Cerebral SPECT imaging: effect on clinical management

This study, performed in 94 consecutive patients referred for evaluation, demonstrates the clinical utility of cerebral SPECT imaging. In a significant percentage of patients (47%), the additional information provided by SPECT resulted in an alteration in clinical management. Long-term follow-up will be necessary to determine the effect of these management decisions on patient outcome.

Pseudomonas aeruginosa outbreak associated with a contaminated blood-gas analyser in a neonatal intensive care unit

Over a 10 month period in a neonatal intensive care unit there was an outbreak of infection caused by Pseudomonas aeruginosa (resistant to ticarcillin, timentin) which involved 24 newborns. There was extensive morbidity and mortality (38%) associated with the infections, which presented as septicaemia (N = 6) (five succumbed and four had coexisting pneumonia), pneumonia (N = 6), meningitis (one, died), conjunctivitis (N = 1), otitis externa (N = 1), conjunctivitis plus otitis externa (N = 1). In addition there were two pseudosepticaemias and six colonized infants, three of whom were treated for the presence of P. aeruginosa in endotracheal aspirates. There was always at least one baby colonized or infected with P. aeruginosa during the outbreak. Environmental surveillance and genomic DNA fingerprinting of isolates identified the blood gas analyzer port as the likely reservoir for the outbreak. Further spread of the organism did not occur after commencement of staff education on vigilant and careful handwashing, especially after use of the blood-gas analyser.

Isolation and characterization of a monomethioninesulfoxide variant of interferon alpha-2b

PURPOSE

To isolate and characterize a monomethioninesulfoxide variant of the commercially available therapeutic protein interferon alpha-2b.

METHODS

The methionine (Met)-oxidized variant was isolated by reverse-phase high performance liquid chromatography and characterized by SDS-PAGE, peptide mapping and mass spectrometric analysis of the trypsin/V8-generated peptide fragments. The biological and immunological activities of the isolated variant were also evaluated.

RESULTS

The rHuIFN alpha-2b variant was found to contain a Met sulfoxide residue at position 111 of the rHuIFN alpha-2b molecule. The far-UV CD spectra showed a slight loss of alpha-helical content and an increase in the beta-sheet contribution. The CD spectra indicate that both chromatographic conditions and Met oxidation contribute to the observed secondary structure changes. Both interferon alpha-2b main component and its methionine-oxidized variant showed different reactivity to monoclonal antibodies employed in immunoassays for the protein.

CONCLUSIONS

A monomethioninesulfoxide rHuIFN alpha-2b variant was found to be present in the rHuIFN alpha-2b bulk drug substance in solution. The Met(111) residue was identified as Met sulfoxide by comparative tryptic/V8 mapping and mass spectrometric analysis. Nevertheless, the oxidation of the Met(111) residue did not seem to have a detectable effect on the biological activity of the molecule.

The function of the soluble interleukin 6 (IL-6) receptor in vivo: sensitization of human soluble IL-6 receptor transgenic mice towards IL-6 and prolongation of the plasma half-life of IL-6

Interleukin 6 (IL-6) is considered an important mediator of acute inflammatory responses. Moreover, IL-6 functions as a differentiation and growth factor of hematopoietic precursor cells, B cells, T cells, keratinocytes, neuronal cells, osteoclasts, and endothelial cells. IL-6 exhibits its action via a receptor complex consisting of a specific IL-6 receptor (IL-6R) and a signal transducing subunit (gp130). Soluble forms of both receptor components are generated by shedding and are found in patients with various diseases such as acquired immune deficiency syndrome, rheumatoid arthritis, and others. The function of the soluble (s)IL-6R in vivo is unknown. Since human (h)IL-6 acts on human and murine target cells, but murine IL-6 on murine cells only, we constructed transgenic mice expressing the hsIL-6R. We report here that in the presence of hsIL-6R, mice are hypersensitized towards hIL-6, mounting an acute phase protein gene induction at significantly lower IL-6 dosages compared to control animals. Furthermore, in hsIL-6R transgenic mice, the detected acute phase response persists for a longer period of time. The IL-6/IL-6R complex prolongs markedly the Il-6 plasma half-life. Our results reinforce the role of the hsIL-6R as an agonistic protein, help to understand the function of the hsIL-6R in vivo, and highlight the significance of the receptor in the induction of the acute phase response.

Hormone replacement therapy in the aged. A state of the art review

The use of hormone replacement therapy (HRT) in the immediate postmenopause for the relief of menopausal symptoms and for the prevention of osteoporosis and cardiovascular disease is well established. The continuation of treatment beyond the age of 60 years is likely to maximise these long term benefits and there is now increasing evidence to suggest that commencing treatment de novo in women of this age is likely to be beneficial. Many women remain symptomatic well into their sixties and the introduction of HRT at this stage will not only relieve these symptoms but will also conserve bone density and reduce future osteoporotic fracture risk. Furthermore, HRT appears to reduce the risk of cardiovascular disease, even in those women with pre-existing heart disease. The possible association between HRT and breast cancer remains controversial. Overall, there seems to be a slight increase in risk with long term HRT usage (longer than 10 years) but certain subgroups of women may be more at risk. This review discusses the merits and potential problems of prescribing HRT to the elderly and gives some guidance on the type, dose and route of administration of estrogen and progestogen to be used. Poor compliance with HRT is a major problem and the more widespread use of pretreatment counselling together with a wider range of products should have a positive impact in this area. The final decision about whether to continue or commence HRT in the elderly should be an informed one made by the woman and her clinician together.

Monoclonal antibody alpha IR-3 inhibits non-small cell lung cancer growth in vitro and in vivo

The ability of monoclonal antibody (mAb) alpha IR-3 to interact with non-small cell lung cancer (NSCLC) cells was investigated. MAb alpha IR-3 inhibited specific binding of 125I-IGF-I and 125I-alpha IR-3 to a panel of 8 NSCLC cell lines with high affinity (IC50 = 200 and 50 ng/ml, respectively). 125I-alpha IR-3 bound with high affinity (Kd = 40 ng/ml) to a single class of sites (Bmax = 8,000/cell) using NCI-H838 cells. 125I-alpha IR-3 was internalized when exposed to NCI-H838 or H1299 cells at 37 degrees C but not 4 degrees C. alpha IR-3 immunoprecipitated major 90 and 130 kD proteins. IGF-I stimulated and alpha IR-3 inhibited the clonal growth of NCI-H1299 cells. alpha IR-3 slowed the growth of NCI-H157 and H838 xenografts in nude mice. In a biodistribution study 125I-alpha IR-3 was preferentially localized to the tumor as opposed to other organs. These data suggest that IGF-I may be a regulatory agent in NSCLC.

In vivo measurement of aromatase inhibition by letrozole (CGS 20267) in postmenopausal patients with breast cancer

Thirteen postmenopausal women with advanced breast cancer were enrolled in an open randomized Phase I trial of a new p.o. active aromatase inhibitor, CGS 20267 (letrozole). The primary aim of the trial was to assess the impact of two doses of letrozole (0.5 and 2. 5 mg/day) on the peripheral aromatization of androstenedione to estrone. An in vivo isotopic technique was used to measure peripheral aromatization in each patient before treatment. The patients were then randomly assigned to one of the two doses, and measurements of aromatization were repeated after 6 weeks. At 0.5 mg and 2.5 mg/day, letrozole inhibited aromatization by 98.4% (97.3 to >99.1) and >98.9% (98.5 to >99.1; geometric means and ranges), respectively. Plasma estrogen levels were also measured before and during treatment. At the dose of 0.5 mg/day estrone and estradiol levels fell by 82.0% and 84.1% (geometric means), respectively. At the dose of 2.5 mg/ day, the estrogens fell by 80.8% and 68.1%, respectively. There were no significant differences between the doses in aromatase inhibition. No formal statistical analysis was performed on the estrogen data. Letrozole is therefore a highly effective inhibitor of aromatase, causing near complete inhibition of the enzyme in peripheral tissues at the doses investigated. The falls in estrogen levels were greater than those seen with earlier generation aromatase inhibitors.

Comparative clearance performance of two dialyser units used in the CVVHD mode

Continuous renal replacement therapies are now commonly used modes of support in acute renal failure (ARF). This study compared the clearance performance and it's degradation over time of two dialysers, one of flat plate configuration, and one of hollow fibre configuration (Asahi PAN 06 hollow fibre dialyser, Domedica, Sydney, and Hospal AN69HF flat plate dialyser, Gambro, Sydney) used in the CVVHD mode. Data were obtained from seven patients. Urea clearance was determined at commencement of dialysis and then at 12 hour intervals up to 48 hours post commencement. At each study time, urea clearance was determined at dialysis fluid (DF) flows of 500, 1000, 1500 and 2000 ml/hr. The procedure was repeated for each patient using the alternate dialyser. Comparisons of the two dialyser's urea clearance did not demonstrate any significant difference at any of the time periods studied. Overall, clearance was dependent upon (DF) flow with the diffusive clearance initially equal to DF flow but falling to 0.7 and 0.85 times increase in DF flow at 48 hours.

Free amino acids can replace protein-bound amino acids in test diets for studies in rainbow trout (Oncorhynchus mykiss)

Effects of reducing dietary concentration of protein-bound amino acids on growth, feed intake and composition of gain in rainbow trout were studied in four experiments. Average initial body weights ranged between 29 +/- 0.7 and 55 +/- 0.5 g per trout. Diets contained approximately 20 MJ digestible energy/kg dry matter. Each diet was fed to satiation to four replicate groups of 20 trout. Feed intake and growth rates were recorded for each group. Body composition was analyzed in representative groups at the start of each experiment and in all experimental groups at the end of each experiment. Reduction of dietary protein concentration to < 380 g/kg dry matter caused significantly lower growth rates and reduced protein concentrations of gain, but these reductions in growth could be offset by the addition of 10 crystalline essential amino acids. Fish meal was completely replaced by a mixture of wheat gluten and crystalline amino acids without negative influences on growth. In the absence of fish meal, almost half the wheat gluten could be replaced by crystalline amino acids in diets containing about 32 g N x 6.25/kg dry matter without significant influences on growth. In such diets, concentrations of individual amino acids may be varied widely with no variation in other amino acids or nutrients.

Response of rainbow trout (Oncorhynchus mykiss) growing from 50 to 170 g to supplements of either L-arginine or L-threonine in a semipurified diet

We studied the effects of increasing dietary concentrations of either L-arginine or L-threonine on growth, feed intake, feed conversion ratio and composition of gain in rainbow trout. Semipurified diets containing 20.1 MJ digestible energy/kg dry matter, with wheat gluten and crystalline amino acids as sole sources of amino acids, were fed to rainbow trout (initial mean body weight 47 +/- 0.7 g). In one series of 12 diets, arginine concentration ranged from 5.0 to 23.8 g/kg dry matter; in a second series of 12 diets, threonine concentration ranged from 3.7 to 21.0 g/kg dry matter. Each diet was fed to a group of 20 fish. During the experiment of 51 feeding days, dry matter intake, weight gain, feed conversion ratio, protein concentration of gain and total protein deposition followed exponential functions. For achieving 95% of the potential maximum protein deposition, dietary concentrations of 11.6 g arginine and 10.4 g threonine/kg dry matter were required. Arginine and threonine were both utilized most efficiently at dietary concentrations of approximately 6 g/kg dry matter. At low dietary concentrations of arginine, deposition of this amino acid exceeded the quantity fed. Recommended dietary concentrations of arginine and threonine will depend on the trait desired in the trout.

Response of rainbow trout (Oncorhynchus mykiss) growing from 50 to 150 g to supplements of DL-methionine in a semipurified diet containing low or high levels of cystine

We studied the effect of increasing dietary concentrations of DL-methionine on growth, feed intake, feed conversion ratio and the composition of gain in rainbow trout. Twenty-four groups of 20 trout initially weighing 51 +/- 0.5 g/trout were fed semipurified diets containing 20.1 MJ digestible energy and either 3.0 or 5.8 g cystine/kg dry matter. At each level of cystine, 12 levels of methionine (2 to 11 g/kg dry matter) were achieved by supplementation with graded quantities of DL-methionine. During an experiment of 49 feeding days, no significant effect of the level of dietary cystine was found for any performance trait. Nonlinear responses to increasing dietary methionine concentrations were found for feed intake, growth rate, protein concentration of gain and protein deposition, whereas fat concentration of gain decreased concurrently. Dietary methionine was utilized most efficiently at a concentration of 3.5 g methionine/kg dry matter or 0.17 g/MJ digestible energy. Ninety-five percent of the plateau deposition of body protein was achieved at a dietary methionine concentration of 8 g/kg dry matter or 0.40 g/MJ digestible energy. For achieving 98%, the required concentration was 9.0 g/kg or 0.49 g/MJ. Recommended dietary methionine concentration will depend on the trait chosen.

Magnesium deficiency in critically ill patients

A study was performed to assess the value of estimation of intracellular magnesium in peripheral blood cells (red and mononuclear blood cells) in critically ill patients as an index of tissue magnesium content. A magnesium loading test was used to diagnose magnesium depletion in 16 critically ill patients. Patients were divided into magnesium depleted and non-depleted groups according to their response to the loading test. Pre-infusion plasma and intracellular (blood cell) magnesium levels were measured. There were no significant difference between the magnesium depleted (mean plasma magnesium 0.81 mmol.l-1, red blood cell magnesium 2.34 mmol.l-1, mononuclear blood cell magnesium 25.16 mmol.kg-1 dry weight) and non-depleted groups (mean plasma magnesium 0.90 mmol.l-1, red blood cell magnesium 2.18 mmol.l-1, mononuclear blood cell magnesium 18.1 mmol.kg-1 dry weight). We conclude that the diagnosis of magnesium depletion cannot be excluded in the face of normal plasma, red blood cell or mononuclear blood cell concentrations of magnesium.

A prospective study of microorganisms in urine and bladder biopsies from interstitial cystitis patients and controls

OBJECTIVES

Interstitial cystitis (IC) is a chronic inflammatory condition of the bladder of unknown etiology. We tested the hypothesis that a microorganism would be found at higher prevalence in urine or bladder tissue from women with IC than from control women.

METHODS

Urine and bladder tissue were obtained at cystoscopy from 11 IC patients and 7 control subjects. These specimens were cultured for a variety of fastidious and nonfastidious bacteria, mycobacteria, fungi, and viruses. In addition, special staining techniques were used to examine biopsy specimens and cytospun urine, and tissue sections and outgrowths of explanted bladder cells were examined by electron microscopy.

RESULTS

Cultures of urine from 6 of 11 IC patients grew five different bacteria (Corynebacterium sp. Klebsiella pneumoniae, Lactobacillus sp, Streptococcus constellatus, and Streptococcus morbillorum), human cytomegalovirus, or Torulopsis glabrata; one of these organisms (Lactobacillus sp) was found in urine from 2 patients. Although contamination by urethral organisms is possible, the prevalence of microorganisms in urine of IC patients (6 of 11) was significantly greater than in urine of control subjects (0 of 7) (P < 0.05). Acridine orange staining revealed rods with appropriate morphology in urine from 4 of the 5 IC patients who had positive bacterial cultures and yeastlike organisms in urine and bladder tissue specimens that grew Torulopsis. Additionally, rodlike organisms were seen in urine from 2 IC patients with negative bacterial cultures and cocci were seen in the urine of 1 control patient. Biopsy specimens from 2 IC patients grew Torulopsis sp or Lactobacillus sp, in agreement with the results of acridine orange staining and culture of urine from these patients; in contrast, specimens from 3 control subjects grew small numbers of Pseudomonas sp or Staphylococcus epidermidis, but no organisms were cultured from urine or seen in acridine orange-stained tissue smears. All other cultures and stains were negative.

CONCLUSIONS

These data do not provide evidence that IC is associated with infection or colonization by a single microorganism. However, they do generate the hypothesis that the prevalence of microorganisms, especially bacteria at low concentrations, is greater in the urine of IC patients than of control subjects. If these results are confirmed by other controlled studies, the question of whether the presence of these organisms is a cause or a result of IC should be addressed.

Culture of bladder epithelium from cystoscopic biopsies of patients with interstitial cystitis

Interstitial cystitis is a chronic disease of unknown etiology characterized by bladder pain and urinary frequency and urgency. The epithelium may be critical in its pathogenesis; the hallmarks of the disease are visible epithelial defects (Hunner's ulcers and epithelial ruptures). Areas denuded of epithelium are commonly seen, and defects in epithelial permeability are characteristic. We report here the culture and characterization of epithelial cells from cystoscopic bladder biopsies obtained from 7 female patients with interstitial cystitis. Within 4 to 14 days cellular outgrowths appeared from explants incubated in cell medium. Monolayers reached confluence after 6 weeks. Cells of the monolayer were cytokeratin-positive and smooth muscle actin-negative, confirming their epithelial origin. They exhibited epithelial cell ultrastructure including intermediate filaments and junctional complexes. Vesicles bounded by a trilaminar plasma membrane and lateral interdigitations were also present. This is the first report of the culture of bladder epithelium from interstitial cystitis patients. Epithelial cells may be targets for initiating agents and inflammatory effects of interstitial cystitis and should be useful for studies of the pathogenesis of this disease.

The effects of oral 4-hydroxyandrostenedione on peripheral aromatisation in post-menopausal breast cancer patients

This study investigated the influence of the aromatase inhibitor 4-hydroxyandrostenedione (4OHA, formestane), given orally, on peripheral aromatase activity and plasma oestradiol (E2) levels in post-menopausal women with advanced breast cancer. The aim was to establish whether an optimal dose could be identified that had a pharmacological effectiveness comparable with that of parenteral 4OHA. A total of 13 post-menopausal women were studied before treatment and after a minimum of 4 weeks on treatment with one or more of the following doses: 125 mg once daily (od), 125 mg b.i.d. (bd) and 250 mg od. In all, seven aromatase studied were performed at 125 mg od; four, at 125 mg bd; and ten, at 250 mg od. Three patients were studied at all doses. E2 was measured concurrently and was available at all dose increments for seven patients. Given at doses of 125 mg od, 125 mg bd and 250 mg od, treatment with formestane inhibited in vivo aromatisation by 62.3% +/- 9.5%, 70.0% +/- 5.1% and 57.3% +/- 5.3%, respectively (mean +/- SEM). Corresponding values for plasma E2 suppression were 30.7% +/- 6.5%, 43.4% +/- 4.5% and 42.9% +/- 6.7%, respectively. Thus, apart from a somewhat better suppression of plasma E2 levels by the two higher doses as compared with 125 mg od, no significant difference in the degree of aromatase inhibition or plasma E2 suppression was observed. The suppression of E2 by oral 4OHA at 125 mg bd or 250 mg od approaches that achieved by the recommended parenteral schedule of 250 mg fortnightly, but inhibition of aromatase at this dose was substantially inferior. The findings are consistent with a hypothesis that 4OHA given orally may cause substantial plasma oestrogen suppression during part of the day, but neither the od nor the bd regimens investigated in the present study were capable of producing optimal aromatase inhibition.

Activity of melphalan in combination with the glutathione transferase inhibitor sulfasalazine

Glutathione (GSH) transferases (GST), a family of detoxification enzyme proteins, are suggested to play an important role in tumor cell resistance to melphalan. The GST-activity inhibitor ethacrynic acid has been shown to increase the antitumor activity of melphalan in vitro as well as in vivo. In this study we determined the activity and toxicity of melphalan in combination with another GST-activity inhibitor, sulfasalazine, an agent used to treat ulcerative colitis. We entered 37 previously treated patients with advanced cancer of different histologies on sulfasalazine given at the individually calculated maximum tolerated dose (MTD) and melphalan given at doses beginning at 20 mg/m2. The main toxicity arising from this combination was nausea and vomiting, whereas increased myelosuppression was not observed. A partial response was seen in 2/4 of the ovarian cancer patients only. Plasma sulfasalazine levels varied between 2.5 and 47.1 micrograms/ml. Although reductions in GSH/GST levels were observed in peripheral mononuclear cells of certain patients following sulfasalazine treatment, there was no correlation between the extent of reduction and the plasma sulfasalazine level. A larger patient population must be studied to determine the usefulness of this combination.

Clinical and endocrine effects of the oral aromatase inhibitor vorozole in postmenopausal patients with advanced breast cancer

Vorozole is an orally active, nonsteroidal aromatase inhibitor. Twenty-four postmenopausal patients with advanced breast cancer who had relapsed after treatment with tamoxifen received three separate daily doses of vorozole (1, 2.5, and 5 mg) each for 1 month in a randomized, double-blind, phase II study. There was significant suppression (P < 0.001) of serum estradiol at all three doses (median reduction, 91, 90, and 89%, respectively). There was a significant trend (P = 0.02) for estradiol to be suppressed below the detection limit of the assay (3 pmol/liter) more frequently with an increasing dose of vorozole; 13, 31, and 40% respectively. Estrone and estrone-sulfate levels were likewise reduced at each dose by 52-55% and 64-69%, respectively. There was no significant effect at any dose on aldosterone, testosterone, androstenedione, 17 alpha-hydroxyprogesterone, or thyroid-stimulating hormone levels. A small reduction in cortisol was seen at the 5 mg dose, although the relevance is unclear given that 17 alpha-hydroxyprogesterone levels did not rise. Eight patients (33%) achieved an objective response (2 complete remission, 6 partial remission) with a median response duration of 13 months. Four patients (17%) achieved disease stabilization for more than 6 months. Patients who had responded previously to tamoxifen were more likely to respond to vorozole. There were no significant clinical side effects and the drug was well tolerated. These data suggest that vorozole is a potent and selective oral aromatase inhibitor for use in postmenopausal breast cancer.

Conscious and unconscious coping with loss

Sixty-seven persons were identified 1 to 2 months after the death or life-threatening illness of their spouse and followed for 25 months. Intake measures included a) a revised Ways of Coping Scale, a structured assessment of ego defenses, sociodemographic information, and other baseline variables. Fifty-six completed follow-up. Outcome measures included deaths, hospitalization, self-rated health, depressive symptoms, symptoms of anxiety, and separation distress. In our analyses, bereavement was used as a covariate and found to be unrelated to outcome. Low self-ratings on coping by making a change and problem-focused planning predicted higher scores on separation distress at 13 months (p < or = .05). Participants who used less problem-focused planning were at risk for higher depression scores 13 months after the stressful event (p < or = .05). Low ego-defensive work and high neurotic ego-defensive ratings predicted high depression scores at 13 months (p < or = .05). At 25 months, coping by self-blame was inversely related to scores on separation distress (p < or = .05). Coping variables predicted neither scores on anxiety symptom scales nor the outcomes of hospitalization or death over the 25-month study period. These observations counter some prevailing clinical assumptions about coping with a loss and emphasize the value of empirical studies of coping as a mediator of outcome during the stress of a loss.

Validation of a croup score and its use in triaging children with croup

The Syracuse croup scoring system was validated in 165 children with croup who were admitted to an intensive therapy unit for assessment over a one year period. The unit served as a croup triage point for Cardiff and its environs. A score of > 5 was taken as an indication that a patient was at risk of upper airway obstruction and was used to support a triage decision by the junior hospital doctor to admit a patient to the intensive therapy unit. All patients with an initial score < or = 5 were considered safe for transfer to a general paediatric ward and none of these required subsequent admission to intensive care. This score was then tested on a further 134 children with croup, in order to identify those patients who required specialised monitoring, observation or treatment in intensive care. A score of > 5 gave a specificity of 100% and a sensitivity of 80%. Croup scoring continued after admission on the general paediatric wards. Two patients who were originally admitted to the intensive therapy unit with a score > 5 improved within 6 h and were transferred to the general ward with a score < or = 5. These children subsequently required readmission to the intensive therapy unit. Our tracheal intubation rate of 2% was low and may relate to the routine use of regular adrenaline nebulisation. We recommend this scoring system to other paediatric departments for initial triaging decisions and for documenting progress on the wards.

A prospective study of widowhood and changes in symptoms of depression in a community sample of the elderly

This survey examines changes in depressive symptomatology (CES-D) during bereavement in 1046 elderly subjects, of whom 139 became widowed during follow-up. Depression scores increased during the first year of bereavement, but generally returned to pre-widowhood levels thereafter. However, depression scores remained elevated among young-old widows (65-74-year-olds) well after the first year of widowhood. Using cut-off scores, rates of high depressive symptoms remained somewhat elevated over baseline levels. Increases in depression scores during bereavement were not explained by socio-economic variables, health habits and health status. It is concluded that particularly young-old widows are at risk of developing chronic depressive symptomatology during bereavement that may warrant clinical attention.