Competition of adenine nucleotides for a 1,3-[3H]-dipropyl-8-cyclopentylxanthine binding site in rat vas deferens

1. The binding of 1,3-[3H]-dipropyl-8-cyclopentylxanthine ([3H]-DPCPX), a specific adenosine A1 receptor antagonist, was examined in rat vas deferens membrane preparations using radioligand binding techniques. 2. 1,3-[3H]-Dipropyl-8-cyclopentylxanthine bound to these preparations with a KD of 1.07 +/- 0.14 nmol/L (n = 6). The density of [3H]-DPCPX binding sites was 133.38 +/- 5.57 fmol/mg protein. 3. Computer analysis indicated that nucleosides competed for [3H]-DPCPX binding at two distinct sites. The rank order of potency at the higher affinity site corresponded to R-phenylisopropyladenosine (R-PIA) > or = 2-chloroadenosine (2-CIADO) > or = cyclopentyladenosine (CPA) > or = N-ethylcarboxamidoadenosine (NECA) > s-phenylisopropyladenosine (s-PIA). Ki values were in the low nmol/L range. The rank order of nucleoside potency at the lower affinity site corresponded to R-PIA > or = CPA > or = NECA > or = 2-CIADO > S-PIA. Ki values were in the low mumol/L range. 4. Nucleotides competed for [3H]-DPCPX binding at a single site only. The rank order of potency at this site corresponded to alpha, beta-methylene ATP > or = beta, gamma-methylene ATP > or = ATP. Ki values were in the high mumol/L range. The site seemed to correspond with one of the two binding sites predicted by nucleoside competition binding. 5. The ATP-regenerating compound myokinase did not significantly change the competition curve for ATP, indicating that the competition for [3H]-DPCPX binding observed in the presence of ATP was due to an effect of ATP per se and not to an action of a degradation product. 6. The results demonstrate that in rat vasa deferentia there exist two distinct binding sites for [3H]-DPCPX. One of these sites binds only nucleosides and may represent an adenosine A1 receptor, as usually defined. The other site binds both nucleosides and nucleotides and may represent an atypical adenosine A1 receptor, an atypical P2 or a P3 purinoceptor.

Cell cycle markers in the hippocampus in Alzheimer's disease

Using immunohistochemistry we have analysed the nuclear expression of cyclins A, B, D, and E in neurones in the hippocampi of control subjects and patients suffering from various neurodegenerative disorders including. Alzheimer's disease (AD). Cyclins A and D could not be detected but varying degrees of cyclin E expression were found in all patient groups including control subjects. Cyclin B expression was not detected in control subjects but it was expressed in the subiculum, dentate gyrus and CA1 region in patients with AD-type pathology and in the CA2 region and the dentate gyrus of cases of Pick's disease. These results suggest that some neurones may have re-entered the cell cycle. The expression of cyclin E without cyclin A expression may indicate an arrest in G1 with the possibility of re-differentiation and exit from G1 to G0. The expression pattern of cyclin E indicates that re-entry into the cell cycle is possible even in control patients, but it is accentuated in patients with AD-related pathology. However, cyclin B was only expressed in AD patients and occurred in areas that were severely affected by pathology. Neurones with cyclin B-reactive nuclei in AD were AT8 positive but did not contain fully developed tangles. In neurones, where cyclin B is expressed, it would appear that the G1/S checkpoint has been bypassed and that the cell cycle is arrested in G2. It is proposed that these neurones do not have the opportunity for subsequent re-differentiation. Since factors known to be present in G2 seem to be responsible for microtubule destabilisation and hyperphosphorylation of tau we hypothesise that cell cycle disturbances may be important in the pathogenesis of AD.

Differential age-related processing limitations in recall and recognition tasks

The degree to which processing resources are responsible for age differences in performance on recall and recognition tasks was examined in this study. To examine this, a secondary task incorporating a memory component (digit preloads) was implemented during retrieval. Results revealed that older adults, relative to younger adults, exhibited greater decrements in secondary task performance as the difficulty of the secondary task increased. These age differences were greater in the recall task than in the recognition task. Hierarchical regression analyses indicated that speed accounted for the largest proportion of age-related variance in the recall task while both speed and working memory contributed to much of the secondary task variance. Results confirm the hypothesis that recall requires greater processing capacity than recognition and that older adults have greater processing-capacity limitations than younger adults.

Open surgical exploration after failed endopyelotomy: a 12-year perspective

PURPOSE

Factors that have a role in endopyelotomy failure have not been fully elucidated but are believed to include high grade hydronephrosis and the presence of crossing vessels at the ureteropelvic junction.

MATERIALS AND METHODS

We retrospectively analyzed the importance of renal function, hydronephrosis, ureteral stents, surgeon experience and crossing vessels in determining the outcome of endopyelotomy.

RESULTS

Of 401 percutaneous antegrade endopyelotomies performed at our medical center during the last 12 years 60 failed and 54 of these patients underwent surgical exploration. Patients with high grade hydronephrosis and poor initial renal function were much less likely to have successful endopyelotomy than those with moderate hydronephrosis or good renal function (success rates 50 versus 96 and 54 versus 92%, respectively, p <0.001). The most common findings at exploration included severe extrinsic fibrosis and intrinsic fibrotic stenosis. Obstructing crossing vessels were present in 13 patients explored, suggesting a possible role in causing failure in only 4% of all endopyelotomy patients.

CONCLUSIONS

Patients with high grade hydronephrosis and poor initial renal function are much more likely to experience endopyelotomy failure. Crossing vessels appear to have a less significant role in endopyelotomy failure than has been previously suggested.

A multicenter clinical trial investigating the use of a fluoroscopically controlled cutting balloon catheter for the management of ureteral and ureteropelvic junction obstruction

PURPOSE

We assessed the efficacy of a fluoroscopically controlled cutting balloon catheter for the treatment of ureteropelvic junction and ureteral strictures.

MATERIALS AND METHODS

A multicenter trial was performed that included 66 endopyelotomies and 49 endoureterotomies. To our knowledge this study represents the largest number of patients with ureteropelvic junction obstruction and ureteral strictures tested with this device to date.

RESULTS

With a mean followup of 7.8 months (range 1 to 17.9) the patency rate was 77% for endopyelotomy, with 72% of the primary and 100% of the secondary ureteropelvic junction obstructions remaining patent. The endoureterotomy patients were followed for an average of 8.7 months (range 1.2 to 17.0), with a patency rate of 55%.

CONCLUSIONS

A cutting balloon endoscopic incision is effective in the majority of cases, with patency rates for endopyelotomies and endoureterotomies that mirror current endourological reports using other, albeit more time intensive and more invasive, incisional techniques.

Mediators of long-term memory performance across the life span

An individual-differences approach was used to examine the component processes that predict episodic long-term memory performance. A total of 301 participants ages 20-90 received a 7-hr cognitive battery across 3 days. Key constructs hypothesized to affect long-term memory function were assessed, including multiple measures of working memory and perceptual speed. Latent-construct, structural equation modeling was used to examine the relationship of these measures and age to different types of long-term memory tasks. Speed was a key construct for all 3 types of memory tasks, mediating substantial age-related variance; working memory was a fundamental construct for free and cued recall but not spatial memory. The data suggest that both speed and working memory are fundamental to explaining age-related changes in cognitive aging but that the relative contributions of these constructs vary as a function of the type of memory task.

Physical restraint of patients in a psychiatric hospital

Use of physical restraint occurs within British psychiatric hospitals yet there has been little evaluative research on current practice. The present study aims to describe a group of disturbed in-patients who had required physical restraint at some point during the course of their stay in hospital and to classify the reasons for its use. Cases were identified using Case Register data and information obtained from patients' records. In the 48 episodes of physical restraint identified, patients were predominantly schizophrenic (60%), male (67%) and had been restrained because of physical violence to others (44%) or because they were attempting to abscond (31%). Although the majority of patients were compulsorily detained prior to the use of physical restraint, three remained informal. The findings are discussed in the context of the legal justifications for use of restraint. Further research on current practice is required to enable formulation of clear guidelines.

Construction of a transcription map around the gene for ataxia telangiectasia: identification of at least four novel genes

We have constructed YAC, PAC, and cosmid contigs in the ataxia-telangiectasia gene region and used the assembled clones to isolate expressed sequences by exon trapping and hybridization selection. In the interval between D11S1819 and D11S2029, exons and cDNAs for potentially 13 different genes were identified. Three of these genes, F37, K28, and 6.82, are large novel genes expressed in a variety of different tissues. K28 shows sequence homology to the Rab GTP binding protein family and gene 6.82 homology to the rabbit vasopressin activated calcium mobilizing receptor, while gene F37 has no homology to any known sequence in the database. Three further clones, exon 6.41 and cDNAs K22 and E74, from the interval between D11S1819 and D11S2029, appear to be expressed endogenous retrovirus sequences. The fourth large novel genes, E14, together with two further possible novel genes, E13 and E3, was identified from exons and cDNAs in the more telomeric 300-kb interval between markers D11S2029 and D11S2179. These are in addition to the genes for mitochondrial acetoacetyl-CoA-acetyltransferase (ACAT) and the ATM gene in the same region. Genes E3, E13, and E14 do not show homology to any known genes. K28, 6.82, ACAT, and ATM all appear to have the same transcriptional orientation toward the telomere.

Characteristics of in-patients transferred to a locked ward in a Scottish psychiatric hospital

OBJECTIVE

To identify and characterise in-patients transferred from open wards to the locked facility (IPCU) of a psychiatric teaching hospital, and to classify reasons for transfer.

DESIGN

Retrospective case note study using the Lothian Psychiatric Case Register. A reason for transfer classification was devised.

SETTING

Intensive Psychiatric Care Unit (IPCU) of the Royal Edinburgh Hospital.

SUBJECTS

All in-patients transferred from other wards of the Royal Edinburgh Hospital to the IPCU during one year.

RESULTS

Over one year there were 131 transfer episodes involving 97 patients. Ninety-eight per cent of episodes could be allocated to one of six categories of reason for transfer, with physical violence to others being commonest (30%). Patients' mean age was 31 years. There was a predominance of schizophrenics (51%) and males (66%). In 20% of transfers, patients were not detained under mental health legislation. Associations emerged between schizophrenia and physical violence, hypomania/mania and generally disruptive behaviour, personality disorder and self harm. In half of all transfers the patient had already been an in-patient for at least 1 month. Fifty-seven per cent of patients were transferred more than once over the preceding five years. Most (90%) transfers originated from acute wards, and patients stayed in the IPCU less than two weeks (70%) before returning to the open wards (23% less than 24 hours).

CONCLUSIONS

Local locked wards deal with a range of disturbed behaviour and can be an important component in the spectrum of secure provision. Further evaluative research is required.

Massive hemorrhage from renal vein injury during percutaneous renal surgery: endourological management

PURPOSE

Although minor venous injuries respond to simple maneuvers, major venous injuries pose a significant therapeutic problem and may be under diagnosed. We present our experience with major injury to the renal vein during percutaneous renal surgery.

MATERIALS AND METHODS

Four patients had massive hemorrhage during percutaneous renal surgery associated with major injury to the renal vein, and 3 also had renal insufficiency. All 4 patients and 1 additional patient with renal insufficiency and massive hemorrhage from an arteriovenous fistula following percutaneous renal surgery were treated nonoperatively with a selectively positioned and inflated Council balloon catheter.

RESULTS

Hemorrhage was controlled and renal function was unaffected in all 5 patients.

CONCLUSIONS

Renal vein injuries can be associated with massive hemorrhage. Patients with major vascular injuries from percutaneous renal surgery and concomitant renal insufficiency can be treated without open exploration or angiographic embolization using a Council balloon catheter.

Expression of cell division markers in the hippocampus in Alzheimer's disease and other neurodegenerative conditions

Recent studies, showing that cell cycle-related nuclear proteins p105 and Ki-67 are associated with Alzheimer's disease (AD)-related cytoskeletal pathology, suggested that these proteins, in addition to their functions in regulating the cell cycle, may have more specialised functions in the adult nervous system. In order to test this hypothesis we studied the expression of the cell cycle-related proteins Ki-67, pCNA and p53 in the hippocampi of 33 subjects, including some with AD or other neurodegenerative disorders and some with no neurological disease. By immunohistochemistry we found nuclear expression of Ki-67 in all subregions of the hippocampus, with the highest levels in the dentate gyrus. Both neurons and glial cells expressed this protein. The proportion of cells positive for Ki-67 and the distribution pattern varied considerably depending on the pathological diagnosis. Neuronal nuclear expression of Ki-67 was increased in AD but was also elevated in young Down's syndrome subjects and in those with Pick's disease. Expression of this protein was therefore not AD-specific. We did not find nuclear pCNA or p53 expressed in our patient groups. Contrary to previous studies AD-type neurofibrillary tangles were not labelled with any of the cell cycle markers used. The presence of nuclear Ki-67 expression indicates that some hippocampal neurons are not in the quiescent G0 phase but have re-entered the cell cycle. The absence of nuclear pCNA or p53 suggests that the cycle is arrested in G1. The significance of our findings and their relationship to the production of neurodegenerative cell death via an apoptotic mechanism are discussed.

Carcinoma of the bronchus in the Yorkshire region of England 1976-1990: trends since 1984

We wished to confirm that, in patients with lung cancer, trends in demography and histology, together with modest improvements in survival, first seen in the 1976-1983 cohorts, continued to 1990. All lung cancer patients resident in Yorkshire are notified to the Cancer Registry, whose database was analysed for this report. A total of 38,275 patients were notified. There was no change in annual notification for males but an increase from 513 to 815 annual notifications in females between 1976 and 1990. Mean age increased by 3 yrs, in males to 67.4 yrs and in females to 67.2 yrs. Histological confirmation rate increased from 43% to 60% (mean age from 60.8 to 64.5 yrs). Annual notifications of adenocarcinoma increased consistently from 108 to 253. Two year surgical survival improved from 37.4 to 44.3%, doubling in subjects aged > or = 70 yrs to 43.8%. Over the 15 year period, there was no improvement in survival aged < 60 yrs, but a significant improvement in the 60-69 and > or = 70 yrs age groups. Analysis of survival by quartiles showed significant improvement at all levels (first interval 20 to 24 days, median 79 to 91 days, third interval 224 to 266 days). The modest improvement in outlook was confirmed, confined to older subjects after 1983, and partially masked by increasing age. Survival after surgery is now independent of age.

Protein engineering to create biologically active peptides: recombinant human rhinoviruses that display peptide sequences

This paper describes the use of human rhinovirus to display peptides corresponding to biologically active sequences. While this system can be used to reconstruct essentially any biologically active sequence for which there is a corresponding ligand that can be used for its selection, we have focused on using this system to display immunogens from dangerous pathogens as a means to develop vaccines. Five mutagenesis approaches are illustrated as ways to generate functionally active moieties. The mutagenesis approaches illustrated can be employed with any of a large number of possible display vectors; however, human rhinovirus might be especially useful in cases where it will be important to derive the benefits of delivery by a live-virus approach. Examples are shown in which reconstruction of immunogens corresponding to the V3 loop of the gp120 glycoprotein of the human immunodeficiency virus type 1 (HIV-1) on the surface of rhinovirus has yielded apparently effective mimics of the HIV-1 immunogens (as measured by their ability to be neutralized by anti-HIV-1 antibodies as well as their ability to elicit the production of antibodies capable of neutralizing HIV-1 in cell culture). This system offers the opportunity to reconstruct functionally important moieties that derive from proteins or pathogens that are either too dangerous or difficult to isolate for use as vaccine preparations themselves.

Inhibition of calcium oxalate urolithiasis in a rat model of lithogenesis using bisphosphonates

Bisphosphonates bind renal calculi and inhibit calcium oxalate crystal growth in vitro. We evaluated their ability to inhibit calcium oxalate urolithiasis in a lithogenic rat model. Male Sprague-Dawley rats (four groups, eight rats each) were fed 1.0% ethylene glycol in their drinking water for 6 weeks. All rats had implantation of a 50- to 60-mg zinc pellet in their urinary bladder at the beginning of the 6-week period. The control group received no treatment. The other three groups received six weekly intraperitoneal injections of one of three bisphosphonates: pamidronate (APD), clodronate (CLO), or methylene diphosphonate (MDP). At the end of 6 weeks, the zinc pellet was retrieved and weighed; the kidneys were sectioned and stained to evaluate inflammation, tubular dilation, and crystal deposition; and blood and urine samples were analyzed for calcium and creatinine. There were no detectable biochemical differences between the control and the treatment groups. Zinc pellets removed from control animals had a significantly greater increase in weight secondary to crystal deposition than those from the treatment groups (mean 28.4% for control v 18.9%, 15.3%, and 18.6%, respectively, for animals given APD, CLO, and MDP). The control animals also had significantly higher scores for inflammation, tubular dilation, and crystal deposition than animals treated with MDP and CLO. Older and newer-generation bisphosphonates have an inhibitory effect on calcium oxalate urolithiasis that is demonstrable at relatively infrequent dosing intervals in vivo. More frequent dosing or higher doses may allow greater inhibition of stone formation.

The effects of additional pathology on the cognitive deficit in Alzheimer disease

The diagnosis of Alzheimer disease (AD) according to current criteria is a combined clinical and pathological exercise. The clinical discrimination of AD from other types of dementia may be complicated when the patient suffers from more than one disease. In particular the concomitant presence of other neurological conditions may significantly influence the severity of cognitive deficit. In this study we analyze the extent of the influence of vascular and other neurodegenerative pathology on the cognitive deficit in a consecutive series of 88 prospectively assessed elderly subjects. We find that, for any given level of cognitive deficit, the densities of either all plaques or neuritic plaques alone in the neocortex are significantly lower in cases of AD mixed with other CNS pathology than in cases of AD with no other CNS pathology. In AD combined with cerebrovascular disease, the total plaque density makes a significant contribution to cognitive deficit, while neurofibrillary tangle (NFT) densities do not. In contrast, in pure AD tangle density is the major determinant of cognitive deficit. Our findings draw attention to the influence of coexisting brain pathologies on the clinical manifestation of dementia in subjects with AD. These findings indicate that pathological diagnostic criteria for AD should take into account such additional pathology in demented subjects. They also improve understanding of the circumstances in which the amyloid component of AD can play a decisive role in precipitating clinical dementia.

Percutaneous renal surgery

Percutaneous renal surgery involves instrumentation of the renal collecting system (renal pelvis and calyces) via direct percutaneous access to diagnose and treat a multitude of urological conditions. This chapter will outline the indications, techniques, complications and results of this relatively new and effective operative approach.

Identification and analysis of expression of human VACM-1, a cullin gene family member located on chromosome 11q22-23

We have localized the human homolog of the rabbit vasopressin-activated calcium-mobilizing receptor VACM-1 to a region close to the gene for ataxia telangiectasia ATM on chromosome 11q22-23. We have determined the complete amino acid sequence of the human Hs-VACM-1 protein, which is 780 amino acids long. The human and rabbit sequences are highly conserved, differing at only seven amino acids. Northern analysis of the human gene showed expression in a wide range of human tissues. The Hs-VACM-1 gene has homology with the Caenorhabditis elegans gene Ce-cul-5, a member of a family of cullin genes that are involved in cell cycle regulation and that might, when mutated, contribute to tumor progression.

Adenocarcinoma of the cervix: a regional retrospective study

A retrospective study using data from the Yorkshire Cancer Registry was undertaken to investigate the incidence, characteristics and prognosis of cases of cervical adenocarcinoma in the Yorkshire Region. Three hundred and twenty-six women resident in the Yorkshire Region formed the basis of the study. The overall five year survival for adenocarcinoma of the cervix is 53%. This was influenced by stage, lymph node involvement and differentiation. 37 out of 122 surgically treated patients received inappropriate treatment. There is a need for improved data collection in the treatment of these patients. This lends weight to the argument that cancer of the cervix should be managed in cancer units.

Mediators of long-term memory performance across the life span

An individual-differences approach was used to examine the component processes that predict episodic long-term memory performance. A total of 301 participants ages 20-90 received a 7-hr cognitive battery across 3 days. Key constructs hypothesized to affect long-term memory function were assessed, including multiple measures of working memory and perceptual speed. Latent-construct, structural equation modeling was used to examine the relationship of these measures and age to different types of long-term memory tasks. Speed was a key construct for all 3 types of memory tasks, mediating substantial age-related variance; working memory was a fundamental construct for free and cued recall but not spatial memory. The data suggest that both speed and working memory are fundamental to explaining age-related changes in cognitive aging but that the relative contributions of these constructs vary as a function of the type of memory task.

The substantia nigra as a site of synaptic integration of functionally diverse information arising from the ventral pallidum and the globus pallidus in the rat

Voluntary behaviour in mammals requires the integration of information from different parts of the cerebral cortex, notably the limbic, associative and sensorimotor areas, in a neural network that eventually controls the muscles. One region of the brain that has been proposed to subserve such a function are the basal ganglia which receive inputs from all cortical areas. Although information from different cortical areas passes through the basal ganglia as a series of separate parallel pathways there are several sites where integration of the diverse information could occur. In this study we the identify a neural network at the synaptic level that may underlie a powerful mechanism for the integration, within the basal ganglia, of the diverse types of information arising from the cortex. By double anterograde tracing and immunocytochemistry at both the light and electron microscopic levels, we show that individual neurons in the substantia nigra pars reticulata and dopaminergic neurons in the pars compacta each receive multiple GABAergic synaptic inputs both from neurons in the ventral pallidum (which receive input from limbic areas via the nucleus accumbens) and from neurons in the globus pallidus (which receive input from associative and sensorimotor cortices via the neostriatum). Thus, information subserving functions such as emotion, motivation, cognition and movement converges onto basal ganglia output neurons, leading eventually to the muscles, and also on to the dopaminergic neurons which themselves subserve an integrative role by modulating the flow of information from the cortex through the basal ganglia at the level of the neostriatum and nucleus accumbens.

Fever following intracavitary bacillus Calmette-Guerin therapy for upper tract transitional cell carcinoma

PURPOSE

We attempted to identify the source of fever during intracavitary upper tract instillation of bacillus Calmette-Guerin (BCG).

MATERIALS AND METHODS

Of 34 patients who had previously undergone percutaneous resection of upper tract transitional cell carcinoma 18 received weekly intracavitary BCG through the nephrostomy tubes for 6 consecutive weeks. After treatment 6 all patients underwent nephroscopy and biopsy, and all cases were retrospectively reviewed. Parameters analyzed were BCG related symptoms, maximum temperature during treatment, maximum renal pelvic pressure during treatment, culture results, chest x-ray findings, pretreatment serum creatinine concentration, serum liver enzyme values, untoward events and treatments performed for BCG related complications.

RESULTS

No obvious pattern in appearance of fever occurred. During 88 treatment episodes evaluated there were 14 temperature elevations to more than 100F in 7 patients (39%). Positive urine cultures were associated with fever in only 4 cases and none was positive for Mycobacterium. There was no correlation between greater renal pelvic pressures and fever. All chest radiographs and serum creatinine levels were unchanged, and liver enzymes were normal in all but 1 patient. Two patients had prolonged fever with elevations to greater than 104F following treatment: 1 died in a motor vehicle accident and 1 died after the third BCG infusion led to overwhelming sepsis. No source of fever was identified in either patient.

CONCLUSIONS

Patients with low grade fever coincident with upper tract BCG may be treated conservatively simply by withholding the infusion. Fever greater than 103F should be considered an emergency condition with high potential for mortality. Immediate and aggressive attempts at identifying a source along with institution of antituberculous therapy are priorities.

Adult age differences in the effects of environmental context on memory performance

In two experiments, we examined the hypotheses that the memory performance of older adults is more dependent than that of younger adults on environmental context, and that the integration of to-be-remembered items with contextual cues benefits older more than younger adults. When younger and older adults were shown simple line drawings that were not explicitly associated with the external environment, there was no effect on recall of a change in environmental context for either age group. However, when subjects heard sentences that connected the simple drawings with environmental cues, an environmental context effect was observed. Both age groups recalled more in the same than in a different environment, and the magnitude of the facilitation effect of the familiar context was equal for younger and older adults. However, the integration of the to-be-remembered items with the context facilitated recall regardless of the context present at retrieval, and this effect was larger for younger adults, suggesting that the younger adults were better able to use the provided integrations than were the older adults.

The Glidewire technique for overcoming urethral obstruction

PURPOSE

Using the hydrophilic Terumo Glidewire we developed a less traumatic, yet effective alternative method to filiforms and followers for cases of urethral obstruction.

MATERIALS AND METHODS

The initial step and cornerstone of our method is the passage of the Glidewire per urethra in a manner similar to a filiform. After the appropriate intravesical location of the Glidewire is confirmed using a ureteral catheter, it is exchanged for a standard polytetrafluoroethylene (Teflon) coated guide wire. Urethral dilation and/or catheter placement is then performed.

RESULTS

This technique was successful in 19 of 20 attempts, several of which followed unsuccessful passage of filliform catheters. Urethral obstruction due to strictures, bladder neck contractures and benign prostatic hyperplasia in our group was treated effectively. Furthermore, no complications occurred due to the technique.

CONCLUSIONS

The Glidewire method is safe and effective for treating most cases of urethral obstruction. Therefore, we recommend this technique over standard filiforms and followers when flexible or rigid cystourethroscopy is not immediately available.

Use of structural imaging to study the progression of Alzheimer's disease

Computed tomographic scans in the temporal lobe orientation are a valuable way of studying the medial temporal lobe. In patients with histopathologically-confirmed Alzheimer's disease the size of the medial temporal lobe is almost half that in age-matched controls and the rate of atrophy shown by yearly scans (15% per year) is 10-fold greater. Such a rapid rate of atrophy probably follows a catastrophic event in the brain indicating that Alzheimer's disease is distinct from accelerated normal ageing. The degree of medial temporal lobe atrophy is related to the density of neurofibrillary tangles in the hippocampus; it is a useful guide to diagnosis and has potential as a screening tool in populations. It is proposed that measurement of the rate of atrophy in asymptomatic individuals may be a predictor of Alzheimer's disease and could be used to monitor the effectiveness of therapies designed to retard the rate of neurodegeneration.

The female athlete triad: causes, diagnosis, and treatment

The female athlete triad of disordered eating, amenorrhea, and osteoporosis affects women and girls in many sports, but the messages conveyed to those in "appearance" sports like gymnastics may play a role. Because the triad may result in irreversible bone loss and death, early detection is imperative. Friends, parents, coaches, and physicians can be alert to behaviors like eating alone, trips to the bathroom during or after meals, and the use of laxatives. Other signs and symptoms of the female athlete triad may include fatigue, anemia, depression, cold intolerance, lanugo, and eroded tooth enamel from frequent vomiting. Multidisciplinary treatment typically involves education, determining contributing factors, restoring adequate nutrition, and prescribing estrogen therapy when appropriate.

Amygdala input to medial prefrontal cortex (mPFC) in the rat: a light and electron microscope study

This paper describes the termination pattern and synaptic connectivity of the pathway from the basolateral nucleus of the amygdala (BLA) to the medial prefrontal cortex (mPFC; areas 25, 32, and 24b) of the rat. Discrete injections of the anterograde tracer Phaseolus vulgaris-leucoagglutinin (PHA-L) were made in the BLA and detailed light microscopical observations made of the distribution of PHA-L labelled fibres and boutons in the mPFC. Labelled fibres were distributed in two tiers: predominantly within deep layer 1/layer 2 and also in layers 5/6. Fibre plexi in layers 2 and 5 were highly varicose. Electron microscopical examination of 120 labelled boutons in area 32 (60 in layer 2 and 60 in layer 5) indicated that 116 (97%) established asymmetrical synaptic contacts with dendritic spines and 4 (3%) were in synaptic contact with small dendritic shafts. No significant differences in target structures were found between layers 2 and 5. The results indicate that BLA input to mPFC in the rat predominantly innervates spine bearing dendrites in layers 2 and 5. This suggests that the neuronal operations of these processes are influenced by direct feedforward excitation from the BLA.

Synaptic connections between spiny neurons of the direct and indirect pathways in the neostriatum of the rat: evidence from dopamine receptor and neuropeptide immunostaining

The flow of cortical information through the basal ganglia occurs through the so-called 'direct pathway' and 'indirect pathways'. The object of the present work was to attempt to determine whether spiny neurons in the neostriatum that give rise to the direct pathway (i.e. the striatonigral/entopeduncular pathway) and those giving rise to the indirect pathways (i.e. striatopallidal pathway) are synaptically interconnected. The approach was to carry out double immunocytochemistry at the electron microscopic level using antibodies against peptides or dopamine receptor subtypes that are selectively associated with the neurons that give rise to the direct (substance P or D1 receptors) and indirect pathways (enkephalin or D2 receptors). Sections of perfuse-fixed rat neostriatum were immunostained to reveal both substance P immunoreactivity and D2 receptor immunoreactivity or enkephalin and D1 receptor immunoreactivity, respectively. Double peroxidase methods were employed using different chromogens that were distinguishable at both the light and electron microscopic levels. In the electron microscope substance P-immunoreactive terminals were seen in synaptic contact with dendritic structures that displayed immunoreactivity for D2 receptor. Similarly, enkephalin-immunoreactive terminals were seen in synaptic contact with D1-immunoreactive dendritic structures. Thus, axon collaterals of neurons giving rise to the direct pathway form synaptic contacts with neurons that give rise to the indirect pathway and axon collaterals of neurons giving rise to the indirect pathway form synaptic contact with neurons that give rise to the direct pathway. These results indicate that the two pathways of information flow through the basal ganglia are synaptically linked at the level of the neostriatum.

KEYWORDS

spiny neurons, direct pathway,indirect pathways, rat neostriatum

New technique in managing ureteropelvic junction obstruction: percutaneous endoscopic pyeloplasty

Endopyelotomy is currently advocated for management of the obstructed ureteropelvic junction (UPJ). Healing of the stented UPJ occurs by secondary intention. Regardless of the method employed, success rates approach 85%. In order to increase the rate of success, we have devised a method of performing endopyelotomy in conjunction with endoscopic suturing of the incised UPJ. Two methods were developed to allow for the placement of a single absorbable monofilament suture. In the first method, endopyelotomy is carried out in the standard antegrade manner, and endoscopic suturing is performed with the use of a second retroperitoneal access sheath at the UPJ. In the second method, endoscopic placement of the suture is carried out through the standard renal access sheath, with suturing performed via the nephroscope. We have performed endoscopic pyeloplasty in eight patients. With a mean follow-up of 12 months, the procedure was successful in seven of these patients. Endoscopic suturing of the UPJ is technically demanding, but once sufficient expertise is gained, it may be utilized for immediate tissue coaptation, possibly decreasing urinary extravasation and, it is hoped, maximizing the caliber of the UPJ.

Crossing vessels at the ureteropelvic junction: do they influence endopyelotomy outcome?

The majority of crossing vessels probably are inconsequential. Bleeding should not be a concern if the incision is made laterally. The optimal way to improve endopyelotomy results is to determine which crossing vessels truly are significant, and the authors describe the clinical trial that might be carried out to answer the question.

Hippocampal pathology reflects memory deficit and brain imaging measurements in Alzheimer's disease: clinicopathologic correlations using three sets of pathologic diagnostic criteria

Neurofibrillary tangles (NFT), neuritic plaques and amyloid load were quantified in sections of the hippocampus at the level of the lateral geniculate body in 41 consecutive cases fulfilling pathological criteria for diagnosis of Alzheimer's disease (AD) and coming to autopsy after longitudinal study during life. A strong correlation was found between NFT density in the hippocampus and cognitive impairment scores obtained shortly before death, particularly with scores of memory impairment. Weaker and less consistent correlations were found for hippocampal neuritic plaques and amyloid load with cognitive/memory deficits. No significant correlations were found between hippocampal pathology and either age of onset or disease duration. All three measures of hippocampal pathology were inversely correlated with the minimum medial temporal lobe (MTL) width, a measure of the MTL atrophy made from temporal-lobe-oriented X-ray computed tomography scans performed during life; the strongest correlation being between atrophy of the MTL and NFT density in the hippocampus.

Chimeric rhinoviruses as tools for vaccine development and characterization of protein epitopes

Chimeric human rhinoviruses (HRVs) have the potential to serve as vaccines against a wide variety of diseases. Such vaccines can be developed optimally by generating libraries of chimeric HRVs displaying immunogens from dangerous pathogens or tumor cells in many different conformations. Extremely large numbers of conformationally defined presentations of foreign epitopes can be produced efficiently by flanking transplanted epitopes with linkers, or adapters, of small segments of randomized amino acids. In addition, the individual residues of the immunogenic sequences can be encoded in proportion to their prevalence in databases, generating composite immunogens that function as mimotopes. The diversity of sequences and conformations improves the likelihood of generating immunologically valuable vaccine candidates. Chimeric viruses thus generated can be propagated and purified to select for viruses whose growth and physical stability are like those of wild-type HRV. Viruses containing a foreign epitope in antigenically relevant conformations can then be captured by immunoselection with neutralizing antibodies directed against the foreign pathogen. Using this approach, we have been able to generate HRV chimeras that present V3 loop sequences of the human immunodeficiency virus type 1 (HIV-1) in immunologically relevant conformations. Antisera directed against such chimeras can neutralize multiple strains of HIV-1 in cell culture, suggesting that the HRV14:HIV-1 chimeras may be presenting their V3 loop sequences in manners that mimic those of multiple strains of HIV. Immunologically interesting chimeras can be examined using X-ray crystallography to yield detailed information about the structures of chimeras with immunogenic epitopes. This information may lead to a greater understanding of key functional and structural elements of immunogenicity. The chimeric HRV system allows one to present virtually any protein epitope or mimitope thereof, identify viruses with immunological characteristics that mimic those of the foreign pathogen, and examine the structures of these immunogenic sequences at the atomic level.

Influence of the apolipoprotein E genotype on amyloid deposition and neurofibrillary tangle formation in Alzheimer's disease

The effect of the apolipoprotein E genotype on the development of late onset Alzheimer's disease is still debated. Neuropathological studies of Alzheimer's disease have found a great extent of amyloid deposition in cortex and blood vessel walls in association with the apolipoprotein E epsilon 4 genotype [Rebeck G. W. et al. (1993) Neuron 11, 575-580; Schmechel et al. (1993) Proc. natn. Acad. Sci. U.S.A. 90, 9649-9653]. In contrast, the relationship of apolipoprotein E genotype to neurofibrillary pathology in Alzheimer's disease has been less clear. In this study we present evidence on the influence of the apolipoprotein E genotype on Alzheimer's disease related pathology in a series of 76 autopsy cases that had pathology that fulfilled the CERAD criteria for Alzheimer's disease. We found that the presence of the apolipoprotein E epsilon 4 allele is correlated with increased amounts of both amyloid and neuritic pathology in the neocortex as determined using an image analysis system. Comparison of plaque and tangle densities with the allele doses of epsilon 2 and epsilon 4 revealed a striking parallelism, suggesting that the alleles exert their effects very early in the pathological process before deposition of plaques and tangles. Although the apolipoprotein E epsilon 2 allele had a protective effect against both amyloid deposition and neurofibrillary tangle formation, in the presence of the epsilon 4 allele this protective effect against neuritic pathology was less marked than against amyloid deposition. This differential effect on amyloid deposition and the accumulation of neuritic pathology suggests that different molecular mechanisms are involved in the effect of apolipoprotein E on amyloid deposition and on tau phosphorylation.

Fibrous coagulum: a new cause of retained fragments following extracorporeal shock wave lithotripsy

PURPOSE

A previously unrecognized cause of retained fragments following extracorporeal shock wave therapy is identified.

MATERIALS AND METHODS

Nine patients referred for percutaneous stone extraction following failure of multiple shock wave lithotripsy treatments had retained fragments embedded in soft tissue. The stones were evaluated by chemical analysis and the tissue was evaluated histologically.

RESULTS

All stones contained calcium and histopathology confirmed the presence of fibrous tissue. Radiographs were unable to predict the presence of the substance preoperatively.

CONCLUSIONS

We identified fibrous coagulum as a cause of retained fragments following shock wave lithotripsy. The material is soft tissue and cannot be ablated by further shock wave lithotripsy. These findings confirm that repeated shock wave lithotripsy is contraindicated, since stone fragmentation and passage may be inhibited by fibrous coagulum.

Percutaneous management of transitional cell carcinoma of the renal collecting system: 9-year experience

PURPOSE

We establish the effectiveness of percutaneous resection of transitional cell carcinomas of the renal collecting system.

MATERIALS AND METHODS

A retrospective analysis was done of 36 kidneys treated during a 9-year period. Adjunctive therapy with bacillus Calmette-Guerin was given in 19 cases.

RESULTS

Of 36 kidneys 6 were treated by immediate nephroureterectomy for aggressive disease, leaving 30 units treated by a complete course. The recurrence rate was 33%, which varied with histology as specific recurrence rates for grades 1 to 3 tumors (18%, 33% and 50%, respectively). The only cancer related mortalities occurred with grade 3 tumors. These tumors also had a higher incidence of understanding and vascular complications. Bacillus Calmette-Guerin therapy showed no significant improvement in survival.

CONCLUSIONS

With vigilant followup, percutaneous management of transitional cell carcinoma of the renal collecting system is an acceptable alternative to nephroureterectomy in patients with grade 1 disease, grade 2 disease who are at risk for renal insufficiency and medical contraindications to a major open operation.

Knee injuries in young athletes

The differential diagnosis of children's knee injuries includes not only the typical adult injuries to bone, ligament, and cartilage, but also growth plate injuries. Bony contours are not as well defined in children due to incomplete ossification, and the practitioner must look for certain types of injuries based on the history and the physical findings because radiographic signs may be difficult or impossible to see.

Incidence of negative hematuria in patients with acute urinary lithiasis presenting to the emergency room with flank pain

OBJECTIVES

To determine the incidence of negative hematuria in patients with acute urinary lithiasis presenting to the emergency room with flank pain.

METHODS

We retrospectively reviewed all 140 patients who presented with flank pain to the Long Island Jewish Medical Center emergency department from January 1, 1992, through December 31, 1992, and underwent intravenous urogram (IVU). We then calculated the incidence of negative hematuria in patients with acute urinary lithiasis (AUL) diagnosed by IVU based on the complete urinalysis alone or in combination with the urine dipstick test for blood.

RESULTS

We found a 14.5% incidence of negative hematuria in patients with AUL when looking at the urinalysis alone. To our knowledge, this has never been reported in the literature. We also found that by considering a negative combination (urinalysis plus urine dipstick test) as a new definition of negative hematuria, the incidence of negative hematuria in patients with AUL was only 5.5% (P < 0.031).

CONCLUSIONS

This is the first report in the literature documenting the incidence of negative hematuria in patients with AUL to be 14.5%. With the addition of the combination of urinalysis and urine dipstick test for hematuria, the incidence is only 5.5% and, therefore, represents a low yield when evaluated by IVU.

Urolume endourethral prosthesis for the treatment of urethral stricture disease: long-term results of the North American Multicenter UroLume Trial

OBJECTIVES

To evaluate the long-term results of the UroLume endourethral prosthesis for the treatment of recurrent bulbar urethral strictures.

METHODS

In a multicenter, prospective study 175 patients with recurrent bulbar urethral strictures were enrolled in a Food and Drug Administration (FDA) trial of the UroLume endourethral prosthesis. One hundred thirty-nine patients were available for follow-up at 1 year, and 81 patients were available for follow-up at 2 years.

RESULTS

Clinically and statistically significant results were seen at 1 year and sustained at 2 years. Re-treatment rate was down from 75.2% preinsertion to 14.3% 1 year postinsertion of the prosthesis. Explantation was required in only 3% of patients.

CONCLUSIONS

Based on these and European data, the UroLume endourethral prosthesis offers a significant advantage over the currently available treatments for recurrent bulbar urethral strictures.

Immunocytochemical localization of D1 and D2 dopamine receptors in the basal ganglia of the rat: light and electron microscopy

The modulatory actions of dopamine on the flow of cortical information through the basal ganglia are mediated mainly through two subtypes of receptors, the D1 and D2 receptors. In order to examine the precise cellular and subcellular location of these receptors, immunocytochemistry using subtype specific antibodies was performed on sections of rat basal ganglia at both the light and electron microscopic levels. Both peroxidase and pre-embedding immunogold methods were utilized. Immunoreactivity for both D1 and D2 receptors was most abundant in the neostriatum where it was mainly contained within spiny dendrites and in perikarya. Although some of the immunoreactive perikarya had characteristics of interneurons, most were identified as medium-sized spiny neurons. Immunoreactivity for D1 receptor but not D2 receptor was associated with the axons of the striatonigral pathway and axons and terminals in the substantia nigra pars reticulata and the entopeduncular nucleus. In contrast, D2 immunoreactivity but not D1 immunoreactivity was present in the dopaminergic neurons in the substantia nigra pars compacta and ventral pars reticulata. In the globus pallidus, little immunoreactivity for either D1 or D2 receptor was detected. At the subcellular level, D1 and D2 receptor immunoreactivity was found to be mainly associated with the internal surface of cell membranes. In dendrites and spines immunoreactivity was seen in contact with the membranes postsynaptic to terminals forming symmetrical synapses and less commonly, asymmetrical synapses. The morphological features and membrane specializations of the terminals forming symmetrical synapses are similar to those of dopaminergic terminals previously identified by immunocytochemistry for tyrosine hydroxylase. In addition to immunoreactivity associated with synapses, a high proportion of the immunoreactivity was also on membranes at non-synaptic sites. It is concluded that dopamine receptor immunoreactivity is mainly associated with spiny output neurons of the neostriatum and that there is a selective association of D1 receptors with the so-called direct pathway of information flow through the basal ganglia, i.e. the striatoentopeduncular and striatonigral pathways. Although there is an association of receptor immunoreactivity with afferent synaptic inputs a high proportion is located at extrasynaptic sites.

Endoscope modifications for laser prostatectomy

Prior to the development of the technique of laser prostatectomy, contemporary modifications to resectoscope design for transurethral prostatectomy had been scant. With the introduction of laser prostatectomy and the characterization of the "mini-TURP" technique, a new demand for improved continuous-flow cystoscopes and resectoscopes has developed. The ideal cystoscope design for laser prostatectomy would require the following: (1) continuous irrigant flow for optimum cooling of the laser element; (2) a large inflow port so that flow is not impaired by the presence of the fiber in the working channel; (3) a large outflow port to maximize irrigant flow; and (4) a fiber stabilizer to enable easy manipulation of the fiber in the center of the viewing field. The ideal resectoscope design for laser prostatectomy would require the following: (1) continuous flow of irrigant for cooling of the laser fiber; (2) stabilization of the laser fiber in the center of the field of view; (3) the ability to interchange electrocautery loops with laser fibers without changing the sheath; and (4) the ability to apply laser energy to tissue with the same Iglesias action used in transurethral resection of the prostate (TURP). This review analyzes the features of the new continuous-flow cystoscopes and resectoscopes manufactured specifically for use in laser prostatectomy. All manufacturers were requested to submit their most up-to-date literature and photographs of the specific instruments they manufacture. The technical specifications, advantages, and disadvantages of each instrument are discussed.

Extensive dilation of distal ureter for endoscopic treatment of large volume ureteral disease

Two patients with large volume disease in markedly dilated ureters were treated endoscopically by wide dilation of the ureteral orifice and passage of larger nonureteroscopic endoscopes. The larger instruments provided better vision and the ability to work with larger tools, which greatly facilitated treatment without complication in patients who otherwise would have undergone an open procedure.

Laparoscopic transperitoneal bladder diverticulectomy: surgical technique

A large bladder diverticulum causing poor emptying in an 84-year-old man was removed laparoscopically in a 6.5-h operation. The patient was discharged from the hospital on the third postoperative day, having had minimal analgesic requirements. A Council catheter and stylet in the diverticulum greatly facilitated identification of the sac with the laparoscope. Difficulties with intracorporeal knot tying were avoided by using the Lapra-Ty system. Experienced laparoscopic surgeons may find this method of diverticulectomy valuable. With experience, the operating time should be reduced.

Chimeras from a human rhinovirus 14-human immunodeficiency virus type 1 (HIV-1) V3 loop seroprevalence library induce neutralizing responses against HIV-1

A chimeric virus library was designed whereby sequences corresponding to the V3 loop of human immunodeficiency virus type 1 (HIV-1) were presented on the surface of human rhinovirus 14. The V3 loop sequences consisted of a relatively conserved segment of seven amino acids and five adjacent residues that were allowed to vary in proportion to their seroprevalence among HIV-1 isolates of North America and Europe. A technique called random systematic mutagenesis was used to incorporate the composite V3 loop sequences flanked by zero to two randomized amino acids. This library could contain 2.7 x 10(8) members having diverse sequences and conformations. Immunoselection of a portion of this library by using two neutralizing V3 loop-directed monoclonal antibodies followed by selection for desirable growth and purification characteristics yielded a set of chimeric rhinoviruses, five of which are described. The inserted sequences in the five chimeras do not match those of any known isolate of HIV-1. Nonetheless, all five chimeras were neutralized by antibodies directed against different strains of HIV-1 and were able to elicit the production of antibodies that bind V3 loop peptides from diverse HIV-1 isolates. Moreover, antisera derived from four of the five chimeras were capable of neutralizing one or more strains of HIV-1 in cell culture. This study demonstrates that random systematic mutagenesis in conjunction with antibody screening is a powerful and efficient means to obtain antigenic chimeras with relevant immunogenic properties.