Hypospadias trends in two US surveillance systems

OBJECTIVE: Hypospadias is a common congenital anomaly, the cause of which is unknown. Unexplained increases in the rates of hypospadias occurred in five European countries in the 1970s and 1980s. We examined data from two birth defects surveillance systems in the United States for evidence of similar trends. METHODOLOGY: The Metropolitan Atlanta Congenital Defects Program (MACDP) provided birth prevalence rates from 1968 to 1993. The nationwide Birth Defects Monitoring Program (BDMP) provided rates from 1970 to 1993. MACDP data are population-based and could be categorized by the severity of the hypospadias. BDMP data allowed analysis of rate trends for the four census regions of the United States. RESULTS: Data from both surveillance systems showed an approximate doubling of hypospadias rates in the 1970s and 1980s. MACDP data showed that the rate of severe cases increased while the ratio of mild to severe cases decreased. BDMP data showed that hypospadias rates increased markedly in all four regions of the United States. CONCLUSIONS: The observed increases are unlikely to be attributable to increased sensitivity of the surveillance systems or the identification of more mild cases by physicians over time, because either trend would have increased rather than decreased the ratio of mild to severe cases. If real, these trends represent the largest number of cases and the first report of an increase in hypospadias rates outside of Europe. Additional investigation of a possible increase in hypospadias rates is warranted.     

Analyses of mutation and loss of heterozygosity of coding sequences of the entire transforming growth factor beta type II receptor gene in sporadic human gastric cancer

Mutations in the transforming growth factor beta type II receptor (TGFbetaRII) gene have been detected in several human cancer types exhibiting microsatellite instability. Using intron primers previously reported for examination of the entire coding region of the TGFbetaRII gene, 29 sporadic gastric cancers were screened with non-radioactive single strand conformation polymorphism and subsequent DNA sequencing analysis. Mutations of the TGFbetaRII gene were detected in three out of 29 tumors (10%). Two cases showed deletions in a polyadenine tract in both alleles and was positively associated with replication error. One case had an insertion of GA dinucleotide sequence in one allele. Mutations of the TGFbetaRII gene were restricted to exon 3 and other coding regions were not affected. Loss of heterozygosity was detected by analyzing a polymorphic site in intron 2. Three out of nine (33%) informative cases, which were all of intestinal type and advanced cases, showed loss of heterozygosity but neither TGFbetaRII mutation nor replication error was found in these cases. Immunoreactivity of TGFbetaRII in tumor tissues was reduced to a different extent in the gastric cancer with genetically abnormal transforming growth factor. Although the numbers studied are small, homozygous (A)10 deletion or loss of heterozygosity of TGFbetaRII is involved in tumorigenesis and progression of at least some part of sporadic gastric cancer.      

The duration of phorbol-inducible ErbB2 tyrosine dephosphorylation parallels that of receptor endocytosis rather than threonine-686 phosphorylation: implications for the physiological role of protein kinase C in growth factor receptor signalling

Tumour cell growth may be accelerated by protein kinase C (PKC) agonists such as phorbol esters and receptor tyrosine kinases, but receptor tyrosine kinases are in turn desensitized to growth factors by PKC agonists. To clarify this apparent PKC bifunctionality, we have used phosphoantibodies to determine the relationship between PKC- dependent phosphorylation events affecting the ErbB2 oncoprotein in G8/DHFR 3T3 cells. Neither the kinetics nor the extent of phorbol- induced juxtamembrane domain (Thr686) phosphorylation vary directly with C-terminal (Tyr1222) dephosphorylation, with Tyr1222 continuing to be dephosphorylated long after Thr686 phosphorylation has also declined. Platelet-derived growth factor (PDGF) mimics the short-term effects of phorbol on Thr686 and Tyr1222 phosphorylation, and confocal microscopy reveals that both of these PKC agonists induce rapid internalization of PKC-modified ErbB2. Phorbol causes sustained cytoplasmic accumulation of PKC-phosphorylated receptors, however, whereas PDGF triggers the appearance of this ErbB2 subset only briefly. Metabolic labelling and co-precipitation studies fail to implicate heterologous molecules in either the tyrosine dephosphorylation or internalization of PKC-modified ErbB2. Taken in the context of earlier juxtamembrane domain mutagenesis studies, these findings indicate that phorbol-activated PKC may desensitize growth factor receptors to extracellular ligands solely by triggering sustained receptor internalization. We submit that PKC-dependent juxtamembrane domain phosphorylation represents a physiological mechanism for shortening the duration and enhancing the specificity of growth factor signalling by promoting internalization of liganded and unliganded receptors, respectively.      

Intracranial chondroma of the occipital lobe

A case report of an intracranial chondroma is discussed with emphasis on magnetic resonance imaging.     

Recognition and management of neuropsychiatric complications in Parkinson's disease

Parkinson's disease is primarily considered a motor disease characterized by rest tremor, rigidity, bradykinesia and postural disturbances. However, neuropsychiatric complications, including mood and anxiety disorders, fatigue, apathy, psychosis, cognitive impairment, dementia, sleep disorders and addictions, frequently complicate the course of the illness. The pathophysiologic features of these complications are multifaceted and include neuropathophysiologic changes of a degenerative disease, exposure to antiparkinsonian treatments and emotional reactions to having a disabling chronic illness. Changes in mental status have profound implications for the well-being of patients with Parkinson's disease and of their caregivers. Treatment is often efficacious but becomes a challenge in advanced stages of Parkinson's disease. In this article, we review the key clinical features of neuropsychiatric complications in Parkinson's disease as well as what is known about their epidemiologic characteristics, risk factors, pathophysiologic features and management.     

The N170 occipito-temporal component is delayed and enhanced to inverted faces but not to inverted objects: an electrophysiological account of face-specific processes in the human brain

Behavioral studies have shown that picture-plane inversion impacts face and object recognition differently, thereby suggesting face-specific processing mechanisms in the human brain. Here we used event-related potentials to investigate the time course of this behavioral inversion effect in both faces and novel objects. ERPs were recorded for 14 subjects presented with upright and inverted visual categories, including human faces and novel objects (Greebles). A N170 was obtained for all categories of stimuli, including Greebles. However, only inverted faces delayed and enhanced N170 (bilaterally). These observations indicate that the N170 is not specific to faces, as has been previously claimed. In addition, the amplitude difference between faces and objects does not reflect face-specific mechanisms since it can be smaller than between non-face object categories. There do exist some early differences in the time-course of categorization for faces and non-faces across inversion. This may be attributed either to stimulus category per se (e.g. face-specific mechanisms) or to differences in the level of expertise between these categories.     

Lower dose capecitabine has a more favorable therapeutic index in metastatic breast cancer: retrospective analysis of patients treated at M. D. Anderson Cancer Center and a review of capecitabine toxicity in the literature.

BACKGROUND: Capecitabine is active against anthracycline- and taxane-pretreated metastatic breast cancer. Post-marketing use of capecitabine at the FDA-approved dose (2500 mg/m2/day) leads to unacceptable toxicity in many patients. Dose reductions anecdotally improve tolerability without compromising efficacy. This retrospective analysis was designed to verify these anecdotal reports. Patients and methods: We retrospectively reviewed the records of 141 consecutive patients with metastatic breast cancer identified from pharmacy records as receiving capecitabine outside of a clinical trial between May 1998 and February 1999. Responses were defined as clinical improvement (ID), stabilization of disease (SD) for 6 weeks or longer, or progression (PD). Patients were grouped according to the starting dose level of capecitabine: A=2500+/-5% (dose range 2385-2560) mg/m2/day; B=2250+/-5% (range 2130-2350) mg/m2/day; C < or = 2000+5% (range 1000-2100) mg/m2/day. We also reviewed the safety profile of capecitabine at these doses and performed a safety review of capecitabine in phase II and III metastatic breast and colorectal cancer trials. RESULTS: Clinical data were available for 113 patients (105 for response, 106 for toxicity). The median age was 52.5 years and the mean number of prior metastatic chemotherapy regimens was 2 (range 0-7). The mean capecitabine starting dose was 2220 mg/m2/day and the median number of cycles administered was 4 (range 1-19). The mean tolerated dose was 2040 mg/m2/day (range 960-2670). Grade 3/4 toxic effects at dose levels A, B and C, respectively, included palmar-plantar erythrodysesthesia (33%, 63%, 20%), diarrhea (13%, 12%, 3%), stomatitis (8%, 0%, 3%), and nausea/vomiting (4%, 6%, 5%). Forty per cent of all patients required capecitabine dose reductions; fewer patients treated with 2000 mg/m2/day required dose modification (28%). Five per cent of the patients required discontinuation of capecitabine owing to toxicity. Patients started at the lowest doses of capecitabine did not have poorer response rates or shorter time to progression. CONCLUSIONS: This retrospective analysis supports a starting dose of 2000 mg/m2/day because of its superior therapeutic index; however, patients may still have toxic effects and individualization of dosing is necessary. A phase III, multicenter, randomized study to establish the safety and efficacy of different doses of capecitabine is urgently needed.