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Biomedical subjects

J C White

Publications and source records attributed to J C White.

At least 19 recordsLinked to original sources
PubMed1999

Apocrine gland carcinoma of the axilla: review of the literature and recommendations for treatment.

Apocrine gland carcinoma is a rare form of sweat gland neoplasm with a distinctive cytologic appearance. Although the region of the axilla remains the most common site for these tumors, apocrine gland carcinoma of the anogenital region, eyelid, ear, chest, wrist, lip, foot, toe, and finger have been reported. Classically, these slow-growing lesions present as painless, colorless or reddish, firm or cystic nodules. More than half of the reported patients with apocrine carcinoma had lymph node metastases at the time of diagnosis. Wide local excision is standard therapy for these lesions. A therapeutic lymph node dissection is indicated for confirmed lymph node metastases and may have a role in the setting of a large or highly aggressive tumor with narrow surgical margins. Although apocrine gland carcinoma responds poorly to chemotherapy, adjuvant radiotherapy may be used in advanced local or regional disease. The authors describe a 69-year-old man with a large recurrent apocrine gland carcinoma of the axilla treated with en bloc excision with axillary dissection and offer a pertinent review of the English literature and recommendations for treatment.

Aged↗
PubMed1998

Defects in embryonic hindbrain development and fetal resorption resulting from vitamin A deficiency in the rat are prevented by feeding pharmacological levels of all-trans-retinoic acid.

Vitamin A is required for reproduction and normal embryonic development. We have determined that all-trans-retinoic acid (atRA) can support development of the mammalian embryo to parturition in vitamin A-deficient (VAD) rats. At embryonic day (E) 0.5, VAD dams were fed purified diets containing either 12 micrograms of atRA per g of diet (230 micrograms per rat per day) or 250 micrograms of atRA per g of diet (4.5 mg per rat per day) or were fed the purified diet supplemented with a source of retinol (100 units of retinyl palmitate per day). An additional group was fed both 250 micrograms of atRA per g of diet in combination with retinyl palmitate. Embryonic survival to E12.5 was similar for all groups. However, embryonic development in the group fed 12 micrograms of atRA per g of diet was grossly abnormal. The most notable defects were in the region of the hindbrain, which included a loss of posterior cranial nerves (IX, X, XI, and XII) and postotic pharyngeal arches as well as the presence of ectopic otic vesicles and a swollen anterior cardinal vein. All embryonic abnormalities at E12.5 were prevented by feeding pharmacological amounts of atRA (250 micrograms/g diet) or by supplementation with retinyl palmitate. Embryos from VAD dams receiving 12 micrograms of atRA per g of diet were resorbed by E18.5, whereas those in the group fed 250 micrograms of atRA per g of diet survived to parturition but died shortly thereafter. Equivalent results were obtained by using commercial grade atRA or atRA that had been purified to eliminate any potential contamination by neutral retinoids, such as retinol. Thus, 250 micrograms of atRA per g of diet fed to VAD dams (approximately 4.5 mg per rat per day) can prevent the death of embryos at midgestation and prevents the early embryonic abnormalities that arise when VAD dams are fed insufficient amounts of atRA.

Animals↗
PubMed1998

Utilization of sorbed compounds by microorganisms specifically isolated for that purpose.

A bacterium obtained by enrichment on nonsorbed phenanthrene was unable to degrade phenanthrene sorbed to polyacrylic beads and had little activity on phenanthrene sorbed to lake-bottom sediment. A bacterium obtained by enrichment on phenanthrene sorbed to polyacrylic beads readily mineralized the compound sorbed to the beads or the sediment. Degradation by the second bacterium of phenanthrene sorbed to beads 38-63 microns or 63-150 microns in diameter was more rapid than the rate of desorption of the hydrocarbon in the absence of the bacterium. Little degradation of sorbed, nonleachable phenanthrene in soil was effected by another isolate obtained by enrichment with the nonsorbed hydrocarbon, but a mixed culture and the bacterium obtained by enrichment on the sorbed compound extensively degraded phenanthrene. Because microorganisms specifically obtained for their capacity to degrade sorbed phenanthrene are more active than species not specialized for use of the bound compound, we suggest that microorganisms enriched on nonsorbed compounds may not be appropriate for evaluation of biodegradation and bioremediation of sorbed compounds.

Bacteria↗
PubMed1998

Mortality is increased by procalcitonin and decreased by an antiserum reactive to procalcitonin in experimental sepsis.

OBJECTIVES: Procalcitonin (ProCT), the precursor to the calcitonin hormone, is abnormally increased in experimental and clinical systemic inflammation, including sepsis. Initially, we investigated the effects of supraphysiologic amounts of ProCT administered to animals with septic peritonitis. Subsequently, we evaluated the efficacy of prophylactic and therapeutic immune blockade of ProCT in this lethal model of sepsis. DESIGN: Prospective, experimental, controlled study. SETTING: Animal research laboratory approved by the American Association for the Accreditation of Laboratory Animal Care at a Veterans Affairs Medical Center. SUBJECTS: Young male Golden Syrian hamsters, weighing 90 to 120 g. INTERVENTIONS: In the first study, serum ProCT concentrations were measured in animals at 0, 3, 6, 12, and 24 hrs after induction of sepsis by intraperitoneal implantation of pellets containing Escherichia coli (5 x 10(8) colony-forming units/pellet). In the second study, with mortality as the end point, 30 microg/kg of isolated, purified human ProCT in 10% hamster serum (experimental) or an equal volume of 10% hamster serum (control) were administered intravenously at the time of the E. coli peritoneal implantation. In the third study, experimental animals received intraperitoneal injections of a multiregion-specific goat antiserum reactive to hamster ProCT 1 hr before and 24 hrs after E. coli implantation, while control animals received nonimmune goat serum at the same time points. In the final study, the same antiserum was administered in five divided doses during the 24 hrs after the insertion of E. coli. MEASUREMENTS AND MAIN RESULTS: In the initial study, ProCT concentrations were increased shortly after induction of sepsis and peaked at 12 hrs. Administration of exogenous ProCT to septic animals significantly increased mortality compared with control animals (93% vs. 43%, p=.02). Prophylactic blockade of ProCT almost completely protected the animals from the lethal effects of sepsis: the 102-hr mortality rate in the experimental group was 6% compared with 62% in the control group (p < .003). In the therapeutic trial, the 102-hr mortality rate was 54% in experimental animals compared with 82% in control animals (p < .045). CONCLUSIONS: These results demonstrate that increased ProCT exacerbates mortality in experimental sepsis, whereas neutralization of ProCT increases survival. Thus, ProCT, in addition to being an important marker of severity of systemic inflammation and mortality, is an integral part of the inflammatory process and directly affects the outcome.

Animals↗
PubMed1998

Serum calcitonin precursors in sepsis and systemic inflammation.

High serum levels of the calcitonin (CT) prohormone, procalcitonin (pro-CT), and its component peptides occur in systemic inflammation and sepsis. Using two different assays, we undertook a prospective study to determine the utility of serum precalcitonin peptides (pre-CT) as markers in this condition. Twenty-nine patients meeting criteria for the systemic inflammatory response syndrome were studied daily in two intensive care units. Sera were collected, and APACHE II scores were determined until recovery or death. All patients had markedly elevated serum pre-CT. Prognostically, peak values were the most important. The highest values portended mortality, and a lower level could be ascertained below which all patients survived. Peak pre-CT levels were significantly higher in patients with infection documented by blood cultures than in those patients with no documented infection from any source (P < 0.05). Mature CT remained normal or only moderately elevated. Compared with the serum pre-CT levels, receiver operating characteristic curve analysis revealed that the APACHE II scores, although more cumbersome, were better overall predictors of mortality. Thus, pre-CT is an important serum marker for systemic inflammatory response syndrome and is predictive of outcome. It also provides data concerning the presence of severe infection and may prove to be clinically useful for proactive patient care.

Adult↗
PubMed1997

Wrapping things up: a qualitative analysis of the closing moments of the medical visit.

The purpose of this preliminary study is to develop an operational definition of the closure phase of the medical visit. A listening group developed a definition of closure by consensus based on audiotaped data from 22 office visits to physicians. The group noted new problems in closure not previously raised. Closure was defined as the final phase of the medical visit in which the doctor and patient shift perspective to the future, finalize plans, and say goodbye. Two distinct organizational frameworks of closure are outlined. Thirty-six percent of closures were interrupted in some way. New problems occurred in 23% of visits, even those with open-ended beginnings and early physician requests for all patient concerns. Doctors' communication involved expression of emotion, patient education, clarification, summary, and parting comments. Patient communication included expression of emotion, information sharing, and parting comments. Doctors' communication skills for closure are proposed. Closure is a distinctive phase of the visit with an organizational framework and specific tasks. The frequency of new problems in closure suggests that physicians may have the potential to improve their effectiveness.

Clinical Competence↗
PubMed1997

Health risk factors and health-seeking behavior in lesbians.

Lesbians may engage in behavior that places their health at risk and may delay health care and screening more than do their heterosexual counterparts. This article examines influences on lesbians' health risk factors and health-seeking behaviors. A statewide, self-administered survey of members of a lesbian community organization was performed. Univariate and bivariate analyses were calculated, and linear regression was used to examine models of health risks and health-seeking behavior. Of 324 respondents, 90% had disclosed sexual orientation to at least one provider, 22% reported seeking care without symptoms (preventive care), and 23% reported waiting until symptoms are at their worst or never seeking care. Young age, belief in the importance of lung cancer, difficulty of getting health care when needed, reliance on the partner for health support, and fewer male partners were all associated with greater health risk for lesbians. Difficulty obtaining health care, difficulty communicating with the primary care provider, discomfort in discussing depression, and degree of comfort in discussing menopause were all associated with a delay in seeking health care. Sensitive communication with lesbians and further identification of lesbians' specific barriers to care may improve health-seeking behavior and provide more opportunities for screening and risk factor counseling in this population.

Adolescent↗
PubMed1997

On the use of upper extremity proximal nerve action potentials in the localization of focal nerve lesions producing axonotmesis.

Ulnar, median, and radial proximal nerve action potentials (PNAPs) were recorded from the axilla and supraclavicularly, with stimulation of the nerves at the elbow or the radial groove, in 30 control subjects for each nerve. In addition to routine nerve conduction studies, wrist to elbow median nerve action potentials were recorded proximal to the lesion in 76 patients with carpal tunnel syndrome of varying degrees of severity to determine the effect that the distal lesion might have on more proximal nerve conduction. Utilizing this information, PNAPs, standard nerve conduction studies, and needle electrode examinations were carried out in patients with focal elbow area nerve or brachial plexus lesions producing axonotmesis. PNAPs confirmed the site of the lesions producing axonotmesis when localization was possible with standard nerve conduction and/or needle electrode studies and were the sole means by which localization of the lesions producing only sensory axonotmesis was accomplished.

Action Potentials↗
PubMed1997

Recompression treatments during the recovery of TWA Flight 800.

After the crash of TWA flight 800, U.S. Navy (USN) and civilian divers recovered the aircraft and the victims' remains from 117 feet of sea water (fsw). Safety information was gathered from observations, interviews, and medical and diving records. Of 752 dives employing surface decompression using oxygen (SDO2), 10 divers required recompression treatments, mainly for type 2 decompression sickness (DCS). When using hot water heating, the DCS risk was high until the dive profiles were modified. Divers made nearly 4,000 no-decompression scuba dives. In eight scuba divers and one tender treated with recompression, the diagnoses included DCS (3), arterial gas embolism (AGE) (1), and vascular headache (2). All USN divers recovered fully. The experience is consistent with previous work suggesting an increase in DCS risk in warmer SDO2 divers. The USN SDO2 tables can be made safer by limiting bottom time and extending decompression. Even under stressful conditions, rapid ascents resulting in AGE are uncommon. Vascular headaches can mimic DCS by responding to oxygen.

Accidents, Aviation↗
PubMed1996

Porocarcinoma of the heel. A case report with unusual histologic features.

BACKGROUND: Eccrine porocarcinoma is an uncommon neoplasm of the intraepidermal sweat gland duct. METHODS: A case of porocarcinoma of the right heel in a male age 51 years is described with a review of pertinent literature. The surgically excised neoplasm was evaluated by routine histology and transmission electron microscopy. RESULTS: The porocarcinoma showed extensive nuclear pleomorphisms with frequent, multinucleated tumor giant cells, focal epidermotrophic spread within the epidermis, a peripheral, eccrine syringofibroadenoma-like growth pattern, and an origin in a contiguous eccrine poroma. Ultrastructurally, the squamous tumor cells contained rare intracytoplasmic lumens. CONCLUSIONS: The extensive nuclear pleomorphism with frequent tumor giant cells was an unusual feature of the porocarcinoma. Its epidermotrophic spread within the epidermis and its origin in a contiguous eccrine poroma supported the diagnosis of porocarcinoma. The eccrine syringofibroadenoma-like growth pattern in the periphery of the tumor was a unique and previously undescribed feature of the porocarcinoma. The presence of intracytoplasmic lumens in squamous tumor cells mimicked embryonic development of the intraepidermal sweat gland duct.

Acrospiroma↗
PubMed1996

Effects of granulocyte colony stimulating factor in a nonneutropenic rodent model of Escherichia coli peritonitis.

Despite improved antimicrobials and advances in caring for critically ill patients, mortality from sepsis is still unacceptably high. Upregulation of the cellular immune system is one strategy for decreasing mortality in subjects with severe sepsis, which appears to be promising. Granulocyte colony stimulating factor (G-CSF) has been used successfully to decrease mortality in neutropenic subjects with sepsis. In this study, we have investigated whether pretreatment with G-CSF decreases mortality in non-neutropenic rodents with lethal Escherichia coli peritonitis. We implanted agar pellets impregnated with 5 x 10(8) cfu of Escherichia coli into the peritoneal cavities of rats pretreated with 50 micrograms/kg of G-CSF or an equal volume of 5% dextrose in water (D5W). Survival of these animals increased from 38 to 78% with G-CSF pretreatment. We also demonstrated an 11-fold increase in the number of polymorphonuclear leukocytes (PMNs) in animals treated with G-CSF. This increase in cells was seen initially only in the peripheral circulation. Twenty-four hours after induction of peritonitis, however, there was a three-fold greater increase in number of PMNs recovered from the peritoneal cavities of animals pretreated with G-CSF as compared to those treated with D5W. PMNs recovered from the peritoneal cavities of these animals had significantly elevated bactericidal activity (74% killing vs 53% killing) as compared to those cells recovered from the peritoneal cavities of control animals. These results indicate that G-CSF pretreatment improves survival of non-neutropenic animals with lethal Escherichia coli peritonitis by enhancing the cellular arm of the immune response.

Animals↗
PubMed1995

Lesbian health care. What a primary care physician needs to know.

Many primary care physicians take care of lesbians and women sexually active with women without being aware of their patients' sexual orientation. These women have unique medical and psychosocial needs that each physician must consider. Lesbian identity or being sexually active exclusively with women influences care in areas such as sexually transmitted diseases, risk of human immunodeficiency virus infection, counseling, cancer risk, screening, parenting, depression, alcohol use, and violence. We review an approach to taking a history with all women that facilitates open, comfortable communication with lesbians. We also review specific medical and psychosocial areas of primary care in which caring for lesbians is different from caring for other women. Further research is needed on lesbian health issues to provide appropriate guidelines to clinicians.

Adolescent↗
PubMed1993

The transfer of patients' ethics information among cooperating institutions: a future function of ethics networks.

With increasing use of ethics resources by health care teams, the number of patients transferred from one care setting to another who may have had ethics consultations is rising rapidly. There has been virtually no discussion in the ethics literature and no experience in our community addressing questions concerning the continuity of ethics care and the transfer of ethics information. Our ethics committee faced the following questions during a recent consultation. Should there be continuity of ethics care between institutions? If so, what should be the nature of the communication? How is continuity best accomplished? Do ethics consultants or committees incur additional liability following the transfer of care? Where should the boundaries of confidentiality be drawn? How can existing health care ethics networks facilitate continuity of ethics care? We address these ethical and logistical questions and hope to encourage others to report their views on these issues.

Communication↗
PubMed1993

Gastrointestinal transit is not impaired by regional loss of myenteric neurons in rat jejunum.

Chronic absence of myenteric neurons from a 5-cm segment of rat jejunum causes alterations in myoelectric activity. Spike potentials characteristic of phase III activity of the migrating motor complex (MMC) are present; however, the number of propagating spike potentials through the myenterically denervated region is reduced. The objective of this study was to examine the effect of the regional loss of myenteric neurons on gastrointestinal transit of a solid marker in the fasted rat. The rate of gastric emptying was not affected by the absence of the myenteric plexus in a 5-cm segment of the jejunum. However, 15 days after either myenteric denervation or vehicle treatment of a segment of jejunum, a more cephalad distribution and decreased rate of intestinal propulsion of the solid marker was observed in the small intestine. This delay in small intestinal transit observed at 15 days was not seen at 48 and 120 days. The decrease in transit at 15 days can be attributed to the handling of the bowel during the surgical procedure. The mouth-to-cecum transit time (MCT) was also not affected by chronic absence of the myenteric plexus. Furthermore, the MCT indicated that bacterial overgrowth, a common manifestation when gut motility is disrupted, did not occur in the small intestine after the experimental destruction of the myenteric plexus. The results of this study indicate that the regional loss of the myenteric plexus does not impair gastrointestinal transit in the fasted rat.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Novel antagonists of the 5-HT3 receptor. Synthesis and structure-activity relationships of (2-alkoxybenzoyl)ureas.

A series of benzoylureas derived from bicycle amines were prepared and evaluated for 5-HT3 antagonist activity on the rat isolated vagus nerve. From among these compounds, those analogues which were ortho substituted by an alkoxy group on the benzoyl function were shown to be potent 5-HT3 antagonists with similar or greater potency than the standard agent ondansetron. NMR and X-ray crystallography studies showed these o-alkoxy compounds to exist as a planar, hydrogen-bonded, tricyclic ring system. In molecular modeling studies on endo-N-[[(8-methyl-8-azabicyclo[3.2.1]octan-3-yl-amino] carbonyl]-2-(cyclopropylmethoxy)benzamide (30) the central hydrogen-bonded ring was able to mimic an aromatic ring present in previously reported 5-HT3 antagonists.

Animals↗