Physiological effects of mercury-contaminated Oxisols on common bean and oat

The heavy metal mercury (Hg) is one of the most complex and toxic pollutants. When present in soils, it may impair plant growth, but the intensity of damage depends on the physical-chemical properties of the soil such as pH, clay, and organic matter content, which in turn affects Hg sorption and bioavailability. Understanding Hg potential damage to staple food crops is of paramount relevance. Here, we evaluated the physiological effects of Hg in Phaseolus vulgaris (common bean) and Avena sativa (oat) cultivated in two Oxisols with contrasting properties: Rhodic Acrudox (RA) and Typic Hapludox (TH). We performed four independent experiments (one per species/soil combination) that lasted 30 days each. Treatments were composed by HgCl₂ concentrations in soils (0 to 80 mg kg^-1 Hg). At the end of the experiment, we determined the impact of Hg on photosynthesis, nutritional status, and oxidative stress. Cultivation in TH contaminated with Hg resulted in oxidative stress in common bean and decreased photosynthesis/P accumulation in oat. No deleterious effects on physiological variables were detected in both species when cultivated in the RA soil. In general, we conclude that the lower Hg sorption in the TH soil resulted in toxicity-like responses, while acclimation-like responses were observed in plants cultivated in RA, reinforcing soil physical-chemical properties as key features driving Hg toxicity in Oxisols. Graphical abstract.

Jarisch-Herxheimer reaction among syphilis patients in Rio de Janeiro, Brazil

The Jarisch-Herxheimer reaction (JHR) is a syndrome observed after antimicrobial treatment of some infectious diseases. The syndrome has clinical characteristics of an inflammatory reaction to antibiotic treatment. A prospective study of patients with a clinical and laboratory diagnosis of syphilis was conducted at a sexually transmitted diseases clinic in Rio de Janeiro, Brazil. Patients were treated with benzathine penicillin and observed for the JHR. A total of 115 patients were included in this study. Fifty-one patients (44%) had secondary syphilis; 37 (32%), primary; 26 (23%), latent; and one (1%), tertiary syphilis. Ten patients (9%) developed the JHR. All JHRs occurred in patients with secondary and latent syphilis. No patients experienced an allergic reaction to penicillin. The JHR occurred less frequently than in previous studies. It is important that health-care professionals recognize the clinical characteristics of the JHR so that it is not misinterpreted as an allergic reaction to penicillin.

Somatic and germline mutation in GRIM-19, a dual function gene involved in mitochondrial metabolism and cell death, is linked to mitochondrion-rich (Hurthle cell) tumours of the thyroid

Oxyphil or Hürthle cell tumours of the thyroid are characterised by their consistent excessive number of mitochondria. A recently discovered gene, GRIM-19 has been found to fulfil two roles within the cell: as a member of the interferon-β and retinoic acid-induced pathway of cell death, and as part of the mitochondrial Complex I assembly. In addition, a gene predisposing to thyroid tumours with cell oxyphilia (TCO) has been mapped to chromosome 19p13.2 in one family. A cluster of genes involved in mitochondrial metabolism occurs in this region; one of these is GRIM-19. We have searched for GRIM-19 mutations in a series of 52 thyroid tumours. Somatic missense mutations in GRIM-19 were detected in three of 20 sporadic Hürthle cell carcinomas. A germline mutation was detected in a Hürthle cell papillary carcinoma arising in a thyroid with multiple Hürthle cell nodules. No mutations were detected in any of the 20 non-Hürthle cell carcinomas tested, nor in any of 96 blood donor samples. In one of the sporadic Hürthle cell papillary carcinomas positive for GRIM-19 mutation, we have also detected a ret/PTC-1 rearrangement. No GRIM-19 mutations were detected in any of the six cases of known familial Hürthle cell tumour tested, so that our results do not support the identification of GRIM-19 as the TCO gene. The GRIM-19 mutations we have detected are the first nuclear gene mutations specific to Hürthle cell tumours to be reported to date; we propose that such mutations can be involved in the genesis of sporadic or familial Hürthle cell tumours through the dual function of GRIM-19 in mitochondrial metabolism and cell death.

[Craniopharyngiomas. Clinicopathological aspects in different age groups]

Craniopharyngiomas are rare brain tumors of the hypothalamo-pituitary region, developing from embryonic remnants of Rathke's pouch and sac. Their overall incidence is 0.13 per 100,000 person years. Most frequently, they are suprasellar, start growing in childhood and originate neurological and hormonal symptoms. We retrospectively studied patients treated in our institution for craniopharyngioma in the last 10 years, in order to evaluate their clinical, imaging and pathological characteristics. Of the 32 patients analysed, 18 were females and 14 males with ages ranging between 6 and 81 years (early onset group--EOG aged 5-14 years: 7 patients; middle age onset group--MAOG aged 15-49 years: 15 patients; late age onset group--LOG aged > or = 50 years: 10 patients). Visual impairment was the most frequent presenting clinical feature in EOG (71.4%) and MAOG (86.6%), while in the LOG personality and cognitive changes including memory loss predominated (60%). Headaches were very frequent in all groups (EOG 42.8%, MAOG 60%, LOG 40%). Meningitis and seizures were presenting features, each in one patient. Regarding endocrine symptoms and signs, growth failure was present in 57.2% of the EOG. Amenorrhea was present in 5 of 10 female patients of the MAOG. Preoperatively, TSH was deficient in 25%, ACTH in 15.6% and gonadotropin in 25% of the patients. There were no cases of diabetes insipidus. Preoperative CT and MR revealed a calcified mass in 12 (37.5%), a partially cystic mass in 20 (62.5%) and a lesion involving or extending into the third ventricle in 7 (21.9%) patients. Twenty seven (84.4%) patients were treated primarily by surgery. In 4 (12.5%) cases the tumour was considered inoperable and 1 (3.1%) patient refused surgery; all were in the LOG. Surgical approach was transsphenoidal in 2/27 (7.4%) (all of them in the LAOG) and by craniotomy in the others. The tumour removable was considered complete in 10 (37%--EOG 2/7, MAOG 6/15, LOG 2/5) and subtotal in 17 (62.9%) patients. Eight (29.6%) patients were reoperated for recurrent tumour. Postoperative radiotherapy was administered in 12 cases with residual tumor, and 3 inoperable tumors were treated primarily by conventional external radiotherapy. Pathological study revealed the adamantinomatous type in 25 (92.6%) and the papillary type in 2 (7.4%--all men in the MAOG) tumors. The average follow-up was longer in the EOG (82.6 +/- 40.7 months) than in MAOG (57.2 +/- 48.5 months) and in LOG (48 +/- 92 months). Four (12.5%) patients died, 1 during the follow-up period due to a radiation-induced astrocytoma and 3 in the postoperative period because of cerebral hemorrhage and hydrocephalus (1 in the EOG and 2 in the LOG). In summary, we found the clinical presentation to be different in the 3 age groups, with a large number of patients in the MAOG. In this group were the only examples of the papillary form. Better prognosis was associated with a total resection at initial surgery.

Prevalence and risk factors of clinical diabetic polyneuropathy in a Portuguese primary health care population

OBJECTIVE

Distal symmetrical polyneuropathy in diabetics (DPN) has a variable prevalence around 30% and increases the risk for foot ulcers and amputations. We aimed at evaluating the prevalence of clinical DPN and associated risk factors in patients followed in primary care centers.

MATERIAL AND METHODS

101 type 2 diabetics were evaluated and 8 were excluded due to the presence of other causes of neuropathy. The remaining 93 had a mean age of 65.4 +/- 10.1 years and a mean diabetes duration of 10.1 +/- 11.1 years, 60.2% were women and 39.8% men. DPN was defined as the presence of both altered sensitivities and reflexes, regardless of symptoms.

RESULTS

Seventy-two (80%) patients had symptoms of polyneuropathy, but DPN was present only in 29 (32.2%). Calluses (37.8%) and trophic skin (74.4%) and nail (75.6%) changes were found in both feet. There was a significant positive association of DPN with age (69.0 +/- 9.1 vs 63.3 +/- 9.9 years, p=0.01), disease duration (15.7 +/- 13.5 vs 7.2 +/- 8.8 years, p=0.001), feet skin changes (38.8 vs 13.0%, p=0.04) and myocardial infarction/ischemia (14.8 vs 1.7%, p=0.03).

CONCLUSIONS

This sample of diabetic patients cared by family doctors presented a high prevalence of DPN. Aging, disease duration, the presence of feet skin changes and myocardial infarction/ischemia are factors that increase the prevalence of the disease. Primary care doctors awareness of the problem might help to decrease the associated morbidity.

[Fluid and electrolyte disorders]

OBJECTIVE: To review the major concepts involving electrolyte disorders in pediatrics, with special emphasis on the diagnosis and treatment.METHOD: Systematic literature review, searching through classic pediatric textbooks, periodic electronic databases, such as Medline, Lilacs and other sources. RESULTS: Electrolyte disorders are among the most common events in pediatric medical practice, specially in emergency care, where, depending upon the magnitude, they may represent significant risk to patient life or to the development of permanent sequelae. Dehydration, independent of etiology, has its importance defined by the severity of water deficit (mild, moderate or severe) and by the proportion of sodium waste in relation to water deficit (isotonic, hypotonic and hypertonic), and should be correctly recognized to guide adequate treatment. Sodium disorders have major risks of central nervous system compromise and potassium disorders are specially linked to cardiac arrhythmia, always deserving special attention and care. On the other hand, calcium, phosphorus and magnesium disorders are more related to neuromuscular function alterations and, although less threatening, they need adequate recognition and management.CONCLUSION: Knowledge of the several mechanisms involved in water and electrolyte metabolism is crucial to the correct comprehension, diagnosis and management of fluid and electrolyte disorders in pediatrics.

[Pulmonary thromboembolism in a female with resistance to activated protein C]

Primary or acquired hypercoagulable states favour thrombotic events. The identification of prothrombotic states is of immediate practical usefulness in the orientation, prophylaxis and treatment of pulmonary embolism. Detection of individuals resistant to activated protein C. the most frequent laboratory anomaly in the study of patients with venous thromboembolism, offers a better approach for these patients as well as a better prophylaxis and orientation of their direct relatives concerning thromboembolic events. The authors describe the clinical case of a young woman, previously healthy, who developed serious pulmonary thromboembolism, the resolution of which was difficult and the evolution unusual. Later, a state of resistance to activated protein C (aPCr) was identified. Concerning the case described, the authors reflect on hypercoagulable situations, especially "aPCr" states.

Inefficiency of the anticoagulant therapy in the regression of the radiation-induced optic neuropathy in Cushing's disease

Radiation-induced optic neuropathy is a rare complication (prevalence less than 1%) following radiotherapy of the sellar region. However, the vasculopathy in Cushing's disease predisposes to radiation-induced injury. We report the case of a 24-year-old man with Cushing's disease since he was 16. The hormonal study including bilateral inferior petrosal sinus catheterization diagnosed a pituitary right lesion, but imagiology was always negative. He underwent a transsphenoidal microadenomectomy and the pathological study showed the presence of corticotrophic hyperplasia but no adenoma. Secondary hypothyroidism and hypogonadism as well as permanent diabetes insipidus were diagnosed and because the patient was not cured he underwent a second transsphenoidal total hypophysectomy. After that and because he was still hypercortisolemic, pituitary external irradiation was given in a total dose of 6000 rad. Six months later he developed progressive bilateral visual loss. Cerebral MR revealed focal enhancement of the enlarged optic nerves and chiasm, associated with demyelination areas of the posterior visual pathways. Treatment was tried first with high doses of corticosteroids and later with anticoagulants-heparin EV. 1000 U/h during 7 days followed by warfarin, but unsuccessfully, probably because the patient was already amaurotic at the beginning of the last treatment.

[Medical aspects of urinary tract lithiasis]

The authors review some etiological, clinical and diagnostic aspects of nephrolithiasis, describing briefly the approach that should be taken to study this disease. Some of the practical aspects of its treatment are also discussed.

[Symptomatic Chiari type II malformation]

The Chiari type II malformation is the leading cause of death in infants with myelomeningocele. The authors report 17 cases of symptomatic Chiari type II malformation occurring in two distinct age dependent population. In Group I, 13 neonates and infants in the first year of life presented with cranial nerve and brain stem dysfunction characterized by vocal cord paralysis, apnea, dysphagia and laryngeal stridor. In Group II, 4 patients developed signs and symptoms after the first year of life. In this group, the presentation was more insidious and included neck pain and cerebellar manifestations. The surgical treatment consisted initially in shunt implantation or revision and when there was no improvement, posterior fossa decompression was performed. The response to the surgical treatment differed considerably between the two groups: older patients improved promptly after surgery and there was no casualties; in newborn and infants, especially those under 6 months of age, the mortality rate was 46.1%. The authors stress that prompt diagnosis and surgical intervention should be performed in order to produce a favorable outcome.

[Visceral larva migrans. Report of 3 cases]

We report three cases of children with visceral larva migrans confirmed by enzyme-linked immunosorbent assay (ELISA), in Goiânia. Pulmonary interstitial infiltrates with dry cough and peripheral eosinophilia characterised the first case. Clinical and laboratorial finding in the second case included dry cough, pulmonary infiltrates, peripheral eosinophilia and hypergammaglobulinaemia. A persistent eosinophilia, between 1987-1989, without apparent cause led to the confirmation of parasite infection in the third case.