Neuropeptide precursor processing detected by triple immunolabeling

Peptides that play critical physiological roles are often encoded in precursors that contain several gene products. Differential processing of a polypeptide precursor by cell-specific proteolytic enzymes can yield multiple messengers with diverse distributions and functions. We have isolated SDNFMRFamide, DPKQDFMRFamide, and TPAEDFMRFamide from Drosophila melanogaster. The peptides are encoded in the FMRFamide gene and have a common C-terminal FMRFamide but different N-terminal extensions. In order to investigate the regulation of expression of FMRFamide peptides, we generated antisera to distinguish between the structurally related neuropeptides. We established a triple-label immunofluorescence protocol using antisera raised in the same host species and mapped the neural distribution of SDNFMRFamide, DPKQDFMRFamide, and TPAEDFMRFamide. Each peptide has a unique, nonoverlapping cellular expression pattern, suggesting that the precursor is differentially processed. Thus, our data indicate that D. melanogaster contains cell-specific proteolytic enzymes to cleave a polypeptide protein precursor, resulting in unique expression patterns of neuropeptides.

Cost of chickenpox in Canada: part II. Cost of complicated cases and total economic impact. The Immunization Monitoring Program-Active (IMPACT)

OBJECTIVE

Primarily, to determine the direct medical costs and productivity losses associated with complicated chickenpox (hospitalized cases) and, secondarily, to quantify the overall economic burden of chickenpox in Canada.

METHODS

Direct medical resource consumption patterns were determined by chart review of 160 otherwise healthy children and 40 children with leukemia hospitalized for chickenpox. Children were selected from the database of the Immunization Monitoring Program Active (IMPACT), a network of 11 tertiary-care hospitals in Canada that collected information at the time of hospitalization from January 1991 to March 1996. An additional 26 healthy children hospitalized were recruited prospectively by IMPACT. Productivity losses (time lost from work and daily activities) were assessed by caregiver interviews. Treatment costs were determined from the patient, Ministry of Health, and societal perspectives.

RESULTS

The average societal per case cost for complicated chickenpox in healthy children was $7060 and $8398, respectively, from the retrospective and prospective assessments. For children with leukemia, the direct medical cost was estimated at $7228. These costs were combined with a cost established previously for uncomplicated chickenpox. The estimated yearly overall economic impact of chickenpox in Canada was $122.4 million, with $24.0 million attributable to Ministry of Health costs, assuming an estimated yearly incidence of 346 527 cases and a 0.54% rate of hospitalization for healthy children.

CONCLUSIONS

Direct medical costs are the major cost driver in the care of complicated chickenpox. However, in the context of the overall economic burden of the disease, uncomplicated chickenpox is the major cost driver, contributing 89% to the total cost.

Regulation of Drosophila FMRFamide neuropeptide gene expression

Physiologically important peptides are often encoded in precursors that contain several gene products; thus, regulation of expression of polypeptide proteins is crucial to transduction pathways. Differential processing of precursors by cell- or tissue-specific proteolytic enzymes can yield messengers with diverse distributions and dissimilar activities. FMRFamide-related peptides (FaRPs) are present throughout the animal kingdom and affect both neural and gastrointestinal functions. Organisms have several genes encoding numerous FaRPs with a common C-terminal structure but different N-terminal amino acid extensions. We have isolated SDNFMRFamide, DPKQDFMRFamide, and TPAEDFMRFamide contained in the Drosophila FMRFamide gene. To investigate the regulation of expression of FMRFamide peptides, we generated antisera to distinguish among the three neuropeptides. We have previously reported the distribution of SDNFMRFamide and DPKQDFMRFamide. In this article, we describe TPAEDFMRFamide expression. TPAEDFMRFamide antisera stain cells in embryonic, larval, pupal, and adult thoracic and abdominal ganglia. In addition, TPAEDFMRFamide-immunoreactive material is present in a lateral protocerebrum cell in adult. Thus, TPAEDFMRFamide antisera staining of neural tissue is different from SDNFMRFamide or DPKQDFMRFamide. In addition, TPAEDFMRFamide antisera stain larval, pupal, and adult gut, while SDNFMRFamide and DPKQDFMRFamide do not. TPAEDFMRFamide immunoreactivity is present in cells stained by FMRFamide antisera. Taken together, these data support the conclusion that TPAEDFMRFamide is differentially processed from the FMRFamide polypeptide protein precursor and may act in both neural and gastrointestinal tissue.

Differential processing of neuropeptides influences Drosophila heart rate

Peptides that play critical physiological roles are often encoded in precursors that contain several structurally-related gene products. Differential processing of a precursor by cell-specific processing enzymes can yield multiple messengers with diverse distributions and activities. We have reported the isolation of SDNFMRFamide, DPKQDFMRFamide, and TPAEDFMRFamide from adult Drosophila melanogaster. The peptides are encoded in the FMRFamide gene and have a common C-terminal FMRFamide but different N-terminal extensions. In order to investigate the processing of the FMRFamide polypeptide protein precursor, we generated antisera to distinguish among the structurally-related neuropeptides. Utilizing a triple-label immunofluorescent protocol, we mapped the distribution of the peptides. Each peptide has a unique, non-overlapping cellular expression pattern in neural tissue suggesting that the precursor is differentially processed. In order to identify a biological activity of the peptides, we established an in vivo heart rate assay. SDNFMRFamide decreases heart rate but DPKQDFMRFamide and TPAEDFMRFamide do not, indicating that the N-terminal residues are critical for this activity. SDNFMRFamide immunoreactivity is present in the aorta, implying that SDNFMRFamide acts locally to affect heart rate; DPKQDFMRFamide and TPAEDFMRFamide antisera do not stain cardiac tissue. Our data support the conclusion that Drosophila contains cell-specific proteolytic enzymes to differentially process a polypeptide protein precursor resulting in unique expression patterns of structurally-related, yet functionally distinct neuropeptides.

Blunt trauma-induced bilateral chylothorax

This report describes the case of a man who presented in a delayed manner after blunt trauma with bilateral chylothoraces, a rare result of trauma. He presented with shortness of breath and chest pain. A diagnostic workup resulted in the determination of traumatic chylothorax. His course in the hospital identified a disruption at a level of the 5th thoracic vertebra. No surgical ligation was required because his leak spontaneously sealed after conservative measures. The anatomy, physiology, mechanisms, and management of this injury are discussed.

Involvement of intermediary metabolites in the pathway of extracellular Ca2+-induced mitogen-activated protein kinase activation in human fibroblasts

Human fibroblasts in culture will grow in serum-free medium containing serum replacement factors, but without protein growth factors, as long as the Ca2+ level is 1.0-2.0 mM. When the Ca2+ is reduced to 0.1 mM, the cells stop cycling, but they can be reinduced to cycle by raising the Ca2+ level to 1.0 mM Ca2+ or to higher concentrations that result in activation of mitogen-activated protein kinase (MAPK). We now report that exposure of human fibroblasts to extracellular Ca2+ increased the level of inositol (1,4,5)-trisphosphate in the cytoplasm and caused a transient rise in the concentration of intracellular free Ca2+. Ca2+-induced MAPK activation was partly abolished by treatment of the cells with pertussis toxin. It was also decreased by treatment of cells with thapsigargin, which depletes intracellular Ca2+ stores; with phorbol 12-myristyl 13-acetate (PMA), which down-regulates protein kinase C (PKC); with the calmodulin antagonists N-(6-aminohexyl)-5-chloro-1-naphthalenesulphonamide HCl (W-7), and calmidazolium (24571); as well as with lanthanum, a Ca2+ channel inhibitor. Ca2+ stimulation did not result in phosphorylation of the c-raf-1 protein. Our results suggest that extracellular Ca2+ stimulates MAPK activation through a pathway(s) involving a pertussis toxin-sensitive G protein, phospholipase C, intracellular free Ca2+, calmodulin, and PKC.

Antisera to multiple antigenic peptides detect neuropeptide processing

Peptides act as critical messengers of essential physiological function. Frequently, several peptides are encoded in the same precursor and, often, there is structure relatedness among the gene products. The complexity of protein precursors and presence of homologous peptides raises issues about regulation of gene expression and function of structurally-related peptides. We have determined the cellular location of DPKQDFMRFamide and SDNFMRFamide encoded in the Drosophila FMRFamide gene. We raised antisera that distinguish between the two peptides and conducted double label immunostaining utilizing antisera raised in the same host species. We found that DPKQDFMRFamide and SDNFMRFamide are present in distinct distribution patterns. We also established that the peptides are present in cells stained by FMRFamide antisera. Thus, our data are consistent with the conclusion that Drosophila contains cell-specific proteolytic processing enzymes capable of posttranslationally cleaving a polypeptide protein precursor to yield unique expression patterns of neuropeptides that may have diverse activities.

High-altitude cerebral edema evaluated with magnetic resonance imaging: clinical correlation and pathophysiology

CONTEXT

Because of its onset in generally remote environments, high-altitude cerebral edema (HACE) has received little scientific attention. Understanding the pathophysiology might have implications for prevention and treatment of both this disorder and the much more common acute mountain sickness.

OBJECTIVES

To identify a clinical imaging correlate for HACE and determine whether the edema is primarily vasogenic or cytotoxic.

DESIGN

Case-comparison study.

SETTING

Community hospitals accessed by helicopter from mountains in Colorado and Alaska.

PATIENTS

A consecutive sample of 9 men with HACE, between 18 and 35 years old, 8 of whom also had pulmonary edema, were studied after evacuation from high-altitude locations; 5 were mountain climbers and 4 were skiers. The control group, matched for age, sex, and altitude exposure, consisted of 3 subjects with high-altitude pulmonary edema only and 3 who had been entirely well at altitude. Four patients with HACE were available for follow-up imaging after complete recovery.

MAIN OUTCOME MEASURES

Magnetic resonance imaging (MRI) of the brain during acute, convalescent, and recovered phases of HACE, and once in controls, immediately after altitude exposure.

RESULTS

Seven of the 9 patients with HACE showed intense T2 signal in white matter areas, especially the splenium of the corpus callosum, and no gray matter abnormalities. Control subjects demonstrated no such abnormalities. All patients completely recovered; in the 4 available for follow-up MRI, the changes had resolved entirely.

CONCLUSIONS

We conclude that HACE is characterized on MRI by reversible white matter edema, with a predilection for the splenium of the corpus callosum. This finding provides a clinical imaging correlate useful for diagnosis. It also suggests that the predominant mechanism is vasogenic (movement of fluid and protein out of the vascular compartment) and, thus, that the blood-brain barrier may be important in HACE.

Abstracting women: essentialism in women's health research

Women's desire to take control of their own bodies creates a natural affinity between the projects of feminism and women's health research. Feminists have used the categories of woman/women, gender, and sex as foundation terms to designate the subject of feminist theories. Universal categories, which have been exposed as essentialist by postmodern and poststructural critiques, create falsely unified subject positions that fail to account for the diversity of women and also fail to acknowledge the situated interests of the dominant groups whose perspectives they reflect. Because it adopts these same categories, research in women's health is also permeated with this essentialized understanding, whether or not it is overtly feminist. In this paper, we point out the dangers of the unreflective use of woman/women, gender, and sex in women's health research. We conclude, that for political purposes, however, a carefully considered "strategic essentialism" can be warranted in research aimed at improving women's health.

Outbreak of Crimean-Congo haemorrhagic fever in Quetta, Pakistan: contact tracing and risk assessment

In December 1994 in a private hospital in Quetta, Pakistan, 3 health-workers contracted Crimean-Congo haemorrhagic fever (CCHF) after surgery on a bleeding patient who later died. We conducted a retrospective study to determine transmission risks among contacts. Fifty contacts gave blood for antibody tests and answered questions about exposure. Two of four people exposed percutaneously and one of five with cutaneous exposure contracted CCHE The person with cutaneous exposure was a surgeon who tore his glove during surgery and noted blood on his hand but no cut. There were no anti-CCHF antibodies or CCHF cases among persons whose skin came into contact with body fluids other than blood (0/4), who had skin-to-skin contact (0/16) with patients or were physically close to them (0/21). Three index case relatives reported that although 10 family members had cutaneous exposure, none developed CCHF. The family refused blood tests. CCHF transmission in resource-constrained settings can be limited by focusing on avoiding health worker contact with blood.

Examination-induced distress in a public examination at the completion of secondary schooling

BACKGROUND

The context for this study was the Higher School Certificate examination in New South Wales, Australia.

AIMS

The main research aim was to investigate the association between the Higher School Certificate, the reported distress and anxiety levels of the adolescent students who prepare for and sit for the examination, and various other internal and environmental variables.

SAMPLE

The random sample consisted of 445 students in their last two years of secondary schooling, with approximately equal numbers of males and females from a diverse range of ethnic backgrounds.

METHODS

Analysis was carried out using principal components analysis and multiple regression.

RESULTS

The most significant contribution to distress associated with the examination was made by the personality trait, anxiety proneness. Lower socio-economic status, self-confidence, academic and verbal self-concepts and perceived ability to cope were also found, to a lesser extent, to be associated with increased distress. The interactions sex with ethnic background and year with ethnic background were of particular interest. Students who were male and had an English speaking background, and students in year 11 who had an English speaking background were least likely to experience distress than others in the context of the examination.

CONCLUSIONS

Whilst results must be treated with caution, particular groups of students potentially vulnerable to distress were identified and directions for future research indicated.

Dromyosuppressin and drosulfakinin, two structurally related Drosophila neuropeptides, are uniquely expressed in the adult central nervous system

Drosophila myosuppressin (TDVDHVFLRFamide; DMS) and sulfakinin (FDDYGHMRFamide; DSK) have similar C-terminal structures. To determine the neuronal expression patterns of these structurally related peptides, we have generated DMS- and DSK-specific antisera to multiple antigenic peptides and performed double-label immunochemistry with antisera raised on different animals of the same species host animal. Our data indicate that DMS and DSK staining patterns in the adult central nervous system are unique and nonoverlapping.

The multiple meanings of long-term gastrostomy in children with severe disability

Although the physiological implications of long-term gastrostomy for children with severe disability are well documented in the nursing literature, little is known about the psychosocial effect of this technological intervention. This study documents and interprets the perspective of expert nurses and parents to reveal conflictual social processes associated with gastrostomy decision-making and the intense moral dilemma that these processes create. The findings suggest that gastrostomy denotes multiple meanings for parents and health care providers, and that an appreciation for these meanings can have a significant positive impact on nursing care for these children and their families.

Peritoneovenous shunts in patients with intractable ascites: palliation at what price?

Intractable ascites carries great morbidity by affecting appetite, mobility, and quality of life. Peritoneovenous shunts (PVSs) are utilized to abate intractable ascites, although long-term efficacy is unestablished. Thirty male and 18 female cirrhotics, 55 +/- 12 (standard deviation) years of age, failed multiple large-volume paracenteses and diuretic therapy before undergoing PVS. Data were collected until death or the present time. Nine patients (19%) are alive and palliated, four with working shunts [average follow-up (ave. f/u), 30 months] and five without shunts (ave. f/u, 19 months). Thirty-two (67%) patients died: 18 palliated with functional shunts (survival time, 4.4 +/- 5.7 months), 8 unpalliated with dysfunctional shunts (ave. f/u, 3.9 +/- 4.5 months), 4 unpalliated with shunts removed (ave. f/u 5.5 +/- 4.7 months), and 2 with unknown shunt function at death. Function was lost to occlusion in 26 patients, infection in 9, and ligation for disseminated intravascular coagulation in 3. Thirteen patients underwent 18 shunt replacements. At death/present time, 22 (46%) patients were palliated with functioning shunts. Seven patients were lost to follow-up. PVSs provide palliation for intractable ascites short term, but commonly occlude within 1 year. Despite palliation, complications with PVSs are high, and survival is limited.

Multiple antigenic peptides designed to structurally related Drosophila peptides

We have isolated TDVDHVFLRFamide (DMS), FDDYGHMRFamide (DSK), and DPKQDFMRFamide from Drosophila melanogaster. These peptides, structurally related by a common C-terminus -XRFamide, where X = L or M, are encoded by three different genes. To determine cellular expression, we have generated antisera to multiple antigenic peptides and performed double-label immunofluorescence using antisera raised in the same species host animal. Our results indicate that DMS and DSK immunoreactive materials have unique, non-overlapping expression patterns, while DMS and DPKQDFMRFamide immunoreactive materials colocalize in two superior protocerebrum neurons, and DSK and DPKQDFMRFamide immunoreactive materials colocalize in one superior protocerebrum neuron, one subesophageal ganglion neuron, and three thoracic ganglia neurons.

Deconstructing the gender neutrality of chronic illness and disability

Although a great deal has been written in the fields of women's health and disability/chronic illness, there is surprisingly little cross-fertilization. The dominant narrative within society orients us toward a view of chronic illness and disability that is gender neutral and devoid of social context. Examination of the ways in which chronic illness and disability are differently experienced by men and women creates a foundation upon which the implications of the dominant narrative can be explored. In this analysis, the authors find clinical, sociopolitical, and theoretical implications that derive from the traditional reluctance to consider the intersection of these fields of study. They conclude with recommendations for broadening our vision, correcting the omissions within our knowledge, and rethinking our part in contributing to inequities within society.

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Caring for dying children: nurses' experiences

Interviews with 25 nurses in this grounded theory study show that when nurses recognized that a child's death was inevitable, they struggled with both grief distress and moral distress. Their distress occurred within the context of the nurse-patient relationship. Nurses employed a range of strategies to manage their distress. Several conditions facilitated or constrained nurses' strategies, and resulted in far-reaching implications both professionally and personally.

Football injuries in a rural area

This study was conducted to analyze the frequency and characteristics of football injuries in a rural hospital setting and compare it to the national data. More than 6,000 patients with a sport-related injury presenting to the emergency medicine department at the Marshfield Clinic between June 1, 1988 and June 1, 1994 were collected prospectively. Eight hundred forty-three (14% of total) patients sustained football-related injuries. A chart abstraction form was then used to retrospectively review football injuries documenting types, sites, and mechanism of injury, along with demographic aspects. The peak age sustaining football injuries was 17 years old (17.5%). Most of the football injuries occurred during school activities (73.7%). The most common site injured was the finger (16.5%), followed by the knee (15.7%). Sprains/strains were the most common diagnosis representing 40.2% of injuries overall. The most common mechanism resulting in a football-related injury was as a result of being blocked or tackled (52.7%). Surgery was required on 4.9% of individuals injured while playing football. Most patients (69.7%) were expected to recover from their injury within 14 days. There were more injured football players from our area in the age group 15 to 24 years as compared to the national data available. Diagnosis, site injured, and mechanism of injury from our study were comparable to other national publications. Prospective studies are needed to address the problem of football-related injuries. Such studies would require a multidiscipline team of experts.