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Biomedical subjects

G A Miller

Publications and source records attributed to G A Miller.

At least 91 records · Page 5Linked to original sources
PubMed1994

Comparison of DNA probe and ELISA microbial analysis methods and their association with adult periodontitis.

The purposes of this study were two-fold: to compare the DNA probe and enzyme linked immunosorbent assay (ELISA) microbial identification tests and correlate the levels of microorganisms with adult periodontitis. A single plaque sample were taken from each of 2 sites in 52 patients. Twelve of these patients were also sampled during and after treatment. The experimental site had clinical indicators of disease (bleeding on probing, probing and attachment loss of > or = 6 mm) and the contralateral site (control) was clinically healthy. A total of 176 plaque samples were collected, divided, processed, and sent for both types of quantitative microbial analyses. All of these samples were used to compare the DNA probe and ELISA methods while only the initial 104 pretreatment sites were used to correlate microorganisms/method with clinical indicators of adult periodontitis. DNA probes were used to assay for A. actinomycetemcomitans, P. gingivalis, P. intermedia, E. corrodens, F. nucleatum, T. denticola, and C. rectus. An ELISA utilizing monoclonal antibodies was used to assay for P. gingivalis, E. corrodens, T. denticola, and C. rectus. Comparison of the two methods revealed that the ELISA test identified P. gingivalis and C. rectus significantly more often than the DNA probe method and that T. denticola was detected more frequently with the DNA probe. The sensitivities and specificities varied widely among organisms and by test. P. gingivalis, as identified by ELISA, had the highest degree of sensitivity and specificity (0.90 and 0.82 respectively) to clinical indicators of adult periodontitis.

Adult↗
PubMed1993

Early use of cisplatin is safe after partial hepatectomy.

Although cisplatin is widely used in the treatment of liver tumors, little information is available concerning its effect on liver regeneration. This report evaluates the effect of cisplatin on liver regeneration after hepatectomy (HPx). One hundred sixty male Sprague-Dawley rats were placed into five experimental groups following 70% hepatectomy. Group I (untreated controls, n = 32) received 0.9% saline intraperitoneally (IP); group II (n = 31), cisplatin 4 mg/kg IP; group III (n = 36), cisplatin 10 mg/kg IP; group IV (n = 34), cisplatin 20 mg/kg IP; and group V (n = 27), doxorubicin 6 mg/kg intravenously (IV). Five additional sham groups underwent celiotomy without hepatectomy (n = 106) followed by the above treatment protocols. Liver regeneration was evaluated by liver weight, DNA incorporation measured by tritiated thymidine (3H-TdR), and quantitative image analysis (QIA) of hepatic nuclei at 18, 24, 36, 48, and 72 hours, and 5 days postoperatively. 3H-TdR incorporation peaked at 36 hours and was similar in hepatectomized controls group I (404 +/- 110 counts per minute [CPM]/mg liver weight) and cisplatin-treated rats (groups II to IV) (P > .05, ANOVA). All sham groups were similar to controls. QIA of feulgen-stained touch preps identified polyploid, stem line, and proliferating nuclei in both controls and treated groups. At 36 hours, QIA showed differences in mitotic status of sham, control, and adriamycin-treated HPx rats, consistent with 3H-TdR incorporation. In contrast, although cisplatin-treated rats receiving 4 mg/kg showed proliferating nuclei, QIA demonstrated decreasing hepatocyte proliferation with higher doses of cisplatin (10 mg/kg, and 20 mg/kg).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

Memory template comparison processes in anhedonia and dysthymia.

Anhedonic subjects, potentially at risk for psychopathology because of a deficient ability to experience pleasure, have demonstrated a large N200 component in the event-related brain potential (ERP). The present experiment attempted to determine the psychological significance of this finding in light of Näätänen's (1990) distinction between N2a and N2b subcomponents. Anhedonics were contrasted with controls and dysthymics, an at-risk group reporting depression. Across groups, N2a was larger when a tone mismatched a longer run of preceding identical tones. Thus, an involuntary mismatch process appears to be intact in both at-risk groups. However, the three groups produced distinct N2bs as a function of stimulus sequence. The N2b finding for anhedonics is consistent with Knight's (1984, 1992) model of early stimulus processing deficits in schizophrenia.

Adolescent↗
PubMed1993

Depressive personality in nonclinical subjects.

OBJECTIVE: This study explored the reliability and clinical correlates of the depressive personality in nonclinical subjects. In particular, the authors were interested in determining the relationship between depressive personality and mood disorders. METHOD: The subjects were 185 college students who were selected by using a battery of screening inventories assessing a variety of psychopathological symptoms and traits. The subjects were given structured diagnostic interviews that included a section on depressive temperament. RESULTS: There were significant relationships between depressive personality and lifetime. DSM-III diagnoses of major depression and dysthymia. However, the magnitude of the associations was modest, indicating that these are distinct, although overlapping constructs. In addition, the subjects with depressive personality (N = 36) had significantly greater impairment and a higher rate of mood disorders in their first-degree relatives than did the subjects without depressive personality (N = 149). Moreover, these results were evident even after the subjects with a lifetime history of mood disorder were excluded. CONCLUSIONS: These data suggest that depressive personality is a clinically important condition that is not subsumed by existing mood disorders categories but can be viewed as falling within the affective spectrum.

Adolescent↗
PubMed1992

Potential of a recombinant antigen as a prophylactic vaccine for day-old broiler chickens against Eimeria acervulina and Eimeria tenella infections.

A genetically engineered Eimeria tenella antigen (GX3262), produced as a fusion protein with beta-galactosidase and identified with a monoclonal antibody, induced partial but significant protection in young broiler chickens against experimental E. tenella and Eimeria acervulina infections. The antigen appears to share a T-helper cell epitope with the parasite as evidenced by (a) booster inoculation with either the recombinant antigen or with a small number of live oocysts enhanced the protective immunity in GX3262 primed chickens, and (b) ability of the antigen to induce in vitro stimulation of T-cells from chickens immunized with antigen or parasite. These observations suggest the feasibility of a single vaccination of 1 or 2-day-old broilers with GX3262 to induce an acceptable degree of protective immunity. The implications of the observations reported here are far reaching in terms of a practical coccidiosis vaccine for poultry, and show for the first time that 1-day-old broiler chickens can be efficiently vaccinated with a recombinant antigen against one or more species of Eimeria.

Amino Acid Sequence↗
PubMed1992

Early stimulus processing in dysthymia and anhedonia.

Previous event-related brain potential (ERP) research has found that dysthymic subjects differ from control subjects during later stages of information processing. An important issue that emerges from this literature is whether differences found in these ERP components, typically associated with cognitive processing, can be attributed to earlier differences in basic perceptual processing. This study was undertaken to determine whether early processing deficits are apparent in dysthymic persons. Responses of dysthymics (n = 23) were compared with those of anhedonic (n = 15) and normal control (n = 17) subjects. ERPs were recorded while subjects heard tones at 55, 65, 75, 85, and 95 dB. Overall, N1-P1 and N1-P2 components of the ERP increased in a strong linear fashion as stimulus intensity increased. Dysthymics did exhibit a smaller N1-P2 response than normal subjects, which suggests the presence of difficulties in initial perceptual processing.

Adult↗
PubMed1992

Digital filtering: background and tutorial for psychophysiologists.

Digital filtering offers more to psychophysiologists than is commonly appreciated. An introduction is offered here to foster the explicit design and use of digital filters. Because of considerable confusion in the literature about terminology important to both analog and digital filtering, basic concepts are reviewed and clarified. Because some time series concepts are fundamental to digital filtering, these are also presented. Examples of filters commonly used in psychophysiology are given, and procedures are presented for the design and use of one type of digital filter. Properties of some types of digital filters are described, and the relative advantages of simple analog and digital filters are discussed.

Analog-Digital Conversion↗
PubMed1992

Treatment of acutely infected arthroplasties with incision, drainage, and local antibiotics delivered via an implantable pump.

Twelve patients with acutely (symptomatic less than ten weeks) infected arthroplasties were treated with minimal debridement and intraarticular antibiotic, amikacin, delivered via an implantable pump. The infection was suppressed in ten cases. Intraarticular levels of amikacin were obtained in eight cases. These levels ranged from greater than 150 micrograms/ml to 1688 micrograms/ml. The systemic level of amikacin remained below 10 micrograms/ml in all but one case. Duration of hospitalization averaged 19 days. There were no significant toxic side effects to amikacin.

Acute Disease↗
PubMed1991

Semantic networks of English.

Principles of lexical semantics developed in the course of building an on-line lexical database are discussed. The approach is relational rather than componential. The fundamental semantic relation is synonymy, which is required in order to define the lexicalized concepts that words can be used to express. Other semantic relations between these concepts are then described. No single set of semantic relations or organizational structure is adequate for the entire lexicon: nouns, adjectives, and verbs each have their own semantic relations and their own organization determined by the role they must play in the construction of linguistic messages.

Attention↗
PubMed1991

Primary carcinoid tumour of the ileum associated with massive gastrointestinal haemorrhage.

A case of massive gastrointestinal haemorrhage due to a 3 mm primary carcinoid tumour of the ileum is described. Previously described instances of this problem have been due to larger tumours. The site of the haemorrhage was suggested by a technetium-labelled RBC isotope scan. The lesion was visualized by 'on-table' endoscopy via the colon and ileo-caecal valve. The patient did well after segmental resection of the lesion. This case highlights the diagnosis and current approach to massive lower gastrointestinal haemorrhage.

Carcinoid Tumor↗
PubMed1991

HTLV-I-associated leukemia/lymphoma in south Florida.

We report here 10 cases of adult T-cell leukemia/lymphoma (ATL) seen in South Florida between February 1988 and July 1989. All were seropositive for human T-lymphotropic virus type I (HTLV-I) and seronegative for human immunodeficiency virus type 1 (HIV-1). DNA extracted from tumor biopsies/peripheral blood lymphocytes of nine patients was shown by the polymerase chain reaction (PCR) to contain HTLV-I proviral DNA. Blot hybridization of DNA extracted from seven patients with an HTLV-I cDNA probe revealed a monoclonal pattern of proviral integration consistent with a diagnosis of ATL. Eight of the 10 patients were women. Six patients were from Haiti, three from Jamaica, and one from the Bahamas. All patients had very aggressive non-Hodgkin's lymphoma. Two patients presented with sinus and retro-orbital involvement; another had gastric lymphoma that perforated. Nine patients developed hypercalcemia. Eight patients died within 1 year of diagnosis. Two were lost to follow-up. During the course of this study, 66 new cases of non-Hodgkin's lymphoma were diagnosed at this hospital. Ten of these cases were ATL. The prevalence of HTLV-I-related lymphoma in this sample was 15%. Since tissue from all patients was not available for HTLV-I screening, however, it is possible that other cases of ATL went undetected. We conclude from this initial survey that a retroviral etiology should be considered in patients from populations known to be at risk for HTLV-I infection who present with non-Hodgkin's lymphoma.

Adult↗
PubMed1991

Accuracy of cultures of material from swabbing of the superficial aspect of the wound and needle biopsy in the preoperative assessment of osteomyelitis.

The pathogens that were identified on cultures of material obtained by swabbing of the superficial aspect of the wound and needle biopsy were compared with those that were isolated from material that was obtained at débridement from sixty patients who had post-traumatic or postoperative osteomyelitis. The cultures of material that was obtained by superficial swabbing of the wound and needle biopsy were inadequate for prediction of the presence of aerobic organisms. Moreover, the failure to isolate anaerobes from the material obtained by needle biopsy did not rule out the presence of anaerobic organisms. Therefore, tissue for culture of aerobic and anaerobic organisms must be obtained during operative débridement in order to identify all pathogenic organisms. Fungi were isolated from the material obtained by biopsy in two patients. In addition, histological examination of the tissue obtained at biopsy led to the diagnosis of epidermoid carcinoma in two patients in whom this diagnosis had not been suspected before biopsy. Cultures were negative for mycobacteria in all patients. An additional ten patients who had a tibial non-union and latent osteomyelitis were studied. In nine of them, cultures of material obtained by needle biopsy showed no growth. Six of these nine patients had an exacerbation of the osteomyelitis after intramedullary nailing for the non-union. Therefore, the absence of growth of organisms from tissue obtained at needle biopsy does not rule out the possibility that osteomyelitis may be reactivated after intramedullary nailing with reaming.

Bacteria↗
PubMed1991

Comparison of indium-111 nonspecific polyclonal IgG with indium-111-leukocytes in a canine osteomyelitis model.

Osteomyelitis was surgically produced in the proximal tibia of ten dogs. A sham operation was performed on the other tibia. Early (3 hr) and late (20 hr) imaging was performed 1, 4, 7, 10, and 13 wk later, while the osteomyelitis progressed from acute to chronic. Indium-111-IgG had a significantly greater accumulation at the osteomyelitis site than 111In-leukocytes, both during early (p = 0.001) and late (p = 0.03) imaging, and at each of the weeks studied (p less than 0.001). During early imaging, both agents gave equivalent lesion to background ratios. On the late images, the 111In-leukocytes gave significantly higher lesion-to-background ratios than 111In-IgG (p less than 0.001) and higher ratios than they did during the early images (p less than 0.001). Both agents had greater accumulation in acute osteomyelitis than in chronic osteomyelitis (p less than 0.02). Osteomyelitis in the surgical site can be distinguished from the uptake in the sham surgery site using 111In-leukocytes, but not when using 111In-IgG.

Animals↗
PubMed1990

The clinical features, management and outcome of persistence of the arterial duct presenting in adult life.

We have reviewed the 25 patients who, between 1973 and 1988, presented to the Brompton Hospital in adulthood with persistence of the arterial duct (ductus arteriosus). As pulmonary arteriolar resistance is the main determinant of management and prognosis in this condition, the patients were divided into groups with either normal or mild elevation of resistance (less than 10 units/m2: 19 patients) or with severe elevation (greater than 10 units/m2: 6 patients). Patients with normal pressures or mild elevation tended to be older (mean age 45 years). Many (70%) were asymptomatic, but dyspnoea with signs of left heart failure was the commonest presenting complaint. Surgical closure of the duct was performed in 16 with good result in all. Survival for the entire group, however, was long. There was a symptomatic indication for surgery (due to hyperdynamic circulation) in 5. In those with severely elevated pulmonary arteriolar resistance, the mean age of presentation was 31 years and the survival short. The commonest presenting symptom was dyspnoea. Surgical closure of the duct was attempted in two patients but with a poor outcome in both. All patients with an elevated resistance had developed this complication by the third decade of life. Significant elevation was not a feature of older patients, suggesting that, in this age group, the risk of elevation is slight. Surgery, nonetheless, may be indicated for relief of symptoms due to a large systemic to pulmonary shunt.

Adult↗
PubMed1990

Clinical correlates of angiographically diagnosed idiopathic pulmonary hypertension.

During 1970-87 43 patients with unexplained pulmonary hypertension (mean pulmonary arterial pressure greater than 25 mm Hg) were admitted to the Brompton Hospital and classified by angiographic criteria as having either symmetrical peripheral pulmonary artery pruning (thought to represent primary plexogenic pulmonary arteriopathy), n = 21, or asymmetrical pulmonary arterial occlusions (thought to represent chronic thromboembolic disease), n = 22. Patients with symmetrical pulmonary arteriopathy had significantly higher mean pulmonary arterial pressures (67 mm Hg) at the time of presentation than those with asymmetrical pulmonary arteriopathy (49 mm Hg). Clinical distinction between these two groups was impossible. Survival from the time of diagnosis was similarly poor in the two groups (26 weeks and 38 weeks) and did not correlate with any of the haemodynamic measurements. The difficulties in making distinctions between these conditions are discussed.

Adolescent↗
PubMed1990

Symptomatic os supra naviculare. A case report.

Accessory bones are common anomalies in the foot. They often may become symptomatic. The authors present such a case in which the patient was successfully treated by surgical incision of the accessory ossicle.

Adult↗