Hemispace differences in the visual perception of size in left hemiParkinson's disease

The visual perception of size in different regions of external space was studied in Parkinson's disease (PD). A group of patients with worse left-sided symptoms (LPD) was compared with a group with worse right-sided symptoms (RPD) and with a group of age-matched controls on judgements of the relative height or width of two rectangles presented in different regions of external space. The relevant dimension of one rectangle (the 'standard') was held constant, while that of the other (the 'variable') was varied in a method of constant stimuli. The point of subjective equality (PSE) of rectangle width or height was obtained by probit analysis as the mean of the resulting psychometric function. When the standard was in left space, the PSE of the LPD group occurred when the variable was smaller, and when the standard was in right space, when the variable was larger. Similarly, when the standard rectangle was presented in upper space, and the variable in lower space, the PSE occurred when the variable was smaller, an effect which was similar in both left and right spaces. In all these experiments, the PSEs for both the controls and the RPD group did not differ significantly, and were close to a physical match, and the slopes of the psychometric functions were steeper in the controls than the patients, though not significantly so. The data suggest that objects appear smaller in the left and upper visual spaces in LPD, probably because of right hemisphere impairment.

Episodic memory meets working memory in the frontal lobe: functional neuroimaging studies of encoding and retrieval

Recent functional-neuroimaging studies have provided a wealth of new information suggesting that regions of the prefrontal cortex play a role in episodic memory encoding and retrieval. This review seeks to evaluate the results of these studies in the context of one general model that has proposed that the left prefrontal cortex is preferentially involved in episodic memory encoding, whereas the right prefrontal cortex is preferentially involved in episodic memory retrieval, irrespective of the type (e.g., modality) of information being remembered. The origins of this framework are considered in some detail and then all relevant functional-neuroimaging studies are critically reviewed. The results of this review fail to provide support for the functional-asymmetry model, suggesting instead that episodic memory encoding and retrieval may actually involve similar regions of the lateral prefrontal cortex when all factors relating to the type of stimulus material (i.e., modality), are appropriately controlled.

Ventral hernia repair: a study of current practice

Ventral wall hernias are common; despite this, there are no guidelines on the best surgical management. The aim of this study was to examine the types of repair in use for abdominal wall hernias in the West of Scotland over a 3-month period. Data were gathered on 120 patients. There were 60 incisional, 32 umbilical, and 28 epigastric hernias. The main indication for repair was pain (78%), while 12 patients (10%), presented acutely with incarceration or strangulation. The most common method of repair was sutured (55%), followed by mesh (29%) and Mayo repair (16%). There was no correlation between use of mesh and hernia size or whether repair was for a recurrent hernia. Surgical practice varies widely in the repair of ventral wall hernias. Clinical trials are required to establish the best method of repair for this common condition.

Dopamine and the representation of the upper visual field: evidence from vertical bisection errors in unilateral Parkinson's disease

It has been suggested that dopamine is an important neurotransmitter in the brain mechanisms which represent the upper visual field. This idea was tested with a vertical line bisection task in unilateral Parkinson's disease. Stimuli of a range of lengths were presented on a large screen in three positions (left, centre and right) and at two viewing distances (0.6 and 1.5m). The patients, who were compared with a group of normal age-matched controls, comprised 16 sufferers from predominantly unilateral disease, 8 with more severe left-sided symptoms (LPD) and 8 with more severe right-sided symptoms (RPD). The LPD group consistently set the bisecting cursor below the midpoint of the stimulus lines, and their bisection error became larger as the length of the line increased. In contrast, the controls set the cursor above the midpoint of the line, an error which also increased with line length. The settings of the RPD group were similar to those of the controls. The results suggest altitudinal neglect in left unilateral PD, and support the hypothesis of dopaminergic involvement in the coding of upper visual space, with the proviso that the perceptual component of this involves the right hemisphere in humans.

Late degeneration in rabbit tissues after irradiation by heavy ions

In 1974, using the rabbit as a model, we began long-term experiments designed to help in the evaluation of the hazards to man from extended exposure to heavy ions in space. Such exposure would occur, for example, during the construction of solar power stations in stationary orbits or on round trips to Mars. Our experiments with 400 MeV/nucleon Ne ions and 570 MeV/nucleon Ar ions have shown that true late effects of a degenerative nature are manifested only years after irradiation. At the appropriate doses (the high end of the experimental dose range), the magnitudes of the late effects are comparable with those encountered in human patients given radiation therapy with neutrons. Such comparisons show that the rabbit experiments are applicable to man. Given that basis, the results from the low end of the experimental dose range lead to the conclusion that astronauts subjected to the radiation fluxes anticipated during flights of the above duration could experience late radiation effects one or more decades after exposure. Late degenerative changes will occur in tissues of the central nervous system, terminally differentiating systems and stem cell populations. The studies also indicate that individual tissues may be "prematurely aged" by radiation in the sense that the "life spans" of those tissues can be decreased without the appearance of malignancies.

The role of dynamic imaging in sentinel lymph node biopsy in breast cancer

The aim of this study was to evaluate the role of dynamic imaging in sentinel lymph node (SLN) biopsy in breast cancer. Patients with T1/T2, N0 invasive breast cancer underwent SLN localisation using intra-dermal injection of 15 MBq of 99mTc-nanocolloid. Gamma camera anterior-oblique dynamic imaging commenced simultaneously with tracer administration for 45 min, and was followed by anterior and lateral static imaging. Dynamic imaging data was reformatted into image files of different time-frames. Patterns of uptake were analysed using the sequences of dynamic frames and time-activity curve (TAC). SLN localisation was successful in 70/73 studies (96%) in 72 patients. Imaging information was present within the first 15 min of dynamic imaging in 67/70 studies (96%). Critical analysis of dynamic data helped to differentiate true SLN from secondary echelon nodes in eight studies and transient foci of radioactivity in six studies. In 17 studies, SLN contained metastatic disease. The detection of SLN metastasis was independent from the use of dynamic imaging. Dynamic imaging improves the interpretation of preoperative SLN imaging for breast cancer, but does not contribute significantly to the successful detection of SLN. Hence, preoperative dynamic imaging is not necessary in SLN biopsy for breast cancer.

Disruption of estimation of body-scaled aperture width in Hemiparkinson's disease

A group of patients with left-sided symptoms of Parkinson's disease (LPD) was compared with a group of patients with right-sided symptoms (RPD) and with a group of healthy age-matched controls on body-scaled judgements of aperture width. Participants judged whether or not they would fit through a life-sized schematic doorway shown on a large screen. A staircase technique was used to find the door width for which 50% of the judgements were positive. The ratio between this measure and the width of the participant's body at the shoulders (the aperture to shoulder - A/S ratio) was calculated. The A/S ratio was approximately 1.5 in the LPD group, approximately 0.9 in the RPD group, and approximately 1.1 in the control group, suggesting that the visual representation of the doorway (or that of its relationship to perceived body-size) is compressed in LPD (and perhaps expanded in RPD). The A/S ratios were invariant with viewing distance (0.6 or 1.5 m), the contrast polarity of the display (white on dark, or vice versa) and the doorway surround (blank, or vertical or horizontal stripes). The findings are discussed with reference to the neural representation of external space and of the body, and to the motor problems of Parkinson's disease.

Evidence from a line bisection task for visuospatial neglect in left hemiparkinson's disease

The perception of extrapersonal space in Parkinson's disease was examined with two line bisection tasks. One was a conventional pencil and paper test, the line bisection section of the Behavioural Inattention Test. In the other, the stimuli were displayed on a large (2x2.4 m) screen and varied in length (48-480 mm) and also in location on the screen (left, centre and right). They were presented at two viewing distances (0.6 and 1.5 m). Subjects remotely adjusted the position of a cursor until it appeared to bisect the stimulus line, using two push-buttons, one in each hand. The PD participants (n=18) had a marked asymmetry of motor symptoms. They were divided into two groups, those with predominantly left-sided motor symptoms (LPD, n=9), and those with predominantly right-sided motor symptoms (RPD, n=9). The control group (n=9) were all right-handed. No significant differences between the groups were found on the BIT bisection task. In contrast, when the stimuli were presented on the screen, LPD subjects showed a significant rightward bias in their settings of the cursor, particularly for lines on the left and centre of the screen, which was greater, the longer the stimulus line. The RPD group bisected lines slightly to the left, in common with the control group (pseudo-neglect). In a second experiment, Parkinsonian subjects repeated this task, but with the buttons reversed between the hands, so that the cursor was moved to the left by the right hand, and vice versa, but the pattern of results was the same as in the first experiment. The data suggest a small but reliable neglect in left hemiparkinson's disease, which is contralateral to the non-dominant (and probably worse affected) hemisphere. The dissociation between the response and the bisection error suggests a visuospatial impairment in LPD.

An audit of post-pyloromyotomy feeding regimens

A retrospective audit was carried out to assess patient outcome in relation to the timing of feeding after pyloromyotomy for hypertrophic pyloric stenosis. Fifty-two patients received the first feed within 8 hours of surgery and 49 patients were fed between 13 and 20 hours post-operatively. Seventy-seven per cent of patients in the early group vomited compared to 53% in the late group. Sixty-one per cent of patients in the early group produced large vomits compared to 29% in the late feeding group. However, time to establish feeding and post-operative stay were comparable in both groups. We recommend feeding to be delayed for 12 hours after pyloromyotomy unless the patient is distressed because of hunger in which case the parents are warned of the increased risk of vomiting.

The relationship between Y chromosome DNA haplotypes and Y chromosome deletions leading to male infertility

Microdeletions on the short arm of the Y chromosome have defined three non-overlapping regions (AZFa, b, c) recurrently deleted among infertile males. These regions contain several genes or gene families involved in male germ-cell development and maintenance. Even though a meiotic origin for these microdeletions is assumed, the mechanisms and causes leading to microdeletion formation are largely unknown. In order to assess whether some Y chromosome groups (or haplogroups) are predisposed to, or protected against, deletion formation during male meiosis, we have defined and compared Y chromosome haplogroup distribution in a group of infertile/subfertile males harbouring Yq deletions and in a relevant Northwestern European control population. Our analyses suggest that Y chromosome deletion formation is, at least in the study populations, a stochastic event independent of the Y chromosome background on which they arise and may be caused by other genetic and/or environmental factors.

Practice patterns of massage therapists

OBJECTIVES

To describe the practice patterns of licensed massage therapists (LMTs).

DESIGN

Cross-sectional survey.

SUBJECTS

One hundred and twenty-six (126) massage practices randomly selected from the Greater Boston Area yellow pages.

OUTCOMES MEASURES

Practitioner demographics, training, practice characteristics, and fees.

RESULTS

The response rate was 65%. Most respondents were Caucasian (95%) and female (80%). Their mean age was 41 years old. Half held a college degree; on average, practitioners received 1000 hours of training in massage therapy. The majority were in group practices (59%) and saw an average of 20 patients per week. The typical visit lasted 50-60 minutes; the cost was $60 and rarely covered by insurance (5%). Half of respondents offered sliding scales to patients, but only 11% accepted Medicaid patients. Respondents reported less than 1 visit per week from pediatric and adolescent patients (<21 years old).

CONCLUSIONS

Most LMTs are female and Caucasian. The costs of massage therapy are almost entirely paid out-of-pocket by patients (95%). LMTs infrequently care for children.

Short-wavelength automated perimetry and standard perimetry in the detection of progressive optic disc cupping

OBJECTIVE

To compare progression in short-wavelength automated perimetry (SWAP) and white-on-white (standard) perimetry in eyes with progressive glaucomatous changes of the optic disc detected by serial stereophotographs.

METHODS

Forty-seven glaucoma patients with at least 2 disc stereophotographs more than 2 years apart, along with standard perimetry and SWAP examinations within 6 months of each disc photo of the same eye, were included in the study. The mean follow-up time was 4.1 years (range, 2.0-8.9 years). Baseline and follow-up stereophotographs were then graded and compared for the presence of progression. Progression in standard perimetry and SWAP, using the Advanced Glaucoma Intervention Study scoring system and a clinical scoring system, was compared between eyes with progressive change on stereophotographs and those without.

RESULTS

Twenty-two of 47 eyes showed progressive change by stereophotographs. There was a statistically significant difference in the mean change in Advanced Glaucoma Intervention Study scores for both standard perimetry (P<.004) and SWAP (P<.001) between the progressed and nonprogressed groups. The sensitivity, specificity, and area under the receiver operator characteristic curve were higher using SWAP than standard perimetry when evaluated by either algorithm. This was statistically significant only in the area under the receiver operator characteristic curve for the Advanced Glaucoma Intervention Study scoring system (P =.04).

CONCLUSIONS

Short-wavelength automated perimetry identified more patients than standard perimetry as having progressive glaucomatous changes of the optic disc. Compared with standard perimetry, SWAP may improve the detection of progressive glaucoma. Arch Ophthalmol. 2000;118:1231-1236

Asymmetric frontal activation during episodic memory: the effects of stimulus type on encoding and retrieval

Recent functional neuroimaging studies have suggested that the left prefrontal cortex is preferentially involved in the encoding of episodic memory whilst the right prefrontal cortex is preferentially involved in the retrieval of episodic memory, irrespective of the type (e.g. modality) of information being remembered. In the present PET activation study, a 2 x 2 design was employed to investigate the relationship between encoding and retrieval of verbal and non-verbal material in episodic memory. Accordingly, seven healthy volunteers were scanned whilst encoding and then recalling stimuli which either emphasised visual or verbal processes. When encoding and retrieval tasks were compared directly, significantly greater prefrontal activation was observed in the encoding conditions, regardless of modality, although these changes were bilaterally distributed. In contrast when the verbal and visual memory tasks were compared directly, the former was associated with rCBF changes that were predominantly located in the left lateral frontal cortex whilst the latter was associated with rCBF changes that were predominantly located in the right lateral frontal cortex. These results suggest that encoding and retrieval may actually involve similar regions of the lateral prefrontal cortex when all factors relating to the type of stimulus material (i.e. modality), are appropriately controlled.

Chiropractic care for children

OBJECTIVE

To describe the practice characteristics and pediatric care of chiropractors.

STUDY DESIGN

Cross-sectional, descriptive survey.

SETTING

Chiropractic practices in the Boston, Mass, metropolitan area.

PARTICIPANTS

One hundred fifty licensed chiropractors.

MAIN OUTCOME MEASURES

Demographics, practice characteristics, and fee structure. Practitioners were also asked about their approach to childhood immunizations and a clinical scenario. Data were analyzed using simple descriptive statistics.

RESULTS

Ninety (60%) chiropractors responded. All were white and 65% were men. Respondents had on average 122 patient visits weekly, of which 13 (11%) were from children and adolescents. Typical visit frequency ranged from 1 to 3 times weekly. Average visit fees were $82 and $38 (initial and follow-up) and 49% of the fees were covered by insurance. Seventy percent of the respondents recommended herbs and dietary supplements. For pediatric care, 30% reported actively recommending childhood immunizations; presented with a hypothetical 2-week-old neonate with a fever, 17% would treat the patient themselves rather than immediately refer the patient to a doctor of medicine, doctor of osteopathy, or an emergency facility.

CONCLUSIONS

Children and adolescents constitute a substantial number of patients in chiropractics. An estimated 420000 pediatric chiropractic visits were made in the Boston metropolitan area in 1998, costing approximately $14 million. Pediatric chiropractic care is often inconsistent with recommended medical guidelines. National studies are needed to assess the safety, efficacy, and cost of chiropractic care for children.

Septic arthritis in hemophilia with central venous catheter: a case report

A case is reported of septic arthritis in a child with human immunodeficiency virus-negative hemophilia A associated with a Staphylococcus aureus catheter-associated septicemia. The infection occurred in relation to the use of a totally implantable central venous catheter. The organism was eventually eradicated with antibiotics injected via the catheter. With increasing use of such catheters in the hemophilic population, clinicians should be alerted to the possibility of septic arthritis for prompt diagnosis and treatment.

Comparison of long-term variability for standard and short-wavelength automated perimetry in stable glaucoma patients

PURPOSE

To quantify and compare, on a point-by-point basis, the long-term variability of standard and short-wavelength automated perimetry in a group of stable glaucoma patients.

METHODS

From a group of 53 glaucoma patients experienced in visual field testing, we identified one eye, randomly chosen, from each of 25 glaucoma patients whose condition was found to be stable, based on both standard and short-wavelength automated perimetry visual field criteria. On each of three visits during a period of up to 3 months, each patient performed one standard and one short-wavelength automated perimetry 24-2 visual field in a random order on a Humphrey visual field analyzer. The long-term variability (also referred to as test-retest variability) was defined as the SD of the three threshold decibel values at each test location. The long-term variability for each test point (mean +/- SD) was determined separately for both standard visual fields and short-wavelength automated perimetry.

RESULTS

With all 52 test locations of the 24-2 field averaged, the global long-term variability, mean (+/- SD) for standard visual fields and short-wavelength automated perimetry was 2.37 +/- 2.03 dB (95% confidence interval, 2.26-2.48 dB) and 2.92 +/- 2.03 dB (95% confidence interval, 2.81-3.03 dB), respectively (P <.0001). In 16 of the 52 visual field locations, long-term variability on short-wavelength automated perimetry was significantly higher than long-term variability on standard visual fields. In addition, the long-term variability increased with greater distance from the point of fixation for both standard visual fields and short-wavelength automated perimetry. The long-term variability decreased closer to fixation, more for standard visual fields than for short-wavelength automated perimetry.

CONCLUSIONS

In a group of stable glaucoma patients, mean long-term variability was 0.55 dB higher for short-wavelength automated perimetry than for standard visual fields. This needs to be taken into consideration when serial visual fields are evaluated for change.

Homeopathy and naturopathy: practice characteristics and pediatric care

OBJECTIVE

To describe the practice characteristics and pediatric care of homeopathic practitioners (HPs) and naturopathic doctors (NDs).

DESIGN

Cross-sectional, descriptive survey.

SETTING

Homeopathic and naturopathic practices in Massachusetts.

PARTICIPANTS

Homeopathic practitioners (N = 42) and NDs (N = 23) identified from the yellow pages, regional and national society membership lists, schools, magazine advertisements, and by word-of-mouth. The response rate was 55% (23/42) for HPs and 65% (15/23) for NDs.

MAIN OUTCOME MEASURES

Demographics, practice characteristics, fee structure, and amount of pediatric care. Practitioners were asked for their approach to childhood immunizations and to treating a febrile neonate. Data were analyzed using simple descriptive statistics.

RESULTS

Almost all respondents were white. Among the HPs, 13 (57%) were licensed medical doctors. Naturopathic doctors and HPs reported having an average of only 25 to 40 patient visits per week, but children and adolescents accounted for up to one third of these visits. Nearly all reported treating children, but fewer than half of the practitioners reported any formal pediatric training. Initial patient visits typically lasted more than 1 hour and cost $140 to $150. Follow-up visits were scheduled every 4 to 6 weeks and lasted more than 30 minutes on average. Insurance covered less than one third of the patient visits, and sliding scale payments were offered by less than half of the respondents. Most practitioners reported that they did not actively recommend immunizations and fewer than half of the nonphysician practitioners reported that they would refer a 2-week-old neonate with a fever to a medical doctor or emergency medical facility.

CONCLUSIONS

Many patients using homeopathy and naturopathy are children. Visits to these providers are frequent and fees are primarily paid out-of-pocket. Failure on the part of these providers to recommend immunizations or recognize potentially serious illnesses is cause for concern.

Small incision nonendoscopic browlift

PURPOSE

To determine the efficacy of a nonendoscopic brow/forehead lift.

METHODS

Case series of 12 patients. Small scalp and upper eyelid blepharoplasty incisions were used to elevate the brows/forehead and perform protractor myectomy.

RESULTS

All patients achieved an aesthetically pleasing eyebrow and forehead lift with reduction of vertical and horizontal glabellar creases. Complications included one patient who experienced prolonged ecchymosis after corrugator muscle resection and one patient who had asymmetric lid folds after surgery. The length of follow-up ranged from 9 to 35 months.

CONCLUSIONS

The small incision nonendoscopic browlift technique provides a useful alternative to the endoscopic approach.

Classification and behavior of canine mammary epithelial neoplasms based on life-span observations in beagles

As part of a study of the effects of low-level radiation, 1,343 Beagles, including 671 males and 672 females, were evaluated over their full lifetime for the occurrence of mammary neoplasia; there were 139 control males and 138 control females and 532 irradiated males and 534 irradiated females. All nodules found in surgical specimens or at necropsy were evaluated histologically. The overall incidence, metastasis and recurrence rates, and contribution to mortality of mammary neoplasms were determined. Based on this unique opportunity to correlate morphologic characteristics with ultimate biological behavior of all mammary tumors in a defined canine population, we propose a histogenetically based reclassification of epithelial mammary tumors. Of the 672 female dogs, 70.8% (476) had at least one mammary neoplasm; 60.7% (408) had more than one. Two male dogs had mammary neoplasms. Of 1,639 mammary carcinomas in the 672 females, 18.7% (307) were classified as ductular carcinomas (arising from the small interlobular or intralobular ductules), whereas 80.7% (1,322) were classified as adenocarcinomas of other histogenetic origin. Of 73 fatal carcinomas, ductular carcinomas accounted for 48 fatalities (65.8%), whereas other adenocarcinomas accounted for only 20 fatalities (27.4%). Radiation had no effect on this ratio. Ductular carcinomas also had a higher rate of metastasis than did adenocarcinomas. Existing classifications of mammary carcinomas do not recognize the characteristic morphologic features, the degree of malignancy, and the prognostic importance of these ductular carcinomas. Metastasis rates did not differ between simple and complex carcinomas or between those lesions and adenocarcinomas in mixed tumors. True carcinosarcomas metastasized more frequently (100%, or 5/5) than did adenocarcinomas in mixed tumors (34.4%, or 22/64), emphasizing the importance of not lumping these tumors under the classification of malignant mixed tumors.