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.

Alpha2-adrenergic receptor-mediated Ca2+ influx and release in porcine myometrial cells

We studied the mechanisms underlying alpha2-adrenergic receptor (AR)-mediated increase in intracellular free calcium ([Ca2+]i) in freshly dispersed myometrial cells from sows in the luteal phase of the estrous cycle. After the blockade of beta-ARs with propranolol, epinephrine increased [Ca2+]i dose-dependently in both the presence and absence of extracellular Ca2+. The rank order of alpha antagonists in inhibiting [Ca2+]i response to epinephrine was yohimbine > WB4101 >> prazosin in both the presence and absence of extracellular Ca2+, suggesting that epinephrine acts on alpha(2A)-ARs to increase Ca2+ influx as well as Ca2+ release from intracellular stores. Thapsigargin, the blocker of the Ca2+ pump in the sarcoplasmic reticulum, abolished the release but did not affect the influx. Pertussis toxin (PTX) inhibited the influx but failed to change the release. Nimodipine, an L-type Ca2+ channel blocker, nearly abolished the influx. The peak increase in [Ca2+]i caused by epinephrine was reached within 20 sec of administration. Intracellular cAMP concentrations were also decreased at 20 sec post-epinephrine. Epinephrine enhanced the L-type Ca2+ channel current, whereas forskolin suppressed it. Maximization of intracellular cAMP content by applying 8-bromo-cAMP (100 microM) blocked the effect of epinephrine on the current. U-73122, a phospholipase C inhibitor, reduced the Ca2+ release by epinephrine and oxytocin. Our results suggested that 1) activation of alpha2-ARs induces Ca2+ influx through opening L-type Ca2+ channels as well as inducing Ca2+ release from intracellular stores, and 2) a PTX-sensitive G protein couples negatively to adenylyl cyclase, leading to a decrease in cAMP formation which may be involved in the activation of Ca2+ channels. In addition, our results are consistent with the coupling of alpha2-ARs to a PTX-insensitive G protein (G(q)) to release Ca2+ from intracellular stores.

Giant-cell tumor of bone around the knee

BACKGROUND

In most of the reported series, almost half of the giant-cell tumors involved the knee region. The characteristics of the lesions were usually benign but often locally aggressive and easily recurrent neoplasms. Some surgeons performed intralesional excision combined with local adjunctive chemical coagulant, and bone grafting or methylmethacrylate cement packing. These methods could both decrease local recurrence and retain the function of joint.

METHODS

From January, 1984 to December, 1994, a review was made of the results for eighteen patients who had been managed consecutively at the Veterans General Hospital-Taipei for giant-cell tumor of bone around the knee. Fourteen instances had occurred in the proximal tibia and four, in the distal femur. According to the classification of Campanacci, nine lesions were Stage II and nine, Stage III. Eleven patients had been managed with intralesional excision of the tumor with local adjunctive application; the other seven had en bloc resection and reconstructive procedures.

RESULTS

All patients had been followed for a mean of fifty-six months (range 22 to 125 months). The overall recurrence rate was 11% (2/18). The intralesional excision had 18% (2/11) recurrence; there was no recurrence in the en bloc resection (0/7). The complication rate was 16% (4/18); 9% (1/11) for intralesional excision and 42% (3/7) for en bloc resection, respectively. The mean functional score was 28 points (range, 22 to 30) in the intralesional excision group and 21 points (range, 11 to 30) in the en bloc resection group.

CONCLUSIONS

En bloc resection with reconstruction had a lower rate of recurrence, but a higher rate of complication and poor functional results. Intralesional excision, combined with a local adjunctive application and packed with bone grafting or methylmethacrylate cement, was an acceptably good method with satisfactory results, which either decreased local recurrence or retained the function of the joint.

Evolution of the vertical reduction mammaplasty: the S approach

The vertical reduction mammaplasty has been popularized over recent years. It always produces marked puckering of the excess skin and requires revision surgery for the persistent dog-ears that develop. Minor complications are often common. As a result, the evolution with S approach is developed. A series of 36 consecutive patients who underwent the S approach reduction mammaplasty is presented. The S approach can be described as having 1) superior dermoglandular pedicle, 2) simple and safe S-shaped skin marking, 3) suspension of the residual glandular tissues transversely to the periosteum of the 5th rib, and 4) short-scar closure. The surgical techniques are described in a step-by-step fashion. An analysis is made of the results obtained from these patients. The mean follow-up period of this study is 21 months. As a result of surgical operation, the symptoms of breast hypertrophy were markedly improved. According to patient assessment, neck, back, or chest pain decreased from 64% to 25%, shoulder grooving improved from 56% to 25%, stooped posture decreased from 42% to 14%, intetrigo improved from 36% to 8%, psychological embarrassment decreased from 33% to 8%. The postoperative complications included minimal areolar epidermolysis (11%), hypertrophic scar (8%), etc. All mammograms revealed hypertrophic patterns of the breast. The glandular tissues removed had a mean of 480 g from each breast. Two breasts (3%) had fibroadenomas. The sternal notch-nipple distance changed from a mean of 30.5 cm preoperatively to 20.5 cm, the length of infraareolar scar was 9 cm in average. Eighty-one percent of patients had minimal postoperative ptosis, and the sensitivity of nipple-areola complex was unchanged in 75% of patients. Nine patients (24%) retained the ability to lactate for more than 1 month postoperatively. Twenty-two patients (61%) were very satisfied with their operation, and eight (22%) were adequately satisfied. The technique presented is a simple and safe procedure that provides satisfactory results for patients with breast hypertrophy.

The double-blind test of sodium hyaluronate (ARTZ) on osteoarthritis knee

BACKGROUND

At this time, no definite treatment exists for osteoarthritis disease. Hyaluronate (ARTZ) is one of the most important components of synovial fluid. It is generally accepted that hyaluronic acid protects the articular cartilage and soft tissue surfaces from trauma during joint function.

METHODS

Ninety patients with 116 knees diagnosed as early arthritis (mild to moderate) by four senior orthopaedic surgeons were selected to join this study. The trial design was applied with a double-blind model. The selected patients were randomly injected with 2.5 ml drugs (ARTZ or placebo) intra-articularly once a week for five consecutive weeks without the use of local anesthetic drugs. Evaluation results included grading of subjective and objective symptoms and daily activities. The follow-up period was up to six months after initial injection.

RESULTS

According to the results of clinical evaluation and statistical analysis, SPH (ARTZ) is quite effective for osteoarthritis knees, and significantly better than the placebo. The effective peak was one week after five injections of ARTZ. The effective period could last up to three months without additional treatment. The efficacy of ARTZ on osteoarthritis knees was more prominent for relief of motion pain and improvement of knee movement. No side effects developed during a six month period.

CONCLUSIONS

Based on clinical results here, SPH is a safe drug for administration as an alternative approach to treat the osteoarthritis knee.

Inhibition of beta-myosin heavy chain gene expression in pressure overload rat heart by losartan and captopril

AIM

To study the effects of losartan and captopril on beta-myosin heavy chain (MHC), and alpha-MHC gene expression.

METHODS

Pressure overload was produced by abdominal aortic coarctation (AAC) in rats. alpha- and beta-MHC mRNA were measured by Northern blot.

RESULTS

In left ventricular myocardium of sham-operated rats, the alpha-MHC mRNA predominated, while the beta-MHC mRNA was only detectable. In response AAC, there was a 70-fold increase in the beta-MHC mRNA (P < 0.01), while alpha-MHC mRNA reduced to 26% (P < 0.01). Losartan (3 mg.kg-1.d-1, i.g. for 11 d) to AAC rats caused inhibitions of beta-MHC by 96% and alpha-MHC by 86% gene expression without lowering blood pressure. A reduction in beta-MHC mRNA was also seen in captopril-treated rats (30 mg.kg-1.d-1, i.g. for 11 d), but the inhibitory effect of captopril on alpha-MHC mRNA was less than that of losartan (44% vs 86%, P < 0.05).

CONCLUSIONS

The shift of MHC isoform induced by pressure overload is due to up-regulation of beta-MHC and down-regulation of alpha-MHC gene expression. Inhibition of beta-MHC gene expression by losartan is achieved primarily by direct blockade of angiotensin II type I receptors in the myocardium, independent on hemodynamics.

Refined frontalis fascial sling with proper lid crease formation for blepharoptosis

Ptosis of the upper eyelid is a complicated problem, and many surgical techniques have been developed for the treatment of ptosis. Frontalis sling with autogenous fascial strip for the correction of severe ptosis with poor levator function is still well accepted. The treatment necessitates an understanding of the etiology of ptosis, detailed history taking, degree of ptosis, the levator function, the anatomic basis of the ptosis and lid crease, and a historic review of surgical procedures. The refinement of our procedure consists of a circular type of frontalis sling with an autogenous fascial strip, harvested from fasciae latae or temporalis fascia, with evenly balanced strength and partial lid resection, including a semilunar segment of skin flap and orbicularis muscle and moderate amount of protruded orbital fat from the orbital septum. The fascial strip is anchored simultaneously to the upper margin of the tarsal plate and incision margin of the pretarsal lid to produce a proper lid crease. This procedure has been successful in the management of 64 lids (46 patients) with a severe degree of ptosis and poor levator function. Satisfactory results have been achieved in 57 lids (89 percent) according to the modified criteria of Berke after an average follow-up period of 18.5 months. Most patients (87.5 percent) have mild lid lag (1 to 3 mm) after the operation, but 58 lids (90.6 percent) achieved a proper lid crease height of 3 to 6 mm.

The N-terminal region of the third intracellular loop of the parathyroid hormone (PTH)/PTH-related peptide receptor is critical for coupling to cAMP and inositol phosphate/Ca2+ signal transduction pathways

Structural determinants within the parathyroid hormone (PTH)/PTH-related peptide (PTHrP) receptor that mediate G-protein activation of adenylate cyclase and phospholipase C are unknown. We investigated the role of the N-terminal region of the third intracellular loop of the opossum PTH/PTHrP receptor in coupling to two signal transduction pathways. We mutated residues in this region by tandem-alanine scanning and expressed these mutant receptors in COS-7 cells and/or Xenopus oocytes. All mutant receptors retained high affinity PTH binding in COS-7 cells, indistinguishable from wild-type receptors. Receptors with tandem-alanine substitutions in two N-terminal segments (377RVL379 and 381TKLR384) demonstrated impaired adenylate cyclase and phospholipase C activation. Receptor mutants with single-alanine substitutions scanning these two segments showed three different signaling defects in COS-7 cells. 1) Two mutant receptors (V378A and L379A) had reduced inositol phosphate (IP), but normal cAMP responses to PTH. 2) Mutant receptor T381A showed reduced cAMP, but wild-type IP responses to PTH. 3) Mutant receptor K382A demonstrated both markedly reduced cAMP and IP production due to PTH. In oocytes, mutants T381A and K382A showed decreased PTH-stimulated cAMP accumulation and intracellular Ca2+ mobilization. Thus, the N-terminal region of the third intracellular loop of this receptor plays a critical role in coupling to both Gs- and Gq-mediated second-messenger generation.

Structure of pp32, an acidic nuclear protein which inhibits oncogene-induced formation of transformed foci

pp32 is a nuclear protein found highly expressed in normal tissues in those cells capable of self-renewal and in neoplastic cells. We report the cloning of cDNAs encoding human and murine pp32. The clones encode a 28.6-kDa protein; approximately two-thirds of the N-terminal predicts an amphipathic alpha helix containing two possible nuclear localization signals and a potential leucine zipper motif. The C-terminal third is exceptionally acidic, comprised of approximately 70% aspartic and glutamic acid residues; the predicted pI of human pp32 is 3.81. Human and murine pp32 cDNAs are 88% identical; the predicted proteins are 89% identical and 95% similar. Although the structure of pp32 is suggestive of a transcription factor, pp32 did not significantly modulate transcription of a reporter construct when fused to the Gal4 DNA-binding domain. In contrast, in cotransfection experiments, pp32 inhibited the ability of a broad assortment of oncogene pairs to transform rat embryo fibroblasts, including ras + myc, ras + jun, ras + E1a, ras + mutant p53, and E6 + E7. In related experiments, pp32 inhibited the ability of Rat 1a-myc cells to grow in soft agar, whereas it failed to affect ras-induced focus formation in NIH3T3 cells. These results suggest that pp32 may play a key role in self-renewing cell populations where it may act in the nucleus to limit their sensitivity to transformation.