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Biomedical subjects

G W Ross

Publications and source records attributed to G W Ross.

At least 55 records · Page 3Linked to original sources
PubMed1996

Evidence against the operation of selective mortality in explaining the association between cigarette smoking and reduced occurrence of idiopathic Parkinson disease.

To investigate the association between idiopathic Parkinson disease (IPD) and reduced frequency of prior cigarette smoking, the authors compared the 29-year follow-up mortality rates and IPD incidence rates of men who were either cigarette smokers or nonsmokers at the time of enrollment in the Honolulu Heart Study (1965-1968). Based on IPD cases detected up to June 30, 1994, the age-adjusted incidence rate in smokers was less than half that in nonsmokers: 34.4 versus 94.2 cases per 100,000 person-years of pre-illness follow-up, respectively. When data were stratified by 5-year age group, lower IPD incidence in smokers was observed at all ages between 50 and 90 years. Age-specific mortality trends for smokers and nonsmokers with and without IPD suggested that increased mortality in IPD patients was mostly associated with IPD itself and not with smoking. The slight excess mortality in smokers without IPD, versus nonsmokers without IPD, appeared insufficient to account for the "missing" incident IPD cases in smokers. These IPD incidence and mortality data are not highly consistent with the "selective mortality" hypothesis, which attributes reduced prior smoking frequency, typically reported by persons with IPD, to accelerated mortality in undiagnosed IPD-affected persons who smoke. The "protective" association of cigarette smoking with IPD occurrence may thus be real, suggesting the need for further study of biologic mechanisms of protection.

Age Distribution↗
PubMed1996

Age-related changes in stroke risk in men with hypertension and normal blood pressure.

BACKGROUND AND PURPOSE: Stroke is a major contributor to total morbidity and mortality in older individuals, and hypertension is an important risk factor for stroke. Relatively few data exist on whether this relationship changes with age. METHODS: To examine age-related changes in the relationships between risk of stroke and hypertension, we examined the 6-year incidence of stroke among men aged 45 to 81 years using updated blood pressure data from three examinations of Japanese-American men from the Honolulu Heart Program. RESULTS: Both the prevalence of hypertension (systolic blood pressure > or = 160 mm Hg or diastolic blood pressure > or = 95 mm Hg or the use of antihypertensive medication) and the 6-year incidence of stroke increased significantly with increasing age (P < .01). The increase in thromboembolic stroke incidence with age was more marked in those who were normotensive at baseline (2.7/1000 in those aged 45 to 54 years to 23.9/1000 in those > or = 65 years; P < .001) than in hypertensive men (20.6/1000 in those aged 45 to 54 years to 33.5/1000 in those > or = 65 years; P < .01). The age-related increase in risk of thromboembolic stroke among normotensive men resulted in a decrease in the percentage of strokes attributable to hypertension (50% in those aged 45 to 54 years to 18% in those > or = 65 years; P < .05). Similar trends were seen for hemorrhagic stroke. There were no age-related changes in the relationships of other major atherosclerotic risk factors with stroke. The hypertension/stroke relationships were present after multivariate adjustment for age, smoking, cholesterol, and other factors. CONCLUSIONS: In view of the greater prevalence of hypertension and the proven efficacy of treatment in the elderly, these findings do not negate the value of aggressive screening and treatment of hypertension in this age group. However, it appears that other unidentified factors have an increasing role in the causation of stroke with advancing age.

Age Factors↗
PubMed1996

Epidemiologic observations on Parkinson's disease: incidence and mortality in a prospective study of middle-aged men.

We determined age-specific and age-adjusted incidence rates and mortality rates of idiopathic Parkinson's disease (PD) in a cohort of men followed for 29 years. Since enrollment in 1965, the Honolulu Heart Study has followed 8,006 American men of Japanese or Okinawan ancestry. Rescreening of the entire cohort, completed in 1994, included attempts to detect all prevalent and incident cases of PD, parkinsonism, and related conditions. PD incidence rates and age-incidence patterns were similar to rates previously published for Caucasian men in Europe and the United States, and were higher than incidence rates published for Asian men living in Asian nations. Prevalence patterns appeared to correspond more closely to patterns observed in developed nations than in Asian nations. PD was associated with markedly increased mortality that appeared to result from effects of both absolute age and disease duration. There was no firm evidence for differences in birth cohort risks of PD. These data may have implications for maturational and environmental theories of PD etiology.

Aged↗
PubMed1996

Case-control study of idiopathic Parkinson's disease and dietary vitamin E intake.

A nested case-control study of 84 incident cases of patients with idiopathic Parkinson's disease (PD) detected by June 30, 1994 and 336 age-matched control subjects, compared previously-documented intake of total dietary vitamin E and of selected vitamin E-containing foods. All study subjects had been followed for 27 to 30 years after diet recording in the 8,006-man Honolulu Heart Study cohort. We determined PD outcomes by periodic cohort re-examination and neurologic testing, private physician reports, examination of O'ahu neurologists' office records, and continual death certificate and hospital discharge diagnosis surveillance. Data on vitamin E intake, obtained from three dietary data sets at the time of cohort enrollment (1965 to 1968), included a food-frequency questionnaire and a 24-hour photograph-assisted dietary recall administered by trained dietitians. Although absence of PD was significantly associated with prior consumption of legumes (adjusted OR = 0.27, 95% CI 0.09 to 0.78), a dietary variable preselected for high vitamin E content, neither food categories nor quartiles nor continuous variables of vitamin E consumption were significantly associated with PD occurrence. Though consistent with prior reports of PD protection afforded by legumes, and with speculation on the possible benefits of dietary or supplemental vitamin E in preventing PD, these preliminary data do not conclusively document a beneficial effect of dietary vitamin E on PD occurrence.

Aged↗
PubMed1995

Cigarette smoking and protection from Parkinson's disease: false association or etiologic clue?

We reviewed 46 published reports associating cigarette smoking and Parkinson's disease. Although the majority indicated an approximate halving of smoking frequency in persons with Parkinson's disease, many observers have suggested that the effect could be a spurious result. That the association may be real is suggested by at least six observations: (1) the consistency of findings between independent studies of different design, conducted by different investigators, in different nations, over 35 years; (2) the association's predominance and strength in prospective studies; (3) the apparent detection of a dose-response relation; (4) the inability to explain the association by confounding variables; (5) the flaws in certain arguments against the association's validity; and (6) the identification of a similar association, of similar magnitude, between smoking and reduced occurrence of Alzheimer's disease. A protective association of cigarette smoking for Parkinson's disease may constitute an important etiologic clue.

Female↗
PubMed1994

Posterior cortical atrophy. Neuropathologic correlations.

OBJECTIVE: A subgroup of patients with progressive dementia has been reported with a marked predominance of symptoms attributed to the dysfunction of the posterior parieto-occipital cortex. These cases have been referred to as posterior cortical atrophy. The objective of this study was to determine whether posterior cortical atrophy is associated with distinct, uniform neuropathologic findings. DESIGN: Three individuals with progressive dementia that began with higher visual dysfunction (posterior cortical atrophy) were followed up to definitive neuropathologic diagnosis. RESULTS: Three separate neuropathologic entities were discovered: subcortical gliosis, Alzheimer's disease, and Creutzfeldt-Jakob disease. CONCLUSION: Posterior cortical atrophy is a clinically homogeneous but pathologically heterogeneous syndrome.

Aged↗
PubMed1994

Body mass index and thromboembolic stroke in nonsmoking men in older middle age. The Honolulu Heart Program.

BACKGROUND AND PURPOSE: While evidence suggests that obesity has an independent relation to coronary artery disease, similar findings for stroke have not been established. The purpose of this study was to examine the relation between body mass index and the risk of thromboembolic stroke independently of other risk factors. METHODS: Since 1965, the Honolulu Heart Program has followed a cohort of men in a prospective study of cardiovascular disease. This article examines the relationship between the baseline measurement of body mass index and the risk of thromboembolic stroke in 1163 nonsmoking men in older middle age (55 to 68 years). Men who had an elevated risk of stroke due to hypertension, diabetes, and other risk factors were excluded from the analysis. RESULTS: After 22 years of follow-up, the rate of stroke increased significantly with increasing levels of body mass (P < .01). In the bottom tertile of the body mass index, the rate of thromboembolic stroke was 28.7 per 1000 (11/383). In the middle tertile, the rate was increased by 40% to 40.7 per 1000 (16/393), and in the top tertile, the rate of thromboembolic stroke was 55.4 per 1000 (21/387), a twofold excess compared with the bottom tertile. After adjustment for age and the residual effects of confounding risk factors, including systolic blood pressure and serum glucose, the estimated relative risk of stroke for the average body mass index in the top tertile (26.6 kg/m2) compared with that in the bottom tertile (20.3 kg/m2) was 2.1 (95% confidence interval, 1.1 to 4.1). These findings were not affected by coronary events that occurred in the course of follow-up, nor did they appear to be influenced by deaths from other causes. CONCLUSIONS: We conclude that elevated body mass is associated with an increased risk of thromboembolic stroke in nonsmoking men in older middle age who are free of commonly observed conditions related to cardiovascular disease.

Age Factors↗
PubMed1990

Olfactory neuroblastoma. Additional immunohistochemical characterization.

A panel of 12 antibodies was used to further characterize the immunohistochemical staining profile of olfactory neuroblastoma. The following results were obtained for the 11 neoplasms that were immunostained: neuron-specific enolase 11/11(+), S-100 protein 8/11(+), microtubule-associated protein-2 8/11(+), class III beta-tubulin isotype 9/11(+), neurofilament 200 kD 8/11(+), synaptophysin 7/11(+), glial fibrillary acidic protein 1/11(+), chromogranin A 1/11(+), vimentin 1/11(+), keratin (CAM 5.2) 4/11(+), keratin (AEI/AE3) 0/11(+), and epithelial membrane antigen 0/11(+). Expression of two intermediate filaments was found in 4 of the 11 tumors. The authors' data showing that 72% of olfactory neuroblastomas were S-100 protein positive and only one was immunoreactive for glial fibrillary acidic protein agree with other published immunohistochemical studies. With only a single exception, each of the 11 neoplasms was labeled with one or more antibodies that detect neuronal cytoskeletal proteins (class III beta-tubulin isotype, microtubule-associated protein-2, neurofilament 200 kD). These immunohistochemical results are complementary to the reported electron microscopic findings of intermediate filaments and microtubules in olfactory neuroblastomas.

Adult↗
PubMed1990

Clear cell tumor of the lung. A clinicopathologic, immunohistochemical, and ultrastructural study of eight cases.

We studied eight clear cell tumors of the lung (CCTL) to better define their clinical, immunohistochemical, and ultrastructural features, and to clarify their distinction from other neoplasms, particularly metastatic renal cell carcinoma. Patients ranged in age from 31 to 67 years (mean, 51 years). Seven patients had clinically benign, asymptomatic lesions measuring less than 2 cm in diameter that were devoid of necrosis. The eighth patient had a symptomatic, partially necrotic CCTL 4.5 cm in diameter that metastasized to the liver and peritoneum; the patient died of tumor 17 years after diagnosis. Ultrastructural study of seven CCTL showed interdigitating cell processes (all cases), primitive cell junctions (five of seven cases), intracytoplasmic glycogen (all cases), and rare dense core granules (two of seven cases). Immunohistochemically, paraffin-embedded sections from all eight CCTL were negative for cytokeratin (CK), epithelial membrane antigen (EMA), chromogranin, and vimentin. Focal staining was seen for S-100 protein (three of eight cases), neuron-specific enolase (three cases), synaptophysin (one case), and Leu 7 (one case). Although these findings suggest that at least some CCTL exhibit neuroendocrine differentiation, the tumor's histogenesis remains uncertain. Of more practical importance, the combined absence of CK, EMA, and vimentin in formalin-fixed, paraffin-embedded CCTL virtually precludes confusion with renal cell carcinoma. Although traditionally considered benign, CCTL larger than 2 cm that are symptomatic, and focally necrotic should be regarded as potentially malignant neoplasms.

Adenocarcinoma↗
PubMed1989

Gliomatosis peritonei associated with a ventriculoperitoneal shunt.

The authors describe a seven-month-old male patient with non-teratomatous gliomatosis peritonei secondary to the placement of a ventriculoperitoneal shunt. The glial nodules were discovered during microscopic examination of bilateral herniorrhaphy specimens. The glial nature of the implants was confirmed immunohistochemically. The pathogenesis and implications of this finding are discussed, and shunt-related tumor transplantations are briefly reviewed.

Cerebrospinal Fluid Shunts↗
PubMed1989

Unusual sinonasal small-cell neoplasms following radiotherapy for bilateral retinoblastomas.

Two patients developed sinonasal small-cell neoplasms that arose 22 years and 37 years, respectively, following radiotherapy for bilateral retinoblastomas. The tumors were composed of small cells with scant cytoplasm and had a few scattered Homer-Wright rosettes. Immunohistochemically, one tumor was positive for keratin (CAM 5.2 and AE1/AE3), epithelial membrane antigen, and neuron-specific enolase. The other neoplasm was immunoreactive for keratin (CAM 5.2 only) and neuron-specific enolase; it also had focal immunopositivity for S-100 protein, desmin, and muscle-specific actin. Both were negative for CEA, vimentin, melanocyte-specific antigen (HMB45), chromogranin A, synaptophysin, Leu-7, 200 kd neurofilament, and retinal S-antigen. Despite aggressive multimodal therapy, the patients died of metastatic tumor 7 months and 10 months following their initial diagnosis, respectively. Although osteosarcoma is the most frequent second cancer following bilateral retinoblastomas, some patients develop clinically aggressive sinonasal small-cell tumors that are difficult to place into conventional classifications. Both of our cases showed evidence of multidirectional differentiation; one tumor labeled with epithelial and neural markers, and the other expressed epithelial, neural, and myogenous antigens.

Adult↗
PubMed1989

Lack of histopathological correlation of malignant ependymomas with postoperative survival.

It is widely believed that an important determinant of clinical behavior and prognosis in patients harboring an ependymoma is the histological grade of malignancy of the tumor. Excluding from the present analysis examples of ependymoblastoma (a highly cellular, embryonal tumor occurring in children, with a notably poor prognosis and a tendency to subarachnoid spread), an attempt was made to correlate 15 cases of histologically malignant ependymoma with clinical recurrence and postoperative patient survival times. Ten patients (67%) were alive from 15 months to 14 years after surgery (median survival time 8.8 years); one patient had a histologically benign recurrence 11 years after surgical resection. Five patients (33%) died from a local recurrence of their tumor; their postoperative survival times ranged from 13 months to 6 years (median 2.5 years). The prognosis of malignant ependymomas is therefore highly variable. No correlation was possible between the tumor's histological features, site, or likelihood of recurrence. This lack of clinicohistopathological concordance contrasts with the known correlations that exist in astrocytomas.

Adolescent↗
PubMed1989

Hemimegalencephaly, hemifacial hypertrophy and intracranial lipoma: a variant of neurofibromatosis.

A case is presented of a 30-year-old, mentally retarded and epileptic patient, with a progressive hemifacial hypertrophy since birth. Repeated biopsies revealed the neurofibromatous nature of her facial lesion. Autopsy also revealed an ipsilateral hemimegalencephaly, as well as meningeal lipomas and osteomas. This combination of lesions represents an unusual variant within the spectrum of neurofibromatosis.

Adult↗
PubMed1988

Relapse of herpes simplex encephalitis after conventional acyclovir therapy.

Acyclovir sodium is the drug of choice for the treatment of herpes simplex encephalitis. We treated an immunocompetent patient with a ten-day course of intravenous acyclovir sodium at the recommended dosage of 10 mg/kg every eight hours for clinically apparent herpes simplex encephalitis. After marked improvement, his condition deteriorated four days after completing acyclovir therapy. A subsequent brain biopsy specimen disclosed acyclovir-sensitive herpes simplex virus type 1. A longer duration of acyclovir therapy (14 to 21 days) should be considered for treating herpes simplex encephalitis.

Acyclovir↗
PubMed1988

Immunohistochemical differences between intracranial germinomas and their gonadal equivalents. An immunoperoxidase study of germ cell tumors with epithelial membrane antigen, cytokeratin, and vimentin.

Twenty-six intracranial germ cell tumours (11 germinomas, 10 teratomas, 2 endodermal sinus tumours, 1 teratocarcinoma, and 2 undifferentiated embryonal carcinomas) and 26 gonadal germ cell tumours (13 testicular seminomas, 2 ovarian dysgerminomas, 9 ovarian teratomas, and 2 myometrial choriocarcinomas) were studied by immunoperoxidase with monoclonal antibodies (MAbs) against epithelial membrane antigen (EMA), cytokeratin, and vimentin. Typical tumour cells in three of the 11 germinomas (two of the latter being situated in the posterior fossa) expressed both EMA and cytokeratin, whereas those in the seminomas and dysgerminomas did not. In one seminoma, a few multinucleated giant cells expressed cytokeratin. In three of seven germinomas, vimentin-positive tumour cells were found, but all seminomas and dysgerminomas were negative. In the other forms of intracranial and gonadal germ cell tumours, epithelial and mesenchymal elements displayed the expected patterns of immunoreactivity to the respective determinants. The immunoperoxidase differences between the intracranial germinomas and their gonadal equivalents indicate that, in the former, early epithelial or mesenchymal differentiation of the primordial germ cells may be present. The findings draw attention to the heterogeneous cellular composition of these otherwise morphologically homogeneous-appearing tumours and, especially in the posterior fossa, to their transitional links to the immature teratomas.

Adolescent↗
PubMed1988

Ectopic midline spinal ganglion in diastematomyelia: a study of its connections.

The connections of an ectopic midline spinal ganglion associated with an asymptomatic sacral diastematomyelia were studied. The ganglion was intercalated in the ventral root of one hemicord and sent its efferents to the dorsal root of the other hemicord. The afferents joined the anterior root to form a midline intradural spinal nerve in the cauda equina. Islands of ectopic glia were present in both roots and the spinal nerve. Both the midline position of the ganglion and the glial heterotopias can be tentatively explained by the failure of incorporation of the dorsal cell wedge ("Zwischenstrang") into the divided neural tube.

Choristoma↗
PubMed1987

Expression of epithelial membrane antigen in perineurial cells and their derivatives. An immunohistochemical study with multiple markers.

Paraffin-embedded surgical pathology specimens from skin (5) and muscle (2) biopsies, from Morton's neuromas (3), traumatic neuromas (8), schwannomas (21), neurofibromas (12), and from one perineurioma and one neurothekeoma were studied by immunoperoxidase histochemistry and antibodies against epithelial membrane antigen (EMA), Leu 7 epitopes (Leu 7), S-100 protein (S-100) and cytokeratins. Normal, reactive and neoplastic perineurial cells stain consistently for EMA, whereas Schwann cells express Leu 7 and/or S-100 positivity. None of the immunoreactive cells stained for cytokeratin. Our findings indicate that perineurial and Schwann cells can easily be distinguished by their different patterns of immunoreactivity with the above markers.

Cell Line↗