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Biomedical subjects

J Mielke

Publications and source records attributed to J Mielke.

At least 19 recordsLinked to original sources
PubMed2006

[Choroidal effusion syndrome after embolization of an indirect cavernous sinus fistula via the superior ophthalmic vein].

Embolization of a cavernous sinus fistula (SCF) via the superior ophthalmic vein (SOV) was reported to be an almost uncomplicated procedure, even after ligature of the vein at the end of the procedure. We report about a complication of this therapy. A 58-year-old female had a successful embolization of a right indirect cavernous sinus fistula via the SOV. At the end of the operation the SOV was ligated because of the danger of bleeding. Directly after surgery she experienced general worsening of the right eye with signs of venous congestion and marked effusion syndrome. The patient underwent total heparinization to achieve an opening of venous collaterals. Under local therapy with atropine 1% eye drops a decrease of the intraocular pressure was observed. The effusion syndrome was completely resolved within 1 month. If embolization of a cavernous sinus fistula is performed via the SOV, the ligature of the vein at the end of the procedure leads to thrombosis, which can reduce the venous stream from the eye and orbit. A secondary effusion syndrome with ocular hypertension because of a ciliolenticular block situation is possible and requires appropriate therapy. It is not possible to assess the capacity and time of opening of the venous collateral system before surgery. Therefore a transient outflow disturbance should be considered.

Carotid-Cavernous Sinus Fistula↗
PubMed2006

[Effect of timolol on central corneal thickness and endothelial cell density].

BACKGROUND: The measurement of corneal thickness plays an increasing role in glaucoma screening and diagnosis. The influence of a variety of drugs on corneal thickness is well established. Especially for antiglaucomateous drugs this effect seems to be important. However, little is known about the influence of beta receptor antagonists on corneal thickness. The aim of this study was to provide evidence of the effect of timolol on central corneal thickness and endothelial cell density. MATERIALS AND METHODS: Ten healthy volunteers (five women and five men) with a mean age of 29 years (range 25 to 56 years) were examined in a double-blind, prospective and randomised pilot study. Intraocular pressure, corneal thickness and endothelial cell density was estimated before as well as fifteen minutes, 24, 48, 72 and 96 hours after application of timolol 0.5 % eye drops twice daily. The partner eye received sodium hyaluronate eye drops twice daily and served as a control. RESULTS: The application of timolol showed a decrease of intraocular pressure from initially 12 mmHg to 9 mmHg after four days (p = 0,0188) as well as an increase of corneal thickness from 537 microm to 557 microm after four days (p = 0,0659). There was no change of intraocular pressure (p = 0,9935) or corneal thickness (p = 0,9998) in the control eyes. There was also no effect of timolol (p = 0,2782) or sodium hyaluronate (p = 0,1940) on endothelial cell density. CONCLUSIONS: The study provides evidence of the influence of beta receptor antagonists on corneal thickness. This effect may be caused by receptor mediated influences on corneal ion and fluid transport. Further studies are needed to show if the increase of corneal thickness after application of topical timolol has clinical importance.

Adult↗
PubMed2006

[Protein kinase C isoforms in corneal epithelium and endothelium].

BACKGROUND: Protein kinase C (PKC) plays a key role in cell metabolism. Three subgroups and 12 isoforms have been isolated so far, catalysing specific functions in cell metabolism. The demonstration of PKC subtypes in corneal tissue has been inconsistent. The aim of this study was to verify the expression of several PKC subgroups and isoforms in human and bovine corneal epithelial and endothelial cells. MATERIALS AND METHODS: PKC subgroups and isoforms were studied using polyclonal antibodies. RESULTS: Antibodies to PKC-alpha, -delta, -epsilon and -zeta, representing all three PKC subgroups, bound in human and bovine corneal epithelium and endothelium. No binding was found for antibodies to PKC-beta2. CONCLUSIONS: For the first time the presence of all three PKC subgroups was demonstrated in human and bovine corneal epithelial and endothelial cells. Further studies are needed to show the role of these subgroups in cellular functions such as cell proliferation and differentiation.

Adult↗
PubMed2005

[Epidemic keratoconjunctivitis. Detecting adenoviruses].

OBJECTIVE: The validity of the 15-min adenovirus assay SAS Adenotest was evaluated compared with virus detection by polymerase chain reaction (PCR) from conjunctival swabs. METHODS: In 75 patients with assumed epidemic keratoconjunctivitis, adenovirus detection from conjunctival swabs was performed by the immunochromatographic assay SAS Adenotest and PCR. RESULTS: In 25 patients adenovirus was detected by PCR, 18 of whom were detected by the SAS Adenotest and 7 of whom were not. No false positive results occurred. Sensitivity was 72% and specificity was 100%. CONCLUSIONS: The results indicate that rapid adenovirus detection with the SAS Adenotest is a useful tool in early epidemic keratoconjunctivitis. An additional PCR should be performed when clinical symptoms persist for 5 days or more.

Adenoviridae↗
PubMed2005

Epilepsy in sub-Saharan Africa: its socio-demography, aetiology, diagnosis and EEG characteristics in Harare, Zimbabwe.

OBJECTIVE: To assess epileptics with regard to socio-demographic characteristics, aetiology, EEG results and classification. DESIGN: A descriptive cohort study from 1997 to 2001. SETTING: Parirenyatwa Group of Hospitals in Harare, Zimbabwe. SUBJECTS: A total of 229 consecutive epileptic subjects. RESULTS: The mean (s.d.) follow-up was 3.2 (1.14) years. The mean (s.d.) age of subjects was 23.4(11.8) years and 56% of them were males, over one third (43.1%) were unemployed and had secondary education (48%). Over one fourth (26.6%) of the subjects were first borns and had a family history of epilepsy (25.8%). Most of the subjects had Generalised Tonic Clonic Seizures (TCS). Over half (51.5%) of the subjects had their first onset of seizures after the age of 20 years. Lack of sleep (7.9%) and emotional disturbance (5.4%) were described by subjects as the frequent provoking factors for epileptic attacks. One hundred and fourteen subjects had electroencephalogram (EEG) results. Of these, 96 (41.9%) subjects had abnormal EEG results and only 18 (7.9%) had normal EEG results a majority (43.8%) of whom were of generalised slow waves. Majority of the subjects (52.8%) sought treatments from biomedical drugs, but some started with traditional herbs (20.5%) and then biomedical drugs, whereas others sought biomedical drugs then resorted to traditional herbs (20.1%). Phenobarbital and carbamazepine were taken by over 40% of the subjects. CONCLUSION: The findings of this study seem to suggest that these referrals to a specialised epilepsy outpatient clinic for further management may be attributed to socio cultural issues in our African settings about the actual nature of the condition, hence the delay in treatments and diagnosis of seizures as well as under diagnoses of non-epileptic seizure disorders that may lead to the condition becomes uncontrollable. Inexpensive drugs such as phenobarbital and phenytoin can be able to control most of the epileptic seizures, if they can be made available in primary health care centres.

Adolescent↗
PubMed2004

[Aqueous humor dynamics].

Intraocular pressure is mainly controlled by the rate of aqueous humor production and the resistance to its outflow. Aqueous humor formation is the result of fast unidirectional secretion and slow contradirectional reabsorption. The most striking evidence of endogenous regulation of the ciliary epithelial secretion is provided by the observation of the circadian rhythm. Aqueous humor formation is mainly controlled by the interaction of inhibiting alpha(2)-adrenoreceptors and stimulating beta-adrenoceptors. The role of the central nervous system in the regulation of this process remains unclear and the precise mechanism of outflow regulation is not fully understood. The aqueous humor passes into the anterior chamber and leaves the eye by two routes: the direct outflow pathway through the trabecular meshwork or the indirect outflow pathway through the ciliary muscle. Further biochemical, biological and pharmacological investigations are necessary to determine the fundamental process of aqueous humor formation, outflow and regulation.

Absorption↗
PubMed2002

Disability in an urban black community in Zimbabwe.

PURPOSE: This study was undertaken to establish which health conditions are primarily responsible for disability and morbidity in a high-density area in Harare, Zimbabwe. METHOD: House-to-house screening visits were followed up by medical examination and interview of those identified as having a functional limitation. RESULTS: Information was obtained during screening on 10,839 residents. Of these, 608 were examined by medical professionals. The rate of disability/morbidity was 5.6% for the whole sample. Headaches and migraine were the most common problem. These were followed by back pain, hypertension and osteoarthritis. HIV/AIDS was the fifth most common condition. Depression, based on responses to a screening tool, was evident in one-third of the subjects. Common activity limitations included difficulty with the performance of housework activities and with walking. HIV/AIDS resulted in the most severe activity limitation, in that cognitive functions were also affected. CONCLUSION: The middle-aged and elderly with osteoarthritis and young women with depression constitute vulnerable groups who are not in a position to demand services. The older women particularly need assistance as they are bearing the double burden of their own degenerative conditions and the results of the HIV/AIDS pandemic.

Black or African American↗
PubMed2002

Auditory- and somatosensory-evoked potentials in cerebral malaria and anaesthesia: a comparison.

BACKGROUND AND OBJECTIVE: Parallels exist between the coma associated with cerebral malaria and general anaesthesia. They both produce reversible loss of consciousness. In the case of cerebral malaria and in the absence of other complications, patients recover without sequelae. General anaesthetics are so designed that patients recover from their anaesthetics very quickly and show no 'after effects'. This study compares brain function in these two clinical conditions by examining auditory- (AEPs) and median nerve somatosensory-evoked potentials (SEPs). The AEPs studied (waves Pa and Nb) are thought to arise from the primary auditory cortex and the median nerve SEPs (waves P15, N20, P25, N35, P45) from the pons, thalamus and primary somatosensory cortices. METHODS: Six comatosed patients with malaria (three males, three females) aged between 19 and 38 yr were studied in Zimbabwe. Their Glasgow Coma Scores on admission were 4, 3, 6, 7, 7 and 11. Their AEPs and median nerve SEPs were recorded daily over 4 days. The data were compared with those previously collected in the UK on patients and volunteers anaesthetized with desflurane, isoflurane, sevoflurane and propofol. RESULTS: In general, patients with cerebral malaria showed AEPs and SEPs similar to those of light to moderate anaesthesia i.e. 0.5-1.25 measure of anaesthetic potency (MAC), where 1 MAC is the minimum alveolar concentration necessary to prevent movement to surgical incision in 50% of patients. The appearance of the AEPs and SEPs bore no relationship to the degree of coma. The auditory brainstem-evoked response was retained in all degrees of coma, as would be expected. Otherwise, it would not be possible to interpret the waveform. In most instances, the early cortical complex Pa/Nb/Pb of the AER was present. When comatose patients emerged from malarial coma or were stimulated by talking loudly to them, they showed changes in the Pa/Nb/Pb complex similar to those seen on awakening from anaesthesia. The somatosensory-evoked response showed clear P15, N20 and P25 peaks at the expected latencies, and in some instances the waveforms of cerebral malaria and lightly anaesthetized volunteers were very similar. CONCLUSIONS: The sensory-evoked responses of the cerebral malaria patients recorded in this study were not markedly different from those seen in light-to-moderately anaesthetized patients and volunteers. The profound depression of the AEPs and SEPs associated with deeper levels of anaesthesia were not seen, with the exception of one patient several hours before death.

Adolescent↗
PubMed2001

Cryptococcus myelitis: atypical presentation of a common infection.

Cryptococcus neoformans is associated with as much as 45% of meningitis in patients admitted for hospital care in Zimbabwe, and it is an important opportunistic infection in patients infected with the human immunodeficiency virus. Cases of cryptococcosis presenting as a spinal cord syndrome have been reported from Zimbabwe and South Africa, but these were all cases of Cryptococcus vertebral osteomyelitis. We describe 3 unusual patients who presented with a myelitis-like syndrome without vertebral osteomyelitis.

AIDS-Related Opportunistic Infections↗
PubMed2001

[Massive intraocular invasion of conjunctiva by squamous cell carcinoma--a case report].

BACKGROUND: Squamous cell carcinoma of the conjunctiva is a mostly solitary growing tumor located at the limbus region, which seldom invades the eye. We present an unusual case of conjunctival carcinoma with marked intraocular involvement, which appeared primarily as a chronic inflammation with corneal ulcer. CASE REPORT: A 89-year-old female patient was referred to our institution with a suspected ulcus rodens of the cornea. Since one year a refractory conjunctivitis persisted despite of different local treatment. At first presentation, a marked bacterial keratoconjunctivitis with circular necrosis of the conjunctiva, corneal infiltration and perforation was seen. Visual acuity of the right eye was light perception. The left eye was unremarkable. Enucleation of the right eye was performed. Histopathologic examination revealed the diagnosis of squamous cell carcinoma of the conjunctiva with intraocular involvement. There was a marked infiltration of the choroid even behind the equator. No metastases were found. CONCLUSION: Advanced squamous cell carcinoma associated with superinfection may present as a primary inflammatory process. There may be extensive involvement of the choroid. Metastases are probably rare even in advanced cases of this type of carcinoma.

Aged↗
PubMed2001

[Pseudohypopyon of cholesterol crystals occurring 16 years after retinal detachment in x-linked retinoschisis].

BACKGROUND: Cholesterol crystals of the anterior chamber can be found as a marked feature of advanced cholesterosis bulbi; typically following i. o. hemorrhage after severe trauma, retinal detachment or M. Coats. CASE REPORT: A 39-year-old male patient with longstanding (16 years) retinal detachment in his right eye due to x-chromosomal linked retinoschisis presented with a clinical picture of a hypopyon and mature cataract. Ultrasonography showed a retrolental mass. Phacolytic uveitis was suspected and pars plana lentectomy and vitrectomy was performed. Intraoperatively subretinal chrystals could be detected. A specimen of the aqueous humor and subretinal fluid was evaluated biochemically and histologically and revealed cholesterol crystals. CONCLUSIONS: Cholesterosis bulbi may be similar to lentogenic uveitis and should be included in the differential diagnosis of such processes. To our knowledge this is the first case of cholesterol crystals of the anterior chamber sixteen years after retinal detachment in x-linked retinoschisis.

Adult↗
PubMed2001

[Bee sting of the cornea - a case report].

BACKGROUND: Bee stings of the cornea are very rare, though its response can range from minimal inflammation to severe damage like lens dislocation, cataract formation, iris atrophy, ophthalmoplegia and optic neuropathy. We report on a patient with typical, severe findings. PATIENT: A 42-year-old patient presented with an acute, corneal bee sting of the left eye, after he was stung only a few hours ago. The patient suffered from pain, blurred vision and epiphora. The left eye showed edema of the upper and lower eyelid, conjunctival hyperemia, chemosis, striate keratitis, a purulent infiltration of the cornea above the limbus at the 7 o'clock meridian and a massive hypopyon. Further examinations showed regular ophthalmological findings. Vision acuity was 1,0/0,4. Under therapy inflammation decreased quickly. One week after we could lokalize the stinger in the depth of the corneal infiltration and it was removed surgically. After one month the eye only showed a minimal infiltration of the cornea with fine neovascularisations. Visual acuity was 0,8. CONCLUSION: Clinical reactions to bee stings of the cornea are caused by toxical and immunological effects of different components of the bee venom. These toxical and/or inflammatory reactions can lead to severe intraocular damage. Treatment of choice is the systemic and local application of steroids and antibiotics as well as local therapy with antihistamins.

Adult↗
PubMed2000

Impact of HIV infection on meningitis in Harare, Zimbabwe: a prospective study of 406 predominantly adult patients.

OBJECTIVE: To determine the causative organisms and characteristics of patients presenting with features of meningitis. DESIGN: A prospective cross-sectional study. SETTING: Two tertiary university-affiliated hospitals in Harare, Zimbabwe. PATIENTS: Four-hundred and six patients clinically suspected to have meningitis. MAIN OUTCOME MEASURES: Causative organisms of meningitis; clinical and cerebrospinal fluid characteristics. RESULTS: Four-hundred and six predominantly adult (95% were aged > or = 18 years) patients were suspected to have meningitis. Of the 200 patients confirmed to have meningitis, 89 (45%) had cryptococcal meningitis (CM), 54 (27%) had mononuclear meningitis (MM), 31 (16%) had pyogenic meningitis (PM), 24 (12%) had tuberculous meningitis (TBM) and 2 (1%) had undefined meningitis. HIV seropositivity was 100% in CM, 83% in MM, 81% in PM and 88% in TBM patients. In-hospital mortality rate was 38.8% for CM, 34.9% for MM, 68% for PM and 66.7% for TBM. HIV seropositivity was 80% in the 206 patients not found to have meningitis. CONCLUSIONS: All patients suspected to have meningitis had a high HIV sero positivity irrespective of whether they were later confirmed to have meningitis or not. CM was the most common type of meningitis seen. In-hospital mortality was high irrespective of the cause of meningitis.

AIDS-Related Opportunistic Infections↗