Case report of metallic mercury injury

OBJECTIVE

Injury and poisoning from metallic mercury has become a rare event. Review of the literature and a case report of pediatric metallic mercury injury are presented.

DESIGN

A case report.

SETTING

The Emergency Department at St. Louis Children's Hospital.

PATIENTS OR PARTICIPANTS

A 15-year-old boy.

INTERVENTIONS

None.

MAIN OUTCOME MEASURES

None.

RESULTS

The 15-year-old boy fell on a broken mercury thermometer. A subcutaneous abscess formed on his left forearm during the next five days. He had no signs or symptoms of mercury toxicity. His wound was debrided in the operating room and healed completely after several months.

CONCLUSIONS

This case shows elemental mercury from a thermometer as a potential, if unusual, source of mercury toxicity.

A paradigm of experimentally induced mild hyperthyroidism: effects on nitrogen balance, body composition, and energy expenditure in healthy young men

Although T3 exerts major regulatory actions in both animals and humans, most clinical studies of T3 administration have been relatively short term. The present study examined the effects of more than 2 months (63 days) of low dose T3 treatment on nitrogen balance, body composition, 24-h energy expenditure (EE), and protein turnover in seven healthy men studied at an in-patient metabolic unit. Subjects were also randomly assigned to either high or low fat diets to determine the effects of diet composition. T3 treatment produced significant losses in both lean mass (1.5 +/- 0.3 kg) and fat mass (2.7 +/- 0.4 kg) by 6 weeks, with similar reductions in both at 9 weeks. The high fat diet somewhat attenuated the loss of body fat. Nitrogen balance was significantly negative for the first 3 weeks of T3 treatment, but tended to return to baseline thereafter. There were no significant effects of treatment on protein turnover at 9 weeks, although there was a slight increase in leucine oxidation (P = 0.07). Despite the apparent adaptation in nitrogen balance, total 24-h EE and sleeping EE were significantly increased at 9 weeks. We conclude that although healthy men are able to adapt to mild hyperthyroidism in terms of nitrogen balance, they exhibit significant and persistent changes in fat and fat-free mass as well as energy balance.

Effects of IL-10 on systemic inflammatory responses during sublethal primate endotoxemia

IL-10 protects mice from LPS-induced lethality. To determine the effects of IL-10 on LPS-induced inflammatory responses, six Papio anubis baboons were i.v. injected with a sublethal dose of LPS (Salmonella typhimurium; 500 microg/kg) directly preceded by either human rIL-10 (n = 3, 500 microg/kg) or diluent (n = 3). IL-10 strongly inhibited LPS-induced release of TNF, IL-6, IL-8, and IL-12 (all p < 0.05). By contrast, IL-10 did neither influence the activation of the coagulation system (plasma levels of thrombin/antithrombin III complexes), nor the activation of the fibrinolytic system (plasma levels of tissue-type plasminogen activator, plasminogen activator inhibitor type I, and plasmin/alpha 2-antiplasmin complexes). IL-10 modestly attenuated neutrophilic leukocytosis and neutrophil degranulation (plasma concentrations of elastase/alpha1-antitrypsin complexes) (both p < 0.05). Changes in surface TNF receptor expression on circulating granulocytes were not affected by IL-10. These results suggest that during sublethal endotoxemia the predominant anti-inflammatory effect of IL-10 treatment is inhibition of proinflammatory cytokine release.

Effects of IL-10 on systemic inflammatory responses during sublethal primate endotoxemia

IL-10 protects mice from LPS-induced lethality. To determine the effects of IL-10 on LPS-induced inflammatory responses, six Papio anubis baboons were i.v. injected with a sublethal dose of LPS (Salmonella typhimurium; 500 microg/kg) directly preceded by either human rIL-10 (n = 3, 500 microg/kg) or diluent (n = 3). IL-10 strongly inhibited LPS-induced release of TNF, IL-6, IL-8, and IL-12 (all p < 0.05). By contrast, IL-10 did neither influence the activation of the coagulation system (plasma levels of thrombin/antithrombin III complexes), nor the activation of the fibrinolytic system (plasma levels of tissue-type plasminogen activator, plasminogen activator inhibitor type I, and plasmin/alpha 2-antiplasmin complexes). IL-10 modestly attenuated neutrophilic leukocytosis and neutrophil degranulation (plasma concentrations of elastase/alpha1-antitrypsin complexes) (both p < 0.05). Changes in surface TNF receptor expression on circulating granulocytes were not affected by IL-10. These results suggest that during sublethal endotoxemia the predominant anti-inflammatory effect of IL-10 treatment is inhibition of proinflammatory cytokine release.

Elevated levels of NO in both unchallenged and LPS-challenged C. parvum-primed mice are attributable to the activity of a cytokine-inducible isoform of iNOS

Elevated levels of nitric oxide (NO2-/NO3-) were detected in the serum of mice 3-7 days after priming with Corynebacterium parvum (Propionibacterium acnes). The serum NO2-/NO3- response was completely inhibited when C. parvum-primed (C. parrum) mice were treated with N(G)-monomethyl-L-arginine (L-NMMA) or aminoguanidine (AG) on days 6 and 7 post priming. The response was also inhibited when the mice were treated with interleukin-10 (IL-10) and the cytokine was most effective when given in multiple doses beginning on the day of priming. In contrast to L-NMMA and AG, IL-10 had no effect on the serum NO2-/NO3- response when administered to the mice on days 6 and 7 post priming. The inducible isoform of NOS (iNOS) appeared to be responsible for the elevated NO2-/NO3- response in C. parvum mice because iNOS transcripts were readily detected in their livers. Moreover, these transcripts as well as the circulating levels of NO2-/NO3- were dramatically reduced when the mice were treated with anti-tumor necrosis factor alpha (anti-TNF-alpha) or anti-interferon-gamma (anti-IFN-gamma) monoclonal antibodies (mAbs) during the priming interval. There was a modest increase (less than twofold) in the serum NO2-/NO3- response following a lipopolysaccharide (LPS) challenge to C. parvum mice (C. parvum/LPS mice). LPS had a more dramatic stimulatory effect if the levels of NO2-/NO3- preexisting in C. parvum/LPS mice were reduced by treatment with L-NMMA, AG, or IL-10 before the challenge. Thus the levels of NO2-/NO3- that preexisted in C. parvum/LPS mice appeared to influence their ability to mount a NO2-/NO3- response subsequent to the LPS challenge. The NO2-/NO3- response did not contribute to lethality in C. parvum/LPS mice because anti-TNF-alpha and anti-IFN-gamma mAbs were protective but had no effect on serum NO2-/NO3- levels when administered to mice 24 h before the LPS challenge.

Predictors of prognosis and risk of acute renal failure in patients with Rocky Mountain spotted fever

BACKGROUND

Acute renal failure has long been associated with severe Rocky Mountain spotted fever (RMSF). Despite many descriptions of the protean manifestations of this disease, relatively little is known concerning the risk factors for acute renal failure. Only a few studies have examined the outcome of patients infected with Rickettsia rickettsii who develop renal insufficiency, and these studies had methodological problems.

OBJECTIVE

To study the incidence, risk factors, and outcomes of acute renal failure in a large group of hospitalized patients with definite or probable RMSF.

METHODS

The clinical records of 114 patients with definite or probable RMSF were retrospectively reviewed to identify clinical and biochemical abnormalities at the time of admission that were associated with the development of acute renal failure and subsequent mortality. Renal failure was defined as a serum creatinine (Cr) above 2 mg/dL. Logistic regression was used to study the association between these variables and the outcomes during hospitalization: death and the development of acute renal failure.

RESULTS

The mortality rate in this series was 14%; 19% of the patients developed acute renal failure. The development of acute renal failure increased the odds ratio (OR) of dying by a factor of 17 (P = 0.001). Factors at the time of hospitalization that were associated at a univariate level with subsequent mortality included elevated serum Cr, increased age, increased level of AST, increased level of bilirubin, decreased serum sodium and platelet count, the presence of neurological involvement, and being male. Both the presence of neurological involvement and an elevated serum Cr at presentation were independently associated with increased mortality by multivariate analysis. Three patients developed acute renal failure that required hemodialysis, and only 1 of these 3 patients survived; he was ultimately discharged with a normal serum Cr. Factors at presentation that were associated with the development of acute renal failure included increased bilirubin, increasing age, thrombocytopenia, and the presence of neurological involvement. Both age and decreased platelet count at presentation were independently associated with the development of acute renal failure by multivariate analysis.

CONCLUSION

Acute renal failure was a frequent complication of RMSF in this series of patients from a tertiary referral medical center. The presence of acute renal failure was strongly associated with death. Clinical and biochemical variables are useful in predicting which patients will develop acute renal failure.

The endocrinology of obesity

Numerous endocrine alterations are associated with obesity (Table 1). The majority of the alterations are secondary to obesity and must be considered simply associated and potentially in the pathogenesis of the complications of obesity. The discovery of new endocrine peptides such as leptin that signal body fat content will increase our understanding of the regulation of body fat content. As a result, therapies will most certainly be developed that are directly targeted at the alterations in endocrine function.

Proton-decoupled phosphorus-31 magnetic resonance spectroscopy in the evaluation of native and well-functioning transplanted kidneys

RATIONALE AND OBJECTIVES

To evaluate whether decoupling improves signal-to-noise ratio and frequency resolution of in vivo kidney spectra, and to compare native and well-functioning transplant kidneys.

METHODS

Proton decoupling in conjunction with three-dimensional chemical shift imaging (3D-CSI) in phosphorus-31 magnetic resonance (MR) spectroscopy was used with a spatial resolution of 64 cm3 and 17-minute acquisition time to compare native (n = 10) and well-functioning transplant (n = 9) kidneys.

RESULTS

Proton decoupling improved peak amplitudes by almost 30%, as well as chemical shift resolution of in vivo kidney spectra. No statistically significant differences in phosphometabolite ratios and renal spectra were observed between healthy volunteers and patients with nonrejecting transplants. The phosphodiester-phosphomonoester ratio was 3.02 +/- 0.88, phosphomonoester-inorganic phosphate ratio was 1.07 +/- 0.44, and inorganic phosphate-adenosine triphosphate ratio was 0.58 +/- 0.22 after correction for saturation effects.

CONCLUSION

Improved spectra of native and transplant kidneys can be obtained in vivo with MR spectroscopy by using a short acquisition time.

Azithromycin in the treatment of periodontal disease. Effect on microbial flora

Azithromycin is an azalide antibiotic with excellent in vitro activity against a wide variety of oral bacteria. It has a long half-life, good tissue penetration and is preferentially taken up by phagocytes. We investigated the microbiological efficacy of azithromycin as an adjunct to the non-surgical treatment of adult chronic periodontitis; its clinical efficacy is dealt with in a separate paper. 46 patients were treated in a double-blind placebo controlled trial. Microbiological assessment of the same periodontal pocket (initially > 6 mm) was made at weeks 0, 2, 3, 6, 10 and 22. Either azithromycin 500 mg 1 x daily for 3 days or placebo was given at week 2. Particular attention was paid to the numbers of black pigmented anaerobes and spirochaetes present since these are the most commonly implicated pathogens in periodontal disease. Pigmented anaerobes were significantly reduced at weeks 3 and 6 in patients who received azithromycin compared to placebo and remained lower, although not significantly so, throughout the study. Counts of spirochaetes were significantly reduced throughout the study in patients who received azithromycin compared to placebo. Our microbiological study suggests that azithromycin may be useful as an adjunct in the treatment of periodontal disease.

Administration of interleukin-10 at the time of priming protects Corynebacterium parvum-primed mice against LPS- and TNF-alpha-induced lethality

Several laboratories have described the protective effects of interleukin-10 (IL-10) in mouse models of lethal endotoxemia. In most of these experiments, protection was observed in normal mice that were given a lethal dose of LPS. However, we failed to observe protection with IL-10 in LPS-challenged mice that had been primed with Corynebacterium parvum (Proprionibacterium acnes). We have extended our studies with IL-10 in C. parvum-primed mice and in some cases have observed protection that appears to depend on the strength of the sensitization to C. parvum. When IL-10 was administered to mice at the time of priming, it was particularly effective in blocking sensitization, as evidenced by the inability of treated mice to mount a strong inflammatory cytokine response when subsequently challenged with LPS. Following such treatment with IL-10, C. parvum-primed mice were also protected from a subsequent lethal challenge with rMuTNF-alpha. In addition, the mice were protected against LPS- and TNF-alpha-induced lethality with a single dose of an anti-TNF-alpha or anti-IFN-gamma mAb given at the time of priming. Our results suggest that TNF-alpha and IFN-gamma are produced early after priming with C. parvum and are at least partly responsible for the enhanced sensitivity of the mice to LPS and TNF-alpha. IL-10 affords protection to the mice because of its ability to block the C. parvum-induced TNF-alpha and IFN-gamma responses.

Clinical, biochemical and pathological predictors of poor response to intravenous cyclophosphamide in patients with proliferative lupus nephritis

BACKGROUND

Reports in the literature on the outcome of lupus nephritis (LN) treated with intravenous (i.v.) cyclophosphamide have varied considerably. Previous studies have suggested that less than 25% of patients with LN will progress to end stage renal failure (ESRD) after 5 years. In addition it has been reported that serum creatinine and chronic histologic changes on kidney biopsy are useful markers of renal prognosis. Whether treatment with cyclophosphamide alters the predictive value of these markers in LN patients is not clear. The aim of this study was to review our experience of treating a large cohort of patients with LN treated with i.v. cyclophosphamide and to identify biochemical and histological features at the time renal biopsy which predict outcome in these patients.

DESIGN

We retrospectively reviewed our experience with 43 consecutive patients who met criteria for either World Health Organization (WHO) classification III (focal proliferative) or IV (diffuse proliferative) LN and were treated with monthly i.v. cyclophosphamide. Biochemical indices of renal function and lupus disease activity were recorded. Renal biopsies, performed within two months of commencing therapy, were reviewed by two experienced pathologists and classified according to WHO classification as well as activity and chronicity index. The primary outcome variable for the analysis was the development of ESRD.

RESULTS

Patients were followed for a mean of 2 years after renal biopsy. The mean dose of cyclophosphamide received by patients was 8.3 g. One patient died during follow up and 22 (51%) progressed to ESRD. A higher serum creatinine (p = 0.003) and higher score for interstitial fibrosis (p = 0.001) were associated with shorter renal survival. There was no significant association between activity index or its components or in the total chronicity score and survival free from the need for dialysis.

CONCLUSION

In our experience more than half of patients treated with i.v. cyclophosphamide for LN progress to ESRD and a high serum Cr and a high degree of interstitial fibrosis on renal biopsy before treatment are associated with a worse renal prognosis.

Renal transplantation in adults with thrombotic thrombocytopenic purpura/haemolytic-uraemic syndrome

BACKGROUND

Thrombotic thrombocytopenic purpura/haemolytic-uraemic syndrome (TTP/HUS) is a rare cause of renal failure in adults. There is little data concerning the outcome of adult patients who receive a renal transplant for TTP/HUS:

METHODS

We have carried out a survey of 22 transplant centres in the USA to determine the outcome of patients who developed ESRD from TTP/HUS and latter received a renal transplant.

RESULTS

Twelve of the 22 centres responded to our inquiry. Seven centres had not transplanted any patients with TTP/HUS, and five centres had transplanted a total of 24 grafts in 17 patients with TTP/HUS: Thirty-three per cent of patients demonstrated definite clinical and pathological evidence of recurrence of TTP/HUS: An additional 16% of patients demonstrated pathological evidence of possible recurrence of TTP/HUS in the absence of clinical manifestations. The overall 1-year graft survival rate was 42% and the 2-year graft survival rate was 35%. In our experience recurrence TTP/HUS was associated with universal graft failure. Although cyclosporin A does occasionally cause a thrombotic angiopathy in patients with no history of TTP/HUS, we found no evidence that it should be avoided in patients with a previous history of ESRD from TTP/HUS who subsequently receive a renal transplant.

CONCLUSIONS

TTP/HUS frequently recurres in adults who receive a renal transplant, with a 2-year graft survival rate of 35%.

Iron chelates bind nitric oxide and decrease mortality in an experimental model of septic shock

The hydroxamic acid siderophore ferrioxamine B [FeIII(HDFB)+] and the iron complex of diethylenetri-aminepentaacetic acid [FeIII(DTPA)2-] protected mice against death by septic shock induced by Corynebacterium parvum + lipopolysaccharide. Although FeIII(DTPA)2- was somewhat more effective than FeIII(HDFB)+, the iron-free ligand H4DFB+ was significantly more effective than DTPA. The hydroxamic acid chelator has a much higher iron affinity than the amine carboxylate, allowing for more efficient formation of the FeIII(HDFB)+ complex upon administration of the iron-free ligand. Electrochemical studies show that FeIII(DTPA)2- binds NO stoichiometrically upon reduction to iron(II) at biologically relevant potentials to form a stable NO adduct. In contrast, FeIII(HDFB)+ is a stable and efficient electrocatalyst for the reduction of NO to N2O at biologically relevant potentials. These results suggest that the mechanism of protection against death by septic shock involves NO scavenging and that particularly effective drugs that operate a low dosages may be designed based on the principle of redox catalysis. These complexes constitute a new family of drugs that rely on the special ability of transition metals to activate small molecules. In addition, the wealth of information available on siderophore chemistry and biology provides an intellectual platform for further development.

Errors in derivations of the Coburn-Forster-Kane equation for predicting carboxyhemoglobin

An error identified in a 1993 textbook of military medicine led to an investigation of derivations of the Coburn-Forster-Kane equation (CFKE) for predicting carboxyhemoglobin (COHb) levels. Reviews of the scientific literature, military documents, and personal interviews revealed that errors were made in earlier derivations of the CFKE. One flawed derivation was used by the U.S. Army until 1985, and another is still used by the National Institute for Occupational Safety and Health (NIOSH). The original and later CFKE derivations are reviewed and errors in the equations are identified. The effect of the errors is discussed.

Trisomy 15 in hematological malignancies: six cases and review of the literature

We report six cases of trisomy 15 in patients with hematological malignancy. In four cases trisomy 15 was the sole abnormality and in two cases it was associated with sex chromosome loss. The patient age range was 6-91 years, and three patients were male. Four patients had myelodysplasia (refractory anemia), one patient each had acute myeloid leukemia and acute lymphoblastic leukemia. A literature review identified ten other cases of trisomy 15 as the sole abnormality in hematological malignancies. Trisomy 15 as the sole autosomal abnormality in hematological malignancy is uncommon, but can occur in both myeloid and lymphoid malignancies. It appears to occur most frequently in myelodysplasia.

Preliminary investigation of the Irie inferior vena caval filter

PURPOSE

In vitro and in vivo investigations were performed to evaluate the Irie retrievable inferior vena caval (IVC) filter.

MATERIALS AND METHODS

The clot capturing performance of the Irie and five other IVC filters were assessed in both horizontal and vertical orientations within a pulsed-flow circuit with 240 clot challenges for each filter. Subjective comparisons of the flow disturbance characteristics of the Irie and three other filters were also performed. In vivo studies consisted of 13 Irie filter insertions and eight attempted retrievals in 11 pigs. Histologic evaluation of the IVC was performed with the Irie filter in situ and following retrieval.

RESULTS

In vitro testing demonstrated the clot capturing capability and flow disturbance characteristics of the Irie filter to be similar to those of other IVC filters. Filter deployment problems occurred during three of the 13 insertions. Six of the eight retrieval procedures were successful; four filters were retrieved 1 month after insertion. Follow-up cavography demonstrated two tilted filters and three caval perforations.

CONCLUSION

The performance of the Irie filter is similar to that of other currently available IVC filters. The filter can be retrieved after neointimal incorporation of the struts into the IVC wall.

No change in complication rate using spring-loaded gun compared to traditional percutaneous renal allograft biopsy techniques

The previous methods to biopsy renal allografts at our institution involved the use of the Franklin-Silverman or Tru-Cut needles. Unfortunately they had a significant rate of post biopsy bleeding secondary to deep penetration when excess force was used to penetrate a tough transplant capsule. Although spring loaded biopsy devices have been widely used for native kidney biopsies over the past three years, the complication rate for renal allograft biopsies has not been sufficiently evaluated. We describe our experience using a disposable spring loaded biopsy device on transplanted renal grafts. Fifty-four biopsies were performed with the device, all under ultrasound guidance. The ASAP automatic biopsy system by Medi-tech was used comprising of a spring loaded gun with a 15 cm long 15 GA needle echogenic tip and 17 mm specimen notch. All patients were ultrasounded immediately post biopsy to look for hematomas. Compared to 55 previous biopsies performed using Tru-Cut needles, we conclude that the ASAP automated biopsy system proved equally effective in obtaining adequate tissue for diagnosis with fewer post-biopsy hematomas compared to traditional biopsy methods.

Early and late stimulation of ob mRNA expression in meal-fed and overfed rats

ob protein is hypothesized to be a circulating feedback signal in the regulation of energy balance. Obese, overfed rats have high levels of ob mRNA expression and suppressed voluntary food intake, indicating the presence of a potent satiety factor. The objectives of this experiment were to determine whether feeding rats their normal daily intake in three meals, compared with ad libitum feeding, increased ob mRNA expression and to determine the degree of obesity required to stimulate expression of ob mRNA. Rats were fed ad libitum, were tube-fed their normal intake in three meals a day, or were tube-fed twice normal intake, ob mRNA was measured by Northern blot analysis after 0, 2, 7, 14, 21, and 32 d of tube-feeding. After only 2 d ob mRNA was threefold higher in tube-fed animals than in ad libitum controls. By day 21 there was a further increase in ob mRNA expression in overfed rats which were at 130% control weight. These results suggest that a metabolic consequence of meal-feeding increases ob mRNA expression in the absence of increased food intake or weight gain. There is a further increase in ob mRNA expression once significant obesity is established.

Survival of family medicine in a corporate health care environment: lessons from the United Kingdom

The preservation of small, independent family practices within a changed health care delivery environment is a goal worth pursuing. Properly organized, such practices would maintain the special fiduciary relationship between physicians and patients. Fundholding practices, which are a growing organizational form of general practice in the United Kingdom, are described as a model that could serve as the basis for an American alternative to corporate medicine.

Intramolecular G-quartet motifs confer nuclease resistance to a potent anti-HIV oligonucleotide

We have identified a potentially therapeutic anti-human immunodeficiency virus (HIV)-1 oligonucleotide composed entirely of deoxyguanosines and thymidines (T30177, also known as AR177: 5'-g.tggtgggtgggtggg.t-3', where asterisk indicates phosphorothioate linkage). In acute assay systems using human T-cells, T30177 and its total phosphodiester homologue T30175 inhibited HIV-1-induced syncytium production by 50% at 0.15 and 0.3 microM, respectively. Under physiological conditions, the sequence and composition of the 17-mer favors the formation of a compact, intramolecularly folded structure dominated by two stacked guanine quartet motifs that are connected by three loops of TGs. The molecule is stabilized by the coordination of a potassium ion between the two stacked quartets. We now show that these guanine quartet-containing oligonucleotides are highly resistant to serum nucleases, with t1/2 of 5 h and >4 days for T30175 and T30177, respectively. Both oligonucleotides were internalized efficiently by cells, with intracellular concentrations reaching 5-10-fold above the extracellular levels after 24 h of incubation. In contrast, single-base mutated variants or random sequence control oligonucleotides that could not form the compactly folded structure had markedly reduced half-lives (t1/2 from approximately 3 to 7 min), low cellular uptake, and no sequence-specific anti-HIV-1 activity. These data suggest that the tertiary structure of an oligonucleotide is a key determinant of its nuclease resistance, cellular uptake kinetics, and biological efficacy.