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PubMed2004

[Design and use of patient pathways in general surgery].

BACKGROUND: Clinical pathways are a new initiative intended to reduce costs while maintaining or even improving the quality of care. Based on treatment guidelines, patient pathways display an optimal sequence of staff actions in the preoperative, operative, and postoperative in- and outpatient treatment. METHODS: In this study, patient pathways were developed for selected elective general surgical disease entities following a new modular approach. All elements of care and their direct costs to the hospital were identified. Multidisciplinary teams of physicians, nurses, and administrative staff constructed and implemented the patient pathways. RESULTS: In the 1-year pilot phase, we developed and implemented 7 pathways with 16 subpathways: open herniorrhaphy, laparoscopic cholecystectomy and fundoplication, thyroidectomy, surgical treatment of diverticulitis and colon carcinoma and kidney transplantation. CONCLUSIONS: Patient pathways combine the management of care, hospital processes, and costs in a new integrated concept. Patient pathways streamline and standardize care, facilitate communication, and contribute to cost control efforts.

Cholecystectomy, Laparoscopic↗
PubMed2000

Maintenance and control of redox poise in Rhodobacter capsulatus strains deficient in the Calvin-Benson-Bassham pathway.

Carbon dioxide serves as the preferred electron acceptor during photoheterotrophic growth of nonsulfur purple photosynthetic bacteria such as Rhodobacter capsulatus and Rhodobacter sphaeroides. This CO2, produced as a result of the oxidation of preferred organic carbon sources, is reduced through reactions of the Calvin-Benson-Bassham reductive pentose phosphate pathway. This pathway is thus crucial to maintain a balanced intracellular oxidation-reduction potential (or redox poise) under photoheterotrophic growth conditions. In the absence of a functional Calvin-Benson-Bassham pathway, either an exogenous electron acceptor, such as dimethylsulfoxide, must be supplied or the organism must somehow develop alternative electron acceptor pathways to preserve the intracellular redox state of the cell. Spontaneous variants of Rba. capsulatus strains deficient in the Calvin-Benson-Bassham pathway that have become photoheterotrophically competent (in the absence of an exogenous electron acceptor) were isolated. These strains (SBP-PHC and RCNd1, RCNd3, and RCNd4) were shown to obviate normal ammonia control and derepress synthesis of the dinitrogenase enzyme complex for the dissipation of excess reducing equivalents and generation of H2 gas via proton reduction. In contrast to previous studies with other organisms, the dinitrogenase reductase polypeptides were maintained in an active and unmodified form in strain SBP-PHC and the respective RCNd strains. Unlike the situation in Rba. sphaeroides, the Rba. capsulatus strains did not regain full ammonia control when complemented with plasmids that reconstituted a functional Calvin-Benson-Bassham pathway. Moreover, dinitrogenase derepression in Rba. capsulatas was responsive to the addition of the auxiliary electron acceptor dimethylsulfoxide. These results indicated a hierarchical control over the removal of reducing equivalents during photoheterotrophic growth that differs from strains of Rba. sphaeroides and Rhodospirillum rubrum deficient in the Calvin-Benson-Bassham pathway.

Carbon Dioxide↗
PubMed1999

Microbial genomes and "missing" enzymes: redefining biochemical pathways.

A biochemical pathway is the representation of a defined set of substrates, enzyme reactions and products linked together to generate an outcome beneficial to a living cell. Microbial genome sequence data are unparalleled resources for understanding cellular metabolism without the prior definitions imposed by classical biochemistry. Simple analysis of three well-studied biochemical pathways (the tricarboxylic acid cycle, pentose phosphate pathway and glycolysis) from the 17 publicly available microbial genomes has shown that these pathways may rarely occur as previously defined. Therefore, following whole-genome sequencing it has become necessary to redefine the "classical" biochemical steps leading from substrate to end-product for each pathway. Often, unique or alternative reactions appear to be required in order to maintain pathway functionality where expected enzyme reactions (as defined by the presence or absence of the corresponding genes) are "missing". Conversely, such enzymes may be accounted for by: (1) the presence of low sequence similarity or novel genes encoding enzymes performing the same or similar functions, (2) the presence of multienzyme proteins, (3) incorrectly assigned gene identities in genome databases, and (4) known enzyme functions that have yet to be correlated with a gene sequence. Most importantly, the presence of a gene sequence does not necessarily ensure that its corresponding enzyme is actually functional. This may be due to the presence of nonactive remnant genes, evolutionary pressures leading to loss of function, inactivating mutations, the lack of transcription/translation, and post-translational processing. Modifications at the gene and/or functional levels, as well as the possible use of alternative enzymes, must be considered when reconstructing biochemical pathways for fully sequenced microbial genomes.

Bacteria↗
PubMed1998

On the cutaneous receptors contributing to withdrawal reflex pathways in the decerebrate spinal rat.

Previous studies indicate that the withdrawal reflex system in the rat has a "modular" organization, each reflex pathway performing a specific sensorimotor transformation. Here, we wished to clarify which cutaneous receptors contribute to this system and to determine whether there are differences in this respect between reflex pathways of different muscles. Withdrawal reflexes of the peroneus longus, extensor digitorum longus, and semitendinosus muscles were recorded with EMG techniques during high reflex excitability in decerebrate spinal rats (n=26). While maintained innocuous pressure on glabrous skin could elicit a sustained reflex activity in all muscles studied, vibration of glabrous skin (10-300 Hz) always failed to evoke a reflex response, suggesting that slowly adapting, but not rapidly adapting, low-threshold mechanoreceptive fibers from this type of skin contribute to withdrawal reflex pathways. Thermal stimulation in the innocuous range, i.e., cooling from 32 to 17 degrees C, or warming the skin from 32 to 41 degrees C, always failed to produce reflex responses, indicating that neither cold nor warm receptors contribute to withdrawal reflex pathways. When either cooling or warming the skin to the noxious temperatures of 1 degrees C or above 45 degrees C, respectively, a reflex discharge was often evoked in the muscles studied. Intradermal administration of histamine, a potent pruritogenic substance, produced very weak, or no, reflex response. In contrast, mustard oil produced vigorous reflex responses in all muscles studied. These findings suggest that some chemonociceptors contribute only weakly, or not at all, to withdrawal reflex pathways. The present data suggest that a selective set of cutaneous receptors contribute to withdrawal reflex pathways and that different withdrawal reflex pathways receive input from essentially the same cutaneous receptor types.

Animals↗
PubMed2003

Development of clinical pathway in S-1 chemotherapy for gastric cancer.

We have developed a clinical pathway to enable the safe continuous administration of S-1 (TS-1) in ambulatory care for patients with advanced gastric cancer. The S-1 clinical pathway includes a pathway for clinicians, a pathway for patients, and such assist tools as a medication diary, an explanatory document containing instructions relating to patient compliance, a table of associations between adverse reactions and prodromes, and general principles for dose reduction and withdrawal. These pathways and assist tools will improve the patient's perception of adverse reactions, thereby contributing to early discovery and rapid action against adverse events. The S-1 clinical pathway has been used with ten patients. S-1 administration has been continued in seven patients. In four of the seven patients, continued administration on the occurrence of adverse reactions was made possible by the use of appropriate measures such as drug withdrawal or dose reduction. It was confirmed that the S-1 clinical pathway was a useful tool for cancer chemotherapy in ambulatory care.

Adult↗
PubMed2003

Prospective, randomized, controlled trial between a pathway of controlled rehabilitation with early ambulation and diet and traditional postoperative care after laparotomy and intestinal resection.

INTRODUCTION: In an era of dwindling hospital resources and increasing medical costs, safe reduction in postoperative stay has become a major focus to optimize utilization of healthcare resources. Although several protocols have been reported to reduce postoperative stay, no Level I evidence exists for their use in routine clinical practice. METHODS: Sixty-four patients undergoing laparotomy and intestinal or rectal resection were randomly assigned to a pathway of controlled rehabilitation with early ambulation and diet or to traditional postoperative care. Time to discharge from hospital, complication and readmission rates, pain level, quality of life, and patient satisfaction scores were determined at the time of discharge and at 10 and 30 days after surgery. Subgroups were defined to evaluate those who derived the optimal benefit from the protocol. RESULTS: Pathway patients spent less total time in the hospital after surgery (5.4 vs. 7.1 days; P = 0.02) and less time in the hospital during the primary admission than traditional patients. Patients younger than 70 years old had greater benefits than the overall study group (5 vs. 7.1 days; P = 0.01). Patients treated by surgeons with the most experience with the pathway spent significantly less time in the hospital than did those whose surgeons were less experienced with the pathway (P = 0.01). There was no difference between pathway and traditional patients for readmission or complication rates, pain score, quality of life after surgery, or overall satisfaction with the hospital stay. CONCLUSIONS: Patients scheduled for a laparotomy and major intestinal or rectal resection are suitable for management by a pathway of controlled rehabilitation with early ambulation and diet. Pathway patients have a shorter hospital stay, with no adverse effect on patient satisfaction, pain scores, or complication rates. Patients younger than 70 years of age derive the optimal benefit, and increased surgeon experience improves outcome.

Adult↗
PubMed1985

Stimulation of the hexose monophosphate pathway by pyrroline-5-carboxylate reductase in the lens.

Addition of pyrroline-5-carboxylate (P5C) or its precursors to rat lenses cultured for 24 hr in TC-199 medium containing 14C-glucose results in an apparent concentration-dependent increase in hexose monophosphate-pentose (HMP) pathway activity. Addition of proline, the reduction product of P5C, did not result in an increase, suggesting that stimulation of the HMP pathway is related to the reduction of P5C to proline by the enzyme P5C reductase. No apparent feedback inhibition on P5C reductase was observed. Stimulation of HMP pathway activity by P5C was also observed in the lenses of Philly and Nakano mouse, two models of congenital osmotic cataracts. Compared with its genetic control, the Swiss--Webster mouse, generally no difference in the lenticular levels of HMP pathway activity was observed in the Philly mouse--even after the onset of cataract. Stimulation of the HMP pathway in the Philly lens by P5C, however, was consistently lower than its control. In the lenses from the Nakano mouse and its genetic control, the Balb/c mouse, no difference in the percentage stimulation of the HMP pathway resulting from the addition of P5C was observed, but HMP pathway activity in the Nakano lens was consistently lower than that of the control.

Aging↗
PubMed1985

An exuberant retinocollicular pathway in Siamese kittens: effects of competition and abnormal activity on its maturation.

Retinocollicular pathways were studied in normally pigmented and Siamese adult cats and newborn kittens. In addition, retinocollicular pathways were studied in Siamese cats which were unilaterally enucleated on the day of birth and in Siamese cats which were reared in a stroboscopically illuminated environment. In adult Siamese cats the ipsilateral retinocollicular pathway is spatially less extensive than it is in adult normally pigmented cats. In contrast, the ipsilateral retinocollicular pathway in newborn Siamese kittens is widespread, while that of newborn normally pigmented kittens is restricted, as it is in normally pigmented adults. This comparison indicates that the spatial restriction of the retinocollicular pathway occurs after birth in Siamese cats. After enucleation or stroboscopic rearing the ipsilateral retinocollicular pathway in Siamese cats remains widespread. These results demonstrate the importance of interactions with afferents from other sources and the requirement for appropriate neural activity in the normal maturation of this initially exuberant pathway.

Age Factors↗
PubMed1987

Neuronal organization underlying visually elicited prey orienting in the frog--III. Evidence for the existence of an uncrossed descending tectofugal pathway.

A complete transverse hemisection of the neuraxis just caudal to the optic tectum in the frog, Rana pipiens, results in a failure to orient toward stimuli in one visual hemifield [Kostyk and Grobstein (1986) Neuroscience 21, 41-55]. This finding indicates that each tectal lobe gives rise to a crossed descending pathway adequate to cause turns in a direction contralateral to that tectal lobe, and suggests that each may also give rise to an uncrossed descending pathway adequate to cause turns in the ipsilateral direction. To determine whether there is in fact such an uncrossed pathway, we have studied the orienting behavior of frogs after lesions which interrupt crossed pathways. Two groups of animals were studied. In one group we made midline lesions of the ansulate commissure, through which run the major crossed descending projections from both tectal lobes. In the other group, we combined a complete transverse hemisection with removal of the tectal lobe on the same side of the brain, leaving intact only an uncrossed pathway from one tectal lobe. A persistence of orienting turns was observed in both groups of animals. In both, the direction of the turns was that expected on the assumption that an uncrossed pathway would cause ipsilateral turns. We conclude that such a pathway exists. While both groups of animals turned in the expected directions, they did so for stimuli at unexpected locations. Increasingly eccentric stimulus locations to one side of the mid-sagittal plane were associated with increasing amplitude turns to the other. The observation suggests that tectal regions mapping areas of visual space to one side of the mid-sagittal plane are capable of triggering turns not only in that direction but in the opposite direction as well. In the case of ansulate commissure section, mirrored orienting responses were observed for tactile stimuli as well. These and other behavioral anomalies described in the preceding papers [Kostyk and Grobstein (1986) Neuroscience 21, 41-55 and 57-82] suggest that between the topographic retinotectal projection and the premotor circuitry for orienting there may exist an intermediate processing step, one in which stimulus location is represented in a generalized spatial coordinate frame.

Animals↗
PubMed2004

Optic radiation involvement in optic pathway gliomas in neurofibromatosis.

PURPOSE: Optic pathway gliomas (pilocytic astrocytomas) in neurofibromatosis type 1 (NF-1) typically involve some combination of the optic nerves, chiasm, or optic tracts. Involvement of the optic radiations is rare. DESIGN: This paper describes seven patients with NF-1 with gliomas involving the pregeniculate optic pathway in addition to the optic radiations. METHODS: A retrospective database review was made of all patients with NF-1 and optic pathway gliomas seen by one of the authors (G.T.L.) at the Children's Hospital of Philadelphia from July 1993 to October 2001. Patients with involvement of pregeniculate optic pathway and the optic radiations were identified. From November 2001 to February 2003, patients were sought prospectively. Cases were also identified from the practice of another author (M.C.B.) at Arkansas Children's Hospital. RESULTS: Four patients from Children's Hospital of Philadelphia (three of 83 total NF-1/optic pathway gliomas from July 1993 to October 2001 and one prospectively) and three from Arkansas Children's Hospital were identified. Two had expanding mass lesions within the white matter of the temporal or parietal lobes, which were histopathologically demonstrated to be pilocytic astrocytomas. The other five had radiographic involvement of the optic radiations but did not undergo biopsy. In three of the cases the vision was 20/200 or worse in each eye. CONCLUSIONS: Optic pathway gliomas in NF-1 may rarely involve the optic radiations. Optic radiation involvement may signal a more aggressive optic pathway glioma in patients with neurofibromatosis-1.

Child, Preschool↗
PubMed2006

A clinical pathway for treating pneumonia in the nursing home: part I: the nursing perspective.

OBJECTIVES: This paper examines nursing staff's perspectives on the utility and sustainability of a clinical pathway for treating nursing home residents with pneumonia. DESIGN: A qualitative (case study) design was used. SETTING: Data were collected from 6 nursing homes in Southern Ontario (5 from metro regions and 1 from a nonmetro region). Nursing homes were drawn from a larger randomized controlled trial of a clinical pathway for nursing home-acquired pneumonia conducted between 2001 and 2005. The clinical pathway was designed to assist in the identification, diagnosis, and management of pneumonia, including a decision tool for determining the appropriate location of treatment (hospital versus nursing home). PARTICIPANTS: A total of 7 focus groups and 1 one-on-one interview were conducted between February 2003 and May 2004. Interview data were analyzed using the template style, described by Miller and Crabtree, to identify key themes. FINDINGS: Nurses strongly supported the idea of the clinical pathway and believed that providing pneumonia care in the nursing home was better for the resident. As a result of using the clinical pathway, nurses felt that pneumonia was being identified, diagnosed, and treated earlier, resulting in fewer hospitalizations. In addition to the benefits to resident care, the nurses felt that their skills and knowledge also improved. Nurses generally supported the implementation of the pathway although some concern was expressed about the additional responsibility and resources that would entail. CONCLUSIONS: The implementation of a clinical pathway for treating pneumonia in nursing homes and quick access to a backup clinician are desired by nurses who also believe it will result in better care and fewer hospitalizations of residents.

Aged↗
PubMed2006

Mannan-binding lectin (MBL)-mediated opsonization is enhanced by the alternative pathway amplification loop.

The complement system is a humoral effector in the innate immune system. Three activation pathways exist in the complement system, known as the classical pathway, the lectin pathway and the alternative pathway. Dysfunction of lectin pathway activation is caused by MBL deficiency. MBL deficiency in a cohort of healthy Caucasian blood bank donors was investigated with MBL genotyping and MBL plasma concentration. Recognition of the yeast-derived zymosan by MBL was investigated with Western blot. The involvement of the alternative pathway amplification loop in enhancing MBL-mediated opsonization of zymosan was investigated in a novel opsonophagocytosis assay for flow cytometry. Sera deficient for MBL, factor D or properdin were tested, and purified MBL, factor D or properdin were used to recover opsonization. The optimal receiver-operator characteristic (ROC) cut-off value for dividing the Caucasian cohort in MBL-sufficient and MBL-deficient was calculated at 0.7 microg/ml. Thirty-eight percent of the group had concentrations below 0.7 microg/ml. Zymosan eluates opsonized with MBL-sufficient sera contain high oligomers of MBL, while eluates from MBL-deficient donors contained hardly any MBL. The MBL-, factor D- and properdin-deficient sera showed reduced opsonophagocytosis by human control neutrophils, as compared to normal MBL-sufficient sera. This reduction in opsonization was restored to normal levels by addition of purified MBL, factor D and properdin. The absence of opsonization in the factor D- and properdin-deficient sera, but presence in normal serum after blocking with anti-C1q-F(ab)2 and anti-MBL-F(ab)2, demonstrates the involvement of the amplification loop in MBL-initiated zymosan opsonization, even at very low serum concentrations (up to 3%, v/v). In conclusion, our data demonstrate that the MBL-mediated route of complement activation depends on the alternative pathway amplification loop for optimal opsonization of zymosan.

Cohort Studies↗
PubMed1997

Why use clinical pathways rather than practice guidelines?

BACKGROUND: Financial pressures from managed care organizations, the government, and other "stakeholders" have resulted in the production of practice guidelines and clinical pathways. Clinical pathways involve all segments of a health care system and may prove to be more beneficial and less hazardous to patients and health care providers. METHODS: A historical narrative describing the development of clinical pathways by the Southwestern Surgical Congress (SWSC) and the Southeastern Surgical Congress (SESC) is made. The motivations, the benefits, and the hazards of both clinical pathways and practice guidelines are discussed. RESULTS: Clinical pathways have proven to reduce length of stay (LOS), complications, and cost, and provide increased patient satisfaction whereas practice guidelines from some specialties show improved quality of care when compared with nonspecialists. However, many practice guidelines are developed by specialists on "best practice" standards, and few have documented studies proving their effectiveness. CONCLUSIONS: Eleven clinical pathways were developed by the SWSC and the SESC and are in the process of revision and study for efficacy. They will be disseminated in the American Surgeon and on the SWSC web site for review and comment. In 1998, both congresses hope to publish the efficacy of selected pathways by describing their effect on LOS and charge for those diagnostic-related groups.

Critical Pathways↗
PubMed1998

Standardized clinical care pathways for major thoracic cases reduce hospital costs.

BACKGROUND: Standardized clinical care pathways have been developed for postoperative management in an attempt to contain costs in an era of rising health care costs and limited resources. The purpose of this study was to assess the effect of these pathways on length of stay, hospital charges, and outcome for major thoracic surgical procedures. METHODS: All anatomic lung (segmentectomy, lobectomy, and pneumonectomy) and partial and complete esophageal resections performed from July 1991 to July 1997 were retrospectively analyzed for length of stay, hospital charges, and outcome. A prospectively developed database was used. Clinical care pathways were introduced in March 1994. Comparisons were made between the procedures performed before (group I) and after (group II) pathway implementation. Common to both pathways are early mobilization and prudent x-ray and laboratory analysis. In addition, the pathway for esophagectomies emphasizes overnight intubation with 24-hour intensive care unit care, and staged diet advancement. The discharge goal was postoperative day 10. For lung resection the emphasis is early postoperative extubation with overnight intensive care unit management. The discharge goal was postoperative day 7. RESULTS: Group I esophagectomies (n = 56) had significantly greater hospital charges compared with group II (n = 96) ($21,977 +/- $13,555 versus $17,919 +/- $5,321; p < 0.04, in actual dollars) and ($29,097 +/- $18,586 versus $19,260 +/- $6,000; p < 0.001, in dollars adjusted for inflation) and greater length of stay (13.6 +/- 6.9 versus 9.5 +/- 2.8 days; p < 0.001). Group I lung resections (n = 185) had a significantly greater length of stay compared with group II (n = 241) (8.0 +/- 6.2 versus 6.4 +/- 3.8 days; p < 0.002); although charges trended downward ($13,113 +/- $10,711 versus $12,404 +/- $7,189; not significant) in actual dollars, charges were significantly less in dollars adjusted for inflation ($17,103 +/- $13,211 versus $13,432 +/- $8,056; p < 0.01). The most significant decreases in charges for esophagectomies were in miscellaneous charges (61% in dollars adjusted for inflation), pharmaceuticals (60%), laboratory (42%) and radiologic (39%) tests, physical therapy charges (35%), and routine charges (34%). For lung resections the greatest savings occurred for pharmaceuticals (38%), supplies (34%), miscellaneous charges (25%), and routine charges (22%). Mortality was similar (esophagectomies: I, 3.6%; II, 0%; lung resections: I, 0.5%; II, 0.8%; not significant). CONCLUSIONS: Introduction of standardized clinical pathways has resulted in a marked reduction of length of stay for all major thoracic surgical procedures. Total charges were reduced for both esophagectomies (34%) and lung resections (21%) with continued quality of outcome.

Aged↗
PubMed1999

The feedback pathway from horizontal cells to cones. A mini review with a look ahead.

The feedback pathway from HCs to cones forms the basis of the surround responses of the bipolar cells and is essential for the spectral opponency of horizontal cells. The nature of this feedback pathway is an issue of debate. Three hypothesis are presented in literature: (1) a GABAA-ergic feedback pathway; (2) a GABA-independent feedback pathway that modulates the Ca-current in cones; and (3) an electrical feedback pathway. In this review the evidence for the various pathways will be discussed. The conclusion is that the available evidence favors the hypothesis that feedback modulates the Ca-current in the cones in a GABA independent way. An alternative role of GABA in the outer plexiform layer is discussed and finally the functional consequences of the negative feedback pathway from horizontal cells to cones are presented.

Animals↗
PubMed2005

Anatomical pathways that link perception and action.

Pathways linking action to perception are generally presented as passing from sensory pathways, through the thalamus, and then to a putative hierarchy of corticocortical links to motor outputs or to memory. Evidence for more direct sensorimotor links is now presented to show that cerebral cortex rarely, if ever, receives messages representing receptor activity only; thalamic inputs to cortex also carry copies of current motor instructions. Pathways afferent to the thalamus represent the primary input to neocortex. Generally they are made up of branching axons that send one branch to the thalamus and another to output centers of the brain stem or spinal cord. The information transmitted through the classical "sensory" pathways to the thalamus represents not only information about the environment and the body, but also about instructions currently on their way to motor centers. The proposed hierarchy of direct corticocortical connections of the sensory pathways is not the only possible hierarchy of cortical connections. There is also a hierarchy of the corticofugal pathways to motor centers in the midbrain, and there are transthalamic corticocortical pathways that may show a comparable hierarchy. The extent to which these hierarchies may match each other, and relate to early developmental changes are poorly defined at present, but are important for understanding mechanisms that can link action and perception in the developing brain.

Animals↗
PubMed1999

Differential sensitivities of the two visual pathways of the chick to labelling by fluorescent retrograde tracers.

This study investigates the neurone structure-specific differences of sensitivities of fluorescent tracers. The tracers were used for retrograde labelling of contralateral projections in the two visual pathways of the chick. Rhodamine B Isothiocyanate (RITC), Fluorogold (FG) and True blue (TB) were injected into either the visual Wulst (thalamofugal pathway) or the nucleus rotundus (Rt; tectofugal pathway) and the retrogradely labelled neurones in the nucleus geniculatus lateralis pars dorsalis (GLd) or the optic tectum, respectively, were counted. Differential retrograde labelling in the two pathways was observed. In the thalamofugal pathway, both the contralateral and ipsilateral GLd cells were labelled by all three tracers (RITC, FG and TB). However, in the tectofugal pathway, whereas RITC labelled both the ipsilateral and contralateral tectal neurones, FG or TB labelled effectively only the ipsilateral tectal neurones. It was clear that FG and TB were taken up by the nerve endings and transported part-way along the axon but failed to be transported to the cell bodies of the contralateral tectal neurones. In addition, red beads and green beads were also injected into Rt and the differential labelling was also observed. Red beads labelled both ipsilateral and contralateral tectal neurones but green beads labelled only the ipsilateral tectal neurones. Since the contralateral tectal projections consist of divergent axon collaterals, the present study suggests that various retrograde tracers are not transported in these axon collaterals to label cell bodies. The contralaterally projecting neurones in the thalamofugal pathway are not axon collaterals and they were labelled by all of the tracers used.

Animals↗
PubMed2000

Detection of complement alternative pathway mRNA and proteins in the Alzheimer's disease brain.

Previous research on complement activation in the Alzheimer's disease (AD) brain has focused almost exclusively on the classical complement pathway. The alternative pathway represents another important arm for complement activation, converging with the classical cascade at the C5 cleavage step. Here, we show that mRNA for a critical alternative pathway component, factor B, is present in AD frontal cortex and that the factor D cleaved split products of factor B, Bb and Ba, are significantly increased, indicating alternative pathway activation. By contrast, the two major inhibitors of alternative pathway activation, factor H and factor I, are present at the level of mRNA and protein but are not significantly upregulated. Immunohistochemical analysis reveals significant positive staining in AD sections for all three components. Taken together with previous reports demonstrating alternative pathway activation by amyloid beta peptide, these findings suggest that conditions conducive to chronic alternative pathway activation may exist in the AD brain.

Aged↗