Electrocardiographic findings of methanol toxicity: a cross-sectional study of 356 cases in Iran

BACKGROUND

Methanol is widely used in industry; however, methanol poisoning is not common. In this regard, a number of outbreaks have been recently reported due to inappropriate processing of alcoholic beverages. Shiraz, a city located in the southern part of Iran, faced one of such outbreaks in 2020 during COVID-19 pandemic. There is no sufficient literature on the electrocardiographic findings in methanol toxicity. This study aimed to address this gap in the literature.

METHOD

A total of 356 cases with methanol toxicity referred to Shiraz University of Medical Science Tertiary Hospitals (Faghihi and Namazi) in March and April, 2020. The clinical findings of blindness and impaired level of consciousness, lab data such as arterial blood gas, electrolytes, and creatinine, and the most common findings from ECGs were collected.

RESULTS

The most common ECG findings were J point elevation (68.8%), presence of U wave (59.2%), QTc prolongation (53.2% in males and 28.6% in females), and fragmented QRS (33.7%). An outstanding finding in this study was the presence of myocardial infarction in 5.3% of the cases. This finding, to the best of our knowledge, has only been reported in a few case reports. Brugada pattern (8.1%) and Osborn wave (3.7%) were the other interesting findings. In multivariate analysis, when confounding factors were adjusted, myocardial infarction, atrioventricular conduction disturbances, sinus tachycardia, and the prolonged QTC > 500 msecond were four independent factors correlated with methanol toxicity severity measured with arterial blood PH on arterial blood gas measurements, with odds ratios of 12.82, 4.46, 2.32 and 3.15 (P < 0.05 for all), respectively.

CONCLUSION

Electrocardiographic variations during methanol intoxication are remarkable and well-correlated with poisoning severity. Myocardial infarction was an egregious and yet a common concerning finding in this sample, which need to be ruled out in methanol toxicity.

Prognostic factors in methanol poisoning

The aim of this study was to assess the clinical and laboratory factors in methanol poisoned patients to determine the prognosis of their toxicity. This survey was done as a prospective cross-sectional study in methanol-poisoned patients in Loghman-Hakim hospital poison center during 9 months from October 1999—June 2000. During this time 25 methanol-poisoned patients were admitted. The mortality rate was 12 (48%). Amongst survivors, three (23%) of the patients developed blindness due to their poisoning and the other 10 (77%) fully recovered without any complication. The mortality rate in comatose patients was nine (90%) while in non-comatose patients it was three (20%) ( P < 0.001). There was a significant difference in mean pH in the first arterial blood gas of patients who subsequently died (6.82 ± 0.03) and survivors (7.15 ± 0.06) ( P < 0.001, M-W). The mean time interval between poisoning and ED presentation in deceased patients were (46 ± 15.7) hours, in survived with sequelae were (16.7 ± 6.7) and in survived without sequelae were (10.3 ± 7.2) hours ( P < 0.002, K-W). We found no significant difference between the survivors versus the patients who died regarding methanol. Simultaneous presence of ethanol and opium affected the outcome of the treatment for methanol intoxication favourably and unfavourably, respectively. In our study, poor prognosis was associated with pH < 7, coma on admission and >24 hours delay from intake to admission. Human & Experimental Toxicology (2007) 26: 583—586.

Homocysteine serum levels in diabetic patients with non proliferative, proliferative and without retinopathy

Homocysteine has been associated with extracellular matrix changes. The diabetic retinopathy is a neurovascular complication of diabetes mellitus and it is the leading cause of vision loss among working adults worldwide. In this study, we evaluate the role of homocysteine in diabetic retinopathy analyzing the plasma levels of homocysteine in 63 diabetic type 2 patients with nonproliferative retinopathy (NPDR), 62 patients with proliferative diabetic retinopathy (PDR), 50 healthy subjects used as control group, and 75 randomly selected patients.

A liver abscess deprived a healthy adult of eyesight: endogenous endophthalmitis associated with a pyogenic liver abscess caused by serotype K1 Klebsiella pneumonia

Klebsiella pneumonia usually causes urinary tract infections, pneumonia, and other infectious diseases in hospitalized and immunocompromised patients. Among the types of Klebsiella pneumonia, serotype K1 is known to be a highly virulent pathogen. We herein report the case of a healthy 63-year-old man with a pyogenic liver abscess and bilateral endogenous endophthalmitis caused by serotype K1 Klebsiella pneumonia. Although the patient received percutaneous abscess drainage and antibiotic therapy, he lost his eyesight. To improve the poor prognoses of ocular complications, providing both an earlier diagnosis and treatment is critical.

Effects of biomarkers of oxidative stress damage on prevalence and severity of visual disability among black Central Africans

BACKGROUND

Because of the demographic transition, lifestyle changes, urbanization, and nutrition transition, Central Africans are at higher risk of ocular diseases associated with oxidative stress and visual disability. This study aimed to estimate the normal values of oxidant status defined by oxidized low-density lipoprotein (Ox-LDL), 8-Isoprostane and 8-hydroxy-deoxyguanosine (8-OHdG) and to determine their pathogenic role in the prevalence and the severity of visual disability among these black Africans.

METHODS

This was a cross-sectional study, run in a case-control study randomly selected from Kinshasa province, DR Congo. The study included 150 type 2 diabetes mellitus (T2DM) patients (cases) matched for sex and age to 50 healthy non diabetic controls. Logistic regression models were used to identify independent determinants of visual disability.

RESULTS

The presence rates were 8.5% for blindness, 20.5% for visual impairment and 29% for visual disability including blindness and visual impairment. After adjusted for taro leaves intake, red beans intake, T2DM, aging, waist circumference, and systolic blood pressure, we identified low education level (OR=3.3 95%CI 1.5-7.2; p=0.003), rural-urban migration (OR=2.6 95% CI 1.2-5.6; p=0.017), and high Ox-LDL (OR=2.3 95% CI 1.1-4.7; p=0.029) as the important independent determinants of visual disability. After adjusted for education, intake of red beans, intake of taro leaves, triglycerides, and T2DM, we identified no intake of safou fruit (OR=50.7 95% CI 15.2-168.5; p<0.0001), rural-urban migration (OR=3.9 95%CI 1.213; p=0.012), and high 8-OHdG (OR=14.7 95% CI 3.9-54.5; p<0.0001) as the significant independent determinants of visual disability. After adjusted for education level, no intake of red beans, no intake of Taro leaves, triglycerides, and T2DM, we identified no intake of Safou fruit (OR=43.1 95% CI 13.7-135.4; p<0.0001), age ≥ 60 years (OR=3.4 95% CI 1.3-9; p=0.024), and high 8-Isoprostane (OR=11 95% CI 3.4-36.1; p<0.0001) as the significant independent determinants of visual disability.

CONCLUSIONS

Visual disability remains a public health problem in Central Africa. Antioxidant supplement, fruit intake, nutrition education, control of migration, and blocking of oxidative stress are crucial steps for delayed development of vision loss.

Biological risk of older adults with visual impairments

OBJECTIVES

To investigate whether biological markers of health differ among older adults with visual impairment compared to those with normal vision.

DESIGN

We use data from the National Health and Nutrition Examination Survey (1999 - 2006) to investigate clinically defined at-risk levels for 10 biological markers.

SETTING

Survey participants were non-institutionalized.

PARTICIPANTS

Nationally representative (U.S.) sample of older adults age 65 and older, categorized as having blindness (20/200 or worse), low vision (20/40 to 20/100) or normal vision (better than 20/40).

INTERVENTION

Separate binary logistic regressions (one for each biomarker, with two at-risk cut points for BMI: obese and underweight) were computed to determine the odds of having at-risk levels of each biomarker.

MEASUREMENTS

Biomarkers included: systolic and diastolic blood pressure, high-density lipoprotein, low-density lipoprotein (LDL) cholesterol, total cholesterol, glycated hemoglobin, body mass index (BMI), fasting triglycerides, C-reactive protein, and plasma homocysteine.

RESULTS

Older adults who were blind were more likely to have high-risk levels of LDL cholesterol, homocysteine, and to be underweight (BMI>18.5). Similarly, older adults with LV were more likely to have high-risk levels of homocysteine compared to older adults with normal vision.

CONCLUSION

As several of the high-risk biomarkers associated with visual impairment were diet-related, our results suggest the importance of nutrition and diet programs aimed towards educating older people who are visually impaired.

Genetic analysis of Lrp5 function in osteoblast progenitors

The low-density lipoprotein receptor-related protein (Lrp)-5 regulates osteoblast proliferation and bone formation through its expression in duodenum by modifying the gut serotonin-bone endocrine axis. However, its direct role, if any, in osteoblast progenitor cells has not been studied thus far. Here, we show that mice with a Dermo1-Cre-mediated disruption of Lrp5 in osteoblast progenitor cells have normal embryonic skeletogenesis and normal skeletal growth and development postnatally. Histomorphometric analysis of 3-month-old adult mice revealed normal osteoblast numbers, bone formation rate, and bone mass in Lrp5(Dermo)(-/-) mice. In addition, analysis of two osteoporosis pseudoglioma (OPPG) patients revealed a three- to fivefold increase in their serum serotonin levels compared to age-matched controls. These results rule out a direct function of Lrp5 in osteoblast progenitor cells and add further support to the notion that dysregulation of serotonin synthesis is involved in bone mass abnormalities observed in OPPG patients.

Lingual infarction and sudden blindness due to giant cell arteritis

A 72-year-old woman suffered from giant cell arteritis (GCA) which developed into lingual infarction and monocular blindness. Temporary obscuration of vision and lingual symptoms such as increasing malaise, pain and intermittent claudication may precede the catastrophic results of arteritis. Emphasis is laid on early recognition and treatment of GCA.

Sudden-onset blindness in sickle cell disease due to retinal artery occlusion

Central retinal artery occlusion (CRAO) is a rare and potentially devastating cause of acute blindness in sickle cell disease (SCD) that is unique compared to classic sickle retinopathy. Few details related to this complication in SCD are known, including its risk factors, pathogenesis, presentation, treatment and outcomes. We present three patients with SCD and retinal artery occlusion. The overall variability in clinical presentation, treatment and prognosis reported in the literature underscores the need for a greater understanding of these factors as they relate to this complication in SCD.

Characterization of the IGF system in 15 patients with Alström syndrome

BACKGROUND

Alström syndrome (ALMS) is a rare recessively inherited progressive disease (OMIM 203800). Among its diverse spectrum of clinical features are phenotypes associated with deficiencies of the GH/IGF-I axis, including short stature, obesity, insulin resistance, hypertriglyceridaemia and heart failure.

PATIENTS AND MEASUREMENTS

To characterize the IGF system in ALMS, we evaluated a subset of 15 young adults with ALMS for hepatic, renal and thyroid function. Glycaemic and hormone measurements such as insulin, GH, FSH, LH, testosterone and 17-beta-oestradiol were clinically assessed. In addition, we measured IGF-I, IGF-II, IGF binding-protein-3 (IGFBP-3) and acid labile subunit (ALS - the subunits that constitute the main somatomedin complex in the circulation), and IGFBP-1 and IGFBP-2 (known to influence the bioavailability of the IGFs).

RESULTS

A significantly lower height was observed in ALMS patients compared to age-matched controls. ALMS patients were clinically obese (by weight and body mass index (BMI) standards) and leptin levels correlated with BMI. Renal and hepatic dysfunction was implicated in some patients by increased values of blood urea nitrogen (BUN) and creatinine, and transaminases, respectively. One-third of the patients presented with fasting hyperglycaemia and 80% were hyperinsulinaemic. TSH was slightly increased in 20% of patients. Baseline FSH and LH in females were within the normal range, while half of the males had abnormally low testosterone values. Male patients with hypogonadism showed significantly lower testosterone, oestrogen and ALS levels. Baseline GH values were not found to be increased. ALS and IGFBP-1 were significantly reduced and IGFBP-2 was markedly increased in ALMS patients compared to age-matched controls. The IGFs and IGFBPs were not significantly different between males and females affected with ALMS. No significant association was observed between IGFs or IGFBPs levels and weight, height, BMI, glycaemia, hyperinsulinaemia and testosterone levels. However, we found a significant association of gamma-glutamyltransferase (GGT) with IGFBP-2. IGF-I levels were significantly associated with LH in female patients.

CONCLUSIONS

In summary, the reduction of ALS and the increase of IGFBP-2 points to a growth hormone deficiency (GHD) condition in ALMS. However, further tests, including GH dynamics, are needed to determine whether, or to what degree disturbances in the GH/IGF axis contribute to the relatively short stature.

Melatonin and human chronobiology

With the development of accurate and sensitive assays for measuring melatonin in plasma and saliva, it has been possible to advance our understanding of human chronobiology. In particular, the dim light melatonin onset (DLMO) is expected to have an increasingly important role in the diagnosis of circadian phase disorders and their treatment with appropriately timed bright light exposure and/or low-dose melatonin administration. The phase angle difference (PAD) between DLMO and mid-sleep can be used as a marker for internal circadian alignment and may also be used to differentiate individuals who are phase advanced from those who are phase delayed (a long interval indicates the former and a short interval indicates the latter). To provide a corrective phase delay, light exposure should be scheduled in the evening and melatonin should be administered in the morning. To provide a corrective phase advance, light exposure should be scheduled in the morning and melatonin should be administered in the afternoon/evening. The study of patients with seasonal affective disorder (SAD), as well as individuals who are totally blind, has resulted in several findings of interest to basic scientists, as well as psychiatrists and sleep specialists.

Optic neuritis with residual tunnel vision in perchloroethylene toxicity

CASE REPORT

In a 57-year-old female owner of a dry-cleaning shop, we describe the association of severe bilateral optic neuritis with unexpectedly high concentrations of perchloroethylene/metabolites in the blood and of chloroform in urine. Visual disturbances consisted of complete blindness for 9 days in the left eye, for 11 days in the right eye, with bright phosphenes and pain on eye rotation. Only central (2-3 degrees radius) vision recovered in the following months.

CONCLUSION

Although environmental concentrations of perchloroethylene were within normal limits, we measured five-fold increases in vapors emitted when ironing freshly dry-cleaned fabrics, and suggest that inhalation of perchloroethylene vapors was the cause of this case of ocular nerve toxicity, recapitulating a previous report of major perchloroethylene toxicity.

The 14-year incidence of visual loss in a diabetic population

OBJECTIVE

The purpose of the study was to estimate the 14-year incidence of visual loss in a diabetic population and to examine its relationship to potential risk factors.

DESIGN

Cohort study.

PARTICIPANTS

A population-based sample of younger onset diabetic persons diagnosed younger than 30 years of age and taking insulin (n = 880) were examined at baseline, 4 years, 10 years, and 14 years.

INTERVENTION

Visual acuity (VA) as measured by the Early Treatment Diabetic Retinopathy Study protocol was performed.

MAIN OUTCOME MEASURES

Visual impairment (VI), defined as a VA of 20/40 or worse in the better eye; blindness, defined as a VA of 20/200 or worse in the better eye; and doubling of the visual angle were measured.

RESULTS

Cumulative 14-year incidences of VI, doubling of the visual angle, and blindness were 12.7%, 14.2%, and 2.4%, respectively. In univariate analyses, loss of vision as measured by doubling of the visual angle is associated with older age, longer duration of diabetes, higher glycosylated hemoglobin, higher systolic and diastolic blood pressure, presence of proteinuria, more pack-years smoked, presence of macular edema, and more severe retinopathy. In logistic regression analyses, incidence of doubling of the visual angle is associated independently with retinopathy (odds ratio [OR], 1.07; 95% confidence interval [CI], 1.03, 1.11 for each level), glycosylated hemoglobin (OR, 1.46; 95% CI, 1.28, 1.66 for each 1%), proteinuria (OR, 2.32; 95% CI, 1.39, 3.88 for presence), and age (OR, 1.45; 95% CI, 1.20, 1.75 for 10 years). In addition, a change in glycosylated hemoglobin from baseline to the 4-year examination is associated with loss of vision (OR, 1.15; 95% CI, 1.02, 1.30 for a 1% increase).

CONCLUSIONS

Loss of vision continues to be significant in persons with diabetes. These results suggest that prevention of retinopathy through control of glycemia will have a beneficial effect on visual outcome.

Nonphotic entrainment of the human circadian pacemaker

In organisms as diverse as single-celled algae and humans, light is the primary stimulus mediating entrainment of the circadian biological clock. Reports that some totally blind individuals appear entrained to the 24-h day have suggested that nonphotic stimuli may also be effective circadian synchronizers in humans, although the nonphotic stimuli are probably comparatively weak synchronizers, because the circadian rhythms of many totally blind individuals "free run" even when they maintain a 24-h activity-rest schedule. To investigate entrainment by nonphotic synchronizers, we studied the endogenous circadian melatonin and core body temperature rhythms of 15 totally blind subjects who lacked conscious light perception and exhibited no suppression of plasma melatonin in response to ocular bright-light exposure. Nine of these fifteen blind individuals were able to maintain synchronization to the 24-h day, albeit often at an atypical phase angle of entrainment. Nonphotic stimuli also synchronized the endogenous circadian rhythms of a totally blind individual to a non-24-h schedule while living in constant near darkness. We conclude that nonphotic stimuli can entrain the human circadian pacemaker in some individuals lacking ocular circadian photoreception.

Endocrine disorders in septo-optic dysplasia (De Morsier syndrome)--evaluation and follow up of 18 patients

Septo-optic dysplasia (SOD) is characterized by hypoplasia of the optic nerve, various types of forebrain defects and hormonal deficiencies. We have studied the clinical and endocrinological characteristics of 18 such patients retrospectively to: (1) better define the endocrine abnormalities in children with SOD; and (2) to find approaches for the interdisciplinary long-term care of children with SOD. The children were seen at the Children's Hospital of the University of Munich from 1976 to 1992 (8 boys, 10 girls; age at initial presentation: 1 day-13 years of age, mean 1.9 years). Unilateral hypoplasia of the optic nerve was found in 7 cases, bilateral hypoplasia in 11. Sonographic, CCT or MRI yielded the following results: 4 of the patients had a cavum septum pellucidum, 3 patients had hypoplasia of the cerebellum, 1 aplasia of the corpus callosum and 1 aplasia of the fornix. An empty sella with or without an ectopic pituitary was seen in 4 cases. Height standard deviation score (SDS) at time of diagnosis was -4.0 to +0.4, mean -2.92. Endocrine deficiencies were present in all 11 patients who had undergone endocrinological investigations. Seven patients suffered from isolated growth hormone (GH) deficiency or multiple hypopituitarism. One had diabetes insipidus centralis, 2 had hypogonadotropic hypogonadism, 1 had hypothyroidism and 2 adrenal insufficiency. Hypothalamic testing was performed only in a subset of patients: in 5 of 11 children tested a thyrotropin releasing hormone (TRH test), in two out of nine a gonadotropin releasing hormone (GnRH) test, and in three out of six GH releasing hormone (GHRH) test yielded abnormal results. High prolactin levels were measured in two out of five patients.

CONCLUSION

SOD is characterized by optic nerve hypoplasia and a variety of endocrine deficiencies. In addition, forebrain malformations are present in most SOD patients. Hormonal disorders are present in some SOD patients which may be of hypothalamic origin and need to be investigated systematically.

Melatonin and the pituitary-thyroid axis status in blind adults: a possible resetting after puberty

OBJECTIVE

Increased levels of free thyroid hormones have been previously described in prepubertal blind subjects and have been thought to be a consequence of a partial target organ refractoriness due to the early and prolonged lack of light perception. The aim of this study was to clarify whether this abnormality is permanent or transient and the interrelationships between melatonin and thyroid hormone secretion.

MEASUREMENTS

Total and free thyroid hormones, TSH, thyroxine-binding globulin (TBG), reverse triiodothyronine (rT3) and melatonin were measured in plasma samples obtained at 0800 h (two hours after lights-on) in a group of 11 totally (group 1) and 16 partially (group 2) blind adult patients and in 10 age-matched healthy subjects.

RESULTS

Both totally and partially blind patients showed melatonin levels higher than in controls (330 +/- 106 pmol/l, group 1 and 361 +/- 159 pmol/l, group 2, respectively; controls: 53 +/- 12 pmol/l, P < 0.001 vs both groups), but fT4, fT3, T4, T3 TSH, rT3 and TBG concentrations showed no significant differences from controls.

CONCLUSIONS

A possible resetting of pituitary-thyroid axis regulation can occur in blindness after puberty; variations of melatonin secretion could play a role in this. The inhibitory effect of melatonin on thyroid gland function found in animals does not seem to occur in humans. Elevated melatonin levels, both in patients with total blindness and in those with light perception only, suggest that more complex mechanisms other than light signalling are involved in the changes of melatonin secretion in blindness.

Effects of exposure to morning bright light in the blind and sighted controls

Seven blind subjects and 11 sighted controls were exposed to 3300 lux of cool-white fluorescent light for either 1 h or 15 min in the morning for 2 weeks during the winter. Serum 25-hydroxyvitamin D3 concentration, melatonin concentration in saliva, body temperature from the armpit, subjective sleepiness, and depressive symptoms were measured before and after the 2-week trial. The intervention resulted in a significant elevation in the concentration of melatonin at 21.00 hours in the healthy controls but at 23:00 hours in the blind subjects. The body temperatures measured were increased in the controls but decreased in the blind in the morning following the cessation of the intervention, and these opposite changes resulted in significant differences in the temperatures between the two groups. The decreases in the body temperature were associated with the increases in the levels of melatonin in the blind but not in the controls. Bright light administered in the morning decreased subjective sleepiness and improved mood in the healthy controls and in the blind subjects as well. The intervention had no effect on the levels of vitamin D in either of the two groups.

Normal plasma insulin-like growth factor I levels and impaired final stature in adult blind subjects

The aim of this study was to determine if changes in IGF-1 levels and in final stature occur in blind adult subjects. Eighteen subjects (4 females and 14 males) with total blindness (Group 1) and 26 subjects (5 females and 21 males) with only light perception (Group 2), living at an Institute for blind adult subjects in Naples, Italy, were studied. Their height and weight were compared to British standards. Plasma morning IGF-1 levels, measured by IRMA method were compared to those of 18 normal controls (6 females and 12 males) matched for age and weight. A high prevalence of short stature was demonstrated especially in Group 1 (p = 0.00005 by chi-square for trend test) but was also present in Group 2 (p = 0.02). No alterations in weight distribution were observed in both groups. Basal IGF-I levels in both Group 1 and Group 2 were similar to those of controls: IGF-1 (M +/- SE), 30.9 +/- 2.9 nmol/L and 37.9 +/- 2.7 nmol/L, respectively, vs 33.3 +/- 2.9 nmol/L, NS. High prevalence of final short stature in both groups confirms a negative influence of total or partial blindness on growth. These complex mechanisms appear to involve more than alterations in GH and IGF-I secretion.

[Effect of the changes of epiphysial functions on the central and peripheral immune system in mice]

Endocrine function of thymus estimated by titer of thymic serum factor is inhibited in pubertal mice CBA/Ca under conditions of pharmacological inhibition of epiphysis function by beta-adrenoblocking agent anapriline. After blinding and epithalamine and melatonine introduction the content of thymic hormone considerably increases. Melatonine is characterized by manifestation of effect in earlier periods of research. In mice with hyperfunction of epiphysis mass, cell character of thymus and spleen increase as well as the content of thymosine-like activity in supernatant of cultures of splenocytes. And on the contrary, in animals with hypofunction of epiphysis the values of studied immunological indices decrease. Immunopotentiating effect of epiphysial factors is observed not only in vivo but also in vitro and decreases in thymectomized mice. The change of the concentration of glucocorticoids in the organism is of significance in the mechanism of epiphysis effect on the immune system.

Reduced increase in plasma renin activity on water-deprivation in blind hereditary microphthalmic rats

We compared the plasma renin activity (PRA) before and after 24-h water-deprivation in blind hereditary microphthalmic rats and Donryu rats. In the congenitally blind rats with a morphologically abnormal suprachiasmatic nucleus (SCN), hypovolemia induced significantly less elevation of the PRA and significantly more increase in the hematocrit value than in normal rats. The changes after water-deprivation in the blind rats were quite similar to those reported in rats with SCN lesions. However, the free-running circadian rhythms persisted in these blind rats, whereas those in rats with SCN lesions were completely eliminated. Thus, it is likely that SCN cells are involved in regulation of the PRA, and that if this is the case these cells are different from those containing the circadian pacemaker.