Delayed auditory brainstem response in thiamin-deficient rats.

Shigematsu, Yosuke; Nakai, Asami; Kuriyama, Masami; Kikawa, Yoshiharu; Konishi, Ikuo; Sudo, Masakatsu; Itokawa, Yoshinori

doi:10.3177/jnsv.36.209

Cited by 7 publications

(3 citation statements)

References 16 publications

(8 reference statements)

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“…In animal models, severe dietary thiamin deficiency is known to impair markedly the function of different tissues, including the auditory and visual pathways in the brainstem (Rinehart et al 1949;Rodger 1953;Hakim et al 1983;Shigematsu et al 1990), the endocrine pancreas Sundaresan 1988, 1991), the haemopoietic system (Rinehart et al 1948;Thornberg et al 1981) and the heart (Gubler 1969;Sutherland et al 1974). Impairment of the same organs and tissues has been observed also in human thiamin deficiency (see Inouye and Katsura 1965;Hell et al 1976;Lonsdale, 1982).…”

Section: Discussionmentioning

confidence: 99%

Further studies on erythrocyte thiamin transport and phosphorylation in seven patients with thiamin‐responsive megaloblastic anaemia

Rindi

Patrini

Laforenza

et al. 1994

J of Inher Metab Disea

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Erythrocyte thiamin metabolism and transport were investigated in 7 patients from Brazil, Israel and Italy suffering from thiamin-responsive megaloblastic anaemia (TRMA) associated with diabetes mellitus and sensorineural deafness. All patients discontinued thiamin therapy for 4-7 days before the investigation. TRMA patients showed invariably reduced total thiamin levels in erythrocytes (percentage reduction compared with healthy controls, -46.8+3%; mean+SEM). The proportions of individual thiamin compounds, expressed as a percentage of total thiamin content, were within the normal range, whereas their absolute amounts were significantly decreased in the following order: thiamin monophosphate>thiamin pyrophosphate>thiamin. Thiamin pyrophosphokinase activity was also reduced as compared with controls (mean reduction+SEM, -25.9+1%). The saturable, specific component of thiamin uptake, which normally prevails at physiological concentrations of thiamin (< 2/~mol/L), was absent in erythrocytes obtained from TRMA patients, while the non-saturable (diffusive) component of uptake was normally present.These results confirm observations made previously in two patients and demonstrate that TRMA is consistently associated with a state of thiamin deficiency, which is presumably secondary to reduced thiamin cellular transport and absorption (caused by lack of a membrane-specific carrier), and to impaired intracellular pyrophosphorylation.Investigators from our group recently showed that erythrocytes obtained from patients with thiamin-responsive megaloblastic anaemia (TRMA, McKusick 249270), exhibit no saturable, specific component of thiamin transport as well as a reduced thiamin pyrophosphokinase (EC 2.7.6.2; TPK) activity, resulting in decreased red cell total MS received 22.3.94 Accepted 16.5.94

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Section: Discussionmentioning

confidence: 99%

Further studies on erythrocyte thiamin transport and phosphorylation in seven patients with thiamin‐responsive megaloblastic anaemia

Rindi

Patrini

Laforenza

et al. 1994

J of Inher Metab Disea

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“…It is reasonable to assume that the deficiency in both specific transport and TPKase activity could produce a sort of thiamine hypovitaminosis, causing metabolic alterations in various tissues such as the auditory pathways in the brain stem (Rinehart et al, 1949;Hakim et al, 1983;Shigematsu et al, 1990), the endocrine pancreas (Failer, 1959;Rathanaswami and Sundaresan, 1988) and the haemopoietic system (Rinehart et al,. 1948;Thornber et al, 1981), whose function is known to be greatly impaired by severe dietary thiamine deficiency.…”

Section: Discussionmentioning

confidence: 99%

Thiamine transport by erythrocytes and ghosts in thiamine‐responsive megaloblastic anaemia

Rindi

Casirola

Poggi

et al. 1991

J of Inher Metab Disea

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A 9-year study of thiamine metabolism and cellular transport was performed in two patients with thiamine-responsive megaloblastic anaemia associated with diabetes mellitus and sensorineural deafness, in their relatives, and in age-matched controls from the same area. The ratios between the content of thiamine and that of its phosphoesters in erythrocytes were within the normal range, whereas the absolute values of thiamine and thiamine compounds were reduced by about 40% as compared to controls. Thiamine pyrophosphokinase activity was about 30% lower than in controls. Thiamine treatment restored the levels of thiamine and thiamine compounds to normal values, whereas kinase was unaffected. Both the saturable (specific, predominant at low, less than 2 mumol/L, physiological concentrations of thiamine) and the non-saturable component of thiamine transport were investigated. Erythrocytes and ghosts from patients exhibited no saturable component, this abnormality being specific for the patients and not shared by their parents. It is concluded that the cells from thiamine-responsive megaloblastic anaemia patients contain low levels of thiamine compounds, probably due to their inability to take up and retain physiological concentrations of thiamine, as a result of the lack of the saturable, specific component of transport and reduced thiamine pyrophosphokinase.

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“… 3 Moreover, auditory tests in some studies have pointed more toward brainstem sites of lesion. 6 , 7 Indeed, a major concern before surgery is that a patient may have a proximal lesion in the brainstem, which may not be amenable to receiving a cochlear implant. No data were available to guide us regarding outcomes of cochlear implantation in patients with the thiamine-responsive megaloblastic anemia syndrome.…”

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confidence: 99%

Cochlear implant and thiamine-responsive megaloblastic anemia syndrome

Hagr

2014

Annals of Saudi Medicine

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Thiamine-responsive megaloblastic anemia syndrome is a rare autosomal recessive disorder defined by the occurrence of megaloblastic anemia, diabetes mellitus, and bilateral sensorineural deafness, responding in varying degrees to thiamine treatment. We report a precedence case for the treatment of deafness associated with the typical triad of thiamine-responsive megaloblastic anemia in a 4-year-old boy who showed a poor use of preoperative hearing aids but demonstrated significant improvements in hearing ability 1 year after receiving a cochlear implant.

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Delayed auditory brainstem response in thiamin-deficient rats.

Cited by 7 publications

References 16 publications

Further studies on erythrocyte thiamin transport and phosphorylation in seven patients with thiamin‐responsive megaloblastic anaemia

Further studies on erythrocyte thiamin transport and phosphorylation in seven patients with thiamin‐responsive megaloblastic anaemia

Thiamine transport by erythrocytes and ghosts in thiamine‐responsive megaloblastic anaemia

Cochlear implant and thiamine-responsive megaloblastic anemia syndrome

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