Office planning for the 21st century: considerations for the geriatric patient.
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Biomedical subjects
Publications and source records attributed to M Schwartz.
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INTRODUCTION: Androgen insensitivity syndrome (AIS) is a X-linked rescessive disorder characterized by impairment of the androgen-dependant male sexual differentiation. The cause of AIS is in most cases a mutation in the gene of the androgen receptor on the X chromosome. In this study we describe an Icelandic family with two girls with AIS. A search for mutations in the androgen receptor gene was performed in order to identify the genetical and molecular basis for AIS in this family. MATERIAL AND METHODS: Genomic DNA was isolated from two girls with complete AIS and their close relatives. PCR was used to amplify all eight exons of the androgen receptor gene of the two AIS girls and SSCP used to screen for mutations. DNA fragments showing abnormal SSCP pattern were subjected to nucleotide sequencing. PCR based diagnostic method was developed and used to detect the mutation causing AIS in the family. RESULTS AND CONCLUSIONS: Using SSCP and DNA sequencing a CGA to CAA missense mutation in exon 5 at codon 752 was identified. The mutation causes in an Arg to Gln amino acid substitution (R752Q mutation) in the ligand binding domain of the androgen receptor and a complete androgen insensitivity. Members of the family were genotyped using a PCR based method for identification of the mutant allele. The results strongly indicated a de novo mutation in a germ cell of the maternal grandmother, as the mutation was not found in her blood leucocytes. The diagnostic test provided a basis for genetic counselling for the family.
STUDY DESIGN: Laboratory experiment. OBJECTIVE: To compare the efficacy of different head immobilization techniques during motion simulating ambulance transport. BACKGROUND: A significant number of neurologic injuries associated with cervical spine fractures arise or are aggravated during emergency extrication or patient transport. Previous studies have not addressed the effect of head immobilization on the passive motion that could occur across the neck during transport. METHODS: Three different head-immobilization methods were compared in six healthy young adults by using a computer-controlled moving platform to simulate the swaying and jarring movements that can occur during ambulance transport. In all tests, the trunk was secured by means of a commonly used "criss-cross" strapping technique. Efficacy of head immobilization was evaluated using measures of head motion and neck rotation. RESULTS: None of the three immobilization techniques was successful in eliminating head motion or neck rotation. Movement of the trunk contributed substantially to the lateral bending that occurred across the neck. A new product involving the placement of wedges underneath the head provided some small, but statistically significant improvements in fixation of the head to the fracture board; however, there was no improvement in terms of the relative motion occurring across the neck. CONCLUSIONS: Somewhat improved fixation of the head to the fracture board can be achieved by placing wedges under the head; however, the benefits of any fixation method, in terms of cervical spine immobilization, are likely to be limited unless the motion of the trunk is also controlled effectively. Future research and development should address techniques to better control head and trunk motion.
Accumulated evidence suggests that increased body iron stores may increase the risk of colorectal cancer, possibly via catalyzing oxidation reactions. We examined the relationship between iron status and colorectal cancer in a case-control study nested within the New York University Women's Health Study cohort. For 105 incident cases of colorectal cancer with an average follow-up of 4.7 years and 523 individually matched controls, baseline levels of serum iron, ferritin, total iron binding capacity (TIBC) and transferrin saturation were determined as indicators of body iron stores, and total iron intake was assessed based on their diet and supplement intake. Overall, there were no associations between the risk of colorectal cancer and any of these indices except for serum ferritin, which showed a significant inverse association. When analyzed by subsite, there was an increasing trend in risk of cancer of the proximal colon with increasing total iron intake (p-value for trend = 0.04). In addition, a significantly increased risk of colorectal cancer associated with higher total iron intake [odds ratio (OR) = 2.50; 95% confidence interval (CI): 1.06-5.87] was observed among subjects with higher intake of total fat. Our results do not support a role of increased body iron stores in the development of colorectal cancer, but suggest that luminal exposure to excessive iron may possibly increase the risk in combination with a high fat diet.
BACKGROUND: With an hypothesis that post-chemotherapy changes in serum prostate-specific antigen (PSA) levels might serve as a surrogate marker for assessing prostate cancer outcome (i.e., survival), we studied the relationship between pretherapy and post-therapy prognostic factors and survival in patients with androgen-independent prostate cancer. METHODS: A prognostic model for survival based on pretherapy and post-therapy parameters was developed from the clinical data on 254 patients with androgen-independent prostate cancer treated with 11 different protocol therapies at Memorial Sloan-Kettering Cancer Center. The model was validated by use of an independent dataset of 541 patients enrolled in two randomized phase III trials. RESULTS: In multivariate analysis, a post-therapy decline in PSA levels of 50% achieved in 12 weeks was a statistically significant factor associated with survival (two-sided P = .0012). A similar outcome was obtained with the use of an 8-week time frame. Elevated pretherapy level of serum lactate dehydrogenase (two-sided P = .0001), lower pretherapy level of hemoglobin (P = .0001), and younger age (two-sided P = .0430) had a statistically significant negative impact on outcome. Median survival times were 23, 17, and 9 months for low-, intermediate-, and high-risk groups of patients defined by the prognostic model, respectively. CONCLUSION: This study confirms the prognostic value of a post-therapy decline in PSA of 50% or greater from baseline in relation to survival in patients with androgen-independent prostate cancer treated with a variety of therapies. Two consecutive determinations at 4-week intervals can be used as an end point for efficacy in phase II trials of therapies in this disease.
Methods for the determination of a semi-synthetic cyclic hexapeptide (I, MK-0991) in human plasma based on high-performance liquid chromatography (HPLC) with tandem mass spectrometric (MS-MS) detection using pneumatically assisted electrospray (ion spray, ISP) and turbo ion spray (TISP) interfaces were developed. Drug and internal standard (II, an isostere of I) were isolated from plasma by solid-phase extraction (SPE). The eluent from SPE was evaporated to dryness, the residue was reconstituted in mobile phase and injected into the HPLC system. The use of ISP, TISP and heated nebulizer (HN) interfaces as sample introduction systems were evaluated and showed that the heated nebulizer was not adequate for analysis due to thermal instability and/or adsorption of I and II to glass surfaces of the interface. Compounds I and II were chromatographed on a wide pore (300 A), 150x4.6 mm C8 analytical column, and the HPLC flow-rate of 1.2 ml/min was split 1:20 prior to introduction to the ISP or TISP interface of the mass spectrometric system. The MS-MS detection was performed on a PE Sciex API III Plus tandem mass spectrometer operated in selected reaction monitoring mode (SRM). The precursor-->product ion combinations of m/z 1093.7-->1033.6 and 1094.7-->1033.6 were used to quantify I and II, respectively, after chromatographic separation of the analytes. The assay was validated in the concentration range of 10-1000 ng/ml using ISP, and 2.5-500 ng/ml of plasma using TISP with good precision and adequate accuracy. The effects of HPLC mobile-phase components on the ionization efficiency and sensitivity of detection in the positive ionization mode, the evaluation of the matrix effect, and limitations in sensitivity of detection of I due to the formation of multiply charged species are presented.
Congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency is caused by mutations in the gene CYP21 encoding the enzyme steroid 21-hydroxylase. In addition to deletions, approximately 20 different point mutations have been reported, and still novel mutations are detected. This makes genetic diagnosis as well as carrier detection of 21-hydroxylase deficiency a complicated matter. We developed a simple nonradioactive assay based on the polymerase chain reaction (PCR) in combination with denaturing gradient gel electrophoresis (DGGE) to screen for mutations in the CYP21 gene. DGGE allows a fast scanning of PCR-amplified segments of genes for the presence or absence of any single base pair alterations. We have performed this technique on the coding sequence and intron-exon junctions of CYP21. Our results emphasize that this procedure constitutes a fast and reliable approach when performing diagnosis of 21-hydroxylase deficiency.
We have investigated 68 unrelated 21-hydroxylase deficient Danish patients, representing 136 alleles, and determined the mutational spectrum of the CYP21 gene. The most frequent mutations detected were deletion of CYP21 and the splice mutation in intron 2 (I2-splice). Segregation analysis showed evidence of a de novo mutation in each of two patients. Three novel mutations were detected: G64E in exon 1, Q262X in exon 7, and A362V in exon 8. G64E and A362V were introduced in the CYP21 cDNA by in vitro site-directed mutagenesis, and the two corresponding proteins were transiently expressed in COS-7 cells. The activity of 21-hydroxylase was determined using the two hormone substrates 17-hydroxyprogesterone and progesterone. The analysis showed no enzyme activity for any of the substrates, a result that correlates well with the severity of the patients' disease.
Non-lethal OI III (OMIM 259420) is caused by structural aberrations of collagen I. We report four novel glycine substitutions, one in the a1 (I) chain of collagen I (G688S) and three in the a2 (I) chain (G241D, G247C, G883V). In each of two families (G241D and G883V), we found parental mosaicism for the substitution explaining recurrence and intrafamilial variability of OI. The G247C and the G883V are the most N-terminally and C-terminally, respectively, placed cysteine and valine substitutions reported. The new substitutions add important information to the genotype-phenotype map and in particular the importance of a-chain stoichiometry is underlined. Data regarding the G688S substitution may suggest a different effect of the two a-chains in the development of dentinogenesis imperfecta (DI).
Essential tremor (ET) is the most prevalent extrapyramidal disorder, yet its diagnosis is still controversial. This article introduces new findings that pertain to this diagnostic problem. Twenty-three patients with ET were studied. Patients with parkinsonism, cerebellar signs, severe head injury, or those under neuroleptic medication were excluded. Twenty-five normal subjects served as control subjects. Visuomotor tests involving tracking and tracing along three different paths with both the right and left hands, were used. Performance was assessed by measuring test duration, directional error, the proportion of the cumulative test time during which directional error exceeded half the maximal possible level (PT50%), the mean distance from the model path, the velocity of the hand movement, and the number of tracking interruptions. In 15 of 23 patients performance was the same as in the control subjects. These patients were defined as having a "simple condition" of ET (ETs). Considerable visuomotor impairment was found in eight patients who were regarded as having a "complex condition" of ET (ETc). Patients with ETc had significantly lower tracking speed, more tracking interruptions, longer test duration, greater directional error, greater PT50%, and greater distance from path than patients with ETs or control subjects. Most patients with ET appear to have normal visuomotor capabilities (ETs) but some display significant visuomotor disturbances (ETc). Considering the presence of similar impairments in patients with early Parkinson's disease and the increased prevalence of parkinsonism in patients with ET, it is possible that preclinical parkinsonism exists in patients with ETc. Further follow up of patients with ETc is necessary to verify this possibility.
This study compared the satiating properties of three liquid lunches (450 kcal each), one dominant in protein (71.5% of energy), a second in carbohydrates (99% of energy) and a third containing an equal mixture of the first two formulations, in a within-subjects, repeated measures design. At an ad libitum dinner meal, 12 women consumed 31% more kilocalories in the high-carbohydrate lunch condition than in the high-protein lunch condition and 20% more kilocalories than in the mixture lunch condition. Similar results emerged for the amounts of protein and fat ingested at dinner. Subjects also reported significantly greater pre-dinner hunger and excitement about eating in the carbohydrate lunch condition than in the protein lunch condition. Greater enjoyment of dinner was also found after the carbohydrate lunch than after the mixture and protein lunches.
The irreversible loss of function after axonal injury in the central nervous system (CNS) is a result of the lack of neurogenesis, poor regeneration, and the spread of damage caused by toxicity emanating from the degenerating axons to uninjured neurons in the vicinity. Now, 100 years after Ramon y Cajal's discovery that CNS neurons--unlike neurons of the peripheral nervous system--fail to regenerate, it has become evident that (a) CNS tissue is indeed capable of regenerating, at.least in part, provided that it acquires the appropriate conditions for growth support, and (b) that the spread of damage can be stopped and the postinjury rescue of neurons thus achieved, if ways are found to neutralize the mediators of toxicity, either by inhibiting their action or by increasing tissue resistance to them. In most physiological systems the processes of tissue maintenance and repair depend on the active assistance of immune cells. In the CNS, however, communication with the immune system is restricted. The accumulated evidence from our previous studies suggests that the poor posttraumatic repair and maintenance in the CNS is due at least in part to this restriction. Key factors in the recovery of injured tissues, but missing or deficient in the CNS, are the processes of recruitment and activation of immune cells. We therefore propose the development of immune cell therapies in which the injured CNS is exogenously provided with an adequate number of appropriately activated immune cells (macrophages for regrowth and autoimmune T cells for maintenance), controlled in such a way as to derive maximal benefit with minimal risk of disease. It is expected that these self-adjusting cells will communicate with the damaged tissue, monitor tissue needs, and control the dynamic course of CNS healing.
This study examined the potential of L-Deprenyl, a selective monoamine oxidase-B (MAO-B) inhibitor, for the treatment of neuroleptic-induced parkinsonism (NIP). Thirty-one consecutive schizophrenic or schizophreniform patients were treated with haloperidol in a flexible dose design. Nineteen of them developed NIP and were administered adjunctive L-Deprenyl 10 mg/d for six weeks in an open fixed-dose design. One patient had to be withdrawn from the study because of exacerbation of the NIP. Severity of NIP was mild to moderate throughout the whole study period in all other cases. Five patients were considered to require biperiden 2-4 mg/d in addition to L-Deprenyl after two weeks of treatment, although they did not differ from the other 13 patients in any of the variables studied. A significant improvement in NIP was found in both groups of patients, with no psychotic exacerbation or a change in the dosage of haloperidol. These findings suggest that selective MAO-B inhibitors may be effective in some patients with mild to moderate NIP.
BACKGROUND: The Society of Thoracic Surgeons National Database Committee is committed to risk stratification and assessment as integral elements in the practice of cardiac operations. The National Cardiac Surgery Database was created to analyze data from subscribing institutions across the country. We analyzed the database for valve replacement procedures with and without coronary artery bypass grafting to determine trends in risk stratification. METHODS: The database contains complete records of 86,580 patients who had valve replacement procedures at the participating institutions between 1986 and 1995, inclusive. The 1995 harvest of data was conducted in late 1996 and available for evaluation in 1997. These records were used to conduct an in-depth analysis of risk factors associated with valve replacement and to provide prediction of operative death by using regression analysis. Regression models were made for six subgroups. RESULTS: Adverse patient risk factors, including diabetes, hypertension and reoperation, but not ventricular function, increased over time. There were trends with regard to increasing age of the various population subsets. The types of prostheses used remained similar over time, with more mechanical prostheses than bioprostheses used for both aortic and mitral valve replacement. There was a trend toward increased use of bioprostheses in aortic replacements and decreased use in mitral replacements between 1991 and 1995 than between 1986 and 1990. The mortality rate was determined by patient subset for primary operation and reoperation and by urgency status. The modeling showed that the predicted and observed mortality correlated for all age groups and within patient subsets. CONCLUSIONS: Risk modeling is a valuable tool for predicting the probability of operative death in any individual patient. This large, multiinstitutional database is capable of determining modern operative risk and should provide standards for acceptable care. The study illustrates the importance of risk stratification for early death both for the patient and the surgeon.
This analysis summarizes the first report of the Society of Thoracic Surgeons National Congenital Heart Surgery Database Committee in association with Summit Medical Systems. Twenty-four centers joined the program at various dates of entry resulting in 18,894 enrolled patient records. This report compiled the relevant clinical features of 18 congenital heart categories over a 4-year period (1994-1997), which included 8,149 patient records. The data analyses are largely descriptive in character. Missing data points were described and not omitted in the analysis. Statistical analysis was not performed due to missing data points in some categories. Certain trends, however, could be identified and are discussed. The first Society of Thoracic Surgeons National Congenital Heart Surgery Database Report has succeeded in establishing a finite record that can be improved to establish universal national and international utility, risk stratification, and scholarly outcome analyses.
The adult mammalian central nervous system (CNS) fails to regenerate its axons following injury. A comparison between its postinjury response and that of axons of nervous systems capable of regeneration reveals major differences with respect to inflammation. In regenerative systems, a large number of macrophages rapidly invade the injured site during the first few hours and days after the injury. Following their activation/differentiation through interaction with the host tissue, they play a central role in tissue healing through phagocytosis of cell debris and communication with cellular and molecular elements of the damaged tissue. Relative to the peripheral nervous system (PNS), macrophage recruitment in the adult mammalian CNS is delayed and is restricted in amount and activity. It was recently proposed that in injured mammalian CNS tissue, implantation of macrophages stimulated by prior co-culture with segments of peripheral (sciatic) nerves can compensate, at least in part, of the restricted postinjury inflammatory reaction. In the present study, this experimental paradigm is further explored and shows that there is no conflict between the systemic use of anti-inflammatory compounds and treatment with stimulated macrophages to promote regrowth of neuronal tissue.
The genesis of immune privilege high in the evolutionary tree suggests that immune privilege is necessary, if not advantageous for the progressive development of the CNS. Upon reaching a certain degree of complexity, it seems as if the CNS was obliged to restrain the immune system from penetrating the blood-brain barrier. CNS autoimmunity against myelin proteins is known to be a contributory factor in the pathophysiology of multiple sclerosis and in the animal model of experimental autoimmune encephalomyelitis (EAE) (Wekerle, 1993). Such autoimmunity has therefore been regarded as detrimental and hence obviously undesirable. However, recent findings in our laboratory suggest that T-cell autoimmunity to CNS self-antigens (Moalem et al., 1999), if expressed at the right time and the right place, can do much good in the CNS. We shall review the experiments briefly, and then discuss their implications for our understanding of immune privilege and CNS maintenance after injury.
The limitation of immune responsiveness in the mammalian CNS has been attributed to the intricate nature of neuronal networks, which would appear to be more susceptible than other tissues to the threat of permanent disorganization when exposed to massive inflammation. This line of logic led to the conclusion that all forms of CNS inflammation would do more harm than good and, hence, the less immune intervention the better. However, mounting evidence indicates that some forms of immune-system intervention can help to protect or restore CNS integrity. We have shown that the innate immune system, represented by activated macrophages, can facilitate the processes of regeneration in the severed spinal cord. More recently, we found that autoimmune T cells that are specific for a component of myelin can protect CNS neurons from the catastrophic secondary degeneration, which extends traumatic lesions to adjacent CNS areas that did not suffer direct damage. The challenge, therefore, is to learn how to modify immune interactions in the traumatized CNS in order to promote its post-injury maintenance and repair.