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Biomedical subjects

G Alexander

Publications and source records attributed to G Alexander.

At least 55 records · Page 3Linked to original sources
PubMed1998

Perinatal mortality and its relationship to the reporting of low-birthweight infants.

OBJECTIVES: This study examined changes in the reporting of very low-birthweight infants in Alabama from 1974 to 1994 and the impact on perinatal mortality rates. METHODS: Linked live birth, neonatal death, and stillbirth records of infants born weighing less than 1500 g were compared. RESULTS: The changes in mortality over time ranged from a drop from 100% to 92% in the under-500-g group to a drop from 39% to 4% in the 1000-to 1499-g group. The percentage of total births weighing less than 500 g increased by 155%; the percentage of 1000- to 1499-g births increased by only 7%. As a result, the percentage of neonatal mortality attributable to live births below 500 g increased from 3% to 32%. CONCLUSIONS: Increased reporting of births below 500 g has masked improvements in neonatal mortality.

Alabama↗
PubMed1997

Comparison of warfarin use in total knee replacement vs total hip replacement.

The purpose of this retrospective study was to determine the efficacy of warfarin prophylaxis against deep vein thrombosis (DVT) in total hip arthroplasty (THA) vs total knee arthroplasty (TKA). A review of venograms in 223 patients with THA and in 189 cases of TKA was carried out. The overall DVT rate in THA was 22%. The overall DVT rate in TKA was 46%. We conclude that combined or alternate methods need to be used to decrease the rate of DVT following TKA to that of THA.

Aged↗
PubMed1996

Early increase in plasma parathyroid hormone levels following liver transplantation.

BACKGROUND/AIMS: The pathogenesis of post-transplantation bone loss is poorly understood, although glucocorticoid therapy is believed to play an important role. In the present study we have measured plasma parathyroid hormone concentrations in the first few months after orthotopic liver transplantation, in order to examine the potential contribution of hyperparathyroidism to bone disease. PATIENTS AND METHODS: Twenty-seven patients aged 32-54 years, 12 male, undergoing liver transplantation were studied prospectively before and for 3 months after operation. Plasma parathyroid hormone and serum 25-hydroxyvitamin D concentrations were measured by radioimmunoassay. RESULTS: Plasma parathyroid hormone levels were normal in all but two patients prior to transplantation. There was a highly significant increase in plasma parathyroid hormone concentrations at 1 and 2 months (p < 0.0005 and 0.001, respectively, versus baseline); by 3 months, values were close to those obtained preoperatively. Serum 25-hydroxyvitamin D concentrations showed no significant change over the study period. However, 74% of the patients had subnormal values at baseline. CONCLUSIONS: An early and transient increase in plasma parathyroid hormone after liver transplantation may be responsible for the high rates of bone loss which occur during the first few post-operative months. Prevention of post-transplantation bone disease is most likely to be achieved by peri-operative intervention with an anti-resorptive agent.

Adult↗
PubMed1996

Testosterone replacement therapy improves mood in hypogonadal men--a clinical research center study.

The effect of testosterone (T) replacement on changes in mood was studied for 60 days in 51 hypogonadal men. All patients were withdrawn from their prior T replacement for at least 6 weeks before enrollment. Of these patients, 18 received T enanthate 200 mg im every 20 days, 16 received sublingual T cyclodextrin (SLT) at a dose of 2.5 mg three times daily, and 17 received SLT at a dose of 5.0 mg three times daily. The total treatment period was 60 days. The patients were asked to respond to a questionnaire on 7 consecutive days before the start of treatment and on 7 consecutive days before their visits to the clinic on days 21, 41, and 60 of treatment. The following mood parameters were assessed using a 7-point Likert rating scale: angry, alert, irritable, full of pep (energy), sad/blue, tired, friendly, nervous, and well/good. When compared with the baseline period, T replacement led to significant decreases in anger (P = 0.0045), irritability (P = 0.0009), sadness (P = 0.0033), tiredness (P = 0.0035), and nervousness (P = 0.0291), and significant improvement in energy level (P = 0.0020), friendliness (P = 0.0072), and sense of well-being (P = 0.024) in all subjects as a group. Analyses of the area under the curve (AUC) of baseline serum T levels before T replacement showed significant positive correlations between serum T (AUC) and friendliness (r = 0.29, P < 0.05) and sense of well-being (r = 0.27, P < 0.05), and significant negative correlations with nervousness (r = -0.27, P < 0.05), irritability (r = -0.29, P < 0.05) and tiredness (r = -0.28, P < 0.05). Similar correlations were found between serum dihydrotestosterone (DHT) and some of the mood parameters. After T replacement in the hypogonadal men, these correlations between AUC of serum T levels and the positive and negative mood scores disappeared. These results were corroborated in a subsequent study in which 30 hypogonadal men were supplemented with SLT 5 mg three times daily for 6 months. The patients were less nervous (P = 0.0025) and more alert (P = 0.0004), friendly (P = 0.042), and energetic (P = 0.0001) during the 6-month treatment period compared with baseline. We conclude that T replacement therapy in hypogonadal men improved their positive mood parameters, such as energy, well/good feelings, and friendliness and decreased negative mood parameters including anger, nervousness, and irritability, and direct correlations between serum T and DHT with mood scores were only observed in the baseline period when serum androgen levels were below the normal range. The latter observation suggests that once a minimally adequate serum T/DHT level was achieved by T replacement therapy, further increases in serum T/DHT levels did not further contribute to the improvement in mood variables.

Administration, Sublingual↗
PubMed1996

Sublingual testosterone replacement improves muscle mass and strength, decreases bone resorption, and increases bone formation markers in hypogonadal men--a clinical research center study.

To study the effects of androgen replacement therapy on muscle mass and strength and bone turnover markers in hypogonadal men, we administered sublingual testosterone (T) cyclodextrin (SLT; 5 mg, three times daily) to 67 hypogonadal men (baseline serum T, < 8.4 nmol/L) recruited from 4 centers in the U.S.: Torrance (n = 34), Durham (n = 12), New York (n = 9), and Salem (n = 12). Subjects who had received prior T therapy were withdrawn from injections for at least 6 weeks and from oral therapy for 4 weeks. Body composition, muscle strength, and serum and urinary bone turnover markers were measured before and after 6 months of SLT. We have shown previously that this regimen for 60 days will maintain adequate serum T levels and restore sexual function. Total body (P = 0.0104) and lean body mass (P = 0.007) increased with SLT treatment in the 34 subjects in whom body composition was assessed. There was no significant change in total body fat or percent fat. The increase in lean body mass was mainly in the legs; the right leg lean mass increased from 8.9 +/- 0.3 kg at 0 months to 9.2 +/- 0.3 kg at 6 months (P = 0.0008). This increase in leg lean mass was associated with increased leg muscle strength, assessed by leg press (0 months, 139.0 +/- 4.0 kg; 6 months, 147.7 +/- 4.2 kg; P = 0.0038). SLT replacement in hypogonadal men led to small, but significant, decreases in serum Ca (P = 0.0029) and the urinary calcium/creatinine ratio (P = 0.0066), which were associated with increases in serum PTH (P = 0.0001). At baseline, the urinary type I collagen-cross linked N-telopeptides/creatinine ratio [75.6 +/- 7.9 nmol bone collagen equivalents (BCE/mmol] was twice the normal adult male mean (41.0 +/- 3.6 nmol BCE/mmol) and was significantly decreased in response to SLT treatment at 6 months (68.2 +/- 7.7 nmol BCE/mmol; P = 0.0304) without significant changes in urinary creatinine. Serum skeletal alkaline phosphatase did not change. In addition, SLT replacement caused significant increases in serum osteocalcin (P = 0.0001) and type I procollagen (P = 0.0012). Bone mineral density did not change during the 6 months of SLT treatment. We conclude that SLT replacement therapy resulted in increases in lean muscle mass and muscle strength. Like estrogen replacement in hypogonadal postmenopausal females, androgen replacement therapy led to decreased bone resorption and urinary calcium excretion. Moreover, androgen replacement therapy may have the additional benefit of increasing bone formation. A longer term study for several years duration would be necessary to demonstrate whether these changes in bone turnover marker levels will result in increased bone mineral density decreased fracture risks, and reduced frailty in hypogonadal men.

Administration, Sublingual↗
PubMed1996

Heart-lung-liver transplantation.

We report three patients with cystic fibrosis and one patient with primary biliary cirrhosis and plexogenic pulmonary hypertension who have undergone heart-lung-liver transplantation as a combined procedure. Liver transplantation was necessary in the three patients with cystic fibrosis because of portal hypertension secondary to either hepatic fibrosis or established cirrhosis in addition to their advanced lung disease. Three of the four patients were alive at 20, 50, and 100 months after transplantation (one patient with cystic fibrosis died on day 16 of pneumonia) with well-preserved pulmonary function (forced expiratory volume in 1 second 110%, 49%, and 100% predicted, respectively), normal hepatic function and New York Heart Association class 1 performance status. Heart-lung and concurrent liver transplantation is a feasible and successful procedure with a satisfactory long-term outcome in selected patients with advanced pulmonary and hepatic disease.

Adult↗
PubMed1995

Patient decision-making in relation to extensive restorative dental treatment. Part II: Evaluation of a patient decision-making model.

A theoretical model was proposed and tested to evaluate some of the factors involved in patients' decisions to undergo extensive restorative dental treatment. This model incorporates aspects of the environment within which the decision occurred (the patient/provider relationship, social influence and the role of cues in initiating treatment) and internal values held by the individual (perceptions of value of and barriers to treatment). Value of treatment was measured using aesthetics, function, health motivation and self-esteem. Barriers to treatment included fears and anxieties about treatment, the costs of treatment, the time involved in obtaining treatment and access to care. Data were collected by mailed questionnaire from 188 patients at a North American state university dental school who had received over $1,500 of restorative dental treatment during 1990/91. Data were analysed using path analysis multiple regression. The most important determinant in the decision to undergo treatment was patient/provider relationship. As expected, barriers exerted an inverse effect upon the outcome and had twice the influence compared with the patients' perceived value of treatment. Cues and social influence were not shown to play a significant role in initiating restorative dental treatment.

Adult↗
PubMed1995

Patient decision-making in relation to extensive restorative dental treatment. Part I: Characteristics of patients.

This paper presents descriptive and demographic data gathered in response to a mailed questionnaire of 188 patients at the University of Michigan School of Dentistry who had incurred costs of at least $1500 on restorative dental treatment between January 1990 and december 1991. The development and testing of the behavioural model used is described in part II. Descriptive information included primary reason for treatment, cues to treatment, previous attendance, aspects of the patient/practitioner relationship, treatment costs, satisfaction with appearance and insurance coverage.

Adult↗
PubMed1995

Use of type III venous flaps: single- and multistaged procedures.

Two cases are presented in which the principles of type III (arteriovenous) venous flaps were applied in single- and multistage procedures. In the first case, the flap was used for correction of a post-thermal burn adduction contracture of the first web space of the hand as a one-stage microvascular free flap and in the other for the resurfacing of a post-traumatic defect on the dorsum of the foot as a two-stage transfer. A brief review, along with the technique, advantages, mode of survival, and feasibility of using type III venous flaps, is presented. A simple classification of type III venous flaps is also suggested.

Adult↗
PubMed1995

Localization of met-enkephalin and vasoactive intestinal polypeptide in the brains of male zebra finches.

An interconnected series of brain nuclei controls song learning and behavior in male zebra finches (Poephila guttata). This study examined the distribution of fibers, terminals, and somata immunoreactive for two neuropeptides, methionine-enkephalin (ENK) and vasoactive intestinal polypeptide (VIP), in song-control nuclei of adult males. In addition, the broad pattern of major regions of labeling throughout the forebrain and midbrain was determined. The telencephalic song-control nuclei MAN (magnocellular nucleus of the anterior neostriatum), Area X of the striatum, HVC (higher vocal center), and RA (robust nucleus of the archistriatum) contained abundant ENK immunoreactivity, including labeled fibers and somata. In addition, intensely labeled fibers and terminals were seen in the thalamic nucleus DLM (medial portion of the dorsolateral nucleus of the anterior thalamus). High levels of VIP immunoreactivity were also seen in MAN, HVC, and RA, but this label consisted of fiber and terminals only. Area X and surrounding striatum contained extremely sparsely distributed VIP-labeled processes. Somata positive for VIP were not seen throughout cortical regions such as the neostriatum and hyperstriatum but were abundant in the lateral striatum (paleostriatum augmentatum, PA) and may contribute to a dense field of terminal labeling seen in the globus pallidus. The apparent presence of a robust VIP-positive striato-pallidal projection is not typical of major basal ganglia pathways in vertebrates, raising the possibility that passerine birds have diverged from the typical amniote pattern.

Animals↗
PubMed1995

Elevated exhaled nitric oxide in patients with hepatopulmonary syndrome.

The hypoxaemia of hepatopulmonary syndrome, seen in severe chronic liver dysfunction, occurs as a result of precapillary pulmonary arterial dilatation and arteriovenous communications. These abnormalities contribute to the mismatch between ventilation and perfusion, and the right to left blood flow shunting. Nitric oxide (NO) is a powerful vasodilator concerned with the regulation of pulmonary vascular tone in man. Using a chemiluminescence analyser, we have measured endogenously produced NO in the exhaled air of three patients with the hepatopulmonary syndrome, six normoxaemic cirrhotic patients and six healthy volunteers. The subjects breathed NO-free air throughout the measurements. The molar rate of production of exhaled NO was raised almost threefold in the patients with hepatopulmonary syndrome compared with normal volunteers and with normoxaemic cirrhotic patients. Hypoxia per se, achieved in the normal volunteers by breathing a hypoxic gas mixture, reduced rather than increased the exhaled NO. One hepatopulmonary syndrome patient received an orthotopic liver transplant and achieved normoxaemia after 3 months. The exhaled NO also returned to normal. Increased pulmonary production of NO could contribute to the development of the hepatopulmonary syndrome.

Blood Gas Analysis↗
PubMed1995

Pharmacokinetics, bioefficacy, and safety of sublingual testosterone cyclodextrin in hypogonadal men: comparison to testosterone enanthate--a clinical research center study.

We studied and compared the pharmacokinetics and bioefficacy of two doses of sublingual testosterone cyclodextrin (SLT; 2.5 and 5.0 mg, administered three times per day) with testosterone enanthate (TE; 200 mg) given once every 20 days by im injections over a 60-day study period in 63 hypogonadal men. After SLT administration, serum testosterone (T) levels peaked at 20 min and then fell, reaching baseline levels by 360 min. The calculated half-lives were 60.3 +/- 7.5 and 68.8 +/- 5.0 min after a single dose of 2.5 and 5.0 mg SLT, respectively. The mean area under curve (AUC) of serum T was computed over 20-day periods for the 3 treatment groups. The mean net AUC of serum T after TE administration was about 4- and 2-fold higher than that in the 2.5 and 5 mg groups over the last 20 days. Serum estradiol and dihydrotestosterone followed the same pattern as serum T. Serum estradiol to T ratios decreased after T replacement in all 3 groups, whereas serum dihydrotestosterone to T ratios were not significantly changed by T treatment. Suppression of serum LH and FSH levels was more marked in the patients treated with TE than in those given SLT. Similarly, serum sex hormone-binding globulin levels showed significant decreases with androgen replacement only in the TE and SLT 5.0 mg range groups. There were no significant adverse effects based on comprehensive physical examinations, urea, electrolytes, and renal or liver function tests. Hematocrit levels increased in the TE-treated group, but remained slightly lower than baseline levels in the SLT groups. Serum high density lipoprotein cholesterol showed a small, but significant, decrease with time of treatment in all groups. Despite the differences in the AUC of serum T levels achieved by different androgen replacement therapies, all patients showed significant improvements in sexual motivation and performance, with no significant difference between the treatment groups. We conclude that SLT may be a useful addition to the currently available injectable and transdermal delivery systems for treatment of hypogonadal men. Because of the ease of administration, rapid reversibility of effects, and lower AUC of serum T levels achieved compared to those of TE injections, SLT may be especially suitable for treatment of boys with delayed puberty and older men with androgen deficiency.

Administration, Sublingual↗
PubMed1995

Coancestry in apparently sporadic primary pulmonary hypertension.

OBJECTIVE: To examine sporadic cases of primary pulmonary hypertension of coancestry. DESIGN: An epidemiologic study of families of patients with primary pulmonary hypertension. SETTING: A university-affiliated referral population. PARTICIPANTS: Family members of 13 patients with primary pulmonary hypertension. MEASUREMENTS: Family pedigrees involving grandparents, parents, siblings, and children were supplemented by genealogic records. Coefficients of kinship (Ck) were calculated for the patients with primary pulmonary hypertension who demonstrated coancestry and compared with 500 sets of controls drawn at random from genealogic records. RESULTS: Two patients with sporadic primary pulmonary hypertension demonstrated coancestry. The great-great grandfather and great-great grandmother of one patient were the great-grandfather and great-grandmother of the other patient. No other cases of primary pulmonary hypertension were identified in these two families. The CK of the affected individuals (CK = 10.02 x 10(-5)) suggests strongly that the observed relationship did not occur by chance alone. Among 500 random sets of matched controls, only two sets yielded CK of 10.02 x 10(-5) or greater (p = 0.004). Coancestry could not be identified for the other five families of patients with sporadic primary pulmonary hypertension for whom genealogic records were available. CONCLUSIONS: The finding of coancestry in patients with sporadic primary pulmonary hypertension suggests that a genetic basis exists for some patients with apparently sporadic primary pulmonary hypertension. Familial primary pulmonary hypertension may be more common than previously recognized.

Adult↗
PubMed1995

Education and audit can improve the identification of excessive drinkers among medical inpatients.

This study investigated the effect of education and audit on the identification and management of medical inpatients with excessive alcohol consumptions by use of a cross-sectional survey of medical and nursing notes, compared with historical controls. We report the proportion of medical and nursing notes containing qualitative and quantitative drinking histories, the use of the CAGE questionnaire, and notification of alcohol consumption in discharge summaries. A total of 1,979 out of 2,680 (74%) notes of eligible patients were examined. The number of medical notes containing quantitative alcohol histories rose from 175/792 (22%) among historical controls, to 242/690 (35%) after training of junior medical and nursing staff, and to 241/497 (48%) after feedback of results in a clinical audit meeting. The number of medical notes with no recorded alcohol history changed from 309/792 (39%) to 287/690 (42%) to 152/497 (31%), respectively (chi 2 for trend = 97.2, p < 0.0001). The number of nursing notes containing quantified alcohol histories rose from 31/792 (4%) among historical controls, to 123/690 (18%) after training, and to 237/497 (48%) after feedback of results in a clinical audit meeting. The number of nursing notes with no recorded alcohol history fell from 309/792 (90%), to 512/690 (74%), to 205/497 (41%) respectively (chi 2 for trend = 353.7, p < 0.0001). The proportion of patients found to be drinking excessively rose from 40/792 (5.1%) to 57/690 (8.3%) to 45/497 (9.1%) (chi 2 for trend = 8.25, p = 0.004). There was little worthwhile improvement in use of the CAGE questionnaire and in discharge summaries. Education and audit are effective ways of improving the identification of excessive drinkers by both junior doctors and nurses alike. Other aspects of management are less responsive.

Alcoholism↗
PubMed1994

Assessing positive and negative symptoms in children and adolescents.

OBJECTIVE: The purpose of this study was to test the reliability and validity of a new assessment instrument for positive and negative symptoms in severely disturbed children and adolescents (Kiddie-PANSS). METHOD: The Positive and Negative Syndrome Scale for adult schizophrenia was modified through successive field trials on the basis of developmental characteristics of children and adolescents. The scale was then given to 34 inpatients (19 children, mean age = 9.35 years, and 15 adolescents, mean age = 14.33 years) with DSM-III-R diagnoses of schizophrenia, psychosis not otherwise specified, schizoaffective, affective, conduct, personality, and developmental disorders determined independently by child psychiatrists. All patients with schizophrenia were placed in the schizophrenic group, and all others were placed in a general inpatient group. The Kiddie-PANSS ratings were given by three trained child psychiatrists after a 30-35-minute structured interview. The Achenbach Child Behavior Checklist, the Scale for the Assessment of Positive Symptoms, and the Scale for the Assessment of Negative Symptoms were also administered in order to determine criterion-related association. RESULTS: Intraclass correlation coefficients revealed that all subscales and total psychopathology were reliably assessed among raters. The Kiddie-PANSS and Scale for the Assessment of Positive Symptoms/Scale for the Assessment of Negative Symptoms correlated with one another, indicating criterion-related association. Differences on measures of positive, negative, and general psychopathology, as measured by the Kiddie-PANSS, between the patients with schizophrenia and the general inpatient group were highly significant. CONCLUSIONS: The Kiddie-PANSS shows good interrater reliability and criterion-related validity. In a cohort of inpatient children and adolescents the scale successfully differentiated schizophrenic patients from nonschizophrenic patients.

Adolescent↗