Commitments for Ethically Responsible Sourcing, Use, and Reuse of Patient Data in the Digital Age: Co-Creation Process (Preprint)

BACKGROUND

Personal information, including health-related data, may be used in ways we did not intend when it was originally shared. However, the organizations that collect these data do not always have the necessary social license to use and share it. Although some technology companies have published principles on the ethical use of artificial intelligence, the foundational issue of what is and is not acceptable to do with data, not just the analytical tools to manage it, has not been fully considered. Furthermore, it is unclear whether input from the public or patients has been included. In 2017, the leadership at a web-based patient research network began to envision a new kind of community compact that laid out what the company believed, how the company should behave, and what it promised both to the individuals who engaged with them and to the community at large. While having already earned a social license from patient members as a trusted data steward with strong privacy, transparency, and openness policies, the company sought to protect and strengthen that social license by creating a socially and ethically responsible data contract. Going beyond regulatory and legislative requirements, this contract considered the ethical use of multiomics and phenotypic data in addition to patient-reported and generated data.

OBJECTIVE

A multistakeholder working group sought to develop easy-to-understand commitments that established expectations for data stewardship, governance, and accountability from those who seek to collect, use, and share personal data. The working group cocreated a framework that was radically patient-first in its thinking and collaborative in the process of its codevelopment; it reflected the values, ideas, opinions, and perspectives of the cocreators, inclusive of patients and the public.

METHODS

Leveraging the conceptual frameworks of cocreation and participatory action research, a mixed methods approach was used that included a landscape analysis, listening sessions, and a 12-question survey. The methodological approaches used by the working group were guided by the combined principles of biomedical ethics and social license and shaped through a collaborative and reflective process with similarities to reflective equilibrium, a method well known in ethics.

RESULTS

Commitments for the Digital Age are the output of this work. The six commitments in order of priority are (1) continuous and shared learning; (2) respect and empower individual choice; (3) informed and understood consent; (4) people-first governance; (5) open communication and accountable conduct; and (6) inclusivity, diversity, and equity.

CONCLUSIONS

These 6 commitments-and the development process itself-have broad applicability as models for (1) other organizations that rely on digitized data sources from individuals and (2) patients who seek to strengthen operational policies for the ethical and responsible collection, use, and reuse of that data.

Identification of LAMA1 mutations ends diagnostic odyssey and has prognostic implications for patients with presumed Joubert syndrome

Paediatric neurology syndromes are a broad and complex group of conditions with a large spectrum of clinical phenotypes. Joubert syndrome is a genetically heterogeneous neurological ciliopathy syndrome with molar tooth sign as the neuroimaging hallmark. We reviewed the clinical, radiological and genetic data for several families with a clinical diagnosis of Joubert syndrome but negative genetic analysis. We detected biallelic pathogenic variants in LAMA1, including novel alleles, in each of the four cases we report, thereby establishing a firm diagnosis of Poretti-Boltshauser syndrome. Analysis of brain MRI revealed cerebellar dysplasia and cerebellar cysts, associated with Poretti-Boltshauser syndrome and the absence of typical molar tooth signs. Using large UK patient cohorts, the relative prevalence of Joubert syndrome as a cause of intellectual disability was 0.2% and of Poretti-Boltshauser syndrome was 0.02%. We conclude that children with congenital brain disorders that mimic Joubert syndrome may have a delayed diagnosis due to poor recognition of key features on brain imaging and the lack of inclusion of LAMA1 on molecular genetic gene panels. We advocate the inclusion of LAMA1 genetic analysis on all intellectual disability and Joubert syndrome gene panels and promote a wider awareness of the clinical and radiological features of these syndromes.

Variants in GNAI1 cause a syndrome associated with variable features including developmental delay, seizures, and hypotonia

PURPOSE

Neurodevelopmental disorders (NDDs) encompass a spectrum of genetically heterogeneous disorders with features that commonly include developmental delay, intellectual disability, and autism spectrum disorders. We sought to delineate the molecular and phenotypic spectrum of a novel neurodevelopmental disorder caused by variants in the GNAI1 gene.

METHODS

Through large cohort trio-based exome sequencing and international data-sharing, we identified 24 unrelated individuals with NDD phenotypes and a variant in GNAI1, which encodes the inhibitory Gαi1 subunit of heterotrimeric G-proteins. We collected detailed genotype and phenotype information for each affected individual.

RESULTS

We identified 16 unique variants in GNAI1 in 24 affected individuals; 23 occurred de novo and 1 was inherited from a mosaic parent. Most affected individuals have a severe neurodevelopmental disorder. Core features include global developmental delay, intellectual disability, hypotonia, and epilepsy.

CONCLUSION

This collaboration establishes GNAI1 variants as a cause of NDDs. GNAI1-related NDD is most often characterized by severe to profound delays, hypotonia, epilepsy that ranges from self-limiting to intractable, behavior problems, and variable mild dysmorphic features.

Development, behaviour and sensory processing in Marshall-Smith syndrome and Malan syndrome: phenotype comparison in two related syndromes

BACKGROUND

Ultrarare Marshall-Smith and Malan syndromes, caused by changes of the gene nuclear factor I X (NFIX), are characterised by intellectual disability (ID) and behavioural problems, although questions remain. Here, development and behaviour are studied and compared in a cross-sectional study, and results are presented with genetic findings.

METHODS

Behavioural phenotypes are compared of eight individuals with Marshall-Smith syndrome (three male individuals) and seven with Malan syndrome (four male individuals). Long-term follow-up assessment of cognition and adaptive behaviour was possible in three individuals with Marshall-Smith syndrome.

RESULTS

Marshall-Smith syndrome individuals have more severe ID, less adaptive behaviour, more impaired speech and less reciprocal interaction compared with individuals with Malan syndrome. Sensory processing difficulties occur in both syndromes. Follow-up measurement of cognition and adaptive behaviour in Marshall-Smith syndrome shows different individual learning curves over time.

CONCLUSIONS

Results show significant between and within syndrome variability. Different NFIX variants underlie distinct clinical phenotypes leading to separate entities. Cognitive, adaptive and sensory impairments are common in both syndromes and increase the risk of challenging behaviour. This study highlights the value of considering behaviour within developmental and environmental context. To improve quality of life, adaptations to environment and treatment are suggested to create a better person-environment fit.

Bi-allelic Loss-of-Function CACNA1B Mutations in Progressive Epilepsy-Dyskinesia

The occurrence of non-epileptic hyperkinetic movements in the context of developmental epileptic encephalopathies is an increasingly recognized phenomenon. Identification of causative mutations provides an important insight into common pathogenic mechanisms that cause both seizures and abnormal motor control. We report bi-allelic loss-of-function CACNA1B variants in six children from three unrelated families whose affected members present with a complex and progressive neurological syndrome. All affected individuals presented with epileptic encephalopathy, severe neurodevelopmental delay (often with regression), and a hyperkinetic movement disorder. Additional neurological features included postnatal microcephaly and hypotonia. Five children died in childhood or adolescence (mean age of death: 9 years), mainly as a result of secondary respiratory complications. CACNA1B encodes the pore-forming subunit of the pre-synaptic neuronal voltage-gated calcium channel Ca_v2.2/N-type, crucial for SNARE-mediated neurotransmission, particularly in the early postnatal period. Bi-allelic loss-of-function variants in CACNA1B are predicted to cause disruption of Ca²⁺ influx, leading to impaired synaptic neurotransmission. The resultant effect on neuronal function is likely to be important in the development of involuntary movements and epilepsy. Overall, our findings provide further evidence for the key role of Ca_v2.2 in normal human neurodevelopment.

De novo and biallelic DEAF1 variants cause a phenotypic spectrum

PURPOSE

To investigate the effect of different DEAF1 variants on the phenotype of patients with autosomal dominant and recessive inheritance patterns and on DEAF1 activity in vitro.

METHODS

We assembled a cohort of 23 patients with de novo and biallelic DEAF1 variants, described the genotype-phenotype correlation, and investigated the differential effect of de novo and recessive variants on transcription assays using DEAF1 and Eif4g3 promoter luciferase constructs.

RESULTS

The proportion of the most prevalent phenotypic features, including intellectual disability, speech delay, motor delay, autism, sleep disturbances, and a high pain threshold, were not significantly different in patients with biallelic and pathogenic de novo DEAF1 variants. However, microcephaly was exclusively observed in patients with recessive variants (p < 0.0001).

CONCLUSION

We propose that different variants in the DEAF1 gene result in a phenotypic spectrum centered around neurodevelopmental delay. While a pathogenic de novo dominant variant would also incapacitate the product of the wild-type allele and result in a dominant-negative effect, a combination of two recessive variants would result in a partial loss of function. Because the clinical picture can be nonspecific, detailed phenotype information, segregation, and functional analysis are fundamental to determine the pathogenicity of novel variants and to improve the care of these patients.

Further delineation of Malan syndrome

Malan syndrome is an overgrowth disorder described in a limited number of individuals. We aim to delineate the entity by studying a large group of affected individuals. We gathered data on 45 affected individuals with a molecularly confirmed diagnosis through an international collaboration and compared data to the 35 previously reported individuals. Results indicate that height is > 2 SDS in infancy and childhood but in only half of affected adults. Cardinal facial characteristics include long, triangular face, macrocephaly, prominent forehead, everted lower lip, and prominent chin. Intellectual disability is universally present, behaviorally anxiety is characteristic. Malan syndrome is caused by deletions or point mutations of NFIX clustered mostly in exon 2. There is no genotype‐phenotype correlation except for an increased risk for epilepsy with 19p13.2 microdeletions. Variants arose de novo, except in one family in which mother was mosaic. Variants causing Malan and Marshall‐Smith syndrome can be discerned by differences in the site of stop codon formation. We conclude that Malan syndrome has a well recognizable phenotype that usually can be discerned easily from Marshall–Smith syndrome but rarely there is some overlap. Differentiation from Sotos and Weaver syndrome can be made by clinical evaluation only.

Clinical and molecular characterization of KCNT1-related severe early-onset epilepsy

OBJECTIVE

To characterize the phenotypic spectrum, molecular genetic findings, and functional consequences of pathogenic variants in early-onset KCNT1 epilepsy.

METHODS

We identified a cohort of 31 patients with epilepsy of infancy with migrating focal seizures (EIMFS) and screened for variants in KCNT1 using direct Sanger sequencing, a multiple-gene next-generation sequencing panel, and whole-exome sequencing. Additional patients with non-EIMFS early-onset epilepsy in whom we identified KCNT1 variants on local diagnostic multiple gene panel testing were also included. When possible, we performed homology modeling to predict the putative effects of variants on protein structure and function. We undertook electrophysiologic assessment of mutant KCNT1 channels in a xenopus oocyte model system.

RESULTS

We identified pathogenic variants in KCNT1 in 12 patients, 4 of which are novel. Most variants occurred de novo. Ten patients had a clinical diagnosis of EIMFS, and the other 2 presented with early-onset severe nocturnal frontal lobe seizures. Three patients had a trial of quinidine with good clinical response in 1 patient. Computational modeling analysis implicates abnormal pore function (F346L) and impaired tetramer formation (F502V) as putative disease mechanisms. All evaluated KCNT1 variants resulted in marked gain of function with significantly increased channel amplitude and variable blockade by quinidine.

CONCLUSIONS

Gain-of-function KCNT1 pathogenic variants cause a spectrum of severe focal epilepsies with onset in early infancy. Currently, genotype-phenotype correlations are unclear, although clinical outcome is poor for the majority of cases. Further elucidation of disease mechanisms may facilitate the development of targeted treatments, much needed for this pharmacoresistant genetic epilepsy.

Heterozygous truncation mutations of the SMC1A gene cause a severe early onset epilepsy with cluster seizures in females: Detailed phenotyping of 10 new cases

OBJECTIVE

The phenotype of seizure clustering with febrile illnesses in infancy/early childhood is well recognized. To date the only genetic epilepsy consistently associated with this phenotype is PCDH19, an X-linked disorder restricted to females, and males with mosaicism. The SMC1A gene, which encodes a structural component of the cohesin complex is also located on the X chromosome. Missense variants and small in-frame deletions of SMC1A cause approximately 5% of Cornelia de Lange Syndrome (CdLS). Recently, protein truncating mutations in SMC1A have been reported in five females, all of whom have been affected by a drug-resistant epilepsy, and severe developmental impairment. Our objective was to further delineate the phenotype of SMC1A truncation.

METHOD

Female cases with de novo truncation mutations in SMC1A were identified from the Deciphering Developmental Disorders (DDD) study (n = 8), from postmortem testing of an affected twin (n = 1), and from clinical testing with an epilepsy gene panel (n = 1). Detailed information on the phenotype in each case was obtained.

RESULTS

Ten cases with heterozygous de novo mutations in the SMC1A gene are presented. All 10 mutations identified are predicted to result in premature truncation of the SMC1A protein. All cases are female, and none had a clinical diagnosis of CdLS. They presented with onset of epileptic seizures between <4 weeks and 28 months of age. In the majority of cases, a marked preponderance for seizures to occur in clusters was noted. Seizure clusters were associated with developmental regression. Moderate or severe developmental impairment was apparent in all cases.

SIGNIFICANCE

Truncation mutations in SMC1A cause a severe epilepsy phenotype with cluster seizures in females. These mutations are likely to be nonviable in males.

Clinical and genetic aspects of KBG syndrome

KBG syndrome is characterized by short stature, distinctive facial features, and developmental/cognitive delay and is caused by mutations in ANKRD11, one of the ankyrin repeat-containing cofactors. We describe 32 KBG patients aged 2-47 years from 27 families ascertained via two pathways: targeted ANKRD11 sequencing (TS) in a group who had a clinical diagnosis of KBG and whole exome sequencing (ES) in a second group in whom the diagnosis was unknown. Speech delay and learning difficulties were almost universal and variable behavioral problems frequent. Macrodontia of permanent upper central incisors was seen in 85%. Other clinical features included short stature, conductive hearing loss, recurrent middle ear infection, palatal abnormalities, and feeding difficulties. We recognized a new feature of a wide anterior fontanelle with delayed closure in 22%. The subtle facial features of KBG syndrome were recognizable in half the patients. We identified 20 ANKRD11 mutations (18 novel: all truncating) confirmed by Sanger sequencing in 32 patients. Comparison of the two ascertainment groups demonstrated that facial/other typical features were more subtle in the ES group. There were no conclusive phenotype-genotype correlations. Our findings suggest that mutation of ANKRD11 is a common Mendelian cause of developmental delay. Affected patients may not show the characteristic KBG phenotype and the diagnosis is therefore easily missed. We propose updated diagnostic criteria/clinical recommendations for KBG syndrome and suggest that inclusion of ANKRD11 will increase the utility of gene panels designed to investigate developmental delay. © 2016 The Authors. American Journal of Medical Genetics Part A Published by Wiley Periodicals, Inc.

Large-scale discovery of novel genetic causes of developmental disorders

Despite three decades of successful, predominantly phenotype-driven discovery of the genetic causes of monogenic disorders, up to half of children with severe developmental disorders of probable genetic origin remain without a genetic diagnosis. Particularly challenging are those disorders rare enough to have eluded recognition as a discrete clinical entity, those with highly variable clinical manifestations, and those that are difficult to distinguish from other, very similar, disorders. Here we demonstrate the power of using an unbiased genotype-driven approach to identify subsets of patients with similar disorders. By studying 1,133 children with severe, undiagnosed developmental disorders, and their parents, using a combination of exome sequencing and array-based detection of chromosomal rearrangements, we discovered 12 novel genes associated with developmental disorders. These newly implicated genes increase by 10% (from 28% to 31%) the proportion of children that could be diagnosed. Clustering of missense mutations in six of these newly implicated genes suggests that normal development is being perturbed by an activating or dominant-negative mechanism. Our findings demonstrate the value of adopting a comprehensive strategy, both genome-wide and nationwide, to elucidate the underlying causes of rare genetic disorders.

Delineation of the 3p14.1p13 microdeletion associated with syndromic distal limb contractures

Distal limb contractures (DLC) represent a heterogeneous clinical and genetic condition. Overall, 20-25% of the DLC are caused by mutations in genes encoding the muscle contractile apparatus. Large interstitial deletions of the 3p have already been diagnosed by standard chromosomal analysis, but not associated with a specific phenotype. We report on four patients with syndromic DLC presenting with a de novo 3p14.1p13 microdeletion. The clinical features associated multiple contractures, feeding problems, developmental delay, and intellectual disability. Facial dysmorphism was constant with low-set posteriorly rotated ears and blepharophimosis. Review of previously reported cases with a precise mapping of the deletions, documented a 250 kb smallest region of overlap (SRO) necessary for DLC. This region contained one gene, EIF4E3, the first three exons of the FOXP1 gene, and an intronic enhancer of FOXP1 named hs1149. Sanger sequencing and locus quantification of hs1149, EIF4E3, and FOXP1 in a cohort of 11 French patients affected by DLC appeared normal. In conclusion, we delineate a new microdeletion syndrome involving the 3p14.1p13 locus and associated with DLC and severe developmental delay.

Identification of critical regions and candidate genes for cardiovascular malformations and cardiomyopathy associated with deletions of chromosome 1p36

Cardiovascular malformations and cardiomyopathy are among the most common phenotypes caused by deletions of chromosome 1p36 which affect approximately 1 in 5000 newborns. Although these cardiac-related abnormalities are a significant source of morbidity and mortality associated with 1p36 deletions, most of the individual genes that contribute to these conditions have yet to be identified. In this paper, we use a combination of clinical and molecular cytogenetic data to define five critical regions for cardiovascular malformations and two critical regions for cardiomyopathy on chromosome 1p36. Positional candidate genes which may contribute to the development of cardiovascular malformations associated with 1p36 deletions include DVL1, SKI, RERE, PDPN, SPEN, CLCNKA, ECE1, HSPG2, LUZP1, and WASF2. Similarly, haploinsufficiency of PRDM16–a gene which was recently shown to be sufficient to cause the left ventricular noncompaction–SKI, PRKCZ, RERE, UBE4B and MASP2 may contribute to the development of cardiomyopathy. When treating individuals with 1p36 deletions, or providing prognostic information to their families, physicians should take into account that 1p36 deletions which overlie these cardiac critical regions may portend to cardiovascular complications. Since several of these cardiac critical regions contain more than one positional candidate gene–and large terminal and interstitial 1p36 deletions often overlap more than one cardiac critical region–it is likely that haploinsufficiency of two or more genes contributes to the cardiac phenotypes associated with many 1p36 deletions.

TUBA1A mutation-associated lissencephaly: case report and review of the literature

Lissencephaly is a disorder of neuronal migration resulting in abnormal cerebral cortical sulcation and gyration. Affected children present with microcephaly, developmental delay, and early-onset epileptic seizures. Recently, de novo missense mutations in the tubulin α-1A (TUBA1A) gene were identified as causing a distinctive radiologic phenotype comprising of posteriorly predominant lissencephaly with dysgenetic corpus callosum, cerebellar and brainstem hypoplasia, and more recently, polymicrogyria. We describe a 14-month-old girl with TUBA1A mutation-associated lissencephaly, and summarize the clinical and neuroradiologic findings of 19 cases in the literature.

A high-yielding serum-free, suspension cell culture process to manufacture recombinant adenoviral vectors for gene therapy

We have developed an efficient, reproducible, and scaleable cell culture process for a recombinant adenoviral vector expressing therapeutic transgenes for clinical trials. HEK 293 cells - which support the propagation of E1 deficient adenovirus - were first adapted to serum free media and suspension growth. Subsequent studies focused on the infection, virus production and harvest from suspension culture bioreactors. Future studies are planned to address the kinetics of adenovirus production in HEK 293 as well as in other cell lines.

Mutations in CHD7 in patients with CHARGE syndrome cause T-B + natural killer cell + severe combined immune deficiency and may cause Omenn-like syndrome

More than 11 genetic causes of severe combined immunodeficiency (SCID) have been identified, affecting development and/or function of T lymphocytes, and sometimes B lymphocytes and natural killer (NK) cells. Deletion of 22q11.2 is associated with immunodeficiency, although less than 1% of cases are associated with T-B + NK + SCID phenotype. Severe immunodeficiency with CHARGE syndrome has been noted only rarely Omenn syndrome is a rare autosomal recessive form of SCID with erythroderma, hepatosplenomegaly, lymphadenopathy and alopecia. Hypomorphic recombination activating genes 1 and 2 mutations were first described in patients with Omenn syndrome. More recently, defects in Artemis, RMRP, IL7Ralpha and common gamma chain genes have been described. We describe four patients with mutations in CHD7, who had clinical features of CHARGE syndrome and who had T-B + NK + SCID (two patients) or clinical features consistent with Omenn syndrome (two patients). Immunodeficiency in patients with DiGeorge syndrome is well recognized--CHARGE syndrome should now be added to the causes of T-B + NK + SCID, and mutations in the CHD7 gene may be associated with Omenn-like syndrome.

Comparative potencies of 3,4-methylenedioxymethamphetamine (MDMA) analogues as inhibitors of [3H]noradrenaline and [3H]5-HT transport in mammalian cell lines

BACKGROUND AND PURPOSE

Illegal 'ecstasy' tablets frequently contain 3,4-methylenedioxymethamphetamine (MDMA)-like compounds of unknown pharmacological activity. Since monoamine transporters are one of the primary targets of MDMA action in the brain, a number of MDMA analogues have been tested for their ability to inhibit [3H]noradrenaline uptake into rat PC12 cells expressing the noradrenaline transporter (NET) and [3H]5-HT uptake into HEK293 cells stably transfected with the 5-HT transporter (SERT).

EXPERIMENTAL APPROACH

Concentration-response curves for the following compounds at both NET and SERT were determined under saturating substrate conditions: 4-hydroxy-3-methoxyamphetamine (HMA), 4-hydroxy-3-methoxymethamphetamine (HMMA), 3,4-methylenedioxy-N-hydroxyamphetamine (MDOH), 2,5-dimethoxy-4-bromophenylethylamine (2CB), 3,4-dimethoxymethamphetamine (DMMA), 3,4-methylenedioxyphenyl-2-butanamine (BDB), 3,4-methylenedioxyphenyl-N-methyl-2-butanamine (MBDB) and 2,3-methylenedioxymethamphetamine (2,3-MDMA).

KEY RESULTS

2,3-MDMA was significantly less potent than MDMA at SERT, but equipotent with MDMA at NET. 2CB and BDB were both significantly less potent than MDMA at NET, but equipotent with MDMA at SERT. MBDB, DMMA, MDOH and the MDMA metabolites HMA and HMMA, were all significantly less potent than MDMA at both NET and SERT.

CONCLUSIONS AND IMPLICATIONS

This study provides an important insight into the structural requirements of MDMA analogue affinity at both NET and SERT. It is anticipated that these results will facilitate understanding of the likely pharmacological actions of structural analogues of MDMA.

22q11 Deletion in children with cleft lip and palate--is routine screening justified?

OBJECTIVE

To ascertain the prevalence of 22q11 deletion in children with a diagnosis of cleft lip and/or palate that had been referred to the Cleft Lip & Palate Service, Newcastle-upon-Tyne.

DESIGN

Retrospective analysis of results of 22q11 FISH testing performed in all such referrals.

PARTICIPANTS

191 children, of whom 13 had a bilateral cleft lip and palate, two had a median cleft, 77 had a cleft palate only, 44 had a unilateral cleft lip, 47 had a unilateral cleft lip and palate and eight had a submucous cleft palate.

RESULTS

nine patients had a positive 22q11 FISH test.

CONCLUSION

This represents a higher percentage than has been previously reported. All children with cleft lip and/or palate should routinely have a 22q11 FISH test in view of the implications of a diagnosis of velocardiofacial syndrome.

SALL4mutations in Okihiro syndrome (Duane-radial ray syndrome), acro-renal-ocular syndrome, and related disorders

Okihiro/Duane-radial ray syndrome (DRRS) is an autosomal dominant condition characterized by radial ray defects and Duane anomaly (a form of strabismus). Other abnormalities reported in this condition are anal, renal, cardiac, ear, and foot malformations, and hearing loss. The disease is the result of a mutation in the SALL4 gene, a human gene related to the developmental regulator spalt (sal) of Drosophila melanogaster. SALL4 mutations may also cause acro-renal-ocular syndrome (AROS), which differs from DRRS by the presence of structural eye anomalies, and phenotypes similar to thalidomide embryopathy and Holt-Oram syndrome (HOS). The SALL4 gene product is a zinc finger protein that is thought to act as a transcription factor. It contains three highly conserved C2H2 double zinc finger domains, which are evenly distributed. A single C2H2 motif is attached to the second domain, and at the amino terminus SALL4 contains a C2HC motif. Seventeen of the 22 SALL4 mutations known to date (five of which are presented here for the first time) are located in exon 2, and five are located in exon 3. These are nonsense mutations, short duplications, and short deletions. All of the mutations lead to preterminal stop codons and are thought to cause the phenotype via haploinsufficiency. This assumption is supported by the detection of six larger deletions involving the whole gene or single exons. This article summarizes the current knowledge about SALL4 defects and associated syndromes, and describes the clinical distinctions with similar phenotypes caused by other gene defects.

Influence of oscillating dietary crude protein concentration on performance, acid-base balance, and nitrogen excretion of steers

Decreasing dietary N inputs into beef cattle feeding operations could potentially decrease environmental concerns relating to air and water quality. Previous studies with sheep suggest that oscillating dietary CP concentrations may improve N use efficiency and thereby decrease dietary N requirements. Therefore, two studies were conducted to determine the effects of oscillating dietary CP concentrations on performance, acid-base balance, and manure characteristics of steers fed high-concentrate diets. Steers were fed to a constant backfat thickness in both studies. In the first trial, 92 steers (mean BW = 408 +/- 2.8 kg; four pens/treatment) were fed the following diets: 1) constant 12% CP, 2) constant 14% CP, and 3) 10 and 14% CP oscillated at 2-d intervals. Steer performance and carcass characteristics were measured. In the second trial, 27 steers were individually fed the same three experimental dietary regimens (nine steers/treatment). Animal performance, arterial acid-base balance, plasma metabolites, and fecal characteristics were measured. In both trials, steers fed the 14% CP diet tended (P < 0.10) to have greater ADG and gain:feed than steers fed the 12% CP diet. Steers fed the oscillating CP regimen had intermediate performance. In Trial 1, steers fed the 14% CP diet tended (P = 0.09) to have smaller longissimus area and higher quality grades than steers fed the oscillating CP regimen. Protein retentions (g/d) calculated from NRC (2000) equations were greater (P = 0.04) for steers fed the 14% CP diet than steers fed the 12% CP diet. Steers fed the oscillating CP regimen tended (P = 0.08) to have greater calculated protein retention (g/d) than steers fed the 12% CP diet. Steers fed the 14% CP diet had greater (P < 0.05) calculated urinary N excretion than steers fed the 12% CP or oscillating CP regimens. Venous plasma concentrations of urea N were greater (P < 0.001) in steers fed the 14% CP diet than in steers fed the 12% CP diet; steers fed the oscillating CP regimen were intermediate but fluctuated over days. Based on arterial blood gas concentrations, acid-base balance was not significantly affected by dietary CP regimen. Results of these trials suggest that the CP requirement of steers in these studies was greater than 12% of the diet DM, and/or that the degradable CP requirement was greater than 6.3% of diet DM. However, the effects of oscillating dietary CP were minimal.

Monitoring adenovirus infections with on-line and off-line methods

Several known process monitoring methods were tested for their efficacy in the detection of adenovirus infections. The methods that we explored include several indirect indications of viral infections, including metabolic rate analysis, secondary gauges of respiration, cell size measurement, cell number and cell viability determination, and changes in capacitance. Direct indications of the adenovirus infection were also applied, including total viral particle and infectious particle measurements, as well as a flow cytometry method for detecting infected cells. All of the methods tested in the study provide some positive indication of an adenovirus infection. Many of the methods require repeated sampling, which may limit their utility in a manufacturing process. All of the indirect measures of viral infection may be limited by the fact that they do not uniquely identify an infection. The simplest monitoring methods appear to be detection of changes in respiration or the capacitance of the culture, both of which seem to provide a clear indication of an infection. Further work will be required to demonstrate that these indications are characteristic of only a successful and productive adenovirus infection.

A clinical study of 57 children with fetal anticonvulsant syndromes

BACKGROUND

Anticonvulsants taken in pregnancy are associated with an increased risk of malformations and developmental delay in the children. To evaluate the pattern of abnormalities associated with prenatal anticonvulsant exposure further, we undertook a clinical study of 57 children with fetal anticonvulsant syndromes.

METHODS

Fifty two children were ascertained through the Fetal Anticonvulsant Syndrome Association and five were referred to the Aberdeen Medical Genetics Service. Pregnancy and medical history were obtained through a standardised questionnaire and interview and the children were examined.

RESULTS

Thirty four (60%) were exposed in utero to valproate alone, four (7%) to carbamazepine alone, four (7%) to phenytoin alone, and 15 (26%) to more than one anticonvulsant. Forty six (81%) reported behavioural problems, 22 (39%) with hyperactivity or poor concentration of whom four (7%) had a diagnosis of attention deficit and hyperactivity disorder. Thirty four (60%) reported two or more autistic features, of whom four had a diagnosis of autism and two of Asperger's syndrome. Forty four (77%) had learning difficulties, 46 (81%) had speech delay, 34 (60%) had gross motor delay, and 24 (42%) had fine motor delay. Nineteen (33%) had glue ear and 40 (70%) had joint laxity involving all sizes of joints. Of 46 who had formal ophthalmic evaluation, 16 (34%) had myopia.

CONCLUSIONS

Speech delay, joint laxity, glue ear, and myopia are common in the fetal anticonvulsant syndromes and autistic features and hyperactivity form part of the behavioural phenotype.

Mutation analysis of LMX1B gene in nail-patella syndrome patients

Nail-patella syndrome (NPS), a pleiotropic disorder exhibiting autosomal dominant inheritance, has been studied for >100 years. Recent evidence shows that NPS is the result of mutations in the LIM-homeodomain gene LMX1B. To determine whether specific LMX1B mutations are associated with different aspects of the NPS phenotype, we screened a cohort of 41 NPS families for LMX1B mutations. A total of 25 mutations were identified in 37 families. The nature of the mutations supports the hypothesis that NPS is the result of haploinsufficiency for LMX1B. There was no evidence of correlation between aspects of the NPS phenotype and specific mutations.

Disposition of L-732,531, a potent immunosuppressant, in rats and baboons

L-732,531 is a semi-synthetic analog of the macrolide tacrolimus (Prograf(R)). Like tacrolimus, L-732,531 is a potent immunosuppressant. In this study, its absorption, distribution, metabolism, and excretion were studied in rats and baboons. In rats, its blood and plasma levels were similar, whereas in baboons, its blood levels were, on average, twice as high as those in plasma. This was consistent with the in vitro blood-to-plasma ratio of L-732, 531, which in these two species, as well as in humans, was much lower than that of tacrolimus and showed a minimal concentration dependence. After iv administration to rats, the blood and plasma clearance of L-732,531 decreased from approximately 60 ml/min/kg at 0.2 mg/kg to 30 ml/min/kg when dosed at 1 and 3 mg/kg. After oral administration, plasma area under the concentration vs. time curve (AUC) and maximal plasma concentration (Cmax) increased more than proportionally to the dose. At 1, 5, and 15 mg/kg, plasma AUC was 29, 466, and 2832 ng.hr/ml, respectively, and Cmax was 10, 129, and 304 ng/ml, respectively. Bioavailability, although compromised by nonlinear kinetics, was estimated to be between 8% and 18%. In baboons, the clearance of L-732,531 was lower than that in rats, especially when calculated from blood concentrations (12 ml/min/kg at 0.2 mg/kg and 8 ml/min/kg at 1 mg/kg). After oral dosing, baboon plasma AUC and Cmax were much lower than those in rats, but as in rats, they increased more than proportionally with increasing doses. The bioavailability of L-732,531 in baboons was estimated at 3%, 9%, and 24% when animals were dosed at 5, 15, and 26 mg/kg po, respectively. After oral administration of [3H]L-732,531 at 5 mg/kg, approximately 32% of the radioactivity was recovered in bile and urine of rats, compared with 9% in baboons. High-performance liquid chromatography profiles of rat and baboon plasma, bile, urine, and feces indicated that L-732,531 was metabolized extensively to a complex mixture of products. Some intact parent drug was observed in feces of orally dosed animals, indicating incomplete absorption. In vitro, L-732,531 was metabolized more extensively by baboon liver microsomes than rat or human microsomes. Its metabolism in human liver microsomes was shown to be catalyzed primarily by cytochrome P450 3A isozymes.

Random X inactivation in a girl with a balanced t(X;9) and an abnormal phenotype

X inactivation is the process by which mammalian females achieve dosage compensation by transcriptionally silencing one X chromosome. In chromosomally normal females, this process is random. However, most females with one abnormal X chromosome demonstrate complete skewing of X inactivation, presumably as the result of cell selection. We present a mentally retarded girl with a 46,X,t(X;9)(q28;q12) karyotype. Analysis of this patient's lymphocytes, using late replication banding and methylation assays for the androgen receptor (AR) and fragile X mental retardation (FMR1) genes, did not show the predicted nonrandom X inactivation pattern. Thus, this patient is functionally disomic for Xq28-qter in a proportion of her cells, most likely resulting in her abnormal phenotype. This case demonstrates the utility of correlating X inactivation patterns with phenotype in females with one structurally abnormal X chromosome, and suggests that both cytogenetic and molecular X inactivation studies should be included in the routine study of these individuals.

Comparison of anesthetic and cardiorespiratory effects of tiletamine-zolazepam-xylazine and tiletamine-zolazepam-xylazine-butorphanol in ferrets

Nine ferrests were used in a crossover study to determine the anesthetic effects of intramuscular (i.m.) administration of a low dose of tiletamine-zolazepam (1.5 mg/kg body weight)-xylazine (1.5 mg/kg body weight); a high dose of tiletamine-zolazepam (3 mg/kg body weight)-xylazine (3 mg/kg body weight); and tiletamine-zolazepam (1.5 mg/kg body weight)-xylazine (1.5 mg/kg body weight)-butorphanol (0.2 mg/kg body weight). All ferrets became laterally recumbent within two minutes following the administration of each drug combination. The tiletamine-zolazepam-xylazine-butorphanol combination induced significantly longer (p less than 0.05) durations of tail clamp analgesia (mean +/- standard deviation [SD], 90.0 +/- 17.1 min versus 17.8 +/- 15.8 min and 41.9 +/- 26.3 min) and endotracheal intubation (mean +/- SD, 84.8 +/- 21.7 min versus 5.2 +/- 10.3 min and 26.3 +/- 29.8 min) than the low-dose tiletamine-zolazepam-xylazine and high-dose tiletamine-zolazepam-xylazine combinations, respectively. Heart rates and the times from dorsal recumbency to standing were not significantly different among the three treatment groups. However, systolic blood pressure was significantly lower in the tiletamine-zolazepam-xylazine-butorphanol group. Ventilatory function was more depressed in the tiletamine-zolazepam-xylazine-butorphanol group than in the low-dose tiletamine-zolazepam-xylazine and high-dose tiletamine-zolazepam-xylazine groups. A short period of hypoxia was observed in the tiletamine-zolazepam-xylazine-butorphanol-treated ferrets. Tiletamine-zolazepam-xylazine-butorphanol was found to be the best of the three combinations evaluated in these ferrets. The addition of butorphanol to the low-dose tiletamine-zolazepam-xylazine combination greatly enhanced the duration of analgesia, endotracheal intubation, and dorsal recumbency. However, since hypoxemia occurred during the tiletamine-zolazepam-xylazine-butorphanol anesthesia, oxygen (O2) insufflation is recommended. Doubling the dose of the low-dose tiletamine-zolazepam-xylazine increased the duration of analgesia and endotracheal intubation without prolonging the recovery when compared to the low-dose tiletamine-zolazepam-xylazine group.

AIDS Clinical Trials Group Study 094: a phase I/II trial of ABV chemotherapy with zidovudine and recombinant human GM-CSF in AIDS-related Kaposi's sarcoma

PURPOSE

To define the maximum tolerated dose of doxorubicin when combined with fixed doses of bleomycin, vincristine, zidovudine, and recombinant human granulocyte macrophage colony-stimulating factor (rhGM-CSF) in patients with advanced AIDS-related Kaposi's sarcoma.

PATIENTS AND METHODS

Twenty male patients were treated with zidovudine at doses of either 100 or 200 mg by mouth every 4 hours, and cytotoxic chemotherapy with bleomycin 10 U/m2 and vincristine 1.4 mg/m2 by vein every 2 weeks. Four successive cohorts received fixed doses of doxorubicin given intravenously every 2 weeks: two cohorts each received 10 mg/m2 (levels 1, 2) or 20 mg/m2 (levels 3, 4). The first cohort received rhGM-CSF at a dose of 10 micrograms/ kg, given subcutaneously on days 2 through 11 (level 1). Due to toxicity, the dose of rhGM-CSF was reduced to 5 micrograms/kg (levels 2, 3) and then to 2.5 micrograms/kg (level 4).

RESULTS

The dose-limiting toxicity was severe neutropenia, occurring in 10 patients. Severe neutropenic episodes occurred after a median of three cycles of chemotherapy, with the nadir occurring after 14 days (median). Moderate neutropenia occurred in 14% of all cycles administered. Constitutional toxicities of moderate or greater severity occurred in four patients. Five of 10 patients at a doxorubicin dose of 20 mg/m2 (levels 3 and 4) experienced severe neutropenia. Thus, doxorubicin at 10 mg/m2, with BV (bleomycin, vincristine chemotherapy), zidovudine (100 mg five times daily), and rhGM-CSF (5 micrograms/kg/day), was defined as the maximum tolerated dose.

CONCLUSIONS

The maximum tolerated dose of doxorubicin is 10 mg/ m2 every 2 weeks when given in combination with BV chemotherapy, zidovudine, and rhGM-CSF. While the addition of rhGM-CSF at doses of 2.5 to 5 micrograms/kg decreased the duration of neutropenia, it did not prevent the occurrence of severe neutropenia from combined myelotoxic therapy.

Catastrophic failure of a conforming type of total knee replacement: a case report

A case study is presented to illustrate the concept of femoral component failure secondary to polyethylene wear in a 67 year old man, 13 years after he had conforming type total knee replacements. This case illustrates the theory that this observed problem may be a leading cause of failure in conforming and nonconforming total knee replacements in the future.

Bovine hereditary zinc deficiency: lethal trait A 46

Bovine hereditary zinc deficiency, also referred to as Adema disease, is an autosomal recessive disorder which results in inadequate amounts of zinc being absorbed from the gastrointestinal tract and leads to a number of clinical abnormalities. Using semen from a homozygous affected bull and obligate heterozygote cows in embryo transfer studies, 7 offspring were obtained. These included 5 affected calves and 1 heterozygous carrier; the seventh calf died within 48 hours of birth undiagnosed. One unaffected, unrelated bull calf was raised as a control. All the calves were raised and maintained under similar management conditions designed to minimize secondary complications that would obscure the clinical and biochemical observations of a zinc deficient state. The first clinical manifestation of zinc deficiency was diarrhea, followed by skin lesions, poliosis, and a decreased ability to sustain a suckle reflex. Trace mineral analysis of plasma blood samples revealed that plasma zinc concentrations of all the calves were normal at birth; however, they gradually declined in affected calves over the course of 3-8 weeks postpartum to below 0.5 ppm. Biochemical analysis of serum samples showed alkaline phosphatase activity consistently paralleled changes in the plasma zinc concentrations. The oral administration of zinc acetate caused a reversal of all clinical, biochemical, and histologic abnormalities in affected calves. The study of these affected calves allows further insight into the biological role of zinc as well as provides an animal model for the continued investigation of the human homologue acrodermatitis enteropathica.

Hypoglycemia in four dogs with smooth muscle tumors

Tumor-associated hypoglycemia has been reported in dogs with pancreatic beta-cell tumors, hepatic tumors, and, rarely, with other neoplasms. This article describes 4 dogs with marked hypoglycemia associated with smooth muscle tumors (jejunal leiomyoma, gastric leiomyoma and leiomyosarcoma, and splenic leiomyosarcoma). Presenting clinical signs included grand mal seizures, lethargy, weakness, ataxia, and, in 1 dog, polyuria/polydipsia. The serum insulin concentration was low in 1 dog and normal in the other dog evaluated. Immunohistochemical staining for insulin was negative in the 4 tumors; the 3 tumors arising from the stomach and jejunum stained diffusely positive for glucagon. Blood glucose concentrations rapidly returned to normal after complete surgical resection of the tumors, and clinical signs associated with hypoglycemia resolved. Long-term follow-up available in 3 of the 4 dogs found no recurrence of clinical signs related to hypoglycemia at 15, 31, and 38 months after surgery, respectively.

Production responses to various doses and ratios of estradiol benzoate and trenbolone acetate implants in steers and heifers

At each of three locations, 400 steers and an equal number of heifers were randomized to 10 treatment groups. The purpose of the studies was to evaluate the response of feedlot steers and heifers to single implants containing a combination of estradiol benzoate (EB) and trenbolone acetate (TBA) at two different ratios each at three doses. The selected ratios corresponded to 1E2(estradiol-17 beta):5TBA and 1E2:10TBA. The two ratios were each tested at three different EB/TBA doses (1:5 at 20/70, 40/140, and 60 mg/210 mg, 1:10 and 14/100, 28/200, and 42 mg/300 mg). The test groups were compared to those given each of the compounds alone (60 mg of EB or 300 mg of TBA), as well as to groups reimplanted with Synovex S or Synovex H implants and untreated controls. Steers (P < .01) and heifers (P < .05) implanted with the 1:10 E2:TBA implants gained faster and had better feed conversion (FC) than their counterparts given 1:5 E2:TBA over the 140-d trial. The results indicated that both estradiol benzoate and trenbolone acetate contributed to the efficacy of the combination implant. Contour plots of ADG and FC indicate that increasing the amount of EB above approximately 36 and 37 mg does not significantly increase the response of steers. The results of these studies indicate that the 28 EB/200 TBA dose is close to optimal for growth promotion and feed conversion in both heifers and steers. In steers, carcass value was increased (P < .01) in all test groups except the group give TBA only. Despite a slight reduction in marbling score and percentage of Choice carcasses, carcasses of steers treated with either 28 mg of EB/200 mg of TBA or 42 mg of EB/300 mg of TBA were more valuable (P < .05) than carcasses from steers in any of the 1:10 ratio EB/TBA groups. Carcass values for groups reimplanted with Synovex S or Synovex H or implanted with EB alone were not significantly different from those for groups implanted with any dose of the 1:10 EB/TBA ratio.

Phase I AIDS Clinical Trials Group (075) study of adriamycin, bleomycin and vincristine chemotherapy with zidovudine in the treatment of AIDS-related Kaposi's sarcoma

OBJECTIVE

To determine the toxicity and maximum tolerated dose of doxorubicin (adriamycin) in combination with fixed doses of bleomycin, vincristine (ABV) and zidovudine in patients with advanced AIDS-related Kaposi's sarcoma.

PATIENTS AND METHODS

Twenty-six HIV-seropositive men with Kaposi's sarcoma were treated daily with 100 mg zidovudine orally every 4 h, along with combination chemotherapy using bleomycin 10 U/m2 and vincristine 1.4 mg/m2 (maximum, 2 mg) given intravenously in 2-week cycles. In addition, three successive cohorts of eight patients received escalating doses of doxorubicin each beginning with no doxorubicin (level I), doses of 10 mg/m2 (level II), and 15 mg/m2 (level III).

RESULTS

The major dose-limiting toxicity experienced with the combination therapy was severe neutropenia in eight patients, four of whom received level III doxorubicin (15 mg/m2). Therefore, 10 mg/m2 of doxorubicin in combination with zidovudine and BV chemotherapy was defined as the maximum tolerated dose. Other dose-limiting toxicities included neuropathy (n = 2), cutaneous toxicity associated with bleomycin (n = 1), and diarrhea (n = 1). Seventeen patients (71%; 95% confidence interval, 46-85) experienced either partial (n = 13) or clinical complete remission (n = 4) to therapy after a median of five cycles (range, 2-9).

CONCLUSION

The maximum tolerated dose of doxorubicin is 10 mg/m2 when given in combination with zidovudine and BV chemotherapy. Response rates observed with the combined antiretroviral and chemotherapy regimen are similar to those previously reported with ABV chemotherapy alone.

Coping styles, opioid blockade, and cardiovascular response to stress

We investigated the hypothesis that the effects of Monitoring and Blunting coping styles are mediated in part by endogenous opioids. Mean arterial pressure (MAP) and heart rate (HR) were measured in 39 males before, during, and after a mental arithmetic stressor. Each subject experienced the protocol once under opioid blockade (naltrexone) and once in a placebo condition, in counterbalanced order. Monitoring and Blunting were assessed using the Miller Behavioral Style Scale. High Blunting and high Monitoring were both associated with poorer MAP recovery under opioid blockade than in the placebo condition. Similar effects were noted for Blunting on the measure of HR. These results indicate that the coping styles of Monitoring and Blunting may be associated with enhanced opioid mediation of cardiovascular recovery from stress.

Adriamycin, bleomycin and vincristine chemotherapy with recombinant granulocyte-macrophage colony-stimulating factor in the treatment of AIDS-related Kaposi's sarcoma

OBJECTIVE

To determine the maximum tolerated dose of granulocyte-macrophage colony-stimulating factor (GM-CSF) that would reduce the severity and duration of neutropenia from combination cytotoxic chemotherapy in the treatment of AIDS-related Kaposi's sarcoma (KS).

DESIGN

Phase I, dose escalation.

SETTING

Outpatient clinic of a university hospital.

PATIENTS

HIV-seropositive patients with advanced KS.

INTERVENTIONS

Combination chemotherapy consisting of adriamycin, bleomycin, and vincristine (ABV), with escalating doses of recombinant human GM-CSF (rhGM-CSF). Patients were treated for a median of six cycles (range, between two and seven cycles) of biweekly chemotherapy with GM-CSF administered in divided daily subcutaneous doses on days 2-12. Serum cytokine levels of interleukin (IL)-1 beta, IL-6, and tumor necrosis factor (TNF)-alpha were measured before, during, and after therapy to correlate with response to therapy.

RESULTS

A GM-CSF dose of 250 micrograms/m2 was well tolerated, whereas the next dose escalation, of 500 micrograms/m2, was associated with dose-limiting toxicities, including grade 3 fever, fatigue, and diarrhea. GM-CSF produced predictable cyclic increases in granulocytes, allowing for delivery of full-dose chemotherapy on schedule. All patients were HIV-p24-antigen-negative at study entry; no activation of p24 antigenemia was observed after repeat testing. Consistent changes in cytokine levels were not observed. Responses included one complete and three partial responses, and two patients with stable disease parameters.

CONCLUSIONS

We conclude that GM-CSF can be administered safely to patients with AIDS-related KS receiving myelosuppressive chemotherapy, resulting in granulocytic response, without up-regulation of HIV p24 antigen levels in serum.

Intravenous immune globulin use in patients with human immunodeficiency virus-related thrombocytopenia who require dental extraction

Five patients with human immunodeficiency virus (HIV)-related immune thrombocytopenia who were undergoing dental extraction were treated with intravenous immune globulin (IVIG). All patients received IVIG, 1 gram per kg, the day before the dental extraction and again the day of the dental extraction. Four patients had a previous history of minor clinical bleeding. The median baseline platelet count before extraction was 20 X 10(9) per liter (range 13 to 44). The median peak platelet count was 100 X 10(9) per liter (range 56 to 528) following infusion. This peak response was achieved by day 2 in 3 patients and by days 5 and 7 in 1 patient each. No patients had complications or toxicity from the infusions or perioperative bleeding. No patients required blood product transfusions for the surgical procedure. In conclusion, IVIG infusion should be considered in patients with HIV-related immune thrombocytopenia requiring surgical procedures when a prompt rise in platelet count is desired.

Intravenous immunoglobulin in the treatment of human immunodeficiency virus-related thrombocytopenia

Fourteen patients with sexually transmitted human immunodeficiency virus (HIV)-related immune thrombocytopenia were treated with intravenous gammaglobulin (IVIG). The patients were treated with a uniform program consisting of 1 g/kg of IVIG on day 1 and day 2, followed by 1 g/kg on day 15. Most patients had pretreatment bleeding symptoms, which included petechiae, spontaneous and traumatic ecchymoses, gum bleeding, and epistaxis. Median baseline platelet count was 17,000/mm3 (range 3-61,000/mm3). After the infusion of the IGIV, all patients had a resolution of their bleeding by day 8. The median maximum platelet count achieved with the IGIV was 220,000/mm3 (range 76-426,000/mm3). No patient achieved either a sustained complete or partial remission after the conclusion of the IVIG therapy. Toxicities were minimal with the majority being headache and nausea. In conclusion, patients with sexually transmitted HIV infection and immune thrombocytopenia respond favorably to IVIG. This treatment should be considered as first-line therapy for patients with HIV-related immune thrombocytopenia who require immediate but temporary increase in their platelet count, attributable to symptoms or signs of clinical bleeding or because of the need for an invasive procedure.

The long-term use of zidovudine in patients with severe immune-mediated thrombocytopenia secondary to infection with HIV

Various treatments for HIV-related thrombocytopenia have been reported. Since etiologies of the thrombocytopenia may differ with regard to risk group treatment outcomes may also vary. We have recently studied the long-term use of zidovudine in individuals with sexually transmitted HIV infection and severe thrombocytopenia. Twenty-five men, median age 34 years (range, 23-51 years), were treated with zidovudine (1000 mg/day) for a median duration of 12 months (range, 2.5- less than 26 months). Nineteen patients (76%) had had episodes of symptomatic bleeding secondary to thrombocytopenia prior to study entry. All patients bleeding symptoms resolved with therapy. Six (24%) achieved a complete response, with normalization of platelet counts, while 11 patients (44%) achieved a partial response, giving an overall response rate of 68%. The median time to partial or complete normalization of platelet counts was 12 weeks (range, 4-62 weeks). Toxicities were minimal during the study period. Only one patient developed an AIDS-defining diagnosis while on therapy. We conclude that patients with sexually transmitted HIV infection and immune thrombocytopenia may need a prolonged period of therapy with zidovudine to achieve a platelet response. Other treatment modalities may be required for the 30% of patients who do not respond to zidovudine.

Interferon-alpha maintenance therapy after cytotoxic chemotherapy for treatment of acquired immunodeficiency syndrome-related Kaposi's sarcoma

A prospective phase I clinical trial with recombinant interferon-alpha-2b as maintenance therapy after cytotoxic chemotherapy was conducted. Twenty-one homosexual and bisexual males with extensive mucocutaneous or visceral epidemic acquired immunodeficiency syndrome (AIDS)-Kaposi's sarcoma (KS) were studied. After a complete response (6 patients) or partial response (15 patients) from chemotherapy consisting of Adriamycin (20 mg/m2), bleomycin (10 U/m2), and vincristine (1.4 mg/m2; 2 mg maximum), patients were given interferon-alpha (IFN-alpha) in an attempt to prolong disease-free survival. Three dose levels of daily IFN-alpha were tested: 5, 10, and 15 million U. The maximum tolerated dose was 10 million units. Dose-limiting toxicities included recurrent grade 3 fatigue, diarrhea, and fever, which resulted in the termination of therapy in eight patients (38%). Hematologic toxicities were infrequent (four patients; 19%). Responses were observed in two patients on IFN-alpha, both at the 10-million-U dose level. The median duration of response on IFN-alpha therapy following chemotherapy was 8 weeks (range, 3-11). We conclude that the duration of IFN-alpha maintenance response following cytotoxic chemotherapy is short with response to residual disease observed in a minority of cases at this dose and schedule. Additional trials of maintenance therapy in patients with advanced AIDS-KS combining antiretroviral agents are in progress.

Treatment of epidemic Kaposi's sarcoma with combination chemotherapy (vincristine and bleomycin) and zidovudine

Advanced AIDS-associated Kaposi's sarcoma often requires systemic cytotoxic chemotherapy. Despite high response rates, the majority of the patients die of opportunistic infections (OIs). Effective anti-retroviral agents in combination with cytotoxic chemotherapy may be useful in preventing the development of OIs in addition to increasing the tumor response. Twelve patients with extensive EKS were treated with a non-myelosuppressive drug regimen consisting of bleomycin and vincristine (BV) in combination with the anti-retroviral agent, zidovudine (ZDV). The dose of ZDV was 200 mg orally every four hours (full dose) in eight patients (Group I) or 100 mg orally every four hours (half dose) in four patients (Group II). Toxicity was acceptable with only 3 patients (all from Group I) requiring blood transfusions. ZDV dose reduction due to granulocytopenia was required in 6 patients (5 in Group I and 1 in Group II). Only two patients developed OIs during 27.5 cumulative months of therapy. The overall response rate was 83% in both groups with 4 patients achieving complete remission (CR) and 6 patients acheiving a partial remission (PR). We conclude that a combination of (BV) chemotherapy and ZDV can be used safely with high response rates. Prospective studies of such combination regimens are currently in progress.

Changes in amphetamine-induced anorexia and stereotypy during chronic treatment with antidepressant drugs

Amphetamine-induced anorexia and stereotyped behaviour were studied in rats, following pretreatment with the antidepressants DMI, inprindole and mianserin. A complex drug-dependent and dose-dependent pattern of results was obtained. Acute pretreatment with DMI and iprindole enhanced amphetamine anorexia and stereotypy; at high doses only, the enhancement of anorexia disappeared during chronic treatment. Mianserin had no effects acutely, but chronic treatment with high doses attenuated anorexia and enhanced stereotypy. High doses of all three drugs attenuated anorexia and enhanced stereotypy during withdrawal. The most parsimonious account of these results is that the acute affects of DMI and iprindole are artefactual, and that chronic administration of all three antidepressants increased dopaminergic function and decreased beta-adrenergic function.

Behavioural changes during withdrawal from desmethylimipramine (DMI). II. Increased resistance to extinction

Rats withdrawn from chronic treatment with the tricyclic antidepressant desmethylimipramine (DMI) showed increased resistance to extinction in a runway and in continuously reinforced lever pressing. Changes were not seen in animals maintained on DMI. In acquisition, in the runway, there were no significant differences between groups; in the Skinner box, animals maintained on DMI performed worse than controls, but withdrawn animals recovered to control levels of performance. It is suggested that the effect on extinction may be mediated by a decrease in the efficacy of the dorsal noradrenaline bundle, which develops during chronic DMI treatment, but is masked by the presence of DMI. The implications of the conclusion for the " revised catecholamine hypothesis of depression" are discussed.

Behavioural changes during withdrawal from desmethylimipramine (DMI). I. Interactions with amphetamine

Amphetamine anorexia in rats was potentiated by acute pretreatment with the tricyclic antidepressant desmethylimipramine (DMI), but was not significantly different from controls following chronic DMI pretreatment. During withdrawal from DMI, amphetamine anorexia was attenuated after 2 weeks or 2 months pretreatment, but not after 1 week of treatment. The locomotor stimulant and stereotypy inducing effects of amphetamine were slightly enhanced during withdrawal from chronic DMI. The results are discussed in relation to known neurochemical actions of DMI.