Direct health care costs of managing perianal Crohn's Disease in a population based cohort

BACKGROUND

Crohn's disease is a chronic condition that places a high health care cost burden. Perianal Crohn's disease (pCD) is a difficult phenotype to treat due to poorer response to medical and surgical therapies. No study has assessed if this translates to higher healthcare costs. The aim is to assess the cost of treating pCD and compare to the cost of non-perianal Crohn's disease (CD).

METHODS

This is a retrospective case-control cohort study in a population-based setting. The direct healthcare costs for patients with pCD were calculated over 12 months. Data was compared to the control group of non-perianal CD patients on biologic treatment, with the use of the Mann-Whitney rank test to assess significance.

RESULTS

187 Crohn's patients were included (39 pCD, 148 CD). Per patient, annual cost was €17,779.19 and €17,576.86 respectively (p = .9391). Medications were responsible for the majority of cost at 78% and 92% of total cost in pCD and CD, respectively (€13,886.04 in pCD, and €16,007.10 in CD), of which biologics were the main driver. Surgical costs were higher in the pCD group due to a higher cost of luminal surgery (€2633.88 in pCD vs €209.79 in CD, p = .0270).

CONCLUSION

This is the first study to assess the cost of treating perianal Crohn's disease in a real-world population. Although the costs were similar overall to non-perianal Crohn's patients, the perianal cohort had higher surgical costs from luminal surgery. This demonstrates the potential to apply early intensive treatment to reduce future surgical cost.

The Fetus with Ganglionic Eminence Abnormality: Head Size and Extracranial Sonographic Findings Predict Genetic Diagnoses and Postnatal Outcomes

BACKGROUND AND PURPOSE

Ganglionic eminence abnormalities on fetal MR imaging are associated with cerebral malformations. Their presumed genetic basis and associated postnatal outcomes remain largely unknown. We aimed to elucidate these through a multicenter study.

MATERIALS AND METHODS

Between January 2010 and June 2020, seven hospitals in 2 countries performing fetal MR imaging examinations identified fetal MR imaging studies demonstrating ganglionic eminence enlargement, cavitation, or both. Cases with no genetic diagnosis, no whole exome sequencing, or no outcome of a liveborn child were excluded. Head size was classified as large (fronto-occipital diameter > 95th centile), small (fronto-occipital diameter <5th centile), or normal.

RESULTS

Twenty-two fetuses with ganglionic eminence abnormalities were identified. Of 8 with large heads, 2 were diagnosed with MTOR mutations; 1 with PIK3CA mutation-producing megalencephaly, polymicrogyria, polydactyly, hydrocephalus (MPPH) syndrome; 3 with TSC mutations; 1 with megalencephaly capillary malformation syndrome; and 1 with hemimegalencephaly. Cardiac rhabdomyoma was present prenatally in all cases of TSC; mutation postaxial polydactyly accompanied megalencephaly capillary malformation and MPPH. Of 12 fetuses with small heads, 7 had TUBA1A mutations, 1 had a TUBB3 mutation, 2 had cobblestone lissencephaly postnatally with no genetic diagnosis, 1 had a PDHA1 mutation, and 1 had a fetal akinesia dyskinesia sequence with no pathogenic mutation on trio whole exome sequencing. One of the fetuses with a normal head size had an OPHN1 mutation with postnatal febrile seizures, and the other had peri-Sylvian polymicrogyria, seizures, and severe developmental delay but no explanatory mutation on whole exome sequencing.

CONCLUSIONS

Fetal head size and extracranial prenatal sonographic findings can refine the phenotype and facilitate genetic diagnosis when ganglionic eminence abnormality is diagnosed with MR imaging.

Burning Feet, Dilated Heart and Failed Kidneys

Fabry's disease, X-linked lysosomal storage disease, results from deficient activity of alpha galactosidaseA (α-GalA). Renal manifestation usually begins at third decade of life. We report a 16 year male with initial presentation with end stage renal disease (ESRD) and the diagnosis confirmed by presence of myeloid bodies on electron microscopy of kidney biopsy and low serum α-GalA level.

Tetracyclines for Treatment of Tularemia: A Case Series

Tetracyclines for tularemia have been associated with higher failure rates. There were 48 cases of tularemia at the University of Missouri between 1988 and 2015. We retrospectively analyzed 17 patients with tularemia who were successfully treated with tetracyclines, and 9 of these patients also underwent aspiration or incision and drainage.

Use of erythrocyte sedimentation rate and C-reactive protein to predict osteomyelitis recurrence

PURPOSE

To determine the association between both erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) and osteomyelitis recurrence.

METHODS

Records of 81 males and 27 females aged 10 to 87 (median, 54) years who underwent antibiotic/ surgical treatment for primary (n=68) or recurrent (n=40) osteomyelitis that was related (n=26) or unrelated (n=82) to a prosthesis were reviewed. Of the 40 cases of osteomyelitis recurrence followed up for a median of 23.4 (range, 0.6-74.0) months, 7 and 33 were related and unrelated to a prosthesis, respectively. The cutoff points of lowest ESR and CRP for osteomyelitis recurrence were calculated. Risk factors for osteomyelitis recurrence were determined.

RESULTS

Osteomyelitis recurrence was associated with diabetes mellitus, ischaemic heart disease, non-healing wound, infection in the lower limb, and infection with methicillin-resistant Staphylococcus aureus. The cutoff points of CRP ≥5 mg/l and ESR ≥20 mm/h were used for osteomyelitis recurrence. Risk factors for osteomyelitis recurrence were ESR ≥20 mm/h, infection with methicillin-resistant S aureus, and infection in the lower limb.

CONCLUSION

ESR was more sensitive, specific, and independently associated with osteomyelitis recurrence and should be used to guide the duration of antibiotic treatment.

Modality of choice for renal replacement therapy for children with acute kidney injury: Results of a survey

Information on current practices in India for management of renal replacement therapy (RRT) in acute kidney injury (AKI) is lacking. We mailed a questionnaire to 26 pediatric nephrology centers across India to obtain information on the current choice of dialysis modality for management of AKI in children. Acute intermittent peritoneal dialysis was available at all centers surveyed, whereas intermittent hemodialysis and continuous RRT were available in 86% and 17% centers, respectively. Peritoneal dialysis was the predominant modality (accounting for more than 80% of all dialysis) in 14 of the 22 centers, while 4 centers used hemodialysis more commonly. The most important factors influencing the modality choice were patient size, hemodynamic stability, and duration of AKI. These results provide insight into the choice of modality and factors influencing their selection in the management of pediatric AKI in our country.

Autoantibodies as biomarkers for the prediction of neuropsychiatric events in systemic lupus erythematosus

OBJECTIVE

Neuropsychiatric events occur unpredictably in systemic lupus erythematosus (SLE) and most biomarker associations remain to be prospectively validated. This study examined a disease inception cohort of 1047 SLE patients to determine which autoantibodies at enrolment predicted subsequent neuropsychiatric events.

METHODS

Patients with a recent SLE diagnosis were assessed prospectively for up to 10 years for neuropsychiatric events using the American College of Rheumatology case definitions. Decision rules of graded stringency determined whether neuropsychiatric events were attributable to SLE. Associations between the first neuropsychiatric event and baseline autoantibodies (lupus anticoagulant (LA), anticardiolipin, anti-β(2) glycoprotein-I, anti-ribosomal P and anti-NR2 glutamate receptor) were tested by Cox proportional hazards regression.

RESULTS

Disease duration at enrolment was 5.4 ± 4.2 months, follow-up was 3.6 ± 2.6 years. Patients were 89.1% female with mean (±SD) age 35.2 ± 13.7 years. 495/1047 (47.3%) developed one or more neuropsychiatric event (total 917 events). Neuropsychiatric events attributed to SLE were 15.4% (model A) and 28.2% (model B). At enrolment 21.9% of patients had LA, 13.4% anticardiolipin, 15.1% anti-β(2) glycoprotein-I, 9.2% anti-ribosomal P and 13.7% anti-NR2 antibodies. LA at baseline was associated with subsequent intracranial thrombosis (total n=22) attributed to SLE (model B) (HR 2.54, 95% CI 1.08 to 5.94). Anti-ribosomal P antibody was associated with subsequent psychosis (total n=14) attributed to SLE (model B) (HR 3.92, 95% CI 1.23 to 12.5, p=0.02). Other autoantibodies did not predict neuropsychiatric events.

CONCLUSION

In a prospective study of 1047 recently diagnosed SLE patients, LA and anti-ribosomal P antibodies are associated with an increased future risk of intracranial thrombosis and lupus psychosis, respectively.

Urinary indices during relapse of childhood nephrotic syndrome

Sodium retention is the hallmark of idiopathic nephrotic syndrome (INS). Sodium retention could be secondary to activation of renin-angiotensin-aldosterone axis or due to an intrinsic activation of Na(+)K(+) ATPase in the cortical collecting duct. Urine potassium/urine potassium + urine sodium (UK(+)/UK(+) + UNa(+)) is a surrogate marker for aldosterone activity and can be useful in differentiating primary sodium retention from secondary sodium retention in children with INS. This was a cross-sectional study of children with INS, presenting to our center from June 2007 to June 2008. Children were categorized into those with steroid responsive and steroid nonresponsive nephrotic syndrome. One hundred and thirty-four children with nephrotic syndrome were analyzed. The FeNa(+) was significantly lower during relapse than in remission but no such difference was observed with UK(+)/UK(+) + UNa(+). The values of FeNa(+) and UK(+)/UK(+) + UNa(+) across various categories of nephrotic syndrome were similar. Correlating FeNa(+) and UK(+)/UK(+) + UNa(+) with cut-off of 0.5 and 60%, respectively, we found 50% of steroid responsive children and 36% of steroid nonresponders having a corresponding UK(+)/UK(+) + UNa(+) of <60% along with low FeNa(+) of <0.5%, favoring primary sodium retention. Urinary indices did not vary with the type of steroid response. In early relapse, the urinary indices revealed an overlap of both primary and secondary sodium retention in most stable edematous children with nephrotic syndrome.

SF-36 summary and subscale scores are reliable outcomes of neuropsychiatric events in systemic lupus erythematosus

OBJECTIVE

To examine change in health-related quality of life in association with clinical outcomes of neuropsychiatric events in systemic lupus erythematosus (SLE).

METHODS

An international study evaluated newly diagnosed SLE patients for neuropsychiatric events attributed to SLE and non-SLE causes. The outcome of events was determined by a physician-completed seven-point scale and compared with patient-completed Short Form 36 (SF-36) health survey questionnaires. Statistical analysis used linear mixed-effects regression models with patient-specific random effects.

RESULTS

274 patients (92% female; 68% Caucasian), from a cohort of 1400, had one or more neuropsychiatric event in which the interval between assessments was 12.3 ± 2 months. The overall difference in change between visits in mental component summary (MCS) scores of the SF-36 was significant (p<0.0001) following adjustments for gender, ethnicity, centre and previous score. A consistent improvement in neuropsychiatric status (N=295) was associated with an increase in the mean (SD) adjusted MCS score of 3.66 (0.89) in SF-36 scores. Between paired visits when the neuropsychiatric status consistently deteriorated (N=30), the adjusted MCS score decreased by 4.00 (1.96). For the physical component summary scores the corresponding changes were +1.73 (0.71) and -0.62 (1.58) (p<0.05), respectively. Changes in SF-36 subscales were in the same direction (p<0.05; with the exception of role physical). Sensitivity analyses confirmed these findings. Adjustment for age, education, medications, SLE disease activity, organ damage, disease duration, attribution and characteristics of neuropsychiatric events did not substantially alter the results.

CONCLUSION

Changes in SF-36 summary and subscale scores, in particular those related to mental health, are strongly associated with the clinical outcome of neuropsychiatric events in SLE patients.

A randomized prospective study comparing two flexible epidural catheters for labour analgesia

BACKGROUND

Previous studies evaluating stiff epidural catheters found that the three-holed design provided superior labour analgesia compared with an end-holed design. This was believed due to improved medication distribution. Recently, flexible epidural catheters with both designs have been shown to be superior to the stiff epidural catheters. We investigated the success of labour analgesia comparing the flexible three-holed with the flexible end-holed epidural catheter.

METHODS

This was a prospective, single-blinded randomized study. We enrolled 500 parturients in active labour. The primary outcome was complete relief of labour pain assessed at 30 min. We also assessed the occurrence of paresthesias, intravascular and intrathecal placement, catheter replacement, and treatment of breakthrough pain during labour. Comparisons were made using Pearson's chi(2), with significance determined at the 0.05 level.

RESULTS

Four hundred and ninety-three subjects completed the study. Initial analgesia was similar (complete labour analgesia: end-holed=85% vs 80% 95% CI of difference: 13% to -3%; P=NS). The incidence of paresthesia was similar (end-holed=3.6% vs 5.3%; P=NS). There was one intrathecal and three intravascular catheters in the three-holed group and two intravascular catheters in the end-holed group. The number of supplemental boluses and catheter replacements required during labour was similar between the groups.

CONCLUSIONS

There were no differences in the initial analgesia success rate, complications, or labour analgesia between end-hole vs multi-hole flexible epidural catheters.

Growth in Pediatric Renal Transplant Recipients

One of the fundamental challenges in managing pediatric renal transplant recipient is to ensure normal growth and development. The goal of renal transplant is not just to prolong life but to optimize quality of life. Short stature during childhood may be associated with academic underachievement and development of comorbidities such as attention deficit hyperactivity disorder, learning disability, and mood disorders. The most important factors affecting growth are use of corticosteroids, allograft function, and age and height deficit at the time of transplant. Aggressive conservative management of chronic renal failure and early use of growth hormone therapy will help in optimizing height at time of transplant. Early transplant, steroid minimization or withdrawal, and growth hormone therapy will help in achieving normal adult height in a majority of renal post transplant population. Steroid avoidance to achieve good growth still needs to be validated.

Intrathecal morphine reduces breakthrough pain during labour epidural analgesia

BACKGROUND

When using the combined spinal-epidural (CSE) technique for labour analgesia, parturients often experience breakthrough pain after the spinal medication has receded. We tested the hypothesis that a small dose of intrathecal morphine would reduce breakthrough pain.

METHODS

This was a randomized, double-blind, placebo-controlled trial. Subjects were randomized to receive either 100 microg of morphine (MS) or placebo (PLCB) with the spinal injection of bupivacaine and fentanyl. Assessments included need for supplementation during labour analgesia, use of pain medications for 24 h after delivery, and side-effects. The primary end-point was the rate of breakthrough pain.

RESULTS

Sixty subjects were enrolled, 55 subjects completed the trial. The MS group had a significantly lower rate of breakthrough pain than the PLCB group [0.6 (0.6) vs 1.1 (0.8) episodes per patient; P < 0.01], and longer time to first episode of breakthrough pain (300 vs 180 min; P = 0.03). The MS group used 75% less opioid medications during the subsequent 24 h, but had a 17% incidence of nausea.

CONCLUSIONS

The addition of small dose of morphine to the spinal component of the CSE technique improved the effectiveness of epidural labour analgesia and reduced the need for pain medications over 24 h, but resulted in a small increase in nausea.

Video assisted fiberoptic intubation for temporomandibular ankylosis

In the era of fiberoptics, securing of the airway under general anesthesia in small children with temporomandibular joint ankylosis without a flexible pediatric fiberoptic endoscope requires considerable skill. We describe the use of an adult flexible fiberoptic laryngoscope with a video camera system to visualize the glottis from one nostril while the tracheal tube was passed from the other nostril.

Vasopressin infusion in children with catecholamine-resistant septic shock

AIM

To describe use of vasopressin infusion for catecholamine-refractory septic shock in children.

METHODS

We report successful use of vasopressin infusion in three children with septic shock, in whom hypotension and poor perfusion persisted despite use of multiple infusions of vasopressors and inotropes.

RESULTS

All three had a rapid improvement in hypotension and perfusion after starting vasopressin infusion, allowing tapering of other infusions. Two children recovered completely.

CONCLUSIONS

Vasopressin appears to be useful in treatment of catecholamine-refractory septic shock in children.

Differential protein acetylation induced by novel histone deacetylase inhibitors

Histone deacetylase (HDAC) inhibitors induce the hyperacetylation of nucleosomal histones in carcinoma cells resulting in the expression of repressed genes that cause growth arrest, terminal differentiation, and/or apoptosis. In vitro selectivity of several novel hydroxamate HDAC inhibitors including succinimide macrocyclic hydroxamates and the non-hydroxamate alpha-ketoamide inhibitors was investigated using isolated enzyme preparations and cellular assays. In vitro selectivity for the HDAC isozymes (HDAC1/2, 3, 4/3, and 6) was not observed for these HDAC inhibitors or the reference HDAC inhibitors, MS-275 and SAHA. In T24 and HCT116 cells these compounds caused the accumulation of acetylated histones H3 and H4; however, the succinimide macrocyclic hydroxamates and the alpha-ketoamides did not cause the accumulation of acetylated alpha-tubulin. These data suggest "selectivity" can be observed at the cellular level with HDAC inhibitors and that the nature of the zinc-chelating moiety is an important determinant of activity against tubulin deacetylase.

Agrobacterium-mediated genetic transformation and development of herbicide-resistant sugarcane (Saccharum species hybrids) using axillary buds

Direct regeneration from explants without an intervening callus phase has several advantages, including production of true type progenies. Axillary bud explants from 6-month-old sugarcane cultivars Co92061 and Co671 were co-cultivated with Agrobacterium strains LBA4404 and EHA105 that harboured a binary vector pGA492 carrying neomycin phosphotransferase II, phosphinothricin acetyltransferase (bar) and an intron containing beta-glucuronidase (gus-intron) genes in the T-DNA region. A comparison of kanamycin, geneticin and phosphinothricin (PPT) selection showed that PPT (5.0 mg l(-1)) was the most effective selection agent for axillary bud transformation. Repeated proliferation of shoots in the selection medium eliminated chimeric transformants. Transgenic plants were generated in three different steps: (1) production of putative primary transgenic shoots in Murashige-Skoog (MS) liquid medium with 3.0 mg l(-1) 6-benzyladenine (BA) and 5.0 mg l(-1) PPT, (2) production of secondary transgenic shoots from the primary transgenic shoots by growing them in MS liquid medium with 2.0 mg l(-1) BA, 1.0 mg l(-1) kinetin (Kin), 0.5 mg l(-1) alpha-napthaleneacetic acid (NAA) and 5.0 mg l(-1) PPT for 3 weeks, followed by five more cycles of shoot proliferation and selection under same conditions, and (3) rooting of transgenic shoots on half-strength MS liquid medium with 0.5 mg l(-1) NAA and 5.0 mg l(-1) PPT. About 90% of the regenerated shoots rooted and 80% of them survived during acclimatisation in greenhouse. Transformation was confirmed by a histochemical beta-glucuronidase (GUS) assay and PCR amplification of the bar gene. Southern blot analysis indicated integration of the bar gene in two genomic locations in the majority of transformants. Transformation efficiency was influenced by the co-cultivation period, addition of the phenolic compound acetosyringone and the Agrobacterium strain. A 3-day co-cultivation with 50 micro M acetosyringone considerably increased the transformation efficiency. Agrobacterium strain EHA105 was more effective, producing twice the number of transgenic shoots than strain LBA4404 in both Co92061 and Co671 cultivars. Depending on the variety, 50-60% of the transgenic plants sprayed with BASTA (60 g l(-1) glufosinate) grew without any herbicide damage under greenhouse conditions. These results show that, with this protocol, generation and multiplication of transgenic shoots can be achieved in about 5 months with transformation efficiencies as high as 50%.

Follow-up of Australian Aboriginal Patients Following Open-Heart Surgery in Western Australia

BACKGROUND

To date there has been only one published report pertaining to the outcomes following open-heart surgery in Australian aboriginal patients.

METHODS

The records of 57 consecutive aboriginal patients who underwent open-heart surgery at our institution over a 6-year period were retrospectively reviewed. Attempts were made to contact the patient by telephone, by letter, through their listed next of kin, general practitioners, community nurse or through the aboriginal liaison officer.

RESULTS

There were 38 males and 19 females. Forty-five patients had coronary artery bypass grafting, 10 had isolated valve procedures while 2 had a combined operation. Mechanical prostheses were used for all valve replacements. There was a high incidence of diabetes, hypertension, hypercholesterolemia and smoking. There was one hospital death. Follow-up ranged from 6 months to 6 years with a mean of 3.09 years. Forty-four of the 56 (78.6%) hospital survivors were contactable while 21.4% were not contactable. There were two late deaths. Of the coronary patients who could be contacted, only 79% were taking Aspirin and a similar number Statin. 23% patients had recurrence of angina. There were five episodes of anticoagulation related complications in three patients. Only 44% of the patients were conversant with anticoagulation.

CONCLUSIONS

The follow-up of the aboriginal patients was disappointing. The compliance with the medications was sub-optimal. There was a high incidence of recurrence of angina and anticoagulation related complications. The results raise concern about the use of mechanical prosthesis in these patients.

Ossification of the ligamentum flavum

We report the case of a 32-year-old South Korean male who presented with bilateral leg weakness, spastic gait and associated sensory loss from below the T5 dermatome. MRI and CT scans of the spine confirmed the presence of calcified ligamentum flavum from T1-T6. A thoracic laminectomy resulted in an excellent post-operative recovery with full return of all functions. This case review will discuss the differences that exist between ossification of the posterior longitudinal ligament (OPLL) and ossification of the ligamentum flavum (OLF), but also the similarities at a molecular and possibly at a genetic level. We have reviewed the reported literature of patients presenting with progressive lower limb spacity due to OLF, and an excellent outcome is achieved using decompressive laminectomy.

Potent, highly selective, and non-thiol inhibitors of protein geranylgeranyltransferase-I

The design, synthesis, and biological evaluation of a family of peptidomimetic inhibitors of protein geranylgeranyltransferase-I (PGGTase-I) are reported. The inhibitors are based on the C-terminal CAAL sequence of many geranylgeranylated proteins. Using 2-aryl-4-aminobenzoic acid derivatives as mimetics for the central dipeptide (AA), we have attached a series of imidazole and pyridine derivatives to the N-terminus as cysteine replacements. These non-thiol-containing peptidomimetics show exceptional selectivity for PGGTase-I over the closely related enzyme protein farnesyltransferase (PFTase). This selectivity is retained in whole cells where the inhibitors were shown to block the geranylgeranylation of Rap-1A without affecting the farnesylation of small GTP-binding proteins such as Ras.

Structure-based design and synthesis of lipophilic 2,4-diamino-6-substituted quinazolines and their evaluation as inhibitors of dihydrofolate reductases and potential antitumor agents

The synthesis and biological activities of 14 6-substituted 2,4-diaminoquinazolines are reported. These compounds were designed to improve the cell penetration of a previously reported series of 2,4-diamino-6-substituted-pyrido[2,3-d]pyrimidines which had shown significant potency and remarkable selectivity for Toxoplasma gondii dihydrofolate reductase (DHFR), but had much lower inhibitory effects on the growth of T. gondii cells in culture. The target N9-H analogues were obtained via regiospecific reductive amination of the appropriate benzaldehydes with 2,4,6-triaminoquinazoline, which, in turn, was synthesized from 2,4-diamino-6-nitroquinazoline. The N9-CH3 analogues were synthesized via a regiospecific reductive methylation of the corresponding N9-H precursors. The compounds were evaluated as inhibitors of DHFR from human, Pneumocystis carinii, T. gondii, rat liver, Lactobacillus casei, and Escherichia coli, and selected analogues were evaluated as inhibitors of the growth of tumor cells in culture. These analogues displayed potent T. gondii DHFR inhibition as well as inhibition of the growth of T. gondii cells in culture. Further, selected analogues were potent inhibitors of the growth of tumor cells in culture in the in vitro screening program of the National Cancer Institute with GI50s in the nanomolar and subnanomolar range. Crystallographic data for the ternary complex of hDHFR-NADPH and 2,4-diamino-6-[N-(2', 5'-dimethoxybenzyl)-N-methylamino]pyrido[2,3-d]pyrimidine, 1c, reveal the first structural details for a reversed N9-C10 folate bridge geometry as well as the first conformational details of a hybrid piritrexim-trimetrexate analogue.

Inhibiting geranylgeranylation blocks growth and promotes apoptosis in pulmonary vascular smooth muscle cells

The activity of small GTP-binding proteins is regulated by a critical step in posttranslational processing, namely, the addition of isoprenoid lipids farnesyl and geranylgeranyl, mediated by the enzymes farnesyltransferase (FTase) and geranylgeranyltransferase I (GGTase I), respectively. We have developed compounds that inhibit these enzymes specifically and in this study sought to determine their effects on smooth muscle cells (SMC) from the pulmonary microvasculature. We found that the GGTase I inhibitor GGTI-298 suppressed protein geranylgeranylation and blocked serum-dependent growth as measured by thymidine uptake and cell counts. In the absence of serum, however, GGTI-298 induced apoptosis in these cells as measured by both DNA staining and flow cytometry. The FTase inhibitor FTI-277 selectively inhibited protein farnesylation but had a minor effect on growth and no effect on apoptosis. To further investigate the role of geranylgeranylated proteins in apoptosis, we added the cholesterol synthesis inhibitor lovastatin, which inhibits the biosynthesis of farnesyl and geranylgeranyl pyrophosphates. This also induced apoptosis, but when geranylgeraniol was added to replenish cellular pools of geranylgeranyl pyrophosphate, apoptosis was reduced to baseline. In contrast, farnesol achieved only partial rescue of the cells. These results imply that geranylgeranylated proteins are required for growth and protect SMC against apoptosis. GGTase I inhibitors may be useful in preventing hyperplastic remodeling and may have the potential to induce the apoptotic regression of established vascular lesions.

Selective inhibition of type-I geranylgeranyltransferase in vitro and in whole cells by CAAL peptidomimetics

In this paper we describe the synthesis of a family of CAAL peptidomimetics as GGTase-I inhibitors. These inhibitors lack the central dipeptide AA in the key CAAL carboxy terminal sequence of geranylgeranylated proteins and are more selective for GGTase-I over FTase. In whole cells, these compounds are very potent inhibitors of the processing of the geranylgeranylated protein Rap1A without affecting the farnesylated protein H-Ras. One derivative, GGTI-298, inhibited cell division by blocking cells in the G1 phase of the cell cycle.

Conformationally restricted analogues of trimethoprim: 2,6-diamino-8-substituted purines as potential dihydrofolate reductase inhibitors from Pneumocystis carinii and Toxoplasma gondii

Twenty-two 2,6-diamino-8-substituted purines (2-23) were synthesized, in which rotation around the two flexible bonds of trimethoprim (TMP), linking the pyrimidine ring to the side chain phenyl ring, was restricted by incorporation into a purine ring, in an attempt to increase the potency and selectivity of TMP against dihydrofolate reductase (DHFR) from the organisms that often cause fatal opportunistic infections in patients with AIDS, i.e., Pneumocystis carinii (pc) and Toxoplasma gondii (tg). The syntheses of analogues 2-20 were achieved via a one-pot reaction of 2,4,5,6-tetraaminopyrimidine and the appropriately substituted benzaldehyde or phenyl acetaldehyde, in acidic methoxyethanol. Analogues 21-23 were synthesized via nucleophilic displacement of 2,6-diamino-8-(chloromethyl)purine with the appropriate anilines or 2-naphthalenethiol. The compounds were evaluated as inhibitors of pcDHFR and tgDHFR with rat liver (rl) DHFR as the mammalian reference enzyme. Compound 11, the 3',4'-dichlorophenyl analogue, was as potent as TMP and had a selectivity ratio of 13 for pcDHFR, which ranked it as one of the three most selective inhibitors of pcDHFR (compared to rlDHFR) known to date. It also displayed a selectivity ratio of 38 for tgDHFR. None of the other analogues showed any improvement compared to TMP in potency or selectivity. In the preclinical in vitro screening program of the National Cancer Institute, compound 11 showed a GI50 of 10(-6) M for the inhibition of the growth of 17 tumor cell lines.

Synthesis and biological evaluation of nonclassical 2,4-diamino-5-methylpyrido[2,3-d]pyrimidines with novel side chain substituents as potential inhibitors of dihydrofolate reductases

Nine novel 2,4-diamino-5-methyl-6-substituted-pyrido[2,3-d]pyrimidines, 2-10, were synthesized as potential inhibitors of Pneumocystis carinii dihydrofolate reductase (pcDHFR) and Toxoplasma gondii dihydrofolate reductase (tgDHFR). Compounds 2-5 were designed as conformationally restricted analogues of trimetrexate (TMQ), in which rotation around tau 3 was constrained by incorporation of the side chain nitrogen as part of an indoline or an indole ring. Analogue 6, which has an extra atom between the side chain nitrogen and the phenyl ring, has its nitrogen as part of a tetrahydroisoquinoline ring. Analogues 7-9 are epiroprim (Ro 11-8958) analogues and contain a pyrrole ring as part of the side chain substitution on the phenyl ring similar to epiroprim. These analogues were designed to investigate the role of the pyrrole substitution on the phenyl ring of 2,4-diamino-5-methyl-6-(anilinomethyl)pyrido[2,3-d]pyrimidines. Molecular modeling indicated that a pyrrole substituent in the ortho position of the side chain phenyl ring was most likely to interact with pcDHFR in a manner similar to the pyrrole moiety of epiroprim. Analogue 10, in which a phenyl ring replaced a methoxy group, was synthesized to determine the contribution of a phenyl ring on selectivity, lipophilicity, and cell penetration. The synthesis of analogues 2-4 was achieved via reductive amination of 2,4-diamino-5-methyl 6-carboxaldehyde with the appropriately substituted indolines. The indolines were obtained from the corresponding indoles via NaCNBH3 reductions. Analogues 5-10 were synthesized by nucleophilic displacement of 2,4-diamino-5-methyl-6-(bromomethyl)-pyrido[2,3-d]pyrimidine with the 5-methoxyindolyl anion, 6,7-dimethoxytetrahydroisoquinoline, the appropriately substituted pyrroloaniline or 2-methoxy-5-phenylaniline. The pyrroloanilines were synthesized in two steps by treating the substituted nitroanilines with 2,5-dimethoxy-tetrahydrofuran to afford the nitropyrrole intermediates, followed by reduction of the nitro group with Raney Ni. The analogues were more potent than trimethoprim and epiroprim and more selective than TMQ and piritrexim against pcDHFR and tgDHFR. Compounds 5 and 10 had IC50 values of 1 and 0.64 microM, respectively, for the inhibition of the growth of T. gondii cells in culture, and showed excellent culture IC50/enzyme IC50 ratios, which were correlated with their calculated log P values, indicating a direct relationship between calculated lipophilicity and cell penetration.

2,4-diamino-5-deaza-6-substituted pyrido[2,3-d]pyrimidine antifolates as potent and selective nonclassical inhibitors of dihydrofolate reductases

Fifteen novel nonclassical and two classical 2,4-diamino-6-(benzylamino)pyrido[2,3-d]pyrimidine antifolates were synthesized as potential inhibitors of Pneumocystis carinii, (pc) Toxoplasma gondii, (tg) rat liver (rl), and human (h) recombinant dihydrofolate reductases (DHFR). These analogues lack a 5-methyl substitution which has been shown to be important for increased hDHFR inhibitory activity. In addition, they contain a reversal of the C9-N10 bridge present in folates and most antifolates. The synthesis of the compounds involved the reaction of 2,4,6-triaminopyrimidine with the sodium salt of nitromalonaldehyde to afford the key intermediate 2,4-diamino-6-nitropyrido[2,3-d]pyrimidine (7), in a single step. Reduction of 7 to the 2,4,6-triaminopyrido[2,3-d]pyrimidine (8), followed by reductive amination with the appropriate benzaldehydes or phenylacetaldehydes afforded the target compounds. N9 methylation of these analogues was carried out using formaldehyde and sodium cyanoborohydride. The analogues demonstrated significant inhibition of pcDHFR and tgDHFR. N9 methylation significantly increased DHFR inhibitory potency. Compound 11, the 3'4'5'-trimethoxy-substituted analogue with a selectivity ratio of 9.4 for tgDHFR (compared to rlDHFR) was the most selective analogue of the nonclassical series. Compound 22, the N9 methyl 2'5'-dimethoxy-substituted analogue was the most potent analogue against tgDHFR (IC 50 = 6.3 nM) and was the second most selective analogue for tgDHFR (compared to rlDHFR) in the nonclassical series. The naphthyl-substituted analogues 23-25 were generally more potent against rlDHFR than against pcDHFR and tgDHFR. Selected analogues were also evaluated against Streptococcus faecium (sf) DHFR, Escherichia coli (ec) DHFR, Lactobacillus casei (lc) DHFR and tgDHFR with hDHFR as the mammalian reference, under slightly different assay conditions than those employed for rlDHFR. Analogues 11 and 22 had selectivity ratios of greater than 100 for tgDHFR (compared to hDHFR). Analogue 22 in particular, was the most selective analogue of the nonclassical series against tgDHFR (selectivity ratio = 303.5) with excellent potency (28 nM). Analogue 11, also displayed significant selectivity for sfDHFR (selectivity ratio = 4902). Compound 22 was evaluated in vivo for the inhibition of the growth of T.gondii trophozoites in mice, where at 50 mg/kg orally, it demonstrated distinct prolongation of survival without toxicity. Compounds 11, 12 and 21-23 were evaluated as antitumor agents in the National Cancer Institutes preclinical in vitro screening program. Compounds 12, 22, and 23 showed GI50s for tumor growth inhibition in the 10 -6 - 10 -7 M range.

6-substituted 2,4-diamino-5-methylpyrido[2,3-d]pyrimidines as inhibitors of dihydrofolate reductases from Pneumocystis carinii and Toxoplasma gondii and as antitumor agents

The synthesis and biological activity of 15 6-substituted 2,4-diamino-5-methylpyrido[2,3-d]-pyrimidines are reported. These compounds were synthesized in improved yields by modifications of procedures previously reported by us. Specifically, dimethoxyphenyl-substituted compounds with H and CH3 at the N-10 position and trimethoxyphenyl-substituted compounds with N-10 ethyl, isopropyl, and propargyl moieties were synthesized. These compounds were evaluated as inhibitors of dihydrofolate reductases (DHFR) from Pneumocystis carinii, Toxoplasma gondii, and rat liver, and selected analogues were evaluated as inhibitors of the growth of T. gondii and tumor cells in culture. All the compounds showed increased selectivity (vs rat liver DHFR) for T. gondii DHFR compared to trimetrexate. In general, for the trimethoxy-substituted analogues, increasing the size of the N-10 substituent from a methyl group to larger groups resulted in a decrease in selectivity and potency for both P. carinii and T. gondii DHFR. For the dimethoxy-substituted analogues, N-10 methylation in general decreased potency but increased selectivity for T. gondii DHFR. In an attempt to improve the cell penetration of these analogues, the N-10 naphthyl-substituted analogues were also synthesized. These analogues displayed excellent cell penetration and inhibition of T. gondii cells in culture. Further, these analogues were potent inhibitors of the growth of tumor cells in the preclinical in-vitro screening program of the National Cancer Institute with IC50s in the nanomolar range.