The effect of Nd:YAG radiation at nanosecond pulse duration on dentine crater depth

The effect of laser parameters on laser-dentine interaction is little known. The aim of this in vitro study was to determine the effect on dentine crater depth of Nd:YAG laser radiation in relation to pulse repetition rate, total delivered energy, dentine site and the presence or absence of a dye. One hundred and forty-four sound third molars were extracted and sectioned transversely to provide 288 upper and lower cut surfaces. The upper surfaces were painted with a layer of dye (IR5) suitable for absorption at 1064 nm. The specimens were divided into 12 sub-groups each containing 12 upper and 12 lower specimens. These were exposed to a Nd:YAG laser with a 30 nanosecond (ns) pulse duration. This laser operated in a non-contact mode (spot diameter 165 microm) with pulse repetition rates of 2.5, 5.4 and 10.5 Hz. Four total energies were delivered at each repetition rate; 2.3, 3.63, 3.96, 4.29 joule (J) at 2.5 Hz repetition rate; 2.3, 2.64, 3.63, 4.29 J at 5.4 and 10.5 Hz repetition rates. Five outer and three inner sites were irradiated on each specimen. Each dentine crater depth was measured five times using a Reflex Microscope and a three-dimensional centre of gravity derived. An upper and lower specimen were taken from each sub-group and viewed under a scanning electron microscope (SEM). ANOVA was applied: total delivered energy and dyed/undyed were found to have a statistically significant effect on crater depth (p<0.0001). In general increasing energy and the presence of dye produced deeper craters. Inner/outer dentine location and repetition rate were not found to be statistically significant. All craters were carbonised.

The portrayal of ECT in American movies

OBJECTIVE

To describe the portrayal of electroconvulsive therapy (ECT) in American films. This has not been systematically studied previously, despite some notorious ECT scenes in the history of American cinema and the impact of films on audiences.

METHOD

All movies depicting or making reference to ECT were identified from a number of sources. Available movies were viewed on at least two occasions.

RESULTS

22 films, beginning with The Snake Pit and ending with Requiem for a Dream, portraying or making reference to ECT were made between 1948 and 2000. 20 (91%) of these movies were obtained and viewed.

CONCLUSION

Having commenced its movie career as a severe but helpful remedy for personal distress, ECT on film has become a progressively more negative and cruel treatment, leaving the impression of a brutal, harmful, and abusive maneuver with no therapeutic benefit.

Merging nitrogen management and renewable energy needs

The ARBRE (ARable Biomass Renewable Energy) project, the first large-scale wood-fueled electricity generating plant in the U.K., represents a significant development in realising British and European policy objectives on renewable energy. The plant is fueled by a mix of wood from short rotation coppice (SRC) and forest residues. Where feasible, composted/conditioned sewage sludge is applied to coppice sites to increase yields and improve soil structure. In the Yorkshire Water region, typical total N:P:K composition of composted/conditioned sludge is 2.9:3.8:0.3, respectively. Sludge application is calculated on the basis of total nitrogen (N) content to achieve 750 kg N ha(-1), for 3 years" requirement. Willow coppice forms a dense, widely spaced, root network, which, with its long growing season, makes it an effective user of nutrients. This, in combination with willow"s use as a nonfood, nonfodder crop, makes it an attractive route for the recycling of sewage sludge in the absence of sea disposal, banned under the EC Urban Waste Water Treatment Directive (UWWTD). Further work is required on the nutritional requirements of SRC in order to understand better the quantities of sludge that can be applied to SRC without having a detrimental impact on the environment. This paper suggests the source of N rerouting under the UWWTD and suggests the likely expansion of SRC as an alternative recycling pathway.

Treatment planning for success: wise choices for maxillary single-tooth implants

The purpose of this article is to demonstrate to general practitioners who have no experience with dental implant treatment the esthetic limitations of such treatment. The criteria for wise case selection will be described so that esthetic excellence can be predictably achieved in general practice. A checklist of criteria will be provided as a treatment-planning tool to determine if a patient is likely to have an esthetically successful outcome.

Time trends in HIV incidence among homosexually active men seen at sexual health clinics in Australia, 1993-1999

BACKGROUND

Increases in sexual risk behaviour have recently been reported among homosexually active men in Australia and in other industrialised countries, potentially facilitating an increase in HIV incidence.

OBJECTIVE

To monitor HIV incidence among homosexually active men seen through a network of sexual health clinics in Australia.

STUDY DESIGN

Selected metropolitan public sexual health clinics provided counts of the number of people seen at the clinics during a calendar year, the number voluntarily tested for HIV antibody and the number newly diagnosed with HIV infection, broken down by sex, age group, HIV exposure category and HIV antibody testing history. HIV incidence was estimated among homosexually active men with a history of a negative test in the 12 months prior to last being seen in a calendar year.

RESULTS

Of 23924 men seen at the clinics in 1993-1999 with a reported history of male homosexual contact, 7440 (31.1%) had a negative test in the 12 months prior to last being seen in a calendar year. The percentage of men with a recent negative test declined significantly over time, from more than 33% in 1994-1996 to 29% in 1999 (P=0.003), and with increasing age, from 34.3% among men aged 25-29 years to 27.4% among men aged 40 years or older (P<0.0005). A total of 5346 (71.9%) men were retested for HIV antibody within 12 months of the last negative test. The percentage of men retested declined significantly over time, from 77.8% in 1994 to 67.2% in 1999 (P=0.021) but did not change by age group (P=0.132). Overall, 56 men were newly diagnosed with HIV infection. Estimated HIV incidence was 2.1% in 1993-1999; incidence did not change significantly by year (P=0.498) or age group (P=0.757).

CONCLUSION

HIV incidence has remained stable among homosexually active men seen through a network of sexual health clinics in Australia.

Management of hepatic cysts by percutaneous drainage and instillation of tetracycline hydrochloride

This paper reports two cases of benign hepatic cysts successfully treated by the instillation of tetracycline hydrochloride. The patients presented with solitary large symptomatic hepatic cysts and underwent ultrasound guided needle aspiration followed by the instillation of tetracycline hydrochloride. The cyst size diminished without complication and the patients have remained symptom free. We review the treatment of this uncommon entity and propose that injection of tetracycline hydrochloride is an effective nonoperative treatment of symptomatic solitary hepatic cysts.

Patterns of trauma injuries in rural versus urban Jamaica

Trauma admissions to St Ann's Bay Hospital in rural Jamaica and The University Hospital of the West Indies (UHWI) in the capital city of Kingston are compared. Trauma accounted for 19% and 22% of surgical admissions to UHWI and the St Ann's Bay Hospital, respectively. Sixty-three per cent of trauma cases admitted to the St Ann's Bay Hospital and 56% to the UHWI were due to unintentional injuries (95% CI, -0.05, 0.19). The main cause of unintentional injuries at both hospitals was motor vehicle accidents, accounting for 43% and 37% at UHWI and St Ann's Bay Hospital respectively (95% CI, -0.04, 0.17). The prevalence of falls was significantly higher in St Ann's Bay Hospital compared with UHWI, 41% and 26% respectively (95% CI, 0.10, 0.21). Intentional injuries accounted for 37% of cases in St Ann's Bay Hospital and 44% at UHWI (95% CI, -0.20, 0.04). The prevalence of firearm injuries was significantly higher at the UHWI than in St Ann's Bay Hospital, 55% and 18% respectively (95% CI, -0.15, -0.05). There was no significant difference in age and injury severity scores in the two hospitals but patients remained in hospital significantly longer at UHWI.

Mitral valve replacement with mechanical prostheses in children: improved operative risk and survival

OBJECTIVE

The purpose of this study was to assess the early and late outcome following mitral valve replacement (MVR) with mechanical prostheses in children.

PATIENTS AND METHODS

Between 1981 and 2000, 44 consecutive children (mean age 6.8+/-4.7 years, 2 months--16 years) underwent mechanical MVR in Southampton. Twenty-three children were less than 5-years-old and nine were infants. Disease aetiology was congenital in 37, rheumatic in four, infective in two and Marfan's syndrome in one. Mitral regurgitation was present in 36 and mitral stenosis in eight. Concomitant procedures were performed in 13, including aortic valve replacement (AVR) in seven. Follow-up was complete (mean 6.4+/-4.8 years, 1 month--18.1 years).

RESULTS

The overall operative mortality was 14% (six patients). Before and after 1990 operative mortality was 31 vs 3.6% (P=0.02). From 1990, operative mortality for infants was zero out of six, for children less than 5-years-old was one out of 16 (one death after emergency AVR and MVR) and for older children it was 0/12. Seven children experienced valve or anticoagulation treatment-related events and eight had a mitral valve re-operation. Ten-year freedom from thromboembolism, prosthetic valve infection, bleeding, paravalvular leak and a mitral valve re-operation was 92.8+/-5.2, 97.3+/-2.7, 97.7+/-2.3, 97.2+/-2.7 and 75+/-9.7%, respectively. Overall 10-year survival was 78+/-7% (four late deaths); for children under vs over 5 years it was 61+/-11 vs 95.2+/-4.6% (P=0.02), for atrio-ventricular septal defect (AVSD) vs other pathology 55+/-15 vs 89+/-6.1% (P=0.05) and for those operated before 1990 vs after 1990 it was 63+/-8.1 vs 86+/-8.2% (P=0.04).

CONCLUSIONS

Mechanical MVR, in the current era, carries a low operative risk across the spectrum of paediatric age. Late survival is better for older children and those having no-AVSD pathology but it has improved substantially during the 1990s irrespective of age and disease aetiology.

Inhibition and enhancement of the spontaneous emission of quantum dots in structured microresonators

Spontaneous emission of quantum dot systems in laterally structured microcavities that exhibit photon confinement in all three directions has been studied by time-resolved photoluminescence spectroscopy. For on-resonance conditions, we find that the dot emission rate is increased substantially over that of the unstructured planar cavity. For off-resonance conditions, we are able to suppress the emission rate by an order of magnitude by using cavities with metal coatings, which we attribute to the suppression of leaky optical modes in these structures.

Preparation guidelines for full and partial coverage ceramic restorations

Aesthetic awareness of dental patients has produced a growing demand for posterior tooth-coloured restorations. This has led to the development of posterior composite resins and, more recently, posterior all-ceramic restorations. In the last decade, modern technological advances have allowed the production of stronger ceramics and better luting techniques, which have led to the use of all-ceramic restorations in posterior sites. The preparation guidelines for posterior ceramic restorations outlined in this paper emphasize rounded internal line angles and a chamfer or rounded shoulder finish-line.

Spectrum of AIDS-defining illnesses in Australia, 1992 to 1998: influence of country/region of birth

OBJECTIVE

To examine the influence of country/region of birth on spectrum of AIDS-defining illness.

METHODS

National surveillance data for 4,629 adolescents and adults diagnosed with AIDS from 1992 through 1998 were analyzed. Country of birth was grouped into five broad categories (Australia, other predominantly industrialized country regions, sub-Saharan Africa, Asia-Pacific, and other regions with predominantly developing countries). Proportions of AIDS-defining illnesses were calculated and compared by country/region of birth. Role of country/region of birth in the distribution of AIDS-defining illnesses was further assessed using logistic models.

RESULTS

Of the 4,488 (97.0%) AIDS cases with country of birth recorded, 1,120 (25.0%) were born outside Australia. In multivariate analyzes, AIDS cases born in sub-Saharan Africa had an increased risk of tuberculosis (odds ratio [OR], 18.7; confidence interval [CI], 9.2-38.2) and cryptococcosis (OR, 2.4; CI, 1.1-5.4), but a decreased risk of esophageal candidiasis (OR, 0.3; 0.1-0.8) and Pneumocystis carinii pneumonia (OR, 0.5; 0.3-0.9) compared with AIDS cases born in Australia. Tuberculosis risk was also elevated among AIDS cases born in Asia-Pacific (OR, 9.6; 5.3-17.5) and other developing country regions (OR, 3.1; 0.9-10.4). Risk of AIDS-defining illnesses was similar for AIDS patients born in Australia and other industrialized country regions. Country of birth had no influence on risk of cytomegalovirus (CMV)-related disease and Mycobacterium avium complex (MAC) infection. Differential AIDS-defining illness risk was more pronounced among AIDS patients born in developing countries who had resided in Australia for less time.

CONCLUSIONS

Differential risk by country/region of birth for some AIDS-defining illnesses, especially among more recent arrivals from developing countries, suggests that environmental microbial habitats are important determinants of opportunistic infection risk. Similar risk of CMV disease and MAC infection is consistent with the ubiquitous nature of these microbial agents and suggests that previously reported low prevalence from developing countries may reflect poor diagnostic capacity rather than level of risk.

The effect of Nd:YAG pulse duration on dentine crater depth

OBJECTIVES

The effect of alteration of laser parameters on laser-dentine interaction, in particular the effect of pulse duration, has not been well documented. The aim of this in vitro study was to determine the effect on dentine crater depth of Nd:YAG laser pulse duration, and total delivered energy, dentine site and the presence or absence of dye.

METHODS

Ninety-six sound third molars were extracted and sectioned transversely to provide 192 upper and lower cut surfaces. The upper surfaces were painted with a layer of dye (IR5) suitable for absorption at 1064 nm. The specimens were divided into 16 sub-groups and exposed to two Nd:YAG lasers; one of pulse duration 7 ms and the second of pulse duration 35 ps. Both lasers operated in a non-contact mode (spot diameter 165 microm) with repetition rates of 10.5 and 10 Hz, respectively. Four total energies (2.28, 2.64, 3.6, 4.2 J) were delivered to eight dyed and eight undyed sub-groups. Eight outer and five inner sites were irradiated on each specimen. Dentine crater depth was measured five times using a Reflex Microscope and a three-dimensional centre of gravity derived. An upper and lower specimen were taken from each sub-group and viewed under a SEM.

RESULTS

ANOVA and multiple regression analysis were applied and the following factors were found to have a statistically significant effect on crater depth (p<0.0001): total delivered energy, pulse duration and inner/outer location.

CONCLUSIONS

Increasing energy and pulse duration produced deeper craters. Similarly inner dentine sites produced deeper crater depths. Only craters produced at the ms pulse duration were carbonised. It would appear that laser-dentine interaction has a non-thermal component at picosecond pulse duration.

Advances in operative dentistry and fixed prosthodontics

The rapid developments in biomaterials has led not only to improved materials but also to the development of clinical techniques made possible by these advances. Adhesive dentistry remains one of the fastest changing fields and this will most likely continue well into the next decade. Patients' aesthetic awareness and, to some extent, concern about amalgam has produced a growing demand for posterior tooth-coloured restorations. Originally this was met by ceramo-metal crowns and subsequently by the development of posterior composite resins. Recent development of stronger ceramics and better luting have now made all-ceramic restorations possible in posterior sites. Several new techniques for cavity preparation are emerging as alternatives to the conventional handpiece while the quest for amalgam alternatives continues. As with all recent developments there are, by definition, few long-term clinical data yet available to allow a comprehensive evaluation of the relevant materials and techniques. This paper is a summary of the most significant recent advances in fixed prosthodontics and operative dentistry.

Chronic relapsing pancreatitis in a child. Use of the Puestow procedure to achieve ductal drainage

A case of chronic relapsing pancreatitis presenting in an 8-year-old African Jamaican girl is outlined. Aggressive supportive management failed to control pain and vomiting. The Puestow Procedure effectively procedure aborted these symptoms. The use of the Puestow procedure should not be inordinately delayed in chronic relapsing pancreatitis if symptoms persist, since it may not only control pain but also halt declining pancreatic function.

Voiding cystourethrograms and urinary tract infections: how long to wait?

OBJECTIVES

Many authorities recommend an interval of at least 3 to 6 weeks after a urinary tract infection (UTI) before performing a voiding cystourethrogram (VCUG). However, such an interval may reduce the likelihood of completing the procedure. This study was performed to investigate whether the length of the interval between a UTI and the performance of the VCUG influences the presence or severity of reflux, and whether it influences the likelihood of actually having the study performed.

DESIGN

We reviewed 352 admissions of children under 10 years old whose discharge diagnoses indicated UTIs. These admissions occurred over a 27-month period between October 1994 and December 1996 at the Children's Hospital of Austin, Texas. We identified 213 patients with confirmed UTIs and no other previously defined urinary tract pathology. These patients were divided into 2 groups according to whether they had a VCUG scheduled to be performed either within 1 week after the diagnosis of a UTI (the early group), or later than 1 week after the diagnosis (the late group). We compared the presence and severity of reflux in the 2 groups as well as the proportion of scheduled VCUGs that were actually performed.

RESULTS

Reflux was present in 19% of the patients studied within 1 week after UTI (95% confidence interval [CI]: 12.9-26.4) and in 18% of those studied after 1 week (95% CI: 6. 7-34.5). This difference was not statistically significant (chi(2) =. 034; DF = 1). However there was a substantial difference between the 2 groups with regard to the number of scheduled VCUGs actually performed. Whereas 100% of the scheduled VCUGs in the early group were performed, only 48% (95% CI: 35.9-60.1) of those scheduled in the late group were performed. This difference is statistically significant (chi(2) = 89.6; DF = 1).

CONCLUSIONS

In the hospitalized children who underwent VCUGs within a week after diagnosis of UTI, the presence of reflux is not significantly different from those studied later. Furthermore, late scheduling of VCUGs resulted in failure to perform the procedure in more than half of the patients. Some of the patients who were not evaluated would be expected to have vesicoureteral reflux and thus be at risk for chronic renal disease. Therefore, the traditional recommendation to perform the VCUG at 3 to 6 weeks after the diagnosis of UTI should be reconsidered, especially for hospitalized children.

Aortic valve replacement in children: are mechanical prostheses a good option?

OBJECTIVE

The choice of the most appropriate substitute in children with irreparable aortic valve lesions remains controversial. The aim of this study was to assess early and late outcomes following aortic valve replacement (AVR) with mechanical prostheses in children.

PATIENTS

Fifty-six patients (42 male, 14 female, mean age 11.2, range 1-16 years) undergoing AVR with mechanical prostheses between October 1972 and January 1999 were evaluated. Thirty-six patients (64.2%) underwent previous cardiac surgery. Disease aetiology was congenital in 47 patients (congenital aortic stenosis in 33, and other congenital abnormalities in 14) (83.9%), infective in four (7. 1%), rheumatic in two (3.4%), and three (5.3%) had connective tissue disorders. Haemodynamic indication for AVR was aortic regurgitation (AR) in 24 (42.8%), aortic stenosis (AS) in 22 (39.2%) and mixed disease in ten (17.8%). Twenty-eight patients (50.0%) were in New York Heart Association (NYHA) class III-IV before surgery. Concomitant procedures were performed in 31 patients (55.3%), including aortic root enlargement in 28 (50%). The mean size of implanted valves was 22.4 mm (range 17-27 mm). All patients received long-term anticoagulation treatment with sodium warfarin, aiming to maintain an international normalized ratio (INR) between 2.5-3.0. The mean follow-up was 7.3 years (range 0-26, total 405 patient-years).

RESULTS

Operative mortality was 5.3% (three patients). Three patients developed complete heart block requiring pacing, two of them permanently. Late events included valve thrombosis (one), transient stroke (one), paravalvular leak of a mitral prosthesis (one), aneurysm of sinus of Valsalva (one) and pannus ingrowth (one). There was no major haemorrhagic event. Five patients required re-operation (8.9%), but none due to outgrowth of the valve. Regarding actuarial freedom from thrombo-embolism, any valve-related event and re-operation at 20 years was 93, 86.6 and 86. 4%. There were three late deaths. Actuarial survival, including operative mortality, at 10 and 20 years was 91 and 84.9%. The actuarial survival for the group of the patients with congenital AS (n=33) at 10 and 20 years was 93.5%, whereas for the children with other congenital heart problems (n=14) this was 85.7 and 64.3% (P=0. 09). At the latest clinical evaluation, 44 children were in NYHA class I and six were in class II. The mean gradient across the aortic prosthetic valve on echocardiography was 17.9 mmHg (range 0-47 mmHg).

CONCLUSIONS

Mechanical AVR, with enlargement of the aortic root if necessary, remains an excellent treatment option in children. It is associated with acceptable operative mortality, low incidence of late events and re-operation, and provides good long-term survival. It clearly represents a good alternative to available biological substitutes, including the pulmonary autograft (Ross procedure).

Alcohol, cannabis and cocaine usage in patients with trauma injuries

Sera from 111 patients with trauma injuries, who presented to the Accident and Emergency Unit (A&E), University Hospital of the West Indies, during a 3-month period, were screened for blood alcohol. Urine specimens were analysed for metabolites of cannabis and cocaine. Sixty-two per cent (62%) of patients were positive for at least one substance and 20% for two or more. Positivity rates were as follows: cannabis (46%), alcohol (32%) with 71% of these having blood alcohol levels (BAC) greater than 80 mg per decilitre; cocaine (6%). Substance usage was most prevalent in the third decade of life. The patients who yielded a positive result were significantly younger than those who were negative. There was no significant difference in age or substance usage between the victims of interpersonal violence or road traffic accidents. In the group designated "other accidents", patients were significantly older and had a lower incidence of substance usage than the other two groups. Cannabis was the most prevalent substance in all groups. Fifty per cent (50%) and fifty-five per cent (55%) of victims of road accidents and interpersonal violence, respectively, were positive for cannabis compared with 43% and 27% for alcohol, respectively. There was no significant difference in Hospital Stay or Injury Severity Score between substance users and non-users.

The persistence and clonal spread of a single strain of Acinetobacter 13TU in a large Scottish teaching hospital

This study describes the persistence and spread of a single strain of Acinetobacter 13TU in a large Scottish teaching hospital. Acinetobacter spp. are reported with increasing frequency as a cause of nosocomial infection. The species most implicated in these infections is Acinetobacter baumannii. Following an outbreak of infection with Acinetobacter 13TU within the intensive therapy unit (ITU) of Edinburgh Royal Infirmary (ERI) during 1994-1995, the current epidemiological Acinetobacter situation within the hospital was monitored to determine whether or not control of infection procedures instigated at that time had been successful in controlling the outbreak. Sixty-eight strains of Acinetobacter spp were isolated from clinical specimens received from various wards in the ERI and other associated hospitals over a 7-month period. Each isolate was typed phenotypically by the API20NE system and genotypically by pulsed field gel electrophoresis (PFGE) in order to compare them with the previous outbreak strain. Fifty-three percent of the isolates collected were originally identified as A. junii by API 20 NE, of which 83% (mainly from ITU) were shown to be genotypically related to the previous outbreak strain. Subsequent tDNA fingerprinting of one of the original outbreak strains showed it to be a member of the genospecies 13TU and not A. junii as originally thought.

Trauma aetiology and cost in the Accident and Emergency Unit of the University Hospital of the West Indies

Trauma accounted for 37% of 22,311 patients seen in the Accident and Emergency Unit (A&E Unit) at the University Hospital of the West Indies (UHWI) during 1996. Thirty-nine per cent of injuries were intentional and 18% were due to motor vehicle accidents. Knives, machetes and rocks accounted for 75% of the injuries compared with 5% for gunshot wounds. Passengers were injured in about 40% of motor vehicle accidents and pedestrians in 19%. The admission rate was 16% and the orthopaedic clinic received 75% of the patients referred to specialist clinics. Victims of motor vehicle accidents made up a greater proportion of admissions (24%) than those of intentional violence (13%). The average cost of caring for each patient in the A&E unit was US$70 resulting in an annual cost of US$578,000.

(Alpha)3(beta)1 integrin regulates epithelial cytoskeletal organization

Epithelial cell morphology and cytoskeletal organization are determined by interactions, with both adjacent cells and the extracellular matrix, which are mediated by integrins and cadherins. Little is known, however, of the relative contributions of integrins and cadherins to maintaining the sub-cortical cytoskeleton characteristic of epithelial cells. Since most studies that utilize integrin-blocking antibodies result in a loss of both cell-cell adhesion and sub-cortical cytoskeletal organization, it has been difficult to distinguish whether integrins and cadherins both mediate cytoskeletal assembly in epithelial cells. Therefore, cells derived from kidney collecting ducts of (alpha)3(beta)1 integrin-deficient mice were used to examine the role of integrins in epithelial cell morphology and cytoskeletal organization. In primary cell culture, (alpha)3(beta)1 integrin-deficient kidney collecting duct cells maintain cadherin-mediated cell-cell adhesions but fail to form the sub-cortical cytoskeleton that is characteristic of epithelial cells, and instead assemble actin stress fibers. Moreover, the cell-cell junctions in mutant cells were irregular, rather than being uniformly oriented perpendicular to the culture substrate. These results demonstrated that integrins have an primary and essential function in establishing and maintaining the sub-cortical cytoskeleton that is characteristic of epithelial cells. To further study the role of (alpha)3(beta)1 integrin in establishing and maintaining cytoskeletal organization in tubular epithelial cells, we derived immortalized cell lines from wild-type and (alpha)3(beta)1 integrin-deficient kidney collecting ducts that duplicated the cytoskeletal and cadherin organization observed in primary cells. E-cadherin and (alpha)- and (beta)-catenin were complexed together in equal amounts in membranes of wild-type and (alpha)3(beta)1 integrin-deficient cells. However, association of the cadherin:catenin complex with (alpha)-actinin was greatly decreased in mutant cells, indicating that integrin-mediated assembly of the sub-cortical cytoskeleton is essential for subsequent association of the cytoskeleton with the cadherin:catenin complex. These results present direct evidence for integrin:cadherin cross-regulation in which cadherin function is dependent on the presence of an integrin.

The protein kinase C inhibitor CGP41251 suppresses cytokine release and extracellular signal-regulated kinase 2 expression in cancer patients

Components of cell signaling pathways provide important targets for anticancer drugs. Protein kinase C (PKC) is a serine/threonine-specific kinase that regulates cell growth and differentiation. It is also implicated in tumor promotion. The staurosporine analogue CGP41251 is a PKC inhibitor, and it is currently in a Phase I clinical trial for treatment of advanced cancer. However, it is difficult to define its biological activity. We have used two approaches to measure the in vivo biological response to CGP41251: (a) sequential whole blood samples were taken from 27 patients before and during treatment and incubated with mitogen (PHA), and cytokine [tumor necrosis factor (TNF)-alpha and interleukin (IL)-6] release was measured ex vivo; and (b) peripheral blood lymphocytes were isolated from seven of these patients, and the levels of extracellular signal-regulated kinase 2 were measured by Western blotting. Response to PHA was significantly lowered during treatment (P < 0.001 for TNF-alpha production; P < 0.03 for IL-6). This was most evident at 7 and 28 days after the start of treatment in patients receiving higher doses (150-300 mg/day; P = 0.002 and P = 0.02, respectively, for TNF-alpha and P = 0.001 and P = 0.003, respectively, for IL-6 release). Whole blood cytokine production returned to pretreatment levels after drug administration ceased. The levels of extracellular signal-regulated kinase 2 were reduced by 50-97% during treatment in all seven patients tested. These results show for the first time that a PKC inhibitor can block in vivo signaling pathways in cancer patients. The assays we describe complement toxicity studies in selecting relevant doses for Phase II trial of novel agents, particularly when biological activity occurs at doses below those that cause obvious side effects.