Excellent translational research in oncology: A journey towards novel and more effective anti-cancer therapies

Comprehensive Cancer Centres (CCCs) serve as critical drivers for improving cancer survival. In Europe, we have developed an Excellence Designation System (EDS) consisting of criteria to assess "excellence" of CCCs in translational research (bench to bedside and back), with the expectation that many European CCCs will aspire to this status.

START (STrAtegies for RelaTives) study: a pragmatic randomised controlled trial to determine the clinical effectiveness and cost-effectiveness of a manual-based coping strategy programme in promoting the mental health of carers of people with dementia

BACKGROUND

Two-thirds of people with dementia live at home, receiving most care from family carers, about 40% of whom have clinically significant depression or anxiety. This impacts on the person with dementia, families and society, predicting care breakdown. There are currently no clinically effective and cost-effective NHS family carer interventions.

OBJECTIVES

To assess the STrAtegies for RelaTives (START) intervention in the short (4 and 8 months) and long term (1 and 2 years) compared with treatment as usual (TAU).

DESIGN

Randomised, parallel-group, superiority trial with blinded assessment recruiting participants 2:1 (intervention to TAU) to allow for therapist clustering.

SETTING

Three UK mental health services and one neurological service.

PARTICIPANTS

Family carers of people with dementia.

INTERVENTION

Eight-session manual-based coping intervention delivered by supervised psychology graduates to individuals.

MAIN OUTCOME MEASURES

Affective symptoms [Hospital Anxiety and Depression Scale-total (HADS-T)] and cost-effectiveness. Secondary measures: anxiety and depression symptoms and caseness, quality of life (QoL), abusive behaviour and long-term care home admission.

RESULTS

Two hundred and sixty participants were randomised (173 intervention, 87 TAU). We used intention-to-treat analysis in the short term (152 intervention, 77 TAU) and in the long term (140 intervention, 69 TAU). In the short term, the intervention group had lower HADS-T [mean difference -1.80, 95% confidence interval (CI) -3.29 to -0.31; p=0.02] and higher quality-adjusted life-years (QALYs) (mean difference 0.03, 95% CI -0.01 to 0.08). Costs were no different between groups [mean £ 252 (95% CI -£ 28 to £ 565) for intervention group]. The cost-effectiveness acceptability curve showed a greater than 99% chance of being cost-effectiveness at a £ 30,000/QALY willingness-to-pay threshold and a high probability of cost-effectiveness based on the HADS-T score. Carers in the intervention group had less case-level depression [odds ratio (OR) 0.24, 95% CI 0.07 to 0.76], a trend towards reduced case-level anxiety (OR 0.30, 95% CI 0.08 to 1.05), lower Hospital Anxiety and Depression Scale-anxiety (HADS-A) (-0.91, 95% CI -1.76 to -0.07; p = 0.03) and Hospital Anxiety and Depression Scale-depression (HADS-D) (-0.91, 95% CI -1.71 to -0.10; p = 0.03) and higher Health Status Questionnaire (HSQ) QoL (mean difference 4.09, 95% CI 0.34 to 7.83). Group differences in abusive behaviour (OR 0.48, 95% CI 0.18 to 1.27) and the person with dementia's quality of life-Alzheimer's disease (QoL-AD) (mean increase 0.59, 95% CI -0.72 to 1.89) were not significant. In the long term, the intervention group had lower HADS-T (mean difference -2.58, 95% CI -4.26 to -0.90; p = 0.03) and higher QALYs (mean difference 0.03, 95% CI -0.01 to 0.06). Carers in the intervention group had less case-level depression (OR 0.14, 95% CI 0.04 to 0.53), a trend towards reduced case-level anxiety (OR 0.57, 95% CI 0.26 to 1.24), lower HADS-A (-1.16, 95% CI -2.15 to -0.18) and HADS-D (1.45, 95% CI -2.32 to -0.57), and higher HSQ (mean difference 7.47, 95% CI 2.87 to 12.08). Thirty-two (18.7%) people with dementia in the intervention group and 17 (20.2%) in TAU were admitted to a care home (hazard ratio 0.83, 95% CI 0.44 to 1.56; p = 0.56). There were no significant differences between groups in abusive behaviour (OR 0.83, 95% CI 0.36 to 1.94), the person with dementia's QoL-AD (0.17, 95% CI -1.37 to 1.70) or costs (£ 336, 95% CI -£ 223 to £ 895) for intervention group. The probability that the intervention would be seen as cost-effective at £ 30,000/QALY threshold and cost-effectiveness on the HADS-T remained high.

CONCLUSIONS

The START intervention was clinically effective and cost-effective in the short and longer term. The results are robust to the sensitivity analyses performed. Future work is needed to consider mechanism of action; the effects on people with dementia in clinical terms (cognition, neuropsychiatric symptoms, longer-term care home admission); and on health and social care costs. In addition, we will explore the effects of carer abusive behaviour on the care recipient's care home admission and if this then reduces abusive behaviour. We would also like to implement START and evaluate this implementation in clinical practice.

TRIAL REGISTRATION

Current Controlled Trials ISCTRN70017938.

Long-term clinical and cost-effectiveness of psychological intervention for family carers of people with dementia: a single-blind, randomised, controlled trial

BACKGROUND

Two-thirds of people with dementia live at home supported mainly by family carers. These carers frequently develop clinical depression or anxiety, which predicts care breakdown. We aimed to assess the clinical effectiveness (long-term reduction of depression and anxiety symptoms in family carers) and cost-effectiveness of a psychological intervention called START (STrAtegies for RelaTives).

METHODS

We did a randomised, parallel-group trial with masked outcome assessments in three UK mental-health services and one neurological-outpatient dementia service. We included self-identified family carers of people with dementia who had been referred in the previous year and gave support at least once per week to the person with dementia. We randomly assigned these carers, via an online computer-generated randomisation system from an independent clinical trials unit, to either START, an 8-session, manual-based coping intervention delivered by supervised psychology graduates, or treatment as usual (TAU). The primary long-term outcomes were affective symptoms (Hospital Anxiety and Depression Scale total score [HADS-T]) 2 years after randomisation and cost-effectiveness (health and social care perspectives) over 24 months. Analysis was by intention to treat, excluding carers with data missing at both 12 and 24 months. This trial is registered ISCTRN70017938.

FINDINGS

From November 4, 2009, to June 8, 2011, we recruited 260 carers. 173 carers were randomly assigned to START and 87 to TAU. Of these 260 participants, 209 (80%) were included in the clinical efficacy analysis (140 START, 69 TAU). At 24 months, compared with TAU the START group was significantly better for HADS-T (mean difference -2·58 points, 95% CI -4·26 to -0·90; p=0·003). The intervention is cost effective for both carers and patients (67% probability of cost-effectiveness at the £20 000 per QALY willingness-to-pay threshold, and 70% at the £30 000 threshold).

INTERPRETATION

START is clinically effective, improving carer mood and anxiety levels for 2 years. Carers in the control TAU group were seven times more likely to have clinically significant depression than those receiving START. START is cost effective with respect to carer and patient outcomes, and National Institute for Health and Care Excellence (NICE) thresholds. The number of people with dementia is rapidly growing, and policy frameworks assume that their families will remain the frontline providers of (unpaid) support. This cost-neutral intervention, which substantially improves family-carers' mental health and quality of life, should therefore be widely available.

FUNDING

National Institute for Health Research Health Technology Assessment programme 08/14/06.

Cost effectiveness of a manual based coping strategy programme in promoting the mental health of family carers of people with dementia (the START (STrAtegies for RelaTives) study): a pragmatic randomised controlled trial

OBJECTIVE

To assess whether the START (STrAtegies for RelatTives) intervention added to treatment as usual is cost effective compared with usual treatment alone.

DESIGN

Cost effectiveness analysis nested within a pragmatic randomised controlled trial.

SETTING

Three mental health and one neurological outpatient dementia service in London and Essex, UK.

PARTICIPANTS

Family carers of people with dementia.

INTERVENTION

Eight session, manual based, coping intervention delivered by supervised psychology graduates to family carers of people with dementia added to usual treatment, compared with usual treatment alone.

PRIMARY OUTCOME MEASURES

Costs measured from a health and social care perspective were analysed alongside the Hospital Anxiety and Depression Scale total score (HADS-T) of affective symptoms and quality adjusted life years (QALYs) in cost effectiveness analyses over eight months from baseline.

RESULTS

Of the 260 participants recruited to the study, 173 were randomised to the START intervention, and 87 to usual treatment alone. Mean HADS-T scores were lower in the intervention group than the usual treatment group over the 8 month evaluation period (mean difference -1.79 (95% CI -3.32 to -0.33)), indicating better outcomes associated with the START intervention. There was a small improvement in health related quality of life as measured by QALYs (0.03 (-0.01 to 0.08)). Costs were no different between the intervention and usual treatment groups (£252 (-28 to 565) higher for START group). The cost effectiveness calculations suggested that START had a greater than 99% chance of being cost effective compared with usual treatment alone at a willingness to pay threshold of £30,000 per QALY gained, and a high probability of cost effectiveness on the HADS-T measure.

CONCLUSIONS

The manual based coping intervention START, when added to treatment as usual, was cost effective compared with treatment as usual alone by reference to both outcome measures (affective symptoms for family carers, and carer based QALYs).

TRIAL REGISTRATION

ISCTRN 70017938.

Clinical effectiveness of a manual based coping strategy programme (START, STrAtegies for RelaTives) in promoting the mental health of carers of family members with dementia: pragmatic randomised controlled trial

OBJECTIVE

To assess whether a manual based coping strategy compared with treatment as usual reduces depression and anxiety symptoms in carers of family members with dementia.

DESIGN

Randomised, parallel group, superiority trial.

SETTING

Three mental health community services and one neurological outpatient dementia service in London and Essex, UK.

PARTICIPANTS

260 carers of family members with dementia.

INTERVENTION

A manual based coping intervention comprising eight sessions and delivered by supervised psychology graduates to carers of family members with dementia. The programme consisted of psychoeducation about dementia, carers' stress, and where to get emotional support; understanding behaviours of the family member being cared for, and behavioural management techniques; changing unhelpful thoughts; promoting acceptance; assertive communication; relaxation; planning for the future; increasing pleasant activities; and maintaining skills learnt. Carers practised these techniques at home, using the manual and relaxation CDs.

MAIN OUTCOME MEASURES

Affective symptoms (hospital anxiety and depression total score) at four and eight months. Secondary outcomes were depression and anxiety caseness on the hospital anxiety and depression scale; quality of life of both the carer (health status questionnaire, mental health) and the recipient of care (quality of life-Alzheimer's disease); and potentially abusive behaviour by the carer towards the recipient of care (modified conflict tactics scale).

RESULTS

260 carers were recruited; 173 were randomised to the intervention and 87 to treatment as usual. Mean total scores on the hospital anxiety and depression scale were lower in the intervention group than in the treatment as usual group over the eight month evaluation period: adjusted difference in means -1.80 points (95% confidence interval -3.29 to -0.31; P=0.02) and absolute difference in means -2.0 points. Carers in the intervention group were less likely to have case level depression (odds ratio 0.24, 95% confidence interval 0.07 to 0.76) and there was a non-significant trend towards reduced case level anxiety (0.30, 0.08 to 1.05). Carers' quality of life was higher in the intervention group (difference in means 4.09, 95% confidence interval 0.34 to 7.83) but not for the recipient of care (difference in means 0.59, -0.72 to 1.89). Carers in the intervention group reported less abusive behaviour towards the recipient of care compared with those in the treatment as usual group (odds ratio 0.47, 95% confidence interval 0.18 to 1.23), although this was not significant.

CONCLUSIONS

A manual based coping strategy was effective in reducing affective symptoms and case level depression in carers of family members with dementia. The carers' quality of life also improved.

TRIAL REGISTRATION

Current Controlled Trials ISCTRN70017938.

Functional interactions between BRCA1 and the checkpoint kinase ATR during genotoxic stress

The BRCA1 gene encodes a tumor suppressor that is mutated in 50% of familial breast cancers. The BRCA1 protein has been implicated in the DNA damage response, as DNA damage induces the phosphorylation of BRCA1 and causes its recruitment into nuclear foci that contain DNA repair proteins. The ataxia-telangiectasia-mutated (ATM) gene product controls overall BRCA1 phosphorylation in response to gamma-irradiation (IR). In this study, we show that BRCA1 phosphorylation is only partially ATM dependent in response to IR and ATM independent in response to treatment with UV light, or the DNA replication inhibitors hydroxyurea (HU) and aphidicolin (APH). We provide evidence that the kinase responsible for this phosphorylation is the ATM-related kinase, ATR. ATR phosphorylates BRCA1 on six Ser/Thr residues, including Ser 1423, in vitro. Increased expression of ATR enhanced the phosphorylation of BRCA1 on Ser 1423 following cellular exposure to HU or UV light, whereas doxycycline-induced expression of a kinase-inactive ATR mutant protein inhibited HU- or UV light-induced Ser 1423 phosphorylation in GM847 fibroblasts, and partially suppressed the phosphorylation of this site in response to IR. Thus, ATR, like ATM, controls BRCA1 phosphorylation in vivo. Although ATR isolated from DNA-damaged cells does not show enhanced kinase activity in vitro, we found that ATR responds to DNA damage and replication blocks by forming distinct nuclear foci at the sites of stalled replication forks. Furthermore, ATR nuclear foci overlap with the nuclear foci formed by BRCA1. The dramatic relocalization of ATR in response to DNA damage points to a possible mechanism for its ability to enhance the phosphorylation of substrates in response to DNA damage. Together, these results demonstrate that ATR and BRCA1 are components of the same genotoxic stress-responsive pathway, and that ATR directly phosphorylates BRCA1 in response to damaged DNA or stalled DNA replication.

Precise measurement of the J = 1 to J = 2 fine structure interval in the 2( 3)P state of helium

We measure the J = 1 to J = 2 fine structure interval in the ( 3)2P state of helium to be 2 291 175.9(1.0) kHz. We use laser excitation of an atomic beam along with an integrated electro-optic modulator technique to obtain this result. The result is consistent (2.9+/-3.2 kHz) with what could be considered an earlier version of this experiment but is not in good agreement ( 20+/-5 kHz and 22+/-8 kHz) with the two other precision determinations of this interval. The current theoretical prediction lies between and overlaps the experiments.

Localization of human BRCA1 and its loss in high-grade, non-inherited breast carcinomas

Although the link between the BRCA1 tumour-suppressor gene and hereditary breast and ovarian cancer is established, the role, if any, of BRCA1 in non-familial cancers is unclear. BRCA1 mutations are rare in sporadic cancers, but loss of BRCA1 resulting from reduced expression or incorrect subcellular localization is postulated to be important in non-familial breast and ovarian cancers. Epigenetic loss, however, has not received general acceptance due to controversy regarding the subcellular localization of BRCA1 proteins, reports of which have ranged from exclusively nuclear, to conditionally nuclear, to the ER/golgi, to cytoplasmic invaginations into the nucleus. In an attempt to resolve this issue, we have comprehensively characterized 19 anti-BRCA1 antibodies. These reagents detect a 220-kD protein localized in discrete nuclear foci in all epithelial cell lines, including those derived from breast malignancies. Immunohistochemical staining of human breast specimens also revealed BRCA1 nuclear foci in benign breast, invasive lobular cancers and low-grade ductal carcinomas. Conversely, BRCA1 expression was reduced or undetectable in the majority of high-grade, ductal carcinomas, suggesting that absence of BRCA1 may contribute to the pathogenesis of a significant percentage of sporadic breast cancers.

Microsurgical selective peripheral neurotomy in the treatment of spasticity in cerebral-palsy children

Spasticity represents the most handicapping sequelae of cerebral palsy in children. In this study, 28 children with spastic cerebral palsy were treated over the last 4 years by microsurgical selective peripheral neurotomy: 28 times the posterior tibial nerve for spastic foot deformity, 3 times the ulnar and median nerves for spastic flexion of wrist and fingers, 2 times the sciatic nerve for spastic knee flexion associated with spastic foot deformity and 3 times obturator nerves for spastic adductors. Results on spasticity with follow-up ranging from 3 to 48 months were as follows: spastic foot deformity was corrected in all patients with pure spasticity, 2 out of the 3 children with ulnar and median neurotomy improved, knee flexion and hip adduction were improved in the other 5 patients. Selective peripheral neurotomy is an effective procedure in the treatment of segmental harmful spasticity after failure of a well-conducted conservative treatment associating physiotherapy and antispasmodic medications. It must be performed before the fixed deformities and other orthopedic complications arise.

Cytokine activation through sublethal hemorrhage is protective against early lethal endotoxic challenge

OBJECTIVES

To determine the immunologic consequences of nonlethal hemorrhage on subsequent exposure to lipopolysaccharide (LPS) and to determine the role of interleukin 1 beta (IL-1) specifically in mediating the response to LPS with and without prior hemorrhage.

DESIGN

Prospective, randomized, controlled experimental trial.

PARTICIPANTS

Male BALB/c mice and transgenic mice deficient in IL-1 converting enzyme.

INTERVENTIONS

Animals were subjected to hemorrhage (by cardiac puncture), LPS challenge by intraperitoneal injection, or hemorrhage followed 24 hours later by LPS challenge. Mortality was assessed every 4 hours for 96 hours following hemorrhage or LPS exposure. Serum IL-1 levels were determined 24 hours after exposure to hemorrhage and LPS.

SETTING

University of South Florida Core General Surgery Research Facility, Tampa.

MAIN OUTCOME MEASURES

Mortality and serum IL-1 levels.

RESULTS

Hemorrhage alone resulted in complete survival, whereas LPS alone resulted in near-complete (95%) mortality. Hemorrhage, when given 24 hours before LPS challenge, afforded significant protection compared with LPS alone (67% survival vs 5% survival; P < .001). Serum IL-1 levels 24 hours after exposure to LPS were significantly lower in prehemorrhaged mice than in those receiving LPS alone. Transgenic mice incapable of producing biologically active IL-1 were further protected, demonstrating near-complete (95%) survival following hemorrhage and LPS challenge.

CONCLUSIONS

Cytokine activation through nonlethal hemorrhage attenuates subsequent IL-1 response to early immunologic challenge. Such immune suppression appears to be protective early on and is supported by the near-complete immunity to LPS in animals incapable of producing biologically active IL-1.

Severity and mortality of experimental pancreatitis are dependent on interleukin-1 converting enzyme (ICE)

Interleukin-1 beta (IL-1 beta) is produced in large amounts during acute pancreatitis and is believed to play a role in disease progression. Because secretion of IL-1 beta is dependent on intracellular processing of pro-IL-1 beta by IL-1 converting enzyme (ICE), we aimed to determine the efficacy of a novel ICE inactivator (VE-13045) in inhibiting secretion of active IL-1 beta in vivo and if the loss of ICE activity would affect the severity and mortality of experimental pancreatitis. Severe hemorrhagic pancreatitis was induced in adult rats by infusion of bile acid into the pancreatic duct. Animals were randomized to receive VE-13045 or vehicle before induction of pancreatitis. To confirm our findings and to ensure that the results were not model dependent, a second series of experiments was conducted using mice possessing a homozygous knockout of the ICE gene in which lethal pancreatitis was induced by feeding a choline-deficient, ethionine-supplemented diet. The severity of pancreatitis was assessed for both experiments by standard surrogate markers, blind histologic grading, and serum IL-1 beta and tumor necrosis factor-alpha (TNF-alpha) levels. Pancreatic IL-1 beta mRNA induction was assessed by differential RT-PCR. Acute pancreatitis was associated with a 120-fold increase in IL-1 beta mRNA, which was not affected by ICE inhibition or gene deletion. Cytokine processing and secretion were affected, as evidenced by decreased serum levels of IL-1 beta and TNF-alpha (p < 0.001) in all animals with an inactive ICE enzyme. This lack of cytokine production increased survival from 32% to 78% following bile salt pancreatitis (p < 0.01) and from 24% to 80% following diet-induced pancreatitis (p < 0.005). Both ICE-defective groups demonstrated decreased pancreatic necrosis, edema, inflammation, wet weight (all p < 0.05), and amylase and lipase (p < 0.01). In vivo blockade or genetic deletion of ICE inhibits pancreatitis-induced secretion of proinflammatory cytokines without altering IL-1 mRNA production and is associated with decreased pancreatitis severity and dramatic survival benefits.

A framework for integrated quality improvement

The importance of maintaining and improving quality is well understood in most health care organizations. This work becomes more challenging as internal and external conditions rapidly change. A quality improvement framework was developed to help clinicians and administrators organize intergrated, multifaceted quality programs that have the flexibility necessary for success in today's fast-paced health care environment.

Relief of YY1 transcriptional repression by adenovirus E1A is mediated by E1A-associated protein p300

YY1 represses transcription when bound upstream of transcriptional initiation sites. This repression can be relieved by adenovirus E1A. Here, we present genetic evidence that the ability of E1A to relieve YY1 repression was impaired by mutations that affect E1A binding to its associated protein p300. This suggests that E1A may modulate the repressor activity of YY1 by binding to p300, which may be physically complexed with YY1. A YY1/p300 protein complex in vivo was demonstrated by several independent approaches, and the YY1-interacting domain was mapped to the carboxy-terminal region of p300, distinct from the E1A-binding site. Unlike E2F/RB, the YY1/p300 complex is not disrupted by E1A. Functional studies using recombinant p300 demonstrated unequivocally that p300 is capable of mediating E1A-induced transcriptional activation through YY1. Taken together, these results reveal, for the first time, a YY1/p300 complex that is targeted by E1A and demonstrate a function for p300 in mediating interactions between YY1 and E1A. Our data thus identify YY1 as a partner protein for p300 and uncover a molecular mechanism for the relief of YY1-mediated repression by E1A.

Inhibition of cell proliferation by p107, a relative of the retinoblastoma protein

The cellular protein p107 shares many structural and biochemical features with the retinoblastoma gene product, pRB. We have isolated a full-length cDNA for human p107 and have used this clone to study the function of p107. We show that, like pRB, p107 is a potent inhibitor of E2F-mediated trans-activation, and overexpression of p107 can inhibit proliferation in certain cell types, arresting sensitive cells in G1. Several experiments, however, showed that growth inhibition by pRB and p107 did not occur through the same mechanism. First, in the cervical carcinoma cell line C33A, p107 was able to block cell proliferation, whereas pRB could not, even though both proteins were potent inhibitors of E2F-mediated transcription in this cell line. Second, growth arrest by pRB and p107 was rescued differentially by various cell cycle regulators. Third, some mutants of p107 that cannot associate with adenovirus E1A were still able to inhibit cell proliferation, whereas analogous mutants in pRB are known to be unable to block cell growth. Together, these results suggest a biological role of p107 that is related, but not identical, to that of pRB.

Characterization of primary rabbit kidney cultures that express proximal tubule functions in a hormonally defined medium

Primary cultures of rabbit-kidney epithelial cells derived from purified proximal tubules were maintained without fibroblast overgrowth in a hormone-supplemented serum-free medium (Medium RK-1). A hormone-deletion study indicated that the primary cultures derived from purified rabbit proximal tubules required all of the three supplements in Medium RK-1 (insulin, transferrin, and hydrocortisone) for optimal growth but did not grow in response to EGF and T3. In contrast, the epithelial cells in primary cultures derived from an unpurified preparation of rabbit kidney tubules and glomeruli grew in response to EGF and T3, as well as insulin, transferrin, and hydrocortisone. These observations suggest that kidney epithelial cells derived from different segments of the nephron grow differently in response to hormones and growth factors. Differentiated functions of the primary cultures derived from proximal tubules were examined. Multicellular domes were observed, indicative of transepithelial solute transport by the monolayers. The proximal tubule cultures also accumulated alpha-methylglucoside (alpha-MG) against a concentration gradient. However, little or no alpha-MG accumulation was observed in the absence of Na+. Metabolic inhibitor studies also indicated that alpha-MG uptake by the primaries is an energy-dependent process, and depends upon the activity of the Na+/K+ ATPase. Phlorizin at 0.1 mM significantly inhibited 1 mM alpha-MG uptake whereas 0.1 mM phloretin did not have a significant inhibitory effect. Similar observations have been made concerning the Na+-dependent sugar-transport system located on the lumenal side of the proximal tubule, whereas the Na+-independent sugar transporter on the peritubular side is more sensitive to inhibition by phloretin than phlorizin. The cultures also exhibited PTH-sensitive cyclic AMP synthesis and brush-border enzymes typical of proximal cells. However, the activities of the enzymes leucine aminopeptidase, alkaline phosphatase, and gamma-glutamyl-transpeptidase were lower in the cultures than in purified proximal-tubule preparations from which they are derived.

The development of serum-free hormone-supplemented media for primary kidney cultures and their use in examining renal functions

We have demonstrated the primary kidney cultures and defined medium can be used for several purposes. First, primary kidney cultures can be examined in defined medium to evaluate the physiological significance of studies made with established kidney cell lines. Secondly, new kidney epithelial cell culture systems can be developed, using primary cultures and defined medium. The studies presented here have demonstrated several possible approaches towards these ends. First, a hormone-supplemented serum-free medium (Medium K-1) developed for an established dog kidney epithelial cell line (MDCK) was used to grow primary cultures of baby mouse kidney epithelial cells without fibroblast overgrowth. The primary cultures of baby mouse cells not only grew in response to each of the five supplements in Medium K-1, but also possessed several of the differentiated kidney functions observed in the MDCK cell line. Secondly, defined media were developed for primary cultures of rabbit kidney epithelial cells directly. The rabbit cells were shown to require a different set of supplements than MDCK cells to attain optimal growth. Furthermore primary cultures derived from purified rabbit proximal tubules required a different set of supplements than primary cultures derived from unpurified rabbit kidney tissue. These new primary culture systems should prove invaluable in examining renal transport functions in vitro.

Ocular hypertension: a comparative follow-up of black and white patients

Forty-four eyes in 25 black patients are compared with 92 eyes of 47 white patients in a population with ocular hypertension followed up for 1 to 12 years in a glaucoma clinic. The black patients present at a younger age than the whites and their mean initial intraocular pressure is significantly higher. The fact that more black ocular hypertensives developed glaucoma--8 eyes (18.1%) in the black population as compared with 5 eyes (5.4%) in the white population--is attributed to these two differences.