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Biomedical subjects

J Huth

Publications and source records attributed to J Huth.

At least 19 recordsLinked to original sources
PubMed2003

[Cystic adenoid carcinoma of the larynx: two cases].

Adenoid cystic carcinoma is the most common malignant tumor of the minor salivary glands in the head and neck. Laryngeal localization is rare due to the poor distribution of the accessory salivary glands in this area. It arises exceptionally before 20 years and no risk factor is known. Diagnosis is a histological finding because symptoms do not differ greatly from other laryngeal tumors. Histological features, stage, quality of tumor resection and nerve invasion are prognostic factors. These tumors grow slowly and local recurrence or systemic metastasis are exceptional. Surgery is the treatment of choice but outcome is always fatal, after a long clinical course in many patients.

Aged↗
PubMed1996

Experimental simulations of the photodecomposition of carbonates and sulphates on Mars.

There is indirect spectroscopic evidence for the presence of sulphates and carbonates on the martian surface, and such minerals are also found in SNC meteorites, which are thought to be of martian origin. But although carbonates are expected to be abundant in the martian regolith, attempts to detect them directly have been unsuccessful. Here we report laboratory studies of the decompostion of calcium carbonate and magnesium sulphate under ultraviolet irradiation, which mimic the conditions under which photodecomposition of surface minerals by solar ultraviolet light might occur on Mars. We find that, even for a low abundance of carbonate minerals in the martian regolith, the rate of CO2 release due to photodecomposition is higher than the rate of CO2 loss from the atmosphere by solar-wind-induced sputtering processes, making this process a potential net source of atmospheric CO2 over time. SO2 is also released from the sulphate, albeit more slowly. The rate of carbonate degradation is high enough to explain the apparent absence of these compounds at the martian surface.

Calcium Carbonate↗
PubMed1996

Curious Consequences of Strong Coupling in NMR Experiments Involving Selective Pulses

This study is concerned with the effects of applying selective pulses to systems with strong second-order scalar couplings in isotropic phase, where different transitions (rs) are associated with different transition matrix elements F+(rs). Two unusual features can be distinguished: the nutation angle ("flip angle") depends on the matrix element of the irradiated transition (rs), and, in contrast to the behavior of an isolated spin-(1/2) system, the norm of the three single-transition operators [I(rs)x, I(rs)y, I(rs)z] associated with the fictitious spin-(1/2) space of the irradiated transition (rs) is generally not conserved. It is necessary to consider the single-transition operators [I(rp)x, I(rp)y, I(rp)z] and [I(sq)x, I(sq)y, I(sq)z] associated with all connected transitions (rp) and (sq) that share a common energy level r or s with the irradiated transition (rs). If the pulse applied to the (rs) transition is sufficiently selective, the transverse components I(rp)x, I(rp)y, I(sq)x, and I(sq)y, can be neglected, since their expectation values remain equal to zero after application of a selective pulse to the (rs) transition, but the longitudinal components I(rp)z and I(sq)z acquire nonvanishing expectation values. When the selective pulse affects several transitions simultaneously, the response varies from one transition to another, depending on the matrix elements and the connectivities. These effects manifest themselves in unusual amplitudes and phases of signals excited by selective pulses, in particular in selective two-dimensional correlation spectra.

Journal Article↗
PubMed1995

Advance directives and the Patient Self-Determination Act: what is a nurse to do?

Since the Patient Self-Determination Act was enacted in 1991, asking patients whether they have advance directives (eg, a Living Will and a Durable Power of Attorney for Health Care Decisions) has become part of the admission procedures at health care facilities. However, questions may still remain about what exactly is the role of the health care provider in this part of the admission process. In many health care settings, the nurse has the responsibility to ask the patient about advance directives. If this occurs during preparation for surgery or other medical procedures, it adds responsibility for the nurse in an already hectic time. This article defines advance directives and examines their place in the admission process. The article further addresses to what extent health care providers are responsible for discussing patients' rights and advance directives and suggests methods that may facilitate the nurse's role in this responsibility.

Advance Directives↗
PubMed1993

Ewing's sarcoma of the mandible: a case report.

The authors report the case of an 8-year-old boy with a Ewing's sarcoma localized to the mandible. The therapeutic modalities consisting of induction chemotherapy, surgical removal of the involved portion of the mandible with reconstruction using a parascapular osteo-cutaneous free flap, and maintenance chemotherapy are described. Emphasis is placed on the importance of performing a wide resection and the use of a multidisciplinary team approach in the treatment of these unusual tumours.

Cell Nucleolus↗
PubMed1992

["Conservative" transmandibular buccopharyngectomy].

Tumors of the amygdaline region were up until now most often treated by transmandibular buccopharyngectomy (TMBP) with a systematic sacrifice of the mandibular angle. This exercise justified by wide carcinological imperatives, a larger surgical facility and simple immediate postoperative follow-up, in fact systematically shows a substantial esthetic and functional prejudice. This principle was reinforced by the occurrence of osteitis during the first attempts of osseous reconstruction using steel wires opposite the mandibular angle (Dargent, Charachon, 1963). In 1989, Gehanno and Beauvillain published a mandibular conservation technique by vertical paramedian osteotomy, right in front of the mental nerve, shifted from the future field of radiation, with osteosynthesis by titanium plates. This technique appeals to us because it is easy to use, reliable and carcinologically safe. We have currently adopted it with satisfaction for 8 of our patients over an 18-month period, without any case of osteitis and with both good esthetic and functional results.

Bone Plates↗
PubMed1990

Amperometric determination of ammonium ions with a microbial sensor.

A sensor for NH+4 ions has been developed, which consists of immobilized micro-organisms (Bacillus subtilis, Pseudomonas aeruginosa, Trichosporon cutaneum) in combination with an electrochemical transducer. This sensor is based on the measurement of acceleration of respiration after addition of NH+4 in the presence of glucose. The physiological background of this signal and its connection with NH+4 ion uptake and/or metabolism is discussed. The response time of the sensor is about 5-10 s for NH+4 ions. A linearity was observed between 0.005 and 0.15 mmol dm-3 NH+4 ions. The sensitivity of the sensor remained almost constant for 12 days. The sensor was used to determine NH+4 ions in a microbial fermentation broth.

Bacillus subtilis↗
PubMed1990

Acute adrenocorticotropin-(1-24) (ACTH) adrenal stimulation in eumenorrheic women: reproducibility and effect of ACTH dose, subject weight, and sampling time.

Assessment of adrenal reserve and the diagnosis of adrenal insufficiency by acute adrenocortical stimulation with ACTH-(1-24) has been well established. Alternatively, estimation of adrenocortical enzymatic activities by this method for the detection of inherited or acquired biosynthetic abnormalities has been less well characterized. Some of the discrepancies between studies estimating adrenocortical enzymatic activities in different pathological conditions (e.g. hyperandrogenism) may result from the different stimulation protocols used. The objective of this prospective study was to establish the inherent variability of the adrenal response to acute ACTH-(1-24) stimulation and to determine the effect of sampling time, stimulation dose, and subject weight on the same. Forty-one normal female volunteers were recruited (mean age, 29.1 yr), 30 within 90-110% ideal body weight and 11 weighing more than 120% ideal body weight. Three protocols were designed to study 1) the effects of sampling time, ACTH-(1-24) dose, and subject weight on adrenal response; 2) the effect of time of the day on the variability of basal steroid levels and the adrenal response to stimulation; and 3) the long term reproducibility of the adrenal response to ACTH-(1-24). Androstenedione, 17-hydroxyprogesterone, 11-deoxycortisol, dehydroepiandrosterone, and cortisol were measured in serum under basal and stimulated conditions. All subjects had normal basal levels of testosterone, androstenedione, dehydroepiandrosterone sulfate, and PRL. The acute iv administration of 0.10, 0.25, and 1.0 mg ACTH-(1-24) elicited similar and maximal steroid responses, with all steroid levels reaching a plateau 60-90 min poststimulation regardless of subject weight. Sampling of basal steroid levels every 5 min in the morning (AM; beginning 0700-0900 h) or evening (PM; 1500-1700 h) did not reveal any difference in steroid variability. Only the mean basal cortisol level was higher in AM than PM testing (P less than 0.03). Although the mean levels of dehydroepiandrosterone and 17-hydroxyprogesterone 60 min after stimulation were significantly higher in AM than PM studies, these differences were minimal. Ten volunteers underwent an average of four (range, 2-6) adrenal stimulation studies using 1.0 mg ACTH-(1-24) over a 1-yr period. The long term coefficient of variation (CV) for basal steroid levels ranged from 15-28%. Calculations of net adrenal response (delta steroid O-T and area delta steroid O-T) were less reproducible (CV, 0-82%) than measures of absolute response (steroid T, area steroid T, and %steroid T; CV, 7-32%). This difference in CV between the measures of net and absolute adrenal responses was significant for all steroids except androstenedione.(ABSTRACT TRUNCATED AT 400 WORDS)

17-alpha-Hydroxyprogesterone↗
PubMed1990

[Transposition of the temporal muscle and surgery of the middle third of the face. Technic, indications and results].

The authors reemploy the technique using the temporal muscle to fill in large surgical cavities after tumoral surgery of the middle 1/3 of the face. The purpose of this technique is to prevent crust formation after radiotherapy, and to improve esthetic results by preventing further cutaneous retraction. They expose their own technique, the results and the indications from 8 cases.

Adult↗
PubMed1989

[Giant cell tumor of the temporal bone. Clinical study of a case. Histologic and therapeutic remarks].

A case of giant cell tumor of the temporal bone is reported. The surgical difficulties encountered in this case are presented and therapeutic modalities for this tumor, consisting of radical surgery and post operatoire radiotherapy, one defined and discussed. Comments are made concerning this rare tumor location, its occurrence in young adults, and difficulties in establishing a histologic diagnosis.

Adult↗
PubMed1988

[Nitrogen regulation in microorganisms].

The central role of NH4+-assimilation in the microbial metabolization of several inorganic nitrogen sources and the regulation of its key enzymes--glutamate dehydrogenases (GDH--EC 1.4.1.2. and EC 1.4.1.4.), glutamine synthetase (GS--EC 6.3.1.2.) and glutamate synthase (GOGAT--EC 1.4.1.3.)--are presented. In excess of ammonia gramnegative bacteria as well as yeasts assimilate this ion in a NADH + H+ or NADPH + H+ dependent reaction by GDH. Under NH4+-limitation--in natural environments rather the rule than the exception--the ammonia assimilation is ATP dependent and catalyzed via GS and GOGAT. Subsequently the connection between the nitrogen metabolization and the resulting changes in the extracellular pH of growing yeast cultures is discussed. The stoichiometric exchange between NH4+ and H+ led to the assumption that in the physiological pH-range an energy dependent NH4+/H+ transport is the preferred++ mechanism of ammonia uptake for NH4+ excess as well as for NH4+ shortage.

Ammonia↗
PubMed1983

Resection of pulmonary metastases from nonseminomatous testicular tumors. Correlation of clinical and histological features with treatment outcome.

Clinical and histological correlates of survival in patients undergoing complete resection of pulmonary metastases from nonseminomatous testicular carcinoma were determined in 25 Stage C patients aged 17-38 years treated from 1969-1978. All patients had orchiectomy and retroperitoneal lymphadenectomy. Nineteen patients received combination chemotherapy before resection, and all received chemotherapy after resection. Three patients had four additional thoracotomies for pulmonary recurrence. Survival was measured from time of first thoracotomy to time of last followup or death. Actuarial survival for the entire group at one, two, and five years was 80, 63, and 59%, respectively. Median follow-up of the survivors was 3.5 years. Patients in low tumor burden groups such as those with no tumor in retroperitoneal nodes, with unilateral metastases, or with single metastases had better prognosis, as did patients whose primary tumors were moderately well differentiated. Characteristics of pulmonary metastases that favorably influenced the prognosis were the presence of mature teratoma, presence of few mitoses, lack of mononuclear infiltrate, and lack of desmoplastic response. These findings confirm the effectiveness of multimodality therapy which includes the resection of pulmonary metastases for Stage C nonseminomatous carcinoma of the testes. In addition, they suggest that consideration should be given to the stratification of prospective clinical trials on the basis of tumor burden and histologic characteristics of the primary and metastatic lesions.

Adolescent↗
PubMed1981

[Lymphogranulomatosis and heart involvement].

In the early extralymphatic affection of the organs without relevant clinical and roentgenological findings the diagnosis of the lymphogranulomatosis makes difficulties. It is referred to the peculiarities of the extra-nodal manifestation. The case of a lymphogranulomatosis with early participation of the heart is described and it is gone more fully into the differential diagnosis. Disturbances of the regression of excitation in the ECG are etiologically ambiguous and may be the first recognizable findings of a penetration of a tumour into the pericardium.

Adult↗
PubMed1979

Plasma thyrotropin-releasing hormone, prolactin, thyrotropin, and thyroxine concentrations following the intravenous or oral administration of thyrotropin-releasing hormone.

In a further evaluation of the use of oral thyrotropin-releasing hormone (TRH) in puerperally lactating women, a radioimmunoassay for its measurement has been developed. Its concentration in plasma as well as that of prolactin (PRL), thyrotropin (TSH) and thyroxine (T4) were measured following either intravenous or oral administration of TRH. Basal concentrations of TRH in 14 normally cycling women ranged from less than 5 to 17 pg/ml. Two luteal phase studies produced peaks in plasma TRH 5 to 10 minutes after 100 micrograms of TRH administered intravenously with a return to basal concentrations within 2 to 3 hours. In 10 normally menstruating women, ingestion of 10 mg of TRH orally resulted in plasma TRH which peaked at 423 +/- 123 pg/ml (standard error of the mean) at 30-minutes. Plasma PRL, TSH, and T4 also increased and remained slightly elevated at 4 hours. These 8-hour studies were performed in a puerperal lactating woman who had ingested 10 mg of TRH orally twice a day for 7 days prior to blood sampling. TRH concentrations declined throughout each day while TSH rose slightly in the first 1 to 2 hours but remained within normal limits. The prolonged administration of 10 mg of TRH orally twice daily to three puerperally lactating women resulted in elevations in plasma TRH 2 to 3 hours following hormone administration, yet no significant increases in plasma TSH were observed. Both endogenous TRH and TSH were measured before and after 22 nursing events in nine puerperally lactating women. There was no change in the concentration of either substance and all values were similar to those obtained in normally menstruating women.

Administration, Oral↗
PubMed1978

Nursing-mediated prolactin and luteinizing hormone secretion during puerperal lactation.

Alterations in plasma prolactin (PRL) concentrations in response to nursing in puerperally lactating women are often significant beyond the 90th postpartum day, yet the increment appears unrelated to the frequency or duration of the nursing stimulus. Tonic gonadotropin secretion is low, assuming a more episodic secretory pattern either when the frequency of breast-feeding is reduced or when weaning takes place. Significant increments in peripheral concentrations of luteinizing hormone can be seen in response to weaning coincident with a fall in peripheral plasma PRL concentration. At the same time, peripheral estrogen concentrations increase, suggesting that a specific set point for ovarian responsiveness to gonadotropins exists. Whether this set point is related solely to the peripheral concentration of gonadotropins or whether it is also related to the peripheral PRL concentration is not known at this time.

Female↗
PubMed1975

Inhibition of cyclic gonadotropin secretion by endogenous human prolactin.

The resumption of cyclic uterine bleeding reportedly accompanies the use of human prolactin (HPRL)-suppressing agents in postpill galactorrhea-amenorrhea. In this laboratory, HPRL suppression with L-dopa was variable and short lived. Basal plasma HPRL levels were elevated before and after as much as five months of therapy. Galactorrhea persisted and mean gonadotropin concentrations were subnormal. An immediate and sustained attenuation of HPRL secretion ( less than 200 per cent) followed the use of 2-Br-alpha-ergocryptine (CB-154). Cyclic gonadotropin secretion resumed and was accompanied by ovulation and, in one instance, pregnancy. The cessation of galactorrhea was positively correlated with the rise in the daily concentration of 17 beta-estradiol. Cyclic postovulatory menstruation continued after the cessation of CB-154 treatment. HPRL levels remained normal. The daily patterns of human follicle-stimulating hormone (HFSH) and human tuteinizing hormone (HLH) secretion created by the suppression of HPRL displayed an inherent rhythmicity identical to that observed at the time of menarche. The inhibitory effects of HPRL appeared directed at cyclic rather than tonic gonadotropin secretion. At the same time, diminished ovarian estrogen production seemed to increase mammary gland sensitivity to HPRL, leading to lactation. One may postulate, therefore, that the ingestion of sex steroids is associated with an over-all suppression of endogenous cyclic and, to a lesser extent, tonic gonadotropin secretion secondary to which ovarian function is attenuated. Without physiologic concentration of circulating estrogen, HPRL induces mammary alveolar function with the production of a milklike secretion.

Amenorrhea↗