Intrinsic factor secretion in gastric atrophy

Ataxic gait following total gastrectomy for gastric cancer

A 58-year-old woman, who had undergone total gastrectomy for early gastric cancer 9 years previously, visited the outpatient clinic complaining of progressive difficulty in walking for 15 d. Laboratory examinations showed macrocytic anemia and a decreased serum vitamin B12 concentration and increased serum concentrations of folate, vitamin E and copper. Magnetic resonance imaging showed multifocal high signal intensities along the posterior column of the cervical and thoracic spinal cord. Treatment consisted of intramuscular injections of vitamin B12 for 7 d, which increased her serum level of vitamin B12 to normal. This was followed by weekly intramuscular injections of vitamin B12 for another 2 wk and oral administration of vitamin B12 three times per day. After comprehensive rehabilitation for 4 wk, she showed sufficient improvements in strength and ataxic gait, enabling her to return to her normal daily activities.

Reversal of protein-bound vitamin B12 malabsorption with antibiotics in atrophic gastritis

The role of bacteria in the bioavailability of protein-bound vitamin B12 was examined in eight elderly subjects who had atrophic gastritis and in eight normal controls. On separate days and in random order, vitamin B12 absorption tests were performed using either radiolabeled crystalline or protein-bound vitamin B12. At the same time, bacterial samples were collected from the upper gastrointestinal tract. The tests and gastrointestinal aspirates were performed before and during tetracycline therapy. Crystalline vitamin B12 was absorbed to the same extent in the two study groups. Atrophic gastritis subjects absorbed significantly less protein-bound vitamin B12 than normal controls (mean +/- SEM, 0.7% +/- 0.2% vs. 1.9% +/- 0.5%, respectively). However, protein-bound vitamin B12 absorption in these subjects normalized after antibiotic therapy. These results suggest that the small amounts of vitamin B12 released from the protein binders is readily absorbed (as shown in vitro) and/or metabolized by bacteria.

Clinically significant vitamin B12 deficiency secondary to malabsorption of protein-bound vitamin B12

Protein- (chicken serum) bound [57Co]cyanocobalamin absorption was evaluated in five hypochlorhydric patients who had developed B12 deficiency despite having normal absorption of unbound crystalline vitamin B12. All five patients had decreased urinary excretion of protein-bound B12 (0.06--0.34%) as compared to twelve normal controls (0.61--5.6%), P less than .001. Improvement in protein-bound B12 absorption in four of the five patients occurred with the exogenous administration of hydrochloric acid, pepsin, gastric intrinsic factor, or a combination thereof. Vitamin B12 deficiency developing in the setting of hypochlorhydria may result from deficiency of acid-peptic digestion of B12 bound to protein and/or a relative deficiency of intrinsic factor. This digestive defect is not detected with tests which measure the absorption of unbound crystalline B12 but is detected by a simple test which employs B12 bound to chicken serum as the form of protein-bound B12.

The functional state of the gastrointestinal tract after ulcer surgery. A ten-year prospective follow-up study

Of 35 patients operated upon for peptic ulcer and subjected to absorption tests before operation, 26 could be followed up with absorption tests for 1, 6, and 10 years after operation. The following operations had been performed on the latter: antrectomy with gastroduodenostomy in 10, antrectomy with selective vagotomy and gastroduodenostomy in 9, and other operations in 7. None had recurrence of the ulcer or disturbing abdominal complaints during the follow-up period. Ten years after operation there was an increase in the mean value of the Schilling test, and all patients had a normal serum B12 vitamin level. On the other hand, a decrease was noticed in the mean value of the d-xylose test and an increase in that of faecal dry-weight fat content. At the time of the 10th year follow-up examination, 6 patients had an impaired d-xylose absorption and 7 an impaired fat absorption. According to the increase in the mean body weight and the serum protein and haemoglobin concentration, the nutritional status had not worsened.

Gastric atrophy in childhood

Images