Purified samples of lactoferrin, isolated from buffalo colostrum, were subjected to hydrolysis using trypsin, chymotrypsin, pepsin, subtilisin and proteinase K. The first three proteinases produced two major fragments of approximately 35 and 23 kDa together with small molecular mass peptides. Trypsin and chymotrypsin partly digested lactoferrin, while pepsin converted all the intact lactoferrin into fragments. Subtilisin hydrolysis produced fragments of 40 and 26 kDa together with low molecular mass peptides. However, SDS-PAGE of the proteinase K hydrolysis product gave a clear band at 40 kDa together with a band indicating a substantial quantity of low molecular mass peptides (< 14.4 kDa). Upon ion-exchange chromatography this product gave two major fractions, which were further purified by gel filtration and identified as the C and N lobes from their N-terminal sequences. Thus, the 40 kDa band in SDS-PAGE of the proteinase K hydrolysis product contained two fragments of equal molecular mass. On further hydrolysis with proteinase K, the N lobe was completely hydrolysed into low molecular mass peptides, while only a small fraction of the C lobe was converted into small products. This suggested that an inhibitory fragment was present in the C lobe that was released on hydrolysis to small fragments and prevented complete digestion of the C lobe by high-affinity binding to the active site of proteinase K. This fragment was isolated from the lactoferrin-proteinase K complex and its sequence determined to be Val-Ala-Gln-Gly-Gly-Ala-Ala-Gly-Leu-Ala. Circular dichroism studies indicated a high alpha-helical content in the native lactoferrin while comparatively lower helical structures were present in the N and C lobes. In addition, the iron saturations of the N and C lobes appeared to be lower than that of the native protein.
The Andaman islands were known to be endemic for leptospirosis during the early part of the century. Later, for about six decades no information about the status of the disease in these islands was available. In the late 1980s leptospirosis reappeared among the settler population and several outbreaks have been reported with high case fatality rates. Besides settlers, these islands are the home of six primitive tribes of which two are still hostile. These tribes have ample exposure to environment conducive for transmission of leptospirosis. Since no information about the level of endemicity of the disease among the tribes is available, a seroprevalence study was carried out among all the accessible tribes of the islands. A total of 1557 serum samples from four of the tribes were collected and examined for presence of antileptospiral antibodies using Microscopic Agglutination Test (MAT) employing 10 serogroups as antigens. An overall seropositivity rate of 191% was observed with the highest rate of 53.5% among the Shompens. The seropositivity rates in the other tribes were 16.4% among Nicobarese, 222% among the Onges and 14.8% among the Great Andamanese. All of the tribes except the Onges showed a similar pattern of change in the seroprevalence rates with age. The prevalence rates were rising from low values among children to reach a peak in those aged 2140 years and then declined. Among Onges the seroprevalence rates continued to rise beyond 40 years. In all the tribes, seroprevalence rates were found to be significantly higher among the males. The commonest serogroups encountered were Australis followed by Grippotyphosa, Icterohaemorrhagiae, Pomona and Canicola.
OBJECTIVE: To explore British African-Caribbean (AfC) nutrient intake by migration status (place of birth), diet (traditional Caribbean or more European) and age and relate this ecologically to coronary heart disease (CHD) mortality rates. DESIGN: Cross-sectional. SETTING: Inner-city Manchester, UK. SUBJECTS: Two hundred and fifty-five adults of AfC origin aged 25-79 years, randomly sampled from population registers. RESULTS: Caribbean-born people (mean age 56, and mean time in Britain 30 years) had significantly lower per cent energy from total and saturated fat than younger British-born AfC people (mean age 29 years) (31.3% vs. 35%, difference in total fat 3.7%, 95%CI 2-5%; in saturated fat 10.9% vs. 12.6%, difference 1.7%, 95%CI 1-2.5%). The Caribbean-born group also ate more fruit (+84g/day-1, 95%CI 36-132g/day-1) and green vegetables (+26 g/day-1, 95%CI 3-49 g/day-1). Men following a traditional diet (> or = 5 days week-1) similarly had a lower per cent energy from fat, at 30.4%, than less traditional eaters, at 33.1% (difference 2.7%, 95%CI 0.7-4.8%). African-Caribbean women, at relatively greater CHD risk than AfC men, had higher body mass indices (BMIs) than AfC men. Compared with national data, AfC subjects consumed some 7% and 5% less energy from total fat and saturated fat, respectively, with over 9% more from carbohydrate. However, there was marked convergence towards the national average in the youngest AfC groups aged 25-34 years, whatever their place of birth. CONCLUSIONS: Caribbean birthplace has an independent effect on total fat intake and percentage of energy from fat. Together with higher fruit and vegetable intake, these results are consistent with the dietary fat/antioxidant/CHD hypothesis.
The present investigation reports the antispermatogenic effect of the orally active highly purified gossypol acetic acid at 7.5 mg and 10 mg/day for 180 days in langur monkeys. The results revealed a dose-dependent response in semen analysis as well as testicular morphology. Uniform severe oligospermia was observed in the lower dose (7.5 mg) group, while azoospermia was observed in 2 out of 5 animals in the higher dose (10 mg) group and the remaining animals showed severe oligospermia. Scanning electron microscopy of spermatozoa revealed deleterious abnormalities in the head and midpiece. Testicular morphology revealed a decrease in the seminiferous tubule diameter and arrest of spermatogenesis. The lower dose group had a germ cell population up to primary spermatocytes while the higher dose group had only Sertoli cells and spermatogonia. Withdrawal of treatment for 180 days led to the recovery of all the parameters studied, to normalcy.
Ribosome inactivating proteins from plants have been widely used for the preparation of immunotoxins and hormonotoxins, which have potential application in the therapy of diseases such as cancer. However, these hybrid toxins have been found to be less cytotoxic than native ribosome inactivating proteins. Therefore, it is important to understand the factors that control the intrinsic toxicity of RIPs and the hybrid toxins prepared using them. Here, a hybrid toxin has been prepared by coupling ricin B-chain to momordin and the cytotoxicity of this hybrid toxin has been compared to that observed in case of native ricin. In the two cell types used here, thymocytes and macrophages, the conjugate was found to be about 40 fold less toxic than native ricin. Kinetics of inhibition of protein synthesis showed that prior to onset of inhibition the conjugate exhibits a longer lag phase than native ricin. The rates of inhibition of protein synthesis by the conjugate were also found to be slower than ricin. Analysis of the results suggests that in addition to cell surface binding, the B-chain of ricin facilitates another step in the transmembrane translocation of ricin A-chain to the cytosol.
Pigeonpea flour was substituted at levels of 0, 5, 10, 15, 20, 25% to wheat flour and whole wheat meal for bread and Chapatti making, respectively. Blends were prepared up to 50% for cookie making. Increasing levels of pigeonpeas in the blends significantly increased the protein and mineral content of the baked products. The bread from 10% pigeonpea flour blend with 2-3% vital gluten and 0.5% SSL had high loaf volume and loaf quality. Blends containing 15% pigeonpea flour were acceptable for Chapatti and 30% pigeonpea flour with 0.25% SSL were acceptable for cookie making.
Telomerase is an RNA-dependent polymerase that synthesizes telomeric DNA (TTAGGG)n repeats. The overall goal of our work was to establish human cancer models that can be used to design clinical trials with telomerase inhibitors. The objectives of this study were (1) to set up a human breast cancer system that allows evaluation of the effects of telomerase inhibitors in cultured cells using a non-amplified telomerase assay and (2) to test this system using two drugs (cisplatin and TMPyP4) that affect the telomerase expression in breast cancer cells in culture. We first compared the telomerase activity in a variety of human breast cancer cell lines to that of other tumour types using a new biotinylated-primer extension assay. Our method, based on a non-amplified primer extension assay shows the direct incorporation of 32P-labelled nucleotides induced by telomerase on human telomeric primers. The 32P-dGTP labelled telomerase-extended 5'-biotinylated (TTAGGG)3 primer can subsequently be separated using streptavidin-coated magnetic beads. As compared to other non-amplified method, we showed that this procedure improved the characterization and the quantification of the banding pattern resulting from telomerase extension by reducing the radioactive background. Using this method, we observed that telomerase activity varies markedly in a panel of 39 human cancer cell lines. For example, MCF7 breast cancer cells in culture showed intermediate telomerase activity corresponding to 33.8+/-3.4% of that of the HeLa cells (reference cell line). Similarly, the telomere length varied with each cell line (average: 6.24+/-6.16). No correlation between the level of telomerase and telomere length was observed, suggesting that a high processivity is not required to maintain telomeres and that, in some cell lines, another mechanism of telomere elongation can maintain telomere length. From this study, we selected MCF7 and MX1 models that showed reproducible telomerase activity and a relatively limited telomere length for the testing of potential telomere-telomerase interacting agents. Using cisplatin and a new porphyrin-derived compound TMPyP4, we showed that our model was able to detect a down-regulation of the telomerase activity in MCF7 cells in culture and in a human MX1 tumour xenografts. Based on these results, a breast cancer model for evaluating telomerase and telomere interactive agents is proposed.
Methotrexate (MTX) is a folate antagonist widely used both as an anticancer drug and as an immunosupressant. Administration of an 8-day methotrexate and folinic acid regime may be associated with pleuritic chest pain and pneumonitis. We have reviewed the toxicity seen in 168 consecutive patients treated with low-dose MTX for persistent trophoblastic disease. Twenty-five per cent of patients developed serosal symptoms, pleurisy was the commonest complaint. The majority of patients had mild to moderate symptoms which were controlled with simple analgesia and did not necessitate a change in treatment; 11.9% had severe symptoms which necessitated a change in treatment. One patient developed a pericardial effusion and a second patient developed severe reversible peritoneal irritation. The possible aetiology and pathophysiology of methotrexate-induced serosal toxicity is discussed.
Acetylcholinesterase (AChE) is released to the external medium when microfilariae (m.f.) of Setaria cervi, a bovine filarial parasite, are maintained in vitro. Intense enzyme staining at amphids, excretory pores, anal vesicle and phasmids suggest an active secretion of AChE from m.f. Excretory-secretory products of m.f. displayed two electromorphic variants of AChE when resolved by 6% nondenaturing PAGE. The two isoforms of AChE (A and B) were separated on the basis of charge by DEAE sepharose CL 6B column following gel filtration. The two isoforms showed differing kinetic properties with respect to substrate specificity and inhibitor sensitivity. Anti-Nippostrongylus brasiliensis AChE antibodies cross-reacted with the affinity purified secretory AChE in ELISA. Immunoblotting of purified AChEs with cross-reacting anti-AChE antibodies revealed the presence of an approximately 75 kD protein in the isoenzyme A and an approximately 45 kD protein in B, whereas both proteins were present in the enzyme purified via affinity chromatography on edrophonium sepharose column.