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Biomedical subjects

J Hennessey

Publications and source records attributed to J Hennessey.

11 recordsLinked to original sources
PubMed1992

Dibucaine elicits platelet procoagulant activity in factor VIII and factor X activation by a mechanism involving a sulfhydryl-dependent enzyme.

Dibucaine, a potent inhibitor of platelet aggregation and platelet release, was found to enhance the ability of fresh gel-filtered or washed human platelets to support factor VIII activation and factor X activation. Dibucaine-treated platelets increased the peak of factor VIII clotting activity by 2-fold compared to activity with untreated platelets. Similarly platelets optimally stimulated by dibucaine (1.0-1.5 mM for 5 min at 37 degrees C) supported as much factor X activation by factors IXa and VIII (measured in a chromogenic assay) as platelets optimally stimulated by ionophore A23187 (15 microM). An assay of platelet calcium-dependent sulfhydryl proteases was devised and used to test the effect of various inhibitors on these platelet proteases. The membrane-permeable sulfhydryl inhibitor Thiolyte MB inhibited platelet calcium-dependent protease activity; whereas, membrane-impermeable Thiolyte MQ did not. Thiolyte MB also blocked the ability of dibucaine-stimulated platelets to support factor X activation. Incubation of fresh, gel-filtered platelets with calpain inhibitor II (N-Ac-L-L-Normethioninal) completely inhibited the calcium-dependent sulfhydryl protease activity of these platelets but did not affect their ability to support factor X activation after subsequent incubation with dibucaine. These data support the interpretation that an intracellular SH-dependent enzyme, which may not be calpain, is involved in the expression of platelet procoagulant activity in dibucaine-treated platelets.

Bridged Bicyclo Compounds↗
PubMed1992

Evaluation of a microcarrier process for large-scale cultivation of attenuated hepatitis A.

Microcarrier culture was investigated for the propagation of attenuated hepatitis A vaccine in the anchorage-dependent human fibroblast cell line, MRC-5. Cells were cultivated at 37 degrees C for one to two weeks, while virus accumulation was performed at 32 degrees C over 21 to 28 days. The major development focus for the microcarrier process was the difference between the cell and virus growth phases. Virus antigen yields, growth kinetics, and cell layer/bead morphology were each examined and compared for both the microcarrier and stationary T-flask cultures. Overall, cell densities of 4-5 x 10(6) cells/ml at 5-10 milligrams beads were readily attained and could be maintained in the absence of infection at either 37 degrees C or 32 degrees C. Upon virus inoculation, however, substantial cell density decreases were observed as well as 2.5 to 10-fold lower per cell and per unit surface area antigen yields as compared to stationary cultures. The advantages as well as the problems presented by the microcarrier approach will be discussed.

Antigens, Viral↗
PubMed1991

The predictive value of idiopathic failure to fertilize on the first in vitro fertilization attempt.

OBJECTIVE: To investigate the subsequent performance of patients with idiopathic fertilization failure on the first in vitro fertilization (IVF) cycle. DESIGN: A retrospective study of 2,322 consecutive patients undergoing their initial IVF cycle. SETTING: Advanced infertility treatment in an IVF/general infertility clinic. PATIENTS: In 5 years, 94 couples with unexplained failed oocyte fertilization had 270 cycles of treatment. Each couple's performance was tracked through subsequent cycles of treatment. INTERVENTIONS: In vitro fertilization with husband and donor sperm. MAIN OUTCOME MEASURE(S): Investigated retrospectively after 5 years of data collection. RESULTS: Sixty-five couples of the original 94 had a second IVF attempt. Fifty of these successfully fertilized oocytes with husband's sperm and 4 with donor sperm. Nineteen of the 65 couples who continued treatment achieved a pregnancy, and only one couple had continuing fertilization failure. CONCLUSIONS: The prognosis in the study group was surprisingly favorable despite the initial failed IVF treatment cycle.

Adult↗
PubMed1990

Multiple-sited (heterotopic) pregnancy after in vitro fertilization and gamete intrafallopian transfer.

Pregnancies occurring simultaneously in different body sites (heterotopic pregnancies) are a rare condition thought to occur in 1 of 30,000 spontaneous pregnancies. Individual cases may occur after in vitro fertilization (IVF) or gamete intrafallopian transfer (GIFT). In the past 4 1/2 years, our unit has performed 6,204 IVF/GIFT or pronuclear stage transfer cycles of treatment. Ten such pregnancies proven by surgical, ultrasound, and histological diagnosis have occurred. In the same period 640 IVF, 355 GIFT, and 6 pronuclear stage transfer clinical pregnancies were achieved. This suggests that the incidence of heterotopic pregnancy after assisted reproduction is closer to 1 of 100 pregnancies. Clinicians managing early complications of IVF, GIFT, and/or pronuclear stage transfer pregnancies should be aware of this relatively high incidence of concomitant intrauterine and extrauterine pregnancy.

Female↗
PubMed1989

The use of polyelectrolyte-fractionated porcine factor VIII in the treatment of a spontaneously acquired inhibitor to factor VIII.

Polyelectrolyte-fractionated porcine factor VIII concentrate is a recent addition to the therapeutic choices for treatment of factor VIII inhibitor patients, but cross-reactivity of the inhibitor with porcine factor VIII limits its usefulness in some cases. Hemophilic patients with inhibitor titers greater than or equal to 50 Bethesda units/micromilligrams often demonstrate sufficient cross-reactivity (10-20%) to prevent the achievement of a satisfactory plasma factor VIII level and a therapeutic response with porcine factor VIII. We have studied plasma from five women with high-titer, spontaneously acquired factor VIII inhibitors to determine the degree of cross-reactivity with porcine factor VIII. Four of the five had little or no detectable inhibitor to porcine factor VIII despite high titers to human factor VIII (26-143 Bethesda units/micromilligrams). One of these patients, with a titer of 53 Bethesda units/micromilligrams against human factor VIII, was treated successfully with porcine factor VIII concentrate, given for serious hemorrhagic complications. These studies and other reports support the conclusion that the majority of high-titer spontaneous factor VIII inhibitors exhibit little cross-reactivity with porcine factor VIII and can be treated successfully with this product.

Adult↗
PubMed1989

The pediatric intensive care unit environment as a source of stress for parents.

Parents of children hospitalized in one of five midwestern pediatric intensive care units (ICU) were interviewed about the stress experienced from aspects of the ICU environment. Subjects were 324 mothers and 186 fathers of 350 children. Data were collected using the Parental Stressor Scale: Pediatric ICU which assesses seven dimensions of the environment: Child's Behavior and Emotions, Child's Appearance, Sights and Sounds, Procedures, Staff Communication, Anomie, and Parental Role Alteration. The dimensions Child's Behavior and Emotions and Parental Role Alteration were found to be the most stressful aspects of the experience. The items from the dimension Child's Behavior and Emotions that were most stressful were seeing my child in pain, seeing the child frightened and sad, and the inability of the child to communicate with the parent. The items from the Parental Role Alteration dimension with the highest stress scores were: feeling unable to protect my child and not knowing how to best help my child. Findings suggest that alterations in the parent-child relationship are more stressful than aspects of the physical environment. In particular, feeling helpless in the parenting role is a great source of stress for parents.

Adaptation, Psychological↗
PubMed1989

Testing a theoretical model: correlates of parental stress responses in the pediatric intensive care unit.

This study was designed to evaluate a theoretical framework, based on stress theory, which identifies potential sources of stress in parents of children hospitalized in an intensive care unit (ICU). The framework suggests that personal, situational, and ICU environmental stress stimuli interactively impact on the overall parental stress response. Multiple regression techniques were used to evaluate the interaction of personal family factors, situational stimuli, and ICU environmental stressors and to assess their impact upon the overall parental stress response. Data were collected from 510 parents of children hospitalized in one of five midwestern ICUs. Instruments used were the Parental Stressor Scale: Pediatric ICU (Carter & Miles, 1984), the State-Trait Anxiety Scale (Spielberger, Gorsuch, & Luschene, 1970), the Review of Life Experiences Scale (Hurst, Jenkins, & Rose, 1978), and a personal-experiential questionnaire. Results indicate that a number of personal and situational variables were predictive of higher stress. In addition two aspects of the ICU environment contributed the most variance to the overall stress of parents: alterations in the parental role and the child's behavioral and emotional responses. In evaluating the full framework, one personal variable (Trait Anxiety); two situational variables (perception of severity and type of admission); and three ICU environmental dimensions, (parental role alteration, the child's behavior and emotional response, and the child's appearance) significantly predicted stress (State Anxiety). The findings support the theoretical framework underlying this study as a useful model for studying and evaluating parental stress during a child's admission to an ICU. Results also suggest that additional personal family and situational factors, such as uncertainty, may need to be added to the model to more fully predict parental stress responses.

Adolescent↗
PubMed1978

Estrogen excretion patterns in induced ovulation.

Observation of response to gonadotropins in the treatment of anovulation has allowed us to define the estrogen excretion pattern which leads to a successful single pregnancy. The typical pattern shows a low pretreatment urinary total estrogen excretion; treatment with gonadotropins, of human pituitary origin, is continued for about 14 days. There is a predictable rate of rise of preovulatory estrogen excretion (30 microgram/24 hr2). Human choronic gonadotropin--about 4000 IU--should be given when an estrogen excretion of 75-100 microgram/24 hr has been obtained. The use of this pattern of ovarian response is put forward as a useful guide in the planning of gonadotropin therapy.

Anovulation↗
PubMedDate not supplied

Seminal plasma biochemistry. I. Preliminary report: a possible mechanism for the liquefaction of human seminal plasma and its relationship to spermatozoal motility.

Based on indirect evidence it has been suggested that the liquefaction of human seminal plasma involves fibrinolytic and proteolytic enzymes and that the coagulum is formed by proteins. In this preliminary investigation evidence is presented for the involvement of seminal plasma sialyltransferase in liquefaction which suggests that the coagulum may be composed of glycoproteins. It is proposed that the glycoproteins form a polymer by the chelation of divalent metal ions via the carboxylic acid moieties of the sialic acid groups of the glycoproteins. The glycoprotein polymer may then be dismantled by the reduction of the meal ions by the oxidation of L-ascorbic acid, possibly allowing enzymes to complete the liquefaction process. A total of 100 semen samples from 30 male subjects whose semen profiles were considered "normal" by an independent assessor, were examined for the following: (i) liquefaction time of the seminal plasma; (ii) seminal plasma sialyltransferase activity; (iii) spermatozoal motility, defined as directional or nondirectional; (iv) spermatozoal count, and (v) seminal plasma content of free L-ascorbic acid, dehydroascorbic acid and glutathione. Linear regression analysis showed a significant correlation between sialyltransferase activity and the liquefaction time for seminal plasma. Similarly, multilinear regression analysis of the data showed that as the seminal plasma levels of L-ascorbic acid, total dehydroascorbic acid and glutathione increase, there is a decrease in spermatozoal motility and a decrease in the liquefaction time of the seminal plasma. The possible metabolic relationship of seminal plasma L-ascorbic acid and glutathione is discussed and a metabolic pathway is suggested.

Ascorbic Acid↗