A recent study with dogs has defined an age-related period of transient hyperexcitability in the laryngeal adductor neurons. This observation suggests that age-related neurologic instability of laryngeal mechanisms and abnormal laryngeal closure may be a cause of transient upper airway obstruction, inducing potentially fatal central apnea that could result in the sudden infant death syndrome. Since hyperthermia has been implicated as a cofactor in sudden and unexpected infant death, its effect on laryngeal excitability requires clarification. This investigation has found that both the latency and threshold of the laryngeal adductor reflex decreases during hyperthermia. Thus, hyperthermia effectively enhances this reflex during its age-related period of hyperexcitability, and is capable of triggering upper airway-induced central apnea of sufficient severity to result in death. The effect of temperature on latency is attributed to changes in axonal conduction and synaptic transmission velocities. Temperature-dependent changes in synaptic transmission are hypothesized as the cause of the observed threshold changes.

Aging↗

PubMedDate not supplied

Expression of alpha-smooth muscle actin in small bronchioloalveolar adenocarcinoma of the lung: assessment and comparison with noguchi criteria.

The Noguchi criteria are useful in assessing the prognosis of patients with small lung adenocarcinoma. Although there is a significant difference in prognosis between type A or B and type C, it is difficult in some cases to distinguish these types accurately by microscopy. In this study, we used immunohistochemistry to examine alpha-smooth muscle actin (alpha-SMA) produced by active fibroblasts in 25 pulmonary adenocarcinomas less than 2 cm in diameter. Eleven of type C (61%) showed positive staining for alpha-SMA, whereas no positive cases were seen in type A or B. The incidence of cancerous blood vessel and lymphatic invasion were significantly higher in alpha-SMA positive cases than in negative cases, and the positive cases showed poorer prognosis. These findings indicate that immunohistochemical detection of alpha-SMA is useful and essential for histological typing by the Noguchi criteria.

Actins↗

PubMedDate not supplied

Renovascular hypertension: a case of intimal fibroplasia with congenital anomaly of the renal artery.

We report a case of renovascular hypertension caused by fibromuscular dysplasia (intimal fibroplasia) with congenital anomaly of the renal artery. Arteriography revealed complete occlusion from the root to the middle of the right renal artery and a collateral artery from the right lumbar artery. Histological examination showed intimal fibroplasia and three arterioles in the intima of the renal artery.

Adult↗