Improved glycaemic control with dipeptidyl peptidase-4 inhibition in patients with type 2 diabetes: vildagliptin (LAF237) dose response

OBJECTIVE

A novel treatment option for diabetic patients is the enhancement of incretin hormone activity by inhibition of the enzyme dipeptidyl peptidase-4 (DPP-4). This study was designed to establish a dose of the DPP-4-inhibitor vildagliptin (LAF237) that was effective in reducing HbA1c levels and was safe and well tolerated in patients with type 2 diabetes.

PATIENTS AND METHODS

The study of 279 patients with type 2 diabetes consisted of a 4-week run-in phase where patients received placebo and a 12-week active treatment phase where they received one of the following dosages of vildagliptin: 25 mg twice daily, 25, 50 or 100 mg once daily (qd), or placebo.

RESULTS

There was a statistically significant reduction in HbA1c levels in the vildagliptin 50 mg qd (p=0.003) and 100 mg qd groups (p=0.004) compared with the placebo group. The mean 4-h postprandial glucose level was significantly reduced from placebo in the vildagliptin 50 mg qd group (p = 0.012) and mean 4-h postprandial insulin was significantly increased from baseline vs. placebo in the vildagliptin 100 mg qd group (p=0.022). The assessment of beta-cell function (HOMA-B) was significantly increased in the vildagliptin 100 mg qd treatment group (p=0.007). The incidence of adverse events was similar in all treatment groups including placebo.

CONCLUSIONS

Vildagliptin, at 50 and 100 mg qd, was effective in reducing HbA1c levels compared with placebo in patients with type 2 diabetes. Vildagliptin at dosages up to 100 mg qd appeared safe and well tolerated.

Selective reduction of multifetal pregnancy using high-intensity focused ultrasound in the rabbit model

OBJECTIVE

High-order multifetal pregnancies carry a significant risk of obstetric complications and poor pregnancy outcome. Selective reduction has traditionally been performed using transabdominal and transvaginal ultrasound-guided intracardiac injection of potassium chloride. We have previously shown that high-intensity focused ultrasound (HIFU) can create a coagulative tissue necrosis in the sheep fetus. The objective of this study was to investigate the feasibility of non-invasive selective fetal reduction using HIFU in a rabbit model.

METHODS

A protocol for HIFU-induced tissue coagulation was developed in the rabbit model. The fetal heart was targeted with ultrasound-guided tissue ablation by a HIFU beam. Five time-mated does between 20-29 days' gestation underwent transabdominal fetal cardiac ablation in a total of 11 fetuses. The HIFU system consisted of a 7-MHz high-power transducer, operated at 2000 W/cm2. The fetal heart rate was observed using real-time ultrasound with Doppler flow velocimetry. All lesions were assessed macroscopically and by histological analysis.

RESULTS

Severe bradycardia leading to asystole was observed in all targeted fetuses with ultrasound examination. Dissection of fetuses demonstrated a necrotic intrathoracic lesion similar in size to the HIFU focus (approximately 1 x 9 mm). None of the surrounding fetuses was found to have bradycardia during the procedure or a macroscopic lesion on dissection.

CONCLUSION

In this pilot study HIFU seems promising to ablate even highly vascularized tissue in the fetus.

A prospective study of the use of nitrous oxide inhalation sedation for dental treatment in anxious children

AIM

To determine baseline data in relation to procedures undertaken during nitrous oxide inhalation sedation sessions within the Hospital Dental Service.

STUDY DESIGN

A prospective study.

METHODS

Data was collected over a twelve-month period for patients attending the Department of Paediatric Dentistry, Dundee Dental Hospital, Dundee, Scotland, for dental treatment using nitrous oxide inhalation sedation. Overall behaviour and the outcome of treatment were assessed by the dentist providing sedation using the Frankl and Houpt Behaviour Rating Scales respectively.

RESULTS

Data was available for 312 patients (F:169; M:143) with a median age of 11.0 (inter-quartile range 8.8, 12.7) years. Overall, 93% of patients successfully completed treatment using sedation. The majority of treatments comprised dental extractions; 19.8% and 41.3% were primary and permanent tooth extractions respectively. Regarding permanent teeth, nearly 50% were first permanent molar extractions compared with just over 30% for first premolars. Nearly three-quarter of cases were treated using a mixture of 30% nitrous oxide and 70% oxygen, with a median sedation time of 35.7 minutes. Only 7% of cases failed to commence or complete treatment and overall, there was a greater failure rate amongst visiting Community Dental Officers, compared with Hospital-based clinicians.

CONCLUSION

Extraction of first permanent molar teeth can be successfully achieved using inhalation sedation. There is both a need for further postgraduate training in sedation techniques as well as the necessity to train further Specialists in Paediatric Dentistry to undertake care within the Community Dental Service.

Nitrous oxide inhalation sedation: what do patients, carers and dentists think about it?

AIM

To determine the acceptability and efficacy of nitrous oxide inhalation sedation for dental treatment to children and to compare these results with the responses of both the accompanying adult and the treating dentist.

STUDY DESIGN

A prospective, questionnaire-based survey was used.

METHODS

Fifty consecutive patients (ASA I and II) attending the Department of Paediatric Dentistry, Edinburgh Dental Institute, between 2002 and 2003 for dental treatment using nitrous oxide inhalation sedation were recruited for the study. Each patient, the accompanying adult and the dental sedationist completed a short questionnaire which sought details about the acceptability and efficacy of the sedation technique. Overall behaviour and the outcome of treatment were assessed by the dentist providing sedation using the Frankl and Houpt Behaviour Rating Scales respectively.

RESULTS

Three sets of questionnaires were completed for fifty patients (M:27; F:23), mean age 10.4 years (range: 5.3-15.8 years). Acceptance of both local analgesia and dental treatment was perceived as greater amongst patients and carers compared with treating dentists (chi2 = 11.31, P = 0.004, 2 df and chi2 = 22.52, P < 0.001, 2 df respectively). Furthermore, dentists observed that inhalation sedation helped fewer male patients with local analgesia and fewer female patients with dental treatment (chi2 = 6.83, P < 0.009, 1 df and chi2 = 3.85, p < 0.050, 1 df respectively). A greater proportion of dentists observed that patients would manage treatment without sedation and would not require sedation for future dental treatment than both patients and their accompanying carer (chi2 = 8.00, P < 0.018, 2 df and chi2 = 18.61, P < 0.001, 2 df respectively). In general, the majority of patients were co-operative and successfully completed dental treatment with inhalation sedation.

CONCLUSION

Dentists' perception of nitrous oxide inhalation sedation was generally less enthusiastic than that of patients and carers.

Partial caries removal and cariostatic materials in carious primary molar teeth: a randomised controlled clinical trial

OBJECTIVE

To determine the durability and effectiveness of a black copper cement (BCC) and a conventional glass ionomer cement (GIC) when used to restore primary molars following partial caries removal (PCR) and to compare these results with conventional cavity preparation and restoration.

DESIGN

Split-mouth randomised controlled clinical trial.

SETTING

Department of Paediatric Dentistry, Dundee Dental Hospital, Dundee, 1998-1999.

SUBJECTS

Patients with previously unrestored, matched carious cavities in non-pulpally involved primary molars.

INTERVENTIONS

Three treatment groups: (1) Partial caries removal followed by lining with BCC and restoration with GIC (PCR:BCC); (2) Partial caries removal and restoration with GIC alone (PCR:GIC), and (3) Complete caries removal and conventional restoration (CR). Restoration durability and effectiveness was assessed both clinically and radiographically over 24 months.Main outcome measures Median survival time (MST) of restorations.

RESULTS

Forty-four patients (F: 31; M: 13), mean age 6.8 years (range: 3.7-9.5), had 120 restorations placed (PCR:GIC: 43; CR: 41; PCR:BCC: 36). Eighty-six molars (29 patients) (PCR:GIC: 30; CR: 29; PCR:BCC: 27) were reviewed at 24 months. The median survival times (MST) with 25% and 75% quartiles in parenthesis were as follows: PCR:BCC, MST = 24 months (6, 24); PCR:GIC, MST = 24 months (24, 24) and CR, MST = 24 months (24, 24). The MST for PCR:BCC restorations was significantly less than for PCR:GIC and CR restorations (W = 1163.5, P = 0.028 and W = 1081.0, P = 0.004 respectively).

CONCLUSION

There were no differences in the proportions of restorations lost between restoration types, although PCR:BCC restorations did have significantly more abscess/sinus formation over the 24-month study period.

An audit of the implementation of guidelines in relation to the prevention of dental caries

AIM

To determine the implementation of national clinical guidelines in relation to the targeted prevention of dental caries in the permanent teeth of 6-16-year-olds presenting for dental care amongst training grade staff working within the Hospital Dental Service.

METHODS

Patient records were reviewed prospectively with regard to caries risk assessment, behaviour modification and tooth protection. Following dissemination of the results and reinforcement of fundamental points from the guideline, a second audit was conducted one month later. The results were assessed by chi2 (chi2) analysis.

RESULTS

One hundred patient records were reviewed in both Audit One (M:52; F:48) and Audit Two (M:61; F:39). Caries risk assessment was poorly recorded in both Audits One and Two (13% and 17%, respectively). There was an improvement in radiographic reporting between the first and second audit, from 53% to 80% (chi2 = 16.36, P = 0.001). Dietary advice and toothbrushing instruction were recorded in 36% and 41% of records in Audit One, whilst in Audit Two this had improved to 68% and 92%, respectively (chi2 = 20.51, P = 0.001 and chi2 = 58.38, P = 0.001). There was a statistically significant improvement in the prescription of fissure sealants in Audit Two (chi2 = 38.97, P = 0.001), although not in the prescription of topical fluoride application (chi2 = 1.71, P = 0.192).

CONCLUSION

Amongst training grade staff, there appears to be failure of implementation of certain aspects of SIGN guidelines for caries prevention. Clinical audit, however, would appear to improve guideline implementation.

Surgical removal of supernumerary teeth and the fate of incisor eruption

AIM

The aims of this study were firstly to determine the fate of unerupted permanent maxillary incisor teeth following supernumerary tooth removal and secondly to make recommendations regarding the management of such incisor teeth following supernumerary tooth extraction.

STUDY DESIGN

This is a retrospective study.

METHODS

Records of children attending the Departments of Paediatric Dentistry, Edinburgh Dental Institute, Lothian Primary Care NHS Trust and Dundee Dental Hospital, Tayside University Hospitals Trust between 1995 and 2002 were examined with regard to non-eruption of one or both maxillary central incisors in association with supernumerary teeth requiring surgical removal. Subsequent permanent maxillary incisor eruption was recorded and in those cases of incisor non-eruption, further surgical interventions were noted.

RESULTS

In all 118 sets of patient records were included in the study (87 males, 31 females) with a mean age at presentation of 8.8 years (range 5.3-11.6 years). Failure of eruption of the associated permanent maxillary central incisor teeth occurred in 27% of cases, in relation to both conical and tuberculate supernumerary teeth. All tuberculate supernumerary teeth associated with non-eruption cases were palatally placed and 59% were adjacent to maxillary incisors with near complete apex formation. To facilitate incisor eruption in these cases, 41% required surgical exposure of the non-erupted incisor tooth and 59% required surgical exposure with bonding of an orthodontic bracket and gold chain for orthodontic traction.

CONCLUSION

Non-erupted permanent maxillary incisor teeth with near complete apical formation, associated with palatally placed, tuberculate-shaped supernumerary teeth, may benefit from having an orthodontic bracket and gold chain placed at the same time as the surgical procedure to remove the supernumerary tooth to facilitate future orthodontic traction.

Development and Validation of a Radioligand Binding Assay to Measure Insulin Specific IgG Subclass Antibodies in Human Serum

The objective was to develop and validate a radioligand binding assay for insulin antibodies (IABs) of the IgG1, IgG2, IgG3, and IgG4 subclasses in human serum. The validation studies focused on determining specificity, capacity, linearity, sensitivity, and precision of each assay. It was seen that our assay for IAB IgG subclasses is specific and has sufficient capacity to measure each of the subclasses in human serum. Moreover, the linear region and limits of detection and quantitation for each assay are clearly determined.

Adenocarcinoma of the prostate: an expensive way to die

The costs of radical prostatectomy and radiation therapy for localized carcinoma of the prostate are well known, the costs of terminal care for men with metastatic disease less so. We sought to determine the costs of terminal care incurred with prostate cancer in the last year of life. A retrospective chart review was conducted at five military medical centers identifying 32 patients who had died from prostate cancer from 1995 to 1997. The data investigated were: duration of metastatic disease, days hospitalized in the last year of life, palliative procedures (surgery or radiation), chemotherapy and need for transfusions. The mean duration of symptomatic metastatic disease was 3.4 y. The mean duration of hospitalization in the last year of life was 19 days. Seven patients (22%) required channel transurethral resection of the prostate (TURP). Three patients (9%) required either percutaneous nephrostomies or stenting. The mean number of transfusions required was 5.4. Eighteen patients (56%) underwent bilateral simple orchiectomy (BSO), 14 (44%) used LHRH agonists and 11 (34%) used anti-androgens. The mean total cost of hospitalization, studies, outpatient visits to physicians, palliative procedures and hormonal therapy was US dollars 24660 in the last year of life. Comparatively, the cost of radical prostatectomy is US dollars 12250 and three-dimensional conformal radiation therapy is US dollars 13823. Our estimation of costs due to metastatic disease is at best an underestimation. Men dying of prostate cancer incur significant costs in the last year of life. Based upon recent epidemiological data the cost of death due to prostate cancer in the US is over three quarters of a billion dollars a year.

Complete embedding and close step-sectioning of radical prostatectomy specimens both increase detection of extra-prostatic extension, and correlate with increased disease-free survival by stage of prostate cancer patients

The objectives of this work were to evaluate the efficacy of controlled close step-sectioned and whole-mounted radical prostatectomy specimen processing in prediction of clinical outcome as compared to the traditional processing techniques. Two-hundred and forty nine radical prostatectomy (RP) specimens were whole-mounted and close step-sectioned at caliper-measured 2.2-2.3 mm intervals. A group of 682 radical prostatectomy specimens were partially sampled as control. The RPs were performed during 1993-1999 with a mean follow-up of 29.3 months, pretreatment PSA of 0.1-40, and biopsy Gleason sums of 5-8. Disease-free survival based on biochemical or clinical recurrence and secondary intervention were computed using a Kaplan-Meier analysis. There were no significant differences in age at diagnosis, age at surgery, PSA at diagnosis, or biopsy Gleason between the two groups (P<0.05). Compared with the non-close step-sectioned group, the close step-sectioned group showed higher detection rates of extra-prostatic extension (215 (34.1%) vs, 128 (55.4%), P<0.01), and seminal vesicle invasion (50 (7.6%) vs 35 (14.7%), P<0.01). The close step-sectioned group correlated with greater 3-y disease-free survival in organ-confined (P<0.01) and specimen-confined (P<0.01) cases, over the non-uniform group. The close step-sectioned group showed significantly higher disease-free survival for cases with seminal vesicle invasion (P=0.046). No significant difference in disease-free survival was found for the positive margin group (P=0.39) between the close step-sectioned and non-uniform groups. The close step-sectioned technique correlates with increased disease-free survival rates for organ and specimen confined cases, possibly due to higher detection rates of extra-prostatic extension and seminal vesicle invasion. Close step-sectioning provides better assurance of organ-confined disease, resulting in enhanced prediction of outcome by pathological (TNM) stage.

The way forward for dental sedation and primary care?

OBJECTIVES

Firstly to determine the current provision of sedation in primary dental care in an area of Scotland without local secondary care support and secondly, to investigate dental practitioners' desire for formal postgraduate training in sedation techniques.

DESIGN

A prospective postal questionnaire-based study.

SETTING

Grampian Primary Care NHS Trust, UK, 2001.

SUBJECTS

Questionnaires were sent to all NHS dental practitioners and community dental service clinicians (N = 194] employed through Grampian Primary Care NHS Trust, Scotland during March - April 2001. The questionnaires sought details about personal status and the use and perceived need for conscious sedation techniques in practice in addition to the stated desire for postgraduate training in sedation techniques.

RESULTS

One hundred and thirty-six questionnaires were returned (70%). Forty-nine per cent of respondents reported current sedation use, with intravenous sedation the favoured technique (82%), followed by oral sedation (33%) and inhalation sedation (19%). Seventy-four per cent of participants considered that there was a need for sedation in their own practice and 68% were interested in further postgraduate training in sedation techniques.

CONCLUSION

Nearly three-quarters of practitioners who responded felt that there was a need for sedation in their own practice, although less than half were able to offer sedation to their patients. Nearly 70% of practitioners felt there was a need for postgraduate training in sedation techniques.

Cultural beliefs of Asian Americans associated with terminal illness and death

OBJECTIVES

Cultural competence often focuses on the skills of the professional; whereas, this article focuses on the needs of the patient.

DATA SOURCES

Research studies, review articles, book chapters, and clinical practice.

CONCLUSIONS

Patients benefit from health care professionals that are attuned and able to nurture patients in a process of identifying their needs regarding terminal illness and death. The health care professional's ability and sensitivity to be culturally aware, knowledgeable, and open directly influences the patient's quality of life and death.

IMPLICATIONS FOR NURSING PRACTICE

As the population becomes more diverse, health care professionals must develop cultural competence to add value to themselves, the profession of nursing, and health care in the future.

Black copper phosphate cement: does it have a future?

The aim of this study was to compare the in vitro compressive strength and solubility of a black copper cement with one established restorative material (a conventional glass ionomer cement) and two temporary restorative materials (a zinc phosphate and a zinc polycarboxylate cement). The mean compressive strength of black copper cement varied with the powder: liquid ratio, with an intermediate ratio having a comparable strength to that of the zinc polycarboxylate cement (the best material in this respect). The solubility of the black copper cement at all mixing ratios was significantly greater than that of all other test materials.

Activation of PTHrP gene expression in squamous carcinoma cell lines by mutant isoforms of the tumor suppressor p53

We have evaluated the status of p53 expression in three squamous carcinoma cell lines that express high levels of PTHrP mRNA and protein and also cause hypercalcemia when grown in nude mice. All three of these lines possess a single p53 allele, each of which harbors a missense point mutation that gives rise to it mutant p53 protein with a denatured conformation. Using site-directed mutagenesis, we created a p53 expression construct bearing a missense mutation at codon 158, identical to that expressed by one of the cell lines. This construct and p53 constructs expressing representative denatured conformation mutants were then used to develop stably transfected lines, which expressed increased levels of PTHrP mRNA. Promoter-specific RNase protection indicated that this increase was due primarily to transcripts originating from the two TATA promoters, and not the GC-rich initiator element within the PTHrP gene. Cotransfection of mutant p53 expression vectors with a series of reporter constructs under the control of the human PTHrP promoter region showed that mutant p53 isoforms activated constructs containing multiple promoter elements and flanking sequences, but failed to activate constructs with individual promoters in isolation. These findings suggest that the activation of PTHrP gene expression by mutant p53 isoforms displaying a denatured conformation is dependent on interactions with sequences in the PTHrP gene regulatory region beyond the basal TATA promoters.

Referral of children to a general anaesthetic dental service in Tayside

OBJECTIVE

To determine the adequacy of child referral for dental general anaesthesia (DGA) by local dental practitioners, given the recent guidance document to dentists from the General Dental Council and in addition, to determine the subsequent treatment and factors which influence treatment selection.

DESIGN

A prospective study.

SETTING

Department of Paediatric Dentistry, Dundee Dental Hospital, Dundee.

SUBJECTS

Children [n = 84] who were referred for dental extractions under general anaesthetic over a three month period.

RESULTS

Non-surgical dental extractions under general anaesthetic were requested in nearly 90% of referrals. In the majority of cases, the referral was deemed inadequate; e.g. the medical history was not mentioned in the majority of cases (85.7%) despite nearly one-fifth of patients having a relevant medical history. In general, referring practitioners under-estimated the extent of disease, requiring treatment plans to be changed in 76% of cases; all changes represented an increase in the number of dental extractions undertaken. The most common reasons for general anaesthetic use were: multiple dental extractions (73.8%); the patient's anxiety (63.1%); and patient's age (41.7%). As an alternative to general anaesthesia, treatment was undertaken successfully using inhalation sedation in nearly 15% of cases.

CONCLUSION

Dental extractions under general anaesthetic are still a common reason for referral. Referring practitioners frequently provide inadequate information, in addition to under-estimating the treatment required. Alternative forms of anxiety management are available and should be considered for children requiring dental extractions.

Parathyroid hormone-related protein maintains mammary epithelial fate and triggers nipple skin differentiation during embryonic breast development

Prior reports have demonstrated that both parathyroid hormone-related protein (PTHrP) and the type I PTH/PTHrP receptor are necessary for the proper development of the embryonic mammary gland in mice. Using a combination of loss-of-function and gain-of-function models, we now report that PTHrP regulates a series of cell fate decisions that are central to the survival and morphogenesis of the mammary epithelium and the formation of the nipple. PTHrP is made in the epithelial cells of the mammary bud and, during embryonic mammary development, it interacts with the surrounding mesenchymal cells to induce the formation of the dense mammary mesenchyme. In response, these mammary-specific mesenchymal cells support the maintenance of mammary epithelial cell fate, trigger epithelial morphogenesis and induce the overlying epidermis to form the nipple. In the absence of PTHrP signaling, the mammary epithelial cells revert to an epidermal fate, no mammary ducts are formed and the nipple does not form. In the presence of diffuse epidermal PTHrP signaling, the ventral dermis is transformed into mammary mesenchyme and the entire ventral epidermis becomes nipple skin. These alterations in cell fate require that PTHrP be expressed during development and they require the presence of the PTH/PTHrP receptor. Finally, PTHrP signaling regulates the epidermal and mesenchymal expression of LEF1 and (β)-catenin, suggesting that these changes in cell fate involve an interaction between the PTHrP and Wnt signaling pathways.

Loss of heterozygosity frequency at the Trp53 locus in p53-deficient (+/-) mouse tumors is carcinogen-and tissue-dependent

Mutagenic carcinogens rapidly induced tumors in the p53 haploinsufficient mouse. Heterozygous p53-deficient (+/-) mice were exposed to different mutagenic carcinogens to determine whether p53 loss of heterozygosity (LOH) was carcinogen-and tissue-dependent. For 26 weeks, C57BL/6 (N4) [corrected] p53-deficient (+/-) male or female mice were exposed to p-cresidine, benzene or phenolphthalein. Tumors were examined first for loss of the wild-type p53 allele. p-cresidine induced p53 LOH in three of 13 bladder tumors, whereas hepatocellular tumors showed p53 LOH in carcinomas (2/2), but not in adenomas (0/3). Benzene induced p53 LOH in 13 of 16 tumors examined. Finally, phenolphthalein induced p53 LOH in all tumors analyzed (21/21). Analysis of the p-cresidine-induced bladder tumors by cold single-strand conformation polymorphism (SSCP) analysis of exon 4-9 amplicons failed to demonstrate polymorphisms associated with mutations in tumors that retained the p53 wild-type allele. p-cresidine induced a dose-related increase in lacI mutations in bladder DNA. In summary, these data demonstrate that loss of the wild-type allele occurred frequently in thymic lymphomas and sarcomas, but less frequently in carcinomas of the urinary bladder. In the bladder carcinomas other mechanisms may be operational. These might include (i) other mechanisms of p53 inactivation, (ii) inactivating mutations occurring outside exons 4-9 or (iii) p53 haploinsufficiency creating a condition that favors other critical genetic events which drive bladder carcinogenesis, as evidenced by the significant decrease in tumor latency. Understanding the mechanisms of p53 LOH and chemical carcinogenesis in this genetically altered model could lead to better models for prospective identification and understanding of potential human carcinogens and the role of the p53 tumor suppressor gene in different pathways of chemical carcinogenesis.

Restoration of primary teeth: a study of copper phosphate cement

OBJECTIVE

To determine the survival of 'PD' Black Copper Cement when used as a dental filling material in carious primary teeth.

DESIGN

A prospective study.

SETTING

Dundee Dental Hospital, Dundee.

SUBJECTS

Fifty children with carious primary molars had 82 dental restorations placed in the initial study. For the follow-up study, 45 restorations were available.

RESULTS

Over 65% of the Black Copper Cement restorations placed in the initial study failed. Modification of restoration technique reduced the total loss of filling material to 18% of cases.

CONCLUSION

To take advantage of the cariostatic properties of black copper cement may require it to be used as a lining under a less soluble restorative material.

Prostate cancer in men age 50 years or younger: a review of the Department of Defense Center for Prostate Disease Research multicenter prostate cancer database

PURPOSE

Prostate cancer in men age 50 years or younger traditionally has accounted for approximately 1% of those diagnosed with prostate cancer. Prior studies of prostate cancer in men of this age led many clinicians to believe that they have a less favorable outcome than older men. Most of these studies were conducted before the advent of prostate specific antigen (PSA) screening programs. We evaluated a surgically treated cohort of men age 50 years or younger to determine whether disease recurred more frequently among them than in those 51 to 69 years old in the PSA era.

MATERIALS AND METHODS

We reviewed the medical records of 477 men who underwent radical prostatectomy between 1988 and 1997. Age, ethnicity, preoperative PSA, clinical and pathological stage, margin and seminal vesicle involvement, and recurrence were compared between 79 men age 50 years or younger (study group) and 398, 51 to 69 years old (comparison group). Disease-free survival rates were compared using Kaplan-Meier and Cox regression techniques.

RESULTS

There were 6 (7.6%) recurrences in the study group (79) and 107 (26.9%) in the comparison group (398). The disease-free survival curves were significantly different (log-rank p = 0.010). Age remained a significant prognostic factor (Wald p = 0.033) in multivariate Cox regression analyses that controlled for race, clinical and pathological stage, and pretreatment PSA. Similar results were found when the comparison group was limited to 116 patients 51 to 59 years old (log-rank p = 0.034, Wald p = 0.069).

CONCLUSIONS

These data suggest that patients in the PSA era who underwent radical prostatectomy and were age 50 years or younger have a more favorable disease-free outcome compared to older men.

Nateglinide alone and in combination with metformin improves glycemic control by reducing mealtime glucose levels in type 2 diabetes

OBJECTIVE

To evaluate the efficacy and tolerability of nateglinide and metformin alone and in combination in type 2 diabetic patients inadequately controlled by diet, focusing on changes in HbA1c, fasting plasma glucose (FPG), and mealtime glucose excursions.

RESEARCH DESIGN AND METHODS

In this randomized double-blind study, patients with an HbA1c level between 6.8 and 11.0% during a 4-week placebo run-in received 24 weeks' treatment with 120 mg nateglinide before meals (n = 179), 500 mg metformin three times a day (n = 178), combination therapy (n = 172), or placebo (n = 172). HbA1c and FPG were evaluated regularly, and plasma glucose levels were determined after Sustacal challenge at weeks 0, 12, and 24. Hypoglycemia and other adverse events were recorded.

RESULTS

At study end point, HbA1c was reduced from baseline with nateglinide and metformin but was increased with placebo (-0.5, -0.8, and +0.5%, respectively; P < or = 0.0001). Changes in FPG followed the same pattern (-0.7, -1.6, and +0.4 mmol/l; P < or = 0.0001). Combination therapy was additive (HbA1c -1.4% and FPG -2.4 mmol/l; P < or = 0.01 vs. monotherapy). After Sustacal challenge, there was a greater reduction in mealtime glucose with nateglinide monotherapy compared with metformin monotherapy or placebo (adjusted area under the curve [AUC]0-130 min -2.1, -1.1, and -0.6 mmol x h(-1) x l(-1); p < or = 0.0001). An even greater effect was observed with combination therapy (AUC0-130 min -2.5 mmol x h(-1) x l(-1); P < or = 0.0001 vs. metformin and placebo). All regimens were well tolerated.

CONCLUSIONS

Nateglinide and metformin monotherapy each improved overall glycemic control but by different mechanisms. Nateglinide decreased mealtime glucose excursions, whereas metformin primarily affected FPG. In combination, nateglinide and metformin had complementary effects, improving HbA1c, FPG, and postprandial hyperglycemia.

Parathyroid hormone-related peptide stimulates proliferation of highly tumorigenic human SV40-immortalized breast epithelial cells

Parathyroid hormone-related protein (PTHrP) is the main mediator of humoral hypercalcemia of malignancy (HHM) and it is produced by many tumors, including breast cancers. Breast epithelial cells as well as breast cancer tumors and cell lines have been reported as expressing PTHrP and the PTH/PTHrP receptor, suggesting that PTHrP may act as an autocrine factor influencing proliferation or differentiation of these cell types. We investigated PTHrP gene expression, PTH/PTHrP receptor signaling, and PTHrP-induced mitogenesis in three immortalized human mammary epithelial cell lines that exhibit differential tumorigenicity. The most tumorigenic cells expressed the highest levels of PTHrP messenger RNA (mRNA) and protein. We used reverse-transcription polymerase chain reaction (RT-PCR) and immunoblotting to detect the PTH/PTHrP receptor transcripts and proteins in all of the three cell lines. Treatment with human PTHrP(1-34) [hPTHrP(1-34)] and hPTH(1-34) increased intracellular cyclic adenosine monophosphate (cAMP) but not free Ca2+ in the nontumorigenic line. These agonists increased both cAMP and free Ca2+ levels in the moderately tumorigenic line, but only increased free Ca2+ in the highly tumorigenic line. Application of the PTH/PTHrP receptor antagonist [Asn10,Leu11,D Trp12]PTHrP(7-34) or PTHrP antibodies reduced [3H]thymidine incorporation in a dose-dependent fashion in the highly tumorigenic cell line but did not affect the other lines. Thus, treatment with a PTH/PTHrP receptor antagonist reduced cell proliferation, suggesting that PTHrP signaling mediated by the phospholipase C (PLC) pathway stimulates proliferation of a highly tumorigenic immortalized breast epithelial cell line.

K-ras and p53 in pancreatic cancer: association with medical history, histopathology, and environmental exposures in a population-based study

Pancreatic cancer is a highly fatal cancer with few identified risk factors. Increased risk of pancreatic cancer in tobacco smokers and among diabetic patients is well established, and some reports have suggested associations with coffee consumption and occupational exposure to organochlorines. At present, there is little information regarding the possible association of these risk factors with the known genetic alterations found in pancreatic cancers, such as activation of the K-ras oncogene and inactivation of the p53 tumor suppressor gene. Knowledge of such relationships may help to understand the molecular pathways of pancreatic tumorigenesis. We investigated the association between these molecular defects and risk factors for pancreatic cancer in 61 newly diagnosed patients identified through an ongoing study of pancreatic cancer in the San Francisco Bay Area. Interview information was obtained regarding environmental exposures, medical history, and demographic factors. Serum levels of dichlorodiphenyltrichloroethylene (DDE) and polychlorinated biphenyls were available on a subset of 24 patients. Tumor blocks were located from local hospitals and used for K-ras mutational analysis at codon 12 and for p53 protein immunohistochemistry. The molecular analyses were facilitated through the use of laser capture microdissection, which provides a reliable method to obtain almost pure populations of tumor cells. Mutations in K-ras codon 12 were found in 46 (75%) of 61 pancreatic cancers. A prior diagnosis of diabetes was significantly associated with K-ras negative tumors (P = 0.002, Fisher's exact test). The absence of this mutation was also associated with increased serum levels of DDE, although this association was not statistically significant (P = 0.16, Wilcoxon's test). There was no difference in polychlorinated biphenyl levels between the K-ras wild-type and mutant groups. Immunohistochemical staining for p53 protein did not differ by patient characteristics or clinical history, but significant associations were found with poor glandular differentiation (P = 0.002, chi2 trend test), severe nuclear atypia (P = 0.0007, chi2 trend test), and high tumor grade (P = 0.004, chi2 trend test). Our results are suggestive of the presence of K-ras codon 12 mutation-independent tumorigenesis pathways in patients with prior diabetes and possibly in patients with higher serum levels of DDE. Our results also support a role for the p53 tumor suppressor protein in the maintenance of genomic integrity.

CYP2C40, a unique arachidonic acid 16-hydroxylase, is the major CYP2C in murine intestinal tract

We recently identified five different murine CYP2C cDNAs from a murine cDNA library. When expressed in a bacterial cDNA expression system, all five recombinant proteins metabolized arachidonic acid but produced distinctly different profiles. In addition, some CYP2C mRNAs were found in extrahepatic tissues, as well as in liver. Immunoblots with an antibody raised against recombinant CYP2C38, which recognizes all five murine CYP2Cs, demonstrated that among extrahepatic tissues, colon and cecum contained the highest amount of CYP2Cs. The highest concentration of CYP2Cs occurred in cecum and colon (cecum >/= proximal colon >> distal colon), with lower levels in duodenum, jejunum, and ileum. Immunohistochemical studies revealed that CYP2Cs were localized principally in epithelial cells and autonomic ganglia in gut and colon. Polymerase chain reaction amplification of reverse-transcribed mRNA using murine CYP2C-specific primers followed by cloning and sequencing identified CYP2C40 as the major CYP2C isoform expressed in murine intestinal tract. Recombinant CYP2C40 metabolized arachidonic acid in a regio- and stereospecific manner to 16(R)-HETE (hydroxyeicosatetraenoic acid) as the major product. To our knowledge, CYP2C40 is the first enzyme known to produce primarily 16-HETE. We conclude that CYP2C40 is one of the major cytochrome P450 proteins in the mouse intestinal tract. In the light of vasoactive and anti-neutrophilic effects of 16-HETE, we hypothesize that CYP2C40 may play an important role in endogenous biological functions in intestine.

The use of dimethylmethylene blue for virus photoinactivation of red cell suspensions

Phenothiazine dyes and light have been known to have virucidal properties for over seventy years. This review will describe recent progress in the use of one phenothiazine dye, dimethyl-methylene blue, for photo-inactivation of a number of RNA and DNA viruses in red cell suspensions under conditions that minimally affect red cell in vitro properties during 42-day 1-6 degrees C storage. Dimethylmethylene blue has a higher affinity for nucleic acid than the closely related phenothiazine, methylene blue. Virus photoinactivation appears to be mediated by singlet oxygen. The kinetics of photoinactivation depends on the virus studied, but for a given virus, is similar for both intracellular and extracellular forms. The similarity for inactivation of intracellular and extracellular virus suggests that a common target, such as nucleic acid, is involved. Finally, lymphocytes, which can harbour transfusion-associated viruses and can mediate transfusion-associated-graft-versus host disease, are sensitive to dimethylmethylene blue photoinactivation under virucidal conditions.

Multicenter patient self-reporting questionnaire on impotence, incontinence and stricture after radical prostatectomy

PURPOSE

We determined the incidence of patient self-reported post-prostatectomy incontinence, impotence, bladder neck contracture and/or urethral stricture, sexual function satisfaction, quality of life and willingness to undergo treatment again in a large multicenter group of men who underwent radical prostatectomy. We also determined whether the morbidities of sexual function satisfaction, quality of life and bladder neck contracture and/or urethral stricture are predictable from demographic and postoperative prostate cancer factors.

MATERIALS AND METHODS

A self-reporting questionnaire was completed and returned by 1,069 of 1,396 eligible patients (77%) who underwent radical prostatectomy between 1962 and 1997. Of the respondents 868 (85.7%) underwent surgery after 1990 and in all prostatectomy had been done a minimum of 6 months previously. Questionnaire results were independently analyzed by a third party for morbidity tabulation and the association of patient reported satisfaction.

RESULTS

The patient self-reported incidence of any degree of post-prostatectomy incontinence, impotence and bladder neck contracture or urethral stricture was 65.6%, 88.4% and 20.5%, respectively. The incidence of incontinence requiring protection was 33% and only 2.8% of respondents had persistent bladder neck contracture or urethral stricture. Although incontinence and impotence significantly affected self-reported sexual function satisfaction, quality of life and willingness to undergo treatment again (p = 0.001), 77.5% of patients would elect surgery again. This finding remained true even after adjusting for demographic variables, and the time between surgery and the survey by multiple logistic regression.

CONCLUSIONS

Although radical prostatectomy morbidity is common and affects self-reported overall quality of life, most patients would elect the same treatment again. Impotence and post-prostatectomy incontinence were significantly associated with sexual function satisfaction, quality of life and willingness to undergo treatment again. Bladder neck contracture and/or urethral stricture was associated with willingness to undergo treatment again after adjusting for demographic variables and time from surgery to the survey.

Improving the epilepsy service: the role of the specialist nurse

There is currently a wide variation in the level of service provided for patients with epilepsy across the UK. Evidence is becoming available to suggest that improvements in local service provision may be achieved through the intervention of a specialist nurse. Using practical examples, this article explores the roles of the epilepsy specialist nurse, and examines how they may benefit patients and improve services. Functions such as liaison, patient assessment and management, counselling, provision of information, education, and audit are considered. It is hoped that the improved co-ordination and management of epilepsy services, that is achieved through specialist nurse intervention, will lead to improved patient outcomes and increased cost-effectiveness.

Regulation of parathyroid hormone-related protein gene expression in murine keratinocytes by E1A isoforms: a role for basal promoter and Ets-1 site

PTHrP gene expression was evaluated in a murine keratinocyte line, Pam 212K, transformed with E1A and ras. We found that the 12S-E1A oncogene, with or without ras transformation, markedly reduced PTHrP mRNA expression. Using transient transfection assays, we found that the 12S isoform repressed activity from a 5'PTHrP-driven reporter gene. E1A-induced repression of PTHrP reporter constructs appears to be mediated by sequences within minimal promoter region. The 13S-E1A isoform did not repress PTHrP reporter gene activity, and a 13S-deletion mutant that lacked the repressor domains activated a subset of reporter constructs. Mutation of an Ets-1 binding site upstream of the basal promoter substantially decreased activation of reporter constructs by this 13S-deletion mutant. These findings suggest that the E1A oncoprotein may serve as a model for both activation and repression of PTHrP gene expression.

Educating lay carers of people with learning disability in epilepsy awareness and in the use of rectal diazepam: a suggested teaching protocol for use by healthcare personnel

A high proportion of people with learning disabilities have epilepsy and often their epilepsy is of an intractable nature. Nurses within the large learning disability institutions are obliged, on a regular basis, to administer rectal diazepam to control these patients' serial seizures. As a result of the "community care" initiative, the process of discharging adult people from institutions into care settings in the community is underway. Consequently, and increasingly, the learning disabled are being cared for by non-medical/non-nursing (lay) community home carers who are required to gain a working knowledge of epilepsy as well as a degree of proficiency in the first aid management of seizures and in the use of rectal diazepam. Medical and nursing staff involved in the care of adults with learning disability are now liable to be approached by lay care organisations for appropriate training. This article, therefore, will outline the training programme employed at Gogarburn Hospital to educate lay community care staff in general epilepsy awareness and in the administration of rectal diazepam to adults with learning disability and epilepsy. This programme could be adapted and implemented by colleagues in their own areas.

Gastric gas and fluid emptying assessed by magnetic resonance imaging

Magnetic resonance imaging (MRI) was used to characterize the volumes and rates of gastric emptying of both liquid and gas following the ingestion of beverages of varying carbonation and carbohydrate levels. Eight subjects drank 800 ml each of four test beverages in a counterbalanced order: water, a non-carbonated carbohydrate-electrolyte solution (NC), a lightly carbonated carbohydrate-electrolyte solution (PC), and a carbonated cola (CC). T2-weighted, echoplanar images (25-30 contiguous slices, 1 cm thick, 256 x 128 matrix, TE = 80, 40 cm FOV) of the abdomen were collected at minutes 3,110, 20, 30, 45, and 60 following beverage ingestion. Images were analyzed for gas and liquid volumes. Water and NC emptied the most rapidly, with half times of 21(3) and 31(3) min, respectively [mean (SE)]. PC emptied significantly slower [47 (6) min] and CC slower yet [107 (8) min]. The carbonation content of the beverage accounted for 84% of the variation in emptying time, whereas carbohydrate content did not account for any significant variation. The gastric gas volume of the CC was higher at 2 min post-ingestion compared with all other drinks; however, the rate of emptying of the gas was the same among all beverages. Significantly greater total gastric volumes (gas+ liquid) were associated with the ingestion of CC, and accordingly produced a greater severity of gastric distress, as evaluated with a gastric distress inventory. The high gastric gas volumes (approximately 600 ml) after ingestion of CC suggested a potential source of error in body composition using standard hydrostatic weighing methods. This prediction was tested in nine additional subjects. Ingestion of 800 ml of CC prior to hydrostatic weighing resulted in a 0.7% underestimate of body density and thus an 11% overestimate of percentage body fat compared to measurements made before beverage consumption.

Development of a teaching module for quality-of-life assessment of terminal patients. The AACE Multi-Institutional Palliative Cancer Education Section. American Association for Cancer Education

To enhance the teaching of students to assess quality of life of patients with serious disease, the AACE Palliative Cancer Education Section has developed a teaching module. The module, which focuses on four desired learning objectives, is to be used in an hour-long small-group session. The authors describe the development of the module, as well as its objectives, teaching method, evaluation, and future challenges.

PTHrP regulates epidermal differentiation in adult mice

Emerging evidence suggests that parathyroid hormone-related peptide (PTHrP) serves as a regulator of the development and/or differentiation of a number of organs, including endochondral bone, the tooth, and the mammary gland. Although disruption of the PTHrP gene by homologous recombination results in a lethal chondrodystrophy, PTHrP-knockout mice that have been rescued by the transgenic replacement of the peptide in cartilage display abnormalities in ectodermally derived structures including the skin. At 6-8 wk of age, these rescued PTHrP-knockout mice displayed a markedly thinned epidermis and striking hyperkeratosis, hypoplastic sebaceous glands, and a fibrotic dermis. In contrast, transgenic mice that overexpress PTHrP by virtue of the human keratin-14 promoter displayed a thickened ventral epidermis with marked acanthosis and papillomatosis, hyperplastic sebaceous glands, and a cellular dermis. The absence of PTHrP appeared to result in the reduction of the basal keratinocyte compartment and premature acquisition of suprabasal and granular differentiation markers, whereas overexpression of the peptide generated reciprocal findings. No difference in the epidermal proliferation rate was found in PTHrP-null skin and although an increase was observed in keratin 14-PTHrP transgenic animals, their epidermis did not express the hyperplasia marker K6. Finally, the replacement of PTHrP in the basal keratinocytes of rescued PTHrP-knockout mice under the direction of the keratin 14 promoter reversed the abnormalities seen in PTHrP-null skin. These findings suggest that PTHrP regulates the rate of keratinocyte differentiation in the skin of adult mice.

Effect of decreased milking frequency of cows in late lactation on milk somatic cell count, polymorphonuclear leucocyte numbers, composition and proteolytic activity

The effects of reducing the frequency of milking of cows in late lactation on milk somatic cell count (SCC), polymorphonuclear leucocyte (PMN) content, chemical composition and proteolytic activity were investigated. Intermittent milking is frequently practised by Irish farmers in late lactation, and the objective of this study was to determine whether this procedure could be linked to altered quality of milk. Seventeen Holstein Friesian cows in late lactation (> 215 d in milk) were assigned to two treatment groups, and were either milked twice a day until drying-off (control group) or milked intermittently as the yield fell (test group). Milk composition and enzymic characteristics were measured on two occasions. At the first sampling, day 7, test cows were on once daily milking and at the second, day 15, the test cows were being milked every second day. Milk yields were significantly lower in test than control animals and decreased between days 7 and 15 in both groups. Milk SCC and PMN levels were increased on reducing milking frequency and, at day 15, the increase was not linked to decreased milk yield. Milk lactose levels were significantly decreased and pH, alpha-lactalbumin levels, plasmin activity and plasminogen activity significantly increased by reducing milking frequency. In conclusion, reduced frequency of milking in late lactation leads to the production of milk that is abnormal in character and this may be linked to reduced quality of dairy products manufactured from such milk.

A sterile syringe for every drug user injection: how many injections take place annually, and how might pharmacists contribute to syringe distribution?

Our objectives were to estimate the annual number of injections by injection drug users (IDUs) in the United States of America, and to describe the potential role of pharmacists in providing IDUs with a sterile syringe for every injection. We estimated the number of annual injections by IDUs for the United States, selected U.S. states, and selected U.S. cities according to the following formula: number of injections per year = (number of IDUs) x (average number of injections per IDU per day) x 365. Data were obtained from published articles, personal communications with local experts, and selected national databases. We also reviewed published and unpublished studies of pharmacy kits, pharmacist attitudes, and pharmacist practices in the United States and abroad. Between 920 million and 1.7 billion injections by IDUs take place each year in the United States. We estimated 12 million injections per year in San Francisco and >80 million in New York City. A similar number of syringes would be needed to satisfy the goal of a sterile syringe for every injection. Pharmacy-based strategies, including the sale of kits for injection drug use, have provided sterile syringes to IDUs in Europe, Australia, and New Zealand. Modification of laws restricting syringe purchase and possession has led to marked increases in purchase of syringes from pharmacies and reductions in needle-sharing. In conclusion, large numbers of syringes would be required to provide a sterile syringe for every injection, but significant numbers of pharmacists seem to be willing to play a central role in syringe sale and distribution. Outreach programs should emphasize that using a sterile syringe for every injection is the optimal HIV prevention practice for IDUs who cannot or will not stop injecting. Pharmacy-based syringe sale or distribution has the potential to augment current efforts to prevent HIV infection in IDUs, their sex partners, and their children.

Feline infectious peritonitis viruses arise by mutation from endemic feline enteric coronaviruses

Feline infectious peritonitis virus (FIPV) strains from six cats and three different geographic areas were compared genetically with feline enteric coronavirus (FECV) isolates obtained from cats inhabiting the same environments. Sequence comparisons were made from 1.2- to 8.9-kb segments on the 3' end of the genome. FECV/FIPV pairs from the same catteries or shelters were 97.3-99.5% related but were genetically distinct from FIPV and FECV strains obtained from cats living in geographically distinct environments. The high genetic similarity between FECVs and FIPVs from the same environment strongly suggested a common ancestry. Based on the presence of deletion mutations in the FIPVs and not in the FECVs, it was concluded that FIPVs evolved as mutants of FECVs. The mutations are deletions in the FIPVs and not insertions in the FECVs since similar sequences are present in other strains that have segregated earlier from a common ancestor. Therefore, the order of descent is form FECV to FIPV. Mutations unique to FIPVs were found in open reading frames (ORFs) 3c in 4 of 6 isolates and/or 7b in 3 of 6 isolates. When the study was extended to include 7 additional FIPV isolates, 11/13 of the FIPVs sequenced were found to have mutated 3c ORFs.

The Epilepsy Outcome Scale: the development of a measure for use with carers of people with epilepsy plus intellectual disability

This paper describes the development of a new scale for the assessment of epilepsy in people with learning disabilities. The scale was developed and validated in consultation with principal carers, and reflects their concerns about seizures, their impact and their treatment. Further testing of the scale revealed high internal consistency, testretest reliability and a robust factor structure. The scale can be completed in 5-10 min and may be useful as an outcome measure both in clinical practice and in research trials.

Strength of core build-up materials in endodontically treated teeth

PURPOSE

To compare the in vitro strength of a reinforced glass ionomer and a light-cured glass ionomer used as an alternative to amalgam in core construction to restore endodontically treated mandibular molar teeth.

MATERIALS AND METHODS

The root canals of 120 extracted human mandibular molar teeth were prepared chemomechanically and obturated with laterally condensed cold gutta-percha. The crown of each tooth was sectioned leaving only one cusp standing. Gutta-percha was removed from the pulp chamber in all teeth. The volume of the pulp chamber was measured and the teeth ranked in ascending order of chamber volume. The specimens were divided into six groups of 20, allocating teeth with similar chamber volumes into each group. In three of the groups, gutta-percha was removed from the coronal 3-4 mm of each root canal. The teeth were restored with one of three materials, a cermet cement (Ketac-Silver), a resin-reinforced glass ionomer (Vitremer), or amalgam (Contour). Core preparation was carried out after 48 hours, reducing each core height to 6 mm. The specimens were thermocycled for 24 hours and then mounted in dental stone. A control group of 20 unrestored human mandibular molars was mounted in cold cure acrylic. Each tooth was tested in a Nene machine with a compressive load applied at 90 degrees to the occlusal surface at a crosshead speed of 5 mm/minute.

RESULTS

There was no statistically significant difference between the experimental groups (P > 0.05), but the control group was significantly stronger (P < 0.001). Extension of core material into the coronal root canal system did not increase the fracture resistance of any of the experimental materials. Regression analysis of the results revealed no correlation between the volume of the pulp chamber and the load to fracture.

CYP2J subfamily cytochrome P450s in the gastrointestinal tract: expression, localization, and potential functional significance

Our laboratory recently described a new human cytochrome P450 arachidonic acid epoxygenase (CYP2J2) and the corresponding rat homologue (CYP2J3), both of which were expressed in extrahepatic tissues. Northern analysis of RNA prepared from the human and rat intestine demonstrated that CYP2J2 and CYP2J3 mRNAs were expressed primarily in the small intestine and colon. In contrast, immunoblotting studies using a polyclonal antibody raised against recombinant CYP2J2 showed that CYP2J proteins were expressed throughout the gastrointestinal tract. Immunohistochemical staining of formalin-fixed, paraffin-embedded intestinal sections using anti-CYP2J2 IgG and avidin-biotin-peroxidase detection revealed that CYP2J proteins were present at high levels in nerve cells of autonomic ganglia, epithelial cells, intestinal smooth muscle cells, and vascular endothelium. The distribution of this immunoreactivity was confirmed by in situ hybridization using a CYP2J2-specific antisense RNA probe. Microsomal fractions prepared from human jejunum catalyzed the NADPH-dependent metabolism of arachidonic acid to epoxyeicosatrienoic acids as the principal reaction products. Direct evidence for the in vivo epoxidation of arachidonic acid by intestinal cytochrome P450 was provided by documenting, for the first time, the presence of epoxyeicosatrienoic acids in human jejunum by gas chromatography/mass spectrometry. We conclude that human and rat intestine contain an arachidonic acid epoxygenase belonging to the CYP2J subfamily that is localized to autonomic ganglion cells, epithelial cells, smooth muscle cells, and vascular endothelium. In addition to the known effects on intestinal vascular tone, we speculate that CYP2J products may be involved in the release of intestinal neuropeptides, control of intestinal motility, and/or modulation of intestinal fluid/electrolyte transport.

Molecular cloning, expression, and functional significance of a cytochrome P450 highly expressed in rat heart myocytes

A cDNA encoding a P450 monooxygenase was amplified from reverse transcribed rat heart and liver total RNA by polymerase chain reaction using primers based on the 5'- and 3'-end sequences of two rat pseudogenes, CYP2J3P1 and CYP2J3P2. Sequence analysis revealed that this 1,778-base pair cDNA contained an open reading frame and encoded a new 502 amino acid protein designated CYP2J3. Based on the deduced amino acid sequence, CYP2J3 was approximately 70% homologous to both human CYP2J2 and rabbit CYP2J1. Recombinant CYP2J3 protein was co-expressed with NADPH-cytochrome P450 oxidoreductase in Sf9 insect cells using a baculovirus expression system. Microsomal fractions of CYP2J3/NADPH-cytochrome P450 oxidoreductase-transfected cells metabolized arachidonic acid to 14,15-, 11,12-, and 8, 9-epoxyeicosatrienoic acids and 19-hydroxyeicosatetraenoic acid as the principal reaction products (catalytic turnover, 0.2 nmol of product/nmol of cytochrome P450/min at 37 degrees C). Immunoblotting of microsomal fractions prepared from rat tissues using a polyclonal antibody raised against recombinant CYP2J2 that cross-reacted with CYP2J3 but not with other known rat P450s demonstrated abundant expression of CYP2J3 protein in heart and liver. Immunohistochemical staining of formalin-fixed paraffin-embedded rat heart tissue sections using the anti-CYP2J2 IgG and avidin-biotin-peroxidase detection localized expression of CYP2J3 primarily to atrial and ventricular myocytes. In an isolated-perfused rat heart model, 20 min of global ischemia followed by 40 min of reflow resulted in recovery of only 44 +/- 6% of base-line contractile function. The addition of 5 microM 11, 12-epoxyeicosatrienoic acid to the perfusate prior to global ischemia resulted in a significant 1.6-fold improvement in recovery of cardiac contractility (69 +/- 5% of base line, p = 0.01 versus vehicle alone). Importantly, neither 14,15-epoxyeicosatrienoic acid nor 19-hydroxyeicosatetraenoic acid significantly improved functional recovery following global ischemia, demonstrating the specificity of the biological effect for the 11, 12-epoxyeicosatrienoic acid regioisomer. Based on these data, we conclude that (a) CYP2J3 is one of the predominant enzymes responsible for the oxidation of endogenous arachidonic acid pools in rat heart myocytes and (b) 11,12-epoxyeicosatrienoic acid may play an important functional role in the response of the heart to ischemia.

Predominant expression of an arachidonate epoxygenase in islets of Langerhans cells in human and rat pancreas

Our laboratory recently described a new human cytochrome P450 arachidonic acid epoxygenase (CYP2J2) and the corresponding rat homolog (CYP2J3). Immunoblotting studies using a polyclonal antibody raised against recombinant human CYP2J2 confirmed CYP2J protein expression in human and rat pancreatic tissues. Immunohistochemical staining of formalin-fixed paraffin-embedded rat and human pancreas using the anti-CYP2J2 IgG and avidin-biotin-peroxidase detection revealed that CYP2J2 protein expression was highly localized to cells in the islets of Langerhans, with minimal staining in pancreatic exocrine cells. Colocalization studies using antibodies to the glucagon, insulin, somatostatin, and pancreatic polypeptide as markers for alpha-, beta-, delta-, and PP cells, respectively, showed that CYP2J protein expression was abundantly present in all four cell types, but was highest in the glucagon-producing alpha-cells. Direct evidence for the epoxidation of arachidonic acid by pancreatic cytochrome P450 was provided by documenting, for the first time, the presence of epoxyeicosatrienoic acids in vivo in human and rat pancreas by gas chromatography/mass spectrometry. Importantly, the levels of immunoreactive CYP2J2 in different human pancreatic tissues were highly correlated with endogenous epoxyeicosatrienoic acid concentrations. We conclude that human and rat pancreas contain an arachidonic acid epoxygenase belonging to the CYP2J subfamily that is highly localized to islet cells. These data together with previous work showing effects of epoxyeicosatrienoic acids in stimulating insulin and glucagon secretion from isolated rat pancreatic islets support the hypothesis that epoxygenase products may be involved in stimulus-secretion coupling in the pancreas.

CYP2J subfamily P450s in the lung: expression, localization, and potential functional significance

Cytochrome P450 (P450) monooxygenases catalyze the epoxidation of arachidonic acid to form epoxyeicosatrienoic acids, which modulate bronchial smooth muscle tone and airway transepithelial ion transport. We recently described a new human P450 arachidonic acid epoxygenase (CYP2J2) and the corresponding rat homologue (CYP2J3). Northern analysis of lung RNA using CYP2J cDNA probes demonstrated that CYP2J2 and CYP2J3 mRNAs were expressed in the lung. Immunoblotting of microsomal fractions prepared from human and rat lungs using a polyclonal antibody raised against recombinant human CYP2J2 revealed a single 56-kDa band confirming abundant pulmonary CYP2J2 and CYP2J3 protein expression. Immunohistochemical analysis of formalin-fixed paraffin-embedded human and rat lung sections using the anti-human CYP2J2 IgG and avidin/biotin/peroxidase detection showed that CYP2J proteins were primarily expressed in ciliated epithelial cells lining the airway. Prominent staining was also noted in nonciliated airway epithelial cells, bronchial and pulmonary vascular smooth muscle cells, pulmonary vascular endothelium, and alveolar macrophages, whereas less intense staining was noted in alveolar epithelial cells. Endogenous epoxyeicosatrienoic acids were detected in both human and rat lung using gas chromatography/mass spectrometry, thus providing direct evidence for the in vivo human and rat pulmonary P450 metabolism of arachidonic acid. Based on these data, we conclude that CYP2J2 and CYP2J3 are abundant pulmonary arachidonic acid epoxygenases and that CYP2J products, the epoxyeicosatrienoic acids, are endogenous constituents of human and rat lung. In addition to known effects on airway smooth muscle tone and transepithelial electrolyte transport, the localization of CYP2J proteins to vascular smooth muscle and endothelium suggests that epoxyeicosatrienoic acids may also be involved in the modulation of pulmonary vascular tone.