Biomedical subjects
Publications and source records attributed to R Nathan.
A technique is described for use of a metallic nasal tube protector to guard against accidental cutting into the endotracheal tube, its pilot tube, or an esophageal stethoscope when performing maxillary osteotomy.
A photographic method for measuring two-dimensional changes in NADH fluorescence and hemoglobin distributions in the rat cerebral cortex in vivo has been developed. Intracellular NADH was excited by UV light peaking at 360 nm and the emission was observed through a window with the maximum transmission at 450 nm. The fluorescence photographs (360 leads to 450 nm) required 20-25 sec exposures at the aperture opening of f/5.6 and the reflectance photographs (360 leads to 360 nm) 10 sec exposures at f/32. The digitization of photographic images was achieved either by a PDP-8-controlled microdensitometer coupled to an A/D converter or by a combination of a manually operated microdensitometer and a computer-controlled digitizer. In the latter case, a photographic negative was scanned with a Joyce-Loebl microdensitometer in parallel lines 170 mum apart, and the densitometric tracings were digitized with a PDP-8-controlled TV digitizer. The digital data were processed by DEC PDP-10 computer and the results were displayed in 3-dimensional surfaces. Nitrogen anoxia caused increases in fluorescence at 450 nm ranging from 10 to 75% fo the normoxic fluorescence intensities (after correcting for the logarithmic characteristics of the photographic films) and decreases in reflectance intensities in the range of 10-30%. The spatial resolution of the present technique is limited to approximately 30 mum X 30 mum on the cortical surface and the time resolution to 10-25 sec. The optical properties of the cerebral cortex in vivo appear to be controlled primarily by blood vessel patterns and hemodynamic factors and secondarily by the redox state of the tissue. Evidence for a heterogeneous redox response of the cerebral cortex toward N2 anoxia was obtained.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Early chromatin condensation in interphase cells (G1) of human peripheral blood lymphocytes has been induced without virus or cell fusion by exposure to allogeneic or xenogeneic mitotic cells. The event, although similar in some ways to the phenomenon described as "premature chromosome condensation," "chromosome pulverization," and "prophasing," differs in that it does not require the presence of viruses and cell fusion before mitosis proceeds in the G1 cell. Early chromatin condensation in interphase cells induced by mitotic cells only, consists of chromatids in the early or late G1 phase of the cell cycle that are not pulverized or fragmented at mitosis. Some of the chromosomes are twice as long as the metaphase chromosomes and exhibit natural bands. Almost twice as many of these bands are produced as by trypsin treatment of metaphase chromosomes. The nuclear membrane is intact and nucleoli are present, to which some chromosomes are attached. The DNA content of the precocious chromosomes in G1 is half the amount of the metaphase complement.
We present a large-scale social marketing programme of insecticide-treated nets in 2 rural districts in southwestern Tanzania (population 350,000) and describe how the long-term child health and survival impact will be assessed. Formative and market research were conducted in order to understand community perceptions, knowledge, attitudes and practice with respect to the products to be socially marketed. We identified Zuia Mbu (Kiswahili for 'prevent mosquitoes') as a suitable brand name for both treated nets and single-dose insecticide treatment sachets. A mix of public and private sales outlets is used for distribution. In the first stage of a stepped introduction 31 net agents were appointed and trained in 18 villages: 15 were shop owners, 14 were village leaders, 1 was a parish priest and 1 a health worker. For net treatment 37 young people were appointed in the same villages and trained as agents. Further institutions in both districts such as hospitals, development projects and employers were also involved in distribution. Promotion for both products was intense and used a variety of channels. A total of 22,410 nets and 8072 treatments were sold during the first year: 18 months after launching, 46% of 312 families with children aged under 5 years reported that their children were sleeping under treated nets. A strong evaluation component in over 50,000 people allows assessment of the long-term effects of insecticide-treated nets on child health and survival, anaemia in pregnancy, and the costs of the intervention. This evaluation is based on cross-sectional surveys, and case-control and cohort studies.
Explore the source record for details and available documents.
Electrical stimulation has been sporadically used in the treatment of hemiplegia. Reported benefits include decreasing spasticity, providing a supplementary means for range of motion exercises, increasing strength, and improving local blood flow in a paretic or paralyzed limb. Some studies have also shown functional gains in the hemiplegic upper limb following treatment with electrical stimulation. Nevertheless, there have been very few reports of the use of neuromuscular stimulation to achieve new hemiplegic upper limb activity not possible without the electrical stimulation. This is a case report of a head injury patient who was able to begin ambulation with a walker, without physical assistance, for the first time in the 16 yr since his injury. A new electrical stimulation device (Handmaster) initially used therapeutically, and then functionally, provided a reliable, strong grasp and release and was instrumental in achieving the new level of function. The device proved to be easy to use in the home, giving the patient microprocessor-controlled therapeutic and patterned functional electrical stimulation.
A new hybrid functional electrical stimulation orthosis system for the upper limb has been designed to allow for ease of use in the home as a daily treatment modality, as well as offer the opportunity for function enhancement. In a pilot study, the system was used by ten patients with chronic stable hemiparesis secondary to cerebral vascular accident and head injuries. The patients were referred by their treating physicians or therapists after meeting the inclusion criteria of good general health, being greater than one year after head injury, or being ten months post-stroke, with no observed neurologic changes in the prior six weeks. Each of these patients had received prolonged physical therapy, either continuous from the initial inpatient rehabilitation treatment or on an intermittent basis over a period of years. The baseline status for factors related to increased muscle tone, i.e., passive range of motion at the wrist and elbow, posture at rest, posture immediately following activity, and spasticity were quantified before the treatment protocol with the functional electrical stimulation orthosis. Active range of motion and tests of functional use of the involved upper limb were also assessed. The patients were instructed in the protocol, trained in the use of the system, and then used the electrical orthosis at home for up to several hours per day. Follow-up assessments were at six months. A statistically significant improvement was noted in all muscle tone/spasticity parameters measured. A separate report will describe the effects on voluntary motion and functional capabilities.