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Biomedical subjects

P Klein

Publications and source records attributed to P Klein.

At least 55 records · Page 3Linked to original sources
PubMed2000

Analysis of helical axes, pivot and envelope in active wrist circumduction.

OBJECTIVE: To study active wrist circumduction and planar moves, in terms of anatomical angles and envelope and of finite helical axes and mean pivot point. DESIGN: We measured the position of the "mean pivot point" and its mean distance to the axes as anatomical angles in an in vivo full range movement. BACKGROUND: The mean pivot point has been used in in vitro and roentgen stereophotogrammetric studies of wrist kinematics. However, the distribution of "3D centers of rotation" has never been presented in a non-invasive in vivo study. METHODS: A light 6 degrees of freedom electrogoniometer was built and employed in vivo to measure circumduction, flexion-extension and radioulnar deviation on both wrists of twenty one volunteers. RESULTS: Results were in general agreement with previously published ranges of wrist planar motion. The circumduction envelope proved to be a relevant representation of active wrist motion. The "mean pivot point" displayed a relative dispersion in localization of this point. CONCLUSION: The pivot results suggest that the wrist acts as a universal joint but with a non fixed location in the capitate head. The major axis of wrist envelope was not skew. RELEVANCE: The envelope and the precise knowledge of the helical axis pivot and its mean distance to the axes could give precious information on wrist functionality and stability after surgical or conservative treatment.

Adult↗
PubMed2000

Neoadjuvant radio-chemotherapy in advanced primarilynon-resectable carcinomas of the pancreas.

AIM: To investigate the feasibility of neoadjuvant radio-chemotherapy (RCT) in the treatment of primarily non-resectable pancreas carcinoma the parameters tumour regression, possibility of subsequent resection and tolerability were examined. METHOD: Between 1995 and 1997, 27 patients with locally inoperable (assessed by CT criteria) pancreatic carcinoma received radio-chemotherapy for 5 weeks comprising irradiation (55.8 Gy) and chemotherapy with 5-fluorouracil (5-FU, 1000 mg/m(2)/day; 120 h continuous infusion) and mitomycin C (10 mg/m(2)i.v.-bolus, day 2 and day 30) during the first and fifth week of radiotherapy. Two target volumes were irradiated with fractionated doses of 1.8 Gy up to a total of 50.4 Gy. Radiation was applied once a day five times a week and target volume 1 was irradiated with the same fractionated dose, and an additional boost of 5.4 Gy to make an overall total of 55.8 Gy. RESULTS: Sixteen patients underwent explorative laparotomy, 10 of these were resected (eight Whipple's procedures, two distal pancreatic resections), while six could not be resected due to peritoneal carcinosis (n=3), local irresectability (n=2) and liver cirrhosis (n=1). A further nine patients were found to have unresectable tumours on CT and did not undergo surgery after restaging (five of these patients were staged as < >, three patients had distant metastases and one patient refused surgery). In two patients RCT was abandoned because of progression of disease. CONCLUSIONS: The study protocol described is feasible without significant acute toxicity and when used the resectability rate was improved; the survival rate, however, was not improved. Additional intra-arterial or intraportal application of such drugs as mitomycin C or cisplatin may be necessary.

Adenocarcinoma↗
PubMed2000

Comparison of succinylcholine with two doses of rocuronium using a new method of monitoring neuromuscular block at the laryngeal muscles by surface laryngeal electromyography.

We compared the onset of neuromuscular block with succinylcholine (1 mg kg-1) and two doses of rocuronium (0.6 and 0.9 mg kg-1) at the adductor pollicis muscle using electromyography (EMG) and acceleromyography (AMG), and at the adductor laryngeal muscles with a new electromyographic method using a disposable surface electrode attached to the cuff of a tracheal tube. At the larynx, the mean (+/- SD) time to 90% block and the onset time of succinylcholine (38 +/- 15 and 47 +/- 19 s, respectively) were significantly shorter (P < 0.01) than for rocuronium 0.6 mg kg-1 (92 +/- 42 and 106 +/- 38 s) and rocuronium 0.9 mg kg-1 (52 +/- 31 and 64 +/- 30 s). We found that, with comparable degrees of neuromuscular block, the onset time of succinylcholine at the adductor pollicis was significantly shorter (P < 0.01) than for rocuronium 0.6 mg kg-1 and 0.9 mg kg-1 (EMG, 80 +/- 39 vs 145 +/- 48 s and 99 +/- 31 s; AMG, 90 +/- 39 vs 124 +/- 53 s and 106 +/- 38 s). Clinical duration at the adductor pollicis (AMG) was significantly longer (P < 0.01) for both rocuronium groups than for succinylcholine (T4:T1 = 0.7, 54 +/- 18 and 77 +/- 21 vs 8 +/- 6 min). The surface laryngeal electrode proved non-invasive, easy to use and reliable in measuring onset of the neuromuscular block at the larynx.

Adult↗
PubMed2000

Lateral asymmetry in activation of hypothalamic neurons with unilateral amygdaloid seizures.

PURPOSE: Reproductive disorders are unusually frequent among women with temporal lobe seizures. The particular type of disorder may be related to the laterality and focality of epileptiform discharges. Here we examined whether unilateral amygdaloid seizures activate hypothalamic neurons involved in reproductive function and reproductive endocrine secretion in female rats and whether such activation shows lateral asymmetry. METHODS: Numbers of Fos-immunoreactive (Fos-ir) neurons in various hypothalamic regions were compared for three groups of animals: (a) unilateral amygdala-kindled, (b) implanted but unstimulated, and (c) unimplanted. RESULTS: Fos-ir neurons showed strong ipsilateral occurrence in the medial preoptic, ventrolateral part of the ventromedial, and ventral premammillary nuclei, sexually dimorphic regions involved in reproductive endocrine regulation. No significant lateral asymmetry was observed for other investigated hypothalamic regions. CONCLUSIONS: Unilateral amygdaloid seizures activate hypothalamic neurons that regulate reproductive endocrine secretion in a laterally asymmetric fashion. This may explain the clinical association of different reproductive endocrine disorders with left and right temporal epileptiform discharges.

Amygdala↗
PubMed2000

Conjugation of camptothecins to poly-(L-glutamic acid).

Conjugation of water-insoluble cancer chemotherapeutic drugs to macromolecular polymers can lead to improved pharmaceutical properties and improved therapeutic ratios due to accumulation of the polymer-drug conjugate in tumor tissue through the enhanced permeability and retention (EPR) to macromolecules associated with tumor vasculature. Pharmaceutical shortcomings of certain active camptothecins including difficulty in formulation and instability of the active lactone form due to interactions with human albumin might be improved by conjugation to polymers. In this report, conjugations of camptothecin (CPT), 10-hydroxy-CPT, and 9-amino-CPT to poly-(L-glutamic acid) (PG) are described; coupling was accomplished either through the 20(S)-hydroxyl or 9 and 10 substituents with and without the use of a glycine linker. Studies using a PG paclitaxel conjugate (PG-TXL), which is currently in Phase I testing, demonstrated that PG enhanced aqueous solubility, prolonged plasma residence time, and greatly increased the distribution of paclitaxel to tumor tissue in a murine model. In this report, we describe the use of similar conjugation technology for CPT derivatives and demonstrate that these difficult to formulate compounds can be rendered water soluble, that their maximum tolerated doses are increased, and that they retain substantial anti-tumor activity in syngeneic and xenogeneic tumor models. Preliminary data suggest that PG with molecular weights between 37 and 50 kDa with CPT loading between 14% and 37% with or without glycine linkers display enhanced efficacy compared with nonconjugated camptothecins administered at their maximum tolerated dose.

Animals↗
PubMed2000

Helping the urban poor stay with antiretroviral HIV drug therapy.

Recent studies have documented dramatic decreases in opportunistic infections, hospitalizations, and mortality among HIV-infected persons, owing primarily to the advent of highly active antiretroviral medications. Unfortunately, not all segments of the population living with HIV benefit equally from treatment. In San Francisco, only about 30% of the HIV-infected urban poor take combination highly active antiretroviral medications, as compared with 88% of HIV-infected gay men. Practitioners who care for the urban poor are reluctant to prescribe these medications, fearing inadequate or inconsistent adherence to the complicated medical regimen. Persons typically must take 2 to 15 pills at a time, 2 to 3 times a day. Some of the medications require refrigeration, which may not be available to the homeless poor. Most homeless persons do not have food available to them on a consistent schedule. Therefore, they may have difficulty adhering to instructions to take medications only on an empty stomach or with food. Lack of a safe place to store medications may be an issue for some. In addition, many urban poor live with drug, alcohol, or mental health problems, which can interfere with taking medications as prescribed. Inconsistent adherence to medication regimens has serious consequences. Patients do not benefit fully from treatments, and they will become resistant to the medications in their regimen as well as to other medications in the same classes as those in their regimen. Development of resistance has implications for the broader public health, because inadvertent transmission of multidrug-resistant strains of HIV has been demonstrated. Concern that the urban poor will not adhere to highly active antiretroviral medication regimens has led to debate on the role of clinicians and public health officials in determining who can comply with these regimens. Rather than define the characteristics that would predict adherence to these regimens, the San Francisco Department of Public Health created a program to support adherence among those who may have the greatest difficulty complying with complicated highly active antiretroviral medication regimens. The program, dubbed the Action Point Adherence Project, was conceived through a community planning process in preparation for a city-wide summit on HIV/AIDS that took place in January 1998. Action Point is funded by the city and the county of San Francisco. Now in its 10th month, the program continues to show promising evidence of improving clients' biological and social indicators.

Adult↗
PubMed2000

[Methods for postoperative evaluation of complete excision of the mesorectum].

This study aimed at a more objective evaluation of the specimen after total mesorectal excision [14]. For this reason, a method yielding a simple stained preparation of the totally excised mesorectum was developed. By postoperative injection of 10 ml of an ink solution into the A. rectalis superior of 15 specimens, the arterial mesorectal vascular tree was filled. All specimens had been collected by means of total mesorectal excision. In two specimens, in wich the mesorectal sheath fascia had been injured due to the surgical manipulation, we observed the leakage of ink from the mesorectum even during the injection. In three further specimens, some ink leakage in the form of dots occurred from small opened arterioles after the injection was performed. No ink leakage was observed in the remaining specimens. Prior to the ink injection, thirteen specimens were macroscopically tested and found intact. Three of the fifteen specimens exhibited minor lesions of the mesorectum that would not have been detected macroscopically without ink tagging. The comparison of the findings provided by the surgeon with the histopathological evaluation showed that those specimens in which no ink leakage occurred had an unimpaired mesorectal sheath fascia. These specimens coorespond to the complete excision of the mesorectum and the removal of the tumor in a cancer-sealed package as long as the circumferential rim of the specimen has not been infiltrated by the tumor.

Coloring Agents↗
PubMed2000

Paclitaxel-induced apoptosis and mitotic arrest assessed by serial fine-needle aspiration: implications for early prediction of breast cancer response to neoadjuvant treatment.

The extent of tumor reduction from neoadjuvant chemotherapy for breast cancer correlates with outcome. We investigated whether the initial cellular responses to paclitaxel are related to the extent of tumor reduction. Eleven women with breast cancer received paclitaxel (every 2 weeks for 4 cycles) as neoadjuvant treatment. Serial fine-needle aspirations (FNA; 25-gauge, 1 pass) were obtained before treatment and at 24, 48, 72, and 96 h after the first paclitaxel dose. Microscopic counts of apoptotic and mitotic indices were performed. The change in cancer volume from treatment was determined using radiological measurements with allowance for change in the histopathological amount of cancer. Apoptotic and mitotic responses usually subsided within 4 days. The duration of the initial apoptotic response was different for women with different treatment results. Cumulative apoptotic response for the first 4 days inversely correlated with the proportion of residual cancer after neoadjuvant treatment. FNA is a versatile clinical method to obtain breast cancer cells for therapy response studies. Apoptotic response to the first dose of paclitaxel is almost complete within 4 days, implying that more frequent (weekly) paclitaxel dosing might be beneficial. The apoptotic response to the first dose of paclitaxel appeared to predict the amount of cancer reduction from this treatment. This is a promising start toward the development of an early chemopredictive assay for paclitaxel treatment of breast cancer.

Antineoplastic Agents, Phytogenic↗
PubMed1999

Acute toxicity and sublethal effects of white phosphorus in mute swans, Cygnus olor.

Among the waterfowl affected by white phosphorus (P4) at a military base in Alaska are tundra (Cygnus columbianus) and trumpeter (C. buccinator) swans. To estimate the toxicity of P4 to swans and compare the toxic effects to those of mallards (Anas platyrhynchos), we dosed 30 juvenile mute swans (C. olor) with 0 to 5.28 mg P4/kg body weight. The calculated LD50 was 3.65 mg/kg (95% CI: 1.40 to 4. 68 mg/kg). However, many of the swans still had P4 in their gizzards after dying, as determined by "smoking gizzards" and characteristic odor, and a lower LD50 might be calculated if all of the P4 had passed into the small intestines. We attribute the retention of P4 in swans to the possibility that P4 pellets were mistaken for the similarly sized grit in their gizzards. Most swans took 1 to 4.5 days to die in contrast to the few hours normally required in mallards and death appeared to be related more to liver dysfunction than to hemolysis. White phosphorus affected several plasma constituents, most notably elevated aspartate aminotransferase, blood urea nitrogen, lactate dehydrogenase, and alanine aminotransferase.

Analysis of Variance↗
PubMed1999

Limitation in gamma probe localization of the sentinel node in breast cancer patients with large excisional biopsy.

BACKGROUND: Radiolocalization and selective biopsy of the sentinel node to correctly predict the status of remaining lymph nodes may provide an alternative to axillary dissection in selected breast cancer patients with clinically negative lymph nodes. STUDY DESIGN: In a nonrandomized, multicenter clinical trial, gamma probe localization for lymphatic mapping and sentinel node biopsy along with axillary dissection was performed on 75 patients with invasive breast cancer and clinically negative lymph nodes. The accuracy of the sentinel node biopsy to correctly predict the status of the remaining axillary lymph nodes was established through standard pathologic investigation. RESULTS: A sentinel node was identified in 70 of 75 patients with a technical success rate of 93%. Of these 70 patients, 21 (30%) had axillary nodal metastases identified pathologically. Four of these 21 (19%) had sentinel nodes negative for metastases. All 4 false-negative patients had prior excisional biopsies. The false-negative group had a larger mean maximal biopsy dimension than the true-positive group. Eleven of the 21 patients with axillary metastases had a diagnosis made by core needle biopsy with no false negatives. CONCLUSIONS: The accuracy of the sentinel node biopsy in correctly predicting the status of remaining axillary lymph nodes may be limited in patients with large excision before radiolocalization of the sentinel node. Our findings suggest that excisional biopsy should be avoided prior to lymphatic mapping for sentinel node biopsy.

Adult↗
PubMed1999

Organ-preserving surgery for multicentric carcinoma of the pancreas.

Multicentric ductal carcinoma of the pancreas is usually treated by total pancreatectomy if surgically resectable. We present a case of metachrone, multicentric ductal carcinoma of the pancreas which was treated using an organ-preserving method. The reasons for doing so and the oncological and functional outcomes are discussed.

Adenocarcinoma↗
PubMed1999

Association of low preoperative serum albumin concentrations and the acute phase response.

OBJECTIVE: To investigate the incidence of a preoperative acute phase response and its association with low albumin concentrations. DESIGN: Prospective open study. SETTING: Teaching hospital, Germany. SUBJECTS: 225 patients who were to undergo major abdominal operations, and who had no acute infections. INTERVENTIONS: Measurements of serum concentrations of albumin, C-reactive protein (CRP), alpha-1 antitrypsin, and interleukin-6 (IL-6). RESULTS: Abnormal concentrations of acute phase proteins (indicating an acute phase response) were detected in 43 of 225 patients (19%). The mean (SD) albumin concentration in these patients (35[5]g/L) was lower than that of patients who did not mount an acute phase response preoperatively (40[5]g/L). High concentrations of CRP (> or =60mg/L) were associated with low albumin concentrations (33[5]g/L); high alpha-1 antitrypsin concentrations (> or =4.0g/L) were associated with low albumin concentrations (34[6]g/L); and high IL-6 concentrations (> or =4pg/ml) were associated with low albumin concentrations (37[6]g/L) compared with a mean(SD) albumin concentration of 40(5)g/L in patients who had no evidence of an acute phase response. CONCLUSION: A metabolic response to disease referred to as an acute phase response may explain low preoperative albumin concentrations. This association interferes with the association of low preoperative albumin concentrations and malnutrition. It is a new aspect of preoperative risk evaluation and may indicate a potential for prevention.

Acute-Phase Proteins↗
PubMed1999

Fat partitioning of lidocaine in tumescent liposuction.

Despite the fact that toxicity is associated with tumescent liposuction, even with large quantities of injected lidocaine, no study to date has quantitated the percentage of injected lidocaine removed by aspiration, or the quantity partitioned into the aspirated fat. The aim of this study was to quantitate, on a mass basis, the percentage of injected lidocaine removed by aspiration both in the fat as well as the fluid component of the aspirate. Eight consecutive patient aspirate samples were analyzed as part of an ongoing study. An in vivo partition coefficient of lidocaine in fat vs. fluid was derived that suggests that the lidocaine diffuses preferentially into the fat matrix prior to suctioning. A distribution factor was derived that relates the effective aspirate concentration to the instilled concentration, allowing an estimate of lidocaine recovery based on the amount injected.

Adipose Tissue↗
PubMed1999

A randomized equivalence trial comparing the efficacy and safety of Luffa comp.-Heel nasal spray with cromolyn sodium spray in the treatment of seasonal allergic rhinitis.

BACKGROUND: The objective of the clinical study was to investigate the efficacy and tolerance of a homeopathic nasal spray in cases of hay fever (seasonal allergic rhinitis) in comparison with the conventional intranasal cromolyn sodium therapy. PATIENTS AND METHODS: In total, 146 outpatients with symptoms of hay fever were enrolled into the clinical study (randomized, double-blind, equivalence trial) (time of treatment: 42 days). The homeopathic remedy (Luffa comp.-Heel trade mark Nasal Spray, dosage: 0.14 ml per application, 4 times per a day / naris) consisted of a fixed combination made up of Luffa operculata, Galphimia glauca, histamine, and sulfur. The main outcome measure of the efficacy was the quality of life as measured by means of the Rhinoconjunctivitis Quality of Life-Questionnaire (RQLQ). The tolerance of the trial medication was registered by means of global assessment, rhinoscopy, recording of adverse events and with the aid of vital and laboratory parameters. RESULTS: The results of the study demonstrate a quick and lasting effect of the treatment. This effect was independent from the medication applied and produced a nearly complete remission of the hay fever symptoms. The RQLQ global score changed significantly in the course of the treatment, indicating therapeutic equivalence between the two forms of treatment. Adverse systemic effects did not occur. Local adverse events appeared in 3 patients. CONCLUSIONS: The study proved that, for the treatment of hay fever, the homeopathic nasal spray is as efficient and well tolerable as the conventional therapy with cromolyn sodium.

Administration, Intranasal↗
PubMed1999

[Galenic, concerted choice and compliance in hormonal replacement therapy].

A survey was conducted in May-June 1998 among 394 French menopausal women in order to better understand opinions, attitudes and habits of HRT users. Matters such as information, importance of a concerted choice between doctor and patient and treatment improvement were also mentioned for a better compliance.

Choice Behavior↗