Differences in gastric emptying between highly selective vagotomy and posterior truncal vagotomy combined with anterior seromyotomy

Gastric emptying has been reported to be both delayed and unchanged following posterior truncal vagotomy combined with anterior seromyotomy (PTV + AS). When compared to highly selective vagotomy (HSV), our clinical experience was that PTV + AS not uncommonly produced postprandial distress. We studied gastric emptying of both liquids and solids 3 and 12 months following HSV and PTV + AS to determine what if any differences there were in gastric emptying between the two procedures. We compared these results with those from studies done in both normal subjects and unoperated duodenal ulcer patients. In 26 duodenal ulcer patients with perforation (n = 18) or bleeding (n = 8), who were treated with HSV (n = 10) or PTV + AS (n = 16), gastric emptying of liquids and solids was evaluated at 3 months and 12 months postoperatively. At 3 months, gastric emptying of liquids was delayed in both the HSV and PTV + AS groups as compared to values in both normal subjects and unoperated duodenal ulcer patients. The emptying of solids was markedly delayed by PTV + AS in contrast to HSV at 3 months (167.1 +/- 28.4 minutes vs. 79.9 +/- 16.7 minutes; P <0.05). The lag duration was not affected. A limited number of patients studied at 12 months showed similar and near-normal emptying of solids in both the HSV and PTV + AS groups (67.5 +/- 7.0 minutes vs. 70 +/- 6.6 minutes). PTV + AS in contrast to HSV produces more marked delayed emptying of liquids and solids at 3 months; with time (1 year) these values return to near normal.

Treatment of large skeletal defects in the lower extremities using double-strut, free vascularized fibular bone grafting

This article reports on the use of double-strut, free vascularized fibular grafts to treat six patients with infected nonunion or traumatic bone loss in the femur or tibia after prolonged treatment and multiple operations. The defects were 6-13 cm long. Five patients achieved solid union within 6 months, and one patient required additional cancellous grafting to achieve union at the distal end of the fibula. One patient experienced a stress fracture due to strenuous exercise, and union was achieved 3 months after reapplying an external fixator. Although three patients had some restricted knee motion, all patients had a satisfactory outcome in regard to walking, and no limb-length discrepancies were noted in any patient.

Vascularized iliac bone graft for displaced femoral neck fractures in young adults

From November 1989 to September 1994, a total of 26 patients (18 men and 8 women) with acute displaced femoral neck fractures were treated with closed reduction and Knowles pinning combined with vascularized iliac bone grafting. Mean patient age was 37.5 years (range: 24-48 years). The mean time interval from injury to surgery was 3.6 days (range: 1-10 days). One patient experienced loss of the reduction at 6 weeks postoperatively and subsequently went on to hip replacement. Mean follow-up for the remaining 25 patients was 56.2 months (range: 20-78 months). All fractures united within 4 months. The average union time was 3.3 months. Plain radiographs confirmed the presence of avascular necrosis in 2 patients during the final follow-up; 1 of these patients developed systemic lupus erythematous 1 year after the fracture and had been treated with high doses of corticosteroid. Functional and radiographic results were satisfactory in the remaining patients.

Enhanced tolerance to light stress of transgenic Arabidopsis plants that express the codA gene for a bacterial choline oxidase

Arabidopsis thaliana was transformed with the codA gene from Arthrobacter globiformis. This gene encodes choline oxidase, an enzyme that converts choline to glycinebetaine. The photosynthetic activity, monitored in terms of chlorophyll fluorescence, of transformed plants was more tolerant to light stress than that of wild-type plants. This enhanced tolerance to light stress was caused by acceleration of the recovery of the photosystem II (PS II) complex from the photo-inactivated state. The transformed plants synthesized glycinebetaine, but no changes were detected in the relative levels of membrane lipids or in the relative levels of fatty acids in the various membrane lipids. Transformation with the codA gene increased levels of H2O2, a by-product of the reaction catalyzed by choline oxidase, by only 50% to 100% under stress or non-stress conditions. The activity of ascorbate peroxidase and, to a lesser extent, that of catalase in transformed plants were significantly higher than in the wild-type plants. These observations suggest that H2O2 produced by choline oxidase in the transformed plants might have stimulated the expression of H2O2 scavenging enzymes, with resultant maintenance of the level of H2O2 within a certain limited range. It appears that glycinebetaine produced in vivo, but not changes in membrane lipids or in the level of H2O2, protected the PS II complex in transformed plants from damage due to light stress.

Anaerobic treatment of poultry mortalities in a modified LB-UASB system

The efficiency of a modified LB-UASB system in treating poultry mortalities was tested. The anaerobic digestion system consisted of an upflow anaerobic sludge blanket (UASB) and three leachbeds (LB). The LBs were batch-loaded with mortality to be treated. The LBs were sequentially connected to the UASB, one at a time. Leachate from a connected LB was fed to the UASB while effluent from the UASB overflowed to the LB to form a closed loop. When the concentrations of leachate from the first LB became so low that it could no longer support accelerated methanogenesis in the UASB, it was replaced by a second LB containing a new batch of mortality. Concentrated leachate from the second LB allowed the UASB to continue operation at higher loading rates (LR), thus, alleviating the problems of lengthy LR build-up and idling time. Meanwhile, the off-lined LB continued to mature independently. The UASB was connected to a third LB when the second LB entered accelerated methanogenesis phase. Operation of the first LB was stopped when CH4 production rate from it became marginal. The remaining solids material was replaced by a new batch of mortality to start the second cycle. The first cycle was completed when fermentation in the third LB was ended. The modified LB-UASB system performed significantly better than the original system. It took an average of only 86 days to treat one batch of mortality, yet, the methane yield was about 40% higher. The average methane yield was 0.28 m3 (kg wet weight)-1. Strategies to optimize system performances are discussed.

A Markov chain model to assess the efficacy of screening for non-insulin dependent diabetes mellitus (NIDDM)

BACKGROUND

The high prevalence and severe consequences of non-insulin dependent diabetes mellitus (NIDDM) in Taiwan calls for urgent measures to detect this disease in the asymptomatic phase. However, the efficacy of early detection of NIDDM is highly dependent on its natural history from the disease-free state, through the asymptomatic to the symptomatic phase and death from NIDDM or other causes.

METHODS

In order to project the above progression, a five-state illness-and-death Markov chain model was proposed to estimate these transition parameters using data from two rounds of a blood sugar screening programme for NIDDM in Puli, in central Taiwan.

RESULTS

Results showed that the annual incidence for asymptomatic NIDDM was 10.67 per 1000 (95% CI: 8.26-13.79) and the average duration between the asymptomatic and symptomatic phases (the sojourn time) was 8 years (95%CI: 5.74-11.29). The 10-year survival rate for asymptomatic NIDDM (79.35%) was better than that for symptomatic NIDDM (69.45%). Prediction of deaths from NIDDM was performed to assess how the efficacy of screening for NIDDM varied by different screening frequencies (annual, biennial, 4-yearly and the control group). Results indicated there is no substantial difference in mortality reduction from NIDDM among the annual, biennial and 4-yearly screening regimens. However, a 4-yearly screening regimen significantly reduced deaths from NIDDM by 40% (95% CI: 26-51%).

CONCLUSIONS

A long sojourn time and the substantial reduction in mortality suggest that a 4-yearly screening regime for NIDDM would be most effective and feasible in Taiwan. The proposed five-state Markov chain model can be applied to other similar NIDDM screening projects.

Pseudoxanthoma elasticum. Case report

Pseudoxanthoma elasticum is an uncommon disorder of elastin with characteristic skin laxity. Rhytidectomy of the excessive redundant skin is necessary for cosmetic improvement, and reports of surgical management are rare. We report a case of pseudoxanthoma elasticum with involvement of neck, axillae, breasts, abdomen, thighs, and perineum, together with angioid streaking of fundi. Rhytidectomy of the lax cervical skin was undertaken with satisfactory results after a 13 month follow-up. We have reviewed other published reports to obtain a better understanding of the genetics, histopathology, vascular and ophthalmological manifestations, and also the surgical implications of pseudoxanthoma elasticum.

Acute closed humeral shaft fractures treated with dynamic compression plate

BACKGROUND

To define the efficacy of dynamic compression plates (DCPs) for the treatment of closed humeral shaft fractures.

METHODS

A total of 165 patients with closed humeral shaft fractures were studied retrospectively. There were 120 patients who underwent open reduction and internal fixation with DCPs and no bone grafting (BG). Forty-five patients received the same procedures with BG. The mean follow-up period was 93 months.

RESULTS

In the DCP without BG group, the average blood loss was 350 ml, operation time was 105 minutes, hospital stay was 8.5 days and fracture union time was 13.5 weeks. In the DCP with BG group, the average blood loss was 525 ml, operation time was 115 minutes, hospital stay was 7.9 days and fracture union time was 9.2 weeks.

CONCLUSIONS

In our experience, DCPs are effective for surgical fixation of humeral shaft fractures. Prophylactic BG is recommended for cases with more comminution.

Efficacy of breast-cancer screening for female relatives of breast-cancer-index cases: Taiwan multicentre cancer screening (TAMCAS)

Although the efficacy of mass screening for breast cancer has been established in Western countries, this strategy may be too costly for other countries with low incidence rates of breast cancer. We propose an alternative approach to screen female relatives of breast-cancer-index cases from hospitals, as part of the Taiwan multicentre cancer screening (TAMCAS) project. In order to assess the efficacy of this programme, and to estimate how often this high-risk group should be screened, we firstly elucidated the disease natural history from the pre-clinical screen-detectable phase (PCDP) by estimating the relevant parameters based on Markov chain models. We further predicted the proportion of interval cancers, advanced breast tumours and deaths from breast cancers by different screening frequencies. Results showed that the estimate of mean sojourn time (MST) for this high-risk group (1.9 years; 95% CI.1.18-4.86) is shorter than that for females from the general population. Analysis of a surrogate endpoint based on regional lymph-node spread and tumour size shows that annual screening for this high-risk group is likely to confer a significant 33% reduction in breast-cancer mortality compared with a non-significant 25 and 20% reduction for 2 yearly and 3-yearly screening regimes respectively. The above results suggest that a 1-year interval might be appropriate for this high-risk group. A simple cost-effectiveness analysis indicates a cost per year of life saved for mass screening ($72,480) 15 times that for the high-risk group ($4,851 ).

Partial or complete circular duodenectomy with highly selective vagotomy for severe obstructing duodenal ulcer disease: an initial experience

OBJECTIVE

To evaluate partial and complete circular duodenectomy combined with highly selective vagotomy (HSV) for relief of gastric retention.

DESIGN

A retrospective, case-comparison study.

SETTING

University hospital referral center.

PATIENTS

Eighteen patients with severe obstructing duodenal ulcer disease defined by failure of a saline load test and endoscopic narrowing of the gastric outlet to 5 mm or less.

METHODS

In patients with severe obstructing ulcer the diseased duodenal segment was excised with electrocautery (partial excision, 10 patients; complete excision, 8 patients). An HSV was then done. Postoperative fasting gastric residuum measurement and measurement of the emptying of liquids and solids was done at 3 months and patients were weighed at 3 and 12 months.

RESULTS

No patient experienced postoperative gastric retention or required reoperation in a 2-year follow up. The early emptying of liquid (20 minutes) in complete circular duodenectomy plus HSV was more rapid than in normal subjects and duodenal ulcer patients. The emptying of solids was slightly delayed in partial duodenectomy plus HSV compared with duodenal ulcer patients but not with normal controls. The emptying of solids in duodenal ulcer patients was more rapid than in normal controls. Weight gain was excellent at 3 and 12 months.

CONCLUSION

Partial duodenectomy and complete circular duodenectomy plus HSV are more efficacious than alternative nonresective procedures in restoring gastric emptying to near normal and restoring weight in patients with obstructing duodenal ulcer.

Heterotopic ossification after cemented or uncemented bateman bipolar hemiarthroplasty

BACKGROUND

This is a retrospective study to evaluate the incidence of heterotopic ossification (HO) in cemented and uncemented femoral neck fractures treated with Bateman bipolar hemiarthroplasty.

METHODS

From October 1985 to July 1990, there were 451 cases of displaced intracapsular fractures of the femoral neck treated with Bateman bipolar hemiarthroplasty (261 uncemented vs 190 cemented) at the Veterans General Hospital-Taipei.

RESULTS

After an average follow-up of 46 months, there was more HO in the cemented group than in the uncemented group (p = 0.014, chi-squared test). The average surgical time was approximately 20 minutes longer and the average blood loss was approximately 160 ml more in the cemented Bateman bipolar hemiarthroplasty group.

CONCLUSIONS

HO formation is more common in cemented Bateman bipolar hemiarthroplasty than in the uncemented procedure. The incidence of HO is not related to age or sex.

Regulation of extracellular calcium-activated cation currents by cAMP in parathyroid cells

Parathyroid cells express Ca2+-sensing receptors that couple changes in the extracellular Ca2+ concentration ([Ca2+]o) to increases in the intracellular free Ca2+ concentration ([Ca2+]i) and to the suppression of parathyroid hormone secretion. Using whole cell patch clamping, we previously identified voltage-independent Ca2+-conducting currents in bovine parathyroid cells that increased with rising [Ca2+]o and were blocked by Cd2+ and nifedipine. Because cAMP-dependent phosphorylation regulates dihydropyridine-sensitive Ca2+ channels in other systems, we tested whether cAMP modulates these currents. At 0.7 mM Ca2+, nonselective Ca2+-conducting currents were suppressed by 30-50% when the recording pipette was perfused with cAMP. High-[Ca2+]o-induced increases in membrane currents were also abrogated. The effects of cAMP were reversible and dose dependent (3 x 10(-9) to 3 x 10(-3) M) and required ATP in the pipette solution. Perfusion of the cell interior with the catalytic subunit of protein kinase A mimicked the effects of cAMP, as did perfusion of the bath with the adenylate cyclase activator forskolin. These findings support the idea that cAMP-dependent phosphorylation suppresses high-[Ca2+]o-induced cation currents and may play a role in regulating ion fluxes in parathyroid cells.

Vascularized iliac bone graft for treating avascular necrosis of the femoral head

BACKGROUND

Nontraumatic avascular necrosis of the femoral head (ANFH) is a common disorder causing disability of the hip joint. The means for optimally treating this disease are still controversial. In this study we evaluated the relatively new technique of vascularized iliac bone grafting for treating ANFH.

METHODS

From March 1990 to March 1992, 17 hips (15 patients) with ANFH were treated using the vascularized iliac bone grafting technique in our hospital. The patients included 12 men and three women, with an average age of 38 years. Steinberg's classification was used to categorize the severity of hip disease. The clinical results were classified as excellent, good, fair and poor according to symptoms, hip function and roentgenographic changes after surgery. Life-table analysis was applied to assess graft survival and the log rank test was used to compare statistical differences between the steroid-related and nonsteroid-related groups.

RESULTS

Cumulatively, 16 hips (14 patients), excluding one patient (one hip) lost to follow-up, were clinically evaluated for an average of 68 months. Among 12 hips at Steinberg stage II, eight progressed to stage IV, three to stage III and only one remained at stage II. Although most hips at stage II showed mild to moderate disease progression on plain radiography, 58% of the hips (7/12) that progressed to less than IVb showed good to excellent results. In the three hips at stage III, one progressed to stage IVa and two to stage V. In the two hips at stage IV, one remained at stage IV at final follow-up and the other was lost to follow-up. The steroid-related and nonsteroid-related groups did not differ with respect to clinical results. Both groups had 63% (5/8) good to excellent results (p > 0.05, log rank test). Only four hips were converted to prosthetic arthroplasties at final follow-up. Overall, 63% (10/16) of the hips had good to excellent results, 12% had fair results and 25% had poor results. Graft survival after seven years of follow-up was 63%.

CONCLUSIONS

While treatment of ANFH still poses a challenge to orthopedic surgeons, the vascularized iliac bone grafting technique is a clinically acceptable option for treating the early stages of ANFH.

Performances of mesophilic anaerobic digestion systems treating poultry mortalities

A closed-loop anaerobic digestion system consisting of a leachbed (LB) and an upflow anaerobic sludge blanket (UASB) was tested as an alternative for the disposal of poultry mortalities. This paper compares the performances of three LB-UASB treatment systems with different initial moisture contents in the LBs. Each LB was loaded with one chicken and 5, 10 or 18 liters of water. The LBs initially carried out he hydrolysis/acidification phase while the UASBs the methanogenesis phase. Due to repeated inoculation by the UASBs, the LBs with 10 and 18 liters of water started producing methane on day 5, while the one with 5 liters of water on day 19. However, methane production rates were low before day 40 for the LB with 10 liters of water and day 60 for the other LBs. Methane production gradually improved as the LBs continued to receive ungranulated sludge from the UASBs. The LBs eventually became balanced methane reactors. Continued balanced fermentation in the LBs resulted in leachates with very low substrate concentrations that could no longer support high-rate methanogenesis in the UASBs. Consequently, methane production rates from the UASBs decreased quickly while that from the LBs reached peak levels. Cumulative methane production from each LB eventually exceeded that from its connecting UASB. After 118 days of digestion, 414, 437 and 470 liters of methane were produced from the three systems, respectively. Cumulative methane production from the LBs with 5 and 18 liters of water accounted for 63% of the total methane produced from their respective systems. The LB with 10 liters of water produced 75% of the total methane from that system. Methane yields ranged from 0.485 to 0.554 m3 (Kg TS)-1. About 86% of the initial dry weight was biodegraded. All three systems performed very well with little operational problems. Overall, the systems that started with 10 liters of water in the LB performed the best. Strategy for enhancing system performances and implementing farm applications are discussed.

Effect of antioxidant in endothelial cells exposed to oxidized low-density lipoproteins

Antioxidants such as probucol and alpha-tocopherol have been shown to attenuate the oxidation of low-density lipoproteins (LDL) and atherosclerotic lesions in animal models of atherosclerosis. The purpose of this study is to determine the protection effect of antioxidants on endothelial cells when exposed to oxidized and native LDL. In a cell-free system, we found that probucol, alpha-tocopherol, and ascorbic acid inhibited copper-induced LDL oxidation by a dose-dependent fashion (from 1 microM to 10 mM). In porcine aortic endothelial cells, antioxidants alone did not change basal endothelin-1 (ET-1) secretion. When porcine aortic endothelial cells were exposed to LDL and oxidized-LDL, both of them stimulated ET-1 secretion dose-dependently, whereas oxidized-LDL elicited higher ET-1 secretion. However, probucol, alpha-tocopherol, and ascorbic acid did not prevent LDL or oxidized-LDL induced ET-1 secretion. Furthermore, nimodipine inhibited both of native and oxidized LDL induced ET-1 secretion. Since Ca2+ channel blocker reduced the elevation of induced ET-1 secretion, the [Ca2+]i is possibly involved for the regulation of ET-1 secretion. Our results suggest that antioxidants can only prevent the oxidation of LDL rather than oxidized and native LDL-induced ET-1 secretion in vascular endothelial cells. The increase in the [Ca2+]i of endothelial cells through the opening of voltage-dependent Ca2+ channels may be involved in the LDL-induced ET-1 release.

Coupling of calcium receptors to inositol phosphate and cyclic AMP generation in mammalian cells and Xenopus laevis oocytes and immunodetection of receptor protein by region-specific antipeptide antisera

Ca2+ and other divalent cations modulate parathyroid hormone secretion by interacting with cell-surface Ca2+-sensing receptors (CaRs). We assessed the ability of these receptors to couple to Ca2+ mobilization, inositol phosphate (InsP) accumulation, and cyclic AMP production in different expression systems. In Xenopus laevis oocytes injected with bovine parathyroid CaR cRNA, the addition of extracellular cations to 1.5 mM Ca2+, 5.5 mM Mg2+, or 10 microM Gd3+ significantly increased 45Ca efflux (p < 0.01). InsP accumulation also increased dramatically when adding these cations to human embryonic kidney (HEK) 293 cells stably transfected with wild-type bovine parathyroid CaR cDNA. Raising the extracellular [Ca2+] ([Ca2+]o) from 0.1 to > 1.4 mM in oocytes and to > 1.0 mM in HEK 293 cells stimulated significant increments in 45Ca efflux and InsP accumulation, respectively (p < 0.05). In contrast, Ca2+ and Mg2+ increased InsPs to a lesser extent in COS 7 cells transiently transfected with CaR cDNA. In HEK 293 cells stably expressing CaR cDNA, there were significant reductions in cAMP content when adding high Ca2+, Mg2+, Gd3+, or the CaR modulator NPS R-467. Three region-specific anti-CaR peptide antisera immunoblotted bands of approximately 140 and 155 kDa in membranes from CaR-transfected HEK 293 cells and bovine parathyroid tissue. Immunocytochemistry demonstrated strong cell-surface staining in CaR-transfected HEK 293 cells and parathyroid tissue, which was absent when antisera were preabsorbed with CaR peptides. These results indicate that the activation of the recombinant CaR by extracellular Ca2+ can couple negatively to adenylate cyclase but positively to phospholipase C (PLC), the latter at physiological [Ca2+]o.

Closed humeral shaft fractures: a prospective evaluation of surgical treatment

OBJECTIVE

We tried to define the roles of the rigid dynamic compression plate (DCP) and the semi-rigid Ender nail (EN) in the treatment of closed humeral shaft fractures.

DESIGN

A prospective, randomized clinical study was performed with detailed comparison parameters.

MATERIALS AND METHODS

Ninety-one closed humeral shaft fractures were treated. Randomly, 30 humeri were treated with open reduction and internal fixation with DCP and no bone grafting (BG), 29 were treated with the same procedure but with BG, and 32 were treated with closed reduction and internal fixation with Ender nails. The average follow-up period was 32 months (range, 13-54 months).

MEASUREMENTS AND MAIN RESULTS

In the group with DCP without BG, the average blood loss was 270 mL, operation time was 92 minutes, hospital length of stay was 6.5 days, and union time was 12.5 weeks. In the group with DCP with BG, the average blood loss was 325 mL, operation time was 108 minutes, hospital length of stay was 6.9 days, and union time was 9.4 weeks. In the EN group, the average blood loss was 114 mL, operation time was 54 minutes, hospital length of stay was 5.6 days, and union time was 9.9 weeks. Analysis of variance and Fisher's exact test were used to evaluate the statistical significance.

CONCLUSION

In our experience, for humeral shaft fractures fixed surgically, EN is better than DCP without BG. When DCP is chosen for the means of fixation, prophylactic BG is recommended, especially in cases with more comminution.

Segmental tibial fractures treated with interlocking nails. A retrospective study of 33 cases

We treated 33 segmental tibial fractures with interlocking nails between 1986 and 1991. All fractures were managed with calcaneal traction, closed reduction, reaming and fixation with a Grosse-Kempf interlocking nail. The patients were followed for at least 15 months. The mean duration to union was 17 (12-20) weeks for the distal fractures and 20 (12-34) weeks for the proximal ones. There were only 3 cases of delayed union of the proximal fracture, 2 of which united after dynamization by removal of distal screws and 1 after autogenous bone grafting. There were 2 cases of deep infection, which were diagnosed after the fractures were united. The infection was treated with removal of the nail, reaming, and antibiotic treatment intravenously for 2 weeks and orally for 4 weeks. All patients returned to their previous activity level. We conclude that segmental tibial fractures can be treated with an interlocking nail and have a high rate of union and a low complication rate.

Immunomagnetic isolation of islets from the rat pancreas

Islets were selectively isolated from rat pancreatic digests using magnetic microspheres coated with anti-islet monoclonal antibodies. The isolation process was optimized as a function of bead concentration and time of incubation with the tissue digest. Apparent and normalized islet yields of 92 +/- 6% and 81 +/- 7%, respectively, were obtained by incubating the digests with 10(7) beads/mL for 40 min followed by isolation of the bead-coated islets under a magnetic field. While some fragmentation occurred, the isolation process did not alter islet functionality as demonstrated by an insulin secretion response to glucose stimulation equivalent to that of handpicked controls. The technique is fast, reproducible, and potentially scaleable to larger pancreases as a secondary purification step.

Parathyroid Ca(2+)-conducting currents are modulated by muscarinic receptor agonists and antagonists

Parathyroid cells express Ca(2+)-conducting cation currents, which are activated by raising the extracellular Ca2+ concentration ([Ca2+]o) and blocked by dihydropyridines. We found that acetylcholine (ACh) inhibited these currents in a reversible, dose-dependent manner (50% inhibitory concentration approximately equal to 10(-8) M). The inhibitory effects could be mimicked by the agonist (+)-muscarine. The effects of ACh were blunted by the antagonist atropine and reversed by removing ATP from the pipette solution (+)-Muscarine enhanced the adenosine 3',5'-cyclic monophosphate (cAMP) production by 30% but had no effect on inositol phosphate accumulation in parathyroid cells. Oligonucleotide primers, based on sequences of known muscarinic receptors (M1-M5), were used in reverse transcriptase-polymerase chain reaction (RT-PCR) to amplify receptor cDNA from parathyroid poly (A)+ RNA. RT-PCR products displayed > 90% nucleotide sequence identity to human M2- and M4-receptor cDNAs. Expression of M2-receptor protein was further confirmed by immunoblotting and immunocytochemistry. Thus parathyroid cells express muscarinic receptors of M2 and possibly M4 subtypes. These receptors may couple to dihydropyridine-sensitive, cation-selective currents through the activation of adenylate cyclase and ATP-dependent pathways in these cells.

Mechanisms of bradykinin-induced insulin secretion in clonal beta cell line RINm5F

We investigated the mechanisms underlying bradykinin (BK)-induced rise in intracellular Ca++ concentration [Ca++]i and insulin secretion using clonal beta cell line RINm5F. Incubation with a range of concentrations of BK increased in concentration-dependent manners both insulin secretion (BK of 10 nM to 10 microM) and [Ca++]i (BK of 100 nM to 100 microM). In Ca++-containing medium, BK (1 microM) induced a biphasic [Ca++]i rise, which was characterized by a Ca++ peak and a sustained Ca++ phase. In the Ca++-free medium, BK failed to increase insulin secretion and induced only a Ca++ peak without the sustained Ca++ phase. Thapsigargin (1 microM), an inhibitor of the Ca++ pump in the endoplasmic reticulum, abolished the Ca++ peak and the sustained phase. Nimodipine (1 microM), a voltage-dependent Ca++ channel blocker, abolished the BK-induced sustained Ca++ phase and inhibited BK-induced insulin release. The BK1 receptor agonist des-Arg9-BK (1 microM) did not change either [Ca++]i or insulin secretion. Both the BK-induced insulin secretion and rise in [Ca++]i were inhibited by a selective BK2 receptor antagonist, HOE 140 (3.3-100 nM), in concentration-dependent manners but were not by a BK1 receptor antagonist des-Arg9,Leu8-BK (1 microM). Pretreatment with pertussis toxin (0.1 microg/ml) did not block the BK-induced insulin secretion or increase in [Ca++]i. U-73122 (4, 6 and 8 microM), a phospholipase C inhibitor, antagonized both the BK-induced insulin secretion and the increase in [Ca++]i in a concentration-dependent and parallel manner. BK increased intracellular concentrations of inositol-1,4,5-trisphosphate (IP3). Neither (p-amylcinnamoyl)anthranilic acid (100 microM), a phospholipase A2 inhibitor, nor N(G)-nitro-L-arginine methylester (100 microM), a nitric oxide synthase inhibitor, inhibited these effects of BK. Taken together, these findings suggested that in beta cells, BK activates BK2 receptors, which, in turn, activate a pertussis toxin-insensitive G protein. The G protein couples to phospholipase C, which promotes the formation of IP3 and diacylglycerol. IP3 releases [Ca++]i from the intracellular Ca++ store, probably the endoplasmic reticulum, which triggers Ca++ influx via voltage-dependent Ca++ channels and thus increases insulin secretion.

Effect of U-73122 on calcium channel activity in porcine myometrial cells and pancreatic beta-cell line RINm5F

AIM

To study the effect of U-73122, putative phospholipase C (PLC) inhibitor, on cytosolic Ca2+ concentration ([Ca2+]i) and voltage-dependent calcium channels (VDCC).

METHODS

To record whole cell calcium current (ICa) by perforated patch-clamp and to measure cytosolic free calcium concentration ([Ca2+]i) with Fura-2.

RESULTS

U-73122 inhibited KCl-induced and Bay-K-8644-induced increase in [Ca2+]i dose-dependently. U-73122 decreased markedly depolarization-induced ICa both in RINm5F and porcine myometrial cells in a concentration-dependent manner. The effect of U-73122 was more potent in porcine myometrial cells than that in RINm5F cells. U-73343 (an analog of U-73122), that does not inhibit PLC, also reduced the ICa by 50%.

CONCLUSION

U-73122 inhibited VDCC and [Ca2+]i in both RINm5F and porcine myometrial cells.

Core decompression in treating ischemic necrosis of the femoral head

BACKGROUND

The application of core decompression in the treatment of ischemic necrosis of femoral head (INFH) is to preserve the joint at early stage of the disease. Although excellent results have been obtained in many series, its effectiveness is questionable because of high rates of failure. This study is to evaluate the effectiveness of this technique in our patients with INFH receiving core decompression as the sole treatment.

METHODS

Although 91 patients were treated with core decompression in Veterans General Hospital-Taipei from 1980 to 1993, only 71 were considered as the valid cases after having been followed for 24 to 165 months (mean 56.7 months). Of 84 hips treated, 49 hips were steroid induced, 20 idiopathic, 14 alcohol related, and one related to trauma. Twenty-five hips were at Steinberg stage I, 32 at stage II, nine at stage III, 17 at stage IV, and one at stage VI.

RESULTS

The results were poor in 22 (26.19%) hips since the patients required hip prosthesis. Fair results were rated in 37 (44.05%) hips since progressive collapse occurred in the femoral head and the patients suffered from moderate hip pain. Good results were found in nine (10.71%) hips since the lesion showed no progression and the patients had only occasional pain. Excellent results were obtained in 16 (19.05%) hips since the patients had no pain and the lesion had no progressive change. The satisfactory rate in the nonsteroid-related hips (33% or 12/35) was significantly higher than in the steroid-related hips (27% or 13/49). The overall satisfactory result was only 30%.

CONCLUSIONS

Although core decompression may not be effective in preventing progression of INFH, it may relieve temporary pain and delays the need for hip arthroplasty in some patients.

[A study on the risk factors of Binswanger's leukoencephalopathy (BE)]

A matched case-control study (1:1) was carried out among 122 hospitalized patients with Binswanger's leukoencephalopathy to explore the possible risk factors of BE. Data collected were processed with conditional logistic regression analysis. Individual logistic analysis showed that family history of vascular dementia, history of hypertension, diabetes, coronary heart disease, transient cerebral ischemic attacks (TIAs), cerebral ischemia, cerebral hemorrhage, renal disfunction, alcohol intake smoking were risk factors while healthy life style played protective effect. Body weight index, average family income, education level and type A behavior scores did not show close relations with BE. Multiple regression analysis showed that hypertension, TIAs, coronary heart disease, diabetes and family history of vascular dementia were independent risk factors.

Different DNA contact schemes are used by two winged helix proteins to recognize a DNA binding sequence

The hepatocyte nuclear factor 3 (HNF-3)/fork head (fkh) family contains a large number of transcription factors which recognize divergent DNA sequences via a winged-helix binding motif. In this report we present studies on the DNA binding properties of winged-helix HNF-3/fkh homologues 1 (HFH-1) and 2 (HFH-2) which recognize a shared DNA binding site with different affinities. To explore how HFH-1 and HFH-2 proteins recognize this DNA binding sequence, the binding affinities of these two HFH proteins toward a series of DNA sites containing a single strand trimer loop insertion at different positions were studied. This insertion induces a bend of approximately 80 degrees in the DNA binding site (prebending). HFH-1 and HFH-2 were shown to recognize DNA sites prebent at many nucleotide positions on both strands of the DNA sequence. Both HFH-1 and HFH-2 were more sensitive to mismatch insertions on the sense strand of the DNA binding site, especially within the AAAATAAC sequence. Our data suggest that the recognition helix (helix 3) recognizes the AAAATAAC sequence and that the helix 3/DNA interaction results in bending of the DNA which narrows the major groove in the AAAATAAC sequence. Furthermore, the binding affinities of HFH-1 and HFH-2 toward DNA binding sites with base-pair reversion in the AAAATAAC sequence was also investigated. Different patterns of response from HFH-1 and HFH-2 to both prebent and base-pair reverted binding sites was observed. Our results demonstrate that even two highly conserved members of the winged-helix family may contact the same DNA sequence differently.