Parkinson's disease in populations of African origin: a review

Several studies have reported a lower prevalence of Parkinson's disease (PD) in populations of African origin than in populations of European origin, raising the possibility that the former are protected against PD. However, the confounding effects of low case ascertainment and high selective mortality on PD prevalence estimates in populations of African origin cannot be ruled out at this time. One hypothesis consistent with available data is that populations of African origin are vulnerable to vascular parkinsonism, which is associated with high mortality.     

Gene-marking to trace origin of relapse after autologous bone-marrow transplantation

Bone marrow harvested for autologous bone-marrow transplantation may contain residual malignant cells even when it is judged to be in remission. Genetic marking and subsequent detection of these cells in recipients would give useful information about the origin of relapse after transplantation. We transferred the neomycin-resistance gene into bone-marrow cells harvested from children with acute myeloid leukaemia in remission. Two patients have relapsed since reinfusion of the marked cells. In both, the resurgent blast cells contained the neomycin-resistance gene marker; thus, remission marrow can contribute to disease recurrence. This method of tracking malignant cells should enable the development of better marrow purging strategies.     

Dobzhansky''s genetics and the origin of species: is it still relevant?

The activity and regional distribution of D-amino acid oxidase (DAO), an enzyme that inactivates D-serine, were examined in the medulla and spinal cord of the rat by biochemical and histochemical procedures. DAO activity was noticeably low or absent in the nucleus of the solitary tract, ventrolateral medulla and intramediolateral cell column of the spinal cord. This may be indicative of a neuromodulatory role for endogenous D-serine (at the NMDA-glycine site) in in the central control of blood pressure.     

Infection by hepatitis virus among the indigenous populations of South America: a review of the problem

Diagnostic uncertainty, particularly prior to the receipt of test results, is common in medicine. When randomized trials are being conducted to evaluate therapies in these situations, patients must be randomized in the absence of a definitive diagnosis. This article explores some of the implications of diagnostic uncertainty for the design and analysis of randomized clinical trials, using specific therapeutic examples to illustrate the important points.     

Polymorphic Alu insertions and the Asian origin of Native American populations

A rapid PCR-based assay was used to study the distribution of 5 polymorphic Alu insertions in 895 unrelated individuals from 30 populations, 24 from North, Central, and South America. Although a significant level of interpopulation variability was detected, the variability was less than that observed in a worldwide population survey. This is consistent with the bottleneck effect and genetic drift forces that may have acted on the migrating founder groups. The results corroborate the Asian origin of native American populations but do not support the multiple-wave migration hypothesis supposedly responsible for the tri-partite Eskaleut, Nadene, and Amerind linguistic groups. Instead, these populations exhibit three major identifiable clusters reflecting geographic distribution. Close similarity between the Chinese and native Americans suggests recent gene flow from Asia.     

Trading genes along the silk road: mtDNA sequences and the origin of central Asian populations

Central Asia is a vast region at the crossroads of different habitats, cultures, and trade routes. Little is known about the genetics and the history of the population of this region. We present the analysis of mtDNA control-region sequences in samples of the Kazakh, the Uighurs, the lowland Kirghiz, and the highland Kirghiz, which we have used to address both the population history of the region and the possible selective pressures that high altitude has on mtDNA genes. Central Asian mtDNA sequences present features intermediate between European and eastern Asian sequences, in several parameters-such as the frequencies of certain nucleotides, the levels of nucleotide diversity, mean pairwise differences, and genetic distances. Several hypotheses could explain the intermediate position of central Asia between Europe and eastern Asia, but the most plausible would involve extensive levels of admixture between Europeans and eastern Asians in central Asia, possibly enhanced during the Silk Road trade and clearly after the eastern and western Eurasian human groups had diverged. Lowland and highland Kirghiz mtDNA sequences are very similar, and the analysis of molecular variance has revealed that the fraction of mitochondrial genetic variance due to altitude is not significantly different from zero. Thus, it seems unlikely that altitude has exerted a major selective pressure on mitochondrial genes in central Asian populations.     

Evidence of chromosome 9 origin of the euchromatic variant band within 9qh

Fluorescence in-situ hybridization studies using a whole chromosome 9 painting probe were performed on three individuals from two different families, who carry a chromosome 9 variant with an extra band within the elongated 9qh region. The results confirm the euchromatic nature of the extra band, and provide evidence that it is of chromosome 9 origin. This variant band, which may not be very rare, thus possibly results from a duplication of a segment of 9qh plus band p12 or part of band q21.     

Transgender and gender variant populations with mental illness: Implications for clinical care.

There is a scarcity of literature on clinical care for transgender and gender variant populations with serious mental illness. At times, gender identity issues among individuals with serious mental illness have been labeled as delusions that should not be reinforced by providers. However, there are significant limitations to attributing gender variance among populations with mental illness solely to a psychotic process. The following case study research demonstrates the variation in gender identity issues among individuals with serious mental illness. These individuals may experience gender dysphoria exclusively in the context of acute psychosis or may have gender identity issues that are distinct from the mental illness. Denial of an individual's gender variant presentation by treatment staff may heighten distress, thus interfering with a collaborative treatment alliance while posing additional barriers to recovery from mental illness. Implications and applications for clinical training and further research will be presented in order to promote awareness and competent care of gender issues when co-occurring with mental illness. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Relationships among isoacceptor tRNAs seems to support the coevolution theory of the origin of the genetic code

A new method for looking at relationships between nucleotide sequences has been used to analyze divergence both within and between the families of isoaccepting tRNA sets. A dendrogram of the relationships between 21 tRNA sets with different amino acid specificities is presented as the result of the analysis. Methionine initiator tRNAs are included as a separate set. The dendrogram has been interpreted with respect to the final stage of the evolutionary pathway with the development of highly specific tRNAs from ambiguous molecular adaptors. The location of the sets on the dendrogram was therefore analyzed in relation to hypotheses on the origin of the genetic code: the coevolution theory, the physicochemical hypothesis, and the hypothesis of ambiguity reduction of the genetic code. Pairs of 16 sets of isoacceptor tRNAs, whose amino acids are in biosynthetic relationships, occupied contiguous positions on the dendrogram, thus supporting the coevolution theory of the genetic code.     

Ductectatic mucinous cystadenocarcinoma of the pancreas: a rare variant

A rare case of the ductectatic variant of mucinous pancreatic cystadenocarcinoma in a 64 year-old man, presenting with painless obstructive jaundice, is reported. CT scan revealed a multicystic lesion of the pancreatic head, which caused biliary obstruction. Endoscopic retrograde pancreatography (ERP) revealed the characteristic grapelike cluster pattern of pancreatic ductectatic neoplasms. Pancreaticoduodenectomy was then successfully performed. Pancreatic ductectatic mucinous cystadenocarcinoma is a rare entity, presenting, usually, with obstructive pancreatitis, and is histologically indistinguishable from the classic malignant mucinous cystic neoplasm. ERP is the diagnostic method of choice and should be performed in any case of susceptible pancreatic lesions.     

Lutzomyia longipalpis is a species complex: genetic divergence and interspecific hybrid sterility among three populations

The sand fly Lutzomyia longipalpis is the vector of Leishmania donovani chagasi in Latin America. An analysis of genetic variability at 27 enzyme coding loci among three laboratory populations of Lu. longipalpis revealed substantial genetic polymorphism. Levels of genetic distance between all pairwise comparisons of colonies were very high, and consistent with those previously reported among separate species in the genus Lutzomyia. Between 7% and 22% of the loci studied were diagnostic for any two of the colony populations. Experimental hybridization between colonies resulted in the production of sexually sterile male progeny. Our results provide strong evidence that Lu. longipalpis exists in nature as a complex of at least three distinct species. The possible effects of colonization on the genetic makeup of laboratory populations is considered in extending our results to natural populations.     

Latex allergy: a relevant issue in the general pediatric population

Although latex allergy is a widely recognized problem of the pediatric myelomeningocele population and of frequent users of latex products, it is often overlooked in the general pediatric population. The prevalence of latex in common household items and in medical environments increases one's exposure and thus one's possibility of sensitization to latex. Latex allergy may range from mild local reactions such as erythema to more severe systemic reactions such as asthma or anaphylaxis. The immunoglobulin E-mediated mechanism of these reactions has been confirmed serologically by the presence of latex-specific immunoglobulin E with radioallergosorbent testing. Because avoidance of latex is currently the only way to prevent reactions, the identification of household items that contain latex is extremely important. However, because inadvertent exposure to latex is not uncommon, Medic-Alert bracelets and an Epi-Pen should be provided for children allergic to latex. Pediatric nurses should consider latex allergy as a possible diagnosis in situations of unexplained allergic or anaphylactic reactions and should be aware of optimal therapeutic interventions.     

Pulmonary lipomatosis: a variant of placental transmogrification

An unusual pulmonary lesion is presented. The patient is a 55-year-old white man with a 2-week history of pleuritic chest pain, shortness of breath, and bronchopneumonia. The patient had also a history of smoking and chronic cough for 12 years. Chest radiographic studies showed a 20-cm bulla in the left upper lobe. A left upper lobectomy was performed obtaining an almost completely collapsed lobe with destruction of the normal architecture by a meshwork of yellowish tissue. Histologically, there were strikingly papillary structures composed almost exclusively of mature adipose tissue with small collections of inflammatory cells. Minimal emphysema in the adjacent lung parenchyma was observed. The case herein presented most likely represents part of the spectrum of placental transmogrification or placentoid bullous lesions of the lung.     

Mid-ventricular obstruction: a variant of obstructive cardiomyopathy

In two patients with clinical and catheterization findings of hypertrophic obstructive cardiomyopathy, the level of intraventricular obstruction was found to be in the mid-ventricular area rather than at the junction of the inflow and outflow tracts. One patient died suddenly shortly after unsuccessful outflow tract myectomy. In vivo recognition of this probably rare variant form of obstructive cardiomyopathy rests mainly on the angiograhic appearance of the left ventricle and on the recording of pressures in multiple sites of the left ventricular cavity. Surgical relief of the obstruction in these patients is not likely to be obtained by a transaortic left ventricular outflow myectomy but may require either papillary muscle resection by the transatrial or transventricular approach or mid-ventricular septectomy, or both.     

Condom use as a dependent variable: measurement issues relevant to HIV prevention programs

The value of condoms in efforts to slow the spread of HIV infection has been well established in the literature. Behavioral science faces the challenge of promoting condom use through intervention programs. As these programs are evaluated, multiple issues should be considered in relation to measuring participant use of condoms for the purposes of preventing HIV infection. Lack of attention to these issues is likely to create a large number of Type I and Type II errors. Ten common sources of error are described and corresponding recommendations for eliminating these errors are offered. A review of published studies shows that there is little consistency relevant to controlling for these sources of error. Incorporation of standardized methodology will allow for more accurate program evaluation and benefit researchers by facilitating comparisons across studies.     

Rosaceous lymphedema: a rare variant of a common disorder

Surgical reconstruction of the trachea is a relatively complex procedure. We had 20 cases of tracheal stenosis. We have a modest experience of 16 tracheal reconstructions for acquired tracheal stenosis. Two patients underwent laser treatment while another two died before any intervention. The majority of these cases were a result of prolonged ventilation (14 cases), following organophosphorous poisoning (11 cases), Guillain-Barré syndrome, bullet injury, fat embolism and surprisingly only one tumor, a case of mucoepidermoid carcinoma, who had a very unusual presentation. There were 12 males and 4 females in this series, age ranging from 12-35 years. The duration of ventilation ranged from 1-21 days and the interval from decannulation to development of stridor was between 5-34 days. Six of them were approached by the cervical route, 5 by thoracotomy and cervical approach, 2 via median sternotomy and 3 by thoracotomy alone. Five of them required an additional laryngeal drop and 1 required pericardiotomy and release of pulmonary veins to gain additional length. The excised segments of trachea measured 3 to 5 cms in length. All were end to end anastomosis with interrupted Vicryl sutures. We have had no experience with stents or prosthetic tubes. Three patients developed anastomotic leaks which were controlled conservatively. Almost all of them required postoperative tracheo-bronchial suctioning with fibreoptic bronchoscope. We had one death in this series due to sepsis.     

Metatraits: Evidence relevant to the validity of the construct and its implications.

Further evidence for the metatrait construct was obtained by comparing correlations among theoretically related variables for Ss traited on both constructs, untraited on both constructs, or traited on 1 construct and untraited on another. Using hierarchical multiple regression, Ss traited on both constructs evidenced a substantially higher correlation between the 2 constructs than Ss untraited on 1 or both constructs. These findings replicated across 3 theoretical relationships. Study 2 showed that the effects of traitedness are not a function of the certainty or importance with which Ss view the traits being correlated but are hypothesized to represent the presence vs absence of a trait structure in personality. The implications of the results for construct validation are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Lipomata of the inferior vena cava: a normal variant?

Recently, focal fat collections adjacent to the intrahepatic portion of the inferior vena cava (IVC) have been described as a normal variant. We present seven similar cases, and demonstrate the computed tomographic and sonographic findings. The differential diagnosis is discussed. We believe that the origin of these masses has not yet been satisfactorily proven, and that they may arise within the IVC. They appear to be benign, but there is a risk that they may be mistaken for more sinister pathology.