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Biomedical subjects

D Buchholz

Publications and source records attributed to D Buchholz.

116 records · Page 7Linked to original sources
PubMed1986

The temperature dependence of post-vibration tension recovery in intact and skinned rat tracheal smooth muscle.

The contraction kinetics of rat tracheal smooth muscle were studied by analysing the time course of tension recovery after the cessation of a 2 s length vibration (100 Hz, sinusoidal) in activated preparations. An initial fast component of tension recovery reflects the rearrangement of those crossbridges previously detached by vibration. The subsequent slow component could be related to the kinetics of the regular actin-myosin interaction. Both components still occur independently of the duration and type of activation (electrical field stimulation and 0.1 mM 1(-1) acetylcholine), the bath temperature (16, 22, 28 and 37 degrees C), and of the functional behaviour of the cell membrane (intact or Triton X-100 skinned preparations). The time constants of post-vibration tension recovery were increased distinctly during prolonged activation, low temperature, and after skinning (lack of calmodulin). The activation enthalpy was calculated according to Arrhenius by using the time constant of the slow component of post-vibration tension recovery. It amounted to 94.7 +/- 0.6 kJ mol-1 for the intact preparation and 97.2 +/- 1.0 kJ mol-1 for the skinned one (temperature range 16-28 degrees C). These results provide further evidence that vibration affects the contractile system directly and that the kinetics of post-vibration tension recovery reflect the kinetics of actin-myosin interaction.

Actins↗
PubMed1983

Herpes zoster ophthalmicus and delayed contralateral hemiparesis caused by cerebral angiitis: diagnosis and management approaches.

Four patients with herpes zoster ophthalmicus and delayed contralateral hemiparesis are described, and their findings are compared with those in patients previously reported in the English language literature. The current patients evidenced multifocal ipsilateral cerebral angiitis by angiography and multifocal infarcts in the distribution of the ipsilateral middle cerebral artery by computed tomographic scanning. Cerebrospinal fluid showed mononuclear pleocytosis, positive oligoclonal bands, and an elevated immunoglobulin G index. Two patients were treated with corticosteroids and acyclovir, and 1 with corticosteroids alone, all without apparent response. Necrotizing angiitis ipsilateral to the herpes zoster ophthalmicus was demonstrated postmortem in 1 patient with multifocal cerebral infarction and progressive leukoencephalopathy. Neither herpes varicella zoster immunocytochemical reactivity nor viral inclusions were seen. The leukoencephalopathy associated with herpes varicella zoster either may be caused by cerebral angiitis or, as previously reported, may be a temporally remote manifestation of persistent herpes varicella zoster infection. The cerebral angiitis associated with herpes varicella zoster is histologically similar to granulomatous angiitis, and both may be related to herpes varicella zoster infection of the cerebral vasculature.

Acyclovir↗
PubMed1976

Spontaneous and centrally induced behaviors in normal and thalamic opossums.

Electrical stimulation of localized areas of the opossum medulla and cerebellum induced goal-oriented eating and grooming behaviors of stereotyped gagging. Following radical telencephalic lesions, these animals showed considerable behavioral capacity and in many cases continued to demonstrate centrally induced responses. Animals with lesions, however, failed to groom or show active food-seeking behavior, and they showed poor thermoregulation in the heat, presumably because of the loss of thermoregulatory grooming. These deficits following removal of the telencephalon appear to have resulted from disruption of important sources of control over behaviors rather than from loss of basic consummatory response mechanisms, since grooming and eating, while less directed, could still be elicited by central stimulation. These results support the view that the lower brain stem may contain intrinsic neural circuits for the integration of complex behaviors.

Agonistic Behavior↗