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Biomedical subjects

H Hawkins

Publications and source records attributed to H Hawkins.

At least 19 recordsLinked to original sources
PubMed2001

Activity-based costing via an information system: an application created for a breast imaging center.

Activity-based costing (ABC) is a process that enables the estimation of the cost of producing a product or service. More accurate than traditional charge-based approaches, it emphasizes analysis of processes, and more specific identification of both direct and indirect costs. This accuracy is essential in today's healthcare environment, in which managed care organizations necessitate responsible and accountable costing. However, to be successfully utilized, it requires time, effort, expertise, and support. Data collection can be tedious and expensive. By integrating ABC with information management (IM) and systems (IS), organizations can take advantage of the process orientation of both, extend and improve ABC, and decrease resource utilization for ABC projects. In our case study, we have examined the process of a multidisciplinary breast center. We have mapped the constituent activities and established cost drivers. This information has been structured and included in our information system database for subsequent analysis.

Accounting↗
PubMed2001

Conceptual database modeling: a method for enabling end users (radiologists) to understand and develop their information management applications.

As medical technology advances at a rapid pace, clinicians become further and further removed from the design of their own technological tools. This is particularly evident with information management. For radiologists, clinical histories, patient reports, and other pertinent information require sophisticated tools for data handling. However, as databases grow more powerful and sophisticated, systems require the expertise of programmers and information technology personnel. The radiologist, the clinician end-user, must maintain involvement in the development of system tools to insure effective information management. Conceptual database modeling is a design method that serves to bridge the gap between the technological aspects of information management and its clinical applications. Conceptual database modeling involves developing information systems in simple language so that anyone can have input into the overall design. This presentation describes conceptual database modeling, using object role modeling, as a means by which end-users (clinicians) may participate in database development.

Database Management Systems↗
PubMed2001

Fatal neonatal echovirus 6 infection: autopsy case report and review of the literature.

A full-term, healthy male neonate was delivered by caesarian section to a 26-year-old primigravida woman who had a history of fever and upper respiratory tract infection. On the fourth day of life, the neonate developed a sepsis-like syndrome, acute respiratory and renal failure, and disseminated intravascular coagulopathy. He died 13 days after birth. Postmortem examination revealed jaundice, anasarca, massive hepatic necrosis, adrenal hemorrhagic necrosis, renal medullary hemorrhage, hemorrhagic noninflammatory pneumonia, and severe encephalomalacia. Echovirus type 6 was isolated from blood, liver, and lungs. Although uncommon, echovirus type 6 infection may produce a spectrum of pathologic findings similar to those seen with the more commonly virulent echovirus type 11.

Adrenal Glands↗
PubMed2001

Role of nitric oxide in vascular permeability after combined burns and smoke inhalation injury.

Patients with severe burn and/or smoke inhalation injury suffer both systemic and pulmonary vascular hyperpermeability. We hypothesized that nitric oxide (NO) produced by inducible nitric oxide synthase (iNOS) plays a role in the changes in microvascular permeability seen with this injury. To test the hypothesis, we administered mercaptoethylguanidine (MEG), a selective iNOS inhibitor, to conscious sheep subjected to a combined smoke inhalation and third-degree burn injury to 40% of total body surface area. The sheep were surgically prepared for chronic study with lung and prefemoral lymph fistulas in order to estimate microvascular permeability. Both the groups and a control group of animals showed an increase in iNOS protein and message in their lungs. The control animals showed significant increases in either plasma or lymph NO2-/NO3- (NOx) concentration at 24 h after injury, with associated cardiac depression and hemoconcentration. The airway epithelium stained for nitrotyrosine. In the treatment group, NOx did not increase significantly in plasma or lymph throughout the experiment, there was no nitrotyrosine staining, hemodynamic depression was not observed, and the fluid requirement was significantly less than in the control group. Changes in pulmonary microvascular permeability were significantly suppressed by inhibition of iNOS. However, there was no significant difference between the two study groups in the microvascular permeability of burned tissue. These data suggest that NO produced by iNOS plays an important role in the changes in systemic and pulmonary microvascular permeability in combined smoke inhalation/third-degree burn injury, but does not affect the vascular permeability of third-degree-burned tissue in this type of injury.

Animals↗
PubMed2000

Insulin-like growth factor-I cDNA gene transfer in vitro and in vivo.

Our hypothesis is that gene transfer of an IGF-I CMV-cDNA with cholesterol containing cationic liposomes is an efficient tool for transient transfection of growth factors in vitro and in vivo. In vitro, we transiently cotransfected IGF-I cDNA with a CMV construct and a Lac Z beta-galactosidase cDNA/CMV construct using cholesterol containing cationic liposomes and measured beta-galactosidase and IGF-I mRNA and protein. In vivo, we subcutaneously injected 3-month-old male Sprague-Dawley rats with IGF-I cDNA and beta-galactosidase cDNA into rat skin. After IGF-I and beta-galactosidase were cotransfected into PC12 cells, Northern blot analysis showed that the peak time of IGF-I expression was 2 days for mRNA and 5 days for protein. In vivo, a cDNA/liposome ratio of 1:2 was most effective. IGF-I protein expression in IGF-I-transfected skin resulted in significant transfection from day 5 to day 7. In situ determination of beta-galactosidase activity confirmed that transfections resulted in a restricted expression area.

Animals↗
PubMed2000

Both dermal matrix and epidermis contribute to an inhibition of wound contraction.

Contracture is a major detriment to functional recovery from large wounds. To determine the relative value of dermal replacement and epidermal coverage in inhibiting wound contraction, five full-thickness wounds (all 5 x 5 cm2) were placed on the back of 8 swine and treated in the following manner: (1) open wound, (2) porcine acellular dermis (analogous to AlloDerm for human use), (3) porcine acellular dermis with epidermal autograft placed 7 days postwounding, (4) porcine acellular dermis with immediate epidermal autograft, and (5) conventional-thickness autograft. Scar dimensions and punch biopsies were taken at days 14 and 30 postwounding. The planimetry results demonstrated that wound contraction was significantly greater with the open wounds (group 1) than all other wounds with a dermal substitute. Furthermore, wounds with initial epidermal coverage had significantly less contraction than unepithelialized wounds (14.8 +/- 1.1 cm2 at day 14 in wound group 2 vs. 20.4 +/- 0.6 cm2 in wound group 4; p < 0.05). Biopsy results revealed that wounds with initial epithelial coverage had the least amount of inflammation. These findings suggest that both dermal matrix and epidermal coverage contribute to an inhibition of wound contraction and that prompt epithelial coverage appears to impede contraction by reducing inflammation.

Animals↗
PubMed2000

Advance health care planning and the GP. Is it time to move forward?

AIM: Legislation relating to advance health care planning was introduced into Queensland in 1998. All states and territories apart from Western Australia, New South Wales and Tasmania now have legislation relating to this issue. The aim of this pilot study was to: determine current usage of advance health directives (AHDs) in an individual general practice; and encourage appropriate use of AHDs in general practice. METHOD: One hundred clinical records were audited for evidence of advance health care planning and 100 adult patients were surveyed regarding advance care preferences. RESULTS: One percent of clinical records showed evidence of advance health care discussion and 5% of those surveyed stated they had a current AHD. Only 10% of those surveyed were aware of AHDs; 70% wanted to know more about them; 83% wished family members to be substitute decision makers regarding health matters if the individual was too ill to be involved; 54% nominated doctors to be among their preferred decision makers. CONCLUSIONS: Lack of familiarity with advance health care planning options was very common, however most patients wished to be involved in their own advance health care planning or wished to involve a family member. Legislation now exists in the majority of states and territories for this to occur. General practitioners could assist by having suitable information available in waiting rooms and including discussion in consultations where appropriate.

Adolescent↗
PubMed1999

Case of the month: January 1999--Fetus with echogenic mass in third ventricle.

A 29-week gestational age newborn male infant was found to have an echogenic mass in the 3rd ventricle by prenatal ultrasound 2 weeks prior to delivery. At delivery he was poorly responsive and had hydrocephalus and ascites. A CT scan after birth showed cerebral infarction, amorphous tissue in the left hemisphere and numerous calcifications. Despite supportive treatment he died 4 days after birth. Postmortem examination of the brain revealed marked distortion of the architecture and a supratentorial undifferentiated neoplasm consistent with a PNET. The tumor showed extensive areas of hemorrhage and necrosis and involvement of lateral and third ventricles, brain parenchyma, and meninges.

Brain Neoplasms↗
PubMed1999

Fimbria-mediated enhanced attachment of nontypeable Haemophilus influenzae to respiratory syncytial virus-infected respiratory epithelial cells.

Respiratory syncytial virus (RSV) infection is known to predispose children to otitis media and sinusitis due to bacteria such as nontypeable Haemophilus influenzae (NTHI). In this study, we investigated the role of NTHI surface outer membrane protein P5-homologous fimbriae (P5-fimbriae) in attachment to RSV-exposed A549 epithelial cells. Analysis by fluorescence flow cytometry showed that a live P5-fimbriated NTHI strain (NTHIF+) attached to a higher proportion of RSV-exposed A549 cells than to control cells (mean, 68% for RSV versus 29% for control; P = 0.008), while attachment of the P5-fimbriae-deficient isogenic mutant strain (NTHIF-) was significantly lower than in control cells and rose only slightly following RSV exposure (mean, 17% for RSV versus 10% for control, P = 0.229). Attachment of NTHIF+ did not correlate with the amount of RSV antigen expressed by A549 cells. Furthermore, paraformaldehyde-fixed NTHIF+ also demonstrated an enhanced binding to RSV-exposed cells. Observations by transmission electronic microscopy showed that the mean number of bacteria attached per 100 RSV-exposed A549 cells was higher for NTHIF+ than NTHIF- (99 versus 18; P < 0.001). No intracellular bacteria were identified. UV-irradiated conditioned supernatants collected from RSV-infected A549 cultures (UV-cRSV) also enhanced the attachment of NTHIF+ to A549, suggesting the presence of a preformed soluble mediator(s) in UV-cRSV that enhances the expression of receptors for P5-fimbriae on A549 cells. In summary, RSV infection significantly enhances NTHI attachment to respiratory epithelial cells. P5-fimbria is the critical appendage of NTHI that participates in this attachment. In clinical settings, blocking of the P5-fimbria-mediated attachment of NTHIF+ by passive or active immunity may reduce the morbidity due to NTHI during RSV infection.

Antigens, Viral↗
PubMed1998

The effect of profound umbilical artery acidemia in term neonates admitted to a newborn nursery.

OBJECTIVE: To determine whether there were immediate adverse effects of an umbilical artery pH < or = 7.0 in term and near-term infants. STUDY DESIGN: All infants triaged to the newborn nursery with an umbilical artery pH < or = 7.0 from May 1993 through April 1994 (n = 37) were prospectively identified; 35 of the 37 infants were enrolled and matched with nonacidemic control infants (n = 35). Organ system dysfunction (neurologic, renal, hepatic, gastrointestinal) was evaluated either clinically or biochemically with selected blood and urine parameters. RESULTS: Acidemic and control groups were similar for pregnancy complications before labor, but acidemic infants were more often delivered by cesarean section (20/35 vs 6/35, p = 0.001). No differences existed between acidemic and control infants in gestational age, birth weight, neurologic evaluations, hearing deficits, feeding tolerance, and hepatic function. The acidemic group had a higher mean serum creatinine than control infants on day 2 of life (0.90 +/- 0.34 vs 0.71 +/- 0.12 mg/dl, p = 0.005) and a greater number of infants with a urine Chemstrip positive for heme (14/35 vs 3/35, p = 0.005). No differences existed between groups in time to first void, urine specific gravity, and number of infants with microscopic hematuria. CONCLUSION: Term and near-term infants born with an umbilical artery pH < or = 7.0 and triaged to the newborn nursery on the basis of a stable appearance in the delivery room do not have clinical manifestations of hypoxia-ischemia in the 48 hours after birth. The higher mean serum creatinine for acidemic compared with control groups is presumably prerenal in origin and results from processes responsible for profound fetal acidemia. Infants with an umbilical artery pH < or = 7.0 and assessed to be clinically well can be treated similar to nonacidemic infants.

Acidosis↗
PubMed1997

Heparin attenuated neutrophil infiltration but did not affect renal injury induced by ischemia reperfusion.

Although heparin is better known as an anticoagulant, it also has several anti-inflammatory effects. Heparin is known to inhibit neutrophil adhesion, chemotaxis and oxygen free radical production. In addition, heparin is also known to act as an oxygen radical scavenger. Our hypothesis was that heparin would attenuate renal ischemia reperfusion injury. In this study, we investigated whether heparin had a protective effect on renal ischemia reperfusion injury. Sheep (n = 12) were prepared for the chronic study with venous, arterial and urinary catheters inserted. In addition, pneumatic occluders and ultrasonic flow probes were placed on renal arteries. After a 5-day recovery period, the sheep were randomized to either a heparin treatment group (400 IU/kg i.v. bolus 10 minutes before renal artery occlusion, followed by a continuous effusion 25,000 IU in 250 ml of 0.9% NaCl at 10 ml/hr, n = 6) or a control group (n = 6), which received an equivalent volume of 0.9% NaCl. All the sheep then underwent 90 minutes of bilateral renal ischemia followed by 24 hours of reperfusion. Blood urea nitrogen (BUN), serum creatinine (Scr), and creatinine clearance (CrCl) were determined at various intervals during both the ischemic and reperfusion periods. Kidney tissue samples were obtained at autopsy for histologic examination. As a result, there were significant differences in the degree of inflammation (1.50 +/- 1.24 Vs 0.50 +/- 0.79, P < 0.05) between the control and heparin treatment groups, but not in the degree of injury (2.83 +/- 0.44 Vs 2.33 +/- 0.28). In this study, heparin significantly attenuated polymorphonuclear leukocytes (PMNs) infiltration within the interstitium, but it did not affect the degree of renal damage as measured by urinary chemistries or renal tubular damage as assessed by histopathologic evaluation.

Animals↗
PubMed1995

Coal-black hyperpigmentation at birth in a child with congenital adrenal hypoplasia.

Congenital adrenal hypoplasia has been estimated to occur in approximately 1 of 12,500 births. Hyperpigmentation associated with this condition typically appears gradually during a period of months to years. We describe a newborn infant with profound hyperpigmentation in whom adrenal crisis subsequently developed as a result of congenital adrenal hypoplasia.

Adrenal Glands↗
PubMed1990

The diagnostic utility of desmin. A study of 584 cases and review of the literature.

The diagnostic utility of several antibodies against desmin and their optimal staining conditions have not been systematically evaluated. Sections of paraffin-embedded tissues from 584 cases were stained with a monoclonal antibody against desmin (Clone DER 11 from DAKO), using an avidin-biotin-peroxidase technique. The results were tabulated and compared with those from previous reports. The following observations were made: (1) When pronase digestion was performed before staining, desmin was equally demonstrable in tissues fixed in formalin, Zenker's, Bouin's, or B5 fixative; however, desmin staining was lost or significantly diminished in tissues fixed in absolute ethyl alcohol. In contrast, when pronase was not used, a positive staining was demonstrated only in tissue fixed in absolute ethyl alcohol. (2) Positive staining was found in normal muscle (92 of 92 cases), leiomyoma (12 of 13), rhabdomyoma (6 of 6), rhabdomyosarcoma (31 of 31), leiomyosarcoma (18 of 26). (3) Desmin was never found in epithelia, normal mesenchymal tissue other than muscle, tumors stimulating rhabdomyosarcoma, and epithelial tumors. (4) A positive staining was documented in 1 tumor (a fibrous histiocytoma) of 42 benign predominantly spindle cell tumors and in 8 of 89 predominantly spindle cell sarcomas. (5) Desmin was never documented in myoepithelial cells but stained myofibroblasts in 2 of 12 examples of granulation tissue and in 29 of 67 samples containing tumor-associated desmoplasia. The authors' data on the diagnostic sensitivity and specificity of the evaluated antibody should improve the use of desmin in diagnostic pathology.

Antibodies, Monoclonal↗
PubMed1987

Optimal examination of the normally formed perinatal heart.

Because infants rarely suffer coronary artery thrombosis, it is mistakenly assumed that they seldom have significant ischemic myocardial injury. However, ischemic myocardial necrosis (INM) is common in the papillary muscles and subendocardium of stressed newborns and other infants. Standard dissection methods encourage only routine examination and limited sampling of the small perinatal heart, and most myocardial injury is never discovered. After evaluating published methods, a simple technique was developed to open and prepare the normally formed infant heart for optimal macroscopic and microscopic evaluation. Symmetrical anterior incisions of the atria and ventricles allow the atria, ventricles, and outflow tracts to be viewed almost simultaneously. A single change allows the heart to be "unrolled" into a plane for roentgenographic study of injected coronary arteries. The method for sampling the myocardium and the conduction system allows identification of more than 90 per cent of the IMN sites without adding significant costs. The recognition of significant IMN plays a valuable role in evaluating and explaining certain infant deaths.

Coronary Disease↗