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Biomedical subjects

J Miller

Publications and source records attributed to J Miller.

At least 433 records · Page 24Linked to original sources

AS-1 red cells for neonatal transfusions: a randomized trial assessing donor exposure and safety.

BACKGROUND: Despite recent optimism about the use of erythropoietin therapy to treat the anemia of prematurity, very-low-birth-weight infants who are severely ill receive multiple red cell (RBC) transfusions. Many physicians transfuse relatively fresh RBCs to newborn infants, exposing them to multiple donors and possibly increasing their risk of acquiring transfusion-transmitted infections. STUDY DESIGN AND METHODS: A randomized, single-blind clinical trial was conducted to determine, as the primary endpoint, whether RBCs collected from one dedicated donor and stored for < or = 42 days in AS-1 storage media could safely supply all small-volume RBC transfusions (15 mL/kg/dose) needed by very-low-birth-weight infants (0.6-1.3 kg) during the first 84 days of life. Secondary endpoints were the assessment of the possible adverse clinical and biochemical effects of transfusing AS-1 RBCs stored for < or = 42 days. Control infants received identical nursery care, except they received fresh RBCs stored < or = 7 days in CPDA-1. RESULTS: Infants transfused with AS-1 RBCs were exposed to a mean of 1.6 donors,-compared with an exposure to 3.7 donors for infants given CPDA-1 RBCs (p < 0.05). Neither clinical transfusion reactions nor the results of multiple laboratory tests were significantly different in infants who received slow transfusions (15 mL/kg) of AS-1 RBCs stored for < or = 42 days and in infants who received the same volume of CPDA-1 RBCs stored < or = 7 days. CONCLUSION: AS-1 RBCs, usually from only one dedicated donor, can safely supply all RBCs needed by most very-low-birth-weight infants-a practice that decreases donor exposure and likely increases transfusion safety.

Adenine↗

Transplacentally acquired antiviral antibodies and outcome in congenital human cytomegalovirus infection.

The association between transplacentally acquired maternal antibodies and outcome in congenital human cytomegalovirus (HCMV) infection was investigated by analyzing antiviral antibodies in the cord blood from infants with permanent neurologic sequelae and from those without sequelae. Higher levels of antiglycoprotein B and neutralizing antibodies were observed in infants with sequelae. Infants with symptomatic infection and those with > or = 2 sequelae had higher levels of virus binding antibodies. No association between neutralizing titers and progressive hearing loss was noted. These results suggested that the development of sequelae following congenital HCMV infection was not associated with measurable deficits in the maternal antiviral antibody response. Higher levels of anti-gB and neutralizing antibodies in infants with sequelae also suggested that the natural history of this congenital infection is unlikely to be modified by the passive administration of antiviral antibodies in the postnatal period.

Antibodies, Viral↗

Inclusion body myositis in HIV-1 and HTLV-1 infected patients.

Sporadic inclusion body myositis (IBM) is the most common inflammatory myopathy affecting patients over the age of 50 years. Dysimmune and degenerative aetiologies have been postulated, but viral infections have not been associated with the disease. Two HIV-I (human immunodeficiency virus type 1) infected men and one woman infected with HTLV-1 (human T cell leukaemia virus type 1) developed progressive proximal muscle weakness unrelated to antiretroviral therapy. Their muscle biopsies were studied by light and electron microscopy, by immunocytochemistry to determine the expression of major histocompatibility complex (MHC) molecules and identify the type of infiltrating cells and T cell receptor (TCR) subunits, and by reverse transcription-polymerase chain reaction (RT-PCR) and single or double immunocytochemistry to search for retrovirally infected endomysial cells. The clinical features were consistent with sporadic IBM. The muscle biopsies showed primary endomysial inflammation, red-rimmed vacuoles, amyloid deposits, eosinophilic inclusions, and small round fibres in groups, all diagnostic of IBM. The muscle fibres expressed MHC class-1 antigens and were invaded primarily by CD8+ T-lymphocytes preferentially bearing TCR V beta 5.1 and V beta 13 chains. The HIV-1 or HTLV-1 antigens were detected only on endomysial macrophages on or around muscle fibres, but not within the muscle fibres. We conclude that IBM occurs in HIV-1 and HTLV-1 infected individuals and has a clinical, histological and immunological pattern identical to sporadic IBM in the non-retrovirally infected patients. Retroviruses do not directly infect the muscle, but persistent retroviral infections may provide superantigenic stimulation and trigger an endomysial inflammatory response identical to that occurring in sporadic IBM.

Adult↗

Prevalence of spotted fever group rickettsiae in ticks from southern Israel.

The prevalence of spotted fever group rickettsiae was studied in questing ticks collected from southern Israel. Ticks were examined from an agricultural settlement (kibbutz Ze'elim), an endemic site for Mediterranean spotted fever, and from another kibbutz (Re'im) in an adjacent area where the disease has not been reported. Ticks were collected by flagging and CO2 traps from vegetation inside and outside the settlements during 1989/1990 and 1994. In Ze'elim, 98% of the ticks collected were brown dog tick, Rhipicephalus sanguineus (Latreille), whereas in Re'im the predominant species was Rhipicephalus turanicus Pomerantzev (84.6%), with 11.8% of the ticks R. sanguineus and 3.6% Hyalomma excavatum Koch. The presence of rickettsiae in the hemolymph of the ticks was demonstrated by immunofluorescence using polyclonal antibodies made against the human pathogenic Moroccan strain of Rickettsia conorii. Of 549 ticks examined in 1989/1990 from Ze'elim, 7.3% were positive for spotted group rickettsiae, and in Re'im 2.2% of 156 R. turanicus were positive. In 1994, 51 out of 186 (27.4%) ticks in Ze'elim and 3 out of 115 (2.6%) ticks in Re'im were positive. All 20 specimens of H. excavatum were negative for spotted fever group rickettsiae. To our knowledge, this is the 1st report of spotted fever group rickettsiae in R. turanicus from Israel.

Animals↗

Internal fixation in pelvic fractures and primary repairs of associated genitourinary disruptions: a team approach.

Associated urological and orthopedic injuries of the pelvic ring are complex with numerous potential complications. These patients are treated optimally using a team approach. The combined expertise is not only helpful initially when managing these difficult patients, but also later as problems develop. This study describes a treatment protocol and reports the early results of 23 patients with unstable pelvic fractures and associated bladder or urethral disruptions, or both, treated surgically with open reduction and internal fixation of the anterior pelvic ring injuries at the same anesthetic and using the same surgical exposure as the urethral realignments or bladder repairs or both. Early complications occurred in four patients (17%): one patient sustained a fifth lumbar nerve injury caused by the pelvic reduction procedure, and three patients had anterior pelvic internal fixation failures. Late complications occurred in eight patients (35%). There was one deep wound infection (4.3%) that presented 6 weeks after injury. Late urological complications occurred in seven patients (30%). Four of the nine male patients with urethral disruptions had urethral stricture after their primary urethral realignments (44%). Three of the 18 male patients admitted to impotence (16.7%). One of the three had a residual thoracic paraplegia caused by a burst fracture. One of the five female patients had urinary incontinence and required a bladder suspension operation to restore normal function (20%). A low infection rate can be expected despite the use of internal fixation. Early urethral "indirect" realignments avoid more difficult delayed open repairs; however, late urological complication rates are still high. Early "direct" bladder repairs are easily performed at the time of anterior pelvic open reduction and internal fixation. Suprapubic tubes are not necessary to adequately divert the urine when large diameter urethral catheters are used in these patients.

Adolescent↗

The assessment of discomfort in elderly confused patients: a preliminary study.

With the increasing numbers of older adults in our population, nurses are reexamining all aspects of nursing care in order to best meet the needs of these individuals. Normal age changes, the impact of decades of environmental challenges, successful adaptations, acute illnesses, trauma and chronic illnesses combine to create a challenge for accurate and effective assessment of elderly patients. The nurse finds her assessment skills challenged with increasing frequency by the elderly patient who is also acutely confused and experiencing discomfort. The purpose of this study was to explore the clinical utility, validity and reliability of four different approaches to nursing assessment of discomfort with this particularly vulnerable group of elders.

Aged↗

Sex difference in urinary concentrating ability of rats with water deprivation.

Our previous demonstration of sexual dimorphism in the antidiuretic response to exogenous vasopressin prompted us to investigate the response to moderately high levels of endogenous vasopressin stimulated by water deprivation in conscious rats. After 24 h water deprivation, urine flow was significantly higher and urine osmolality lower in females than in males. Plasma concentrations of vasopressin were higher in females than in males after water deprivation, but plasma osmolality did not differ. Gonadectomy, which had no effect in dehydrated males, decreased urine flow and increased urine osmolality in females to levels observed in intact and gonadectomized males. Spontaneous water intake was also measured and found to be lower in males and estrous females than in females in the other phases of the estrous cycle. These observations support the concept that there is a gender difference in the antidiuretic responsiveness to endogenous vasopressin, that this difference is dependent upon the ovarian hormones, and that it may lead to differences in consumptive behavior.

Animals↗

Inhibition of motor axon growth by T-cadherin substrata.

As spinal motor neurons project to their hindlimb targets, their growth cones avoid particular regions along their pathway. T-cadherin is discretely distributed in the avoided caudal sclerotome and on extrasynaptic muscle surfaces (B. J. Fredette and B. Ranscht (1994) J. Neurosci. 14, 7331-7346), and therefore, the ability of T-cadherin to inhibit neurite growth was tested in vitro. T-cadherin inhibited neurite extension from select neuron populations both as a substratum, and as a soluble recombinant protein. Anti-T-cadherin antibodies neutralized the inhibition. Spinal motor neurons were inhibited only during the stages of axon growth across the sclerotome and muscle innervation. Inhibitory responses corresponded to neuronal T-cadherin expression, suggesting a homophilic binding mechanism. These results suggest that T-cadherin is a negative guidance cue for motor axon projections.

Animals↗

The sampling distribution of d'.

The distribution of sample estimated d's, although mathematically intractable, can be tabulated readily by computer. Such tabulations reveal a number of interesting properties of this distribution, including: (1) sample estimated d's are biased, with an expected value that can be higher or lower than the true value, depending on the sample size, the true value itself, and the convention adopted for handling cases in which the sample estimated d' is undefined; (2) the variance of estimated d' also depends on the convention adopted for handling cases in which the sample estimated d' is undefined and is in some cases poorly approximated by the standard approximation formula, (3) the standard formula for a confidence interval for estimated d' is quite accurate with at least 50-100 trials per condition, but more accurate intervals can be obtained by direct computation with smaller samples.

Decision Making, Computer-Assisted↗

Twelve years' experience with non-heart-beating cadaveric donors.

From 1983 to August 1995, the University of Miami Organ Procurement Organization evaluated 41 candidates for non-heart-beating cadaveric donation and determined that 34 patients met the criteria. All patients had irreversible brain injury incompatible with survival. All families gave permission for withdrawal of life support and for tissue and organ donation after cardiac arrest. Thirteen donors died in the operating room, and 9 died in the ICU or emergency department. Four of the 9 patients who died in the ICU had undergone femoral cannulation. The remaining 12 donors were brain-dead but had an unpredicted cardiac arrest before laparotomy. All kidneys were preserved by using machine pulsatile perfusion, and 21 kidneys were transported to other centers. Of the 35 transplanted kidneys, 26 (74%) had immediate function, 6 (17%) had delayed graft function, and 3 (9%) were not used for other reasons. Five of the six transplanted livers had immediate function.

Adolescent↗

The fragmentation of 510 MeV/nucleon iron-56 in polyethylene. I. Fragment fluence spectra.

The fragmentation of 510 MeV/nucleon iron ions in several thicknesses of polyethylene has been measured. Non-interacting primary beam particles and fragments have been identified and their LETs calculated by measuring ionization energy loss in a stack of silicon detectors. Fluences, normalized to the incident beam intensity and corrected for detector effects, are presented for each fragment charge and target. Histograms of fluence as a function of LET are also presented. Some implications of these data for measurements of the biological effects of heavy ions are discussed.

Algorithms↗

The fragmentation of 510 MeV/nucleon iron-56 in polyethylene. II. Comparisons between data and a model.

The results of a Monte Carlo model for calculating fragment fluences and LET spectra are compared to data taken with 600 MeV/nucleon iron ions incident on an accelerator beamline configured for irradiation of biological samples, with no target and with 2, 5 and 8 cm of polyethylene. The model uses a multi-generation nuclear fragmentation code, coupled with a formulation of ionization energy loss based on the Bethe-Bloch equation. In the region where the data are reliable and the experimental acceptance is well understood, many of the features of the experimental spectra are well replicated by the model. To obtain good agreement with the experimental data, the model must allow for at least two generations of fragment production in the target.

Algorithms↗

[Cryptorchism--assessment from an andrologic viewpoint].

This report deals with the pathology, diagnosis and therapy of cryptorchidism from the andrological point of view. Hypothalamic-pituitary gonadal failure and a reduced transformation of gonocytes are the key factors in fertility disorders. The aim of all well-timed therapy must be to improve the fertility potential of the sexually mature male. At present, the determination through biopsy of the fertility index during orchiopexy offers the only possibility of prospective diagnosis in this respect. In the future, it will be necessary to have a standardized procedure in order to guarantee the long-term effect of correctly timed orchiopexy on fertility.

Adolescent↗