[The comparison of microleakage among three different dentin bonding agents in class V cavities]

The use of the etching technique and an enamel bonding agent may effectively reduce microleakage of the cavity wall. However, the reduction of marginal leakage relating to class V cavities, is still unsatisfactory according to the dental literature. Due to the structural difference between the dentin and the enamel, though many new dentin bonding agents have been developed lately, none of them work perfectly. In this experiment, the "silver staining technique" was used to investigate the degree of microleakage in class V resin restorations which were bonded with 3 different dentin bonding agents (Scotchbond, Scotchbond 2 and Denthesive). The sample consists of 21 caries free human molars which were divided into 3 groups: 1) Scotchbond v. s. Scotchbond 2, 2) Scotchbond v. s. Denthesive, 3) Scotchbond 2 v. s. Denthesive. Both buccal and lingual surfaces were prepared for class V cavities. The cavities were then filled with composite resin Silux, and immersed in 50% silver nitrate solution for 2 hours, and followed by washing with distilled water. After that these teeth were immersed in photodeveloping solution under the fluorescent light for 3 hours. On finishing, they were washed again, sectioned vertically into mesial and distal halves with a Isomet sectioner and put under a microscope and evaluated for the degree of microleakage with Dr. Going's method. On statistical analysis, the results of this study showed that the degree of microleakage was not significantly different among the 3 dentin bonding agents in class V resin restorations, either on the gingival wall or the occlusal wall.

Ventricular tachycardia after surgical repair of tetralogy of Fallot: results of intraoperative mapping studies

OBJECTIVES

Four patients with previous repair of tetralogy of Fallot and ventricular tachycardia underwent map-guided surgery to ablate the arrhythmias.

BACKGROUND

Although patients with repaired tetralogy of Fallot are at increased risk of sudden death due to ventricular tachycardia, little is known of the origin and mechanism of this arrhythmia.

METHODS

A customized right ventricular balloon with 112 electrodes was used to record endocardial activation and, where possible, simultaneous epicardial recordings were obtained with a sock electrode array. Three patients had an aneurysm of the right ventricular outflow tract and one had a septal aneurysm. All had moderate to severe pulmonary valve insufficiency. Preoperative electrophysiologic study demonstrated inducible rapid (cycle length 180 to 300 ms) hemodynamically unstable monoform ventricular tachycardias.

RESULTS

Intraoperatively, five different tachycardias (two in one patient) were induced and mapped. The sites of earliest activation were located in the subendocardium of the right ventricular outflow tract in all, but they varied widely among the septum, free wall and parietal band and could not be identified by visible scar. All were due to a macroreentrant circuit initiated by a critical delay in activation beyond a functional arc of block. Two patients treated by cryoablation while the heart was beating and perfused at normal temperature had inducible ventricular tachycardia postoperatively. In the two subsequent patients, the application of cryoablation under anoxic cardiac arrest resulted in noninducibility of arrhythmia.

CONCLUSIONS

Ventricular tachycardia in tetralogy of Fallot in these four patients was caused by macroreentry in the right ventricular outflow tract. Surgical success depends on detailed mapping and cryoablation under anoxic cardiac arrest. In patients at risk of sudden death, map-directed surgery may offer distinct advantages over either implantable devices or drug therapy.

Molecular characterization of glucose-6-phosphate dehydrogenase (G6PD) deficiency by natural and amplification created restriction sites: five mutations account for most G6PD deficiency cases in Taiwan

We have developed a rapid and simple method to diagnose the molecular defects of glucose-6-phosphate dehydrogenase (G6PD) deficiency in Chinese in Taiwan. This method involves the selective amplification of a DNA fragment from human G6PD gene with specific oligonucleotide primers followed by digestion with restriction enzymes that recognize artificially created or naturally occurring restriction sites. Ninety-four Chinese males with G6PD deficiency were studied. The results show that 50% (47 of 94) were G to T mutation at nucleotide (nt) 1376, 21.3% (20 of 94) were G to A mutation at nt 1388, 7.4% (7 of 94) were A to G mutation at nt 493, 7.4% (7 of 94) were A to G mutation at nt 95, 4.2% (4 of 94) were C to T mutation at nt 1024, 1.1% (1 of 94) was G to T mutation at nt 392, and 1.1% (1 of 94) was G to A mutation at nt 487. These results show that the former five mutations account for more than 90% of G6PD deficiency cases in Taiwan. Aside from showing that G to T change at nt 1376 is the most common mutation, our research indicates that nt 493 mutation is a frequent mutation among Chinese in Taiwan. We compared G6PD activity among different mutations, without discovering significant differences between them.

Hypervitaminosis D associated with drinking milk

BACKGROUND

Vitamin D has been added to milk in the United States since the 1930s to prevent rickets. We report the unusual occurrence of eight cases of vitamin D intoxication that appear to have been caused by excessive vitamin D fortification of dairy milk.

METHODS

Medical records were reviewed and a dietary questionnaire was sent to eight patients who had unexplained hypervitaminosis D. Vitamin D analyses with high-performance liquid chromatography were performed on samples of the patients' serum, the dairy milk they drank, and the vitamin D concentrate added to the milk.

RESULTS

All eight patients drank milk produced by a local dairy in amounts ranging from 1/2 to 3 cups (118 to 710 ml) daily. All had elevated serum 25-hydroxyvitamin D concentrations (mean [+/- SD], 731 +/- 434 nmol per liter [293 +/- 174 ng per milliliter]). Six of the eight patients had elevated serum vitamin D3 concentrations. Of the eight patients, seven had hypercalcemia and one had hypercalciuria but normocalcemia (mean serum calcium, 3.14 +/- 0.51 mmol per liter [12.6 +/- 2.1 mg per deciliter]). Analysis of the dairy's vitamin D-fortified milk revealed concentrations of vitamin D3 (cholecalciferol) that ranged from undetectable to as high as 232,565 IU per quart (245,840 IU per liter). An analysis of the concentrate that was used to fortify the milk, labeled as containing vitamin D2 (ergocalciferol), revealed that it contained vitamin D3.

CONCLUSIONS

Hypervitaminosis D may result from drinking milk that is incorrectly and excessively fortified with vitamin D. Milk that is fortified with vitamin D must be carefully monitored.

The vitamin D content of fortified milk and infant formula

BACKGROUND

The fortification of milk and infant formula with vitamin D has had an important role in eliminating rickets in children and osteomalacia in adults. A recent outbreak of vitamin D intoxication caused by drinking milk fortified with excess vitamin D has led to questions about the level of vitamin D in milk from other producers.

METHODS

We used high-performance liquid chromatography to measure vitamin D in samples of 13 brands of milk with various fat contents and 5 brands of infant formula purchased at random from local supermarkets in five Eastern states.

RESULTS

Only 12 (29 percent) of the 42 samples of the 13 brands of milk and none of the 10 samples of the 5 brands of infant formula contained 80 to 120 percent of the amount of vitamin D stated on the label. Twenty-six of the 42 milk samples (62 percent) contained less than 80 percent of the amount claimed on the label. No vitamin D was detected in 3 of the 14 samples of skim milk tested (lower limit of assay, 4.7 IU per quart [5.0 IU per liter]). One milk sample labeled as containing vitamin D2 (ergocalciferol) contained vitamin D3 (cholecalciferol). Seven of the 10 samples of infant formula contained more than 200 percent of the amount stated on the label; the sample with the highest concentration contained 419 percent of the stated amount. None of the samples of infant formula contained less than the amount stated.

CONCLUSIONS

Milk and infant-formula preparations rarely contain the amount of vitamin D stated on the label and may be either underfortified or overfortified. Since both underfortification and overfortification are hazardous, better monitoring of the fortification process is needed.

Huge plexiform neurofibroma of the head and liver--case report

Neurofibromatosis (NF) is a hereditary autosomal dominant disorder. Von Recklinghausen first described NF in 1882, which is now classified as Neurofibromatosis 1 (NF-1). NF-1 is the most commonly encountered NF which affects 1 in 4000 persons. Clinical manifestations of NF-1 include: generalized cutaneous neurofibroma, pigmented skin patches (cafe-au-lait spots), pigmented iris hamartoma (Lisch nodules), skeletal abnormally, CNS tumors, etc. The subject of this case study is a young adult male with a huge plexiform neurofibroma involving both the liver and head regions. The head tumor measured 10 x 8 x 3.5 cm3 in size, weighted approximately 180g with overlying hyperpigmented skin and an underlying congenital skull defect. A CT scan and MRI of the head and neck revealed a well defined lobulated tumor and deformed external ear. A abdominal sonogram, CT scan and MRI showed a huge plexiform neurofibroma with liver invasion. Lisch nodules and multiple cafe-au-lait spots were also found. Surgical removal of the head tumor along with an external ear reconstruction was performed. Satisfactory cosmetic results and improved hearing were achieved.

Analysis of ras gene mutations in gastrointestinal cancers

Point mutations of c-Ki-ras genes were analyzed in 33 samples of human gastrointestinal malignancy. DNA extracted from the frozen tissue was amplified by polymerase chain reaction (PCR) and analyzed by direct sequencing and slot-blot hybridization at codons 12, 13 and 61 of c-Ki-ras. In 7 cases out of 19 colorectal cancers, point mutations were found: 3 cases at codon 12, 1 at codon 13, 2 at codon 61 of c-Ki-ras and one case had double mutations at codon 12 and codon 13. In 11 cases of gastric cancer, 4 showed point mutations: 1 at codon 12 and 3 at codon 13 of c-Ki-ras. In 3 pancreatic carcinomas, 2 had point mutations: one at codon 12 and the other at codon 13 of c-Ki-ras. The results indicate that c-Ki-ras gene point mutations are involved in the tumorigenesis of the human gastrointestinal system.

Monostotic fibrous dysplasia of the clivus. Case report

A case report of monostotic fibrous dysplasia of the clivus in a postadolescent woman is described. Although fibrous dysplasia of craniofacial structures is well documented, involvement of the clivus has not been reported. Diagnosis by clinical, radiographic, and histopathological features is detailed. Implications for the role of surgery and management are discussed.

Serum zinc and copper during long-term total parenteral nutrition

Changes in serum zinc and copper levels were studied in 17 patients who received 18 courses of total parenteral nutrition for 28 to 89 days. Mean serum zinc levels decreased significantly after 4 weeks of therapy in the group without zinc supplementation when compared with pretreatment levels (p less than 0.05) and in a second group who received about 1.5 mg of zinc per day (p less than 0.05). Serum copper levels fell consistently and significantly in patients of both groups. However, no obvious clinical signs or symptoms of zinc or copper deficiencies were observed. Blood transfusions were not able to significantly change the serum levels of zinc or copper. Although serum alkaline phosphatase has been suggested as a functional indicator of zinc deficiency, the concomitant hepatic or skeletal dysfunction of the patients made its interpretation difficult. These findings indicate that a decrease in serum zinc and copper is common during TPN using solutions unsupplemented with these trace elements. Supplementation of TPN solutions with zinc, copper, and other trace elements is recommended.

Two bacteriophage T4 base plate genes (25 and 26) and the DNA repair gene uvsY belong to spatially and temporally overlapping transcription units

The bacteriophage T4 DNA recombination-repair gene uvsY located at or near an origin of DNA replication and adjacent to the late base plate genes 25 and 26. Our present results reveal a complex transcription pattern in the region encompassing these genes. Most significantly, uvsY and two ORFs, downstream of it, all of which are transcribed from a middle promoter before the onset of DNA replication, are also part of a larger late transcription unit which includes the base plate genes 25 and 26. The late genes 25 and 26 are transcribed not only late, but also early from one or several early promoters further upstream. Translation, however, is inhibited by secondary structures which sequester the ribosome binding site in the early transcript. We discuss possible advantages of these transcriptional patterns for T4 DNA recombination, replication, and repair. The predicted and in vivo-expressed 23.9-kDa product of gene 26 is smaller than the reported size of gene 26 protein isolated from base plates, suggesting that nascent gp26 might be processed to a larger protein during assembly.

The construction of endocardial balloon arrays for cardiac mapping

The advent of multichannel recording systems has enabled clinical mapping to be performed on a beat-by-beat basis using multi-electrode arrays. Surgical ablation of ventricular arrhythmias generally requires endocardial mapping. Clinical usage has indicated that an inflatable balloon array is the most practical design and can obviate the need for ventriculotomy by a transatrial introduction in the deflated state. Successful experience with the left ventricular balloon led to the development of a right ventricular balloon array suitably configured to extend into the outflow tract. Custom moulds are used to create an appropriate balloon from liquid latex. Nylon cloth is cut from a cardboard pattern to fashion a stretchable sock to envelope the balloon. Electrodes are formed by stitching 2-mm silver beads to the balloon sock in a preconfigured pattern. Teflon-coated 31 G multi-strand stainless-steel wires 130 mm in length connect the electrode beads by solder to the multipin connectors for easy hookup to the amplifier inputs. Tygon tubing 0.53 cm in diameter fitted to the balloon allows inflation and pressure monitoring. This basic design has been successfully implemented for the last 6 years.

Asthma and eczema in children born to women with migraine

Migraine and asthma have been reported to occur in the same person more commonly than would be expected if they are independent. The large Collaborative Perinatal Project provided an opportunity to see if children born to women with migraine or with the group of disorders characterized by asthma and/or allergies were more likely to manifest asthma or eczema in the first 7 years of life. Among children whose mothers had neither migraine nor asthma/allergies, 3.2% had asthma. Of children whose mothers had migraine, but not asthma/allergies, more than 6% had asthma. The risk of asthma among children born to women who had both migraine and asthma/allergies was greater than the risk associated with each maternal disease. The risk of eczema in children was not appreciably influenced by the mother's propensity to migraine or asthma/allergies. The results of this first study of migraine in one generation and asthma in the next lead to the conclusion that the two disorders are probably related.

Biosynthesis and processing of renal mitochondrial glutaminase in cultured proximal tubular epithelial cells and in isolated mitochondria

Primary cultures of rat renal proximal tubular epithelial cells were used to characterize the biosynthesis and processing of the mitochondrial glutaminase. When the cells were labeled with [35S]methionine in the presence of 20 microM carbonylcyanide m-chlorophenylhydrazone, only a 72-kDa peptide, which co-migrates with the primary translation product of the glutaminase mRNA, was immunoprecipitated. At lower concentrations of carbonylcyanide m-chlorophenylhydrazone, the 68- and 65-kDa peptides that are characteristic of the mature glutaminase and a 71-kDa peptide were synthesized. Pulse-chase experiments suggest that the 72-kDa cytosolic precursor could be quantitatively chased to generate the mature mitochondrial species. The observed kinetics indicate that the 71-kDa species is an intermediate in the import pathway. In addition, the 65-kDa glutaminase peptide was synthesized more rapidly than the 68-kDa peptide, and the two peptides were produced in a final ratio of 3:1, respectively. These results suggest that one subunit of the tetrameric glutaminase may be subject to covalent modification. In vitro processing was also characterized by incubating isolated rat liver mitochondria with the glutaminase precursor that was produced by in vitro translation of acidotic rat renal poly(A+) RNA. This system produced an identical sequence of processing reactions. The in vitro formation of the 71-kDa intermediate required a transmembrane potential. Both the intermediate and the mature forms of the glutaminase were recovered in the mitochondria and were resistant to trypsin digestion. Thus, the glutaminase precursor is rapidly translocated across the inner mitochondrial membrane and initially processed to yield an intermediate. The intermediate is subsequently processed to yield the two peptides that constitute the mature enzyme.

A case of zinc deficiency during long-term total parenteral nutrition

A 54-year-old housewife received total parenteral nutrition (TPN) because of an intestinal fistula and total wound breakdown after an emergency operation for perforation of the ileum and diffuse peritonitis. The TPN regimen reversed the catabolism and resolved the abdominal wound and enterocutaneous fistula. Zinc and copper were not supplemented because there was no licensed parenteral trace element solution available. At week 17 of TPN, eczematoid dermatitis appeared on the face, nasolabial folds and chin, and the perineal area. These changes, coinciding with a serum zinc level of 20 micrograms/dl, were consistent with zinc deficiency. Zinc supplementation was commenced giving 6 mg of elemental zinc intravenously daily. The response to zinc therapy was very dramatic. Not only did the serum zinc level increase, but the skin changes returned to normal within 7 days. The patient gradually resumed her usual diet and TPN was discontinued after an approximate duration of 21 weeks. She was later discharged in good health.

Flow cytometry measurement of nuclear RNA content in uveal melanoma

We retrospectively studied the nuclear RNA content in uveal melanomas with known, long-term follow-up. Thirty patients had spindle cell melanomas, 25 had mixed cell tumors, and 9 had epithelioid cell neoplasms. Epithelioid cell types had a higher nuclear RNA content compared to mixed or spindle cell types (p less than 0.05). Using the Cox proportional hazards model, the nuclear RNA content appeared to be an independent prognostic indicator in uveal melanomas, and an increased nuclear RNA content was associated with a worse prognosis (p = 0.001).

[Evaluation of the effect of glass ionomer liner on microleakage of light-curing composite resin restoration]

Light-curing composite resin restorations with acid etching technique and bonding agents cannot completely reduce the degree of microleakage. One initial report by Dr. Mclean (1985) describing glass ionomers as Class V cavity liners suggested that this product was superior to a resin/dentin bond to avert marginal leakage under a light curing composite. In this study, Wu's silver staining technique was used to evaluate the effect of glass ionomer liner on microleakage of light curing composite-Silux. Twenty one caries-free human molar teeth were selected for study. The Class V cavities were prepared on the buccal and the lingual surface of each tooth. Teeth were divided into 3 groups. Group I: Scotchbond/Silux and Liner/Scotchbond/Silux. Group II: Scotchbond/Silux and Hybond. Group III: Liner/Scotchbond/Silux and Hybond. The degree of microleakage were evaluated with Dr. Going's method by three dentists. The results of this study indicate that Ketac bond Glass ionomer liner was ineffective as a restoration in resisting microleakage on the gingival wall of cavities.

Characterization of primary cell cultures derived from rat renal proximal tubules

Proximal tubules were prepared from rat kidney cortex by collagenase digestion and purified by Percoll gradient centrifugation. Their enrichment was estimated by comparing the specific activities of various cell-specific enzymes in homogenates of renal cortex and of the isolated tubules. The tubules were cultured in a 50:50 mixture of Dulbecco's modified Eagle's and Ham's F12 media supplemented with insulin, transferrin, epidermal growth factor, hydrocortisone, and prostaglandin E1. After 2 to 3 d an extensive outgrowth of epithelial cells developed from the attached tubules. After 5 to 7 d near confluent monolayers were obtained. Hormonal responsiveness, marker enzyme activities, and transport properties were determined to further characterize the primary cultures. The cultured cells exhibited increased cyclic AMP production in response to parathyroid hormone but not calcitonin or vasopressin, consistent with the absence of cells derived from distal and collecting tubules. The cells also retained significant levels of 25-hydroxyvitamin D3-1 alpha-hydroxylase, alkaline phosphatase, and gamma-glytamyl-transpeptidase, three enzymes that are primarily associated with the proximal tubule. The cultured epithelial cells also exhibit a Na+-dependent phosphate and glucose transport systems. Therefore, the cells retain many functional properties that are characteristic of proximal tubules. Thus, the primary cultures should be suitable for the study of processes that occur specifically within this segment of the rat nephron.

Inhibition by volume expansion of phosphate uptake by the renal proximal tubule brush border membrane

Clearance studies and examination of brush border membrane (BBM) vesicle transport were performed in rats that had been volume expanded by 10% of body weight. The results were compared to those obtained in control animals. The data indicate that the phosphaturia which resulted from the expansion procedure was accompanied by an inhibition of proximal BBM phosphate uptake. The BBM uptake of proline and glucose was unchanged. Furthermore, since plasma calcium did not change, the findings are compatible with the view that the membrane transport changes resulted from alterations induced by the saline loading itself, rather than (or in addition to) any changes caused by parathyroid hormone excretion.

Hyperparathyroidism and 1,25-dihydroxyvitamin D deficiency in mild, moderate, and severe renal failure

It has been postulated that hyperparathyroidism in chronic renal failure results from hypocalcemia, occurring, in part, from phosphate retention and/or deficient 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3] synthesis. However, many studies have failed to demonstrate hyperphosphatemia or low 1,25-(OH)2D levels in patients with mild renal failure. We measured creatinine clearance (CCr), fractional excretion of phosphorus (FEP), and serum phosphorus, ionized calcium, and plasma N-terminal PTH, and 1,25-(OH)2D concentrations in 21 normal subjects and 51 patients with renal failure. Patients with mild renal failure (Ccr, greater than 40 mL/min.1.73 m2) had normal mean serum phosphorus and ionized calcium and decreased mean 1,25-(OH)2D levels compared with those in normal subjects. In patients with moderate renal failure (CCr, 20-40), the mean ionized calcium level was normal, plasma PTH levels and FEP were elevated, and the decrement in 1,25-(OH)2D was more pronounced. The mean ionized calcium level was decreased only in the group of patients with severe renal failure (CCr, less than 20). The 1,25-(OH)2D values correlated positively with CCr and negatively with the log of plasma PTH and serum phosphorus concentrations. Log of plasma PTH correlated negatively with CCr and positively with FEP. The ionized calcium concentration correlated very weakly with CCr and the log of the plasma PTH level. These data demonstrate the presence of hyperparathyroidism, normocalcemia, and 1,25-(OH)2D deficiency in renal failure and are consistent with a role for 1,25-(OH)2D in the suppression of parathyroid activity through as yet unidentified mechanisms.

A space-resolved fluorometer and its application to immunoassay

A metal surface has been added into a fluorometer to reflect the excited light and to reduce the light scattering. Due to the total separation of the fluorescent signal and the noise by directing them into different spaces, the resolution could be improved by several orders of magnitude. The same metal surface could also be used for immunoassays. The detection of alpha-fetoprotein in normal rat serum and human standard serum are given as examples. The results indicate that the apparatus and the method have significant advantages.

Inhibitory effects of volume expansion performed in vivo on transport in the isolated rabbit proximal tubule perfused in vitro

To examine the renal tubular sites and mechanisms involved in the effects of hypooncotic volume expansion (VE) on renal electrolyte excretion, we performed clearance and isolated tubular perfusion studies using intact and thyroparathyroidectomized (TPTX) rabbits. We also examined the effect of VE on luminal brush border transport. In the microperfusion studies, proximal convoluted (PCT) and straight (PST) tubules were taken from rabbits without prior VE or after 30 min of 6% (body wt) VE. Acute VE increased the percentage excretion of Na, Ca, and P in TPTX animals and the percentage and absolute excretions of these ions in intact rabbits. In PST from VE animals, fluid flux (Jv) was depressed compared with Jv in PST from nonVE rabbits: Jv = 0.18 +/- 0.03, (VE) vs. 0.31 +/- 0.03 nl/mm.min, (nonVE) P less than 0.02. Phosphate transport (Jp) in the PST from VE animals was also depressed: JP = 1.58 +/- 0.10 (VE) vs. 2.62 +/- 0.47 pmol/mm.min, (nonVE) P less than 0.05. Similar results were obtained with TPTX animals. In the PCT from VE animals, Jv was decreased (0.49 +/- 0.10 (VE) vs. 0.97 +/- 0.14 nl/mm.min, (nonVE) P less than 0.02), but JP was not affected significantly. Transport inhibition was stable over approximately 90 min of perfusion. In the brush border vesicle studies, sodium-dependent phosphate transport was inhibited compared with that in control animals, at the 9-, 30-, and 60-s time points. These findings indicate that the inhibition of renal ionic transport by VE occurs in both PCT and PST and is, in part, the result of a direct effect of VE on tubular transport mechanisms.

Anti-HBc IgM in cases of hepatocellular carcinoma and cirrhosis in Taiwan

The sera of apparently healthy carriers of hepatitis B virus surface antigen enrolled in the Taiwan Prospective Study were tested retrospectively for anti-HBc IgM, to determine whether this test would be useful in predicting the development of hepatocellular carcinoma (HCC) and/or cirrhosis. In comparison with men who did not develop HCC or cirrhosis, the relative risk of those with anti-HBc IgM elevations was 3.4 and 5.6, respectively. Each of these factors was highly statistically significant, although the difference between them was not. Demonstration of anti-HBc IgM titers of greater than 1:1000 in serum probably reflects ongoing low level viral replication but not recent infection. Anti-HBc IgM appears to be a useful prognostic indicator for the future development of HCC and/or cirrhosis.

Migraine and other diseases in women of reproductive age. The influence of smoking on observed associations

From among the pregnant women in the Collaborative Perinatal Project of the National Institute of Neurological and Communicative Disorders and Stroke, we identified 508 who had migraine, and 3192 who had no history of migraine, of taking headache medication during the previous 12 months, and of headaches during the pregnancy. Migraineurs smoked more heavily and had a longer smoking history than their headache-free peers. Among migraineurs, smokers were not more likely to consume analgesics than nonsmokers. Regardless of smoking classification, more migraineurs consumed tranquilizers, amphetamines, and sleeping pills than headache-free women. Among smokers only, migraine was associated with heart disease, thrombosis/phlebitis, asthma, peptic ulcer, and pneumonia. In nonsmokers, migraine was associated with drug sensitivity and other allergies.

Volume expansion-induced changes in renal tubular membrane protein phosphorylation

The influence of volume expansion (VE) on the in vitro phosphorylation of membrane protein in the proximal brush border membrane (BBM) of the thyroparathyroidectomized (TPTX) rat was studied in the presence and absence of cyclic AMP and the results were compared to those obtained in control TPTX and intact animals. The results indicate that the cyclic AMP-independent phosphorylation of a protein band (Mr = 72,000) was stimulated both by VE and by the presence of parathyroid hormone in the circulation, whereas the cyclic AMP-dependent phosphorylation of membrane proteins (Mr = 40,000, 52,000 and 87,000) was inhibited by the same maneuvers. These findings, taken together with data previously available, which demonstrate inhibition of BBM phosphate transport following VE, may provide a link between alterations in phosphate transport in renal BBM vesicles and the phosphorylation of membrane proteins. The results further suggest that membrane protein phosphorylation may be a common mechanism by which a number of agents and maneuvers induce an inhibition of renal tubular phosphate transport.

Quantification and immunolocalization of apolipoprotein E in experimental atherosclerosis

We developed a radioimmunoassay for rabbit apolipoprotein E (apo E) for studying their plasma apo E levels and its accumulation in the aorta of rabbits fed a cholesterol diet. Delipidation of plasma did not increase the apo E immunoreactivity and this immunoreactivity was indistinguishable from that in an apo E-phospholipid complex. The antigenic determinants of apo E in lipoprotein particles were therefore fully reacted with our goat anti-apo E antibodies. In our assay system, the non-ionic detergent Tween-20 was found to be necessary to significantly reduce the non-specific binding of 125I-labeled apo E to polystyrene tubes, and yet not interfere with the assay. In rabbits (n = 6) fed a high cholesterol (1%) diet, plasma apo E increased at least 10-fold above baseline levels and reached maximal levels within 17-20 days after the onset of cho-diet feeding. These levels were sharply reduced only 10 days after resuming a normal diet. Plasma total cholesterol levels went through a similar pattern. Thus, the plasma cholesterol concentration can simply be used to monitor the increase of apo E in cholesterol-fed rabbits. All the cholesterol-fed rabbits developed atherosclerotic fatty streak lesions and apo E located mostly in the thoracic region and was significantly correlated with the accumulation of lipids in the areas of lesion. In addition, the apo E deposition was limited to the aortic areas where lipids were present. On the other hand, apo A-I was not detectable in any lesion area. Our data suggest that apo E or apo E-containing lipoproteins, may be involved in the development of atherosclerosis in cholesterol-fed rabbits.

Genetic markers of an aboriginal Taiwanese population

A group of Taiwan aborigines, the Toroko, was typed for 21 classical genetic loci. This is part of an ongoing program aimed at a comprehensive study of Taiwan aborigines. In this first paper a short summary of historical, archeological, and anthropological data in the literature is made, and results of the present survey are compared with older results from other aborigine tribes. An analysis of other neighboring populations from southeast Asia has also been carried out in order to give a preliminary answer to the question of origin of Taiwanese aborigines. Fifteen populations were studied for 13 loci by tree analysis, principal components, and isolation by distance. Tree analysis and principal component analysis gave results in fairly good agreement and indicate three major population clusters: a northeast cluster (Ainu, Korea, Japan, and Ryukyu); a southeast cluster (south China, Thailand, Vietnam, Philippines, Taiwan, and Toroko); and a third cluster including Malaya and Borneo. The positions of Polynesia, Micronesia, and Melanesia are somewhat peripheral. Analysis of the tree shows some potential cases of convergence, perhaps owing to admixture, and of divergence. The analysis of isolation by distance shows that geographic propinquity is a reasonably good predictor of general similarity in this area.

Modulation of 1,25-dihydroxyvitamin D3 receptor by phospholipids and fatty acids

The structural relationship between several lipids and their respective capacities to inhibit the specific binding of [3H]-1,25 (OH)2 vitamin D3 to chick intestinal cytosol preparations was investigated. The lipids investigated were: synthetic 3-sn-phosphatidylcholine and 3-sn-phosphatidic acid, egg yolk 3-sn-phosphatidylcholine and its corresponding phosphatidic acid, and free unsaturated fatty acids and their esters. The results indicate that at least three structural elements in the phospholipid molecule appear to be important; these are: 1) the structure of the fatty acid, 2) the anionic properties of the phospholipid phosphate group, and 3) the glycerol phosphate portion of the molecule. Our data also demonstrate that the position (1 or 2) and the amount (single vs. double) of unsaturated fatty acids in the phospholipid molecule do not play a major role in the receptor-1,25 (OH)2 vitamin D3 interaction. Furthermore, under equilibrium conditions, kinetic and Scatchard analysis suggest that phospholipids or free fatty acids may bind at a site different from the 1,25 (OH)2 vitamin D3 binding site, and therefore inhibit the hormone binding via a noncompetitive conformational change in the receptor molecule. A model for this phospholipid/free fatty acid binding site is proposed.

Prostaglandin E2 and parathyroid hormone: comparisons of their actions on the rabbit proximal tubule

Recent studies demonstrated that prostaglandin E2 (PGE2) participates in the regulation of glomerular and distal tubular function. A functional role for PGE2 on the proximal tubule has only recently been explored. Thus, we reported that PGE2 antagonizes the phosphaturic effect of PTH in the dog, which suggests that PGE2 may influence the transport functions of the mammalian proximal tubule. The present studies were designed to examine the direct effect of parathyroid hormone (PTH) and PGE2 on the fluxes of fluid (Jv) and phosphate (Jl-b PO4) in the rabbit proximal convoluted and straight tubules (PCT and PST). The activation of adenylate cyclase by the two agents was also examined. Finally, the combined effects of PTH and PGE2 on Jv and Jl-b PO4 were also studied in the PST. In the PCT, PTH (1 microgram/ml) inhibited Jv by 31% (P less than 0.05) but did not alter Jl-b PO4. PGE2 (10(-5) M) failed to act on either Jv or Jl-b PO4. In this segment, PTH stimulated adenylate cyclase but PGE2 did not. In the PST, PTH (1 microgram/ml) inhibited Jv and Jl-b PO4 by 34 and 20%, respectively (P less than 0.01). PGE2 (10(-5) M) also inhibited Jv and Jl-b PO4, by 33 and 12%, respectively (P less than 0.02). In contrast, PGF2 alpha, a related prostanoid, failed to influence these transport parameters. In the PST, PTH activated adenylate cyclase but PGE2 failed to do so. When both PTH (1 microgram/ml) and PGE2 (10(-7) M) were present simultaneously, Jv and Jl-b PO4 were comparable to that seen during control collections.(ABSTRACT TRUNCATED AT 250 WORDS)

An image transform coding scheme based on spatial domain considerations

Image transform coding is first briefly reviewed using conventional viewpoints. Then a new spatial domain interpretation is given to image transform coding. An improvement based on this viewpoint for the Fourier transform coding, which possesses simple spatial domain relations, is presented.

Parathyroid hormone: effects of the 3-34 fragment in vivo and vitro

The biologically active fragment ofparathyroid hormone, consisting of residues 1-34, and its in vitro antagonist, fragment 3-34, were administered separately or in combination to chronically thyroparathyroidectomized dogs. These fragments were also studied in vitro with dog renal cortical membranes. Fragment 3-34 inhibited the stimulation of adenylate cyclase by fragment 1-34 in vitro, but had no agonist or antagonistic effects on renal phosphate transport in vivo.

Potentiation by calcium of the proximal tubular transport effects of parathyroid hormone

Previous studies from this laboratory have demonstrated that a low ('physiological') dose of parathyroid hormone (PTH) effects a phosphaturia in chronically thyroparathyroidectomized (TPTX), hypocalcemic dogs, similar in magnitude to that seen in normal intact animals, without altering proximal tubular reabsorption. In addition, cyclic AMP did not increase following this amount of PTH, despite the phosphaturia. Since calcium is an important modulator of transport events, we studied the effects of restoring serum calcium (Ca) to normal before administering a physiological dose of PTH (0.3-0.5 U/kg). In hypocalcemic dogs given only physiological amounts of PTH, percentage phosphate excretion (%EPO4) rose from 3.81 +/- 1.48 to 18.29 +/- 5.69% (p less than 0.025) without any alteration in proximal tubular function. Ca infusion alone likewise did not change %EPO4 or proximal tubular transport. However, calcium-infused dogs given a physiological dose of PTH showed a reduction in proximal tubular fractional phosphate reabsorption from 0.73 +/- 0.04 to 0.63 +/- 0.04 (p less than 0.005), as well as an increase in %EPO4 (from 5.64 +/- 1.69 to 15.86 +/- 2.82%, p less than 0.001), without any increase in urinary or tissue cyclic AMP. We conclude that the elevation of the serum Ca to normal restores the ability of PTH in physiological amounts to alter proximal tubular PO4 transport. The data also suggest that this action of PTH is mediated by Ca, rather than by the adenylate cyclase system.

Occupational exposure in the academic sector of the R.O.C

This paper deals with occupational exposure in the academic sector of the Republic of China during the past two decades. The Tsing-Hua film badges were used for personnel monitoring. The radiation sources available in the research institutes and universities are listed and illustrated. The number, sex, age and per capita dose equivalent for the radiation workers in the past 21 yr are analyzed. The radioisotope production rate and the dose equivalent received by the workers are compared, and the results indicate that radiation protection has been greatly improved during last decade.

Participation of the renin system in treatment-resistant hypertension as measured by acute blockade of the angiotensin converting enzyme

The acute blood pressure response to the angiotensin converting enzyme inhibitor, captopril, was used to measure participation of the renin-angiotensin system in treatment-resistant hypertension. By 2 h after a single 25-mg oral captopril dose in patients still receiving a diuretic-vasodilator-beta-blocker combination, systolic and diastolic blood pressures had fallen significantly; the decrease in diastolic pressure correlated with the control (immediately pre-captopril) plasma renin activity (r = 0.64, p less than 0.001). Apart from its possible contribution to the underlying hypertension, this captopril-identified renin component may have reflected diuretic and vasodilator-induced renin stimulation that could not adequately be prevented by the renin-lowering properties of the beta-blocker. Captopril, and perhaps other specific antirenin drugs, therefore, may be valuable adjuncts to treatment in patients with hypertension refractory to conventional therapy.