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Biomedical subjects

P Hartmann

Publications and source records attributed to P Hartmann.

At least 55 records · Page 3Linked to original sources

Measurements of chain length distributions in calcium phosphate glasses using 2D 31P double quantum NMR.

31P double quantum (DQ) NMR is used for improved studies of the structure of phosphate glasses. The common Qn notation of the network forming tetrahedral phosphate units with n bridging oxygen atoms is extended to Qn,jkl indicating the Q type of the bonded adjacent units by the additional superscripts j,k and l. It will be shown that: (i) Q1 units have different isotropic chemical shifts depending on whether they form diphosphate anions in the amorphous state (Q1,1) or end groups of chains (Q1,2) and (ii) that even Q2 units possess different isotropic chemical shifts such that in the DQ dimension Q2,11 can be distinguished from Q2,12 and middle groups of longer chains or rings (Q2,22). Based on this result the opportunity for measuring chain length distributions in the amorphous state is discussed and first results for binary calcium phosphate glasses are presented. The advantages and also the limitations of this novel approach will be discussed.

Calcium Phosphates↗

Intracerebellar tuberculoma in a patient with AIDS. A case report.

The incidence of tuberculosis in HIV-infected patients has increased continuously over the past ten years. Extrapulmonary manifestations have become more frequent in AIDS patients than in immunocompetent hosts. Here we report about a patient with an unusual presentation of extrapulmonary tuberculosis. Our case report indicates that differential diagnosis of brain lesions in HIV-infected patients should include tuberculosis. In uncertain cases, it is indispensable to obtain specimens by craniotomy or stereotactic biopsy.

AIDS-Related Opportunistic Infections↗

The macrophage-induced gene mig as a marker for clinical pathogenicity and in vitro virulence of Mycobacterium avium complex strains.

The capacity of 20 Mycobacterium avium complex isolates to multiply intracellularly in human monocyte-derived macrophages was assessed and correlated to the clinical relevance of each isolate and its reactivity with several candidate genetic virulence markers. The strongest correlation with a virulence phenotype was found for a conserved coding sequence of the macrophage-induced gene mig identified by a specific mig restriction fragment length polymorphism type.

Biomarkers↗

Polymerase chain reaction for diagnosis and species differentiation of microsporidia.

Polymerase chain reaction (PCR) techniques have been developed for the detection of microsporidian DNA in different biological samples. We used sequence data of the rRNA gene for the identification of Enterocytozoon bieneusi, Encephalitozoon intestinalis, E. cuniculi, and E. hellem in different biological samples of HIV-infected patients by PCR, Southern blot hybridization, restriction endonuclease digestion analysis, cloning, and comparative genetic sequencing. One primer pair was used for amplification of the entire small subunit (SSU)-rRNA gene of E. bieneusi, E. intestinalis, and E. hellem from samples with electron microscopy confirmed infection. The amplified 1.2 kb SSU-rRNA gene fragments were ligated into a pMOSBlue T-vector, transfected into pMOSBlue competent cells, and were used as positive controls. Several primer pairs and hybridization probes were used to amplify and identify microsporidian DNA from different samples. Light microscopical examination of samples was performed in all patients and transmission electron microscopy was done on a subset of patient samples. DNA products were obtained from all samples with confirmed microsporidial infections. The identity of the DNA fragments was determined by Southern blot hybridization or by restriction endonuclease digestion analysis or by DNA sequencing. The results show that PCR is a reliable and sensitive indicator for the presence of microsporidian DNA in different biological samples of HIV-infected patients. PCR can be used further for species differentiation of microsporidia, even between species which cannot be differentiated by light and/or electron microscopy.

Animals↗

[Cystic form of Pneumocystis carinii pneumonia].

BASIC PROBLEM AND OBJECTIVE: In rare instances Pneumocystis carinii pneumonia (PCP) can occur in a cystic form, characterized by an acute course. The correct diagnosis is often missed. An analysis of a large cohort of patients with PCP was undertaken to determine the incidence and clinical manifestations of this form of the disease. PATIENTS AND METHODS: Data on all HIV-positive patients on the hospital registry, hospitalized with the diagnosis of PCP between January 1988 and July 1996, were retrospectively analysed. To be included in the study, PCP had to have been confirmed microscopically on bronchial lavage or histologically by lung biopsy. The chest radiogram and (if available) computed tomogram of these patients were examined for possible cystic changes, and clinical as well as laboratory findings recorded. RESULTS: Five of 180 patients with PCP had cystic changes (2.8%). The interval between first symptoms and diagnosis ranged from 30 to 200 days (median: 32 days). All five patients (age: 24-49 years; all males) had a far advanced immunological disorder (median CD4 count: 10/microliter) and were in stage C3 (Centers for Disease Control). Three of the five patients had prophylactically inhaled pentamidine (300 mg/month). Bronchial lavage was false-negative in three of the five cases. One patient had a spontaneous pneumothorax. Lactate dehydrogenase levels were normal or only slightly elevated (207-417 U/l; median 305 U/l). Both the cavities and thin-walled cysts were demonstrated radiologically, but were more visible on CT than on the X-ray film. All patients responded well to the medication with cotrimoxazole, but the prognosis was poor with a survival time of only 0.3 to 16 months. CONCLUSION: PCP should be included in the differential diagnosis when HIV patients have cystic lung changes. Invasive diagnostic methods are often required to avoid wrong diagnosis and superfluous therapeutic interventions.

Adult↗

Structured patient education for out-patients with hypertension in general practice: a model project in Germany.

In a model project, office-based physicians in two regions of Germany provided a structured treatment and teaching programme for out-patients with hypertension. The project was carried out in co-operation with the German Hypertension League and designed to evaluate the practicability and efficacy of the implementation in routine primary health care. A total of 111 primary health care practices in two German districts who had participated in a training course were interviewed. In 43 of these offices documented data of all patients who had received the standardised treatment and teaching were evaluated. The programme was well received by the physicians of which 81% rated the training course and 93% the teaching material as 'very good' or 'good'. A total of 466 patients were trained. Data collected on 272 patients (22 weeks after the intervention) demonstrated the efficacy of the programme at treatment level: reduction of body weight (2 kg, P < 0.001) and blood pressure (from systolic 158+/-18 to 148+/-17 mm Hg, P < 0.001; diastolic 91 +/-9 to 86+/-9, P < 0.001). Sixty-five per cent of patients learned for the first time how to perform blood pressure self-monitoring during the programme. The number of blood pressure readings by the patients' increased significantly from 1+/-3 measurements per week before, to 8+/-7 measurements per week after the programme (P < 0.001). The results of the study demonstrate the practicability and efficacy of the implementation of the programme for patients with hypertension into routine primary health care.

Adult↗

Limited value of PCR for detection of Toxoplasma gondii in blood from human immunodeficiency virus-infected patients.

Cerebral toxoplasmosis is a common, opportunistic, and often life-threatening disease in HIV-infected patients. Diagnosis is supported mainly by clinical evidence and computerized tomography or magnetic resonance imaging scans, but brain images may share features with other brain diseases occurring in HIV-infected patients. To determine the diagnostic value of PCR for the detection of Toxoplasma gondii in blood from HIV-infected patients, we examined 89 blood samples from 59 HIV-infected patients. PCR and Southern blot hybridization were done with DNA extracted from blood samples from 20 patients with confirmed cerebral toxoplasmosis and from 10 patients with suspected but not confirmed cerebral toxoplasmosis. The samples were taken before and 7 to 10 days after the beginning of antiparasitic therapy. For 9 patients who suffered from cerebral toxoplasmosis more than 6 months prior to the study and for 20 patients without any evidence for toxoplasmosis only one blood sample per patient was examined. PCR gave positive results with 5 of the 20 blood samples from patients who suffered from cerebral toxoplasmosis. After 7 to 10 days of therapy PCR results became negative in all these five cases. No amplification was seen with DNA from blood samples from the other 54 patients as the target. The results presented here show that PCR testing of blood samples from HIV-infected patients is of limited value for the diagnosis of cerebral toxoplasmosis. The sensitivity was only 25%, but the specificity was very high (100%), so this technique may be useful for discriminating between cerebral toxoplasmosis and other brain diseases which may be mistaken for toxoplasmosis.

HIV Infections↗

Glare sensitivity and visual acuity after excimer laser photorefractive keratectomy for myopia.

BACKGROUND: Following excimer laser photorefractive keratectomy (PRK), an increase in glare sensitivity and a reduction in contrast sensitivity can occur owing to changes in the cornea (structure and topography). In this study, an attempt was made to quantify and document objectively a change in those subjective perceptual factors. METHODS: Snellen visual acuity and disability glare were measured with the Berkeley glare test preoperatively as well as 1, 3, 6, 9, and 12 months postoperatively, after excimer laser photorefractive keratectomy (PRK) on 32 myopic patients (46 eyes). During the postoperative progress checks, haze was graded and contrast sensitivity was measured with the Vistech chart. All the data were statistically analysed by multiple regression. RESULTS: One year after PRK, a reduction in visual acuity (VA) measured with the low acuity contrast chart (10%) with and without glare could still be found, despite the fact that acuity measurements with a high contrast Snellen chart showed the same VA 6 months postoperatively as well as before the treatment. The lowest VA could be measured 1 month postoperatively; thereafter, the acuity increased despite the increase in haze that occurred during the first 3 months. CONCLUSION: Disability glare and a reduction in contrast sensitivity could be observed in most patients after PRK treatment with the Meditec laser system with its scanning slit. The future will show if new technology and a broader flattening area of 6 to 7 mm can minimise these postoperative complications.

Adult↗

Structured treatment and teaching programme for type 2 diabetic patients on conventional insulin treatment: evaluation of reimbursement policy.

The aim of the study was to evaluate the practicability and efficacy of a structured treatment and teaching programme (STTP) for type 2 diabetic outpatients on conventional insulin treatment after introducing remuneration for physicians. Reimbursement policy for the STTP was introduced in the state of Brandenburg, Germany, in July 1993. Between August 1993 and February 1994, 108 physicians and their assistants participated in a postgraduate seminar, which is a prerequisite for remuneration. A standardised interview was performed with 103 physicians and their paramedical personnel. Twenty of the practices who had performed STTP were visited in order to collect data on all the patients who had participated in the programme up to September, 1994. Within the first year already 10% of the target group of physicians participated in the seminars. The seminar and the programme were very well accepted. An improvement of HbA1c levels was observed in patients who had started insulin treatment (n = 35: 9.7 +/- 1.6% of total Hb before, 8.2 +/- 1.3% of total Hb after the programme) and in those who were already being treated with insulin before the STTP (n = 125: 9.6 +/- 2.5% of total Hb before, 8.1 +/- 1.4% of total Hb after the programme). The results of the study demonstrate the efficacy and practicability of an STTP for type 2 diabetic patients on conventional insulin therapy in ambulatory health care.

Diabetes Mellitus, Type 2↗

Polymerase chain reaction for microsporidian DNA in gastrointestinal biopsy specimens of HIV-infected patients.

OBJECTIVE: To study the accuracy of polymerase chain reaction (PCR) for microsporidian DNA in gastrointestinal biopsy specimens of HIV-infected patients for the diagnosis of intestinal microsporidiosis. SETTING: Infectious disease in- and outpatient clinic of a university hospital in Cologne, Germany. PATIENTS: Forty-six HIV-infected patients with diarrhoea. METHODS: PCR and Southern blot hybridization were performed using DNA extracted from intestinal biopsy specimens with primers and probes from the small subunit rRNA gene of Enterocytozoon bieneusi and Septata intestinalis. Histological examination of intestinal biopsy specimens was performed using a fluorescence technique. Transmission electron microscopy of intestinal biopsy specimens was performed in 13 patients. RESULTS: Amplification and Southern blot hybridization with species-specific primers and probes gave positive results in 10 patients for E. bieneusi, and in 10 patients for S. intestinalis. Overall, five cases of double infection with E. bieneusi and S. intestinalis were seen when both primer pairs and probes were used. Histological examination showed microsporidian spores in all 15 cases, but light microscopy was unable to distinguish between species in almost all cases. CONCLUSIONS: PCR detection of microsporidian DNA in intestinal biopsy specimens can be used reliably for the diagnosis of intestinal microsporidiosis in HIV-infected patients and is also useful for species differentiation between microsporidia. Infections with S. intestinalis and double infections with two types of microsporidia appear to be more common than previously described.

AIDS-Related Opportunistic Infections↗

Uvitex 2B stain for the diagnosis of Isospora belli infections in patients with the acquired immunodeficiency syndrome.

OBJECTIVE: Fluorescent stains with Uvitex 2B or other fluorochromes are widely used today, especially for the diagnosis of microsporidian infections in human immunodeficiency virus (HIV)-infected patients. Our objective was to ascertain whether the fluorescent stain with Uvitex 2B is also able to detect Isospora belli in stool samples and duodenal/bile juice of HIV-infected patients. DESIGN: Case study. SETTING: University hospital of the University of Cologne, Germany. PATIENTS: Two HIV-infected patients with chronic diarrhea who had intestinal infections with I. belli. METHODS: Stool was concentrated by a modified water-ether sedimentation method, and duodenal/bile juice was concentrated by centrifugation. Wet-mount preparations were examined by phase-contrast and bright-field microscopy, and smears were stained with a modified acid-fast stain and a fluorescent stain with Uvitex 2B. RESULTS: Using the fluorescent stain with Uvitex 2B, the oocysts of I. belli stained bright white/blue fluorescent and showed a structure similar to that of the oocysts in acidfast stains. CONCLUSIONS: Staining with Uvitex 2B is a suitable method for the diagnosis of I. belli infections. This technique can be used for the diagnosis of three important gastrointestinal parasites (viz, microsporidia, cryptosporidia, and I. belli) responsible for diarrhea in HIV-infected patients.

AIDS-Related Opportunistic Infections↗

[Cost effectiveness and evaluation of a structured therapy and education program for insulin-treated type II diabetic patients in Bradenburg].

The aim of the study was to evaluate the practicability and efficacy of a structured treatment and teaching programme (STTP) for Type II diabetic outpatients on conventional insulin treatment after introducing a remuneration for physicians. Reimbursement policy was introduced in the state of Brandenburg, Germany, in July 1993. Between August 1993 and February 1994, 108 practices in Brandenburg participated in a postgraduate seminar, which is a prerequisite for remuneration. Within the first year 10% of the target group of physicians participated in the seminars. A standardised interview was performed with 103 physicians. Twenty of the practices who had performed STTP were visited in order to collect data on all the patients who had participated in the programme. The seminar and the programme were well accepted. An improvement of HbA1c levels was observed in patients (n = 54) who had started insulin treatment (9.7 +/- 1.6% of total Hb before, 8.2 +/- 1.3% of total Hb after the programme) and in those (n = 189) who were already being treated with insulin before the STTP (9.6 +/- 2.5% of total Hb before, 8.1 +/- 1.4% of total Hb after the programme). The results of the study demonstrate the efficacy and practicability of an STTP for Type II diabetic patients on conventional insulin therapy in ambulatory health care.

Aged↗

Effective antibody response in newborn babies living in Maldives to simultaneous vaccination against hepatitis B, poliomyelitis, diphtheria and tetanus.

The antibody responses of Maldivian infants early in their life to simultaneous immunization against hepatitis B virus, poliomyelitis, diphtheria and tetanus were investigated. The vaccines were given at 6, 10 and 14 weeks of age. Among 243 newborn babies from HBsAg-negative mothers, 103 received three doses of oral poliomyelitis (OPV) and diphtheria and tetanus (DTV) vaccines; 105 were similarly immunized but received in addition the recombinant hepatitis B vaccine (HBV); 35 were immunized with the HBV recombinant vaccine alone. The antibody response to all of the vaccines was effective. No significant differences among the groups were observed. Hepatitis B vaccination of infants neither affected nor was affected by the contemporary administration of OPV and DTV vaccines.

Adult↗

Immunologically confirmed disseminated, asymptomatic Encephalitozoon cuniculi infection of the gastrointestinal tract in a patient with AIDS.

Microsporidia are obligate intracellular protozoan parasites that infect a broad range of vertebrates and invertebrates. They are increasingly recognized as human pathogens, especially in patients infected with human immunodeficiency virus (HIV). Organisms of the genus Encephalitozoon have been implicated as a major cause of disseminated microsporidian infections in persons with AIDS. Until recently, E. hellem was the only Encephalitozoon species confirmed by antigenic or nucleic acid methods to have infected humans. We describe the clinical course and morphological features of a case of disseminated microsporidian infection with Encephalitozoon cuniculi in an HIV-infected patient with chronic sinusitis, rhinitis, and keratoconjunctivitis. Parasites were found in conjunctival swab, nasal discharge, sputum, urine, stool, and duodenal biopsy specimens, but no pulmonary, renal, or gastrointestinal symptoms were documented. The patient was treated with albendazole (400 mg po b.i.d.), resulting in complete remission of his ocular and nasal symptoms, and microsporidian spores disappeared from all sites. To our knowledge, this case is only the second of E. cuniculi infection in humans that has been confirmed by either antibody- or nucleic acid-based methods, and it is the first in which an Encephalitozoon species has been found in the intestinal tract of a human. Microsporidiosis is an important emerging opportunistic infection in HIV-infected patients and, as documented in this report, has an expanding clinicopathologic spectrum.

Acquired Immunodeficiency Syndrome↗