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Biomedical subjects

J H Fox

Publications and source records attributed to J H Fox.

At least 19 recordsLinked to original sources
PubMed2002

Natural history of mild cognitive impairment in older persons.

BACKGROUND: Cognitive abilities of older persons range from normal, to mild cognitive impairment, to dementia. Few large longitudinal studies have compared the natural history of mild cognitive impairment with similar persons without cognitive impairment. METHODS: Participants were older Catholic clergy without dementia, 211 with mild cognitive impairment and 587 without cognitive impairment, who underwent annual clinical evaluation for AD and an assessment of different cognitive abilities. Cognitive performance tests were summarized to yield a composite measure of global cognitive function and separate summary measures of episodic memory, semantic memory, working memory, perceptual speed, and visuospatial ability. The authors compared the risk of death, risk of incident AD, and rates of change in global cognition and different cognitive domains among persons with mild cognitive impairment to those without cognitive impairment. All models controlled for age, sex, and education. RESULTS: On average, persons with mild cognitive impairment had significantly lower scores at baseline in all cognitive domains. Over an average of 4.5 years of follow-up, 30% of persons with mild cognitive impairment died, a rate 1.7 times higher than those without cognitive impairment (95% CI, 1.2 to 2.5). In addition, 64 (34%) persons with mild cognitive impairment developed AD, a rate 3.1 times higher than those without cognitive impairment (95% CI, 2.1 to 4.5). Finally, persons with mild cognitive impairment declined significantly faster on measures of episodic memory, semantic memory, and perceptual speed, but not on measures of working memory or visuospatial ability, as compared with persons without cognitive impairment. CONCLUSIONS: Mild cognitive impairment is associated with an increased risk of death and incident AD, and a greater rate of decline in selected cognitive abilities.

Aged↗
PubMed2000

gamma-diketone peripheral neuropathy. I. Quality morphometric analyses of axonal atrophy and swelling.

Quantitative morphometric analysis was used to characterize expression of myelinated axon swelling and atrophy in rat peripheral nerve during 2,5-hexanedione (HD) intoxication. HD was administered by gavage according to different daily dosing regiments (100, 175, 250, or 400 mg/kg/day) and four proximodistal nerve regions (5th lumbar spinal nerve, proximal and distal sciatic nerve, and tibial nerve) were examined morphometrically. Morphometric determinations were made at four behavioral endpoints (unaffected, slight, moderate, and severe toxicity) and were correlated to electrophysiologic measurements of peripheral nerve function. Results show that, for all HD dose rates, onsets of behavioral neurotoxicity and nerve dysfunction were generally related to development of abundant axon atrophy. The proximodistal manifestation of atrophy was dependent upon the dosing rate; i.e., the atrophy response produced by subacute intoxication with higher daily dosing rates (250 and 400 mg/kg/day) was restricted to distal nerve regions whereas subchronic induction with lower dosing rates (100 and 175 mg/kg/day) produced abundant fiber atrophy in all proximodistal areas. In contrast to atrophy, axonal swellings constituted an inconsistent minor morphologic response, the expression of which was dependent upon subchronic dosing rates (100-250 mg/kg/day). Subacute HD administration (400 mg/kg/day) produced significant changes in neurobehavior and nerve electrophysiologic parameters in the absence of peripheral axon swelling. Thus, conditional expression of swellings suggests they are an epiphenomenon related to low-dose induction rates. Fiber atrophy, however, was numerically dominant, correlated with nerve dysfunction, and occurred at all dosing levels. These characteristics suggest atrophy is a neurotoxicologically significant feature of gamma-diketone peripheral neuropathy.

Animals↗
PubMed2000

Transcervical placement of a Malecot catheter after hysteroscopic evaluation provides for easier entry into the endometrial cavity for women with histories of difficult intrauterine inseminations and/or embryo transfers: a prospective case series.

OBJECTIVE: To evaluate a new technique designed to improve access to the endometrial cavity through tortuous and/or stenotic endocervical canals in women with histories of difficult IUIs, ETs, or endometrial biopsies. DESIGN: Prospective case series. SETTING: Tertiary care center. PATIENT(S): Women with histories of difficult intrauterine procedures because of tortuous and/or stenotic endocervical canals who continued to undergo treatment. INTERVENTION(S): Hysteroscopic evaluation and/or correction of the endocervix, followed by transcervical placement of a Malecot catheter (CR Bard Inc., Covington, GA) for an average of 10 days. MAIN OUTCOME MEASURE(S): Improvement in the ease of access to the endometrial cavity during IUIs or ETs. RESULT(S): Thirty-two of 36 patients had significantly easier procedures after the placement and removal of a Malecot catheter. CONCLUSION(S): Hysteroscopic evaluation and placement of a Malecot catheter is a useful technique that allows easier entry through the cervical canal in patients in whom previous IUIs, ETs, and endometrial biopsies have been difficult. This procedure may lead to improved pregnancy rates, particularly with IVF-ET, as the ease of ET has been correlated with improved implantation rates.

Adult↗
PubMed2000

The number of eight-cell embryos is a key determinant for selecting day 3 or day 5 transfer.

OBJECTIVE: To select patients for day 3 vs. day 5 embryo transfer. DESIGN: Retrospective analysis of assisted reproduction technology (ART) cycles comparing outcomes of day 3 and day 5 transfers. SETTING: ART program of Brigham and Women's Hospital. PATIENT(S): Patients with day 3 or day 5 embryo transfers (n = 221 and 141, respectively). INTERVENTION(S): Cycles with eight or more zygotes were stratified by the number of eight-cell embryos available on day 3 (none, one or two, or three or more). MAIN OUTCOME MEASURE(S): Number of blastocysts, implantation rates, ongoing pregnancy rates, and number of fetal heart beats. RESULT(S): With no eight-cell embryos on day 3, 0% and 33% pregnancies resulted from day 5 vs. day 3 transfers. With one or two eight-cell embryos on day 3, ongoing and high order multiple rates were not different between day 3 and day 5 transfers. With three or more eight-cell embryos, day 5 transfer resulted in a decrease in multiple gestations but no difference in ongoing pregnancy rates compared with day 3 transfer. CONCLUSION(S): With no eight-cell embryos on day 3, a day 3 transfer is warranted. With one or two eight-cell embryos, any benefit of day 5 transfer appears to be equivocal. With three or more eight-cell embryos, day 5 transfer is recommended.

Adult↗
PubMed2000

Acute sarcocystosis in a captive white-tailed deer in Virginia.

A 19-mo-old female captive white-tailed deer in a public wild animal park in Richmond (Virginia, USA) was necropsied and evaluated histologically following spontaneous death after a 1 wk period of lethargy in a captive herd of 22 deer. An acute necrotizing pneumonia was associated with intraendothelial protozoal schizonts that were identified immunohistochemically as Sarcocystis spp. This is the first confirmed report of acute sarcocystosis in a wild ruminant.

Acute Disease↗
PubMed1997

Avian pox in eastern screech owls and barred owls from Florida.

Avian pox was diagnosed in two eastern screech owls (Otus asio) and two barred owls (Strix, varia) living in different regions of Florida (USA) between November 1994 and October 1995. Avian poxvirus infection was confirmed by the presence of eosinophilic intracytoplasmic epidermal inclusions (Bollinger bodies) on light microscopy of tissue from all four owls. Additionally, typical poxvirus particles were demonstrated by electron microscopy of a lesion from one of the eastern screech owls. These are the first published case reports of avian pox in eastern screech owls and barred owls.

Animals↗
PubMed1996

A randomized clinical trial to evaluate the clinical effects of split- versus single-dose human menopausal gonadotropins in an assisted reproductive technology program.

OBJECTIVE: To compare the effect of twice (split) versus once (single) daily administration of hMG on assisted reproductive technology (ART) cycle parameters. DESIGN: A randomized clinical trial. SETTING: Hospital-based academic ART program. PATIENTS: A total of 171 patients undergoing their initial ART cycle were enrolled. All patients received one of two hMG regimens and were excluded from the study if they were receiving medications other than leuprolide acetate (LA) and hMG for ovulation induction. INTERVENTIONS: Subjects were randomized to receive an initial dose of 300 IU/d of hMG in either split-dose (i.e., 150 IU twice daily) or single-dose fashion for four successive days after down-regulation with LA. Thereafter, their daily dose was individualized, maintaining a split-or single-dose schedule. All cycles were managed in accordance with our standard ART protocols. MAIN OUTCOME MEASURES: Cancellation rate, total hMG requirements, number of days treated with hMG, E2 and P responses, oocyte yield and maturity, fertilization rate, total number of embryos, embryo quality, number of embryos transferred, implantation rate, clinical and ongoing-delivered pregnancy rates. RESULTS: Split-dose hMG administration resulted in a significantly higher implantation rate, but significantly lower normal and polyspermic fertilization rates than single-dose hMG administration. No significant differences were noted between the two dosage protocols with respect to the other outcome measures. CONCLUSIONS: Split-dose hMG administration may be associated with significantly higher implantation rates; single-dose hMG with significantly higher fertilization rates. Although our data also demonstrate a trend toward higher clinical and ongoing-delivered pregnancy rates with split-dose therapy, demonstration of a significant difference would require a multicenter trial. Based on our data, clinicians may want to consider split-dose therapy for patients with repeated implantation failures.

Adult↗
PubMed1995

Morphological correlates of auditory sensitivity in anuran amphibians.

It is largely unknown how the presence and morphology of various auditory structures, including extratympanic structures, affect auditory sensitivity in anuran amphibians. This study examines body size, tympanum size, the presence versus absence of the tympanum, the 'external' versus 'internal' status of the tympanum, and the amphibian and basilar papilla (AP and BP) hair cell counts, as they relate to physiological estimates of auditory sensitivity, within both AP- and BP-sensitive frequency ranges. The BP sensitivity is positively correlated with tympanum area, which is positively correlated with body size. The AP sensitivity is also correlated with body size, perhaps through mediation by extratympanic factors. Tympanum presence affects only BP sensitivity, whereas the external/internal status of the tympanum is irrelevant. Lastly, AP hair cell count correlates with AP sensitivity, irrespective of possible sensory convergence effects.

Animals↗
PubMed1994

Severe panencephalic Pick's disease with Alzheimer's disease-like neuropil threads and synaptophysin immunoreactivity.

We report a case of a 69-year-old woman with an 11-year history of progressive dementia, who was found at autopsy to have classic Pick's disease pathology, as well as extensive paired helical filament -- immunoreactive neurities, with few Alzheimer's disease (AD)-like neurofibrillary tangles and no senile plaques. Both Pick bodies and neuritic degeneration were extensive in the neocortex and hippocampal complex. In addition, synaptophysin immunostaining of the hippocampal complex showed a bilaminar pattern of immunoreactivity in the outer molecular layer as previously described in AD.

Alzheimer Disease↗
PubMed1994

Early diagnosis and treatment of cervical pregnancy in an in vitro fertilization program.

This is a report of three cervical pregnancies, one of which was a heterotopic twin cervical pregnancy that occurred in combination with a single intrauterine pregnancy. Transvaginal ultrasound examination was sufficient to establish the diagnosis in two of three patients, and MRI scanning was conclusive in the third. Early diagnosis lead to intervention before 7 weeks gestation in all cases with no complications. The incidence of cervical pregnancy may be higher in IVF-ET than recognized previously.

Adult↗
PubMed1993

Differential effects of oral glucose-mediated versus intravenous hyperinsulinemia on circulating androgen levels in women.

OBJECTIVE: To determine whether transient endogenous or continuous exogenous hyperinsulinemia produced different changes in circulating gonadal steroid levels because insulin is a putative regulator of gonadal steroid secretion in polycystic ovarian syndrome (PCOS). DESIGN: An oral glucose tolerance test (OGTT) and a 2-hour euglycemic clamp (+100 microU/mL [718 pmol/L] steady-state insulin levels) were performed in obese patients with PCOS (n = 7) in nonobese patients with PCOS (n = 5), and in age- and weight-matched ovulating normal women (obese normal n = 7, nonobese normal n = 6). RESULTS: Despite increased insulin levels, the levels of T and androstenedione (A) decreased in three of the four groups during the OGTT (nonobese normal women showed a slight increase in T during the OGTT). In contrast, the continuous 2-hour insulin infusion resulted in increased androgen levels. When all four groups were pooled, the difference in the changes in A levels between the two tests was significant, and the difference in T levels between the two tests approached significance. CONCLUSIONS: Transient physiological hyperinsulinemia produced by an oral glucose load was associated with a decrease rather than an increase in circulating androgen levels. The effects on circulating androgen levels of oral glucose-mediated increases in insulin levels were significantly different from those of a continuous intravenous insulin infusion. Sustained hyperinsulinemia produced by exogenous insulin infusion appeared to be required to increase androgen levels in women; transient physiological increases in insulin levels after an oral glucose load were insufficient to produce hyperandrogenism. Postmeal hyperinsulinemia does not contribute to hyperandrogenism in women.

Adult↗
PubMed1992

Clinical correlates of high signal lesions on magnetic resonance imaging in Alzheimer's disease.

The pathophysiology and clinical significance of high signal lesions, visualized on magnetic resonance imaging (MRI) in patients with Alzheimer's disease (AD), remain controversial. Since they are known to correlate with vascular disease and vascular risk factors, we reviewed the clinical correlates of periventricular high signal (PVH) and subcortical white matter lesions (WML) in a sample of 106 patients with probable AD, excluding persons with treated vascular risk factors or symptomatic cerebrovascular and cardiovascular disease. Grade 2 PVH were seen in 26 (25%) and scattered WML were identified in 29 (18%). PHV were associated with advancing age and gait disturbance. WML were associated with gait disturbance and incontinence. Neither radiologic finding was related to dementia severity. The findings suggest that these lesions are common in patients with AD even when those with evidence of cerebrovascular disease are excluded; their presence, therefore, should not preclude a diagnosis of AD. Additionally, the data suggest that HSL on MRI may be one of many risk factors associated with functional disability in persons with probable AD.

Aged↗
PubMed1992

Ovarian hyperstimulation and follicular aspiration. Effect on ovulatory function.

The return of normal function of the reproductive axis immediately after hyperstimulation and follicular aspiration is of both physiologic and clinical interest. These cycles may be utilized for the replacement of cryopreserved embryos, for repeated ovarian stimulation or for any alternative treatment that relies upon normal ovulatory function. Thirty-five women were randomly assigned to be monitored in the first (n = 11), second (n = 13) or third (n = 11) menstrual cycle after in vitro fertilization (IVF). Five of 35 patients (14.3%) failed to ovulate, 2 in each of the first and second menstrual cycles and 1 in the third cycle after IVF. Six (20%) ovulatory cycles demonstrated luteal phase deficiencies. The defective luteal phases were evenly distributed between cycles immediately after IVF and those more remote in time from the procedure.

Academic Medical Centers↗
PubMed1992

The effect of baseline complex ovarian cysts on in vitro fertilization outcome.

STUDY OBJECTIVE: To determine the effect of baseline complex ovarian cysts on controlled ovarian hyperstimulation and in vitro fertilization (IVF) outcome. DESIGN: Retrospective analysis with stratification by stimulation regimen and the presence or absence of surgically documented endometriosis. PATIENTS: Two hundred sixty-one women undergoing IVF from May 1, 1989 to December 31, 1990. MAIN OUTCOME MEASURES: The outcome measures assessed were the maximum estradiol (E2) concentration on day of human chorionic gonadotropin (hCG) administration, number of follicles with maximum diameter greater than or equal to 15 mm, number of follicles with maximum diameter greater than or equal to 12 mm, number of days to hCG administration, number of ampules of human menopausal gonadotropin (hMG) used, number of oocytes retrieved and fertilized, number of embryos transferred, and pregnancy and cycle cancellation rates. RESULTS: There were no statistical differences between cyst and noncyst groups in any of the above parameters of IVF performance. In a single subgroup, patients with endometriosis stimulated with hMG and patients with cysts had significantly lower E2 concentrations than patients without cysts. CONCLUSION: The presence of a complex cyst on a baseline ultrasound does not appear to adversely affect IVF cycle outcomes.

Endometriosis↗
PubMed1991

A 'stress' test for memory dysfunction. Electrophysiologic manifestations of early Alzheimer's disease.

Long-latency event-related potentials (P300) were assessed in patients with early probable Alzheimer's disease (AD), age-matched controls, and young adults during a task that imposed various degrees of demand on memory. Although patients with AD did not differ from age-matched controls when one item had to be remembered, their P300 potential was dramatically reduced in amplitude or absent with increasing memory load. Aged controls did not differ from young adults on this measure. P300 latency, however, did not differentiate patients with AD. Thus, electrophysiological abnormalities detected in the context of mnemonic demand may provide a sensitive marker of the early stages of probable AD.

Adult↗
PubMed1991

Maze learning in Alzheimer's disease.

Alzheimer's disease (AD) patients and normal elderly controls performed a block of 10 trials on a finger maze, followed by a 45-min period during which verbal learning measures were administered. Subjects then performed an additional 10 trials on the original maze, followed by 10 trials on a new maze. The AD patients and a subset of control subjects decreased mean completion time across Blocks 1 and 2, suggesting skill acquisition. Mean time on Block 3 was significantly less than mean time on Block 1, suggesting skill generalization. A subset of controls did not show the above pattern. The results of this study suggest that AD patients are able to acquire and generalize a cognitively mediated perceptual-motor skill.

Aged↗