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Biomedical subjects

M Herman

Publications and source records attributed to M Herman.

At least 55 records · Page 3Linked to original sources
PubMed1998

A modified method of intracytoplasmic sperm injection without the use of polyvinylpyrrolidone.

In a controlled study we compared the outcome of intracytoplasmic sperm injection (ICSI) performed by two different methods. The oocytes from 20 patients were equally divided into two groups and injected either by conventional ICSI using polyvinylpyrrolidone (PVP) or by a modified PVP-free ICSI procedure. While in the conventional ICSI method the spermatozoon is aspirated into the injection pipette, in the modified ICSI procedure the spermatozoon is attached to the end of the narrow micropipette by aspirating its tail. The sperm head is never drawn into the pipette. Accordingly, even a fast-moving spermatozoon can be 'caught' easily. As a result of such an aspiration the spermatozoon loses its motility. Therefore, PVP is required neither to slow down the movement of the spermatozoon nor to facilitate the movement of the solution in the injection pipette. A total of 230 mature oocytes were injected by both methods and the results were analysed. No differences were observed in survival rate between the two ICSI procedures (89% and 91%, respectively). However, the proportion of normally fertilized oocytes was significantly higher after microfertilization by modified ICSI (74%) when compared with the outcome of the conventional ICSI method (62%). The frequency of abnormal fertilization was not influenced by the method of ICSI used. The cleavage rate and quality of resulting embryos were also comparable. In conclusion, we have demonstrated a modified ICSI method which does not require the use of PVP. When compared with the conventional ICSI procedure, even better fertilization rates can be achieved. The proposed ICSI modification may provide an alternative procedure for elimination of the potentially harmful effects which may be associated with conventional ICSI.

Cleavage Stage, Ovum↗
PubMed1998

The femoral artery-femoral vein polytetrafluoroethylene graft: a 14-year retrospective study.

BACKGROUND: The use of the femoral vessels for permanent haemodialysis access has been neglected during the last two decades. Since 1981 femoral artery-vein loop polytetrafluoroethylene grafts have been constructed in our chronic haemodialysis patients. This study examines results obtained in patients with this particular graft over the last 14 years. METHODS: This clinical study is retrospective in nature. Overall 35 patients, with 37 femoral grafts, are included. Inclusion and exclusion criteria for this type of graft are given and the surgical procedure detailed. RESULTS: Seven patients had femoral grafts used as primary dialysis access. Twenty-eight patients had femoral grafts used after multiple access failures. There was no perioperative mortality. Immediate thrombotic non-function of the graft occurred in three patients. In the long term no patient death was related to the femoral grafts. Twenty-seven (73%) grafts had no long-term complications. The leading cause for graft 'loss' was patient death; in the first year 10 grafts were lost, eight because of patient death. All eight patients died with functioning grafts. Median graft survival was 21 months in all patients and 28 months in non-diabetic patients. Twenty-seven (73%) grafts were patent at the end of the first year, 33% of grafts were still patent after 5 years. Worsening claudication occurred in four patients; one diabetic required foot amputation. Four patients had late graft thrombosis; only two patients had bacteraemia originating from the femoral graft. Urea reduction ratio greater than 60% was measured in 87.5% of patients. CONCLUSION: The femoral artery vein graft is a good primary and secondary haemodialysis access. Both infection and thrombosis rates are low and graft survival is comparable, if not superior to, that of upper-limb grafts. The graft is easy to cannulate, can be used early, is easily protected, and is cosmetically acceptable.

Adult↗
PubMed1998

The impact of antioxidant and splanchnic-directed therapy on persistent uncorrected gastric mucosal pH in the critically injured trauma patient.

BACKGROUND: Critically ill trauma patients with gastric intramucosal acidosis, as measured by gastric tonometry, have an increased incidence of multiple organ dysfunction syndrome despite supranormal O2 delivery. We altered our resuscitation protocol to maximize splanchnic blood flow and decrease oxygen-derived free radical damage. DESIGN: Prospective clinical trial with historical controls. METHODS: The protocol differed from control by including administration of folate, mannitol, and low-dose isoproterenol. All patients had gastric tonometers and pulmonary artery catheters. If the intramucosal pH (pHi) was less than 7.25, splanchnic-sparing inotropic and vasodilatory agents were used to optimize systemic cardiac output. Two groups of trauma patients with persistent intramucosal acidosis at 24 hours (pHi < 7.25) were compared: a control group (n = 7), and patients who received the splanchnic/antioxidant protocol (n = 13). RESULTS: The two groups were similar based on Acute Physiology and Chronic Health Evaluation II score, Injury Severity Score, age, cardiac index, oxygen delivery, and oxygen consumption. The "splanchnic therapy" group had fewer organ system failures as well as shortened length of intensive care unit and hospital stay. Three of 7 patients in the control group and 2 of 13 patients in the splanchnic therapy group had a final pHi < 7.25. CONCLUSION: Gastric tonometry-guided resuscitation and antioxidant/splanchnic therapy in critically ill trauma patients with persistent gastric mucosal acidosis may decrease multiple organ dysfunction syndrome.

APACHE↗
PubMed1998

CO2 asphyxia increases plasma norepinephrine in rats via sympathetic nerves.

The objective of this study was to determine whether the plasma norepinephrine (NE) increase in rats exposed to CO2 asphyxia was due to adrenal gland release or sympathetic nerve ending (SNS) release. Plasma NE was measured by high-performance liquid chromatography in hypertensive and normotensive rats using the following protocol: control session, CO2 exposure, N2 exposure, reserpine + CO2, and adrenalectomy + CO2. Four strains of male and female rats were used: spontaneously hypertensive rats, Wistar-Kyoto rats, and two congenic strains with different Y chromosomes. The same rats were used throughout the experiment (n = 80). Blood pressure measured by aortic telemetry increased approximately 50-60 mmHg in response to CO2 in all strains. CO2 increased NE 6-10x in all strains and both genders. N2 produced a significant increase in NE (73% of CO2 response). Reserpine significantly decreased (67%) plasma NE after CO2. Adrenalectomy did not significantly reduce the NE response to CO2. In conclusion, the increase in plasma NE after CO2 was associated with SNS release and not adrenal medullary release, was mainly due to hypoxia, and was not a specific response to CO2.

Adrenalectomy↗
PubMed1998

Paraganglioma of the cauda equina: case report and review of the MRI features.

We report a case of paraganglioma of the cauda equina and review the MRI features in 11 previously published cases with MRI description. On T1-weighted images, paraganglioma is isointense relative to spinal cord and shows moderate to intense enhancement after Gd-DTPA application, usually with heterogeneous texture. On T2-weighted images, different findings were found. MRI features do not allow to distinguish paraganglioma of the cauda equina from majority of other tumors in this region.

Cauda Equina↗
PubMed1997

High-Resolution Spectroscopic Investigation of nu16 in trans-1,2-Dichloroethane

We report on the first detailed rovibrational analysis in 1,2-dichloroethane. It concerns the a-type nu16 absorption band of gaseous trans-1,2-dichloroethane at 1232 cm-1, which we have recorded using a Fourier transform interferometer, under room temperature and jet-cooled experimental conditions. The rotational analysis of the almost diatomic-like prominent R and P structures in nu16 is performed for trans-1,2-12C2H435Cl2 and trans-1,2-12C2H435Cl37Cl. The nuclear spin statistics is discussed for various isotopomers and isomers of 1,2-dichloroethane. The complex absorption pattern observed at the band center is tentatively assigned in terms of overlapping Q branches, arising from fundamental bands involving different isotopomers in natural abundance (with 35Cl and 37Cl), and from related hot bands involving the three lowest vibrational modes in the molecule, nu6, nu10, and nu18. Copyright 1997 Academic Press. Copyright 1997Academic Press

Journal Article↗
PubMed1997

Characterization of ligand binding, DNA binding and phosphorylation of progesterone receptor by two novel progesterone receptor antagonist ligands.

In order to gain a better understanding of the distinctive mechanisms of the various types of antiprogestins, we have characterized in vitro ligand binding, specific DNA binding and phosphorylation of progesterone receptor (PR) from T47D cells after treatment of cells with progestins (progesterone, R5020) and antiprogestins (RU486, ZK98299, Org 31806 and Org 31710). Treatment of the cells with R5020 or PR antagonists, with the exception of ZK98299, resulted in a quantitative upshift of PR-A and PR-B indicative of ligand/DNA-induced phosphorylation of PR. Treatment of cells with RU486, Org 31710 or Org 31806, but not R5020 or ZK98299 resulted in detectable PR-progesterone response element complexes (PR-PREc) as assessed by gel mobility shift assay. Although treatment of cells with ZK98299, a type I PR antagonist, did not induce phosphorylation, the antiprogestins, Org 31806 and Org 31710, in a manner identical to RU486, did. Our data suggest that Org 31806 and Org 31710 affect properties of PR from T47D cells that are similar to RU486.

Binding, Competitive↗
PubMed1997

A longitudinal study of substance use and abuse in a single class of medical students.

PURPOSE: A longitudinal study to ascertain the attitudes toward, and habits of, substance use among a single class of medical students. METHOD: A single class from a northeastern medical school was surveyed in both its first year (February 1991, 176 students) and its third year (May 1993, 170 students). The students were asked to report how frequently during the prior year they had used drugs or alcohol, and whether their use of each substance had increased, decreased, or remained the same since entering medical school; to identify any family members with histories of alcohol or drug problems; and to report any incidence during the prior year of ten behaviors associated with substance dependence. The students were also asked to indicate their agreement or disagreement with 11 attitudinal statements. Additional attitudinal items asked the students to identify three major deterrents to the abuse of drugs and alcohol, and what they had done if they had become aware of a classmate with a drug or alcohol problem. Chi-square analysis and two-tailed t-tests were used to compare data from the two surveys. RESULTS: The response rates in the first and second surveys were 96.9% and 81.8%, respectively. Use of licit and illicit substances was comparable to that of chronological peers and prior national studies of medical trainees. Most of the students admitted to using alcohol at least once in the prior year (91.8% and 95%, respectively). In both years marijuana was the illicit drug used most often. Although there was a slight increase over time in the use of benzodiazepines (2.4% to 5.8%) and a decrease in the use of marijuana (29.4% to 21.7%), these changes were not significant. Few of the students in their third year reported using any substance other than alcohol more than once a month. In general, a greater percentage of the students reported a decrease rather than an increase in the use of a substance since entering medical school; the primary exception was for wine. As they progressed in their training, the students became less concerned about the effect of substance use on their performance and more likely to be embarrassed about admitting to an addiction. Although in each year a few of the students appeared to be at risk for substance dependence (8.9% and 3.5%, respectively), no student came to the attention of the administration because of problems related to substance use. While most of the students were unaware of any classmate who had a problem, half of those who were aware had done nothing, and the balance had rarely sought assistance from the faculty or administration. CONCLUSION: Although there was no evidence that substance use was a major problem, a few of the students appeared to be at risk for drug or alcohol dependence. Appropriate intervention, support, and referral systems should be identified for the few who may be at risk, and increased educational efforts are needed to help all students address this issue with their peers and, ultimately, with their patients.

Adult↗
PubMed1997

Presentation and management of hydromyelia in children with Chiari type-II malformation.

Hydromyelia in patients with myelomeningocele and Chiari-II malformation is a relatively frequent finding on MRI studies. However, not all children develop symptoms from the hydromyelia that requires treatment. Furthermore, treatment of hydromyelia in spina bifida patients is rather complex due to the associated malformations. The authors retrospectively analyzed 231 MRI studies carried out on spina bifida patients who presented neurological deterioration. Hydromyelia was found in 48.5% of the patients. Forty-five children with severe hydromyelia required treatment. These patients were first divided into 2 groups: those with holocord hydromyelia, and those with a segmental lesion. Fifteen patients presented symptoms characteristic of symptomatic Chiari-II malformation: neck rigidity; swallowing difficulty; pain in the upper extremeties; weakness or spasticity in the upper extremeties. Eighteen patients presented symptoms typical of the tethered cord syndrome: scoliosis; worsening bladder and/or bowel function; pain in the lower extremeties; weakness or spasticity in the lower extremeties. Twelve patients presented a mixed-type symptomatology. These patients subsequently underwent posterior cervical decompression, tethered cord release or insertion of a hydromyelia-pleural shunt according to the type of presenting symptoms and to the extent of the hydromyelic lesion. A pattern of successful treatment was identified for each type of presenting clinical and radiological picture. This has allowed the authors to determine an algorithm for optimal treatment of hydromyelia associated with Chiari-II malformation and myelomeningocele, which is proposed here.

Age of Onset↗
PubMed1997

Integrating primary care and methadone maintenance treatment: implementation issues.

Linking primary medical care with methadone maintenance treatment brings critical services to drug users, many with HIV/AIDS, tuberculosis and other illnesses. However, a variety of important philosophical, ethical, and systems issues may impede the process of implementing a "linked" service delivery model. Conflicting paradigms, such as the traditional "doctor-patient" relationship with its emphasis on continuity of care and the substance abuse treatment model of limit-setting and behavioral consequences, create tension in the treatment system. This article describes these tensions and uses clinical vignettes to demonstrate how to address these implementation issues. In conclusion, solutions are proposed for successfully integrating services for medically ill substance abusers.

Adult↗
PubMed1997

Clinical response to clozapine treatment of 11 chronic patients in a state psychiatric hospital.

The aim of this study was to evaluate the clinical response to clozapine of 11 treatment-resistant patients with schizophrenia. Nine male and two female inpatients of a state psychiatric hospital, with at least a 2-year history of unresponsiveness to adequate trials of at least three antipsychotics and from chemically distinct groups, were challenged with clozapine. Clinical assessment involved baseline and repeated post-baseline ratings using the Brief Psychiatric Rating Scale (BPRS), the Clinical Global Impressions Scale (CGI), the Nurses Observation Scale for Inpatient Evaluation (NOSIE-30), and the Abnormal Involuntary Movement Scale (AIMS). Progression to lower categories of care was used as an additional outcome measure. Statistically significant reductions were achieved in global symptomatology, positive psychotic symptoms, and hostility. A statistically significant improvement occurred on the Social Interest factor; however, improvements in the remaining negative symptoms were not statistically significant. Reductions in psychopathology enabled eight patients to progress to lower categories of care with five patients moving to community care. The results indicate that clozapine was effective in treating hospital patients with a very severe form of mental illness.

Adult↗
PubMed1997

[Less common metastases of colorectal adenocarcinoma].

The authors present an account on four patients, treated because of colorectal carcinoma who had solitary secondaries of a colorectal tumour at less common sites. Twice a secondary in the urinary bladder wall was found once in the right cerebral hemisphere and once in the humerus.

Adenocarcinoma↗
PubMed1997

[Magnetic resonance in cardiology--a new alternative in noninvasive diagnosis].

The authors describe their initial experience with examination of the heart by magnetic resonance (MR) and discuss its position in the diagnostic algorithm of cardiac examinations:. They made 31 MR examinations of the heart in 30 patients. Echocardiography preceded 29 examinations. MR proved to be particularly useful where echocardiography did not lead to a decisive conclusion and called for confirmation by another method, or where it could not be carried out or its result was not consistent with the patient's clinical condition or the results of other examinations. The quality of the MR image was influenced most by the possibility of ECG gating. The latter was not possible in 16 patients (51.6%). In three of these (18.8%) the images were of such poor quality that they did not provide adequate diagnostic information. Images suitable for evaluation were obtained in 28 examinations (90.3%)--in these patients the MR information was valuable for establishment of the diagnosis. Magnetic resonance is a new possible method in the non-invasive diagnosis of heart disease. In the majority of cases it follows after echocardiographic examination which remains due to its accessibility the basic non-invasive method for examination of the heart.

Adolescent↗
PubMed1996

[Neurosarcoidosis. Role of new examination methods for early diagnosis and therapy].

BACKGROUND: Affection of the nervous system is one of the most serious forms of sarcoidosis. The objective of the present work was to evaluate the prevalence and manifestations of this disease, contemporary opportunities of its diagnosis and the importance of early adequate therapy. METHODS AND RESULTS: Neurosarcoidosis was diagnosed in seven patients (4 men and 3 women) from a total number of 211 patients with sarcoidosis in 1977 to 1993. The mean age of the patients with neurosarcoidosis was 47 years. In six patients affection of the nervous system was the first clinical manifestation of the disease. In four patients it was paresis of the facial nerve, in two instances diabetes insipidus, in two instances affection of the spinal cord with subsequent spastic triparesis or paraparesis of the lower extremities, in one instance the disease was manifested by neuralgia of the trigeminal nerve. The serious character of the disease is apparent from the fact that only in two instances complete regression of symptoms occurred. In three patients regression was partial, in one instance the affection persisted without changes and in one instance it progressed to metabolic breakdown with a fatal outcome. In the differential diagnosis examination of the nervous system by computed tomography, magnetic resonance and possibly perimyelography proved to be helpful. In all instances there was a typical finding in cerebrospinal fluid. Lymphomonocytic pleocytosis was present, a raised protein content, elevated gammaglobulin levels. The diagnosis was assisted by radiograms of the chest and biopsy. The latter was made from intrathoracic or subcutaneous nodes, in one instance from muscle. As auxiliary methods the following were used: tuberculin test, bronchoalveolar lavage, pulmonary gallium scintigraphy, serum level of angiotensin converting enzyme and immunological examination. CONCLUSIONS: The authors emphasize the necessity of early diagnosis and intensive initial treatment with corticoids or antimalaria drugs, which may prevent the development of irreversible changes. Magnetic resonance appears to be the most promising examination method in neurosarcoidosis.

Adult↗