Fatal presentation of ornithine transcarbamylase deficiency in a 62-year-old man and family studies

Ornithine transcarbamylase deficiency (OTCD) resulting from deficiency of the mitochondrial enzyme OTC shows extensive phenotypic heterogeneity influenced by allelic heterogeneity and modifying environmental influences such as protein intake. We report the fatal late-onset presentation of OTCD in a 62-year-old man with the V337L mutation, a previous presentation in his grandson and negative clinical and biochemical screening of the proband's three daughters.

Parkin-proven disease: common founders but divergent phenotypes

OBJECTIVE

To compare and contrast clinical and genetic findings in six probands with parkinsonism with a parkin exon 3 438- to 477-bp deletion (Ex3Delta40) to search for evidence of a common founder.

METHOD

Clinical review, parkin gene sequencing, dosage studies, and high-resolution genotype/haplotype analysis were performed.

RESULTS

All subjects had two or more signs consistent with a diagnosis of possible or probable PD with age at onset younger than 45 years (mean +/- SD 29.3 +/- 10.2 years, range 16 to 42 years). Affected individuals were either homozygotes, compound heterozygotes, or Ex3Delta40 carriers with one normal parkin allele. Haplotype analysis revealed both Ex3Delta40 and Ex7 924 C-->T (R275W) mutations originated from common founders, the former most probably of Irish descent. Although three cases had Ex7 924 C-->T (R275W) and Ex3Delta40 mutations, their clinical presentation and mode of inheritance were variable.

CONCLUSION

Parkin mutations on common parkin haplotypes provide testable hypotheses of parkin function in genetically defined parkinsonism.

Deep vein thrombosis in a tiler wearing tight knee pads

Venous compression is a rare but accepted cause of Deep Venous Thrombosis. We report a case of DVT caused by extrinsic compression of the popliteal vein by constricting elasticated knee pads. The knee pads were worn at work by a Tiler who did not have any hypercoagulability disorder.

Evaluation of 50 probands with early-onset Parkinson's disease for Parkin mutations

BACKGROUND

Early onset PD has been associated with different mutations in the Parkin gene, including exon deletions and duplications.

METHODS

The authors performed an extensive mutational analysis on 50 probands with onset of PD at younger than 50 years of age. Thirteen probands were ascertained from a registry of familial PD and 37 probands by age at onset at younger than 50 years, blind to family history. Mutational analysis was undertaken on the probands and available family members and included conventional techniques (single strand conformation polymorphism analysis and sequencing) and a newly developed method of quantitative duplex PCR to detect alterations of gene dosage (exon deletions and duplications) in PARKIN:

RESULTS

Using this new technique, the authors detected eight alterations of gene dosage in the probands, whereas 12 mutations were found by conventional methods among the probands and another different mutation in an affected family member. In total, the authors identified compound heterozygous mutations in 14%, heterozygous mutations in 12%, and no Parkin mutation in 74% of the 50 probands. We expanded the occurrence of Parkin mutations to another ethnic group (African-American).

CONCLUSION

The authors systematically screened all 12 Parkin exons by quantitative PCR and conventional methods in 50 probands. Eight mutations were newly reported, 2 of which are localized in exon 1, and 38% of the mutations were gene dosage alterations. These results underline the need to screen all exons and to undertake gene dosage studies. Furthermore, this study reveals a frequency of heterozygous mutation carriers that may signify a unique mode of inheritance and expression of the Parkin gene.

Primary torsion dystonia due to the Tor1A GAG deletion in an Irish family

BACKGROUND

Early, limb-onset primary torsion dystonia (PTD) is commonly due to a trinucleotide GAG deletion in the TOR1A (DYT1) gene on chromosome 9q34. The majority of carriers of this mutation conform to a characteristic phenotype that is similar in different ethnic populations.

AIM

To describe the clinical features of affected members of a large Irish family with PTD due to the TOR1A deletion.

METHODS

Fourteen consenting family members from three generations were examined according to a standardised protocol.

RESULTS

Five affected individuals were identified. Two had a somewhat atypical phenotype with focal and segmental upper-limb dystonia without further progression.

CONCLUSION

The authors describe the clinical features of PTD due to the TOR1A GAG deletion in an Irish family illustrating the presence of intrafamilial phenotypic variability.

Tardive dystonia of the larynx in a quadriplegic patient: an unusual cause of stridor

We describe a case of a quadriplegic brain-damaged man with severe upper airway obstruction. A diagnosis of tardive dystonia affecting the vocal folds was made and confirmed by flexible nasopharyngoscopy. Emergency tracheotomy was required. The tardive movement disorder resolved with discontinuation of thioridazine. This case serves to heighten awareness of potentially serious airway complications associated with the use of anti-psychotics and anti-emetics particularly in those with organic brain disease.

Absence of utrophin in intercalated discs of human cardiac muscle

Utrophin is the autosomal homologue of dystrophin. In normal skeletal muscle it is localised only to neuromuscular and myotendinous junctions, nerves and vascular tissue. In Xp21 muscular dystrophies, utrophin is also detected on the sarcolemma of skeletal and cardiac muscle, while dystrophin is absent or reduced. In normal cardiac muscle, some reports have demonstrated utrophin at intercalated discs and T-tubules. We have re-examined the distribution of utrophin in normal human cardiac muscle using a panel of eight monoclonal antibodies against different epitopes in N- and C-terminal domains. In contrast to previous studies, utrophin was not detected at the intercalated discs or T-tubules, although labelling of blood vessels was strong. We conclude that the primary location of utrophin in normal heart is in the vascular system. In addition, our results show that the utrophin on cardiac blood vessels is full length, similar to that of skeletal muscle blood vessels.

LC/MS determination of the intracellular concentration of two novel aryl phosphoramidate prodrugs of PMPA and their metabolites in dog PBMC

LC/MS assays were developed to determine the plasma and intracellular concentrations of two aryl phosphoramidate prodrugs of the nucleotide analog 9-[2-R-(phosphonomethoxy)propyl]adenine. LC/MS was used to demonstrate the presence of high concentrations of PMPA in peripheral blood mononucleocytes following oral administration of prodrugs in dogs. High concentrations of PMPA and active metabolite were detected in MT-2 cells incubated with prodrug using an ion-pairing LC/MS assay.

Pain and emotion: new research directions

Recently, there has been growing interest in the relation between pain and emotion. Numerous recent studies have been conducted in this area. This article provides an introduction to this interesting area by highlighting selected research topics including studies on: stress and pain, negative emotional states and pain, catastrophizing and pain, the fear of pain, emotional regulation processes and pain, the effects of enhancing emotional regulation on pain, and the relation of emotional distress to treatment seeking in persons having pain. The article concludes with a discussion of important directions for future research in this area.

Race, ethnicity, and the patient-caregiver relationship

Shortly before his death in 1995, Kenneth B. Schwartz, a cancer patient at Massachusetts General Hospital (MGH), founded The Kenneth B. Schwartz Center at MGH. The Schwartz Center is a non-profit organization dedicated to supporting and advancing compassionate health care delivery, which provides hope to the patient, gives support to caregivers, and encourages the healing process. The center sponsors the Schwartz Center Rounds, a monthly multidisciplinary forum where caregivers reflect on important psychosocial issues faced by patients, their families, and their caregivers, and gain insight and support from fellow staff members. Racial discrimination is a pervasive problem with multiple damaging effects. It is naïve to believe that medicine is somehow immune to race-based practices, but there is a growing literature detailing poorer disease-specific outcomes in minority populations for a range of illnesses. A recent study in the New England Journal of Medicine has implicated physician prejudice as a significant contributing factor. The March 1999 Schwartz Center Rounds sought to explore the influence of ethnic bias on the patient-provider interaction and the quality of health care delivery. Using a different format with a current affairs video clip and an interactive panel discussion, participants were encouraged to identify the often subconscious racial prejudices which may undermine their relationships with patients. Staff members were challenged to think creatively about how institutions and individuals might promote "cultural competence" and a more equitable health care environment.

Docetaxel (Taxotere) in combination with platinums in patients with non-small cell lung cancer: trial data and implications for clinical management

Docetaxel (Taxotere; Aventis, Antony, France) is among the most effective agents for the treatment of non-small cell lung cancer and its use in combination with cisplatin is a logical development. Docetaxel has been combined with cisplatin and is well-tolerated with promising activity in phase II studies. Extensive phase II investigations in the first-line setting recorded response rates of 32% to 52% survival (median, 8 to 12 months) with 33% to 48% of patients alive at 1 year. Neutropenia is dose-limiting. However, the incidence of severe neuropathy is low and clinically significant nephrotoxicity is uncommon. Following these encouraging findings, the combination of docetaxel with cisplatin has been studied in two randomized phase III trials that compare the new combination against reference regimens. These studies have completed accrual and data are expected shortly. The combination of docetaxel with carboplatin is also active and feasible. Neutropenia is the main adverse event and grade II or III neurotoxicity is uncommon. In phase II trials combining doses of 65 to 100 mg/m2 docetaxel with doses of carboplatin designed to maintain an area under the curve of 5 to 7.5 mg/mL/min, response rates have ranged from 30% to 67%.

Docetaxel (Taxotere) shows survival and quality-of-life benefits in the second-line treatment of non-small cell lung cancer: a review of two phase III trials

The potential benefits of docetaxel (Taxotere; Aventis, Antony, France) to patients with previously-treated non-small cell lung cancer have been evaluated in two prospective randomized phase III trials. In one study, patients with stage IIIB/IV non-small cell lung cancer who had failed previous cisplatin-based chemotherapy were randomized to receive either docetaxel (100 or 75 mg/m2, once every 3 weeks) or best supportive care. Median survival was significantly longer for patients treated with docetaxel 75 mg/m2 (7.5 months v 4.6 months) as was 1-year survival (37% v 11%). A second trial, also in platinum-pretreated patients, randomized patients to docetaxel 100 mg/m2, docetaxel 75 mg/m2, or vinorelbine/ifosfamide. Median survival was similar across the three study groups. Thirty-two percent of patients assigned to docetaxel 75 mg/m2 and 21% to docetaxel 100 mg/m2, were alive at 1 year, versus 19% on the vinorelbine/ifosfamide arm. Docetaxel offers clinically meaningful benefits in the second-line setting. The recommended dose is 75 mg/m2 once every 3 weeks. The adverse events observed were predictable, tolerable, and manageable. These phase III trials showed that docetaxel provided clinical benefits to patients with non-small cell lung cancer.

The Everglades Nutrient Removal Project test cells: STA optimization--status of the research at the north site

The Everglades is an oligotrophic ecosystem that is being adversely impacted by hydrologic changes and nutrient-rich runoff generated from urban and agricultural sources. The Stormwater Treatment Area (STA) Optimization Research and Monitoring program is mandated by the 1994 Everglades Forever Act and will assist the South Florida Water Management District in developing operational strategies that maximize performance of emergent macrophyte STAs. The primary objective of this research is to examine how hydrologic conditions may influence STA performance. The study was conducted in 0.2 ha, shallow, fully lined test cells located within the perimeter of the Everglades Nutrient Removal Project. Experiments were designed to examine the effect of increased and decreased hydraulic loading rate (HLR) on wetland performance and to determine, if possible, the HLR at which STA treatment fails to reduce outflow total phosphorus concentration to the interim target of 50 microg-P/L. To date, two HLR experiments have been completed at the north site. Preliminary data indicated at all HLRs tested that particulate phosphorus and dissolved organic phosphorus ratios remained virtually unchanged from inflow to outflow. The dissolved organic and particulate compounds within these test cells are extremely recalcitrant, and are not easily assimilated within the system. High HLRs may not result in detention times long enough to mineralize these forms into easily assimilated inorganic compounds, resulting in mean TP concentrations greater than 50 microg-P/L.

Early lumen loss after repeat coronary intervention for in-stent restenosis

The purpose of this study was to compare the effects of balloon angioplasty versus repeat stenting on the early angiographic outcome in patients with in-stent restenosis. The treatment of in-stent restenosis using balloon angioplasty alone often yields excellent early results, but is associated with a high rate of late recurrence. In the SCRIPPS trial, patients with restenosis were treated either with balloon angioplasty alone or placement of additional stents to optimize angiographic results before randomization and exposure of the restenotic segment to gamma radiation or placebo. In patients undergoing repeat catheter based intervention for the treatment of in-stent restenosis, quantitative coronary angiography was used to compare the results of balloon angioplasty alone versus repeat stenting on early lumen loss. After a mean delay time interval of 71 min, the early loss was 0.35 +/- 0.34 mm in the balloon angioplasty alone group compared to 0.01 +/- 0.34 mm in the repeat-stenting group (P = 0.004). The early loss index in the balloon angioplasty alone group (12.8 +/- 12.9%) was significantly greater than in the repeat stenting group (0.7 +/- 12.1%; P = 0.003). Although balloon angioplasty for in-stent restenosis often provides excellent immediate angiographic results, luminal diameters are significantly reduced in the early time period after balloon dilatation. Repeat stenting nearly abolishes this early luminal loss.

A novel mitochondrial 12SrRNA point mutation in parkinsonism, deafness, and neuropathy

The objective of this study was to determine whether a mitochondrial DNA mutation and defective oxidative phosphorylation are present in a pedigree with maternally inherited sensorineural deafness, levodopa-responsive parkinsonism, and neuropathy. We sequenced the mitochondrial-encoded ribosomal RNA, cytochrome c oxidase, and transfer RNA genes by cycle sequencing. A polymerase chain reaction-based restriction enzyme assay with mismatched primers was employed to show heteroplasmy of a novel 12SrRNA mutation in the proband and to screen control subjects. Spectrophotometric mitochondrial respiratory chain assays were performed in transformed lymphoblasts from the proband and 12 normal controls. A novel, heteroplasmic, maternally inherited 12SrRNA point mutation (T1095C) was found in the pedigree. Respiratory chain enzyme analysis in cultured lymphocytes from the proband revealed a significant reduction in cytochrome c oxidase activity. Secondary structure predicts that this mutation disrupts a highly conserved loop in the small subunit ribosomal RNA, which is important in the initiation of mitochondrial protein synthesis. The mutation was not found in 270 controls of diverse ethnic origins. We conclude that this mutation is pathogenic and causes an oxidative phosphorylation defect by interfering with mitochondrial protein synthesis.