Biomedical subjects

K V Luong

Publications and source records attributed to K V Luong.

10 recordsLinked to original sources

PubMed2000

Normocalcemic hyperparathyroidism in Vietnamese immigrants living in southern California.

OBJECTIVE: To characterize the normocalcemic hyperparathyroidism in Vietnamese immigrants living in southern California. METHODS: Of 14 Vietnamese patients with primary hyperparathyroidism who were observed between 1991 and 1996, 50% (7 patients; 2 men and 5 women) had normal and/or fluctuating levels of serum total calcium. When the serum calcium was corrected for the albumin, the "corrected" calcium was lower than the measured serum total calcium. Their mean age was 56.4 +/- 11.4 years. All patients had normal serum levels of albumin and serum phosphate. RESULTS: Women were affected more often than men by a ratio of 5:2. The serum-ionized calcium as well as intact PTH were increased in all patients. Five patients underwent surgery with confirmation of parathyroid adenomas. Two patients refused surgery. They did not have osteitis fibrosa cystica by radiological examination. One patient had low plasma levels of 25-hydroxyvitamin D. Five of 7 normocalcemic patients (70%) were born in the month of December compared with 2 of seven hypercalcemic patients (30%). CONCLUSION: The blood ionized calcium and intact parathyroid hormone are necessary for confirmation of normocalcemic hyperparathyroidism. Most of our normocalcemic hyperparathyroid patients (70%) were born in the month of December. We postulate that a combination of exposure to solar ultraviolet light during the formation of the fetal parathyroid glands and stimulation from low vitamin D levels in the wintertime may be related to the development of hyperparathyroidism. However, it is difficult to prove a definite correlation between normocalcemic hyperparathyroidism and their month of birth (December), especially when these observations were seen in a small group of patients.

Adult↗

PubMed2000

Hyperthyroidism and asthma.

Two patients presented with new onset of thyrotoxicosis and they then developed episodic wheezing a few months afterward. The asthmatic attacks improved when the patients were rendered in a euthyroid state with treatment. The present paper discusses the relationship between two diseases, hyperthyroidism and asthma, and the underlying factors potentially contributing to their conditions. The present findings suggest that asthma may develop in a susceptible individual with hyperthyroidism and it is possible that the reactive oxygen species may be a contributory factor in exacerbating wheezing in our hyperthyroid patients.

Adult↗

PubMed2000

Folate and vitamin B12-deficiency anemias in Vietnamese immigrants living in Southern California.

BACKGROUND: Although the occurrence of iron deficiency anemia and hemoglobinopathies in Vietnamese immigrants has been reported, folate and vitamin B12 deficiencies have not. Proper diagnosis and effective treatment is necessary to achieve a complete correction of anemia. METHODS: We retrospectively analyzed the records of Vietnamese immigrants seen in our medical clinic from 1991 to 1993. Fifty-nine anemic patients (48 females and 11 males) had low levels of red blood cell (RBC) folate and/or serum vitamin B12. RESULTS: The patients' mean age was 37.7+/-17 years. Mean hemoglobin and hematocrit values were 11.4+/-0.7 g/dL and 34.4%+/-2.2%, respectively. Mean corpuscular volume (MCV) was normal in 40 patients (68%) (mean, 89.1+/-5 fL) and low in 19 patients (32%) (mean, 69.7+/-6 fL). Forty-four patients had low RBC folate levels (mean, 157.7+/-41.7 ng/mL). Twenty patients had low serum vitamin B12 levels (mean, 165.6+/-47 pg/mL). Fourteen patients had ferritin levels of <20%. CONCLUSIONS: Concomitant folate, vitamin B12, and iron deficiencies or hemoglobinopathies might have been responsible for either normal or low MCV in some of our anemic patients. In this ethnic group, RBC folate and serum vitamin B12 levels should be determined in all anemic patients.

Adolescent↗

PubMed1999

Organic arsenic intoxication from bird's nest soup.

OBJECTIVE: To present a case of organic arsenic intoxication after consumption of bird's nest soup in a Vietnamese patient. METHOD: We have described the clinical picture of a patient with organic arsenic intoxication, and high levels of urine arsenic after consumption of bird's nest soup. RESULT: Withdrawal of bird's nest soup coincided with a decrease in urinary arsenic levels and the disappearance of peripheral neuropathy. CONCLUSION: This case illustrates the environmental contamination of bird's nest soup with organic arsenic. A prompt removal of the source from the diet resulted in clinical improvement.

Arsenic Poisoning↗

PubMed1998

Aquagenic urticaria: report of a case and review of the literature.

OBJECTIVE: To present a case of aquagenic urticaria and to review the literature regarding this very rare physical urticaria. METHOD: We described the clinical history of a patient with aquagenic urticaria. A water challenge test was performed, with plasma histamine levels measured before and after the challenge. RESULT: Our patient presented with a history of severe itching and wheals within five minutes of contact with water, regardless of its temperature or source (sea or tap water). A water challenge produced hives but serum histamine levels did not change. Prophylaxis with antihistamine or anticholinergic medications was not effective. CONCLUSION: Exposure to water can cause urticaria in susceptible patients and antihistamine and anticholinergic medication may not prevent the reaction. The mechanism of this phenomenon remains poorly understood.

Adult↗

PubMed1995

Cement burn.

People working with cement should be aware of the potential for cement burn. The alkalinity of cement is due to the exothermic reaction of calcium oxide with water, which forms calcium hydroxide. Prolonged exposure of the skin to wet cement may result in a caustic burn.

Adult↗

PubMed1993

1,25-Dihydroxyvitamin D3 inhibits Na(+)-dependent phosphate transport in osteoblastic cells.

In the present work we investigated the influence of vitamin D3 metabolites on Na(+)-dependent phosphate (Pi) transport in the clonal osteoblastic cell line UMR-106. The vitamin D3 metabolite 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] dose-dependently inhibited Pi transport with a half-maximal concentration of approximately 5 x 10(-11) M. The effect of 1,25(OH)2D3 was first observed after 8 h of preincubation period. Inhibition of phosphate uptake was relatively specific for the 1,25(OH)2D3 analogue of vitamin D3. The potency order was 1,25(OH)2D3 >> 24,25-dihydroxyvitamin D3 > 25-[3H]hydroxyvitamin D3. Kinetically, 1,25(OH)2D3 decreased the maximal velocity of the phosphate uptake system, whereas the affinity for phosphate was unaffected. Activation of protein kinase C (PKC) in UMR-106 cells stimulated Na(+)-dependent Pi transport. Nonetheless, the inhibitory effect of 1,25(OH)2D3 on Pi transport was not related to downregulation of PKC. Chemical determination of intracellular Pi showed a 50% reduction after 24-h preincubation with 10(-8) M 1,25(OH)2D3. We conclude that 1,25(OH)2D3 inhibits Na(+)-dependent phosphate transport in osteoblastic cells. This in turn leads to intracellular Pi depletion. The physiological implication of this phenomenon on the effects of vitamin D on osteoblasts in situ is discussed.

Biological Transport↗

PubMed1991

Voltage-dependent phosphate transport in osteoblast-like cells.

Phosphate ion (Pi) in sufficient concentrations is crucial for bone mineralization. The osteoblast (OB) may be responsible for the transport of Pi into the bone interstitium, where mineralization occurs. We previously characterized a Na(+)-dependent Pi transporter (NaPi) in the osteoblastic UMR-106-01 cell line. In the present study, the alteration of Na(+)-dependent Pi transport by changes in membrane potential was investigated. Depolarizing the cells with increasing concentrations of ambient K+ and valinomycin resulted in a progressive decline in Na(+)-dependent Pi uptake to a maximum of 28% at a membrane potential of -18 mV compared to control Na(+)-dependent Pi uptake at a membrane potential of approximately -60 mV. Hyperpolarizing the cells with SCN- increased Na(+)-dependent Pi uptake over control by 50% at an SCN- concentration of 70 mM. Determination of membrane potential by using the fluorescent probe, DiSC3(5), showed that the addition of Pi to cells in Na(+)-containing medium resulted in a small depolarization. These data show that NaPi activity can be altered by membrane potential changes and that the initiation of Na(+)-dependent Pi uptake is associated with depolarization of the plasma membrane of UMR-106-01 cells. Taken together, the cotransport of Na+ and Pi results in the movement of a net positive charge into the cell.

Benzothiazoles↗

PubMedDate not supplied

Complement abnormalities with lower extremities discomfort in Vietnamese immigrants.

The objective was to measure complement C'l esterase inhibitor (CIINH) in a group of Vietnamese outpatients with lower extremities discomfort of undetermined etiology. All 25 female patients were followed between 1992 and 1995. Their age ranged from 24 to 82 years old (mean age, 46.68 +/- 13.77). They presented with unexplained lower extremities discomfort. They were found to have low levels of CIINH (mean, 11.36 +/- 1.44 mg/dL versus control subjects, 15.64 +/- 2.22 mg/dL). Twenty-one patients were treated with oral Danazol 200 mg daily for 1-2 months. The improvement of the symptoms in our patients coincided with increased CIINH level in all of our patients (pretreatment, 11.33 +/- 1.46 mg/dL versus posttreatment, 16.82 +/- 2.98 mg/dL with p < 0.001) and the return to normal functional activity of CIINH associated with and without Danazol treatment. These patients may represent a form of androgen-responsive limited to the lower extremity's discomfort associated with low levels of CIINH, normal levels of Clq and normal ratio of C4d/C4 that differentiated them from angioedema (hereditary or acquired form), having no known precipitating factors or a family history of hereditary angioedema.

Adult↗

PubMedDate not supplied

Headache and complement C'1-esterase inhibitor deficiency in Vietnamese immigrants living in southern California.

The objective was to measure complement C'1-esterase inhibitor (C1INH) in a group of Vietnamese outpatients with headache. All 51 patients (7 males and 44 females), with either migraine or chronic tension-type headache, were evaluated during 1994 and 1995. Their ages ranged from 15 to 69 years old (mean age, 37.5 years). They were found to have low levels of C1INH (mean, 11 +/- 2 mg/dL versus control subjects, 15 +/- 2 mg/dL with p < 0.0001). Twenty patients (5 males and 15 females) were treated with a low dose of danazol, 200 mg daily for 1-2 months. The improvement of the headache coincided with the return to normal levels of C1INH in all of our patients (pretreatment, 11 +/- 2 mg/dL versus post-treatment, 16 +/- 2 mg/dL with p < 0.001). The levels of C1q and C4d/C4 ratios did not change as a result of treatment with danazol. Our patients may represent a form of androgen-responsive headache, which is associated with low levels of C1INH, normal levels of C1q and normal C4d/C4. It differentiated them from angioedema (hereditary or acquired form); they had no known precipitating factors or a family history of angioedema.

Adolescent↗